June 1997 Gasification Archive

For more information to help people develop better stoves for cooking with biomass fuels in developing regions, please see our web site: http://www.bioenergylists.org

From verhaarp at janus.cqu.edu.au Sun Jun 1 06:27:14 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:12 2004
Subject: charcoal briquette production
Message-ID: <1.5.4.32.19970601102721.006b2354@janus.cqu.edu.au>

To S.K.B. Chandraratna

At 17:26 9/05/97 -0700, you wrote:
>Please send me some information about wood charcoal production. I would
>like to produce charcoal briquettes from coconut shells.

Clip

Please do not spoil the beautiful charcoal from coconut shells by converting
it into briquettes.
The shells (not the fibrous outer layers) make perfect charcoal, hard, long
burning (and with a very low ash content, if I remember correctly).
Generally briquettes are a solution for converting dusty, finely divided
carbonaceous matter into a shape that is easier to handle.

Regards,

Peter Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From larcon at sni.net Sun Jun 1 11:12:59 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
Message-ID: <v01540b01afb73e06ce34@[204.133.251.5]>

Mike Antal has written:

>Straw should be baled, converted to high-yield charcoal, and burned, with
>the ash returned to the field. Best regards, Michael.

(RWL): I believe Mike is one of the most skilled in biomass-charcoal
conversion processing and it is good to hear from him. I have these
questions:

1. Could you describe the process you have been developing - and its
yield, economics, market-readiness, etc.

2. How are you making use of the pyrolysis gases?

3. Are you creating briquettes?

Thanks in advance Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phait at transport.com Sun Jun 1 12:01:52 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:13 2004
Subject: charcoal briquette production
Message-ID: <199706011600.JAA15759@butch.transport.com>

>To S.K.B. Chandraratna
>
>At 17:26 9/05/97 -0700, you wrote:
>>Please send me some information about wood charcoal production. I would
>>like to produce charcoal briquettes from coconut shells.
>
>Clip
>
>Please do not spoil the beautiful charcoal from coconut shells by converting
>it into briquettes.
>The shells (not the fibrous outer layers) make perfect charcoal, hard, long
>burning (and with a very low ash content, if I remember correctly).
>Generally briquettes are a solution for converting dusty, finely divided
>carbonaceous matter into a shape that is easier to handle.
>
>Regards,
>
>Peter Verhaart
>Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
>Phone: +61 79 331761 Fax: +61 79 331761 or 332112
>E-mail:p.verhaart@cqu.edu.au
>Dear Peter,
I agree with your response.However, the briquette configuration allows for
more efficient burning and distribution options. If the intent is local use
then you are probably right. However, if they want to ship the end product
they should briquette it.
Several years ago I got involved in making briquettes out of Macadamian Nut
shells.They were hard,hot,and looked like a small pile of broken briquettes.
If the Coconut shells were crushed to the same size as the Mac. Nut shell
you would have a compromise between the two of us. They would burn
efficiently in our HTA Stove and be efficient to ship.
Where is SKB from? Do they have the following ingredients; Anthracite
dust,Calcium Carbonate,Potassium Nitrate,Char(powdered charcoal Coconut
shells) and a binder like Cornstarch?
He can Type in Charcoal briquettes on the Internet, and with a little work
find Kingsford's formula or equivalent.The latest most modern Briquette
factory in the USA was recently built in Kentucky by Hickory Specialties out
of Nashville, Tennessee. They Make the best briquette in America,The Jack
Daniels Brand. It is made out of Hickory Wood charcoal that is a residue
from their liquid smoke operation.
When I know how important the Harmonic Thermal Array is to the needs of
efficient fuel burning, I get very excited when I see people considering
making briquettes. From a world fuel point of view they are the safest,most
compact,benign,and calibratable way to transport,store, and use carbon energy.
The major Briquette development program that is going on in China, right
now, is utilizing the mountains of Coal DUST that you mentioned. I was in
China in 1988 and met the Minister of Metallurgy at the Sheraton Hotel in
Shanghai who told me that they had been working on a world fuel briquette
for seven years( low Sulphur). I have that briquette right hear in front of
me and it is impressive.They are looking at the export opportunity of the
briquette and I am very happy about that as you might expect.
The organization of energy is the way to go in my opinion. Random dumping
and burning a pile is not.
We utilize the heat above and below the HTA 4 hour burning array.It is a
Million Year Old bad habit to dump unorganized fuel into a black hole.
Briquettes make it easier to organize. Beauty is not the issue in efficient
burning,organzation is.

Remember,"It is better to briquette than to not briquette at all. However,
if beauty is your charcoal goal, then may God have mercy on your soul."(This
is not intended to insult but rather to make a point as to how important it
is to finally reach a concensus on the best overall way to deal with any
kind of Charcoal.The Chinese are way ahead of the world in this regard.

It is easy to see in the American distribution of Charcoal that the majority
of it is in briquette form. There must be a reason for that? Possibly
uniformity of formula , burning predictability and shipping efficiency. What
I do is to burn 75% less briquettes in the Pyromid to do the same job as an
ordinary barbeque(NATURAL FUEL STOVE).I believe this is the direction we
have all been striving for. Pyromid or not.

Note the straw snip-it from Ronal.The straw briquette is the only way to
go, if possible.If it is not possible, from an economic point of view, then
at least break the mass down to increase the HTA surface burning area and
distribution and storage efficiency.

Cheers and efficient HTA fuel burning,

Paul Hait
phait@transport.com

From Preso9 at aol.com Sun Jun 1 17:17:05 1997
From: Preso9 at aol.com (Preso9@aol.com)
Date: Tue Aug 31 21:35:13 2004
Subject: drop-in range
Message-ID: <970601171618_-262697746@emout16.mail.aol.com>

Is this a good place to inquire about dropin ranges using conventional coils?
Or do you have LINK you would like me to use?

Joe

From phoenix at transport.com Sun Jun 1 18:22:53 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <v01540b01afb73e06ce34@[204.133.251.5]>
Message-ID: <3391EF38.61BE@transport.com>

Ronal W. Larson wrote:
>
> Mike Antal has written:
>
> >Straw should be baled, converted to high-yield charcoal, and burned, with
> >the ash returned to the field. Best regards, Michael.
>
> (RWL): I believe Mike is one of the most skilled in biomass-charcoal
> conversion processing and it is good to hear from him. I have these
> questions:
>
> 1. Could you describe the process you have been developing - and its
> yield, economics, market-readiness, etc.
>
> 2. How are you making use of the pyrolysis gases?
>
> 3. Are you creating briquettes?
>
> Thanks in advance Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning

I would like to join this narrowly focused discussion to report a
warning. Not everything in the world needs to be or should be burned to
heat something else. Straw represents a waste product that is part of a
ongoing biological contract between consumers and producers which is
necessary to maintain the life of soil biology. Using the nitrogen
provided in rainfall, an entire host of bacteria work to digest
carbonaceous materials to produce recyclable food for plants to insure
future soil fertility. In our typically Western style, we pursue a
resource until it is gone, many times to a mere memory. I give you the
examples of the bison for hides and tongues, carrier pigeons, whales,
tuna, driftnets, petroleum, old growth forest, etc. If we do not
consider the WHOLE of the problem, we will be in a HOLE due to
starvation even if we have the ability to boil water. Soil is a
resource and needs to be conserved as a resource. Burning dung is
perhaps one of the best examples of short sightedness I can quote.

I would like to add to these statements by saying that I don't think an
energy efficient, simple stove will solve the total problem. Say we can
wave our hands and we provide a great, efficient stove design using
local materials for construction and consumption. How long will it be
before the next crisis brought on by localized overpopulation for
available resources will surface? I think eventually, mankind will need
to balance resources, technology and local population. I realize this
is not a subject of this forum but I would like us to think of the
larger issue as well. Treat the disease as part of the solution and not
just the symptom. If you think selling a new stove design is a problem
in the starving areas, think of explaining limited family size.

Art Krenzel
10505 N.E. 285th Street
Battle Ground, WA 98604
(360)666-1883 ph.
(360)666-1884 FAX

From english at adan.kingston.net Sun Jun 1 19:30:16 1997
From: english at adan.kingston.net (english@adan.kingston.net)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <3391EF38.61BE@transport.com>
Message-ID: <199706012329.SAA01635@adan.kingston.net>

Dear Art and .....
you wrote;
> I would like to join this narrowly focused discussion to report a
> warning. Not everything in the world needs to be or should be burned to
> heat something else. Straw represents a waste product that is part of a
> ongoing biological contract between consumers and producers which is
> necessary to maintain the life of soil biology. Using the nitrogen
> provided in rainfall, an entire host of bacteria work to digest
> carbonaceous materials to produce recyclable food for plants to insure
> future soil fertility.

May I add that those materials, trees or crops, living or dead
shield the soil surface from the erosive effects of wind and
rain. Haiti may be one of the worst examples. In a global sense,
there is no substitute for top soil.

> In our typically Western style, we pursue a
> resource until it is gone, many times to a mere memory. I give you the
> examples of the bison for hides and tongues, carrier pigeons, whales,
> tuna, driftnets, petroleum, old growth forest, etc. If we do not
> consider the WHOLE of the problem, we will be in a HOLE due to
> starvation even if we have the ability to boil water. Soil is a
> resource and needs to be conserved as a resource. Burning dung is
> perhaps one of the best examples of short sightedness I can quote.
>
> I would like to add to these statements by saying that I don't think an
> energy efficient, simple stove will solve the total problem. Say we can
> wave our hands and we provide a great, efficient stove design using
> local materials for construction and consumption. How long will it be
> before the next crisis brought on by localized overpopulation for
> available resources will surface? I think eventually, mankind will need
> to balance resources, technology and local population. I realize this
> is not a subject of this forum but I would like us to think of the
> larger issue as well. Treat the disease as part of the solution and not
> just the symptom. If you think selling a new stove design is a problem
> in the starving areas, think of explaining limited family size.
>
> Art Krenzel

Agreed!

Question: In, for example, dry or highly populated regions where wood
is unavailable, what might be the portion of available crop residues
diverted for cooking purposes? If general accuracy is difficult, give
me an isolated example,.... please.

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From CREEDJ at aol.com Sun Jun 1 21:36:22 1997
From: CREEDJ at aol.com (CREEDJ@aol.com)
Date: Tue Aug 31 21:35:13 2004
Subject: No Subject
Message-ID: <970601213534_1074508117@emout04.mail.aol.com>

From english at adan.kingston.net Sun Jun 1 21:42:24 1997
From: english at adan.kingston.net (english@adan.kingston.net)
Date: Tue Aug 31 21:35:13 2004
Subject: Verhaart message
In-Reply-To: <199705311706.KAA07863@butch.transport.com>
Message-ID: <199706020141.UAA06543@adan.kingston.net>

> >I think our Eindhoven downdraft system (what there is of it) has the
> >advantage of simplicity, high temperature (regrettably primarily
> >concentrated on the grate) and clean burning. The cons are that the pan has
> >to be part of a more or less hermetically gastight system to maintain draft.
> >This calls for accurate machining of the pans, either a machined flat bottom
> >to make good contact with an equally flat plate or an accurately dimensioned
> >outer diameter fitting into an equally accurately made hole.
> >
> >One thing that surprises me is:
> >
> >Why the Hell is everybody ignoring the SWOSTHEE STOVE?
> >
> >Does nobody receive and read Sadhana and has nobody asked prof. Mukunda for
> >a reprint?
> >
> >I am going to make one. If anybody else is interested I can fax parts of the
> >article containing the dimensions.
> >
Dear Stovers

All this talk of different stove designs and no pictures or drawings.
I was serious about getting them on the web. If you have a snap shot,
send it to me, I'll scan it and send it back. If you already have
images as *.JPG, *.BMP , or in some other graphic file format less
than 1 mega bite on your computor, try attaching it to an email to
me. If your interested in raising the profile of this issue or simply
facilitating understanding and discussion, a web page is a very
simple and inexpensive tool .

I have been unable to source the book 'Stove Images' in Canada. So
now I'll be snail mailing the publishers in Germany.

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From J.J.Todd at geog.utas.edu.au Mon Jun 2 00:48:57 1997
From: J.J.Todd at geog.utas.edu.au (John Todd)
Date: Tue Aug 31 21:35:13 2004
Subject: emissions measurements
In-Reply-To: <v01540b09afb550bf51f8@[204.133.251.2]>
Message-ID: <3.0.1.32.19970602145030.006910f4@postoffice.sandybay.utas.edu.au>

Dear Stovers
Regarding discussion about laboratory facilities for testing emissions.
We have a well equipped laboratory for measuring particulate emissions from
wood burning. It is used for testing woodheaters (wood-stoves) of the sort
used in North America and Australia for domestic heating. Full lab costs
are quite high, around $1000 (Aus) per day depending what facilities are
required.
But there is some potential for involving postgraduate students so that the
University picks up all the costs. The catch is that we have to have a
student willing to work on the particular topic and the studies usually run
over quite long periods (6 months to several years). I would be pleased to
see if I could get student(s) interested in a project on emissions from
cooking stoves.
Regards John Todd

*************************
Assoc. Prof. John Todd
Dept of Geog. and Environmental Studies, University of Tasmania
GPO Box 252-78, HOBART, Tas. 7001 Australia
ph (03) 6226 2390, fax (03) 6226 2989
e-mail J.J.Todd@geog.utas.edu.au

From prasad at tn7.phys.tue.nl Mon Jun 2 05:11:51 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:13 2004
Subject: Verhaart message
In-Reply-To: <v01540b00afb528a27c1e@[204.133.251.2]>
Message-ID: <9706020901.AA24514@tn7.phys.tue.nl>

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From b.tremeer at mail1.remote.uva.nl Mon Jun 2 06:01:17 1997
From: b.tremeer at mail1.remote.uva.nl (Grant Ballard-Tremeer)
Date: Tue Aug 31 21:35:13 2004
Subject: Lab Testing of Stoves
Message-ID: <199706020952.LAA13613@mail.uva.nl>

Last week Art and Alex wrote the following:

(snip)
>> Most likely there is not one stove design that does all things. The
end
>> user needs to prepare list of priority needs and local resources
>> available to solve the problem and from that, the correct design is to
>> be "spec'd". A stove for Somalia may not look like the stove for
>> Tibet. Different is OK!
>
>I like that!
(snip)

This idea used to be my anthem - and one of the reasons I say that stoves
should be tested in different ways depending on the target context - and,
naturally, the results should not, then, be compared between different
tests. This is particularly important if some 'high tech' lab does tests
on
such devices (such as Skip Hayden's) - cooking task, type of fuel etc.
should suit those of the particular target community I think.

Regards, Grant

-----------------------------------
Grant Ballard-Tremeer
International Institute for Energy Conservation - Europe (IIEC)
31 Pitfield Street, London N1 6HB
Telephone: +44 171 490 7616 Fax: +44 171 490 7626
http://www.iiec.org

From b.tremeer at mail1.remote.uva.nl Mon Jun 2 06:01:50 1997
From: b.tremeer at mail1.remote.uva.nl (Grant Ballard-Tremeer)
Date: Tue Aug 31 21:35:13 2004
Subject: Rogerio comments of 5/26
Message-ID: <199706020952.LAA13617@mail.uva.nl>

Dear Rogerio and all... you mentioned my hobby horse (stove testing), so
knowing that I'm not following the main thread of the discussion, I'm off
on that - sorry!

>......................RCM> We weight for a week the wood consumption of
a
>family with the traditional semi-open woodstove , e.g. the U shape. Some
>called it shielded fire. After a new improved close fired stove was
built,
>we weighted again the fuelwood consumed for a week.

This is good, a real life test, but your results may be misleading (in
either a positive or negative way) - there are a few things to watch out
for here (perhaps you know this anyway, but just incase):

1) conditions (for example the weather, or the number of people being
cooked for) may change from one week to the next, this would change the
amount of fuel used naturally. To get around this measure fuel use for a
number of households - then after some time (I recommend longer than a
week, yes, done properly this is rather time consuming) install improved
stoves in half of the homes (randomly chosen is best), continue monitoring
in all the households. Then when you draw up graphs of daily fuel use you
can see whether the ones without improved stoves also changed. Then its
possible to get an indication of the real effect of the stove with a
little
maths.

2) a family will react to a new stove in a number of ways, they might use
the stove only a little at the start (do you know whether they use the new
one exclusively?), they may use it more (because its a novelty, or because
its truely is a better stove). It may take time to learn how to use it. If
its a nice stove to use fuel savings may be 'taken up' in improved comfort
levels. When I mean to say is that its a good idea to go back after a few
months and do some more monitoring in all the households. Also it may be
useful to ask questions about stove usage (how often used, for what) each
day when weighing fuel.

3) a last point: investigate do people use other fuels too? An enclosed
stove naturally does not give light, so this might increase paraffin use
(which is paid for whereas wood, possibly is not)? Not a bad thing (I
think) but its useful to know the full energy picture...

Are these comments any use? Keep up the good work!
Grant

From REEDTB at compuserve.com Mon Jun 2 08:00:44 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:13 2004
Subject: Corncobs - great, unavailable fuel
Message-ID: <199706020759_MC2-17AD-566E@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
ALSO: The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HI!

When I first began working on biomass I focussed on corncobs as a major ag
residue that is also a great fuel - dry, medium burning rate. However,
farmers with modern equipment shell the corn leave the cobs in the field
except for seed corn which must be brought in. If there was a market for
cobs as fuel ($40/ton?) they would be harvested, but are generally not
available in the US.

How are things overseas?

TOM REED

From krksmith at uclink4.berkeley.edu Mon Jun 2 08:59:05 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:13 2004
Subject: Straw cooking
Message-ID: <199706021258.FAA15172@uclink4.berkeley.edu>

I am in China at the moment where I have been learning about a new
community-scale producer-gas system using straw and distributing the gas to
households for cooking. More when I know more/K

p.s. Estimates are that crop residues are the principal cooking fuel in
perhaps 15-20% of the world's households. Wood comprises something like 20-25%.

At 07:40 AM 5/30/97 -1000, you wrote:
>Dear Tom: Your comment on straw has awaken me from hibernation here.
>Straw should be baled, converted to high-yield charcoal, and burned, with
>the ash returned to the field. Best regards, Michael.
>
>
>

From zourarakis at nosapp.nr.state.ky.us Mon Jun 2 09:06:20 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:13 2004
Subject: Greedy algorithms for reduced C shared utilization
Message-ID: <97060208395228@nosapp.nr.state.ky.us>

Ron, Alex, and others:

The question of how much ag waste/residue should be left in place to protect our
soil resources and churn our nutrient/bioenergy cycles in (agro)ecosystems HAS
come up in the bioenergy list before (over 1 year ago!). Because I found it to
be the ONLY focused piece of research and data on the subject, I recommend you
get in touch with David Lightle (USDA-ARS). He is doing good work on crop resi
due equivalents taking into account erosion mainly. His contact data are:

David Lightle, Agronomist
USDA-NRCS
National Soil Survey Center
100 Centennial Mall North
Lincoln, Nebraska 68508 - 3866
402-437-4008
fax: 402-437-5336
e-mail: dlightle@nssc.nrcs.usda.gov

There is a draft of his study called: A soil conditioning index for cropland ma
nagement systems. It is dated 10-25-96. It does contain data you can use to *APP
ROXIMATE** a management scheme that contemplates shared use for that reduced C
in your crop residues.

David can also direct you to sources for RUSLE (revised Universal Soil Loss Equa
tion). Now, the experts are revising coefficients to include things such as "
near surface" residue (i.e. plant roots and crowns), which in some cases you mi
ght be harvesting and bailing (if you get too greedy) with the corn stover and
straw for burning, building, fodder, etc. instead of leaving it on the soil.

Manure and the like. There are out there scores of best management practices (B
MPs). Because of pathogen, nutrient and reduced C content, manure misuse of mis
magement is POTENTIALLY disastrous to waterbodies. Rarely so to soil/cropping sy
stems, which are usually (even if you use large amounts of synthetic fertilizer)
in need for organic matter and nutrient recycling.

Ag/natural resource managers put together conservation (soil/water) plans that
include a mix of appropriate BMPs in order to optimize different functions. The
most common is physical yield (grain, meat, wool, etc.); in the last 2 decades
the shift has been to include environmental quality functions, minimizing pollu
tant loads to surface/ground water through runoff/infiltration. Unlike some othe
r disciplines, agroecosystem management does not have (as of yet) a general set
of equations to work with. As a matter of fact, the hottest area (thanks to the
pervasive presence of cheaper and cheaper data management systems) in agricultu
re is site-specific management (or precision agriculture). GPS/GIS coverages are
available for soil types and soil cover. Because each field represents an indivi
dual idiosyncracy, crop/livestock/soil/water/nutrient management practices can
/must be developed to ensure: economic viability (farmer stays in business), en
vironmental soundness (on site and off-site damages to environment minimized) an
d social equity (your community stays intact); all of these requirements for sus
tainable agriculture.

With regards to diverting reduced C to uses other than preserving (agro)ecosys
tem integrity... Apparently in Denmark they have mastered the issue of straw
*SURPLUS* burning without hurting productive resources. But in a warmer environ
ment (remember that temperature has an exponential effect on oxidation of orga
nic matter all other things remaining constant), the amounts to be left if soils
need to be protected from rainfall/wind should increase real fast.

More questions? In the US the USDA-NRCS people survey crop residue amounts left
SITE-SPECIFICALLY each year. I would start with their data working my way into
RUSLE (let's assume you use synthetic fertilizers; if your agro-ecosystem manag
ement scheme is organic, then I'd say you will be FORCED to use much of your
waste/residue in trying to close your nutrient cycles) and from there whatever
is left.... BURN (or build, sell, etc.).

One more item (manure/dung): in some cases burning, digesting, exporting come
to mind as VERY viable alternatives because of shallow soils that can't possibl
y take all the P, pathogen and reduced C load (I believe there is lots of work
in upper midwest states: WI, MN, IA with dairy and beef lots). Then, unless you
export your manure, you saturate your soil/crops real quick and have to store
or dispose. Of course land application of digestor sludge has some of the same
problems.

Nuff said.

Demetrio.

From zourarakis at nosapp.nr.state.ky.us Mon Jun 2 09:29:36 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:13 2004
Subject: Greediness every which way.
Message-ID: <97060209242726@nosapp.nr.state.ky.us>

Ron, Alex and others:

Not long ago someone asked about the import of CO2 fixation biochemistry in fuel
crop production schemes. I succintly answered that you want to reserve your best
(most productive) agroecosystems for food/fodder and then move on to marginal
situations with biofuel harvesting. This is just one man's opinion considering
that food is still a priority in many areas in the world. If fuel is locally a
higher priority than food, then perhaps you can try inverting the assignment of
crops/practices. Just remember that 1-3 percent of solar energy impinging upon
the land surface is converted to primary photosynthates. The rest is not con
verted in to reduced H. Now ... THAT is the true challenge.

Cheers.

Demetrio.

From REEDTB at compuserve.com Mon Jun 2 11:03:53 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:13 2004
Subject: Barbecues, 3 hole improved
Message-ID: <199706021102_MC2-17AD-35A9@compuserve.com>

Glad to have Pete's opinion on barbecues. I was beginning to think I was
"weird", not liking the time and mess required. (My bread machine is one
of the most elegant cooking devices known to man. Microwaves are another.
Cooks only the food, not the "oven" and not the cook.)

I really enjoyed seeing your "J" stove demonstrated by Etienne at
Eindhoven. Too bad it isn't easier for EVERYONE on the list to make and
test EVERY stove so we would all have the same experience-perspective.
Can't you make a Markleen/Erector set kit of parts that would simulate all
stoves?

I have been attracted to the 3 stove stove. How about a u shaped hole
under the pit to provide air/no air condition and a little tighter seals
around the logs? It might be an easy sell in many countries.

Later, TOM REED

From REEDTB at compuserve.com Mon Jun 2 11:05:49 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:13 2004
Subject: Tom Reed response to Prasad
Message-ID: <199706021102_MC2-17AD-35AF@compuserve.com>

Ron - I stand corrected on your time use, and I applaud your attitude of
making what we know works available to those in desperate need today.

However, I will amend my statement to guess that the number of hours/year
of TRUE research, trying to understand cooking at its most basic, is small.
Glad to see that Paul Hait seems to do both R&D and sales. Pyrolysis
alone is complicated enough; coupled with the practical needs of
gasification or cooking, it is a Gorgon knot that we won't cut completely
in a decade, if then. But at least we are working on it.

Back to work on it,

Regards, TOM REED

From zourarakis at nosapp.nr.state.ky.us Mon Jun 2 11:16:16 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
Message-ID: <97060211085903@nosapp.nr.state.ky.us>

Art Krentzel:

Whole farm planning, perhaps an offspring of watershed management or ecosystem
management is being developed as a concept. You are right! Whole(some)ness is a
must. My pet peeve is ** MANAGEMENT **. Currently I am involved a little more
than I would like with adult continuing education on sustainable land and water
use practices. If one could add forest and biomass resources in general, one
would be in nat. resources heaven! It used to be that LISA (low input sustaina
ble agriculture) lured researchers with her siren's songs. LISA now dead (low
input *OBVIOUSLY* leads to low output), SARE rules (Sustainable ag, research
and ed), and seems to be in good health.

Truth is, there is no low input anything. Management on the part of landowners/
ag producers/farmers/ etc. IS input. Eyes/acre Wes Jackson said. Now with infor
mation technology one can dream of keeping an eye on systems, monitoring, asses
sing, feeding production functions.

I wonder if we can think beyond transfer functions and get into how much return
each penny invested in manager training brings. This is true not only for subsis
tence situations but also for "developed" environments.Sustainable human capital
, that in the end is all that matters.

Demetrio.

From verhaarp at janus.cqu.edu.au Mon Jun 2 17:32:37 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:13 2004
Subject: Verhaart message
Message-ID: <1.5.4.32.19970602213210.006b9e68@janus.cqu.edu.au>

>From Piet Verhaart

Dear AlexAt

21:41 1/06/97 -0500, you wrote:
>
>All this talk of different stove designs and no pictures or drawings.
>I was serious about getting them on the web. If you have a snap shot,
>send it to me, I'll scan it and send it back. .....
Chop.

I will look around, scan and attach.
Thank you on behalf of at least one stover.
Piet Verhaart>
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From larcon at sni.net Mon Jun 2 19:01:40 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:13 2004
Subject: Todd on emissions measurements
Message-ID: <v01540b00afb88e9f9873@[204.133.251.5]>

John Todd said:

>Regarding discussion about laboratory facilities for testing emissions.
>We have a well equipped laboratory for measuring particulate emissions from
>wood burning. It is used for testing woodheaters (wood-stoves) of the sort
>used in North America and Australia for domestic heating. Full lab costs
>are quite high, around $1000 (Aus) per day depending what facilities are
>required.

(RWL): Many of the questions on this list related to stove performance
have focused on CO, CH4, and efficiency. Does your lab have these
capabilities as well as for particulates? Has your lab done any work on
rural cook stove improvements?

>But there is some potential for involving postgraduate students so that the
>University picks up all the costs. The catch is that we have to have a
>student willing to work on the particular topic and the studies usually run
>over quite long periods (6 months to several years). I would be pleased to
>see if I could get student(s) interested in a project on emissions from
>cooking stoves.

(RWL): I hope you (and any others at Universities) will try do so. My
impression is that some good thesis topics are lurking out there.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 2 19:11:34 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:13 2004
Subject: Art Krenzel on warnings
Message-ID: <v01540b02afb89b0381c1@[204.133.251.5]>

Art Krenzel wrote in part:

snip

>I would like to join this narrowly focused discussion to report a
>warning. Not everything in the world needs to be or should be burned to
>heat something else. Straw represents a waste product that is part of a
>ongoing biological contract between consumers and producers which is
>necessary to maintain the life of soil biology. Using the nitrogen
>provided in rainfall, an entire host of bacteria work to digest
>carbonaceous materials to produce recyclable food for plants to insure
>future soil fertility. In our typically Western style, we pursue a
>resource until it is gone, many times to a mere memory. I give you the
>examples of the bison for hides and tongues, carrier pigeons, whales,
>tuna, driftnets, petroleum, old growth forest, etc. If we do not
>consider the WHOLE of the problem, we will be in a HOLE due to
>starvation even if we have the ability to boil water. Soil is a
>resource and needs to be conserved as a resource. Burning dung is
>perhaps one of the best examples of short sightedness I can quote.
>
(RWL): Art: I agree with all parts of the above. But straw and
dung are now widely used - and used badly. What is the best way out of the
present bad situation?

>I would like to add to these statements by saying that I don't think an
>energy efficient, simple stove will solve the total problem. Say we can
>wave our hands and we provide a great, efficient stove design using
>local materials for construction and consumption. How long will it be
>before the next crisis brought on by localized overpopulation for
>available resources will surface? I think eventually, mankind will need
>to balance resources, technology and local population. I realize this
>is not a subject of this forum but I would like us to think of the
>larger issue as well. Treat the disease as part of the solution and not
>just the symptom. If you think selling a new stove design is a problem
>in the starving areas, think of explaining limited family size.

(RWL): I've recently been reading in the discipline of ecological
economics. One of the best proponents (and founder of a society with that
name) is Herman Daly. His latest (1996) book is "Beyond Growth", Beacon
Press. I have a one page piece on this book in the next issue of "Solar
Today" - as a way of getting more people to pay increased attention to the
need to move faster towards sustainable development (not towards
"sustainable growth"). Reading this book made me also want to say more
about population issues. Thanks for raising the issue.

But I don't think that working on stove improvement need distract
from these larger issues. Crudely speaking, it seems there is one
population-concerned group that sees population control as being
accomplished primarily through misery (poverty); since the better the
future looks, the more that poor have children. Thus this group is not
anxious to make the future look better and might argue against improved
stove programs.

There is another group that sees population control as being
accomplished through raising the standard of living of the poorest - based
on the observation that the affluent countries are generally approaching
ZPG. My hope is that stove research is in this latter category - and that
the link to the first group is in drawing attention to the serious
over-expansion of the world's economy - that continued population expansion
anywhere is not in anyone's best interest. When taking this view, I am not
arguing for ever-continuing expansion of the world economy - only for a
catch-up by the poorest countries.

Can this stoves list concur that stove development is not
counterproductive to a rapid move to ZPG?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 2 19:11:34 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:13 2004
Subject: Part I of Koopman message
Message-ID: <v01540b01afb890630285@[204.133.251.5]>

Stovers: The following message was forwarded to me by CREST ("BOUNCE
stoves@crest.org: Message too long (>40000 chars)"), because it
contained a lengthy binary file (which showed up in my mail as five
separate messages). So I have deleted this last binary part and ask those
who are interested in it to communicate directly with Auke, or perhaps Auke
can first indicate another approach - such as an attachment?

Ron

>
>Microsoft Mail v3.0 IPM.Microsoft Mail.Note
>From: Koopmans, Auke (FAORAP)
>To: stoves
>Subject: Re: Auke Koopman's response
>Date: 1997-06-02 13:51
>Priority:
>Message ID: 1BCCAE29
>Conversation ID: 1BCCAE29
>Attachments:
> ENER-DB.XLS
>
>ùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù
>
>
>In reply to the RWL's message:
>>
>>By the way, the use of agricultural use such as husks, straw, dung, coconut
>>husks, corn cobs, leaves, grass, etc. is widespread here in South-east
>Asia.
>
> (RWL): Can you add anything about techniques used in Southeast Asia
>to make the combustion of these lightweight materials proceed more cleanly?
>
>
>>I have some information on amounts used in various countries but can't find
>>it at the moment.
>
> (RWL): If and when found I think many on this list would like to hear
>about charcoal amounts.
>
> (RWL): Also, the name "FAO" has come up several times recently. Could
>you give some indication of the extent of FAO activities in stove
>development and/or deployment?
>
>>
>>Regards Ron
>
>Ronal W. Larson, PhD
> -----------------------------
>
>Straw, and other fluffy materials are often used in traditional stoves. The
>main drawback is that feeding the fuel needs constant attention (continuous
>feeding of the straw) and produces smoke as well as large amounts of ash.
>The ash is often used to keep pots warm by removing the ash from the stove,
>shoving it to the side with pots with food put on/on it (haybox principle).
>Ricehusks etc. are often burned either in stoves with inclined grates or in
>specially designed stoves. The book Stove Images gives quite a few
>pictures/photograph of such stoves.
>
>
>In the attachment (EXCELL file Ener-DB.XLS) you will find some data on
>energy use within the Asian region. Total Primary Enenergy Supply or TPES
>(all types of energy), TPES Biomass (biomass only), TPES Fuelwood and
>Charcoal, Total Final Energy Supply (TFS) for fuelwood, charcoal, bagasse,
>ricehusks, dung and other residues. The data given are based on energy
>balances published by the countries concerned (where available).
>Unfortunately, most of the countries do not publish data on biomass energy
>use, reason that many of the cells in the spreadsheet are blank even though
>it is known that large amounts of wood and residues are used as fuel.
>
>
>FAO in this case is the Regional Wood Energy Development Programme or RWEDP
>of FAO. We are based in Bangkok, Thailand and work with 16 countries in the
>region. Our main interest is threefold: First of all to get biomass energy
>into the energy planning process. In many countries here in Asia biomass
>energy accounts for over 50% of all energy used in the countries - yet
>energy planners are not considering it. This in many cases is caused by the
>fact that so little information is available on biomass energy use, biomass
>is often considered as something of the past (out-dated), dirty, biomass
>energy use will disappear, etc. Although the data point to the fact that
>biomass energy is becoming less important when judged by the share in the
>overall energy picture, the physical amounts of biomass energy used are
>often still increasing.
>
>Our second interest lies on the resource side (fuelwood sources, fuelwood
>trade, employment generation, etc.) while the third part is biomass energy
>conversion/conservation.
>
>With regard to the latter we spend considerable time and efforts in training
>people from the region in the field of cookstove technology, conversion
>devices for small scale industries, etc. Within this context we publish also
>information a.o. a Compendium of Stoves used in India and in China (Field
>Document or FD 41 and FD 40), a Development Manual for Improved Solid
>Biomass Burning Cookstoves (FD44), etc. We also try to assist the countries
>with exchange of information through workshops such as on Institutional
>Stoves (organized in Indonesia in 1995), Stoves for use with Residues
>(Vietnam 1995), Space Heating Stoves (Pokhara, Nepal 1996 - for those who
>read Boiling Point published by ITDG, most of the articles in the last issue
>on Heating Stoves were provided by RWEDP), Stove Images (RWEDP provided
>quite a bit of information materials, etc. and also took care of the
>distribution of Stove Images in Asia), etc.
>
>In case anyone would like to receive a copy of the publications, please send
>a message to the:
>Chief Technical Advisor Dr. W. Hulscher
>at email address:
>
>rwedp@field.fao.org
>
>or snail mail or fax to
>
>FAO-RWEDP
>Maliwan Mansion
>Phra Atit Road 39
>Bangkok 10200
>Thailand
>Tel. +66-2-2802760
>Fax +66-2-2800760
>
>Many of our activities related to cookstoves are being carried out jointly
>with ARECOP which is the Asian Regional Cookstove Programme. ARECOP is the
>Asian part of FWD or the Foundation for Woodstove Development (earlier
>referred to by list members). FWD, which is based in Nairobi appears to be
>slumbering. In the next few weeks I will hopefully meet Steven Karekezi, the
>Executive Secretary of FWD at a meeting of the Household Energy Development
>Organizations Network (HEDON) in Germany. I will check with him what FWD is
>doing and/or what they can do for the list members.
>
>In case you need further specific information please contact me directly at
>the same address or at
>auke.koopmans@field.fao.org.
>
>Regards,
>
>Auke Koopmans
>Wood Energy Conservation Specialist
>
>
>[[ ENER-DB.XLS : 3388 in ENER-DB.XLS ]]
>
>
>--Boundary (ID IjeyXlh+bbYClty0VjXdHg)
>Content-type: APPLICATION/OCTET-STREAM; NAME=ENER-DB.XLS
>Content-description: ENER-DB.XLS
>Content-transfer-encoding: X-UUENCODE
>
>The following binary file has been uuencoded to ensure successful
>transmission. Use UUDECODE to extract.
>
>begin 600 ENER-DB.XLS
>MT,\1X*&Q&N$`````````````````````.P`#`/[_"0`&```````````````"
>M`````0``````````$````@````$```#^____``````````!U````________

(The remainder deleted by RWL to expedite delivery of the foregoing)

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phoenix at transport.com Tue Jun 3 02:01:35 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <199706012329.SAA01635@adan.kingston.net>
Message-ID: <3393B31A.1C69@transport.com>

english@adan.kingston.net wrote:
>
> Dear Art and .....
> you wrote; I think eventually, mankind will need
> > to balance resources, technology and local population. I realize >>this is not a subject of this forum but I would like us to think of >>the larger issue as well. Treat the disease as part of the solution >>and not just the symptom. If you think selling a new stove design is >>a problem in the starving areas, think of explaining limited family >>size.
>> Art Krenzel
>
> Agreed!
>
> Question: In, for example, dry or highly populated regions where wood
> is unavailable, what might be the portion of available crop residues
> diverted for cooking purposes? If general accuracy is difficult, give
> me an isolated example,.... please.
>
> Alex English
> RR 2 Odessa Ontario
> Canada K0H 2H0
> 613-386-1927

How about the old adage "if you use something, put it back". If one
uses something for food, such as grain, put the residues and secondary
products back into the ground for more food. If the residues can be
processed through an animal before it is returned, all the better. This
is what I call the "NO LANDFILLS" option. The soil is one resource
which requires constant maintenance. The biological cycle for
replacement is very long.

If some forms of biomass are used for shelter or heat, replant it for a
similar use in the future.

In these general terms the "system" could continue at the present levels
of production unless localized overuse prevents the timely recovery of a
resource. The proactive response is to apply the best technology to
solve the current problems and/or redistribute the users and resources
more equitably. The "no action" response is to suffer through the
ravages of localized overpopulation.

Rural areas should not be mined for their resources to supply others.
Part of the purchase cost of the materials needs to include the cost of
replanting the replacement crops and the replanting should be mandatory
in one to two years after harvesting.

Good question, Alex! This answer provides my insight into some of the
solutions to the problem. What are your thoughts?

Art Krenzel
Battle Ground, WA

From antal at wiliki.eng.hawaii.edu Tue Jun 3 14:19:27 1997
From: antal at wiliki.eng.hawaii.edu (Michael Antal)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <v01540b01afb73e06ce34@[204.133.251.5]>
Message-ID: <Pine.HPP.3.95.970603074737.9704D-100000@wiliki.eng.hawaii.edu>

Dear Ron: thanks for the kind words. We do not believe that more basic
research is required on high-yield charcoal. The important knowledge is
given in M.J. Antal, et al., Energy Fuels, 1996, 10, 652-658 and two U.S.
patents. I am willing to mail a reprint of the paper to anyone who is
interested. We will not be publishing more on this subject, since the
paper contains what is needed.

The technology is being commercialized by a group of entrepreneurs and
investors in California. Their Business Plan calls for the formation of
the company during the summer, and the first commercial reactor in
operation one or two years later. I do not care to say more than this at
the present time. Altho I have seen such enterprises start and stop many
times, I am optimistic that this one will succeed. If it does, stove
researchers may want to give more attention to charcoal burning stoves in
the future.

We flare the gases and plan to use the heat to dry the feed biomass. As
our reactor is semi-batch, the steam exits largely before the combustible
pyrolysis gases. Hence we do not have a big problem with emissions (which
are small anyway since most of the carbon is converted to charcoal, i.e.
the process is efficient), but I still worry a little about EPA
regulations at the commercial level.

We are not currently making briquettes, but this would be an option for
powdery products, like charcoal from bagasse.

Finally for my friends that are concerned about agriculture, I remark that
we have a regular demand from horticultural specialists for charcoal as a
rooting medium. Apparently charcoal is well known to be an ideal medium
for growing plants (better than peat). High yield charcoal can be
manufactured very cheaply. I expect that a market will develop for the
use of charcoal as a soil additive (like peat, only better). I think
there is a possibility that the large scale return of charcoal to the soil
may be a realistic solution to the CO2 problem.

Charcoal is the big sleeper in the renewable fuels area. I think we are
on the edge of witnessing some remarkable things with this old/new fuel.

Best regards, Michael.

On Sun, 1 Jun 1997, Ronal W. Larson wrote:

> Mike Antal has written:
>
> >Straw should be baled, converted to high-yield charcoal, and burned, with
> >the ash returned to the field. Best regards, Michael.
>
>
> (RWL): I believe Mike is one of the most skilled in biomass-charcoal
> conversion processing and it is good to hear from him. I have these
> questions:
>
> 1. Could you describe the process you have been developing - and its
> yield, economics, market-readiness, etc.
>
> 2. How are you making use of the pyrolysis gases?
>
> 3. Are you creating briquettes?
>
> Thanks in advance Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>

From zourarakis at nosapp.nr.state.ky.us Tue Jun 3 15:43:22 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:13 2004
Subject: Charcoal as soil additive
Message-ID: <97060315375291@nosapp.nr.state.ky.us>

Mike and others:

I would not hold my breath. Charcoal-C used this way would be taken out of circu
lation as it is probably nearly 100 % refractory to microbial attack in soils.
It could have some "activated charcoal" properties, that could sequester some
ions out of soil solution. The most interesting effects would be contrary to
each other: 1. soil conditioner; at large particle sizes it could increase macro
porosity and water movement (_good_ in humid climates) or could be used as mulch
in semiarid conditions (water conservation reducing water vapor phase transport)
and 2. due to low bulk density it would runoff toward waterbodies, impacting
aesthetics, wildlife, etc. (but probably inocuous chemically): the charcoal flo
tilla....

Cheers. Demetrio.

Demetrio P. Zourarakis, PhD

From verhaarp at janus.cqu.edu.au Tue Jun 3 17:32:01 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
Message-ID: <1.5.4.32.19970603210543.006bc8ec@janus.cqu.edu.au>

At 14:52 1/06/97 -0700, you wrote:
.........................
>How long will it be before the next crisis brought on by localized
overpopulation for available resources will surface? I think eventually,
mankind will need to balance resources, technology and local population. .....

Hear, hear.
At present every improvement in health, living conditions etc. in the poor
parts of the world results in an increase in population, tending to restore
the old situation.
Every animal pollutes and needs a certain amount of space so nature can
reprocess the waste products. The only species we seem to excempt from this
rule is the human one. I would say that humans need a lot of space in order
to survive. Space (meaning surface area) being constant, the only variable
is the number of humans. I would suggest an average of two per square
kilometer being the goal to aim for.
One sure thing is that, if we don't do it, nature will, and in much less
pleasant ways such as famine, epidemics and wars. This is already happening,
of course.

Meanwhile I will keep thinking about the untimate woodburning cookstove.

Regards,
Peter Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From larcon at sni.net Tue Jun 3 23:45:19 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
Message-ID: <v01540b05afba8b247c7a@[204.133.251.2]>

Mike said:

>. I am willing to mail a reprint of the paper to anyone who is
>interested.

(RWL): Thanks for a very complete response. I'd like a copy of the paper
and will probably have a few more questions after that. Good luck with
your commercial venture - and congratulations for getting to that step.

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phoenix at transport.com Wed Jun 4 00:33:38 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:13 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <Pine.HPP.3.95.970603074737.9704D-100000@wiliki.eng.hawaii.edu>
Message-ID: <3394F080.1DDF@transport.com>

Michael Antal wrote:
>
> Dear Ron: thanks for the kind words. We do not believe that more basic
> research is required on high-yield charcoal. The important knowledge is
> given in M.J. Antal, et al., Energy Fuels, 1996, 10, 652-658 and two U.S.
> patents. I am willing to mail a reprint of the paper to anyone who is
> interested. We will not be publishing more on this subject, since the
> paper contains what is needed.

Hello Mike,

Please send me a reprint of the paper if you would. It might do as well
to electronically read in a copy (Microsoft Word ver 6 or so) as an
attachment to your electronic reply to Stoves@crest and save the postage
and paper. Let's practice what we preach electronically.

Thank you.

Art Krenzel
10505 N.E. 285th Street
Battle Ground, WA 98604
phoenix@transport.com

From phait at transport.com Wed Jun 4 02:09:47 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
Message-ID: <199706032326.QAA05167@butch.transport.com>

>Michael Antal wrote:
>>
>> Dear Ron: thanks for the kind words. We do not believe that more basic
>> research is required on high-yield charcoal. The important knowledge is
>> given in M.J. Antal, et al., Energy Fuels, 1996, 10, 652-658 and two U.S.
>> patents. I am willing to mail a reprint of the paper to anyone who is
>> interested. We will not be publishing more on this subject, since the
>> paper contains what is needed.
>
>Hello Mike,
>
>Please send me a reprint of the paper if you would. It might do as well
>to electronically read in a copy (Microsoft Word ver 6 or so) as an
>attachment to your electronic reply to Stoves@crest and save the postage
>and paper. Let's practice what we preach electronically.
>
>Thank you.
>
>Art Krenzel
>10505 N.E. 285th Street
>Battle Ground, WA 98604
>phoenix@transport.com
>

Dear Mike,

Count me in also. I would be very interested in getting a copy of the paper.
It was encouraging to see that Charcoal and briquettes have a future.

Sincerely,
Paul Hait
President
Pyromid Inc.
3292 S Hwy 97
Redmond,Oregon 97756
541.548.1041

From ahe1 at cableol.co.uk Wed Jun 4 16:47:42 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal Energy Fuels 1996
Message-ID: <9706042046.AA24564@mars.cableol.net>

At 08:05 03/06/97 -1000, you wrote:

>given in M.J. Antal, et al., Energy Fuels, 1996, 10, 652-658 and two U.S.
>patents. I am willing to mail a reprint of the paper to anyone who is

I would be keen to read this if you could email it? If it is too large
contact me anyway and I will send the postage.

>times, I am optimistic that this one will succeed. If it does, stove
>researchers may want to give more attention to charcoal burning stoves in
>the future.

I have just subscribed to this list and fully intended to lurk before
posting, however one of my interests which drew me to your group was the
co-generation of heat and charcoal, which is a high value luxury good in
this country.
>We flare the gases and plan to use the heat to dry the feed biomass. As
>our reactor is semi-batch, the steam exits largely before the combustible
>pyrolysis gases. Hence we do not have a big problem with emissions (which
>are small anyway since most of the carbon is converted to charcoal, i.e.
>the process is efficient), but I still worry a little about EPA
>regulations at the commercial level.

Oddly enough in England there is an exemption from the environmental agency
inspections for charcoal burning.

>Finally for my friends that are concerned about agriculture, I remark that
>we have a regular demand from horticultural specialists for charcoal as a
>rooting medium. Apparently charcoal is well known to be an ideal medium
>for growing plants (better than peat). High yield charcoal can be
>manufactured very cheaply. I expect that a market will develop for the
>use of charcoal as a soil additive (like peat, only better). I think
>there is a possibility that the large scale return of charcoal to the soil
>may be a realistic solution to the CO2 problem.

The two points you make are interesting, the carbon locking of charcoal
fines as a soil ameliorant may be a valid selling point, we add them to
composted arboricultural waste from one of the London boroughs purely to
dispose of a messy by-product, this will no doubt appall many of you on the
list. However one side effect of this is supposed to be the ability to
adsorb and neutralise herbicides in the soil.
>
>Charcoal is the big sleeper in the renewable fuels area. I think we are
>on the edge of witnessing some remarkable things with this old/new fuel.

I hope so, I would be very pleased to hear of any way of increasing the
efficiency of metal ring kilns, we operate 5 and due to restrictions of
firing only once per week this limits our thruput to 10tonnes input
1.5tonnes approx yield
AJH

From verhaarp at janus.cqu.edu.au Wed Jun 4 18:27:16 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
Message-ID: <1.5.4.32.19970604222722.006a6684@janus.cqu.edu.au>

Dear Mike

Could you do me one of the same asArt Krenzel requested. Word is OK, I don't
have that, I still make do with WordPerfect 5/1 for Windows, but Wordpad can
translate Word into RTF, which in turn is intelligible to WP.
Directly in RTF would be easier.
Thanx in advance.

Peter Verhaart

At 21:35 3/06/97 -0700, Art wrote:

>Hello Mike,
>
>Please send me a reprint of the paper if you would. It might do as well
>to electronically read in a copy (Microsoft Word ver 6 or so) as an
>attachment to your electronic reply to Stoves@crest and save the postage
>and paper. Let's practice what we preach electronically.
>
>Thank you.
>
>Art Krenzel
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From zourarakis at nosapp.nr.state.ky.us Wed Jun 4 20:36:13 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal Energy Fuels 1996
Message-ID: <97060420335105@nosapp.nr.state.ky.us>

AJH:

Interesting your comment on sorption of herbicides by charcoal. If you read my
comment to Mr. Antal's suggestion of disposing charcoal into soils, I allowed
for sorptive properties to exist. I made some other points regarding potential
movement with water as runoff (charcoal is light, right?).

Keep the soil connection going. Yours in biofuel cropping systems,

Demetrio.

From english at adan.kingston.net Wed Jun 4 22:43:14 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking, Art
In-Reply-To: <3393B31A.1C69@transport.com>
Message-ID: <199706050242.VAA06989@adan.kingston.net>

Art, Demetrio, and other thread followers;

I always write exactly what I'm thinking, until I reread what I
wrote.
I was looking for some empirical data. So I shall restate this
question with a small edit.

> > Question: In, for example, dry or highly populated regions where wood
> > is unavailable, what is the portion of available crop residues
currently being
> > diverted for cooking purposes? If general accuracy is difficult, give
> > me an isolated example,.... please.
Perhaps someone like Kirk Smith in China or Auke Koopmans in
Thailand could comment.

Art wrote;
> How about the old adage "if you use something, put it back". If one
> uses something for food, such as grain, put the residues and secondary
> products back into the ground for more food.

Ok , say the residues are left in the field in a hot climate.
Is not the carbon rapidly oxidized ? Aside from nutrient cycling,
what is the role of dead organic matter in tropical soil ecology?

> If the residues can be
> processed through an animal before it is returned, all the better.

Not necessarily. Ideally, from a top soil preservation stand point,
soil needs to be rootbound and leaf covered at all times. Some
midwest farmers have started removing corn stover, after combining
the grain, for animal feed and bedding. This would be fine if they
had managed to over come the logistical difficulties and under seeded
a cover crop . Hard to do with grain corn.

It wasn't long ago that
the "ideal" was a residue free soil surface. Times have changed and I
gather, from reading a report on soils and the new "no-till" and
"minimum" tillage practices , that Corn, with its powerful Carbon
reducing ability and grown under these practices, is starting to
offer some net benefits to the soil managers.

I look forward to hearing back from Dave Lightle on this topic.

> This
> is what I call the "NO LANDFILLS" option. The soil is one resource
> which requires constant maintenance. The biological cycle for
> replacement is very long.
>
> If some forms of biomass are used for shelter or heat, replant it for a
> similar use in the future.
>
> In these general terms the "system" could continue at the present levels
> of production unless localized overuse prevents the timely recovery of a
> resource. The proactive response is to apply the best technology to
> solve the current problems and/or redistribute the users and resources
> more equitably. The "no action" response is to suffer through the
> ravages of localized overpopulation.
>
> Rural areas should not be mined for their resources to supply others.
> Part of the purchase cost of the materials needs to include the cost of
> replanting the replacement crops and the replanting should be mandatory
> in one to two years after harvesting.
>
> Good question, Alex! This answer provides my insight into some of the
> solutions to the problem. What are your thoughts?

I think of the farm I own... with its gravelly knolls, devoid of
organic matter, that wouldn't even produce half of a decent crop
in a wet year. I think of my wifes sheep flock which we " manage" to
intensively graze in small paddocks so as to effectively cycle
nutrients. And of the time I intend to spend tommorro spreading
manure on those pastures just before it rains ( I hope) , so as to
maximize growth. I'll probably end up maximizing parasite loads as
well. Its a paradoxical planet. I am none the less eager to here of
the best compromises that others have come up with while trying to
meet their needs.

Alex

> Art Krenzel
> Battle Ground, WA

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Wed Jun 4 22:43:17 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:14 2004
Subject: Contribution from new "stoves" member
Message-ID: <v01540b01afbbadce887c@[204.133.251.3]>

>From: Andrew Heggie <ahe1@cableol.co.uk>

>I am a woodland worker in the SE of England with 25years experience of local
>woodlands, I am of a very parochial outlook as I am not at all well
>travelled, I suspect I am becoming a member of a third world post developed
>economy:
-). I have an interest in stove technology as industrial uses for
>wood no longer exist here, all small wood must travel 120+miles by road to
>nearest pulpmill. This coupled with the high wages in an economy linked to
>financial services means wood as a resource is being underutilised. We burn
>charcoal in conventional ring kilns and sell firewood. I am interested in
>aspects of efficiency,pollution, environmental damage and co generation with
>an inclination to KISS and small is beautiful. I work in association with an
>environmental charity who are proponents of bioregionality.
>

Andrew:

This is a very interesting situation you describe. In Colorado,
there is a problem where the forests are losing their health because fires
have been suppressed and there are too many crowded small trees. The
forests would become much healthier and safer for nearby residences if they
were regularly thinned out. The societal benefits of thinning far exceed
the costs of thinning, but the value of the wood alone does not. Do you
(or anyone on the list) have a similar problem and any solutions to better
utilization of such "remote" forests?

Regards Ron

(the above sent to me as a private message - that I felt would be
interesting to the full group. For some unknown reason, I received it back
once.)

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 4 22:43:13 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:14 2004
Subject: Andrew Heggie on Antal mail
Message-ID: <v01540b07afbbc3729dff@[204.133.251.3]>

Mike said:
>>We flare the gases and plan to use the heat to dry the feed biomass. As
>>our reactor is semi-batch, the steam exits largely before the combustible
>>pyrolysis gases. Hence we do not have a big problem with emissions (which
>>are small anyway since most of the carbon is converted to charcoal, i.e.
>>the process is efficient), but I still worry a little about EPA
>>regulations at the commercial level.

Andrew said:
>Oddly enough in England there is an exemption from the environmental agency
>inspections for charcoal burning.

(RWL): Andrew - I believe that Michael meant that EPA has regulations to
prohibit venting of pyrolysis gases during charcoal production - not during
charcoal consumption. In the US, "burning" would refer to consumption. In
the UK, could "burning" mean production or consumption or both?

(RWL): In the UK, are there environmental regulations cover charcoal
production?

Andrew said:

snip

>I would be very pleased to hear of any way of increasing the
>efficiency of metal ring kilns, we operate 5 and due to restrictions of
>firing only once per week this limits our thruput to 10tonnes input
>1.5tonnes approx yield

(RWL): We have had some conversation on this list relative to a similar
size metal ring kiln - that had a 2 day cycle. Could you describe some
dimensions and details of firing?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From english at adan.kingston.net Wed Jun 4 22:56:34 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <v01540b01afb73e06ce34@[204.133.251.5]>
Message-ID: <199706050256.VAA07697@adan.kingston.net>

Michael
I am up to my eyeballs in a greenhouse business. Could you provide
some references related to charcoal as a rooting and growing medium.

Alex

PS: I wonder if a nose full of charcoal is better than a nose full
of peat.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Thu Jun 5 07:57:30 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking, Art
Message-ID: <199706051156.GAA19490@adan.kingston.net>

Art, Demetrio, and other thread followers;

I always write exactly what I'm thinking, until I reread what I
wrote.
I was looking for some empirical data. So I shall restate this
question with a small edit.

> > Question: In, for example, dry or highly populated regions where
> > wood is unavailable, what is the portion of available crop
> > residues
currently being
> > diverted for cooking purposes? If general accuracy is difficult,
> > give me an isolated example,.... please.
Perhaps someone like Kirk Smith in China or Auke Koopmans in
Thailand could comment.

Art wrote;
> How about the old adage "if you use something, put it back". If one
> uses something for food, such as grain, put the residues and
> secondary products back into the ground for more food.

Ok , say the residues are left in the field in a hot climate.
Is not the carbon rapidly oxidized ? Aside from nutrient cycling,
what is the role of dead organic matter in tropical soil ecology?

> If the residues can be
> processed through an animal before it is returned, all the better.

Not necessarily. Ideally, from a top soil preservation stand point,
soil needs to be rootbound and leaf covered at all times. Some midwest
farmers have started removing corn stover, after combining the grain,
for animal feed and bedding. This would be fine if they had managed
to over come the logistical difficulties and under seeded a cover crop
. Hard to do with grain corn.

I look forward to hearing back from Dave Lightle on this topic.

> This
> is what I call the "NO LANDFILLS" option. The soil is one resource
> which requires constant maintenance. The biological cycle for
> replacement is very long.
>
> If some forms of biomass are used for shelter or heat, replant it
> for a similar use in the future.
>
> In these general terms the "system" could continue at the present
> levels of production unless localized overuse prevents the timely
> recovery of a resource. The proactive response is to apply the best
> technology to solve the current problems and/or redistribute the
> users and resources more equitably. The "no action" response is to
> suffer through the ravages of localized overpopulation.
>
> Rural areas should not be mined for their resources to supply
> others. Part of the purchase cost of the materials needs to include
> the cost of replanting the replacement crops and the replanting
> should be mandatory in one to two years after harvesting.
>
> Good question, Alex! This answer provides my insight into some of
> the solutions to the problem. What are your thoughts?

I think of the farm I own... with its gravelly knolls, devoid of
organic matter, that wouldn't even produce half of a decent crop in a
wet year. I think of my wifes sheep flock which we " manage" to
intensively graze in small paddocks so as to effectively cycle
nutrients. And of the time I intend to spend tommorro spreading
manure on those pastures just before it rains ( I hope) , so as to
maximize growth. I'll probably end up maximizing parasite loads as
well. Its a paradoxical planet. I am none the less eager to here of
the best compromises that others have come up with while trying to
meet their needs.

Alex

> Art Krenzel
> Battle Ground, WA

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From ahe1 at cableol.co.uk Thu Jun 5 13:45:26 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:14 2004
Subject: Demetrio adsorbtion property of charcoal
Message-ID: <9706051745.AA24431@mars.cableol.net>

At 20:33 04/06/97 -0400, you wrote:
>AJH:
>
>Interesting your comment on sorption of herbicides by charcoal. If you read my
>comment to Mr. Antal's suggestion of disposing charcoal into soils, I allowed
>for sorptive properties to exist. I made some other points regarding potential
>movement with water as runoff (charcoal is light, right?).

Yes your post arrived as I sent mine, which was queued as I log on only
mornings and evenings.

I had not considered the run off problem, obviously the charcoal is very
light. I was searching for alternative markets and knew activated charcoal
had this property. Activated charcoal has been treated, by steam I think, to
pit the suface and increase surface area, I assume our fines have a large
surface area.
One memory from the past is an earthenware jug used by my grandmother in
which she drew off rainwater from a butt (which incidentally only received
water from a heavy downpour as a gap had to be jumped by the stream from the
roof so first washings were lost) and the bottom was filled with charcoal,
water being drawn off by a tap. Reading that the local water utility was
finding boreholes contaminated by three residual herbicides which requires
50kGBP investment per bore to remove,I wondered if a carbon filter might be
used instead. I thought after saturation it could be drained and then
burned, I take it as long as the furnace is hot enough any chemical retained
would dissociate, and energy recovered. I did a simple search on charcoal
and found" Using activated charcoal to inactivate agricultural chemical
spills ag442" ( I do not have the url to hand)
Regards AJH

From shaase at neosdenver.com Thu Jun 5 13:46:12 1997
From: shaase at neosdenver.com (Scott Haase)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <1.5.4.32.19970604222722.006a6684@janus.cqu.edu.au>
Message-ID: <339705E8.2A92@neosdenver.com>

Mike:

Your offer to send a copy of your paper is getting a lot of response. Is
it possible for you to post your article to the list so that we can all
download it and you only have to do it once? IF not, I also would like
to get a copy of your paper as well.

Thanks,

Scott

*************************
Scott Haase
NEOS Coporation
165 South Union Blvd., Suite 260
Lakewood, CO 80228 USA
Phone: (303) 980-1969
Fax: (303) 980-1030
email: shaase@neosdenver.com

From elk at arcc.or.ke Fri Jun 6 03:42:22 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:14 2004
Subject: No Subject
Message-ID: <v01510101afbd8942cdcf@[199.2.222.97]>

Hello;

I've been working on a very simple hand operated charcoal briquetter (made
from water pipes) for use in the informal sector to salvage waste sawdust
here in East Africa.

I've some very promising results so far using cement as a binder at between
8 & 10% inclusion, but would appreciate as much information on alternative
binders as is available. As you can imagine, the ash residue is significant
when cement is used.

Of interest though, the high ash content does act as a fire retardant,
allowing for a prolonged even heat over approximately twice the length of
burning time expected from normal artisanal charcoal.

In addition to information on binders, I'd like any literature available on
appropriate (for field use) carbonising methods. The object is to reduce
all aspects of sawdust charcoal briquette production to the absolute
simplest level possible.

If you are able to post this info request on the Web, and/or forward this
message to others who may have experience or interest in the subject, I'd
be most grateful.

Elsen Karstad
Nairobi

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From REEDTB at compuserve.com Fri Jun 6 08:42:55 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
Message-ID: <199706060842_MC2-17FA-19EE@compuserve.com>

I am so glad to hear Mike's voice in this STOVE forum which includes
CHARCOAL as a sub-subject. I first heard Mike claim that he could make
over 45% charcoal from wood in Thailand in 1985, and since the total carbon
content of wood is only about 48-52% carbon in proximate analyses, this was
greeted with skepticism by the naive. Of coarse CHARCOAL =/ CARBON, since
charcoal can contain up to 30% volatile matter, depending on its
preparation.

Mike's process (has it a handy name?) is the biggest breakthrough in
charcoal making in 20,000 years. It speaks poorly of the concern of the
the developed countries for developing countries and global warming that he
has had so much trouble getting the process commercialized.

Good luck this Summer Mike and good luck to your California investors.

Regards, TOM REED

From REEDTB at compuserve.com Fri Jun 6 08:46:00 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:14 2004
Subject: Charcoal as soil additive
Message-ID: <199706060845_MC2-17F7-4C2D@compuserve.com>

Thanks for your comments on "Charcoal as a Soil Additive". I hope that it
will start another thread here, and I'm also putting this in BIOENERGY,
since there are members there who may not have caught Mike Antal's comment
that charcoal is a good soil additive.

I am strictly a learner here. I would LIKE to believe that charcoal is a
good soil additive. I have read a paper from Japan praising its use,
(since lost). Downdraft gasification typically produces 3-6% of
"CHAR-ASH", (all the minerals of the wood, 20-50%, plus unconverted
carbon, probably quite active since leached by CO2 and H2O above 800C). We
also produce SEA-SWEEP, a charcoal-like oil absorbent and I have spread
both new and oil saturated material on my garden with mixed results.

Demetrio says charcoal could runoff with rain water and have a negative
effect. Counter this with charcoal can turn tan dirt into the "black dirt"
prefered (naively) by gardeners. All dirt runs off, so charcoal dirt
probably wouldn't be identified as charcoal.

So, I hope that we will get "expert" opinion from CREST. Maybe "we" can
even write a white (or black : } ) paper, Bourbaki style, on the subject.
[Tom Miles can be editor :( ]

Regards, TOM REED

From REEDTB at compuserve.com Fri Jun 6 08:46:12 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:14 2004
Subject: Housekeeping details
Message-ID: <199706060845_MC2-17F7-4C3B@compuserve.com>

I hate to interrupt the flow of information on world shaking issues with
housekeeping comments, but they are necessary now and then.

1) It is so easy to press the "REPLY" button on our E-mail processor that
we don't pay attention to who is replying to whom. So, I get lots of
letters from STOVES to STOVES and don't know what's going on. Please
identify at least your name at the beginning of the note. (My letterhead
above is added automatically by the program ASPELL in Compuserve. I often
trim it when writing those who don't need all this info, but better more
than less.)

2) Subject: It is very important to either keep the same SUBJECT header
when appropriate, or change it when the subject changes.

3) Spelling: We are fortunate that meaning often survives spelling and
grammar errors, but enough errors eventually makes meaning muddy. Again,
my ASPELL program underlines all my errors in red and I fix most of them.
It also underlines all your errors as well, and half the words are
misspelled in some of your transmissions. If you don't care about your
image, it doesn't worry me, but I thought you should know that I can't help
seeing them.

Back to content, TOM REED

From b.tremeer at mail1.remote.uva.nl Fri Jun 6 09:02:56 1997
From: b.tremeer at mail1.remote.uva.nl (Grant Ballard-Tremeer)
Date: Tue Aug 31 21:35:14 2004
Subject: Doing something practical
Message-ID: <199706061253.OAA00773@mail.uva.nl>

Hello all

Continuing the theme of doing something practical (not that I have anything
against the discussion on soil and charcoal, not sure I follow it all
though...) I have recently been reading a copy of the magazine Joint
Implementation Quarterly (have a look at http://www.northsea.nl/jiq). Joint
Implementation is a potential mechanism for implementing committments under
the climate change convention (I'm working on a pilot version (they call
then AIJs, Activities Implemented Jointly) to be implemented between South
Africa and the Netherlands). In the April 1997 issue there is an article on
Sustainable Energy Management in Africa (in Burkina Faso). I thought this
article may generate some interesting debate here on the stoves list:

"The overall goal of the AIJ project is to contribute US$ 2.4 million of
additional resources to rural development activities which will reduce CO2
emissions and enhance carbon sinks by about 1.5 million tons of CO2 during
a period of 5 years (project preparations take one year more) to be
acheived through:
* managing 300 000 ha of community based forest;
* promoting efficient charcoal processing technologies;
* introducing solar photovoltaic systems for household lighting and water
pumping systems; and
* introducing efficient kerosene cooking stoves that will replace the use
of fuelwood."

and "The project will encourage the use of better charcoal processing
techniques, and sustainable harvest of forests for charcoal production and
trade." and "Introduction of carbonisation technologies may improve
efficiency by 25%."

and then "On average over 3.2 million tons of wood were harvesting for
woodfuel (charcoal). Burning 1 kg of charcoal induces 6.8 kg of net CO2
emission, while 0.28 kg of kerosene (equivalent in energy terms) induces
only 0.87 kg of CO2. Thus, the ration of CO2 emitted by charcoal versus
kerosine while producing equal amounts of energy is 7.8:1."

Money comes from the Norwegian Ministry of Foreign Affairs... "totals 2.4
million US$, while the amount of CO2 reduced is almost 1.5 million tons.
Thus, the cost per ton of CO2 avoided is US$ 1.60".

And believe me, this is VERY, VERY cheap for a country like Norway (they
could expect to pay more than 20 US$ per ton for the same reduction there,
at least). And this is just pilot phase - wait until carbon gets a tradable
price.

I have more to say, but no time to say it,
I'm very interested in comments please!

Grant

>From Tom Reed:
>Grant asked if the global warming community couldn't help. (Good idea,
>whether they are right or wrong about warming. They are absolutely
right=
>about conserving.) The first step to enlisting their help is to get a
back
>of the envelope estimate as to how much pollution they emit using bad
>fuels, and how much more they emit converting wood to charcoal. A back
>of the envelope estimate, if it showed a significant contribution to
global
>warming, would convince some and suggest to others that a better study
>should be funded. [Then they would likely spend all their money for a
>decade on studying the current problem with statisticians, spectrometers
>and satelites and probably not spend any money on trying to cure it.]

From elk at arcc.or.ke Fri Jun 6 09:50:47 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:14 2004
Subject: Sawdust Charcoal Briquetting
Message-ID: <v01510103afbda0c854a2@[199.2.222.131]>

Hello;

I've been working on a very simple hand operated charcoal briquetter (made
from water pipes) for use in the informal sector to salvage waste sawdust
here in East Africa.

Of interest though, the high ash content does act as a fire retardant,
allowing for a prolonged even heat over approximately twice the length of
burning time expected from normal artisanal charcoal.

If you are able to post this info request on the Web, and/or forward this
message to others who may have experience or interest in the subject, I'd
be most grateful.

Elsen Karstad
Nairobi

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From phoenix at transport.com Fri Jun 6 11:15:19 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:14 2004
Subject: Demetrio adsorbtion property of charcoal
In-Reply-To: <9706051745.AA24431@mars.cableol.net>
Message-ID: <33982A13.1B41@transport.com>

Andrew Heggie wrote:
>
> I had not considered the run off problem, obviously the charcoal is very
> light. I was searching for alternative markets and knew activated charcoal
> had this property. Activated charcoal has been treated, by steam I think, to
> pit the suface and increase surface area, I assume our fines have a large
> surface area.
> One memory from the past is an earthenware jug used by my grandmother in
> which she drew off rainwater from a butt (which incidentally only received
> water from a heavy downpour as a gap had to be jumped by the stream from the
> roof so first washings were lost) and the bottom was filled with charcoal,
> water being drawn off by a tap. Reading that the local water utility was
> finding boreholes contaminated by three residual herbicides which requires
> 50kGBP investment per bore to remove,I wondered if a carbon filter might be
> used instead. I thought after saturation it could be drained and then
> burned, I take it as long as the furnace is hot enough any chemical retained
> would dissociate, and energy recovered. I did a simple search on charcoal
> and found" Using activated charcoal to inactivate agricultural chemical
> spills ag442" ( I do not have the url to hand)
> Regards AJH
Interesting concept but could contain some serious pitfalls. I work in
the field of water remediation using "activated carbon" which is
somewhat different than "charcoal". We use activated carbon to remove a
wide range of organics in our business but the process is not as simple
as putting some activated charcoal into a jug and pouring water on top.
The chemical process of organic adsorbtion onto activated carbon is a
surface factor which depends upon the degree of activation of the carbon
substrait, the carbon affinity for the organic material, concentration
of the organic material, exposure time, surface contamination by other
organics, etc. Properly made, fresh charcoal may be activated however,
within hours it becomes coated with a wide range of materials and
becomes less "active". While I was with the US Air Force doing poison
gas drills with NATO in Europe using gas masks with coconut charcoal,
the charcoal component was sealed in plastic bags. We were given the
guidance that once opened, the charcoal would be considered ineffective
for gaseous organic removal after 24 hours due to surface contamination
by various airborne components.

In water, the charcoal would need to be broken into fine particles to
maximize surface area of the attracting surface. The water would need
to spend at least 10-15 minutes coursing through tortuous channels to
assure good exposure to the attracting effects of activated carbon. If
the particle sizes were large, the time to adsorb would be longer.
Eventually, the surface of the activated carbon would be coated with
organics so you would need some method of detecting "organic
breakthrough" to prevent downstream contamination by believing that the
clean up would continue forever. In a low use situation where water
small amounts of water would be drained off bottom occasionally, the
potential to remove pesiticides exists in such a system however to do it
repeatedly with reliable assurance that all the organics are gone would
require some design enhancement.

Regarding the burning of materials containing pesticides, this is
normally not achievable in small home fires. There are time, turbulence
and temperature factors which must be controlled to assure the organic
materials are consumed in the burning. Otherwise it will merely
evaporate the organic components into the air and possibly allow them to
recondense where ever the vapor oncentration is sufficiently high and
the temperature is cool enough for condensation to occur.

Part of the pieces of the puzzle are in place by using fresh charcoal
but the guaranteed, proper use of activated carbon for pesticide removal
is more complex than putting a layer of charcoal in a jug of water and
expecting repeatable organic removal.

Your grandmother probably noted the flavor enhancement (not tasting the
flavor of the accumulated residue rinsed off the roof) by using charcoal
in this way which is a version of water cleanup. She is to be commended
for her resourcefulness!

Art Krenzel

From antal at wiliki.eng.hawaii.edu Fri Jun 6 13:38:35 1997
From: antal at wiliki.eng.hawaii.edu (Michael Antal)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <199706050256.VAA07697@adan.kingston.net>
Message-ID: <Pine.HPP.3.95.970606073715.21387E-100000@wiliki.eng.hawaii.edu>

Dear Alex: I am unaware of any scholarly references on this. It is simply
well known to horticulturalists. Sorry. Regards, Michael Antal.

On Wed, 4 Jun 1997, *.English wrote:

>
> > Finally for my friends that are concerned about agriculture, I remark that
> > we have a regular demand from horticultural specialists for charcoal as a
> > rooting medium. Apparently charcoal is well known to be an ideal medium
> > for growing plants (better than peat).
> > Best regards, Michael.
>
> Michael
> I am up to my eyeballs in a greenhouse business. Could you provide
> some references related to charcoal as a rooting and growing medium.
>
> Alex
>
> PS: I wonder if a nose full of charcoal is better than a nose full
> of peat.
> Alex English
> RR 2 Odessa Ontario
> Canada K0H 2H0
> 613-386-1927
>

From antal at wiliki.eng.hawaii.edu Fri Jun 6 13:40:34 1997
From: antal at wiliki.eng.hawaii.edu (Michael Antal)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <339705E8.2A92@neosdenver.com>
Message-ID: <Pine.HPP.3.95.970606073822.21387F-100000@wiliki.eng.hawaii.edu>

Friends: I am not prepared to post my paper on the web or e-mail it to
you. The paper contains photos and figures which are not likely to travel
well by electrons. Also, I don't preach e-mail, I only use it. If you
want a copy of the paper, please give me your address and we will mail it
to you for free. Regards, Michael.

On Thu, 5 Jun 1997, Scott Haase wrote:

> Mike:
>
> Your offer to send a copy of your paper is getting a lot of response. Is
> it possible for you to post your article to the list so that we can all
> download it and you only have to do it once? IF not, I also would like
> to get a copy of your paper as well.
>
> Thanks,
>
> Scott
>
> *************************
> Scott Haase
> NEOS Coporation
> 165 South Union Blvd., Suite 260
> Lakewood, CO 80228 USA
> Phone: (303) 980-1969
> Fax: (303) 980-1030
> email: shaase@neosdenver.com
>
>
>

From antal at wiliki.eng.hawaii.edu Fri Jun 6 13:51:35 1997
From: antal at wiliki.eng.hawaii.edu (Michael Antal)
Date: Tue Aug 31 21:35:14 2004
Subject: Mike Antal on Straw cooking
In-Reply-To: <199706060842_MC2-17FA-19EE@compuserve.com>
Message-ID: <Pine.HPP.3.95.970606074945.21387I-100000@wiliki.eng.hawaii.edu>

Dear Tom: thanks! Best regards, Michael.

On Fri, 6 Jun 1997, Thomas Reed wrote:

> Thomas B. Reed 303 278 0558 V Colorado School of Mines
> 1810 Smith Rd., 303 278 0560 FX Department Chem Eng
> Golden, CO 80401 ReedTB@Compuserve.com
> ALSO: The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dear Mike and all:
>
> I am so glad to hear Mike's voice in this STOVE forum which includes
> CHARCOAL as a sub-subject. I first heard Mike claim that he could make
> over 45% charcoal from wood in Thailand in 1985, and since the total carbon
> content of wood is only about 48-52% carbon in proximate analyses, this was
> greeted with skepticism by the naive. Of coarse CHARCOAL =/ CARBON, since
> charcoal can contain up to 30% volatile matter, depending on its
> preparation.
>
> Mike's process (has it a handy name?) is the biggest breakthrough in
> charcoal making in 20,000 years. It speaks poorly of the concern of the
> the developed countries for developing countries and global warming that he
> has had so much trouble getting the process commercialized.
>
> Good luck this Summer Mike and good luck to your California investors.
>
> Regards, TOM REED
>
>
>

From ahe1 at cableol.co.uk Fri Jun 6 15:41:45 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:14 2004
Subject: Demetrio adsorbtion property of charcoal
Message-ID: <9706061941.AA31656@mars.cableol.net>

At 08:17 06/06/97 -0700, you wrote in reply to my observation:
>Andrew Heggie wrote:
<snipped>
Very useful comments and food for thought. I would be interested to learn
more of the activating process.
>Your grandmother probably noted the flavor enhancement (not tasting the
>flavor of the accumulated residue rinsed off the roof) by using charcoal
>in this way which is a version of water cleanup. She is to be commended
>for her resourcefulness!
25 years departed unfortunately!
>
>Art Krenzel
Thank you
Regards AJH

From english at adan.kingston.net Fri Jun 6 22:27:38 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:14 2004
Subject: Pictures are on Web
Message-ID: <199706070227.VAA26731@adan.kingston.net>

Dear Stovers

Peter Verhaart's stove development pictures can now be linked to
through the web page address
http://www1.kingston.net/~english/Stoves.html

There must be a good deal of useful information that could be
loaded on to this site and still more that could be linked to from
this site.

To be properly developed, someone with relevant experience would
have to come forward to act as an editor.

For now I have piggybacked this on to the free personal space that
our internet provider offers its customers. It come with the one
stipulation that it be strictly non-commercial.

Run with it stovers!
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From phoenix at transport.com Sat Jun 7 00:08:21 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:14 2004
Subject: Demetrio adsorbtion property of charcoal
In-Reply-To: <9706061941.AA31656@mars.cableol.net>
Message-ID: <3398DF8F.1B80@transport.com>

Andrew Heggie wrote:
>
> At 08:17 06/06/97 -0700, you wrote in reply to my observation:
> >Andrew Heggie wrote:
> <snipped>
> Very useful comments and food for thought. I would be interested to learn
> more of the activating process.
> >Your grandmother probably noted the flavor enhancement (not tasting the
> >flavor of the accumulated residue rinsed off the roof) by using charcoal
> >in this way which is a version of water cleanup. She is to be commended
> >for her resourcefulness!
> 25 years departed unfortunately!
> >
> >Art Krenzel
> Thank you
> Regards AJH
The REAL expert on charcoal activation, in my humble opinion, is Tom
Reed who is already logged on this forum. Tom, please take it away!

Art Krenzel

From english at adan.kingston.net Sat Jun 7 13:08:27 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:14 2004
Subject: Activated Charcoal
In-Reply-To: <33982A13.1B41@transport.com>
Message-ID: <199706071708.MAA11133@adan.kingston.net>

The following can also be found at
http://lep.cl.msu.edu/msueimp/htdoc/modc3/51292004.html
------------------------------------------------------

Using Activated Charcoal to Inactivate Agricultural Chemical Spills

The following article was written by F.H. Yelverton, J.B.
Weber, G. Peedin and W.D. Smith of North Carolina State
University and printed in the Long Island Horticulture
News.

Large quantities of pesticides are handled by farmers and
farm workers; thus pesticide accidents may occur even when
the most stringent safety guidelines are followed. If a
pesticide spill occurs, proper corrective measures can help
prevent environmental contamination of soil and water
resources.

Inactivating Pesticide Spills
If a pesticide is spilled accidently, or the wrong
pesticide is applied, or a an excessive rate is applied,
the best solution is to apply a material that will adsorb
or inactivate the pesticide. Once the pesticide has been
adsorbed, it is biologically inactive and cannot cause
environmental contamination by running off into surface
waters or leaching into groundwater.

Activated charcoal (activated carbon) is the universal
adsorbing material for most pesticides. Powdered activated
charcoal is made up of very small carbon particles that
have a high affinity for organic chemicals such as
pesticides. Activated charcoal has a large surface area to
which organic molecules can bind. When it is applied to
pesticide-contaminated soil, the pesticide molecules are
attracted to the charcoal particles and bind to them when
they come into contact.

Amount of Activated Charcoal
The amount of activated charcoal to apply to a pesticide-
contaminated area varies with the chemical characteristics
of the particular pesticide. The rate ranges from about
100 to 400 pounds of activated charcoal per acre (2.3 to
9.2 pounds per thousand square feet) for each pound of
active ingredient of a pesticide applied per acre. A
general rule is to apply about 200 pounds of activated
charcoal per acre (4.6 pounds per thousand square feet) for
each pound of pesticide active ingredient per acre.

For example, if trifluralin (Treflan 4EC) was inadvertently
applied to an area at a rate of 1 quart per acre, there
would be 1 pound of active ingredient of trifluralin per
acre (Treflan contains 4 pounds of active ingredient per
gallon and 1 quart is 1/4 gallon, so each quart contains 1
pound). To completely inactivate this area, you would need
to broadcast apply 200 pounds of activated charcoal (see
Table 2 for conversion to square feet). Your county
Extension agent can assist you in determining a rate of
activated charcoal to apply to a given area.

SEE PRINTED ALERT FOR TABLE.

Activated charcoal can be applied by various methods. It
can be applied in the dry form with a lime spreader.
However, activated charcoal particles are easily moved by
wind, so it may be difficult to distribute the charcoal
evenly when applied in the dry form. The easiest method is
to suspend the charcoal in water and apply it by hand with
a watering can (for small areas) or a power sprayer.
Because activated charcoal does not mix easily with water,
use a 0.5 percent solution of a nonionic surfactant
(equivalent to 1 quart per 50 gallons) to enhance its
suspension in the water. Note that charcoal particles are
very abrasive and can damage spray equipment (particularly
roller type pumps).

The activated charcoal should be incorporated with a disk
or rototiller into the upper few inches of soil so that the
activated charcoal will come into contact with the
pesticide. Uniform application of activated charcoal
followed by thorough mixing is the key to inactivating a
pesticide-contaminated area.

Cleaning Up Mixing Areas
On many farms, pesticide levels in soils are quite high in
areas where pesticides are mixed. Unfortunately, most
mixing occurs close to a water source, and usually in the
vicinity of a well. Often, pesticides have been mixed in
these areas for many years and soil concentrations have
accumulated over time. These areas are distinguishable by
dead or dying vegetation or the absence of any living
plants. High pesticide levels in soils close to a well can
be hazardous because of the high probability that
groundwater or well water will be contaminated.

Activated charcoal can also be used to clean up these
areas. However, it is impossible to determine the levels
of pesticide residues in the soil. In this area, as well
as in the case of some pesticide spills, soil pesticide
levels may exceed 50 to 100 pounds of active ingredient per
acre. Fortunately, these areas usually total only a few
hundred square feet. To treat these areas, it is necessary
to measure the contaminated area, guess at the level of
pesticide residue, and adjust the activated charcoal rate
accordingly.

If pesticides have been mixed on the site for many years
and no living vegetation is visible, assume that the level
of contamination is higher than if some living vegetation
is visible but shows symptoms of injury or disease. For
example, if the contaminated area is 20 feet by 20 feet
(400 square fee) and you assume that the pesticide level in
the soil is equivalent to 50 pounds per acre, you would
need to apply the activated charcoal at a 10,000-pound-per-
acre rate in order to apply 200 pounds of charcoal per
pound of active ingredient. For a 400-square-foot area,
you would need to apply and incorporate only 92 pounds of
activated charcoal.

Applying too much activated charcoal should not cause
problems, and it is therefore always best to guess on the
high side. A few weeks after applying the charcoal, plant
some type of seed in the treated area. If the seeds
germinated and plants look healthy several weeks later, the
pesticide spill has been inactivated. If plants still do
not grow, the area may need to be re-treated.

Buying Activated Charcoal
Activated charcoal is manufactured by many companies such
as ICI Americas, Inc. and West Virginia Pulp and Paper
Company. It is available through your local agricultural
chemical dealer. Two commonly used agricultural carbons
are Gro-Safe (ICI Americas) and NuChar S-A (Westvaco).
Activated charcoal usually costs about $1 per pound or
less.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From shell at wolfenet.com Sat Jun 7 14:00:17 1997
From: shell at wolfenet.com (Ronald Kent)
Date: Tue Aug 31 21:35:14 2004
Subject: Activated Charcoal
In-Reply-To: <33982A13.1B41@transport.com>
Message-ID: <199706071759.KAA32166@wolfenet.com>

> From: "*.English" <english@adan.kingston.net>
> To: stoves@crest.org
> Date: Sat, 7 Jun 1997 13:07:21 -0500
> Subject: Activated Charcoal
> Reply-to: stoves@crest.org

> The following can also be found at
> http://lep.cl.msu.edu/msueimp/htdoc/modc3/51292004.html
> ------------------------------------------------------
>
>
> Using Activated Charcoal to Inactivate Agricultural Chemical Spills
snip

Please be aware that activated charcoal has a surface area of >400 sq.m/g
to as much as 2500 sq.m/g.
Ordinary charcoal may be less than 5 sq.m/g. Adsorbtion of pesticides
etc. is a surface dependent effect. The only effect of ordinary char is
to change the pH of the soil it contacts. The char also aerates soil in
an ag mix and does allow some ion exchange.
For non gaseous adsorbtion , activated charcoal made from lignite and from
petroleum coke is often used because of its lower cost.

From rmiranda at sdnnic.org.ni Sat Jun 7 17:55:21 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:14 2004
Subject: Verhaart message
Message-ID: <199706071556.PAA12619@ns.sdnnic.org.ni>

I will send you a photo of the "plancha stove that we promote in Honduras "

Rogerio

At 09:41 PM 6/1/97 -0500, you wrote:
>
>> >I think our Eindhoven downdraft system (what there is of it) has the
>> >advantage of simplicity, high temperature (regrettably primarily
>> >concentrated on the grate) and clean burning. The cons are that the pan has
>> >to be part of a more or less hermetically gastight system to maintain draft.
>> >This calls for accurate machining of the pans, either a machined flat bottom
>> >to make good contact with an equally flat plate or an accurately dimensioned
>> >outer diameter fitting into an equally accurately made hole.
>> >
>> >One thing that surprises me is:
>> >
>> >Why the Hell is everybody ignoring the SWOSTHEE STOVE?
>> >
>> >Does nobody receive and read Sadhana and has nobody asked prof. Mukunda for
>> >a reprint?
>> >
>> >I am going to make one. If anybody else is interested I can fax parts of the
>> >article containing the dimensions.
>> >
>Dear Stovers
>
>All this talk of different stove designs and no pictures or drawings.
>I was serious about getting them on the web. If you have a snap shot,
>send it to me, I'll scan it and send it back. If you already have
>images as *.JPG, *.BMP , or in some other graphic file format less
>than 1 mega bite on your computor, try attaching it to an email to
>me. If your interested in raising the profile of this issue or simply
>facilitating understanding and discussion, a web page is a very
>simple and inexpensive tool .
>
>I have been unable to source the book 'Stove Images' in Canada. So
>now I'll be snail mailing the publishers in Germany.
>
>
>
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927
>
>
--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From phoenix at transport.com Sun Jun 8 14:18:44 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:14 2004
Subject: Verhaart message
In-Reply-To: <199706071556.PAA12619@ns.sdnnic.org.ni>
Message-ID: <339AE50F.30E2@transport.com>

Rogerio Carneiro de Miranda wrote:
>
> I will send you a photo of the "plancha stove that we promote in Honduras "
>
> Rogerio
>
> At 09:41 PM 6/1/97 -0500, you wrote:
> >
> >> >I think our Eindhoven downdraft system (what there is of it) has the
> >> >advantage of simplicity, high temperature (regrettably primarily
> >> >concentrated on the grate) and clean burning. The cons are that the pan has
> >> >to be part of a more or less hermetically gastight system to maintain draft.
> >> >This calls for accurate machining of the pans, either a machined flat bottom
> >> >to make good contact with an equally flat plate or an accurately dimensioned
> >> >outer diameter fitting into an equally accurately made hole.
> >> >
> >> >One thing that surprises me is:
> >> >
> >> >Why the Hell is everybody ignoring the SWOSTHEE STOVE?
> >> >
> >> >Does nobody receive and read Sadhana and has nobody asked prof. Mukunda for
> >> >a reprint?
> >> >
> >> >I am going to make one. If anybody else is interested I can fax parts of the
> >> >article containing the dimensions.
> >> >
> >Dear Stovers
> >
> >All this talk of different stove designs and no pictures or drawings.
> >I was serious about getting them on the web. If you have a snap shot,
> >send it to me, I'll scan it and send it back. If you already have
> >images as *.JPG, *.BMP , or in some other graphic file format less
> >than 1 mega bite on your computor, try attaching it to an email to
> >me. If your interested in raising the profile of this issue or simply
> >facilitating understanding and discussion, a web page is a very
> >simple and inexpensive tool .
> >
> >I have been unable to source the book 'Stove Images' in Canada. So
> >now I'll be snail mailing the publishers in Germany.
> >
> >
> >
> >Alex English
> >RR 2 Odessa Ontario
> >Canada K0H 2H0
> >613-386-1927
> >
> >
> --------------------------------------------------------------------------
> Rogerio Carneiro de Miranda Telefax: (505) 276 0555
> PROLENA(Nicaragua)
> Apartado Postal C-321 Managua Nicaragua
> E-mail: rmiranda@sdnnic.org.ni
> -------------------------------------------------------------------------
Dear Rogerio and Alex,

Please put the pictures of the Eindhoven, Plancha and Swosthee Stoves in
the forum for comments. Thank you for your efforts to promote the
general information flow through photos, Alex. This is where "a picture
is worth a 1000 words" for certain!

From verhaarp at janus.cqu.edu.au Sun Jun 8 19:43:25 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:14 2004
Subject: Pictures are on Web
Message-ID: <1.5.4.32.19970608234314.006ae468@janus.cqu.edu.au>

Dear Alex,

A great job, I just had a look at the Web page. The pictures are
very clear and sharp. I had some misgivings as they took up so little space
on the disk, between 10 and 20 kb.
Let's see if there are others out there with pictures. I hope this also
shows the necessity of having a good description with the pictures.
Best regards,
Peter Verhaart

At 22:26 6/06/97 -0500, you wrote:
>Dear Stovers
>
>Peter Verhaart's stove development pictures can now be linked to
>through the web page address
>http://www1.kingston.net/~english/Stoves.html
>
Chop
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From rmiranda at sdnnic.org.ni Sun Jun 8 20:38:21 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:14 2004
Subject: Rogerio comments of 5/29
Message-ID: <199706081839.SAA14027@ns.sdnnic.org.ni>

>From RWL last message:

>>(RWL) For a family of 5, what is a typical wood consumption per week?

RCM> From our old and informal test, we found variables values. Family size
changes from 6 to 10, and wood consumption per family from 60 to 93
kg/week. We couldn't find a clear relationship that we could express in
wood consuption per capita. It might be caused to different operation
procedures of the stove.

----------------------------------------------------------------------------
-----
(RWL) I guess the metal plate must be about 50 x 40 cm for inside
>>dimensions of 40x 30. What is the thickness of this plate and how much
>>would it alone cost in Managua?

RCM> thickness of 1/8 of inch and price of 4USD.

----------------------------------------------------------------
RCM> The strategy that I visualize must concentrate in :
>>>
>>>4. Do not support donation of the stoves, by microcredit financing, as
>>>Grameen Bank.
>>
>> (RWL): Rogerio - this is not clear to me. Please explain a bit more.
>>
RCM> I mean to not donate the stoves. The recipient family must borrow the
money from a microcredit loan institution , and pay back according to their
possibilities. Also, cost sharing schemes could be discussed, where the
family must provide some basic material like bricks,cement, sand, mud, etc.

Usually, when stoves are 100% donated, the recipient family does not take
good care of the new stove.

ROGERIO

--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From rmiranda at sdnnic.org.ni Sun Jun 8 20:38:22 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:14 2004
Subject: Rogerio comments of 5/26
Message-ID: <199706081839.SAA14024@ns.sdnnic.org.ni>

Dear Grant and stovers: Thanks for your useful comments. Next time we will
take it in consideration. Our early tests were much informal, and in fact we
have problems with the rain, since some families didn't bother to keep the
firewood away from the rain. the only biomass fuel used is firewood
mainly from oaks and pine. Since this was done in the capital Tegucigalpa,
every family has electricity for lights. Some familie does have also a
kerosen or a LPG stove. But most of the cooking is done at the woodstove,
for cost reasons and some foods like beans and tortillas are (in their
perspective) better cooked with wood.

Thanks

Rogerio
=============

At 10:30 AM 6/2/97 +0100, you wrote:
>Dear Rogerio and all... you mentioned my hobby horse (stove testing), so
>knowing that I'm not following the main thread of the discussion, I'm off
>on that - sorry!
>
>>......................RCM> We weight for a week the wood consumption of
>a
>>family with the traditional semi-open woodstove , e.g. the U shape. Some
>>called it shielded fire. After a new improved close fired stove was
>built,
>>we weighted again the fuelwood consumed for a week.
>
>This is good, a real life test, but your results may be misleading (in
>either a positive or negative way) - there are a few things to watch out
>for here (perhaps you know this anyway, but just incase):
>
>1) conditions (for example the weather, or the number of people being
>cooked for) may change from one week to the next, this would change the
>amount of fuel used naturally. To get around this measure fuel use for a
>number of households - then after some time (I recommend longer than a
>week, yes, done properly this is rather time consuming) install improved
>stoves in half of the homes (randomly chosen is best), continue monitoring
>in all the households. Then when you draw up graphs of daily fuel use you
>can see whether the ones without improved stoves also changed. Then its
>possible to get an indication of the real effect of the stove with a
>little
>maths.
>
>2) a family will react to a new stove in a number of ways, they might use
>the stove only a little at the start (do you know whether they use the new
>one exclusively?), they may use it more (because its a novelty, or because
>its truely is a better stove). It may take time to learn how to use it. If
>its a nice stove to use fuel savings may be 'taken up' in improved comfort
>levels. When I mean to say is that its a good idea to go back after a few
>months and do some more monitoring in all the households. Also it may be
>useful to ask questions about stove usage (how often used, for what) each
>day when weighing fuel.
>
>3) a last point: investigate do people use other fuels too? An enclosed
>stove naturally does not give light, so this might increase paraffin use
>(which is paid for whereas wood, possibly is not)? Not a bad thing (I
>think) but its useful to know the full energy picture...
>
>Are these comments any use? Keep up the good work!
>Grant
>
>-----------------------------------
>Grant Ballard-Tremeer
>International Institute for Energy Conservation - Europe (IIEC)
>31 Pitfield Street, London N1 6HB
>Telephone: +44 171 490 7616 Fax: +44 171 490 7626
>http://www.iiec.org
>
>
>
--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From rmiranda at sdnnic.org.ni Sun Jun 8 20:41:53 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:14 2004
Subject: FWD in Central America
Message-ID: <199706081843.SAA14064@ns.sdnnic.org.ni>

Dear stovers: I just came from Guatemala where I met Mr. Manuel Tay
Oroxtom who is the regional coordinator for FWD at CEMAT. He mentioned to
me that in these days CEMAT doesn't have resources to promote FWD activities
in the region. So, they have no activity at the moment related to woodstoves.

However, Mr. Oroxtom himself, has a workshop where he manufacture metal
parts for woodstoves and also has qualified personnel to install the parts
into a brick body at the client residence. It is a "plancha" model, which
we have described in this list in the past weeks.

regards

Rogerio
--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From english at adan.kingston.net Sun Jun 8 22:53:51 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Something Practical ?, part 2
Message-ID: <199706090253.VAA26389@adan.kingston.net>

Dear Stovers

Today I hauled out all our thermocouples and oilburner test
equiptment (Bacharach) in an effort to accurately describe a test
fire of micro proportions, at least compared to what I am used to.

The following description ( A. English test burn #1) with a drawing
(fig A) is available through the site
http://www1.kingston.net/~english/Stoves.html

14 oz of cedar kindling were
placed vertically in a 5" cylinder with under and over fire air
(both controllable) with a 3" cylinder acting as a flame chamber
just above the over fire air inlet. CO2, temp and smoke were
monitored in the 5" chimney , 6" above the flame chamber.

With both air supplies wide open the fuel was "top lit" with a
propane burner. It quickly developed visually clean exhaust gasses.
A turbulent and audible (micro roar) flame was largely contained with
in the flame chamber. For the first fifteen minutes the CO2 tested
at between 3.5% and 5% , Temperature fluctuated between 650F
and 850F , smoke was about a 2 on a Bacharach scale of 0-10

Reducing under fire air caused a loss of flame and heavy smoke.
Cutting off over fire air caused the flame go quiet and extend up
high into the chimney, with a soot plume. (CO2 tested at 15% during
this stage, smoke at about 8 or 9)
Reducing over fire air yielded slightly higher CO2 (5.5%) and
slightly higher temperatures( 900F).

After 20 minutes it lost its flame. ( I think it used up the
volatiles) I kept it going for an hour by dropping small pieces in
from the top. As the fire burned down the temperature would drop to
about 450F but could be easily brought back up to 800 F with the
addition of a little more fuel. The highest recorded temp. was
1050F.( with over fire air shut off)

Total fuel consumed=2 lbs ( at 12% moisture)
( sorry about the British units)

Conclusions: I have a long way to go!

So now I have a more tangible respect for the challenge.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Sun Jun 8 22:53:57 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Something Practical ?, part 1
Message-ID: <199706090253.VAA26392@adan.kingston.net>

Dear Stovers
Last week I decided to try my first top down fire in a pail. I didn't
try to duplicate Ron and Tom's " two can" charcoal maker. I did
arrange 1"*2"*8" pieces of cedar vertically in the bottom of a 20
litre pail and light it from the top. It started "cleanly" and burned
with a gentle consistency that surprised me. The flame wobbled around
from one edge to another apparently drawing fresh air over the
opposite side and down onto the surface of the fuel. It burned
steadily for at least an hour. Makes me think!!

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Mon Jun 9 00:04:52 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Trees vs straw - questions for Demetrio
Message-ID: <v01540b03afc0ce779913@[204.133.251.9]>

Demetrio, on June 2 gave us some guidance on straw removal.

I'd like to ask Demetrio, as our list expert on soils, to talk a
little bit more about the essentials of planting trees vs relying on straw.
This relates to the fact that trees have much longer roots and can tap
into deep nutrient levels that can disappear with time as the water seeps
to the water table.

Are there particular soils or regions where tress must be planted
to maintain soil productivity? I'm looking for further guidance on how
hard we should push against using straws and for planting of trees for
energy purposes.

Thanks for your references to David Lightle and other resources.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 9 00:05:53 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Pete Verhaart on population desity
Message-ID: <v01540b03afc0e4d1d964@[204.133.251.9]>

Pete Verhaart said on June 4:

> I would say that humans need a lot of space in order
>to survive. Space (meaning surface area) being constant, the only variable
>is the number of humans. I would suggest an average of two per square
>kilometer being the goal to aim for.

Because this sounded nice but low, I offer the following additions
to your remarks. I believe 2 persons per square km was just about the
Australian density a decade ago. The US. density is about 30 per sq km, I
believe (I only have an old Almanac).

Using a total earth surface area of about 0.5 billion square km, we
are already at more than 10 persons per sq km. So if the earth's land area
is about 25%, we must already be at 20 times your optimum. Have I done all
this correctly?

Pete - was your point that you are glad to be living in Australia?
- or that more countries should start moving to the Australian level? Or??
I am afraid that you should keep your population numbers secret or you
will soon be inundated.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 9 00:06:10 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Karstad on Sawdust Charcoal Briquetting
Message-ID: <v01540b05afc0f3453e98@[204.133.251.9]>

On the 6th, Elsen Karstad (a new list member from kenya) said:

>I've been working on a very simple hand operated charcoal briquetter (made
>from water pipes) for use in the informal sector to salvage waste sawdust
>here in East Africa.

(RWL): Would you describe how this briquetter works? (and its cost and
productivity, etc) In the US, the standard shape of a briquette is that
of a "pillow". Are your briquettes of that shape (or could be)? I ask
partly because the "Pyromid" stove design (discussed before you joined the
list) from Paul Hait requires such a shape for best operation.

<snip>

>In addition to information on binders, I'd like any literature available on
>appropriate (for field use) carbonising methods. The object is to reduce
>all aspects of sawdust charcoal briquette production to the absolute
>simplest level possible.

(RWL): I am going to send separately ideas on a (field use)
charcoal-making stove - but not one designed for turning sawdust into
charcoal.

(RWL): There is a sawdust burning stove that seems quite clever - sawdust
is packed around a vertical "broomstick" and a low horizontal "broomstick".
After removing the "broomsticks", and (I think) bottom lighting - the
stove operates more or less without an ability to control power output.
Hopefully, othesr will give this stove a name and better description. The
advantage for Kenya is presumably more usable energy per kg of sawdust.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From REEDTB at compuserve.com Mon Jun 9 00:06:31 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:15 2004
Subject: Charcoal - ash and moisture content
Message-ID: <v01540b00afc0dafa89a4@[204.133.251.9]>

Stovers - Tom Reed inadvertently sent this to "stoves-digest" rather than
"stoves" - so I am forwarding it to all. Regards Ron

Pete and all:

Pete seems to say that low ash is desirable in charcoal. It is probably
much more complicated than this.

Kingsford puts (10%) a lot of ash intentionally into charcoal to SLOW the
combustion process. (High density, as in coconut shell charcoal may
accomplish the same.) The ash may also be catalytic for burning the CO
formed at the C-air interface to CO2. It may act as a binder. The world
of charcoals is as complicated as the world of biomasses and "one
generalization won't fit all".

I continue to learn about "charcoal" at a great rate and appreciate all the
comments found in "STOVES", but filed under CHARCOAL in my E-files. I wish
I had a graduate student or two to follow up my suspicions and put the
world of charcoals on a more scientific basis.

The manufacture of the various charcoals is equivalent to removing water in
six stages. In my mind I use the word "XCOAL" for charcoal, X being the
number of water molecules removed in the generalized biomass formula,

C H1.4 O0.6 = C 0.6(H2O) H0.2

X
0.1 Torrefied Wood
0.2 Sea Sweep (our oil absorbent)
0.3 Cooking charcoal
0.4 Metallurgical charcoal
0.5 Chemical Charcoal, activated charcoal
0.6 Seldom achieved charcoal

I arrived at this conclusion after looking at ultimate analyses for a wide
range of charcoals. It would take a year of graduate student time to make
this more accurate.

In any case, COOKING CHARCOAL is a buffered reaction and is more uniform
than one would think from the above continuum. During the production of
charcoal by heating the reaction is endothermic in the range 20-280C; then
exothermic from 280-440; then endothermic at higher temperatures. So, it
is easy to get to 440, difficult to exceed it. In the production of Sea
Sweep, we have to quench the product to keep it from self heating to 440 C.

This is all at atmospheric pressure of course. If one now adds in pressure
as a variable one enters the world of vacuum pyrolysis of Chretian Roy and
pressure pyrolysis of Mike Antal.

Sorry I don't know the answers to all this, but knowing subtle questions is
a first step.

Your skeptical reader, TOM REED

From larcon at sni.net Mon Jun 9 00:25:13 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Verhaart and the Swosthee stove
Message-ID: <v01540b02afc0c88232b3@[204.133.251.9]>

Stovers:

Peter Verhaart said about a week ago:

>One thing that surprises me is:
>
>Why the Hell is everybody ignoring the SWOSTHEE STOVE?
>
>Does nobody receive and read Sadhana and has nobody asked prof. Mukunda for
>a reprint?
>
>I am going to make one. If anybody else is interested I can fax parts of the
>article containing the dimensions.

(RWL): Pete - I'd appreciate receiving the dimensions - but I need much
more. Can you supply a bit more on how to reach Prof. Mukunda and/or the
article citation.

Perhaps you could also describe both the Swosthee stove and Sadhana
as well.

If FAXing is much easier than mailing, please use a friend's 24-hour FAX:
303/331-0316, with my name somewhere shown. Otherwise you will have to
send a warning first to my home phone/computer/FAX.

Thanks in advance. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 9 00:35:08 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: 3 Paul Hait comments last week
Message-ID: <v01540b01afc117c3b7d3@[204.133.251.7]>

Paul Hait said on 31 May, mainly replying to Art and Alex:

<Snip>

> What we need to add to
>our cell design is a bellows or a fan. However, right now it is only three
>parts and costs less the $5.00.

(RWL): Paul: This is the first time I have heard this cost or price.
Could you clarify which? This is not the Pyromid, but a design in process?

(PH):
>Organized arrangement of fuel as compared to
>random arrangement is one of the keys to efficient fuel burning. Also we
>take advantage of both the heat up and down in our cell. Air control to the
>fuel source is also important and the control of the releasing energy from
>the fuel source is the final step.

(RWL): I understand your use of briquette spacing - and of the two way
energy flow and the air control, but not the "final step". Are these last
two ideas separate or one idea?

B. Next part on P Hait comments in message of 31 May in reply mostly to
Rogerio and myself:

>>
>>Dear Ronal and Rogerio,
>Congratulations! Count me in on planning if you want. The list is on the move!
>
(RWL): Paul is referring to a stove conference (and possible competition)
in Nicaragua.

Rogerio - is this still a possibility? Who might defray costs for those
who might need help?

> snip>

(PH):
>The internet conferance is a good idea to start with. Also, I think it would
>be great to go to see Rogerio. However, Central Oregon represents what the
>world wishes it had in fuel. We are the end goal and not the end. It never
>hurts to see what your shooting at. Just a thought.
>
(RWL): Paul - I'm glad you are not giving up. Oregon has a great deal to
offer as well. Maybe two conferences?

C. Last part on P Hait comments in message of 31 May in reply to Tom Reed:
Paul said:

<snip>

>Out of the knowledge we got with the Pyromid I sent you, we now have the
>Campmaster, The Super Grill, and the HTA World stove.

(RWL): It is this last stove that I believe is the one that Paul was
referring to above - and earlier in this 3rd note was saying might be a
dual-fuel (wood/charcoal) stove. We need to hear more about Paul's
on-going tests.

<Snip>

> We have the best cause
>in the World with the least amount of awareness. Wouldn't it be great to
>have Ross Perot ,Warren Buffit,Donald Trump, Bill Gates,and Bill Clinton get
>fired up to put a little money into this problem?They should. And we should
>bring it to their attention.

(RWL): Paul is our most enthusiastic spokesperson in making this case. I
think we generally agree on the seriousness of the problem. And although
we can't have a single solution, I think we are making progress in getting
a better set of options. Thanks Paul.

(RWL): Your ideas in these three notes are a great continuing efort.
Sorry for the long delay in comments. I had a busy week last week. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 9 00:35:45 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Grant on JI
Message-ID: <v01540b00afc10f16adf1@[204.133.251.7]>

On the 6th, Grant Ballard-Tremeer said:

<snip>
> Joint
>Implementation is a potential mechanism for implementing committments under
>the climate change convention (I'm working on a pilot version (they call
>then AIJs, Activities Implemented Jointly) to be implemented between South
>Africa and the Netherlands).

(RWL): If the funds come from Norway, do they alone get rights to the
carbon credits? Why would Norway not use their own engineers?

(GB-T):
>"The overall goal of the AIJ project is to contribute US$ 2.4 million of
>additional resources to rural development activities which will reduce CO2
>emissions and enhance carbon sinks by about 1.5 million tons of CO2 during
>a period of 5 years (project preparations take one year more) to be
>acheived through:
>* managing 300 000 ha of community based forest;
>* promoting efficient charcoal processing technologies;
>* introducing solar photovoltaic systems for household lighting and water
>pumping systems; and
>* introducing efficient kerosene cooking stoves that will replace the use
>of fuelwood."

(RWL): Could you give more data on how each of these technical options
leads to the overall average of $1.60/ton CO2 mentioned later? For
instance PV cannot be helping much.

(GB-T):
>and then "On average over 3.2 million tons of wood were harvesting for
>woodfuel (charcoal). Burning 1 kg of charcoal induces 6.8 kg of net CO2
>emission, while 0.28 kg of kerosene (equivalent in energy terms) induces
>only 0.87 kg of CO2. Thus, the ration of CO2 emitted by charcoal versus
>kerosine while producing equal amounts of energy is 7.8:1."

(RWL): I'm surprised that encouraging kerosene can count towards
carbon credits (kerosene being presumably a nonrenewable source of the
carbon). Is this because you are looking at methane and other gas release
during the carbonization process?

(GB-T):
>Money comes from the Norwegian Ministry of Foreign Affairs... "totals 2.4
>million US$, while the amount of CO2 reduced is almost 1.5 million tons.
>Thus, the cost per ton of CO2 avoided is US$ 1.60".
>
> And believe me, this is VERY, VERY cheap for a country like Norway (they
>could expect to pay more than 20 US$ per ton for the same reduction there,
>at least). And this is just pilot phase - wait until carbon gets a tradable
>price.

(RWL): What is your estimate of the future tradeable price? What is your
estimate for the benefit - cost ratio at $1.60 per ton?

(GB-T):
>I have more to say, but no time to say it,
>I'm very interested in comments please!
>
>Grant

(RWL): I have been exploring this JI approach also through a US expert on
JI. But the US is way behind Europe in these areas. Not many US utilities
are yet interested, although reforestation is being supported. Do you
have any other references relating rural energy use (stoves) to JI?

(RWL): I think this is a great new thread. Thanks for bringing it up!

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From gayathri at aero.iisc.ernet.in Mon Jun 9 00:41:02 1997
From: gayathri at aero.iisc.ernet.in (Gayathri)
Date: Tue Aug 31 21:35:15 2004
Subject: Charcoal - ash and moisture content
Message-ID: <9706091505.AA20767@aero.iisc.ernet.in>

From zourarakis at nosapp.nr.state.ky.us Mon Jun 9 09:09:38 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:15 2004
Subject: Trees vs straw - questions for Demetrio
Message-ID: <97060908283910@nosapp.nr.state.ky.us>

Ron:

Nothing like a good soil survey.

I am opening the Soil Survey of Hart Co., KY. I chose this one for two reasons:
a. it was completed in 1993; b. Hart Co. has 41 percent (110,000acres) of land
cover under forests. About 113,000 acres were under crops (42 K acres), pasture
(55K acres), idle crop/pastureland (rest). Notice taht about 19K acres of poten
tial cropland is used as woodland, and about 49K acres of potential cropland are
used as pasture. This, following some data research and analysis I did for Out
look 2000 (Comparative Risk Project, EPA funded), has to do with demographics
and socio-economic factors. In KY, average farmer age is about 55 years old, and
average farm size is 150 acres. Meaning that letting farmland go back to woods
and shifting to livestock implies _LOWER_ management. About 60 percent of farmer
s are part-timers. You see how we soon get out of "pure" or "applied" science/
engineering to go into what really matters: nat/ag resource management skills
and people they are embodied in.

Going back to soils.

The survey has different sections. Skipping for a moment the soils stuff, you
get to a section on "use and management of soils". This comprises subsections
on crops and pasture, woodland management and productivity, recreation, wildlif
e habitat, and engineering.

Concentrating on woodland management and productivity, we find that the survey
provides you with a comprehensive table that lists the soil names and mapping
unit symbol as a row entry, and the associated attributes:

1. Management concerns (erosion hazard -slight-moderate-severe; equipment limi
tation -same categories; seedling mortality -same categories; plant competition
-same categories).
2. Potential productivity (common trees - by species; site index 0->100; volume
in cubic feet/yr/acre; and trees to plant -by species).

Now, at this point one has to remember that soils with low site indices should
be left to natural woods, i.e. not managed for timber production, perhaps yes
for wildlife habitat). Site index indicates the quality of a forest site based
on the height achieved by dominant species at an arbitrarily chosen age. This is
where I refer you to a forester...

However, soil mapping units (general and detailed) give clues, based on their
description as to what soil is suited best for forest (natural or implanted),
crop/hay/pasture or both. For example, soils like the Caneyville series can be
part of mapping units that are on a 20-30 percent slopes, very rocky and silt
loam in texture. THIS particular soil and associated soils are suitable for
pasture and woodland only, poorly suited to row crops. Depth to bedrock is 20
to 40 inches, with clay to clay loam subsoil. The Caneyville series is a Typic
Hapludalf (not bad, not good).

If one takes the Crider soil (State soil of KY!), a Typic Paleudalf (pretty good
for these parts), the depth to bedrock is over 60 inches. This soil is present
in detailed mapping units on 2-6 percent slopes, eroded (erosion removed alrea
dy 75 percent of surface layer!!!!). Very well suited for crops, but... OF COUR
SE you can plant trees too.

There is about 11 percent of county acreage under _A_ Caneyville, while only 4
percent is under _A_ Crider soil.

The very complex issue of land management is not entirely resolved, as you can
imagine. One thing we use is the Land Capability Classification. Classes are in
dicated as I, II,... VII. Classes I thru IV _CAN_ be used for cropping (this now
is used in a general way, less rigid than a few years ago), classes V thru VII
have severe limitations that make it unsuitable for crops. This classification
does not substitute for the specific woodland and engineering suitability class
ifications I mentioned above. This brings us to the criteria for choosing crops
as the management option. A table is provided in the survey with the land capa
bility classification and yields/acre under high and low management schemes for
each mapping unit (soil).

So, there you have it . If a manager wants to charge a fee for bird watching,
hunting, fishing, sight seeing, hiking, etc. and wants to have a wildlife mana
gement area on a Crider soil, then it is fine. It is HIS/HER management scheme.
If he wants to grow corn on a steep Caneyville, he/she will probably go broke,
and worse yet, will cause an environmental catastrophe at the watershed level,
scouring the solum to the bedrock and siltating the streams below.

>From my undergraduate forestry classes, I remember foresters advocating the use
of best land for growing timber. Perhaps whole farm planning should include some
crossing-over in an agroforestry scheme, but like I mentioned before it depends
on what is your dearest commodity: food, fiber, fodder, fuel. The mix is u to
you/the economy (any ecol-economists?), the allocation to soils is up to techno
logical/scientific knowledge. And if you have not gotten a soil survey for your
county.... WHAT ARE WAINTING FOR? Contact your local conservation district offi
ce!!!

Yours in land productivity,

Demetrio P. Zourarakis, PhD

From elk at arcc.or.ke Mon Jun 9 11:01:49 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:15 2004
Subject: sawdust charcoal briquettes
Message-ID: <v01510102afc1ecc6aa5c@[199.2.222.132]>

Ron;

My briquetter couldn't be simpler- three pipes are involved- One is a two
foot section of one inch pipe with a four inch long by three fifths pipe
circ. breech located one inch from the end. The second pipe, of three
quarter inch diam. and 10 inches long, is the piston, plugged at the distal
end and operating inside the 1 inch dia. 'cylinder'. Pipe no. 3, which
should have a section of steel bar inside for added strength, is the
handle. This can be any length over 6 ft.

I have mounted the array on a steel table, bolted to the floor. Near the
output end of the cylinder is the first of three pivots, a bolt welded to
the pipe and running through the table allowing horizontal movement. The
second pivot attaches the piston to the 'handle' approximately one quarter
along it's length from the third pivot which is at the end of the handle.

To operate, pull the handle back to it's full extend where the piston is
clear of the breech. Load the breech with the moist carbonised sawdust and
8-10% cement mixture (I have welded a hopper around the breech, and use a
wooden pedstle to ram material into the breech), and grasping the distal
end of the handle, ram the material into the cylinder with the piston. The
leverage is approximately 4ft of movement at the end of handle to an 8
inch stroke in the cylinder (anybody want to calculate the pressure on the
briquette if the operator exerts 20 kg of effort?). I've made several
hacksaw slices in the cylinder between the breech and the output to allow
for liquid to escape.

The product is approx 15 to 20% moisture (I'll doublecheck that) is a
cylindrical briquette averaging 3 inches in length. Initial hardness and
cohesiveness is good, allowing for the necessary handling in sundrying. A
day and a half of tropical sun dries thoroughly. The cement binder works
best if a reasonable amount of time is allowed for drying.A briquette sinks
slowly in water, to give an idea of density.

I will be running some extensive trials on productivity soon, but
initially, it appears that two people could produce 150 kg of biquettes per
day with carbonising and sundrying activities included. In Kenya, assuming
a very nominal cost for sawdust and no transport element, this would
provide a good degree of motivation (financial return on effort) within the
informal sector.

Total cost of materials, assuming new pipes, would be in the region of U.S.
$10.00 with another $3.00 for welding etc.

We do have a type of sawdust 'stove' here, along the lines of your
broomstick design, but use is restricted to bath water heating, as output
temperatures are low. I have made one with a mind to using it for preparing
staff meals, but failed to get my three gal. tea pot to boil. It's now
sidelined.

Regards;

Elsen

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From larcon at sni.net Mon Jun 9 11:24:14 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Alex on charcoal maker
Message-ID: <v01540b00afc1c36885f0@[204.133.251.14]>

Alex said:

>Last week I decided to try my first top down fire in a pail. I didn't
>try to duplicate Ron and Tom's " two can" charcoal maker. I did
>arrange 1"*2"*8" pieces of cedar vertically in the bottom of a 20
>litre pail and light it from the top. It started "cleanly" and burned
>with a gentle consistency that surprised me. The flame wobbled around
>from one edge to another apparently drawing fresh air over the
>opposite side and down onto the surface of the fuel. It burned
>steadily for at least an hour. Makes me think!!

(RWL): A few questions:

1. Did you have any air supply holes other than "fresh air over the
opposite side" ? If so, did you or could you exercise control of that
(especially primary) supply?

2. What was the situation at the end of the hour? Did it then smoke? How
did you extinguish?

3. What was the charcoal yield (%)? Quality? Uniform over the cross-section?
Or was this a combustor?

4. If a combustor - what cook stove values would it have?

5. Was the fuel close-packed?

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From shell at wolfenet.com Mon Jun 9 12:22:36 1997
From: shell at wolfenet.com (Ronald Kent)
Date: Tue Aug 31 21:35:15 2004
Subject: Grant on JI Calculations Question
In-Reply-To: <v01540b00afc10f16adf1@[204.133.251.7]>
Message-ID: <199706091623.JAA03571@wolfenet.com>

> On the 6th, Grant Ballard-Tremeer said:
>
> <snip>

> (GB-T):
> >and then "On average over 3.2 million tons of wood were harvesting for
> >woodfuel (charcoal). Burning 1 kg of charcoal induces 6.8 kg of net CO2
> >emission, while 0.28 kg of kerosene (equivalent in energy terms) induces
> >only 0.87 kg of CO2. Thus, the ration of CO2 emitted by charcoal versus
> >kerosine while producing equal amounts of energy is 7.8:1."

IF charcoal were 100% carbon, 1kg would burn to form 44/12 kg of CO2 or
3.67kg. This is the ratio of molecular weight of CO2 to carbon.
Where does the figure of 6.8 kg come from?

> (RWL): I'm surprised that encouraging kerosene can count towards
> carbon credits (kerosene being presumably a nonrenewable source of the
> carbon). Is this because you are looking at methane and other gas release
> during the carbonization process?
>
>Ron Kent

From english at adan.kingston.net Mon Jun 9 14:07:27 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Alex on charcoal maker
In-Reply-To: <v01540b00afc1c36885f0@[204.133.251.14]>
Message-ID: <199706091807.OAA15103@adan.kingston.net>

> 1. Did you have any air supply holes other than "fresh air over the
> opposite side" ? If so, did you or could you exercise control of that
> (especially primary) supply?

There were three small holes around the outside, which I quickly
plugged with tin foil. There were also three 3/8" copper tubes
carrying "secondary air" from below the pail , up through the fuel to
the top of the fuel. These had sporadic blue flame attachment. There
was a grate below the fuel and there could have been small leaks of
air through the tin foil and around the edge of the copper, however I
think these were minor influences on what I observed.
>
> 2. What was the situation at the end of the hour? Did it then smoke? How
> did you extinguish?

I'm sorry you asked . I went to bed before it was done. It was taking
to long..... I'll have to do it again.
>
> 3. What was the charcoal yield (%)? Quality? Uniform over the cross-section?
> Or was this a combustor?

There were just a very few pieces left in the morning.... I'l have to
do it again.
>
> 4. If a combustor - what cook stove values would it have?

I'm inclined to think that there was a good deal of excess air but
much less than an open fire. Let me see if I can get some
measurements.
>
> 5. Was the fuel close-packed?

Yes. Not jammed in but closer than it would have been for raw
material, as I was using small lumber scraps.

Science at its best!!! Alex
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From kyemill at cyberramp.net Mon Jun 9 21:40:04 1997
From: kyemill at cyberramp.net (Kye Miller)
Date: Tue Aug 31 21:35:15 2004
Subject: wood burning stoves
Message-ID: <339CD10E.2097@cyberramp.net>

Hi!

Well this may not be the place to come,but my mother has an old wood
burning stove and I have let the rain rust out the oven in side and the
outside where the smoke goes out the flue. Is there any place to buy
replacement part for these and are you that place.
Thank you for reading my message,
Kye Miller

From english at adan.kingston.net Mon Jun 9 22:54:24 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Something Practical, Part 1b
Message-ID: <199706100254.WAA04721@adan.kingston.net>

Dear Ron and others

I went back to the 20 litre pail this evening with much better
results. I filled the bottom with vertically placed 1"*2" *5" pieces
of cedar weighing 4 lbs and through some crumpled paper on top. I
chopped the end off a metal funnel forming a cone with 9" top dia.
and 3" bottom dia. Screwed a piece of 5" stove pipe(15" long) to the
outside of the funnel, lit the paper and placed the large end of the
funnel over the burning paper and on top of the wood, such that the
stove pipe formed a chimney. The pail diameter at this point is about
11", leaving about an inch all around. It took between 2 and 5
minutes for the flame clean up. The chimney draft was sufficient to
keep all the fire going up the centre. There was no air supply other
than what was sucked around the outside of the cone. The orange/
yellow flame extended to the top of the stove pipe. It burned that
way for the next 50 minutes. Temp. at the top of the flame was
between 1200F and 1300F , CO2 between 8% and 11%, Smoke test between
3and 5 on the Bacharach scale. (I have seen some oil furnaces that
weren't much better.) The whole affair took place on a scale. The
steady weight loss matched the other indicators. The cone/chimney
tilted as the supporting material crumbled. I occasionally jiggled
and straightened it, with no change in the flame. After 55minutes the
flame increased slightly for 5 minutes and then died. A bluish flame
then hovered above the remaining fuel below the cone. I removed the
cone/ chimney, covered the top of the pail with rock wool, and
sprayed water on the outside of the pail for 5 minutes. When I
returned in an hour the the remaining charcoal was cool and weighed
about 1lbs. The pieces in the centre were essentially the size and
shape of the original wood. Toward the out side they had obviously
been partly consumed, such that the remaining charcoal took on the
shape of the cone.

Yes Ron ,I could cook with this . There are many improvements
or options that should be explored. I look forward to trying them.

Simply yours

Alex

PS Ron or Tom could you explain or discuss the differences between
this trial and your own two can fires.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From prasad at tn7.phys.tue.nl Tue Jun 10 04:53:43 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:15 2004
Subject: Verhaart and the Swosthee stove
In-Reply-To: <v01540b02afc0c88232b3@[204.133.251.9]>
Message-ID: <9706100843.AA01423@tn7.phys.tue.nl>

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From verhaarp at janus.cqu.edu.au Tue Jun 10 06:28:49 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:15 2004
Subject: Pete Verhaart on population desity
Message-ID: <1.5.4.32.19970610102834.006ad0c0@janus.cqu.edu.au>

At 19:31 8/06/97 -0600, you wrote:
>Pete Verhaart said on June 4:
>
>> I would say that humans need a lot of space in order
>>to survive.
>
> Because this sounded nice but low, I offer the following additions
>to your remarks. I believe 2 persons per square km was just about the
>Australian density a decade ago. The US. density is about 30 per sq km, I
>believe (I only have an old Almanac).
>
> Using a total earth surface area of about 0.5 billion square km, we
>are already at more than 10 persons per sq km. So if the earth's land area
>is about 25%, we must already be at 20 times your optimum.

Have I done all
>this correctly?
>
> Pete - was your point that you are glad to be living in Australia?
>- or that more countries should start moving to the Australian level?

Both

It was a rather flippant message, we must get our numbers down, we have
beaten all our natural enemies and thus, like the Cane toad(Bufo marinus) in
Queensland and the rabbit in the whole of Australia we are overrunning all
available space. We have only our brain to evolve ways to curb our numbers
and we are not using it.
I realise it is a difficult problem, especially in the third world and the
Stove list is not the place to solve it. I was mainly expressing my delight
at seeing someone else on the list touching on this problem.

Thanks for your comment, Ron.
Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Tue Jun 10 06:28:55 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:15 2004
Subject: Charcoal and briquettes
Message-ID: <1.5.4.32.19970610102836.006af93c@janus.cqu.edu.au>

>From Piet Verhaart

At 19:31 8/06/97 -0600, Ron wrote:
>Stovers - Tom Reed inadvertently sent this to "stoves-digest" rather than
>"stoves" - so I am forwarding it to all. Regards Ron
>
>Pete and all:
>
>Pete seems to say that low ash is desirable in charcoal. It is probably
>much more complicated than this.
>
>Kingsford puts (10%) a lot of ash intentionally into charcoal to SLOW the
>combustion process. (High density, as in coconut shell charcoal may
>accomplish the same.) The ash may also be catalytic for burning the CO
>formed at the C-air interface to CO2.

May be catalytic? Is there anything more detailed on catalysis of CO to CO2?
K, Ca, Al, Si?
I remember our downdraft stove producing negligible CO as long as volatiles
were produced. As soon as the flames disappeared the CO went sharply up. (I
stand to be corrected by Etienne and/or Prasad.)
I had read somewhere that water vapour also catalysed the CO to CO2 reaction
and, until something better cropped up, that was the explanation of the CO
increase. Regrettably we did not get down to do the simple experiment of
feeding some steam into the char burning J-stove.

We almost without exception used white fir with a very low ash content.

>It may act as a binder.

At one stage we played with the idea of using some of the tar as a binder.
The raw briquettes would have to be fired again, this time without access of
air.

An idea to get a high yield of charcoal was to carbonize at the lowest
possible temperature when the tar would remain in the charcoal mass. Raising
the temperature slowly would decompose the tars into (secondary) char and
lighter volatiles.

>
>I continue to learn about "charcoal" at a great rate and appreciate all the
>comments found in "STOVES", but filed under CHARCOAL in my E-files. I wish
>I had a graduate student or two to follow up my suspicions and put the
>world of charcoals on a more scientific basis.
>
chop

Just fixed up the Subject heading, hope the spelling has no glitches.
Spelling checkers never get the 'there, their' right and my Eudora checks no
spelling, have t do it all myself.

Chars and cheers,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Tue Jun 10 06:28:56 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:15 2004
Subject: Verhaart and the Swosthee stove
Message-ID: <1.5.4.32.19970610102839.006a24cc@janus.cqu.edu.au>

Dear Ron,

At 19:31 8/06/97 -0600, you wrote:
>
>Stovers:
>
>Peter Verhaart said about a week ago:
>
clip
>(RWL): Pete - I'd appreciate receiving the dimensions - but I need much
>more. Can you supply a bit more on how to reach Prof. Mukunda and/or the
>article citation.
>
> Perhaps you could also describe both the Swosthee stove and Sadhana
>as well.
>
chop

I'll fax a sketch of the Swosthee stove to your friend's address. I also
faxed sketches to Greg Brown some days ago as well as relevant parts of the
article.

Sadhana is the new name for the Journal of the Indian Institute of Science.
There are two versions of the journal, Prasana and Sadhana. Both words are
from Sanskrit and mean something appropriate. Prasana may treat civil
engineering. Sadhana does Mechanical Engineering, Physics, Fluid Dynamics
etc. The name change came in the early 80's. I remember myself liking the
change in contrast to Prasad. I am sure Prasad could correct me on proper
names and on the facts.
During that period Sadhana devoted two issues to woodburning cookstoves.
These issues were later bundled into "Wood Heat for Cooking".

Here follows the part of the article I sent to Greg. The title is:

Portable single pan wood stoves of high efficiency
for domestic use.
It appeared in Sadhana in December 1988, nine years ago!

Swosthee Stove

4. Rationale for design

4.1 Concepts involved
Details about how to design wood stoves, available theoretical models and
experimental data are
summarised in Krishna Prasad et al (1985). More details are available in
Bussman et al (1983) and De
Lepeleire & Christiaens (1983). Despite the above Emmons & Athreya (1982)
have the following to say:
"The current scientific understanding of 'wood combustion' is not mature
enough to provide a reliable
quantitative prediction ... The final design of a stove should be determined
experimentally". Therefore for
about one. and a half years during 1984-85, many attempts were made by us to
meet the specifications listed
earlier; three concepts were attempted, a dozen configurations were built
and tested. Concepts tried out
were
(i) pyrolysis of wood/biomass in a chamber and burning the products with air,
(ii) combustion of the fuel to produce hot cinders, allowing atmospheric
air and the pyrolysis
products to pass through hot cinders to produce some CO and H, and
burning this mixture
with air at the top of the stove, and
(iii) combustion of the fuel in a chamber with swirling air.

Verhaart (1982) gives tutorial sketches of the first two concepts, though no
details of any prototypes
attempted are available. However the authors got a few models built and
tested. The first concept was
successful in obtaining good combustion on the average, but hardly any
control was possible. In fact it was
found that loading the chamber with more fuel than can be consumed at the
required rate causes a sudden
release of pyrolysis gases, which tend to make the combustion fuel-rich,
causing sooting and smoke, and
resulting in large heating rates. Thus it was apparent that without a
fuel-feeding device there was no
possibility of varying the beating rate, particularly of lowering it when
needed for simmering. Since this
control is an important requirement, the design was abandoned.
The second concept, also taken from wood gasifier designs, did not quite
succeed since there were problems
of uneven power during the operation.
The third concept was implemented in a few designs and one of them led to a
useable version (which we
denote by the code S-1 during further discussion; see table 1 for details of
symbols used to represent
different stove models). Elements of this design are
(1) a vertically arranged duct to carry hot gases and to create the
necessary draft,
(2) a combustion chamber below, and
(3) a loading region, there being no separate chimney.
The vertical duct carrying combustion products provides the draft for air to
be taken in at the sides in the
lower region of the stove. The air is drawn in along a tangential direction
providing for a longer residence
time inside the chamber. Hot gases are taken out along the vertical duct
which has provision for creating
Circulation of gases inside it such that combustion can be completed within
the height provided for the duct.
The release of hot gases in an opening of small cross-section was expected
to improve the efficiency as in
gas stoves.
In order to ensure that the heat retained in the body of the stove is small,
the entire stove is made from thin
sheet metal. Further, to reduce heat losses to the ambient, the stove is
covered with low density insulation
of alumino silicates on the entire outer surface. When field tests were
being conducted after completing the
development, factors contributing to the high efficiency were reviewed. We
found that the temperature of
the gases transferring heat to the vessel plays a critical role. While
premixing without adequate control on
mixture ratio may keep the average temperature lower than the optimum and
the efficiency may fall, high
efficiency may still be obtained if the combustion is diffusion-dominant and
the flame 'transfers most of the
heat to the vessel. The only problem with the second mode is higher levels
of soot and smoke. Thus, one
is led to two different designs, both capable of high efficiency but
producing different pollutant levels in the
flue gases. The designs based on premixing are christened
SWOSTHEE-single-pan wood stoves of high
efficiency (Mukunda & Shrinivasa 1985; S-1 and S-2 refer to this design with
rated power, based on fuel
consumption rate, of 1 and 2 kW respectively). The models based on
diffusion-dominated combustion as
discussed above are called Modified Swosthee and are denoted by MS-1.5 and
MS-4 for 1,.5 and 4kW
ratings respectively (Mukunda et al 1986).
+++++++++++++++++++++++++++++++++++

Mukunda: how to reach.
You could gamble on: mukunda@aero.iisc.ernet.in
else get to him via Mrs. Gayathri, whose address is:
gayathri@aero.iisc.ernet.in

> If FAXing is much easier than mailing, please use a friend's 24-hour FAX:
>303/331-0316, with my name somewhere shown.

I tried, but a human voice spoke up after 4 rings and the faxing did not
succeed. I'll try at a more godly hour at your end, assuming a 17 hour time
difference.

>Otherwise you will have to
>send a warning first to my home phone/computer/FAX.
>
>Thanks in advance. Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>
>
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Tue Jun 10 06:28:49 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:15 2004
Subject: Something Practical ?, part 2
Message-ID: <1.5.4.32.19970610102831.006a7cf8@janus.cqu.edu.au>

Dear Alex

At 22:52 8/06/97 -0500, you wrote:
chop
>The following description ( A. English test burn #1) with a drawing
>(fig A) is available through the site
>http://www1.kingston.net/~english/Stoves.html
>
Had a brief look at it (I had just got my third and final call for lunch). I
would say it has things in common with Ron/Tom's charcoal producing 2-can stove.

>With both air supplies wide open the fuel was "top lit" with a
>propane burner. It quickly developed visually clean exhaust gasses.
>A turbulent and audible (micro roar) flame was largely contained with
>in the flame chamber. For the first fifteen minutes the CO2 tested
>at between 3.5% and 5% , Temperature fluctuated between 650F
>and 850F , smoke was about a 2 on a Bacharach scale of 0-10

Sounds familiar. Did you only measure CO2, not CO?
>
>Reducing under fire air caused a loss of flame and heavy smoke.
>Cutting off over fire air caused the flame go quiet and extend up
>high into the chimney, with a soot plume. (CO2 tested at 15% during
>this stage, smoke at about 8 or 9)

Yes. I fiddled around with the bottom valve and managed to get the flames
going again a few times.

>After 20 minutes it lost its flame. ( I think it used up the
>volatiles)

That is very quick. You could probably extend this period by adjusting the
bottom air supply.

Chop
>
>Conclusions: I have a long way to go!
>
Don't we all?
>
>Alex
>
You shuold get some (or a lot) comment from Tom and/or Ron.

Cheers,
Peter Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From english at adan.kingston.net Tue Jun 10 07:28:22 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Re. Something practical ? part 2,1b
Message-ID: <199506102330.TAA01134@adan.kingston.net>

Dear Peter +

I don't (yet) have a CO tester.
Do you know what the current best CO levels are for these small wood
cooking stoves ?
Is it correct that you need temperatures over 1200F to burn the CO?
My lastest effort with the 'pail/cone' had flame temperatures just
over this threshold.
The cone falling down over the fuel achieves what I think you were
after with the Jak stove. It certainly reduced the excess air.

If you do any sketches of the Swosthee or others send them along and
I'll web them.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From jsg at crest.org Tue Jun 10 14:08:03 1997
From: jsg at crest.org (Jon Guth)
Date: Tue Aug 31 21:35:15 2004
Subject: GEM
Message-ID: <339D9778.431B@crest.org>

GEMs

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http://gem.crest.org

Vol.1 Issue 1

IN THIS ISSUE:

-GEM: What Is It and How Can It Help You?
-Newsworthy Gems
-Help Build the GEM On-Line Library - Where Are Your Gems?
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the manufacturer pass along the unit savings downstream, a $5 incentive
becomes far greater when it reaches the consumer. (Consumer discounts
can reach as high as $15 with a $5 manufacturer=s rebate.) Second, by
allocating wholesale rebates to a large quantity of lamps from
manufacturers, utilities can stipulate performance criteria, such as
maximum levels of harmonic distortion and minimum efficiency levels.
Manufacturers= rebate programs can create financial leverage while
transforming the market for energy-efficient products.

HELP FIND GEMS

Do you know about a great web site or document at a web site not listed
in the GEM library? Help build this valuable online library by
e-mailing the Web address (URL) to gemkeeper@crest.org. If each user
contributes just one unique URL this library will grow by thousands of
documents, saving each of us precious time and gaining us access to
resources not previously available or easily accessible.

PLEASE DISTRIBUTE FREELY.

THANKS!

*****************************************************************************
The Global Energy Marketplace (GEM) is a project of the Center For
Renewable Energy and Sustainable Technology (CREST), and is supported by
the U.S. Environmental Protection Agency's Office of Policy, Planning
and Evaluation (OPPE).

--
Jonathan Guth, GEM Project Manager
Center for Renewable Energy and Sustainable Technology (CREST)
1200 18th St., NW Suite 900 Washington, DC 20036
Phone: (202)-530-2234 Fax: (202)-887-0497
E-Mail: jsg@crest.org Web: http://gem.crest.org

From jsg at crest.org Tue Jun 10 15:50:19 1997
From: jsg at crest.org (Jon Guth)
Date: Tue Aug 31 21:35:15 2004
Subject: GEM follow-up
Message-ID: <339DAE86.CC3@crest.org>

As a short follow-up to the previous posting of the GEM e-newsletter,
I thought it might be appropriate to explain its posting.

The Global Energy Marketplace (GEM) is a relatively new project being
undertaken by CREST to promote renewable energy, energy-efficiency, and
greenhouse gas reductions. The GEM on-line database contains numerous
electronic resources in the areas of bioenergy, geothermal, small-hydro,
hydrogen, wind, and solar, in addition to its many resources on
energy-efficiency. It may be able to assist you whether you're a
preofessional in the energy field, a researcher, a policy-maker, or just
interested in renewable energy and efficiency in general.

As such, I thought it would be of interest to the subscribers of this
discussion group. If indeed you are interested, and happen to also know
of some useful electronic resources or case studies that are not in the
database already, please submit the URL to gemkeeper@crest.org
GEM will become infinitely more valuable to all of its users if its
users help build it as well. Any and all submissions will be considered.
Thank you.

Sincerely,

Jon Guth
--
Jonathan Guth, GEM Project Manager
Center for Renewable Energy and Sustainable Technology (CREST)
1200 18th St., NW Suite 900 Washington, DC 20036
Phone: (202)-530-2234 Fax: (202)-887-0497
E-Mail: jsg@crest.org Web: http://gem.crest.org

From english at adan.kingston.net Tue Jun 10 22:28:21 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:15 2004
Subject: Something Practical, Part 1b cont.
Message-ID: <199706110228.WAA32320@adan.kingston.net>

Dear All +

I did another cone and pail burn this evening. The fuel was the same.
This time I insulated the pail, including the top around the chimney
thus restricting the air supply. I also slipped a cerafelt liner into
the chimney to act as a combustion chamber. Giving it unrestricted
air pushed the flame temperature up to just over 1700F. Restricting
the air to a "minimum" resulted in flame temperatures between 1400F
and 1500F , with CO2 up around 15% and a smoke plume. The 'flame
stage' lasted 1.5 hours( 50% longer), leaving charcoal the same as
before. With restricted air the flame was much lazier than before.

I think what is needed is to
come up with a simple way to effectively mix additional air at the
apex of the cone, and still control it. Any suggestions ?

Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Wed Jun 11 00:22:44 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Pete Verhaart on population density
Message-ID: <v01540b06afc3d1214e56@[204.133.251.4]>

Pete Verhaart said on June 10:

<snip>

> We have only our brain to evolve ways to curb our numbers
>and we are not using it.
>I realise it is a difficult problem, especially in the third world and the
>Stove list is not the place to solve it. I was mainly expressing my delight
>at seeing someone else on the list touching on this problem.

(RWL) Pete: If we only "solve" the stove problem (and not the population
problem), we will only have put off disaster a decade or two. As you know,
many smart developed countries (the US not among them) are experiencing an
actual population decline (Italy, France, Japan (I think)). China will
continue to grow for a few more decades, but they took the drastic steps
needed hopefully soon enough. But only disaster seems possible for such
countries as Bangladesh and India (and most of Africa), where the average
woman is still having three or four children. The time lag is about a
lifetime - or 70 years. India will probably become the most populous
country even if it gets its act together tomorrow.

Like you, I now feel obliged to say the above as much as I can. I
think the stove community may be among the best to see the problem - but
you are right: we can't solve it - but it can't hurt to talk about it.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 11 00:22:45 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: Alex on charcoal maker
Message-ID: <v01540b04afc3c647c1b3@[204.133.251.4]>

Alex said in message of 9 June at 14:06

(RWL): >> 1. Did you have any air supply holes other than "fresh air over the
>> opposite side" ? If so, did you or could you exercise control of that
>> (especially primary) supply?
>
>There were three small holes around the outside, which I quickly
>plugged with tin foil. There were also three 3/8" copper tubes
>carrying "secondary air" from below the pail , up through the fuel to
>the top of the fuel. These had sporadic blue flame attachment. There
>was a grate below the fuel and there could have been small leaks of
>air through the tin foil and around the edge of the copper, however I
>think these were minor influences on what I observed.

(RWL): I am pretty sure you have more primary air supply than you think.
I have found it very difficult to close off the primary air (the best way
to really seal it off is with a water seal) and I therefore assume you have
a fair amount of leakage. I urge you to try to control the air through the
three "plugged" holes - and also to better close up the secondary air pipe
feedthroughs (if you go back to this configuration).
I would guess that the three 3/8" holes are not supplying enough
secondary air. (especially compared to those in your next test) - and this
is why you had a fairly "gentle" flame.

<snip>

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 11 00:23:07 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:15 2004
Subject: English on Charcoal-making stove
Message-ID: <v01540b03afc3b133cdf1@[204.133.251.4]>

Alex - I am very impressed. You have made at least two excellent
innovations - namely:
1) the conical shaped start of the chimney ( I don't know if this is best
for cooking - since we must flare out again to accomodate the cook pot, but
I have not tried it and now must)
2) a simple means of introducing secondary air (I tried this with a
shorter closer fit of two cylinders - and it didn't work. Now I am
encouraged to go back and try a wider separation between them.)

Some more questions below.

Alex said (in message dated 6/9 at 22:53):

>I went back to the 20 litre pail this evening with much better
>results.

(RWL): Could you give the dimensions. Apparently this pail is not cylindrical?

>I filled the bottom with vertically placed 1"*2" *5" pieces
>of cedar weighing 4 lbs and through some crumpled paper on top.

(RWL): I have found better (more uniform pyrolysis) operation with a grate.
If you have one, could you describe it.

> I chopped the end off a metal funnel forming a cone with 9" top dia.
>and 3" bottom dia. Screwed a piece of 5" stove pipe (15" long) to the
>outside of the funnel, lit the paper and placed the large end of the
>funnel over the burning paper and on top of the wood, such that the
>stove pipe formed a chimney. The pail diameter at this point is about
>11", leaving about an inch all around. It took between 2 and 5
>minutes for the flame clean up.

(RWL): Can you explain what you mean by "flame clean up".

> The chimney draft was sufficient to
>keep all the fire going up the centre. There was no air supply other
>than what was sucked around the outside of the cone.

(RWL): I presume you mean "no secondary air supply"? I find that primary
air control is essential to control the power level. If you did vary
primary air flow, could you give the max and min weight rate loss (pounds
per hour or minute)

>The orange/
>yellow flame extended to the top of the stove pipe. It burned that
>way for the next 50 minutes. Temp. at the top of the flame was
>between 1200F and 1300F , CO2 between 8% and 11%, Smoke test between
>3and 5 on the Bacharach scale. (I have seen some oil furnaces that
>weren't much better.)

(RWL): Could you or did you measure either CO or total hydrocarbons?
Would you give a reference for the Bacharach scale and describe what 3-5
means. I rarely see any color or opacity to the exhaust gases.

> The whole affair took place on a scale. The
>steady weight loss matched the other indicators. The cone/chimney
>tilted as the supporting material crumbled. I occasionally jiggled
>and straightened it, with no change in the flame. After 55minutes the
>flame increased slightly for 5 minutes and then died.

(RWL): I don't remember ever seeing this slight flame increase - usually I
am forced to increase the primary air supply at this time to maintain the
slight rolling boil I strive for in an efficiency test.

> A bluish flame
>then hovered above the remaining fuel below the cone.

(RWL): I presume this is combustion of charcoal?

>I removed the
>cone/ chimney, covered the top of the pail with rock wool, and
>sprayed water on the outside of the pail for 5 minutes.

(RWL): I use the term "rock wool" to mean a loose permeable material
and "sheet rock" for a hard impermeable material. Was yours loose and
permeable? (and if so why?) I typically invert a cook pan or other large
can over the chimney. I have only rarely used water.
The difficult part for me is closing the secondary air holes -
which is why I like your approach so much - of bringing the secondary air
down on the outside of the inverted cone (which also does a nice job of
preheating the secondary air!). For many tests I find it easiest to shake
out the charcoal into another closeable chamber - but this is not
acceptable for a final model.

>When I
>returned in an hour the the remaining charcoal was cool and weighed
>about 1lbs. The pieces in the centre were essentially the size and
>shape of the original wood. Toward the out side they had obviously
>been partly consumed, such that the remaining charcoal took on the
>shape of the cone.

(RWL): I think about 95 % of my tests have been within 1% of the (1/4=)
25% conversion efficiency you found. Can I assume that you did not see any
wood pieces that were not converted fully to charcoal? I recently ran a
test with about half oak and half redwood and found only partial conversion
of the oak. This multiple fuel testing needs more work - this was only a
first crude test for another reason (of setting the system into the
ground),

For simplicity in cooking for the user, I think you may have to
keep the chimney fixed in space. If you did not have primary air holes,
and do in the future, the charcoal consumption should be less.

>
>Yes Ron ,I could cook with this . There are many improvements
>or options that should be explored. I look forward to trying them.
>
(RWL): I'll bet we will look back in the future and ask how come we missed
hundreds of great innovations like those you found.

>PS Ron or Tom could you explain or discuss the differences between
>this trial and your own two can fires.

(RWL): I've tried above. I look forward to your next several tests -
which I believe should include:
1. Simulate cooking with a boiling water test (the pot will
introduce enough air resistance to foul up stove optimization if you don't
do it). Let us know how much water you can evaporate from the cook pot
with a given amount of wood
2. Different chimney diameters and heights. Getting it as low as
possible will help reduce radial radiative losses.
3. Different primary air supply arrangements. The stove
literature emphasizes the advantages of a large turndown ratio.
4. Different means of improving the convective heat transfer to
the heat pot (with a surrounding cylindrical ring - maybe a cm away from
the pot.)

You have moved the charcoal-making stove development process along
a great deal. Congratulations. I hope others will be encouraged to join
in, based on your endorsement. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From sepado at emirates.net.ae Wed Jun 11 07:53:36 1997
From: sepado at emirates.net.ae (Feysal Ahmed Yusuf (SEPADO))
Date: Tue Aug 31 21:35:15 2004
Subject: Gulf News, Today 11 June, Abu Dhabi
Message-ID: <199706111153.PAA15835@ns2.emirates.net.ae>

Dear Stovers;

I am pleased to forward herewith, An article that was extracted from GULF
NEWS of today, 11 June, for your information, please.

Also, I am pleased to see the good correspondences that was going on during
my absence.

Thanks.

Faisal Hawar.
MD,SEPADO.
_____________________________________________________________________
Somalia Environmental Protection and Anti Desertification Organization
SEPADO, P.O. Box 27750, Abu Dhabi, United Arab Emirates (UAE).
Tel : +971 - 2 - 215 243 ; Fax: +971-187-02215243 ;
Email:Sepado@emirates.net.ae, H-Page: http://members.tripod.com/~sepado/
_____________________________________________________________________

--------------------------------The article ----------
GULF NEWS (Dated 11 June 1997), Abu Dhabi, UAE.

Gulf urged to shun Somali charcoal

By Justin Colledge-Wiggins, Staff Reporter
Abu Dhabi - The Gulf states should halt imports of charcoal from Somalia due
to the alarming rate trees are being felled there to manufacture charcoal,
resulting in a sharp increase in desertification, says one of Somalia's
first environmental groups founded in the UAE. Almost 10,000 tonnes of
charcoal is being exported from Somalia each month, and it has a devastating
effect on the landscape due to the destruction of acacia bushes, says Feysal
Ahmed Yusuf, Managing Director of the Somali Environmental Protection and
Anti-Desertification Organisations (SEPADO) communication office in Abu
Dhabi.

Reports from Somalia describe the indiscriminate use of pesticides which
contaminate water resources, and trees being laid waste for charcoal
production. The result is large tracts of the country being reduced to
desert. Consequently, four Somalis living in Abu Dhabi have set up an action
group to tackle these problems through international collaboration. Success
has come early for the SEPADO, says Yusuf. Talks with the UAE's Federal
Environment Agency have been encouraging and could result in the UAE
stopping imports of Somali charcoal.

Trees and bushes provide essential protection for soil - providing
protection from wind, rain and sun. Their roots also bind the soil together
and help in topsoil formation. SEPADO is desperately lobbying governments
about the problems created by Somali charcoal exports. Realising that many
nomads' livelihoods depend on its production, they are looking for ways in
which nomads can make a living from sustainable projects, says Yusuf.

SEPADO, headed and founded by Feysal Ahmed Yusuf, a Somali, has benefited
from publicity on the BBC Somalia service and is now collaborating with the
United Nations Environmental Programme and the World Wide Fund for Nature.
Somalia has watched its environment deteriorate as rare animals are hunted
for the hard currencies earned from their skins and bones, say the
executives of SEPADO. The uncontrolled use of insecticides is also taking
its toll. "We have found camels that died after drinking water polluted with
insecticides," says Yusuf, and nomads could die if they drank the same
water.

http://www.gulf-news.com/

----------
From: Peter Verhaart <verhaarp@janus.cqu.edu.au>
To: stoves@crest.org
Subject: Re: Pete Verhaart on population desity
Date: 10 June 1997 14:28

Have I done all
>this correctly?
>
> Pete - was your point that you are glad to be living in Australia?
>- or that more countries should start moving to the Australian level?

Both

Thanks for your comment, Ron.
Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Wed Jun 11 08:04:10 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:15 2004
Subject: Pete Verhaart on population density
Message-ID: <1.5.4.32.19970611120359.006be55c@janus.cqu.edu.au>

Dear Ron,

I am glad you have similar thoughts on population density, I had no
idea. It again proves that it is good to say what you think now and then.
Bye the way, Indonesia's population is also still expanding and it is hard
to say where it will end. As in many other Asian and African and possibly
Latin American countries, children are an investment for old age and it will
take a lot to convince them of the dangers for those children.

At 22:22 10/06/97 -0600, you wrote:
>Pete Verhaart said on June 10:
>> We have only our brain to evolve ways to curb our numbers
>>and we are not using it.....
>
>(RWL) Pete: If we only "solve" the stove problem (and not the population
>problem), we will only have put off disaster a decade or two. As you know,
>many smart developed countries (the US not among them) are experiencing an
>actual population decline (Italy, France, Japan (I think)). China will
>continue to grow for a few more decades, but they took the drastic steps
>needed hopefully soon enough. But only disaster seems possible for such
>countries as Bangladesh and India (and most of Africa), where the average
>woman is still having three or four children. The time lag is about a
>lifetime - or 70 years. India will probably become the most populous
>country even if it gets its act together tomorrow.
>
> Like you, I now feel obliged to say the above as much as I can. I
>think the stove community may be among the best to see the problem - but
>you are right: we can't solve it - but it can't hurt to talk about it.
>
>Regards Ron
>
Regards,

Pete
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From zourarakis at nosapp.nr.state.ky.us Wed Jun 11 08:26:17 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:15 2004
Subject: Donkey dung power (DDP)
Message-ID: <97061108260229@nosapp.nr.state.ky.us>

From: SMTP%"P.H.Starkey@reading.ac.uk" 11-JUN-1997 06:03:28.07
To: sard-news <sard-news@nygate.undp.org>
CC:
Subj: Donkey workshop press release

**************************************************************************
Improving donkey management and utilisation: workshop press release

Donkeys were the focus of a five-day workshop held in Debre Zeit, Ethiopia
May 5-9 1997. Eighty-five participants from 23 countries around the globe
assembled to discuss the current and potential contributions of Equus
asinus, the domestic donkey, as an affordable and sustainable power source
for rural development. With a potential productive life in excess of 20
years, the donkey has outlived many a tractor on the farms of numerous
African countries.

The approximately 15 million donkeys of Africa represent a resource that
has not yet been fully utilised. Despite serving as beasts of burden and
as sources of power for carts and plows, donkeys the world over suffer
institutional and policy level neglect. Because it is perceived as a low
priority, low status animal, the donkey has been largely ignored by
national research, educational and extension services. Donkeys, however,
have become a significant element of many African farming systems. They
are highly valued by those that use them on a daily basis. Donkeys are
especially important for the role they play in transport of goods, persons
and household necessities. They provide essential links between agricultural
production and commodity marketing. Donkeys are now gaining increasing
recognition as hardy, low cost and tractable sources of power and income
generation for rural and urban women and men across Africa. Their
tolerance of hard work, drought and disease and their survival
mechanisms have thrust them to the fore in areas where harsh environmental
conditions have decimated many cattle herds in recent years.

This unique workshop was aimed at furthering international understanding
of the donkey as a valuable working animal. It brought together research
scientists from the fields of nutrition, physiology, veterinary medicine,
socio-economics and engineering, as well as extension agents, training
coordinators, educators, harness makers, animal welfare specialists and
donkey enthusiasts. The five days of presentations, discussions,
demonstrations and field trips were aimed at furthering international
understanding of the donkey as a valuable working animal. The workshop
produced plans for projects as varied as brochures describing effective
donkey harnessing techniques, a new methodology for rapid field assessment
of donkey health and welfare and children's books featuring donkey
stories. There were calls for increased study of donkey numbers,
distribution and use around the continents, expansion of knowledge of
affordable ways to improve feeding and health of working donkeys in
Africa, and testing of low cost, lightweight carts, tools and harnesses
for use by donkeys and their owners.

The workshop was arranged by the Animal Traction Network for Eastern and
Southern Africa (ATNESA) with support from The Netherlands' government.
The local Ethiopian organising committee was supported by several
governmental and non-governmental organisations and organisations,
including the Institute of Agricultural Research. A full report of the
workshop will be available from ATNESA in mid June 1997. Over 70 submitted
papers, comprising both case histories and experimental studies of donkey
use, will be published in thematic resource books in 1998.

A more detailed summary of the workshop can be requested by e-mail from:
ATNESA@reading.ac.uk

Further information on this workshop and other ATNESA activities is also
available from the national animal traction networks and from:

Dr T E SIMALENGA (ATNESA Chair)
Faculty of Agriculture, University of Fort Hare
Private Bag X1314, Alice 5700, SOUTH AFRICA
Tel: + 27-404-22232; Fax: + 27-404-31730
Email: TIM.S@ufhcc.ufh.ac.za

Bertha MUDUMBURI (ATNESA Secretariat)
Agritex Institute of Agricultural Engineering
PO Box 330, Borrowdale, Harare, ZIMBABWE
Tel: + 263-4-860019 /55; Fax: + 263-4-860136
Email: Atnesa@harare.iafrica.com

Dr ALEMU Gebre Wold (Donkey workshop secretariat)
Institute of Agricultural Research (IAR)
PO Box 2003, Addis Ababa, ETHIOPIA
Tel: + 251-1-511802; Fax: + 251-1-611222
Email: c/o sam.vander@telecom.net.et

Professor Paul STARKEY (ATNESA Technical Adviser)
Animal Traction Development, Oxgate, 64 Northcourt Avenue
Reading RG2 7HQ, UNITED KINGDOM
Tel: + 44-118-9872152; Fax: + 44-118-9314525
Email: P.H.Starkey@reading.ac.uk

**************************************************************************

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From elk at arcc.or.ke Wed Jun 11 09:08:51 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:16 2004
Subject: two-can stove: primary air inlet control
Message-ID: <v01510100afc4797f0f3f@[199.2.222.132]>

Stovers;

With reference to the two-can primary air inlet control my immediate
response (seeing as life in Kenya is pretty close to ground level) would be
to partially or fully block the apertures with earth or sand as needed to
control airflow.

Sand is also an effective fire extinguisher both for safety and to ensure
the charcoal produced by the stove is out after cooking. Reuseable too!

I've caught toe bug and am building a larger version of the stove now- with
a couple modifications. Will keep the group informed.

On the sawdust charcoal briquetting scene; it's taking for ever to
carbonise 500 kg of sawdust using the partially vented 'big pile'
technique. Wouldn't it be nice if we could come up with a two-can type
stove utilising sawdust?

Any information availble on capturing the vented gasses from the
carbonising sawdust? I could certainly use additional fuel for my fishmeal
plant boiler. It's burning 50% by-product fishoil and 50% kerosene at the
moment.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From E.Moerman at stud.tue.nl Wed Jun 11 09:37:30 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:16 2004
Subject: Charcoal and briquettes
Message-ID: <13064.s335192@popserver.tue.nl>

>From Piet Verhaart:

> May be catalytic? Is there anything more detailed on catalysis of CO to CO2?
> K, Ca, Al, Si?
> I remember our downdraft stove producing negligible CO as long as volatiles
> were produced. As soon as the flames disappeared the CO went sharply up. (I
> stand to be corrected by Etienne and/or Prasad.)
> I had read somewhere that water vapour also catalysed the CO to CO2 reaction
> and, until something better cropped up, that was the explanation of the CO
> increase. Regrettably we did not get down to do the simple experiment of
> feeding some steam into the char burning J-stove.
--------

Etienne:
For the catalytic effects of trace metals and moisture see

Laurendeau, N.M., 1979. Heterogeneous kinetics of coal char gasification and
combustion. In: Prog. Energy Combust. Sci., Vol.4, pp. 221-270.

This is a very good overview article on biomass combustion. There must be
more and more recent publications on the subject too. I know
there is a very detailed microscopic study from the mid-80's, but I cannot
think of the name right now.
Pete is right about the CO increasing rapidly when the flames disappear. By
the way I also did experiments with other types of wood and even with
briquettes of agricultural waste (ash content of 10-15%) all with the same
result. Very low and equally low CO/CO2 ratios (ratio around 0.025%) for an
excess air factor around 1.8. When the excess air factor became smaller than
1.3 or larger than 2.3 the CO/CO2 ratios increased rapidly. When flames
disappear the excess air factor becomes larger than 2.3.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Wed Jun 11 09:37:35 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:16 2004
Subject: Re. Something practical ? part 2,1b
Message-ID: <13069.s335192@popserver.tue.nl>

Alex English:

> Do you know what the current best CO levels are for these small wood
> cooking stoves ?
> Is it correct that you need temperatures over 1200F to burn the CO?
> My lastest effort with the 'pail/cone' had flame temperatures just
> over this threshold.
> The cone falling down over the fuel achieves what I think you were
> after with the Jak stove. It certainly reduced the excess air.
>
---------

Etienne:
The best CO/CO2 levels I ever found for small woodstoves were measured at
Eindhoven for the downdraft stove (CO/CO2 ratio below 0.02% and CO below
0.01 vol.%). At Eindhoven we expect that high temperature are required, the
temperatures in the downdraft stove are at least 1000 K and usually around
1150 K. When the stove was new, less battered and better insulated
temperatures over 1350 K were measured.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From CKEZAR34 at aol.com Wed Jun 11 13:11:50 1997
From: CKEZAR34 at aol.com (CKEZAR34@aol.com)
Date: Tue Aug 31 21:35:16 2004
Subject: population density
Message-ID: <970611130803_2021273394@emout20.mail.aol.com>

Stove people
Pete Verhaart said on June 10:
>> We have only our brain to evolve ways to curb our numbers
>>and we are not using it.....

A further comment on population.
One day several years ago the staff of the House Science Committee were
pondering what was the most energy using system. After discovering the
refrigerator and the automobile we computed the energy used by us. People -
us - turned out to be the most intense energy user of any system by far.
Think of this when we ponder energy demand and supply and then think about
the environment . Guess what system stresses the environment beyone any
other system?

C. A. Kezar

From english at adan.kingston.net Wed Jun 11 15:49:41 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: English on Charcoal-making stove
In-Reply-To: <v01540b03afc3b133cdf1@[204.133.251.4]>
Message-ID: <199706111949.PAA26756@adan.kingston.net>

Dear Ron++

>
> Alex said (in message dated 6/9 at 22:53):
>
> >I went back to the 20 litre pail this evening with much better
> >results.
>
> (RWL): Could you give the dimensions. Apparently this pail is not cylindrical?
(AE): I don't have it near me at the moment but the top may be half
an inch larger than the bottom. Not significant.

> >I filled the bottom with vertically placed 1"*2" *5" pieces
> >of cedar weighing 4 lbs and through some crumpled paper on top.
>
> (RWL): I have found better (more uniform pyrolysis) operation with a grate.
> If you have one, could you describe it.

(AE):There is no grate, the wood is sitting on the bottom of the
pail. I presume you are using the space below the grate to "
manifold" the your primary (underfire) air for even distribution. I
sealed up the holes I made previously, this time with rock wool
insulation. I guess I had better weld over the holes so we don't have
to debate the permeability of my various plugs.
>
> > I chopped the end off a metal funnel forming a cone with 9" top dia.
> >and 3" bottom dia. Screwed a piece of 5" stove pipe (15" long) to the
> >outside of the funnel, lit the paper and placed the large end of the
> >funnel over the burning paper and on top of the wood, such that the
> >stove pipe formed a chimney. The pail diameter at this point is about
> >11", leaving about an inch all around. It took between 2 and 5
> >minutes for the flame clean up.
>
> (RWL): Can you explain what you mean by "flame clean up".
(AE): I am referring to visible smoke. I think the newspaper produces
pyrolysis products to quickly for the limited draft during start up
when everything is relatively cold.

> > The chimney draft was sufficient to
> >keep all the fire going up the centre. There was no air supply other
> >than what was sucked around the outside of the cone.
>
> (RWL): I presume you mean "no secondary air supply"? I find that primary
> air control is essential to control the power level. If you did vary
> primary air flow, could you give the max and min weight rate loss (pounds
> per hour or minute)
(AE): If you accept that my plugged holes were really plugged, as I
do. Then the only air to the wood was from over the edge of the pail
and then down around the outside of the cone. There is leakage
between the cone and the 5" chimney. I thought this might be a useful
source of secondary air however with the current arrangement the
mixing is minimal. I believe this can be improved with a second cone
placed over the first, with a space between, whose large and small
opening diameters are smaller than the cone below. This would place
fresh preheated air directly in the path of the"rich" flame exiting
the lower cone. However I do not yet see the easy way of controlling
that second flow rate independent of the primary over fire air.

The weight change averaged about 1oz/min. The scale has a large error
factor. Almost as large as the record keeper.

> >The orange/
> >yellow flame extended to the top of the stove pipe. It burned that
> >way for the next 50 minutes. Temp. at the top of the flame was
> >between 1200F and 1300F , CO2 between 8% and 11%, Smoke test between
> >3and 5 on the Bacharach scale. (I have seen some oil furnaces that
> >weren't much better.)
>
> (RWL): Could you or did you measure either CO or total hydrocarbons?
> Would you give a reference for the Bacharach scale and describe what 3-5
> means. I rarely see any colour or opacity to the exhaust gases.

(AE): No CO or Hydrocarbons. For the moment I am limited to using a
oil burner test kit made by Bacharach. If this develops a little
further I know someone I might be able to pester into doing a more
complete and reputable analysis. The smoke test involve sucking the
flue gasses through a filter with ten strokes of a hand operated
piston pump, and then comparing the filter to a chart. Clean is zero.
Black is 10. You can get readings up to about 5 without visible
smoke. This would depend somewhat on the lighting conditions and who
is looking. The burn 1b, that took place on the scale, was visually
very clean.
>
> > The whole affair took place on a scale. The
> >steady weight loss matched the other indicators. The cone/chimney
> >tilted as the supporting material crumbled. I occasionally jiggled
> >and straightened it, with no change in the flame. After 55minutes the
> >flame increased slightly for 5 minutes and then died.
>
> (RWL): I don't remember ever seeing this slight flame increase - usually I
> am forced to increase the primary air supply at this time to maintain the
> slight rolling boil I strive for in an efficiency test.
>
> > A bluish flame
> >then hovered above the remaining fuel below the cone.
>
> (RWL): I presume this is combustion of charcoal?
(AE): Yes
>
> >I removed the
> >cone/ chimney, covered the top of the pail with rock wool, and
> >sprayed water on the outside of the pail for 5 minutes.
>
> (RWL): I use the term "rock wool" to mean a loose permeable material
> and "sheet rock" for a hard impermeable material. Was yours loose and
> permeable? (and if so why?) I typically invert a cook pan or other large
> can over the chimney. I have only rarely used water.
> The difficult part for me is closing the secondary air holes -
> which is why I like your approach so much - of bringing the secondary air
> down on the outside of the inverted cone (which also does a nice job of
> preheating the secondary air!). For many tests I find it easiest to shake
> out the charcoal into another closeable chamber - but this is not
> acceptable for a final model.
(AE): Rock wool is similar to fibreglass pink insulation. I am told
it has a higher tolerance to heat. I don't consider it very
permeable. It does an adequate, if not perfect, job of sealing smoke
in low pressure situations. I weighted it with a metal shelf to
improve the seal.
>
> >When I
> >returned in an hour the the remaining charcoal was cool and weighed
> >about 1lbs. The pieces in the centre were essentially the size and
> >shape of the original wood. Toward the out side they had obviously
> >been partly consumed, such that the remaining charcoal took on the
> >shape of the cone.
>
> (RWL): I think about 95 % of my tests have been within 1% of the (1/4=)
> 25% conversion efficiency you found. Can I assume that you did not see any
> wood pieces that were not converted fully to charcoal?
(AE): Correct.
>(RWL): I recently ran a
> test with about half oak and half redwood and found only partial conversion
> of the oak. This multiple fuel testing needs more work - this was only a
> first crude test for another reason (of setting the system into the
> ground),
>
> For simplicity in cooking for the user, I think you may have to
> keep the chimney fixed in space. If you did not have primary air holes,
> and do in the future, the charcoal consumption should be less.

>
> >
> >Yes Ron ,I could cook with this . There are many improvements
> >or options that should be explored. I look forward to trying them.
> >
> (RWL): I'll bet we will look back in the future and ask how come we missed
> hundreds of great innovations like those you found.
>
> >PS Ron or Tom could you explain or discuss the differences between
> >this trial and your own two can fires.
>
> (RWL): I've tried above. I look forward to your next several tests -
> which I believe should include:
> 1. Simulate cooking with a boiling water test (the pot will
> introduce enough air resistance to foul up stove optimization if you don't
> do it). Let us know how much water you can evaporate from the cook pot
> with a given amount of wood
> 2. Different chimney diameters and heights. Getting it as low as
> possible will help reduce radial radiative losses.
> 3. Different primary air supply arrangements. The stove
> literature emphasizes the advantages of a large turndown ratio.
> 4. Different means of improving the convective heat transfer to
> the heat pot (with a surrounding cylindrical ring - maybe a cm away from
> the pot.)
>
> You have moved the charcoal-making stove development process along
> a great deal. Congratulations. I hope others will be encouraged to join
> in, based on your endorsement. Ron

(AE): Endorsement???
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
(AE)=
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Thu Jun 12 00:26:54 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: English on Charcoal-making stove
Message-ID: <v01540b06afc50d51e9c8@[204.133.251.13]>

Some notes following Alex' message of June 11:

>(AE):There is no grate, the wood is sitting on the bottom of the
>pail. I presume you are using the space below the grate to "
>manifold" the your primary (underfire) air for even distribution. I
>sealed up the holes I made previously, this time with rock wool
>insulation. I guess I had better weld over the holes so we don't have
>to debate the permeability of my various plugs.

(RWL): No - I'd rather see you try using the three bottom holes. For
cooking, I think it is very valuable to have as much control as possible
over the power output. If you could control something else, I wouldn't care
about the 3 bottom holes.
I am surprised that you can get such good charcoal production
without primary air holes - I will try to do something similar soon. There
is a big advantage to not having primary airholes (in snuffing the charcoal
at the end of the pyrolysis preiod). If another way can be found to have
power control, them I am delighted to do without primary air holes.
The grate probably isn't terribly important.

<snip>

>(AE): If you accept that my plugged holes were really plugged, as I
>do. Then the only air to the wood was from over the edge of the pail
>and then down around the outside of the cone. There is leakage
>between the cone and the 5" chimney. I thought this might be a useful
>source of secondary air however with the current arrangement the
>mixing is minimal. I believe this can be improved with a second cone
>placed over the first, with a space between, whose large and small
>opening diameters are smaller than the cone below. This would place
>fresh preheated air directly in the path of the"rich" flame exiting
>the lower cone. However I do not yet see the easy way of controlling
>that second flow rate independent of the primary over fire air.
>
(RWL): I also don't see a way in your (or our two-can geometry either) to
vary them independently. Two ways in your sealed-bottom design to get some
variability however might be to 1) change the chimney height (by slipping
one cylinder inside another) or 2) using a damper valve in the chimney,

> The weight change averaged about 1oz/min. The scale has a large error
> factor. Almost as large as the record keeper.

(RWL): In previous discussions on this list, we have noted that completely
combusting 1 kg of wood (about 18 Megajoules) in one hour (3600 seconds) is
a 5 kW stove. With 25% charcoal by weight (about 30 MJ per kg), or about
40% by energy content, the 1 kg starting value drops to about 3 kw. Your 4
pounds (1.8 kg) of wood starting value gives about 5.4 kW level

>> >Yes Ron ,I could cook with this . There are many improvements
>> >or options that should be explored. I look forward to trying them.

(snip)

>> You have moved the charcoal-making stove development process along
>> a great deal. Congratulations. I hope others will be encouraged to join
>> in, based on your endorsement. Ron
>
>(AE): Endorsement???

(RWL): Oops - wishful thinking. Sorry. What are your current thoughts on
a charcoal-making design as being appropriate for for further development
as a cookstove?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Thu Jun 12 00:26:53 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: Karstad on primary air inlet control
Message-ID: <v01540b07afc51b0f244d@[204.133.251.13]>

Elsen said:

>With reference to the two-can primary air inlet control my immediate
>response (seeing as life in Kenya is pretty close to ground level) would be
>to partially or fully block the apertures with earth or sand as needed to
>control airflow.
>
>Sand is also an effective fire extinguisher both for safety and to ensure
>the charcoal produced by the stove is out after cooking. Reuseable too!
>
>I've caught toe bug and am building a larger version of the stove now- with
>a couple modifications. Will keep the group informed.

(RWL): Glad to hear it. You or someone might wish to try a design
suggested by (too-silent) list member Tom Duke about a year ago. I can't
remember whether he tried it (Tom?), but the basic idea was to dig two
parallel holes in the ground with two horizontal holes between them at the
height of the primary (bottom) and secondary (mid-height) air supplies.
Wooden plugs in the smaller hole would control the pyrolysis/combustion in
the larger chamber. With Alex' approach this could collapse to a single
hole in the ground. What I am trying these days has some of Tom Duke's
idea with a metal "liner" - and Elsen's use of dirt to smother the
secondary air holes when needed.

>
>On the sawdust charcoal briquetting scene; it's taking for ever to
>carbonise 500 kg of sawdust using the partially vented 'big pile'
>technique. Wouldn't it be nice if we could come up with a two-can type
>stove utilising sawdust?

(RWL): We have mentioned on this list many months ago a design by a
Professor Grover in India. I saw a modification in Zimbabwe that was
supposed to be an improvement. This is a large squarish "donut" shape,
with a removable and sealable (with sand) top. A fire is set in the center
of the donut, heating the material loaded into the donut (which presumably
could be sawdust). Gases are driven off, able to exit only at the lower
inside of the donut, which then are ignited by the fire there and
eventually take over from the previously lit fire. Cooking takes place
using the pyrolysis gases. Charcoal is left over at the end. The Zimbabwe
design could be "relit" many times. I believe it was patented. There may
have been "vanes" to better move the inner wall temperature rise into the
"sawdust". Perhaps our list members from India or Zimbabwe (Lasten) can
give more on these designs.

>
>Any information availble on capturing the vented gasses from the
>carbonising sawdust? I could certainly use additional fuel for my fishmeal
>plant boiler. It's burning 50% by-product fishoil and 50% kerosene at the
>moment.

(RWL): I guess you can put boiler tubes above or into the interior of the
"donut". Mike Antal's design is probably amenable to using sawdust also.

How big (kW or kg per hour) is your boiler?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From elk at arcc.or.ke Thu Jun 12 06:10:54 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:16 2004
Subject: carbonising
Message-ID: <v01510102afc5a5da0ed8@[199.2.222.97]>

RWL asked;

>How big (kW or kg per hour) is your boiler?

400 kg/hr water consumption. It's an old Perkins, circa 1956 like me.

One very basic question (this is a problem with newcomers to a discussion
group I can see), can the vented gasses from the carbonising process during
charcoal production be piped and burnt like natural gas/propane? If so,
what effect does the initial moisture content of the wood have?

Your patience is appreciated, stovers!

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From english at adan.kingston.net Thu Jun 12 07:34:51 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: English on Charcoal-making stove
In-Reply-To: <v01540b06afc50d51e9c8@[204.133.251.13]>
Message-ID: <199706121134.HAA22135@adan.kingston.net>

(RWL):- Thanks for the info on the Bacharach scale. I will try to
find a kit
(AE): The kit I am using is listed in the Grainger catalogue for
US$480 and includes CO2 tester, smoke tester, thermometer and
draft gauge. I am unsure of its accuracy for use on biomass
combustion. I think it has value at least for relative
comparisons. The colour of the flame has been predicative of excess
air in most cases. Deep orange being low excess air, bright yellow
being high in excess air. I don't completely understand the "Blue"
flame and its relationships with excess air. I understand that a blue
flame indicates a lack of glowing (burning) carbon which is
orange/yellow and normally dominates the" blue ". Comments ?
(RWL):
>What are your current thoughts on
> a charcoal-making design as being appropriate for for further development
> as a cookstove?
(AE): I intend to continue. Charcoal- making or not, it is quite
remarkable how consistent the output of this primitive device appears
to have been. I have done only three fires in a pail. Lets assume that
were just getting started.

Alex

> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From E.Moerman at stud.tue.nl Thu Jun 12 08:04:08 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:16 2004
Subject: two-can stove: primary air inlet control
Message-ID: <7460.s335192@popserver.tue.nl>

E. L. Karstad writes:

> On the sawdust charcoal briquetting scene; it's taking for ever to
> carbonise 500 kg of sawdust using the partially vented 'big pile'
> technique. Wouldn't it be nice if we could come up with a two-can type
> stove utilising sawdust?

---------
Etienne:
Why do you carbonise it, why not briquette it without carbonizing?

etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From phait at transport.com Thu Jun 12 09:13:35 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:16 2004
Subject: 3 Paul Hait comments last week
Message-ID: <199706121307.GAA28306@butch.transport.com>

>Paul Hait said on 31 May, mainly replying to Art and Alex:
>
>
><Snip>
>
>> What we need to add to
>>our cell design is a bellows or a fan. However, right now it is only three
>>parts and costs less the $5.00.
>
>(RWL): Paul: This is the first time I have heard this cost or price.
>Could you clarify which? This is not the Pyromid, but a design in process?
>
>
>(PH):
>>Organized arrangement of fuel as compared to
>>random arrangement is one of the keys to efficient fuel burning. Also we
>>take advantage of both the heat up and down in our cell. Air control to the
>>fuel source is also important and the control of the releasing energy from
>>the fuel source is the final step.
>
>(RWL): I understand your use of briquette spacing - and of the two way
>energy flow and the air control, but not the "final step". Are these last
>two ideas separate or one idea?
>
>
>
>B. Next part on P Hait comments in message of 31 May in reply mostly to
>Rogerio and myself:
>
>>>
>>>Dear Ronal and Rogerio,
>>Congratulations! Count me in on planning if you want. The list is on the move!
>>
>(RWL): Paul is referring to a stove conference (and possible competition)
>in Nicaragua.
>
> Rogerio - is this still a possibility? Who might defray costs for those
>who might need help?
>
>> snip>
>
>(PH):
>>The internet conferance is a good idea to start with. Also, I think it would
>>be great to go to see Rogerio. However, Central Oregon represents what the
>>world wishes it had in fuel. We are the end goal and not the end. It never
>>hurts to see what your shooting at. Just a thought.
>>
>(RWL): Paul - I'm glad you are not giving up. Oregon has a great deal to
>offer as well. Maybe two conferences?
>
>
>C. Last part on P Hait comments in message of 31 May in reply to Tom Reed:
>Paul said:
>
> <snip>
>
>>Out of the knowledge we got with the Pyromid I sent you, we now have the
>>Campmaster, The Super Grill, and the HTA World stove.
>
>(RWL): It is this last stove that I believe is the one that Paul was
>referring to above - and earlier in this 3rd note was saying might be a
>dual-fuel (wood/charcoal) stove. We need to hear more about Paul's
>on-going tests.
>
><Snip>
>
>
>> We have the best cause
>>in the World with the least amount of awareness. Wouldn't it be great to
>>have Ross Perot ,Warren Buffit,Donald Trump, Bill Gates,and Bill Clinton get
>>fired up to put a little money into this problem?They should. And we should
>>bring it to their attention.
>
>(RWL): Paul is our most enthusiastic spokesperson in making this case. I
>think we generally agree on the seriousness of the problem. And although
>we can't have a single solution, I think we are making progress in getting
>a better set of options. Thanks Paul.
>
>
>(RWL): Your ideas in these three notes are a great continuing efort.
>Sorry for the long delay in comments. I had a busy week last week. Ron
>
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>Dear Ronal,
Thanks for the comments. It is clearly obvious that we ultimately need to
get to gether. Where, is a good question? Yesterday I met Art in Portland at
Landa Corp.
Great guy and great company. He had a chance to see one of my HTA proto
types.He seemed to be impressed. Art is a very sharp engineer and has a very
centered set of opinions as to the issues we are all facing.His concern was
how I could burn all fuels in the stove. Also I pointed out that we are
looking very seriously at our two for one solution to get the HTA Stoves to
third world countries. The issue of giving free stoves also came up .I am
reluctant to go into detail on what we are doing until we are sure we can
answer the Doubting Thomas deluge. We do make a Universal Fuel and Function
Stove and the HTA Cell can burn various fuels. Donkey Dung is still untested
since we do not have many Jackasses in Oregon. I would have to go to
Washington DC to test this fuel concept.
I am wondering where you find the time to keep up with the email? Th e
letters are getting more and more interesting and useful.
I am continuing to find that $ is our key problem to finding time to
shearing metal. We have been dealing with New York underwriters too long and
greed is clouding the issue of solving the fuel burning problem. What is
needed is a foundation that is interested in funding the World Stove
programs. Wouldn't it be great if the stovers had their own Rockerfeller
World Stove and Fuel foundation.
It is amazing that a problem of this magnitude gets so little press and
COORDINATED financial attention?
I look forward to hearing from you.

Sincerely,

Paul

From elk at arcc.or.ke Thu Jun 12 10:45:35 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:16 2004
Subject: to carbonise or not.....
Message-ID: <v01510100afc5e3b309b7@[199.2.222.97]>

>Etienne:
>Why do you carbonise it, why not briquette it without carbonizing?

The primary urban domenstic fuel - by a long way- is charcoal here in
Kenya. kerosene follows a poor second.

I am aware of work that has been done on improved stoves ('jikos' in
Swahili), that are designed to use briquetted uncarbonised biomass, but
they have never taken off due to low popularity/poor marketing/acessibility
of fuel plus other social constraints.

Why fight it? Similarly, all concerned U.N. organisations up to just
recently, were trying to fight micronutrient deficiencies in Africa by
advocating a good nourishing mixed diet, full of different couloured
vegetables and meats. Now the U.N. agencies are pushing for fortification
of staple foods, such as sugar, fats and maize meal. They found out that
people only eat what they like and can afford- a very simple and limited
diet indeed for most africans.

I'm not a missionary to change beliefs and habits- if they want charcoal.....

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From zourarakis at nosapp.nr.state.ky.us Thu Jun 12 11:12:44 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:16 2004
Subject: to carbonise or not.....
Message-ID: <97061211034602@nosapp.nr.state.ky.us>

To Elsen K.:

Regarding your comment on micronutrient deficiencies. Are there any source(s) I
can consult on nutrient management in Kenya or other of the countries UN found
problems in? Your observation is extremely interesting. Some people have been
arguing that soils exert extreme influence on "closed" human settlements that
depend on locally grown food (i.e. no external inputs; just cycling).

Couple questions: do they return the ashes to the soils? Do they use any lime or
ground rocks/minerals to amend soils? What proportion of Kenya's agriculture
could be construed as "subsistence" (not sure of definition) agriculture?

Best regards,

Demetrio P. Zourarakis

From english at adan.kingston.net Thu Jun 12 12:24:25 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: Swosthee drawings on Web
Message-ID: <199706121624.MAA30831@adan.kingston.net>

Dear stovers
Thanks to Peter Verhaart there are now two sectional drawings of the
Swosthee Stove on the Web at
http://www1.kingston.net/~english/Stoves

If a good description of it operation and/or emissions exists in the
Stoves archives, let me know and I'll set up a link to it.

Alex

From elk at arcc.or.ke Thu Jun 12 12:38:18 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:16 2004
Subject: to carbonise or not.....
Message-ID: <m0wcCsb-0006auC@arcc.or.ke>

To Demetrio Z.;

Ashes are valued for soil amelioration here, as is all types of manure
except human. The closed system is very prevalent with the exception of the
three staples I had mentioned: sugar, hard fats (commercially produced) and
seasonally, maize meal. Small 'posho mills', hammermills used in grinding
maize to meal, are common in all agricultural trading centres. This would be
considered closed as well.

I'd estimate that at least 70% of the aerable land in Kenya is devoted to
subsistance farming- but don't quote me.

The demographics of Vitamin A deficiency has been pretty well investigated
south of the Sahara. One contact for information would be 'Sight For Life',
a NGO for which I don't have the address for offhand, but R. Pankhurst in
Johannesburg at the following e-mail address would be able to provide you
with some pretty comprehensive information: RONNIE.PANKHURST@Roche.COM

All the Best;

elk

At 11:03 AM 12-06-97 -0400, you wrote:
>To Elsen K.:
>
>Regarding your comment on micronutrient deficiencies. Are there any source(s) I
>can consult on nutrient management in Kenya or other of the countries UN found
>problems in? Your observation is extremely interesting. Some people have been
>arguing that soils exert extreme influence on "closed" human settlements that
>depend on locally grown food (i.e. no external inputs; just cycling).
>
>Couple questions: do they return the ashes to the soils? Do they use any
lime or
>ground rocks/minerals to amend soils? What proportion of Kenya's agriculture
>could be construed as "subsistence" (not sure of definition) agriculture?
>
>Best regards,
>
>Demetrio P. Zourarakis
>
>

From zourarakis at nosapp.nr.state.ky.us Thu Jun 12 12:41:42 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:16 2004
Subject: to carbonise or not.....
Message-ID: <97061212411842@nosapp.nr.state.ky.us>

Elsen: thank you for such prompt response.

Sincerely,

Demetrio.

From english at adan.kingston.net Thu Jun 12 16:32:49 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: (Fwd) Re: Very attractive and informative pages
Message-ID: <199706122032.QAA06735@adan.kingston.net>

> I was looking for http://www1.kingston.net/~english/Stoves,
> but couldn't find that part.
> Ron kent shell@wolfenet.com

My apologies everyone. The last bit was missing. Here
http://www1.kingston.net/~english/Stoves.html
Try again!
Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From phoenix at transport.com Thu Jun 12 17:03:32 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:16 2004
Subject: (Fwd) Re: Very attractive and informative pages
In-Reply-To: <199706122032.QAA06735@adan.kingston.net>
Message-ID: <33A06381.22CA@transport.com>

*.English wrote:
>
> > I was looking for http://www1.kingston.net/~english/Stoves,
> > but couldn't find that part.
> > Ron kent shell@wolfenet.com
>
> My apologies everyone. The last bit was missing. Here
> http://www1.kingston.net/~english/Stoves.html
> Try again!
> Alex
> Alex English
> RR 2 Odessa Ontario
> Canada K0H 2H0
> 613-386-1927
Thank you for the excellent photos and drawings of your experiment. How
did you and others scan in the photos and drawings (What dots per inch)
to have such clear file photos in such useably small files?
I am new to the world of the scanner and have some photos I'd like to
share if the files were not so large.
Thanks!
Art Krenzel

From english at adan.kingston.net Thu Jun 12 22:02:11 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: Nice knowing ya!
Message-ID: <199706130202.WAA18532@adan.kingston.net>

Dear Stovers
Well I just don't have time to tell ya about tonights burn. Gotta run
to the patent office.

See ya Alex
PS Just forget everything you've read lately. Thanks.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Thu Jun 12 22:02:09 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: (Fwd) Re: Very attractive and informative pages
In-Reply-To: <33A06381.22CA@transport.com>
Message-ID: <199706130202.WAA18537@adan.kingston.net>

> Thank you for the excellent photos and drawings of your experiment. How
> did you and others scan in the photos and drawings (What dots per inch)
> to have such clear file photos in such useably small files?
> I am new to the world of the scanner and have some photos I'd like to
> share if the files were not so large.
> Thanks!
> Art Krenzel

Dear Art and others sharers
Send them even if they are large, say up to 1MB. I can muddle around,
"resize" and try to save it in *.jpg format, which is has the
smallest file size and adequate quality for viewing with web
browsers. The Swosthee drawing came to me at about 300KB in *.bmp
file form. I resized it with Paint Shop Pro (available as "
shareware" downloadable off the web) loaded it into Paint and did a
screen capture with Paint Shop Pro, resulting in two jpg file
totalling 66KB.
For display on the web, there isn't any need to scan at greater than
around 70 dpi. Unless you plan to blow the picture up.

Hope this helps. The mouse is your best teacher.

Happy scanning Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Thu Jun 12 23:00:54 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: Two Cone Stove
Message-ID: <199706130300.XAA20594@adan.kingston.net>

Dear Stovers
The application was rejected! So here is tonights results....

I built a second slightly larger cone such that the clearance
between it and the pail was reduced to about 1/4 of an inch. The top
open end is about 3.5", slightly larger than the old one. The old
cone now sits on top of the new one touching in a few random places,
with room for air movement. For the first half of the burn we ( I had
an assistant) fussed around changing the air supply and lifting the
second cone and chimney assembly. We also detached the chimney and
tried burning with the cones only. This makes it difficult to take
samples. All this has given me a real feeling for the very limited
draft that this type of stove operates with. The first half was much
like the previous burn, with a smoky plume attached to the end of
the flame. Looking down into the cones we could see the individual
flames which converge at the cone's outlet were pretty much following
their individual paths up into the chimney. Not enough mixing.

As the pieces of this stove are all separate and loose we were able
to remove the top cone and crimp the top (small end) opening to
reduce its size and hopefully enhance the mixing. We ended up with a
cross or plus sign shaped orifice. This appeared to make a big
difference. The exiting gasses looked clean and I went for the
measuring tools. The second half of the burn, which I forgot to time,
had top-of-the-flame temperatures over 1400F and as high as 1520F.
(approximately 1000K-1100K) CO2 ran from 12% to 17%. What really
surprised me was the four consecutive 0 smoke tests. We'll call them
'1' because I don't believe it could have been zero.

Looking into the top of the chimney, it was clear that the new shape
of the top cone was having an effect. There was much more turbulence.
It was not clear how much effect the flow of air from between the
cones was having.
So now I ( or others, hint hint) need to duplicate this for an entire
burn. If so, then I'll introduce a pot of water, and spoil it all.
A touchy thing this draft.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Fri Jun 13 02:25:46 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: 3 Paul Hait comments last week
Message-ID: <v01540b06afc696adee88@[204.133.251.9]>

Paul Hait said:

>I look forward to hearing from you.

(RWL): Paul - Nice to hear from you again. More later. It's too late.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 02:26:12 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: carbonising (by Karstad)
Message-ID: <v01540b00afc67b497ef9@[204.133.251.9]>

>RWL asked;
>
>>How big (kW or kg per hour) is your boiler?

(EK):
>400 kg/hr water consumption. It's an old Perkins, circa 1956 like me.
>
(RWL): Could you give this also in fuel consumption terms. Maybe also in
feet or meters.

(EK):
>One very basic question (this is a problem with newcomers to a discussion
>group I can see), can the vented gasses from the carbonising process during
>charcoal production be piped and burnt like natural gas/propane?

(RWL): 1) The "vented" gases can certainly be burned ("flared"). But
the flaring seems to almost never be done in remote charcoal making - and
those unflared gases are serious global warming contributors.
2) It is not trivial to do the flaring of pyrolysis gases from
large metal kilns. There are stoves list members trying to develop such
techniques right now and perhaps they can report on their
successes/problems.
3) The piping is possibly also a problem. As Alex English
mentioned today, there is a very small draft here - created by the
combustion of the gases inside a closed chimney. Here you are moving out
of the likely "stoves" area of expertise - but perhaps gasifier experts can
add to this.
4) With the close coupling of flaring in a charcoal-making stove
immediately above the charcoal, these problems probably disappear. Do you
think that you have to pipe gases to the boiler, or can the entire "stove"
be more closely coupled to the boiler?

(EK):
> If so, what effect does the initial moisture content of the wood have?

(RWL): My experience is that the lower the moisture content the better,
but there has not been agreement on this topic in the past.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 02:26:22 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: Alex on Two Cone Stove
Message-ID: <v01540b05afc68fc04dfc@[204.133.251.9]>

Alex said:

<snip on adding a second cone)

>As the pieces of this stove are all separate and loose we were able
>to remove the top cone and crimp the top (small end) opening to
>reduce its size and hopefully enhance the mixing. We ended up with a
>cross or plus sign shaped orifice. This appeared to make a big
>difference. The exiting gasses looked clean and I went for the
>measuring tools. The second half of the burn, which I forgot to time,
>had top-of-the-flame temperatures over 1400F and as high as 1520F.
>(approximately 1000K-1100K) CO2 ran from 12% to 17%. What really
>surprised me was the four consecutive 0 smoke tests. We'll call them
>'1' because I don't believe it could have been zero.

(RWL): I haven't understood exactly where the flame is and ask Alex to
describe this a bit more. What are the dimensions of the "cross or plus"?
(total square inches of aperture?) I presume some flame inside the inner
cone? But some outside also? How much of each?
Hey - 4 zeros sound like zero to me. Is there a relationship
between what you can smell and whether something is 0 or 1?
We haven't talked ever on this list about soot on cook pans. Does
a 0 or 1 mean anything relative to sooting of a pan?

Alex said :
>Looking into the top of the chimney, it was clear that the new shape
>of the top cone was having an effect. There was much more turbulence.

(RWL): I think this is really a great advance; clearly turbulence will
lead to mixing and mixing will give a better flame and shorter chimneys.

(AE): >It was not clear how much effect the flow of air from between the
>cones was having.

(RWL): Does this mean that perhaps the new added outer cone was not
contributing to the new turbulence and cleaness?

(AE): >So now I ( or others, hint hint) need to duplicate this for an entire
>burn. If so, then I'll introduce a pot of water, and spoil it all.

(RWL): Good luck. I wish I could see what you (and others) are doing.

(AE): >A touchy thing this draft.

(RWL): I think most of the whole charcoal-making stove design
understanding will eventually be based on understanding draft and chimneys.
I have looked (admittedly cursorily) at many mechanical engineering and
flow dynamics college texts and never find either subject mentionned. The
best place I have found for understanding (I don't yet these topics is the
ASHRAE handbook (I think this is the "title" - they have many different
kinds of documents).
Modern ME handbooks are silent on these areas, but those from
50-100 years ago are pretty good.
I don't expect to find a discussion of conical chimneys anywhere.
Anyone know how to model or understand such?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 02:26:18 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: Moerman and Karstad on carbonization.
Message-ID: <v01540b04afc68857902b@[204.133.251.9]>

>>Etienne:
>>Why do you carbonise it, why not briquette it without carbonizing?
>
(RWL): If Elsen can (cheaply!) do the briquetting of sawdust, this might
be an excellent fuel for a charcoal-making stove (say 1 inch diameter by 7
inch length). I wish I had some pieces to test. However, I believe there
may be an important feature to natural wood - that gases can flow much more
easily in a longitudinal direction than radially. This would not be true
for a sawdust briquette. Also the sawdust briquette may crumble after
pyrolysis whereas natural wood does not. Still, I hope Elsen will try the
sawdust briquettes and then attempt to pyrolyze some. I think that Etienne
has proposed a very good experiment.

Elsen said:
>The primary urban domenstic fuel - by a long way- is charcoal here in
>Kenya. kerosene follows a poor second.
>
>I am aware of work that has been done on improved stoves ('jikos' in
>Swahili), that are designed to use briquetted uncarbonised biomass, but
>they have never taken off due to low popularity/poor marketing/acessibility
>of fuel plus other social constraints.
>
>Why fight it?

<snip section on foods>
>
>I'm not a missionary to change beliefs and habits- if they want charcoal.....
>

(RWL): Perhaps I may seem to be in a difficult position - asking
some to switch to a charcoal-making stove and others to continue to use
charcoal. But I hope that both can be consistent. The charcoal-making
stove is being claimed to be superior (eventually - after further
development) to both the standard wood burning stoves and to the
charcoal-burning jikos - maybe in all respects: efficiency, pollutant
release, controllability, etc. But it can't do some jobs that charcoal can
do better - such as all the users that Faisal and Paul Hait have identified
- barbecuing, incense burning, etc.
To beat a dead horse - my hope is that charcoal-making stoves will
drive the traditional form of charcoal making out of business and will
reduce, but not eliminate charcoal use - for those cases where charcoal
makes a lot of sense.

I am agreeing with both Etienne and Esten.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 02:26:13 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:16 2004
Subject: English of 6/12 on Charcoal-making stove
Message-ID: <v01540b02afc6834d613a@[204.133.251.9]>

Alex - thanks for the extra information. A few questions/comments below.

>(AE): The kit I am using is listed in the Grainger catalogue for
>US$480 and includes CO2 tester, smoke tester, thermometer and
>draft gauge. I am unsure of its accuracy for use on biomass
>combustion.

(RWL): I wonder if anyone else knows of its (or other monitor) accuracies?

(AE): > I think it has value at least for relative
>comparisons. The colour of the flame has been predicative of excess
>air in most cases. Deep orange being low excess air, bright yellow
>being high in excess air.

(RWL): This is helpful. Do you have a sense of where (%CO2, I guess) it
is best to operate?

(AE): I don't completely understand the "Blue"
>flame and its relationships with excess air. I understand that a blue
>flame indicates a lack of glowing (burning) carbon which is
>orange/yellow and normally dominates the" blue ". Comments ?

(RWL): I gather that blueness normally comes with premixing. I haven't
seen a way to achieve this is a charcoal-making stove.

> (RWL):
>>What are your current thoughts on
>> a charcoal-making design as being appropriate for for further development
>> as a cookstove?
>(AE): I intend to continue. Charcoal- making or not, it is quite
>remarkable how consistent the output of this primitive device appears
>to have been. I have done only three fires in a pail. Lets assume that
>were just getting started.

(RWL): I think that rural cooks should find a major value in consistency -
if the level is controllable. Certainly that is a major feature of all
electric and gas stoves and is the antithesis of cooking on three stones -
where the power level quickly changes from too much to too little - even
though the average may be about correct.

Re: "remarkable how consistent". I have been trying to figure out
why this happens in a charcoal-making stove for some time, and am still
baffled. Perhaps Etienne can repeat an explanation that he proposed a year
or so ago - related as I recall to resistance variations as a function of
temperature.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From TANSYP at IGHMAIL.COM Fri Jun 13 08:01:17 1997
From: TANSYP at IGHMAIL.COM (TANSY PRODUCTION)
Date: Tue Aug 31 21:35:16 2004
Subject: Enquiry
Message-ID: <B0000148488@mailsrv.ighMail.com>

Hello'

We are a company based in Ghana West Africa and we are interested in
briquette making machine
could you give us any information on this?

Thanks

Catherine Asante-Appiah
Managing Director

From english at adan.kingston.net Fri Jun 13 08:08:48 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:16 2004
Subject: Alex on Two Cone Stove
In-Reply-To: <v01540b05afc68fc04dfc@[204.133.251.9]>
Message-ID: <199706131208.IAA30317@adan.kingston.net>

Dear Ron+

> (RWL): I haven't understood exactly where the flame is and ask Alex to
> describe this a bit more. What are the dimensions of the "cross or plus"?
> (total square inches of aperture?) I presume some flame inside the inner
> cone? But some outside also? How much of each?
(AE):By crimping the circular opening at four points we ended up with
a four pointed star, however it is now a three dimensional opening
having four "mountain peaks". The peak to opposite peak dimension is
2" and the valley to opposite valley is about 1.25". The valleys are
vertically about .5" below the peaks. It was done with haste and is
far from symmetrical. I would guess that the crosssectional area is
about 3-4sq".
Because the primary air is being drawn between the outer edge of the
cone and the fuel, there is a zone of combustion near the edge which
consumes the char portion. Flames begin at the outer edge from a few,
perhaps 4-6 points, and stream linearly towards the top exit point
of the cones. These may act as a sort of constant " pilot light"
helping to insure ignition of the gasses. Here I
assume it mixes with pyrolisis products from the rest of the fuel and
perhaps some preheated secondary air to create the bulk of the flame
extending up through the entire 15" chimney. The chimney is a 6"( I
had stated 5" before) stove pipe lined with cerafelt to yield about a
3.5" diameter.
> Hey - 4 zeros sound like zero to me. Is there a
relationship
> between what you can smell and whether something is 0 or 1?
(AE): I don't know. If you ask for "0 or 8" the answer is yes.
> We haven't talked ever on this list about soot on cook pans. Does
> a 0 or 1 mean anything relative to sooting of a pan?
(AE): I take the pan to be the equivalent of a boiler. A trace of
smoke, from 0 up to 1, is actually the target when setting up a
boiler or furnace. Stand by , the pot of water is "on deck".
>
> Alex said :
> >Looking into the top of the chimney, it was clear that the new shape
> >of the top cone was having an effect. There was much more turbulence.
>
> (RWL): I think this is really a great advance; clearly turbulence will
> lead to mixing and mixing will give a better flame and shorter chimneys.
>
> (AE): >It was not clear how much effect the flow of air from between the
> >cones was having.
>
> (RWL): Does this mean that perhaps the new added outer cone was not
> contributing to the new turbulence and cleaness?
(AE): I can see this morning that crimping the top ( outer ) cone
increased the space between the two cones and the probability that
there was a significant effect.
>
> (AE): >So now I ( or others, hint hint) need to duplicate this for an entire
> >burn. If so, then I'll introduce a pot of water, and spoil it all.
>
> (RWL): Good luck. I wish I could see what you (and others) are doing.
(AE): Well, my assistant/supervisor was filming with a new video
camera so you may yet get a chance. Its cheaper than jet fuel. If we
by a "Snapper" for the computer we can " freeze frame" the "action"
and load it onto the web. However you being an "other" means you can
see by doing it yourself. The cone was made by flattening out a piece
of stove pipe, cutting, forming and pop-riveting.
>
> (AE): >A touchy thing this draft.
>
> (RWL): I think most of the whole charcoal-making stove design
> understanding will eventually be based on understanding draft and chimneys.
> I have looked (admittedly cursorily) at many mechanical engineering and
> flow dynamics college texts and never find either subject mentioned. The
> best place I have found for understanding (I don't yet these topics is the
> ASHRAE handbook (I think this is the "title" - they have many different
> kinds of documents).
> Modern ME handbooks are silent on these areas, but those from
> 50-100 years ago are pretty good.
> I don't expect to find a discussion of conical chimneys anywhere.
> Anyone know how to model or understand such?
(AE): It seems to me that one simple way (although materially
expensive) of controlling the output of this burner is to have several
topcone/chimney assemblies which are designed to optomize the draft
turbulence relationship of various desired output levels, and switch
them as required.

Alex
>
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From REEDTB at compuserve.com Fri Jun 13 11:16:21 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:16 2004
Subject: Something Practical, Part 1b cont.
Message-ID: <199706131115_MC2-1870-D2DA@compuserve.com>

Dear Alex, Ron and all stovers:

Great to see experimental resuslts here. I'll look for the drawings on the
WWW.

A caution and encouragement:

The temperature of pre-mixed flames is best known by calculation of the
"adiabatic flame temperature ", the temperature that satisfies the
heat-release/heat capacity equations. The adiabatic flame temperature of
most stoichiometric gas flames is around 2,000C (2200C for acetylene flames
because acetylene has a POSITIVE heat of formation of 54 kcal/mole -
explodes on compression).

If you put a thermocouple in a Bunsen flame you will get readings of
900-1100 C, half the above. Why? Because heat transfer to the TC
increases only linearly with temp while radiation from the TC increases at
the fourth power of T. It requires very specialized apparati to measure
true flame temperatures - Infra red spectroscopy, sodium line reversal etc.

The bright side of this picture is that the temperature measured by the
thermocoupld is a GOOD indication of the relative heat transfer. So, used
that way and calibrated it gives meaningful results (see my paper on heat
of fast pyrolysis - PRASAD in press, BANFF in press).

Onward,=>=>=> TOM REED

From REEDTB at compuserve.com Fri Jun 13 11:16:47 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:16 2004
Subject: sawdust charcoal briquettes
Message-ID: <199706131115_MC2-1870-D2DF@compuserve.com>

Dear Elston Karstad et al:

Thank you for your description of your charcoal briquetter. I might try to
make one, or at least make a sketch from your description.

A few comments.

Wood and other biomass briquetting involves a compression from a density of
.2-.3 to about 1, and so requires a corresponding piston travel of 3 to
five times the length of the final briquetter. This is partly due to the
loose packing of the starting material (low bulk density), but more to the
fact that all biomass has 60-70% void space due to the cellular nature. To
break this down a pressure of 500 to 1,000 atmospheres needs to be applied
with some heat.

Charcoal made from soft materials is easily crushed and if finely ground
requires NO compression - just adhesion.

Have you ever tried letting your slurry dry in patties or in a muffin tin?
Would it hole together?

The Asian Institute of Technology and John Tatom have pioneered "fireball"
charcoal making in which a slurry of starch and water and charcoal is mixed
in a 55 gal drum. The process automatically makes round balls, typically an
inch in diameter. They can be dropped from five feet without breaking.
Bhatacharya at AIT would know about this. John lives in Smyrna, GA. if you
want to call him.

Hope we can get the manufacture of local briquettes together with a good
"Pyromid" type stove technology that can be distributed.

Onward, TOM
REED

From REEDTB at compuserve.com Fri Jun 13 11:17:06 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:16 2004
Subject: Sawdust Charcoal
Message-ID: <199706131115_MC2-1870-D2E0@compuserve.com>

Dear Karstad et al:

The problem with making charcoal in the inverted downdraft stove (top
burning, charcoal making) is that natural draft provides too little air to
create the volatiles. Put a small blower on it and it would be OK.

Incidentally, charcoal can be made using the exhaust of an IC engine (temp
500-700C) passed through the charge. Could be useful with stationary
engines.

Comments?

Tom Reed

From REEDTB at compuserve.com Fri Jun 13 11:23:23 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:16 2004
Subject: Picture Transfers, Vacation
Message-ID: <199706131115_MC2-1870-D2E1@compuserve.com>

TOM REED - ON VACATION - P-TOWN and NEW HARBOR, ME

Dear Pete and All:

I accessed Pete Verhart's new Website,
http://www1.kingston.net/~english/Stoves.html, and found pictures of his
latest stoves, in color. I downloaded them and looked at them at liesure.
It was a breeze, after trying to decode MIME etc. files that are piled up
in my desktop.

I hope that he will continue to accept Stove pictures at his site for a
while until we can formalize this improvement.

I hope he will also paste a title on each picture so we can know what we
are seeing.

~~~~
I am currently flying over Illinois with my lap-top lover, answering a
jillion messages stored up during the week of getting ready for our 50th
wedding anniversary celebration at Hilltop Farm, New Harbor, Me (near
Damarixcota) with 4 children, 4 spouses and 7 grandchildren.

But I will have my laptop-lover with me and will try not to let 100
missives build up ever again.

Yours truly, TOM REED

From elk at arcc.or.ke Fri Jun 13 13:36:54 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:16 2004
Subject: briquetting sawdust (?)
Message-ID: <m0wcaGU-0006Z2C@arcc.or.ke>

O.K.- I'll try it. I suspect though, that with my manual equipment the
sawdust briquettes may expand upon carbonisation. Only one way to tell.

I'll use mollasses as binder on the first try (any ideas on % inclusion?).
I've some experience using 4 in. diam. straw briquettes as fuel & they
snake all over (in addition to smoking) as they expand back to original
volume while burning. They were made for a while here as refugee camp fuel,
but not well rec'd. I think the equipment is mouldering away somewhere here
in Kenya still - orig. and old FAO project I think.

I'll probably need a longer compression barrel, as the friction may not be
as great with uncarbonised raw material, water absorbtion when mixing in the
binder may be a problem, void space & compression requirements .............
< exit stage left, muttering to himself >

------------------------------------------------------------------------------

Tom Reed Asks;

>Have you ever tried letting your slurry dry in patties or in a muffin tin?
>Would it hold together?

Yes, and no. Cement doesn't seem to work as a binder unless the mass is
compressed. There seems little cement wasted via liquid exudate on
compression- which is a good sign.

I've tried the 'fireballs' too- produced in an old cement mixer without the
internal paddles- again the same results as above. I need a final product
that can be transported without disintegrating in sacks on roads that
produce transmitted kinetic energy approxinmately equal to a hardware store
paint shaker.

The pyromid stove does sound intriguing. I'm in Canada (Osoyoos B.C.) at the
end of July. I'll look for one to bring back to Kenya.

elk

From rmiranda at sdnnic.org.ni Fri Jun 13 15:54:45 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:17 2004
Subject: Enquiry(briquetting machines)
Message-ID: <199706131356.NAA15734@ns.sdnnic.org.ni>

At 12:04 PM 6/13/97 -0000, you wrote:
>Hello'
>
>We are a company based in Ghana West Africa and we are interested in
>briquette making machine
>could you give us any information on this?
>
>Thanks
>
>Catherine Asante-Appiah
>Managing Director
>=================================================
>
Dear Catherine: here are three manufactures:

>>>BIOMAX Indústria de Maquinas (briquetting equipment)
>>>Rua Constelacao, 46 - Vila Teresa
>>>93035-000 Sao Leopoldo/RS
>>>Phone: (051) 592-5742
>>>Fax: (051) 592-3559
>>>
>Brasil
>
>>>MORBACH (briquetting equipment)
>>>Rodovia RS-239, 1200
>>>Bairro Roselandia
>>>93352-000 Novo Hamburgo/RS
>>>Phone: (051) 593-5255
>>>Fax: (051) 593-7236
>>>
>>>Brasil
>

>>Joseph P. Marsalka, President
>>Startec, Inc.
>>6479 Reflections Dr.
>>Dublin, OH 43017
>>Tel: 614/792-9988
>>Fax: 614/792-9116
>>
USA

Good luck

Rogerio Miranda
--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From hmrajabu at ucdavis.edu Fri Jun 13 16:20:09 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:17 2004
Subject: briquetting sawdust (?)
In-Reply-To: <m0wcaGU-0006Z2C@arcc.or.ke>
Message-ID: <Pine.GSO.3.95.970613113229.19180A-100000@chip.ucdavis.edu>

Hi Elsen and stovers:

There is a briquetting pilot factory in Moshi, Kilimanjaro (80 miles south
of Nairobi) which started operating in 1987. The plant produces briquettes
mainly from saw dust, of 45cm long, 8-10cm diameter (not sure) and 1.2 kg
weight from a Japanese screw-type machine. The set-up has also
a carbonizing facility for users who prefers charcoal briquettes.

I first visited the plant in 1993 as part of briquette's end-users survey
which I conducted for Tanzania. The survey was conducted mainly to
institutions which uses the KIDC (Kilimanjaro Industrial Development
Center) briquettes like hospitals and schools, and commercial vendors such
as local brewers, bakeries, restaurants, etc,. No survey was done to
household users. Of users surveyed, all uses both fuelwood and KIDC
briquettes for convenience due to unreliable supply of both
briquettes and fuelwood.

Some of the comments which were reported by most users are:

-briquettes are more convenient to use (fire management) and consistent
in performance. (fuelwood quality varies with moisture content/time of the
year)

-briquettes has "stronger fire" during the initial stages.

-apart from the hospitals, others reported necessity of making alterations
in the combustor when switching from fuelwood to briquettes, and vice
versa.

The hospitals were using the briquettes/fuelwood in the hot water boiler,
the schools and other vendors for cooking.

The carbonised briquettes looks pretty good and almost same dimensions (no
expansion) to the original briquettes. KIDC reported that there is very
little local demand for carbonized briquettes. This might be due to the
size of the carbonized briquettes formed which will require the domestic
user to break it into smaller pieces, and hence losses and mess.

When I visited the plant again this year in February there was some
changes on the carbonized briquettes demand. However, the emerged buyers
ordered the carbonized pieces in tonnes and export them out of the
country. The demand on the uncarbonized briquettes has also increased
compared to when I visited in 1993.

As regards to expansion of briquettes during carbonization and
pyrolysis, depends on variuos factors. I am currenty studying combustion
of saw dust and rice straw briquettes and I have the following
observations:

-fractional expansion of briquettes during pyrolysis depends on the
original apparent density and type of raw material

-the expansion is rapid in the initial stages of pyrolysis.

-the expansion increases the rate of pyrolysis.

___________________________________

On Fri, 13 Jun 1997, Elsen L. Karstad wrote:

> O.K.- I'll try it. I suspect though, that with my manual equipment the
> sawdust briquettes may expand upon carbonisation. Only one way to tell.
>
> I'll use mollasses as binder on the first try (any ideas on % inclusion?).
> I've some experience using 4 in. diam. straw briquettes as fuel & they
> snake all over (in addition to smoking) as they expand back to original
> volume while burning. They were made for a while here as refugee camp fuel,
> but not well rec'd. I think the equipment is mouldering away somewhere here
> in Kenya still - orig. and old FAO project I think.
>
> I'll probably need a longer compression barrel, as the friction may not be
> as great with uncarbonised raw material, water absorbtion when mixing in the
> binder may be a problem, void space & compression requirements .............
> < exit stage left, muttering to himself >

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From english at adan.kingston.net Fri Jun 13 22:43:57 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Wise men say, if ....
Message-ID: <199706140243.WAA24217@adan.kingston.net>

Dear Ron and Stovers
....if it sounds to good to be true, it probably is.

My smoke tester was giving a zero reading because it was
sampling fresh air. The rubber tube connecting the sampling tube to
the piston pump, which is obscured by a protective wire coil, had
come apart. The "true" readings are on the opposite end of the
scale (9), inspite of a visually clean burn. I do indeed have a long
way to go.

Tonight's effort included a pot containing two gallon (21.5 lbs) of
water suspended over the chimney. It wasn't a steady test as I
monkeyed with the stove a fare amount. The water temperature rose 100F
over a 1.5 hour burn. The pot, 4" above the chimney, didn't affect
the draft as much as I had expected. The pot was 12" above for the
first half hour. CO2 and Temp. levels were similar to the last half
of the last burn. If this arrangement has merit, and the goal is a
more complete combustion, then there is a gas flow mixing chamber
puzzle to be solved. Comments anyone?

First I would like to here from the more silent
experienced stovers what they see as the intrinsic limitations of
this type of burner. What are the best results for an "upright"
fire? What is the Swosthee story? How different is the Two Can
stove from the Two Cone stove ? I understand the that downdrafters
are a route to more complete combustion. How do they work as cook
stoves? What is their minimum chimney requirement? Perhaps we could
here about the performance data on the stove being developed by
Pyromid.
I am searching for context.
Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From larcon at sni.net Fri Jun 13 23:37:24 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:17 2004
Subject: Tom Reed on draft vs fans
Message-ID: <v01540b06afc7badb0cad@[204.133.251.2]>

Tom said:
>
>The problem with making charcoal in the inverted downdraft stove (top
>burning, charcoal making) is that natural draft provides too little air to
>create the volatiles. Put a small blower on it and it would be OK.
>
(RWL): Just to clarify Tom's response a bit. As indicated by his original
title (Sawdust Charcoal), Tom was referring only to turning the initial
sawdust into charcoal - not to using sawdust in briquetted form. For
instance, note Alex over this last week is getting about a 5 kW output and
25% conversion efficiency without a fan - using instead a 15 inch chimney..

Also (for list newcomers) we had a dialogue about fans for (all
types of) stoves in general on this list a few months ago.

>Incidentally, charcoal can be made using the exhaust of an IC engine (temp
>500-700C) passed through the charge. Could be useful with stationary
>engines.

(Also for list newcomers) Tom is the list coordinator for the crest
"gasification" list.

Tom: has anyone every run the above IC engine (in part) with the
pyrolysis gases so produced from the exhaust? My perception has been that
the gasifier industry sometimes uses charcoal as an input, but not as a
co-product or (in your suggestion) as a by-product. This sounds like a
great use of the exhaust gases - but even better if the 60% of the energy
lost in the charcoal making is also productively used in the same engine.

In a separate message today, Tom said:

>I accessed Pete Verhart's new Website,
>http://www1.kingston.net/~english/Stoves.html, and found pictures of his
>latest stoves, in color.

(RWL): The picture should be credited to Pete, but the website and (from
my non-capable viewpoint) hard digitization work should be credited to Alex
English. (I tried today and kept getting something else - oh well. Alex,
I will try again.)

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 23:37:27 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:17 2004
Subject: Alex on Two Cone Stove
Message-ID: <v01540b05afc7b32a3ddb@[204.133.251.2]>

Alex said:

<snip>

>Because the primary air is being drawn between the outer edge of the
>cone and the fuel, there is a zone of combustion near the edge which
>consumes the char portion. Flames begin at the outer edge from a few,
>perhaps 4-6 points, and stream linearly towards the top exit point
>of the cones. These may act as a sort of constant " pilot light"
>helping to insure ignition of the gasses. Here I
>assume it mixes with pyrolisis products from the rest of the fuel and
>perhaps some preheated secondary air to create the bulk of the flame
>extending up through the entire 15" chimney. The chimney is a 6"( I
>had stated 5" before) stove pipe lined with cerafelt to yield about a
>3.5" diameter.

1). I probably implied or said that I was bothered by this
combustion of some of the outer material (because I was). But if you have
a strong "pilot light" this could be a major advantage. I presume you are
testing indoors - but do you have any sense of the stability of your flame
against wind gusts?
2) Do you get all of your flame in the 15" eight or is there still
some flame above the final exit?
3) Can you describe the cost and properties (and sources) of the
cerafelt? Is this the same as or different from "riser sleeve" (which is
impregnated with a combustible material)? Is this a brittle material?
4) I'd like to keep hearing about the CO2 and temperature levels
as you keep making changes. I'd like to believe that about 10-12% (which
you have been having) is about right.

<snip>

> However you being an "other" means you can
>see by doing it yourself. The cone was made by flattening out a piece
>of stove pipe, cutting, forming and pop-riveting.

(RWL): I take the hint; maybe tomorrow afternoon. For those without a
pop-riveter, I can report good funnel making skills (developed in Ethiopia)
from bending (using a table edge) over the opposite edges of a sheetmetal
semicircle and using a hammer to create a simple seal (using a nail point
as a "punch" to hold the seal). These were always used with the large end
of the funnel up (to get good heat distibution on a "griddle". I'm hoping
that your 6" cylindrical chimney is not critical and might be replaced
sometimes with an inverted cone as well.

<snip)

(AE): It seems to me that one simple way (although materially
>expensive) of controlling the output of this burner is to have several
>topcone/chimney assemblies which are designed to optomize the draft
>turbulence relationship of various desired output levels, and switch
>them as required.

(RWL) - Could be (should be) worth it. Glad there are several alternatives.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 13 23:37:42 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:17 2004
Subject: Hasssan on briquetting sawdust (?)
Message-ID: <v01540b04afc7a6bb522c@[204.133.251.2]>

Hassan said:

>There is a briquetting pilot factory in Moshi, Kilimanjaro (80 miles south
>of Nairobi) which started operating in 1987. The plant produces briquettes
>mainly from saw dust, of 45cm long, 8-10cm diameter (not sure) and 1.2 kg
>weight from a Japanese screw-type machine. The set-up has also
>a carbonizing facility for users who prefers charcoal briquettes.

(RWL): Could you describe this carbonizing facility also. Does it vent
or flare or use the pyrolysis gases? What type of equipment and yield,
etc? Per kg, what is the difference in cost?

<snip>

>This might be due to the
>size of the carbonized briquettes formed which will require the domestic
>user to break it into smaller pieces, and hence losses and mess.
>
(RWL): Can you suggest a range of diameters of a charcoal cylinder that
domestic users would find best? I believe that a household-sized
charcoal-making stove would work best with an input briquette diameter of
about 2 to 4 cm.

>The carbonised briquettes looks pretty good and almost same dimensions (no
>expansion) to the original briquettes. KIDC reported that there is very
>little local demand for carbonized briquettes. This might be due to the
>size of the carbonized briquettes formed which will require the domestic
>user to break it into smaller pieces, and hence losses and mess.

<snip>

>
>As regards to expansion of briquettes during carbonization and
>pyrolysis, depends on variuos factors. I am currenty studying combustion
>of saw dust and rice straw briquettes and I have the following
>observations:
>
>-fractional expansion of briquettes during pyrolysis depends on the
>original apparent density and type of raw material.

(RWL): Could you comment further on this. I think wood always shrinks as
it is pyrolyzed - more in diameter (20%? I think than in length (10%?). Do
you ever see shrinkage for briquettes? Is it the least dense briquette
that expands the most or vice versa?
>
>-the expansion is rapid in the initial stages of pyrolysis.
>
>-the expansion increases the rate of pyrolysis.
>
(RWL): Could you comment on the final strength of these carbonized
briquettes compared to natural charcoal.

How are you investigating this issue of expansion? Is there any
major difference in expansion if combustion of the compressed briquette
occurs directly rather than combustion of the carbonized briquetter?

Hassan - It seems you are deeply into charcoal vs wood issues. As a
long-term member of this list, do you have any further comments on when
each is more or less appropriate? (Including cost issues, responding for
both commercial and residential users) Thanks for a very complete response
on briquetting.

Aside to Elsen - Just to repeat my message from yesterday - the value to me
of the briquetting of sawdust is that you don't lose all the valuable
energy in the usual pyrolysis process. Maybe the breakage problem mostly
goes away if you transfer sawdust briquettes to the customer, who then
produces her own charcoal in a charcoal-making stove. Minimum waste, I
think

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From ahe1 at cableol.co.uk Sat Jun 14 04:13:29 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:17 2004
Subject: Nice knowing ya!
Message-ID: <9706140813.AA00039@mars.cableol.net>

Andrew Heggie
At 22:01 12/06/97 -0500, you wrote:
>Dear Stovers
>Well I just don't have time to tell ya about tonights burn. Gotta run
>to the patent office.
>
>See ya Alex
>PS Just forget everything you've read lately. Thanks.
>Alex English
Luv it

I see you have since regaled us of more valuable thoughts and practice. This
reminds me of the patent agent who wished to develop my stump burning device
( a large tractor steel wheel with all the holes blocked up and a piece of
exhaust pipe running freely through a boss welded to the centre, this being
attached to a domestic vacuum cleaner *exhaust*. The idea being to create a
hole in the stump filled with burning charcoal, the jet of hot air from the
pipe blasting a hole through the stump until soil is reached and then being
deflected to burn the remaining wood from bottom up as the pipe fell to
earth under its own gravity). As a test he had a large dead pine in the rear
garden 20' from the house, I felled and dealt with the tree and late in the
afternoon set the device on the stump, lit the coal and left it humming,
explaining it would take 24 hours to initiate the burn. I returned the next
morning and hearing no signs of activity rang the bell to be greeted by an
irate and red eyed gent. He had been woken at 4am along with neighbours by
the sound of a low flying Concorde engine and a bright orange light. The
device was shooting a long flame and roaring prior to his disconnecting the
electric supply. I went to investigate and a large area 10'diameter of grass
was scorched as was the vacuum tube melted. The stump had actually been
consumed well into the ground with the root buttresses. He felt it was
unsafe to use. This was in 1983 before stump gobblers were prevalent,
subsequent attempts on fresher stumps were not very successful, I think a
combination of resinous and dry stump in dry sand with a warm atmosphere was
the main reason for the runaway.

Which brings me back to stovers, I would like thoughts on the mechanism
which causes the wood at the bottom of the pail to be carbonised rather than
the whole charge simply burn, I use a metal ring kiln to produce charcoal
with low inlets alternating with low chimneys, I take it this combines
updraught and downdraught, gaseous reactions occurring in the dome of the kiln.

I see Thomas Reed says:
>In any case, COOKING CHARCOAL is a buffered reaction and is more uniform
>than one would think from the above continuum. During the production of
>charcoal by heating the reaction is endothermic in the range 20-280C; then
>exothermic from 280-440; then endothermic at higher temperatures. So, it
>is easy to get to 440, difficult to exceed it. In the production of Sea
>Sweep, we have to quench the product to keep it from self heating to 440 C.

I assumed given a small charge and uniform heating the temperature would
rise to 100c and hold whilst all moisture was driven off. Followed by a rise
to 232c at which point the wood starts decomposing. Why does the reaction
stay endothermic to 280c?
In my experience at this stage the temperature rises very rapidly and would
destroy the kiln if not closed down, I have seen a 4 prototype retorts and
one hybrid kiln distort when this has happened.

Am I right in thinking with the pail the wood at the top burns to the
exothermic point 280 c and as the gases are liberated and flared to cook
with the exothermic reaction is continued as a chain reaction down the log,
liberated gases carrying excess sensible heat away, free oxygen being
depleted by the flame above and the physical barrier of the outside layers
of cooler carbon? If so would the moisture in a fresh log quench the
reaction sufficiently to cause the fire to burn top down like a cigar
without leaving charcoal?

I aim for low temp burn for kiln life and as in my relative ignorance and in
the absence of control of heat and pressure to alter the equilibrium of the
reaction to favour retention of carbon and hence higher yield ( I do look
forward to reading Mike Antal's paper) I assume a loss of yield to gaseous
hydrocarbons as the temperature rises.

Using fresh timber ( I know we should not and I am embarrassed by the plight
of Somalia acacias but ours is an urban waste disposal situation which I am
happy to discuss further especially with regard to similar techniques
required to develop cooking by flared gas and heat recovery as efficiency
here will lead to reduced pollution, on which our ring kilns worry me
severely, comments anyone?)we have a 24hr steaming phase, followed by 8hrs
burning till shutdown and cooling for 24hrs. The smaller the kiln the
faster, as stated previously 10-12tonnes of input yield 500 3kg bags plus
100kgs ash+fines. The moisture content of the wood does not vary the yield
as much as I expected, its major effect is to increase the time of the
burning cycle, this makes me feel that insulating the kiln would have little
effect.

Incidently on fresh pine in a 1980 cocoa tin experiment I achieved a 9:1
weight reduction, as the theoretical energy input of the pine was 5.9Mj per
kg and Ronal quoted 30mj/kg for charcoal then as the yield of charcoal per
kg is .1111kg then 3.33mj energy of left in the charcoal, slightly more than
half the input. Is the loss from our kiln likely to be as heat loss from the
walls or unburned hydrocarbons?

Forgive me if I am not too rigorous with my science or technique, this is
the price I pay for misdemeanours in my youth curtailing my further
education 8-)
AJH

From english at adan.kingston.net Sat Jun 14 07:40:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Alex on Two Cone Stove
In-Reply-To: <v01540b05afc7b32a3ddb@[204.133.251.2]>
Message-ID: <199706141140.HAA32117@adan.kingston.net>

> 1). I probably implied or said that I was bothered by this
> combustion of some of the outer material (because I was). But if you have
> a strong "pilot light" this could be a major advantage. I presume you are
> testing indoors - but do you have any sense of the stability of your flame
> against wind gusts?

I have tested inside (a greenhouse with a peak vent) and out and half
way between, but not in very gusty conditions. The breeze one night
certainly affected the draft and therefore the stability of the flame
but didn't threaten to extinguish it. I'll try it in a wind.

> 2) Do you get all of your flame in the 15" eight or is there still
> some flame above the final exit?

A more air " starved" flame (higher CO2) extends above the top of
the chimney. It more typically stops very close to the top.

> 3) Can you describe the cost and properties (and sources) of the
> cerafelt? Is this the same as or different from "riser sleeve" (which is
> impregnated with a combustible material)? Is this a brittle material?

I will have to get back to you on the actual price, but I know its
not cheep. It is flexible (like felt) white, fairly dense compared to
fibre glass or rock wool, and can tolerate temperatures far higher
than what we are dealing with. I can find out exactly if you wish.

> 4) I'd like to keep hearing about the CO2 and temperature levels
> as you keep making changes. I'd like to believe that about 10-12% (which
> you have been having) is about right.

I understand 12% CO2 ( about 1.5 excess air factor) to be a target
for wood stoves. Does this apply to charcoal-making stoves ?
How different is the stociometric equation ?

On another front, there is lots ( a precise term) of heat in the area
between the chimney and he pail. I wonder, do you think it could be
used for baking ? That area could be enlarged into a convection oven.

Alex in wonder land.
>
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Sat Jun 14 07:40:09 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Nice knowing ya!
In-Reply-To: <9706140813.AA00039@mars.cableol.net>
Message-ID: <199706141140.HAA32115@adan.kingston.net>

Dear Andrew+
Great story about the stump remover.
<snip>
> Which brings me back to stovers, I would like thoughts on the mechanism
> which causes the wood at the bottom of the pail to be carbonised rather than
> the whole charge simply burn,
<snip>

With the cone arrangement, it appears that the air supply is taking
the path of least resistance from the outer edge of the cone
directly to the top outlet. Thus bypassing the central mass of wood.
The ring of fire and its extension into the cone above providing
heat. I should measure the temperatures in the middle of the fuel.

<snip>
> Am I right in thinking with the pail the wood at the top burns to the
> exothermic point 280 c and as the gases are liberated and flared to cook
> with the exothermic reaction is continued as a chain reaction down the log,
> liberated gases carrying excess sensible heat away, free oxygen being
> depleted by the flame above and the physical barrier of the outside layers
> of cooler carbon? If so would the moisture in a fresh log quench the
> reaction sufficiently to cause the fire to burn top down like a cigar
> without leaving charcoal?

Sorry, I don't quite follow. Ron or others??

> Forgive me if I am not too rigorous with my science or technique, this is
> the price I pay for misdemeanours in my youth curtailing my further
> education 8-)
> AJH

What???? No rigor!!!! No Education!!!

Keep living.....

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From elk at arcc.or.ke Sat Jun 14 07:57:56 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:17 2004
Subject: sawdust briquettes
Message-ID: <m0wcrSP-0006UjC@arcc.or.ke>

Hassan & Stovers;

Thanks for the information on the Moshi Tanzania birquetting facility.

Interesting that an export market's being developed.

Expansion of briquettes on carbonisation.... is this related to initial
compression? What binder is used in the Tanz. operation?

What, if you know, is the plant capacity V.S. recent production? Are thay
making an operational profit?

Though my intrest centers on the informal sector & manual equipment, if the
larger more turnkey type of operation is actually economically viable in
this region, I think a bit of rooftop advertising is required to wake
related industry up to the potential. A significant reduction of pressure on
bush and forest land would be realised if even a quarter of the currently
wasted sawdust was converted to a domestically acceptable fuel.

If I had a series of 5 photos taken at two year intervals (over the last
decade) overlooking ANY open areas within eastern or central Kenya, the
visible depredation on woody vegetation would certainly make people sit up &
take note!

Regards;

elk

From ahe1 at cableol.co.uk Sat Jun 14 13:58:36 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:17 2004
Subject: Nice knowing ya!
Message-ID: <9706141758.AA07936@mars.cableol.net>

Andrew Heggie in reply to Alex English
At 07:39 14/06/97 -0500, you wrote:

>With the cone arrangement, it appears that the air supply is taking
>the path of least resistance from the outer edge of the cone
>directly to the top outlet. Thus bypassing the central mass of wood.
>The ring of fire and its extension into the cone above providing
>heat. I should measure the temperatures in the middle of the fuel.

As with someone else in the group recently I must apologise for not clearly
conveying that which I was thinking. I can visualise the flame and
associated convection preventing air flowing into the pail and hence this
area becoming a reducing atmosphere once CO is generated from pyrolysis of
the wood. I just cannot see how in the (2hr I thought you wrote) timescale
that the wood at the bottom of the pail would reach 280c by conduction. What
is the conductivity of dry wood and charcoal?

I think the vertically stacked logs is the crux, would random pieces
horizontally stacked work? The traditional Japanese clay kilns are stacked
vertically and have very carefully constructed inlet and chimney. They
appear to have less shattering of the charge, possibly due to slower release
of cell water. We find species with strong parenchymous rays shatter badly
and think this is from trapped water exploding as it boils.

I was surmising that rather than a conduction of heat from the flame zone
down from cell to cell the transfer was of chemical energy as each cell
broke down exothermically once the critical temperature of 280c, posted by
Tom Reed, was reached, this intuitively would transfer heat down the log
faster. As Tom also pointed out this would be self limiting to 440c even in
the absence of losses, loss of heat from the charge occurs by conduction
through the pail and as sensible heat in the gases liberated and
subsequently burned in the cone/chimney. It would be interesting to see the
maximum temperature on the wood surface under the cone as well near the
bottom of the pail.

I watch further developments with interest, I hope it is alright by you but
I am looking to scale up the technology you are researching for your
domestic use, I dream of running a charcoal kiln/retort alongside a pottery
kiln powered by the flared gases.

>What???? No rigor!!!! No Education!!!
>
>Keep living.....
I did not mean rigor as in rigor mortis so I struggle on :-0
AJH

From verhaarp at janus.cqu.edu.au Sat Jun 14 17:36:02 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Tom Reed on draft vs fans
Message-ID: <1.5.4.32.19970614213549.006b0820@janus.cqu.edu.au>

>From Piet Verhaart
To Ron and to Alex, mainly

At 21:37 13/06/97 -0600, you wrote:

>In a separate message today, Tom said:
>
>>I accessed Pete Verhart's new Website,
>>http://www1.kingston.net/~english/Stoves.html, and found pictures of his
>>latest stoves, in color.
>
>(RWL): The picture should be credited to Pete, but the website and (from
>my non-capable viewpoint) hard digitization work should be credited to Alex
>English.
>
Yes, emphatically so, the credit for the website, I mean.

Regards and praise
Piet Verhaart

>
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sat Jun 14 17:41:34 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Piet on two copy messages
Message-ID: <1.5.4.32.19970614214122.006cb74c@janus.cqu.edu.au>

Since yesterday I get two identical copies of every message from
<stoves@crest.org>
Yesterday I had 57 messages.
Aha, an odd number!
Yes, there was one from a non-stoves@crest.org source.
Not a big deal, the trash bin can deal with it.
Piet
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sat Jun 14 18:00:21 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Tom Reed on draft vs fans
Message-ID: <1.5.4.32.19970614220009.006b95fc@janus.cqu.edu.au>

>From Piet

At 21:37 13/06/97 -0600, you Ron wrote:

The Vorpal blade went snickersnack.

>(RWL): The picture should be credited to Pete, but the website and (from
>my non-capable viewpoint) hard digitization work should be credited to Alex
>English. (I tried today and kept getting something else - oh well. Alex,
>I will try again.)

Ron, when you double click on the website (in the message), the comma comes
with and that upsets the delicate system. So, after you are shown the door,
the thing to do is erase the comma and try again.
Artificial intelligence has a long way to go.
Regards
Piet
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sun Jun 15 06:26:08 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Scanning photos and file size
Message-ID: <1.5.4.32.19970615102554.006bf5b4@janus.cqu.edu.au>

>From Piet Verhaart
To Art Krenzel, mainly

At 14:00 12/06/97 -0700, you wrote:
>Thank you for the excellent photos and drawings of your experiment. How
>did you and others scan in the photos and drawings (What dots per inch)
>to have such clear file photos in such useably small files?
>I am new to the world of the scanner and have some photos I'd like to
>share if the files were not so large.
>Thanks!
>Art Krenzel
>
My scanner (HP - 5P) scans photos, producing huge .bmp (bitmap) files. After
saving them I open them in Logitech Photodesk, which enables me to crop them
as well as reduce or enlarge them for printing. Photodesk also enables me to
save the files in several modes. Choosing .jpg makes for the smallest files.
Sometimes this doesn't work. When I wanted to save the Swosthee stove
drawing, the program refused to convert it from .bmp to .jpg and so I
shamefacedly sent a 300 kb file to Alex. Apparently Alex managed to convert
it to a more reasonable size. He might tell you (and me) how he did it.

Looking forward to your pictures.
Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sun Jun 15 06:25:59 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Something Practical ?, part 2
Message-ID: <1.5.4.32.19970615102545.006bba00@janus.cqu.edu.au>

>From Peter Verhaart

At 22:52 8/06/97 -0500, you wrote, among other memorable things:

> 14 oz of cedar kindling were
>placed vertically in a 5" cylinder with under and over fire air
>(both controllable) with a 3" cylinder acting as a flame chamber
>just above the over fire air inlet. CO2, temp and smoke were
>monitored in the 5" chimney , 6" above the flame chamber.
>
>With both air supplies wide open the fuel was "top lit" with a
>propane burner. It quickly developed visually clean exhaust gasses.
>A turbulent and audible (micro roar) flame was largely contained with
>in the flame chamber.

The flame chamber being the pipe section of 76 * 127 mm (sorry, 3" * 5")?

Did you make any arrangements to induce a swirl to the incoming 'over-fire'
air? Like vanes or blades set at an angle to the radial direction?

If you wanted turbulence in the chimney entrance, it might have been better
to leave out the 5" flame chamber, the sudden increase in diameter might
improve mixing.

>For the first fifteen minutes the CO2 tested at between 3.5% and 5%

Quite some excess air.

>Cutting off over fire air caused the flame go quiet and extend up

How did you do that? The drawing does not show any means of adjusting the
slit between the two lengths of 5" pipe.

What was the thinking behind the outer cylinder of 8" pipe?
>
>Total fuel consumed=2 lbs ( at 12% moisture) ( sorry about the British units)
>
So you added another 18 oz to the original 14 oz in a non-batch mode.

>Conclusions: I have a long way to go!
>
And so say all of us!

>From here a warm welcome to "The Others"

Peter
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sun Jun 15 06:25:56 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Drawings and CO emissions
Message-ID: <1.5.4.32.19970615102538.006b8620@janus.cqu.edu.au>

Dear Alex
I had a look at the pictures this morning and found no discernable change,
they still look very good. I made a printout of Fig. A. to study it at
leisure. It printed well, all figures are legible. I will comment on it
later, it looks interesting.

>Dear Peter
>I messed around a bit to get the drawings on the web ina smaller
>format. I hope it meets with your approval. Now we need some
>description and data to go with it.
>

>Do you know the CO emissions levels for kerosene stoves ?

No, I am a qualitative sort of person. Prasad and/or Etienne will have
access to these figures, being both more orderly as well as closer to the
source.
I am mailing this through stoves@crest.org so they will also see this message.
Best regards,
Peter
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Sun Jun 15 06:26:13 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:17 2004
Subject: Something Practical, Part 1b
Message-ID: <1.5.4.32.19970615102549.006bd688@janus.cqu.edu.au>

Dear Alex
At 22:53 9/06/97 -0500, you wrote:
>Dear Ron and others
>
>I went back to the 20 litre pail this evening with much better
>results. I filled the bottom with vertically placed 1"*2" *5" pieces
>of cedar weighing 4 lbs and through some crumpled paper on top. I
>chopped the end off a metal funnel forming a cone with 9" top dia.
>and 3" bottom dia. Screwed a piece of 5" stove pipe(15" long) to the
>outside of the funnel, lit the paper and placed the large end of the
>funnel over the burning paper and on top of the wood, such that the
>stove pipe formed a chimney. The pail diameter at this point is about
>11", leaving about an inch all around. It took between 2 and 5
>minutes for the flame clean up.

We did something similar in Eindhoven. I think we called it the "sinking
chimney" stove. It was different from yours in that we had no cone but a
flat flange at the bottom end of the chimney (probably about 1 m long). The
bucket was cylindrical and the idea was for the chimney to sink as the fuel
was consumed. As usual, there was not enough time nor enough people to do a
sufficient number of experiments on it. It did burn if I remember. Etienne
might be able do dig up more on this subject.
Your idea of the perforated cone is a distinct improvement, lots of jets of
air into the hot volatiles could quite well do a thorough job of combusting.

>When I returned in an hour the the remaining charcoal was cool and weighed
>about 1lbs.

??? 11 lbs charcoal from 4 lbs of cedar wood, what happened?

>
>Yes Ron ,I could cook with this . There are many improvements
>or options that should be explored. I look forward to trying them.

Yes, I hope you will.

Looking forward to more results. Things really are moving in the Stove List,
thanks in no small measure to your presence.

Peter
>
>PS Ron or Tom could you explain or discuss the differences between
>this trial and your own two can fires.

Let Piet put his penny in. The airflow in your case would have some downward
component which could account for your finding partly consumed charcoal
close to the wall of the bucket. This clearly did away with the need for a
perforated bottom, making for simplicity. Your arrangement might promote
more turbulence and you probably have a taller chimney.

Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From BTrout1003 at aol.com Sun Jun 15 09:24:18 1997
From: BTrout1003 at aol.com (BTrout1003@aol.com)
Date: Tue Aug 31 21:35:17 2004
Subject: Merrimac Stove
Message-ID: <970615092344_2021709101@emout01.mail.aol.com>

Sir,
As A Civil War era re-enactor, I am interested in shielded fire stoves
used during this time, particularly the "Merrimac Stove" shaped as was the
upper portion of the iron clad that it acquired its name from.
If you have any information on this type of stove, I would ask that you
reply to
me at the e-mail address listed for forwarding to me.

Thank
You,
John E.
Sever
11th
P.V.I. Co. I
Cook

From phait at transport.com Sun Jun 15 10:43:47 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:17 2004
Subject: Merrimac Stove
Message-ID: <199706151436.HAA06777@butch.transport.com>

>Sir,
> As A Civil War era re-enactor, I am interested in shielded fire stoves
>used during this time, particularly the "Merrimac Stove" shaped as was the
>upper portion of the iron clad that it acquired its name from.
> If you have any information on this type of stove, I would ask that you
>reply to
>me at the e-mail address listed for forwarding to me.
>
> Thank
>You,
> John E.
>Sever
> 11th
>P.V.I. Co. I
> Cook
>DearJohn E.

We manufacture a Merrimac Stove. It is called the Pyroduo 816. Call Lara
Wettig at 541.3178720 or email phait@transport.com. and ask for literature
and details.
Thank you.

Sincerely,
Paul W. Hait
President
Pyromid Outdoor Cooking Systems

From E.Moerman at stud.tue.nl Sun Jun 15 17:06:09 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:17 2004
Subject: Moerman and Karstad on carbonization.
Message-ID: <39987.s335192@popserver.tue.nl>

> (RWL): If Elsen can (cheaply!) do the briquetting of sawdust, this might
> be an excellent fuel for a charcoal-making stove (say 1 inch diameter by 7
> inch length). I wish I had some pieces to test. However, I believe there
> may be an important feature to natural wood - that gases can flow much more
> easily in a longitudinal direction than radially. This would not be true
> for a sawdust briquette. Also the sawdust briquette may crumble after
> pyrolysis whereas natural wood does not. Still, I hope Elsen will try the
---------

Etienne:
Crumbling depends a little on the type of material that goes into the
briquette. My experience is that they hardly crumble at all. Most types
seem to have quite a lot of ash (1-15%). I expect that the use of molasses
as a binder produces this amount of ash. The ash seems to prevent crumbling
for a long time.

-------

> (RWL): Perhaps I may seem to be in a difficult position - asking
> some to switch to a charcoal-making stove and others to continue to use
> charcoal. But I hope that both can be consistent. The charcoal-making
> stove is being claimed to be superior (eventually - after further
> development) to both the standard wood burning stoves and to the
> charcoal-burning jikos - maybe in all respects: efficiency, pollutant
> release, controllability, etc. But it can't do some jobs that charcoal can
> do better - such as all the users that Faisal and Paul Hait have identified
> - barbecuing, incense burning, etc.
----------

Etienne:
As you probably expect by now, I don't agree that charcoal stoves are
superior to woodstoves. Woodstoves exist that are cleaner than charcoal
stoves, controllability or efficiency.
Clean: downdraft stove
Efficiency: shielded fires and similar stoves
Controllability: this is mainly a matter of correct fuel feeding.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Sun Jun 15 17:06:11 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:17 2004
Subject: Alex on Two Cone Stove
Message-ID: <39991.s335192@popserver.tue.nl>

> (AE): >A touchy thing this draft.
>
> (RWL): I think most of the whole charcoal-making stove design
> understanding will eventually be based on understanding draft and chimneys.
> I have looked (admittedly cursorily) at many mechanical engineering and
> flow dynamics college texts and never find either subject mentionned. The
> best place I have found for understanding (I don't yet these topics is the
> ASHRAE handbook (I think this is the "title" - they have many different
> kinds of documents).
> Modern ME handbooks are silent on these areas, but those from
> 50-100 years ago are pretty good.
> I don't expect to find a discussion of conical chimneys anywhere.
> Anyone know how to model or understand such?

-------

Etienne:
Have a look at

Buoyancy induced flows and transport
by
B. Gebhart
Y. Jaluria
R.L. Mahajan
B. Sammakia

ISBN 0-89116-402-2

I don't think that draft in small- and medium-scale will be understood with
a reasonable degree of detail. The problem is that the flows are not fully
developed. They are only fully developed after 20 or more times the diameter
of the flow channel. However the first part is most interesting from the
point of combustion devices. The best option so far numerical mathematics.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Sun Jun 15 17:06:14 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:17 2004
Subject: to carbonise or not.....
Message-ID: <39984.s335192@popserver.tue.nl>

Elsen:
> The primary urban domenstic fuel - by a long way- is charcoal here in
> Kenya. kerosene follows a poor second.

------

Etienne:
I didn't realize that. In the lab I find normal briquettes just as
convenient as carbonised ones, except that they are cleaner. However if
there is no demand for it what can you do?

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From elk at arcc.or.ke Mon Jun 16 06:27:10 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:17 2004
Subject: and two steps back.... sawdust charcoal briquetting
Message-ID: <v01510100afcad26b3969@[199.2.222.130]>

Gloom & Depression- I attempted to briquette from my first batch of sawdust
charcoal (20% carbonised material by weight from damp sawdust), and I
couldn't!

Appears that particle size is restricting the binding properties of cement
and increasing friction in the barrel of my manual briquetter. Adding more
water to the mixture increases barrel friction to siezure.

My first trials involved hammermilled charcoal dust (bottom of bag
material) using a 2mm mill screen. I'll now mill up a batch of the
carbonised sawdust to ascertain if there are any other factors involved
other than particle size with this sawdust charcoal.

As I obviously cannot expect the 'informal sector' to have access to
hammermills, I'll try the following:

1) using molasses as a binder

2) A stainless steel pipe as compression cylinder in an attempt to reduce
friction.

3) Etienne's suggestion on briquetting sawdust. Forget the carbonisation
and use appropriate stoves, and/or carbonise after briquetting (like the
tanzanian plant does).

I'll be able to do everything but No. 2) today, so stay tuned.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From english at adan.kingston.net Mon Jun 16 06:56:51 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Something Practical ?, part 2
In-Reply-To: <1.5.4.32.19970615102545.006bba00@janus.cqu.edu.au>
Message-ID: <199706161056.GAA24398@adan.kingston.net>

Dear Peter+
Looking back at this first try I can see the benefit in doing
something, anything with an effort to observe, measure and interpret.

> Did you make any arrangements to induce a swirl to the incoming 'over-fire'
> air? Like vanes or blades set at an angle to the radial direction?

The swirl surprised me. I didn't use vanes. It seems, that like
water down a drain, at higher flow rates the tendency is to swirl.
Having the large amount of excess air gave it a high enough flow
rate.

> If you wanted turbulence in the chimney entrance, it might have been better
> to leave out the 5" flame chamber, the sudden increase in diameter might
> improve mixing.

I suppose that would cause back eddies ?

>
> >For the first fifteen minutes the CO2 tested at between 3.5% and 5%
>
> Quite some excess air.

Yup.

>
> >Cutting off over fire air caused the flame go quiet and extend up
>
> How did you do that? The drawing does not show any means of adjusting the
> slit between the two lengths of 5" pipe.

I blocked the space between the 5" pipe and the 8" pipe with
fibreglass insulation.

> What was the thinking behind the outer cylinder of 8" pipe?

I tried some other fires with the 8" pipe first, then decided it
would be a good wind break and preheat chamber.

> >
> >Total fuel consumed=2 lbs ( at 12% moisture) ( sorry about the British units)
> >
> So you added another 18 oz to the original 14 oz in a non-batch mode.
Yes, approximately.

Alex

>
> >Conclusions: I have a long way to go!
> >
> And so say all of us!
>
> >From here a warm welcome to "The Others"
>
> Peter
> Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
> Phone: +61 79 331761 Fax: +61 79 331761 or 332112
> E-mail:p.verhaart@cqu.edu.au
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Mon Jun 16 06:56:54 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Nice knowing ya!
In-Reply-To: <9706141758.AA07936@mars.cableol.net>
Message-ID: <199706161056.GAA24401@adan.kingston.net>

Dear Andrew and stovers

>. I just cannot see how in the (2hr I thought you wrote) timescale
> that the wood at the bottom of the pail would reach 280c by conduction. What
> is the conductivity of dry wood and charcoal?

> I think the vertically stacked logs is the crux, would random pieces
> horizontally stacked work?

I did a small batch of random pieces of cedar lumber trimmings,
tossed into the pail, about four inches deep. ( I rigorously forgot
to weight it.) I placed my thermocouple in the middle of the fuel,
1.5" (4cm) from the bottom of the pail. It took 23 minutes to reach
280C and another 15 to reach 440C. The temperature climbed steadily
to over 700C , when the volitiles were used up. The burn lasted 50
minutes. I was not choking the fire. I then removed the chimney and
cones and placed a piece of insulation over the top of the pail. The
temperature began dropping immediately and continued steadily. It
produced a lovely batch of charcoal.

I think your correct that conduction from the outside and above has
less to do with the pyrolisis occurring in the middle than the "cell
to cell" creeping that you describe below.

>
> I was surmising that rather than a conduction of heat from the flame zone
> down from cell to cell the transfer was of chemical energy as each cell
> broke down exothermically once the critical temperature of 280c, posted by
> Tom Reed, was reached, this intuitively would transfer heat down the log
> faster. As Tom also pointed out this would be self limiting to 440c even in
> the absence of losses, loss of heat from the charge occurs by conduction
> through the pail and as sensible heat in the gases liberated and
> subsequently burned in the cone/chimney. It would be interesting to see the
> maximum temperature on the wood surface under the cone as well near the
> bottom of the pail.

With these small batches the whole mass approaches flame temperature
by the time the flames quit.

> I watch further developments with interest, I hope it is alright by you but
> I am looking to scale up the technology you are researching for your
> domestic use, I dream of running a charcoal kiln/retort alongside a pottery
> kiln powered by the flared gases.

Good luck!

This evening I filled the pail ( mostly horizontally stacked) with
Manitoba Maple twigs and branches (up to 2" or 5cm dia, some a little
green), and a couple of White Oak blocks placed near the bottom, (2"
*4"*4" or 5*10*10cm) to a depth of 11"(28cm). I lit it up outside
in the wind. It started well, but flame surged and puffed a bit due
to the wind. After 15 minutes the flame struggled and quit. A few
damp twigs supporting the cone, near the side of the pail ( the
pail was not insulated so I think these sticks were to cool) had not
burned sufficiently to allow the cone to stay close enough to
sufficient fuel to provide adequate flame, or "pilot light". I forced
the cone down and the process started up again. I insulated the pail
and the occasional jiggle of the chimney ( maybe 2 or 3 times) was
enough to complete the burn in about a total of 65 minutes. During
the latter part of the burn the chimney temperature exceeded 1700F
(900C). I think it had something to do with the Oak. The exhaust was
visually clean with smoke reading around 7 and CO2 -12%. At one point
we doubled the chimney height and had a roaring smoky flame. Holding
that second chimney so that air could leak in at the joint cleaned it
up.

Starting with 6.5 lbs (3kg) of fuel, it finished with 1.2 lbs of
charcoal and ash. I think with a greater depth of fuel, more top
edges of the fuel will come into contact with the flow of O2 as it
moves along the underside of the lower cone. I think this would lead
to a greater portion of the fuel being consumed, depending on the
relative downward speed of the pyrolisis.

I think I think........more trials more trials Alex

P.S. Some pictures of the two cone charcoal maker experiment are now
at http://www1.kingston.net/~english/Stoves.html

> AJH
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927

From english at adan.kingston.net Mon Jun 16 07:53:24 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:17 2004
Subject: Moerman and Karstad on carbonization.
In-Reply-To: <39987.s335192@popserver.tue.nl>
Message-ID: <199706161153.HAA25541@adan.kingston.net>

Dear Etienne and all.
>
> Etienne:
> As you probably expect by now, I don't agree that charcoal stoves are
> superior to woodstoves.

Are you including charcoal-making stoves in this assessment ?

> Woodstoves exist that are cleaner than charcoal
> stoves, controllability or efficiency.
> Clean: downdraft stove
> Efficiency: shielded fires and similar stoves
> Controllability: this is mainly a matter of correct fuel feeding.

Setting aside a lack of understanding of smoke related health and
pollution effects, I gather that the market place in developing
countries has voted for charcoal. Is this strictly custom or are
transportation and handling issues paramount.

Ron has pointed out that the charcoal-making stove may
have a side benefit of producing a marketable product while
performing regular daily activities. I liken this to the early
pioneers in this part of the world, who having very few surpluses in
their lives were able to "salt away" butter as a daily byproduct from
their homestead cow and sell it to the townfolk for some much needed
cash.

I am ignorant of charcoal stove emissions. How bad are they?

Alex

>
> Etienne
> ---------------------------------------------
> Mr. Etienne Moerman E.Moerman@stud.tue.nl
> Joh. Buyslaan 71 tel. +31-40-2571491
> 5652 NJ EINDHOVEN The Netherlands
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Mon Jun 16 10:06:10 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:17 2004
Subject: Heggie on kiln operation
Message-ID: <v01540b05afc8fcbdf631@[204.133.251.15]>

Andrew Heggie said:
<skip (a stump burner saga that is beyond the scope of this list)>

>Which brings me back to stovers, I would like thoughts on the mechanism
>which causes the wood at the bottom of the pail to be carbonised rather than
>the whole charge simply burn, I use a metal ring kiln to produce charcoal
>with low inlets alternating with low chimneys, I take it this combines
>updraught and downdraught, gaseous reactions occurring in the dome of the kiln.

(RWL): With only partial understanding of this topic, I want to take a shot
at some answers. I hope that Kirk Smith will chime in as I believe he has
some recent quite complete tests on such kilns (in Thailand).

1. The reason that the charge doesn't burn is that the air supply
is strictly limited. The draft is low because the chimney height is low.
2. There is certainly both updraft and downdraft in a ring kiln -
but the important thing is that the draft is mostly from the wood side into
the charcoal side. Thus the pyrolysis zone is traveling against the
airflow.
3. The alternating of the chimney positions with the input
positions partway through the making is critical to being sure that the air
flow is against the pyrolysis travel.
4. I don't believe any major chemical reactions take place in the
dome. The main reactions are right at the pyrolysis zone - where CO and
CH4 and H2 (and lots else) are being produced. These same gases travel
relatively unchanged (because there is no oxygen left to enter into a
chemical reaction) to the exit and are being vented through the chimney.

<snip>

(AE)
>I assumed given a small charge and uniform heating the temperature would
>rise to 100c and hold whilst all moisture was driven off.

(RWL): As I understand usual kiln operation, the upper vents are left open
until it appears that all the moisture is driven off. During this period
all gas flow is upward and not through the chimneys. Then the top vents are
closed and the chimneys begin to operate (working because they fill with
lighter hot gases (not being flared, they are not very hot). The above
assumes bottom lighting.
Apparently there are occasions with more dense fuel charges when top
lighting is used for a short time with the upper vents open, and then
switching to the normal alternating lower input and output ports (and
closed top vents).
In the charcoal-making stoves, the operation is different. There is
no initial period of driving off moisture, and lighting is always at the
top and the pyrolysis zone only and always moves downward. I believe this
is true for Alex's two-cone approach and is certainly true of the "two can"
method. The similarity is that air flow (up) is still in the opposite
direction from the pyrolysis zone travel (down).

(AE): > Followed by a rise
>to 232c at which point the wood starts decomposing. Why does the reaction
>stay endothermic to 280c?

Here I start needing chemical engineers (Ron West, who has comented
on this several times in the past, is on vacation in Turkey). I believe
you need in all three charcoal-making cases to think in terms of a moving
(relatively high temperature) pyrolysis zone (able to slowly move because
enough of the radiation from one pyrolysis zone strikes "below" (in an air
flow sense) the corresponding pyrolysis zone on a neighboring piece of
wood. The temperature is well above 232 C, I believe - and is presumably a
function of the air flow and rate of energy release. I think it is not
easy (but is possible) to predict this temperature, and it includes all the
forms of energy loss. The pyrolysis zone moves inward into the wood pieces
(by conduction) as well as downward (mostly by radiation), but the gases
released above the pyrolysis zone don't see enough oxygen to further
combust. I can't answer the question "why".

(AE):
>In my experience at this stage the temperature rises very rapidly and would
>destroy the kiln if not closed down, I have seen a 4 prototype retorts and
>one hybrid kiln distort when this has happened.

(RWL): I believe the large temperature rise only occurs when there is no
wood left to pyrolyze and the manufactured charcoal begins to combust, with
much greater heat release. Of course combustion can only occur when oxygen
is present - and skilled operators know when to shut down.
I may not have understood your use of the term "at this stage",

>
>Am I right in thinking with the pail the wood at the top burns to the
>exothermic point 280 c and as the gases are liberated and flared to cook
>with the exothermic reaction is continued as a chain reaction down the log,
>liberated gases carrying excess sensible heat away, free oxygen being
>depleted by the flame above and the physical barrier of the outside layers
>of cooler carbon?
1. The above has some meaning, but I would scratch the idea of 280
C as a limit.
2. The idea of a "chain reaction" presumably relates to the
radiative heat transfer effect.
3. The free oxygen is depleted not by the flame above but rather
by the pyrolysis zone below. If any oxygen is left over as it flows up
past the pyrolysis zone, it would be creating CO2 rather than the desired
CO - on the surface of the hot charcoal.
4. The "physical barrier" makes some sense as I believe most of
the pyrolysis gases travel upward inside the more highly permeable charcoal
above rather than exiting laterally.

(AE): >If so would the moisture in a fresh log quench the
>reaction sufficiently to cause the fire to burn top down like a cigar
>without leaving charcoal?

(RWL): Perhaps. It is certainly not easy (maybe not possible) to use
fresh wood - nor wood above a certain moisture content. But I think it
more likely that one could sustain neither pyrolysis nor combustion.
Probably this is why there is bottom lighting for moist wood - probably
starting with drier kindling.

(AE):
>I aim for low temp burn for kiln life and as in my relative ignorance and in
>the absence of control of heat and pressure to alter the equilibrium of the
>reaction to favour retention of carbon and hence higher yield ( I do look
>forward to reading Mike Antal's paper) I assume a loss of yield to gaseous
>hydrocarbons as the temperature rises.

(RWL): The issue of yield (meaning retained hydrogen and oxygen) and
temperature is an important one and relates to Tom Reed's message of June 8
("Charcoal - ash and moisture content"). My perception is that some
(most?) charcoal customers also prefer the higher releasable gas content of
the higher yield charcoal (up to a point).

(AE):
>Using fresh timber ( I know we should not and I am embarrassed by the plight
>of Somalia acacias but ours is an urban waste disposal situation which I am
>happy to discuss further especially with regard to similar techniques
>required to develop cooking by flared gas and heat recovery as efficiency
>here will lead to reduced pollution, on which our ring kilns worry me
>severely, comments anyone?)we have a 24hr steaming phase, followed by 8hrs
>burning till shutdown and cooling for 24hrs. The smaller the kiln the
>faster, as stated previously 10-12tonnes of input yield 500 3kg bags plus
>100kgs ash+fines. The moisture content of the wood does not vary the yield
>as much as I expected, its major effect is to increase the time of the
>burning cycle, this makes me feel that insulating the kiln would have little
>effect.

(RWL): 1. Have you ever tried flaring with your ring kilns or seen
any literature on doing so?
2. Could you describe your "steaming" process?
3. Why not delay the charcoal making until natural drying can take
place?

(AE):
>Incidently on fresh pine in a 1980 cocoa tin experiment I achieved a 9:1
>weight reduction, as the theoretical energy input of the pine was 5.9Mj per
>kg and Ronal quoted 30mj/kg for charcoal then as the yield of charcoal per
>kg is .1111kg then 3.33mj energy of left in the charcoal, slightly more than
>half the input. Is the loss from our kiln likely to be as heat loss from the
>walls or unburned hydrocarbons?

1. The number 5.9 MJ/kg sounds low on a wet basis. What moisture
content are you assuming? Did you perform a moisture content test?
2. I believe most of the energy loss is in the unburned
hydrocarbons. But of course some of the initial energy in the wood was
also radiated away. I gather it is very difficult to do a complete energy
balance.
3. I presume "cocoa tin" means all external heating. What
temperature was used?

(AE):
>Forgive me if I am not too rigorous with my science or technique, this is
>the price I pay for misdemeanours in my youth curtailing my further
>education 8-)
>AJH

(RWL) I bet you would get a lot more charcoal than most of us. Being an
Electrical Engineer, I am not giving a very complete description either -
but trying also to explain what I think is going on. I also hope others
will join in.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phait at transport.com Mon Jun 16 10:06:14 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:18 2004
Subject: Nice knowing ya!
Message-ID: <199706161357.GAA09716@butch.transport.com>

>Dear Andrew and stovers
>
>>. I just cannot see how in the (2hr I thought you wrote) timescale
>> that the wood at the bottom of the pail would reach 280c by conduction. What
>> is the conductivity of dry wood and charcoal?
>
>> I think the vertically stacked logs is the crux, would random pieces
>> horizontally stacked work?
>
>I did a small batch of random pieces of cedar lumber trimmings,
>tossed into the pail, about four inches deep. ( I rigorously forgot
>to weight it.) I placed my thermocouple in the middle of the fuel,
>1.5" (4cm) from the bottom of the pail. It took 23 minutes to reach
>280C and another 15 to reach 440C. The temperature climbed steadily
>to over 700C , when the volitiles were used up. The burn lasted 50
>minutes. I was not choking the fire. I then removed the chimney and
>cones and placed a piece of insulation over the top of the pail. The
>temperature began dropping immediately and continued steadily. It
>produced a lovely batch of charcoal.
>
>I think your correct that conduction from the outside and above has
>less to do with the pyrolisis occurring in the middle than the "cell
>to cell" creeping that you describe below.
>
>>
>> I was surmising that rather than a conduction of heat from the flame zone
>> down from cell to cell the transfer was of chemical energy as each cell
>> broke down exothermically once the critical temperature of 280c, posted by
>> Tom Reed, was reached, this intuitively would transfer heat down the log
>> faster. As Tom also pointed out this would be self limiting to 440c even in
>> the absence of losses, loss of heat from the charge occurs by conduction
>> through the pail and as sensible heat in the gases liberated and
>> subsequently burned in the cone/chimney. It would be interesting to see the
>> maximum temperature on the wood surface under the cone as well near the
>> bottom of the pail.
>
>With these small batches the whole mass approaches flame temperature
>by the time the flames quit.
>
>> I watch further developments with interest, I hope it is alright by you but
>> I am looking to scale up the technology you are researching for your
>> domestic use, I dream of running a charcoal kiln/retort alongside a pottery
>> kiln powered by the flared gases.
>
>Good luck!
>
>This evening I filled the pail ( mostly horizontally stacked) with
>Manitoba Maple twigs and branches (up to 2" or 5cm dia, some a little
>green), and a couple of White Oak blocks placed near the bottom, (2"
>*4"*4" or 5*10*10cm) to a depth of 11"(28cm). I lit it up outside
>in the wind. It started well, but flame surged and puffed a bit due
>to the wind. After 15 minutes the flame struggled and quit. A few
>damp twigs supporting the cone, near the side of the pail ( the
>pail was not insulated so I think these sticks were to cool) had not
>burned sufficiently to allow the cone to stay close enough to
>sufficient fuel to provide adequate flame, or "pilot light". I forced
>the cone down and the process started up again. I insulated the pail
>and the occasional jiggle of the chimney ( maybe 2 or 3 times) was
>enough to complete the burn in about a total of 65 minutes. During
>the latter part of the burn the chimney temperature exceeded 1700F
>(900C). I think it had something to do with the Oak. The exhaust was
>visually clean with smoke reading around 7 and CO2 -12%. At one point
>we doubled the chimney height and had a roaring smoky flame. Holding
>that second chimney so that air could leak in at the joint cleaned it
>up.
>
>
> Starting with 6.5 lbs (3kg) of fuel, it finished with 1.2 lbs of
>charcoal and ash. I think with a greater depth of fuel, more top
>edges of the fuel will come into contact with the flow of O2 as it
>moves along the underside of the lower cone. I think this would lead
>to a greater portion of the fuel being consumed, depending on the
>relative downward speed of the pyrolisis.
>
>I think I think........more trials more trials Alex
>
>P.S. Some pictures of the two cone charcoal maker experiment are now
>at http://www1.kingston.net/~english/Stoves.html
>
>> AJH
>>
>>
>>
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927

>Dear Alex,
Thankyou for the order and good luck.You are doing great work and have
stirred the imagination of everybody.Hopefully we will have a chance to meet
some day.

Sincerely,

Paul W. Hait

From larcon at sni.net Mon Jun 16 10:06:19 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Piet on two copy messages
Message-ID: <v01540b03afc8dec2eb0a@[204.133.251.15]>

Stovers:

This below message from Piet has never happened to me. Has it ever
happened to anyone else beside Piet?

Note this note is also being copied to Zach Nobel <zach@crest.org>.
Similar problems are probably better sent to Zach than to the list - and I
presume that Zach will want to know about all such glitches.

Regards Ron

>Since yesterday I get two identical copies of every message from
><stoves@crest.org>
>Yesterday I had 57 messages.
>Aha, an odd number!
>Yes, there was one from a non-stoves@crest.org source.
>Not a big deal, the trash bin can deal with it.
>Piet
>Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
>Phone: +61 79 331761 Fax: +61 79 331761 or 332112
>E-mail:p.verhaart@cqu.edu.au

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From E.Moerman at stud.tue.nl Mon Jun 16 11:12:13 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:18 2004
Subject: Wise men say, if ....
Message-ID: <18749.s335192@popserver.tue.nl>

Alex English:

> come apart. The "true" readings are on the opposite end of the
> scale (9), inspite of a visually clean burn. I do indeed have a long
> way to go.
--------

Etienne:
This is what we observed in our lab for many years. All those so-called
smokeless stoves have virtually no visible smoke, but all have high CO
emissions. We noticed that the smell of the flue gas is a better indicator.
A truely smokeless stove (downdraft stove) does not smell at all, except
perhaps like an electric hairdryer. This is not true for charcoal stoves
which do not smell at all, but still emit a lot of CO.

--------

Alex:
> stove from the Two Cone stove ? I understand the that downdrafters
> are a route to more complete combustion. How do they work as cook
> stoves? What is their minimum chimney requirement? Perhaps we could
> here about the performance data on the stove being developed by
> Pyromid.

-----------

Etienne:
As a cookstove the downdraft stove is a disaster. Due to the high
temperatures (>>1300 K) metal stoves are out of the question. Only stainless
steel can be used which makes the stove far too expensive and requires
well equiped producers. In Bangladesh a clay downdraft Tandoori was tested
in the lab and apparently it performed quite well. Clay or ceramic stoves
might be the solution for downdraft stoves. The efficiencies we
measured for a single pan were mostly below 20%, a second pan gets the
efficiency upto and sometimes slightly over 30% (overall).

For a 12 cm diameter for the fuel bowl, a height for the fuel bowl of about
15 cm and a 10cm chimney diameter a power out put of around 8 kW is obtianed
with clean combustion for White Fir. The minimum chimney length in that case
is abou 60cm. Great performance with a chimney of 1m.

For high power tasks the downdraft processes seem to be ideal. In the lab a
bakery oven was tested. A grate of about 0.2x0.2m provided about 25 kW and
reduced the fuel consumption by almost 20% and reduced the heat-up time by
about the same I think. Also we expect it will do great in kilns, however it
seems that we cannot find the funds for further development together with
Prolena and IT Peru. So it looks like te end of the story.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From bburt at limestone.kosone.com Mon Jun 16 11:58:32 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:18 2004
Subject: Wise men say, if ....
Message-ID: <199706161558.LAA25643@mercury>

From ahe1 at cableol.co.uk Mon Jun 16 19:22:53 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:18 2004
Subject: Nice knowing ya!
Message-ID: <9706162322.AA28852@mars.cableol.net>

Dear Alex and stovers
At 06:56 16/06/97 -0500, you wrote:

>I did a small batch of random pieces of cedar lumber trimmings,
>tossed into the pail, about four inches deep. ( I rigorously forgot
>to weight it.)
UNCLE I give up :-)
> I placed my thermocouple in the middle of the fuel,
>1.5" (4cm) from the bottom of the pail. It took 23 minutes to reach
>280C and another 15 to reach 440C. The temperature climbed steadily
>to over 700C , when the volitiles were used up. The burn lasted 50
>minutes. I was not choking the fire. I then removed the chimney and
>cones and placed a piece of insulation over the top of the pail. The
>temperature began dropping immediately and continued steadily. It
>produced a lovely batch of charcoal.
>

>I think your correct that conduction from the outside and above has
>less to do with the pyrolisis occurring in the middle than the "cell
>to cell" creeping that you describe below.

Yes I am glad I conveyed this meaning to you, Ronal puts a more scientific
slant to it an suggests radiation is the means of heat transfer. From your
measurement of 700C it appears some of the pyrolysis products are burning in
the charge zone rather than in the apparent flame cobustion area below th
cone and above the charge. Or am I mistaken, as Tom Reed says the reaction
reverts to endothermic above 440C where else can the energy come from to
heat the wood over this temperature.

>With these small batches the whole mass approaches flame temperature
>by the time the flames quit.
Which of course is entirely acceptable for the cook stove, a problem however
for scaling up

<snipped account of burn with greener twigs>
>
>
> Starting with 6.5 lbs (3kg) of fuel, it finished with 1.2 lbs of
>charcoal and ash.
This is the order of yield from our kilns using fresh timber.

>at http://www1.kingston.net/~english/Stoves.html
Regular visitor now, makes me twitch :-}
AJH

From ahe1 at cableol.co.uk Mon Jun 16 19:23:21 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:18 2004
Subject: Heggie on kiln operation
Message-ID: <9706162322.AA26807@mars.cableol.net>

Ronal
At 08:05 16/06/97 -0600, you wrote:

> 1. The reason that the charge doesn't burn is that the air supply
>is strictly limited. The draft is low because the chimney height is low.
> 2. There is certainly both updraft and downdraft in a ring kiln -
>but the important thing is that the draft is mostly from the wood side into
>the charcoal side. Thus the pyrolysis zone is traveling against the
>airflow.
> 3. The alternating of the chimney positions with the input
>positions partway through the making is critical to being sure that the air
>flow is against the pyrolysis travel.
(AJH)Yes this largely concurs with what I observe.
> 4. I don't believe any major chemical reactions take place in the
>dome. The main reactions are right at the pyrolysis zone - where CO and
>CH4 and H2 (and lots else) are being produced. These same gases travel
>relatively unchanged (because there is no oxygen left to enter into a
>chemical reaction) to the exit and are being vented through the chimney.
(AJH)Well this is what I came to the list to learn and I guess it makes long
term retention of this technology untenable?

>(RWL): As I understand usual kiln operation, the upper vents are left open
>until it appears that all the moisture is driven off. During this period
>all gas flow is upward and not through the chimneys. Then the top vents are
>closed and the chimneys begin to operate (working because they fill with
>lighter hot gases (not being flared, they are not very hot). The above
>assumes bottom lighting.
(AJH)Yes but we do not have any top vents, steam leaves via the chimneys.
> Apparently there are occasions with more dense fuel charges when top
>lighting is used for a short time with the upper vents open, and then
>switching to the normal alternating lower input and output ports (and
>closed top vents).
(AJH)I cannot at the moment see the advantage
<snipped more analysis on rate of spread of pyrolysis zone which I need more
time to digest>

>(RWL): I believe the large temperature rise only occurs when there is no
>wood left to pyrolyze and the manufactured charcoal begins to combust, with
>much greater heat release. Of course combustion can only occur when oxygen
>is present - and skilled operators know when to shut down.
>
(AJH) I was guessing that pyrolysis products were meeting incoming air in
the pyrolysis zone and producing the large temperature rise, Alex English's
post also seems to point to a sudden rise in temperature above the predicted
440C.
My assumption was that this happens at the point that no free moisture is
left to evaporate ( and hence marking the end of what I termed the steaming
period) and prior to actual loss of charcoal by direct combustion.
Intuitively the air vent are shut or swapped before damage occurs, but as
pyrolysis products are then not burned but emitted then this must be the
period of maximum pollution.
<snipped AJH comments on Alex English's stove
(RWL) 1. The above has some meaning, but I would scratch the idea of 280
>C as a limit.
(AJH) I was using it more as a transition temperature, below this point the
reaction will not take place without external heat (though I thought
pyrolysis was initiated at 232C) and above this point there was spare energy
to propagate the reaction
> 2. The idea of a "chain reaction" presumably relates to the
>radiative heat transfer effect.
(AJH)Point noted
> 3. The free oxygen is depleted not by the flame above but rather
>by the pyrolysis zone below. If any oxygen is left over as it flows up
>past the pyrolysis zone, it would be creating CO2 rather than the desired
>CO - on the surface of the hot charcoal.
(AJH) Yes I used free oxygen illadvisedly here, I did not mean oxygen
existing in the pail or charge but that available from the air spilling
round the edge of the cone.
> 4. The "physical barrier" makes some sense as I believe most of
>the pyrolysis gases travel upward inside the more highly permeable charcoal
>above rather than exiting laterally.
<snipped points attributed to AE but meaning AJH>
>(RWL): The issue of yield (meaning retained hydrogen and oxygen) and
>temperature is an important one and relates to Tom Reed's message of June 8
>("Charcoal - ash and moisture content"). My perception is that some
>(most?) charcoal customers also prefer the higher releasable gas content of
>the higher yield charcoal (up to a point).
(AJH)I jumped into discussion as a newbie without learning the jargon by
proper lurking, I was referring to the yield of charcoal and was unaware of
such sublties of retained volatiles.
<snipped comments by AJH)
>
> (RWL): 1. Have you ever tried flaring with your ring kilns or seen
>any literature on doing so?
(AJH)No on both points, but it does appear desirable environmentally
> 2. Could you describe your "steaming" process?
(AJH) Again I was probably using inadequate terms, I meant that part of the
burn during which visible water vapour is given off, presumably meaning wood
is still drying, though of course the other various stages of pyrolysis and
complete combustion to ash are taking place simultaneously in a large
(2.4m) kiln
> 3. Why not delay the charcoal making until natural drying can take
>place?
(AJH) Lack of space in an urban environment with high transport costs making
storage uneconomical at present, as charcoal is the only saleable product
and the cost appears to be more of retention time in the kiln than loss of
charcoal this is not yet a large consideration.
<snipped description yield : input of charcoal made in a tin>
>
> 1. The number 5.9 MJ/kg sounds low on a wet basis. What moisture
>content are you assuming?
(AJH)From Forestry commission data pine at 150% moisture content expressed
as % of dry wood. Hence 1kg green wood consists of .6kg water .4kg bone dry
wood. From memory as I do not have data to hand I calculated the .6 kg water
evaporated at 100C at 2.7 MJkg subtracted from the .4kg wood at approx
18Mj/kg which I see gives 5.58 so my remembered start conditions are
slightly awry.
>Did you perform a moisture content test?
(AJH)No
> 2. I believe most of the energy loss is in the unburned
>hydrocarbons. But of course some of the initial energy in the wood was
>also radiated away. I gather it is very difficult to do a complete energy
>balance.
(AJH)Yes I noted your earlier comments
> 3. I presume "cocoa tin" means all external heating. What
>temperature was used?
(AJH) This is the experiment given to schoolchildren to make charcoal for
drawing with, a tin with a tightly fitting lid is filled with long straight
twigs, a small hole is punctured in the lid and the tin put in a fire. The
children observe the steam and then the bright yellow flame, after cooling
the charcoal is used for drawing.
Thanks for comment
AJH

From english at adan.kingston.net Mon Jun 16 22:58:38 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:18 2004
Subject: More trials........
Message-ID: <199706170258.WAA26157@adan.kingston.net>

Dear Stovers
Tonight I tried burning hay in the cone burner. The cone formed to
good a seal on the packed hay for the minimal draft to provide
the flaming pilot light that seems so necessary. There was no
shortage of smoke. It might help to have a jagged edge on the cone
for this type of fuel, or perhaps a mixture of wood , twiggs and
grass. Another day!

While cleaning up a work building here I was fortunate to find two
2"*4" weldable steel reducing coupling. Pipe fittings that look like
cones. (Pictures on the web tomorrow or the next day) When put
together small end to small end they form a suitable venturi for the
chimney. I welded them together with a 1/4"(6mm) space between them
and welded one of the large ends to the top of the lower cone. (No
upper cone this time) On top of the venturi I placed a 20" chunk of
3.5" pipe.
Skipping some details, I can say that once it got going,
the arrangement performed well. Modern oil burners have what they
call a flame retention head. This is essentially a well designed
turbulent zone near to the nozzle which enhances the mixing of the
fuel and air and therefore it's combustion.
The venturi gave a similar effect in the region just above it. I did
not get to measure or adjust much, but I think its a step in the
right direction. More details latter.

Alex

P.S. The setting , the hardware and tools, and some much needed
advise are all a part of Burt's Greenhouses, a capitalist backwater
from which swirls of co-operation occasionally materialize. Cheers !
Brian and Ruth
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Tue Jun 17 00:35:33 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: BOUNCE stoves@crest.org: Message too long (>40000 chars)
Message-ID: <v01540b00afcbb369c587@[204.133.251.4]>

Art: This file is the first of 22 that CREST forwarded to me labeled
"BOUNCE".
Not only can CREST not handle this, but I also timed out the first time I
tried to retrieve it. The last two times this happened, I had to ask my
system operator ("sni") to delete the file. I do not even know who sent
them.
If this was headed for Alex English, I suggest a direct transfer. If
intended for the full list, we are going to have to shorten by about a
factor of 20.

Stovers: I guess until further notice from the CREST manager of "stoves"
(Zach Noble), we are going to have to limit all files to 40,000 characters.

Zach: I hope you will give our list the appropriate guidance on how to get
big files like Art's into the system.

Regards to all Ron

>>From stoves-owner@crest.org Mon Jun 16 13:25:40 1997
>Received: from spanky.transport.com (pdx1.transport.com [204.119.17.10])
>by solstice.crest.org (8.8.5/8.7.3) with ESMTP id NAA23843 for
><stoves@crest.org>; Mon, 16 Jun 1997 13:25:26 -0400 (EDT)
>Received: from
m (vanc1-10.transport.com [209.51.65.201]) by spanky.transport.com
(8.8.5/8.6.10) with SMTP id KAA03771; Mon, 16 Jun 1997 10:22:39 -0700
>Message-ID: <33A575E2.3715@transport.com>
>Date: Mon, 16 Jun 1997 10:21:31 -0700
>From: Art Krenzel <phoenix@transport.com>
>Reply-To: phoenix@transport.com
>X-Mailer: Mozilla 3.01 (Win95; I)
>MIME-Version: 1.0
>To: stoves@crest.org
>Subject: One old guy replies....
>Content-Type: multipart/mixed; boundary="------------407A5C1C32BA"
>
>This is a multi-part message in MIME format.
>
>--------------407A5C1C32BA
>Content-Type: text/plain; charset=big5
>Content-Transfer-Encoding: 7bit
>
>I have been reluctant to add "fuel to Alex's fire" so to speak but I am
>one of the guys who has one of those text's on chimney design. I would
>like to pass on a page in the book for your information.
>This is my first scan so help me reduce my file size.
>
>Art Krenzel
>
>--------------407A5C1C32BA
>Content-Type: application/octet-stream; name="Chimdraf.pcx"
>Content-Transfer-Encoding: base64
>Content-Disposition: attachment; filename="Chimdraf.pcx"
>
>CgUBCAAAAABLAaICSwBLAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
>AAAAAAAAAAAAAAABTAECAIAC4AEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
>AAAAAAAAAAAAAAAAAAAAAAAAAADx/8H9z//B/f///////83/wf7C/8H+wf/B+8z/wf7C/8H8
>xf/B/cH3wf3B+cH9wffB/sP/wfzB88H/wfvB+MH6wfnB+sH0wf/B/MH0wfjB+8H1wfDB8sH5
>wfLB8cHzwevB7cHqwefB2rHS/8H93f/B/P//0v/B/u//wfz//87/wf7J/8L9wf7G/8H+xv/B
>/cP/wf7C/8H8w//B+8H9wfzB/sH9wf7B+sH/wfvB/MH6wfnB/cH/wf7B+sP/wfzB/8H5wfrB

About 75% of the first file is hereafter truncated. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From hmrajabu at ucdavis.edu Tue Jun 17 02:09:13 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:18 2004
Subject: Hasssan on briquetting sawdust (?)
In-Reply-To: <v01540b04afc7a6bb522c@[204.133.251.2]>
Message-ID: <Pine.GSO.3.95.970616113616.26014A-100000@chip.ucdavis.edu>

On Fri, 13 Jun 1997, Ronal W. Larson wrote:

> (RWL): Could you describe this carbonizing facility also. Does it vent
> or flare or use the pyrolysis gases? What type of equipment and yield,
> etc? Per kg, what is the difference in cost?

HR: The carbonizing plant is arranged this way:

About 1/2 a tonne of the 45cm briquettes are arranged in a pile/block of
about 1.5 x 1.5 x 1.5 meters^3 and covered by a metal kiln (cover)
with inner ceramic liner. The fire is started at the bottom. The gases are
vented (no flaring) to the atmosphere.

The process is operated by experience of the operator by
regulating the bottom and top vents through observation of the
colour of the vented gases versus time lapsed

When I visited, the kiln was not operating (normally started after
receiving an order). I managed to gather few information from the
operators and observation of some carbonized reject pieces scattered
around. The kiln produces a good number of good pieces and some rejects
which are partially carbonized and others which are almost completely
burned.

I cannot recall the costs/prices, but the uncarbonized were competing well
with the fuelwood especially for customers who buys in bulk. It was also
mentioned by one bulk buyer that there is a lot of cheating in fuelwood
buying because of moisture content and created voids in truck loads
(normally buying in truck-load volumes). Market on the domestic market was
difficutlt to conclude since the factory was not advertising nor sending
briquettes to the local fuel market centers. This is also because the
factory does not meet the demand of even the instiutions they supply.

> (RWL): Can you suggest a range of diameters of a charcoal cylinder that
> domestic users would find best? I believe that a household-sized
> charcoal-making stove would work best with an input briquette diameter of
> about 2 to 4 cm.

HR: I also think 2 - 4 cm is within the range for domestic. I also think
that the domestic users are selective on the size versus the cooking
tast intended. Also experienced charcoal stove users like my mother likes
to mix small and bigger pieces to reduce void spaces. I still remember
when I was a little boy I used to see her put bigger pieces aroung
the perimeter and smaller pieces (up to 1cm) at the center, or where she
intents to start the fire. That way she can start the fire with minimum
kerosene(starter), and never misfires.

> (RWL): Could you comment further on this. I think wood always shrinks as
> it is pyrolyzed - more in diameter (20%? I think than in length (10%?). Do
> you ever see shrinkage for briquettes? Is it the least dense briquette
> that expands the most or vice versa?

HR: My observation is that briquettes shrinks slightly in the radial
direction and expands in the axial direction during pyrolysis

> (RWL): Could you comment on the final strength of these carbonized
> briquettes compared to natural charcoal.

HR: The experiments which I am currently doing are on combustion of
briquettes and wood. In some experiments I have been quenching the burning
pieces at pre-selected times to take measurements on the char and unburned
parts of samples. The Char formed in these conditions is definitely
different from the carbonizig kiln, or charcoal-making stove.

> How are you investigating this issue of expansion? Is there any
> major difference in expansion if combustion of the compressed briquette
> occurs directly rather than combustion of the carbonized briquetter?
>

HR: I think carbonized briquette hardly expands during burning.

> Hassan - It seems you are deeply into charcoal vs wood issues. As a
> long-term member of this list, do you have any further comments on when
> each is more or less appropriate? (Including cost issues, responding for
> both commercial and residential users) Thanks for a very complete response
> on briquetting.

HR: I am currently researching (Ph.D) on wood vs briquettes' combustion
issues. The set-up simulates industrial/commercial conditions (high
temperature (>1000K) and approaching velocities (1-2 m/s)).

In developing countries, and Tanzania in particular increasing
agricultural activities increases demand for fuelwood in agro-processing
industries for crops which needs immediate (local) processing after
harvesting, such as: tea drying, tobacco curing, sugar (brown) making,
etc,.

In these areas fuelwood scarcity increases year after year as the
distance they cover to collect fuel increases each year. As a move to slow
the rate of deforestation the government imposed a condition for the
farmers to grow twice the number of trees they consume each year in order
to reverse the trend.

In the same effort research institution like University of Dar es Salaam
were also urgued by the government to look into technology
and/or alternative fuels for small industries processes and other
commercial consumers of fuelwood like brick making, bakeries, etc,. These
two groups are the MAJOR consumers of TREES (because of the sizes of
fuelwood they prefer in their combustors). Also unlike most of the local
domestic users, they purchase fuelwood from vendors hence briquetting, if
cost effective, can penetrate this market without the need of the
social scientist and reduce the rate of consumption of the local forests .

The use of briquettes presented an attractive option since requires
minimum investment for the combustion units in changing from
fuelwood to briquettes. The problem is briquettes, like fuelwood, can be
made in a wide range of properties. What dimensions and properties are
important or are more sensitive in its combustion?

A good idea for the farmers will be to use briquettes which burns like the
local wood, or better. What should be the briquetting parameters? or
storage time (shelflife) vs conditions (RH)?

> regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From hmrajabu at ucdavis.edu Tue Jun 17 02:30:17 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:18 2004
Subject: sawdust briquettes
In-Reply-To: <m0wcrSP-0006UjC@arcc.or.ke>
Message-ID: <Pine.GSO.3.95.970616231534.7295B-100000@boris.ucdavis.edu>

On Sat, 14 Jun 1997, Elsen L. Karstad wrote:

> Expansion of briquettes on carbonisation.... is this related to initial
> compression? What binder is used in the Tanz. operation?

The expansion of briquettes I mentioned was during the pyrolysis stage of
combustion. I am not sure if the expansion curve will be the same during
carbonization. However, the expansion during pyrolysis was related to the
initial apparent density of the briquettes which in turn can be related to
the die pressure, up to a certain maximum die pressure, among other
things.

The KIDC briquettes are self binding. No binder is used.

>
> What, if you know, is the plant capacity V.S. recent production? Are thay
> making an operational profit?
>

The plant capacity is 1.5 tonnes (metric). Initially, the plant was
subsidized to attract market. The price was thereafter increased to
reflect the costs of making the briquettes. According to them the facility
(KIDC has many activities) is now self dependent.

> Regards;
>
>
> elk
>

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From elk at arcc.or.ke Tue Jun 17 02:53:39 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:18 2004
Subject: preferences & progress
Message-ID: <v01510100afcb193408b1@[199.2.222.129]>

>Setting aside a lack of understanding of smoke related health and
>pollution effects, I gather that the market place in developing
>countries has voted for charcoal. Is this strictly custom or are
>transportation and handling issues paramount.

asks Alex English.

Charcoal smokes less in traditional stoves, It's transported easier and is
broken into easy to handle bits via it's production process. I assume, (&
should know by now, after reading the stover's communications) that there's
more energy per kg in charcoal than wood. The final preference is strongly
'custom' too.

Note that charcoal isn't used much where fuel wood is free for the picking.
This restricts it's primary use to urban areas, and the demographics of
it's use can be charted as a slowly expanding zone around all African
cities as a reflection of growing wood scarcity due to overharvesting.

'Burning Charcoal Issues' is a very concise resume of the why's and
where-fors of African charcoal use posted on the internet by the World
Bank. I found it Via CNN's infoseek using 'charcoal energy' as search kety
words. I've just tried to access at:
http://www.worlbank.org/html/fpd/Energy/energynotes/energy01.html but
cannot raise the article. Maybe stovers in other places would have more
success. I commend WB for this sort of work and wonder where it leads...?

News in from R&D on the briquetting attempts with milled sawdust charcoal
and 10% cement. No go. The briquetter jams every time. Now why would the
milled bottom of bag charcoal have given such nice results while the fresh
carbonised sawdust (irrespective of particle size) have such a high
resistance in the briquetter barrel?

I'll do the mollasses & raw sawdust trials tomorrow, but I think I've found
the problem.... My sawdust is underdone. A lot of dark brown, incompletely
carbonised material. Back to the kiln. I think I might just sink out of
sight for a while until I sort out the procedure!

The charcoal making (twocan type) stove MK 1 is coming out of my welding
shop tomorrow. Looking forward to seeing how my turbo version works. This
is a test of the stover's communication skills. Fabricated straight off the
'net.

My ultimate goal is a twocan sawdust burner- any ideas? I've a couple of
welding machines, and angle grinder or two, three and a half underworked
metalworkers and a mountain of assorted scrap metal within my factory
maintenance section. Maybe not the true joys of hands-on fabrication, but
I'm the one with the matches!

Bye for now;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From hmrajabu at ucdavis.edu Tue Jun 17 04:14:23 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:18 2004
Subject: sawdust briquettes (correction..)
In-Reply-To: <Pine.GSO.3.95.970616231534.7295B-100000@boris.ucdavis.edu>
Message-ID: <Pine.GSO.3.95.970617011108.19118A-100000@chip.ucdavis.edu>

On Mon, 16 Jun 1997, HMRajabu wrote:

> The plant capacity is 1.5 tonnes (metric). Initially, the plant was
(snip)

...1.5 tonnes per day (8 hours)...

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From hmrajabu at ucdavis.edu Tue Jun 17 04:53:39 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:18 2004
Subject: preferences & progress
In-Reply-To: <v01510100afcb193408b1@[199.2.222.129]>
Message-ID: <Pine.GSO.3.95.970617012026.19118B-100000@chip.ucdavis.edu>

On Tue, 17 Jun 1997, E. L. Karstad wrote:

> Note that charcoal isn't used much where fuel wood is free for the picking.
> This restricts it's primary use to urban areas, and the demographics of
> it's use can be charted as a slowly expanding zone around all African
> cities as a reflection of growing wood scarcity due to overharvesting.

Major percent of people living in urban areas are workers or traders,
vendors, etc,. and most live in rented houses. Most landlords restricts
the use of fuelwood stoves because of the mess and smoke. As a matter of
fact it is practically impossible to use fuelwood stove if the house does
not have an outside kitchen. Most urban houses don't have space for the
"luxury" of the outside kitchen.

A recent survey in Dar es Salaam showed that kerosene is cheaper than
charcoal. However, according to the recent energy price policy
(government), kerosene is subsidized to encourage people to switch from
charcoal. It is a cross subsidy, paid by gasoline users.

The defforastation around cities is attributed to charcoal makers.

> _____________________________
> Elsen Karstad
> P.O Box 24371 Nairobi, Kenya
> Tel:254 2 884437
> E-mail: elk@arcc.or.ke
> ______________________________
>

Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From klunne at itc.nl Tue Jun 17 06:40:18 1997
From: klunne at itc.nl (ir W.E. Klunne (ITC Rural Energy Specialist))
Date: Tue Aug 31 21:35:18 2004
Subject: introducing Wim Klunne as a new list member
Message-ID: <33A66966.1E96@ITC.NL>

Dear listmembers,

About two weeks ago I subscribed myself to the stoves newsgroup. By
means of this e-mail I like to introduce myself in order for you to have
at least an idea of who is connected. To be honest, the crest
co-ordinator of the stoves list, Ronal W. Larson, welcomed me to the
list and expressed the hope I would introduce myself to the others. I
appreciated this welcome message and will fulfill his request.

My name is Wim Klunne and I work with the International Institute for
Aerospace Survey and Earth Sciences (ITC) in Enschede, the Netherlands
as rural energy specialist.
More information on the institute can be found at our web-site at
http://www.itc.nl
I am working in the Forest Science Division (info at
http://www.itc.nl/ha2/forest) and I lecture on rural energy, fuelwood
and energy modelling for students from developing countries following a
Professional Masters or Master of Science course at our institute.
Further I supervise PM students on their fieldwork and MSc students on
their MSc research on energy related topics. Students I am working with
mainly follow the Forestry for Rural Development, Forest Survey or Rural
Energy and Development courses.
More information on our MSc course on Rural Energy and Development can
be found at http://www.itc.nl/ha2/forest/energycourse.htm

I joined the stoves-list to get a better insight in the current
developments on stoves, as my expertice on that field is rather limited.
I am employed at ITC for just one year now and do have quite a number of
ideas on improvements of our courses. One of them is to include more on
wood and charcoal stoves and I hope the messages I receive from the
stoves-list will help me in that.
Related to this is a request to members of the stove-list to let me know
of interested web-sites on this topic. I had of course a look at English
photo pages and did several net searches with relevant key words, but I
am very interested in learning more on the topic.

Up till now you cannot expect much input from my site into the
discussions ongoing on the list, but you can be assured the information
offered is appreciated.

Thank you for your attention.

Best regards,

Wim Klunne

=============================================================
ir W.E. Klunne (rural energy specialist)
ITC / LARUS, PO Box 6, 7500 AA Enschede, the Netherlands

phone: +31 53 4874 218
fax: +31 53 4874 399
e-mail: klunne@itc.nl

INTERNET
forest science http://www.itc.nl/ha2/forest
rural energy http://www.itc.nl/ha2/forest/energycourse.htm
personal http://www.itc.nl/~klunne
=============================================================

From verhaarp at janus.cqu.edu.au Tue Jun 17 06:41:55 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:18 2004
Subject: Piet again on two copy messages
Message-ID: <1.5.4.32.19970617104132.00687c68@janus.cqu.edu.au>

>From Piet
Dear Ron,

At 08:05 16/06/97 -0600, you wrote:
>Stovers:
>
> This below message from Piet has never happened to me. Has it ever
>happened to anyone else beside Piet?

>>Since yesterday I get two identical copies of every message from
>><stoves@crest.org>

A thought:
Could there be more than one E-mail address of me at <stoves@crest.org> ?
It started with <verhaarp@janus.cqu.edu.au>; then <verhaarp@cqu.edu.au>
appeared to work as well. At one stage, a few weeks ago, my E-mail facility
was cancelled and it took a day or two to reinstall it. That involved the
latest address change to:
<p.verhaart@cqu.edu.au>,
in keeping with the address format for staff members. It has been shown that
they all still work, maybe I should feel fortunate in receiving only two
copies instead of three.
I will take this up with the University tomorow, after which it is likely
only the <p.verhaart@cqu.edu.au> address will work.
Cheers,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From elk at arcc.or.ke Tue Jun 17 07:59:41 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:18 2004
Subject: Test Equipment
Message-ID: <v01510101afcc28af3b4c@[199.2.222.130]>

Stovers;

Alex English has provided me with some contacts for suppliers of testing
equipment and wonders if standardisation within 'stovers' is advisable.

Any recommendations? Should we, from now on, try to stick to one supplier
after deciding collectively on the most appropriate equipment?

Regards;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From E.Moerman at stud.tue.nl Tue Jun 17 10:53:00 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:18 2004
Subject: Moerman and Karstad on carbonization.
Message-ID: <17569.s335192@popserver.tue.nl>

Etienne:
>> As you probably expect by now, I don't agree that charcoal stoves are
>> superior to woodstoves.
>>
---
Alex:
> Are you including charcoal-making stoves in this assessment ?
>
-------
Etienne:
I only tried to make the charcoal producing stove from Ron L. and Tom R. 2
or 3 times. I did not succeed in obtaining clean combustion and/or blue
flames. So far I have no opinion on this stove.
-------
Alex:
>
> Ron has pointed out that the charcoal-making stove may
> have a side benefit of producing a marketable product while
> performing regular daily activities. I liken this to the early

Etienne:
I have my doubts on the practical implementation of this. First of all I
expect that more wood is used for the same cooking task and part of this is
sold as charcoal. Second normal cooking use of the stove would mean a
production of around 200 g. a day with a sufficiently large size. These
small amounts are not interesting for the charcoal resellers. For them it is
far more convenient to buy one large batch from a producer. The only option
is that some middle (wo)man goes around to buy up the charcoal, transport
and sell it to the reseller. This will drive up the costs. Thirdly if
everybody is switching to charcoal producing stoves there is an insufficient
market for the produced charcoal.

----------

Alex:
> I am ignorant of charcoal stove emissions. How bad are they?

Etienne:
Difficult to say. I only measured them in the downdraft stove. In the
downdraft stove the CO/CO2 ratio gets to slightly below 0.5%, which is about
10 times higher than for White Fir and Corn Stover briquettes. Also the 0.5%
CO/CO2 ratio for charcoal is only obtained for an excess air factor between
1.3 and 1.5, so a very small range indeed. In fact much smaller than for
wood. Comparing the downdraft stove to a normal 'smokeless' stove with White
Fir as a fuel results in about 30 times more CO emissions for the smokeless
stove compared to the downdraft. The emissions from the normal 'smokeless'
stove are less sensitive to the excess air factor and are scattered quite a
lot. If we assume a 30 times higher CO emission from the charcoal stove too
than we would get a CO/CO2 ratio around 6%.

--------

I hope this helps.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Tue Jun 17 12:03:39 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:18 2004
Subject: Wise men say, if ....
Message-ID: <21834.s335192@popserver.tue.nl>

Brian: Burt
>
> In your opinion is the poor CO emissions of the charcoal stoves primarily a
> function of temperature or of mixing.

Etienne:
I find this difficult to say. Of course air is not available in a sufficient
amount for complete surface combustion. What happens with CO when additional
air is supplied I don't know. However I suspect that the main problem is the
temperature since combustion rates depend on the temperature like exp(-E/RT)
and are at most only linearly dependent on the oxygen supply. Remember that
when you provide additional air to the charcoal that its temperature drops
due to the cooling effect of the air flow.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Tue Jun 17 12:03:46 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:18 2004
Subject: Stoves list protocols
Message-ID: <21827.s335192@popserver.tue.nl>

I have only took a renewed interest in the stoves list in the last week or
so. Since I had no time at all previously I deleted about all messages
unseen. At this moment I tend to do the same with quite a lot of messages.
To avoid information overkill and jamming up the internet bandwidth I
suggest that everybody tries to confirm to the following guidelines:

1. The stoves list server does not accept messages larger than 40000 bytes. If
you have attachements or messages that are larger than say 10000 or 20000
bytes (characters) send a message containing a brief description of the
content to the stoves list. Interested subscribers can than request the full
attachement from the original author. Doing this most subscribers that are
not interested don't have their email facilities clogged up and time wasted
on subjects that they are not interested in. In addition the internet lines
get less traffic.

2. Do not copy complete messages just to add 1 or 2 lines with comments. Try
to cut away most of the irrelevant info. This avoids that people have to
thumb through tens of lines to look for new info. Messages like that take a
lot of my time and I tend to throw them away unread. Again the internet
lines get less traffic this way too.

3. If have an answer to an email message that is meant for the author of the
message only, send it to the author directly and not to the stoves list. A
lot of general comments are in my view not appropriate for the stoves list.
When in doubt send it to the stoves list, but when it is obvious that the
message is only meant for 1 or 2 people please mail it to them directly.

If everybody tries to conform to these points as much as possible than we
can reduce the time we spend on the stoves list and use it far more
efficient.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From rcala at reduc.cmw.edu.cu Tue Jun 17 16:58:02 1997
From: rcala at reduc.cmw.edu.cu (Ramon Cala Aiello)
Date: Tue Aug 31 21:35:18 2004
Subject: pyrolysis
Message-ID: <9706171443.aa04960@reduc.cmw.edu.cu>

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From larcon at sni.net Tue Jun 17 18:02:38 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Test Equipment
Message-ID: <v01540b03afcc7cdfde30@[204.133.251.3]>

Today (June 17) Elsen said:

>Alex English has provided me with some contacts for suppliers of testing
>equipment and wonders if standardisation within 'stovers' is advisable.
>
Alex and Elsen - I think this is a valuabel thread to continue. I know
almost nothing on such equipment. I would like epecially to find low cost
equipment that everyone can afford.
I am told that some computerized automobile engine performance
optimization is now done with CO2 sensors. With millions in use, might
that cost be pretty low?
Also, there are many CO sensors available for home safety uses.
Might any be amenable to putting a meter on them rather than an audio
alarm?

>Any recommendations? Should we, from now on, try to stick to one supplier
>after deciding collectively on the most appropriate equipment?

OK - if clearly superior.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 18:02:44 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Burt and Moerman on CO
Message-ID: <v01540b02afcc75d536a2@[204.133.251.3]>

In a message of June 16, Brian Burt quoted Etienne Moerman's message of the
same day:

>> Etienne:
>> This is what we observed in our lab for many years. All those so-called
>> smokeless stoves have virtually no visible smoke, but all have high CO
>> emissions. We noticed that the smell of the flue gas is a better
>indicator.
>> A truely smokeless stove (downdraft stove) does not smell at all, except
>> perhaps like an electric hairdryer. This is not true for charcoal stoves
>> which do not smell at all, but still emit a lot of CO.
>>

and then Brian Burt asked:

>In your opinion is the poor CO emissions of the charcoal stoves primarily a
>function of temperature or of mixing.

Because I think this is a very valuable thread, I want to ask a few more
questions along the same line.

My questions:

1. I hope Etienne will repeat the nature of the CO experiments
with charcoal cookers that he gave about a year or more ago - with as much
detail as possible. Is it universally true that charcoal stoves always
emit excessive CO through the whole burn?
2. I wonder if Paul Hait has measured CO production in the Pyromid?
3. Ron West had a piece 6-8 months ago on the production of CO vs
CO2, noting the great tendency to produce CO2 when CO and O2 were both
present on the surface of charcoal. Ron will be back soon from Turkey; he
has done a good bit of this sort of study. I've left a message.
4. I wonder if anyone else (Kirk Smith?) has CO data of the sort
Etienne is describing. I think that the production of charcoal in the
traditional manner has lots to be concerned with (including massive
production of CO), but if Etienne is correct that CO production is a
serious problem (and that this CO problem can't be solved), then I don't
want to be in the business of promoting charcoal-producing stoves.
5. It looks like I will have to buy a CO monitor unit - anyone have
a favorite?
6. Could Kirk Smith or someone else describe the accepted limits
for CO input?

Also we should welcome Brian to the dialogue. As a co-ordinator, I
know that Brian has been on this list a long time and this might be his
first input. But because he is apparently Alex' boss and also helper on
the two-cone approach, I'd like to hear more about Brian's background and
interest in the stove area. Maybe Alex can do so.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 18:03:43 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Rajabu on kerosene
Message-ID: <v01540b08afccb50a1061@[204.133.251.3]>

>On Tue, 17 Jun 1997, Hassan wrote:
<snip>
>Major percent of people living in urban areas are workers or traders,
>vendors, etc,. and most live in rented houses. Most landlords restricts
>the use of fuelwood stoves because of the mess and smoke. As a matter of
>fact it is practically impossible to use fuelwood stove if the house does
>not have an outside kitchen. Most urban houses don't have space for the
>"luxury" of the outside kitchen.

(RWL): 1. Is the restriction on fuelwood stoves for both those with and
without chimneys leading the smoke outdoors?

>
>A recent survey in Dar es Salaam showed that kerosene is cheaper than
>charcoal. However, according to the recent energy price policy
>(government), kerosene is subsidized to encourage people to switch from
>charcoal. It is a cross subsidy, paid by gasoline users.

(RWL):

1. Can you provide the price of kerosene and the magnitude of the
subsidy in Tanzania?
2. What is your (and everyone's) opinion on the appropriateness of
encouraging kerosene use for cooking? Any idea of the magnitude of the
currency drain (not worrying about the transfer payment, but of the drain
of national finances out of the country.
3. In Tanzania, is there concern about global warming from the use
of fossil resources? (There is little in the US) I am wondering about the
long term social benefit of promoting kerosene stoves - but maybe a short
term use in coutnries like Tanzania to allow forests to come back is
appropriate. But maybe they won't come back if they are not needed for
fuel wood.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 18:03:45 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Wim Klunne - questions on schools
Message-ID: <v01540b06afcca767dc52@[204.133.251.3]>

Stovers:

Wim said:
<snip>

>Further I supervise PM students on their fieldwork and MSc students on
>their MSc research on energy related topics. Students I am working with
>mainly follow the Forestry for Rural Development, Forest Survey or Rural
>Energy and Development courses.

<RWL>: Who are "PM" students? About how many are there? Are there many
such students and programs in the Netherlands and Europe? I don't think we
have very many (or any) here in the states.

<snip on web sites)

>I joined the stoves-list to get a better insight in the current
>developments on stoves, as my expertice on that field is rather limited.
>I am employed at ITC for just one year now and do have quite a number of
>ideas on improvements of our courses. One of them is to include more on
>wood and charcoal stoves and I hope the messages I receive from the
>stoves-list will help me in that.

<snip>

<RWL>: If you are like me, you will become more confused (I find this to
be a very difficult design topic). I wonder if some of your students would
be interested in stove testing and development. They sound like an
excellent potential source of information about cooking in their home
countries and probably with a motivation to improve things. I think we can
find dozens of stove development topics.

Could your type of school and program be organized into a type of
stove competition? (This is an old recurring idea on this list.)

Thank you for providing your introduction. I hope you will have
started a new thread on your type of educational program (and that we can
find a way to attract other instructors like yourself).

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 18:03:47 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Hasssan on briquetting sawdust (part 2)
Message-ID: <v01540b05afcc81b0ffdd@[204.133.251.3]>

On the 16th and 17th, Hassan said:

<snip>

>> (RWL): Could you comment on the final strength of these carbonized
>> briquettes compared to natural charcoal.
>
>HR: The experiments which I am currently doing are on combustion of
>briquettes and wood. In some experiments I have been quenching the burning
>pieces at pre-selected times to take measurements on the char and unburned
>parts of samples. The Char formed in these conditions is definitely
>different from the carbonizig kiln, or charcoal-making stove.

(RWL): Could you further define these differences?

<snip>
>In these areas fuelwood scarcity increases year after year as the
>distance they cover to collect fuel increases each year. As a move to slow
>the rate of deforestation the government imposed a condition for the
>farmers to grow twice the number of trees they consume each year in order
>to reverse the trend.

(RWL): Can you comment on the success of this government edict? In
Tanzania, is the land owned or leased from the government and who owns the
newly planted trees? Did you grow up in Tanzania?

<snip>

> The problem is briquettes, like fuelwood, can be
>made in a wide range of properties. What dimensions and properties are
>important or are more sensitive in its combustion?

(RWL): Knowing that this is your thesis and you are probably still
working on this topic, are there any answers yet that you can report?

>
>A good idea for the farmers will be to use briquettes which burns like the
>local wood, or better. What should be the briquetting parameters? or
>storage time (shelflife) vs conditions (RH)?

(RWL): Same question.

Thanks for a very good response to my earlier questions. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 18:03:51 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:18 2004
Subject: Karstad's preferences & progress
Message-ID: <v01540b07afccacff2cb9@[204.133.251.3]>

Elsen said:

<snip>

>I'll do the mollasses & raw sawdust trials tomorrow, but I think I've found
>the problem.... My sawdust is underdone. A lot of dark brown, incompletely
>carbonised material. Back to the kiln. I think I might just sink out of
>sight for a while until I sort out the procedure!
>
>The charcoal making (twocan type) stove MK 1 is coming out of my welding
>shop tomorrow. Looking forward to seeing how my turbo version works. This
>is a test of the stover's communication skills. Fabricated straight off the
>'net.

(RWL): Depending on your report - "I think I might just sink out of
sight for a while until I sort out the procedure!"
>
>My ultimate goal is a twocan sawdust burner- any ideas? <snip>

<RWL>: 1. Did you mean "two can" sawdust charcoal-maker or sawdust
burner? (I assume charcoal-maker in the following, as the word "two can"
to me means a separate secondary air supply to me needed for using the
pyrolysis gases. We have previously talked about one sawdust burner. ).

2. The Antal charcoal-maker may be ideal. Were you on the stoves
list when this came up?

3. I described also a bit ago a "Grover" stove designed for such
material as sawdust. Unfortunately relatively large and expensive, but
maybe the "donut" shape can work - I think it is like Mike Antal's in
having external thermal input and driving off combustible gases.

4. I'm wondering about a series of vertically stacked book-shaped
containers made out of something like window screen (fine enough mesh to
contain the sawdust),and stacking these together with a small air channel
between them in a square closed 5-10 liter lower box (with a few pluggable
primary air holes at the bottom). Then a slit and an upper can for
combustion of the pyrolysis gases obtained when top lit.
I'm afraid that the window screen might not last long enough. I
think that the temperature will not be a problem for the window screen, but
that it wouldn't last just because of the multiple handlings. The idea is
to get radiation from one "sawdust-filled-open-book" to the next in a
planar version of what happens with round pieces of wood.

Probably a bad idea.

5. The idea of making charcoal from sawdust still seems like a
good idea - but I hope that it is done only with use (not venting) of the
pyrolysis gases. Good luck.

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From english at adan.kingston.net Tue Jun 17 18:58:56 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:18 2004
Subject: Burt and Moerman on CO
In-Reply-To: <v01540b02afcc75d536a2@[204.133.251.3]>
Message-ID: <199706172258.SAA26437@adan.kingston.net>

Not so Dear Ron
you said:
> Also we should welcome Brian to the dialogue. As a co-ordinator, I
> know that Brian has been on this list a long time and this might be his
> first input. But because he is apparently Alex' boss and also helper on
> the two-cone approach, I'd like to hear more about Brian's background and
> interest in the stove area. Maybe Alex can do so.

What ? You want me to publicly assess my boss!
I'll have to think about this.......................
......................this could be fun............stay tuned.......

From bburt at limestone.kosone.com Tue Jun 17 19:08:20 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:18 2004
Subject: Burt and Moerman on CO
Message-ID: <199706172308.TAA19655@mercury>

> What ? You want me to publicly assess my boss! > I'll have to think about this.......................> ......................this could be fun............stay tuned.......> > AlexRemember that assessment begets assessment!!!!!!!Brian

From J.J.Todd at geog.utas.edu.au Tue Jun 17 19:36:16 1997
From: J.J.Todd at geog.utas.edu.au (John Todd)
Date: Tue Aug 31 21:35:18 2004
Subject: Test Equipment
In-Reply-To: <v01540b03afcc7cdfde30@[204.133.251.3]>
Message-ID: <3.0.1.32.19970618093727.0069ed9c@postoffice.sandybay.utas.edu.au>

Ron and others,
snip
>Alex and Elsen - I think this is a valuabel thread to continue. I would
like epecially to find low cost equipment that everyone can afford.
> I am told that some computerized automobile engine performance
>optimization is now done with CO2 sensors. With millions in use, might
>that cost be pretty low?
> Also, there are many CO sensors available for home safety uses.
>Might any be amenable to putting a meter on them rather than an audio
>alarm?
Low cost CO2 and/or CO monitoring equipment would be a marvelous asset to
all those involved in biomass research and development. As Ron mentions,
such sensors are quite common now in cars and domestic gas burning
equipment. Another low cost sensor that might have good application is the
smoke alarm with its particle sensor. What we need is some simple
electronic circuits to give a proportional output from any of these
sensors. I will check with some of my electronic colleagues.
John Todd
*************************
Assoc. Prof. John Todd
Dept of Geog. and Environmental Studies, University of Tasmania
GPO Box 252-78, HOBART, Tas. 7001 Australia
ph (03) 6226 2390, fax (03) 6226 2989
e-mail J.J.Todd@utas.edu.au

From elk at arcc.or.ke Tue Jun 17 20:02:54 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:18 2004
Subject: twocan turbo
Message-ID: <m0we3gq-0006VOC@arcc.or.ke>

Stovers;

My Turbo Twocan Mk I impressed the hell out of my staff- who have been
cooking on either wood, charcoal or kerosene all their lives. I'll describe
it first and outline it's performance second:

Made of 1 mm sheet iron and assembled with an electric welder and an angle
grinder, the unit has an inside diam of 30 cm and stands 70 cm tall. An
outer shell (insulator and fresh air inlet air pre-heater) 1.25 cm distant
from the main body starts 11 cm from the bottom of the stove to 9 cm from
the top. This shell is open both at the top and the bottom. A 3mm air inlet
gap circumvents the inner tube 20 cm from the top. Three 3 cm long by 2 cm
high primary air inlets located 5 cm from the base of the stove are
controlled by a snug rotating band of very light wt. sheet iron with
matching holes. This can be rotated around the base out of alighnment with
the primary air inlets to reduce air flow. These inlets convect air in at an
angle into the base of the stove (pyrolysis chamber) because only three
sides of the inlet have been cut, and the tab of metal has been bent into
the stove at a 30 ' angle.

I'm not sure how to describe this- the top exhaust gas venting has been done
the same way- it's quite simple.... much like pushing a beer can tab into
the can?

In order to add stability to the whole affair , I haven't welded a bottom on
the stove, but poured 5 cm. of concrete into it. The bottom of the primary
air intakes are flush with this, and a few 1/2 cm deep furrows have been
fingered into the concrete from the air inlets in arcs toward the centre.
This concrete plug is poured into the stove after several 3mm wire 'spokes'
have been welded accross the bottom (steel reinforcement) to hold the
concrete in place.

There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
same tab type venting has been performed with an aim to produce swirling
exhaust venting.

The whole affair weighs 18.5 kg, of which I imagine at least 10 kg is cement.

In a 1.5 hour burn, I reduced 6 kg of dry brown olive hardwood to 1.75 kg
charcoal with little ash (A bit of ash was formed at the beginning of the
burn before the stove heated up properly). This is almost 30% conversion.
The amount of partially carbonised wood was insignificant- maybe 50 gm. The
wood was thumb-thick sticks complete with bark, standing vertically to the
level of the secondary air ring.

2.55 ltre water was evaporated (Nairobi is just below 200o m altitude) with
vigorous boiling.

The stove required quite a bit of attention I found, with low primary air
flow resulting in a lot of dense white smoke and no flame in the combustion
chamber, and too much air causing flames directly on the wood. At one point,
about two thirds through the burn, I had shut the air down too much,
resulting in billows of smoke, and upon opening the primary vents to full,
the gasses igninted with an audible pop in the combustion chamber.

The flame was dark orange - not yellow, and was almost entirely resticted to
the combustion area from and above the secondary air inlets. My expected
swirling 'turbo' effect was not observed, though convection was easily
controlled with the valve arrangement on the primary air inlets. The wood
carbonised surprisingly evenly accross the width of the pyrolysis chamber
after being lit in the center.

The water pot was aluminium, and about the same diameter as the stove
itself. Maybe a slightly lengthened combustion chamber with a narower pot
inserted into the stove, held away from the sides by the 'turbo' tabs of the
xhaust vents would provide a more effective heat exchange. A modification
for the next trial?

On the briquetting side, no luck with mollasses + sawdust. My briquetter
jams. Fantastic briquettes from waste charcoal powder collected from a local
vendor's yard. I'll expound on that later. Possibilities.

All for now.

elk

From bburt at limestone.kosone.com Tue Jun 17 20:09:32 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:18 2004
Subject: Test Equipment
Message-ID: <199706180009.UAA03150@mercury>

> > Alex English has provided me with some contacts for suppliers of testing> equipment and wonders if standardisation within 'stovers' is advisable.> > Any recommendations? Should we, from now on, try to stick to one supplier> after deciding collectively on the most appropriate equipment?> > Regards;> > elk> I think the more appropriate consideration here is that of calibration. The Bacharach CO2 tester relies on the resiliency of a rubber membrane and the absorptive capacity of the fluid in the device to work. I think these will both change over time and a method of knowing when to replace is critical. If you have a standard CO2 sample (the Bacharach manual suggests your breath) then whatever tester you are using can be calibrated to that standard. One of the things that we have here is the welding gas for our Mig welder, I would simply have to check with the supplier to get its CO2 content.We are thinking of purchasing a CO tester and any feedback on whats available would be appreciated.Brian BurtBurt's GreenhousesPhone 613-386-3426 Fax 613-386-1211e-mail bburt@limetone.kosone.com

From english at adan.kingston.net Tue Jun 17 22:55:19 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: More trials cont.
Message-ID: <199706180255.WAA02991@adan.kingston.net>

Dear Stovers
Tonight I added a tapered stove pipe extension to the venturi
arrangement, that was described in the last "More trials" and can
now be seen on the Stovers web page. The venturi is surrounded by
another stove pipe such that its air supply is from the top just like
the primary air supply. Each can be controlled, (altered may be a
better word) independently. The 2"(5cm) diameter throat on the
venturi coupled with its cold mass of 1/4"(6mm) thick steel seemed
to be a formidable damper limiting the speed of start-up. To assist
the draft I lengthened the chimney with a piece of 6"(15cm)
stovepipe dropped into the the cone extension on the venturi. This
made for a total height of 42"(107cm) from the primary air at the
base of the bottom cone and 32" (81cm) from the secondary air at the
throat of the venturi. There was no cera felt or refractory material,
just the stove pipe.

When it finally got going the flame above the venturi danced to its
own percussive beat. ( I joined in, but had to quit when I got a
little over heated. ) The flame seemed to be in a steady state of
rapid small explosions. Part of the audio effect was probably due to
the acoustic characteristics of stove pipe. Visually, it was
vertically more compact but still with a few periodic flame
extensions into the upper chimney. There was a large blue component
to this flame.

The CO2 reading were in the 10-12% range.
Temperatures were lower, due I think to the lack of refractory and
presumably the slightly larger amount of excess air, at 1300-1440F
(700-760C). The smoke test readings, with all parts intact, were 3 on
the scale of 0 to 9. I think I now have some evidence that
turbulence is a more limiting factor than temperature.

Forgive me for not cooking on this device. I am focusing on the
combustion challenge for now. I need to see for my self how far
towards a zero smoke test we can go and then have a CO test done.

Next I intend to introduce swirl with the secondary air inlet, then
perhaps refractory and hey, what the heck, maybe even a bluff body.

Dancing with my flame Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Tue Jun 17 23:48:23 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Heggie on kiln operation (#2)
Message-ID: <v01540b05afccf5f25ed7@[204.133.251.19]>

I said in an earlier note:

<snip>

(RWL):
>> Apparently there are occasions with more dense fuel charges when top
>>lighting is used for a short time with the upper vents open, and then
>>switching to the normal alternating lower input and output ports (and
>>closed top vents).

>(AJH) I cannot at the moment see the advantage

(RWL): This came from an earlier off-line conversation with Greg Brown,
who has a large charcoaling kiln with upper vents (which you don't have).
His instructions indiated that this mode was used with coconut hulls - I
believe because the draft was much reduced. I was interested because of
the top-lighting - but this will be of no use without the upper vents -
sorry.

>(AJH) I was guessing that pyrolysis products were meeting incoming air in
>the pyrolysis zone and producing the large temperature rise, Alex English's
>post also seems to point to a sudden rise in temperature above the predicted
>440C.

(RWL): See other note today on the meaning of this temperature limit -
from external heating measurements ata constant temperature (I think).

<snip>

(RWL): >> 3. I presume "cocoa tin" means all external heating. What
>>temperature was used?

>(AJH) This is the experiment given to schoolchildren to make charcoal for
>drawing with, a tin with a tightly fitting lid is filled with long straight
>twigs, a small hole is punctured in the lid and the tin put in a fire. The
>children observe the steam and then the bright yellow flame, after cooling
>the charcoal is used for drawing.

(RWL): I'd never heard or read about this technique for making drawing
charcoal. Thanks. (I think the temperature is not limited to 440C) I
think something similar will work for those working with sawdust and straw.
The concept is a lot like the "Grover donut-shaped" stove. The important
point is that the "bright yellow flame" can be used productively and if
exited low down can be used to further drive the carbonizing reaction.
There is no moving flaming pyrolysis in this situation. I believe Grover
had internal metal vanes to facilitate heat transfer into the interior.

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 23:48:25 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Ramon and pyrolysis
Message-ID: <v01540b03afcce96f6e30@[204.133.251.19]>

Dr. Ramon Cala Aiello said:

>We have been working at the university of camaguey with Biomass for some time-
>now and we would like to control the concentration of the products obtained in-
>the process of pirolysis.We intend to do this by acting on or influencing the-
>reaction to displace from one side or the other the formation of gases such as
>(H2,CH4 and CO), at atmospheric pressure, varying the temperature or other-
>parameters of the process. Furthermore we want to modulate the process chemi-
>cally. Hence we solicit information to this respect in the quickest possible-
>time.

(RWL): Ramon first sent the following message about a month ago to the
gasification list:
(RCA) >My name is Ramon Cala Aiello. I am a phycisist at the University of
>Camaguey in Cuba.
>During the last years I made a fluid bed gasification concept and pyrolysis
>of material like some biomass(straw,wood,and other), characterisation of the
>pyrolysis products and commercial use of these products.Our group is also re
>searching on fluid bed. I'm looking for new aplication of the pyrolysis and
>gasification of biomass.

(RWL): As you know from being on the list for a short time - this is a
very complicated question. I have several questions to see if stove list
members can help.

1. What is your ultimate application goal? I think from your first
message in mid-May that you may be more interested in gasification and not
in charcoal making. However, a scientist like yourself may be able to
contribute greatly to our own stove discussion as we also have recently had
considerable discussion on the making of charcoal. It would be helpful to
our list to hear from you both more on what you have done in the past and
whether you are now turning your interests to stoves and/or charcoal
making. This is not the right group for discussing gasification.

2. Few of us probably know much about Cuba and its stove system. If you
are thinking of using your pyrolysis skills in this stoves area, perhaps
you can also tell us more on current Cuban cooking practices and whether
you consider that serious problems exist.

3. There have been several references to using straw as a feedstock.
Perhaps you could tell us more on what you have accomplished with fluidized
beds and straw.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 23:48:54 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Heggie on pyrolysis
Message-ID: <v01540b04afccf200719c@[204.133.251.19]>

Andrew said in replying today to Alex:

> From your
>measurement of 700C it appears some of the pyrolysis products are burning in
>the charge zone rather than in the apparent flame cobustion area below th
>cone and above the charge. Or am I mistaken, as Tom Reed says the reaction
>reverts to endothermic above 440C where else can the energy come from to
>heat the wood over this temperature.

(RWL): I believe that what Tom Reed was describing in terms of exo- vs
endothermal character related to the external imposition of a temperature.
I don't believe that Tom was referring to the moving flaming pyrolysis zone
- where the temperature can exceed the value of 440C. In some temperature
regimes, the chamber will have to be cooled as pyrolysis occurs with the
release of energy. My understanding is that the amount of energy either
released or required at this constant temperature condition is pretty
small.

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Tue Jun 17 23:49:00 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Moerman (2) on carbonization.
Message-ID: <v01540b06afccfbebc5f6@[204.133.251.19]>

>Etienne in replying to Alex today said:

<snip>

>I only tried to make the charcoal producing stove from Ron L. and Tom R. 2
>or 3 times. I did not succeed in obtaining clean combustion and/or blue
>flames. So far I have no opinion on this stove.

(RWL): I am not sure why it didn't work. I hope Etienne will describe any
differences in his test from what I have described as a two-can test. The
design changes with different dimensions, has to have fairly dry wood,needs
to be well shielded from the wind etc.
I have not claimed a blue flame. In small scale and under some
conditions, Tom says he has approached that condition, but I have not.

>>Alex:
>> Ron has pointed out that the charcoal-making stove may
>> have a side benefit of producing a marketable product while
>> performing regular daily activities. I liken this to the early
>
>Etienne:
>I have my doubts on the practical implementation of this. First of all I
>expect that more wood is used for the same cooking task and part of this is
>sold as charcoal. Second normal cooking use of the stove would mean a
>production of around 200 g. a day with a sufficiently large size. These
>small amounts are not interesting for the charcoal resellers. For them it is
>far more convenient to buy one large batch from a producer. The only option
>is that some middle (wo)man goes around to buy up the charcoal, transport
>and sell it to the reseller. This will drive up the costs. Thirdly if
>everybody is switching to charcoal producing stoves there is an insufficient
>market for the produced charcoal.
>

(RWL): I see the big advantage not on the stove side, but rather on
the charcoal making side, where the energy conversion efficiency rarely
gets to 50% and might be 25% normally (15% by weight). We have heard many
times on this list about how bad charcoal-making is for the environment. By
using the gases, the efficiency is always well over 50% (starting at 40%
without use).

Fortunately, I believe that charcoal-making stoves are also better
than wood-making stoves in terms of the user's health. I have only one
technical test showing CO less than 0.1% (the smallest possible measurement
on the meter at hand), but I usually can't see or smell anything in the
exhaust and not so for most stoves.

As to the number 200 grams - this is per person per day I presume.
So in a family of 5, one fills a 50 kilo bag in 50 days. I think this might
be on the low side. When a woman is earning essentially nothing and men
are earning less than $100 per year, I believe even this small amount will
be seen as meaningful. But maybe the advantge is going to be seen to be the
constancy of output.

There are plenty of problems to solve, but I don't believe
efficiency,controllability, pollution levels, and earning potential are
not among them - at least comapared to the standard alternatives.
Among the problems I still am working on are: 1) safety and
stability, 2) increasing heat transfer efficiency to the cook pot, and 3)
extinguishing the pyrolysis quickly.

>----------
>
>Alex:
>> I am ignorant of charcoal stove emissions. How bad are they?
>
>Etienne:
<snip>

> If we assume a 30 times higher CO emission from the charcoal stove too
>than we would get a CO/CO2 ratio around 6%.

(RWL): I look forward to seeing CO/CO2 measurements on charcoal-buring
stoves like Paul Hait's. I doubt it will prove to be 6%

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 18 01:21:58 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Karstad twocan turbo
Message-ID: <v01540b00afcd0fec7996@[204.133.251.12]>

Elsen said:

>My Turbo Twocan Mk I impressed the hell out of my staff- who have been
>cooking on either wood, charcoal or kerosene all their lives.

(RWL): I'm sure you are not ready to sell yet, but did any of your staff
express a desire to use and buy and/or talk about an acceptable price?

>Made of 1 mm sheet iron and assembled with an electric welder and an angle
>grinder, the unit has an inside diam of 30 cm and stands 70 cm tall. An
>outer shell (insulator and fresh air inlet air pre-heater) 1.25 cm distant
>from the main body starts 11 cm from the bottom of the stove to 9 cm from
>the top.

(RWL): I think you should go all the way to the top with this outer shell
(to get higher efficiency. This is presumably the hottest part of the
stove and therefore the greatest source of radiated heat loss. To keep the
cost the same, you can move everything up - and maybe even forget about
shielding the lower part essentially (except to provide good wind
shielding), because it runs so much cooler.

>This shell is open both at the top and the bottom. A 3mm air inlet
>gap circumvents the inner tube 20 cm from the top.

(RWL): This sounds a little too high up; I'd counsel maybe 35 cm from the
top. I have concluded (maybe incorrectly) that a combustion region that is
a bit taller than it is wide is needed (to improve the draft and allow
space for complete combustion). Note the Alex/Brian design is very tall
for the width. I also believe that a set of holes (maybe 3-5 mm diameter)
may be better than a slit - because I get flame holding better on small
holes.

> Three 3 cm long by 2 cm
>high primary air inlets located 5 cm from the base of the stove are
>controlled by a snug rotating band of very light wt. sheet iron with
>matching holes. This can be rotated around the base out of alighnment with
>the primary air inlets to reduce air flow.

(RWL): I couldn't get a good snug fit when I tried this band approach - I
went to (three, round) plugs.

> These inlets convect air in at an
>angle into the base of the stove (pyrolysis chamber) because only three
>sides of the inlet have been cut, and the tab of metal has been bent into
>the stove at a 30 ' angle.

>I'm not sure how to describe this- the top exhaust gas venting has been done
>the same way- it's quite simple.... much like pushing a beer can tab into
>the can?

(RWL): I've used an old type of hand triangular punch can opener to do
exactly this. Do you have a high power punch in your shop to do this?

>
>In order to add stability to the whole affair , I haven't welded a bottom on
>the stove, but poured 5 cm. of concrete into it.

(RWL): I think this is a great idea - you have solved a major
problem nicely! Wish I had thought of this.

(RWL): I guess these grooves remove the need for a grate? Nice!
>
>There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
>same tab type venting has been performed with an aim to produce swirling
>exhaust venting.

(RWL): I think you can get closer to the top than the 3 cm. distance
>
>The whole affair weighs 18.5 kg, of which I imagine at least 10 kg is cement.
>
>In a 1.5 hour burn, I reduced 6 kg of dry brown olive hardwood to 1.75 kg
>charcoal with little ash (A bit of ash was formed at the beginning of the
>burn before the stove heated up properly). This is almost 30% conversion.

(RWL): About 5% greater than I ever have! (About twice local
in-the-ground kiln performance?)

>The amount of partially carbonised wood was insignificant- maybe 50 gm. The
>wood was thumb-thick sticks complete with bark, standing vertically to the
>level of the secondary air ring.
>
>2.55 ltre water was evaporated (Nairobi is just below 200o m altitude) with
>vigorous boiling.

(RWL): I believe with more care in insulating the top that you will
eventually double this weight of evaporated water for a 6 kg load. The
stove book by Sam Baldwin talks about putting a shield very close (1 cm?)
to the water pot to improve convective heat transfer.

You will improve the boil-away efficiency by cutting back on the
vigor of the boil.

>
>The stove required quite a bit of attention I found, with low primary air
>flow resulting in a lot of dense white smoke and no flame in the combustion
>chamber, and too much air causing flames directly on the wood. At one point,
>about two thirds through the burn, I had shut the air down too much,
>resulting in billows of smoke, and upon opening the primary vents to full,
>the gasses igninted with an audible pop in the combustion chamber.

(RWL): This has happened many times to me also - a case of learning how to
control the primary air input. Can you estimate the turndown ratio? (max
to min power ratio)

>
>The flame was dark orange - not yellow, and was almost entirely resticted to
>the combustion area from and above the secondary air inlets. My expected
>swirling 'turbo' effect was not observed, though convection was easily
>controlled with the valve arrangement on the primary air inlets. The wood
>carbonised surprisingly evenly accross the width of the pyrolysis chamber
>after being lit in the center.

(RWL): I hope Alex will repeat the meaning of dark orange vs. yellow. I
think the turbo effect will have to come from the secondary air inlet port
design. The primary air is too far away.

>
>The water pot was aluminium, and about the same diameter as the stove
>itself. Maybe a slightly lengthened combustion chamber with a narower pot
>inserted into the stove, held away from the sides by the 'turbo' tabs of the
>xhaust vents would provide a more effective heat exchange. A modification
>for the next trial?

(RWL): Yes. The most important thing you can do to increase efficiency.
Maybe you can use the present pot by extending up the outer shield.

A few questions:

1. Was the wood fairly dry? Cut how long ago?
2. Tell us about flame holding - could you tell if the flame was attached
to the secondary air slit?
3. Was this an indoor or outdoor test? Any problem with the wind?
4. How did you know when the wood pyrolysis had ceased?
5. How did you snuff the process and retrieve the charcoal?

A great first test! It will get better.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 18 01:21:57 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: More (Alex) trials cont.
Message-ID: <v01540b01afcd1bc64257@[204.133.251.12]>

Alex - Sorry I have fallen behind in my comments on your tests. I will
still try to ask some more questions later on your earlier reports. Please
keep them coming.

<snip>

>When it finally got going the flame above the venturi danced to its
>own percussive beat. ( I joined in, but had to quit when I got a
>little over heated. ) The flame seemed to be in a steady state of
>rapid small explosions. Part of the audio effect was probably due to
>the acoustic characteristics of stove pipe. Visually, it was
>vertically more compact but still with a few periodic flame
>extensions into the upper chimney. There was a large blue component
>to this flame.

(RWL): I presume that this was due to better mixing - caused by the
venturi. Congratulations. I am going to have to learn more about
venturis.
Can we assume that the "beat" is related to your chimney length?
Approximately what was the rep rate?

>
> The CO2 reading were in the 10-12% range.
>Temperatures were lower, due I think to the lack of refractory and
>presumably the slightly larger amount of excess air, at 1300-1440F
>(700-760C). The smoke test readings, with all parts intact, were 3 on
>the scale of 0 to 9. I think I now have some evidence that
>turbulence is a more limiting factor than temperature.

(RWL): I presume you mean limiting on cleanness?
>
>Forgive me for not cooking on this device. I am focusing on the
>combustion challenge for now. I need to see for my self how far
>towards a zero smoke test we can go and then have a CO test done.
>
>Next I intend to introduce swirl with the secondary air inlet, then
>perhaps refractory and hey, what the heck, maybe even a bluff body.

(RWL): What is a "bluff body"?

(RWL): Good luck - you are making great progress (I think - it is going
too fast for me to keep up). I tried a 7" dia cone test in an 8" stove
pipe today. With the secondary air holes plugged (with dirt as the unit
was imbedded in the ground), I got a shaky flame like that you described.
I preferred it with the air holes open and flame attachment to the
secondary air holes. I did not get any particular advantage from the cone
- but will try some more, with the taller chimneys you have been using.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From english at adan.kingston.net Wed Jun 18 07:56:29 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt and Moerman on CO
In-Reply-To: <199706172308.TAA19655@mercury>
Message-ID: <199706181156.HAA13677@adan.kingston.net>

> > What ? You want me to publicly assess my boss!
> > I'll have to think about this.......................
> > ......................this could be fun............stay tuned.......
> >
> > Alex
>
> Remember that assessment begets assessment!!!!!!!
>
> Brian

Dear Stovers
Here goes...
Brian Burt -Father/Horticulturalist/Farmer/Businessman
As the greenhouses are large consumer of fossil fuels for
heating, he has had a been involved in a search for a practical
alternative for about ten years. He has been doing all his own
furnace and boiler repair for at least that long. Being an
intellectual black hole with a reverse gear and a good logic filter,
he has been a constructive critic/advisor for all our joint
activities. In the last few years we have teamed up for the
development (still in progress) of an agricultural residue burner.
His 'get-on-with-it' approach to work has rubbed off on me.......

......so now I better beget'n back to work.... Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Wed Jun 18 07:56:28 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: More (Alex) trials cont.
In-Reply-To: <v01540b01afcd1bc64257@[204.133.251.12]>
Message-ID: <199706181156.HAA13686@adan.kingston.net>

> Can we assume that the "beat" is related to your chimney length?
> Approximately what was the rep rate?

Beyond assessment with the tools attached to the sides of my head.

> >
> > The CO2 reading were in the 10-12% range.
> >Temperatures were lower, due I think to the lack of refractory and
> >presumably the slightly larger amount of excess air, at 1300-1440F
> >(700-760C). The smoke test readings, with all parts intact, were 3 on
> >the scale of 0 to 9. I think I now have some evidence that
> >turbulence is a more limiting factor than temperature.
>
> (RWL): I presume you mean limiting on cleanness?
Yes.
> >
> >Forgive me for not cooking on this device. I am focusing on the
> >combustion challenge for now. I need to see for my self how far
> >towards a zero smoke test we can go and then have a CO test done.
> >
> >Next I intend to introduce swirl with the secondary air inlet, then
> >perhaps refractory and hey, what the heck, maybe even a bluff body.
>
> (RWL): What is a "bluff body"?

Tis the name given to an obstruction which creates turbulence
(ex. back eddies), at least in a highly technical gas combustion
reference that I have attempted to read.
>
> (RWL): Good luck - you are making great progress (I think - it is going
> too fast for me to keep up). I tried a 7" dia cone test in an 8" stove
> pipe today. With the secondary air holes plugged (with dirt as the unit
> was imbedded in the ground), I got a shaky flame like that you described.
> I preferred it with the air holes open and flame attachment to the
> secondary air holes. I did not get any particular advantage from the cone
> - but will try some more, with the taller chimneys you have been using.

With the two can stove, would you describe the flame as quite or
gentle ? I would like to do a smoke test on it. The device we use is
simple enough that one ought to be able to make one cheaply. More on
this later.

Alex

> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Wed Jun 18 07:56:26 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: CO and Charcoal
Message-ID: <199706181156.HAA13682@adan.kingston.net>

Dear Stovers

I have heard it said that the process of combusting CO to CO2
requires, to some extent, the presence of water vapour. Most fuels
have sufficient H to yield that H2O. Is it possible that the charcoal
has been depleted of H enough starve this process of adequate H2O ?

Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Wed Jun 18 09:53:00 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt Brian
Message-ID: <v01540b03afcd94c7d72b@[204.133.251.6]>

Alex today said that Brian was:

<snip>
>an
>intellectual black hole with a reverse gear and a good logic filter,

(RWL): That's what I was wondering about.

>In the last few years we have teamed up for the
>development (still in progress) of an agricultural residue burner.

(RWL): How about making charcoal as a co-product (from either wood or ag
residue) while you are heating the greenhouses? Can the greenhouse plants
accept all the gases produced or would one need a heat exchanger?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Wed Jun 18 09:53:21 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: More (Alex) trials cont.
Message-ID: <v01540b02afcd8e735a90@[204.133.251.6]>

Alex said:

<snip>

>> >Next I intend to introduce swirl with the secondary air inlet, then
>> >perhaps refractory and hey, what the heck, maybe even a bluff body.
>>
>> (RWL): What is a "bluff body"?
>
>Tis the name given to an obstruction which creates turbulence
>(ex. back eddies), at least in a highly technical gas combustion
>reference that I have attempted to read.

(RWL): I think this is a great direction to take. I think there may be
advantage to letting it get very hot, also - for flame holding benefits.
I've been wondering about using limestone - which was used for gas lighting
at one time ("limelight").

Tom Reed has been using a central hollow "can" (maybe this can be
called a "bluff body") for flame holding in the combustion can. He calls
it a "wick". I need to do more testing with that concept - and believe he
has been getting bluer flames with this geometry.

I believe that the "Grover" or "Heggie-charcoal-pencil-maker"
loaded tight can can also work here with the central can as a "bluff
(loaded) body" - where the dissociation gases are vented (and then flared)
at the level of the secondary air inlets.

<snip>
>
>With the two can stove, would you describe the flame as quite or
>gentle ? I would like to do a smoke test on it. The device we use is
>simple enough that one ought to be able to make one cheaply. More on
>this later.

<snip>

(RWL): The flame I like best (aesthetically) is one that is attached
everywhere at the secondary air holes/slit and smoothly flows upward (no
turbulence) until the flame goes out just below the cook pot. I guess it
could be described as both "quiet and gentle" - but the gases are moving
very rapidly. There is no flickering (unless it is windy). Each small
"flamelet" is somewhat like the flame from a match - but it is inverted -
the air is at the center and the flamelet is surrounded by combustible
gases.

But I think it may be wise instead to strive for turbulence - in
order to get better combustion. I just haven't tried enough of such tests
yet. This is a great area for innovation.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From bburt at limestone.kosone.com Wed Jun 18 10:33:41 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt Brian
Message-ID: <199706181434.KAA29706@mercury>

From elk at arcc.or.ke Wed Jun 18 10:44:02 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:19 2004
Subject: twocan turbo (charcoal making stove)
Message-ID: <v01510101afcdc18a08a2@[199.2.222.151]>

>(RWL): I'm sure you are not ready to sell yet, but did any of your staff
>express a desire to use and buy and/or talk about an acceptable price?

Yes, the interest is there, and in the usual manner, a local artisan would
copy the stove probably using metal from a salvaged 200 litre oil drum.
I've requested my staff to have patience until a few more trials and a lot
more advice results in a more efficient unit. They reckon on a cost of
between $10 and $12 dollars to have it made in the informal sector.

>(RWL): I think you should go all the way to the top with this outer shell
>(to get higher efficiency. This is presumably the hottest part of the
>stove and therefore the greatest source of radiated heat loss. To keep the
>cost the same, you can move everything up - and maybe even forget about
>shielding the lower part essentially (except to provide good wind
>shielding), because it runs so much cooler.

I'm modifying at the moment, with an aim to encase the pot right into the
top of the unit. Not quite sure what to do with the shell now, as heated
air vented up won't come in contact with the pot at all. Maybe seal off the
top, at the top? Could be an expensive niggly bit of welding. The shell
sure did get hot during the first trial though! A pot with a significantly
larger diameter than the stove, on top, rather than in the stove, would
benefit from the conducted air if the shell was moved or extended to the
top. The question is, would this interfere with the top exhaust venting?
Only one way to tell for sure!

>>This shell is open both at the top and the bottom. A 3mm air inlet
>>gap circumvents the inner tube 20 cm from the top.
>
>(RWL): This sounds a little too high up; I'd counsel maybe 35 cm from the
>top. I have concluded (maybe incorrectly) that a combustion region that is
>a bit taller than it is wide is needed (to improve the draft and allow
>space for complete combustion). Note the Alex/Brian design is very tall
>for the width. I also believe that a set of holes (maybe 3-5 mm diameter)
>may be better than a slit - because I get flame holding better on small
>holes.

I'll be able to run two trials with the current modification- I'm extending
the top by 6 cm by raising the height of the combustion chamber. The
exhaust vents remain at the top of the stove. This is to embed the pot into
the top of the stove in order to increase heat contact area. A second trial
will be conducted with a larger pot set on top of the (now extended) stove
and will proved a larger combustion chamber. Stay tuned.

> (RWL): I've used an old type of hand triangular punch can opener to do
>exactly this. Do you have a high power punch in your shop to do this?

With ref. to the 'turbo venting'- This is done with a hammer & chisel-
cutting three sides of a rectangle in the metal & pushing the tab into the
stove to a 45' angle. Nothing high powered here.

>>There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
>>same tab type venting has been performed with an aim to produce swirling
>>exhaust venting.
>
>(RWL): I think you can get closer to the top than the 3 cm. distance

I could simply cut 2cm slices down into the top of the rim and fold a
triangulat tab into the stove- turbo venting again! Simple. Glad you
thought of that.

>(RWL): . Can you estimate the turndown ratio? (max to min power ratio)

I'll need a few more trials before I can estimate that, but I feel it was
basically a three level control, with wide open causing combustion, careful
adjustment of primary air inflow to pyrolisis with gas combustion (setting
changing as the burn progressed) and 'off' causing much smoke and sarcastic
comments.

>(RWL): I hope Alex will repeat the meaning of dark orange vs. yellow. I
>think the turbo effect will have to come from the secondary air inlet port
>design. The primary air is too far away.

Good suggestion- I'll turbo the secondary air inflow somehow- maybe a set
of angled tabs spot welded along the port. So far I've turbo'd both primary
and exhaust vents. All three should be done in the interest of good
science.

>(RWL)A few questions:
>
>1. Was the wood fairly dry? Cut how long ago?
>2. Tell us about flame holding - could you tell if the flame was attached
>to the secondary air slit?
>3. Was this an indoor or outdoor test? Any problem with the wind?
>4. How did you know when the wood pyrolysis had ceased?
>5. How did you snuff the process and retrieve the charcoal?

1) yes, dry- a dead brach plucked from the tree.

2) The flame definitely emenated from the secondary air slit, but most of
the time there was at least one small point of flame directly on the top of
the tallest pieces of fuel. Is this an essential 'pilot light' do you
think?

3) Outdoor test. Wind speed ave 4 km, gusting to 9 I'd say. Wind didn't
have much effect.

4) My trusty forman seemed to be able to ascertain- I found that the valve
adjustments of the primary air inlet became more sensitive in order to
maintain flame in the combustion chamber toward the very end. We peered
inside & saw that all was black & charcoally looking too!

5) Sand extingiuishing- first tossed into the stove, then over the charcoal
on the ground when the stove was emptied by upending.

Second test (with mods) tomorrow.

>(RWL) A great first test! It will get better.

That's what they say! Practice eh?

Regards;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From BeedieD at Cardiff.ac.uk Wed Jun 18 14:09:24 1997
From: BeedieD at Cardiff.ac.uk (David Beedie)
Date: Tue Aug 31 21:35:19 2004
Subject: Charcoal and briquettes
Message-ID: <1863FAC4C7E@nrd1s.cf.ac.uk>

Piet,

> From Piet Verhaart
snip
>
> >Kingsford puts (10%) a lot of ash intentionally into charcoal to SLOW the
> >combustion process. (High density, as in coconut shell charcoal may
> >accomplish the same.) The ash may also be catalytic for burning the CO
> >formed at the C-air interface to CO2.
>
> May be catalytic? Is there anything more detailed on catalysis of CO to CO2?
> K, Ca, Al, Si?
> I remember our downdraft stove producing negligible CO as long as volatiles
> were produced. As soon as the flames disappeared the CO went sharply up. (I
> stand to be corrected by Etienne and/or Prasad.)
> I had read somewhere that water vapour also catalysed the CO to CO2 reaction
> and, until something better cropped up, that was the explanation of the CO
> increase. Regrettably we did not get down to do the simple experiment of
> feeding some steam into the char burning J-stove.

In my measurements of such things in a batch-loaded gasifier-
combustor, the CO increase also coincided with increasing Excess Air
Value of combustion and hence falling combustion temperatures. I
don't know whether or not the 2CO+O2 <> 2CO2 equilibrium is moved to
the right or the left by higher temperatures, but the reaction rate
should increase exponentially with increasing temperature. High
temperature combustion tends to produce few PICs and presumably
favours CO oxidation. So for the machanism behind the sharply
increasing CO after volatilisation ends, the temperature dependence
of the reaction rate seems an obvious possibility ? Do most
stoves end up with far too high Excess Air Values once they're into
the pure char combustion phase ? They might produce lots of CO for
this reason - the gases don't stay hot enough for long enough.

Dave.

*******************************************************
(Dr) David Beedie
School of Engineering, University of Wales, Cardiff, UK

email: BeedieD@cardiff

Tel. 01222 874683 (office); 874000 ext.5927(lab.)
FAX: 01222 874420 - mark for my attention !
762197 (home)
*******************************************************

From ahe1 at cableol.co.uk Wed Jun 18 17:45:30 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:19 2004
Subject: More (Alex) trials cont.
Message-ID: <9706182145.AA25940@mars.cableol.net>

At 07:53 18/06/97 -0600, Ronal wrote:

> I believe that the "Grover" or "Heggie-charcoal-pencil-maker"
>loaded tight can can also work here with the central can as a "bluff
>(loaded) body" - where the dissociation gases are vented (and then flared)
>at the level of the secondary air inlets.

(AJH) I like this idea of using the pencil maker to provide a pressure jet
to assist combustion and it is good of you to credit me with informing you
of the technique, however please do not attribute the idea to me as it is a
traditional teaching aid to the best of my knowledge.

Regards AJH

From ahe1 at cableol.co.uk Wed Jun 18 17:45:35 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:19 2004
Subject: Heggie on kiln operation (#2)
Message-ID: <9706182145.AA15740@mars.cableol.net>

At 21:48 17/06/97 -0600, Ronal wrote in reply to Andrew Heggie:

>
>(RWL): See other note today on the meaning of this temperature limit -
>from external heating measurements ata constant temperature (I think).
(AJH) Yes I think I see, almost like in a lab test, but in the real thing
heat cannot reach an equilibrium and hence the temperature runs away in the
absence of cooling. This would fit in with the problems the retorts have,
they appear to reach 500C very readily, at this stage if the flare gas is
not redirected away from the retort the vessel suffers as I reported in an
earlier post. I know the South African Gaiyard? retor had a facility to
spray water in to prevent this damage.

Incidentally can anyone Identify the type of retort I have seen. An ex-pat
from South Africa has imported a few which are laid out in batches. They
consist of a charge container 60cms +diameter with a hinged circular door.
There is one 7.5cms pipe top let front of the door. This exits to a tee. The
verticle pipe from this vents via a tap to atmosphere. The othe half leads
via a tap to a fire box which is alongside the charge vessel. This firebox
is used as a fairly unsophisticated woodburner and the pipe is perforated
along its length to act as a flare gas burner. There are brick baffles
internally to prevent direct flames on the vessel and the flue is directed
up and over the vessel and out through a chimney at the rear. The whole is
covered by some rockwool type insulation and a semicircular sheet iron
cladding. I have not seen one actually running only cooling down. In use the
wood is loaded into the vessel and a fire lit in the firebox with offal. The
vessel reaches hiigh temperature (Reputedly 500C as temperature verses time
is chalked on the wall to monitor each burn. As soon as gaseous products are
driven off they are ignited in the firebox, very little wood is burned. When
a desired temperature is reached the tap to atmosphere is opened and the tap
to firebox close, gas then being flared off. As I said careful supervision
is necessary as thermal runaway happens quite suddenly, so I am told. The
operater does not encourage too much viewing because of commercial
sensitivity, (an ex employee has already made his own improved double vessel
copy).

I see a number of problems with the design and the taps give clogging
problems, the charcoal appears superior and more uniform than ours and the
yield is 25% (allegedly).
<snip>
>(RWL): I'd never heard or read about this technique for making drawing
>charcoal. Thanks. (I think the temperature is not limited to 440C) I
>think something similar will work for those working with sawdust and straw.
>The concept is a lot like the "Grover donut-shaped" stove. The important
>point is that the "bright yellow flame" can be used productively and if
>exited low down can be used to further drive the carbonizing reaction.
(AJH)This is the basis of what I am aquiring the bits to build. I am
confident there is excess flare gas available but suspect in a large retort
some internal circulation through a cooler will be necessary because of the
worse (better for energy retention) volume to surface area.
(RWL)>There is no moving flaming pyrolysis in this situation. I believe Grover
>had internal metal vanes to facilitate heat transfer into the interior.
(AJH)I am unsure about the vanes, I shall start without them, I am temted to
light a fire on the charge initially to speed things up, hence my reference
to a hybrid retort/kiln. My understanding being : A kiln is a device with
internal burning and a retort with only external.

I had considered a heat pipe with a high boiling point liquid to cool the
interior and transfer heat without the need for circulating fans, this
woould have the effect of automating the cooling as if the boiling of the
liquid was chosen to coincide with the require operating temperature little
cooling would happen at lower temperatures.
Regard AJH

From ahe1 at cableol.co.uk Wed Jun 18 17:45:45 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt Brian
Message-ID: <9706182145.AA05219@mars.cableol.net>

At 10:32 18/06/97 -0700, Brian Burt wrote:

>
>The burner we are working on would definitely require a heat exchanger.
>
(AJH)This is an area I am investigating, are you saying Alex's stove is a
model for this use or are you working on others?

(AJH)The more complex idea I am trying to raise interest on will ( I
think) produce a flare gas which I consider to be a high grade heat and low
grade heat as water below boiling which I consider adequate for space heating.

>in U.S. too) there is a great deal of Peat Moss used it might be
>interesting if some could be replaced by charcoal and make the development
>of the larger scale charcoal maker very interesting.
(AJH)There is a presumption against using peat for local government use here
in Surrey, England because of the ecological status of peat bogs, thopugh
globally horticultural use of peat is small beer compared with that used in
power stations. The smaller parts of the Urban forestry waste we use as our
rawstock (material <3" (7.5cms)diam) is shredded and composted on site for
sale as a peat substitute.

From jrbankston at juno.com Wed Jun 18 21:46:03 1997
From: jrbankston at juno.com (jrbankston@juno.com)
Date: Tue Aug 31 21:35:19 2004
Subject: Test Equipment
In-Reply-To: <v01540b03afcc7cdfde30@[204.133.251.3]>
Message-ID: <19970618.213659.8151.0.jrbankston@juno.com>

Several years ago I monitored a DOE funded project at Virginia Tech which
involved CO2 testing. Dr. Dennis Jaasma who runs a stove testing lab
there was using a sensor from an automobile which was connected to a
computer for monitoring. I do not recall the details, but Dr. Jaasma
probably would be able to give you some guidance. He probably would be a
good member of this list also. His E-mail address is jaasmadr@ vt.edu.

Julian Bankston
jrbankston@juno.com

On Tue, 17 Jun 1997 16:03:47 -0600 larcon@sni.net (Ronal W. Larson)
writes:
>Today (June 17) Elsen said:
>
>>Alex English has provided me with some contacts for suppliers of
>testing
>>equipment and wonders if standardisation within 'stovers' is
>advisable.
>>
>Alex and Elsen - I think this is a valuabel thread to continue. I
>know
>almost nothing on such equipment. I would like epecially to find low
>cost
>equipment that everyone can afford.
> I am told that some computerized automobile engine performance
>optimization is now done with CO2 sensors. With millions in use,
>might
>that cost be pretty low?
> Also, there are many CO sensors available for home safety
>uses.
>Might any be amenable to putting a meter on them rather than an audio
>alarm?
>
>
>>Any recommendations? Should we, from now on, try to stick to one
>supplier
>>after deciding collectively on the most appropriate equipment?
>
> OK - if clearly superior.
>
>Regards Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>
>

From bburt at limestone.kosone.com Wed Jun 18 21:47:14 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt Brian
Message-ID: <199706190147.VAA03051@mercury>

>> >The burner we are working on would definitely require a heat exchanger. > >> (AJH)This is an area I am investigating, are you saying Alex's stove is a> model for this use or are you working on others?Alex's stove is not a model for this use, we are working on another large scale design in the range of 2-5 MBTU/hr.What we are interested in (with apologies to Ron for using this list), are any emissions data for herbaceous biomass burners that already exist.BrianBrian BurtBurt's GreenhousesPhone 613-386-3426 Fax 613-386-1211e-mail bburt@limetone.kosone.com

From english at adan.kingston.net Wed Jun 18 23:00:42 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: Venturi with swirl
Message-ID: <199706190300.XAA13704@adan.kingston.net>

Dear Stovers

Tonight burn featured an addition to the venturi air supply. I
welded 1/2"(12mm) flat bar inbetween two large washers for
2"(5cm) bolts, to form six 1/2" square nozzles directed
tangentially at the venturi's 2" mid point. A picture is on the
Stovers Web Page.

Once again the fire was slow to get up to speed. When it did the
swirl effect was quite evident, though predominantly towards the out
side of the flame. A bluff body may force all the gasses into the
swirl. It was somewhat less pronounced at lower firing rates. Turn
down will be a problem. Measurements were similar to the previous
trial with the exception that I obtained smoke readings of 1 during
the later portion of the burn. Whether this is due to the slowly
rising temperature of the preheated air, or the changing composition
of the pyrolisis gasses, I don't know. I think there is an increasing
amount of char-phase combustion occurring as the cone drops and the
charcoal in the middle approaches the air/flame path along the under
side of the cone. When I stopped this burn the cone was resting on
the charcoal in the middle with all the fuel gone on the outside
edge.

Burn and learn Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Thu Jun 19 00:26:57 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Heggie on kiln operation (#2)
Message-ID: <v01540b03afce2047c4a1@[204.133.251.2]>

On 18 June, Andrew said:

>(AJH)This is the basis of what I am aquiring the bits to build. I am
>confident there is excess flare gas available but suspect in a large retort
>some internal circulation through a cooler will be necessary because of the
>worse (better for energy retention) volume to surface area.

(RWL): Do you think this "excess flare gas" is about 50% of the input -
and are there some applications that you can use it for? It is great to
see that flaring is occuring in one charcoal maker, but it would be much
better to know that the flared gas is being used productively.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Thu Jun 19 00:28:03 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:19 2004
Subject: Karstad (#3) on twocan turbo
Message-ID: <v01540b04afce21f02866@[204.133.251.2]>

On June 18, Elsen said

<snip>

>Yes, the interest is there, and in the usual manner, a local artisan would
>copy the stove probably using metal from a salvaged 200 litre oil drum.
>I've requested my staff to have patience until a few more trials and a lot
>more advice results in a more efficient unit. They reckon on a cost of
>between $10 and $12 dollars to have it made in the informal sector.

(RWL): Sounds reasonable - and even lower than I thought - since you have
a double wall. Would a similar unit manufactured and sold in a developed
country command about $40-$50? What are the current prices of
charcoal-using jikos of different diameters?

(ELK):
>I'm modifying at the moment, with an aim to encase the pot right into the
>top of the unit. Not quite sure what to do with the shell now, as heated
>air vented up won't come in contact with the pot at all. Maybe seal off the
>top, at the top? Could be an expensive niggly bit of welding.
<snip>

(RWL): I think it is worth a test of venting up without seal welding -
there may be mostly parallel flow and little entrainment - and thereby
force the hotter gases even closer to the cook pot.

(ELK): >The shell
>sure did get hot during the first trial though! A pot with a significantly
>larger diameter than the stove, on top, rather than in the stove, would
>benefit from the conducted air if the shell was moved or extended to the
>top. The question is, would this interfere with the top exhaust venting?
>Only one way to tell for sure!

(RWL): The question of appropriate diameter needs a lot of experimental
work. The bigger the diameter the higher the power level, but maybe you
don't want or need more power. The smaller diameter units will be cheaper
too. The height is going to be more related to energy (time of burn) than
power. Maybe a 1.5 hour burn is too much. On the other hand, efficiency
will be higher (even much higher) if every stove is matched to a specific
pot - but the cooks may not want to be so constrained.

<snip>
(ELK):
>I'll be able to run two trials with the current modification- I'm extending
>the top by 6 cm by raising the height of the combustion chamber. The
>exhaust vents remain at the top of the stove. This is to embed the pot into
>the top of the stove in order to increase heat contact area. A second trial
>will be conducted with a larger pot set on top of the (now extended) stove
>and will proved a larger combustion chamber. Stay tuned.

(RWL): I like these both. Both are important variations.

>>(RWL) A few questions:

(ELK):
>2) The flame definitely emenated from the secondary air slit, but most of
>the time there was at least one small point of flame directly on the top of
>the tallest pieces of fuel. Is this an essential 'pilot light' do you
>think?

(RWL): I still feel good seeing a flame attached to the tall pieces - as
it seems more stable. I don't think it is "essential"

(ELK):
>5) Sand extingiuishing- first tossed into the stove, then over the charcoal
>on the ground when the stove was emptied by upending.

(RWL): I have never tried this, but thought I should. Would you say
that the cook would find this difficult? Did it take more than a few
minutes? Is it hazardous to do? Do you have a handle on the stove or need
one?

(RWL): Thanks for the many good answers.

(RWL): Several more suggestions/questions.
1. A stove expert in Zimbabwe told me that an auxiliary oven for
baking would go over well with rural Zimbabwe women. I'd like the opinion
of your workmen and their wives on this value. I'm thinking of another 200
liter can (maybe smaller) which has your unit in a "corner" somehow.

2. I hope you can test someway the sealed (with a number of lower
exhaust holes) central can in the combustion chamber ala the recent Heggie
conversations - with sawdust inside.

3. Can you estimate what size family your 6 kg (1.75 kg charcoal)
design would serve and how many such meals per day.

4. What is the present sales price in various places of a standard
bag of charcoal and how many kilos per bag? Same for wood?

5. Assuming it works well enough, is there a way for you to make
money on this if Kenyan village metalworkers can undersell you? Or can
they? Might there be a Kenya program to fund dissemination training, etc?
Could you sell a kit that could be assembled with a screwdriver?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From jaakko.saastamoinen at vtt.fi Thu Jun 19 03:16:49 1997
From: jaakko.saastamoinen at vtt.fi (Jaakko Saastamoinen)
Date: Tue Aug 31 21:35:19 2004
Subject: CO and Charcoal
Message-ID: <199706190716.KAA22961@vttmail.vtt.fi>

At 07:55 18.6.1997 -0500, you wrote:
>Dear Stovers
>
>I have heard it said that the process of combusting CO to CO2
>requires, to some extent, the presence of water vapour. Most fuels
>have sufficient H to yield that H2O. Is it possible that the charcoal
>has been depleted of H enough starve this process of adequate H2O ?
>
>Alex
>
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927
>Stoves Web Site http://www1.kingston.net/~english/Stoves.html
>

According to the simplified reaction mechanism of Westbrook and Dryer [1],
the rate of oxidation of CO is d[CO]/dt = k*[CO]*[O2]^0.25*[H2O]^0.5, where
k = 1.0*10^14.6 *exp(-167472/RT) (R=8.314 kJ/kmolK, T is temperature in
Kelvins, t is time). Thus increase in the content of water vapour has more
influence on the rate than the corresponding increase in the oxygen content.

There is probably some hydrogen left in charcoal depending on the way of
producing it and on the final temperature. In addition, there is usually
enough H2O in air to enhance the CO oxidation rate. Then the temperature has
more important effect on the rate of oxidation than the H2O content. There
could be some effect in dry areas and also in cold weather. For example here
in Finland we can have outdoor temperatures less than -30 C and then the
outdoor air can contain very little water vapour (even if the relative
humidity is close to 100%).

[1] Westbrook, C.K., and Dryer, F.L., Simplified reaction mechanisms for the
oxidation of hydrocarbon fuels in flames. Combustion Science and Technology,
1981, Vol. 27, pp. 31-43.

Jaakko
__________________________________________
Jaakko Saastamoinen
VTT Energy
Box 1601, 40101 Jyvaskyla
Finland
phone +358 14 672 547, fax +358 14 672 596
__________________________________________

From english at adan.kingston.net Thu Jun 19 07:05:13 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:19 2004
Subject: CO and Charcoal
In-Reply-To: <199706190716.KAA22961@vttmail.vtt.fi>
Message-ID: <199706191105.HAA03360@adan.kingston.net>

> According to the simplified reaction mechanism of Westbrook and Dryer [1],
> the rate of oxidation of CO is d[CO]/dt = k*[CO]*[O2]^0.25*[H2O]^0.5, where
> k = 1.0*10^14.6 *exp(-167472/RT) (R=8.314 kJ/kmolK, T is temperature in
> Kelvins, t is time). Thus increase in the content of water vapour has more
> influence on the rate than the corresponding increase in the oxygen content.
>
> There is probably some hydrogen left in charcoal depending on the way of
> producing it and on the final temperature. In addition, there is usually
> enough H2O in air to enhance the CO oxidation rate. Then the temperature has
> more important effect on the rate of oxidation than the H2O content.
<snip>
Dear Jaakko
Thank you for your excellent response. This give the theoretical
frame work. Does this mean that the gasses from charcoal will need
the same treatment as any other combustibles, time, temperature and
turbulence ? Is there some other reason why charcoal fires tend to
be high in CO emissions ?

Alex
> Jaakko
> __________________________________________
> Jaakko Saastamoinen
> VTT Energy
> Box 1601, 40101 Jyvaskyla
> Finland
> phone +358 14 672 547, fax +358 14 672 596
> __________________________________________
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From verhaarp at janus.cqu.edu.au Thu Jun 19 08:28:57 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:19 2004
Subject: More trials cont.
Message-ID: <1.5.4.32.19970619122845.00687104@janus.cqu.edu.au>

>From Piet Verhaart
To Alex ++

At 22:54 17/06/97 -0500, you wrote:
>Dear Stovers
>Tonight I added a tapered stove pipe extension to the venturi
>arrangement, that was described in the last "More trials" and can
>now be seen on the Stovers web page.

Yes, I saw it, it speaks more than a thousand words.

chop

> The flame seemed to be in a steady state of
>rapid small explosions. Part of the audio effect was probably due to
>the acoustic characteristics of stove pipe. Visually, it was
>vertically more compact but still with a few periodic flame
>extensions into the upper chimney. There was a large blue component
>to this flame.
>
> The CO2 reading were in the 10-12% range.
>Temperatures were lower, due I think to the lack of refractory and
>presumably the slightly larger amount of excess air, at 1300-1440F
>(700-760C). The smoke test readings, with all parts intact, were 3 on
>the scale of 0 to 9.

As I understand it, the smoke test consists of assessing the colour change
of a piece of filter paper after letting through a standard volume of flue gas.
Now, with the downdraft stove we often get small flakes of ash coming out of
the chimney. Since you probably have similar gas velocities, the colour
change might be due to ash, giving a wrong reading for smoke.

chop

>Next I intend to introduce swirl with the secondary air inlet, then
>perhaps refractory and hey, what the heck, maybe even a bluff body.

Yes, a bluff body might stabilize the flame in its wake.

Good to have you on the list.

Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Thu Jun 19 08:29:03 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:19 2004
Subject: twocan turbo
Message-ID: <1.5.4.32.19970619122847.0068d3fc@janus.cqu.edu.au>

>From Piet Verhaart
To Elsen
At 22:13 17/06/97 EAT, you wrote:
>Stovers;
>
>My Turbo Twocan Mk I impressed the hell out of my staff- who have been
>cooking on either wood, charcoal or kerosene all their lives. I'll describe
>it first and outline it's performance second:
>
>Made of 1 mm sheet iron and assembled with an electric welder

Just an electric welder? You must have an expert welder (person) there to be
able to weld 1mm thin sheet.

> and an angle
>grinder, the unit has an inside diam of 30 cm and stands 70 cm tall. An
>outer shell (insulator and fresh air inlet air pre-heater) 1.25 cm distant
>from the main body starts 11 cm from the bottom of the stove to 9 cm from
>the top. This shell is open both at the top and the bottom. A 3mm air inlet
>gap circumvents the inner tube 20 cm from the top. Three 3 cm long by 2 cm
>high primary air inlets located 5 cm from the base of the stove are
>controlled by a snug rotating band of very light wt. sheet iron with
>matching holes. This can be rotated around the base out of alighnment with
>the primary air inlets to reduce air flow. These inlets convect air in at an
>angle into the base of the stove (pyrolysis chamber) because only three
>sides of the inlet have been cut, and the tab of metal has been bent into
>the stove at a 30 ' angle.
>
Can't you send a sketch to Alex to put on his Web page, I find it helps no
end to have a sketch.

You must have quite some facilities for building stoves, you will be the
envy of many.

>I'm not sure how to describe this- the top exhaust gas venting has been done
>the same way- it's quite simple.... much like pushing a beer can tab into
>the can?

I don't understand this. Then the top of the inner cylinder is closed and
the only openings are what you just described. So the gas comes out of the
side of the cylinder. The gases have a volume of 20 cm cylinder to get
mixed between the 3 mm slit and the holes under the top.

>
>In order to add stability to the whole affair , I haven't welded a bottom on
>the stove, but poured 5 cm. of concrete into it.

Very practical.

>The bottom of the primary
>air intakes are flush with this, and a few 1/2 cm deep furrows have been
>fingered into the concrete from the air inlets in arcs toward the centre.
>This concrete plug is poured into the stove after several 3mm wire 'spokes'
>have been welded accross the bottom (steel reinforcement) to hold the
>concrete in place.
>
>There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
>same tab type venting has been performed with an aim to produce swirling
>exhaust venting.

This is a more detailed description of the earlier mentioned "beer can tabs"?
>
>The whole affair weighs 18.5 kg, of which I imagine at least 10 kg is cement.
>
>In a 1.5 hour burn, I reduced 6 kg of dry brown olive hardwood to 1.75 kg
>charcoal with little ash (A bit of ash was formed at the beginning of the
>burn before the stove heated up properly). This is almost 30% conversion.
>The amount of partially carbonised wood was insignificant- maybe 50 gm. The
>wood was thumb-thick sticks complete with bark, standing vertically to the
>level of the secondary air ring.

How did you light the stove, from the top?
>
>2.55 ltre water was evaporated (Nairobi is just below 200o m altitude) with
>vigorous boiling.
>
>The stove required quite a bit of attention I found, with low primary air
>flow resulting in a lot of dense white smoke and no flame in the combustion
>chamber, and too much air causing flames directly on the wood. At one point,
>about two thirds through the burn, I had shut the air down too much,
>resulting in billows of smoke, and upon opening the primary vents to full,
>the gasses igninted with an audible pop in the combustion chamber.
>
Sounds familiar.

chop

>The water pot was aluminium, and about the same diameter as the stove
>itself. Maybe a slightly lengthened combustion chamber with a narower pot
>inserted into the stove, held away from the sides by the 'turbo' tabs of the
>xhaust vents would provide a more effective heat exchange. A modification
>for the next trial?

The pan should not be so close to the combustion zone as to quench the
combustion.

Very interesting and very stimulating.
Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Thu Jun 19 08:29:00 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:19 2004
Subject: Charcoal and CO
Message-ID: <1.5.4.32.19970619122842.0068e688@janus.cqu.edu.au>

>From Piet Verhaart
Dear Dave,
At 19:07 18/06/97 GMT, you wrote:

>>
>> May be catalytic? Is there anything more detailed on catalysis of CO to CO2?
>> K, Ca, Al, Si?
>> I remember our downdraft stove producing negligible CO as long as volatiles
>> were produced.
>
>In my measurements of such things in a batch-loaded gasifier-
>combustor, the CO increase also coincided with increasing Excess Air
>Value of combustion and hence falling combustion temperatures. I
>don't know whether or not the 2CO+O2 <> 2CO2 equilibrium is moved to
>the right or the left by higher temperatures, but the reaction rate
>should increase exponentially with increasing temperature....
>Dave.
>

In the downdraft stove at the instant the volatiles production stops, the
airflow rate does not change. So the air has less to burn e.g. the resulting
gas mixture would be cooler. Yes, you've got a point.

Did you have any means to reduce the air flow rate in your gasifier?
Did you then find reduced CO?

With the downdraft stove an attempt to reduce the airflow rate would affect
the burning rate of the char as well.

I'll have to think about this. Thank you for bringing this up.
Regards,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From E.Moerman at stud.tue.nl Thu Jun 19 08:37:38 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: Moerman (2) on carbonization.
Message-ID: <9472.s335192@popserver.tue.nl>

>
> (RWL): I am not sure why it didn't work. I hope Etienne will describe any
> differences in his test from what I have described as a two-can test. The
> design changes with different dimensions, has to have fairly dry wood,needs
> to be well shielded from the wind etc.
> I have not claimed a blue flame. In small scale and under some
> conditions, Tom says he has approached that condition, but I have not.

Etienne:
I ligthed several cilindrical stoves with secondary air supply at the top. I
did not make the 2-can stove, because I do not have the material.

----------
On the charcoal making stove.

>
> (RWL): I see the big advantage not on the stove side, but rather on
> the charcoal making side, where the energy conversion efficiency rarely
> gets to 50% and might be 25% normally (15% by weight). We have heard many
> times on this list about how bad charcoal-making is for the environment. By
> using the gases, the efficiency is always well over 50% (starting at 40%
> without use).

Etienne:
On that we agree. I just prefer not to use charcoal at all, since it is my
experience that wood can do the job as well as charcoal. But if it has to be
produced something must be done about it for sure.

-----------

Ron L.:
> As to the number 200 grams - this is per person per day I presume.
> So in a family of 5, one fills a 50 kilo bag in 50 days. I think this might
> be on the low side. When a woman is earning essentially nothing and men
> are earning less than $100 per year, I believe even this small amount will
> be seen as meaningful. But maybe the advantge is going to be seen to be the
> constancy of output.

Etienne:
No this was an estimate for the whole family of 5. Anyway I see the biggest
problem in marketing the stuff, not in its intrinsic value.

-----------

Ron L.:
> There are plenty of problems to solve, but I don't believe
> efficiency,controllability, pollution levels, and earning potential are
> not among them - at least comapared to the standard alternatives.
> Among the problems I still am working on are: 1) safety and
> stability, 2) increasing heat transfer efficiency to the cook pot, and 3)
> extinguishing the pyrolysis quickly.

Etienne:
Efficiency, controlability and pollution levels need to be worked on for all
stoves, especially since the addition of pans ruins at least the
controllability and the pollution levels.

---------

> (RWL): I look forward to seeing CO/CO2 measurements on charcoal-buring
> stoves like Paul Hait's. I doubt it will prove to be 6%

Etienne:
Sorry, no time, no money and some missing manuals. The last point can
probably be solved with a little bit of time.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Thu Jun 19 08:37:50 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: One old guy replies....
Message-ID: <9484.s335192@popserver.tue.nl>

Sorry for the duplication, but I made a mistake in the address field.

I received a message that bounced because there was an attachment that was
over 40000 bytes in size. Consequently it was rejected and none of the
subscribers received it. If anybody is interested in receiving it he or she
can request it from me directly. I will keep it for a week. Otherwise I
suggest that you contact the author Art Krenzel.

Sorry I don't know the content (I suspect it is on chimney draft), but right
now it is too much for me to read. Below you find the header and intro of
the message.

Etienne
-----------
Art Krenzel <phoenix@transport.com> writes:

> This is a multi-part message in MIME format.
>
> --------------407A5C1C32BA
> Content-Type: text/plain; charset=big5
> Content-Transfer-Encoding: 7bit
>
> I have been reluctant to add "fuel to Alex's fire" so to speak but I am
> one of the guys who has one of those text's on chimney design. I would
> like to pass on a page in the book for your information.
> This is my first scan so help me reduce my file size.
>
> Art Krenzel
>
> --------------407A5C1C32BA
> Content-Type: application/octet-stream; name="Chimdraf.pcx"
> Content-Transfer-Encoding: base64
> Content-Disposition: attachment; filename="Chimdraf.pcx"
>
--------------------
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Thu Jun 19 08:37:55 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: Test Equipment
Message-ID: <9469.s335192@popserver.tue.nl>

Brian:
> I think the more appropriate consideration here is that of calibration. The
> Bacharach CO2 tester relies on the resiliency of a rubber membrane and the
> absorptive capacity of the fluid in the device to work. I think these will
> both change over time and a method of knowing when to replace is critical.
> If you have a standard CO2 sample (the Bacharach manual suggests your
> breath) then whatever tester you are using can be calibrated to that
> standard. One of the things that we have here is the welding gas for our
> Mig welder, I would simply have to check with the supplier to get its CO2
> content.

Etienne:
Producers of industrial gases also produce calibration gases on request. A
special accurate lab analysis certificate can be obtained from them too.
That's how we do it here.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Thu Jun 19 08:38:08 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: CO and Charcoal
Message-ID: <9477.s335192@popserver.tue.nl>

Alex:
>
> I have heard it said that the process of combusting CO to CO2
> requires, to some extent, the presence of water vapour. Most fuels
> have sufficient H to yield that H2O. Is it possible that the charcoal
> has been depleted of H enough starve this process of adequate H2O ?

Etienne:
H2O is not required for CO oxidation, but it seems to have a strong
catalytic effect. Internally it is depleted when char combustion starts to
occur, but flames from other parts of the fuelbed can provide H2O to a
boundary layer around a piece of charcoal.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Thu Jun 19 08:37:55 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: Test Equipment
Message-ID: <9465.s335192@popserver.tue.nl>

?:
>>Any recommendations? Should we, from now on, try to stick to one supplier
>> after deciding collectively on the most appropriate equipment?
>>

Ron L:
> OK - if clearly superior.

Etienne:
No! One supplier cannot deliver throughout the whole world for reasonable
prices. Just concentrate on the measurement process and accuracy.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Thu Jun 19 08:38:41 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:19 2004
Subject: Burt and Moerman on CO
Message-ID: <9480.s335192@popserver.tue.nl>

Ron L.:
>
> 1. I hope Etienne will repeat the nature of the CO experiments
> with charcoal cookers that he gave about a year or more ago - with as much
> detail as possible. Is it universally true that charcoal stoves always
> emit excessive CO through the whole burn?
> 2. I wonder if Paul Hait has measured CO production in the Pyromid?
> 3. Ron West had a piece 6-8 months ago on the production of CO vs
> CO2, noting the great tendency to produce CO2 when CO and O2 were both
> present on the surface of charcoal. Ron will be back soon from Turkey; he
> has done a good bit of this sort of study. I've left a message.
> 4. I wonder if anyone else (Kirk Smith?) has CO data of the sort
> Etienne is describing. I think that the production of charcoal in the
> traditional manner has lots to be concerned with (including massive
> production of CO), but if Etienne is correct that CO production is a
> serious problem (and that this CO problem can't be solved), then I don't
> want to be in the business of promoting charcoal-producing stoves.
> 5. It looks like I will have to buy a CO monitor unit - anyone have
> a favorite?
> 6. Could Kirk Smith or someone else describe the accepted limits
> for CO input?
>
Etienne:
1. I don't know what you mean by my experiments with charcoal stoves from 1
year ago. My last experiments with charcoal stoves were several years ago.
About new experiments no time, no money. Sorry.
4. Note that I don't say that charcoal is worse for a stove user than wood
in the usual cookstove. I just say that it is apparently not as safe as most
people conclude from the absence of smoke. As far as the charcoal production
is concerned something has to be done indeed.
5.+6. Also buy a CO2 monitor, there are combined sets available. CO
emissions itself don't say very much, far more important is the CO/CO2
ratio!

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From elk at arcc.or.ke Thu Jun 19 09:18:05 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:20 2004
Subject: Charcoal Briquetting & the 2can turbo
Message-ID: <v01510101afcece4d0cdc@[199.2.222.133]>

Stovers;

A breakthrough on the briquetting- my manual briquetter is getting
somewhere now! It's new assignment may be the most appropriate - charcoal
dust salvage.

Nairobi has, by a gut-feel estimate, over 500 well established charcoal
depots. From these, often en-situ for over a decade, most sales are
measured out in heaped 4 litre paint can loads (@ USD $0.36 ). Charcoal is
delivered by the truckload in approx 45kg bags (@ usd $ 4.0 ). Of this, so
my staff estimate, over 10% is charcoal fines, dust & small particles.

A classic characteristic of these charcoal sales points is the tall black
mound of this dust, upon which the rest not only the opened & unopened bags
of charcoal, but often the residence of the vendor. My estimate is, that on
average, each mound is composed of 30 tons of charcoal dust. We are talking
15000 tons raw material immediately available in & around Nairobi alone, &
increasing.

There is a small market for the material existing already with hand molded
dust+mud briquettes as the poor man's charcoal, but the amount of charcoal
dust used for this apparently does not match 'production' except possibly
in slum areas.

-Interlude for question: Does charcoal deterioate with time & moisture?

Yesterday, I purchased 325 kg in 5 bags of this material- which visually
appears to be 95%+ charcoal powder- for the sum of USD eqiuv. $5.91, or
less than 2 cents per kg. from a very pleased vendor.

With simple seiving, and with a cement binder at 8%, my hand briquetter
produces very high quality charcoal briquettes from this material.

As mentioned in a previous correspondence, the cement-bound briquettes are
considered superior by my staff due to their slow burn & even heat.

Two of my casual workers are (eagerly) removing themselves from the daily
wages ($1.25 per day) to go into full time briquetting as from tomorrow &
will expect to earn at least $2.65 per day - calculated on 100 kg/day
production at regular per/kg value of charcoal less input costs. I use
charcoal in my poultry brooders at up to 5 bags per day weather dependant,
and the slower burning cement-binder briquettes are ideal for this purpose.

Alex has offered to post a picture of my briquetter and briquettes as well
as the '2-can turbo' charcoal making stove (under trial 2 at this moment)
on his stovers web site, so I'll courier some photos for him to select from
early next week,

-Alex- what's your courier-friendly physical address?

THIS IS HOT! Any ideas on concept & methods dissemination?

All for now- I'll report 2-can turbo trial number two results later.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From english at adan.kingston.net Thu Jun 19 09:36:38 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: Charcoal Briquetting & the 2can turbo
Message-ID: <199706191336.JAA07181@adan.kingston.net>

Dear Elson

I find your your letters to the list very " grounding".

The address in my e-mail should be enough, to be sure add c/o Burt's
Greenhouse.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From tscole at concentric.net Thu Jun 19 09:49:00 1997
From: tscole at concentric.net (sharon a cole)
Date: Tue Aug 31 21:35:20 2004
Subject: stove restoration
Message-ID: <33A9388E.61C8@concentric.net>

bryant stoveworks, thorndike, maine does restoration and has for a lot
of years.

From REEDTB at compuserve.com Thu Jun 19 10:07:02 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:20 2004
Subject: Imperial vs US gallons
Message-ID: <199706191006_MC2-18C7-2644@compuserve.com>

(TOM REED - on Province Town Neck)

Alex et Al:

Alex said his 2 gallons weighed 21.5 lb. My two gallons weigh 16 lb. For
those not acquainted with the English system, Canadian (and English?)
schoolchildren learn

"A pint of pure water weighs a pound and a quarter"

but in the U.S. they learn

"A Pint's a pound, the world around". (except Canada).

So Alex's gallons were Imperial Gallons, 5/4 of US Gallons. Hope all these
units disappear in a generation or two. (5/4 of 16 lb = 20 lb - oh well).

Am I correct that England has given up on gallons?

Regards, TOM
REED

From REEDTB at compuserve.com Thu Jun 19 10:07:08 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:20 2004
Subject: Two Cone Stove
Message-ID: <199706191006_MC2-18C7-264D@compuserve.com>

Alex et al:

It sounds to me as if your double cone is in principle like our blue flame
burner, but tapered to a smaller size. I need to get on the Web and look
at your pictures.

If you think of a conventional gas stove, the heating flames occur in a
ring about 3-4 in in diameter, about 3/16 in thick, so with an area of 2
in2. This was our thinking in the blue flame stove burner consisting of a
4 inch ID riser sleeve/can with a 3 inch can centrally located to make a
ring, the whole burner lifted about 3/8 to 1/2 inch above the gasifier.
This is described in a paper we presented at Banff and sent today with
modifications to Prasad for publication in ESD. When I return to Colorado,
I will send you the drawings for inclusion on your page.

I hope it is OK to use ENGLISH units here. How's Canada's metrification
going?

Onward, TOM
REED

From REEDTB at compuserve.com Thu Jun 19 10:07:03 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:20 2004
Subject: carbonising (by Karstad)
Message-ID: <199706191006_MC2-18C7-264E@compuserve.com>

RWL, EK et al:

In conventional charcoal making with wet wood some of the wood is burned at
the bottom of the closed pile. 1) Initially the rising hot gases dry the
pile, emitting steam.

2) When most of the pile is dry the emissions are half steam, half
pyrolysis gas, uncombustible.

3) Then the pyrolysis gases reach a stage of combustibility, but need to
keep a source of ignition (propane torch) because they form only an
unstable diffusion flame.

4) Finally, after all volatiles have been driven off the gas is primarily
CO which can be burned with an almost invisible, lilac colored flame.
However, this indicates the charcoal is done and all air ingress should be
halted.
So I would recommend having pre-mixing with some air plus a stable source
of ignition plus a flame holder. Then you can burn the gases in stage 3
(and 4). Also, the more the pile is "stratified", the cleaner the
separation between stages.

HOpe this is useful, TOM
REED

From REEDTB at compuserve.com Thu Jun 19 10:07:22 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:20 2004
Subject: English of 6/12 on Charcoal-making stove
Message-ID: <199706191006_MC2-18C7-2650@compuserve.com>

Dear Ron, Alex et al:

In my book a yellow or orange flame indicates a diffusion flame, ie air
diffusing into unmixed gases with combustion at the interface, as in a
candle.

A blue flame results

1) from mixing with air before ignition as in a Bunsen Burner, carburetor,
propane torch, ....

2) from diffusion of air over a distance of less of less than a few mm, as
in the Alladin type kerosene stoves, or the BOTTOM side of a match (try
it), but not in the flame above the match.

Therefore, in order to get a blue flame it is necessary to keep diffusion
distances very short or get good mixing which we havn't been able to
achieve with natural draft, but is easy with a little forced draft (we did
it at NREL for the inverted downdraft in 1985).

Another source of good combustion equipment is the Dyer company -
flowmeters, draft gauges etc.

Onward,
TOM REED

From REEDTB at compuserve.com Thu Jun 19 10:08:08 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:20 2004
Subject: Tom Reed on draft vs fans
Message-ID: <199706191006_MC2-18C7-2646@compuserve.com>

(TOM REED - on Province Town Neck)

Ron et al:

That's an interesting suggestion (running an engine on the volatiles made
from wood while making charcoal).
I don't think you could run the engine on the volatiles made from the
heating by exhaust heat
while making charcoal (sounds like perpetual motion) but it's an
interesting suggestion. The "volatiles" contain a lot of "condensibles"
that you would need to remove before letting an engine see the balance of
the permanent gases. It would also be necessary to use very dry wood.
However, if you want I will do an energy balance.

I first heard about this possibility from Danny Day and Agua Das. They are
working diligently on making charcoal, so we should ask them. Are you out
there Day and Das??

Onward,
TOM REED

From elk at arcc.or.ke Thu Jun 19 12:44:37 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:20 2004
Subject: 2can turbo charcoal making stove
Message-ID: <m0wekJL-0006bdC@arcc.or.ke>

>I don't understand this. Then the top of the inner cylinder is closed and
>the only openings are what you just described. So the gas comes out of the
>side of the cylinder. The gases have a volume of 20 cm cylinder to get
>mixed between the 3 mm slit and the holes under the top.

asks Piet Verhaart-

The top is closed when a pot is in place. Otherwise open for loading wood &
unloading charcoal. The combustion chamber is only 20cm high x 30 cm diam.

>>There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
>>same tab type venting has been performed with an aim to produce swirling
>>exhaust venting.

This is different from what I imagine the beer can opener venting to be like
in that the flaps fold horizontally out or in- turbo.

>
>How did you light the stove, from the top?

Yes, lit from the top with a handful of dry twigs.

>The pan should not be so close to the combustion zone as to quench the
>combustion.

So right- in today's first trial with the combustion chamber reduced further
by inserting the pot into the top of the stove (I've extended it, but not by
the full depth of the pot- full measurements will accompany trial report), I
had some trouble keeping flame in the combustion chamber.

Piet's comment on the 1mm steel thicknes & the skill of my welder- I checked
& it's actually 1.5 mm thick. (I think... is that the normal thickness of
the steel used in 200 litre drums?).

Many thanks for the comments.

elk

From english at adan.kingston.net Thu Jun 19 12:46:24 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: Imperial vs US gallons
In-Reply-To: <199706191006_MC2-18C7-2644@compuserve.com>
Message-ID: <199706191646.MAA13678@adan.kingston.net>

> (TOM REED - on Province Town Neck)
Dear Tom +

"Province Town Neck" sounds like the Canadian version of "Southern
Redneck"

> Alex et Al:
>
> Alex said his 2 gallons weighed 21.5 lb. My two gallons weigh 16 lb. For
> those not acquainted with the English system, Canadian (and English?)
> schoolchildren learn
>
> "A pint of pure water weighs a pound and a quarter"
>
> but in the U.S. they learn
>
> "A Pint's a pound, the world around". (except Canada).
>
> So Alex's gallons were Imperial Gallons, 5/4 of US Gallons. Hope all these
> units disappear in a generation or two. (5/4 of 16 lb = 20 lb - oh well).

Yes Yes, my kids don't have any feel for Imperial units, and I'm in
to big a hurry to not work from " feel".
>
> Am I correct that England has given up on gallons?

I don't know.

Alex

P.S. You know that the "I am going to quit" letter you sent to the
Bioenergy List is the reason that I am haunting the Stoves list.
>
> Regards, TOM
> REED
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Thu Jun 19 12:46:37 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: English of 6/12 on Charcoal-making stove
In-Reply-To: <199706191006_MC2-18C7-2650@compuserve.com>
Message-ID: <199706191646.MAA13680@adan.kingston.net>

> Dear Ron, Alex et al:
>
> In my book a yellow or orange flame indicates a diffusion flame, ie air
> diffusing into unmixed gases with combustion at the interface, as in a
> candle.
>
> A blue flame results
>
> 1) from mixing with air before ignition as in a Bunsen Burner, carburetor,
> propane torch, ....
>
> 2) from diffusion of air over a distance of less of less than a few mm, as
> in the Alladin type kerosene stoves, or the BOTTOM side of a match (try
> it), but not in the flame above the match.
>
> Therefore, in order to get a blue flame it is necessary to keep diffusion
> distances very short or get good mixing which we havn't been able to
> achieve with natural draft, but is easy with a little forced draft (we did
> it at NREL for the inverted downdraft in 1985).
>
<snip>
Dear Tom +

So can I surmise that turbulence is not necessary for good mixing,
just short diffusion distances. Are these relatively gentle and spread
out flames from woodgas capable of low CO or CO/CO2 ratios.
On a related thread:
This morning Brian and I had a discussion on CO emissions with our
combustion adviser from the local university. ( He may now be a
lurked on the list because I know he has checked out the Stove
archives.) He described their work with fluidized bed combustion,
noting that with temperatures around 900C they could reduce excess
air to practically stoicometric levels, or zero with very low CO.
This was not the case for temperatures around 700-800C. He felt that
temperature was a key for low CO and that this was relevant to other
forms of combustion. How does this relate to the small blue gasifier
flame and its CO emissions ?

I have seen temperatures up around 900C as measured with our
thermocouple, but not with out the "cera felt liner"in the combustion
chamber/chimney. I am also seeing a larger blue component to the
flame, in the latest swirling venturi model of the cone and pail
burner, when the fire really gets going to generate enough draft.

Alex

> Onward,
> TOM REED
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From BeedieD at Cardiff.ac.uk Thu Jun 19 13:10:18 1997
From: BeedieD at Cardiff.ac.uk (David Beedie)
Date: Tue Aug 31 21:35:20 2004
Subject: Charcoal and CO
Message-ID: <19D3D236FF2@nrd1s.cf.ac.uk>

Piet,

[db]
> >In my measurements of such things in a batch-loaded gasifier-
> >combustor, the CO increase also coincided with increasing Excess Air
> >Value of combustion and hence falling combustion temperatures. I
> >don't know whether or not the 2CO+O2 <> 2CO2 equilibrium is moved to
> >the right or the left by higher temperatures, but the reaction rate
> >should increase exponentially with increasing temperature....
[pv's cut]
> >Dave.
> >

[pv]
> In the downdraft stove at the instant the volatiles production
> stops, the airflow rate does not change. So the air has less to
> burn e.g. the resulting gas mixture would be cooler. Yes, you've
> got a point.
> Did you have any means to reduce the air flow rate in your gasifier?
> Did you then find reduced CO?
>
> With the downdraft stove an attempt to reduce the airflow rate would affect
> the burning rate of the char as well.
>
> I'll have to think about this. Thank you for bringing this up.
> Regards,
> Piet Verhaart
> Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
> Phone: +61 79 331761 Fax: +61 79 331761 or 332112
> E-mail:p.verhaart@cqu.edu.au

I made a control system on the gasifier-combustor tuned carefully to
minimise CO emissions. This used combustion temperature as an
indication of the Excess Air Value, and acted on a butterfly valve in
the gasifier's primary air inlet so as to oppose changes in
combustion temperature.

The single controllable parameter allows control over Excess Air
Value, or gasification rate, but not both. If you keep the Excess
Air Value constant in a batch-loaded system, and if you also
happen to have a fixed secondary air flow rate (like my system),
then both the primary air flow and the gasification rate undergo
cyclical changes through the loading cycle as the fuel state changes.
The bottom line is a high thermal release rate at the start and end
of the fuel cycle, and a minimum in the middle. At the end of the
cycle, increase in the primary air flow is no longer able to
stimulate enough extra gasification and an increase in Excess Air
Value is inevitable. CO is kept low while the Excess Air Value -
EXAV - is under control as this maintains an adequate combustion
temperature. But once EXAV can not be controlled to the desired
level the gases are not hot eough for long enough and there is a
sudden and dramatic increase in CO. So the trick with emissions
control is to refuel just before reaching this point.

Also the system must not have too high a proportion of heat losses
else it will reach the critical point at a lower value of EXAV and
will be less amenable to emissions control.

(Disclaimer: I speak with certainty only for the gasifier-combustor I
have worked at length on !).

Dave.
*******************************************************
(Dr) David Beedie
School of Engineering, University of Wales, Cardiff, UK

email: BeedieD@cardiff

Tel. 01222 874683 (office); 874000 ext.5927(lab.)
FAX: 01222 874420 - mark for my attention !
762197 (home)
*******************************************************

From hmrajabu at ucdavis.edu Thu Jun 19 13:47:39 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:20 2004
Subject: Rajabu on kerosene
In-Reply-To: <v01540b08afccb50a1061@[204.133.251.3]>
Message-ID: <Pine.GSO.3.95.970619092606.13810B-100000@chip.ucdavis.edu>

On Tue, 17 Jun 1997, Ronal W. Larson wrote:

> (RWL): 1. Is the restriction on fuelwood stoves for both those with and
> without chimneys leading the smoke outdoors?

This depends more on the landlords, the value of the house, etc,. Most
landlords would prefer the tenants to use electric stove, followed by gas,
kerosene, charcoal, and lastly fuelwood. in that order i guess. It is to
do with the mess and repair costs when looking for a new tenant. Just like
most landlords would prefer tenants who are single or a couple with no
children.

HR> >A recent survey in Dar es Salaam showed that kerosene is cheaper than
> >charcoal. However, according to the recent energy price policy
> >(government), kerosene is subsidized to encourage people to switch from
> >charcoal. It is a cross subsidy, paid by gasoline users.
>
>
> (RWL):
> 1. Can you provide the price of kerosene and the magnitude of the
> subsidy in Tanzania?
> 2. What is your (and everyone's) opinion on the appropriateness of
> encouraging kerosene use for cooking? Any idea of the magnitude of the
> currency drain (not worrying about the transfer payment, but of the drain
> of national finances out of the country.
> 3. In Tanzania, is there concern about global warming from the use
> of fossil resources? (There is little in the US) I am wondering about the
> long term social benefit of promoting kerosene stoves - but maybe a short
> term use in coutnries like Tanzania to allow forests to come back is
> appropriate. But maybe they won't come back if they are not needed for
> fuel wood.

HR:
1. A liter of kerosene and gasoline costs about 35 and 50 cents($),
respectively. However, Diesel fuels are also in the cross subsidy
equation. So the 50 US cents for gasoline also has a diesel component.

2. First let me re-visit my former statement when I said kerosene is
cheaper than charcoal, First of all the price of charcoal varies
considerably with the season. The highest prices being during the rain
season, not only because of the effect of the rain on the raw material or
process, but most charcoal makers works in their farms, etc,.

Charcoal stove might be cheaper in cost/KW-hr compared to kerosene or
even electric stove. But what makes charcoal expensive is the use factor
(I dont know if this is the right term). Most of the heat is lost
during the starting up, and in practice people dont extinguish the
glowing charcoal after finish cooking. So the stove just burns to
extinction. Another point is most of the charcoal stoves in households
are bigger than are needed for most cooking tasks. Just like how people
buy cars. In the case of kerosene stove the use factor is
high because starting-up and cooking starts simultaneously. The flames can
be tuned to cover most size of pots for different cooking tasks. also the
stove is turned off immediately after finish cooking.

My opinion is to encourage people to switch to kerosene, as a short term
measure. The currency drain is justified if the price is to conserve local
environment. In a long term the gorvenment has given priority to rural
electrification. If energy loans can be set up to help people who cannot
afford to buy an electric stove then the pressure in local forests will be
immensely reduced.

3. There is no concern or awareness of global warming. People are more
aware of the of enviromental costs which will be caused (or already
happening in some places) by deforestation.

Hassan

> > > Regards Ron >
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).
---------------------------------------------------------politics!
measure by micrometer/mark with chalk//cut by an axe////

From elk at arcc.or.ke Thu Jun 19 15:10:01 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:20 2004
Subject: 2can turbo charcoal making stove
Message-ID: <m0wemYs-0006bAC@arcc.or.ke>

asks Piet Verhaart-

The top is closed when a pot is in place. Otherwise open for loading wood &
unloading charcoal. The combustion chamber is only 20cm high x 30 cm diam.

>>There are 23 2x2cm exhaust gas outlets around the top 3 cm from the rim- the
>>same tab type venting has been performed with an aim to produce swirling
>>exhaust venting.

This is different from what I imagine the beer can opener venting to be like
in that the flaps fold horizontally out or in- turbo.

>
>How did you light the stove, from the top?

Yes, lit from the top with a handful of dry twigs.

>The pan should not be so close to the combustion zone as to quench the
>combustion.

Piet's comment on the 1mm steel thicknes & the skill of my welder- I checked
& it's actually 1.5 mm thick. (I think... is that the normal thickness of
the steel used in 200 litre drums?).

Many thanks for the comments.

elk

From ahe1 at cableol.co.uk Thu Jun 19 15:12:05 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:20 2004
Subject: Burt Brian
Message-ID: <9706191911.AA29595@mars.cableol.net>

At 21:47 18/06/97 -0700, you wrote:

>What we are interested in (with apologies to Ron for using this list), are
>any emissions data for herbaceous biomass burners that already exist.
>
Yes this is data I am interested, I gather woodburning is actually the third
largest source of dioxin in the atmosphere, as I have said in other posts I
am worried about the pollution from our kilns and burning the gases produced
to recover heat would seem sensible on pollution and economic grounds.

I thought prior to reading this list that charcoal burning was benign, I did
not realise CO levels were bad, although I did know King Phillip of Spain
died from CO poisoning from emissions from a charcoal brasier in his bed
chamber and was found lobster pink in the morning.

Because of problems with uneven burning of batch loads I had thought along
the lines of seperating the various processess to produce more uniform and
homogenous conditions. I was looking at the possibility of seperately
drying, pyrolising and then burning the char, or in my case selling it at
high value.

Again I was considering a pottery kiln as my use for waste heat as the flare
gases should reach these high temperatures and could be sized to match the
charcoal flare gas production. A greenhouse should cause no problems, though
some sort of thermal inertia would need to be introduced to allow for the
uneven liberation of gases over time in a batch retort ( a large insulated
tank of water springs to mind).

AJH

From ahe1 at cableol.co.uk Thu Jun 19 15:12:13 1997
From: ahe1 at cableol.co.uk (Andrew Heggie)
Date: Tue Aug 31 21:35:20 2004
Subject: Heggie on kiln operation (#2)
Message-ID: <9706191911.AA02328@mars.cableol.net>

At 22:28 18/06/97 -0600, you wrote:
>On 18 June, Andrew said:
>
>>(AJH)This is the basis of what I am acquiring the bits to build. I am
>>confident there is excess flare gas available but suspect in a large retort
>>some internal circulation through a cooler will be necessary because of the
>>worse (better for energy retention) volume to surface area.
>
>(RWL): Do you think this "excess flare gas" is about 50% of the input -
>and are there some applications that you can use it for? It is great to
>see that flaring is occurring in one charcoal maker, but it would be much
>better to know that the flared gas is being used productively.
(AJH) I assume you mean Peter Hollands retort I reported on mine is not made
yet.
On desk study at current small user fuel prices if we can recover 50% of the
heat currently lost it will be worth 10% of our wholesale turnover of
charcoal, finding a user is another matter. In UK there is an anomaly in how
small businesses recover value added tax that means a small business selling
energy to a domestic user will benefit by a 8% price advantage, this does
not apply to commercial sales to large companies.

I base my assumptions on 12 tonnes per week throughput with total energy
potential of 9 Gjoules/tonne. Hence 54Gjoules wasted. The coking industry
actually achieved 90%+ heat efficiency, if we assume we can only use 50% of
our waste then 27Gjoules of heat might be sold. Gas oil at this scale is
.0154GBP per kWhr. Therefore as 27 Gjoules=7500 KWhr the equivalent price is
115GBP.

From hmrajabu at ucdavis.edu Thu Jun 19 15:37:02 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:20 2004
Subject: Hasssan on briquetting sawdust (part 2)
In-Reply-To: <v01540b05afcc81b0ffdd@[204.133.251.3]>
Message-ID: <Pine.GSO.3.95.970619114229.23435A-100000@chip.ucdavis.edu>

On Tue, 17 Jun 1997, Ronal W. Larson wrote:

> >HR: The experiments which I am currently doing are on combustion of
> >briquettes and wood. In some experiments I have been quenching the burning
> >pieces at pre-selected times to take measurements on the char and unburned
> >parts of samples. The Char formed in these conditions is definitely
> >different from the carbonizig kiln, or charcoal-making stove.
>
> (RWL): Could you further define these differences?

HR: This is what I know from various references:

The difference is caused by the difference in the "environment"
temperature between the two mechanisms. The pyrolysis reaction during the
combustion of pellets is accelerated by the heat flux radiated back to the
surface from the flame. As char is formed by primary and secondary
reactions of pyrolysis gases and liquids to form char as they move out of
the porous char. With high temperature the secondary reaction residence
time in porous char is reduced with the consequence of reducing
char-forming secondary reactions effectiveness.

> <snip>
> >In these areas fuelwood scarcity increases year after year as the
> >distance they cover to collect fuel increases each year. As a move to slow
> >the rate of deforestation the government imposed a condition for the
> >farmers to grow twice the number of trees they consume each year in order
> >to reverse the trend.
>
> (RWL): Can you comment on the success of this government edict? In
> Tanzania, is the land owned or leased from the government and who owns the
> newly planted trees? Did you grow up in Tanzania?
>
HR:
-What I know is that the government passed the enforcement part to the
local/village governments who further modified it to suit their
conditions. ie some local governments made options to the farmers for
either plant trees or pay special tax when selling their crops. Then the
tax collection is used for afforestation projects. I dont know the overal
success/failure countrywide, but in the tea growing areas, for example,
they started a, -if I translate straight from swahili, "cut one tree,
plant two" campaign a couple of years before the government move.

- Land is leased from the govt. About 50 percent of forests are also govt.
conservation areas (no activities).

-I was born and grew up and still working in Tanzania as a lecturer at the
University of Dar es Salaam, Mechanical Engineering Dept. I am currently
doing a sandwich Ph.D with UCDavis (and UDar). Now doing experiments and
modelling at UCDavis.

> > The problem is briquettes, like fuelwood, can be
> >made in a wide range of properties. What dimensions and properties are
> >important or are more sensitive in its combustion?
>
> (RWL): Knowing that this is your thesis and you are probably still
> working on this topic, are there any answers yet that you can report?

HR:
Not at the moment.

Hassan

> Thanks for a very good response to my earlier questions. Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
>
>

-------------------------------------------------------------------------
Hassan M Rajabu.
Biomass Lab., Bio. & Ag. Engineering Dept. UCDavis. CA 95616.
- (916)752-6623/2-8039/7-7640(H).

From elk at arcc.or.ke Thu Jun 19 16:42:26 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:20 2004
Subject: 2can Turbo trials 2&3
Message-ID: <m0wekJh-0006bbC@arcc.or.ke>

The most important results today were the importance of direct supervision.

In the absence of this, my staff oborted two burns early for fear of running
the stove past the pyrolysis stage & reducing charcoal produced to ash- no
reportable results on charcoal production. I'll run this again tomorrow.

I've increased the depth of the combustion chamber by 4 cm (secondary air
inflow ring to bottom of top exhaust vents). Two options are available now-
insertion of a 28 cm diam. pot into the top of the (30 cm diam) stove, or
resting a larger than 30 cm diam. pot on top of the stove (above the exhaust
vents).

Today's incomplete trials involved the first (and most efficient) method
whereby a pot is inserted directly into the top of the stove. This maximises
the surface contact of heat to the pot by heating both bottom & sides of pot.

The uncovered pot containing 5.6 litres of water was brought to a boil in
ten minutes from maybe 16'C!

When operating, it was impossible to observe the flame and it's activity or
orientation due to the pot sitting into the top of the stove.

Mixed sizes of hardwood (dry brown olive branches again) were used- it
appears uniformity of size is preferred. 8.9 and 8.9 kg charges were loaded
for the two attempts.

It seems that the additional reduction of the volume of the combustion
chamber to 11.5 cm between bottom of pot & secondary air ring makes it
harder to maintain combustion in the chamber. Flame went out several times.
On one occasion, this was due to wood partially blocking the primary air
vents. I'm intalling a 24 cm diam cricle of wire 4 cm above the bottom of
the pyrolisis chamber to avoid this in future & limit the amount of wood put
into the stove. I don't think it's necessary to stuff it as full as
possible, it should help to maintain a 2 cm gap between wood & the sides of
the stove at & immediately above the level of the primary air inlets.

When burning, little or no smoke is observed, and a white rhime of ?calcium?
has deposited around the outside of the exhaust vents- indication of high
temperatures or complete combustion? No soot produced anywhere above the
secondary air inlets.

Update on the est. cost of manufacture- it turns out that the $10 to $12
dollars I mentioned earlier was an offer to buy from my forman- not what it
would cost to make (nice guy, loyal & all). The revised estimate of
production cost in the local informal sector, using salvaged 200 litre drum
metal, is now $20.00

One question to any two-canner; what happens if the charcoal is not
extinguished & the stove is allowed to go out by itself. Will the charcoal
burn down to ash?

All for now- I'll run large pot (not inserted) trials tomorrow, allowing the
full 24 cm height of the combustion chamber to be used.

elk

From ctraxler at safelab.com Thu Jun 19 16:42:54 1997
From: ctraxler at safelab.com (Chad Traxler)
Date: Tue Aug 31 21:35:20 2004
Subject: DIG-L: Thomas R Miles 1916-1997
In-Reply-To: <3.0.32.19970502214659.0077bca4@mail.teleport.com>
Message-ID: <33A7D193.31A8@safelab.com>

This is an automated reply.

Chad Traxler is no longer located at this e-mail address and no
forwarding information is available. If the message regards Hitchings
Associates business, please forward your original message to Dale
Hitchings (dhitchings@safelab.com)

From skip.hayden at cc2smtp.NRCan.gc.ca Thu Jun 19 16:47:54 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:20 2004
Subject: Imperial vs US gallons
Message-ID: <9705198667.AA866764024@cc2smtp.nrcan.gc.ca>

In Canada not only is a pint not a pound as in the world around, it doesn't
exist, as we now use litres, as does the world around (except for the U.S.).

Our old point of reference was that a gallon (imperial) weighed 10 pounds.
Hence your 20 lb calculation is correct.

Skip Hayden

______________________________ Reply Separator _________________________________
Subject: Imperial vs US gallons
Author: stoves@crest.org at internet
Date: 6/19/97 10:07 AM

(TOM REED - on Province Town Neck)

Alex et Al:

Alex said his 2 gallons weighed 21.5 lb. My two gallons weigh 16 lb. Fo=
r
those not acquainted with the English system, Canadian (and English?)
schoolchildren learn =

"A pint of pure water weighs a pound and a quarter"

but in the U.S. they learn

"A Pint's a pound, the world around". (except Canada). =

So Alex's gallons were Imperial Gallons, 5/4 of US Gallons. Hope all the=
se
units disappear in a generation or two. (5/4 of 16 lb =3D 20 lb - oh wel=
l). =

Am I correct that England has given up on gallons?

Regards, T=
OM
REED

From english at adan.kingston.net Thu Jun 19 17:13:35 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: More trials cont.
In-Reply-To: <1.5.4.32.19970619122845.00687104@janus.cqu.edu.au>
Message-ID: <199706192113.RAA22869@adan.kingston.net>

Piet said:>
rip
> As I understand it, the smoke test consists of assessing the colour change
> of a piece of filter paper after letting through a standard volume of flue gas.
> Now, with the downdraft stove we often get small flakes of ash coming out of
> the chimney. Since you probably have similar gas velocities, the colour
> change might be due to ash, giving a wrong reading for smoke.
rip

Dear Piet
There is some fly ash.
I had considered this possibility and think it could bias the
interpretations slightly. However I have now seen enough smoke
readings ranging from 1to 9 that match the
appearance of the flame that I don't believe I can use that excuse.

Alex
P.S. Are there any pictures or drawings you can send of the downdraft
stove ?
> Regards,
> Piet Verhaart
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From verhaarp at janus.cqu.edu.au Thu Jun 19 18:27:41 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:20 2004
Subject: One old guy replies....
Message-ID: <1.5.4.32.19970619222723.006aa420@janus.cqu.edu.au>

>From Piet Verhaart

At 02:38 19/06/97 +0100, you wrote:
>Sorry for the duplication, but I made a mistake in the address field.
>
>
>I received a message that bounced because there was an attachment that was
>over 40000 bytes in size. Consequently it was rejected and none of the
>subscribers received it. If anybody is interested in receiving it he or she
>can request it from me directly. I will keep it for a week. Otherwise I
>suggest that you contact the author Art Krenzel.

Ja, graag, Etienne

Hartelijke groeten, ook van Irma
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From larcon at sni.net Thu Jun 19 20:02:13 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: Verhaart on More trials cont.
Message-ID: <v01540b03afcf45cc15ee@[204.133.251.5]>

Piet Verhaart said today:

<snip>

>As I understand it, the smoke test consists of assessing the colour change
>of a piece of filter paper after letting through a standard volume of flue gas.
>Now, with the downdraft stove we often get small flakes of ash coming out of
>the chimney. Since you probably have similar gas velocities, the colour
>change might be due to ash, giving a wrong reading for smoke.

(RWL): Two points on differences in the two stove geometries:

1. The charcoal-makers produce very little ash, unlike the downdraft,
which consumes all the input material and produces the normal amount of ash
(and ash movement is also helped by gravity).
2. In the region where ash could be produced in the updraft
charcoal-makers, the gas velocity is very low. It is only after secondary
air is introduced and combustion occurs that large velocities are seen.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Thu Jun 19 20:02:22 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: twocan turbo
Message-ID: <v01540b04afcf47cb8de4@[204.133.251.5]>

>>From Piet Verhaart talking To Elsen

(Elsen):
>>I'm not sure how to describe this- the top exhaust gas venting has been done
>>the same way- it's quite simple.... much like pushing a beer can tab into
>>the can?
>
(Piet):
>I don't understand this. Then the top of the inner cylinder is closed and
>the only openings are what you just described. So the gas comes out of the
>side of the cylinder. The gases have a volume of 20 cm cylinder to get
>mixed between the 3 mm slit and the holes under the top.

(RWL): Just to add a bit to what I assume Elsen will say:
1) The upper can is closed by the cook pot
2) The flame is attached at the secondary air inlet and if all is
working right, all combustion is complete before the hot gases reaach to
top/cookpot.
3) There is no mixing - the flame is a diffusion flame - much like
that seen with a match (but inverted - the air is on the inside). Alex'
work on creating turbulence sounds very promising, however.
4) If mixing could somehow be achieved prior to combustion in the
chimney, the chimney might still need to be the same height - to achieve
the needed draft.

(Piet) >How did you light the stove, from the top?

(RWL): This geometry absolutely demands top-lighting.

(Piet)
>The pan should not be so close to the combustion zone as to quench the
>combustion.
>
>Very interesting and very stimulating.

(RWL): If combustion is complete at the pot height (as I think is best),
there need be no concern for quenching. But one can create flames fully
around the pot - and presume that the quenched unburned gases hitting the
pot are brought back up to the required temperature by other parts of the
flame. We don't have much experience with this type of flamelet - which
has air inside (and outside as well), so maybe there is something a bit
different about quenching here.

Question - maybe especially for Elsen. How important is the question of
soot deposition to your workmen and wives? Soot certainly appears, but is
soot or efficiency/convenience/smoke a more important variable for a user?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Thu Jun 19 20:02:25 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: Stoves and Health
Message-ID: <v01540b01afcf1696fe58@[204.133.251.5]>

Today's issue of the Denver Post (p 21A) had a short news report by Erica
Bulman of the Associated Press, saying (in part) in a 7" short piece
entitled World's Pollution Worsens":

"GENEVA - Lumping together everything from homicides to un-healthy
kitchens, the U.N. health agency says the environment is in worse shape
than fives ago and is to blame for many preventable illnesses worldwide.
. Children, especially in developing nations, are hardest hit,
according to a World Health Organization report released Wednesday that
assesses the impact of 1992 Earth Summit in Brazil.

It found that more than 20 percent of chilren in the
least-developed countries die of environmental causes before age 5,
compared with fewer than 1 percent of children in developed countries.
Respiratory infections and diarrheal diseases are the biggest
environment-related health problems, the study found, with air pollution
causing about 3 million premature deaths worldwide.
It blamed 2.8 million of those deaths on indoor air pollution, with
almost all cases occurring in developing countries."

My comments:

1. The world's main health problem seems to be caused by stoves
(but at least here the word "stoves" is not reported.
2. Few people reading this article will realize that the problem
is mainly cooking and stoves.
3. The problem may be getting worse (or maybe just better
reporting) - and probably is under-reported anyway.
4. This report (not the article) may be what persons like Paul
Hait was looking for as a way to get the attention of decision makers.

Questions:
1. Can anyone on this list tell us how to obtain the full report?
2. If anyone has seen it and can add to this very limited summary,
I hope they will do so; are stoves mentioned in the full report - or only
the phrase: "indoor air pollution" (in the US, this refers only to
cigarette smoke and radon).
2. Is there any better data to show whether there is under-reporting?
3. Does WHO ever provide funding for solving such problems, which
they have termed "preventable"?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Thu Jun 19 20:02:34 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: Julian Bankston on Test Equipment
Message-ID: <v01540b02afcf417a1219@[204.133.251.5]>

Dennis: I write as a coordinator of the "stoves" list. Your name was
kindly provided by Julian Bankston, a "stoves" list member as shown below.
I thought it best to also send this message on behalf of our list to all
members of the stoves list, so that you didn't receive a message from too
many. Most of our individual questions would probably be answered if you
could answer the following:

1. Where did you buy the CO2 sensors and at what cost?
2. Were you happy with the automotive-type (lifetime, accuracy,
reproducability, etc)?
3. How did you calibrate the unit?
4. Have you any other low cost sensor recommendations?
5. What references might you have on the technique and on your own work?
6. Can you describe the type of stoves and research that you work on? (If
sometimes low cost for developing countries, then I hope you will join the
list). We are now at about 95 members in some 25-30 countries.

Regards Ron

>Several years ago I monitored a DOE funded project at Virginia Tech which
>involved CO2 testing. Dr. Dennis Jaasma who runs a stove testing lab
>there was using a sensor from an automobile which was connected to a
>computer for monitoring. I do not recall the details, but Dr. Jaasma
>probably would be able to give you some guidance. He probably would be a
>good member of this list also. His E-mail address is jaasmadr@ vt.edu.
>
>Julian Bankston
>jrbankston@juno.com
>
>On Tue, 17 Jun 1997 16:03:47 -0600 larcon@sni.net (Ronal W. Larson)
>writes:
>>Today (June 17) Elsen said:
>>
>>>Alex English has provided me with some contacts for suppliers of
>>testing
>>>equipment and wonders if standardisation within 'stovers' is
>>advisable.
>>>
>>Alex and Elsen - I think this is a valuabel thread to continue. I
>>know
>>almost nothing on such equipment. I would like epecially to find low
>>cost
>>equipment that everyone can afford.
>> I am told that some computerized automobile engine performance
>>optimization is now done with CO2 sensors. With millions in use,
>>might
>>that cost be pretty low?
>> Also, there are many CO sensors available for home safety
>>uses.
>>Might any be amenable to putting a meter on them rather than an audio
>>alarm?
>>
>>
>>>Any recommendations? Should we, from now on, try to stick to one
>>supplier
>>>after deciding collectively on the most appropriate equipment?
>>
>> OK - if clearly superior.
>>
>>Regards Ron
>>
>>Ronal W. Larson, PhD
>>21547 Mountsfield Dr.
>>Golden, CO 80401, USA
>>303/526-9629; FAX same with warning
>>
>>
>>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From english at adan.kingston.net Thu Jun 19 22:50:24 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: Verhaart on More trials cont.
In-Reply-To: <v01540b03afcf45cc15ee@[204.133.251.5]>
Message-ID: <199706200250.WAA02143@adan.kingston.net>

> (RWL): Two points on differences in the two stove geometries:
>
> 1. The charcoal-makers produce very little ash, unlike the downdraft,
> which consumes all the input material and produces the normal amount of ash
> (and ash movement is also helped by gravity).
> 2. In the region where ash could be produced in the updraft
> charcoal-makers, the gas velocity is very low. It is only after secondary
> air is introduced and combustion occurs that large velocities are seen.
Dear Ron
The cone and pail stove version can have high enough velocities to
generate fly ash at the point where the cone is being supported by
the fuel. In order to generate enough gasses to match the swirl
inducing venturi's minimum flow requirements I have been allowing
greater primary air flow and have seen fly ash.It has
been behaving a bit more like a regular wood stove with char
consumption from the outside in. If the bottom of the pail were cone
shaped to match the existing cone then I believe it would consume all
the fuel at a fairly consistent rate. This venturi may be a bit large
to have the desired effect with reduced primary air on this stove.

I'm feeling a bit out in left field, pursuing a technical puzzle.
Isn't it marvelous and relevant, what Elson is doing.

Alex

From english at adan.kingston.net Thu Jun 19 22:50:23 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:20 2004
Subject: Imperial vs US gallons
In-Reply-To: <9705198667.AA866764024@cc2smtp.nrcan.gc.ca>
Message-ID: <199706200250.WAA02140@adan.kingston.net>

>
> In Canada not only is a pint not a pound as in the world around, it doesn't
> exist, as we now use litres, as does the world around (except for the U.S.).
>
> Our old point of reference was that a gallon (imperial) weighed 10 pounds.
> Hence your 20 lb calculation is correct.
>
> Skip Hayden
>
Dear Skip

Have you bought any 2 by 4s lately ?( In metric thats a tooth pick)
Its hard to keep an independent flame of mind when your living
next to the big gasifier to the south. Updraft or downdraft we just
need to stay prepared for which ever way the big chimney sucks.

eh!lex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Fri Jun 20 00:50:12 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: 2can Turbo trials 2&3
Message-ID: <v01540b01afcfb834238d@[204.133.251.11]>

Elsen said:

<snip>
>
>One question to any two-canner; what happens if the charcoal is not
>extinguished & the stove is allowed to go out by itself. Will the charcoal
>burn down to ash?

(RWL): I haven't tried the test in a long time, but have certainly had
it happen.
>
>All for now- I'll run large pot (not inserted) trials tomorrow, allowing the
>full 24 cm height of the combustion chamber to be used.

(RWL): It would be interesting to also try an outer "wind shield" around
the larger pot. It can maybe be supported on several welding rods poked
through the uppermost exhaust holes. Maybe a diameter 2 or 3 cm larger
than the new larger pot. I have had situations where the addition of this
outer shield allowed vigorous boiling when I could not otherwise even
achieve a boil (because the pot was much too big for the stove).

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 20 00:50:17 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: Moerman (3) on carbonization.
Message-ID: <v01540b05afcf510bba69@[204.133.251.5]>

>
>Etienne said:

<snip>
>I ligthed several cilindrical stoves with secondary air supply at the top. I
>did not make the 2-can stove, because I do not have the material.

(RWL): I'm still not sure of the nature of your test. Was the wood
half way up the can? If the wood was all the way to the top of cylindrical
can, there cannot be enough draft to make the system work. If you didn't
have a primary air supply, it can't work. In Alex' work with a cone, his
secondary and primary air supplies are separated at the wide part of the
cone, but he has a tall chimney to give the required draft. Top lighting
without a chimney (the upper can) won't work.

>
>Ron L.:
>> As to the number 200 grams - this is per person per day I presume.
>> So in a family of 5, one fills a 50 kilo bag in 50 days. I think this might
>> be on the low side. When a woman is earning essentially nothing and men
>> are earning less than $100 per year, I believe even this small amount will
>> be seen as meaningful. But maybe the advantge is going to be seen to be the
>> constancy of output.
>
>Etienne:
>No this was an estimate for the whole family of 5. Anyway I see the biggest
>problem in marketing the stuff, not in its intrinsic value.

(RWL): I think that Elsen stated recently that he found 1.75 kg of
charcoal per use. Assuming only two such uses per day,then the 45 kilo bag
gets filled in
less than two weeks. If the producer gets half of the $4.00 price, then
the payback time for a $12 charcoal-making stove is 6 bags or 3 months.

One question is whether the charcoal merchants and/or middlemen are
willing to visit the producer's home once in a while to pick up a number of
bags at this $2.00 price. Or maybe a member of the family will load a
donkey and move to a highway location where they might get $3.00 per bag.
Or maybe they will travel all the way to the ultimate end-user and get the
full $4.00. I ask Elsen what might happen with diferent distances from
highways and cities in Kenya.

Another question is whether the city users will shift to buying
wood - to produce their own charcoal. I'm still working my way through this
analysis - but it will depend on not only the relative costs of wood and
charcoal and the relative stove efficiencies, but also on the ease of use.
More later.

>Etienne:
>Efficiency, controlability and pollution levels need to be worked on for all
>stoves, especially since the addition of pans ruins at least the
>controllability and the pollution levels.
>

(RWL): Elsen is reporting some difficulty now with embedding his pan - but
I predict this will be temporary. I can certainly control the power output
when a pan is in place. The draft just needs to be enough.

It also seems to me that if the flame is out before reaching the
pan, then the pollution level can be low and independent of the pan. I
have only the single CO and CO2 test to say so, but I now usually don't
smell or see any smoke with or without a pan. This was not so for the
first ten or twenty tests.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 20 01:17:15 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:20 2004
Subject: English on More trials cont.
Message-ID: <v01540b00afcfbe46b3fe@[204.133.251.2]>

Alex said:
>The cone and pail stove version can have high enough velocities to
>generate fly ash at the point where the cone is being supported by
>the fuel.

(RWL): I was extrapolating too far from my own experience. I never see
fly ash.

(Alex): In order to generate enough gasses to match the swirl
>inducing venturi's minimum flow requirements I have been allowing
>greater primary air flow and have seen fly ash.

(RWL): What is the mechanism for "allowing"?

(Alex): It has
>been behaving a bit more like a regular wood stove with char
>consumption from the outside in. If the bottom of the pail were cone
>shaped to match the existing cone then I believe it would consume all
>the fuel at a fairly consistent rate. This venturi may be a bit large
> to have the desired effect with reduced primary air on this stove.
>
>I'm feeling a bit out in left field, pursuing a technical puzzle.
>Isn't it marvelous and relevant, what Elson is doing.

It is - but you are doing a great service also. You've tried half a dozen
things I never would have and are concentrating on straw. It's great.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From klunne at itc.nl Fri Jun 20 03:21:42 1997
From: klunne at itc.nl (ir W.E. Klunne (ITC Rural Energy Specialist))
Date: Tue Aug 31 21:35:21 2004
Subject: Wim Klunne - questions on schools
In-Reply-To: <v01540b06afcca767dc52@[204.133.251.3]>
Message-ID: <33AA2F7A.2064@ITC.NL>

Ronal W. Larson wrote:
>
> Stovers:
>
> Wim said:
> <snip>
>
> >Further I supervise PM students on their fieldwork and MSc students on
> >their MSc research on energy related topics. Students I am working with
> >mainly follow the Forestry for Rural Development, Forest Survey or Rural
> >Energy and Development courses.
>
> <RWL>: Who are "PM" students? About how many are there? Are there many
> such students and programs in the Netherlands and Europe? I don't think we
> have very many (or any) here in the states.

<WK> With PM I meant Professional Masters as was described in an earlier
part of my message, but there I forgot to mention the abbreviation.
Excuses.
Those PM students are the ones which follow our PM course on Forestry
for Rural Development. In this course considerable attention is given to
fuelwood issues. This year seven students participated in our fieldwork
in Taita Tavete district in Kenya. The homecountries of them are
Tanzania, Ethiopia, Kenya, Ghana, Nepal, Phillipines and Uganda.
The Forestry for Rural Development (FRD) course is quite unique in the
way that the students learn specific approaches for enhanching the role
of trees and shrubs in the landscape. As far as I know no similar
programme extists anaywhere else.
>
> <snip on web sites)
>
> >I joined the stoves-list to get a better insight in the current
> >developments on stoves, as my expertice on that field is rather limited.
> >I am employed at ITC for just one year now and do have quite a number of
> >ideas on improvements of our courses. One of them is to include more on
> >wood and charcoal stoves and I hope the messages I receive from the
> >stoves-list will help me in that.
>
> <snip>
>
> <RWL>: If you are like me, you will become more confused (I find this to
> be a very difficult design topic). I wonder if some of your students would
> be interested in stove testing and development. They sound like an
> excellent potential source of information about cooking in their home
> countries and probably with a motivation to improve things. I think we can
> find dozens of stove development topics.
>

<WK> Our students (and specially the female ones) indeed are a very good
source for information on cooking habits. On the other hand, the focuas
of our course mainly is at the supply side of biomass (let's say the
trees and shrubs) and not to much on the demand side and devices used.
Therefore attention on stoves will be limited to the general principles
and possible uses. In line with the mission of ITC much attention is
given to spatial variation in energy supply and demand.

> Could your type of school and program be organized into a type of
> stove competition? (This is an old recurring idea on this list.)
>

<WK> I am afraid that won't be possible as we don't give extensive
attention to energy devices. (See the comments above).

> Thank you for providing your introduction. I hope you will have
> started a new thread on your type of educational program (and that we can
> find a way to attract other instructors like yourself).
>
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning

Regards,

Wim Klunne

=============================================================
ir W.E. Klunne (rural energy specialist)
ITC / LARUS, PO Box 6, 7500 AA Enschede, the Netherlands

phone: +31 53 4874 218
fax: +31 53 4874 399
e-mail: klunne@itc.nl

From elk at arcc.or.ke Fri Jun 20 03:44:34 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:21 2004
Subject: 2can Turbo Charcoal Making Stove.
Message-ID: <v01510100afcffc37eef7@[199.2.222.133]>

(RWL)Question - maybe especially for Elsen. How important is the question of
>soot deposition to your workmen and wives? Soot certainly appears, but is
>soot or efficiency/convenience/smoke a more important variable for a user?

Soot is a consideration- my staff's comments have been very complimentary
on how cleanly the stove burns- ref. my comment on the ?calcium? whitish
rhime around the outside of the exhaust vents. One of the major factors of
charcoal cooker popularity in urban areas is the low smoke emmissions.
Grass thatch huts vent wood fire smoke up through the hatch- depositions
also acting to preserve the thatch to some extent I suspect. Not many grass
thatch buildings in the urban areas these days- all corrugated iron roofs
with little consideration for venting, more for insulation (heat &/or
cold). Death to asphyxiation from charcoal fires not uncommon- especially
during cold seasons.

(RWL)Question- One question is whether the charcoal merchants and/or
middlemen are
>willing to visit the producer's home once in a while to pick up a number of
>bags at this $2.00 price. Or maybe a member of the family will load a
>donkey and move to a highway location where they might get $3.00 per bag.
>Or maybe they will travel all the way to the ultimate end-user and get the
>full $4.00. I ask Elsen what might happen with diferent distances from
>highways and cities in Kenya.

The calculation of value-added payback has relevance, but according to my
staff, the charcoal produced by the stove would be used domestically, and
not necessarily sold. The 2can stove is not suitable for 'barbecuing'
meat, so the charcoal produced would be used in a standard 'jiko' for this.
Obviously, the ratio's of food types produced would dictate charcoal V.S.
wood fuel requirements, and I suspect that with current meat prices, there
would be a charcoal surplus of, say, 40% above meat cooking requirements.
This would be used for other cooking applications during rainy or lazy days
when wood is not immediately at hand. Simply stated- I think this stove
would in most situations add efficency by allowing wood to be 'used twice'
in the same home.

It has been discussed that a nationally advocated/enforced program of
partially pre-cooking maize meal (micronising or extruding) would have very
positive reprocussions on energy consumption, fuel use, wood burning,
forest conservation & on. Somebody somewhere has probably calculated how
many kg of wood fuel is required to produce 1 kg of cooked maizemeal- and
by using charcoal...?

Unfortunately, the commercial sector reflects the populace's extremely
conservative attitude to any 'tampering' with their beloved staple foods,
and is hesitant to even add vitamins, let alone precook. Slowly, slowly.

> Another question is whether the city users will shift to buying
>wood - to produce their own charcoal. I'm still working my way through this
>analysis - but it will depend on not only the relative costs of wood and
>charcoal and the relative stove efficiencies, but also on the ease of use.
>More later.

The stove may indeed influence the marketing of wood, but little goes on in
urban areas in Kenya at the moment. Scavaging for wood is done in the less
intensly populated urban areas, but the majority of wood collected is used
directly, not sold.

A few questions for the group-

On the topic of my cement -bound charcoal biriquettes, the high ash content
is a potentially valuable by-product. Some applications that come to mind
are:

1) Animal feed calcium suppliment. Q: what would the bioavailabilty be of
this 'cooked' cement. What is the expected calium content of normal wood
ash, and what's the Ca content of cement?

2) Soil additive/fertilisers Q: is calcium required here in these red
pedalfer type soils? How about it's use in creating more loamy soils from
the goey 'black cotton' gumbo type clay soil (I have heard that calcium can
break up the ionic orientation that characterises clay).

3) Sanitation- 'cooked cement' ash in outhouse holes, .... does it have any
attributes over & above normal ash? Soap manufacture?

4) Construction- I'll run a small test to see if the ash can be used as a
cement- maybe more like a lime. Comments?

Enough for now! Back to the stove's burning trials.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From elk at arcc.or.ke Fri Jun 20 07:34:20 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:21 2004
Subject: 2can Turbo Charcoal Producing Stove - trial 4
Message-ID: <v01510100afd03fa7d5ee@[199.2.222.130]>

Stovers;

Using very dry brown olive hardwood sticks (finger thick, with bark) this
time, and loading the stove lightly (firwood not close packed), the
following results were obtained:

Fuelwood load: 4.35 kg
Charcoal produced: 0.78 kg (18.2% recovery)
Total elapsed burning time: 1hr. 50 min.
Water evaporated from uncovered aluminium pot inserted into stove: 3.94 kg
15 minutes to full boil. (altitude 1850 m. at test site)

No problems were experienced with operation, some flame was observed at
bottom adjacent to primary air supply vents which was difficult to
extinguish without 'flameout' at the level of the secondary air intake.

Low charcoal production is attributed to this lower flame, and there was
indeed more white ash than in any previous trial.

Subsequent trials to be done with larger pieces of wood. This should result
in better charcoal production.

The wood today was very dry, and it was noted that the white 'rhime' at the
exhaust vents did not develop.

This is a very hot stove (wish I had a thermometer) and much heat exits the
exhaust vents. I find that offensive- maybe a water heater hood could be
suspended above the stove, or an oven of some sort (as Ron Larson suggests)
collects the hot exhaust gasses via some sort of collar & flue arrangement.
I'm a bit wary of piping gasses and the occasional belch of smoke diirectly
into an oven though.

Suggestions?

All for now- off fishing for the weekend.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From E.Moerman at stud.tue.nl Fri Jun 20 07:41:56 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:21 2004
Subject: Charcoal and briquettes
Message-ID: <6130.s335192@popserver.tue.nl>

David B.:

> In my measurements of such things in a batch-loaded gasifier-
> combustor, the CO increase also coincided with increasing Excess Air
> Value of combustion and hence falling combustion temperatures. I
> don't know whether or not the 2CO+O2 <> 2CO2 equilibrium is moved to
> the right or the left by higher temperatures, but the reaction rate
> should increase exponentially with increasing temperature. High

Etienne:
We obsereved the same effect of excess air on CO.
For high temperatures the production of CO2 is favoured as long as there is
sufficient O2.

----------

David B.:
> of the reaction rate seems an obvious possibility ? Do most
> stoves end up with far too high Excess Air Values once they're into
> the pure char combustion phase ? They might produce lots of CO for
> this reason - the gases don't stay hot enough for long enough.

Etienne:
This is indeed observed in our lab, but not only for pure char combustion,
but also for volatile combustion we measured high CO for high excess air.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Fri Jun 20 07:42:06 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:21 2004
Subject: CO and Charcoal
Message-ID: <6143.s335192@popserver.tue.nl>

Alex:
> Thank you for your excellent response. This give the theoretical
> frame work. Does this mean that the gasses from charcoal will need
> the same treatment as any other combustibles, time, temperature and
> turbulence ? Is there some other reason why charcoal fires tend to
> be high in CO emissions ?

Etienne:
A very good and detailed answer indeed. Thanks.
Other reasons? Surface combustion requires airflow (usually diffusion) to a
small exterior surface area against an airflow (blowing helps as any
experienced BBQ'er knows). Also high excess air factors cause low
temperatures which reduce the combustion rate substantially as you can see
with the given equation.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From english at adan.kingston.net Fri Jun 20 07:43:55 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:21 2004
Subject: English on More trials cont.
In-Reply-To: <v01540b00afcfbe46b3fe@[204.133.251.2]>
Message-ID: <199706201143.HAA12847@adan.kingston.net>

>
> (Alex): In order to generate enough gasses to match the swirl
> >inducing venturi's minimum flow requirements I have been allowing
> >greater primary air flow and have seen fly ash.
>
> (RWL): What is the mechanism for "allowing"?
>
> Regards Ron

Dear Ron and stovers

The " mechanism" is removing the insulation that I use for plugging
up the space between the chimney and the pail .
With this cone in pail stove the primary air is preheated in that
space on it way from the top of the pail down to the inlet at the
edge of the cone. I've been wondering how much this preheating of
primary air becomes a damper or negative influence on draft due to
its reduced density.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From E.Moerman at stud.tue.nl Fri Jun 20 09:02:14 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:21 2004
Subject: 2can Turbo trials 2&3
Message-ID: <10953.s335192@popserver.tue.nl>

> (RWL): It would be interesting to also try an outer "wind shield" around
> the larger pot. It can maybe be supported on several welding rods poked
> through the uppermost exhaust holes. Maybe a diameter 2 or 3 cm larger
> than the new larger pot. I have had situations where the addition of this
> outer shield allowed vigorous boiling when I could not otherwise even
> achieve a boil (because the pot was much too big for the stove).

Etienne:
The work on the shielded fire resulted in a gap (pan-wall) of at least 5mm
otherwise the airflow is blocked. A 6mm gap provided good draft and high
efficiency, so a diameter 12mm larger than the pot diameter. These distances
might be slightly different for other stoves.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Fri Jun 20 09:02:20 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:21 2004
Subject: Verhaart on More trials cont.
Message-ID: <10946.s335192@popserver.tue.nl>

(Ronal W. Larson) writes:

Etienne:
Not quite! Temperature in the downdraft stove are so high that a substantial
part of the ash is evaporated or dissociated. I have observed a white ash
layer condensed on a cold water-filled and sooted pan. The ash layer was
thick, but very well distributed. It could be removed easily, but this might
be caused by the soot layer that was present at the start of the experiment.
Also there is a lot of fly-ash flakes which disappear through the chimney.
Usually fly-ash flakes and a little bit of ordinary ash is left in the
stove. Gas velocities in the chimney around 1m/s.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From E.Moerman at stud.tue.nl Fri Jun 20 09:02:09 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:21 2004
Subject: Moerman (3) on carbonization.
Message-ID: <10950.s335192@popserver.tue.nl>

>
> (RWL): I'm still not sure of the nature of your test. Was the wood
> half way up the can? If the wood was all the way to the top of cylindrical
> can, there cannot be enough draft to make the system work. If you didn't
> have a primary air supply, it can't work. In Alex' work with a cone, his
> secondary and primary air supplies are separated at the wide part of the
> cone, but he has a tall chimney to give the required draft. Top lighting
> without a chimney (the upper can) won't work.
>

Etienne:
The wood was about half way up, 15-20cm left free. There was a primary air
supply.

---------

Ron L.:
>
> Another question is whether the city users will shift to buying
> wood - to produce their own charcoal. I'm still working my way through this
> analysis - but it will depend on not only the relative costs of wood and
> charcoal and the relative stove efficiencies, but also on the ease of use.
> More later.
>

Etienne:
For the economic and social issues you just have to try. I don't think a
'saloon' analysis will provide the correct answer.

---------
Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From zourarakis at nosapp.nr.state.ky.us Fri Jun 20 10:03:20 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:21 2004
Subject: Imperial vs US gallons
Message-ID: <97062010031698@nosapp.nr.state.ky.us>

Un kilo es un litro (aproximadamente)!

Demetrio.

From zourarakis at nosapp.nr.state.ky.us Fri Jun 20 10:06:35 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:21 2004
Subject: Imperial vs US gallons
Message-ID: <97062010043891@nosapp.nr.state.ky.us>

Skip: also, a pint is not a pound as the world is not round. Gravitational pull
makes one pint "lighter" in the Equator than in any of the poles. Cheers,
Demetrio.

From larcon at sni.net Fri Jun 20 11:18:17 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:21 2004
Subject: 2can Turbo Charcoal Producing Stove - trial 4
Message-ID: <v01540b02afd043805c21@[204.133.251.6]>

Elsen said:

>Stovers;
>
>Using very dry brown olive hardwood sticks (finger thick, with bark) this
>time, and loading the stove lightly (firwood not close packed), the
>following results were obtained:
>
>Fuelwood load: 4.35 kg
>Charcoal produced: 0.78 kg (18.2% recovery)
>Total elapsed burning time: 1hr. 50 min.
>Water evaporated from uncovered aluminium pot inserted into stove: 3.94 kg
>15 minutes to full boil. (altitude 1850 m. at test site)

(RWL): I think a useful figure of merit (FOM) for these stoves is the
ratio of weight of water evaporated to weight of wood input. You approached
FOM=1 here, but a lot of the gain was from the charcoal consumed (18% being
low). I think we can get to FOM=2 eventually - more below. What was the
original weight of water that was in the pan?

>
>No problems were experienced with operation, some flame was observed at
>bottom adjacent to primary air supply vents which was difficult to
>extinguish without 'flameout' at the level of the secondary air intake.
>
>Low charcoal production is attributed to this lower flame, and there was
>indeed more white ash than in any previous trial.
>
I have also had the flame at the bottom. Using three plugs, I could
plug up one hole at a time and that flame would extinguish. Maybe this
flame got to the bottom because of loose packing and the twigs used for
starting.

<snip>
>
>This is a very hot stove (wish I had a thermometer) and much heat exits the
>exhaust vents. I find that offensive- maybe a water heater hood could be
>suspended above the stove, or an oven of some sort (as Ron Larson suggests)

(RWL): To get a higher FOM (higher efficiency), you will have to reduce
the "offensive" exit heating - by dropping the power level. I would guess
that you are still having a vigorous rather than gentle boil. Usually in a
test, I can hold my hand anywhere above the boiling water pan (but I have
usually been using smaller (15 cm rather than 30 cm) diameters).

>collects the hot exhaust gasses via some sort of collar & flue arrangement.
>I'm a bit wary of piping gasses and the occasional belch of smoke diirectly
>into an oven though.
>
>Suggestions?

(RWL): I was thinking of radiation into the oven. But another way could
be to have a brick type oven with exhaust gases into the oven - which is
then later used for baking.

Good progress! Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 20 11:18:18 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:21 2004
Subject: G8 Summit
Message-ID: <v01540b00afd03aa647c6@[204.133.251.6]>

Today starts Denver's three-day hosting of the "Denver Summit of
the Eight" (sometimes "G-8"). Denver's mayor says this is Denver's biggest
ever event - and he may be right - supposedly 5000 reporters.

I go today as a panelist in the alternative TOES (The Other
Economic Summit) and People's Summit - for the small Kaffa (Ethiopia)
Development Association (KDA). Our motivation is to get people interested
in Kaffa - and to its many opportunities and problems.

I also go today (wind announcements by DOE's Secretary Pena) and
tomorrow (solar policy press conference announcement by advocates) as a
reporter (for Solar Today magazine).

Lastly I go as an observer to the TOES-People's Summit workshops
and dialogs - many on sustainability and world economics (on
Friday-Sunday). A few on developing countries (there is considerable
controersy over the G8 talking aobut Aid to Africa and no African leaders
here).

So:

1. Anyone on the list want any special report on what is going on?
2. Anyone have a friend I should try to meet?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Fri Jun 20 11:18:14 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:21 2004
Subject: Moerman on 2can Turbo trials 2&3
Message-ID: <v01540b03afd046e42803@[204.133.251.6]>

>Etienne said:
>The work on the shielded fire resulted in a gap (pan-wall) of at least 5mm
>otherwise the airflow is blocked. A 6mm gap provided good draft and high
>efficiency, so a diameter 12mm larger than the pot diameter. These distances
>might be slightly different for other stoves.

(RWL): This is a very important point. I believe Sam Baldwin's thesis
says something similar - but he had no experimental results.

If one is going to achieve high efficiency, this gap needs to be optimized
very carefully. I have done almost no such optimizing myself.

Etienne - did you collect enough experimental data to show how rapidly this
efficiency chages with the gap spacing? What was the nature of the draft?
I suppose that there is an added tradeoff as extra chimney height can be
used to offset the resistance of closer spacings. But losses go up as
chimney height increases.

I think that Etienne is correct and the 10-15 mm gap I was
suggesting might be too large. But Elsen may not now have enough draft -
which would argue for a larger spacing to reduce the resistance.

I know we hae some good modelers on the list. If they could
combine the heat transfer issues and the draft resistance issues, I believe
they would be making a substantial contribution. Or has this already been
done?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From zourarakis at nosapp.nr.state.ky.us Fri Jun 20 12:43:40 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:21 2004
Subject: G8 Summit
Message-ID: <97062012402810@nosapp.nr.state.ky.us>

Dear Ron:

Would you let us know if proceedings/reports from this summit will be avialable?
I am interested in the sustainable ag/rural development/natural resource mgmt.
portion of the talks/dialogs. Any specifics available on the program/content?

Sincerely,

Demetrio.

Demetrio P. Zourarakis, PhD
Senior Soil Scientist
KY Div. of Conservation - DNR

From verhaarp at janus.cqu.edu.au Fri Jun 20 17:42:08 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:21 2004
Subject: Imperial vs US gallons
Message-ID: <1.5.4.32.19970620214154.006abaf8@janus.cqu.edu.au>

At 10:03 20/06/97 -0400, you wrote:
>Un kilo es un litro (aproximadamente)!
>
>Demetrio.
>
>
Viva o sistem internacional!
Peter
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From phait at transport.com Fri Jun 20 20:48:48 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves and Health
Message-ID: <199706201809.LAA02589@butch.transport.com>

>
>Today's issue of the Denver Post (p 21A) had a short news report by Erica
>Bulman of the Associated Press, saying (in part) in a 7" short piece
>entitled World's Pollution Worsens":
>
> "GENEVA - Lumping together everything from homicides to un-healthy
>kitchens, the U.N. health agency says the environment is in worse shape
>than fives ago and is to blame for many preventable illnesses worldwide.
>. Children, especially in developing nations, are hardest hit,
>according to a World Health Organization report released Wednesday that
>assesses the impact of 1992 Earth Summit in Brazil.
>
> <skip 4 short paragraphs mainly on workplace accidents>
>
> It found that more than 20 percent of chilren in the
>least-developed countries die of environmental causes before age 5,
>compared with fewer than 1 percent of children in developed countries.
> Respiratory infections and diarrheal diseases are the biggest
>environment-related health problems, the study found, with air pollution
>causing about 3 million premature deaths worldwide.
> It blamed 2.8 million of those deaths on indoor air pollution, with
>almost all cases occurring in developing countries."
>
> My comments:
>
> 1. The world's main health problem seems to be caused by stoves
>(but at least here the word "stoves" is not reported.
> 2. Few people reading this article will realize that the problem
>is mainly cooking and stoves.
> 3. The problem may be getting worse (or maybe just better
>reporting) - and probably is under-reported anyway.
> 4. This report (not the article) may be what persons like Paul
>Hait was looking for as a way to get the attention of decision makers.
>
> Questions:
> 1. Can anyone on this list tell us how to obtain the full report?
> 2. If anyone has seen it and can add to this very limited summary,
>I hope they will do so; are stoves mentioned in the full report - or only
>the phrase: "indoor air pollution" (in the US, this refers only to
>cigarette smoke and radon).
> 2. Is there any better data to show whether there is under-reporting?
> 3. Does WHO ever provide funding for solving such problems, which
>they have termed "preventable"?
>
>
>Regards Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>Dear Ronal,
I have been astounded by the activity on the list. I do not know how you
have kept up with it.Congratulations! Alex has added a great deal to the
enthusiasm as well as many others.
The World health artical has said it all. Bad health equals bad efficiency
and smoky stoves. The goal is to use as little fuel as possible. With as
little work to gather it. And as little cost to the user. With as high
useful cooking return for BTU's created in the combustion process in what
ever is the best structure to accomplish this in.With as little smoke in the
home. You have chosen the two can process. Alex has chosen the chimney and
can process. Peter prefers the moving tube system etc. I believe in the HTA
Cell. What is right? Each of us believes in our own devices. The back and
forth that is occuring on the list seems to be both divergent and convergent
at the same time. Too much info for my cache. Not enough time to read all
the email.
How about extracting some hard data from the tests that are being talked
about that starts to build the functional spec. I referred to in my first
letter? As I read through the letters, I find facts that should go into a
reference book on the design of a World Stove. How about the list putting
such a book together for World Stove designers? Also how about some work
being done on making 3rd World homes smoke free? Whose Stove does the best
job in this area? Do you think your Stove creates the least amount of
pollution? If so,why? This seems to me to be a very important topic to open
up on the list in more specific detail. Maybe I am late and you have already
concluded this subject.
We are finishing up our second generation Super Grill and we are now down
to 50 briquettes for 72 people. At $4.00/bag and 150 briquettes / bag (Royal
Oak)that is a retail cost of $1.33. Wholesale is half that cost.This could
be a starting point for a stove comparison discussion.Less than a penny a
person.

Sincerely,

Paul Hait

From krksmith at uclink4.berkeley.edu Fri Jun 20 21:30:44 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves and Health
Message-ID: <199706210130.SAA32701@uclink4.berkeley.edu>

Ron, I was responsible for much of this report (seven trips to Geneva last
year). Next week I will have the details about how people can obtain a
copy. (I will not have my own copy of the final version until Monday. Hope
there were not too many changes by the editors!) Best/K

At 06:02 PM 6/19/97 -0600, you wrote:
>
>Today's issue of the Denver Post (p 21A) had a short news report by Erica
>Bulman of the Associated Press, saying (in part) in a 7" short piece
>entitled World's Pollution Worsens":
>
> "GENEVA - Lumping together everything from homicides to un-healthy
>kitchens, the U.N. health agency says the environment is in worse shape
>than fives ago and is to blame for many preventable illnesses worldwide.
>. Children, especially in developing nations, are hardest hit,
>according to a World Health Organization report released Wednesday that
>assesses the impact of 1992 Earth Summit in Brazil.
>
> <skip 4 short paragraphs mainly on workplace accidents>
>
> It found that more than 20 percent of chilren in the
>least-developed countries die of environmental causes before age 5,
>compared with fewer than 1 percent of children in developed countries.
> Respiratory infections and diarrheal diseases are the biggest
>environment-related health problems, the study found, with air pollution
>causing about 3 million premature deaths worldwide.
> It blamed 2.8 million of those deaths on indoor air pollution, with
>almost all cases occurring in developing countries."
>
> My comments:
>
> 1. The world's main health problem seems to be caused by stoves
>(but at least here the word "stoves" is not reported.
> 2. Few people reading this article will realize that the problem
>is mainly cooking and stoves.
> 3. The problem may be getting worse (or maybe just better
>reporting) - and probably is under-reported anyway.
> 4. This report (not the article) may be what persons like Paul
>Hait was looking for as a way to get the attention of decision makers.
>
> Questions:
> 1. Can anyone on this list tell us how to obtain the full report?
> 2. If anyone has seen it and can add to this very limited summary,
>I hope they will do so; are stoves mentioned in the full report - or only
>the phrase: "indoor air pollution" (in the US, this refers only to
>cigarette smoke and radon).
> 2. Is there any better data to show whether there is under-reporting?
> 3. Does WHO ever provide funding for solving such problems, which
>they have termed "preventable"?
>
>
>Regards Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>
>
>

From larcon at sni.net Fri Jun 20 23:50:53 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:21 2004
Subject: G8 Summit
Message-ID: <v01540b00afd0e5d8e91f@[204.133.251.17]>

Demetrio asked:

>Would you let us know if proceedings/reports from this summit will be
>avialable?

(RWL): President Clinton (as host) releases a fairly lengthy report on
Sunday - with the reputed topics to be:
help to Russia ( a new member this year),
help to Africa (mentioning again the 20% death statistic - but
ignoring stoves,
"core" economic issues (unemployment, monetary system, aging populations
global problems (environmentqal problems, crime, killer viruses,
deforestation,
Chernobyl mess,
Bosnia
European unification (currency)

Nothing is released until the end; reportedly the final document is
95% complete already.

TOES has a $20.00 book of preprints by some of the speakers here. I didn't
buy it but would like to read a library copy. I'll get the title and
source tomorrow.

>I am interested in the sustainable ag/rural development/natural resource mgmt.
>portion of the talks/dialogs. Any specifics available on the program/content?

I went to only one panel other than the one on Kafa, Ethiopia - but
that was half on sustainable agriculture in Cuba. The presenter was Wendy
Hawthorne of Food First (510/654-4400), who has spent 5 years in Cuba
studying your topics - and very happy because she feels Cuba is a leader in
the area - out of necessity. They are down by a factor of 2 in oil
consumption since being let loose by Russia and a factor of 20 lower than
the US. Lots of urban gardens and many low cost approaches to supplying
food.

I asked if there was much use of wood for cooking in Cuba and was
told no. There is a mandatory replanting of trees right now. 96% of the
country is on the grid - but it is not reliable.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From rmiranda at sdnnic.org.ni Sat Jun 21 00:58:07 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves and Health
Message-ID: <199706202300.XAA06279@ns.sdnnic.org.ni>

Dear Ron: This is a "good" sign that the word about Indoor air poluttion
in the developing countries is causing Accute Respiratory Infections-IRA
and consequently death. In Honduras, IRA is the major cause of deaths among
infants, followed by diarrhea. In Nicaragua, Diarrhea is the first,
followed by IRA.

It seems to me that diarrhea gets more attention than IRA, since for
instance down here in Central America USAID and UNICEF strongly support
actions to prevent diarrhea. In the other hand, while this article pointed
out that in the developing world the major cause of IRA is indoor air
pollution, and we know the indoor air pollution in these countries is
mostly related to woodsmoke, no health organization is supporting actions
to prevent IRA.

We the stovers, should in my opinion, speak out about this problem as much
we can, to help increase awareness among decision makers. We need a strongh
advocating organization to make big noise about those points in which we
believe are wrong, and should be improved.

Rogerio

From MandieLee at aol.com Sat Jun 21 02:56:17 1997
From: MandieLee at aol.com (MandieLee@aol.com)
Date: Tue Aug 31 21:35:21 2004
Subject: electric stove info.
Message-ID: <970621025554_-1193732261@emout10.mail.aol.com>

please send info. re: six and eight burner flat top stoves.

mandielee

From english at adan.kingston.net Sat Jun 21 07:54:38 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:21 2004
Subject: Crop Residues as Fuel
Message-ID: <199706211154.HAA17024@adan.kingston.net>

Dear Stovers

Referring back to an earlier thread on sustainable soil management:

I have received the most recent draft(4/15/97) of A SOIL CONDITIONING
INDEX FOR CROPLAND MANAGEMENT SYSTEMS which
Demetrio referenced in his June 2/97 letter to this list. (Thank you
D.Z., for pointing the way) This report refers only to sites
in the USA. I would like to see a similar formula and data set
for tropical and sub-tropical climate regions. I think this report represents a fairly
practical approach to assessing soil sustainability, and would
certainly be useful when trying to answer the question; How much crop
residue can be diverted for fuel, or simply away from the soil that
produced it. ? Although the answer should be highly site and
practice specific, I would guess the answer is "NONE" for most
current " tilled cropland" situations, even here in the cool
Northeast. But then again I am prone to sweeping generalizations.

I will attempt to do a sample calculation for a near by corn field.

This could take a while! Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From REEDTB at compuserve.com Sat Jun 21 08:52:33 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:21 2004
Subject: Charcoal vs wood vs propane
Message-ID: <199706210852_MC2-18E5-5E5A@compuserve.com>

Dear Gang:

I believe I heard both Alex and Ron say they were against charcoal. I have
never understood the passion for charcoal for barbecuing here in the U.S.
Our son Peter is wrestling with whether to buy a charcoal or propane
barbecue for big party tomorrow night. Here are some economic factors to
throw in for the U.S.

Kingsford charcoal costs $8 for a 20 lb bag or $0.40/lb. Energy content
10,000 Btu/lb.
Wood typically costs $100/chord or ton. Energy content 16 M Btu/ton
Propane typically costs $1/gal (4.8 lb), energy content 100,000 Btu/gal.

So the ratio of energy cost is for charcoal, wood propane: $40; $6.25; $2.1
per MBtu (approx GigaJoule). The combustion efficiency of charcoal in Paul
Hait's stove is probably quite high, but most barbecuers pour on the coal,
then let them burn many hours after cooking. Propane is on, cook, then
off. Wood intermediate.

I am still puzzled at the popularity of charcoal around the world.

Yours, TOM REED

From REEDTB at compuserve.com Sat Jun 21 08:52:37 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:21 2004
Subject: Wood combustion
Message-ID: <199706210852_MC2-18E5-5E5B@compuserve.com>

Alex, Ron and Stovers:

The approximate formula for wood is "C H1.4 O0.6". Stochiometric
combustion is then

C H1.4 O0.6 + 1.05 O2 +(1.05X3.76 N2) ===> CO2 + 0.7 H2O + 3.94 N2

(Air contains 79/21 = 3.76 N2 for every O2.) So for stoichiometric
combustion CO2 will be 1/5.64 =
17% CO2.

(Similarly for methane, CH4 + 2O2 + 7.52 N2 ==> CO2 + 2H2O + 7.52 N2
%CO2 = 1/10.52 = 9.5%). Typically excess air is used for combustin, so a
measurement of 12% CO2 sounds OK. However, too much excess air leads to
cold, incomplete combustion.

Yours, TOM REED

From REEDTB at compuserve.com Sat Jun 21 08:52:46 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:21 2004
Subject: Cerafelt, Kaowool etc.
Message-ID: <199706210852_MC2-18E5-5E5C@compuserve.com>

Stovers:

Cerafelt, kaowool and a number of other fibrous insulations are made from a
mineral called mullite. It has a melting point about 1600C to a glass.
Large cylinders are heated with a flame while spinning at high speed that
the fibers spin off, like making cotton candy at the fair.

While it is not cheap in small quantities, it is relatively cheap in large
quantitites, so don't abandon its use for price without more research.

Riser sleeves are made from this same material by vacuum forming short
fibers around a shapped mandrel. John Tatom in Smyrna Georgia used to make
these for stove purposes and could tell us all about it - if he had E-mail.

Yours truly, TOM REED

From rmiranda at sdnnic.org.ni Sat Jun 21 09:09:57 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves/Health /efficiency/research/internet/patnership
Message-ID: <199706210711.HAA06635@ns.sdnnic.org.ni>

At 11:09 AM 6/20/97 -0700, Paul Hait wrote:

>>how about some work
>being done on making 3rd World homes smoke free? Whose Stove does the best
>job in this area? Do you think your Stove creates the least amount of
>pollution? If so,why? This seems to me to be a very important topic to open
>up on the list in more specific detail.

Why we in this list, don't work togheter to do a real job on the 3 world
field ? I propose an interacting project between those that have the mind
for research and those that have the mind for field development, but are
connected only by the internet. We can put our brains togheter and define
the "best" design of a woodstove from our understanding. The majority of
the list members that works in heat flow and termodinamics, etc, could
provide the expertize to design an efficient stove suitable to Honduran
needs, for instance. We in PROLENA here in Central America could promote,
built and monitor the day by day operation of the proposed stove. Then we
would feed back to the list and togheter analize and discuss the results.
The experts would propose adjustments, what we here in the field would then
implement it. We could go on in this process untill we achieve the best
efficient, clean and affordable stove that would be acceptable by the
families in Honduras. After that, we could do the same with Nicaragua, then
Somalia (Faysal organization), and to other needed countries.

In this way, we can use the best brains available on this subject in this
list, at a low cost, to develop specific stoves for each needed country.

What kind of resources would be needed to do such a project ? community
acess, technological expertize, internet connection, and perhaps only
25000 USD/year grant.

Would be anyone interested in further discussing it ?

From english at adan.kingston.net Sat Jun 21 12:34:16 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves/Health /efficiency/research/internet/patnership
In-Reply-To: <199706210711.HAA06635@ns.sdnnic.org.ni>
Message-ID: <199706211634.MAA23094@adan.kingston.net>

> In this way, we can use the best brains available on this subject in this
> list, at a low cost, to develop specific stoves for each needed country.
>
> What kind of resources would be needed to do such a project ? community
> access, technological expertise, internet connection, and perhaps only
> 25000 USD/year grant.
>
> Would be anyone interested in further discussing it ?
>
>
> Rogerio

Dear Rogerio, Paul and stovers all

Yes, surprise surprise, I am.

The internet is being under utilized. We need to get a digital
camera, or a video camera and Snapper ( which is what we are using)
and the necessary software, into the hands of folks in the field
like Rogerio, Elson and I'm sure many others, so that the people who
could offer technical help would have a better "window" on the
world they hope to improve and presumably be able to offer more
relevant advise.

If that is too expensive then how about a scanner. The simplest model
( less than 200USD) would allow the fast exchange of sketches by
individuals, or for posting on the web.

All this is the easy part, coming up with a low cost, clean burning,
quick starting, controllable, biomass fired cooking stove, well.....
that is not so easy.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Sat Jun 21 12:34:17 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves and Health
In-Reply-To: <199706201809.LAA02589@butch.transport.com>
Message-ID: <199706211634.MAA23101@adan.kingston.net>

snip
> Also how about some work
> being done on making 3rd World homes smoke free? Whose Stove does the best
> job in this area? Do you think your Stove creates the least amount of
> pollution? If so,why? This seems to me to be a very important topic to open
> up on the list in more specific detail.
snip
> Paul Hait

Dear Paul

You have obviously made great strides in efficiency. Can you share
with us what you have learned about emissions ?

Alex

P.S. I still don't know what an HTA cell looks like, or how it
works.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Sat Jun 21 12:34:21 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:21 2004
Subject: Wood combustion
In-Reply-To: <199706210852_MC2-18E5-5E5B@compuserve.com>
Message-ID: <199706211634.MAA23105@adan.kingston.net>

Dear Tom
You said
> The approximate formula for wood is "C H1.4 O0.6".

What then would be the approximate formula for the pyrolisis gasses
from wood as seen in the charcoal making stoves like the two can
stove ? Presumably a lower C to H ratio ?

Alex

P.S. I am still very interested in a response to a question I had
"hidden" in an email I sent on Date:Thu, 19 Jun 1997
( Subject: Re: English of 6/12 on Charcoal-making stove)
Restated: How does a relatively small (2kw, I am assuming relatively
high jacket losses for all small appliances) wood
gassifier flame with a pot of cooling water close to the top, (ex.
two can stove), achieve the high temperatures (>900C ?) required for
complete combustion (ex: low CO/CO2 ratio emissions). Even with a
propane stove the amount of excess air and the cooling effect of the
pot must make this difficult. Or am I missing something ?

Still struggling to understand. A.E.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From larcon at sni.net Sun Jun 22 01:30:05 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:21 2004
Subject: Stoves and Health (re: Hait)
Message-ID: <v01540b03afd0fa1aab8f@[204.133.251.17]>

Paul said:

>How about extracting some hard data from the tests that are being talked
>about that starts to build the functional spec. I referred to in my first
>letter? As I read through the letters, I find facts that should go into a
>reference book on the design of a World Stove. How about the list putting
>such a book together for World Stove designers? Also how about some work
>being done on making 3rd World homes smoke free? Whose Stove does the best
>job in this area? Do you think your Stove creates the least amount of
>pollution? If so,why? This seems to me to be a very important topic to open
>up on the list in more specific detail. Maybe I am late and you have already
>concluded this subject.

> We are finishing up our second generation Super Grill and we are now down
>to 50 briquettes for 72 people. At $4.00/bag and 150 briquettes / bag (Royal
>Oak)that is a retail cost of $1.33. Wholesale is half that cost.This could
>be a starting point for a stove comparison discussion.Less than a penny a
>person.

Paul has a point here - the cost per person-meal is certainly an important
ingredient of a spec.

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Sun Jun 22 01:30:12 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: Kirk Smith on Stoves and Health
Message-ID: <v01540b01afd256cc3fc3@[204.133.251.4]>

Kirk said:

>Ron, I was responsible for much of this report (seven trips to Geneva last
>year). Next week I will have the details about how people can obtain a
>copy. (I will not have my own copy of the final version until Monday. Hope
>there were not too many changes by the editors!) Best/K

Kirk: 1. The Denver Post yesterday noted again the 20% children's deaths
before age 5 - but then attributed that to three things that didn't
include indoor air pollution or stoves. I now can't find the exact
reference. I presume that some US (maybe Denver) editor couldn't
understand how indoor air pollution could be responsible for the deaths of
one out of 5 young children.

2. If you can supply any references on the relative magnitudes of
CO and or CO/CO2 from charcoal and wood cooking, you will move our dialog
on a good bit.

3. Thanks for the background on the WHO report and thanks for your
contributions to it. Some of us don't feel too sorry for you for the 7
trips to Geneva - assuming they covered most of your costs.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Sun Jun 22 01:30:14 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: Stoves and Health
Message-ID: <v01540b02afd25d3cc2e1@[204.133.251.4]>

Rogerio said:

<snip>

> In the other hand, while this article pointed
>out that in the developing world the major cause of IRA is indoor air
>pollution, and we know the indoor air pollution in these countries is
>mostly related to woodsmoke, no health organization is supporting actions
>to prevent IRA.
>
>We the stovers, should in my opinion, speak out about this problem as much
>we can, to help increase awareness among decision makers. We need a strongh
>advocating organization to make big noise about those points in which we
>believe are wrong, and should be improved.

(RWL): 1. Does anyone know of such a strong organization? I'm presuming
you are thinking of a group such as Greenpeace, the Red Cross, WHO, UNICEF,
etc.?

2. In the absence of any such present organizational commitment, I
suppose we are the ones to try to do some convincing. The only thing I
know to do is start writing letters to the Boards of these groups (and/or
the editors of their newsletters) - quoting (and maybe explaining) the WHO
report. I hope anyone writing such a letter will share it with "stoves"
(and any responses). If we are members (or not) of such groups, a few such
letters could be important.

3. Thanks for sharing your own knowledge of the statistics.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From owner-stoves at crest.org Sun Jun 22 01:30:05 1997
From: owner-stoves at crest.org (by way of larcon@sni.net Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: Tom Reed on autopyrolysis
Message-ID: <v01540b04afd262a4081b@[204.133.251.4]>

This is another of Tom's messages that "Bounced". I can't see the reason
why. Ron

From: Tom Reed <REEDTB@compuserve.com>
Subject: Re: Nice knowing ya!
To: "INTERNET:stoves@crest.org" <stoves@crest.org>

Dear AJH et al:

I have long suspected that wood can "autopyrolyse" if it is bone dry. =

Thermodynamically it is unstable relative to equilibrium products CH4, CO=
,
CO2 and H2O, but we never get near equilibrium in our 500C pyrolysis
experiments.

Several years ago I tried an experiment to determine if, once ignited, it=

would "autopyrolyse". I had a well insulated cylinder tightly enclosed =
at
the bottom. I ignited it at the top and added a chimney to prevent air
from entering at the top. It generated heat for 12 hours and made charco=
al
to the bottom. I should do it again before I am sure, but maybe some
recent observations suggest that others are seeing the same effect. Were=

your charges bone dry? Remember the pyrolysis is endothermic up to about=

270C, but then become exothermic. =

Could be! TOM REED

From elk at arcc.or.ke Sun Jun 22 13:26:45 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo - trial 4
Message-ID: <m0wfqPD-0006VHC@arcc.or.ke>

Ron;

The original wieght of water in trial 4 was 5.65 kg.

I'll try for FOM of 2. I observed that the stove was adjustable to a pretty
high degree, as there is an immediate response in boil vigor to adjustments
made to primary air venting.

Inserting the pan into the stove top blocks any observation of flame in the
combustion chamber- the distance between pot & wall of stove (pan to wall
gap) is 8mm. It's a distincly odd sensation to operate a wood stove with no
direct view of the cooking flame, and this does require more skill than
cooking over three rocks!

I forgot to mention that this trial was conducted outside in gusty
conditions, with wind ave. 6 km/hr & max 20. I will apply your advice on
blocking primary air holes independantly. The stove's effectively windproof
though.
---------------------------

Alex;

I'll DHL photos of both 2can Turbo & the manual chatcoal briquetter (in
action) Monday- I look forward to seeing them on your stover's page!
(providing they pass your critical review, that is).

Regards;

elk

From phait at transport.com Sun Jun 22 17:01:09 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:22 2004
Subject: Stoves and Health
Message-ID: <199706221420.HAA15489@butch.transport.com>

>Rogerio said:
>
> <snip>
>
>> In the other hand, while this article pointed
>>out that in the developing world the major cause of IRA is indoor air
>>pollution, and we know the indoor air pollution in these countries is
>>mostly related to woodsmoke, no health organization is supporting actions
>>to prevent IRA.
>>
>>We the stovers, should in my opinion, speak out about this problem as much
>>we can, to help increase awareness among decision makers. We need a strongh
>>advocating organization to make big noise about those points in which we
>>believe are wrong, and should be improved.
>
>(RWL): 1. Does anyone know of such a strong organization? I'm presuming
>you are thinking of a group such as Greenpeace, the Red Cross, WHO, UNICEF,
>etc.?
>
> 2. In the absence of any such present organizational commitment, I
>suppose we are the ones to try to do some convincing. The only thing I
>know to do is start writing letters to the Boards of these groups (and/or
>the editors of their newsletters) - quoting (and maybe explaining) the WHO
>report. I hope anyone writing such a letter will share it with "stoves"
>(and any responses). If we are members (or not) of such groups, a few such
>letters could be important.
>
> 3. Thanks for sharing your own knowledge of the statistics.
>
>Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>Dear Ronal,
It seems obvious that the indoor air problem in third world homes could be
corrected by the following steps being taken; having enclosed and properly
exhausted fires, creating a negative draft with a suction fan of sorts(
possibly solar cell powered), using gas stoves, putting a simple close
proximity chimney over a fire, or using an exhausted HTA World Stove. If
these things are not being done , what is being done? I think we all need to
know from Tom Miles,Rogerio or yourself what is the most commonly used third
world stove that is causing the major indoor smoke pollution. Then we should
all look at the cheapest way to exhaust the smoke. This should be Stover
Step1. Stover Step #2 should be the best
overall(wood,charcoal,roots,pyrolisis,briquettes,etc.) fuel approach. Stover
Step #3 should be the best overall stove design with the 1 cent or less/meal
goal.
I realize the importance of basic research to find the answers, but it seems
that what Rogerio is getting at is that one of these days were going to have
to start cutting steel. I am doing that right now and may not have the best
answer but my hopes are that we are getting closer to the solution. as I
have said before I would be happy to make you a Ronal Stove in the plant if
you would like one.You are a great leader and you have my greatest
admiration for your tireless efforts to find a solution to this monumental
World Stove problem.

Sincerely,

Paul W. Hait
President
Pyromid Outdoor Cooking Systems

From phait at transport.com Sun Jun 22 17:06:08 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:22 2004
Subject: Stoves and Health
Message-ID: <199706221425.HAA15512@butch.transport.com>

>Dear Ron: This is a "good" sign that the word about Indoor air poluttion
>in the developing countries is causing Accute Respiratory Infections-IRA
>and consequently death. In Honduras, IRA is the major cause of deaths among
>infants, followed by diarrhea. In Nicaragua, Diarrhea is the first,
>followed by IRA.
>
>It seems to me that diarrhea gets more attention than IRA, since for
>instance down here in Central America USAID and UNICEF strongly support
>actions to prevent diarrhea. In the other hand, while this article pointed
>out that in the developing world the major cause of IRA is indoor air
>pollution, and we know the indoor air pollution in these countries is
>mostly related to woodsmoke, no health organization is supporting actions
>to prevent IRA.
>
>We the stovers, should in my opinion, speak out about this problem as much
>we can, to help increase awareness among decision makers. We need a strongh
>advocating organization to make big noise about those points in which we
>believe are wrong, and should be improved.
>
>Rogerio
>
>
>
>
>At 06:02 PM 6/19/97 -0600, you wrote:
>>
>>Today's issue of the Denver Post (p 21A) had a short news report by Erica
>>Bulman of the Associated Press, saying (in part) in a 7" short piece
>>entitled World's Pollution Worsens":
>>
>> "GENEVA - Lumping together everything from homicides to un-healthy
>>kitchens, the U.N. health agency says the environment is in worse shape
>>than fives ago and is to blame for many preventable illnesses worldwide.
>>. Children, especially in developing nations, are hardest hit,
>>according to a World Health Organization report released Wednesday that
>>assesses the impact of 1992 Earth Summit in Brazil.
>>
>> <skip 4 short paragraphs mainly on workplace accidents>
>>
>> It found that more than 20 percent of chilren in the
>>least-developed countries die of environmental causes before age 5,
>>compared with fewer than 1 percent of children in developed countries.
>> Respiratory infections and diarrheal diseases are the biggest
>>environment-related health problems, the study found, with air pollution
>>causing about 3 million premature deaths worldwide.
>> It blamed 2.8 million of those deaths on indoor air pollution, with
>>almost all cases occurring in developing countries."
>>
>> My comments:
>>
>> 1. The world's main health problem seems to be caused by stoves
>>(but at least here the word "stoves" is not reported.
>> 2. Few people reading this article will realize that the problem
>>is mainly cooking and stoves.
>> 3. The problem may be getting worse (or maybe just better
>>reporting) - and probably is under-reported anyway.
>> 4. This report (not the article) may be what persons like Paul
>>Hait was looking for as a way to get the attention of decision makers.
>>
>> Questions:
>> 1. Can anyone on this list tell us how to obtain the full report?
>> 2. If anyone has seen it and can add to this very limited summary,
>>I hope they will do so; are stoves mentioned in the full report - or only
>>the phrase: "indoor air pollution" (in the US, this refers only to
>>cigarette smoke and radon).
>> 2. Is there any better data to show whether there is under-reporting?
>> 3. Does WHO ever provide funding for solving such problems, which
>>they have termed "preventable"?
>>
>>
>>Regards Ron
>>
>>Ronal W. Larson, PhD
>>21547 Mountsfield Dr.
>>Golden, CO 80401, USA
>>303/526-9629; FAX same with warning
>>
>>
>>
>--------------------------------------------------------------------------
>Rogerio Carneiro de Miranda Telefax: (505) 276 0555
>PROLENA(Nicaragua)
>Apartado Postal C-321 Managua Nicaragua
>E-mail: rmiranda@sdnnic.org.ni
>-------------------------------------------------------------------------
>Dear Rogerio,
I hope I have a chance to meet you someday. Your comments are to the point
and very PRACTICAL! I wish you would order a Campmaster Duo HTA Cell Stove
from Pyromid. I think it may be what you are looking for. I will sell it to
you for wholesale. Call 541.5481041 and ask for Lara.

Sincerely,
Paul Hait
President
Pyromid Inc.

From wheinser at ptd.net Sun Jun 22 21:55:39 1997
From: wheinser at ptd.net (wheinser)
Date: Tue Aug 31 21:35:22 2004
Subject: Eriez Gas Stove`
Message-ID: <33ADD7FD.78E@ptd.net>

I have a Eriez Gas Stove, model # G6769R I am trying to find the age
and value of it. It is in mint condition. If you can help me out in
any way, it would be greatly appreciated. Believe it was made in the
late 20's. Eriez Stove & Mfg. Co., Erie, Pennsylvania
Thank you, Janine

From english at adan.kingston.net Sun Jun 22 22:34:32 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:22 2004
Subject: Stove Complexity
Message-ID: <199706230234.WAA00833@adan.kingston.net>

Dear Stovers

I have continued to test fire the swirl venturi model of the cone
in pail burner with an insulated combustion chamber/chimney.
We sent off the CO2 tester for calibration so I haven't any excess
air reference for these latest tests. Temperatures up to 950C have
measured . Smoke readings tend to be lowest when the flame
turbulence is greatest, and as the burn progresses.........

...... I have just sat here typing and deleting for the last hour as
I attempted to speculate my way through an interpretation of all the
different manifestations that this burner has thrown at me over the
last few days. I don't think I'll waist our time. (now)

On a different vane, the smoke tester that I am using is very simple
and could be made from a bicycle pump. It appears to be useful for
testing wood stove emissions during the combustion of the volatile
portion. I would be interested in trying to correlate it's readings
with CO. It could be the cheapest way to assess the toxicity of
flue gasses. It would not be appropriate for testing flue gasses from
a charcoal fire as I get low readings from them. It must be an
indicator of unburned hydrocarbons. Comments?

I have updated the web page, among other things it includes a link
to a description of the Swosthee that I found in the Stove List
Archives. It mentions an emission of 20ppm CO. This is not credible
to me. How about you?

Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From MAILER-DAEMON at csn.net Sun Jun 22 22:40:19 1997
From: MAILER-DAEMON at csn.net (Mail Delivery Subsystem)
Date: Tue Aug 31 21:35:22 2004
Subject: Gene Shultz and The WHO report
Message-ID: <v01540b0cafd36b2346be@[204.133.251.11]>

Stovers: I sent the message off badly once already (Saturday) and now
(Sunday) can't change the "From". Sorry. Ron

From: GeneShu@aol.com (by way of larcon@sni.net (Ronal W. Larson))

Stovers: Gene Shultz sent this today and I believe would not mind my
sending it on to all. I add a short note at the end. Ron

Ron: I will have something to say about the WHO report toward the end of the
coming week, including some of my own data on the problem. For now, I'm deep
into teaching a summer session intensive course at Wash. U., and leaving
tomorrow for a 5-day field trip, so can't wax very eloquent at the moment. I
really shouldn't take the time to write these words right now. I do have a
fairly well-written manuscript almost finished which I will send to those who
wish to read it, describing the main part of our study in the northeast of
Brazil and in central Mexico on rural kitchen smoke. Anyone wanting it should
let me know, but I hope they will agree to give me comments on it fairly
ASAP. We measured respirable suspended particulates (RSPs). Most kitchens had
unacceptable smoke pollution levels due to inherently smoky fuels, bad stoves
and chimneys (or none), poor ventilation, inadequate fire-building and
maintenance skills, some attitudinal problems that prevented women from
taking even the simplest smoke-avoidance measures, etc. But a minority of
homes had low levels of kitchen smoke, good or adequate stoves/chimneys, and
skilled, savvy cooks. I submit that the key is more complex than just having
a smoke-secure stove/chimney combo that moves the smoke outdoors effectively,
but that is the heart of it. The cook's attitudes and skills are also very
important, including the ability of the cook to get her husband to help her
make her kitchen more smoke-free. Many (certainly not all) men have
mechanical skills that can help, but most of these men don't seem to see
kitchen smoke as any problem, at least not a male problem. So we need to look
at the whole thing, all the reasons for smoke exposure, gender-biased as it
is to women and small children who spend so much time in the family kitchen,
and not stop with the stove alone. Not only are attitudes and skills of the
cook important. The nature of the fuel is also important. In
densely-populated villages, it isn't good enough to just neatly conduct the
smoke outdoors. It comes back in through open windows and doors. Many windows
have no coverings. So more attn is needed to cheap low-smoke fuels as well as
to the stove/chimney. Charcoal isn't affordable. And don't shrug off chimney
(flue) technology as obvious and beneath attn. I have seen an awful lot of
almost-horizontal chimneys, maybe 10% incline at most. I can tell you that
they generate almost nil draft, as you might imagine. So there is much work
to do in public education campaigning, and in assisted self-reliance (ASR)
projects, etc. More to come, but I have to pack for the field trip now. By
the way, I appreciate being on the stoves list. Much of what comes through is
of interest to me although I am not a stover, per se. As you know, I mainly
study the whole problem, globally, the technical and non-technical aspects,
as well as the clean-burning biofuel approach to contributing to solutions.
No need for me to work in improved stoves. You guys are doing that part
really well. Many thanks for calling the Denver Post story to my attn. I've
been waiting for WHO to confirm what all of us observe when we hang out,
gasping, in Third World kitchens. By the way, I haven't any clue as to how I
can send messages to all members of the stove list, or just a few, or
whatever you do. And is there a list for just biofuel enthusiasts? I barely
grasp sending a simple e-mail message. So this one goes to you, only. And I
marvel at the commitment it must take to coordinate all these stovers. Or is
it easier than meets the eye??? Best, Gene Shultz (geneshu@aol.com)

Gene. I would like a copy of your Brazil cooking paper and pledge to send
comments. To send to all just reply to anything you get (which will
automatically go to "stoves@crest.org") Your message will go automatically
to about 95 persons in 25 -30 countries. I do not believe there is a
"biofuels" list, but this list comes fairly close - since almost everything
is burned in stoves. Thank you for offering to send your report. I look
forward to hearing your thoughts on the WHO report.

Stovers: I had thought Gene has been involved only a little on stoves -
but I see I was wrong (despite what he says above). We have not met -
except through our mutual friend Jack Whittier. They both have been
promoting the use of root fuels (buffalo gourd) which dries to an amazingly
hard dense fuel. More energy per year and a lot in the first year. I
thought root fuel turned to charcoal a lot like wood, with a slight amount
more odor.

Gene was also the author of a nice book on the plant Jatropha that
you may remember coming up several months ago. I think Gene is mostly (but
obviously not entirely) retired from Washington University in St. Louis.

Regards Ron

From larcon at sni.net Sun Jun 22 22:41:14 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: English on Wood combustion
Message-ID: <v01540b0fafd38374fd6e@[204.133.251.11]>

Alex asked:

<snip>

>Restated: How does a relatively small (2kw, I am assuming relatively
>high jacket losses for all small appliances) wood
>gassifier flame with a pot of cooling water close to the top, (ex.
>two can stove), achieve the high temperatures (>900C ?) required for
>complete combustion (ex: low CO/CO2 ratio emissions). Even with a
>propane stove the amount of excess air and the cooling effect of the
>pot must make this difficult. Or am I missing something ?

(RWL): Two differences.

1. In the propane or natural gas stove, there is some pressure and a
venturi pulls in the air some distance away and achieves premixing before
combustion. Then the flame height is very small and the pot can be placed
within centimeters of the gas exhaust. The flame combustion can have been
complete before it reaches the cook pot.

2. In the pyrolysis "two-can" stoves, the flame is a diffusion type - no
premixing (but this is well worth studying). Then the flame height is much
greater and the cook pot has to be moved up accordingly. But this is not
necessarily a big deficit, since the chimney in which the flame is situated
creates the small negative pressure needed to draw in both the primary and
secondary air supplies. We might be able to do this with small fans - but
getting the right balance between the primary and secondary fans would be
mighty difficult, I predict.

3. We should probably look closely at un-pressurized kerosene stoves to
see how tall the space should be between kerosene level and cookpot. I
haven't done so. The kerosene lantern has a pretty tall glass chimney both
to provide wind shielding and to draw in the combustion air. Has anyone
ever seen a fan-powered kerosene chimney lantern?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Sun Jun 22 22:41:19 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo - trial 4
Message-ID: <v01540b0eafd370838a08@[204.133.251.11]>

Elsen said:
>The original wieght of water in trial 4 was 5.65 kg.
>
(RWL): I was needing this to estimate the stove efficiency - which
was not high. But not important until you start doing some convection
shielding.

>I'll try for FOM of 2. I observed that the stove was adjustable to a pretty
>high degree, as there is an immediate response in boil vigor to adjustments
>made to primary air venting.

(RWL): I think this "immediate" response is a major advantage of a
pyrolysis stove.

>
>Inserting the pan into the stove top blocks any observation of flame in the
>combustion chamber- the distance between pot & wall of stove (pan to wall
>gap) is 8mm. It's a distincly odd sensation to operate a wood stove with no
>direct view of the cooking flame, and this does require more skill than
>cooking over three rocks!

(RWL): 1. I don't believe you told us whether the 8mm gap gave an
appreciably better FOM than when you had no shield.

2. I agree with your disatisfaction in not being able to see the
flame. However, on reflection, we don't rely on this for either electric
cooking and mostly we don't rely on looking at the flame with gas cooking.
One solution is to use a Pyrex glass pot for the testing. Also, I always
seem to be using shields with enough holes that I can see something - maybe
that also is an acceptable approach. A third approach is to use a shield
with some mica windows. I have an antique kerosene cook stove with this
feature - to shed light mainly. But I haven't tried it with any pyrolysis
stove.

>
>I forgot to mention that this trial was conducted outside in gusty
>conditions, with wind ave. 6 km/hr & max 20. I will apply your advice on
>blocking primary air holes independantly. The stove's effectively windproof
>though.
> <skip>

I am glad to hear about the windproofing - your outer windshield
sounds very successful. How many "tabs" to hold the two pieces of metal
together and what is the separation and size now?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From owner-stoves at crest.org Sun Jun 22 22:41:23 1997
From: owner-stoves at crest.org (by way of larcon@sni.net Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: Andrew Heggie on autopyrolysis
Message-ID: <v01540b0bafd36a62195a@[204.133.251.11]>

Stovers - again a "Bounce" - for unknown reasons. Ron

To: stoves@crest.org
From: Andrew Heggie <ahe1@cableol.co.uk>
Subject: Re: Tom Reed on autopyrolysis

Andrew Heggie in response to:
At 23:31 21/06/97 -0600, Tom Reed wrote:

>I have long suspected that wood can "autopyrolyse" if it is bone dry.
>Thermodynamically it is unstable relative to equilibrium products CH4, CO,
>CO2 and H2O, but we never get near equilibrium in our 500C pyrolysis
>experiments.
My knowledge of chemistry is not well remembered enough to follow this. I
understand that heat pressure and catalysts can shift the balance of
products produced, this is what I understand Mike Antal's paper shows ( I
still eagerly await this Mike!).
>Several years ago I tried an experiment to determine if, once ignited, it
>would "autopyrolyse". I had a well insulated cylinder tightly enclosed at
>the bottom. I ignited it at the top and added a chimney to prevent air
>from entering at the top. It generated heat for 12 hours and made charco=
>al
>to the bottom. I should do it again before I am sure, but maybe some
>recent observations suggest that others are seeing the same effect. Were=
>
>your charges bone dry?
No
>
Essentially this is what my hybrid attempts. I mentioned in an earlier post
that yield of charcoal did not vary in our conventional kiln according to
the moisture content of the input. I had surmised this was because the
driving heat in the pyrolysis zone was provided by the pyrolysis products
burning in air from the inlets as evolved from the wood, Ronal thought the
heat source was the high temperature exothermic pyrolysis and consumption
of some charcoal, the steam and pyrolysis gases being vented in a largely
incombustible and highly polluting manner (Ronal please comment if I
misunderstood you) hence my thoughts that insulating the kilns would not
affect charcoal production. It becomes an entirely different matter when
attempting to make use of the flare gas when the overall heat efficiency
must be increased by an order of magnitude, if you stand near one of our
kilns you would feel how lossy it is.

As I mentioned in an earlier post I think it may be beneficial to first dry
the charge to bone dry before the pyrolysis simply because of the comments
on pollution, at least the phase when steam from the free water is mixing
with pyrolysis gases and preventing their flaring is prevented. It would
seem to have the advantage also of reducing the occupation time of the wood
in the kiln. Obviously steam from the chemical breakdown of the wood is
still one of the gases but it is liberated at 270C and should not quench the
flaring.

>Remember the pyrolysis is endothermic up to about 270C, but then become
exothermic. =

I thought wood decomposed at 232C. I understood the phases in the process to
be a driving off of free water in the cells and cell walls when the rate of
heat input would be 2.7Mjoules per kilo of water driven off accompanied by a
shrinkage of the charge as moisture content went below 20% expressed as % of
dry wood. Then once the charge is bone dry I had envisaged a rapid rise to
232C subject only to the constraints of the specific heat of wood whence the
process would be endothermic and as you say would autopyrolyse. Why is the
temperature range from 232-270C still an endothermic region? Again Ronal
has explained that in the field a different set of conditions will exist
from that in the laboratory when equilibrium conditions will exist as heat
inputs can be controlled, he suggests that temperatures in the pyrolysis
zone can build up above the 440C you suggested, Alex English's measurements
would point to this as he measured 700C in the charge.

I was initially very hopeful that your contention that it would be difficult
for the charge to exceed 440C would make it possible to design the kiln to
be very well insulated and self regulating, now I have a feeling it will be
necessary to incorporate some internal circulation of pyrolysis gases to
cool them and hence cool the charge. I had hoped for comments on my
suggestion a heat pipe could be tailored to be temperature specific for this
purpose. It seems fundamental to run as low a temperature as possible to
maximise charcoal and enable use of cheaper materials for the kiln without
compromising its integrity through heat induced distortion.

By the way I agree with your thoughts on charcoal in barbecues but think the
situation on use as a luxury good is more to do with the back to basics
image and cost is not a consideration, it is to do with risk and lack of
control otherwise the cooking would be done in the kitchen. I find the
substitution of kerosene for controllability and reduction of inefficient
use entirely acceptable, especially if it reduces unsustainable harvesting
of woody products in a third world context. In much the same way that I use
an electric kettle even though it results in 2/3 of the energy used being
dumped at the power station 100% of what remains boils a small amount of
water without heating up a stove. It seems unlikely that 50% of the
population will have access to cash necessary to purchase kerosene so more
efficient stoves continues to be a best option.
AJH

From larcon at sni.net Sun Jun 22 22:41:17 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: G-8 final notes
Message-ID: <v01540b10afd389054c1b@[204.133.251.11]>

Since the word stove never appeared in anything I heard or saw over
the last three days, I will keep this short. The only positive thing I
heard of importance to this list was a general agreement by the majority
that global warming was an issue of importance. The final communique from
Clinton apparently (it may be in tomorrow's paper) will say that the
leaders will say something more specific at the Kyoto meeting. The US was
the biggest holdout at this meeting. The coal industry held a press
conference here on Friday (I couldn't attend) saying that there was no
proof of any global warming relationship to their industry.

I attended a similar solar press conference stating just the
opposite - as the officers announced the creation of "The Solar Century".
This is a big money effort to promote PV through especially cities. It is
largely European (British and German predominance), but with some American
also. I had heard previously about the concerns of insurance companies
about global warming, but here the President of a large German re-insurer
(Dr. Rolf Gerling) said that "all" the insurance industry now were
convinced about global warming. He said that the indexed cost of natural
hazards attributable to the weather are now 8 times larger than in the
60's. So they are investing in the solar industry. If anyone knows of
similar analyses from the insurance industry, I would like to hear them.

The progressive community was here to protest the G-7 agenda. But
a thousand or so were not enough to even make the back pages of the local
papers - and only a very few participants were interested in renewable
energy - and I found none talking about stoves. There would have been 100%
indignation if any knew about stoves and health in developing countries -
but I doubt many knew. We still have our work cut out for us - even within
this community.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From elk at arcc.or.ke Mon Jun 23 05:28:40 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Trial 4
Message-ID: <v01510100afd40bad1e9e@[199.2.222.130]>

(RWL asks)
>>
>>I forgot to mention that this trial was conducted outside in gusty
>>conditions, with wind ave. 6 km/hr & max 20. I will apply your advice on
>>blocking primary air holes independantly. The stove's effectively windproof
>>though.
>> <skip>
>
> I am glad to hear about the windproofing - your outer windshield
>sounds very successful. How many "tabs" to hold the two pieces of metal
>together and what is the separation and size now?

Ron;

I ran 3 pcs of 3/8 inch diam. mild steel roundbar (~8.4 mm) vertically up
the windshield to hold it away from the body of the stove. The top was
sealed 2 cm below the level of the exhaust outlets, so air entering the
secondary inlet is theoretically pre-heated. The shield covers 3/4 of the
entire unit.

-----------------------------------------------

Q: Rather than tearing this stove apart, I'm thinking of starting on 2can
Turbo Mk2 with a combustion chamber of a larger diameter than the pyrolisis
chamber. See any problems there? Efficiency can be increased by inserting a
proportionally larger pot into the stove & thereby increasing the exhaust
gas surface contact area for cooking.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From prasad at tn7.phys.tue.nl Mon Jun 23 06:07:51 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:22 2004
Subject: A pot-pourri of replies
In-Reply-To: <v01540b00afd0e5d8e91f@[204.133.251.17]>
Message-ID: <9706230957.AA13542@tn7.phys.tue.nl>

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From BeedieD at Cardiff.ac.uk Mon Jun 23 16:31:17 1997
From: BeedieD at Cardiff.ac.uk (David Beedie)
Date: Tue Aug 31 21:35:22 2004
Subject: gasifier-combustors and so forth
Message-ID: <v01540b0aafd4825a2af1@[204.133.251.15]>

Stovers: The following is David Beedie's response in an off-list dialogue that
started when I contacted David because of his comments on another list. I
believe it is best to bring David's answers to the full stoves list because
of his good knowledge on much of this discussion - and the following is not
too
repetitive with his recent dialogues on our list.

David said:

>> >The thesis gives the detail (a paper in Combustion Science and
>> >Technology also gives much of it but alas not in colour)...
>>
>> (RWL): I will get the Combustion Science paper ASAP.
>
>I've got spare copies - I'll send you one.
>

>> (RWL): I am mainly wondering whether there is some inherent control
>> advantage in making charcoal and in the top-firing - because there is so
>> little apparent difference in the thermal output over the roughly one-hour
>> charcoaling period. In your gasification is this also true?
>
>No, but my system was controlled with a strategy aimed at minimising
>emissions, as well as preserving a good low excess air value at the
>combustor exit. The latter was to allow the following heat exchanger
>to operate at good efficiency and not lose too much energy up the
>flue. With this strategy a pronounced minimum occurred in thermal
>release.
>
>> >What I am asserting - in my comment above - is that:
>
>> >1/ the devolatilisation (gasification) rate naturally varies strongly
>> >during the fuel cycle; a control system equally strongly regulating
>> >the primary air is necessary to oppose this intrinsic tendency of the
>> >fuel to gasify most readily during the middle of the fuel cycle, if
>> >the energy release rate is to be at all moderated;

>>
>> (RWL): When you say "energy release rate" - is this the same as
>> gasification rate - because you are sending the gas to an engine/generator
>> and you want the gas to be just sufficient to meet the load? Can you do
>> this with two batch units that are phased in and out alternatively?
>
>I'd better clear up a misunderstanding first - there was no engine -
>I worked on a gasifier-combustor - i.e. a controlled fire, just like
>stoves etc, but rather larger and with gasification and combustion
>separated into two chambers.
>By air flow measurements, flue gas species measurements and mass
>balances I derived the mass flux and C:H:O ratios of the volatilising
>fuel and used a correlation from Tom Reed's book to determine its CV
>and hence thermal release rate (mass flux x CV).
>
>
>> (RWL): It would seem that most gasification applications would not be as
>> happy with batch loading -rather preferring some sort of continuous feed.
>> In my application (cooking), an experienced cook can presumably lie with
>> batch-loading, but I wonder how you could justify studying a batch
>> gasifier.
>
>In crop-drying (my application), an operator can be on-hand to reload
>once an hour or so....
>
>
>> >2/ the gas quality in terms of HHV during devolatilisation is indeed
>> >remarkably constant, but about two-thirds of the way thrugh the fuel
>> >cycle - in my system - it abruptly starts to change, due to the
>> >increasing degree of carbonisation.
>> >
>> (RWL): Is this because carbonisation is occuring over a large part of the
>> wood all at one? In my case, the outer carbonisation occurs only over a
>> small region at any one time (and the inner-carbonization effects are
>> somehow fairly constant as well). Maybe I am asking why a cross-wise flow?

>> Is your thesis following a standard practice or were you working on a
>> special batch design?
>
>Once the volatiles have gone from all the charge there is nothing
>much left but carbonised wood and clearly this has a high HHV.
>In a gasifier-combustor there is no requirement for clean gases at
>gasifier exit and although the device was a one-off (intended to be
>developed for production) the cross-wise flow geometry was inherited
>from similar designs of system.
>
>
****************************

>> >It follows from 1/ that the ratio of primary air to
>> >devolatilisation (gasification rate) (expressed relative to the
>> >stoichiometric air required for complete combustion), i.e.
>> >the equivalence ratio, varies strongly throughout the loading
>> >cycle.

****************************
>>
>> (RWL): I have not understood the term "equivalence ratio" or its
>> significance. Should I be getting familiar with it (for
>> charcoal-making/cooking)? I never see it in stove literature,
>
(David):
>E.R. = ratio of air supplied to the gasifier to that required for
>stoichiometric combustion of the amount of gas produced, in the range
>0.1-0.7 throughout the fuel cycle.
>
>[ Confusingly, the term E.R. is also sometimes used in combustion
>texts as, if I remember correctly, the inverse of the excess air
>value, i.e. the ratio of (the ratio of fuel:air) to (the
>stoichiometric ratio of fuel:air).]
>
>
>> >I measured a gradual variation in the composition of the gases
>> >evolved during devolatilisation, and then a rapid change during the
>> >onset of fuel exhaustion. However the gradual change involved gradual
>> >reductions in both H:C and O:C ratios, which counterbalanced each
>> >other in terms of energy per carbon atom.
>> >In terms of energy per unit mass of the volatilisation compound -
>> >taking into account suitable assumptions about the profile of
>> >evolution of the free water (which cannot be distinguished from
>> >chemically bound H2O), if memory serves me correctly (thesis
>> >not to hand at this moment), during devolatilisation there was almost
>> >no change, but at the charring end of the cycle there was a very
>> >steep rise as the volatilisation compound was increasingly strongly
>> >carbon-dominated.
>>
>> (RWL): I don't understand the term "charring end of the cycle" I would
>> have guessed that the end of the cycle was consuming char - not making it?
>> I apologize that I really don't understand gasification - and have never
>> studied it - because I always assumed that it was mainly involved in the
>> consumption of the char - that I want to save. I am really asking whether I
>> should try to understand this change in gas production you are describing,
>> because there may be hints on how to do a better job of charcoal production
>> and cooking with the produced gases.
>
>(David):You're right there - I used the term charring carelessly - what I
>meant was the final part of the cycle when the fuel was practically
>all charred, 'the charred end of the cycle' perhaps?
>
> I wouldn't say that system was particularly instructive to
>charcoal producers, because it produced a relatively low yield and
>burned it anyway during the course of the next charge. What I
>observed mainly relates to the variation during the fuel cycle of the
>fuel's 'desire' to gasify. Not sure if that's useful information to
>you or not ....
>

*******************************************************
(Dr) David Beedie
School of Engineering, University of Wales, Cardiff, UK

email: BeedieD@cardiff

Tel. 01222 874683 (office); 874000 ext.5927(lab.)
FAX: 01222 874420 - mark for my attention !
762197 (home)
*******************************************************

From larcon at sni.net Mon Jun 23 16:31:10 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Trial 4
Message-ID: <v01540b08afd451329e26@[204.133.251.15]>

Elsen said:

<snip>
>Ron;
>
>I ran 3 pcs of 3/8 inch diam. mild steel roundbar (~8.4 mm) vertically up
>the windshield to hold it away from the body of the stove. The top was
>sealed 2 cm below the level of the exhaust outlets, so air entering the
>secondary inlet is theoretically pre-heated. The shield covers 3/4 of the
>entire unit.

(RWL): It will be interesting to see how this changes over time. I
wonder if your three rebars could have any advantages to provide stability
(insteady of your concrete).

(Elsen):
>Q: Rather than tearing this stove apart, I'm thinking of starting on 2can
>Turbo Mk2 with a combustion chamber of a larger diameter than the pyrolisis
>chamber. See any problems there? Efficiency can be increased by inserting a
>proportionally larger pot into the stove & thereby increasing the exhaust
>gas surface contact area for cooking.

(RWL): No. 1. I think this is an excellent next step. I tried
something similar in Ethiopia with an enjira (national "bread") cooker
(griddle) of 60 cm diameter, starting from a 20 liter (roughly 30 cm
diameter) can fuel container size. I first tried a second 20 liter can
above and then a flat disk - but found too nonuniform a temperature in the
center.

2. I switched to a 60 degree cone (starting with semi circle) and
the temperature uniformity across the griddle was quite good. I only
partially solved the problem of maintaining levelness of griddle surface
and the right outer spacing between griddle and cone (using wire mesh).
With a cone, many different sized cook pots can be used. An outer
cylindrical flat "ring" can also rest in the same cone to achieve the
needed close spacing for convective heat transfer to the pot.

3. I also have tried a loose brick framework to do some of this
change in diameter - but I wasn't yet happy with results - although
generally charcoal was produced and the flame was controllable.

4. An important consideration is to not have too large an opening
for the secondary air supply - which will lower the temperature and the CO2
% (and possibly increase CO level). Matching up these diameters is not an
easy task - while simultaneously keeping a wind shield.

5. I think that your approach (with rebars, which I haven't try)
would probably be easier, especially if the cook pot can be sold as part of
the system.

6. Maybe the two cylinders can be held together at the change
diameter with concrete (maybe again reinforced with metal rods/wires). But
this might be too heavy.

7. Another approach that might work is using a wire or rebar
framework at the change diameter - to bring in secondary air at as hot a
temperature as possible (using a double wall). I think the best place for
the secondary air supply is near the diameter of the fuel supply. Whether
the secondary air should point inward or upward (or both) I am not sure.
Getting a "swirl" seems like a good idea. Moving the pyrolysis gases to
the outside away from the centerline (maybe using an interior disk or can)
is important to reduce the height of the flame.

8. The Russian approach to this is with a small tall chimney up
through the center of the water pot. Now the outer surface is at a much
lower temperature and radiative losses are much reduced. Radiation from
the hottest (inner) surfaces is back to other hottest surfaces.

9. Obviously there are dozens of ways to do this - good luck.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 23 16:31:00 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: Prasad: A pot-pourri of replies
Message-ID: <v01540b0bafd48552dd72@[204.133.251.15]>

:K.Krishna Prasad <prasad@tn7.phys.tue.nl> said on 23 June 1997

<snip>

>(i) I was at Eschborn with GTZ in Germany for a meeting of what is called
>HEDON >
<snip>

>Two issues were addressed at the meeting: one concerned the
>health problem ( proposals from WHO); and the second cocerned the
>integration of the stoves work into other activities concerning rural
>development/biomass energy/architecture.

(RWL): I am pleased to hear about the WHO "proposals" Is it premature to
hear about them?

>(ii) Aprops G8 Summit. As the name implies. It works in an extremely
>rarefied atmosphere. I am not at all surprised that there was no mention of
>stoves in the meeting. Ron, I bet you wouldn't have heard of it even, if the
>meeting had not taken place at Denver, CO. I personally would not spend any
>effort let alone a sleepless night on such shenanigans.

(RWL): You are of course right. There was brief mention today that the
final communique does states a commitment to do something about children's
health - but it was not elsewhere detailed. i suppose it makes sense to do
this through WHO.

>
>(iii) Ron, you raised a question about my list of questions on stoves in
>response to a comment from me on Paul Hait's list sometime back. It is
>available in the archives of June 1996. I am almost sure apart from these two
>lists, there were others. One of these days, if I'm able to trace the other
>lists, I shall try and produce a comprehensive list.

(RWL): If anyone can find this and replace Prasad's comments back on the
list, it would be helpful to all. We are now about 4 times bigger
probably. I have lost my files from that period.

>
>(iv) Charcoal business: Ron, if you want a genuine argument about charcoal, it
>is well nigh impossible. An apoplectic response, if you wish to get it, you
>should correspond with <snip> Waclaw Micuta <snip> You will get an
>earful about the criminality of using charcoal.

(RWL): I will try to make this connection. But it would be much easier if
Waclaw was able to respond through the net. Does anyone on this list also
reside in Geneva? I have been impressed by material he has writen on
stoves - but had forgotten that he was so strong against charcoal. I am
only (at this time) against the current methods of making charcoal - not so
much against its manner of use. Do you (or anyone) know the details of the
"criminality"?
This is a thread that we should wring out.

>
>(v) Apropos Rogerio's offer on his willing to try stove ideas, my suggestion
>is that we should all offer him our designs to be tested by him. See next
>point.

(RWL): This can be a huge task. Rogerio - have you the present means to
carry this out?

>
>(vi) I promised to prepare a draft of Joint Memorandum on behalf of the
>group to be sent to aid agencies. Maybe Rogerio's offer will galvanise me
>into producing the document. I shall attempt one in the coming ten days or
>so.

(RWL): Thanks for much new information. Is is obvious how groups outside
Europe can contribute to this effort?

regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From english at adan.kingston.net Mon Jun 23 22:57:44 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:22 2004
Subject: Plancha Stove on the web site.
Message-ID: <199706240257.WAA09584@adan.kingston.net>

Dear Stovers
Plancha Stove: There are pictures and text on the stover's web page,
http://www1.kingston.net/~english/Stoves.html

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From elk at arcc.or.ke Tue Jun 24 05:51:40 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Mk1 - boiling
Message-ID: <v01510100afd55988141c@[199.2.222.129]>

Just an observation:

The @can Turbo took 10 min 15 sec. to bring 5.6 L. water from 17'C to a
vigorous boil. Open alu pot.

My home gas stove took 27 min 24 sec. - same pot, same amt. water. On a 8
cm diam. gas ring on 'full'.

I won't try to dwell on efficiencies..... but for a quick cup of tea.....!

------------------------------------

Conversing with my staff about uses for ash:

Mixed with cow dung, the resultant plaster is used for stabilising the
exterior of mud huts as well as floors. A purported beneficial side effect
is that the entire house becomes mosquito repellent. No comment on
behaviour mod. for flies.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From larcon at sni.net Tue Jun 24 10:37:33 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Mk1 - boiling
Message-ID: <v01540b03afd57e2011c1@[204.133.251.12]>

Elsen said:

>The @can Turbo took 10 min 15 sec. to bring 5.6 L. water from 17'C to a
>vigorous boil. Open alu pot.
>
>My home gas stove took 27 min 24 sec. - same pot, same amt. water. On a 8
>cm diam. gas ring on 'full'.
>
>I won't try to dwell on efficiencies..... but for a quick cup of tea.....!
>

(RWL): This is very interesting. Did both stoves have the "convective
shield (gap of 8 mm)" (Trying to ascertain the difference between energy
release and energy transfer.)

Could both stoves drop to the same degree of "very gentle boil"? I
guess a better way of asking this question is "how long a time period could
you take at the smallest primary air setting?" I am trying to ascertain
your "turndown ratio". To get this number requires measuring the max and
min times to finish pyrolyzing the same weight of fuel (assuming it is
relatively uniform over time). The max time is limited by the size of your
air supply, the diameter of the wood, etc. The min time is probably
limited more by flame holding and how tight the primary air supply can be
kept. A better way to mesure this would be some way of monitoring weight of
the fuel batch (excluding the diminishing pan of water) in real time - and
changing the primary air supply up and down every five minutes or so.

I vaguely remember that gas and electric stoves typically have a
design turndown ratio of 3 (or 5?). I believe when I have tried this max
and min time test that I was roughly in the range of 3 (1/2 hour and 1.5
hour) - but I have never done the test very accurately.

The stove literature emphasizes needing to be able to get to low
power levels for efficiency and high power levels to get the cooking (or
tea making) started quickly. If pyrolyzing stoves have some fundamental
limit (say TDR=3) then you might want a smaller max (longer time to get to
a boil), in order to get a more optimum minimum power level. Someone made
such a determination for your gas stove.

Hopefully you have some low priced help to assist in these tests.

To shorten the 10.25 minutes a bit more, it would be interesting to
try a lid (better if it is insulating (wood?)). Next might be better
insulation and more metal layers everywhere. But this can go on forever.

If you ran your gas stove (is this pressurized propane?) flat out
continuously, how many hours use and what cost for what weight? (I'm
really just trying to figure the cost of your 27.75 minute boil.) In the
US, the cost of time would probably greatly exceed the cost of energy - but
not everywhere. The fastest boils I have seen are obtained with electric
immersion heaters.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phait at transport.com Tue Jun 24 11:11:37 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:22 2004
Subject: G-8 final notes
Message-ID: <199706241404.HAA22385@brutus.transport.com>

> Since the word stove never appeared in anything I heard or saw over
>the last three days, I will keep this short. The only positive thing I
>heard of importance to this list was a general agreement by the majority
>that global warming was an issue of importance. The final communique from
>Clinton apparently (it may be in tomorrow's paper) will say that the
>leaders will say something more specific at the Kyoto meeting. The US was
>the biggest holdout at this meeting. The coal industry held a press
>conference here on Friday (I couldn't attend) saying that there was no
>proof of any global warming relationship to their industry.
>
> I attended a similar solar press conference stating just the
>opposite - as the officers announced the creation of "The Solar Century".
>This is a big money effort to promote PV through especially cities. It is
>largely European (British and German predominance), but with some American
>also. I had heard previously about the concerns of insurance companies
>about global warming, but here the President of a large German re-insurer
>(Dr. Rolf Gerling) said that "all" the insurance industry now were
>convinced about global warming. He said that the indexed cost of natural
>hazards attributable to the weather are now 8 times larger than in the
>60's. So they are investing in the solar industry. If anyone knows of
>similar analyses from the insurance industry, I would like to hear them.
>
> The progressive community was here to protest the G-7 agenda. But
>a thousand or so were not enough to even make the back pages of the local
>papers - and only a very few participants were interested in renewable
>energy - and I found none talking about stoves. There would have been 100%
>indignation if any knew about stoves and health in developing countries -
>but I doubt many knew. We still have our work cut out for us - even within
>this community.
>
> Ron
>
>
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>Dear Ronal,
This is the PR issue that I have been refering to.A simple straight forward
letter to the President from the Crest Group[might help in this regard.
Signed by you ,Tom, Roger,Peter,Alex,myself,and others could help.

Sample letter:

Dear President Clinton,

The Number 1 problem in the World is the inefficient burning of natural
fuels Worldwide. This leads to the Number 2 problem which is bad health and
premature death caused by people breathing smoke in their poorly ventalated
homes.The Number 3 problem is bad water and sanitation, and the Number 4
problem is communication of these first three problems to the G*
nations.
Our country is losing a huge opportunity in solving the Top 3 problems by
not bringing them to the forefront in such meetings as the recent G8
session. Global warming caused by what? Maybe the point would get attention
if all the G8 leaders had to live in the home of a fuel deficient family for
one week and experience the hardship they experience on a daily basis. There
are three billion people(half the population) in the World that are rapidly
reaching the natural fuel deficient state.One and a half billion are already
at that point. After experiencing those third world realities, then you
could come back to the good old USA and attend a typical summer barbeque and
watch the host dump 80 Kingsford briquetts into the 22inch Weber kettle to
cook six Hamburgers. 80 briquettes equals 20,000 BTU's of energy. We know
that the same number of Hamburgers can be cooked with 9 briquettes or less
in Pyromids 12 inch stove/grill or 2250 BTU's. We also know that 80
briquettes is enough energy to cook for 80 people in Pyromid's HTA Cell
Super Grill.This a cost of one cent/meal. What is the matter with us when we
don't take advantage of our American Innovation and bring it to the
forefront and start to spread it throughout the World for the benefit of all
mankind.
Vice President Al Gore knows about the Pyromid and both you and he should
become aware of what the Stovers are doing to attacking this huge and
extremely serious world health and environmental problem.
We hope you will take this letter as seriously as you have the Cigarette
Smoking issue because from a health point of view they are identical only on
a much larger scale.
We look forward to demonstrating our stove concepts with you and discussing
in more detail how this problem can be solved. How about a stove conference
in Washington before the next G8 meeting?

Sincerely,

The Stovers'

From Repfirm at aol.com Tue Jun 24 15:07:41 1997
From: Repfirm at aol.com (Repfirm@aol.com)
Date: Tue Aug 31 21:35:22 2004
Subject: O'Kieffe & Merritt Gas Stove
Message-ID: <970624150717_579298491@emout01.mail.aol.com>

I have just aquired an O'Kieffe & Merritt Gas Stove from a home purchase.
The house was built in '23 and from the looks of the stove it's been there
just as long.

It is gas, has an oven, grilling oven (you know - you pull down the door and
this roaster pan looking thing rolls out) and two bottom broilers. I think
one of the broilers' heating elements is not working, I don't know about the
rest. Anyway - I would like to have it restored (repaired, reglazed interior
and exterior, etc. if possible. I am in Dallas Texas and don't know where to
go. How much would this run and is it worth it?

Any info would be greatly appreciated.

Thanks - Janet

From verhaarp at janus.cqu.edu.au Tue Jun 24 17:52:19 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:22 2004
Subject: G-8 final notes
Message-ID: <1.5.4.32.19970624213410.006a4034@janus.cqu.edu.au>

>From Piet Verhaart

To Paul

At 07:04 24/06/97 -0700, you wrote:
>> Since the word stove never appeared in anything I heard or saw over
>
>Dear President Clinton,
>
>The Number 1 problem in the World is the inefficient burning of natural
>fuels Worldwide. This leads to the Number 2 problem which is bad health and
>premature death caused by people breathing smoke in their poorly ventalated
>homes.The Number 3 problem is bad water and sanitation, and the Number 4
>problem is communication of these first three problems to the G*
>nations.
>Our country is losing a huge opportunity in solving the Top 3 problems by
>not bringing them to the forefront in such meetings as the recent G8
>session. Global warming caused by what? Maybe the point would get attention
>if all the G8 leaders had to live in the home of a fuel deficient family for
>one week and experience the hardship they experience on a daily basis. There
>are three billion people(half the population) in the World that are rapidly
>reaching the natural fuel deficient state.One and a half billion are already
>at that point. After experiencing those third world realities, then you
>could come back to the good old USA and attend a typical summer barbeque and
>watch the host dump 80 Kingsford briquetts into the 22inch Weber kettle to
>cook six Hamburgers. 80 briquettes equals 20,000 BTU's of energy. We know
>that the same number of Hamburgers can be cooked with 9 briquettes or less
>in Pyromids 12 inch stove/grill or 2250 BTU's. We also know that 80
>briquettes is enough energy to cook for 80 people in Pyromid's HTA Cell
>Super Grill.This a cost of one cent/meal. What is the matter with us when we
>don't take advantage of our American Innovation and bring it to the
>forefront and start to spread it throughout the World for the benefit of all
>mankind.
>Vice President Al Gore knows about the Pyromid and both you and he should
>become aware of what the Stovers are doing to attacking this huge and
>extremely serious world health and environmental problem.
>We hope you will take this letter as seriously as you have the Cigarette
>Smoking issue because from a health point of view they are identical only on
>a much larger scale.
>We look forward to demonstrating our stove concepts with you and discussing
>in more detail how this problem can be solved. How about a stove conference
>in Washington before the next G8 meeting?
>
>Sincerely,
>
>The Stovers'
>
>
>
It could be worth a try. You obviously don't like the Weber Kettle.
Piet
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From robinski at laplaza.org Tue Jun 24 22:34:14 1997
From: robinski at laplaza.org (Robin Rice)
Date: Tue Aug 31 21:35:22 2004
Subject: O'Kieffe & Merritt Gas Stove
In-Reply-To: <970624150717_579298491@emout01.mail.aol.com>
Message-ID: <199706250232.UAA22240@laplaza.org>

Greetings from Taos.....if you can get a copy of Sunset magazine from
Sept. 96.....it has all of the information you'll need. I know
because i saved it.....i would die for an old stove.....good luck,
Robin in Taos, NM
Also, i have a friend that had an old stove painted and baked... at
an automobile paint place.....blue...some old chevy p/u blue....it is
a gas in his blue and red kitchen......r
Another thought passed through my mind....my brother had a beautiful
home in Palm Springs, Ca. After he sold it with a wonderful old
stove in the kitchen....the new owner had the satillo tiles stripped
and re-sealed in the whole house....at some point the whole house
blew up and burned down to the ground because the pilot was left on
in the wonderful old stove.... when the fumes reached it..it was all
over.

From: Repfirm@aol.com
Date: Tue, 24 Jun 1997 15:07:24 -0400 (EDT)
To: stoves@crest.org
Subject: O'Kieffe & Merritt Gas Stove
Reply-to: stoves@crest.org

I have just aquired an O'Kieffe & Merritt Gas Stove from a home purchase.
The house was built in '23 and from the looks of the stove it's been there
just as long.

Any info would be greatly appreciated.

Thanks - Janet

From krksmith at uclink4.berkeley.edu Wed Jun 25 00:47:38 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:22 2004
Subject: No Subject
Message-ID: <199706250447.VAA19423@uclink4.berkeley.edu>

Below are WHO data on ARI in LDC children.

The WHO report being discussed in these pages last week is called:

Health and Environment in Sustainable Development (242 pages)

In it, among many other things, are the estimates of 3 million deaths from
air pollution, indoor and outdoor. It makes clear that most of these deaths
is from combustion of solid fuels in households for cooking and
spaceheating. (Indeed, it includes our estimates of the mix of household
fuels by region.)

Cost: US$22.50 from WHO, Geneva
Direct fax orders: 41-22-791-4857 with credit card info
Email orders: publications@who.ch (they also have a webpage)

Table x. Annual mortality in developing-country children under 5
(ARI = acute respiratory diseases, mostly pneumonia)

ARI RELATED: 4.1 MILLION
ARI alone: 3.0
ARI with Measles: 0.64
ARI with Pertussis: 0.26
ARI with Malaria or HIV: 0.23

NEO- OR PERINATAL 3.1 MILLION

DIARRHEA RELATED: 3.0 MILLION
Diarrhea alone 2.7
Diarrhea with Measles or HIV 0.27

MEASLES/TB/TETANUS/PERTUSSIS ALONE 1.2 MILLION

MALARIA ALONE 0.68 MILLION

OTHER 0.2 MILLION

TOTAL 12.2 MILLION

From elk at arcc.or.ke Wed Jun 25 05:40:51 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Mk1 - boiling
Message-ID: <v01510100afd6b770b5ff@[199.2.222.135]>

>(RWL): Did both stoves have the "convective
>shield (gap of 8 mm)" (Trying to ascertain the difference between energy
>release and energy transfer.)

Negative- my kitchen stove has no such modification. Heat transfer contact
area is much lower on the gas range than for 2can

>Could both stoves drop to the same degree of "very gentle boil"? I
>guess a better way of asking this question is "how long a time period could
>you take at the smallest primary air setting?"

I have a problem keeping this stove lit at the lowest primary air vent
settings, so the turndown ratio is not so good. At a guess, I'd say that I
could increase the overall burn time by 30% with fiddly adjustments. I am
modifying the stove in two ways now to attempt to correct this:

1) increase the depth of the combustion chamber by 4 cm by adding an
additional ring above the exhaust air vents (I'll cut 10 .5 cm wide by 1 cm
deep stots in the top of this ring to allow some exhaust gas up to the edge
of the inserted pan) This will hopefully allow better combustion due to
larger mixing volume (somebody on the list has suggested this already) and
allow freer exit of gasses.

2) I'll try a grill at the bottom of the pyrolisis chamber above the
primary air vents in order to see if a more even pyrolisis is obtained. My
last few test burns have been unsatisfactory with both ash produced and
some uncarbonised wood at the bottom. Charcoal yeilds have been between 17
and 24% with up to 12% uncarbonised wood. Tests were stopped when the
charcoal began burning to ash. FOM's still in the region of 1kg fuel to
boil off 1 kg water. Fast though!

Sorry, Ron- as the kitchen (propane) stove is not fully my territory, I'll
have to pass up your suggestion that I run the gas burner flat out in a
timed run until a measurable amount of propane is consumed.

Flame holding: Any suggestions? I'm really tempted to try a kerosene fired
pilot light, but that would be overly complex for what we want.

2can Turbo Mk2 should be ready tomorrow.

Regards;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From mike at esd.co.uk Wed Jun 25 06:14:14 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:22 2004
Subject: Charcoal vs wood vs propane
In-Reply-To: <199706210852_MC2-18E5-5E5A@compuserve.com>
Message-ID: <OysyOEASGOszUAnU@esd.co.uk>

Dear Tom,

A quick attempt to answer your query concerning why charcoal is so
popular around the world. A number of factors are at work. First, it
fits well into the traditional cooking patterns of many cultures -
having a fuel which simmers, warms, etc. for long periods of time is a
real premium in many parts of the world.

Second, the prices for propane and other liquid fossil fuels are not
always as low in the developing world as they are in the US. Even when
they are, their quantities are limited by supply networks, by rationing,
etc. Additionally, they are not always suitable to traditional cooking.

Third, wood is not a real option in most urban areas of the world.
Think of people living in densely populated areas, apartments, etc.
trying to keep and use wood. Also, per unit of useful energy, on a
final end use basis, it is much less efficient than charcoal. Charcoal
is easy to store, weighs relatively little relative to its energy
output, and fits into traditional patterns.

Finally, something nearly everyone forgets, there are well-established
markets, distribution networks, etc. for charcoal. It fits the market,
where, in many cases, there are no liquid or gas distribution networks
for households.

It's all fairly straightforward, and it fits into what the West was
doing within this century (particularly if you substitute coal for
charcoal).

Also, charcoal prices tend to be much lower than perhaps they should be
because producers rarely pay the true economic or financial (replacement
price for charcoal. This lowers its price to consumers, who find it a
relatively inexpensive fuel. Work we carried out in Kenya, the Sudan
and Somalia shows that charcoal can be produced sustainably using
improved traditional production methods and good organisational and
marketing systems. This could be true for many parts of the tropical
developing world, particularly if governments would get their energy
pricing systems right.

So, that's a brief summary of why we think people prefer charcoal in
many parts of the world. Cheers, Mike, Overmoor Farm, Wiltshire,
England
--
Mike Bess

From english at adan.kingston.net Wed Jun 25 07:27:42 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Mk1 - boiling
In-Reply-To: <v01510100afd6b770b5ff@[199.2.222.135]>
Message-ID: <199706251127.HAA27462@adan.kingston.net>

snip
> Flame holding: Any suggestions? I'm really tempted to try a kerosene fired
> pilot light, but that would be overly complex for what we want.

Dear Elsen, Ron ect.
When you turn down the primary air, you are also reducing the heat
production in the fuel. You may be walking a fine line on
temperature. It may help your low end flame holding to insulate the
fuel chamber, and/ or the combustion chamber. I have noticed a
difference with my trials. You may be able to do this by mixing some
local clay with clean sand and packing it into the space between your
shield and the stove where you currently preheat your air. Then
drilling out new air holes. Over the life span of you inner metal the
clay mixture would "fire" into a pottery liner that takes over when
your metal wears out. ( That is a suggestion from some local
potters) A new third cylinder/shield could be added to replace the
one which was just filled in. The added mass would add to the stoves
stability. It may also dampen your rapid start up, but hopefully
improve your turn down performance.

There would be a corresponding drop in you
secondary air temperatures from preheating by the combustion
chamber. I think I may have seen problems with excessive preheat on
one of my variations of the venturi arrangement. The secondary air
loosing density to the point where the week chimney can't draw the
necessary volume of hot air containing sufficient O2 to completely
combust the pyrolisis gasses. I doubt this would be a concern for you
until you try to up the velocity of your secondary air jets by using
smaller holes.Any way, I don't see how your relatively short chimney
can significantly drive such a process.

Keep up the good work and telling us all about it.
Looking forward to the pictures. Alex

>
> 2can Turbo Mk2 should be ready tomorrow.
>
>
> Regards;
>
>
> elk
>
> _____________________________
> Elsen Karstad
> P.O Box 24371 Nairobi, Kenya
> Tel:254 2 884437
> E-mail: elk@arcc.or.ke
> ______________________________
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From E.Moerman at stud.tue.nl Wed Jun 25 12:32:40 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can Turbo Mk1 - boiling
Message-ID: <23583.s335192@popserver.tue.nl>

Elk:
> The @can Turbo took 10 min 15 sec. to bring 5.6 L. water from 17'C to a
> vigorous boil. Open alu pot.
>
> My home gas stove took 27 min 24 sec. - same pot, same amt. water. On a 8
> cm diam. gas ring on 'full'.
>
> I won't try to dwell on efficiencies..... but for a quick cup of tea.....!

Etienne:
5.6 l. for a cup of tea? By the way the power output of gas stoves is
usually quite small since they are quite efficient.

Etienne
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From elk at arcc.or.ke Wed Jun 25 13:09:04 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:22 2004
Subject: 2can turbo - Insulation. Also- carbonised sawdust.....!?
Message-ID: <m0wgvYc-0006aXC@arcc.or.ke>

Alex advises:

>It may help your low end flame holding to insulate the fuel chamber, and/
or >the combustion chamber.

I'll insulate. Makes sense. Maybe ferro-cement plaster onto loose chicken
wire around the fuel chamber.

Thanks!

--------------------------------------------

115 kg briquettes produced using the discarded dust/fines from a charcoal
vendor's mound yesterday. Team of two. Very good for their 2nd day in operation.

My carbonised sawdust is still jamming the manual briquetter. Appearances
are good, carbonisation of this, the second batch, seems complete (crumbles
smoothly between fingers), but the friction in the briquetter barrel is
still to great. Though this 2nd batch material can be extruded, unlike the
first 'half baked' batch which simply siezed up the machine, friction in the
barrel is still too great, and the apparatus vibrates upon expelling the
compacted carbonised sawdust. This breaks up the briquette on exit. In
addition, much more force is required to operate the briquetter. Extra water
seems to make it worse, not better.

The charcoal fines collected from vendor's sites does not do this. Niether
does hammermilled charcoal or hammermilled sawdust charcoal.

What gives? Most frustrating.

Any suggestions or advice, stovers?

elk

From krksmith at uclink4.berkeley.edu Wed Jun 25 22:41:30 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:22 2004
Subject: Deaths from indoor air pollution in China
Message-ID: <199706260241.TAA24608@uclink4.berkeley.edu>

The cover article in this month's issue of the journal, Environmental
Science and Technology, by Keith Florig (Carnegie-Mellon U) uses our China
IAQ Database to calculate the total disease impact of air pollution (indoor
and outdoor) in China. Comes up with more than 1 million deaths per year,
90+% from indoor exposures.

From mike at esd.co.uk Wed Jun 25 23:12:12 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:22 2004
Subject: Household Charcoal Prices
Message-ID: <3+88NEAT$SszUAA2@esd.co.uk>

ear Members,

I am trying to update some work I did several years ago on international
charcoal prices in an attempt to compare their changes relative to
fossil fuels and electricity. This is all part of a on-going economic
analysis of the costs, and benefits, of woody biomass relative to other
fuels. I have long-term charcoal prices for Kenya, Ethiopia and Uganda,
and spot prices from other parts of the world. However, the latter
prices are out of date.

I would be very pleased if anyone could provide me with charcoal prices,
retail or wholesale to enable me to update my comparisons. I'll provide
my results and some first-cut updated analysis as soon as possible.
Thanks, mike@esd.co.uk
--
Mike Bess

--
Mike Bess

From elk at arcc.or.ke Thu Jun 26 05:21:32 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
Message-ID: <v01510100afd7e70e6ead@[199.2.222.131]>

In response to Mike Bess' request on pricing:

One approx. 50 kg bag currently costs:

- Rural, in or near production areas (no transport element) $ 3.27 per bag

- Urban (Nairobi) $ 4.91 per bag

- Briquetted from the only commercial briquetter - KPPCU coffee husk
charcoal -
(when available) $ 6.36 per bag

Rgds;

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From prasad at tn7.phys.tue.nl Thu Jun 26 09:05:33 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:23 2004
Subject: Wood combustion
In-Reply-To: <199706211634.MAA23105@adan.kingston.net>
Message-ID: <9706261255.AA16706@tn7.phys.tue.nl>

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From mike at esd.co.uk Thu Jun 26 15:34:03 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <v01510100afd7e70e6ead@[199.2.222.131]>
Message-ID: <OwoSOBAAHsszUAna@esd.co.uk>

Dear Elsen,

Thanks for the information on charcoal in Kenya. That means prices are
around Ksh 250 per bag in Nairobi, for about Ksh 5-6 per kilogram. This
means, in real terms, that the price of charcoal is still less than it
was ten years ago, which is the same situation we find in Ethiopia,
Tanzania, Malawi and Uganda.

One of the main reasons for keeping track of these prices is that it
shows that fuel price is not THE driving force for people buying new
stoves. The relative price of charcoal (price of charcoal compared to
all other commodities and services) has fallen in almost every urban
area we have studied. That doesn't mean people don't see an increase
and don't think prices are higher.

What it does mean is that buying new energy efficient stoves is driven
by several other factors, and not just price as we so often hear. Our
experience in Ethiopia, where over 300,000 improved charcoal stoves have
been sold since 1992, and where over 17,000 wood biomass stoves (for
injera baking) have sold since 1995, is that people buy the stoves
because of:

* modern,
* new,
* attractive
* safe
* reduces smoke
* saves fuel

in that order of priority. But, price is still important, so, we try to
keep up to date with charcoal prices from all over the world. Any more
assistance on world charcoal prices would be very welcome. Cheers, Mike
--
Mike Bess

From english at adan.kingston.net Thu Jun 26 17:02:27 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <v01510100afd7e70e6ead@[199.2.222.131]>
Message-ID: <199706262102.RAA20043@adan.kingston.net>

snip
> Our
> experience in Ethiopia, where over 300,000 improved charcoal stoves have
> been sold since 1992, and where over 17,000 wood biomass stoves (for
> injera baking) have sold since 1995, is that people buy the stoves
> because of:
>
> * modern,
> * new,
> * attractive
> * safe
> * reduces smoke
> * saves fuel
snip
> Mike Bess
>
Dear Mike or others

If you have any pictures or information on these new stoves ( ex.
cost, style, performance), please send it along.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From jswear at laplaza.org Thu Jun 26 17:57:53 1997
From: jswear at laplaza.org (Jon L. Swearingen)
Date: Tue Aug 31 21:35:23 2004
Subject: G-8 final notes
In-Reply-To: <1.5.4.32.19970624213410.006a4034@janus.cqu.edu.au>
Message-ID: <Pine.SGI.3.95.970626154251.22363B-100000@laplaza.org>

On Wed, 25 Jun 1997, Peter Verhaart wrote:

> >From Piet Verhaart
>
> To Paul
>
> At 07:04 24/06/97 -0700, you wrote:
> >> Since the word stove never appeared in anything I heard or saw over
> >
> >Dear President Clinton,
> >
> >The Number 1 problem in the World is the inefficient burning of natural
> >fuels Worldwide. This leads to the Number 2 problem which is bad health and
> >premature death caused by people breathing smoke in their poorly ventalated
> >homes.The Number 3 problem is bad water and sanitation, and the Number 4
> >problem is communication of these first three problems to the G*
> >nations.
> >Our country is losing a huge opportunity in solving the Top 3 problems by
> >not bringing them to the forefront in such meetings as the recent G8
> >session. Global warming caused by what? Maybe the point would get attention
> >if all the G8 leaders had to live in the home of a fuel deficient family for
> >one week and experience the hardship they experience on a daily basis. There
> >are three billion people(half the population) in the World that are rapidly
> >reaching the natural fuel deficient state.One and a half billion are already
> >at that point. After experiencing those third world realities, then you
> >could come back to the good old USA and attend a typical summer barbeque and
> >watch the host dump 80 Kingsford briquetts into the 22inch Weber kettle to
> >cook six Hamburgers. 80 briquettes equals 20,000 BTU's of energy. We know
> >that the same number of Hamburgers can be cooked with 9 briquettes or less
> >in Pyromids 12 inch stove/grill or 2250 BTU's. We also know that 80
> >briquettes is enough energy to cook for 80 people in Pyromid's HTA Cell
> >Super Grill.This a cost of one cent/meal. What is the matter with us when we
> >don't take advantage of our American Innovation and bring it to the
> >forefront and start to spread it throughout the World for the benefit of all
> >mankind.
> >Vice President Al Gore knows about the Pyromid and both you and he should
> >become aware of what the Stovers are doing to attacking this huge and
> >extremely serious world health and environmental problem.
> >We hope you will take this letter as seriously as you have the Cigarette
> >Smoking issue because from a health point of view they are identical only on
> >a much larger scale.
> >We look forward to demonstrating our stove concepts with you and discussing
> >in more detail how this problem can be solved. How about a stove conference
> >in Washington before the next G8 meeting?
> >
> >Sincerely,
> >
> >The Stovers'
> >
> >
> >
> It could be worth a try. You obviously don't like the Weber Kettle.
> Piet
> Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
> Phone: +61 79 331761 Fax: +61 79 331761 or 332112
> E-mail:p.verhaart@cqu.edu.au
>
> --
> Peter Verhaart <verhaarp@janus.cqu.edu.au> -- anyone
>
Hey, and here in Northern New Mexico we have an old and proud
wood-burning tradition which nobody seems to notice also requires
lots of gasoline to get to the wood and carry it home, also for the
saw. The Patrones are ignoring the possible benefits of the Earthship
which could help poor little senior citizens from losing their land as
they pay those fuel bills to death. It's Lead, Follow, or Get the Hell out
of the Way....(Or get yer butt ran over).
To my mind, the G-8 is simply a pre-War planning session, with
the most important decisions made far away from reporters and
cameras. I'm going to go see the Swami tonight and try to tune myself more
positive....

From english at adan.kingston.net Thu Jun 26 20:51:43 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Pyromid Improved ?&#~!
Message-ID: <199706270051.UAA26992@adan.kingston.net>

Dear Mr. Doe

We just finished firing up the new Pyromid (15) and knew you were
waiting for design input.

Idea numero uno.--
---- for smoke free wood fired grilling-----
Suspend a cone (or pyramid shape will do in a pinch) from the centre
of your grill, ( you will need to stamp a small hole there) this
will funnel the smoke to a tiny swirl venturi sitting on top of the
grill. This will have provision for another pot perched on top.

Yours Radiantly

Alex
P.S. We used the charcoal from our "cone and pail" tests. With this
fuel the Pyromid was truly a rapid cooker.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From rmiranda at sdnnic.org.ni Thu Jun 26 23:32:00 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:23 2004
Subject: Plancha Stove on the web site.
Message-ID: <199706262134.VAA09454@ns.sdnnic.org.ni>

Dear Alex: I just got back from Toronto, Ontario. Great country you are.

Great job putting the stoves pictures on the web. Thanks. I will feed you
with more info and images about the plancha stove in the near future.

Rogerio
==========================================

At 10:56 PM 6/23/97 -0500, you wrote:
>Dear Stovers
>Plancha Stove: There are pictures and text on the stover's web page,
>http://www1.kingston.net/~english/Stoves.html
>
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927
>Stoves Web Site http://www1.kingston.net/~english/Stoves.html
>
>
--------------------------------------------------------------------------
Rogerio Carneiro de Miranda Telefax: (505) 276 0555
PROLENA(Nicaragua)
Apartado Postal C-321 Managua Nicaragua
E-mail: rmiranda@sdnnic.org.ni
-------------------------------------------------------------------------

From larcon at sni.net Fri Jun 27 00:09:51 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:23 2004
Subject: Plancha Stove on the web site.
Message-ID: <v01540b01afd8808b8e8f@[204.133.251.6]>

Alex: said:
>Plancha Stove: There are pictures and text on the stover's web page,
>http://www1.kingston.net/~english/Stoves.html

Alex: I finally got my first chance to look at your web site. Very
nice added service for the "stoves" list. Thank you for doing this. I now
have a better (still not perfect) perception of your tests.

Rogerio: You clearly have a much improved stove over the stove you
are replacing.

I think it is possible to modify a two-can stove to slide the lower
(fuel - pyrolyzing) can in at the lowest level. The upper combustion "can"
would then be the built in the adobe firebox structure where you are now
combusting the wood.
I think the main difficulty will be finding a way to cleanly
"snuff" the pyrolysis when the pyrolysis is complete.
My hope would be that your users would find it more convenient
because they could better control the power level. What can you say about
the present ability to get and keep a specific power level?
I think the cost could go down a bit, because you would not have
the cost of a door.

Approximately what length of cooking time should one strive for in
Nicaragua ? How many kg wood per hour are presently consumed? Is there a
big difference between the desirable maximum (to achieve a rapid boil) and
minimum rates of consumption? Is this achieved by control of the door
opening?

Piet: Thanks also for sending your photos in. What have you
observed with different slit spacings?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phoenix at transport.com Fri Jun 27 02:10:16 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:23 2004
Subject: Plancha Stove on the web site.
Message-ID: <199706270612.XAA19549@spanky.transport.com>

Alex

Would you please tell us the components of the fine video picturing system
you are using to put your pictures of your stoves on your web site? Please
include the software and image manipulation components as well.

Thank you!

Art Krenzel

----------
> From: Rogerio Carneiro de Miranda <rmiranda@sdnnic.org.ni>
> To: stoves@crest.org
> Subject: Re: Plancha Stove on the web site.
> Date: Thursday, June 26, 1997 2:34 PM
>
> Dear Alex: I just got back from Toronto, Ontario. Great country you are.

>
> Great job putting the stoves pictures on the web. Thanks. I will feed
you
> with more info and images about the plancha stove in the near future.
>
> Rogerio
> ==========================================
>
>
>
> At 10:56 PM 6/23/97 -0500, you wrote:
> >Dear Stovers
> >Plancha Stove: There are pictures and text on the stover's web page,
> >http://www1.kingston.net/~english/Stoves.html
> >
> >Alex English
> >RR 2 Odessa Ontario
> >Canada K0H 2H0
> >613-386-1927
> >Stoves Web Site http://www1.kingston.net/~english/Stoves.html
> >
> >
>
--------------------------------------------------------------------------
> Rogerio Carneiro de Miranda Telefax: (505) 276 0555
> PROLENA(Nicaragua)
> Apartado Postal C-321 Managua Nicaragua
> E-mail: rmiranda@sdnnic.org.ni
> -------------------------------------------------------------------------

From english at adan.kingston.net Fri Jun 27 07:28:07 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Video 'Snapper'
In-Reply-To: <199706270612.XAA19549@spanky.transport.com>
Message-ID: <199706271128.HAA08493@adan.kingston.net>

Dear Art and Stovers

The images are captured with a device called ' Snapper'. It comes
with its own software pack (There were some problems but there
is a "patch" that you can download from their website that seems to
have done the trick.) which includes a simpler version of Adobe
Photoshop for image manipulation. This is on Brians computer next
door, when I get the images I usually resize them on Paint Shop Pro,
a downloadable shareware version.

Snapper samples a series of video frames, so it does not capture a
clear image of a fast moving subject. I may have to use a film camera
to get the image I want of the swirling venturi flame.

Alex

> Alex
>
> Would you please tell us the components of the fine video picturing system
> you are using to put your pictures of your stoves on your web site? Please
> include the software and image manipulation components as well.
>
> Thank you!
>
> Art Krenzel

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Fri Jun 27 07:28:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Plancha Stove on the web site.
In-Reply-To: <v01540b01afd8808b8e8f@[204.133.251.6]>
Message-ID: <199706271128.HAA08498@adan.kingston.net>

Dear Ron and stovers

There are about 180 countries in the world with people speaking
countless languages, but they all see with similar eyes. I hope
that some day, this new medium will help to disseminate useful
ideas to the folks with basic unmet needs. Perhaps it is a worthy
goal for this page.

Alex

> Alex: I finally got my first chance to look at your web site. Very
> nice added service for the "stoves" list.

From bburt at limestone.kosone.com Fri Jun 27 07:35:37 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:23 2004
Subject: Video 'Snapper'
Message-ID: <199706271136.HAA25458@mercury>

> Snapper samples a series of video frames, so it does not capture a > clear image of a fast moving subject. I may have to use a film camera > to get the image I want of the swirling venturi flame.> > Alex Actually the video capture tool is called Snappy made by a company called Play INC.(kind of reminds you of stovers eh!)Brian

From mike at esd.co.uk Fri Jun 27 08:35:13 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <199706262102.RAA20043@adan.kingston.net>
Message-ID: <4rOvoAAYx3szUAR7@esd.co.uk>

>Dear Mike or others
>
>If you have any pictures or information on these new stoves ( ex.
>cost, style, performance), please send it along.
>
>Alex
>Alex English
Dear Alex,

We do have pictures, many of them on CD. Can you handle a graphics file
if I download on the Net? If so, what format can you handle. If not,
we can send you several copies. Cheers! Mike

--
Mike Bess

From zourarakis at nosapp.nr.state.ky.us Fri Jun 27 09:11:10 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:23 2004
Subject: G-8 final notes
Message-ID: <97062709091417@nosapp.nr.state.ky.us>

Stovers' (RE: your hypothetical letter):

I have a problem with point 3: "bad water"? Bad quality or bad quantity or both?
How does this relate to 1 and 2? One of my activities is to work on nonpoint sou
rce pollution projects. Are you referring to water contaminated with what???

I think that expanding the discussion of bad air quality to bad water weakens
the letter, unless you make the connection explicit.

Cheers.

Demetrio.

Demetrio P. Zourarakis, PhD

From elk at arcc.or.ke Fri Jun 27 09:17:36 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:23 2004
Subject: FOM (efficiency)
Message-ID: <v01510100afd99788a80d@[199.2.222.150]>

Ron;

A while back you mentioned a FOM efficiency of 2 as an objective (2 kg
water boiled off for 1 kg fuel wood)- is this applicable to a charcoal
producing stove? If not, considering the energy value of residual charcoal,
what would the equivalent be for a 2can?

I've not managed to do better than 25% charcoal production recently & my
FOM is around 1 consistantly- all with the 2can Turbo Mk1. The Mk2 version
is experiencing some developmental delays. First fire tomorrow.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From english at adan.kingston.net Fri Jun 27 09:59:47 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <199706262102.RAA20043@adan.kingston.net>
Message-ID: <199706271400.KAA12110@adan.kingston.net>

>> Dear Alex,
>
> We do have pictures, many of them on CD. Can you handle a graphics file
> if I download on the Net? If so, what format can you handle. If not,
> we can send you several copies. Cheers! Mike

Dear Mike +
There is a long list of file types that Paint Shop Pro, an therefore
I, can handle. *.jpg is what I will eventually save them as.
*.tif, *. gif , *. bmp, *. pcx, are some of the most common that I
have worked with.

Send me something directly, to my email address (
english@adan.kingston.net), and attach your graphics files. Less
than 1MB at a time and I'll let you know how I make out.

Alex

> --
> Mike Bess
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From mike at esd.co.uk Fri Jun 27 10:58:55 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <4rOvoAAYx3szUAR7@esd.co.uk>
Message-ID: <AgDR6DAsJ8szUAmN@esd.co.uk>

In message <4rOvoAAYx3szUAR7@esd.co.uk>, Mike Bess <mike@esd.co.uk>
writes
>>Dear Mike or others
>>
>>If you have any pictures or information on these new stoves ( ex.
>>cost, style, performance), please send it along.
>>
>>Alex
>>Alex English

Dear Alex,

I also forgot to mention that we do have considerable information on the
charcoal and wood stoves in Ethiopia. I can attach a couple of reports
to an email if you are able to handle fairly large files and you can
read in Word. Let me know if you can, and I will send them on. Mike
--
Mike Bess

From english at adan.kingston.net Fri Jun 27 13:18:52 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: 'elk works' on the web
Message-ID: <199706271718.NAA18322@adan.kingston.net>

Dear Stovers
The pictures that Elsen sent are now on the Stovers Web Site.
Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Fri Jun 27 13:23:07 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal Prices- Kenya
In-Reply-To: <4rOvoAAYx3szUAR7@esd.co.uk>
Message-ID: <199706271723.NAA18505@adan.kingston.net>

Dear Mike

Yes I can handle Word files.
They aren't likely to be bigger than most graphics files. I have
received attachments in the many mega byte size range but my internet
provider has discouraged that. So send it along and we will see what
happens.
Alex
> Dear Alex,
>
> I also forgot to mention that we do have considerable information on the
> charcoal and wood stoves in Ethiopia. I can attach a couple of reports
> to an email if you are able to handle fairly large files and you can
> read in Word. Let me know if you can, and I will send them on. Mike
> --
> Mike Bess
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From BeedieD at Cardiff.ac.uk Fri Jun 27 13:30:53 1997
From: BeedieD at Cardiff.ac.uk (David Beedie)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal and CO
Message-ID: <25D6CBB1A99@nrd1s.cf.ac.uk>

Etienne, owing to a massive backlog of messages in my mailbox waiting
to be read - mostly from the prolific stoves authors - I have only
just got to your week-old reply ...

> David B.:
>
> > In my measurements of such things in a batch-loaded gasifier-
> > combustor, the CO increase also coincided with increasing Excess Air
> > Value of combustion and hence falling combustion temperatures. I
> > don't know whether or not the 2CO+O2 <> 2CO2 equilibrium is moved to
> > the right or the left by higher temperatures, but the reaction rate
> > should increase exponentially with increasing temperature. High
>
> Etienne:
> We obsereved the same effect of excess air on CO.

David B.: That's reassuring. I observed the rate of increase of CO
with time to be very dramatic - much more so than the rate of
temperature fall - which is qualitatively consistent with the expected
exponential relationship. Did you also get this effect?

> For high temperatures the production of CO2 is favoured as long as
there is
> sufficient O2.

> David B.:
> > of the reaction rate seems an obvious possibility ? Do most
> > stoves end up with far too high Excess Air Values once they're into
> > the pure char combustion phase ? They might produce lots of CO for
> > this reason - the gases don't stay hot enough for long enough.
>
> Etienne:
> This is indeed observed in our lab, but not only for pure char combustion,
> but also for volatile combustion we measured high CO for high excess air.

Me too. My control system usually prevented out-of-range values of
excess air during volatile combustion so this was not seen. Control
was most critical as fuel 'exhaustion' - i.e. complete carbonisation -
approached.

Another interesting effect I noticed occasionally in gusty conditions
was that large CO impulses would come and go equally dramatically.
Although the cause could not be seen as corresponding changes in the
measured excess air value, corresponding rapid fluctuations COULD be
seen in the combustion temperature. This probably showed that there
really were large excess air value fluctuations which were not seen
owing to the slower response times of the O2 and CO2 sensors.

Dave.

> Etienne
> ---------------------------------------------
> Mr. Etienne Moerman E.Moerman@stud.tue.nl
> Joh. Buyslaan 71 tel. +31-40-2571491
> 5652 NJ EINDHOVEN The Netherlands
>
*******************************************************
(Dr) David Beedie
School of Engineering, University of Wales, Cardiff, UK

email: BeedieD@cardiff

Office Tel. 01222 874683; 874000 ext.5927(lab.)
Office FAX: 01222 874420 - mark for my attention !
Home tel: 481424 (temporary number ...)
*******************************************************

From english at adan.kingston.net Fri Jun 27 22:11:59 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:23 2004
Subject: Lakech Charcoal Stove
Message-ID: <199706280212.WAA00629@adan.kingston.net>

Dear Stovers

Mike Bess has sent some pictures, two of which are now on the web
site. Some text and additional pictures will be added early next
week.

Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From rmiranda at sdnnic.org.ni Sat Jun 28 00:10:20 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:23 2004
Subject: Plancha Stove on the web site.
Message-ID: <199706272212.WAA04589@ns.sdnnic.org.ni>

RWL> wrote:
>
> Rogerio: You clearly have a much improved stove over the stove you
>are replacing.
>
> I think it is possible to modify a two-can stove to slide the lower
>(fuel - pyrolyzing) can in at the lowest level. The upper combustion "can"
>would then be the built in the adobe firebox structure where you are now
>combusting the wood.
> I think the main difficulty will be finding a way to cleanly
>"snuff" the pyrolysis when the pyrolysis is complete.
> My hope would be that your users would find it more convenient
>because they could better control the power level. What can you say about
>the present ability to get and keep a specific power level?
> I think the cost could go down a bit, because you would not have
>the cost of a door.
>
RCM> Ron, what 2-can stove are you mentioning ? Could you refresh my
memory about it? Is that like your charcoal making stove ?

RWL> Approximately what length of cooking time should one strive for in
>Nicaragua ? 40 to 60 minutes
How many kg wood per hour are presently consumed? ?????????????
Is there a big difference between the desirable maximum (to achieve a rapid
boil) and
>minimum rates of consumption? ???????????????
Is this achieved by control of the door opening? also, but mostly the women
traditinaly uses more or less wood to achieve higher energy outputs.

RCM> We should further consulte with Juan Carlos Flores. he is the director
of this project in Honduras, and so he can be more accure with this info.
Observe that the plancha stove pictures are from the Honduran project that
has been running for 2 years now..

Juan Carlos> Can you participate in this discussion and please gather and
help us with the missing info about the operation of the plancha stove ?

Thanks

From phait at transport.com Sat Jun 28 13:15:27 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:23 2004
Subject: 'elk works' on the web
Message-ID: <199706281717.KAA05022@brutus.transport.com>

>Dear Stovers
>The pictures that Elsen sent are now on the Stovers Web Site.
>Alex
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927
>Stoves Web Site http://www1.kingston.net/~english/Stoves.html

>Dear stovers, 6/28/97

I find it very exciting to see the remarkable efforts that are being made by
Alex and others to find an ANSWER to the stove enigma. Have we ever been
exposed to a problem with more variables and unknowns? The first variable
being peoples opinions and customs; and the rest being such things as
different fuels,different moistures,different configurations,different fuel
arrangements,different elevations,different methods of
distribution,different economic conditions,different raw material
sources,different governments,etc,etc,.

Snipit!
At a recent meeting at Coleman, I was told by the President that they intend
to solve the stove problem by BUTINIZING the world????? As some of you may
already know Coleman moved to Colorado and then moved back to Wichita. The
President is gone and I doubt they are going to solve the Worlds Stove
problem with Butane.

I believe we are all suffering from an advanced case of COMPLEX SIMPLICITY.
When I think about life I am amazed at how SIMPLE it is, yet man by nature
makes it COMPLEX. Look at our tax system as an example. Look at our legal
systems.If we had a national sales tax and abided by the Golden Rule life
would be a lot simpler and more productive. What I am getting at is that the
stove problem should be simplified to as few elements as possible. Use the
heat up, use the heat down,and control the air flow to a burning mass of
fuel organized in a Harmonic Thermal Array and restrict the expanding hot
gases long enough to burn most of the primary and secondary gases. Here I go
again.

One million years ago man started a very bad habit. He randomly dumped fuel
into a black hole and burned it at less than 10% efficiency. As a result of
this bad habit we have almost destroyed the World. Today we have answers to
solve this problem yet communication,economics, egos, ignorance, apathy,
greed,and availability of raw materials continues to hamstring getting at
the answer. Stovers need to unit Worldwide under one banner with a
foundation that has as its sole goal to communicate the simplest and most
efficient answers to solving this problem. In short we need to set up a fund
to communicate the urgency of the problem and then deseminate official
design and performance data to those countries that have the biggest needs.
All those interested in setting up this foundation please make yourself
heard. With the right people like Ronal,Tom,Peter,Alex,Rogerio etc.sitting
on a board and properly managing funds from
governments,foundations,companies,and concerned private individuals this
problem would get solved a heck of a lot faster. This R&D Stovers' mutual
admiration society has to focus its fire or we will wind up being as
inefficient as fuel randomly dumped into a black hole. By organizing the
Stovers into a Harmonic Human Array and backing them up with a positive
mental(local ,state,and governmental) attitude and igniting them with the
dream of finding a SIMPLE solution to this COMPLEX problem and then letting
their individual talents feed back on one another, while being given proper
recognition and resources, they should be far more capable of directing
their talents to the target which is finding the best stove solution.The
Stovers board would try to manage this directed human energy system for
productive answers.WHEW!!! COMPLEX-SIMPLICITY?

Ronal,Tom,Alex,Peter,Tom Jr.,Roger,,and others am I nuts or does this
proposal make any sense? Pyromid would be interested in hosting a get
together here in Central Oregon for a small group. Travel and accommodations
would be up to you, but I would think that Oregon might help out or even our
regional economic people or your own governments or states if they were told
how important this problem is and how it is about time it comes to the
forefront and gets proper PR support and funding. Smoke in homes is killing
a lot more people than AIDS.
I look forward to the response to this email. Also , Alex, nice going on the
Stove pictures and I hope you are enjoying your 15 inch Pyromid. Thank you
for the order!

Sincerely,

Paul W. Hait
President
Pyromid Inc.
phait@transport.com
541.5933505
fax541.9231004

From bburt at limestone.kosone.com Sat Jun 28 13:32:42 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:23 2004
Subject: 'elk works' on the web
Message-ID: <199706281733.NAA27947@mercury>

heat up, use the heat down,and control tflow to a burning mass of> fuel organized in a he air Harmonic Thermal Array and restrict the expanding hot> Sincerely,> > Paul W. Hait> President> Pyromid Inc.> phait@transport.com> 541.5933505> fax541.9231004 > > Could you please define what a " Harmonic Thermal Array " is.I would disagree with the necessity of a central meeting being a requirement to solve this or any problem given the advent of the "information highway". Resources might better be spent on the likes of Alex's Web page with a accumulation of concrete data to build on. Peter Drucker defines entrepreneurship as the recombining of inputs to yield a new higher result. Lets try and to a new paradigm making maximum advantage of the WWW and e-mail.BrianBrian BurtBurt's GreenhousesPhone 613-386-3426 Fax 613-386-1211e-mail bburt@limetone.kosone.com

From larcon at sni.net Sat Jun 28 23:24:33 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:23 2004
Subject: Rogerio on Plancha Stove.
Message-ID: <v01540b01afdadc61dc9d@[204.133.251.8]>

Rogerio asked (relative to my comments on modifying his Plancha design)

>RCM> Ron, what 2-can stove are you mentioning ? Could you refresh my
>memory about it? Is that like your charcoal making stove ?

(RWL): Yes - the same. I used the term "two-can" because it was the
name useded by Elsen Karstad in his tests. With a Plancha - the term
"two-can" should probably not be used since there would be only one lower
"can". The pyrolyzing principles would not change at all; the secondary
air inlet space between the lower fuel can and the upper combustion chamber
would have to be designed with standard fuel "can" sizes in mind.

Rogerio also said:

>Juan Carlos> Can you participate in this discussion and please gather and
>help us with the missing info about the operation of the plancha stove ?

(RWL): I would also like to hear more about how the Honduras and
Nicaragua operations are inter-related - and the type of testing and
consumer acceptance programs that are being conducted.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Sat Jun 28 23:24:34 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:23 2004
Subject: FOM (efficiency)
Message-ID: <v01540b00afdb4b2c50c8@[204.133.251.8]>

On June 27, Elsen said:

>Ron;
>
>A while back you mentioned a FOM efficiency of 2 as an objective (2 kg
>water boiled off for 1 kg fuel wood)- is this applicable to a charcoal
>producing stove?

Yes. The rationale is as follows:

1. The input energy (Ui) = energy in charcoal (Uc) + evaporation (Ue)
+losses (Ul)

2. Ui is approximately 17 - 18 MJ/kg (depending on moisture content -
assume 17.33 for convenience) times weight of fuel (Wf)

3. Uc is approximately 30 MJ/kg times charcoal-weight-making-efficiency
(about 25%).

4. Ue is the weight of water evaporated (Ww) times (the heat of
vaporization hfg (about 2.26 MJ/kg) plus the specific heat (cf = .0042
MJ/kg-K) times the temperature difference (about 80K)). If (for
simplicity) all water raised to 100C is evaporated, and FOM = Ww/Wf, then:

Ue = Ww * (2.26+.34) = Wf * FOM * 2.6

5. Ul is everything else (energy lost in hot charcoal, unburned gases, hot
exhaust gases, water heated but not evaporatied, stove parts and pot
heat-up, and radiated heat losses).

6. Dividing through by the input energy to get efficiencies, we get:

1 = Nc + Ne + Rl, where

Nc = 0.25* 30/17.33 = .43 (43% energy left in charcoal)

Ne = FOM * 2.6/17.33 = FOM *.15

Rl = loss ratio

So, with your FOM =1, then 15% of the input energy is going toward
evaporation. Dividing by 1-.43 = .57, means that you have a stove of
conventional character about .15/.57 = 26% efficiency. With FOM = 2, the
conventional efficiency would be 52% - very high for a cook stove. But
such an efficiency (or FOM) is still well less than that for modern gas
water heaters.

To get from FOM =1 to FOM =2 will require especially better
insulation and better heat transfer to the water pot. Maybe your Mark II
(today?) will help show the way. I want to try a tall water jacket
(central "flue") approach - but that will only be helpful for heating or
evaporating water - not for general cooking.

So FOM =2 will be difficult - but I think not impossible - with 25%
charcoal production. I believe the correct efficiency to report at an
FOM=2 would then be N1+N2 = .43+.3 = .73 (73%). At FOM=1, you are now at
about 0.43 + 0.15 = .58 - a lot better than most uses of wood. Of course,
this overstates the efficiency for cooking a lot - since we are not
including the efficiency (about 25%) of later cooking with the manufactured
charcoal. But if you assume that charcoal will continue to be used, either
FOM=1 or FOM=2 are a big improvement over the FOM=0 and 15% by weight
production efficiency that is the present norm.

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From phait at transport.com Sun Jun 29 02:43:19 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:23 2004
Subject: 'elk works' on the web
Message-ID: <199706290645.XAA18731@brutus.transport.com>

>heat up, use the heat down,and control tflow to a burning mass of
>> fuel organized in a he air Harmonic Thermal Array and restrict the
>expanding hot
>> Sincerely,
>>
>> Paul W. Hait
>> President
>> Pyromid Inc.
>> phait@transport.com
>> 541.5933505
>> fax541.9231004
>>
>>
>
>
>Could you please define what a " Harmonic Thermal Array " is.
>
>I would disagree with the necessity of a central meeting being a
>requirement to solve this or any problem given the advent of the
>"information highway". Resources might better be spent on the likes of
>Alex's Web page with a accumulation of concrete data to build on.
>
>Peter Drucker defines entrepreneurship as the recombining of inputs to
>yield a new higher result. Lets try and to a new paradigm making maximum
>advantage of the WWW and e-mail.
>
>Brian
>
>Brian Burt
>Burt's Greenhouses
>Phone 613-386-3426 Fax 613-386-1211
>e-mail bburt@limetone.kosone.com<html><head></head><BODY
bgcolor="#FFFFFF">heat up, use
the heat down,and control tflow to a burning mass of > fuel organized
in a he air Harmonic Thermal Array and restrict the expanding hot >
Sincerely, > > Paul W. Hait > President > Pyromid
Inc. > phait@transport.com > 541.5933505 > fax541.9231004   >
   > Could you please define what a "
Harmonic Thermal Array " is. I would disagree with the necessity
of a central meeting being a requirement to solve this or any problem given
the advent of the "information highway". Resources might better be
spent on the likes of Alex's Web page with a accumulation of concrete data
to build on. Peter Drucker defines entrepreneurship as the
recombining of inputs to yield a new higher result. Lets try and to a new
paradigm making maximum advantage of the WWW and
e-mail. Brian Brian Burt Burt's Greenhouses Phone
613-386-3426
            &nbs
p;            &n
bsp;    Fax 613-386-1211 e-mail
bburt@limetone.kosone.com
></body></html>

Dear Brian, 6/28/97

Thanks for the quick response! I agree that the Internet is a great start
for getting the story out. However, I believe that it will be a long time
before enough people in the third World countries will have enough computers
on the Internet,let alone computers, so that they can be shown how to
improve their lot at the stove level. International media recognition of the
problem and $ support for R&D is what is needed on a large scale. We need
another Eindhoven, only it needs to be a mobile teaching system. In effect a
World Stove Van that visits fuel deficient areas of the world and shows the
latest technologies in efficient natural fuel burning. Let the people pick
the stove that best meets their needs.The foundation sponsors the van.I keep
trying to get us researchers to think like marketers. We have a marketing
problem on a very big scale.
I agree that Alex is making a great effort to pull things together in a
practical way. He is a good man. Great job Alex! Thanks for including
Pyromid in your visual list. I really like the practical stoves in Rogers area.
In answer to the HARMONIC THERMAL ARRAY question. I place fuel in a special
box that organizes the fuel in an array. The box has a catalytic plate on
top that restricts the release of the expanding gases. The plate gets very
hot(1100f).The gases wafe under the plate long enough to burn very
thoroughly.The fuel burns from front to back over a 4 hour period. 25
briquettes cook for 25 people.I also cook with the heat radiating from under
the box(~450f). Heat up and heat down. look at the Pyromid page in Alex's
page. It shows my Super Heat grate. Put the grate in a specially controlled
air flow box and you have an HTA World Stove.

Sincerely,
Paul W. Hait

From REEDTB at compuserve.com Sun Jun 29 05:21:04 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Barbecuing & Charcoal
Message-ID: <199706290520_MC2-196C-BC0F@compuserve.com>

Hillcrest Farm, New Harbor, Maine
6/27/97

Dear Paul Hait and stovers:

We (seventeen) are finishing our 50th anniversary here in Maine. It has
been a glorious week of boat trips, museum trips, shopping (close to
LLBean).

One of our activities has been barbecuing with the Paul Hait Pyromid. I
recommend that any serious stover should get one and try it, and discover
in it previously unknown principles of cooking.

Two of my sons barbecue regularly - several times a week - and were very
impressed with the high heat and low fuel usage. Wednesday noon we had
company for lunch, swelling the ranks to 11 adults and several children. I
was assigned the task of cooking sixteen hamburgers. I didn't think the 12
inch Pyromid could handle it, but it did amazingly well.

The central "engine" of the Pyromid is a array of nine standard 2 inch
horizontal charcoal briquettes below the center of a conical reflecting
stainless steel and aluminum foil array and a 12 inch grill above it. It
took only 6 minutes to light all the briquettes and start cooking, using
Paul's lighter sticks. I put the oven top over the grill and peeked in
occasionally, turned the patties as required etc.

The first eight patties were cooked with no modification. I was amazed at
the quantity of mostly steam emitted. The patties were done, but not
blackened, as on an electric grill. I cooked four at a time, 6-8 minutes
per side, so about 30 minutes required.

At this point my son Peter joined the operation and thought that the
cooking was slowing down, maybe needed more charcoal. We put nine more
briquettes on the array. This greatly increased the heat, causing the fat
to drip into the fire, adding volatile flames to the fire (and a lot more
smoke, runny grease etc.) These cooked much faster and some people liked
them better.

This is a positive feedback cooking situation in which the more fat falls
in the fire, the faster it cooks and so the more fat falls in. It can be
kept in check with a water spray bottle to partially douse the flames.
However, it is no longer the charcoal providing the heat, but the fat, not
a GREAT fuel.
~~~~
This brings up larger issues.

1) Barbecuing (like a taste for tripe) is limited to the rich and poor and
is particularly suitable for large slabs of meat, but not for boiling,
baking, .....

2) Barbecuing seems to be a male thing, mostly.

3) Normall barbecuing with charcoal briquettes is very wasteful of energy.
The Pyromid greatly reduces this waste.

~~~~
I have heard Paul Hait complain bitterly that the Coleman company is trying
to "Butanize the world", while he is trying to charcoalize it. I must say
that for most cooking, the propane-butane stove offers instant lightup,
high or low intensity cooking for whatever period is necessary, then
immediate off.

If you really like the barbecue mode, you can get a butane barbecue that
has the advantages of both butane as a fuel and gives the radiant heat of
barbecue by heating lava rocks. This also works as a substitute fireplace.

Paul believes that the pressurized bottles are dangerous and sites the
fires at Mecca this year. I have never heard of any bottle failures in the
U.S. Does anyone know of other problems? If butane wasn't a fossil fuel
it would be close to perfect.

So, strictly from the viewpoint of the developing country cooks, I should
think butane would be recommended 10-1. How about this Kirk?

And, for a more renewable world, a good wood-gas stove comes closer to the
ideal for general cooking.

Thoughts?

Regards, TOM REED

Note: Paul calls the other fuel "butane" (a c4 hydrocarbon with boiling
point near O C), but in many parts of the world, particularly in winter it
is propane (C3, BP - 20C).

From REEDTB at compuserve.com Sun Jun 29 05:21:10 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: NAME CONTEST
Message-ID: <199706290520_MC2-196C-BC15@compuserve.com>

TOM REED, CSM, reedtb@compuserve.com
ELK et al:

Sounds like you are making great quantitative progress with what you call
the "two can stove". Congratulations - push on! Here are a few comments
for your consideration.

You asked what happens to the charcoal if it is not extinguished when the
volatiles have all been consumed. If you put a thermocouple in the middle
of the charge it will show you

a) initially room temperature air passing by on the way up to the "flaming
pyrolysis" zone (yes, there is a flame buried in the pile - we built a
"transparent gasifier" with gold reflective insulation and could observe
it)

b) a very rapid rise in temperature to about 500 C as the flame approaches
the thermocouple

c) very little drop in temperature as the volatile flame approaches the
bottom grate

d) an immediate sharp rise in temperature as charcoal begins to burn

So, one TC (or dial gauge thermometer) reveals the history quite
accurately. I recommend that we all use such a buried TC for our tests

~~~~
NAME OF STOVE CONTEST:

NAME OF STOVE:

It has been most amusing to follow the changing names given this stove. I
initially (in 1985, patent memos to SERI/NREL) called it an
"UPSIDEDOWNDRAFT GASIFIER" stove by analogy to the conventional "downdraft"
gasifier, well known during WWII and also to emphasize that it cooked with
GAS. After a year or two I realized the "upsidedowndraft", while colorful,
was not informative to non-English speaking people (like Harry LaFontaine).
So I changed to calling it the "Inverted downdraft gasifier-stove". When
Fred Hottenroth produced a commercial model he called it a GASFIRE stove
(1989). I have also called it a WOOD-GAS stove, with strong emphasis on
GAS to avoid confusion with a few thousand wood stoves built through the
ages. Gasifier stoves are NEW (and include the "J" stove of
Verhart-Eindhoven-Antal).

When Ron Larson called me to ask about charcoal making stoves he renamed it
"a CHARCOAL MAKING" stove (1992). Others call it the TOP LIGHTED stove.
Now you call it the TWO CAN" stove.

It seems to me we have here the "blind men and the elephant" syndrome.
Each person sees what he/she thinks is important. Coming from gasifiers
and having used gas stoves, I think WOOD-GAS STOVE (as opposed to WOOD
STOVE) is most descriptive and exciting. Ron comes from Ethiopia where the
possibility of producing charcoal (always a nuisance in my eyes) was the
most important feature.

Now you use TWO CAN STOVE to describe it. Does the fact that it can (but
not necessarily is) be made from two tin cans best catch the essense?

I suggest we all submit our best choices for a single name to catch the
essense. Ron can collect the names and we can all vote. Majority wins and
we all sink or swim with the result.

~~~~~
Fussing over names may seem nit-picking. Nonsense. A good name is almost
as important as a good product.

OIL SHALE is not truly a shale, nor does it contain oil. It is keragenated
marlstone. How much funding would Congress have appropriated for research
on keragenated marlstone. So they lied a little. (And the self-deception
of the oil companies cost them and us a few hundred billion $.

So let's pick an honest, descriptive name that emphasizes what is new.

Yours truly, TOM
REED

From REEDTB at compuserve.com Sun Jun 29 05:21:09 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Turbulent & diffusion blue flames
Message-ID: <199706290520_MC2-196C-BC11@compuserve.com>

Dear Alex +:

You asked>
Can I surmise that turbulence is not necessary for good mixing,
just short diffusion distances. Are these relatively gentle and spread
out flames from woodgas capable of low CO or CO/CO2 ratios.<

You have just crossed to borders of my knowledge. We have all known that a
premixed flame (blue) is very clean and can burn indoors without
significant polution (stoves, Bunsen burners etc.). [Q: How clean Kirk?]
A decade ago I decided that very short diffusion flames could do the same
and I studied the Alladin type kerosene cooker and mantle burners. I
recommend that you all go down to the local hardware stove and study the
circular wicks and air galleries that produce a few thousand tiny blue
flames.

However, I am equating BLUE with CLEAN because these are indoor devices and
no smell generally goes with no emissions. But not necessarily. I hope
Kirk or others have some comments here.

Hope your combustion advisor has some comments on this. Be careful to
recognize "thermocouple flame temperature" as a measure more of heat
transfer (a velocity-temperature product) than actual temperature alone.

Truly yours, TOM REED

PS Today here in Maine 11 of us are travelling to Monhegan Island for the
day. Hence, short notes.

From REEDTB at compuserve.com Sun Jun 29 05:21:19 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Beedie gasifier & STOVE THREADS
Message-ID: <199706290520_MC2-196C-BC12@compuserve.com>

Dear David and Stovers:

I see a drawing together of the stove people and the gasifier people here.
David's recent comments indicate that he uses the language and measurements
of the gasifier group, but is interested in stoves. GREAT!

In the past the stove group has worried a lot about social issues while the
gasifier group tends to think in terms of megawatt generators. I presume
the principles of gasification can be applied to stoves however and that
the gasifier people don't mind social issues.

More recently the stove group has "taken fire" and seems to be actually
building and testing stoves. GREAT.

David, can you give us a quick summary of your gasifier and the principles
that you think apply here in stoves?

~~~~~
If one wanted to index the threads going through the stove list the threads
would include (but not be limited to...)

TECHNICAL:
Primative wood stoves (three stone etc.)
Classical improved wood stoves (swosthee etc.)
Wood-gas stoves
Charcoal stoves
Methods of testing
Methods of making and manufacturing
SOCIAL:
Biomass supply
charcoal
health
Cooking
Acceptance of new stove technology
Stove costs
Stove construction fitted to particular countries

Is this a useful list? Will you add your favorite themes please.

Yours truly, TOM
REED

From REEDTB at compuserve.com Sun Jun 29 05:21:33 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Stoves and Health
Message-ID: <199706290521_MC2-196C-BC1A@compuserve.com>

TOM REED, CSM, reedtb@compuserve.com

Dear Rogerio et al:

How does IRA abreviate "Accute Respiratory Infections"? (Rather than Irish
Republican Army?) Should it be ARI?

It seems to me we are putting the cart before the horse in call attention
to our stove work before we have a practical solution that we could
recommend to the NGOs and others. If we call "wolf!" today, and they find
we have only half-baked ideas about what to do, then when we all agree that
we have a new practical solution they won't listen. That's what happened
in the 1980s with stove research. There were a number of ingenious stoves
that were partial solutions, none that were sufficiently different to fly
on their own. So, naturally the NGOs are wary of "improved" stoves. (The
same thing happened in gasification).

(Some of us are so used to generous funding from BIG organizations that we
can't imagine progress without their help. Personally their "help" hurts
as often as helps.)

So, let's make sure we have a major quantum leap forward before we approach
the NGOs.

Yours truly, TOM REED

From REEDTB at compuserve.com Sun Jun 29 05:21:27 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Charcoal yields vs superficial velocity
Message-ID: <199706290521_MC2-196C-BC18@compuserve.com>

T. B. REED CSM
reedtb@compuserve.com

Etienne et alia:

Etienne is correct that a conventional downdraft gasifier produces very
little ash. Let me be a little more specific. It typically gasifies most
of the charcoal, but leaves about 5% of what should be called "char-ash:"
rather than charcoal. Since the initial ash content of the wood is
typically 1%, this twentyfold reduction in mass increases the ash content
to 20% - but still it is a black ash. (May even be activated carbon and
valuable for water cleanup etc. - someone please run an ioding number on
it.) The new stoves of Mukunda introduce a small amount of air in the
last few cm of the gasification zone and it consumes the rest of the carbon
- and the small amount of remaining tars, down to 50-100 ppm.

HOWEVER: the superficial velocity of the air in the inverted downdraft
(two can, charcoal producing top lighted wood-gas) stove is only 1/20th of
that in the conventional downdraft, and temperatures do not get high enough
for char gasification (>800C), so the charcoal yield is 25% rather than the
5% of conventional. This puzzled me for a very long time, but I am sure
both from theoretical and experimental considerations that this is the
case.

I hope to run a test in which I provide forced draft to the stove and show
that with increasing superficial velocity the charcoal will decrease
continuously to 5%.
~~~~~
There may be another reason for the high charcoal yields. The primary
pyrolysis products generated below 500C can be cracked below 700C. So it
is concievable that increased draft may first increase, then decrease char
yields.

Mike Antal, are you listening and lurking?

VTY, TOM REED

From REEDTB at compuserve.com Sun Jun 29 05:21:16 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Optimum Gaps
Message-ID: <199706290520_MC2-196C-BC17@compuserve.com>

TOM REED, CSM, reedtb@compuserve.com

Dear Ron et al:

You may remember that in our paper at Banff on the "Blue Flame Stove" (did
you ever read it? I never heard any comments) we said that while we had
achieved clean combustion with reasonable power, control and efficiency,
the various dimensions needed to be optimized.

I have not done any optimizing yet nor have you. So we can't complain if
it isn't optimum.

Have a great conference, but don't expect it will help solve the stove
problem.

TOM

From REEDTB at compuserve.com Sun Jun 29 05:21:29 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:23 2004
Subject: Figure of merit
Message-ID: <199706290521_MC2-196C-BC19@compuserve.com>

TOM REED, CSM, reedtb@compuserve.com

Ellsen, Ron and All:

I don't think "Weight water evaporated/weight fuel" is a good figure of
merit - possibly of demerit however. Most cooking requires an initial
burst of heat to reach the boiling point followed by an immediate drop of
3-5 times in power for simmering. So we need a figure of merit that
emphasizes the ability to control, one of teh star advantages of wood-gas
stoves over wood stoves.

Tom Reed

From elk at arcc.or.ke Sun Jun 29 05:27:57 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:23 2004
Subject: A Harmonic Human Array
Message-ID: <m0wiGH2-0006YMC@arcc.or.ke>

Stovers;

As a necomer, I appreciate and enjoy the support and free flowing
information within this group, and applaud crest (who/whatever it is) in
it's efforts and successes to date. Keystone support by Alex, Ronal, Paul &
others are helping it evolve in a natural path along logical lines of least
resistance toward a shared goal.

I enjoy the practical side and strive toward the introduction of products
(that fulfill our environmental criteria) into the market place. This is the
final & ultimate acid test: Marketplace Acceptance.

>From my immediate perspective, I don't feel that any form of political
lobbying or committee work is going to improve on our current rate of
progress. Let's not deviate or dissemble (yet).

elk

From bburt at limestone.kosone.com Sun Jun 29 08:39:07 1997
From: bburt at limestone.kosone.com (Brian Burt)
Date: Tue Aug 31 21:35:23 2004
Subject: Beedie gasifier & STOVE THREADS
Message-ID: <199706291239.IAA06382@mercury>

Is this a useful list? Will you add your favorite themes please.

Yours truly, TOM
REED
----------

This is a very useful list. Perhaps a list of outstanding threads
(questions), could be maintained by Ron (you know ask a busy person) or on
the Stove page. If it were posted periodically, much like Tom Miles post
the general rules and instructions for the lists, it allows a running tab
on the context of the list. Ron you are doing this currently in many of the
responses to direct messages in an attempt to keep threads alive. This
would be just a form of abstracting those issues.

The list might be maintained and refined to reflect progress toward
answering questions and the evolution of new questions. This might allow
someone who is new to the list or only checks the archives infrequently to
quickly be brought up to speed and perhaps feel more comfortable in
participating with a understanding of the context of the list.

If this were maintained with a data base system then the items could be
categorized and related (some issues being sub-issues). The data base could
then be sorted and outputted to a text file to be posted.

To take this idea a bit further you could also itemize "resolved" issues,
those issues on which there is general consensus on. A posting on a web
page could then allow for those type of issues to be reported for others to
build on.

Brian

Brian Burt
Burt's Greenhouses
Phone 613-386-3426 Fax 613-386-1211
e-mail bburt@limetone.kosone.com

From phait at transport.com Sun Jun 29 17:45:50 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:23 2004
Subject: Stoves and Health
Message-ID: <199706292148.OAA31100@brutus.transport.com>

> TOM REED, CSM, reedtb@compuserve.com
>
>Dear Rogerio et al:
>
>How does IRA abreviate "Accute Respiratory Infections"? (Rather than Irish
>Republican Army?) Should it be ARI?
>
>It seems to me we are putting the cart before the horse in call attention
>to our stove work before we have a practical solution that we could
>recommend to the NGOs and others. If we call "wolf!" today, and they find
>we have only half-baked ideas about what to do, then when we all agree that
>we have a new practical solution they won't listen. That's what happened
>in the 1980s with stove research. There were a number of ingenious stoves
>that were partial solutions, none that were sufficiently different to fly
>on their own. So, naturally the NGOs are wary of "improved" stoves. (The
>same thing happened in gasification).
>
>(Some of us are so used to generous funding from BIG organizations that we
>can't imagine progress without their help. Personally their "help" hurts
>as often as helps.)
>
>So, let's make sure we have a major quantum leap forward before we approach
>the NGOs.
>
>Yours truly, TOM REED

One step at a time, but keep up the pressure!

Dear Tom,
It is only by throwing out ideas do we get direction. Your leadership is
much respected by me. I am sure your experience in the Stove area is second
to none.
I await that moment when you feel the World is ready for the perfect stove.
In the mean time I will plug away at selling Pyromids and HTA World Stoves.
1 cent/meal is not a bad place to start. Or 250 BTU's/meal. From my point of
view we Americans are burning far too many BTU's in the WEBER to cook 6
hamburgers.
With the average number of briquettes/grilling in the 22 inch kettle being
65 to 75 or 16,250 to 18,750 BTU's, why not use Pyromids principals? We cook
6 hamburgers with ease with 6 to 9 briquettes, or 1500 to 2250 BTU's.
With a minimum of 8,000,000 22 inch Webers in LA alone barbequing an average
of 2x/week for 6 months using 75 briquettes/grilling, a heck of a lot of
wasted energy is going up in the air (smog).Just imagine all those wasted
briquettes going to Ethiopia. The Worlds balance of energy is out of balance
when it comes to the wasteful use in the developed countries. The Weber is
like a flash-lite with a black reflector that requires 25 batteries to drive
the beam. Pyromid is the flash-lite with the reflector that requires only
two Penlite batteries.
I am glad you did not leave the Crest group. Thanks for the great technical
detail on Kingsford briquettes,wood,and gas.

Have a great summer!

Paul Hait the only legal Pyromaniac.

From verhaarp at janus.cqu.edu.au Sun Jun 29 18:03:30 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:23 2004
Subject: 'elk works' on the web
Message-ID: <1.5.4.32.19970629220333.006b7cb4@janus.cqu.edu.au>

>From Peter Verhaart

To Paul Hait, mainly
At 10:17 28/06/97 -0700, you wrote:
lop
>
>Ronal,Tom,Alex,Peter,Tom Jr.,Roger,,and others am I nuts or does this
>proposal make any sense?

Both!
Good idea.
Regards,
Piet
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From ovencrft at nbn.com Mon Jun 30 01:44:52 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:23 2004
Subject: Stoves and Health
Message-ID: <199706300545.WAA08858@moon.nbn.com>

>> TOM REED, CSM, reedtb@compuserve.com
>>
>>Dear Rogerio et al:
>>
>>How does IRA abreviate "Accute Respiratory Infections"? (Rather than Irish
>>Republican Army?) Should it be ARI?
>>
>>It seems to me we are putting the cart before the horse in call attention
>>to our stove work before we have a practical solution that we could
>>recommend to the NGOs and others. If we call "wolf!" today, and they find
>>we have only half-baked ideas about what to do, then when we all agree that
>>we have a new practical solution they won't listen. That's what happened
>>in the 1980s with stove research. There were a number of ingenious stoves
>>that were partial solutions, none that were sufficiently different to fly
>>on their own. So, naturally the NGOs are wary of "improved" stoves. (The
>>same thing happened in gasification).
>>
>>(Some of us are so used to generous funding from BIG organizations that we
>>can't imagine progress without their help. Personally their "help" hurts
>>as often as helps.)
>>
>>So, let's make sure we have a major quantum leap forward before we approach
>>the NGOs.
>>
>>Yours truly, TOM REED
>
>One step at a time, but keep up the pressure!
>
>Dear Tom,
>It is only by throwing out ideas do we get direction. Your leadership is
>much respected by me. I am sure your experience in the Stove area is second
>to none.
>I await that moment when you feel the World is ready for the perfect stove.
>In the mean time I will plug away at selling Pyromids and HTA World Stoves.
>1 cent/meal is not a bad place to start. Or 250 BTU's/meal. From my point of
>view we Americans are burning far too many BTU's in the WEBER to cook 6
>hamburgers.
>With the average number of briquettes/grilling in the 22 inch kettle being
>65 to 75 or 16,250 to 18,750 BTU's, why not use Pyromids principals? We cook
>6 hamburgers with ease with 6 to 9 briquettes, or 1500 to 2250 BTU's.
>With a minimum of 8,000,000 22 inch Webers in LA alone barbequing an average
>of 2x/week for 6 months using 75 briquettes/grilling, a heck of a lot of
>wasted energy is going up in the air (smog).Just imagine all those wasted
>briquettes going to Ethiopia. The Worlds balance of energy is out of balance
>when it comes to the wasteful use in the developed countries. The Weber is
>like a flash-lite with a black reflector that requires 25 batteries to drive
>the beam. Pyromid is the flash-lite with the reflector that requires only
>two Penlite batteries.
>I am glad you did not leave the Crest group. Thanks for the great technical
>detail on Kingsford briquettes,wood,and gas.
>
>Have a great summer!
>
>Paul Hait the only legal Pyromaniac.
>
>
Wait, there is another legal pyro, thats me, the one and only Oven Crafter.
I have improved bake ovens that I developed without the assistance of any
funding from any source except my small business. These ovens are wood fired
relying on retained heat. (They found little acceptance with the improved
stove crowd of the 70's and 80's with whom I rubbed shoulders with on
occasions, who were enamoured with developing oil drum ovens instead.) But
they bake extreemly well and are surprisingly efficient and clean burning
when built both along traditional lines and with the improvements that I
have developed. They can be astoundingly inefficient if not built well. My
designs were arrived at through constant use and the necessity of earning a
right livlihood not only as a builder but as a user too. My criteria for
success in this world of diminishing resources and escalating contaminants
is as follows:

1. self build
2. use local materials and fuel
3. apply "middle" technology

Self building enhances the doer, not some remote corporation. Local
materials are the most cost effective and keep the economy circulating close
to home. Local fuels, expecially wood, stimulate the propagation of
desperately needed forests, and enhance the forester and keep the economy
close to home. Wood comes from the miracle of photosynthesis the most
efficient solar mechanism in the universe. Oxygen is a by product that will
one day command a hefty price ( how else can one burn oil without oxygen?).
High tech solutions like solar ovens etc. by stimulating the
industrial/military/media complex lead us backwards into the cause of our
problems. Best of all possible places to begin helping the third world
masses is here in the belly of the beast. One North American family living a
voluntarily simplified lifestyle will release enough resources for hundreds
of poor families to lead their own lives better. A small family sized
community serving bakery based on one of my ovens, wood fired, is a prooven
viable simplification of lifestyle here. If you are not yourself living by
the inventions that you promote for others, they will not see your improved
stove but only hanker after your ambience; computors, cars, highways,
$100,000 a year incomes, split level homes, Disneyland and Big Macs. We need
a Jonny Appleseed Stover to arise out of the West, leave his own cosy
improved stove and family and travel the other worlds spreading the word and
the deed. This will work wonders.

ALAN SCOTT

Check out the new web site for OVENCRAFTERS
http://pomo.nbn.com/home/ovncraft

From phait at transport.com Mon Jun 30 03:40:49 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:23 2004
Subject: Stoves and Health
Message-ID: <199706300743.AAA08465@brutus.transport.com>

>>> TOM REED, CSM, reedtb@compuserve.com
>>>
>>>Dear Rogerio et al:
>>>
>>>How does IRA abreviate "Accute Respiratory Infections"? (Rather than Irish
>>>Republican Army?) Should it be ARI?
>>>
>>>It seems to me we are putting the cart before the horse in call attention
>>>to our stove work before we have a practical solution that we could
>>>recommend to the NGOs and others. If we call "wolf!" today, and they find
>>>we have only half-baked ideas about what to do, then when we all agree that
>>>we have a new practical solution they won't listen. That's what happened
>>>in the 1980s with stove research. There were a number of ingenious stoves
>>>that were partial solutions, none that were sufficiently different to fly
>>>on their own. So, naturally the NGOs are wary of "improved" stoves. (The
>>>same thing happened in gasification).
>>>
>>>(Some of us are so used to generous funding from BIG organizations that we
>>>can't imagine progress without their help. Personally their "help" hurts
>>>as often as helps.)
>>>
>>>So, let's make sure we have a major quantum leap forward before we approach
>>>the NGOs.
>>>
>>>Yours truly, TOM REED
>>
>>One step at a time, but keep up the pressure!
>>
>>Dear Tom,
>>It is only by throwing out ideas do we get direction. Your leadership is
>>much respected by me. I am sure your experience in the Stove area is second
>>to none.
>>I await that moment when you feel the World is ready for the perfect stove.
>>In the mean time I will plug away at selling Pyromids and HTA World Stoves.
>>1 cent/meal is not a bad place to start. Or 250 BTU's/meal. From my point of
>>view we Americans are burning far too many BTU's in the WEBER to cook 6
>>hamburgers.
>>With the average number of briquettes/grilling in the 22 inch kettle being
>>65 to 75 or 16,250 to 18,750 BTU's, why not use Pyromids principals? We cook
>>6 hamburgers with ease with 6 to 9 briquettes, or 1500 to 2250 BTU's.
>>With a minimum of 8,000,000 22 inch Webers in LA alone barbequing an average
>>of 2x/week for 6 months using 75 briquettes/grilling, a heck of a lot of
>>wasted energy is going up in the air (smog).Just imagine all those wasted
>>briquettes going to Ethiopia. The Worlds balance of energy is out of balance
>>when it comes to the wasteful use in the developed countries. The Weber is
>>like a flash-lite with a black reflector that requires 25 batteries to drive
>>the beam. Pyromid is the flash-lite with the reflector that requires only
>>two Penlite batteries.
>>I am glad you did not leave the Crest group. Thanks for the great technical
>>detail on Kingsford briquettes,wood,and gas.
>>
>>Have a great summer!
>>
>>Paul Hait the only legal Pyromaniac.
>>
>>
>Wait, there is another legal pyro, thats me, the one and only Oven Crafter.
>I have improved bake ovens that I developed without the assistance of any
>funding from any source except my small business. These ovens are wood fired
>relying on retained heat. (They found little acceptance with the improved
>stove crowd of the 70's and 80's with whom I rubbed shoulders with on
>occasions, who were enamoured with developing oil drum ovens instead.) But
>they bake extreemly well and are surprisingly efficient and clean burning
>when built both along traditional lines and with the improvements that I
>have developed. They can be astoundingly inefficient if not built well. My
>designs were arrived at through constant use and the necessity of earning a
>right livlihood not only as a builder but as a user too. My criteria for
>success in this world of diminishing resources and escalating contaminants
>is as follows:
>
> 1. self build
> 2. use local materials and fuel
> 3. apply "middle" technology
>
>Self building enhances the doer, not some remote corporation. Local
>materials are the most cost effective and keep the economy circulating close
>to home. Local fuels, expecially wood, stimulate the propagation of
>desperately needed forests, and enhance the forester and keep the economy
>close to home. Wood comes from the miracle of photosynthesis the most
>efficient solar mechanism in the universe. Oxygen is a by product that will
>one day command a hefty price ( how else can one burn oil without oxygen?).
>High tech solutions like solar ovens etc. by stimulating the
>industrial/military/media complex lead us backwards into the cause of our
>problems. Best of all possible places to begin helping the third world
>masses is here in the belly of the beast. One North American family living a
>voluntarily simplified lifestyle will release enough resources for hundreds
>of poor families to lead their own lives better. A small family sized
>community serving bakery based on one of my ovens, wood fired, is a prooven
>viable simplification of lifestyle here. If you are not yourself living by
>the inventions that you promote for others, they will not see your improved
>stove but only hanker after your ambience; computors, cars, highways,
>$100,000 a year incomes, split level homes, Disneyland and Big Macs. We need
>a Jonny Appleseed Stover to arise out of the West, leave his own cosy
>improved stove and family and travel the other worlds spreading the word and
>the deed. This will work wonders.
>
>ALAN SCOTT
>
>Check out the new web site for OVENCRAFTERS
>http://pomo.nbn.com/home/ovncraft

>Dear Alan,

It is great to know there are two of us. Great response! I completely agree
with you. Solving the problem locally is the best answer. However, it would
not hurt to to have a JOHNNY APPLE WOOD or JOHNNY CHARCOAL or JOHNNY 2CAN or
JOHNNY PYROLISIS or JOHNNY DOWNDRAFT or JOHNNY JECKO or JOHNNY OVENCRAFTERS
or JOHNNY PYROMID.it is great to get rises out of people and see that we are
all alive and snipping.
Planting trees( like Mesquite ) starts the reforestation cycle. Making
Charcoal from the mesquite in Ronals Stove is the next step. Using the gases
to cook with while making the charcoal is the next step. Burning the
Charcoal in a harmonic thermal array in your stove is the next step. Making
the Charcoal into more uniform briquettes is the next step after the others
are done first.

Thanks for the reply,

Johnny Mesquite ( John Doe )

From elk at arcc.or.ke Mon Jun 30 09:56:25 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:24 2004
Subject: 2can Turbo mk2 - Trial 1 results
Message-ID: <v01510101afdd8818f320@[199.2.222.154]>

Negative. Heap big smoke, little flame. Red eyes.

This stove was made of two different diameter 'cans', a 20 cm wide by 40 cm
high pyrolising (fuel) chamber under a 30 cm wide by 40 cm high combustion
chamber.

Primary air is introduced via the normal 3 controllable vents at bottom
below a grate supporting the wood. Secondary air inlets were 48 4mm drilled
holes in the horizontal ring linking the two cans. The two cans ovelapped
by 10 cm, with the difference split by the 'ring'- The larger upper can
projecting 5 cm below the ring acting as a wind shield, and the smaller can
projecting 5 cm above the ring into the combustion chamber, with the lip
notched & twisted to provide turbulance.

This arrangement introduces the secondary air vertically through the
drilled holes in the connecting ring into the combustion chamber away from
the pyrolisis gasses behind the baffled 5 cm high lip of the lower can.

My idea is to create as much turbulance as possible within a combustion
chamber that is 'stepped' larger than the pyrolisis chamber. This follows
along some of the lines that Alex is investigating with his cones.

As the present secondary air arrangement seems to be of no benefit, I'll
close the air holes in the connecting ring and drill them through the wall
of the pyrolisis chamber at the level of the ring. This will introduce the
secondary air horizontally 5cm below the top baffled lip of the lower
(smaller) can in order to test if turbulance AFTER the introduction of cool
secondary air aids combustion and controllability, as opposed to BEFORE.

Separating variables may prove difficult, as I'm not using holes instead of
a slit for secondary air, but we plod along.... This stove looks nice
anyway.

elk

_____________________________
Elsen Karstad
P.O Box 24371 Nairobi, Kenya
Tel:254 2 884437
E-mail: elk@arcc.or.ke
______________________________

From zourarakis at nosapp.nr.state.ky.us Mon Jun 30 12:52:16 1997
From: zourarakis at nosapp.nr.state.ky.us (DEMETRIO)
Date: Tue Aug 31 21:35:24 2004
Subject: Calling some hardcore stovers...
Message-ID: <97063012490573@nosapp.nr.state.ky.us>

Hi.

Yesterday, on Nat. Public Radio, an interview on "The Splendid Table" featured
the author of the book "License to Grill". He (can't recall last name,first na
me John, nickname "Doc") said that lump hardwood charcoal (in Argentina we used
to call it carbon de len~a), is finding its way into gourmet places for use in
grills, slowly replacing briquettes.
Is this a trend any of you are aware of? Implications?

Demetrio.

From jflores at prolena.sdnhon.org.hn Mon Jun 30 14:45:06 1997
From: jflores at prolena.sdnhon.org.hn (by way of larcon@sni.net Ronal W. Larson)
Date: Tue Aug 31 21:35:24 2004
Subject: Stove price
Message-ID: <v01540b05afdd74faa043@[204.133.251.16]>

Stovers (and especially Juan Carlos Flores): I apologize greatly for not
forwarding this message from last Friday immediately - I did not recognize
then that it had not gone to the full stoves list. Juan is especially
addressing questions to Mike Bess, following his note of last Thursday.

Regards Ron

!!Fecha envio: Thu, 26 Jun 1997 20:23:44 +0100
!!A: stoves@crest.org
!!De: Mike Bess <mike@esd.co.uk>
!!Asunto: Re: Charcoal Prices- Kenya
!!Enviar resp a: stoves@crest.org

Dear Stover

My name is Juan Carlos Flores, I'm Executive Director of
PROLENA/Honduras, the twin of Rogerio's Organization. I was in the
list, and I read your interesting messages about stoves. I just read
this massages and I'm very interesting in it. Now PROLENA is working
in a stove project in Tegucigalpa. We are trying to become a
market activity for the woodstove building. We know that in
Tegucigalpa about the 23% of the people use firewood for cooking, and
the persons are interesting in a improved woodstove. We think the
person could buy a new woodstove and pay it in six months.

Mike said that they in Ethiopia they have sold 300,000 stove, and he
said some reason that people have to get a new stove. Could you tell
me How did you get the money back? Now we are creating a found for
giving to the person a micro credit in order to buy a woodstove. Maybe
you did the same.

Saludos

Juan Carlos

!!Dear Elsen,
!!
!!Thanks for the information on charcoal in Kenya. That means prices are
!!around Ksh 250 per bag in Nairobi, for about Ksh 5-6 per kilogram. This
!!means, in real terms, that the price of charcoal is still less than it
!!was ten years ago, which is the same situation we find in Ethiopia,
!!Tanzania, Malawi and Uganda.
!!
!!One of the main reasons for keeping track of these prices is that it
!!shows that fuel price is not THE driving force for people buying new
!!stoves. The relative price of charcoal (price of charcoal compared to
!!all other commodities and services) has fallen in almost every urban
!!area we have studied. That doesn't mean people don't see an increase
!!and don't think prices are higher.
!!
!!What it does mean is that buying new energy efficient stoves is driven
!!by several other factors, and not just price as we so often hear. Our
!!experience in Ethiopia, where over 300,000 improved charcoal stoves have
!!been sold since 1992, and where over 17,000 wood biomass stoves (for
!!injera baking) have sold since 1995, is that people buy the stoves
!!because of:
!!
!!* modern,
!!* new,
!!* attractive
!!* safe
!!* reduces smoke
!!* saves fuel
!!
!!in that order of priority. But, price is still important, so, we try to
!!keep up to date with charcoal prices from all over the world. Any more
!!assistance on world charcoal prices would be very welcome. Cheers, Mike
!!--
!!Mike Bess

----------------------------------------------------------------------
Juan Carlos Flores Lopez
Director Ejecutivo PROLENA/Honduras
Tel/Fax: (504) 32-0639
P.O.Box 3870 Tegucigalpa, Honduras.
E-Mail: jflores@prolena.sdnhon.org.hn
----------------------------------------------------------------------

From larcon at sni.net Mon Jun 30 14:45:08 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:24 2004
Subject: Allan Scott and Ovens
Message-ID: <v01540b01afdd6ab636d5@[204.133.251.16]>

On June 29, List member Allan Scott (in his first comments to "stoves")
said, in reply to Paul Hait:

>Wait, there is another legal pyro, thats me, the one and only Oven Crafter.
>I have improved bake ovens that I developed without the assistance of any
>funding from any source except my small business. These ovens are wood fired
>relying on retained heat. (They found little acceptance with the improved
>stove crowd of the 70's and 80's with whom I rubbed shoulders with on
>occasions, who were enamoured with developing oil drum ovens instead.) But
>they bake extreemly well and are surprisingly efficient and clean burning
>when built both along traditional lines and with the improvements that I
>have developed. They can be astoundingly inefficient if not built well.

(RWL): Could you give us (without asking you to violate any corporate
secrets) some of the reasons for efficiency and inefficiency?

Why do you feel your ideas "found little acceptance"?

(Allen):
> My
>designs were arrived at through constant use and the necessity of earning a
>right livlihood not only as a builder but as a user too. My criteria for
>success in this world of diminishing resources and escalating contaminants
>is as follows:
>
> 1. self build
> 2. use local materials and fuel
> 3. apply "middle" technology
>
>Self building enhances the doer, not some remote corporation. Local
>materials are the most cost effective and keep the economy circulating close
>to home.

(RWL): It is not obvious how you can make a living in this business if you
promote self-building. Can you explain your business? Maybe there is a
profit-making one and one that isn't?

(Allan):
>Local fuels, expecially wood, stimulate the propagation of
>desperately needed forests, and enhance the forester and keep the economy
>close to home. Wood comes from the miracle of photosynthesis the most
>efficient solar mechanism in the universe. Oxygen is a by product that will
>one day command a hefty price ( how else can one burn oil without oxygen?).
>High tech solutions like solar ovens etc. by stimulating the
>industrial/military/media complex lead us backwards into the cause of our
>problems. Best of all possible places to begin helping the third world
>masses is here in the belly of the beast. One North American family living a
>voluntarily simplified lifestyle will release enough resources for hundreds
>of poor families to lead their own lives better. A small family sized
>community serving bakery based on one of my ovens, wood fired, is a prooven
>viable simplification of lifestyle here. If you are not yourself living by
>the inventions that you promote for others, they will not see your improved
>stove but only hanker after your ambience; computors, cars, highways,
>$100,000 a year incomes, split level homes, Disneyland and Big Macs. We need
>a Jonny Appleseed Stover to arise out of the West, leave his own cosy
>improved stove and family and travel the other worlds spreading the word and
>the deed. This will work wonders.
>
>ALAN SCOTT
>
>Check out the new web site for OVENCRAFTERS
>http://pomo.nbn.com/home/ovncraft

(RWL): Thanks for your first introduction on stoves (or ovens). Are you
announcing a Johnny Appleseed future for yourself?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From larcon at sni.net Mon Jun 30 14:45:11 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:24 2004
Subject: Mike Bess on Charcoal and Stove Characteristics
Message-ID: <v01540b08afdd7b5c201a@[204.133.251.16]>

Last Thursday, Mike said:

>Dear Elsen,
>
>Thanks for the information on charcoal in Kenya. That means prices are
>around Ksh 250 per bag in Nairobi, for about Ksh 5-6 per kilogram. This
>means, in real terms, that the price of charcoal is still less than it
>was ten years ago, which is the same situation we find in Ethiopia,
>Tanzania, Malawi and Uganda.

(RWL): Check me. I think that there are about Ksh 50 = $1.00, so the
price is US$ 0.10 per kilo (natural form). In our local Denver
supermarket, an average is about $3.00 per 20 pound bag or about $0.33 per
kilo (briquette form). This ratio sounds OK to me (based on standard of
living arguments). To you?

(Mike):
>One of the main reasons for keeping track of these prices is that it
>shows that fuel price is not THE driving force for people buying new
>stoves. The relative price of charcoal (price of charcoal compared to
>all other commodities and services) has fallen in almost every urban
>area we have studied. That doesn't mean people don't see an increase
>and don't think prices are higher.

(RWL): I am surprised that prices aren't going up a little in constant
dollar terms. Can you explain why charcoal prices are going down? (Our
local price of electricity is certainly going down in constant dollar terms
- and (because of projected restructuring/deregulation) to continue going
down faster.

(Mike):
>What it does mean is that buying new energy efficient stoves is driven
>by several other factors, and not just price as we so often hear. Our
>experience in Ethiopia, where over 300,000 improved charcoal stoves have
>been sold since 1992, and where over 17,000 wood biomass stoves (for
>injera baking) have sold since 1995, is that people buy the stoves
>because of:
>
>* modern,
>* new,
>* attractive
>* safe
>* reduces smoke
>* saves fuel
>
>in that order of priority. But, price is still important, so, we try to
>keep up to date with charcoal prices from all over the world. Any more
>assistance on world charcoal prices would be very welcome. Cheers, Mike
>--
>Mike Bess

(RWL): Mike: I have heard something like your priority list before, but
this is not the way I see rural stoves actually yet being sold almost
anywhere. I have been in Addis and seen the new improved jikos and
improved enjira cookers and know that they are attractively presented. But
still the vast majority (>90%?) in use (I think) of either type of stove is
not of the improved factory character. Can you comment further on the
source of your priority list (local consumer acceptance studies, etc). Is
this list confirmed also by actual marketplace behavior? Is it a question
of time?

As you indicate, the cost of the stove and charcoal are important.
What are the relative costs and efficiencies of the older and improved
stoves? If we define this characteristic as a payback time, where would
payback time fit in your list of six characteristics above? How big do you
calcualte the payback time to be?

Do the improved jikos have a ceramic insert in a steel jacket (with
door?) with special emphasis for quality control on the ceramic insert
(standard number of holes of a standard size with good quality clay being
used. I believe most of the problems are with the ceramic insert - which
has an average lifetime of a year of so? (I only know a little of the
details, really - from a one hour conversation in Addis)

So (unfortunately, despite the improved efficiency) all people
aren't rushing to buy - presumably because of the cost - which I hope you
will tell us more about.

On the injera cooker - the part I liked best was that it was made
from standard sized very low-weight concrete pieces. Are we talking the
same? My perception is that something like half of all Ethiopian cooking
energy goes into making enjira (a large, delicious "bread" (something like
a pancake) made from a local grain called Teff - not known many other
places in the world. The energy input is relatively high because the cook
surface is huge (60 cm diameter) and must be pretty hot to cook the injera
in about 2 minutes each. A covering is placed over the surface and injera,
but it must be off about half the time, so radiated losses are high.

I had hoped that the stove development lab in Addis would by now
have joined the list. Do you have an e-mail number for them or are you the
best contact?

I spent one month in late 1995 in northern Ethiopia (Mekkele,
Tigray) trying to develop a charcoal-making version of the enjira cooker
(as well as a smaller one for "wat" - the "topping" for the injera). I
felt moderately successful (the enjira was edible), but much work needed to
be done still. Did this work ever come to your attention? Do you think it
might have utility from your knowledge of energy use in Ethiopia? (As I've
said before, the motivation is to replace the present inefficient modes of
charcoal production - and charcoal is widely and badly made and used in
Ethiopia (as in Somalia and Sudan), but I believe the controllability is
quite important in injera making).

I think also many would like to hear more about your sources of
support and other areas you might be working besides Ethiopia. I have not
yet received the report on your stove work in Ethiopia. Have you done any
work on charcoal production?

Regards Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning

From mike at esd.co.uk Mon Jun 30 18:08:23 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:24 2004
Subject: Stove price
In-Reply-To: <v01540b05afdd74faa043@[204.133.251.16]>
Message-ID: <mtvI5QAXrBuzUAjs@esd.co.uk>

Dear Juan Carlos,

I would like to respond to your questions, and any further questions you
might have, at more length. I have just sent a message to Ron about our
work in Ethiopia, which I hope you will see. The 300,000 stoves in
Addis Ababa have been the improved charcoal stove, the Lakech, not the
improved wood stove, the Mirte.

Approximately 10,000 Mirte wood stoves have sold in Addis Ababa over the
past year, and their numbers are going up. We have set up small micro-
credit revolving funds in four cities, including Addis Ababa. I have a
full report we prepared for the British Department for International
Development, which I can send you, if you like. It has a history of the
project, the way the credit schemes are set up and the way they work.
This might be interesting to you. We can also put you in contact with
our senior Ethiopian counterpart who has been involved with this from
the beginning, and who has overseen the credit aspect from the
beginning. He will be coming on email within the next few days, so I
can send you and all the stovers his address.

Let me know if we can be of any help, and if you would like, we can send
you our DFID report with the credit and finance annexes. Cheers, Mike
--
Mike Bess

From mike at esd.co.uk Mon Jun 30 18:08:58 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:24 2004
Subject: Mike Bess on Charcoal and Stove Characteristics
In-Reply-To: <v01540b08afdd7b5c201a@[204.133.251.16]>
Message-ID: <vd2KlOAwlBuzUAhU@esd.co.uk>

Dear Ron,

Wow, I feel like a kid who's just met a lot of new friends! The
questions are almost overwhelming, but extremely stimulating because
they are right on the mark, and it is always good to exchange
information about something you like with new colleagues!

I'll try to answer briefly now. Perhaps the paper I sent will give more
detail, and we are very pleased to send information to all comers. Let
me start at the beginning.

Fifteen years living and working with renewable energy in East Africa,
first on a USAID-World Bank regional project, then with our company
which is based in the UK, Energy for Sustainable Development. Lots of
stove projects - too many, and too many failures. Top down, technology
driven, the whole list. I am proud to say I was there to watch the
Kenya Ceramic Jiko (KCJ) being conceived and born, and I am sad to say
that the parents (to follow the analogy) left it as an orphan and went
on to other things. That's to say, a million KCJs later and no-one I
know of can tell you whether they save energy or not, whether they last
one year, two, etc. because no government interest or involvement, ditto
on donors, and the jiko producers, well, they're great businessmen, and
they just produce. So, I learned a lot from this experience which ties
into some of your questions.

First, don't start something like this unless you are willing to follow
it through, and that means testing, qualilty control, monitoring, etc.
also, don't just train people up and expect them to know all the details
of thermo-dynamics, air flow, etc. that make stoves efficient. So,
don't abandon them after two years (move on to another project and
another country) and expect them to keep the right design, the right
number of holes, the right thickness of the metal, etc....

Ethiopia is where we have really helped to nurture the stove activities,
and tried to apply these, and other, principles. We began work in late-
1989 with the then Ethiopian Energy Authority, now known as the
Ethiopian Energy Research and Studies Centre under a DANIDA (Danish) and
World Bank grant for "cooking efficiency improvement". We had an
excellent kick off with the help of Willem Floor of the World Bank whose
ESMAP programme is one of the hottest and best in the world. We drew up
a needs assessment (860+ household interviews, interviews of over 100
stove producers and merchants), did our homework on previous Ethiopian
and East African work, and Willem helped fight off the World Bank's
civil servants who wanted to stick to the original plan to mass produce
several hundred thousand high cost combined charcoal and wood stoves.

We had been doing fuel price surveys in Addis Ababa since 1988 and knew
charcoal was increasing in use. We also knew wood use in the city was
going down, so, we decided to tackle charcoal first. This is where the
Lakech improved charcoal stove was born. It was a modified, and
improveed version of the KCJ. And, 300,000 stoves have been sold since
1992 when it was introduced. It sells for half the traditional stove,
and I'm surprised you didn't see more Lakech than traditional stoves.
The photos Alex is putting on the Web shows my story; we are seeing
10,000 Lakech being sold every month, and the Mercato, every supermarket
and most small markets are filled with them. We can go into more detail
about the pluses and minuses, but we still try to keep the quality
control, keep providing moulds and templates to producers, TA, etc.
although we've had no government or donor support on this front since
1995. Our destructive tests and our water boiling tests on the Lakech
still show it performing around the 35% mark, which is a 25% improvement
on the already good traditional Ethiopian metal stove. Also, our market
and household results show that almost 50% of all Addis households own
and use a Lakech. The World Bank commissioned an independent survey of
households as a review of our project (within a much bigger World Bank
energy project) and found in September of 1994 that one quarter of all
Addis households had the Lakech (and used it regularly).

The largest, most expensive Lakech now sells for Birr 20 (about US$1.50)
today, compared to the least expensive traditional charcoal metal stove
which sells for around EB 14 (about US$ 1). However, 80% of all Lakech
sell for less than EB 14 (there's been a terrific price war over the
past year), which makes the Lakech cheaper. By the way, when we
introduced the stove for market trials in January 1992, the Lakech sold
for EB 45 (recommended by the biggest producer) to EB 70 (that's when it
was EB 2 to the US$, not EB 6.5 like it is today). Competition, the
learning curve, mass production (by skilled artisans) and the stove
price falls, quality is pretty standard, and 400 are sold every day.

The "traditional" Ethiopian metal stove (there are two main models) is
one of the more efficient metal stoves made. They average 28-30%
compared with the traditional Kenyan jiko's performance of 20% or lower.
High quality craftsmanship has much to do with this. The Lakech liner
will last one year, perhaps a bit longer, but the stove pays for itself
within two months of regular use. The liner is replaced as a matter of
course, and the ceramic shards make great fill for the Addis potholes!

Your comments about affordability and market penetration are really
pretty on the mark for the Mirte ("better") injera cooker, rather than
the Lakech, for reasons I hope I've explained above.

The Mirte injera stove was a tougher nut to crack, as you are well aware
having worked in Mekele. And we did hear something about your work in
Tigray. But, unfortunately we never saw the results (and would like to
know more). Efforts to improve injera baking have been underway at
least since the early-80s as groups like the Mennonites (Burayu
Appropriate Tech Centre) and others tried to improve efficiencies. You
are right. Half of all energy (not just cooking energy, but all energy)
consumed in households in Ethiopia goes towards baking injera. You've
described the baking process right, so I won't repeat.

Enclosing the fire is mandatory, and we and others saw that from the
earliest days. But, how to do so without getting into the Lorena and
Bak dilemmas of self-made stoves, quality and performance all over the
universe....? This was the central problem, and still is, for any high
mase wood stove.

We were fortunate because we had worked with John Parry of Intermediate
Technology Workshops (now Parry Workshops) in Kenya and East Africa on
housing and roofing materials. One of our Ethiopian counterparts
suggested that perhaps a pre-fab multi-section stove made from moulds,
using light weight materials might be the answer to developing a low-
cost energy efficient, marketable stove. Well, two years later (by
1994) and it was. Again, we can discuss technical details, but the
stove uses one mould for the four pieces of the main stove, and one
mould for the chimney rest. It is made by hand (or can be made
mechanically, as it originally was) and can be assembled and
disassembled to be moved, transported,etc.

And, it saves energy while it also appeals to cooks because it removes
the smoke (number one factor), it is clean and modern (number 2 factor),
it is safe from back flashes from flame (number 3 factor) and it saves
energy (number 4 factor). These rankings come from over 500 follow up
interviews from randomly selected households selected from the 17,000
people we have sales records on.

The Mirte (as with the Lakech before), was tested in actual houehold
tests in Addis (four sets of tests over a two year period), in Bahr Dar,
in Awasa. It was cook tested in Gondar, Mekele, Sheshemane,
Nazareth....and each time, cooks liked it because of the reasons cited.
I often wonder what the ranking would have been had our enumerators not
shown up with hats (figuratively speaking) saying "We're interested in
energy efficiency". Frankly, I believe the ranking would have stayed
the same and the cooks would not have put saving energy as numero uno!

Two years of this effort from April 1995 to March 1997 were supported by
the British ODA (now Department for International Development).
Frankly, a more professional donor would be hard to find. They were
interested, but let us go on with the technical and commercial work. We
have four small/micro revolving funds, and 35 active producers,
employing over 100 people all over the country. In fact, Mirte
production started in Mekele in January and nearly 1,000 stoves have
been sold totally commercially, no subsidies, not intermediaries since
then. We have some of the best women artisans making the stoves in
Gondar, Bahr Dar and Mekele. Regional and local authorities have been
totally supportive, and have helped to keep admin and tech costs low
(they pay us simple per diems, provide ground transport, organise promos
and demonstrations, etc.). We're now promoting this all on our own, and
are soliciting corporate sponsorship to expand the Mirte into smaller
urban areas, and rural areas. It's going that direction anyway. And,
we don't want to lose control of quality control, training (in basic
businss and bookkeeping as much as stove quality), technical assistance,
etc. Promotion is a must for this product, as with any, and we've held
over 90 public, market demonstrations in seventeen cities and towns
since September 1995.

A neat feature of the Mirte, which we only discovered as we went along,
is that it can be fabricated with almost any building materials so long
as attention is taken to the mix ratio. The Mirte started out with
pumice and cement (5:1 ratio). Pumice, however, is not found everywhere
in Ethiopia. So, we tried it with red ash/scoria, another common
material that is more widely found than pumice. Bingo, same efficienies
(40% improvement in the lab over traditional injera baking, nearly 50%
in actual household use). Moving to Tigray and Dire Dawa where no
scoria or pumice is found, we tried the predominant building materials-
sand and cement. Again, bingo. The stove performs brilliant. I admit,
the concept of "portability" is stretched when a six piece stove weighs
70 kg, but, people build houses with the same materials. They move the
stove once every three months or so, so, no problem with portability...

The other surprising aspect of the Mirte is that, unless one fools
around with the dimensions of the fire door or starts putting chimneys
on the stove, efficiencies stay pretty high and pretty much the same,
even with a few cracks in the side. It's robust, And, it pays for
itself after less than 3 months for regular household use (twice a week,
30 injeras a session, three hours per session), and in less than a week
if used commercially (ie, for commercial baking - 300 injeras a session,
every day of the week 365 days per year). The stove sells for about EB
35 all over the country, with minor variations (we're not into price
controls). We keep training producers, so competition increases. Some
producers just move sales out to other towns and villages to keep their
profit margins which suits our dissemination strategy very well.

Yet, there are lots of things to do, and improvements to be made. But,
we can talk about that at more length. We believe the proof is in the
pudding. Without active intervention, meaning no overt subsidies or
interference in the market place, the stove is selling like hotcakes.
We realise the "early adopters" are wealthier households and the
commercial bakers (women heads of household who bake for restaurants,
hotels, and, increasingly, for wealthier households). However, the
percolation effect is rapid, and over half of all cumulative sales in
Addis are to low income households (verified by those 500+ random
surveys). We need to stimulate the market more through promotion and
advertising, more people need to be trained, more micro credit needs to
be available....but we estimate sales will top 30,000 by the end of this
year. If we get more support for these other things, the sky's the
limit.

I would like to be able to give you government contacts in Addis, but,
frankly, the Mirte and the Lakech are really low tech and not much
interest to the top government civil servants. They have not paid a bit
of attention to this over the past two years, and are much more
interested in wind turbines, pvs, and biogas.

Fortunately, our Ethiopian counterparts, headed up by Melessew Shanko,
(whose email is not working at this moment), but who can be reached by
telephone on 251 1 613395, or 187398 (fax info later). For the time
being, we are, I'm afraid, the best contacts for this information, but
please feel free to get directly in contact with Melessew. By the way,
our Ethiopian counterparts did up a superb video in Amharic, which sets
out the design, development, use, training, etc. on the stove, and it is
sub-titled in English. It's not the highest picture quality, but it
really puts it all into context, and I can send you a copy once I get
the chance. I think you'll find it very interesting.

Finally, before passing on the message I sent to Demetrio on charcoal,
we are continuing to work in Ethiopia, having worked all over the region
before. We also have a small British grant working with some really
good practitioners in Kenya, Uganda, Tanzania and Ethiopia to expand
commercial production of "institutional" stoves - ie, stoves used for
cooking or baking a lot either for hotels, restaurants and other
commercial establishments, or for schools, hospitals and the like. We
have recently completed an extensive study on biomass in Uganda, its use
and areas for improving its use in households, institutions and small
industry for the European Commission. We're doing some private
exploratory work on stoves in South Africa, so, we're pretty active on
the continent. More on that if you would like.

Concerning charcoal prices, here's my message to Demetrio (I don't know
yet whether what I send to one of the stovers gets passed on to everyone
else, so please excuse me). Also, I've sent Alex half a dozen photos,
with info on each for the Web. I see today he has put up two of them.
Great stuff. Like I began, I feel like a kid whose just found a lot of
new friends. More later, and thanks for the interesting and provocative
questions! Ciao! Mike

Dear Demetrio,

To answer your question briefly, charcoal is cheap (in nominal,
purchasers' terms) for two reasons. First, there is a lot of
competition because it is so widely used. So, regardless its
sustainability, this competition drives down prices. And, you are
right, labour is relatively inexpensive in most developing countries.
So, translating shillings or birr or whatever local currency to dollars,
pounds, etc. makes it look very inexpensive.

Secondly, most charcoal is not sustainably produced (I hope I don't
sound as if I am contradicting myself here). It is produced primarily
as a by product of land clearing (which is usually, up to now, a one off
activity). So, if anything, it has an negative value to the land
holder, and, indeed, very little, if any, resource cost may be paid. If
it is produced off public land (which it often is), then the externality
of using a common good is also not priced - ie, there is no resource
price. This also drives down the price.

Thirdly, because it often is such an informal sector activity, transport
is often either informal (lorries or trucks coming back to big cities
pick up a few bags of charcoal) or illegal. Illegality has a funny way
of reducing prices, but we can discuss this in more detail if you like.

Whatever the case, our work in Kenya and Uganda shows that charcoal can
be produced sustainably on a competitive basis with charcoal produced on
a non-sustainable basis because of modern organisation, higher yields,
closer proximity to markets,etc.

With regard to better charcoal or better stoves, why not both. If we
can improve yields and sustainability of charcoal production and end
use, we really have a very nice sustainable paradigm. We strongly
promote this in all our work, whether in the developing world or the
"West". Just a plug or two for sustainability! Hope that answers some
of your questions, and thanks for the interest. Mike

--
Mike Bess

From verhaarp at janus.cqu.edu.au Mon Jun 30 21:08:34 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:24 2004
Subject: Plancha Stove on the web site.
Message-ID: <1.5.4.32.19970701004428.006a6d28@janus.cqu.edu.au>

>From Piet Verhaart

To Ron, mainly

lop
>
> Piet: Thanks also for sending your photos in. What have you
>observed with different slit spacings?
>
> Regards Ron
>
Ron, I haven't done enough tests by half. I will in the near future. I think
I reported some results on this list about a year ago. I will see if I can
find them.

If I were invested with the necessary powers could I would confer the
honorary title of "Great Inquisitor" on you. I am sure we all profit greatly
from the stream of data you elicit from your victims.
Keep up the good work.

Best regards,
Piet
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

From verhaarp at janus.cqu.edu.au Mon Jun 30 21:08:51 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:24 2004
Subject: Plancha Stove on the web site.
Message-ID: <1.5.4.32.19970701004426.006a5018@janus.cqu.edu.au>

>From Piet Verhaart

To Rogerio, mainly

Great to see the pictures of your Plancha stove on Alex' Web Page. I am very
interested in the performance of this stove because it has a closed steel top.
Without having done any measurements I would expect quite a low efficiency,
defined as:
(heat in the pan(s))/(heat produced by the fuel)

The stove top in our kitchen has four heavy mass electric hot plates. They
can be reasonably efficient because they will rise in temperature until they
reach equilibrium e.g. Watts in = Watts out.
With a combustion fire however, the heat transferred depends on the
temperature difference between fire and pan. With a plate between fire and
pan there are two interfaces, both with a temperature difference.

In the article on the Swosthee Stove mention is made of a steel or aluminium
plate placed between the pan and the fire with only a reduction of 3 to 5 %
points in efficiency, which sounds encouraging.

This is the reason I am going to look into the possibilities of building a
downdraft stove with a hot plate to see if it will produce a decent efficiency.

My downdraft barbeque can be turned down. I have made a slide which controls
the effective grate area and I find it barbecues quite well with only half
the grate exposed e.g. a fire output of 2.5 kW.

Actually I can't understand how they could build Plancha stoves without a
chimney. I suppose the plate was not primarily intended to prevent pans
getting black. Possibly some frying is done directly on the plate and it can
accomodate more than one pan.

With a chimney, of course, one has to watch that the flames don't go
straight into it without transferring any heat to the plate.

Looking forward to further developments.
Best regards,

Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail:p.verhaart@cqu.edu.au

BioEnergy Lists: Improved Biomass Cooking Stoves

June 1997 Biomass Cooking Stoves Archive