September 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 prasad at tn7.phys.tue.nl Mon Sep 1 03:59:34 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:32 2004
Subject: Prasad message on "Smoke and Corn"
In-Reply-To: <199708291252_MC2-1E97-484@compuserve.com>
Message-ID: <9709010751.AA07373@tn7.phys.tue.nl>

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From REEDTB at compuserve.com Mon Sep 1 06:05:39 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:32 2004
Subject: Gas lamp
Message-ID: <199709010607_MC2-1EB4-19BB@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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mike Bess and Stovers:

The WOOD-GAS stove also has the potential for being to converted to
lighting using mantle lamps. In particular, Anil Rajvanshi and I are
working on improving the mantle itself. It is too fragile and is slightly
radioactive, but is still the only option for half the world's population.
When we get an acceptable WOOD-GAS stove we can start working on lighting.
Food first.

TOM REED

From shashi at md2.vsnl.net.in Tue Sep 2 11:37:06 1997
From: shashi at md2.vsnl.net.in (SHASHI KUMAR)
Date: Tue Aug 31 21:35:32 2004
Subject: Gasification of wood and agro wastes
Message-ID: <1.5.4.32.19970902161041.006631f4@md2.vsnl.net.in>

>From
Shashi Kumar
Aum Consultancy Pvt Ltd.,
89 A, Santhome High Road,
Madras -600028 ( South India)

Dear Sirs,
We have been reading your correspondence on the gasification process and the
stove designs. We are interested in a modern design of gasification of agro
wastes, such as paddy husk, saw wood powder, and groundnut shells etc. Is
it possible to have a continuous process of gasification of the same? We
would like to have a stove which can gasify 20000Kgs of paddy husk per day
of 24 hrs working. Can you indicate the quantity of bio-gas that can be
generated per Kg of paddy husk?
We being Consultants , sourcing different technologies for our various
clients, would like to get associated with you on business terms for mutual
benefits. We look forward to your interest in the matter so that we can
discuss further in the matter in person.

Thanking you,
Yours faithfully
Shashi Kumar

From owl at owlsnest.com Tue Sep 2 23:44:44 1997
From: owl at owlsnest.com (owl@owlsnest.com)
Date: Tue Aug 31 21:35:32 2004
Subject: Is Your Web Site A Secret?
Message-ID: <199709030340.XAA25291@owlsnest.com>

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From krksmith at uclink4.berkeley.edu Wed Sep 3 11:25:23 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:32 2004
Subject: No Subject
Message-ID: <199709031527.IAA25301@uclink4.berkeley.edu>

Publication notice

The United Nations Development Programme has published a 176-page report
entitled

Energy After Rio: Prospects and Challenges

which has several useful sections related to household biomass use in
developing countries including several pages on the non-engineering aspects
of improved stoves programs.

It is available from

Energy and Atmosphere Programme
Sustainable Energy and Environment Division
UNDP
1 UN Plaza
New York City 10017

You can probably obtain single copies for no cost, although if they receive
too many requests you may be referred to the UN Bookstore.

Best/K

----------------------------------------------------------------------------
Prof. Kirk R. Smith, EHS Fax: 510-642-5815
SPH, 140 Warren #7360 Email: KrkSmith@uclink4.berkeley.edu
University of California
Berkeley CA 94720 Senior Fellow, Program on Environment
Phone: 510-643-0793 East-West Center, Honolulu HI

From wrw2 at cconnect.net Wed Sep 3 23:41:48 1997
From: wrw2 at cconnect.net (william r wilson)
Date: Tue Aug 31 21:35:32 2004
Subject: part list
Message-ID: <01BCB8C4.1ED66880@ppp151.cconnect.net>

need drive belt for js-20000 jet stream oven

From taz at marsweb.com Wed Sep 3 23:57:09 1997
From: taz at marsweb.com (Leslie McDonald)
Date: Tue Aug 31 21:35:32 2004
Subject: Majastic cook stoves
Message-ID: <340E30B4.6553@marsweb.com>

I am trying to find out the year our stove was manufactured. I haven't
had any luck so far. Any help would be appreciated. thanks

From krksmith at uclink4.berkeley.edu Fri Sep 5 02:19:31 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:32 2004
Subject: No Subject
Message-ID: <199709050621.XAA31712@uclink4.berkeley.edu>

Note, the next issue of the stove journal, Boiling Point, put out by the
Intermediate Technology Development Group of the UK, is to be devoted to
health issues. The editor,
Elizabeth Bates <elizabethb@itdg.org.uk>, is soliciting short articles for
inclusion in the issue.

From elk at arcc.or.ke Fri Sep 5 05:26:14 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <v01510104b03587e313d0@[199.2.222.151]>

Stovers;

Been a quiet week! Where is everyone?

I've been running two and sometimes 3 trials per day on five variants of
the 2can, and come to the conclusion that pre-heated secondary air is not a
good thing.

As Alex intimated previously, the hot air attenuates too much & the O2
level drops as the air expands.

On the other hand, insulation around the combustion chamber does help, but
not (apparently) a great deal. Indications are that insulation will improve
FOM by around 5% only.

After discarding several stove designs incorporating different methods of
preheating secondary air, the following general observations on the
charcoal-making stove have been made:

1) Fuelwood should be loosly packed for even burning.Dry wood obviously
gives the best results in terms of charcoal production and flame holding.

2) Top-lighting with kindling and paper can result in obstruction to
airflow. Carbonised residue of kindling should be physically broken up.

3) The single most critical control parameter is the exhaust gap. This
should be narrow enough to control airflow and burn rate while being large
enough to maintain sufficient air inflow via secondary inlets to maintain a
flame in the combustion chamber. I've seen no need to make this a variable
control, but it might be an idea worth investigating.

4) Turbulance at the point where secondary air combusts volatile gasses
reduces flame holding. A laminar air flow is best.

5) The best way to extinguish live charcoal produced by the stove is within
a closed metal can. Leave a very small pin-prick hole somewhere, or the can
will slowly 'implode' on cooling if well sealed.

6) A perforated 'fuel cell' allows for the most even & controlled pyrolisis
of fuelwood. Solid walled fuel enclosures inhibit pyrolisis at point of
contact with the wood.

7) Control devices on secondary air inflow should be designed to allow for
100% closure of airflow. If the stove is working properly, the primary air
should be completely closed just before water comes to a boil (8 to 10
minutes after lighting) and remain closed until 8 to 10 minutes before
complete pyrolisis. The latter timing may be reduced as the stove is
improved, but flame holding normally fails just before pyrolisis of the
fuelwood is complete, and primary air can be introduced at this time to
continue cooking. When the flame fails for the first time like this, plenty
of white smoke is produced. When pyrolisis is complete, flame failure is
not accompanied by smoke- time to harvest your charcoal.

In view of the above, I'm reconstructing the 2can Mk 1 as pictured in
Alex's website to receive ambient temp. secondary air directly. The outer
skin which acted as an insulator, secondary air pre-heater and windbreak
has been removed and refactory cement will be used as insulation.

To date, my best reproduceable result has been FOM 1.0 and 23% charcoal. I
don't know if I'm going to improve on this.... I'm focussing on control and
convenience, as well as cost of manufacture now. Size variants are next,
all going well, from 500gm fuelchambers to a 200 litre drum.

Once I've settled on a final design, which should be soon, I'll ask Alex to
update the Website with more photos and some design sketches. Then I hope
several stovers will construct their own & we can work toward optimisation.

All for now;

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 Sep 5 21:42:34 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
In-Reply-To: <v01510104b03587e313d0@[199.2.222.151]>
Message-ID: <199709060144.VAA02953@adan.kingston.net>

Summary: "Laminar is best" Phooey. Turbulent is bester. So there.

> Stovers;
>
> Been a quiet week! Where is everyone?

ZZZZZZZZZ oh, OH, good morning Elsen, Stovers. Have I missed
anything.

> After discarding several stove designs incorporating different methods of
> preheating secondary air, the following general observations on the
> charcoal-making stove have been made:

This is good!

> 1) Fuelwood should be loosly packed for even burning.Dry wood obviously
> gives the best results in terms of charcoal production and flame holding.
>
> 2) Top-lighting with kindling and paper can result in obstruction to
> airflow. Carbonised residue of kindling should be physically broken up.
>
> 3) The single most critical control parameter is the exhaust gap. This
> should be narrow enough to control airflow and burn rate while being large
> enough to maintain sufficient air inflow via secondary inlets to maintain a
> flame in the combustion chamber. I've seen no need to make this a variable
> control, but it might be an idea worth investigating.
>
> 4) Turbulance at the point where secondary air combusts volatile gasses
> reduces flame holding. A laminar air flow is best.

Now I have to object. This is a gross generalization extrapolated
from a particular set of circumstances........... However, if it
works, use it.

This problem of combustion gas mixing under natural convection has
many solutions demonstrated by the current oil stoves for space
heating. Most of them use many small air holes, and a web of
stainless steel (a porous bluff body) to cause turbulence in the
flame. In one case a hybrid uses a mesh cylinder which is positioned
vertically with a solid top. Presumably this shortens and stabilizes
the flame. I think a shorter flame is a worthwhile goal. The question
is how? (Did someone mention a venturi.)

> 5) The best way to extinguish live charcoal produced by the stove is within
> a closed metal can. Leave a very small pin-prick hole somewhere, or the can
> will slowly 'implode' on cooling if well sealed.
>
> 6) A perforated 'fuel cell' allows for the most even & controlled pyrolisis
> of fuelwood. Solid walled fuel enclosures inhibit pyrolisis at point of
> contact with the wood.
>
> 7) Control devices on secondary air inflow should be designed to allow for
> 100% closure of airflow. If the stove is working properly, the primary air
> should be completely closed just before water comes to a boil (8 to 10
> minutes after lighting) and remain closed until 8 to 10 minutes before
> complete pyrolisis. The latter timing may be reduced as the stove is
> improved, but flame holding normally fails just before pyrolisis of the
> fuelwood is complete, and primary air can be introduced at this time to
> continue cooking. When the flame fails for the first time like this, plenty
> of white smoke is produced. When pyrolisis is complete, flame failure is
> not accompanied by smoke- time to harvest your charcoal.

I have seen the same thing.

I did a small demo for my relatives with a juice can and wet sand
around the base to control primary air. When the sand started to
sizzle, I knew it was about finished. The pyrolysis zone had
travelled down to the base. Time to harvest.

ale

> 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 verhaarp at janus.cqu.edu.au Sat Sep 6 02:05:19 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <1.5.4.32.19970906060635.006a734c@janus.cqu.edu.au>

Dear Elsen,

At 12:27 5/09/97 EAT, you wrote:
>Stovers;
>
>Been a quiet week! Where is everyone?

Mea culpa maxima!
I will give comment in the near future. You are doing great work. Don't get
discouraged by our silent admiration.

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

From larcon at sni.net Sat Sep 6 12:48:12 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:33 2004
Subject: Gasification of wood and agro wastes
Message-ID: <v01540b00b0372be4c056@[204.133.251.22]>

Shashi:

You said:

>From
>Shashi Kumar
>Aum Consultancy Pvt Ltd.,
>89 A, Santhome High Road,
>Madras -600028 ( South India)
>
>
>Dear Sirs,
>We have been reading your correspondence on the gasification process and the
>stove designs. We are interested in a modern design of gasification of agro
>wastes, such as paddy husk, saw wood powder, and groundnut shells etc. Is
>it possible to have a continuous process of gasification of the same? We
>would like to have a stove which can gasify 20000Kgs of paddy husk per day
>of 24 hrs working. Can you indicate the quantity of bio-gas that can be
>generated per Kg of paddy husk?

(RWL): The "stoves" list discussion of gasification (actually mostly
charcoal-making) has been mostly limited to household scale stoves (a small
discussion also of using the same principles with units of scale up to
about 2 meters). All of our discussion has been about batch stoves, with
top-lighting of a solid biomass material which would make "chunk" charcoal.
Most of your proposed materials would probably not be successful, although
there certainly are means of producing charcoal from fine material and
using the waste gases. You should review our past mention of work by
Professor Grover (of India) on this subject.

To gasify 20,000 kg per day of material, our group would be
thinking of many thousands of separate cook stoves. A major part of the
motivation for such stoves is the superior production of charcoal - with
productive utilization (through cooking) of the valuable waste gases
usually lost in charcoal making. Since you have not mentioned charcoal, I
believe you should send almost this same message to the "gasification"
list, also under "CREST". If you are interested in efficient charcoal
production from your materials, I hope you will join our "stoves" list.

>We being Consultants , sourcing different technologies for our various
>clients, would like to get associated with you on business terms for mutual
>benefits. We look forward to your interest in the matter so that we can
>discuss further in the matter in person.
>
>Thanking you,
>Yours faithfully
>Shashi Kumar

(RWL): Best of luck in your endeavors. 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 Sep 6 23:55:23 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <v01540b04b036704edb0d@[204.133.251.22]>

Summary - some more comments and questions on Elsen's further tests and new
results and conclusions.

Elsen:

>Been a quiet week! Where is everyone?
>
Ron: For me - catching up from the heavy US labor day weekend - and
waiting for your promised report - which was excellent.

Elsen:
>I've been running two and sometimes 3 trials per day on five variants of
>the 2can, and come to the conclusion that pre-heated secondary air is not a
>good thing.
>
>As Alex intimated previously, the hot air attenuates too much & the O2
>level drops as the air expands.

Ron: I'm not understanding this issue. I've often used some preheating
(can't quantify how much temperature rise) as part of the wind shielding
and didn't notice a problem. Why do we see so much in stove and furnace
literature about preheating air, if there is a problem? Any theorists out
there on this topic?

Elsen:
>On the other hand, insulation around the combustion chamber does help, but
>not (apparently) a great deal. Indications are that insulation will improve
>FOM by around 5% only.

Ron: This is an interesting observation. We need a total energy balance
(which is very difficult to do, I'm afraid). I would have guessed a bigger
influence of upper insulation.
In efficiency terms, an FOM change of 5% gives an efficiency
improvement of less than 1% (2% if all wood were consumed instead of about
half the initial energy coming out as charcoal). These estimates assume
that fairly wet wood is used with an initial wood energy of 15 MJ/kg (and
latent heat of water-steam of 2.5 MJ/kg). Thus the ratio of efficiencies is
about 1/6 of the ratio of weights (which is the FOM). I am surprised that
the impact of radial heat loss is not greater. The question is where the
2/3 of that energy not in the charcoal goes, if not radially. See below
for more on this. Actually, if your efficiency as a stove is around 33%,
(FOM=1) this is pretty good in the world of stoves.

Elsen:
>After discarding several stove designs incorporating different methods of
>preheating secondary air,

Ron: Maybe you can tell us more about those you didn't like.

Elsen:
>the following general observations on the
>charcoal-making stove have been made:
>
>1) Fuelwood should be loosly packed for even burning. Dry wood obviously
>gives the best results in terms of charcoal production and flame holding.

Ron: With relatively non-uniform branches, I think you should put in
as much wood as you can. With straight pieces - and used milled pieces,
more looseness is very important. Do you agree - or how can we define
looseness?
>
>2) Top-lighting with kindling and paper can result in obstruction to
>airflow. Carbonised residue of kindling should be physically broken up.
>
Ron: I agree; I find good results with pine needles. What are you using
to start with?

>3) The single most critical control parameter is the exhaust gap. This
>should be narrow enough to control airflow and burn rate while being large
>enough to maintain sufficient air inflow via secondary inlets to maintain a
>flame in the combustion chamber. I've seen no need to make this a variable
>control, but it might be an idea worth investigating.

Ron: Are you still in the 6 mm range?
>
>4) Turbulance at the point where secondary air combusts volatile gasses
>reduces flame holding. A laminar air flow is best.

Ron: I just received Alex' disagreement with you on this point (and will
respond to his comments also). Is your reason for favoring laminarity only
that of flame holding (which is a plenty good reason)? This seems like a
very important point of disagreement (and I only have used laminarity, so
am in no position to argue).
>
>5) The best way to extinguish live charcoal produced by the stove is within
>a closed metal can. Leave a very small pin-prick hole somewhere, or the can
>will slowly 'implode' on cooling if well sealed.

Ron: And in your case, you are always adding the closed metal can, I
gather - not moving the charcoal to the can.
>
>6) A perforated 'fuel cell' allows for the most even & controlled pyrolisis
>of fuelwood. Solid walled fuel enclosures inhibit pyrolisis at point of
>contact with the wood.

Ron: This is still amazing to me. I haven't tried this, but can see that
it should certainly give better conversion near the container wall. I
would never have guessed that this would work. See also below on this,
however.
>
>7) Control devices on secondary air inflow should be designed to allow for
>100% closure of airflow.

Ron: I think this is the first time you have said you did this. This must
be only for final extinguishment? Or did you mean "primary air" in this
sentence?

>If the stove is working properly, the primary air
>should be completely closed just before water comes to a boil (8 to 10
>minutes after lighting) and remain closed until 8 to 10 minutes before
>complete pyrolisis.

Ron: This conclusion must be a function of the fact that you have
perforated metal for the fuel holder (which allows plenty of air to enter
radially inward, below the pyrolysis zone, I would think). Are you
controlling this type of primary air also? I am worried that you have
essentially no air control (if the optimum is zero primary), and therefore
may not be able to optimize efficiency/FOM. Is this possibly a reason not
to use perforated metal (and thereby maybe accept incomplete pyrolysis)?

>The latter timing may be reduced as the stove is
>improved, but flame holding normally fails just before pyrolisis of the
>fuelwood is complete, and primary air can be introduced at this time to
>continue cooking. When the flame fails for the first time like this, plenty
>of white smoke is produced. When pyrolisis is complete, flame failure is
>not accompanied by smoke- time to harvest your charcoal.

Ron: I have found essentially the same. At the end of the run, maybe
little primary air can get in through the perforated metal as the pyrolysis
zone is so low. Might this be the reason for losing the flame?
>
>In view of the above, I'm reconstructing the 2can Mk 1 as pictured in
>Alex's website to receive ambient temp. secondary air directly. The outer
>skin which acted as an insulator, secondary air pre-heater and windbreak
>has been removed and refactory cement will be used as insulation.
>
Ron: I haven't seen the new pictures yet. But this sounds like an
invitation to have more problems with any wind. I presume the new picture
will show how wind shielding is accomplished.

>To date, my best reproduceable result has been FOM 1.0 and 23% charcoal. I
>don't know if I'm going to improve on this....

Ron: I would think the FOM should be a strong function of moisture
content. Are you still using a combination of wet and dry fuel? I also
think FOM should be reduced with excess secondary air. Is it possible that
the secondary air is too large and should be reduced?

I've been trying to think through the question you asked several
weeks ago about optimizing the boiling - as a way of improving FOM. I
found a chapter (#13) on boiling in the book "Convective Heat Transfer" by
Louis C. Burmeister, This shows that the heat transfer coefficient from
metal to water can decrease by more than a factor of 10 with a relatively
small change in the metal - water temperature difference. There is an
optimum rate of bubble formation. Above this value, the steam production
serves as a "film" barrier to good heat transfer. There are also material
and surface finish (polished has the best and worst temperatures closer
together) effects. To summarize, I believe you want first to be sure that
all steam bubbles formed make it to the top surface. You do not want to
form a continuous film, which will occur at a higher stove-gas temperature.
Perhaps you are already at the right power level, but maybe you should
either raise or lower the power level to improve the FOM.

All this makes me wonder whether one can really do comparisons
using evaporation techniques, unless everyone is using the same pot.

>I'm focussing on control and
>convenience, as well as cost of manufacture now. Size variants are next,
>all going well, from 500gm fuelchambers to a 200 litre drum.
>
>Once I've settled on a final design, which should be soon, I'll ask Alex to
>update the Website with more photos and some design sketches. Then I hope
>several stovers will construct their own & we can work toward optimisation.
>
>All for now;
>
>elk

Elsen - good work!

1. Can you say a bit more about your convenience ideas? Are any of your
units being used by local families for ordinary cooking? What do the cooks
now think about the convenience of your units?

2. Now the list needs to have a good hard argument about turbulence. See
my upcoming note to Alex.

3. My only real concern now is the idea of your dropping to zero primary
air - which you may need because of your perforated fuel "cage". I wonder
if we might find some other solution to the partial pyrolysis problem near
the cell boundary. Maybe there can be something like a "crinkly-solid"
wall (amplitude of a few mm?) or maybe a "spongy-but-not permeable" wall.

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 Sep 7 07:09:22 1997
From: phait at transport.com (Paul w. Hait)
Date: Tue Aug 31 21:35:33 2004
Subject: a stoves mailing list
Message-ID: <199709071111.EAA18380@spanky.transport.com>

>Looks great to me!
>
>Art Krenzel
>
>----------
>> From: Ronal W. Larson <larcon@sni.net>
>> To: stoves@crest.org
>> Subject: Re: a stoves mailing list
>> Date: Friday, August 29, 1997 9:21 PM
>>
>> I started making a stoves mail list from the first three responses - and
>> found all were k's. This seems to be so improbable that I decided to
>stop
>> while ahead and ask the group whether the following format is the right
>> one. Ron

>> Paul W Hait/ President of Pyromid Inc.
Plant 3292 S. Hwy.97 Redmond,Oregon 97756
or PO Box 4665 Sunriver, Oregon 97707
541.593.3505/ FAX 541. 923.1004
E-mail phait@transport.com
>>
>> Elsen Karstad, P.O Box 24371 Nairobi, Kenya
>> Tel:254 2 884437
>> E-mail: elk@arcc.or.ke
>>
>> Ronald Kent, PO Box 23131, Federal Way, WA 98093
>> 253/952-6478
>> shell@wolfenet.com
>>
>> Art Krenzel, 10505 N.E. 285th Street, Battle Ground, WA 98604
>> (360)666-1883 Phone, (360)666-1884 FAX
>> phoenix@transport.com
>>
>> Ronal W. Larson, PhD
>> 21547 Mountsfield Dr.
>> Golden, CO 80401, USA
>> 303/526-9629; FAX same with warning
>

From REEDTB at compuserve.com Sun Sep 7 08:35:24 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: ELK stove
Message-ID: <199709070837_MC2-1F76-6DE5@compuserve.com>

How exciting this continuing back and forth of new experiments and
observations from those active in stoves! I presume this is the first time
in the history of our solar system that so widely separated a group of
dedicated individuals have cooperated to work toward so important a goal.

Each successful experiment seems to lead to others and we are making rapid
progress toward the dream of a clean burning, SIMPLE wood-gas stove. I
know the excitement of several runs per day.

I also have long sought the answer to the top lighting, and I know what you
mean about not having the paper or other ignition source obstruct gas flow
after startup. I have long dreamt (and occasionally tested) a pyrotechnic
lighter/distributor. At the touch of a match, it would ignite instantly
over the whole surface and burn to a char mesh (0.5-1.0 cm openings) which
would sit on top of the fuel and give an even distribution to the rising
gases as they approach the burner. I have experimented with wide mesh
burlap or jute woven circles soaked in ammonium nitrate. They worked to
SOME extent, but I need to get some KNO3 as oxidant. (The ammonium nitrate
seems to consume itself and not affect the burlap.) (... Does anyone
know why gunpowder uses KNO3 instead of NaNO3 which contains a higher
proportion of O2?)

I have railed against the name "charcoal making stove" and I'll rail again.
Certainly charcoal making is a major feature for our prospective users in
SOME parts of the world. However, WOOD-GAS really describes more
accurately the feature that distinguishes this stove from all the thousands
of WOOD stoves developed in the last 20,000 years. And, "cooking with gas"
is a very desirable feature to anyone who has used both wood and gas
(propane) for cooking. There is no comparison in time, control,
cleanliness, simplicity.

Looking forward to a sufficient description of the ELK stove on the AE
website so that I can make one and catch up on the progress of the last few
months.

Yours truly, TOM REED

From REEDTB at compuserve.com Sun Sep 7 08:35:46 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: Figures of merit for gasifiers and stoves
Message-ID: <199709070837_MC2-1F76-6DF4@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Netters:

Here is a subsection I recently wrote for our upcoming book. I would be
interested in your comments. Sorry about the less than perfect formatting,
but maybe this is better than encoding.

1.2 Gasifier Comparison with "Figures of Merit"

While it is necessary to collect data specific to particular gasifiers,
it is quite difficult to compare performance between different types and
sizes. There are a number of "figures of merit" that reduce data from
various gasifiers to a common denominator so that one can compare gasifiers
that are widely different in scale and type, just as the listing of "price
per kg" of various products in the supermarket makes it possible to
determine unit costs without carrying a computer to the store.

1.2.1 SUPERFICIAL GAS VELOCITY, SGV (AREA THRUPUT)

The superficial gas velocity (SGV) is easily calculated from the most
basic information on gasifiers, ie
SGV = Gas production (m3/sec)/Internal Cross Section Area (m2)
The superficial velocity has long been used to compare widely different
gasisfiers. Many other factors are easily derived from this number or used
to derive this number.

The word "superficial" refers to the fact that it is based on the gas
production measured at normal temperature and pressure (not at gasifier
temperature) and uses the gasifier internal diameter without reference to
internal fuel or equipment. The word "velocity" refers to the fact that
m3/m2-sec has the units of velocity, m/sec (or m/hr), so the SGV refers to
the velocity below the grate corrected to room temperature. (Cute?) It
might be more properly called the area thruput, but we will use the
historic term here.
In addition, the SGV has a major influence on the conditions and products
of gasification and these will be discussed in Volume II.

The following table illustrates comparison of the SGV of a number of
gasifiers.
Table 1 Maximum Reported Superficial Gas Velocity of Various Gasifiers
GASIFIER TYPE ID AREA MAX FLOW SV
m m2 m3/sec m3/m2-sec
Imbert Nozzle Downdraft 0.30 0.071 0.045 0.63
SERI Air Stratified Downdraft 0.15 0.018 0.005 0.28
SERI Oxygen Str Downdraft 0.15 0.018 0.004 0.24
Syn-Gas - Air Str Downdraft 0.76 0.454 0.776 1.71
Syn-Gas - Oxy Str Downdraft 0.76 0.454 0.485 1.07
Buck Rogers Str Downdraft 0.61 0.292 0.126 0.43

(Notes: From Reed, 1988, Hanbook....; Imbert gasifier measured at ID, not
constriction. Buck Rogers from Chern thesis, 1985. )

The SERI experimental gasifier had the lowest thruput, while it's
offspring, the Syn-Gas gasifier has the highest (due to its enclosed
refractory top). None of these relations would be evident from the raw
data, and were not evident at the time of operation.

THERMAL POWER: If one knows the heating value of the gas (HV), the
thermal thruput is calculated from:
P(th) = HV X SGV
The air gasifiers listed above typically produce gas with a heating value
of 5 MW/m3. The oxygen gasifiers produce a gas with a heating value of 10
MW/m3. These give the power thruputs shown in Table 1 .
~~~~~
Gasifier SGV Pth Pel SFV
SGProduction
m3/m2-s MWth MWe mm/sec m3/m2-hr
Imbert 0.6 3.2 0.95 0.5 84
Buck Rogers 0.4 2.2 0.65 0.3 57
SERI Air 0.3 1.4 0.42 0.2 37
SERI Oxygen 0.2 1.2 0.36 0.2 32
Syn-Gas - Air 1.7 8.6 2.57 1.2 228
Syn-Gas - Oxygen 1.1 5.4 1.61 0.8 143
Notes: gas heat content 5 MJ/m3; El efficiency 30%; particle size 3
cm; 18 Gj/m3, gasifier efficiency 0.7.
~~~~
ELECTRIC POWER:
If the efficiency [e (p)] of power generation using the gas is known, the
power thruput is given by
P(e) = e (p) X HV X SV
and values for the gasifiers above are shown in Table 2.

SUPERFICIAL FUEL VELOCITY (SFV):

If one knows the bulk density of the fuel, the fuel density (typically
200 kg/m3 for wood chips) , the heating value of the fuel (typically 18
GJ/m3), the efficiency of gasification (typically 0.7) and the heating
value of the fuel one can calculate the velocity of fuel flow at steady
state in the gasifier from the energy balance as
SFV = r X e (g)X SGV X HG/HF
These velocities are shown in Table 2. (They are shown in mm/sec because
they are so small relative to the gas velocities. Multiply by 3.6 to get
m/hr.)

1.2.2 SUPERFICIAL GAS PRODUCTION (SGP):
While superficial gas velocity is a measure of gas production per unit
cross section, the superficial gas production is a measure of production
rate per unit volume, where h is the active bed height of the of the
gasifier (where heat losses occur and insulation is required).

SGP = Gas volume per sec/gasifier volume = SGV/ h´A
(m3gas/m3vessel-sec)

(As a reference, biogas digestors typically produce 1 m3 of gas/m3 of
vessel per hour. We once calculated the methane production from cow
stomachs as 7 m3 gas/m3 stomach-hr. It is seen in Table ? that gasifiers
produce gas at 50-200 times the rate.)
In fluidized beds, the active zone only depends on the vessel dimensions.
In fixed bed gasifiers the height of the bed is difficult to determine, and
depends particularly on fuel size and moisture content. These will be
discussed in more detail in Volume II. For now the 3,6,9 RULE illustrates
the calculation. Typically the flaming combustion zone is 3 particle
diameters and the char gasification zone is 6 particle diameters, so the
active zone is 9 particle diameters or 36 cm high. Thus the active bed
height for a 4 cm particle fuel will be Vessels may be much larger, but the
remainder is typically fuel magazine. The SGP for the various gasifiers
of Table 1 are shown in Table 2.

1.2.3 Significance of SGV and SGP:

While the SGV is a measure of how big the "footprint" of the gasifier
will be (cross section area), the SGP is a measure of the volume occupied,
and the relative mass and construction cost. It is also inversely
proportional to heat loss. The SGV of a fluidized bed is typically high
because of the necessity of supporting the fuel on a column of gas, and so
fluidized bed gasifiers tend to be quite tall. The SGV of fixed bed
gasifiers is much lower because of the very compact reaction zones.
However, fixed bed gasifiers typically have higher gas production per unit
volume as shown by the SGP figures above. ...(Waiting for data on
fluidized bed SGP and SFV.) But Fbs are typically 3-10 m tall, compared to
reaction zones of 0.2-1m in fixed bed gasifiers.)

Stovers: I believe that the wood-gas stove gasifier has a superficial gas
velocity of 0.02 m/s, over an order of magnitude less than the gasifiers
above. I believe this explains the charcoal yield of 25% rather than <5%
in the gasifiers above, due to the lower pyrolysis temperatures.
~~~~
I hope some of you will wish to calculate the SGV and SGP figures for
your own gasifiers and that you may wish to send them to me. I may include
them in the database, and I will include them in discussion. I also hope
that you may know other names that are officially used.

Thanks to all, TOM REED

From REEDTB at compuserve.com Sun Sep 7 08:52:12 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <199709070837_MC2-1F76-6DE6@compuserve.com>

Good comments on extinguishing. Also consider the possibility of having
water under the grate so that as the fire gets close, it can boil the water
and automatically extinguish the flame.

Good comments on need for absolute air cutoff and fine control. I have
mentioned before that dry wood MAY auto-pyrolyse, once started. So, it is
necessary to have VERY LITTLE air, once the stove is going well, to provide
gas for cooking. So, your air control needs to be logarithmic - then off.

I agree that the insulation needs in the pyrolysis zone are minimal.
However, I'm surprised to hear you say that it isn't very important in the
combustion zone. I have observed the inside of my 1/2 inch thick riser
sleeves glowing brightly with the outside can too hot to touch. Maybe your
air flow is different, so maybe my surprise is unfounded.

Regards, TOM REED

From english at adan.kingston.net Sun Sep 7 19:09:04 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
In-Reply-To: <v01540b04b036704edb0d@[204.133.251.22]>
Message-ID: <199709072310.TAA19044@adan.kingston.net>

Ron said in reference to Elsen's comments:
> I am surprised that
> the impact of radial heat loss is not greater. The question is where the
> 2/3 of that energy not in the charcoal goes, if not radially.

We need an exhaust temperature and an excess air factor to determine
the amount of heat exiting the stove with the flue gasses. I went to
the local scrap metal dealer today. I now have the materials to build
some Elk Stoves and boil some water. I'll see if I can measure the
various energy flows.

Elsen, is the water boiling all the way up the sides of your pot? I
visited with Eric Brunet of the Brace Research Institute a
few weeks ago while he made apple sauce in a 20 litre pot on one of
their "improved stoves". The shield around the pot extended to the
top and the sauce was boiling all the way up the sides.

Has anyone seen a pot with heat exchange fins on the outside?

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 verhaarp at janus.cqu.edu.au Sun Sep 7 19:31:08 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:33 2004
Subject: ELK stove
Message-ID: <1.5.4.32.19970907233225.006b2718@janus.cqu.edu.au>

Dear Tom,

At 08:37 7/09/97 -0400, you wrote, among many other things:
>I have experimented with wide mesh
>burlap or jute woven circles soaked in ammonium nitrate. They worked to
>SOME extent, but I need to get some KNO3 as oxidant. (The ammonium nitrate
>seems to consume itself and not affect the burlap.) (... Does anyone
>know why gunpowder uses KNO3 instead of NaNO3 which contains a higher
>proportion of O2?)

Or instead of NaNO3. Same reason, only KNO3 is not hygroscopic. The (wet)
NH4NO3 probably melts and runs out of the burlap.

Will get back on the discussions soon.

Be of good cheer,

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 elk at arcc.or.ke Mon Sep 8 01:55:39 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:33 2004
Subject: turbulance & the charcoal making stove
Message-ID: <v01510100b039698f6b8d@[199.2.222.151]>

In defense of laminar secondary air inflow for efficient combustion of
pyrolisis gasses within the charcoal making stove............... Alex?

I guess it depends on the calorific value of the gas- comparisons with
liquid fuels may not be valid. Bluff bodies may act as surface attractants
to concentrate gasses in a specific area for more intense & thouough
combustion.

More trials being conducted on 2can mk5

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 Mon Sep 8 04:16:42 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:33 2004
Subject: Response to English
Message-ID: <v01510102b0397c56d4e2@[199.2.222.131]>

>We need an exhaust temperature and an excess air factor to determine
>the amount of heat exiting the stove with the flue gasses. I went to
>the local scrap metal dealer today. I now have the materials to build
>some Elk Stoves and boil some water. I'll see if I can measure the
>various energy flows.
>

Glad to get some support, Alex! Theory's fine, but the Field Test is Best!
I've instrument envy, Alex. Very curious to receive your test results.

>
>Elsen, is the water boiling all the way up the sides of your pot? I
>visited with Eric Brunet of the Brace Research Institute a
>few weeks ago while he made apple sauce in a 20 litre pot on one of
>their "improved stoves". The shield around the pot extended to the
>top and the sauce was boiling all the way up the sides.

Yes, the water is boiling all the way up & 'round. I reckon that the rate
of evap. due to boiling decreases with lowered water levels as the trial
continues.

>
>Has anyone seen a pot with heat exchange fins on the outside?
>
Nope. Trust you to think of that. How about spirals? Longer path.
I'm using aluminium pots- as per the local standards.

>Alex

elk

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

From REEDTB at compuserve.com Mon Sep 8 09:40:37 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: Rice Hull Gasification
Message-ID: <199709080942_MC2-1F97-C91C@compuserve.com>

I would send this to you directly, but you didn't include your E-mail
address in your statistics.

If you are interested in gasification of quantities of biomass STOVES is
the wrong forum - you should send "subscribe gasification" to
majordomo@crest.Org because there we discuss small and large gasifiers for
rice husk (paddy) and other biomass. You should look into the archived
files since there has been considerable discussion of rice husks.

Louisiana State University has just published "A Study of the Market for
Rice Husk-to-Energy Systems and Equipment" in cooperation with the National
Renewable Energy Lab (NREL), ( I was one of the authors.) It discusses
gasification of rice hulls at all scales. You can get a copy from Prof.
Lakshman Velupillai at 504 388 6963; 504 388 6775FAX.

We also have other books on rice hull and general gasification for sale at
the Biomass Energy Foundation (see below).

Yours truly, TOM REED
~~~~
BOOKS FROM THE BEF PRESS

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We also act as a clearinghouse to locate technical assistance for biomass
projects. Thomas
B. Reed
HANDBOOK OF BIOMASS DOWNDRAFT GASIFIER ENGINE SYSTEMS
T. B. Reed and A. Das Over a million wood gasifiers were used to power
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~~~~

Date: Sat, 6 Sep 1997 10:53:51 -0600
From: larcon@sni.net (Ronal W. Larson)
Subject: Re: Gasification of wood and agro wastes

Shashi:

You said:

>From
>Shashi Kumar
>Aum Consultancy Pvt Ltd.,
>89 A, Santhome High Road,
>Madras -600028 ( South India)
>
>
>Dear Sirs,
>We have been reading your correspondence on the gasification process and
the
>stove designs. We are interested in a modern design of gasification of
agro
>wastes, such as paddy husk, saw wood powder, and groundnut shells etc. Is
>it possible to have a continuous process of gasification of the same? We
>would like to have a stove which can gasify 20000Kgs of paddy husk per day
>of 24 hrs working. Can you indicate the quantity of bio-gas that can be
>generated per Kg of paddy husk?

To gasify 20,000 kg per day of material, our group would be
Thinking of many thousands of separate cook stoves. A major part of the
motivation for such stoves is the superior production of charcoal - with
productive utilization (through cooking) of the valuable waste gases
usually lost in charcoal making. Since you have not mentioned charcoal, I
believe you should send almost this same message to the "gasification"
list, also under "CREST". If you are interested in efficient charcoal
production from your materials, I hope you will join our "stoves" list.

>We being Consultants , sourcing different technologies for our various
>clients, would like to get associated with you on business terms for
mutual
>benefits. We look forward to your interest in the matter so that we can
>discuss further in the matter in person.
>
>Thanking you,
>Yours faithfully
>Shashi Kumar

From REEDTB at compuserve.com Mon Sep 8 09:40:38 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <199709080942_MC2-1F97-C924@compuserve.com>

Replying to the following:
>RON I've been trying to think through the question you asked several
weeks ago about optimizing the boiling - as a way of improving FOM. I
found a chapter (#13) on boiling in the book "Convective Heat Transfer" by
Louis C. Burmeister, This shows that the heat transfer coefficient from
metal to water can decrease by more than a factor of 10 with a relatively
small change in the metal - water temperature difference. There is an
optimum rate of bubble formation. Above this value, the steam production
serves as a "film" barrier to good heat transfer.

COMMENT: There is certainly a maximum rate of heat transfer to water
through metal, above which film formation lowers heat transfer (above 2kW
/cm2 if memory serves). HOWEVER, I don't think we approach this rate even
with modern electric or gas stoves. So we are challenged to increase heat
transfer, since time to boil and cook and probably inverse of total heat
loss is directly proportional to heat transfer rate times heated area.

>RON: All this makes me wonder whether one can really do comparisons
using evaporation techniques, unless everyone is using the same pot.

>I'm focussing on control and
>convenience, as well as cost of manufacture now. Size variants are next,
>all going well, from 500gm fuelchambers to a 200 litre drum.
>
>Once I've settled on a final design, which should be soon, I'll ask Alex
to
>update the Website with more photos and some design sketches. Then I hope
>several stovers will construct their own & we can work toward
optimisation.
>
Can't wait, TOM REED

From REEDTB at compuserve.com Mon Sep 8 09:40:57 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:33 2004
Subject: T. Reed to Stoves Mailing List
Message-ID: <199709080942_MC2-1F97-C91A@compuserve.com>

Here's my data in your format:

Thomas B. Reed, PhD
1810 Smith Rd.,
Golden, CO 80401 USA
PH: 303 278 0558 FAX 303 278 0560; reedtb@compuserve.com

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

How come you didn't put E-mail in your format????

TOM

From prasad at tn7.phys.tue.nl Mon Sep 8 09:55:14 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:33 2004
Subject: T. Reed to Stoves Mailing List
In-Reply-To: <199709080942_MC2-1F97-C91A@compuserve.com>
Message-ID: <9709081346.AA12986@tn7.phys.tue.nl>

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From remco at ds5500.cemr.wvu.edu Mon Sep 8 12:54:39 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:33 2004
Subject: Wood Stoves.
Message-ID: <34143D4B.45D4@ds5500.cemr.wvu.edu>

Wood stoves, I presume. I am interested in the topic and have always
wondered if someone has built one that distinctly seperated the gasifier
and gas combustor. The gasifier could be the controllable part while
the gas combustor automatically reacted by increasing or decreasing air
inflow to combust all of the available "smoke".

Curiously yours

Remco deJong
rdejong@wvu.edu

From elk at arcc.or.ke Mon Sep 8 14:55:42 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:33 2004
Subject: ...and two steps back...
Message-ID: <m0x88wB-0006ekC@arcc.or.ke>

Stovers;

It's been one of those days where the spanner that's been thrown into the
works hasn't lodged anywhere that helps the machine at all. Devolution.

After cutting away the windshield/secondary air preheater from the stove
pictured in AE's website (my original one), I had arranged for the 3mm
secondary air slit be widened a trifle (50% to 4.5mm). The result was more
like 1 cm.

Result: what happens to a wood gas charcoal making stove with too much
secondary air. Begin with poor lighting, as the too-large secondary air
inlet reduces the chimney flue flow of air up the stove & thereby restricts
primary air inflow. End with poor flame holding due (I think) to both wind
interference and non-laminar flow due to lack of upward flue flow. Again-
heap big smoke- little job satisfaction. You know you've gotten something
wrong when the occasional gust of wind results in smoke spouting
horizontally from the secondary air vent- coinciding usually with a 'flame out'.

The end results could have been worse- I perversly ran two trials anyway-
Ave. 1 hr 40 burn time, FOM .74 & 17% charcoal production. 20 min. to boil
5.5 kg water.

Did I ever downplay the importance of secondary air gaps? I think I did & I
was wrong. Another variable to seriously consider. At last count there were
about 7 serious variables in this stove. Several of which I have ignored to
date.

I'll answer more of your specific questions tomorrow, Ronal. I'm undertaking
some damage control on the stove at the moment & may return a bit of the
wind baffling too.

There's no doubt in my mind that pre-heating the secondary air does
influence flame holding. In what way? I assumed by O2 attenuation via air
expansion, but maybe there's another factor or two. I've applied insulation
on two stoves with known performances, resulting in increased temperature to
secondary air, and found that flame holding was reduced so much that the
stoves were rendered useless. A third stove design incorporated secondary
air rising (and heating) between two sheets of metal comprising the wall of
the pyrolisis chamber. Flame held well at first, and then became
unmanageable as the pyrolisis zone lowered and increasingly heated the
rising secondary air.

Ron; with reference to a previous correspondence, I've been setting my goals
at a FOM of 2 and 25% charcoal production. Is this still reasonable? I seem
to have hit the wall at FOM 1 and about 22%.

Tom: I know that 'cooking with gas' is an ideal that most East Africans
would aspire to & appreciate, but don't underplay the selling point of
charcoal production. The ability of NGO's & the 'marketplace' to disseminate
this stove once it's introduced to the public will probably be more a
function of the charcoal production issue more than what the flame actually
feeds on- at least hereabouts. That's the novelty and the financial
incentive combined. Controllability will simply be expected, so it better be
there.

A perforated fuel cell: It depends on the distance between the inner stove
wall and the fuel cell wall. Too big a gap dilutes pyrolisis gasses and
reduces flame holding at the 'lip' of the combustion chamber where secondary
air is introduced. Keep it to about 1 to 3 cm outside of a 20 cm diameter
fuel cell (for example), and there should be no difference between a
'krinkly-solid' or 'spongey' pyrolisis container wall and the perforated
fuel cell arrangement. Primary air enters from the bottom of the cell only.
A grid holds the fuel a couple cm above the vent and allows even air flow
upward into the cell. The resultant even pyrolisis of the wood fuel allows
gasses to exit the cell radially as well as vertically. This allows for a
greater concentration of gas at the 'lip'- the combustion interface between
fuel cell and secondary air inflow. This is also, in my mind, what a 'bluff
body' does.... it forces gas out from the centre of the stove to the edges
and concentrates it where the flame holding points are. This is always at
the edges. Tall unstable flame rising vertically up the centre of the stove
isn't good. This is what contacts the pot bottom and creates soot. We want a
short combustion chamber to concentrate heat on the objective- the cooking
pot. I've tried a disc held on three legs 2cm above the fuel cell rim and
level just above the secondary air inlet; it really looks like you're
cooking with gas (except the flame is yellow). The problem was that the heat
is forced out, not up & the FOM fell considerably. Flame held well though.

Too much! We might need to focus on fewer variables for a while. I like
sound of the newer perspectives on evolution- genetic saltation, or jumps,
finding recombinations that do surprising things. But that's not real
developmental science though is it? What's the difference between 'gut feel'
& guesswork?

Tomorrow's another trial. Thanks for your support, stovers. The questions
and suggestions are very important & keep things in perspective. This is
certainly a group effort!

elk

From english at adan.kingston.net Mon Sep 8 22:08:56 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:33 2004
Subject: Wood Stoves.
In-Reply-To: <34143D4B.45D4@ds5500.cemr.wvu.edu>
Message-ID: <199709090210.WAA20992@adan.kingston.net>

Dear Remco
Welcome aboard.

> Wood stoves, I presume. I am interested in the topic and have always
> wondered if someone has built one that distinctly separated the gasifier
> and gas combustor. The gasifier could be the controllable part while
> the gas combustor automatically reacted by increasing or decreasing air
> inflow to combust all of the available "smoke".

This list is primarily concerned with biomass cooking stoves for
the people who rely on them. Much of the recent discussion on this
list is about "close-coupled" gasifiers. Specifically a charcoal
making gasifier where the gasses are combusted right above the fuel.
Check the webpage listed below for additional information.

A few weeks ago I saw a pellet stove (still under development) which
is designed to burn high ash fuels in a similar manner only with out
the charcoal. However it relied on the flames to keep the pellets hot
enough to completely gasify. ( Not on the webpage)

The experiments that I did with the charcoal making gasifier come
close to fitting your description. I combusted the gasses in a
chamber above the gasifier. Distinct in so far as there was
essentially no heat transfer from the combustion chamber to the
gasifier and very little flame, if any, in the gasifier. Additional
information is on the webpage.

I hope you don't have to much trouble with the somewhat random
presentation of the webpage.

Here's to curiousness, Alex

> Curiously yours
>
> Remco deJong
> rdejong@wvu.edu
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From ShelC50 at aol.com Mon Sep 8 22:57:24 1997
From: ShelC50 at aol.com (ShelC50@aol.com)
Date: Tue Aug 31 21:35:33 2004
Subject: Antique Stove
Message-ID: <970908224506_67431626@emout09.mail.aol.com>

I too am trying to find out a year that my stove was manufactured. It is a
Chambers Stove...very old but very beautiful..I believe it was one of the
very first Chambers made...Did you find a source to locate the Year? If so
would you mind passing that information on to me. I have the model no. and
the Serial No. But am guessing the year to be 1920.

Thank you

From rovers at ad1.vsnl.net.in Tue Sep 9 09:15:59 1997
From: rovers at ad1.vsnl.net.in (Mr. Jwalant Desai)
Date: Tue Aug 31 21:35:33 2004
Subject: Biogas
Message-ID: <341535E9.1121@ad1.vsnl.net.in>

Dear Sir,

As you must be well aware India has ample of human, animal and
agricultural waste.
We have a group of people with us who are interested to generate power,
methane from bio waste.
We request you to send us all relevant details and catalogues regarding
the same.
Feel Free to contact the undersigned for any further details.
Hoping to hear from you very soon.
Best regards.
Jwalant Desai.

Rovers Marketing Pvt.Ltd.
302, sarthak complex,
Nr. Swastik Cross Road,
C.G.Road, Ahmedabad. 380009.
Gujarat.
India.

Phone : 0091 79 6447226.
Fax : 0091 79 6640270.
E-mail: rovers@ad1.vsnl.net.in

PS : While sending catalogues/samples always send by
DHL Courier [ Courier Mode ].

From rovers at ad1.vsnl.net.in Tue Sep 9 09:29:37 1997
From: rovers at ad1.vsnl.net.in (Mr. Jwalant Desai)
Date: Tue Aug 31 21:35:34 2004
Subject: Biogas.
Message-ID: <34153623.2BCD@ad1.vsnl.net.in>

Dear Sir,

PS : While sending catalogues/samples always send by
DHL Courier [ Courier Mode ].

From larcon at sni.net Tue Sep 9 23:33:21 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: ...and two steps back...
Message-ID: <v01540b06b03b87010b76@[204.133.251.19]>

Summary - This is a response to Elsen's message of 9 September on various
negative results.

elk:
<snip>
>After cutting away the windshield/secondary air preheater from the stove
>pictured in AE's website (my original one), I had arranged for the 3mm
>secondary air slit be widened a trifle (50% to 4.5mm). The result was more
>like 1 cm.
>
>Result: what happens to a wood gas charcoal making stove with too much
>secondary air. Begin with poor lighting, as the too-large secondary air
>inlet reduces the chimney flue flow of air up the stove & thereby restricts
>primary air inflow. End with poor flame holding due (I think) to both wind
>interference and non-laminar flow due to lack of upward flue flow. Again-
>heap big smoke- little job satisfaction. You know you've gotten something
>wrong when the occasional gust of wind results in smoke spouting
>horizontally from the secondary air vent- coinciding usually with a 'flame
>out'.
>
>The end results could have been worse- I perversly ran two trials anyway-
>Ave. 1 hr 40 burn time, FOM .74 & 17% charcoal production. 20 min. to boil
>5.5 kg water.

Ron: I'm afraid I don't quite appreciate the geometry any more. Does this
new geometry have a solid or a perforated fuel container? If perforated,
it would seem very sensitive to wind. The lack of "upward flue flow" can
probably ge handled with more combustion zone height.

elk:
>Did I ever downplay the importance of secondary air gaps? I think I did & I
>was wrong. Another variable to seriously consider. At last count there were
>about 7 serious variables in this stove. Several of which I have ignored to
>date.

ron: Interesting that you see 7 variables. My list of 9 includes (working
from bottom to top and inside to outside, with priority (meaning presumed
forgiveness of error and/or my lack of understanding) of 1 (high) to 3
(low) :
primary air control mechanism (3)
grate design (3)
fuel container height and diameter (3)
secondary air gap (2)
combustion chamber height (1)
wind shield design (2) (includes secondary air heating)
* pot support design (1)
cookpot shield spacing (1)
combustion chamber insulation (2)

I think I have spoken about all but the pot support design question. What
I have thus far tried is:
1) using the combustion chamber to support the pot (almost every
design does this). The disadvantages are
a) there is a blockage of the air flow
b) the outer wall needs to be rigid (and more costly)
c) there is little opportunity to use conductive heat transfer
d) there is relatively poor stability

2) hanging the cookpot from a tripod. The disadvantages:
a) bulky
b) must fiddle considerably to get concentricity with shields.

What I want to suggest here is that supporting the cookpot from the bottom
may be a better approach. This is the way my kitchen works. With an
electric element, there is a broad conductive contact between element and
pot. With a gas burner (lower efficiency than electric heating) the flame
(pre-mixed)is much smaller and very close to the pot bottom. Conduction
can't be as important but exists at the bottom.

The question then is where the bottom support should exist. The
options are:

a) There could be just one support which presumably is best if
centrally located (chemistry lab equipment is singly supported off-center,
though). The single solid "rebar" or "pipe" has to be stiff enough and
straight enough to withstand vigorous stirring. This might be the least
cost, because there is only one support. Portable propane stoves seem to
take this approach. There needs to be some "disk" that supports the pot -
not cheap to attach to the single support. There will have to be an easy
way to get this rod/pipe through the fuel container. If this single support
is hollow, it can be used to bring (too hot?) secondary air from the
primary air region below the grate. More air is needed in the interior in
general, and this might be a good way to do it. Interior flame holding
might be augmented this way.

b) There could be three smaller supports - presumably with better
rigidity. The options are:
1) inside the fuel can - This one is rather like the
single support approach, but no advantage for interior secondary air. To
remove the fuel can, or to snuff the hot charcoal, will probably require
first removing the three supports.
2) outside the fuel can - one difficulty here is removing
the fuel container which, with fixed supports, could only be done
vertically. One moveable support would allow easy horizontal movement of
the fuel container. Snuffing the hot charcoal looks easier with this
approach.

After trying to describe these three options (for the first time),
I guess I favor the last - (but I haven't tried any - but I hope to). In
all cases, I am thinking of a heavy cast concrete bottom, with the
necessary holes of the right diameter and depth in the right places (and
primary air supplied horizontally through the concrete). The main benefits
of all this is supposed to be:
better heat transfer to the pot
better rigidity
a much cheaper outer shield(s)

Any comments from anyone?

Elsen:
>I'll answer more of your specific questions tomorrow, Ronal. I'm undertaking
>some damage control on the stove at the moment & may return a bit of the
>wind baffling too.

Ron: Looking forward to them

Elsen
>There's no doubt in my mind that pre-heating the secondary air does
>influence flame holding. In what way? I assumed by O2 attenuation via air
>expansion, but maybe there's another factor or two. I've applied insulation
>on two stoves with known performances, resulting in increased temperature to
>secondary air, and found that flame holding was reduced so much that the
>stoves were rendered useless.

Ron: If the geometry was the 3-can design, are we talking about insulating
the lower outer "pail"?

>A third stove design incorporated secondary
>air rising (and heating) between two sheets of metal comprising the wall of
>the pyrolisis chamber. Flame held well at first, and then became
>unmanageable as the pyrolisis zone lowered and increasingly heated the
>rising secondary air.

Ron: Is this the same geometry (without insulation)? With no insulation,
the system worked well at first but not at the end?
Can we conclude that a partial shield perhaps coming half-way down
the pyrolysis chamber might work?

>
>Ron; with reference to a previous correspondence, I've been setting my goals
>at a FOM of 2 and 25% charcoal production. Is this still reasonable? I seem
>to have hit the wall at FOM 1 and about 22%.

Ron: Now, I think that FOM=2 might not be possible. On the charcoal
production. I think 25% (based on wet weight) is certainly possible - more
based on the dry weight. Any idea of your present moisture content?
The FOM of 2 will imply an efficiency of a normal stove of about
2/3 (based on note of a week or so ago). This is possible for electric and
gas stoves - but maybe not for a wood stove. If we think we can get to 50%
conventional efficiency (25% if you ignore the charcoal production), I
believe the FOM will be about 1.5.
We have to hope that Alex will be able to see where the lost energy
is going before we can determine whether FOM = 2 is possible.

Elsen:
>Tom: I know that 'cooking with gas' is an ideal that most East Africans
>would aspire to & appreciate, but don't underplay the selling point of
>charcoal production. The ability of NGO's & the 'marketplace' to disseminate
>this stove once it's introduced to the public will probably be more a
>function of the charcoal production issue more than what the flame actually
>feeds on- at least hereabouts. That's the novelty and the financial
>incentive combined. Controllability will simply be expected, so it better be
>there.

Ron: Well said. Remember also that doing away with the present highly
inefficient production of charcoal should be a high priority endeavor.
I'll bet Kenyans understand this environmental aspect of a charcoal-making
stove also.
>
Elsen:
>A perforated fuel cell: It depends on the distance between the inner stove
>wall and the fuel cell wall. Too big a gap dilutes pyrolisis gasses and
>reduces flame holding at the 'lip' of the combustion chamber where secondary
>air is introduced. Keep it to about 1 to 3 cm outside of a 20 cm diameter
>fuel cell (for example), and there should be no difference between a
>'krinkly-solid' or 'spongey' pyrolisis container wall and the perforated
>fuel cell arrangement.

Ron:
Since my last comment on perforation, I have thought of another
alternative approach to giving more uniform charcoal- "dimpling" (with a
ball-peen hammer?) of the fuel container. Haven't tried it yet either, but
this should be much easier than the other two ideas.

Elsen"
> Primary air enters from the bottom of the cell only.

Ron - This I don't understand; it would seem that it could enter radially
also (as you say below)

Elsen
>A grid holds the fuel a couple cm above the vent and allows even air flow
>upward into the cell. The resultant even pyrolisis of the wood fuel allows
>gasses to exit the cell radially as well as vertically. This allows for a
>greater concentration of gas at the 'lip'- the combustion interface between
>fuel cell and secondary air inflow. This is also, in my mind, what a 'bluff
>body' does.... it forces gas out from the centre of the stove to the edges
>and concentrates it where the flame holding points are. This is always at
>the edges. Tall unstable flame rising vertically up the centre of the stove
>isn't good. This is what contacts the pot bottom and creates soot. We want a
>short combustion chamber to concentrate heat on the objective- the cooking
>pot. I've tried a disc held on three legs 2cm above the fuel cell rim and
>level just above the secondary air inlet; it really looks like you're
>cooking with gas (except the flame is yellow). The problem was that the heat
>is forced out, not up & the FOM fell considerably. Flame held well though.

Ron: 1. It would seem that good combustion zone insulation should keep
the FOM up.
2. I wonder if adding some central secondary air (through a central
pipe of same length as the wood, going through your central disk) might
tend to bring the hot gases back in to the center more.

Elsen:
>Too much! We might need to focus on fewer variables for a while. I like
>sound of the newer perspectives on evolution- genetic saltation, or jumps,
>finding recombinations that do surprising things. But that's not real
>developmental science though is it? What's the difference between 'gut feel'
>& guesswork?

Ron: Whew! genetic saltation and jumps! I think even without these we
will still find plenty of "recombinations that do surprising things". I'll
prefer your gut feeling over guesswork.

Elsen:
>Tomorrow's another trial. Thanks for your support, stovers. The questions
>and suggestions are very important & keep things in perspective. This is
>certainly a group effort!
>
Ron: With you doing most of the work. Sorry about that.

Regards Ron

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

From larcon at sni.net Tue Sep 9 23:33:27 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: Wood Stoves.
Message-ID: <v01540b07b03bbdebf275@[204.133.251.19]>

Summary - Questions for Alex and Remco on a gasifying space-heating (?) stove.

Alex said:
>A few weeks ago I saw a pellet stove (still under development) which
>is designed to burn high ash fuels in a similar manner only with out
>the charcoal. However it relied on the flames to keep the pellets hot
>enough to completely gasify. ( Not on the webpage)

Ron: Could you describe this stove a little more. Was there a restricted
primary supply and a secondary air supply? (or more like yours, with a
single supply?)

With space heating, I think the "two-can" design can work - if you
can adjust the primary air after pyrolysis is complete - to supply a lot
more and simply burn up the charcoal. This doesn't work efficiently for
cooking because all the charcoal is being consumed from the bottom up - and
a long way from the cookpot. The charcoal is more valuable to be saved and
possibly sold for use in cook stove designs optimized for charcoal fuel.
With space heating, you don't care as much about efficiency since you are
trying to get it out of chimney flue, not into a cook pot. All of which
you know, but maybe will help new member Remco deJong.

Remco, you said:
> The gasifier could be the controllable part while
> the gas combustor automatically reacted by increasing or decreasing air
> inflow to combust all of the available "smoke".

This shows some insight into what we have been talking about a good
bit on this list. It still seems quite surprising to me that the "gas
combustor automatically reacts", without any control of what we call
"secondary air". What background do you bring to this issue. I hope you
will consider joining the stoves list.

Regards Ron

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

From larcon at sni.net Tue Sep 9 23:32:55 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: Alex English on turbulence
Message-ID: <v01540b02b03b733163e8@[204.133.251.19]>

Summary - trying to learn more about laminar vs turbulent flames:

1. On Sept. 5, Elsen said:

>4) Turbulance at the point where secondary air combusts volatile gasses
>reduces flame holding. A laminar air flow is best.

2. On the same day, Alex said, in response:

>Now I have to object. This is a gross generalization extrapolated
>from a particular set of circumstances........... However, if it
>works, use it.
>
>This problem of combustion gas mixing under natural convection has
>many solutions demonstrated by the current oil stoves for space
>heating. Most of them use many small air holes, and a web of
>stainless steel (a porous bluff body) to cause turbulence in the
>flame. In one case a hybrid uses a mesh cylinder which is positioned
>vertically with a solid top. Presumably this shortens and stabilizes
>the flame. I think a shorter flame is a worthwhile goal. The question
>is how? (Did someone mention a venturi.)
>

and then on the 8th, Elsen said:
>In defense of laminar secondary air inflow for efficient combustion of
>pyrolisis gasses within the charcoal making stove............... Alex?
>
>I guess it depends on the calorific value of the gas- comparisons with
>liquid fuels may not be valid. Bluff bodies may act as surface attractants
>to concentrate gasses in a specific area for more intense & thouough
>combustion.

So my questions are:

1. To Elsen: What was your testing to show that laminar was better?

2. To Alex: a. Same question for you on turbulence (especially in this
geometry)?
b. Elsen (on the 8th) picks up on your discussion of
liquids - should there be a difference in your view?
c. Can you add more on the likely dimensions for a stainless wire
mesh for the elk design?
d. Is there a difference in your mind between pre-mixing and
turbulence (I haven't seen a way to do the former)?
e) What is a "hybrid"?

3. To Elsen and Alex: a) I don't understand the term "surface attractants"
- Is this different from a (permeable) stainless steel mesh in your mind.
b) Are there some catalytic surfaces that we should be considering?

4. To anyone - Where do we go to read about the theory (preferably with
experimental verification) of this topic?

Observation - I see much of the design of any charcoal-making stove being
built around the need for a chimney to provide the small pressure
differences that allow both primary and secondary air to flow (to be drawn
in). With a blunt (bluff?) body,the added flow resistance will require a
taller chimney to get the same air flows, which counteracts one of the
reasons for putting in the body in the first place (which is to get a
shorter flame). I certainly like the idea of any added body that will
assist in flame holding. Presumably if this body is "small", there will
not be much influence on the needed height.

This is a great topic - which I hope someone can help resolve.

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

From larcon at sni.net Tue Sep 9 23:32:50 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <v01540b04b03b823aec30@[204.133.251.19]>

Summary: Some comments on Alex' message of 7 September.

Alex said:
<snip>
>
>Elsen, is the water boiling all the way up the sides of your pot? I
>visited with Eric Brunet of the Brace Research Institute a
>few weeks ago while he made apple sauce in a 20 litre pot on one of
>their "improved stoves". The shield around the pot extended to the
>top and the sauce was boiling all the way up the sides.
>
Ron: Can you contact Brunet and invite him into the stoves list? Any idea
of efficiencies (or Figures of Merit)? What was their spacing and height
for the shield? What does this stove look like?

Alex:
>Has anyone seen a pot with heat exchange fins on the outside?

Ron: Not I, However, I think we should be looking more closely at the
Russian samovar design: a central chimney within a water jacket. The
radiating outer surface can be no hotter than boiling water. In general,
chimney diameters can be a lot narrower than they are, and possibly the
Russians have optimized something here. Unfortunately, we will probably
have a tough time getting people to switch from the presently available
cheap aluminum pots.

Regards Ron

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

From Bluzharpr at aol.com Wed Sep 10 00:45:30 1997
From: Bluzharpr at aol.com (Bluzharpr@aol.com)
Date: Tue Aug 31 21:35:34 2004
Subject: Charcoal stove
Message-ID: <970910004725_2084584510@emout15.mail.aol.com>

I'm not quite sure I'm in the right place, but I'm looking for some
information about how to make your own charcoal. I've browsed through some
of the archives and seen some information about charcoal stoves. If anyone
could give me any specific information or lead me to a source that would give
detailed step-by-step processes for making fairly small quantities (for
personal use), I would appreciate it. Thanks a lot.

Jeff

From elizabethb at itdg.org.uk Wed Sep 10 07:59:00 1997
From: elizabethb at itdg.org.uk (Elizabeth Bates)
Date: Tue Aug 31 21:35:34 2004
Subject: Biogas.
Message-ID: <199709101158.HAA21486@solstice.crest.org>

The journal 'Biogas Forum' is probably useful. It is published four
times a year by Bremen Overseas Research and Development Association,
Breitenweg 55, D-28195 Bremen, Germany. Tel:0421 13718, Fax: 0421 165
5323. The editor is Ludwig Sasse and it comprises articles and an events
guide.
Elizabeth Bates
Intermediate Technology
Myson House, Railway Terrace
Rugby CV21 3HT UK
Tel: +44 -1788 560631 Fax: +44 -1788 540270
Email: elizabethb@itdg.org.uk
Url: http://www.oneworld.org/itdg
Intl: http://www.itdg.org.pe
X-mailer: Pegasus Mail for Windows (v2.23)

From celtic1 at ibm.net Wed Sep 10 15:42:32 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:34 2004
Subject: Gas wicks.
Message-ID: <3416F710.33A1@ibm.net>

I have been studying a document printed from kingston.net......by T.B.
Reed and Ronal Larson, from the Biomass Foundation, in Colorado.

The article describes an inverted downdraft gasifier stove in various
configurations. In the burner section of the stove, they show a line
drawing of a "gas wick". Maybe I'm missing something, but can anyone
tell me what this is? Is it a mantle....similar to a Kerosene heater or
white gas lantern? or am I over thinking the whole subject? This subject
is obsessive, any help is appreciated.

Steve:

From celtic1 at ibm.net Wed Sep 10 17:00:18 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:34 2004
Subject: External power sources;
Message-ID: <3417096D.510@ibm.net>

In cruising the "Stoves" realm, I continuously see references to
unavailability of power sources..etc. My field of expertise is, wood
burning camping stoves. Specifically Zip Sierra stoves. These stoves use
wood, pine cones, dried animal droppings...etc for fuel. When initially
ignited, there is a AA powered blower that produces the blast furnace
effect (14,000BTU per hr). The battery is replaceable with a solar
panel, which gives an unlimited source of power. These stoves are only
5inches in diameter, and burn for up to 30 minutes per load of
combustables. Might not the use of solar cells to power blowers, be a
consideration?

Sincerely;
Stephen Allen: Celtic1@Ibm.net

From sylva at iname.com Wed Sep 10 18:08:28 1997
From: sylva at iname.com (Andrew Heggie)
Date: Tue Aug 31 21:35:34 2004
Subject: 2cans, 3cans & non-stop trials
Message-ID: <9709102210.AA04263@mars.cableol.net>

Summary, an existing water boiler integral and surrounding chimney

>Alex:
>>Has anyone seen a pot with heat exchange fins on the outside?
>
>Ron: Not I, However, I think we should be looking more closely at the
>Russian samovar design: a central chimney within a water jacket. The
>radiating outer surface can be no hotter than boiling water. In general,
>chimney diameters can be a lot narrower than they are, and possibly the
>Russians have optimized something here. Unfortunately, we will probably
>have a tough time getting people to switch from the presently available
>cheap aluminum pots.
AJH:The Kelly Kettle an Irish design manufactured for use by anglers is a
small aluminium conical vessel with a central chimney and a crude firebox
with an air opening at the bottom, boils .5litre water in <5min on a handful
of small twigs.

From english at adan.kingston.net Wed Sep 10 21:51:26 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:34 2004
Subject: 2cans, 3cans & non-stop trials
In-Reply-To: <v01540b04b03b823aec30@[204.133.251.19]>
Message-ID: <199709110153.VAA10892@adan.kingston.net>

> Ron: Can you contact Brunet and invite him into the stoves list? Any idea
> of efficiencies (or Figures of Merit)? What was their spacing and height
> for the shield? What does this stove look like?

He knows that the List exists. His internet provider is a problem at
home.

The stoves were a simple shielded fire type with an opening to accept
the ends of two or three long pieces of wood into an inner combustion
cylinder which also supported the pot. An outer cylindrical shield
extended from the base up around the combustion chamber and up to
near the rim of the pot. They were designed to fit both the
traditional three legged cast iron pots and the modern aluminium
type. I think they were in the 35% efficiency range, based on the
boiling water test. They had similar arrangements for charcoal
burning stoves. Some resembling the Lakech or Jiko with pot shields.

I'll scan some drawings onto the web page soon.

The Brace Research Institute has a long list of publications about
their work with "Appropriate Technology". You can reach them at:
AE1200@Musica.McGill.CA

Alex
>
>
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
>
>
>
>
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 Sep 10 21:51:32 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:34 2004
Subject: Wood Stoves.
In-Reply-To: <v01540b07b03bbdebf275@[204.133.251.19]>
Message-ID: <199709110153.VAA10894@adan.kingston.net>

>
> Alex said:
> >A few weeks ago I saw a pellet stove (still under development) which
> >is designed to burn high ash fuels in a similar manner only with out
> >the charcoal. However it relied on the flames to keep the pellets hot
> >enough to completely gasify. ( Not on the webpage)
>
> Ron: Could you describe this stove a little more. Was there a restricted
> primary supply and a secondary air supply? (or more like yours, with a
> single supply?)

The intriguing part of this stove was that all the air was
brought in above the fuel. The pellets sit on a small grate maybe
10cm in diameter at the base of a cylinder about 25cm tall. Forced
air is introduced through small holes aimed tangentially and located
spirally up the cylinder. The goal is to keep the pellets at around
1100-1200F, below the temperature at which the ash will tend to slag
and above the temperature for char gasification. I don't know to what
extent the over fire air drops down to react with the pellets. I
think its output is around 15000Btus/hr. It could make a good model
for a cooking stove.

For more information contact Dell-Point Technologies Inc.
514-865-6212
Fax 514-435-2007
They say that commercial production will start in 1997-98.

Alex
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
>
>
>
>
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 Sep 10 21:52:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:34 2004
Subject: Alex English on turbulence
In-Reply-To: <v01540b02b03b733163e8@[204.133.251.19]>
Message-ID: <199709110153.VAA10933@adan.kingston.net>

Dear Ron+
You said:
> So my questions are:
>
> 1. To Elsen: What was your testing to show that laminar was better?
>
> 2. To Alex: a. Same question for you on turbulence (especially in this
> geometry)?

I was trying to suggest that there are likely many options which have
not yet been tried. There are many practical problems associated
with the venturi geometry that I have used, but I see it as one end
of a continuem with the "geometry you have been using at the other
end. One of my next trials will look like a point in the middle of
that line.

> b. Elsen (on the 8th) picks up on your discussion of
> liquids - should there be a difference in your view?

As far as the flame mixing goes I don't see a difference, but that
doesn't mean there isn't one. Would someone with more technical
understanding please speak up. I would be interested to observe the
oil stoves without their chimneys to see how unstable the flame is.

I suspect one difference is that the "liquid" oil fuel needs to be
exposed to the flame in order to vaporize. I doubt that the oil
stove could be a two stage burner the way that the wood gasifiers
can.

> c. Can you add more on the likely dimensions for a stainless wire
> mesh for the elk design?

For starters try placing some expanded metal in a tepee shape with
the outer edge just above the secondary air holes.

> d. Is there a difference in your mind between pre-mixing and
> turbulence (I haven't seen a way to do the former)?

I suppose both are vehicles to the same end. The propane stove uses
premixing and the propane fridge has a small wire dome to enhance
turbulence. Our choices do seem to be limited to the later.

> e) What is a "hybrid"?

I was referring to an oil stove which used an expanded metal cylinder
with a solid cap. Mixer combined with a bluff body. Perhaps a misuse
of the term.

> 3. To Elsen and Alex: a) I don't understand the term "surface
attractants"

Me neither.

> - Is this different from a (permeable) stainless steel mesh in your mind.
> b) Are there some catalytic surfaces that we should be considering?
>
> 4. To anyone - Where do we go to read about the theory (preferably with
> experimental verification) of this topic?
>
> Observation - I see much of the design of any charcoal-making stove being
> built around the need for a chimney to provide the small pressure
> differences that allow both primary and secondary air to flow (to be drawn
> in). With a blunt (bluff?) body,the added flow resistance will require a
> taller chimney to get the same air flows, which counteracts one of the
> reasons for putting in the body in the first place (which is to get a
> shorter flame). I certainly like the idea of any added body that will
> assist in flame holding. Presumably if this body is "small", there will
> not be much influence on the needed height.

Small in volume and in mass. If it is effective, what you lose from
resistance to flow you should gain back from enhanced combustion,
higher temperatures and more bouancy.

Alex

> This is a great topic - which I hope someone can help resolve.
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
>
>
>
>
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 Sep 11 00:09:30 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: Biogas.
Message-ID: <v01540b03b03ce438ef25@[204.133.251.27]>

Elizabeth - just a few questions below:

You said
>The journal 'Biogas Forum' is probably useful. It is published four
>times a year by Bremen Overseas Research and Development Association,
>Breitenweg 55, D-28195 Bremen, Germany. Tel:0421 13718, Fax: 0421 165
>5323. The editor is Ludwig Sasse and it comprises articles and an events
>guide.
>Elizabeth Bates
>Email: elizabethb@itdg.org.uk

Ron:
1. Will this journal deal with "gas" from anaerobic digestion processes or
more from gasifiers and charcoal-making stoves? Or both? (In the US, I
would say that biogas is reserved for the anaerobic digestion process.)

2. Might you or anyone have an e-mail address for Ludwig Sasse?

3. I have heard that there are difficulties (impossibilities?) in using
(anaerobic) biogas in standard gas burner stoves. Are you possibly also
saying this stoves list should be involved in this topic?

Regards Ron

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

From ferguson at antenna.nl Thu Sep 11 00:09:54 1997
From: ferguson at antenna.nl (Eric T. Ferguson)
Date: Tue Aug 31 21:35:34 2004
Subject: ...and two steps back...
Message-ID: <v01540b05b03d0ec6eec8@[204.133.251.27]>

Stovers: This message came in to me - perhaps inadvertently. I will try
to get something together that summarizes the charcoal-making wood-gas
stove for Eric and others who may have recently joined up. I'm sure that
Eric is not the only one baffled by our spasmodic conversations.

In addition, I believe that Eric's description of this cook-pot support he
described below will be of interest and of value.

Eric (new list member) - I think there is merit in your description below.
As you read more about this stove design, I hope you will determine whether
there can be a combined air gap and some means of getting the three legs
(perhaps bent back) down to the ground. I have used a similar cone with a
charcoal-making injera cooker. I believe it was 30 cm diameter for the
fuel chamber and 60 cm for the cook plate - with about a 1-2 cm high gap
for the secondary air supply. In that case everything was supported on the
outside - not through anything like your three supports. Hope you can
describe something that will allow the outer skin to not have to carry much
weight. Good luck and thanks for signing in in this way.

ps - follow Alex' lead on getting diagrams.

Regards Ron

Dear Ronal,

I am a newcomer to this Stoves mailing list. The discussion sounds
interesting, but I cannot follow it, as everybody refers to designs that
are known by all, and that are not described again. I am intrigued by the
reference to secondary air holes and several chambers, and by the idea of
making charcoal.

Where can I get an overview that allows me to follow the discussion? I
worked on improved woodstoves from 1979 to 1986, as colleague to the
Woodburning Stoves Group at Eindhoven University of Technology.

Drawings are hard to send by ordinary e-mail: are they avaialble as for
instance Word 6.0 documents, which you could attach, and I can then print
out?

You also wrote:
> Date sent: Tue, 9 Sep 1997 21:39:14 -0600
> Subject: Re: ...and two steps back...
> ....
> I think I have spoken about all but the pot support design question.
> ..... supporting the cookpot from the bottom may be a better approach.
> ..... The options are:
> a) There could be just one support ......
> b) There could be three smaller supports - presumably with better
> rigidity. The options are:
> 1) inside the fuel can - This one is rather like the
> single support approach, but no advantage for interior secondary air. To
> remove the fuel can, or to snuff the hot charcoal, will probably require
> first removing the three supports.
> 2) outside the fuel can - one difficulty here is removing
> the fuel container which, with fixed supports, could only be done
> vertically. One moveable support would allow easy horizontal movement of
> the fuel container. Snuffing the hot charcoal looks easier with this
> approach.
> ......
> Any comments from anyone?

A design successfully used (eg. in the Senegalese Sakkanal charcoal stove)
was to support the cookpot on a conical surface (metal sheet, semi-apex
angle say 60 degrees) onto which three radial iron rods (5 to 6 mm
diameter) had been welded. The pot rests on the rods, and that ensures the
correct gap between (conical) stove wall and the botttom of the cookpot,
even for cookpots of different size. The bottom/inner edge of the conical
surface joined onto the cylindrical combustion chamber (with grate); the
outer/upper edge joined onto a fixed cylindrical windscreen that completely
surrounded the cookpot. Does this make sense to you?

Greetings,

Eric Ferguson

|dr.ir. Eric T. Ferguson (MacFergus B.V.) |
|van Dormaalstraat 15, 5624 KH EINDHOVEN, Netherlands. |
|e-mail: e.ferguson@antenna.nl. phone:+31-40-2432878; fax:+31-40-2467036|

From larcon at sni.net Thu Sep 11 00:10:07 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: Charcoal stove
Message-ID: <v01540b04b03ce68178a2@[204.133.251.27]>

Summary: Some non-stove charcoal-making issues

Jeff "Bluzharpr" said:

>I'm not quite sure I'm in the right place, but I'm looking for some
>information about how to make your own charcoal. I've browsed through some
>of the archives and seen some information about charcoal stoves. If anyone
>could give me any specific information or lead me to a source that would give
>detailed step-by-step processes for making fairly small quantities (for
>personal use), I would appreciate it. Thanks a lot.
>
>Jeff

Ron:

1. I sent Jeff (not a list member) an old description of charcoal-making
stoves - that may help him - especially if he needs to do any cooking.

2. A better way may be to simply put some suitably shaped wood (a vine -
shaped like a pencil) into an (almost closed) can set into a fire, as
mentioned by Andrew Heggie a while back.

3. I found this subject (charcoal pencils) in a search of the Web on
"charcoal making" a while back. Almost all of the messages related to our
stoves list. The search was done using the aol search engine - I was very
impressed with its speed and what it picked up.

4. Other charcoal making activity showed up under a barbeque web site and
one for pyrotechnics. Now I wish I had looked further - maybe would have
found water purification.

5. Anybody else seen anything for Jeff on charcoal-making?

6. Jeff - just put a sealable can (maybe a paint can) with a small nail
hole in the center of the top into any old fire - set the hole so that the
pyrolysis gases can be ignited easily. I would guess that a 1 gallon paint
can will probably have been fully pyrolyzed in 30-45 minutes. Keep tuning
us in if you want to use the pyrolyzing gases as well as make charcoal.
Good luck.

Regards Ron

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

From prasad at tn7.phys.tue.nl Thu Sep 11 03:58:09 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:34 2004
Subject: External power sources;
In-Reply-To: <3417096D.510@ibm.net>
Message-ID: <9709110749.AA15219@tn7.phys.tue.nl>

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From elk at arcc.or.ke Thu Sep 11 07:14:39 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:34 2004
Subject: Answers, answers - Charcoal Making Stove trials
Message-ID: <v01510101b03d8ca073f2@[199.2.222.130]>

Stovers;

A few answers to some of the queries that have come in over the past few
days- my apologies for delayed response.

I've been puzzling over this problem I've seen with pre-heating secondary
air & feel that up to a point (no data) there's a benefit, but over a
certain temperature (no data) it's negative. Maybe though, the expansion of
air causes some sort of turbulance & 'lock' thereby reducing airflow
through secondary air vents to the combustion chamber...? In the 3-can
design this happened when the lower outer 'pail', as you put it was
insulated. It seems that when the secondary air is very hot, a large
compensation must be made by opening primary air, and flame holding at the
'rim' is replaced by flame inside the fuel- ashes are produced- not
charcoal.

Insulation on the combustion chamber- my 5% estimate must be taken as an
estimate only, though close observation and resultant data from over 40
trials on both insulated % non-insulated stoves seems to bear this out. I'm
sure an energy balance would show the greatest 'leak' being hot exhaust
gasses. You've got to keep a chiney flue going to maintain a partial vacume
in the stove, and full heat transfer to the contents of the cooking pot
would, in my imagination, cool exhaust gas to the point where the chiney
wouldn't draw....???? Maybe this is the 'wall I keep hitting at FOM=1. Good
to hear you say that FOM 2 may not be possible Ronal. This may be the
reason. Alex?

Speaking of chimneys, the physics of which I know very little, How does a
'smoke trap' work & could it have an application in our stove? It's a ledge
built into the chimney just above the fireplace that keeps 'blowback' to a
minimum.

Packing the fuel into the stove: I recommend about 25% less than could be
achieved maximally.

To light stoves I'm using small tigs 'tented' over a small amount of paper
on top of the vertically placed legths of fuel wood - dry brances ave. 2.5
cm dia. This lights well & quickly enough. The pot can usually be put in
place within 3 to 5 minutes.

Primary air entering via the bottom of a perforated fuel cell should not be
able to simultaneously enter via side perforations in my estimation.
Preforations start at the level of the grid, so all air must travel up into
the fuel wood. Maybe some air could exit radially low down & re-enter from
the side perforations further up the cell, but this seems improbable.

What I mean by 'surface attractant' visavis bluff bodies (not mesh) is how
flowing gas would cling to a surface- as in an airplane wing. Would
lee-side turbulant zones increase or decrease combustion? Decrease I'd
think, unless secondary air was somehow injected into the space - as per
you suggestion Ronal.

I'm varying the exhust gaps- it's difficult to specify 6 mm without
considering another aspect: If the pot is fully inserted into the stove, a
6mm gap between pot & stove wall up the length of the pot is, in my
observation, too little. What I do is cut up to 30 (vertical) 3cm deep by
3mm wide angle-grinder slices into the top of the stove & curl the
resultant tabs with pliers out or in as required to optimise exhaust flow.
The pot is 1.5 cm distant from stove wall.

A laminar air flow definately assists flame holding in my view. I've tried
'turbo' mixing with angled tabs at flame holding and secondary air inlet
points, and this has reduced flame holding.

Miss-type on closure of secondary air when I was mentioning that a
requirement for primary air control is 100% closure- I have tried valving
secondary air, but lost flame holding due to resultant turbulance. It all
gets a bit confusing with too many controls. I hope to construct a stove
soon that has controls on three points- primary, secondary and exhaust, in
order to investigate optimal settings.

By stating that optimum is a zero primary airflow setting, I mean to say
that this is the slowest boil and flame holding is maintained. I don't
think this has much to do with my perforated fuel cell. Turndown is
controlled by primary air. What I'm seeing is in order to re-establish
flame after 'flame out' in mid burn, a medium primary air opening is better
than wide open for restarting combustion in the stove. Once flame is
established, primary air can certainly be set wide open for maximum heat,
but I feel that in theory, maximum charcoal production is obtained with
zero primary air throughout the entire burn. Comment? I think this point
is important & maybe I've been accidentally limiting stove performances
here. Maybe I've seen autopyrolisis & have been confused on a few
occasions.

S'mattrafact, I've just this moment completed a trial on stove5 where
primary wasn't at zero most of the time, due to poor flame holding, and
though FOM wasn't the best (.87), 25% charcoal was produced. Hmmm. (Sudden
sensation of new horizons opening up). This stove variant uses a
double-walled fuel cell without perforation, where secondary air is drawn
up through holes in the stove bottom set between the 'skins' & preheated by
pyrolisis heat. The outer skin is 2 cm taller than the inner & the gap
between the two, allowing upward secondary air flow, is 1 cm. The cell is
about 4 cm distant from the outer stove wall, and this space could (though
I hav'nt yet) be filled with clay or cement. Inside cell diameter is 20 cm,
and stove base is 30 cm, standing on 3 legs. Primary air is also from
below, directly into the fuel cell which contains a grate to hold wood 2 cm
above the bottom. The object is to reduce the amount of fuel by reducing
fuel cell size and still cook in a resonably large pot. NOTE: maizemeal is
cooked in 20 minutes, so why not scale a fuel cell to this?

I don't have a new picture on Alex's websit- The 2can mk1 is the stove
pictured, and is one of the best performers to date. I've got a lot of bits
and pieces to cobble together to produce the optimum stove from the various
variants I've been testing.

My woodfuel moisture content is negligable., and I've very rarely achieved
charcoal production rates above 25%. I suspect incomplete pyrolisis when I
do. What are the expectations on commercial operations?

Secondary air- I normally start a new stove with deliberatly low secondary
air flow & gradually increase it by grinding, bending or otherwise
adjusting gaps. The low FOM shouldn't be a result of this airflow.

I've not issued any stoves to the local families yet. I want to standardise
a bit more first, and improve on controls. There's a lot of admiration
though, and I've got a few potential 'customers' listed. Max impact
requires release after a bit more polish & practicality.

Enough said- I'm going outside to stick my head down the mouth of a hot
stove in order to gain a new perspective on all this.

Now making the 3can variant using 25 liter paint tins and sheet metal
insulation as suggested by Ronal & running another trial on the
double-walled fuel cell stove- with sand between cell & stove wall. I'll
open up primary & let'r rip!

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 Sep 11 07:59:26 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:34 2004
Subject: Gas wicks.
In-Reply-To: <3416F710.33A1@ibm.net>
Message-ID: <199709111201.IAA29323@adan.kingston.net>

> In the burner section of the stove, they show a line
> drawing of a "gas wick". Maybe I'm missing something, but can anyone
> tell me what this is? Is it a mantle....similar to a Kerosene heater or
> white gas lantern? or am I over thinking the whole subject? This subject
> is obsessive, any help is appreciated.

Dear Steve
Your "over thinking" is matched by the authors "overly poetic" name
for what is essentially a combustion chamber. Perhaps the authors
have a more historical vocabulary.

Obcessively Your, Alex
PS. I also got involved through a question about "fans". No fans
certainly make for design challenges.

>
> Steve:
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From jsummers at labor.state.id.us Thu Sep 11 10:09:54 1997
From: jsummers at labor.state.id.us (Jeff Summers)
Date: Tue Aug 31 21:35:34 2004
Subject: Charcoal Stove
Message-ID: <41BF1B6CE2D8CF11B3E200805FCCA92102DBCE@LABOR_EXCH1>

Ron,

Thanks so much for giving me all the information. That sure was a lot
of info you emailed me. I think I may try the paint can or some similar
method. After reading you're message here, I found that page on
pyrotechnics, which has a method I may try. At this point, I'm just
looking to make charcoal to use for BBQing. If my horizons expand, I
certainly know where to come! Thanks again for your enthusiastic help.

Jeff

From verhaarp at janus.cqu.edu.au Thu Sep 11 17:51:12 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:34 2004
Subject: ...a giant step forward...
Message-ID: <1.5.4.32.19970911215226.006d0484@janus.cqu.edu.au>

Beste Eric,

Vroeger of later moest het er toch van komen. Welkom bij de Stovers!
Wat mij intrigeert is: 'Mac Fergus bv'. Klinkt heel interessant.

Groeten, ook aan Monica en van Irma.

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 larcon at sni.net Thu Sep 11 18:12:08 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: External power sources;
Message-ID: <v01540b04b03dfcd2dd90@[204.133.251.1]>

Summary - A reply on solar cells and stoves:

Stephen:

You said:
>In cruising the "Stoves" realm, I continuously see references to
>unavailability of power sources..etc. My field of expertise is, wood
>burning camping stoves. Specifically Zip Sierra stoves. These stoves use
>wood, pine cones, dried animal droppings...etc for fuel. When initially
>ignited, there is a AA powered blower that produces the blast furnace
>effect (14,000BTU per hr). The battery is replaceable with a solar
>panel, which gives an unlimited source of power. These stoves are only
>5inches in diameter, and burn for up to 30 minutes per load of
>combustables. Might not the use of solar cells to power blowers, be a
>consideration?
>
>Sincerely;
> Stephen Allen: Celtic1@Ibm.net

Ron:
I spend a fair amount of time worrying about PV as well as stoves,
so thought I'd take a shot at this topic - which has come up earlier
through Tom Reed. I think the fan idea certainly needs further
investigation. However, I don't think it should be used with a battery
alone or PV alone - as both being overly costly. A AA battery of this type
probably gives about 5 watt-hours of output. At 50 cents, this is about
$100 per kWh. With a 1 Watt solar panel (about the smallest size
available), you should be able to get the first cost down to about $10 -
but this is a pretty steep first cost for developing countries - and the
biggest problem is that you will be underutilizing the 1 watt unless you
cook all day long. So you need several rechargeable batteries to amortize
the $10 cost appropriately. In this way you should be able to get the cost
down below $1.00 per kWh (large scale are often cited these days at about
$.30/kWh). Nevertheless, the first cost is going to probably drive the
average rural stove buyer to avoid an electric fan. (An average stove cost
is probably closer to $5.00 total) With the sophisticated US/European
camper, these costs are probably not excessive and further tests of sales
certainly seem appropriate.

Stephen - You asked in another message about Tom Reed's use of the term
"wick" - and I will let Tom respond to that.

Because of your excellent questions and interest, I am taking the
liberty of signing you up for the "stoves" list. Please feel free to drop
off at any time, if we are not on target for such questions.

Regards Ron

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

From larcon at sni.net Thu Sep 11 18:12:17 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: Wood Stoves (continued, and a pellet stove and turbulence).
Message-ID: <v01540b06b03e07b86d24@[204.133.251.1]>

Summary - This responds to three sets of answers from Alex)

> Alex said on Sept. 10 about a pellet stove he has seen:
>
>The intriguing part of this stove was that all the air was
>brought in above the fuel. The pellets sit on a small grate maybe
>10cm in diameter at the base of a cylinder about 25cm tall. Forced
>air is introduced through small holes aimed tangentially and located
>spirally up the cylinder. The goal is to keep the pellets at around
>1100-1200F, below the temperature at which the ash will tend to slag
>and above the temperature for char gasification. I don't know to what
>extent the over fire air drops down to react with the pellets. I
>think its output is around 15000Btus/hr. It could make a good model
>for a cooking stove.
>
>For more information contact Dell-Point Technologies Inc.
>514-865-6212
>Fax 514-435-2007
>They say that commercial production will start in 1997-98.
>
>Alex

Ron: Alex,

1. Probably no e-mail address for Dell-Point? Hope you'll invite them
into the list, if possible.

2. This seems pretty small for space-heating. Is this the intended use now?

3. The forcing is grid electricity - through a double stove wall?

4. How often are pellets thrown in? What weight each time?

5. Some electric sparking to keep ignition?

6. Start with paper?

7. Use a chimney?

Thanks for the added info.

I don't see a need to respond to you other two notes from yesterday. On
the subject of turbulence - you answered very well.

On the subject of the "Brunet" stove, I think I see the design -
which sounds like a nice low cost design. I will look for your photes. I
sent an invitation to join us, to the e-mail address you provided. I have
known Tom Lawand of Brace for many years and have a high regard for their
work (in many development areas).

Regards Ron

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

From larcon at sni.net Thu Sep 11 18:12:13 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: interior chimneys, continued
Message-ID: <v01540b05b03e03175691@[204.133.251.1]>

>Summary, an existing water boiler integral and surrounding chimney

Andrew Heggie said (on Sept. 10):

>AJH:The Kelly Kettle an Irish design manufactured for use by anglers is a
>small aluminium conical vessel with a central chimney and a crude firebox
>with an air opening at the bottom, boils .5litre water in <5min on a handful
>of small twigs.

Ron: Andrew - the last clause sounds like you are implying high
efficiency. Have you seen any efficiency measurements and/or could you
make such a measurement?
Is the total capacity 0.5 liters?
Is the large or small part of the cone pointed up?
Could you describe how the water-tight sealing is accomplished?
(The type of "lip-rolling" - is it something that could be done by a rural
tinsmith?)
Do you see an easy way to modify the existing Kelly Kettle to be
used with a lower charcoal-making fuel container"
Who is Kelly and how long have these been around?
Why associated with anglers?
I have missed your inputs on large charcoal-making operations.
What is new?

Thanks for the added Kelly comment. I have to say that I own a
samovar (combined wood or electric!!) purchased in Kyrgystan for about $20,
I think - the best "stove" buy I've made yet (at least if I had 220v
available). Now I am forced to make an efficiency (with wood) measurement
myself. The Kyrgyz are approximately 100% electrified and they are also
nomadic - we saw these combined wood-electric units in common use on
picnics. (It is moderately heavy, incidentally)

Regards Ron

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

From eman at ghostly.net Thu Sep 11 19:27:10 1997
From: eman at ghostly.net (eman@ghostly.net)
Date: Tue Aug 31 21:35:34 2004
Subject: CHOCOLATE HEAVEN!!!
Message-ID: <199709112321.SAA00621@dfw-ix7.ix.netcom.com>

Death By Chocolate Cookies

Be careful when you eat these cookies... Because they melt in your hands, not in your mouth!

For the recipe:
Send $2.00 and a self addressed stamped envelope (or email address) to:

Innovative Concepts
Attn: Nicole
PO Box 2471
Carmichael, CA 95609-2471

From larcon at sni.net Thu Sep 11 21:07:14 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:34 2004
Subject: A mailing list
Message-ID: <v01540b04b03e33089a1b@[204.133.251.42]>

Stovers:
Here is a new version of the requested "stoves" mailing list.
Still in progress. I changed the rules a little. Formerly, I was waiting
for an approval. Now I am showing addresses whereever I found them - and
include the e-mail if that was all that was available. Some addresses
below are not in every message sent to the list. Please let me know what
to take out. I have not finished, but I won't add any names of people who
have not communicated to myself or to the full list, unless they ask to be
included. Past silence will be honored. Some have sent me an address and
I lost it somewhere - please try again.

Other questions (what should I change? are:
1) I have made all addresses a maximum of 4 lines long.
I used an e-mail address where only that was available.
2) I have moved titles to appear after the name
Should we drop all - since this list is inconsistent?
3) I have progressively indented the four lines - for ease in reading.
4) I have added one (only) affiliation (and deleted some)
5) I have deleted the words "phone" and "e-mail", but kept "FAX"
6) Phone number area codes are not consistent - but kept the way sent
(Is the symbol "+" a critical part of an area code?)
7) I have added web pages where known
8) Where there is no affiliation, it is because I didn't want to
make one up.

Sorry for those I didn't have time yet to add in (and there are a lot). I
will try to add more in the next week or so. This is to get reactions - it
is not meant to be complete - although now a lot longer.

Ron

Alex English
RR 2 Odessa; Ontario,Canada K0H 2H0
613-386-1927
english@adan.kingston.net; http://www1.kingston.net/~english/Stoves.html

David Beedie (Dr.)
School of Engineering, University of Wales, Cardiff, UK
01222 874683, FAX: 01222 762197 (home)
BeedieD@cardiff

Mike Bess
mike@esd.co.uk

Dan Campbell (EHP, USAID)
1611 North Kent St, #300, Arlington, Virginia 22209 USA
campbelldb@cdm.com www.access.digex.net/~ehp

Jamie Craighill (Wood Smoke Coordinator)
PO BOX 47600, Olympia WA 98504-7600
(360) 407-6832, fax (360) 407 6802
JCRA461@ecy.wa.gov

Eric T. Ferguson, dr.ir. (MacFergus B.V.)
van Dormaalstraat 15, 5624 KH EINDHOVEN, Netherlands.
+31-40-2432878; fax:+31-40-2467036|
e.ferguson@antenna.nl

Charles M. Gitundu (RETAP-Renenewable Energy Technology Assistance Programme)
Kenya
rteretap@nbnet.co.ke

Paul Hait (Pyromid Stoves)
phait@transport.com (John Doe)

Andrew Heggie
ahe1@cableol.co.uk

Daniel M. Kammen (STPP Program, Princeton University)
444 Robertson Hall, Princeton University, Princeton, NJ 08544-1013
609-258-2758, Fax: 609-258-6082
kammen@princeton.edu, WWW: http://www.wws.princeton.edu:80/~kammen/

Elsen Karstad
P.O Box 24371 Nairobi, Kenya
254 2 884437
elk@arcc.or.ke

Ronald Kent
PO Box 23131, Federal Way, WA 98093
253/952-6478
shell@wolfenet.com

C. A. Kezar (Chuck)
1807 Clovermeadow Dr. Vienna VA 22182 USA
703-255-3325
ckezar34@aol.com

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

Ronal W. Larson, PhD (Ron, Larson Consulting)
21547 Mountsfield Dr., Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

Rogerio Carneiro de Miranda (ATP/PROLENA/Nicaragua)
Apartado Postal C-321, Managua, Nicaragua
telefax (505) 276 2015
rmiranda@sdnnic.org.ni

Etienne Moerman
Joh. Buyslaan 71; 5652 NJ EINDHOVEN, The Netherlands
+31-40-2571491
E.Moerman@stud.tue.nl or emoerman@iaehv.nl

Krishna Prasad (Eindhoven University)
prasad@tn7.phys.tue.nl

Thomas B. Reed (The Biomass Energy (non-profit) Foundation)
1810 Smith Rd., Golden, CO 80401
303 278 0558; 303 278 0560 FAX
ReedTB@Compuserve.com

Kirk R. Smith, (Prof. EHS)
SPH, 140 Warren #7360, University of California, Berkeley CA 94720
510-643-0793, Fax: 510-642-5815
KrkSmith@uclink4.berkeley.edu

Peter (Piet) Verhaart
6 McDonald St Gracemere Q 4702 Australia
+61 79 331761 Fax: +61 79 331761 or 332112
p.verhaart@cqu.edu.au

Ronald E, West (Prof., Univ. of Colorado, ret.}
westr@magellan.Colorado.EDU

From celtic1 at ibm.net Thu Sep 11 21:18:49 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:35 2004
Subject: External power sources;
In-Reply-To: <v01540b04b03dfcd2dd90@[204.133.251.1]>
Message-ID: <34189784.2110@ibm.net>

Ronal W. Larson wrote:
>
> Summary - A reply on solar cells and stoves:
>
> Stephen:
>
> You said:
> >In cruising the "Stoves" realm, I continuously see references to
> >unavailability of power sources..etc. My field of expertise is, wood
> >burning camping stoves. Specifically Zip Sierra stoves. These stoves use
> >wood, pine cones, dried animal droppings...etc for fuel. When initially
> >ignited, there is a AA powered blower that produces the blast furnace
> >effect (14,000BTU per hr). The battery is replaceable with a solar
> >panel, which gives an unlimited source of power. These stoves are only
> >5inches in diameter, and burn for up to 30 minutes per load of
> >combustables. Might not the use of solar cells to power blowers, be a
> >consideration?
> >
> >Sincerely;
> > Stephen Allen: Celtic1@Ibm.net
>
> Ron:
> I spend a fair amount of time worrying about PV as well as stoves,
> so thought I'd take a shot at this topic - which has come up earlier
> through Tom Reed. I think the fan idea certainly needs further
> investigation. However, I don't think it should be used with a battery
> alone or PV alone - as both being overly costly. A AA battery of this type
> probably gives about 5 watt-hours of output. At 50 cents, this is about
> $100 per kWh. With a 1 Watt solar panel (about the smallest size
> available), you should be able to get the first cost down to about $10 -
> but this is a pretty steep first cost for developing countries - and the
> biggest problem is that you will be underutilizing the 1 watt unless you
> cook all day long. So you need several rechargeable batteries to amortize
> the $10 cost appropriately. In this way you should be able to get the cost
> down below $1.00 per kWh (large scale are often cited these days at about
> $.30/kWh). Nevertheless, the first cost is going to probably drive the
> average rural stove buyer to avoid an electric fan. (An average stove cost
> is probably closer to $5.00 total) With the sophisticated US/European
> camper, these costs are probably not excessive and further tests of sales
> certainly seem appropriate.
>
> Stephen - You asked in another message about Tom Reed's use of the term
> "wick" - and I will let Tom respond to that.
>
> Because of your excellent questions and interest, I am taking the
> liberty of signing you up for the "stoves" list. Please feel free to drop
> off at any time, if we are not on target for such questions.
>
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
Thank you Ron for putting me on the mailing list, I look forward to
participating in this worthwhile endeavor, and hope to contribute as
much as possible.

Steve.

From skip.hayden at cc2smtp.NRCan.gc.ca Thu Sep 11 22:36:46 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:35 2004
Subject: A mailing list
Message-ID: <9708118740.AA874042711@cc2smtp.nrcan.gc.ca>

Ron: Here is my address

A.C. Skip Hayden, Advanced Combustion Technologies
ETB/CETC, 1Haanel Drive, Ottawa, Canada K1A 1M1
(613) 996-3186; FAX (613) 992-9335
e-mail: skip.hayden@nrcan.gc.ca

From english at adan.kingston.net Thu Sep 11 22:40:31 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Compromise Stove
Message-ID: <199709120242.WAA11679@adan.kingston.net>

Summary: More possibilities for the charcoal making stove.

Dear Stovers
I have tried out an arrangement which I feel is a compromise between
the venturi that I was previously using and the cylinder which Ron
and Elsen have been using.

I used the cutoff milk can as the base pyrolyser. The same as with
my last venturi trial. It is 30cm in diameter with the top tapering
in to a 20cm opening. A 20pound propane tank with the bottom( inside
of the 21cm diameter stand), and the top, cut out, served as the
combustion chamber/ chimney. The 21cm dia. ring stand, which is about
2cm tall, was drilled with about 70-6mm secondary air holes. The tank
is also about 30cm in diameter through its cylindrical portion. The
rounded top was cut off.

During normal operation ( with no bluff bodies or obstructions)
the flame attachment was as good as I have seen. The gasses burned
vigorously in the throat, about 10-14cm above the fuel.

Then the piece of the propane tank which was cut out ( an 8cm disc)
was lower down to the opening to obstruct the flow. I was astonished
to see that the flames shot out horizontally around the disc towards
the out side of the chimney. I had expected it to snuff the flames or
at least cause an increase in smoke, but it did not.

While messing around with the disc it accidentally dropped through to
below the secondary air throat. Now the gasses were being forced to
flow right up into the secondary air jets. The flames shot towards
the centre with excellent attachment and stability.

I need to find a cooking pot to fit this tank so I can run some
tests.

I found the results to be very encouraging. . It was to
dark to get pictures for the web. I'll post some tomorrow.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From remco at ds5500.cemr.wvu.edu Fri Sep 12 00:52:34 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
In-Reply-To: <v01540b06b03e07b86d24@[204.133.251.1]>
Message-ID: <3418CA2E.5C9A0AD8@ds5500.cemr.wvu.edu>

Automotive type exhaust sensors use zirconia and platinum and other rare
materials to sense oxygen in the exhaust stream of spark ignited
engines. I do not really know how they work but do know that
stoichiometric operation of SI engines is virtually impossible without
them. The simple ones, called exhaust gas oxygen sensors or EGO's, cost
in the neighborhood of $15 and have output of ~0 volt when they sense
any oxygen in the exhaust (lean operation) and ~800 mVolt when there is
no oxygen in the exhaust (rich operation). The engine controller
essentially senses a square wave from the sensor and balances the binary
states by trimming the fuel injectors.

There are fancy sensors that have a seperate oxygen pump that pumps O2
into or out of one of these cells with the amount of oxygen pumped being
proportional to the oxygen concentration in the exhaust. These are
often referred to as UEGO's or universal exhaust gas oxygen sensors
(made by NGK) and are applied in spark ignited lean burn situations.
Another type of sensor is available that has similar output as the
simple cell outlined above but has "tails" in the rich and lean regions.

The latest round of on-board-diagnostics for cars uses an EGO before and
after the catalytic converter.

These sensors are resistant to high temperatures and regularly work at
12000 F. The problem is that they foul easily. Once the micro-pores in
them clog, they are rendered useless.

The fouling problem would render them ineffective for wood stove use, I
suspect.

Remco deJong

From phoenix at transport.com Fri Sep 12 02:10:29 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:35 2004
Subject: A mailing list
Message-ID: <199709120615.XAA05153@brutus.transport.com>

Hi Ron!

Great Job on the List! I thought it might be longer due to the wild
activity on the site but am pleased to see the Rogue's Gallery of Stoves
List in any case.

Thank you!

Art Krenzel

From elk at arcc.or.ke Fri Sep 12 04:44:16 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:35 2004
Subject: Alex's 11/9/97 stove trial
Message-ID: <v01510102b03eba861e9c@[199.2.222.134]>

>Then the piece of the propane tank which was cut out ( an 8cm disc)
>was lower down to the opening to obstruct the flow. I was astonished
>to see that the flames shot out horizontally around the disc towards
>the out side of the chimney. I had expected it to snuff the flames or
>at least cause an increase in smoke, but it did not.

This is as I've observed as well, though I found FOM was lowered due to
what I expect was more radially radiated heat. Stove walls take more
punishment as well.

This stove has no exhaust gas control? The '6mm gap' that we discuss? I'd
expect that flame height in the combustion chamber was quite high as a
result. What was your observation?

The issue of horizontal flame as directed by a disc is intriguing, I've
spent some time trying to figure out how this could be best put to
advantage, as it effectively shortens the height of the combustion chamber
allowing for several obvious efficiency and construction cost advantages.
This is much more like 'cooking with gas'.

How was primary air controlled & did you at any time close it completely?

Waiting to see your photos Alex- this sounds like a curvaciuos stove- I like it!

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 Sep 12 07:21:50 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Wood Stoves (continued, and a pellet stove and turbulence).
In-Reply-To: <v01540b06b03e07b86d24@[204.133.251.1]>
Message-ID: <199709121123.HAA26439@adan.kingston.net>

Summary; Responses to the Master Inquisitor about the Pellet Stove
> Ron: Alex,
>
> 1. Probably no e-mail address for Dell-Point?

I don't know.
>
> 2. This seems pretty small for space-heating. Is this the intended use now?

It is probably more of a large room heater, than a house heater.
I think they have achieved a high thermal efficiency , around 85%.
By keeping the output low they would have a better chance of low flue
gas temperatures with a moderately sized appliance. This may be one
of the few biomass space heaters that won't bake the room's
occupants in a modern insulated house.
>
> 3. The forcing is grid electricity - through a double stove wall?

Yes.
>
> 4. How often are pellets thrown in? What weight each time?

I don't know.
>
> 5. Some electric sparking to keep ignition?

No.

> 6. Start with paper?

Probably.
>
> 7. Use a chimney?

Yes.

>
> Thanks for the added info.

Your welcome.

Alex
>
Snip
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From skip.hayden at cc2smtp.NRCan.gc.ca Fri Sep 12 07:26:19 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
Message-ID: <9708128740.AA874074511@cc2smtp.nrcan.gc.ca>

One comment:

Zirconium oxide sensors, although cheap, work well when you
are around stoichiometry. However, they are extremely
non-linear, so that as excess air increases, their accuracy
falls off. In the stove application, particularly if the
excess air was changing, they effectiveness would be very
limited.

Skip Hayden
Advanced Combustion Technologies
ETB/CETC, 1 Haanel Drive, Ottawa, Canada K1A 1M1
skip.hayden@nrcan.gc.ca

From english at adan.kingston.net Fri Sep 12 09:54:03 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Correction to Comprimise
Message-ID: <199709121356.JAA00164@adan.kingston.net>

Dear Stovers

The disc that was lower in as an obstruction was 20cm in diameter,
not 8cm. It was essentially the same diameter as the throat, ( or
waist? Elsen!) of the burner.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From CAMPBELLDB at cdm.com Fri Sep 12 11:53:43 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:35 2004
Subject: Fwd: Health impacts of indoor air pollution from cooking/heating stoves
Message-ID: <9709121551.AA13153@cdm.com>

To: dan
Subject: Health impacts of indoor air pollution from cooking/heating stoves
From: "Dan Campbell" <CAMPBELLDB>
Date: 12 Sep 97 11:53:20

Health Impacts of Indoor Air Pollution from Stoves Used for Cooking/Heating

Below is a listing of 19 selected studies from "An Annotated Bibliography on
Acute Respiratory Infections and Indoor Air Pollution," a draft bibliography
published by EHP in June 1997. Of the 19 studies, only 2 Malaysian studies
failed to find a relationship between exposure to indoor smoke and negative
health impacts. The listing includes country, author, and a brief description
that includes the type of fuel if mentioned, health impact, etc.

COUNTRY AUTHOR
Africa Grobbelear, JP
Indoor smoke from biomass fueled fire is a significant factor in "hut lung,"
a form of pneumoconiosis among rural African women.

Asia Chen, BH
ARI in children associated with household smoke exposures in Nepal. In China,
smoke a strong risk factor for lung cancer in women.

Colombia Dennis, RJ
Woodsmoke exposure associated with the development of obstructive airway
disease (OAD) among women & may be responsible for 50% of all OAD cases.

Gambia Armstrong, JR
ALRI inchildren < 5 due to regular carriage on mother's back while cooking.
Proxy measure for smoke from cooking fires.

Gambia de Francisco, A.
Exposure to smoke during cooking was the strongest risk factor for ARI deaths
in children < 2 years old.

India Awasthi, S.
Use of dung cakes as cooking fuel associated with respiratory diseases in
children. Overcrowded bedrooms another significant factor.

India Behera, D.
Study of 3,605 women who used 4 types of cooking fuels: biomass, LPG, kerosene
& mixed fuels. Mixed fuel users had more respiratory symptoms (16.7%),
followed by biomass (12.6%), kerosene (11.4%) & LPG (9.9%). Women who smoked &
that were also exposed to cooking fuels experienced respiratory sympotoms more
often that non- smokers (33% vs. 13%)

Kenya Wafula, EM
Repeated 24 hour measurements of respirable suspended particles (RSP) &
nitrogen dioxide (NO2) were carried out in houses where most cooking was done
on open fires using firewood & crop residues s fuel. The mean of 24 hour
average RSP concentration (1400 mg/m3) & evening peak levels (up to 3600
mg/m3) indicate that negative health impacts due to smoke from biomass
combustion are likely to occur among pre-school children & women.

Malaysia Azizi, BH
No association between exposure to kerosene & wood stoves & respiratory
illness. Avoidance of exposure to mosquito coil smoke & passive smoking could
reduce asthma prevalence by 29%.

Malaysia Azizi, BH
No evidence that domestic air pollution had an adverse effect. Overcrowding
predisposes to ARI and breasatfeeding is an important protective factor.

Mexico Perez-Padilla, R.
A study of women over 40 years old showed a causal role of domestic wood smoke
exposure in chronic bronchitis and chronic airflow obstruction.

Nepal Pierson, WE
Woodsmoke is known to contain compounds such as carbon monoxide, nitrogen
oxides, sulfur oxides, & respirable particulate matter. Woodsmoke fumes have
shown mutagenic activity in short-term bioassay tests.

Nigeria Johnson, AW
Significant association between ALRI & domestic exposure to wood smoke in
pre-school children.

Pap. New Gui. Anderson, HR
Most likely possibilites for lung diseases are domestic wood smoke and acute
chest infections. Study of 46 men & 24 women.

Saudi Arabia Dossing, M
Indoor exposure to open fire from wood or biomass seems to be a risk factor of
chronic obstructive lung disease among women.

South Africa Kossova, D.
Of 132 infants with severe lower respiratory tract disease, 70% had a history
of daily heavy smoke exposure from cooking and/or heating fires.

USA Larson, TV
Animal toxicological studies show that wood smoke exposure can disrupt
cellular membranes, depress macrophage activity, destroy respiratory cells, &
cause aberration in biochemical enzyme levels.

USA Robin, LF
A study of Navajo children revealed an increased risk of ALRI for children
living in households that cooked with wood, had indoor air concentrations of
respirable particles > or = to 65 micrograms/m3, & where the primary caretaker
was other than the other.

Zimbabwe Collins, DA
Significant association between ARI & exposure to atmospheric woodsmoke
pollution in young children. A sampling of 40 kitchens revealed levels of
atmospheric pollution in excess of WHO recommended exposure limits.

From remco at ds5500.cemr.wvu.edu Fri Sep 12 13:36:10 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
In-Reply-To: <9708128740.AA874074511@cc2smtp.nrcan.gc.ca>
Message-ID: <34198D26.7FF9@ds5500.cemr.wvu.edu>

Skip Hayden wrote:
>
> One comment:
>
> Zirconium oxide sensors, although cheap, work well when you
> are around stoichiometry. However, they are extremely
> non-linear, so that as excess air increases, their accuracy
> falls off. In the stove application, particularly if the
> excess air was changing, they effectiveness would be very
> limited.
>
> Skip Hayden
> Advanced Combustion Technologies
> ETB/CETC, 1 Haanel Drive, Ottawa, Canada K1A 1M1
> skip.hayden@nrcan.gc.ca

These sensors are binary, ~0 volt at any oxygen at all, ~800m/volt at
no oxygen

From skip.hayden at cc2smtp.NRCan.gc.ca Fri Sep 12 14:00:51 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
Message-ID: <9708128740.AA874098171@cc2smtp.nrcan.gc.ca>

True, but the basic ZrO2 sensors are as I described. The car ones are just to
run three-way catalysts where you must have minimal oxygen in order to reduce
the NOx to N2.

Skip Hayden

______________________________ Reply Separator _________________________________
Subject: Re: Feed back sensors
Author: stoves@crest.org at internet
Date: 9/12/97 1:40 PM

From remco at ds5500.cemr.wvu.edu Fri Sep 12 15:32:21 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
In-Reply-To: <9708128740.AA874098171@cc2smtp.nrcan.gc.ca>
Message-ID: <3419A864.3FFC@ds5500.cemr.wvu.edu>

>True, but the basic ZrO2 sensors are as I described. The car ones are just to
>run three-way catalysts where you must have minimal oxygen in order to reduce
>the NOx to N2.

Skip Hayden

Most NOx in SI engines is NO and the basic NO reducing reactions are:
CO + NO yield 1/2 N2 + CO2, and
NO + H2 yield 1/2 N2 + H2O

The engine controllers toggle the binary states of the EGO to get the
exhaust mixture, including CO and NO, that reacts most completely in the
catalytic converter.

But the point of my bringing up the EGO sensors is as an example of a
feedback loop sensor. I think an EGO would foul in a woodstove and
probably not be suitable.

I wonder if someone has done work in the feedback sensors for woodstoves
area?

I am noting that this list seems to be geared toward the development of
very-low-cost yet highly efficient cookstoves to help ameliorate third
world deforestation and other issues. My interests are more American,
in that I am looking to save labor by burning large chunks of wood and
gains in efficiency. I can afford a sensor and have plenty of
electricity around to operate controllers etc.

Remco deJong

From skip.hayden at cc2smtp.NRCan.gc.ca Fri Sep 12 16:10:49 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:35 2004
Subject: Feed back sensors
Message-ID: <9708128741.AA874105971@cc2smtp.nrcan.gc.ca>

Having worked with a number of advanced combustion woodstoves, I am not
convinced that an O2 sensor would necessarily help, except perhaps in turning
down the air opening as the firing rate decreases near the end of the burn. Some
of the units we have today, particularly (but not limited to) Canadian designs,
have extremely clean and effective combustion with simple air control, but
complex air patterns within the appliance. At the tail end of the burn, the
temperature drops and the natural draft follows, so that consequent heat loss
may not be very significant. However, if you were relying on and FD or ID fan
system, turning down the draft might be a useful function.

Skip Hayden

______________________________ Reply Separator _________________________________
Subject: Re: Feed back sensors
Author: stoves@crest.org at internet
Date: 9/12/97 3:35 PM

>> >
>> > One comment:
>> >
>> > Zirconium oxide sensors, although cheap, work well when you
>> > are around stoichiometry. However, they are extremely
>> > non-linear, so that as excess air increases, their accuracy
>> > falls off. In the stove application, particularly if the
>> > excess air was changing, they effectiveness would be very
>> > limited.
>> >
>> > Skip Hayden
>> > Advanced Combustion Technologies
>> > ETB/CETC, 1 Haanel Drive, Ottawa, Canada K1A 1M1
>> > skip.hayden@nrcan.gc.ca
>
>> These sensors are binary, ~0 volt at any oxygen at all, ~800m/volt at
>> no oxygen

>True, but the basic ZrO2 sensors are as I described. The car ones are just to
>run three-way catalysts where you must have minimal oxygen in order to reduce
>the NOx to N2.

Skip Hayden

Most NOx in SI engines is NO and the basic NO reducing reactions are:
CO + NO yield 1/2 N2 + CO2, and
NO + H2 yield 1/2 N2 + H2O

The engine controllers toggle the binary states of the EGO to get the
exhaust mixture, including CO and NO, that reacts most completely in the
catalytic converter.

But the point of my bringing up the EGO sensors is as an example of a
feedback loop sensor. I think an EGO would foul in a woodstove and
probably not be suitable.

I wonder if someone has done work in the feedback sensors for woodstoves
area?

I am noting that this list seems to be geared toward the development of
very-low-cost yet highly efficient cookstoves to help ameliorate third
world deforestation and other issues. My interests are more American,
in that I am looking to save labor by burning large chunks of wood and
gains in efficiency. I can afford a sensor and have plenty of
electricity around to operate controllers etc.

Remco deJong

From remco at ds5500.cemr.wvu.edu Fri Sep 12 16:34:23 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:35 2004
Subject: Why feed back sensors?
In-Reply-To: <9708128741.AA874105971@cc2smtp.nrcan.gc.ca>
Message-ID: <3419B6ED.3FBC@ds5500.cemr.wvu.edu>

My stove experience is limited to a few Jotuls, army potbelly stoves and
a Warm Morning updraft unit. (The army ones were updraft as well) so I
don't have a lot of experience, but in thinking about wood stoves I
concluded that that a.) you have to burn all of the wood and not let any
go up the chimney, and b.) you have to get as much heat from the exhaust
as possible. My thinking is that in order to burn all of the wood you
have to burn with some amount of excess air, but if you want the most
effective heat transfer from the smoke you want it to be as hot as
possible, ie. use as little excess air as possible. From that
perspective I deduce that you want to operate in the neighborhood of
~.95 equivalence ratio (or 1.05 lambda). To do this reliably you would
need a feedback loop of some sort.

I am not a combustion engineer and may be out in left field

byenow Remco deJong

From verhaarp at janus.cqu.edu.au Fri Sep 12 17:21:49 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:35 2004
Subject: A mailing list
Message-ID: <1.5.4.32.19970912212304.006cb688@janus.cqu.edu.au>

Dear Ronal,

As far as I am concerned, it is perfect.

> 6) Phone number area codes are not consistent - but kept the way sent
> (Is the symbol "+" a critical part of an area code?)

No, the + I understand to mean that what comes after is what you have to
dial after you have dialled the country code.

So you sorted on the first names, good for me.
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 english at adan.kingston.net Fri Sep 12 20:25:11 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Picture of C Stove
Message-ID: <199709130027.UAA01182@adan.kingston.net>

Dear Stovers
You can view a picture of the my latest "stove" by visiting the
Webpage or its sub page http://www1.kingston.net/~english/Curva.htm

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 Sat Sep 13 12:38:01 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:35 2004
Subject: an apology
Message-ID: <v01540b00b040732969a4@[204.133.251.14]>

Stovers:

I made a number of errors in forwarding the Sept. 10 message from
dr. E.T. Ferguson without making it clear where his and my words were
separated, and I did so without asking his permission to quote a private
message to myself. I hope he will accept my apologies for a breach of
netiquette.

Regards Ron

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

From ferguson at antenna.nl Sat Sep 13 18:20:17 1997
From: ferguson at antenna.nl (Eric T. Ferguson)
Date: Tue Aug 31 21:35:35 2004
Subject: Apology accepted
Message-ID: <199709132220.AA21300@antenna.nl>

Ron Larson wrote:
> I made a number of errors in forwarding the Sept. 10 message from
> dr. E.T. Ferguson without making it clear where his and my words were
> separated, and I did so without asking his permission to quote a private
> message to myself. I hope he will accept my apologies for a breach of
> netiquette.

Ron's apology is accepted with thanks, and the matter is closed. I am
looking forward to constructive collaboration with all the other "stovers".

Greetings

Eric

|Eric T. Ferguson, van Dormaalstraat 15, 5624 KH EINDHOVEN, Netherlands|
|e-mail: e.ferguson@antenna.nl. phone:+31-40-2432878; fax:+31-40-2467036|

From celtic1 at ibm.net Sun Sep 14 02:16:25 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:35 2004
Subject: I Understand!
Message-ID: <341B802A.B43@ibm.net>

I am very new to the subject of gasifier and or charcoal producing
stoves. However after some excellent information derived from this
archive, and list, I built a two can stove of my own. It didn't take
long, (60min), or cost much, ($5.00), but it illustrated the theory and
practice of everything I had read in a way nothing else could have! To
anyone who hasn't tried it....build one. This stove is built from 2
1Litre paint cans, some brass angle brackets, (I can't help it, but it
has to look good), and some pop rivets for convenience. The gasifier
section has a fuel grill mounted 3cm above the base of the can, made
from 1/4in hardware cloth. Primary air intake is only a series of 1/8"
holes, (about 40), drilled in the base, and in a can bottom removed from
the burner can. The disc is pop riveted to the gasifier bottom, and
supplied with a rudimentary handle. The burner assembly is located 1cm
above the gasifier unit (secondary air intake). I didn't know what to
expect, having guessed at some of the dimensions.....but I'll be
*"=%$#@@##$.....if it didn't work....sure I got smoke.....sure it only
burned for 35minutes...but at 2am in my back yard, in the dark....I saw
exactly what I needed to understand what I had only been reading
about.At about 10 minutes even surface combustion was achieved, the
flame danced about 2cm above the combustibles, the colouration was
white, blue, alternating with yellow. At this point there was no smoke
that I could discern. The burn lasted for 35min...at which time I sealed
the unit....charcoal production was at about 20%....I believe the
primary intake needs to be increased dramatically, as the flame seemed
to be starving, the secondary intake is already adjustable from 0-4cm,
so I will play with that.....sorry if I seem to be going over old
ground, but this is all new to me, anyway...three other stoves are in
production...each with significant design changes....in a day or two
we'll see. Again thank you to ALL for the new facination.

From celtic1 at ibm.net Sun Sep 14 02:45:52 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:35 2004
Subject: Exchanger fins.
Message-ID: <341B872C.26C4@ibm.net>

Alex I saw a reference to heat exchanger fins for pots......MSR
manufactures such a device...aimed mainly at the camping market,
basically it captures heat normally lost to the atmosphere, and
redirects to the cooking vessel. (MSR= Mountain Safety Research) Web
searches will bring multiple links:
Sincerely; Stephen:

From english at adan.kingston.net Sun Sep 14 08:33:04 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Exchanger fins.
In-Reply-To: <341B872C.26C4@ibm.net>
Message-ID: <199709141235.IAA01202@adan.kingston.net>

> Alex I saw a reference to heat exchanger fins for pots......MSR
> manufactures such a device...aimed mainly at the camping market,
> basically it captures heat normally lost to the atmosphere, and
> redirects to the cooking vessel. (MSR= Mountain Safety Research) Web
> searches will bring multiple links:
> Sincerely; Stephen:

Here is the URL http://www.msrcorp.com/msr/xpdset.html
Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From bburt at adan.kingston.net Sun Sep 14 10:36:43 1997
From: bburt at adan.kingston.net (Brian Burt)
Date: Tue Aug 31 21:35:35 2004
Subject: Energy Consumption of Pyrolysis
Message-ID: <199709141438.KAA04914@adan.kingston.net>

?re: energy consumption of pyrolysis?

Here are Sunday morning ponderings. Charcoal energy content is about 1/3 of
the total content of wood (?), what is the net proceeds of pyrolysis, i.e.
energy given off by pyrolysis (as a percent of total content of wood)? The
remainder of the energy will be contained in the producer gas.

Brian

From english at adan.kingston.net Sun Sep 14 22:28:02 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Test Data
Message-ID: <199709150230.WAA02256@adan.kingston.net>

Dear Stovers
I have run a couple of tests on the "Curvacious"charcoal making
stove. The following test I didn't forget to weight the fuel.

Started :
7.75 lbs of wood at 10% moisture.(~ potential heat 55000btus)
24 lbs. water at 80F in the pot
Finished:
with 1.75 lbs of charcoal (22.6%)(~21000btus)
17.6 lbs of water at 212F in the pot

Duration; 1hour and 20 min.
Produced 34000 btus of heat.
8500 btus used absorbed by the water (25% efficiency)

Stack samples were taken from between the pot and the shield above
the water level.
CO2 was fairly stable, average of 12% (excess air factor of 1.75)
(CO over 2000ppm)
Temperature was also stable at 500+/- 25 F Stack loss
6200 btus (18%)

Losses due to start up (10 min) and 'surface loss' must account for
around 57%.
Please challenge these numbers, I don't do this every day.

The stove had an insulated cylindrical combustion chamber 20cm dia
by 15cm tall. On top of this was a metal cross which supported the
pot 3cm higher. The pot was about 20 cm above the secondary air
holes. The rate of boiling could be described as steady, neither a
simmer nor a roar. The primary air was open a tad, with ta slight
increase near the end. Opening it more resulted in a little smoke,
likely due to impingement on the bottom of the pot. Cutting primary
air down resulted in poor attachment with loss of flame. No flame
holding devices were used during this test. A previous test used a
baffle plate below the secondary air holes. This arrangement was
more tolerant of primary air adjustment.

Combustion chamber temperatures stayed around 1050 F, declining
toward the end of the burn. Temperatures at the top of the fuel
started at around 750 F and rose slowly during the burn to a high of
1200F at the end.

Brace Research Institute's tests of various, non charcoal making,
designs yielded efficiencies (PHU, percent heat utilized) of 35% to
44%. Unfortunately they had no exit gas measurements.

Three more pictures have been added to
http://www1.kingston.net/~english/Curva.htm

Quantitatively yours, Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From sylva at iname.com Mon Sep 15 02:38:25 1997
From: sylva at iname.com (Andrew Heggie)
Date: Tue Aug 31 21:35:35 2004
Subject: interior chimneys, continued
Message-ID: <9709150640.AA17043@mars.cableol.net>

At 16:18 11/09/97 -0600, you wrote:
>>Summary, an existing water boiler integral and surrounding chimney

>Ron: Andrew - the last clause sounds like you are implying high
>efficiency. Have you seen any efficiency measurements and/or could you
>make such a measurement?
> Is the total capacity 0.5 liters?
> Is the large or small part of the cone pointed up?
> Could you describe how the water-tight sealing is accomplished?
>(The type of "lip-rolling" - is it something that could be done by a rural
>tinsmith?)
AJH: I have seen the device in use and drunk tea prepared with it, no
measurements but it seemed surprisingly quick.
I have 'phoned the owner and requested details and photos, he says capacity
is 1.4litres which boils on " quote: two handfuls of twigs". Frustrum of
cone is small end up. I cannot remember construction details.
> Do you see an easy way to modify the existing Kelly Kettle to be
>used with a lower charcoal-making fuel container"
AJH:Yes just by separating boiler from firebox, which is how it packs
anyway, I think!
> Who is Kelly and how long have these been around?
> Why associated with anglers?
I have asked for details of maker, other than this I do not know, the one I
saw was sourced from an angling trip in a tackle shop in Eire.
> I have missed your inputs on large charcoal-making operations.
>What is new?
Sorry but reduced circumstances have delayed large scale experiments. I have
had a number of abortive attempts at autopyrolysis in a steel vacuum flask.
The flask either ruptured after a small, but loud, double explosion after I
decided to add some primary oxygen! or the heat losses due to radiation were
very large, as the flask became too hot to handle, I shall have to see if it
works in its original role before I know which. I have further experimented
with the charcoal pencil making method as a demonstrator and have
successfully ignited the gas produced by filling a bottomless beer bottle.

For your address book if you wish
Andrew J. Heggie
Quills
South Road
Woking
Surrey
GU21 4JN
England
+441483 773322
fax +441483 830722

From elizabethb at itdg.org.uk Mon Sep 15 06:04:01 1997
From: elizabethb at itdg.org.uk (Elizabeth Bates)
Date: Tue Aug 31 21:35:35 2004
Subject: Biogas.
Message-ID: <199709151004.GAA16137@solstice.crest.org>

I'm still not clued up as to how to ensure that the message one sends
replies to a particular enquiry on the network. The reply about
biogas was for a Mr Jwalant Desai who made the enquiry on the network
on September 9th asking how to generate power (methane) from
bio-waste.
I have checked to see if there is an e-mail for Mr Ludwig Sasse who
edits the journal ' Biogas Forum', and there does not appear to be one.
Elizabeth Bates
Intermediate Technology
Myson House, Railway Terrace
Rugby CV21 3HT UK
Tel: +44 -1788 560631 Fax: +44 -1788 540270
Email: elizabethb@itdg.org.uk
Url: http://www.oneworld.org/itdg
Intl: http://www.itdg.org.pe

From elk at arcc.or.ke Mon Sep 15 07:10:04 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:35 2004
Subject: Alex's 2nd trial Results- Charcoal Making Stove
Message-ID: <v01510100b042adce66f4@[199.2.222.134]>

Alex;

Now we're cooking!

Your data is invaluable for me, and the start of a foundation that will
allow us to optimise this stove.

In common-man's language corresponding with my simplistic presentation,
your stove performed well:

FOM: .82
Charcoal Production: 22%

I gather your pot was not embedded in the stove?

Keep it up!

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 Sep 15 07:35:36 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:35 2004
Subject: Alex's 2nd trial Results- Charcoal Making Stove
In-Reply-To: <v01510100b042adce66f4@[199.2.222.134]>
Message-ID: <199709151137.HAA16162@adan.kingston.net>

> FOM: .82
> Charcoal Production: 22%
Please refresh my memory on the words that FOM stand for.
>
> I gather your pot was not embedded in the stove?

It is embedded. Check the new pictures.

>
> Keep it up!

I'm not sure I will be able to.
Alex
>
> 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 REEDTB at compuserve.com Mon Sep 15 08:41:17 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:35 2004
Subject: Answers, answers - Charcoal Making Stove trials
Message-ID: <199709150843_MC2-207C-4854@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
ALSO: The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ELK, Alex, Ron et al:

ELK asked about the "smoke trap". Ron and I have recently read (and
skimmed) the complete works of Benjamin Thompson, Count Rumford.

About 1890, he discovered that by putting a shelf and the back bottom of
the chimney (but above the fireplace) the incoming cold air turned around
and was drawn back up with the hot combustion products. Within 10 years he
had converted thousands of chimneys in London to his design.

You have heard me complain that the combustion gas volume is not capable of
filling the chimney in our wood-gas stoves. Maybe a smoke-trap (a 1-3 cm
washer the Od to fit in the chimney) would stabilize the flame and keep it
from heating the combustor walls and feed the downcoming air back into the
burning gases.

Hope to hear if this works - or try it myself

TOM REED

From REEDTB at compuserve.com Mon Sep 15 08:41:01 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:35 2004
Subject: Flame holder - wick
Message-ID: <199709150843_MC2-207C-4848@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
ALSO: The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Stoveifiers:

Ron asked me to explain the term "gas wick" in our blue flame stove.

The wick in a candle serves to bring molten wax into and guide and
stabilize the flame. I used the term for the inner can in the combustor
which gets quite hot and draws the gas and air up along its surface,
permitting blue flame combustion. It also gives a ring of heat as we find
on gas and camping stoves and prevents air from going down the chimney.
(The quantity of hot gas is insufficient to fill a chimney the same size as
the gasifier).

In retrospect it may not be a good name. How about "Flame Holder"?

TOM REED

From elk at arcc.or.ke Mon Sep 15 09:11:26 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:35 2004
Subject: FOM
Message-ID: <v01510100b0430b349ee4@[199.2.222.97]>

Alex asks what FOM stands for...

Well, to me it means how many times you can reconfigure a stove to come up
with the same relative efficiency no matter how often you
changethesevenorninedifferentcriticalcriteriaandthenfindouthatyouhaven't....
..............................

AHEM!

Good question Alex.

I calculate it by dividing the amount of water lost to boiling by the
amount of wood initially loaded into the stove. This does not include the
amount of charcoal produced or the moisture content of wood, so FOM alone
is not much use to us charcoal-making-wood-gas stove makers. FOM and
%charcoal production (from initial wood load) gives me a couple reasonable
working criteria to measure efficiency. Remeber, I'm way out in the field-
unlike you scienterrific lab types.

As to what F and O and M stands for... Ronal?

elk

NB: Has anyone told you that starting with pre-heated water is cheating?

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

From REEDTB at compuserve.com Mon Sep 15 09:11:53 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:36 2004
Subject: Feed back sensors, No. 2
Message-ID: <199709150842_MC2-207C-4846@compuserve.com>

Skip's comment on zirconia sensors needs modifying. The fundamental
formula for this sensor is
Po = - Log p(O2) = RT Log p(O2)/p(standard, usually air)
(Similar to the equation for pH.) They are quite linear in this equation,
provided that the temperature is high enough to eliminate diffusion -
typically above 1000 K. Also it is necessary to know the temperature of
the cell.

They can measure oxygen concentrations as low as 10(-30) atm, and are quite
sensitive. However, measuring the change from 5% air to 6% excess air
would require some care.

I hope someone will give us a practical recipe for using these easily in
our combustion and gasification work.

Yours truly, TOM REED

From REEDTB at compuserve.com Mon Sep 15 12:09:59 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:36 2004
Subject: Research on the Internet
Message-ID: <199709151210_MC2-2074-8F4C@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
ReedTB@Compuserve.com
ALSO: The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Gayathri:

You asked for an article for the current BUN (of India) newsletter. I have
really enjoyed it and I like your mix of articles. Here is one you might
use. I sympathize with your problem of getting new articles and I hope
others will contribute. I'll send this to a few friends (800).

Your netpal, TOM REED
~~~~
BIOMASS RESEARCH THROUGH THE INTERNET

As scientists and engineers, we have been accustomed to conducting research
a day at a time, then reporting results in papers and in meetings, then
waiting for a response from our colleagues "out there". This is a very
slow process with a turnaround time of months or years. No wonder it has
taken so long (13 billion years) for intelligence to make the secrets of
nature consciously manifest.

A new process is at work on the Internet, and it may benefit those least
able to help themselves - the 3 billion poor of the world who are cooking
wastefully with biomass, deforesting their neighborhoods and enhaling the
smoke producing emphesema and glaucoma.

The Center for Renewable Energy and Sustainable Technology (CREST)
maintains a
netsite with a number of special interest nodes - STOVES, GASIFICATION,
DIGESTION, BIOCONVERSION, with a general category, BIOENERGY. Each node
maintains archives and a mailing list. (I am the moderator of the
GASIFICATION list - we currently have 150 members.) To subscribe to any of
these lists, send the message "subscribe <listname>" to
majordomo@crest.Org. (And, if you get tired or bored, or overwhelmed, send
"unsubscribe <listname>".)

The STOVE node has been very active in research in the last six months. We
are working on WOOD-GAS STOVES (and in a sense this work also belongs in
the GASIFICATION node). These stoves are close coupled gasifiers that
generate gas in an inverted downdraft (also called charcoal making) NATURAL
DRAFT gasifier which then leaves 25% charcoal after roasting out the gas
and volatiles. The problem remaining is to mix the gases with air for
clean, intense combustion. Natural draft doesn't provide much power for
the mixing, and some of us have tried "air wicks", others are trying
venturi mixers. Every few days someone makes a new configuration and
reports on the results. It is VERY exciting, and should produce a working
WOOD-GAS STOVE (if one is possible) in a year at most.

[Here's a section you can keep - or leave out:
Reporting research in the STOVES node can be very exciting as illustrated
by the following E-mail letter that I got this morning.

"I am very new to the subject of gasifier and or charcoal producing
stoves. However after some excellent information derived from this
archive, and list, I built a two can stove of my own. It didn't take
long, (60min), or cost much, ($5.00), but it illustrated the theory and
practice of everything I had read in a way nothing else could have! To
anyone who hasn't tried it....build one.

This stove is built from 21Litre paint cans, some brass angle brackets, (I
can't help it, but ithas to look good), and some pop rivets for
convenience. The gasifier
section has a fuel grill mounted 3cm above the base of the can, made
from 1/4in hardware cloth. Primary air intake is only a series of 1/8"
holes, (about 40), drilled in the base, and in a can bottom removed from
the burner can. The disc is pop riveted to the gasifier bottom, and
supplied with a rudimentary handle.

The burner assembly is located 1cm
above the gasifier unit (secondary air intake). I didn't know what to
expect, having guessed at some of the dimensions.....but I'll be
*"=%$#@@##$.....if it didn't work....sure I got smoke.....sure it only
burned for 35minutes...but at 2am in my back yard, in the dark....I saw
exactly what I needed to understand what I had only been reading
about.At about 10 minutes even surface combustion was achieved, the
flame danced about 2cm above the combustibles, the colouration was
white, blue, alternating with yellow. At this point there was no smoke
that I could discern. The burn lasted for 35min...at which time I sealed
the unit....charcoal production was at about 20%...

I believe the primary intake needs to be increased dramatically, as the
flame seemed
to be starving, the secondary intake is already adjustable from 0-4cm,
so I will play with that.....sorry if I seem to be going over old
ground, but this is all new to me, anyway...three other stoves are in
production...each with significant design changes....in a day or two
we'll see. Again thank you to ALL for the new facination."

This illustrates the excitement found in this node better than my words.
(It also illustrates that you should sign your name and address. I don't
know who wrote this or from where. The spelling "colour" might indicate
someplace in the Old British Empire, but your guess is as good as mine.]

The various contributors to this node are weighing in from all over the
world. Alex English (in Canada) has a WWW site,
Stoves: Web Site http://www1.kingston.net/~english/Stoves.html
that has pictures, drawings and discussions on this and many other stoves.
Anyone interested should check out this site. We are getting a lot of
interest in Africa.

It seems to me that this research interaction in STOVES is new in this old
world. (Has anyone found other examples?) I hope we can see similar
interactions on the other nodes, but they have so far confined themselves
to theoretical and economic questions.

I have also appreciated your BUN Website at
Http://144.16.73.100/~mukunda/home.Html.

and I hope this sparks more readers and MORE WRITERS.
~~~~
Yours truly, TOM REED

From REEDTB at compuserve.com Mon Sep 15 13:01:11 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:36 2004
Subject: Energy Consumption of Pyrolysis
Message-ID: <199709151210_MC2-2074-8F48@compuserve.com>

You said....
Here are Sunday morning ponderings. Charcoal energy content is about 1/3 of
the total content of wood (?), what is the net proceeds of pyrolysis, i.e.
energy given off by pyrolysis (as a percent of total content of wood)? The
remainder of the energy will be contained in the producer gas.

In SLOW pyrolysis (as practiced for the last 20,000 years) about 1/3 of the
energy is in the charcoal, 1/3 in the tar and 1/3 in the non-condensible
gases.

In FAST pyrolysis (as practiced the last 15 years in Canada, the US and
Europe) 60% of the energy can be in the wood-oil (Bio-Syn, Bio-Crude,
Syrup, whatever you want to call it) with only 20% in the char and very
little in gas.

Incidentally, I have been chasing down the "energy FOR pyrolysis" (heat Of
pyrolysis plus sensible heats to pyrolyse) for 20 years. It is an elusive
number, possibly as low as ZERO (autopyrolysis) and possibly as high as 30%
of the heat of combustion (5.4 Kj/g or 2400 Btu/lb) for SIMULTANEOUS
PYROLYSIS AND GASIFICATION (SPG).

So, if you have questions in this area, you are one of the healthy ones.

Regards, TOM REED

From codonnel at julian.uwo.ca Mon Sep 15 13:27:12 1997
From: codonnel at julian.uwo.ca (Dr. Cam O'Donnell)
Date: Tue Aug 31 21:35:36 2004
Subject: Diamond stoves
Message-ID: <341D710E.650D@julian.uwo.ca>

Hi,

I'm looking for a picture or color information to restore a "Diamond 25"
wood stove.

Any help in directing me to a source would be appreciated.

Cam

From lunds at hnet.net Mon Sep 15 16:13:56 1997
From: lunds at hnet.net (The Lunds)
Date: Tue Aug 31 21:35:36 2004
Subject: Diamond stoves
In-Reply-To: <341D710E.650D@julian.uwo.ca>
Message-ID: <341DB20F.5A1C@hnet.net>

Hi,
Could we get off of your E-mail list?
Faith Lund
>
>
>
> Cam

From lunds at hnet.net Mon Sep 15 16:18:38 1997
From: lunds at hnet.net (The Lunds)
Date: Tue Aug 31 21:35:36 2004
Subject: Research on the Internet
In-Reply-To: <199709151210_MC2-2074-8F4C@compuserve.com>
Message-ID: <341DB32A.7B3C@hnet.net>

Thomas Reed wrote:
>
> Thomas B. Reed 303 278 0558 V Colorado School of Mines
> ReedTB@Compuserve.com
> ALSO: The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dear Gayathri:
>
> You asked for an article for the current BUN (of India) newsletter. I have
> really enjoyed it and I like your mix of articles. Here is one you might
> use. I sympathize with your problem of getting new articles and I hope
> others will contribute. I'll send this to a few friends (800).
>
> Your netpal, TOM REED
> ~~~~
> BIOMASS RESEARCH THROUGH THE INTERNET
>
> As scientists and engineers, we have been accustomed to conducting research
> a day at a time, then reporting results in papers and in meetings, then
> waiting for a response from our colleagues "out there". This is a very
> slow process with a turnaround time of months or years. No wonder it has
> taken so long (13 billion years) for intelligence to make the secrets of
> nature consciously manifest.
>
> A new process is at work on the Internet, and it may benefit those least
> able to help themselves - the 3 billion poor of the world who are cooking
> wastefully with biomass, deforesting their neighborhoods and enhaling the
> smoke producing emphesema and glaucoma.
>
> The Center for Renewable Energy and Sustainable Technology (CREST)
> maintains a
> netsite with a number of special interest nodes - STOVES, GASIFICATION,
> DIGESTION, BIOCONVERSION, with a general category, BIOENERGY. Each node
> maintains archives and a mailing list. (I am the moderator of the
> GASIFICATION list - we currently have 150 members.) To subscribe to any of
> these lists, send the message "subscribe <listname>" to
> majordomo@crest.Org. (And, if you get tired or bored, or overwhelmed, send
> "unsubscribe <listname>".)
>
> The STOVE node has been very active in research in the last six months. We
> are working on WOOD-GAS STOVES (and in a sense this work also belongs in
> the GASIFICATION node). These stoves are close coupled gasifiers that
> generate gas in an inverted downdraft (also called charcoal making) NATURAL
> DRAFT gasifier which then leaves 25% charcoal after roasting out the gas
> and volatiles. The problem remaining is to mix the gases with air for
> clean, intense combustion. Natural draft doesn't provide much power for
> the mixing, and some of us have tried "air wicks", others are trying
> venturi mixers. Every few days someone makes a new configuration and
> reports on the results. It is VERY exciting, and should produce a working
> WOOD-GAS STOVE (if one is possible) in a year at most.
>
> [Here's a section you can keep - or leave out:
> Reporting research in the STOVES node can be very exciting as illustrated
> by the following E-mail letter that I got this morning.
>
> "I am very new to the subject of gasifier and or charcoal producing
> stoves. However after some excellent information derived from this
> archive, and list, I built a two can stove of my own. It didn't take
> long, (60min), or cost much, ($5.00), but it illustrated the theory and
> practice of everything I had read in a way nothing else could have! To
> anyone who hasn't tried it....build one.
>
> This stove is built from 21Litre paint cans, some brass angle brackets, (I
> can't help it, but ithas to look good), and some pop rivets for
> convenience. The gasifier
> section has a fuel grill mounted 3cm above the base of the can, made
> from 1/4in hardware cloth. Primary air intake is only a series of 1/8"
> holes, (about 40), drilled in the base, and in a can bottom removed from
> the burner can. The disc is pop riveted to the gasifier bottom, and
> supplied with a rudimentary handle.
>
> The burner assembly is located 1cm
> above the gasifier unit (secondary air intake). I didn't know what to
> expect, having guessed at some of the dimensions.....but I'll be
> *"=%$#@@##$.....if it didn't work....sure I got smoke.....sure it only
> burned for 35minutes...but at 2am in my back yard, in the dark....I saw
> exactly what I needed to understand what I had only been reading
> about.At about 10 minutes even surface combustion was achieved, the
> flame danced about 2cm above the combustibles, the colouration was
> white, blue, alternating with yellow. At this point there was no smoke
> that I could discern. The burn lasted for 35min...at which time I sealed
> the unit....charcoal production was at about 20%...
>
> I believe the primary intake needs to be increased dramatically, as the
> flame seemed
> to be starving, the secondary intake is already adjustable from 0-4cm,
> so I will play with that.....sorry if I seem to be going over old
> ground, but this is all new to me, anyway...three other stoves are in
> production...each with significant design changes....in a day or two
> we'll see. Again thank you to ALL for the new facination."
>
> This illustrates the excitement found in this node better than my words.
> (It also illustrates that you should sign your name and address. I don't
> know who wrote this or from where. The spelling "colour" might indicate
> someplace in the Old British Empire, but your guess is as good as mine.]
>
> The various contributors to this node are weighing in from all over the
> world. Alex English (in Canada) has a WWW site,
> Stoves: Web Site http://www1.kingston.net/~english/Stoves.html
> that has pictures, drawings and discussions on this and many other stoves.
> Anyone interested should check out this site. We are getting a lot of
> interest in Africa.
>
> It seems to me that this research interaction in STOVES is new in this old
> world. (Has anyone found other examples?) I hope we can see similar
> interactions on the other nodes, but they have so far confined themselves
> to theoretical and economic questions.
>
> I have also appreciated your BUN Website at
> Http://144.16.73.100/~mukunda/home.Html.
>
> Please remove us from your mailing list.
Thank you. Faith Lund
>

From lunds at hnet.net Mon Sep 15 16:19:58 1997
From: lunds at hnet.net (The Lunds)
Date: Tue Aug 31 21:35:36 2004
Subject: FOM
In-Reply-To: <v01510100b0430b349ee4@[199.2.222.97]>
Message-ID: <341DB37D.F2A@hnet.net>

E. L. Karstad wrote:
>
> Alex asks what FOM stands for...
>
> Well, to me it means how many times you can reconfigure a stove to come up
> with the same relative efficiency no matter how often you
> changethesevenorninedifferentcriticalcriteriaandthenfindouthatyouhaven't....
> ..............................
>
> AHEM!
>
> Good question Alex.
>
> I calculate it by dividing the amount of water lost to boiling by the
> amount of wood initially loaded into the stove. This does not include the
> amount of charcoal produced or the moisture content of wood, so FOM alone
> is not much use to us charcoal-making-wood-gas stove makers. FOM and
> %charcoal production (from initial wood load) gives me a couple reasonable
> working criteria to measure efficiency. Remeber, I'm way out in the field-
> unlike you scienterrific lab types.
>
> As to what F and O and M stands for... Ronal?
>
> elk
>
> Hi,
Please remove us from your E-mail list.
Thanks, Faith Lunde
> ______________________________

From REEDTB at compuserve.com Mon Sep 15 16:41:39 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:36 2004
Subject: FOM
Message-ID: <199709151553_MC2-207D-8FAB@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Ron, Alex, ELK et al:

I was just going to ask for a definition of FOM (Figure of Merit I presume)
when it magically appeared on my screen. Thanks ELK.

I also agree that by itself it doesn't mean a lot. In particular a stove
that burns a long time (with a large magazine) will have a much higher FOM
than one designed to make coffee (boil and pour).

So, RON, how about a simple standardized FOM 2 that you feel is relevant
and an exact description of how to measure it so we can all keep track of
our progress.

Incidentally, I have been hearing enthusiastic descriptions of flames from
the vortex burner, but no one has used the term "blue flame" (ie premixed
or diffusion stoichiometric combustion). Have you seen them in the vortex
burner?

Someone mentioned a chimney shelf the other day. I tried one over the
weekend with no success. There was a 15 inch "candle" (laminar, luminous)
flame endangering the ceiling of my garage! I felt I was running
experiments of 10 years ago! Oh well, two steps forward, one back is still
enough to keep me going. I'll only report FORWARD progress in the future.

Regards to all, TOM REED

From celtic1 at ibm.net Mon Sep 15 21:52:05 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:36 2004
Subject: Unsigned:
Message-ID: <341DE550.2118@ibm.net>

Ron:
You mentioned a letter, not signed, but possibly Old British spelling of
"Colour". You are partially right. I'm new to your list, and got a
little excited after running my first gasifier stove. I am: Stephen
Allen, Pickering, Ontario, Canada. (Previously from Northern Ireland).

From celtic1 at ibm.net Mon Sep 15 21:57:32 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:36 2004
Subject: Unsigned:(Sorry this response should be directed to Tom Reed)
In-Reply-To: <341DE550.2118@ibm.net>
Message-ID: <341DE66C.43EE@ibm.net>

Stephen Allen wrote:
>
Tom:
> You mentioned a letter, not signed, but possibly Old British spelling of
> "Colour". You are partially right. I'm new to your list, and got a
> little excited after running my first gasifier stove. I am: Stephen
> Allen, Pickering, Ontario, Canada. (Previously from Northern Ireland).

From english at adan.kingston.net Mon Sep 15 22:57:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:36 2004
Subject: Vortex Variables
In-Reply-To: <199709151553_MC2-207D-8FAB@compuserve.com>
Message-ID: <199709160259.WAA00281@adan.kingston.net>

Tom wrote:
snip
> Incidentally, I have been hearing enthusiastic descriptions of flames from
> the vortex burner, but no one has used the term "blue flame" (ie premixed
> or diffusion stoichiometric combustion). Have you seen them in the vortex
> burner?
snip
Dear Tom +
After the venturi burner gets heated up the dominant flame colour is
blue. It doesn't show up well in photos or during regular daylight.

Your comments about chimney, or combustion chamber size, are worth
exploring further. Two of the models of charcoal makers that I have
tested use the same pyrolysis chamber at roughly the same output
based on fuel load and burn duration. The curvacious stove has a
combustion chamber 20cm in diameter with thermocouple readings around
625 C. The "attached" flamelets are dispersed within its 4700cc
volume. In contrast the venturi burner has
a chamber diameter of 10cm and thermocouple readings of 1000 C. The
flame fills as little as 700 cc. Is there a theoretical minimum for
the volume of combustion?

I don't understand what exactly is happening in the unused
portions of the larger combustion chamber. I can't " see" fresh air
flowing back down around the pot and in. Is the larger surface area
enough to account for the large difference in temperature? Both were
insulated and both had a similar excess air factor.

1000 C gasses would surely transfer more heat to the pot than the
625 C gasses. We need to affordably get those temperatures up to
improve efficiency and reduce emissions. You can see quite a
difference in these two examples that is not due to insulation.

Did you, or Ron ever do a FOM test on your blue flame cooker?

Alex

> Regards to all, 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 gayathri at cgpl.iisc.ernet.in Tue Sep 16 02:20:11 1997
From: gayathri at cgpl.iisc.ernet.in (Gayathri V)
Date: Tue Aug 31 21:35:36 2004
Subject: Research on the Internet
Message-ID: <199709160624.GAA06838@cgpl.iisc.ernet.in>

Dear Mr.. Faith Lund
Thanks a lot for the immediate response, we really appreciate this.
----------------------------------------------------------------------------
--------------------------------------------
Mrs.Gayathri V
BIOMASS USERS NETWORK - INDIA
Project Engineer
Combustion Gasification and Propulsion Lab.
Dept. of Aerospace Engineering
IISc . Bangalore 560 012
Phone :
(off) +91-80-3092338 or 3348536
(Res) :+91-80-6632717
Fax :
+91-80-3444692 or 3341683
E-mail : gayathri@aero.iisc.ernet.in
gayathri@cgpl.iisc.ernet.in
==========================================================================
"There is nothing like impossible"
==========================================================================

From elk at arcc.or.ke Tue Sep 16 02:50:38 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:36 2004
Subject: burning garages
Message-ID: <v01510100b043fbe93896@[199.2.222.97]>

Tom Reed wrote:

>Someone mentioned a chimney shelf the other day. I tried one over the
>weekend with no success. There was a 15 inch "candle" (laminar, luminous)
>flame endangering the ceiling of my garage! I felt I was running
>experiments of 10 years ago! Oh well, two steps forward, one back is still
>enough to keep me going. I'll only report FORWARD progress in the future.

What? By remaining silent you want to endanger MY garage??

elk

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

From gayathri at cgpl.iisc.ernet.in Tue Sep 16 09:30:06 1997
From: gayathri at cgpl.iisc.ernet.in (Gayathri V)
Date: Tue Aug 31 21:35:36 2004
Subject: Dr. Reed- Thanks
Message-ID: <199709160627.GAA06855@cgpl.iisc.ernet.in>

Dear Dr. Reed,
Thanks so much for your encouragement and support.
We really appreciate this.
Regards
Gayathri
----------------------------------------------------------------------------
--------------------------------------------
Mrs.Gayathri V
BIOMASS USERS NETWORK - INDIA
Project Engineer
Combustion Gasification and Propulsion Lab.
Dept. of Aerospace Engineering
IISc . Bangalore 560 012
Phone :
(off) +91-80-3092338 or 3348536
(Res) :+91-80-6632717
Fax :
+91-80-3444692 or 3341683
E-mail : gayathri@aero.iisc.ernet.in
gayathri@cgpl.iisc.ernet.in
==========================================================================
"There is nothing like impossible"
==========================================================================

From Ebone0615 at aol.com Tue Sep 16 11:02:10 1997
From: Ebone0615 at aol.com (Ebone0615@aol.com)
Date: Tue Aug 31 21:35:36 2004
Subject: Chambers Stove Inq.
Message-ID: <970916110219_315144884@emout06.mail.aol.com>

To Whom It May Concern:

If you know anyone who refurbishes or is a dealer in Chambers stoves circa
1940 (?) could you please direct me to them. I have one in good working
condition that I would like to have appaised for sale. Any help you could
give me in this would be appreciated.

Thank you.

From english at adan.kingston.net Tue Sep 16 11:21:12 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:36 2004
Subject: Unsigned:(Sorry this response should be directed to Tom Reed
In-Reply-To: <341DE66C.43EE@ibm.net>
Message-ID: <199509170325.XAA09080@adan.kingston.net>

Dear Stephen
Welcome to the list, neighbour.
Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From skip.hayden at cc2smtp.NRCan.gc.ca Tue Sep 16 12:54:08 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:36 2004
Subject: Unsigned:(Sorry this response should be directed to T
Message-ID: <9708168744.AA874439783@cc2smtp.nrcan.gc.ca>

I didn't realize that we spelled "Old British" in Canada. That can
really colour my perspectives.

Skip Hayden

______________________________ Reply Separator _________________________________
Subject: Re: Unsigned:(Sorry this response should be directed to Tom
Author: stoves@crest.org at internet
Date: 9/16/97 11:24 AM

> Stephen Allen wrote:
>
> Tom:
> You mentioned a letter, not signed, but possibly Old British spelling of
> "Colour". You are partially right. I'm new to your list, and got a
> little excited after running my first gasifier stove. I am: Stephen
> Allen, Pickering, Ontario, Canada. (Previously from Northern Ireland).

Dear Stephen
Welcome to the list, neighbour.
Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From remco at ds5500.cemr.wvu.edu Tue Sep 16 13:58:23 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:36 2004
Subject: Meer landelijk smaak en kleur
In-Reply-To: <9708168744.AA874439783@cc2smtp.nrcan.gc.ca>
Message-ID: <341ED867.5326@ds5500.cemr.wvu.edu>

Ik hou van kachels, vooral de gene met glaze deuren zo dat je het vuur
kan bekijken.

From kakky at hargray.com Tue Sep 16 17:46:34 1997
From: kakky at hargray.com (Kathy Jeffers)
Date: Tue Aug 31 21:35:36 2004
Subject: Pot Bellied Stove
Message-ID: <341EBC10.3117@hargray.com>

I am interested in purchasing a pot bellied stove from an individual.
The stove is a #119 made in Rome , GA . What should I expect to pay for
this stove?
It is in very good shape.
Thanks
Kathy Y Jeffers

From ovencrft at nbn.com Wed Sep 17 03:12:21 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:36 2004
Subject: Pot Bellied Stove
Message-ID: <199709170714.AAA00463@shell10.ba.best.com>

>I am interested in purchasing a pot bellied stove from an individual.
>The stove is a #119 made in Rome , GA . What should I expect to pay for
>this stove?
>It is in very good shape.
>Thanks
>Kathy Y Jeffers
>
You may be able to get a valuation from Macy's Texas Stove Works at 713 521 7884
ALAN>
ALAN SCOTT

Check out the new web site for OVENCRAFTERS
http://pomo.nbn.com/home/ovncraft

From ovencrft at nbn.com Wed Sep 17 03:12:21 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:36 2004
Subject: Chambers Stove Inq.
Message-ID: <199709170714.AAA00464@shell10.ba.best.com>

>To Whom It May Concern:
>
>If you know anyone who refurbishes or is a dealer in Chambers stoves circa
>1940 (?) could you please direct me to them. I have one in good working
>condition that I would like to have appaised for sale. Any help you could
>give me in this would be appreciated.
>
>Thank you.
>
There is a business that restores and has parts for the Chambers stoves and
can value yours. Macy's Texas Stove Works (713)521 7884
ALAN
ALAN SCOTT

Check out the new web site for OVENCRAFTERS
http://pomo.nbn.com/home/ovncraft

From elizabethb at itdg.org.uk Wed Sep 17 07:47:28 1997
From: elizabethb at itdg.org.uk (Elizabeth Bates)
Date: Tue Aug 31 21:35:36 2004
Subject: Boiling Point & address
Message-ID: <199709171147.HAA26747@solstice.crest.org>

I joined the network some time back but have been relatively quiet
since as I edit a journal on household energy and am not involved in
stoves testing. The journal is called 'Boiling Point' and it is
published by the Intermediate Technology Development Group, in the
UK. If you would like to receive the journal, it is supplied free of
charge, although we welcome donations. I would also like to invite
people on the network to contribute articles to the journal.

Boiling Point is 'a technical journal for those working with stoves
and household energy. It deals with technical, social, financial and
environmental issues and aims to improve the quality of life for poor
communities living in the developing world'.

The journal appears twice per year. About half the journal is devoted
to a particular theme each edition. The next two themes are:
'Household energy, smoke and health' and 'Household energy in urban
areas'. I would very much welcome articles for this journal. If
possible, they should be less than 1500 words in length, with not too
much technical detail, but I welcome drawings and photographs. Hard
copy, disc (ideally WordPerfect), or e-mail formats are fine. If
anyone would like more details please feel welcome to e-mail to the
address below. If you want a copy of the journal, please give full
address.

Elizabeth Bates
Boiling Point Co-ordinator
Intermediate Technology
Myson House
Railway Terrace
Rugby CV21 3HT
UK
Tel: +44 1788 560631
Fax: + 44 1788 540270
Email <elizabethb@itdg.org.uk>
Elizabeth Bates
Intermediate Technology
Myson House, Railway Terrace
Rugby CV21 3HT UK
Tel: +44 -1788 560631 Fax: +44 -1788 540270
Email: elizabethb@itdg.org.uk
Url: http://www.oneworld.org/itdg
Intl: http://www.itdg.org.pe

From REEDTB at compuserve.com Wed Sep 17 08:48:47 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:36 2004
Subject: Vortex Variables - Energy Conversion rate
Message-ID: <199709170850_MC2-20CD-760C@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Alex and Harry:

Alex asks (below) about energy release in his vortex burner for the
inverted downdraft gasifier (also called charcoal maker, top lit etc.)

I have been developing a new (to me) figure of merit for gasification and
flames, ie

Volumetric Energy Conversion = MW/(m3 of reactor) or Btu/(hr-ft3 reactor)

(See my recent note on figures of merit, starting with "superficial gas
velocity" and ending with "superficial gas production")

Fluidized bed gasifiers look 2-10 times more effective than fixed bed
gasifiers when compared on a "superficial gas velocity". (SGV for fixed -
.02-2m3/m2-sec; SGV for fluidized 2-5 m/sec). However, on a VOLUMETRIC
conversion basis the fixed beds look better, (4m3(gas)/(m3reactor - sec) vs
1 m3/m3 for FBs.

Moving along this same line I need to know more about volumetric combustion
energy conversion. Gas flames (as in my home furnace) convert about
100,000 Btu/hr-ft3, 1 MJ/m3, while my 3.5 liter Sable car engine converts
(3.5 l engine, 20 mpg, 60 mph, 120,000 Btu/gal, cylinders firing 1/4 time)
6M Btu/ft3-hr, 60 MJ/m3. (Possibly three times as much at peak power?) (1
MBtu/hr-ft3 ~ 10 MJ/m3-sec).

In general, more gas/air velocity in a flame translates into more energy
conversion, but there is an upper limit. What is it? I have been
designing a small cyclonic incinerator, currently converting about 200,000
Btu/ft3-hr. Am I likely to do much better? Is Alex in the ball park?

A note to Alex: Your TC reading of 600C in the bed is probably accurate -
radiation shielding and good gas contact brings TC, gas and fuel to
equilibrium. Your 1000 C in the gas flame could be 500C too low. No
radiation shielding, no gas TC equilibrium. So, flame temperature useful
for high heat transfer to pot, but VERY difficult to measure absolutely.
Relatively, however, it measures heat transfer to the TC and therefore to
the pot.

WORK in PROGRESS TOM REED

~~~
Subject: Vortex Variables
Reply-To: stoves@crest.org

Tom wrote:
snip
> Incidentally, I have been hearing enthusiastic descriptions of flames
from
> the vortex burner, but no one has used the term "blue flame" (ie premixed
> or diffusion stoichiometric combustion). Have you seen them in the
vortex
> burner?
snip
Dear Tom +
After the venturi burner gets heated up the dominant flame colour is
blue. It doesn't show up well in photos or during regular daylight.

Did you, or Ron ever do a FOM test on your blue flame cooker?

Alex

> Regards to all, 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 REEDTB at compuserve.com Wed Sep 17 08:56:13 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:37 2004
Subject: Whoops! - 1790, not 1890
Message-ID: <199709170850_MC2-20CD-7609@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Stovers:

In commenting on Lord Rumford's chimney shelf, my word processor
accidentally said

>
About 1890, he discovered that by putting a shelf and the back bottom of
the chimney (but above the fireplace) the incoming cold air turned around=

Should have been 1790 of course.

Incidentally, the Rumford Society has a prize for the greatest contribution
to combustion.
Yours truly, TOM REED

From REEDTB at compuserve.com Wed Sep 17 09:40:32 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:37 2004
Subject: Unsigned:(Sorry this response should be directed to Tom Reed)
Message-ID: <199709170850_MC2-20CD-7611@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Steve:

Nice to know you .. Welcome to stoves. Great about your tests. Have you
read any of our archives? (Difficult, but informative.)

TOM

From elk at arcc.or.ke Wed Sep 17 10:02:34 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <v01510100b045a84b5b53@[199.2.222.133]>

Stovers;

I've been concentrating on what I feel is a practical everyman's charcoal
making woodgas stove that could be easily produced in E.Africa's informal
sector.

To date, I've simplified the stove to a minimum using materials readily
available.

An operator familiar with the stove can consistantly convert thumb-thick
dry wood fuel to 20% charcoal and boil off almost (not quite equal) the
same amount of water as the weight of fuel. FOM ranges from .85 to .95.
Burn time is typically between 1hr 30 min. to 1 hr. 55 min. After some 60
trials with various configurations, I'm pretty happy with this.

I've costed the stove in the range of USD 9 to 11.00 dependant on labour
charges at 30% of total, and assuming that electric welding is necessary,
though it might not be with skilled metalworking using rivets.

Familiarisation with the stove's operation is necessary in order to avoid
some very impressive amounts of smoke. Wind resistance is good.

Turndown (min-max power) is good and quick- maybe 4 out of 5 when compared
with gas cooking.

Flame holding is not a problem, though again, the operator must understand
a few basic techniques.

I've not tried wet wood, but assume this would negatively affect flame
holding. I've used both hard and soft woods in the stove with little
observed difference other than bulk density.

The stove incorporates a perforated fuel cell insert attached to the
removable bottom 'lid' which is 2 cm distant from the inside wall of the
stove. This cell has a grid raised 2 cm from the bottom, and an adjustable
primary air vent is built into the bottom (lid). Average fuel load is 4.5
kg of loosely packed dry wood cut neatly in lengths of 27 cm, which is the
inside depth of the fuel cell.

The two 25 l. paint cans, which have had their bottoms cut out, are
slightly narrower at the base than the top. These opened bases are joined
together at five points with narrow strips of metal teaving a 4 mm gap (the
secondary air slit) between the two cans. This slightly hour-glass shaped
tube is 75 cm high, 30 cm diam at either end and 28 cm diam at the middle
secondary air inlet.

As per Ronal's suggestion, a skin of sheet metal is wrapped around the
entire stove from top to bottom and sealed in place at both ends where a
reinforcement rib is located just below the rolled lips of the cans.. This
acts as a partial insulator, a wind shield for secondary air, and a
secondary air pre-heater. Air enters the space between the two skins (the
'waist of the stove) via 24 3mm wide by 8 cm long slits cut through the
outer skin approx one third up from the base of the stove. These cuts are
made with an angle grinder, though several other less sophisticated methods
of making secondary air inlet holes at this point could be used.

An alu cookpot of 28 cm diam (4.5 litre capacity) is inserted into the top
of the stove. This is postioned within a cut-out lid (one of the lids that
come with the 2 orig. 25 litre paint cans- same as the bottom which
supports the fuel cell) with three rolled tabs to hold the rim of the pot
1.5 cm above the stovetop. The gap between pot and cut out lid is 1 cm.

Three well splayed legs hold the stove about 10 cm above the ground,
providing enough stability to stir porridge without rocking the stove.

The stove wall (outer skin) above the mid point level of the secondary air
vent does get very hot & could be a hazard to small children. If a clay or
cement inslation isn't added (which would make the whole stove virtually
immovable & fragile), then maybe chicken mesh could be supported some
distance away from the stove on a simple frame, or a roundbar ring?

I also need to affix handles on the stove at two locations to allow the
stove to be inverted in order to pour out the hot charcoal at the end of
the burn. This can be smothered in a small 4 or 5 litre paint can with
sealable lid.

One last detail is removing the pot- as hot gasses are vented at the rim of
the pot, grasping here with fingertips in order to remove the pot is not
recommended. I've made a simple ring out of round bar with two 'T' shaped
handles that the pot is inserted into while on the stove. This is also a
handle that can be grasped while stirring very thick almost cooked
maize-meal in order to stabilise the stove (the final product is a heavy
cake). Should the flame in the combustion chamber fail, the pot can be
removed and flame usually re-establishes immediately with the inrush of air
through the open stovetop. Primary air vent is cracked open a bit more and
the pot is re-inserted.

And, hey- this stoves LOOKS good!

Comments? Questions? I'll get busy on a sketch.

Alex- what's your fax number for a middle-of-the-night faxed drawing? I'd
appreciate this on your website.

All for now;

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 Wed Sep 17 11:56:18 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
In-Reply-To: <v01510100b045a84b5b53@[199.2.222.133]>
Message-ID: <199709171558.LAA18323@adan.kingston.net>

deer elk,
>
> And, hey- this stoves LOOKS good!

> Comments? Questions? I'll get busy on a sketch.
Last week you mentioned a cooking time of 20 min for maize meal.
1.Are you able to size your fuel charge to the predicted cooking time?
2.What is the cooking time difference for soft wood as compared
with hard wood?
3.What will it take to get a few dozen of these used locally.
4.Is most cooking in Kenya done on a family scale. How many people
would this cook for? Max. Min?

> Alex- what's your fax number for a middle-of-the-night faxed drawing? I'd
> appreciate this on your website.

Middle-of -WHOSE-night? Yours I suspect.

It shall be done.
Fax No. 1-613-386-1211
Can you get photos of all the peices, and the finished product,
scanned locally?

Bravo!

Alex
>
> All for now;
>
>
> 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
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From bburt at adan.kingston.net Wed Sep 17 12:52:16 1997
From: bburt at adan.kingston.net (Brian Burt)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <199709171654.MAA21564@adan.kingston.net>

----------
> From: E. L. Karstad <elk@arcc.or.ke>
> To: stoves@crest.org
> Subject: Twocan trials- 25 litre Paint Can version
> Date: September 17, 1997 7:03 AM
>
> Comments? Questions? I'll get busy on a sketch.
>
> Alex- what's your fax number for a middle-of-the-night faxed drawing? I'd
> appreciate this on your website.
>
> All for now;
>
Dear Elk;

Another option for you is to get hold of a VHS(c) camcorder and record a
tape of everything you might want images of. If you can then get this tape
to me then I can capture images from it and they can be saved for Alex's
web page. This is how most of Alex's imaged have been saved. Hey we could
even get a look at your mug!

Brian Burt
Burt's Greenhouses
Phone 613-386-3426 Fax 613-386-1211
e-mail bburt@adan.kingston.netBrian Burt

From verhaarp at janus.cqu.edu.au Wed Sep 17 16:59:39 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <1.5.4.32.19970917210148.006df2c4@janus.cqu.edu.au>

>From Piet Verhaart

At 12:52 17/09/97 -0700, you wrote:
>
>
>----------
>> From: E. L. Karstad <elk@arcc.or.ke>
>> To: stoves@crest.org
>> Subject: Twocan trials- 25 litre Paint Can version
>> Date: September 17, 1997 7:03 AM
>>
>> Comments? Questions? I'll get busy on a sketch.
>>
>> Alex- what's your fax number for a middle-of-the-night faxed drawing? I'd
>> appreciate this on your website.
>>
>> All for now;
>>
>Dear Elk;
>
>Another option for you is to get hold of a VHS(c) camcorder and record a
>tape of everything you might want images of. If you can then get this tape
>to me then I can capture images from it and they can be saved for Alex's
>web page. This is how most of Alex's imaged have been saved. Hey we could
>even get a look at your mug!
>
>Brian Burt
>Burt's Greenhouses
>Phone 613-386-3426 Fax 613-386-1211
>e-mail bburt@adan.kingston.netBrian Burt
>
>
Can you process PAL video tapes as well?
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 bburt at adan.kingston.net Wed Sep 17 18:18:54 1997
From: bburt at adan.kingston.net (Brian Burt)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <199709172221.SAA08241@adan.kingston.net>

> >Dear Elk;
> >
> >Another option for you is to get hold of a VHS(c) camcorder and record a
> >tape of everything you might want images of. If you can then get this
tape
> >to me then I can capture images from it and they can be saved for Alex's
> >web page. This is how most of Alex's imaged have been saved. Hey we
could
> >even get a look at your mug!
> >
> >Brian Burt
> >Burt's Greenhouses
> >Phone 613-386-3426 Fax 613-386-1211
> >e-mail bburt@adan.kingston.netBrian Burt
> >
> >
> Can you process PAL video tapes as well?

Well yes and no. I cannot deal with PAL directly but I have just phoned the
local camera shop and for $5.00+cost of tape+.15/min (tape minutes) they
will transfer so if you have a tape I could deal with it. Are you
photogenic?

Brian

From MIHWP at ttacs1.ttu.edu Wed Sep 17 19:09:35 1997
From: MIHWP at ttacs1.ttu.edu (Harry W. Parker)
Date: Tue Aug 31 21:35:37 2004
Subject: Vortex Variables - Energy Conversion rate
In-Reply-To: <199709170850_MC2-20CD-760C@compuserve.com>
Message-ID: <34206358.2001@ttacs.ttu.edu>

Hello Tom and all,

(Tom I need to write a more personal note soon but teaching a course on
the internet is "eating my lunch".)

With regard to combustion efficiency I had always considered the volume
of the combustion chamber a minor cost, except in particular
circumstances such as aircraft gas turbines. High volumetric combustion
efficiency comes as a result of very intense mixing of oxygen and fuel.
This high efficiency is achieved by very turbulent, high pressure drop
flow. If I were ranking burners, the pressure drops for air and gas flow
would be an interesting parameter. For fluidized bed combustors
"supporting the weight of bed" is in inherent pressure drop, but they
have many advantages. After combustion the area and related volume for
useful heat exchange become very significant variables.

Harry

From elk at arcc.or.ke Thu Sep 18 03:30:20 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: 2can Paintcan Version-Answers
Message-ID: <v01510100b0469fdfd3b5@[199.2.222.131]>

Alex asks, elk answers;

>1.Are you able to size your fuel charge to the predicted cooking time?

Good question. I've tried a much smaller fuel cell, but widening the gap
'tween inner stove wall & fuel cell perforated wall lowers efficiency-
presumeably by diluting pyrolysis gases prior to contact with secondary
air. Filling in this gap with sand etc. doesn't seem to help either. Maybe
an inverted cone .... where have I heard that before? I'll try a couple
very loosely packed loads of wood to look into this. Maybe just cutting the
pieces of wood shorter will work. I'm onto it.

>2.What is the cooking time difference for soft wood as compared
>with hard wood?

About 20 minutes for a full fuel cell load. We're looking at a weight
reduction of around 25% from hard to soft I'd say seems linear. No hard
data, mind you.....

>3.What will it take to get a few dozen of these used locally.

Making a few dozen stoves. First one (aside from the prototype), is being
made today from more typically available scrap. It won't LOOK so nice
though.

>4.Is most cooking in Kenya done on a family scale. How many people
>would this cook for? Max. Min?

Yes, and between 3 to 5 people dependant on appetite with the 4.5 litre alu pot.

I've reviewed my data inclusive of yesterday's 2 trials, and I see that my
FOM was slightly overstated. Bring it down to and average of .82 Still
fine tuning, so there should be some improvement. I don't know yet wether I
get a better FOM at a slow or vigorous boil....?

On another note, I just heard last night that there's a budding (and very
promising) project starting on a commercial scale to encourage Maasai to
grow accacia trees for charcoal production. Six years produces 3 bags per
tree AND improves grazing. Now all the organisers have to do to optimise is
convince the Maasai that sheep are better than goats... Max Kinyanjui, of
Kenya Ceramic Jiko fame (a long-lost buddy of mine) is working with a large
charcoal roasted meat restaurant on the inception.

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 Thu Sep 18 03:30:17 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <v01510101b046a5f140e3@[199.2.222.131]>

Brian;

I've ordered a PAL 'Snappy', which should be here beginning Oct.

If there's a general hue & cry for images before then (if the drawing I'll
send isns't sufficient for the time being) then I'll be happy to courier
you a tape.

Expect images next month- & my mug too? I wouldn't want to lose credibility!

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 Thu Sep 18 11:44:54 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: Boiling Point
Message-ID: <199709181546.SAA11560@arcc.or.ke>

Elizabeth;

I have no objection to any of my (many, verbose & oft-confused) e-mailed
submissions to the group being extracted, edited (cleaned up) & used in your
publication. Should you so wish, I'd be happy to review prior to
publication. I think we're getting close to a charcoal making wood gas stove
for household use (for instance), & an interesting article could be patched
together from the archives.

There have been many very informative messages, some philosphical, some
technical, others practical, posted within this group that may be of use to
you, and I feel (as we all do) that the more people exposed to the issues
discussed the better.

Keep up the good work & please put me on your mailing list. I'll gladly post
a contribution!

Stovers- comments?

elk

From verhaarp at janus.cqu.edu.au Thu Sep 18 16:45:12 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <1.5.4.32.19970918204720.006c5b14@janus.cqu.edu.au>

>From Piet Verhaart

Dear Brian,

At 18:18 17/09/97 -0700, you wrote:
>> Can you process PAL video tapes as well?
>
>
>Well yes and no. I cannot deal with PAL directly but I have just phoned the
>local camera shop and for $5.00+cost of tape+.15/min (tape minutes) they
>will transfer so if you have a tape I could deal with it. Are you
>photogenic?
>
>Brian
>
My wife says no. I could do shots of her instead.
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 phoenix at transport.com Thu Sep 18 19:40:26 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:37 2004
Subject: Good view of a working stove
Message-ID: <199709182345.QAA29499@brutus.transport.com>

Dear Stovers:

NATIONAL GEOGRAPHIC has a good picture of a working stove from the third
world. On page 70 of the October 1997 issue is an excellent depiction of
the challenge of designing a good working stove capable of using a wide
range of feed stocks without benefit of a chimney. Enjoy!

Art Krenzel
Battle Ground, WA
phoenix@transport.com

From english at adan.kingston.net Thu Sep 18 23:04:37 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: Venturi Test
Message-ID: <199709190306.XAA24335@adan.kingston.net>

Dear Stovers

The following , plus pictures, can be seen at
http://www1.kingston.net/~english/Grail.htm

I finally refitted the venturi burner for a boiling water test. It
now has a 10cm diameter by 18cm tall cylindrical combustion chamber
opening at about 5cm directly under the pot. As is often the
case, it gave me some trouble getting started. So I lost a
good deal of water boiling time. Without the additional chimney it
operates without the intensive vortex or swirl action, however the
flame was still fairly turbulent, thanks to the bluff body. That is
ofcourse while the pot was off and I could see the flame. A thermo
couple near the top of the combustion chamber gave fairly consistent
readings of 1450+/-25F, until the TC quit working. That is 400F
higher than the last test with the curvacious model. The CO2 was
often up around 17-19% with CO over the 2000ppm limit. Having no
adjustment on secondary air, I was forced to cut back on primary air.
This brought CO2 down to 11-13% and CO to 125-350ppm.(CO/CO2 of .002)
At the higher CO2 levels (and the pot removed) the flames extend out
the top of the combustion chamber. At the lower levels they did not.
There was no visible smoke at either time.
In spite of early fumbling it still managed to boil off 7.25 lbs of
water with 7.75 lbs of wood. Certainly no efficiency breakthrough.
Probably a food burning breakthrough.
On a positive note, CO was lower than I expected.

This burner will soon go off to school where a 4th year engineering
student at Queens will try to measure its performance and assist in
its optimization. The way it looks now it certainly isn't "everymans"
stove. I do however think that a practical low emissions burner for
the charcoal maker is a possibility.

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From celtic1 at ibm.net Thu Sep 18 23:18:00 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:37 2004
Subject: Unsigned:(Sorry this response should be directed to Tom Reed)
In-Reply-To: <199709170850_MC2-20CD-7611@compuserve.com>
Message-ID: <3421EDD6.362E@ibm.net>

Thomas Reed wrote:
>
> Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
> Colorado School of Mines & The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Steve:
>
> Nice to know you .. Welcome to stoves. Great about your tests. Have you
> read any of our archives? (Difficult, but informative.)
>
> TOM
Yes I have scanned the archives....not that difficult, learning all the
time.
Inquisitively....Steve:

From celtic1 at ibm.net Thu Sep 18 23:48:19 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:37 2004
Subject: Stove design variations....comments
In-Reply-To: <199709170850_MC2-20CD-7611@compuserve.com>
Message-ID: <3421F50B.12BF@ibm.net>

Stephen Allen wrote: I need feedback...please.

After playing around with 2 can inverted gasifier stoves, I thought I
would try something very different. Using a 1 Litre paint can I built
the typical gasifier unit...fuel grill 2 cm above the bottom of the can,
However I decided to try a sealed unit. At the top lip of the can two
1/2 inch copper pipe fittings were soldered on either side of the can,
1/2 inch pipe connected to these were run to the primary intake holes at
the bottom of the can. The two fittings at the primary intake were left
a air gap of 1 cm. The idea was that if the top of the can was sealed,
then the unburned gases would be forced through the pipes, and back into
the primary intakes....result complete combustion.....WRONG....I found
something totally unexpected. When the lid was in place, the flame
smothered....but when a hollow can was placed on top of the gasifier
base, intense blue flames shot from the unit....when the interior of the
unit was observed, the ports which should have been inlets, were spewing
blue flames....under pressure. The unit burned hot enough to melt most
of the solder....and a large red spot appeared on the side of the heavy
gauge galvanized steel can, which came very close to a molten state. As
you can see, the results I expected ended up being reversed, and I ended
up with a blue flame burner, instead of an exhaust recycler... Any
explanations, are greatly appreciated. ( next time I braze my joints,
not solder).
Steve:

From bburt at adan.kingston.net Fri Sep 19 07:22:46 1997
From: bburt at adan.kingston.net (Brian Burt)
Date: Tue Aug 31 21:35:37 2004
Subject: Stove design variations....comments
Message-ID: <199709191125.HAA05173@adan.kingston.net>

>
> Stephen Allen wrote: I need feedback...please.
>
>

It would be great to get some images of what you are doing Stephen, Alex
could then post them.

?Are you burning top down in your fuel cell?

Brian

From english at adan.kingston.net Fri Sep 19 07:52:46 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: Stove design variations....comments
In-Reply-To: <3421F50B.12BF@ibm.net>
Message-ID: <199709191155.HAA05979@adan.kingston.net>

Dear Steve
If I follow your description, it sounds like you have succeeded in
developing a higher velocity secondary air jet. Extending the intake
for this air down to the ground has increased the effective chimney
height and there by the driving force. Some body help me with the
units. Chimney draft=dif of density(proportional to temp(K))* height
of chimney* acceleration due to gravity.

Another piece of the puzzell?

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From REEDTB at compuserve.com Fri Sep 19 08:22:15 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <199709190824_MC2-2110-C493@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ELK et al:

Sounds like you have a winner stove. Congratulations. Looking forward to
seeing it in Alex's collection.

Should we all stop work now? (More likely we should all make a copy, and
then think about improvements.)

Three cheers, TOM REED

From elk at arcc.or.ke Fri Sep 19 08:49:40 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: Venturi
Message-ID: <v01510101b0481cd05bf3@[199.2.222.152]>

Alex writes;

>This burner will soon go off to school where a 4th year engineering
>student at Queens will try to measure its performance and assist in
>its optimization. The way it looks now it certainly isn't "everymans"
>stove. I do however think that a practical low emissions burner for
>the charcoal maker is a possibility.

Good stuff. I like the Univ. collaboration. I also think that some
modification of the 'burner' area may improve the 2can.

elk

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

From dpennise at uclink4.berkeley.edu Fri Sep 19 19:44:23 1997
From: dpennise at uclink4.berkeley.edu (David Pennise)
Date: Tue Aug 31 21:35:37 2004
Subject: moisture meter advice
Message-ID: <3.0.32.19970919164640.0071e1d8@uclink4.berkeley.edu>

Hello all,

We are looking for some advice in purchasing a wood moisture meter. Any
help would be greatly appreciated. We need to use the moisture meter in
the field to determine the water content of freshly cut and air-dried wood
awaiting carbonization in earth kilns in Kenya. Accuracy to less than one
percent or so is not necessary.

some questions:
-what reliable brands/models would you reccommend?
-pros and cons of using pinless models versus those with pins?
-applicability across different wood species?
-any other important considerations?

Thank you for all of your help.

Sincerely,
David Pennise and Kirk Smith
University of California
Berkeley, CA
email: dpennise@uclink4.berkeley.edu, krksmith@uclink4.berkeley.edu

From english at adan.kingston.net Fri Sep 19 20:54:35 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: Webpage Update
Message-ID: <199709200056.UAA12900@adan.kingston.net>

Dear Stovers
The cross-sectional drawing of Elsen's stove is now at
http://www1.kingston.net/~english/ELK.htm

A cutaway sketch of the Mamou Stove (version 1), the sort of stoves
that were tested by the Brace Research Institute, is at
http://www1.kingston.net/~english/Brace.htm

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Fri Sep 19 21:37:07 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: moisture meter advice
In-Reply-To: <3.0.32.19970919164640.0071e1d8@uclink4.berkeley.edu>
Message-ID: <199709200139.VAA14750@adan.kingston.net>

>
> Hello all,
>
> We are looking for some advice in purchasing a wood moisture meter. Any
> help would be greatly appreciated. We need to use the moisture meter in
> the field to determine the water content of freshly cut and air-dried wood
> awaiting carbonization in earth kilns in Kenya. Accuracy to less than one
> percent or so is not necessary.

> some questions:
> -what reliable brands/models would you reccommend?

I have a Timber Check Moisture Meter, sold by Lee Valley Tools for
$80 Canadian ($60 USD). Its is a pin type whose range is 6-12% in 1%
increments, 14%,18%,22%, 25% and over. It comes with a chart for
adjustments according to species, which may not include the ones
you are testing. It includes some tropical species that are used in
cabinetry. It is very rugged. If you are interested in more
information, I can post the catalogue picture and information on the
web page.

Alex

> -pros and cons of using pinless models versus those with pins?
> -applicability across different wood species?
> -any other important considerations?
>
> Thank you for all of your help.
>
> Sincerely,
> David Pennise and Kirk Smith
> University of California
> Berkeley, CA
> email: dpennise@uclink4.berkeley.edu, krksmith@uclink4.berkeley.edu
>
>
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From english at adan.kingston.net Fri Sep 19 22:05:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:37 2004
Subject: Good view of a working stove
In-Reply-To: <199709182345.QAA29499@brutus.transport.com>
Message-ID: <199709200207.WAA15913@adan.kingston.net>

Dear Art and all.
I have put the relevant portion of that photo at the top of the
webpage.

Alex
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From celtic1 at ibm.net Sat Sep 20 20:53:15 1997
From: celtic1 at ibm.net (Stephen Allen)
Date: Tue Aug 31 21:35:37 2004
Subject: Stove design variations....comments
In-Reply-To: <199709191125.HAA05173@adan.kingston.net>
Message-ID: <34246F09.D47@ibm.net>

Brian Burt wrote:
>
> >
> > Stephen Allen wrote: I need feedback...please.
> >
> >
>
> It would be great to get some images of what you are doing Stephen, Alex
> could then post them.
>
> ?Are you burning top down in your fuel cell?
>
> Brian
>
> :
Yes Brian...I am burning top down, I haven't tried bottom lit yet, but I
will as soon as I repair the stove.
Steve:

From larcon at sni.net Sun Sep 21 23:13:38 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:37 2004
Subject: Good view of a working stove
Message-ID: <v01540b00b04b546c09c1@[204.133.251.34]>

Art Krenzel said:

>NATIONAL GEOGRAPHIC has a good picture of a working stove from the third
>world. On page 70 of the October 1997 issue is an excellent depiction of
>the challenge of designing a good working stove capable of using a wide
>range of feed stocks without benefit of a chimney. Enjoy!

(RWL): Art - Thanks for finding and reporting this picture (which is
apparently of an Afganhi "adobe" (?) stove at a refugee camp in Pakistan).

Alex: This would be a good picture for your web site.

All: This is a location where the type of charcoal-making we have been
doing appears to be out of the question. As Art said - here is a real
challenge. One thought though is that the small material shown in the
photograph (leaves, small twigs, orange peels, etc.) could possibly still
be gasified in an almost closed can centered in a charcoal-making stove,
with the normal small wood on the outside of the can. One would have to
have a briquetting approach also. This only makes sense if there is a need
for charcoal in this (refugee) environment.

Regards Ron

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

From larcon at sni.net Sun Sep 21 23:13:37 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:37 2004
Subject: Stephen Allen tests
Message-ID: <v01540b01b04b5efd854b@[204.133.251.34]>

Summary - A few comments on three recent messages from Stephen Allen (and
a little on those from Alex and Brian).

I. Stephen said (unfortunately this was a week ago on the 14th - I've been
pretty busy on the non-stove parts of my life):

< snip>

> I'll be
>*"=%$#@@##$.....if it didn't work....sure I got smoke.....sure it only
>burned for 35minutes...but at 2am in my back yard, in the dark..

(RWL) Stephen - please - we may be cut off by those automatic filters
concerned about what children may hear.

<snip>

> The burn lasted for 35min...at which time I sealed
>the unit....charcoal production was at about 20%....I believe the
>primary intake needs to be increased dramatically, as the flame seemed
>to be starving, the secondary intake is already adjustable from 0-4cm,

(RWL): My guess is the opposite - that there was too much primary air!
(previously Stephen said:
>Primary air intake is only a series of 1/8"
>holes, (about 40), drilled in the base, and in a can bottom
>removed from the burner can. The disc is pop riveted to the
>gasifier bottom, and supplied with a rudimentary handle.)

Of course, I don't know exactly how tight your primary control mechanism
was, but I have found it is very difficult to control the primary air well
enough. A paint can of this size probably could take more than an hour to
fire with low primary air. 35 minutes is pretty fast, I think - and the
main control element on speed is the primary air supply. A tall chimney
will speed up the process also - how tall was yours?

Stephen
> Again thank you to ALL for the new facination.

(RWL): Thank you for a really motivating report (as others have already
said, and I wish I had done so earlier).

II. Then Stephen said on Thursday:

>Stephen Allen wrote: I need feedback...please.
>
>After playing around with 2 can inverted gasifier stoves, I thought I
>would try something very different. Using a 1 Litre paint can I built
>the typical gasifier unit...fuel grill 2 cm above the bottom of the can,
>However I decided to try a sealed unit.

(RWL): Was this a totally sealed can? Maybe Alex is the expert on this -
with the "primary" air coming down the sides. But you also used the term
"typical gasifier unit". We need clarification on what sort of air holes
are at the bottom.

> At the top lip of the can two
>1/2 inch copper pipe fittings were soldered on either side of the can,
>1/2 inch pipe connected to these were run to the primary intake holes at
>the bottom of the can. The two fittings at the primary intake were left
>a air gap of 1 cm.

(RWL): This is not clear - were there originally 4 primary air holes or
only two? In the following I assume that there was some means of getting
the normal primary air to the bottom.

I don't understand the reference to an "air gap of 1 cm" either.

Stephen
> The idea was that if the top of the can was sealed,
>then the unburned gases would be forced through the pipes, and back into
>the primary intakes....result complete combustion.....WRONG....I found
>something totally unexpected. When the lid was in place, the flame
>smothered....but when a hollow can was placed on top of the gasifier
>base, intense blue flames shot from the unit....when the interior of the
>unit was observed, the ports which should have been inlets, were spewing
>blue flames....under pressure.

(RWL): Stephen - again I don't think I've got the picture. I presume that
when you say "the ports which should have been inlets", we are talking
about the two top ports which you described with the words: ">At the top
lip of the can two
>1/2 inch copper pipe fittings were soldered on either side of the can,"

Could you describe the fit between the "hollow can" and the "gasifier unit".
Do you feel there is no secondary air coming in here?
How tall is the "hollow can"?

Stephen:
> The unit burned hot enough to melt most
>of the solder....and a large red spot appeared on the side of the heavy
>gauge galvanized steel can, which came very close to a molten state. As
>you can see, the results I expected ended up being reversed, and I ended
>up with a blue flame burner, instead of an exhaust recycler... Any
>explanations, are greatly appreciated. ( next time I braze my joints,
>not solder).
>Steve:

(RWL): Let me first repeat the reply to Stephen from Alex of the 19th:
>Dear Steve
>If I follow your description, it sounds like you have succeeded in
>developing a higher velocity secondary air jet. Extending the intake
>for this air down to the ground has increased the effective chimney
>height and there by the driving force. Some body help me with the
>units. Chimney draft=dif of density(proportional to temp(K))* height
>of chimney* acceleration due to gravity.
>
>Another piece of the puzzell?

(RWL): I agree with Alex' conclusion. (I would amend Alex' question to
say that the difference of interior and exterior densities is proportional
to the differences in inverse (absolute) temperatures - with an integral
formulation needed as well.)

I would go further however, and say that your result seems very
exciting and should definitely be pursued. One possibility is to extend
the two (maybe more) "secondary air pipes" (which Alex and I see as the
explanation) upwards and pointing at where a cook-pot would be placed.
With water in this pot, I believe that your high temperatures may be very
helpful in getting high efficiency.

It is not easy to get a blue hot flame and your results are
therefore potentially very important. Good luck in carrying this further.
To the best of my knowledge, nobody else has tried anything like this
exterior (only) secondary air inlet starting at the primary inlet. (I have
tried some extra secondary air as a central column - but saw a very low air
flow) . I think that the higher velocity may be more due to the fact that
you don't have the break for secondary air of other investigators just
above the wood supply. You also may have a taller "chimney". Whatever,
your approach should be continued,

III. Stephen also said in a third message on the 20th:
>Yes Brian...I am burning top down, I haven't tried bottom lit yet, but I
> will as soon as I repair the stove.

(RWL): Bottom lighting should certainly be tried, especially since I'm not
sure I understand your geometry. However, I would be very surprised if it
would work at all.

In this test what was your % charcoal production?
Did you have any control?

Again - sorry for the long delay in responding. I look forward to hearing
more.
Regards Ron

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

From larcon at sni.net Sun Sep 21 23:13:42 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:37 2004
Subject: Twocan trials- 25 litre Paint Can version
Message-ID: <v01540b04b04b882b323d@[204.133.251.34]>

Summary: A few congratulations and comments on Elsen's stove.

Elsen - this is in response to your report of last Wednesday (17 Sep).
Your report was outstanding. Congratulations!!

The only thing I would like to better understand is your use of a
perforated metal fuel cage. I'd sure like to hear what happens with both a
solid can (perforated bottom) and a solid can with "dents" (to keep the
fuel away from the solid wall).

You said:

<snip>
>
>I've costed the stove in the range of USD 9 to 11.00 dependant on labour
>charges at 30% of total, and assuming that electric welding is necessary,
>though it might not be with skilled metalworking using rivets.

a. Can you estimate the present and future labor hours in this total?
b. Can you estimate the number of uses required to retrieve this cost
(assume it is doubled in price perhaps when it gets to the consumer)?

>
>Familiarisation with the stove's operation is necessary in order to avoid
>some very impressive amounts of smoke. Wind resistance is good.

< SNIP>
>
>Flame holding is not a problem, though again, the operator must understand
>a few basic techniques.
>

(RWL): Can you make an estimate of the training time required?

<snip>
> a skin of sheet metal,,,,,,,(snip>......
>acts as a partial insulator, a wind shield for secondary air, and a
>secondary air pre-heater.

(RWL) There was a time when you were concerned about preheating - is this
present system giving less temperature rise?

<snip>
Elsen:
>And, hey- this stoves LOOKS good! <snip>

(RWL): Is it painted? Or not necessary?

Again - I am really impressed by what you have accomplished. I
hope you will start selling soon - or maybe you want to do some more user
tests first? Any comments yet from users? Where do we sign up to be
investors?

II. On FOM On the 15th, Elsen reported in answering a question from Alex:

<snip>

>I calculate it by dividing the amount of water lost to boiling by the
>amount of wood initially loaded into the stove. This does not include the
>amount of charcoal produced or the moisture content of wood, so FOM alone
>is not much use to us charcoal-making-wood-gas stove makers. FOM and
>%charcoal production (from initial wood load) gives me a couple reasonable
>working criteria to measure efficiency. Remeber, I'm way out in the field-
>unlike you scienterrific lab types.

>As to what F and O and M stands for... Ronal?

elk

>NB: Has anyone told you that starting with pre-heated water is cheating?

(RWL): FOM is short for Figure Of Merit. As Elsen said: this is needed
for finding the efficiency and I have given the conversion a few times.
With efficiency you have to know energy content of the wood and the
charcoal. This FOM avoids the need for those assumptions and allows
everyone to communicate on equal terms. I vaguely recall seeing this in a
stove book somewhere. It should be almost twice as high if you are'nt
making charcoal.

One will improve the FOM if "post-heated" water is approximately zero.

Regards Ron

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

From elk at arcc.or.ke Mon Sep 22 11:07:32 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:37 2004
Subject: 2can-answers
Message-ID: <199709221507.SAA04356@arcc.or.ke>

Ronal! Good to hear from you again, I was beginning to worry.....

Thanks for the accolades, but I'm relying on a group effort to optimise
this...ALEX!

Now, back onto you favourite topic of questioning the validity of a
perforated fuel cell;
Firstly, I like the name 'fuel cell', though I must apologise to
Paul@Pyromid for coming close to plagarism- at least I don't have an
'array' of any sort.
Secondly, with a smooth walled unperforated cell, there are definite
problems with both flame holding and uneven burning (down one side only)
which reduces charcoal production significantly.
Thirdly, the space between the fuel cell and the stove wall acts to
insulate & direct heat loss upward.
Fourthly, the metal walls tend to get hot & act a 'spark plug', fifthly,
the cell enclosure reduces fuel load somewhat, which is desirable.
Sixly (?sixly?) Stove life is extended, as the highest rate of steel
oxidation occurs to the cell, and the stove bottom can be dropped out and
repaired or replaced a lot easier than the entire lower can.
Seventhly, I note that turndown control is improved with the perforated
cell- possibly a function of more evenly distributed airflow through the
fuel (see secondly).

I haven't tried dents as an alternate to holes. Can you support a preference?

As for cost, my chaps are taking about 8 man-hours per stove. This could be
reduced by one third I reckon.

At approx USD 0.1 per kg for charcoal bought in small domestic lots, and
producing 20% return on a wood load of 3.75 kg, and costing the stove at
$15.00, I calculate payback in 112 days on charcoal value alone- forget any
associated health, environmental or labour saving benfits.

I don't thing that the stove price will be doubled above cost if it's
produced in the informal 'jua kali' sector. Stephon Gitonga... comment?

One closely supervised demonstration should be sufficient to teach somone
how to use this stove. The commonly used parafin pressure lamp is more
difficult to operate- and more dangerous. A few important points on control
at the beginning and end of the burn are essential, and the motivation to
maximise charcoal production should be sufficient to fine tune skill with
practice. What's advantagious is the relatively long burn time per load of
between 1.5 and 2 hours. This is enough to produce a full meal in the
normal one-burner fashion.

I think that the temperature rise in the secondary air as it flows between
the inner and outer skins is not too great as to adversly affect
combustion, as I have noticed when this air is seriosly pre-heated in other
stove designs. Possibly this is a factor of reduced dwell time due to the
narrow gap between the walls. I'm currently making an 'inflated' stove,
where the only change is that this outer skin will be a further 4 cm
distant from the inner stove wall. This should add to insulation, but may
overheat the secondary air. Stay tuned.

Not painted. Is there paint that will withstand high temperature? I don't
think it's necessary. I'm now using salvaged 200 liter drum steel (2 mm I
think), and the stove still looks good! Have made three so far- all
consistant in function. I'm handing them out to the staff involved in
development for home trials. Stay tuned.

I don't want to get into production or sales. This is a gift. Once we've
optimised, I would like this to be mass produced in the informal sector.
Lets work on spinning it out of the Web & into the real world, O.K.?

Regards;

elk

From tmiles at teleport.com Mon Sep 22 15:05:48 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:37 2004
Subject: Bioenergy Lists and Commands
Message-ID: <3.0.32.19970922111254.009f007c@mail.teleport.com>

BIOENERGY EMAIL LISTS

The bioenergy mailing lists are hosted by the Center for Renewable Energy &
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at CREST.

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(Other Volunteers are Welcome!)
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Thomas R. Miles, Jr., Consultant tmiles@teleport.com

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Portland, Oregon, USA 97225 Tel (503) 292-0107 Fax (503) 605-0208

From CAMPBELLDB at cdm.com Mon Sep 22 16:00:39 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:37 2004
Subject: Survey on health impacts of inddor air pollution
Message-ID: <9709221958.AA03237@cdm.com>

September 22, 1997

Dear Colleague:

The Environmental Health Project (EHP) has established a network to create a
forum for dialogue and information exchange between individuals and
organizations interested in the reduction of indoor air pollution, the testing
of approaches to decrease exposure to indoor air pollution, and the
investigation of the harmful effects of indoor air pollution on the health of
women and children. The network will address these concerns with particular
attention to activities carried out in developing countries.

EHP is funded by the United States Agency for International Development. One
of EHP's areas of interest is the prevention of acute respiratory infections
(ARI), a leading cause of child morbidity and mortality around the world.
Although much research remains to be done, there is growing evidence that
indoor air pollution (from cooking, heating, poor ventilation and smoking)is
an important environmental risk factor for ARI and one which is amenable to
intervention.

The objectives of the network are to:
1. Disseminate information, and create awareness and interest regarding the
health effects of indoor smoke on women and children

2. Serve as a link between health, policy, and energy sectors interested in
addressing the issues surrounding indoor air pollution

3. Stimulate interest in interventions to reduce exposure to indoor air
pollution, e.g. improved stove programs, behavioral change and health
education activities,
research and policy initiatives.

4. Keep EHP and network members informed about relevant research results,
current research, field activities and other initiatives

Planned activities during the next year include:
- Establish an informal and active network, primarily e-mail based
which will allow members to discuss ARI and indoor air pollution issues
individually
and with the entire network.

- Conduct a survey of the information needs, interests and activities
of potential network members

- Disseminate a periodic e-mail bulletin containing information on
current activities of network members, recent publications, notices of
conferences, etc.

- Collaborate with other organizations and agencies active in
promoting improved stove and health issues

In order to meet our objectives, we welcome your suggestions about how to make
this an effective forum for exchange of information. This is your opportunity
to help structure the network in a way that is meaningful to you. It is our
intent to expand coverage in those areas which are of interest to our members
and which need to be more fully addressed.

In order to more fully know your interests we are conducting a survey of
network members. Please complete the survey (see below) and send your
responses to Dan Campbell, EHP Librarian at campbelldb@cdm.com

Thank you for your interest and for taking time to complete and return the
attached survey. Please feel free to browse the EHP website for additional
information about our project (http://www.access.digex.net~ehp).

Sincerely,
Dan Campbell

SURVEY

General Information
1. Type of organization: Check all that apply
International Government Private Nonprofit
Individual Other

2. Major interests: Check all that apply
Research Health Energy Appropriate Technology Fuel
Policy Other (Please specify)_______________

3. Is your work mainly in the US____? abroad?_____? or both ____?

4. If abroad: Would you list below the country(s) you are working in now or
plan to work in the near future.

5. Have you worked in developing countries where indoor air pollution is a
problem?
Yes No

6. Are you or your organization currently working on a stove program in a
developing country?
Yes No Plan to soon

7. What topics are of most interest to you. Please describe below

8. What suggestions do you have to make the network responsive to your needs
and interests?

Thank you for taking the time to answer these questions. We look forward to
your responses

Dan Campbell
email: campbelldb@cdm.com
fax: 1 703 247 8610

From kammen at phoenix.Princeton.EDU Mon Sep 22 18:41:07 1997
From: kammen at phoenix.Princeton.EDU (Daniel M. Kammen)
Date: Tue Aug 31 21:35:37 2004
Subject: Survey on health impacts of inddor air pollution
Message-ID: <v0153050eb04cb385891c@[128.112.71.155]>

please add my student, Majid Ezzati to the mailing list, his
email address in kenya is:

gmc@users.AfricaOnline.Co.Ke

the subject line should indicate "Majid Ezzati"

also, please note that i always receive 2 copies of your messages.

- dan kammen

--------------------------------------------------------------------------
Daniel M. Kammen
Assistant Professor of Public and International Affairs
Chair, Science, Technology and Environmental Public Policy (STEP) Program
201 5 Ivy Lane
Woodrow Wilson School of Public and International Affairs
Princeton University
Princeton, NJ 08544-1013

Tel: 609-258-2758 Fax: 609-258-6082 Email: kammen@princeton.edu
WWW: http://www.wws.princeton.edu/~kammen/
Secretary Jackie Schatz: Tel: 609-258-4821; Email: jackie@wws.princeton.edu
--------------------------------------------------------------------------

From celtic1 at ibm.net Mon Sep 22 20:45:12 1997
From: celtic1 at ibm.net (celtic1@ibm.net)
Date: Tue Aug 31 21:35:37 2004
Subject: Stephen Allen tests
In-Reply-To: <v01540b01b04b5efd854b@[204.133.251.34]>
Message-ID: <34273A42.2F2A@ibm.net>

> > At the top lip of the can two
> >1/2 inch copper pipe fittings were soldered on either side of the can,
> >1/2 inch pipe connected to these were run to the primary intake holes at
> >the bottom of the can. The two fittings at the primary intake were left
> >a air gap of 1 cm.
>

> (RWL): This is not clear - were there originally 4 primary air holes or
> only two? In the following I assume that there was some means of getting
> the normal primary air to the bottom.
>
> I don't understand the reference to an "air gap of 1 cm" either.
>
(SA): There were 4 primary air holes, the gap of 1cm refers to the
space between two of the primary holes and the inlets for the secondary
air.

> Stephen
> > The idea was that if the top of the can was sealed,
> >then the unburned gases would be forced through the pipes, and back into
> >the primary intakes....result complete combustion.....WRONG....I found
> >something totally unexpected. When the lid was in place, the flame
> >smothered....but when a hollow can was placed on top of the gasifier
> >base, intense blue flames shot from the unit....when the interior of the
> >unit was observed, the ports which should have been inlets, were spewing
> >blue flames....under pressure.
>
> (RWL): Stephen - again I don't think I've got the picture. I presume that
> when you say "the ports which should have been inlets", we are talking
> about the two top ports which you described with the words: ">At the top
> lip of the can two
> >1/2 inch copper pipe fittings were soldered on either side of the can,"
>
(SA): correct....these are the top ports.

> Could you describe the fit between the "hollow can" and the "gasifier unit".
> Do you feel there is no secondary air coming in here?
> How tall is the "hollow can"?
>
(SA): The fit between the two cans was airtight, I sealed the joint with
stove cement.
The hollow can is the same size as the lower can....both are
1-litre paint cans. This was being used as a chimney . Secondary air
could only come from the previously mentioned ports.

> Stephen:
> > The unit burned hot enough to melt most
> >of the solder....and a large red spot appeared on the side of the heavy
> >gauge galvanized steel can, which came very close to a molten state. As
> >you can see, the results I expected ended up being reversed, and I ended
> >up with a blue flame burner, instead of an exhaust recycler... Any
> >explanations, are greatly appreciated. ( next time I braze my joints,
> >not solder).
> >Steve:
>
> (RWL): Let me first repeat the reply to Stephen from Alex of the 19th:
> >Dear Steve
> >If I follow your description, it sounds like you have succeeded in
> >developing a higher velocity secondary air jet. Extending the intake
> >for this air down to the ground has increased the effective chimney
> >height and there by the driving force. Some body help me with the
> >units. Chimney draft=dif of density(proportional to temp(K))* height
> >of chimney* acceleration due to gravity.
> >
> >Another piece of the puzzell?
>
> (RWL): I agree with Alex' conclusion. (I would amend Alex' question to
> say that the difference of interior and exterior densities is proportional
> to the differences in inverse (absolute) temperatures - with an integral
> formulation needed as well.)
>
> I would go further however, and say that your result seems very
> exciting and should definitely be pursued. One possibility is to extend
> the two (maybe more) "secondary air pipes" (which Alex and I see as the
> explanation) upwards and pointing at where a cook-pot would be placed.
> With water in this pot, I believe that your high temperatures may be very
> helpful in getting high efficiency.
>
> It is not easy to get a blue hot flame and your results are
> therefore potentially very important. Good luck in carrying this further.
> To the best of my knowledge, nobody else has tried anything like this
> exterior (only) secondary air inlet starting at the primary inlet. (I have
> tried some extra secondary air as a central column - but saw a very low air
> flow) . I think that the higher velocity may be more due to the fact that
> you don't have the break for secondary air of other investigators just
> above the wood supply. You also may have a taller "chimney". Whatever,
> your approach should be continued,
>
> III. Stephen also said in a third message on the 20th:
> >Yes Brian...I am burning top down, I haven't tried bottom lit yet, but I
> > will as soon as I repair the stove.
>
> (RWL): Bottom lighting should certainly be tried, especially since I'm not
> sure I understand your geometry. However, I would be very surprised if it
> would work at all.
>
> In this test what was your % charcoal production?
> Did you have any control?
>
> Again - sorry for the long delay in responding. I look forward to hearing
> more.
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net

From celtic1 at ibm.net Mon Sep 22 20:58:23 1997
From: celtic1 at ibm.net (celtic1@ibm.net)
Date: Tue Aug 31 21:35:38 2004
Subject: Stephen Allen tests
In-Reply-To: <v01540b01b04b5efd854b@[204.133.251.34]>
Message-ID: <34273D60.4D8F@ibm.net>

Ronal W. Larson wrote:
>
> Summary - A few comments on three recent messages from Stephen Allen (and
> a little on those from Alex and Brian).
>
> I. Stephen said (unfortunately this was a week ago on the 14th - I've been
> pretty busy on the non-stove parts of my life):
>
> < snip>
>
> > I'll be
> >*"=%$#@@##$.....if it didn't work....sure I got smoke.....sure it only
> >burned for 35minutes...but at 2am in my back yard, in the dark..
>
> (RWL) Stephen - please - we may be cut off by those automatic filters
> concerned about what children may hear.
>
> <snip>
>
> > The burn lasted for 35min...at which time I sealed
> >the unit....charcoal production was at about 20%....I believe the
> >primary intake needs to be increased dramatically, as the flame seemed
> >to be starving, the secondary intake is already adjustable from 0-4cm,
>
> (RWL): My guess is the opposite - that there was too much primary air!
> (previously Stephen said:
> >Primary air intake is only a series of 1/8"
> >holes, (about 40), drilled in the base, and in a can bottom
> >removed from the burner can. The disc is pop riveted to the
> >gasifier bottom, and supplied with a rudimentary handle.)
>
> Of course, I don't know exactly how tight your primary control mechanism
> was, but I have found it is very difficult to control the primary air well
> enough. A paint can of this size probably could take more than an hour to
> fire with low primary air. 35 minutes is pretty fast, I think - and the
> main control element on speed is the primary air supply. A tall chimney
> will speed up the process also - how tall was yours?
>
> Stephen
> > Again thank you to ALL for the new facination.
>
> (RWL): Thank you for a really motivating report (as others have already
> said, and I wish I had done so earlier).
>
> II. Then Stephen said on Thursday:
>
> >Stephen Allen wrote: I need feedback...please.
> >
> >After playing around with 2 can inverted gasifier stoves, I thought I
> >would try something very different. Using a 1 Litre paint can I built
> >the typical gasifier unit...fuel grill 2 cm above the bottom of the can,
> >However I decided to try a sealed unit.
>
> (RWL): Was this a totally sealed can? Maybe Alex is the expert on this -
> with the "primary" air coming down the sides. But you also used the term
> "typical gasifier unit". We need clarification on what sort of air holes
> are at the bottom.
>
> > At the top lip of the can two
> >1/2 inch copper pipe fittings were soldered on either side of the can,
> >1/2 inch pipe connected to these were run to the primary intake holes at
> >the bottom of the can. The two fittings at the primary intake were left
> >a air gap of 1 cm.
>
> (RWL): This is not clear - were there originally 4 primary air holes or
> only two? In the following I assume that there was some means of getting
> the normal primary air to the bottom.
>
> I don't understand the reference to an "air gap of 1 cm" either.
>
> Stephen
> > The idea was that if the top of the can was sealed,
> >then the unburned gases would be forced through the pipes, and back into
> >the primary intakes....result complete combustion.....WRONG....I found
> >something totally unexpected. When the lid was in place, the flame
> >smothered....but when a hollow can was placed on top of the gasifier
> >base, intense blue flames shot from the unit....when the interior of the
> >unit was observed, the ports which should have been inlets, were spewing
> >blue flames....under pressure.
>
> (RWL): Stephen - again I don't think I've got the picture. I presume that
> when you say "the ports which should have been inlets", we are talking
> about the two top ports which you described with the words: ">At the top
> lip of the can two
> >1/2 inch copper pipe fittings were soldered on either side of the can,"
>
> Could you describe the fit between the "hollow can" and the "gasifier unit".
> Do you feel there is no secondary air coming in here?
> How tall is the "hollow can"?
>
> Stephen:
> > The unit burned hot enough to melt most
> >of the solder....and a large red spot appeared on the side of the heavy
> >gauge galvanized steel can, which came very close to a molten state. As
> >you can see, the results I expected ended up being reversed, and I ended
> >up with a blue flame burner, instead of an exhaust recycler... Any
> >explanations, are greatly appreciated. ( next time I braze my joints,
> >not solder).
> >Steve:
>
> (RWL): Let me first repeat the reply to Stephen from Alex of the 19th:
> >Dear Steve
> >If I follow your description, it sounds like you have succeeded in
> >developing a higher velocity secondary air jet. Extending the intake
> >for this air down to the ground has increased the effective chimney
> >height and there by the driving force. Some body help me with the
> >units. Chimney draft=dif of density(proportional to temp(K))* height
> >of chimney* acceleration due to gravity.
> >
> >Another piece of the puzzell?
>
> (RWL): I agree with Alex' conclusion. (I would amend Alex' question to
> say that the difference of interior and exterior densities is proportional
> to the differences in inverse (absolute) temperatures - with an integral
> formulation needed as well.)
>
> I would go further however, and say that your result seems very
> exciting and should definitely be pursued. One possibility is to extend
> the two (maybe more) "secondary air pipes" (which Alex and I see as the
> explanation) upwards and pointing at where a cook-pot would be placed.
> With water in this pot, I believe that your high temperatures may be very
> helpful in getting high efficiency.
>
> It is not easy to get a blue hot flame and your results are
> therefore potentially very important. Good luck in carrying this further.
> To the best of my knowledge, nobody else has tried anything like this
> exterior (only) secondary air inlet starting at the primary inlet. (I have
> tried some extra secondary air as a central column - but saw a very low air
> flow) . I think that the higher velocity may be more due to the fact that
> you don't have the break for secondary air of other investigators just
> above the wood supply. You also may have a taller "chimney". Whatever,
> your approach should be continued,
>
> III. Stephen also said in a third message on the 20th:
> >Yes Brian...I am burning top down, I haven't tried bottom lit yet, but I
> > will as soon as I repair the stove.
>
> (RWL): Bottom lighting should certainly be tried, especially since I'm not
> sure I understand your geometry. However, I would be very surprised if it
> would work at all.
>
> In this test what was your % charcoal production?
> Did you have any control?
>
> Again - sorry for the long delay in responding. I look forward to hearing
> more.
> Regards Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net

Ron;

At this time I'm running 4 to 5 burns a day.....using 4 different
stoves. Basically I'm trying to create a solid database from which to
draw my conclusions. Everyones input is greatly appreciated. Sorry about
the symbolic language, but I was excited, and symbols best described how
I felt.

Steve:

From rmiranda at sdnnic.org.ni Mon Sep 22 22:00:08 1997
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:35:38 2004
Subject: COST OF WOODSMOK
Message-ID: <3.0.2.16.19970922111239.00973e1e@ns.sdnnic.org.ni>

>Date: Sun, 21 Sep 1997 21:04:30
>To: STOVERS NETWORK
>From: Rogerio Miranda <rmiranda@sdnnic.org.ni>
>Subject: COST OF WOODSMOK
>
>Hi Stovers:
>
>
>We are designing a woodenergy modernization program for Nicaragua. It
includes collecting tax from unsustainable fuelwood dealers and partially
redirect it to an improved woodstove dissemination program.
>
>We need to convince politicians to support our idea, and we need the
support of the Ministry of Health. The Health Ministry doesn't have any
data about woodsmok contamination in Nicaragua, although 70% of the
population uses fuelwood for cooking and Accute Respiratory Infections is
one of the leadings causes of death among infants.
>
>Specificaly we are looking for data relating woodsmok contamination and
its effects on people health and what are it costs. For instance, how much
it cost the nation or the government the lost of productivity and also the
cost of medicines for an ill contaminate person ?
>
>Any clue in how to obtain this info ?
>
>Thanks
>
>Rogerio
>
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
ATP/PROLENA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
telefax (505) 276 2015
EM <rmiranda@sdnnic.org.ni>
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

From skip.hayden at cc2smtp.NRCan.gc.ca Tue Sep 23 07:33:55 1997
From: skip.hayden at cc2smtp.NRCan.gc.ca (Skip Hayden)
Date: Tue Aug 31 21:35:38 2004
Subject: moisture meter advice
Message-ID: <9708238750.AA875025385@cc2smtp.nrcan.gc.ca>

What sort of moisture levels are you looking for? Some
meters are much better than others, dpending on the ranges
involved - be sure to specify whether on "wet" or "dry"
basis.

Skip Hayden

From REEDTB at compuserve.com Tue Sep 23 12:33:41 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:38 2004
Subject: Stove design variations....comments
Message-ID: <199709231236_MC2-2182-C904@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Alex:

I have long used a "rule of thumb" that the draft vacuum will be 0.01 inch
of water per foot of height. (I'll let you transfer that to metric.)

TOM

From REEDTB at compuserve.com Tue Sep 23 12:34:18 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:38 2004
Subject: Nomenclature
Message-ID: <199709231236_MC2-2182-C907@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Stovers:

In developing new fields and new apparatus, it is necessary to develop new
words sto describe what is going on. It is also important NOT to use words
already in use for something else, or confusion will reign.

I seem to detect the use of "fuel cell" to describe what might be called
the fuel magazine or fuel reservoir or simply the gasifier (as opposed to
the upper combustion chamber).

The official meaning of "fuel cell" is an electrochemical device for
generating power by direct chemical reaction rather than combustin. The
simplest ones operate only on hydrogen, others are molten carbonate or
solid oxide cells. I worked on a solid oxide (zirconia) fuel cell for
several years at MIT 1970 to 1975. My associate, Michael Hsu is still
commercializing it. So, when I see "fuel cell" here, I'm puzzled.

Yours, TOM REED

From REEDTB at compuserve.com Tue Sep 23 12:34:20 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:38 2004
Subject: stoves-digest V1 #278
Message-ID: <199709231236_MC2-2182-C908@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Steve Allen et al:

The description of the "recycling" gasifier was very interesting. INTENSE
blue flames is what we are after, and natural draft (maybe .002 inches of
water column!) typically makes very lazy flames.

Stoves have been described in which sealed vessels with small holes were
externally heated and when pyrolysis started jets came out of the holes. I
presume that is related to what you are seeing. (What I am seeing at 6:50
AM is the sun rising over Denver).

I have wondered whether a small steam jet generator placed in the fire
could give us the motive power needed for intense flames. Consider it.

Regards, TOM REED

From CAMPBELLDB at cdm.com Tue Sep 23 13:24:57 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:38 2004
Subject: Survey on health impacts of inddor air pollution
Message-ID: <9709231723.AA18538@cdm.com>

dan

many thanks fro responding to the survey; i will send out a summary of
responses shortly. i'm not sure why you're getting 2 copies of all messaages
and will try to find out why

regards,
dan campbell
ehp

To: stoves@crest.org
Subject: Re: Survey on health impacts of inddor air pollution
From: "Daniel M. Kammen" <owner-stoves@crest.org>
Date: 22 Sep 97 18:46:24
Reply-to: stoves@crest.org

please add my student, Majid Ezzati to the mailing list, his
email address in kenya is:

gmc@users.AfricaOnline.Co.Ke

the subject line should indicate "Majid Ezzati"

also, please note that i always receive 2 copies of your messages.

- dan kammen

From phoenix at transport.com Tue Sep 23 20:44:49 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:38 2004
Subject: Stove design variations....comments
Message-ID: <199709240047.RAA01756@s.transport.com>

Dear Alex and Tom:

I have enclosed a bitmap image of a graph dealing with natural draft
chimneys using stack temperature and chimney height. The graph is from an
Architects Handbook and the stack temperature lines appear to be straight
although I am sure that as the stack height approaches zero there must be a
slight deviation. As such I am not certain that reducing the Y axis (stack
height in feet) by ten naturally reduces the X axis (Draft measured in
inches of water) by ten as the stack height approaches zero.

I am sorry to send this in .bmp format but I do not have any data
compression available that I am aware of. I have tried to send this in the
past but the data exceeded 60k and was difficult for the receivers to
retrieve.

Art Krenzel
phoenix@transport.com

----------
From: Thomas Reed <REEDTB@compuserve.com>
To: INTERNET:stoves@crest.org
Subject: Re: Stove design variations....comments
Date: Tuesday, September 23, 1997 9:35 AM

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Alex:

I have long used a "rule of thumb" that the draft vacuum will be 0.01 inch
of water per foot of height. (I'll let you transfer that to metric.)

TOM
----------

From prasad at tn7.phys.tue.nl Wed Sep 24 08:55:25 1997
From: prasad at tn7.phys.tue.nl (prasad)
Date: Tue Aug 31 21:35:38 2004
Subject: Nomenclature
In-Reply-To: <199709231236_MC2-2182-C907@compuserve.com>
Message-ID: <9709241247.AA25715@tn7.phys.tue.nl>

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From celtic1 at ibm.net Wed Sep 24 15:10:14 1997
From: celtic1 at ibm.net (celtic1@ibm.net)
Date: Tue Aug 31 21:35:38 2004
Subject: stoves-digest V1 #278
In-Reply-To: <199709231236_MC2-2182-C908@compuserve.com>
Message-ID: <34299115.4C57@ibm.net>

Thomas Reed wrote:
>
> Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
> Colorado School of Mines & The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Steve Allen et al:
>
> The description of the "recycling" gasifier was very interesting. INTENSE
> blue flames is what we are after, and natural draft (maybe .002 inches of
> water column!) typically makes very lazy flames.
>
> Stoves have been described in which sealed vessels with small holes were
> externally heated and when pyrolysis started jets came out of the holes. I
> presume that is related to what you are seeing. (What I am seeing at 6:50
> AM is the sun rising over Denver).
>
> I have wondered whether a small steam jet generator placed in the fire
> could give us the motive power needed for intense flames. Consider it.
>
> Regards, TOM REED

(SA): Very cool idea...an engine within an engine, contributing to the
whole. My concern would be, the amount of energy consumed by the steam
generator, will be more than it is capable of delivering as pressurized
draft. At 100% efficiency, (and in a perfect world), it still might be a
losing proposition. If energy needed to produce steam = steam
produced...then the fuel needed for cooking, etc would double. If fuel
is no problem, (as in my interest, camping), then this might be worth
pursuing. Sometimes it seems as if the best ideas come, when a leap of
logic..or sometimes faith leads in a new direction. When all else
fails...try something new.

Steve:

From verhaarp at janus.cqu.edu.au Wed Sep 24 17:12:55 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:38 2004
Subject: The Development Set
Message-ID: <1.5.4.32.19970924211502.006a8f5c@janus.cqu.edu.au>

Dear Stovers,

Instead of venting my most recent thoughts on stoves, charcoal
making or otherwise and certainly not meaning any disrespect of our
experimenters, who deserve nothing but praise, let me paste a poem.
It appeared on 2 August 1988 in the leading Dutch Newspaper NRC-
Handelsblad, unsigned.
Feeling great kinship I cut it out and made some enlarged copies, one of
which has occupied a prominent place in Prasad's office for years. I think
it was still there when we had our Holland holiday in December 1993.

The Development Set

Excuse me, friends, 1 must catch my jet
I'm off to join the Development Set;
mybags are packed, and I've had all my shots,
I have Traveller's cheques and pills for the trots.

The Development Set is bright and noble,
our thoughts are deep and our vision is global
Although we move with- the better classes,
our thoughts are always with the masses.

We discuss malnutrition over steaks
and plan hungertalks during coffeebreaks.
Wether Asian floods or African droughts
we face each issue with open mouth.

The language of the Development Set
stretches the English alphabet;
We use swell words like 'epigenetic',
micro', 'macro' and 'logarithmatic.

It pleasures us to be so esoteric
it's so intellectually atmospheric
And though establishments may be unmoved,
our vocabularies are much improved.

Development Set-homes are'extremely chic,
full of carvings and draped with batik.
Eye-level photographs subtly assure:
your host is at home with the great and the poor.

Enough of these verses - on with the mission!
Our task is as broad as the human condition!
Just pray God the biblical promise is true,
the poor ye shall always have with you.

Pleasant stoving,

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 REEDTB at compuserve.com Wed Sep 24 19:06:58 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:38 2004
Subject: Commercial Charcoal
Message-ID: <199709241856_MC2-21AD-7B94@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Stovers:

(The stove node is by default also the charcoal node.)

I recently performed the following tests on Kingsford and the Jack Daniels
charcoal that I described this Spring (just for the Hell of it).

BRAND KINGSFORD JACK DANIELS
Initial Weight 10.16 9.83
Dried Weight 8.48 7.47
Moisture Content % 19.2 18.9
Weight Burned 3.54 3.52
Ash % of dry 41.7 44.2

I placed the samples in Al foil weighing pans. I used my wife's
self-cleaning oven for both the drying and the ashing.

Many people believe that charcoal is a WONDERFUL fuel. We tend to forget
that charcoal is an excellent absorbent for water (~20% in the dry Denver
climate!), and that the commercial manufacturers add a LOT of clay etc. in
the U.S. There is all sorts of non wood fuels in charcoal briquettes in
the U.S. Caveat Emptor.

Yours truly, TOM REED

From larcon at sni.net Thu Sep 25 00:38:29 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:38 2004
Subject: 2can-answers
Message-ID: <v01540b02b04f843865d9@[204.133.251.21]>

Summary: More dialog on Elsen Karstad's 2-can charcoal-making stoves -
mainly on commercialization issues.

Elsen said on the 22nd:

<snip>

>Now, back onto you favourite topic of questioning the validity of a
>perforated fuel cell;

(RWL): Nope - if you say its better, its my job to try it out both ways -
its just that I have been thinking of the ""cell" as a chimney and
perforated chimneys wouldn't seem to make much sense. Clearly, the lower
paint can (not the "cell" or "cage") is the chimney and the air flow is
behaving just right (amazingly) - it is inward where you want it (below the
pyrolysis zone) and outward where you want it (above the pyrolysis zone).
Again - amazing.

<snip>

> Seventhly, I note that turndown control is improved with the perforated
>cell- possibly a function of more evenly distributed airflow through the
>fuel (see secondly).
>
(RWL): I vaguely recall that there was a time when you had poor turn-down
control. Was this true and how was it solved?

>I haven't tried dents as an alternate to holes. Can you support a preference?
>
(RWL): I said this when I thought that a solid wall was better. The
problem is mine now.

Thanks for the good data on simple payback time. You are
calculating this on the basis of only one stove use per day - is that
(single use) typical? Perhaps the best place to start making sales is with
coffee houses or someone using a stove more often? You would then get
payback time down to a few weeks.

Thanks also for the added data on training. Sounds reasonable.

On the issue of paint - I'm sure that such exists - but I don't
know anything about high temperature paints. I mentioned it because
someone who should know once told me that bright paint helped to sell
stoves. (As does putting the stove in a new-looking box (not a paper
bag).) Might be worth doing if your clientele tells you to do it - even if
adding a $ or so and not lasting very long. I am not an expert on this
subject.

<snip>
Elsen:
>I don't want to get into production or sales. This is a gift. Once we've
>optimised, I would like this to be mass produced in the informal sector.
>Lets work on spinning it out of the Web & into the real world, O.K.?

(RWL): Agreed.
Before you joined the list (seems like a decade ago), we had a
longish discussion on the merits of different ways to commercialize stoves
in places like Kenya. There was no consensus. My own view is that you are
taking the right approach - as the informal sector can produce this (or
any) stove for a lot less than manufacturing plants there in Kenya or
(especially) in places like the US. Nevertheless, this may be a good time
for others to chime in on ways to help in getting a market test of your
charcoal-making stove. If it takes off through a few of your workmen (and
I think it should and will), our inputs are certainly not needed. But if
stove manufacture doesn't take off, I hope you'll let us know - so that
some of the expertise on the list can be exploited in your spin-off trials.
One thought I have had is that charcoal merchants might be motivated to
sell (or trade) such stoves in rural areas - so as to have a more assured
and stable supply of charcoal in the urban areas. An enlightened government
might put some resources in - in order to reduce the wasteful, conventional
methods of making charcoal and/or worrying about health issues - but one
should certainly keep the government out if not needed.

I think our hope is with your workmen - wanting to become
entrepreneurs - as with your briquetter story.

Again congratulations!

Regards Ron

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

From larcon at sni.net Thu Sep 25 00:38:32 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:38 2004
Subject: Stephen Allen tests
Message-ID: <v01540b03b04f94bb46c9@[204.133.251.21]>

Summary - a few questions and comments on Stephen Allen's modifications to
a "1-can stove".

Stephen - thanks for the clarifications in your first message of Sept. 22.
I think I understand your geometry. You said in a second message the same
day:

>Ron;
>
>At this time I'm running 4 to 5 burns a day.....using 4 different
>stoves. Basically I'm trying to create a solid database from which to
>draw my conclusions.
<snip>
>Steve:

(RWL): Wow! You are very busy!

I am still very impressed by your description of results with these
two external secondary air inlets.
1. One very big advantage should be that you can more easily
control the extinguishment of the hot charcoal at the end. You can close
off the two "primary" (really both primary and secondary) air holes and
then cover the top of the chimney and have an air tight system that is not
otherwise possible.
2. Another advantage could be that you have two nice handles. How
hot are these and do you think you could insulate them so as to get dual
use?
3. The unit will be much more rugged and simple to make
(especially if industry were to sell products in tall cans) when the
secondary air is supplied in this way.

I believe our group would benefit from hearing a bit more about
your FOM (water boiled away divided by initial wood weight) and charcoal
percentage. Before you joined the list, we have noted the difficulty in
getting high efficiency (high FOM) and of the stove needing to operate with
a practical load,

I look forward to hearing about all four of your experiments.
Please tell us of those that don't work as well as those that do.

Keep up the good work.

Regards Ron

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

From elk at arcc.or.ke Thu Sep 25 11:31:02 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:38 2004
Subject: missing messages?
Message-ID: <199709251533.SAA06162@arcc.or.ke>

Stovers;

My server's been out for the past 48 hours.

It's apparently lost all messages sent to me during this period.

If anyone has sent anything of importance to me during this period, could
they post directly to me?

Appreciatively;

elk

From REEDTB at compuserve.com Thu Sep 25 12:09:58 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:38 2004
Subject: The Development Set
Message-ID: <199709251210_MC2-21C7-B7AB@compuserve.com>

Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
Colorado School of Mines & The Biomass Energy (non-profit)Foundation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Piet Verhart et al:

Piet's poem (appended) bites deep. Most of us live very well, some at the
expense of other well intentioned GOs and NGOs.

Fortunately, or unfortunately, much of the money available in the 1980s for
"development" overseas has dried up. Many of us are working off our own
monies, and maybe making more progress than if we were heavily funded by
bureaucrats.

Money is necessary for progress - and also the root of all evil, attracting
those less dedicated and giving an impression of progress when little is
being made.

I am SO impressed by the progress being made in STOVES. Cudos all around.
I hope other fields may "catch fire", and we may find the poor benefiting
from our work.

Incidentally, I am reading "Snakes and Ladders" by Gita Meta, analysing the
current India situation with much hope and humor. India seems to me to be
the ideal lead country for renewable energy and sustainable technology
because they are not yet heavily committed to the status quo and they have
the brains, resources and inclination to adopt developing technologies that
work. (And they have 900 M people to feed and energize.)

Regards, TOM REED
~~~~
The Development Set

Excuse me, friends, 1 must catch my jet
I'm off to join the Development Set;
mybags are packed, and I've had all my shots,
I have Traveller's cheques and pills for the trots.

The Development Set is bright and noble,
our thoughts are deep and our vision is global
Although we move with- the better classes,
our thoughts are always with the masses.

We discuss malnutrition over steaks
and plan hungertalks during coffeebreaks.
Wether Asian floods or African droughts
we face each issue with open mouth.

The language of the Development Set
stretches the English alphabet;
We use swell words like 'epigenetic',
micro', 'macro' and 'logarithmatic.

It pleasures us to be so esoteric
it's so intellectually atmospheric
And though establishments may be unmoved,
our vocabularies are much improved.

Development Set-homes are'extremely chic,
full of carvings and draped with batik.
Eye-level photographs subtly assure:
your host is at home with the great and the poor.

Enough of these verses - on with the mission!
Our task is as broad as the human condition!
Just pray God the biblical promise is true,
the poor ye shall always have with you.

Pleasant stoving,

Piet

From verhaarp at janus.cqu.edu.au Thu Sep 25 17:20:30 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:38 2004
Subject: Commercial Charcoal
Message-ID: <1.5.4.32.19970925212253.006a560c@janus.cqu.edu.au>

>From Piet Verhaart
At 18:55 24/09/97 -0400, you wrote:

<chop>

>I recently performed the following tests on Kingsford and the Jack Daniels
>charcoal that I described this Spring (just for the Hell of it).
>
>BRAND KINGSFORD JACK DANIELS
>Initial Weight 10.16 9.83
>Dried Weight 8.48 7.47
>Moisture Content % 19.2 18.9
>Weight Burned 3.54 3.52
>Ash % of dry 41.7 44.2
>

You are talking about charcoal BRIQUETTES, aren't you. From untampered with
charcoal I would expect an ash percentage of no more than 5.

Great if you can sell clay for the price of charcoal.

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 english at adan.kingston.net Thu Sep 25 22:21:10 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:38 2004
Subject: Logical Limbo
In-Reply-To: <199709231236_MC2-2182-C904@compuserve.com>
Message-ID: <199709260223.WAA25474@adan.kingston.net>

> Dear Alex:
>
> I have long used a "rule of thumb" that the draft vacuum will be 0.01 inch
> of water per foot of height. (I'll let you transfer that to metric.)
>
> TOM

Dear Tom and Stovers all,
I have posted a "natural" draft chart on the web page at
http://www1.kingston.net/~english/Chimdr.jpg
It shows that Tom's draft figure is bang on for an average stack
temperature of 1500F and an ambient temperature of 80F.(other
parameters are listed in the chart header).However if you drop your
ave.stack T to 500F your down to .0059 in of water /foot. If we try
and apply this to the model that Steven Allen has described where he
appears to have extended the chimney down on the secondary air intake
side. The average stack temp. must be cut in half thus lossing about
30% of his draft pressure per foot but at the same time he may have
doubled his effective chimney height, netting a gain of 40% over
what he might have had with direct secondary air.

Please assist me out here on this logical limb.
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From doelle at ozemail.com.au Fri Sep 26 07:56:25 1997
From: doelle at ozemail.com.au (doelle)
Date: Tue Aug 31 21:35:38 2004
Subject: The Development Set
In-Reply-To: <199709251210_MC2-21C7-B7AB@compuserve.com>
Message-ID: <342BA6B6.6190@ozemail.com.au>

Dear Thomas,
The truth is a bitter pill to take. I love the poem of Piet as it really
says what happens, Unfortunately.
I am like you, Thomas, I have worked for over 20 years in developing
countries on simple expenses paid, in little apartments or rooms as
accomodation to do my best and I still do so. Nobody believes it when we
tell, but rather think we must swim in money from the so-called
consultancy payment.
I have seen with my own eyes many projects collapsed after heavy monmey
has been paid to consultants etc. I am not surprised that the money for
development has dried up, because it fell into wrong hands. Sad, but
true.
It is a tragedy, however, that the poor suffer and additionally getting
blamed for óverpopulation', since we appear not to understand, that if 1
in 5 children has the chance to survive, that you must have a minimum of
6 in order to have one child surviving 10 years of age.
It is unfortunately our doing.
Let us hope that these discussions are not only academic, but result in
some constructive and cheap, which we may be able to bring ourselves to
a demonstration.
I am still a strong believer in the fact, that a good working pilot
plant for the benefit of local people will raise local joint venture,
provided the cost of construction can be recuperated within 2-3 years.

Not everything is lost, let us battle one, so Piet can at some stage
give us a poem sounding more optimistic.
Best regards
Horst Doelle
Thomas Reed wrote:
>
> Thomas B. Reed; 303 278 0558 V; ReedTB@Compuserve.Com;
> Colorado School of Mines & The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Dear Piet Verhart et al:
>
> Piet's poem (appended) bites deep. Most of us live very well, some at the
> expense of other well intentioned GOs and NGOs.
>
> Fortunately, or unfortunately, much of the money available in the 1980s for
> "development" overseas has dried up. Many of us are working off our own
> monies, and maybe making more progress than if we were heavily funded by
> bureaucrats.
>
> Money is necessary for progress - and also the root of all evil, attracting
> those less dedicated and giving an impression of progress when little is
> being made.
>
> I am SO impressed by the progress being made in STOVES. Cudos all around.
> I hope other fields may "catch fire", and we may find the poor benefiting
> from our work.
>
> Incidentally, I am reading "Snakes and Ladders" by Gita Meta, analysing the
> current India situation with much hope and humor. India seems to me to be
> the ideal lead country for renewable energy and sustainable technology
> because they are not yet heavily committed to the status quo and they have
> the brains, resources and inclination to adopt developing technologies that
> work. (And they have 900 M people to feed and energize.)
>
> Regards, TOM REED
> ~~~~
> The Development Set
>
> Excuse me, friends, 1 must catch my jet
> I'm off to join the Development Set;
> mybags are packed, and I've had all my shots,
> I have Traveller's cheques and pills for the trots.
>
> The Development Set is bright and noble,
> our thoughts are deep and our vision is global
> Although we move with- the better classes,
> our thoughts are always with the masses.
>
> We discuss malnutrition over steaks
> and plan hungertalks during coffeebreaks.
> Wether Asian floods or African droughts
> we face each issue with open mouth.
>
> The language of the Development Set
> stretches the English alphabet;
> We use swell words like 'epigenetic',
> micro', 'macro' and 'logarithmatic.
>
> It pleasures us to be so esoteric
> it's so intellectually atmospheric
> And though establishments may be unmoved,
> our vocabularies are much improved.
>
> Development Set-homes are'extremely chic,
> full of carvings and draped with batik.
> Eye-level photographs subtly assure:
> your host is at home with the great and the poor.
>
> Enough of these verses - on with the mission!
> Our task is as broad as the human condition!
> Just pray God the biblical promise is true,
> the poor ye shall always have with you.
>
> Pleasant stoving,
>
> Piet

From remco at ds5500.cemr.wvu.edu Fri Sep 26 11:18:17 1997
From: remco at ds5500.cemr.wvu.edu (Remco deJong)
Date: Tue Aug 31 21:35:38 2004
Subject: Feedback for your convenience and pollution control.
In-Reply-To: <199709251210_MC2-21C7-B7AB@compuserve.com>
Message-ID: <342BE200.7F93@ds5500.cemr.wvu.edu>

Another angle that I had not considered that could be benefitted by
feedback on woodstoves is pollution. A paper available at,
http://mha-net.clever.net/html/p-tieg02.htm discusses the problems of
woodstove smoke in many of our 'firstworlder' airsheds. A workable
feedback system may help to aleviate these problems and enable more
convenient and efficient stove operation.

The feedback issue was quickly put to bed, perhaps this is sufficient
cause to reopen this issue? Any info on woodstove feedback mechanisms
are appreciated.

Remco

From panalytics at juno.com Fri Sep 26 11:51:03 1997
From: panalytics at juno.com (panalytics@juno.com)
Date: Tue Aug 31 21:35:38 2004
Subject: The Development Set
In-Reply-To: <199709260602.CAA27938@solstice.crest.org>
Message-ID: <19970926.114842.3934.3.panalytics@juno.com>

Thanks for bringing the old song back. My paper copy was long
lost.

Just one observation -- there are doctors and then there are
charlatans; one can't always tell who is what. One spreads cures, the
other miraculous high-potency life-transforming elixirs. One can't always
tell what would work and how. Some simple cures turn out to be
miraculous. And mere promises have a placebo-like effect.

The "development set" has included proponents of large hydro and
nuclear projects in the past. These days democracy, photovoltaics, AIDS
drugs, and what not, are hot sellers. The missionary zeal always had its
appeal and its power, whether it was an evangelist church or a man in
search of big bucks or a woman driven to serve. (Late 19th, early 20th
century records of Westerners in Asia and Africa are testimonials.) And
then, of course, the charm of things foreign and locales exotic. Why,
just yesterday, I saw a poster in a co-worker's office about the old
"Uganda Railways" just over a half century back. "Home for the
Aristocrats!" it said. I wonder if some of those aristocrats or their
children established charity foundations or aid programs under whose
aegis they, and many others, could still go to one of the many homes for
the aristocrats.

Don't take me wrong, I hope. I can one-up most cynics, get into
"less holy than thou" shouting matches. Why, just yesterday I dug up my
copy of a very good paper "What Makes People Cook with Improved Biomass
Stoves?", and noticed that I had scribbled on the cover, "Other People's
Money!" (No offense meant to the authors or members of this group. My
Indian mentality shows.) Why, yesterday's Washington Post front page
story about how UN headquarters could have done something about the
Rwandan genocide before it happened is sickening; is this what, time and
again (one remembers the Sahelian and Ethiopian famines of yesteryears),
the "do-good set" can give us?

But cynicism has its limits; one of the worse results is that one
can't trust any commitment at all. Now, having one's heart broken in
romantic affairs is never an excuse to not start another affair. So,
let's be cynical of cynicism itself. (Yes, this thought came before I
visited the FDR memorial here in Washington.) And, as Jesse Jackson still
keeps saying, "Keep Hope Alive". (He's been saying that less lately,
since the current tenant of the White House has expropriated "Hope".)

Nikhil

From ROOT710 at aol.com Sun Sep 28 01:09:13 1997
From: ROOT710 at aol.com (ROOT710@aol.com)
Date: Tue Aug 31 21:35:39 2004
Subject: chambers stove
Message-ID: <970928011142_1687287133@emout20.mail.aol.com>

I am interested in your Chambers stove. If it is available please contact me
by e-mail at Root710@AOL.com or phone (619) 437-6756. Thanks, John Masters

From elk at arcc.or.ke Sun Sep 28 14:25:38 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:39 2004
Subject: Back on Line
Message-ID: <199709281828.VAA25428@arcc.or.ke>

Stovers;

I think I'm becoming dependant on this form of communication. The Mailing
list is important- a fax or two would have been my next step for keeping in
touch if my server was down for much longer.

Hasn't stopped the trials- I'll summarise tomorrow.

Thanks for the 'digest', Ronal, it's updated me very well.

For fuel cell, now read pyrolisi cell. Understood, Tom & Prasad.

Kirk Smith- Your chaps from ITG have visited. They now have one of my stoves
and some charcoal briquettes.

Peter- the poem fits. Down come the photos.

until tomorrow;

elk

From english at adan.kingston.net Sun Sep 28 20:19:15 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:39 2004
Subject: Welcome to research.
Message-ID: <199709290021.UAA13621@adan.kingston.net>

Dear Stovers especially Ron
Ron likes to here about the failures.

So I'm taking my venturi burner to the lab for a test run. I do a
whole lot of fixing up. Seal it well and add manifolds for the
different air supplies so we can measure everything. Set it all up
for a demo in front of the professor and the student. Do you
think I could get it to work.....barely.......blah!

Professor said "Welcome to research."

busy re searching Alex

Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
Tel 1-613-386-1927
Fax 1-613-386-1211
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

BioEnergy Lists: Improved Biomass Cooking Stoves

September 1997 Biomass Cooking Stoves Archive