August 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 E.Moerman at stud.tue.nl Fri Aug 1 10:52:17 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:30 2004
Subject: Top-lit moisture research
Message-ID: <17578.s335192@popserver.tue.nl>

Tom Reed:

> Ettienne says that they burned pine with 50% moisture, but had trouble at=
>
> 70%. This indicates to me that he is talking about the moisture content
> measured on a dry basis, ie =
>

Etienne:
Correct! I am talking on a dry matter basis.

--------

Tom R.:
> In particular we don't know what the superficial velocity (SV) of the
> Eindhoven downdraft stove was, so we're comparing maybe apples and orange=
> s.
> Can you take a guess Ettienne? =

Etienne:
If you mean by superficial velocity the velocity of the airflow through the
fuelbed, this is around 1 m/s.

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

From JEROMECPA at aol.com Fri Aug 1 16:05:37 1997
From: JEROMECPA at aol.com (JEROMECPA@aol.com)
Date: Tue Aug 31 21:35:31 2004
Subject: stoves
Message-ID: <970801160518_-1273626319@emout08.mail.aol.com>

we have a chambers four burner gas top. is chambers still in business under
the name of chambers and are parts still available?

From REEDTB at compuserve.com Fri Aug 1 18:57:35 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:31 2004
Subject: Small is sometimes beautiful
Message-ID: <199708011843_MC2-1C24-BCCC@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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Harry, Jane, Antonio et al:

[Someone attributed "Small is Beautiful" (by E. F. Schumaker, 1973) to
Amory Lovins (Soft Energy Paths,1977 etc. etc). Probably neither author
will like this.]

Glad to hear this debate on appropriate scale; hope we can keep it
non-acrimonious.
Harry asked for examples of where Small can economically compete with Big,
and a few have been given already - small oil wells (I liked the
pin-cushion analogy), Pcs vs mainframes....

I have been noticing in my travels that in countries that don't have good
telephone systems (most of the world) that cellular phones are taking over.
Saves the cost of installing phone lines, opens competition to non-state
run companies. The advent of the PC is certainly another good example of
small competing with large.

The automobile is a good example of individual cars being more
time-efficient than trains in much of the world. There is a lot of blather
about the beauty of public transportation, but the blatherers always seem
to be using cars.
I
have long felt that Schumaker chose the wrong title for his book. Should
have been "Appropriate Size is Beautiful". The bicycle and motor bikes in
many parts of the world compete very well with public transportation and
cars.

The best counter-example to "Small is Beautiful" was the Mao dictated small
steel production in China that set them back 20 years. Wow! Beware
IDEALOGUES.

So... Let's see if we can find a rational for small vs big.

Manufacturing of standard items has a big edge for at least moderate size.
True, Harry that BIG can bring in efficiencies denied to small. The
CELLULAR PHONE will probably never be produced in mom and pop factories.
CARS are currently produced by mamouth corporations. However, I was
surprised to learn that in India there are thousands of producers of diesel
engines, essentially handmade.

It would seem in part to depend on the level of technology that is
developed. We developed trains before cars because we didn't know how to
make small cheap cars. Likewise computers Main frame vs Pc.

So, very often the problem with small is that we havn't developed the
technology yet.

This discussion is relevant to the STOVE and GASIFIER nodes of CREST.

STOVERS: In the developed countries we KNOW how to cook well and
efficiently - provided we are located on a high tech power transmission
line or gas line, and have a utility distributor in place to provide and
repair. The problem we are trying to solve in STOVES is how to (a) use a
simpler fuel, biomass, and (b) do it without electric power. If we could
all do this easily, it would be widely used (3 billion people). They can
then bypass putting in central power, and maybe use local generation for
power.

GASIFICATION: This in turn depends on being able to generate electric power
simply at a small scale. It is coming along nicely with improved engine
conversion and low tar gasifiers. Keep working on it. The ultimate small
is the integrated gasifier turbine system using combined cycle (IGCC),
(1-50MW) permitting small turbines to achieve a higher efficiency (40-50%)
than large steam plants.

Out of gas...., breakfast calling TOM
REED

From english at adan.kingston.net Fri Aug 1 22:21:37 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:31 2004
Subject: Webpage Update
Message-ID: <199708020222.WAA21027@adan.kingston.net>

Dear Stovers

The Stovers web page has two new (new to the page) offerings (circa
95 and 96) from Tom Reed, both related to the inverted downdraft
gasifier stove. You can link directly with the following
http://www1.kingston.net/~english/T1.htm and
http://www1.kingston.net/~english/T2.htm

I have also put a little bit on the page about my latest experiment,
including a beautiful blue burning bluff body flame picture.
http://www1.kingston.net/~english/Alex3.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 phait at transport.com Sun Aug 3 12:26:16 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:31 2004
Subject: Small is sometimes beautiful
Message-ID: <199708031632.JAA25349@butch.transport.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
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Dear Harry, Jane, Antonio et al:
>
>[Someone attributed "Small is Beautiful" (by E. F. Schumaker, 1973) to
>Amory Lovins (Soft Energy Paths,1977 etc. etc). Probably neither author
>will like this.]
>
>Glad to hear this debate on appropriate scale; hope we can keep it
>non-acrimonious.
>Harry asked for examples of where Small can economically compete with Big,
>and a few have been given already - small oil wells (I liked the
>pin-cushion analogy), Pcs vs mainframes....
>
>I have been noticing in my travels that in countries that don't have good
>telephone systems (most of the world) that cellular phones are taking over.
> Saves the cost of installing phone lines, opens competition to non-state
>run companies. The advent of the PC is certainly another good example of
>small competing with large.
>
>The automobile is a good example of individual cars being more
>time-efficient than trains in much of the world. There is a lot of blather
>about the beauty of public transportation, but the blatherers always seem
>to be using cars.
>I
> have long felt that Schumaker chose the wrong title for his book. Should
>have been "Appropriate Size is Beautiful". The bicycle and motor bikes in
>many parts of the world compete very well with public transportation and
>cars.
>
>The best counter-example to "Small is Beautiful" was the Mao dictated small
>steel production in China that set them back 20 years. Wow! Beware
>IDEALOGUES.
>
>So... Let's see if we can find a rational for small vs big.
>
>Manufacturing of standard items has a big edge for at least moderate size.
>True, Harry that BIG can bring in efficiencies denied to small. The
>CELLULAR PHONE will probably never be produced in mom and pop factories.
>CARS are currently produced by mamouth corporations. However, I was
>surprised to learn that in India there are thousands of producers of diesel
>engines, essentially handmade.
>
>It would seem in part to depend on the level of technology that is
>developed. We developed trains before cars because we didn't know how to
>make small cheap cars. Likewise computers Main frame vs Pc.
>
>So, very often the problem with small is that we havn't developed the
>technology yet.
>
>This discussion is relevant to the STOVE and GASIFIER nodes of CREST.
>
>STOVERS: In the developed countries we KNOW how to cook well and
>efficiently - provided we are located on a high tech power transmission
>line or gas line, and have a utility distributor in place to provide and
>repair. The problem we are trying to solve in STOVES is how to (a) use a
>simpler fuel, biomass, and (b) do it without electric power. If we could
>all do this easily, it would be widely used (3 billion people). They can
>then bypass putting in central power, and maybe use local generation for
>power.
>
>GASIFICATION: This in turn depends on being able to generate electric power
>simply at a small scale. It is coming along nicely with improved engine
>conversion and low tar gasifiers. Keep working on it. The ultimate small
>is the integrated gasifier turbine system using combined cycle (IGCC),
>(1-50MW) permitting small turbines to achieve a higher efficiency (40-50%)
>than large steam plants.
>
>Out of gas...., breakfast calling TOM

>REED

Dear Tom,

I have been out of the loop for the past several weeks attempting to address
our Corporate funding issues. However, I can not help but agree with the
small is beautiful concept.That has been the whole drive at Pyromid. We also
believe in the, Less is beautiful concept. Why cook nine hamburgers with 75
briquettes when you can do it with 9? Why use 20,000 BTU's when you can use
2250 BTU's? Why spend $2.00 when you can do the same job for 30
cents?Etc,etc. By applying basic physics principals of efficient fuel
burning and selecting a shape that collapses
flat(small) when your not using it and opens up when it is needed we
accomplish all our goals. Thus, small is beautiful for storage and true
portability and big is beautiful for use.On the same theme briquettes are
small and wood is bulky.
However, it is important to be able to burn all of the fuels as efficiently
as possible. Therefore, we have the Packlite universal fuel and function stove.

On a different subject. Did you get your stove refund after I sent you the
tester? I saw some paper work that seemed to be incomplete last week.

I am going to be with Terry Turner this week looking at his new light weight
cement stove material for Mike Bess.The stuff pours like whipped cream and
has very high insulative characteristics when it sets up.

I will be in contact with Kirk Smith also to get more details on his EPA
project.

Hope your enjoying the summer and keep your head up while your top down burning.
Your email has been fantastic and we all appreciate your efforts.

Sincerely,
Paul Hait
phait@transport.com

From REEDTB at compuserve.com Sun Aug 3 17:14:40 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:31 2004
Subject: Gasifier Data Base Entries
Message-ID: <199708031714_MC2-1C43-1F8B@compuserve.com>

Some of you may have had a letter or fax from me in the last week, seeking
information, in which case you can ignore this.

If not, the following letter is self-explanatory. I hope you can send me
data on your interests if appropriate.

If you know of anyone in gasification who does not belong to the
GASIFICATION or STOVE network of CREST, please pass this along to them.

Thanks in advance, TOM REED
~~~~
Thomas B. Reed
COLORADO SCHOOL OF MINES
Chemical Engineering and
Petroleum Refining Department
Golden, CO 80401

303/278-0558 Fax: 303/278 0560 E Mail: reedtb@compuserve.com

Dear Sirs:

As you may know, we are completing "VOLUME I: Gasifier Projects and
Manufacturers Around the World" of our two volume "Survey of Biomass
Gasification". (Volume II will cover the science and engineering of
biomass gasification). This work has been funded by the National Renewable
energy Laboratory, NREL, here in Golden, CO. We hope that it will be a
major reference in this field for many years to come.

We currently have a data base with files on more than 80 manufacturers and
research groups. We are completing our final draft and want to be sure
that you are accurately and thoroughly represented.

1) Please look over the enclosed record summary of our current data on
your company/organization and make any corrections necessary. We are
keeping a dynamic spreadsheet on the gasifier community and want to be sure
that it is accurate.
We hope to have the data available on the World Wide Web soon. If you are
not the most appropriate contact, please list an alternate. Fill in as
many of the other blanks as you can, or write "NA"(not applicable). In
particular, under fuels list the fuels you have actually used, not those
you suspect might be OK.

2) In addition to the spreadsheet records, we have extended summaries of a
number of groups based in part on visits and partly on previously published
data. If you have new information about current activities, please send it
and we will incorporate it in our narrative chapters. We can include
drawings and pictures.
3) We may present this material at the Montreal Biomass of the Americas
conference meeting in late August. In any case, we hope to complete the
final draft in September. So we must insist on receiving your reply by
August 10. Just as easy to do it now as later.
Thank you in advance for your cooperation and we assure you that you will
be well represented in our book. You can FAX the handwritten answers
back.
Yours very truly,

Thomas B. Reed, Research Professor
~~~~
GASIFIER DATA SHEET

TYPE: (Large System, >10MW; SMALL; R&D Organization)

PROJECT: (Name, affiliations, partners, ....)

DESCRIPTION: (Fixed bed, updraft, downdraft, Fluidized bed Bubbling,
circulating, high pressure, .....)

CONTACT: (Name of person to receive inquiries)

COUNTRY: (US, Sweden, Mali,...)

PHONE/FAX:

ADDRESS:

E-MAIL:

PURPOSE: (Heat, power, syn-fuels, ...)

STATUS: (Active, planning, holding, defunct)

FUELS: (Fuels actually tested, wood, bagasse, MSW...)

SIZES: (eg. 10 MW, 50 t/d, ....)

UNITS BUILT: (Number built and tested )

COST: (eg. $5M for 5 MW plant; or better, $4,000/kW)

COMMENTS: (Be my guest, brag a little)

From REEDTB at compuserve.com Sun Aug 3 17:27:37 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:31 2004
Subject: sustainability and technical development
Message-ID: <199708031714_MC2-1C43-1F8F@compuserve.com>

1) Great news about the Allied Signal 75 Kw turbines. I see natural gas
as the primary energy source for the next century as oil runs out. The
deposits of gas hydrates at the bottom of the ocean exceed all other fossil
fuel deposists combined. And natural gas can most easily run those
tubines, generating 30% power and 70% heat (useful for both heat and air
conditioning). By removing unstable hydrates from the ocean floor and
converting them to energy, CO2 and H2O, we can reduce the greenhouse effect
from released methane.

2) While modifications may be needed, in principle these turbine
generators can probably run on producer gas which has 1/6 of the energy of
methane. Or inverted downdraft gas which probably has 1/3 or better of the
energy of methane.

3) You are probably more correct than you know in saying that eveyone on
our bioenergy list "believes" in sustainability. However, as I pointed out
in my comments on large scale/small scale, believing in sustainability is
one thing, achieving small scale is quite another, and most of the problems
in achieving it are TECHNICAL. So, let's not have too much talk on
desirability and more on methods of achieving it.

4) It is unfortunate that those with the capability of making technical
advances (like Allied Signal) don't worry too much about the desirability
of achieving sustainability, while those worrying about the desirability
generally can't make any contribution except more talk and anguish. C'est
la vie. So we bumble on in the right direction.

4) Would it be practical for garbage disposals to feed their ground up
solids into a basement tank and digest them for methane?

Onward, TOM REED

From REEDTB at compuserve.com Sun Aug 3 17:45:22 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:31 2004
Subject: Small is sometimes beautiful
Message-ID: <199708031732_MC2-1C42-3424@compuserve.com>

I would love to hear more about the castable insulation. Most people think
all ceramics are thermally insulating, only fibrous or bubbled ceramics
really insulate thermally. Being weak, they generally need a dense
(thermal shock resistant) facing.

I spent 20 years in material science and furnaces at MIT. If you want help
developing insulation, let me know.

I haven't seen the refund yet, but am quite patient.

Thanks, TOM REED

From donj at aloha.net Sun Aug 3 18:40:30 1997
From: donj at aloha.net (Don Jacobs)
Date: Tue Aug 31 21:35:31 2004
Subject: sustainability and technical development
Message-ID: <v01530503b00ab9325b50@[207.12.10.61]>

At 5:14 PM 8/3/97, Thomas Reed wrote:
>Thomas B. Reed 303 278 0558 V Colorado School of Mines
>1810 Smith Rd., 303 278 0560 FX Department Chem Eng
>Golden, CO 80401 ReedTB@Compuserve.com
>ALSO: The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Ron et al:
>
>1) Great news about the Allied Signal 75 Kw turbines. I see natural gas
>as the primary energy source for the next century as oil runs out. The
>deposits of gas hydrates at the bottom of the ocean exceed all other fossil
>fuel deposists combined. And natural gas can most easily run those
>tubines, generating 30% power and 70% heat (useful for both heat and air
>conditioning). By removing unstable hydrates from the ocean floor and
>converting them to energy, CO2 and H2O, we can reduce the greenhouse effect
>from released methane.
>
>2) While modifications may be needed, in principle these turbine
>generators can probably run on producer gas which has 1/6 of the energy of
>methane. Or inverted downdraft gas which probably has 1/3 or better of the
>energy of methane.
>
They also run well on ethanol

Don Jacobs

From eland at netshop.net Sun Aug 3 22:16:22 1997
From: eland at netshop.net (Lars Karstad)
Date: Tue Aug 31 21:35:31 2004
Subject: SAWDUST GASIFICATION PLANT
Message-ID: <199708040217.TAA17861@freya.van.hookup.net>

Jim;

I'm in Cananda at the moment- back 12/8.

what ARE you up to? last discussion didn't indicate this qty. How's briquetting?

rgds;

Elsen

>To: stoves@crest.org
>from: elk@arcc.or.ke
>Subject: Re: SAWDUST GASIFICATION PLANT
>
>At 04:17 PM 29/07/97 -0400, you wrote:
>>Thomas B. Reed 303 278 0558 V Colorado School of Mines
>>1810 Smith Rd., 303 278 0560 FX Department Chem Eng
>>Golden, CO 80401 ReedTB@Compuserve.com
>>ALSO: The Biomass Energy (non-profit)Foundation
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>Dear Jim:
>>
>>>JUST INSTALLED AT HUGE COST A GASIFIER. WE HAVE A DEFORESTATION PROBLEM IN
>>KENYA AND THIS IS OUR CONTRIBUTION. WE PRODUCE 10000000 TONS Of AGRO-WASTE
>>EVERY YEAR.
>>
>>WHICH INDUSTRIES ARE OUR POTENTIAL CUSTOMERS?
>>
>>What kind of gasifier, and what use? How much? What make? Best use is
>>to produce power, but you need distribution system.
>>
>>WHICH EXPERTS ARE CLOSE AT HAND?
>>
>>WHERE ARE THERE SUCCESFUL SIMILAR PROJECTS?
>>
>>REGARDS
>>
>>JIM SHAMOON
>>
>>Jim, you should join the GASIFICATION network and I'll put your questions
>>there. Join by sending the message "subscribe gasification" to
>>majordomo@crest.Org.
>>Since I don't know Kenya, I don't know what experts may be close and what
>>successful projects are nearby. There is a rice hull gasifier that has
>>been operating for 20 years in Mali. I hope others can answer your
>>questions.
>>
>>Good luck, TOM REED Gasification webmaster
>>
>>
>>
L.Karstad

From eland at netshop.net Sun Aug 3 22:16:32 1997
From: eland at netshop.net (Lars Karstad)
Date: Tue Aug 31 21:35:31 2004
Subject: SAWDUST GASIFICATION PLANT
Message-ID: <199708040217.TAA06803@freya.van.hookup.net>

Jim Shamoon;

HOW much sawdust?

Better get a gas turbine generator set up & sell to KPL via the grid!

elk

At 12:45 PM 28/07/97 +0300, you wrote:
>TOM REED
>
>JUST INSTALLED AT HUGE COST A GASIFIER. WE HAVE A DEFORESTATION PROBLEM
>IN KENYA AND THIS IS OUR CONTRIBUTION. WE PRODUCE 10000000 TONS OF
>AGRO-WASTE EVERY YEAR.
>WHICH INDUSTRIES ARE OUR POTENTIAL CUSTOMERS?
>WHICH EXPERTS ARE CLOSE AT HAND?
>WHERE ARE THERE SUCCESFUL SIMILAR PROJECTS?
>
>REGARDS
>JIM SHAMOON
>
>
>
L.Karstad

From Dmi432 at aol.com Mon Aug 4 16:32:53 1997
From: Dmi432 at aol.com (Dmi432@aol.com)
Date: Tue Aug 31 21:35:31 2004
Subject: chambers stove
Message-ID: <970804163243_-423065346@emout05.mail.aol.com>

i have a chambers stove along with an owners manual. i am interested in
selling the stove, it'sin excellent working condition, no problem copying and
mailing the owner's manual if you are interested. do you have any resources
for selling our stove. we also have a working franklin coal stove for sale.
thanks... write back please.

From larcon at sni.net Tue Aug 5 10:00:02 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:31 2004
Subject: chambers stove
Message-ID: <v01540b01b00ce169a6dc@[204.133.251.4]>

I hope you have success - but we are a group that is working mostly on
rural cook stoves in developing countries.

Regards Ron

>i have a chambers stove along with an owners manual. i am interested in
>selling the stove, it'sin excellent working condition, no problem copying and
>mailing the owner's manual if you are interested. do you have any resources
>for selling our stove. we also have a working franklin coal stove for sale.
>thanks... write back please.

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

From phait at transport.com Wed Aug 6 04:54:06 1997
From: phait at transport.com (John Doe)
Date: Tue Aug 31 21:35:31 2004
Subject: Small is sometimes beautiful
Message-ID: <199708060901.CAA16356@butch.transport.com>

>Dear Tom , 8/6/97

Thanks for the reply. Terry Turner, my contact, and I are going to be
getting together this week. I have been bogged down in our funding,a large
Japanese order,and the UPS strike. R&D has a low priority right now.
Unfortunately I have to deal with the day to day issues before I can have fun.
Your ceramic background is very interesting,Tom, and I will definitely keep
that in mind when I evaluate Terry's shaving cream texture super insulation
foamed cement.He says a bag of this material,a form of a stove to pour into,
water, and an egg beater is all you need.The grill or plate is put into the
stove when it is set up.It is strong,super insulative,light,and supposedly
cheap.If it has potential I will let everybody know.
Your refund is on its way. Sorry for the delay.

Sincerely,

Paul

From "cdv at lightspeed.net" at lightspeed.net Wed Aug 6 23:09:44 1997
From: "cdv at lightspeed.net" at lightspeed.net (Diane Vessels)
Date: Tue Aug 31 21:35:31 2004
Subject: antique stove parts
Message-ID: <199708070310.UAA06888@lsbsdi1.lightspeed.net>

HI!

I am looking for a source who has parts for a L&H Electric Range model #
8183L.

Any help you can provide will be appreciated.

Thank you.

From larcon at sni.net Thu Aug 14 00:00:19 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:31 2004
Subject: a stoves project in Haiti
Message-ID: <v01540b01b0182f0c917d@[204.133.251.8]>

Stovers: This is to introduce a charcoal-making "stove"
development opportunity posed by Zach Lea, Chief-of-Party for USAID
activities in Haiti. Zach would like to test making charcoal as part of
small rural commercial fruit-drying operations. This, of course, fits
nicely into this list's past discussions of top-lit, charcoal-making stoves
where the pyrolysis gases are utilized productively rather than being
vented. Food-drying would seem to have world-wide applicability - or at
least whereever charcoal is widely made and used. Haiti is such a place.
This also is a lot more like space heating than cooking - not a typical
problem for Haiti, but of interest in many other countries

A typical "space" to be heated is to be a few meters long, one meter
wide, and one meters tall. The flared gases are to travel in a
"stove-pipe" through this space. The anticipated duration of a "batch" is
many hours. The fruit trays sit on top of this space.

The questions we might be able to answer as a list are like those
we have discussed in the past:

1. What should be the dimensions of the fuel chamber? (I believe
there is an advantage to making it relatively taller since this will allow
a longer time between fuel exchanges - maybe up to 3 or 4 hours. The
difficulty here may be in having sufficient depth below the drying chamber.

2. Does it make sense to perhaps try to keep temperatures low by
doing some water heating? Could there be a third product - hot or purifed
(perhaps even distilled) water?

3. How tall should the drying chamber be to get adequate natural
draft? Or, since an electric grid is not present, should there be a
PV-powered fan (to better control drying time)? Any ideas on the needed
wattage or air flow? (Zach is not thinking of needing a fan.)

4. Zach is thinking of a heat exchanger as part of the
"stove-pipe" made of three horizontal welded oil drums. The fruit trays sit
above these three drums (by a still unspecified distance). This entire
heater and tray geometry sits inside another building with roof. Zach is
assuming a stove pipe out of the space in order to prevent any
contamination of the drying fruit. Can anyone suggest alternatives that
may be cheaper or better in some way?

The main "stoves" problem I see as being unique is that the
fruit-trays only need a temperature rise of (I think) about 10 degrees C -
and presumably needs a fairly uniform interior temperature. I do not yet
see a fool-proof way to keep the drying room temperature low and uniform
(but this is not unique to charcoal-making stoves). Thinking about this a
little has led me to the ideas above on heating water.

Zach and I look forward to hearing your thoughts.

Regards Ron

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

From ovencrft at nbn.com Thu Aug 14 02:10:18 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:31 2004
Subject: a stoves project in Haiti
Message-ID: <199708140611.XAA15411@shell10.ba.best.com>

>
> Stovers: This is to introduce a charcoal-making "stove"
>development opportunity posed by Zach Lea, Chief-of-Party for USAID
>activities in Haiti. Zach would like to test making charcoal as part of
>small rural commercial fruit-drying operations. This, of course, fits
>nicely into this list's past discussions of top-lit, charcoal-making stoves
>where the pyrolysis gases are utilized productively rather than being
>vented. Food-drying would seem to have world-wide applicability - or at
>least whereever charcoal is widely made and used. Haiti is such a place.
>This also is a lot more like space heating than cooking - not a typical
>problem for Haiti, but of interest in many other countries
>
> A typical "space" to be heated is to be a few meters long, one meter
>wide, and one meters tall. The flared gases are to travel in a
>"stove-pipe" through this space. The anticipated duration of a "batch" is
>many hours. The fruit trays sit on top of this space.
>
> The questions we might be able to answer as a list are like those
>we have discussed in the past:
>
> 1. What should be the dimensions of the fuel chamber? (I believe
>there is an advantage to making it relatively taller since this will allow
>a longer time between fuel exchanges - maybe up to 3 or 4 hours. The
>difficulty here may be in having sufficient depth below the drying chamber.
>
> 2. Does it make sense to perhaps try to keep temperatures low by
>doing some water heating? Could there be a third product - hot or purifed
>(perhaps even distilled) water?
>
> 3. How tall should the drying chamber be to get adequate natural
>draft? Or, since an electric grid is not present, should there be a
>PV-powered fan (to better control drying time)? Any ideas on the needed
>wattage or air flow? (Zach is not thinking of needing a fan.)
>
> 4. Zach is thinking of a heat exchanger as part of the
>"stove-pipe" made of three horizontal welded oil drums. The fruit trays sit
>above these three drums (by a still unspecified distance). This entire
>heater and tray geometry sits inside another building with roof. Zach is
>assuming a stove pipe out of the space in order to prevent any
>contamination of the drying fruit. Can anyone suggest alternatives that
>may be cheaper or better in some way?
>
> The main "stoves" problem I see as being unique is that the
>fruit-trays only need a temperature rise of (I think) about 10 degrees C -
>and presumably needs a fairly uniform interior temperature. I do not yet
>see a fool-proof way to keep the drying room temperature low and uniform
>(but this is not unique to charcoal-making stoves). Thinking about this a
>little has led me to the ideas above on heating water.
>
> Zach and I look forward to hearing your thoughts.
>
>
>Regards Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>
>
>
Perhaps you could consider drying fruit as I have done using a simple
inexpensive retained heat brick oven that is heated with wood. No need to
first make charcoal, no need for a fan, no need for oil drums. My web site
shows ovens and plans to build. ALAN
ALAN SCOTT

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

From english at adan.kingston.net Thu Aug 14 07:47:33 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:31 2004
Subject: a stoves project in Haiti
In-Reply-To: <v01540b01b0182f0c917d@[204.133.251.8]>
Message-ID: <199708141148.HAA19782@adan.kingston.net>

Dear Ron and Zach
Sounds like a good project. I assume charcoal is already being
produced in Haiti and that this would replace the current wasteful
and polluting methods.

> 1. What should be the dimensions of the fuel chamber? (I believe
> there is an advantage to making it relatively taller since this will allow
> a longer time between fuel exchanges - maybe up to 3 or 4 hours. The
> difficulty here may be in having sufficient depth below the drying chamber.

With tightly packed fuel I have been able to burn top down at a rate
of about two hours per foot.

I would like to encourage Zach to get started. This top down burning
is easy and each try will lead to thoughts on ways to do it better.
The beauty of "top down" is the steady output. This makes it an
excellent choice for limited temperature drying. Given that the dryer
has good vertical flow, keeping the temperature low should be a
question of pyrolysis chamber size and the under fire air supply
rate. The latter can have a fixed maximum further reducing the
chance of over heating. Something which could be sorted out with
3-4 trials.

What is the fuel? Does it tend to be straight of crooked?
If it is hard to obtain dry fuel, then a fuel dryer should be part of
this design. Dry fuel will yield much more predictable results.

You don't have to fit the chamber all below the dryer. If the heat
exchange in the dryer forms a damper controlled loop from the
chimney, then once a draft is established the hot flue gasses can be
diverted down through the dryer loop.

Good luck Alex

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

From REEDTB at compuserve.com Sat Aug 16 08:55:05 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:31 2004
Subject: a stoves project in Haiti
Message-ID: <199708160855_MC2-1D49-3D16@compuserve.com>

Nice to have a REAL project we can get our collective teeth into. Fruit
drying/cum charcoal production sounds like it combines what we know - with
some of what we don't know.

Before we go very far, here are SCIENTIFIC experiments that need to be
done. We need to know the optimum drying temperature as a function of
humidity.

Most of us have thermostatically controlled electric ovens. Put various
fruits on a cookie sheet and set the oven at 150 F (use an oven thermometer
to calibrate your thermostat). Check time of drying. Try 180 , 200 etc.

I recently tried drying moist raisins for bread making at 210 F and they
blew up like balloons! I then tried 150F and they dried hard. I'll try
again and report.

Other aspects of drying should be similarly tested before making any
pyrolysis units.

I'll be away for 2 weeks. I hope there are lots of answers when I return.

Good luck, TOM REED

From rrook at direct-source.com Sat Aug 16 10:45:31 1997
From: rrook at direct-source.com (Roger Rook)
Date: Tue Aug 31 21:35:31 2004
Subject: construction plans for wood fireplace insert
In-Reply-To: <199708160855_MC2-1D49-3D16@compuserve.com>
Message-ID: <33F5BD6A.60F53569@direct-source.com>

Thomas Reed wrote:

> Thomas B. Reed 303 278 0558 V Colorado School of Mines
> 1810 Smith Rd., 303 278 0560 FX Department Chem Eng
> Golden, CO 80401 ReedTB@Compuserve.com
> ALSO: The Biomass Energy (non-profit)Foundation
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Zach, Ron et al:
>
> Nice to have a REAL project we can get our collective teeth into.
> Fruit
> drying/cum charcoal production sounds like it combines what we know -
> with
> some of what we don't know.
>
> Before we go very far, here are SCIENTIFIC experiments that need to be
>
> done. We need to know the optimum drying temperature as a function of
>
> humidity.
>
> Most of us have thermostatically controlled electric ovens. Put
> various
> fruits on a cookie sheet and set the oven at 150 F (use an oven
> thermometer
> to calibrate your thermostat). Check time of drying. Try 180 , 200
> etc.
>
> I recently tried drying moist raisins for bread making at 210 F and
> they
> blew up like balloons! I then tried 150F and they dried hard. I'll
> try
> again and report.
>
> Other aspects of drying should be similarly tested before making any
> pyrolysis units.
>
> I'll be away for 2 weeks. I hope there are lots of answers when I
> return.
>
> Good luck, TOM REED

I am looking for a place to purchase plans so that we can construct a
wood burning fireplace insert (and perhaps adjust size to fit). I saw a
US Gov doc that says they are out there but have been unable to locate.
Stove Dealers tell me there are none. Any suggestions as to where I
might go or look?

Roger Rook rrook@direct-source.com

From english at adan.kingston.net Sun Aug 17 21:44:12 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
Message-ID: <199708180145.VAA00972@adan.kingston.net>

Dear Ron and Zach
I had some time on a tractor to think about this so here is what I
have come up with. One of the goals is to avoid over heating. Even if
we have the right amount doesn't mean it is distributed evenly.

If you pass the hot flue gasses through a stove pipe running most of
the way through the inside of the barrel(s) heatexchanger so that the
gasses then flow back along the outside of the pipe and exit from the
barrel(s) at the same end, then you may obtain a more even barrel
surface temperature from one end to the other.

Then if you introduce the drier air under the center line of the
barrel so that the air flows evenly up both sides you will get a hot
plum rising straight above the center line of the barrel. To diffuse
the air evenly over the width of the building a saw tooth shaped
piece of sheet steel (ex. old roofing steel cut with snips) could be
placed above the barrel to distribute the warmed air.

The barrels welded together with the two pipe joints at one end
outside the building may offer good control over potential
contamination.

I hope it all makes sense. Alex
PS The drawing is posted at
http://www1.kingston.net/~english/Drier.htm
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From Skarekezi at form-net.com Mon Aug 18 03:48:18 1997
From: Skarekezi at form-net.com (Skarekezi@form-net.com)
Date: Tue Aug 31 21:35:31 2004
Subject: Sawdust gasification plant
Message-ID: <199708180748.DAA10467@solstice.crest.org>

our ref: js12341,afr/env, ro(at,lm)

EMAIL TO: JIM SHAMOON, NAIROBI, KENYA. E-MAIL: IN:stoves@crest.org

FROM: STEPHEN KAREKEZI, AFREPREN/FWD, ELGEYO MARAKWET CLOSE,
KILIMANI, P.O. BOX 30979, NAIROBI, KENYA (TEL: 254 2 566032; FAX: 254
2561464/ 566231/ 740524; E-MAIL: Skarekezi@form-net.com )

DATE: 11 August, 1997

Dear Mr. Shamoon,

SUBJECT: SAWDUST GASIFICATION PLANT

1. Greetings from AFREPREN/FWD. We are interested in the subject
technology and would like to request for more information on
this plant. In particular, we would like to know its location
as we may want to visit it at a later date to help our staff
enhance their working knowledge of gasification plants.

2. Kindly let us know if you require any additional information
or clarification.

Yours Sincerely,

Stephen Karekezi
AFRPREN/FWD.

From ovencrft at nbn.com Mon Aug 18 13:41:23 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:31 2004
Subject: construction plans for wood fireplace insert
Message-ID: <199708181742.KAA10074@shell10.ba.best.com>

Dear Roger, I am a supplier for plans to build brick bake ovens but you are
better off contacting the Masonry Heater Association for a contact there who
may help with your project. They are very concerned with space haeating from
what are essentially modified masonry fireplaces, They can be contacted
through their web page or call the office at (703) 620 3171, or through a
link from my web site below. Also please contact me if you receive this as a
check that this reply got through to you, Thanks ALAN.

> I am looking for a place to purchase plans so that we can construct a
>wood burning fireplace insert (and perhaps adjust size to fit). I saw a
>US Gov doc that says they are out there but have been unable to locate.
>Stove Dealers tell me there are none. Any suggestions as to where I
>might go or look?
>
>Roger Rook rrook@direct-source.com
>
>
>
ALAN SCOTT

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

From ovencrft at nbn.com Mon Aug 18 13:41:25 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
Message-ID: <199708181742.KAA10070@shell10.ba.best.com>

>Dear Ron and Zach
>I had some time on a tractor to think about this so here is what I
>have come up with. One of the goals is to avoid over heating. Even if
>we have the right amount doesn't mean it is distributed evenly.
>
>If you pass the hot flue gasses through a stove pipe running most of
>the way through the inside of the barrel(s) heatexchanger so that the
>gasses then flow back along the outside of the pipe and exit from the
>barrel(s) at the same end, then you may obtain a more even barrel
>surface temperature from one end to the other.
>
>Then if you introduce the drier air under the center line of the
>barrel so that the air flows evenly up both sides you will get a hot
>plum rising straight above the center line of the barrel. To diffuse
>the air evenly over the width of the building a saw tooth shaped
>piece of sheet steel (ex. old roofing steel cut with snips) could be
>placed above the barrel to distribute the warmed air.
>
>The barrels welded together with the two pipe joints at one end
>outside the building may offer good control over potential
>contamination.
>
>
>I hope it all makes sense. Alex
>PS The drawing is posted at
>http://www1.kingston.net/~english/Drier.htm
>Alex English
>RR 2 Odessa Ontario
>Canada K0H 2H0
>613-386-1927
>Stoves Web Site http://www1.kingston.net/~english/Stoves.html
>
The apple trees here are loaded and we are enjoying the harvest of BRICK
OVEN baked apples, apple crumble, apple pie, apple cobbler, apple butter and
now with the oven temperature at just below 200 degrees F for the nest few
days there will be a chance to dry several loads of apples. No need to cut
the fingers on steet metal, scrounge up old toxic oil drums, no need for
charcoal, etc. Just a simple down to earth retained heat brick bake oven
that is fired with bio mass.
ALAN of Ovencrafters.
ALAN SCOTT

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

From jflores at prolena.sdnhon.org.hn Mon Aug 18 16:55:01 1997
From: jflores at prolena.sdnhon.org.hn (jflores@prolena.sdnhon.org.hn)
Date: Tue Aug 31 21:35:31 2004
Subject: Smoke and corn
Message-ID: <199708181851.OAA07332@sdnhon.org.hn>

Dear Stover:

Last week I was in Lempira, Honduras. Lempira is the poorest
"departamento" in Honduras, with the highest rate of dis-nutrition,
and people who doesn't know read and write, in some areas of the
departamento the non writing and non reading people can be more than
90%.

How can you think, in this area the use of firewood is very high. The
people use the smoke for storing the corn and beans, but the most
important is the corn. The put the corn over the stove, so they cook,
and with smoke that the stove make they keep the corn off the insect
and other kind of corn destroyer.

I am not sure about the effect of this kind of technology, the effect
in the corn, What happen with the smoke and the corn?
Does the smoke case any kind of contamination on the corn?

I ask that, because, if We want to make a project in kind of area, we
have to think about that, because, the persons continue use the
traditional woodstave because they need the smoke. Most of the people
in the area have a improved woodstove, but the keep on the old stove,
and nobody know how to solve this problem.

Does anyone have an experience like this?

----------------------------------------------------------------------
Juan Carlos Flores Lopez
Director Ejecutivo PROLENA/Honduras
Tel/Fax: (504) 32-0639
P.O.Box 3870 Tegucigalpa, Honduras.
E-Mail: jflores@prolena.sdnhon.org.hn
----------------------------------------------------------------------

From hmrajabu at ucdavis.edu Mon Aug 18 18:24:08 1997
From: hmrajabu at ucdavis.edu (HMRajabu)
Date: Tue Aug 31 21:35:31 2004
Subject: Smoke and corn
In-Reply-To: <199708181851.OAA07332@sdnhon.org.hn>
Message-ID: <Pine.GSO.3.95.970818151710.15048A-100000@boris.ucdavis.edu>

On Mon, 18 Aug 1997 jflores@prolena.sdnhon.org.hn wrote:

> important is the corn. The put the corn over the stove, so they cook,
> and with smoke that the stove make they keep the corn off the insect
> and other kind of corn destroyer.
>
> I am not sure about the effect of this kind of technology, the effect
> in the corn, What happen with the smoke and the corn?
> Does the smoke case any kind of contamination on the corn?
>

Hi Lopez.

The use of smoke from the stove for preserving seeds is also common for
small farmers in Africa. But the smoked corn or beans are normally used as
seeds and not for food.

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

From rmiranda at sdnnic.org.ni Mon Aug 18 21:37:02 1997
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:35:31 2004
Subject: Smoke and corn
In-Reply-To: <199708181851.OAA07332@sdnhon.org.hn>
Message-ID: <3.0.2.16.19970818170912.2b4fe80c@ns.sdnnic.org.ni>

Juan carlos wrote:
>Dear Stover:
>
>
>I am not sure about the effect of this kind of technology, the effect
>in the corn, What happen with the smoke and the corn?
>Does the smoke case any kind of contamination on the corn?

Juan Carlos: This is a good question. What about the smoked sausage ?

Also we know that woodsmoke is good for wood preservation. In many rural
houses in Nicaragua, the smoke is desirable in order to keep the wooden
houses free of termites and other pests. Is it a good trade off with the
health ?

Rogerio

From english at adan.kingston.net Mon Aug 18 22:06:31 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
In-Reply-To: <199708181742.KAA10070@shell10.ba.best.com>
Message-ID: <199708190207.WAA25838@adan.kingston.net>

Summary: Why not high mass, bricks and mortar, stoves?

Dear Alan +

> The apple trees here are loaded and we are enjoying the harvest of BRICK
> OVEN baked apples, apple crumble, apple pie, apple cobbler, apple butter and
> now with the oven temperature at just below 200 degrees F for the nest few
> days there will be a chance to dry several loads of apples.

Sounds wonderful! Can you make ice cream in that thing?

Seriously though, I think you are suggesting something which is time
honoured. I would like to hear from people with a cultural
perspective as to where these earthen ovens are used, where they
are not and why.

> No need to cut
> the fingers on sheet metal, scrounge up old toxic oil drums, no need for
> charcoal, etc.

>From a current practices perspective I understand that there is a
huge need for charcoal. This is what drives some of the stovers to
look for better ways to produce it.

> Just a simple down to earth retained heat brick bake oven
> that is fired with bio mass.

I guess I'll get "down to earth" as soon as I've used up my scap
pile, "top down".

Convertible, Alex

> ALAN of Ovencrafters.
> ALAN SCOTT
>
> Check out the new web site for OVENCRAFTERS
> http://pomo.nbn.com/home/ovncraft
>
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From ovencrft at nbn.com Tue Aug 19 01:24:31 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
Message-ID: <199708190525.WAA07543@shell10.ba.best.com>

>Summary: Why not high mass, bricks and mortar, stoves?
>
>Seriously though, I think you are suggesting something which is time
>honoured. I would like to hear from people with a cultural
>perspective as to where these earthen ovens are used, where they
>are not and why.
Dear Alex,
Best study of high mass oven use in a rural culture is "The Bread
Ovens of Quebec" by Lise Boily and Jean-Francois Blanchette published by the
National Museum of Man Canada. Page 32 lists some uses of the ovens to dry
things, although there is no mention of fruit. It may seem crazy to think of
using an oven to dry fruit in California but I happen to live on the coast
where it is both damp and foggy in the summer. Nearby at the now defunct
Farralones Institute it is hot and sunny and there were developed there
clever low tech solar fruit dryers for the peace corps trainees in the
1970's. None of them needed fuel, but were effective as long as there was
sunshine. I could find some designs if it is of use to your project.
Meanwhile back on my hobby horse, if there is fruit there is often
tree trimmings, and it was common in the old days to use these to heat
ovens. The prunings for example were bundled up into "faggots" using simple
clamping devises and these bundles were tossed into the fire all at once.
Whatever, one of my points is to demonstrate that in small scale rural
household/village situations it is possible to view a specific problem in a
broader way than we in the west are used to with our tunnel "specialists"
vision. One load of fuel in a high mass oven can be used extreemly
efficiently saving forests and all that, by following the falling heat over
several days if necessary performing a multitude of functions; bread, beans,
crackers, smoking, drying, etc., etc.
There are a few of my ovens in Canada but the nearest to you is
north of Ithica NY at Genoa on a Biodynamic farm. If you are in the area and
want to visit I will send you the address.
Cheers, ALAN
ALAN SCOTT

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

From rrook at direct-source.com Tue Aug 19 20:38:37 1997
From: rrook at direct-source.com (Roger Rook)
Date: Tue Aug 31 21:35:31 2004
Subject: construction plans for wood fireplace insert
In-Reply-To: <199708181742.KAA10074@shell10.ba.best.com>
Message-ID: <33FA3CBB.A3ABE4E6@direct-source.com>

Alan Scott wrote:

> Dear Roger, I am a supplier for plans to build brick bake ovens but
> you are
> better off contacting the Masonry Heater Association for a contact
> there who
> may help with your project. They are very concerned with space
> haeating from
> what are essentially modified masonry fireplaces, They can be
> contacted
> through their web page or call the office at (703) 620 3171, or
> through a
> link from my web site below. Also please contact me if you receive
> this as a
> check that this reply got through to you, Thanks ALAN.
>
> > I am looking for a place to purchase plans so that we can
> construct a
> >wood burning fireplace insert (and perhaps adjust size to fit). I
> saw a
> >US Gov doc that says they are out there but have been unable to
> locate.
> >Stove Dealers tell me there are none. Any suggestions as to where I
> >might go or look?
> >
> >Roger Rook rrook@direct-source.com
> >
> >
> >
> ALAN SCOTT
>
> Check out the new web site for OVENCRAFTERS
> http://pomo.nbn.com/home/ovncraft

dear alan,
thank you so much for your response. I was not even sure my message had
gone out. I will use all of my limited computer skills to try to follow
your suggestions. If I never climb the mountain, I may email you again.

thank you and,
thanks

Roger Rook

From sokmgi at ibm.net Tue Aug 19 22:37:10 1997
From: sokmgi at ibm.net (sokmgi@ibm.net)
Date: Tue Aug 31 21:35:31 2004
Subject: Briquette Machine
Message-ID: <199708200237.CAA91988@out2.ibm.net>

BRIQUETT.DOC

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From english at adan.kingston.net Tue Aug 19 23:10:11 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
In-Reply-To: <199708190525.WAA07543@shell10.ba.best.com>
Message-ID: <199708200311.XAA17683@adan.kingston.net>

> Dear Alex,
> Best study of high mass oven use in a rural culture is "The Bread
> Ovens of Quebec" by Lise Boily and Jean-Francois Blanchette published by the
> National Museum of Man Canada.

Dear Alan
I will try to find a copy. Back in 1980 I visited a rural baker in
the Eastern Townships of Quebec who had built an authentic 'one' out
of river bottom clay. He made wonderful bread and sold it across the
border in Vermont. He eventually built a cabin around and over it to
better utilize the heat.
I am heading for Quebec this weekend where I expect to visit the
Brace Research Institute. Although they are best know for appropriate
solar technology, they also do stove design including earthen
community stoves.

Alex

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

From ovencrft at nbn.com Wed Aug 20 00:25:45 1997
From: ovencrft at nbn.com (Alan Scott)
Date: Tue Aug 31 21:35:31 2004
Subject: Fruit Drier Heat Exchanger
Message-ID: <199708200427.VAA27641@shell10.ba.best.com>

>
>
>> Dear Alex,
>> Best study of high mass oven use in a rural culture is "The Bread
>> Ovens of Quebec" by Lise Boily and Jean-Francois Blanchette published by the
>> National Museum of Man Canada.
>
>Dear Alan
>I will try to find a copy. Back in 1980 I visited a rural baker in
>the Eastern Townships of Quebec who had built an authentic 'one' out
>of river bottom clay. He made wonderful bread and sold it across the
>border in Vermont. He eventually built a cabin around and over it to
>better utilize the heat.
>I am heading for Quebec this weekend where I expect to visit the
>Brace Research Institute. Although they are best know for appropriate
>solar technology, they also do stove design including earthen
>community stoves.
>

I will be most interested in hearing what the Brace Research Institute has
developed out of the high mass oven tradition. I will search for their address.

ALAN Scott
ALAN SCOTT

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

From timo.sirkkala at rovaniemi.fi Wed Aug 20 03:41:56 1997
From: timo.sirkkala at rovaniemi.fi (Sirkkala Timo)
Date: Tue Aug 31 21:35:31 2004
Subject: Testing
Message-ID: <33FB2238.334F@rovaniemi.fi>

Im a new member and testing mailing proceedings.

From Skarekezi at form-net.com Wed Aug 20 06:44:11 1997
From: Skarekezi at form-net.com (Skarekezi@form-net.com)
Date: Tue Aug 31 21:35:31 2004
Subject: Woodstove Trining Modules
Message-ID: <199708201043.GAA00962@solstice.crest.org>

our ref: mb12340,afr/sec/tech, ro(at,lm)

EMAIL TO: MR. MIKE BESS. E-MAIL: IN:stoves@crest.org

FROM: STEPHEN KAREKEZI, AFREPREN/FWD, ELGEYO MARAKWET CLOSE,
KILIMANI, P.O. BOX 30979, NAIROBI, KENYA (TEL: 254 2566032; FAX: 254
2561464/ 566231/ 740524; E-MAIL: Skarekezi@form-net.com or
Stephen_Karekezi@elci.gn.apc.org))

DATE: 20 August, 1997

Dear Mike Bess,

SUBJECT: WOODSTOVE TRAINING MODULES

Greetings from AFREPREN, Nairobi, Kenya. We are requesting that you send
us training materials similar to those sent to Juan Carlos. We are
currently in the process of preparing for a regional workshop.

Kindly let us know if you require any additional information or
clarification.

Yours sincerely,

Stephen Karekezi,
Director,
AFREPREN/FWD

From timo.sirkkala at rovaniemi.fi Thu Aug 21 02:51:05 1997
From: timo.sirkkala at rovaniemi.fi (Sirkkala Timo)
Date: Tue Aug 31 21:35:31 2004
Subject: A NEW WORLD STOVE
Message-ID: <33FC661E.5910@rovaniemi.fi>

Greetings from Finland!

We believe we had a new "World Stove" already developed, which is
technically ready for using.

It is a stove belonging to the group of one pot, chimneyless, metal,
biomass stove, portable and one family size.

The stove is a prefabricated metal sheet which can be assembled at the
site without any tools by naked hands within 30 minutes.

Preliminary testing results from the Finnish official enery testing
institute Jyväskylä according to VITA testing standards are:

It boils 4 litres of water in 20 minutes with 0.45 kg of biomass and
keeps the water simmering 30 minutes by 0.2 kg of biomass.

Who would be interested in field trials of the new stove model?

From english at adan.kingston.net Thu Aug 21 07:36:03 1997
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:35:32 2004
Subject: A NEW WORLD STOVE
In-Reply-To: <33FC661E.5910@rovaniemi.fi>
Message-ID: <199708211137.HAA20761@adan.kingston.net>

I am interested in your stove.
A few questions;

1.Could you send a picture, digital or otherwise, that I
might post on the webpage to show the " Stovers"?
2. Could you describe the fuel options, (size , moisture content,
stoking pattern, ect)?
3. What is the turn down ratio?
4. Have emissions tests been done that you could share with the list?

I would be willing to purchase and test your stove.

Alex

> Greetings from Finland!
>
> We believe we had a new "World Stove" already developed, which is
> technically ready for using.
>
> It is a stove belonging to the group of one pot, chimneyless, metal,
> biomass stove, portable and one family size.
>
> The stove is a prefabricated metal sheet which can be assembled at the
> site without any tools by naked hands within 30 minutes.
>
> Preliminary testing results from the Finnish official enery testing
> institute Jyväskylä according to VITA testing standards are:
>
> It boils 4 litres of water in 20 minutes with 0.45 kg of biomass and
> keeps the water simmering 30 minutes by 0.2 kg of biomass.
>
> Who would be interested in field trials of the new stove model?
>
>
Alex English
RR 2 Odessa Ontario
Canada K0H 2H0
613-386-1927
Stoves Web Site http://www1.kingston.net/~english/Stoves.html

From owner-stoves at crest.org Thu Aug 21 09:44:33 1997
From: owner-stoves at crest.org (by way of larcon@sni.net Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: Prasad message on "Smoke and Corn"
Message-ID: <v01540b01b021539f2899@[204.133.251.13]>

Again - a "bounced" message from Prasad - Ron

>From stoves-owner@crest.org Tue Aug 19 03:00:39 1997
Received: from tn7.phys.tue.nl (tn7.phys.tue.nl [131.155.116.151]) by
solstice.crest.org (8.8.5/8.7.3) with SMTP id DAA04636 for
<stoves@crest.org>; Tue, 19 Aug 1997 03:00:38 -0400 (EDT)
Received: by tn7.phys.tue.nl (5.57/Ultrix3.0-C)
id AA27815; Tue, 19 Aug 97 08:52:00 +0200
From: prasad@tn7.phys.tue.nl (prasad)
Message-Id: <9708190652.AA27815@tn7.phys.tue.nl>
Subject: Re: Smoke and corn
To: stoves@crest.org
Date: Tue, 19 Aug 1997 08:51:59 +0200 (MET DST)
In-Reply-To: <3.0.2.16.19970818170912.2b4fe80c@ns.sdnnic.org.ni> from
"Rogerio Miranda" at Aug 18, 97 05:09:12 pm
X-Mailer: ELM [version 2.4 PL23]
Content-Type: text

From:K.Krishna Prasad
<prasad@tn7.phys.tue.nl>

To:Rogerio and others

Sub: Smoke, corn and mud stoves

It all sounds like old arguments being rehashed. Smoke can get rid of
termites in thatched roof houses, they can dry corn, smoke sausages and what
not. But that hardly answers the trade-off point raised by Rogerio.

Mudstoves are the stuff the stove business started off in late seventies, to
boot using the concept of do-it-yourself. Well a quarter of century later we
seem to have progressed little. We keep still talking of half the population
of the world using biomass for cooking on inefficient stoves.

How does the do-it-yourself tactic propagate among illiterate rural
populations? If I was at the receiving end of this propaganda , it is
natural for me to ask: what stove do you use in your home? Why don't you
tell all those city folks to switch to biomass from gas/electricity? When
that has happened, please come back to me.

Prasad

From mike at esd.co.uk Thu Aug 21 12:43:19 1997
From: mike at esd.co.uk (Mike Bess)
Date: Tue Aug 31 21:35:32 2004
Subject: Prasad message on "Smoke and Corn"
In-Reply-To: <v01540b01b021539f2899@[204.133.251.13]>
Message-ID: <kJGIgKA1vF$zUAoP@esd.co.uk>

Dear Prasad,

I agree with much of what you have just said about how little has
changed, and how much we expect of people when we ourselves do not want
to go back to the old fashioned ways. These are true.

However, I do believe there are a few things we cannot change. First,
it will be a very long time before half the world has an alternative to
biomass. I believe that is a fact. Second, I believe that the
"traditional" donor and NGO approach of do-it-yourself is misguided and
proven virtually unworkable. This is because it misses critical points
in development and what people are looking for.

I believe biomass will be the important fuel for much of the world for
many years. In fact, it is seriously making a comeback in the West, and
that is not a joke. I also believe we must look at 5% solutions to get
at the 100%. That is, let's start with what we can achieve, and work
towards the entire market. That is, if we can market improved, energy
efficient stoves to 5% of the population, let's do it. Let's build up
the learning curve, gain experience, develop economies of scale and
bring the prices down so that another 5% and then 20% ,etc. can afford
it.

Self-built stoves are limiting on an efficiency basis (how does one
maintain efficiency and quality control) and on a consumer interest
basis (how many housewives or cooks want to build stoves themselves?).
There are alternatives. The work being carried out with prefabricated,
very low-cost stoves in Ethiopia (the Mirte) shows that stoves that
double efficiency of use, that reduce smoke, that protect the cook and
that are easier for cooks to use (all characteristics urban cooks look
for) can and are being sold in rural areas on a commercial, non-
subsidised basis. I believe this can be replicated, not perhaps for
100% of the rural population, but certainly for a large portion who can
afford radios and other "modern" items. But, the stove must be
attractive. It must be "modern". It must be marketed to appeal the way
any other "modern" product is. And, of course, it must save fuel, and
address the needs and concerns of cooks. Kerosene may light the world,
but I cannot visualise it, lpg, or electricity cooking most of the
world's meals. Cheers, Mike Bess
--
Mike Bess

From elk at arcc.or.ke Fri Aug 22 05:20:31 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: Still Here!
Message-ID: <v01510101b023328ffa0f@[199.2.222.155]>

I'm still here & monitoring the traffic in the group. I don't think I'll
sidetrack to the fruit drier project- I'm doing daily trials on a 3can
charcoal making stove at the moment. I'll come forward with more
information once there's either something to report or I've lost the plot &
need group guidance.

At this rate, I should submit results to the group early next month.

Still manually churning out charcoal briquettes at the rate of 100 kg/day
using vendors waste (discarded unsaleable fines & powder). This is a neat
viable little method- please forward any interested parties my way, as I
think this can now be considered field tested & should be promoted.

I'm pleased to see that photos of the briquetter are still at Alex's site
http://www1.kingston.net/~english/Stoves.html

Regards;

elk

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

From CAMPBELLDB at cdm.com Fri Aug 22 10:24:10 1997
From: CAMPBELLDB at cdm.com (Dan Campbell)
Date: Tue Aug 31 21:35:32 2004
Subject: Network on health impacts of indoor air pollution from cookstoves
Message-ID: <9708221421.AA02060@cdm.com>

Dear Colleagues:

The USAID sponsored Environmental Health Project (EHP) is establishing an
information network on the health impacts of indoor air pollution caused by
cookstoves. One major objective of the network is to link the health and
energy sectors to stimulate interest in health education and the prevention of
respiratory diseases in existing and future stove programs.

Please contact me if you would like additional information.

Sincerely,
Dan Campbell
EHP
1611 North Kent St, #300
Arlington, Virginia 22209 USA
www.access.digex.net/~ehp

To: stoves@crest.org
Subject: Still Here!
From: "E. L. Karstad" <owner-stoves@crest.org>
Date: 22 Aug 97 12:21:00
Reply-to: stoves@crest.org

At this rate, I should submit results to the group early next month.

I'm pleased to see that photos of the briquetter are still at Alex's site
http://www1.kingston.net/~english/Stoves.html

Regards;

elk

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

From E.Moerman at stud.tue.nl Sun Aug 24 07:55:29 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:32 2004
Subject: Smoke and corn
Message-ID: <6982.s335192@popserver.tue.nl>

Bounced message passed on.

In message Tue, 19 Aug 1997 08:51:59 +0200 (MET DST),
prasad@tn7.phys.tue.nl (prasad) writes:

> From:K.Krishna Prasad
> <prasad@tn7.phys.tue.nl>
>
> To:Rogerio and others
>
> About: Smoke, corn and mud stoves
>
> It all sounds like old arguments being rehashed. Smoke can get rid of
> termites in thatched roof houses, they can dry corn, smoke sausages and what
> not. But that hardly answers the trade-off point raised by Rogerio.
>
> Mudstoves are the stuff the stove business started off in late seventies, to
> boot using the concept of do-it-yourself. Well a quarter of century later we
> seem to have progressed little. We keep still talking of half the population
> of the world using biomass for cooking on inefficient stoves.
>
> How does the do-it-yourself tactic propagate among illiterate rural
> populations? If I was at the receiving end of this propaganda , it is
> natural for me to ask: what stove do you use in your home? Why don't you
> tell all those city folks to switch to biomass from gas/electricity? When
> that has happened, please come back to me.
>
> Prasad
>
---------------------------------------------
Mr. Etienne Moerman E.Moerman@stud.tue.nl
Joh. Buyslaan 71 tel. +31-40-2571491
5652 NJ EINDHOVEN The Netherlands

From larcon at sni.net Mon Aug 25 19:36:51 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: Network on health impacts of indoor air pollution from cookstoves
Message-ID: <v01540b01b027724cad2c@[204.133.251.4]>

Dan (a new list member) - This is a very important message fom USAID; thank
you. I think I speak for most "stoves" list members in asking you to
expand on the "additional information" offer. The topic of indoor air
pollution has come up several times on our list - but we probably only have
half a dozen of our roughly 90 members who routinely are involved in the
measurement of indoor air pollution.

How can we help?

Regards Ron

>Dear Colleagues:
>
>The USAID sponsored Environmental Health Project (EHP) is establishing an
>information network on the health impacts of indoor air pollution caused by
>cookstoves. One major objective of the network is to link the health and
>energy sectors to stimulate interest in health education and the prevention of
>respiratory diseases in existing and future stove programs.
>
>Please contact me if you would like additional information.
>
>Sincerely,
>Dan Campbell
>EHP
>1611 North Kent St, #300
>Arlington, Virginia 22209 USA
>www.access.digex.net/~ehp
>
>
>
>
>
>Content-Type: message/rfc822
>
>Date: 22 Aug 97 12:21:00
>From:"E. L. Karstad" <owner-stoves@crest.org>
>To: stoves@crest.org
>Subject: Still Here!
>Reply-to: stoves@crest.org
>X-Authentication-Warning: solstice.crest.org: majordom set sender to
>owner-stoves@crest.org using -f
>X-Orcl-Application: Mime-Version: 1.0
>X-Orcl-Application: Content-Type: text/plain; charset="us-ascii"
>X-Orcl-Application: Sender: owner-stoves@crest.org
>X-Orcl-Application: Precedence: bulk
>X-Orcl-Application: content-length: 950
>
>
>I'm still here & monitoring the traffic in the group. I don't think I'll
>sidetrack to the fruit drier project- I'm doing daily trials on a 3can
>charcoal making stove at the moment. I'll come forward with more
>information once there's either something to report or I've lost the plot &
>need group guidance.
>
>At this rate, I should submit results to the group early next month.
>
>Still manually churning out charcoal briquettes at the rate of 100 kg/day
>using vendors waste (discarded unsaleable fines & powder). This is a neat
>viable little method- please forward any interested parties my way, as I
>think this can now be considered field tested & should be promoted.
>
>I'm pleased to see that photos of the briquetter are still at Alex's site
>http://www1.kingston.net/~english/Stoves.html
>
>Regards;
>
>
>elk
>
>_____________________________
>Elsen Karstad
>P.O Box 24371 Nairobi, Kenya
>Tel:254 2 884437
>E-mail: elk@arcc.or.ke
>______________________________

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

From larcon at sni.net Mon Aug 25 19:36:52 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: The Karstad 3-can pyrolyzer stove
Message-ID: <v01540b05b0279a3f1003@[204.133.251.4]>

Summary: Questions on Elsen's 3-can pyrolyzer description (of July 16)

Elsen - good to have you back. See comments below.

>I'm still here & monitoring the traffic in the group. I don't think I'll
>sidetrack to the fruit drier project- I'm doing daily trials on a 3can
>charcoal making stove at the moment. I'll come forward with more
>information once there's either something to report or I've lost the plot &
>need group guidance.

(RWL): We need you on the fruit dryer also. I hope you can put some time
into thinking about the issue, even if not able to experiment with it.
>
>At this rate, I should submit results to the group early next month.
>
>Still manually churning out charcoal briquettes at the rate of 100 kg/day
>using vendors waste (discarded unsaleable fines & powder). This is a neat
>viable little method- please forward any interested parties my way, as I
>think this can now be considered field tested & should be promoted.
>
>I'm pleased to see that photos of the briquetter are still at Alex's site
>http://www1.kingston.net/~english/Stoves.html

(RWL): There are huge piles of waste charcoal sitting around Khartoum
also. As near as I can tell, there is no e-mail going into Sudan - so if
anyone has other means, I hope they will pass this simple briquetting idea
along there as well.

My main point today is to ask some more details on your 3-can
stove, as reported as you left on July 16. For convenience, I will repeat
your description here:

>This stove is basic- no welding. Two 25kg paint cans vertically joined with
>a fuel cell can (15 litre?) of a slightly smaller diameter attached to the
>removable lid of the upside down lower can.

(RWL): Could you give the diameters and heights. At the closest
separation, what is the gap width?

> Holes punched through both
>bottom of lower can and lid allow for primary air to enter fuel cell can
>from below only. This is controlled by sand or earth, as the stove rests
>over a shallow depression.

(RWL): This doesn't sound as stable as the earlier use of a heavy
(cemented) bottom. Any concerns? What did your staff learn in your
absence?

> Horizontal triangular secondary air vents with
>sliding valves are cut into the sides of the lower can- near the bottom,
>allowing secondary air into the space between the outer and inner cans
>(lower section). This secondary air will rise in the gap between fuel cell
>can & the outer can, and preheat before encountering gas. Combustion will
>take place around the edge and over the top of the fuel cell extending up
>through the (removed) bottom of the top can into the top can itself.
>Pyrolisis occurs in the fuel cell from top to bottom as usual.
>
>Wew! bet you'll have to read this a couple of times... sorry!
>
(RWL) You're right - but I'm pretty sure I've got it. Did you seem to get
flame holding right at the fuel can rim?

>So... the overall outside picture is of two 25 litre paint cans- the bottom
>one is upside down and resting on it's lid over a shallow depression which
>allows primary air to enter under the stove. This bottom can has had it's
>bottom removed. The top 25 litre can is upright and attached to the lower
>one. The top can also has it's bottom removed. These cans are slightly
>tapered, so the stove will have a slight hourglass shape. There is no slit
>to allow seconday air in at the junction. The cooking pot is inserted into
>the top can through the top can's removable lid. Exhaust gas passes along
>the sides of the cooking pot to escape.

(RWL): I think that the distance from the fuel can to the cook pot bottom
is an important number. Yours? What heighth of cookpot inside and outside
the upper paint can?

>
>A couple unique and hopefully effective features are:
>
>-controllable secondary as well as primary venting.

(RWL): I have tried varying the secondary air slit width some, but never
came to any conclusions, except that it didn't seem to be a critical
dimension. What do you see as you close the secondary air slits? Might
you be able to avoid having good control of the secondary air supply? (use
ceramic plugs?)

>-easily accessed materials (within Kenya, anyway)
>-no welding necessary- a bit of riveting only
>-preheating of secondary air as it passes up past pyrolisis in fuel cell
>-the possibility of insulating the combustion chamber without overheating
>secondary air
>-reasonable wind shielding
>-cheap - est USD 4.00 incl. labour.
>-extinguish produced charcoal by separting the bottom of the stove (the
>upside down lower can's lid) and placing an un-holed 25 l. paint can over
>the fuel cell & onto the lid. Pile dirt around edge so no air can get into
>primary vent holes.

(RWL): A good list of benefits.

Other:
1) It seems that you might easily "hang" a thin cheap insulating metal
foil "shield" around the upper paint can, because of the hourglass shape..

2). Do you think you could do this design all pretty cheaply (as for
the fruit dryer in Haiti, where they are reported to have only plastic
20-25 liter pails) with sheet metal instead of metal pails? I'm wondering
if the fuel could be loaded inside a metal "band" (rather than a can) -
which will allow a lot of flexibility in the height and diameter of the
fuel supply. The band might sit in a sand-filled groove in the (presumed)
piece of concrete (with central air holes.
3) The ability to use vertical primary air holes and sand as a control
mechanism seems important. Has it worked out well? (what size holes with
what spacing?
4) I appreciate your need to get more data - but maybe you can report
your best FOM to date on this new design?

Regards Ron

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

From elk at arcc.or.ke Tue Aug 26 06:54:41 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: 3CAN PYROLISER STOVE
Message-ID: <v01510101b0287fffddaa@[199.2.222.152]>

Stovers- at Ronal's request, here is some more information (possibly a bit
prematurely released) on the 3can stove I'm currently working on.

No rest while you're monitoring the net Ronal! ("Pixie"....???)

I'm struggling a bit with getting the design of the 3can right- much of my
trouble is in communicating modifications to the metalworkers- my fault.

To date we've come up with the best FOM at a poor .85. That was 5.5 kg.
water boiled off using 6.47 kg wood over 1 hr 55 min burning time. 21% good
quality charcoal recovered (1.36 kg).

Controllability isn't too good yet, particularly toward the end to the
burn, when primary air must be opened up a bit to maintain a flame at the
lip of fuel cell(this reduces charcoal production). I'm taking out the
adjustable venting on the secondary air and drilling a ring of 5 mm air
holes (I'll count how many later). Primary air is now controlled by a
sliding valve now- not sand.

I've added a 2cm thick layer of refactory cement, over chicken wire, as an
external insulating layer.

A grate 2.5cm above fuel cell bottom to allow for even primary air flow had
been ommitted- it's going in today, so now we'll see some improvements I
think.

Now, to your questions in specific:

1) Diameters and Heights: Each 25 l paint can is made of .5 mm tinned
sheet steel and stands 36 cm high. Bottom diam is 26 cm, top is 28.5 cm.
Put together, bottom to bottom, the stove stands 72 cm high, with a central
waist of 26 cm dia. and top/bottom diameters of 28.5.

The fuel cell is 30 cm high by 24 cm wide and is attached to a lid that has
a centrally located sliding primary air inlet valve that opens maximum to
approx 22,5 sq.cm. and can completely block airflow when closed. The fuel
cell is inserted into the bottom of the stove, and the lid affixed to the
lower can by slightly bending in several of many rounded closure tabs on
the lid itself (not a modification- the lid comes this way).

The top rim of the fuel cell (which has no wall perforations) is 6 cm
below the mid-section waist of the stove and allows for a 2 cm gap between
itself and the outer stove wall where rising heated secondary air combusts
with pyrolisis volatiles in a ring around the top of the fuel cell.

Secondary air enters from the outside of the stove via 5mm holes located 4
cm above the bottom of the stove- near the bottom of the fuel cell.

The distance between fuel cell rim and bottom of inserted pot is 36 cm, as
the pot is inserted 6 cm into the top of the stove and held in place in the
middle of another lid with the centre cut out and several 5.5 cm tabs
turned up to support the pot at the underside of this 4.5 l capacity pot's
outurned rim. This arrangement allows plenty of space for hot gas to
exhaust the top of the stove after passing the walls of the pot.

2). Flame Holding: seems O.K. & is at the rim as well as over the top of
the fuel cell, but I'm looking for improvement. Maybe my flame holding
problems toward the end of the burn are a result of secondary air becoming
too hot as the pyrolisis zone reaches the bottom of the fuel cell.

I seem stuck on the idea of pre-heating secondary air...is it advantageous?
Comments?

At the end of the session, it's a joy to simply bend back a few tabs on the
lower lid, drop the whole bottom out including the fuel cell, and smother
the smoldering charcoal in the cell by inverting yet another (unmodified)
paint can over the bottom lid/fuel cell assembly. Maybe this should be
called the 4can stove if the extinguishing can is counted in?

3) I'll try your idea of affixing an external shell of thin sheet steel,
Ronal. Good idea, as the stove has a waist that should allow for an
airspace of 2.5 cm in the mid-section where the combustion zone is.

4) No reason why this design couldn't be followed using sheet steel- but
the advantages of using cheap used mass produced paint cans are obvious,
and the 'mating' between lid and can would have to be re-thought, no?

5) I've given up on the sand as a primary air control device- no 'sex
appeal' if y'know what I mean? Unconventional, inconvenient, and messy in
the rainy season. I've put the entire stove on three legs now that hold it
several cm above the ground to allow free primary air access. A wide stance
gives the necessary stability when stirring heavy maize meal porridge.

Enough writing- time to get back to the metal shop.

All the best;

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

From larcon at sni.net Tue Aug 26 15:39:07 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: 3CAN PYROLISER STOVE
Message-ID: <v01540b00b028b13725a2@[204.133.251.17]>

Summary: Offering two new ideaa on improving FOM.

To Elsen: Thanks for your quick response. Now a few questions to better
understand the new geometry.

Elsen said:

>I've added a 2cm thick layer of refactory cement, over chicken wire, as an
>external insulating layer.

(RWL): Does this cover all or only the upper can? Is it fairly easy to
apply? Any estimate on life time? Cost?

Elsen:
> The distance between fuel cell rim and bottom of inserted pot is 36 cm, as
>the pot is inserted 6 cm into the top of the stove and held in place in the
>middle of another lid with the centre cut out and several 5.5 cm tabs
>turned up to support the pot at the underside of this 4.5 l capacity pot's
>outurned rim. This arrangement allows plenty of space for hot gas to
>exhaust the top of the stove after passing the walls of the pot.

(RWL): I should have asked about the diameter of the cook pot also - as I
think the gap spacing is perhaps the single most important parameter in
trying to get high FOM.

1) The cook pot height dimension of 6 cm is probably sub-optimal
for high FOM also. Any idea of the exit temperature of the gases? Perhaps
if the (taller) pot could be supported from the bottom (a tripod?), then a
taller shield (see below) might give a better FOM.

2) The second idea I have is using an interior cylindrical sleeve.
Because of your present hourglass shape - perhaps you can do "easy"
experiments with a series of cylindrical sleeves of different diameters
(and therefore heights) that snugly fit at the bottom at different heights.
These will have the effect of narrowing the gap between the cookpot and
the sleeve (which is now at a hotter temperature also) and presumably
thereofre improving the convective heat transfer to the cookpot. Sam
Baldwin's book, confirmed by Etienne Moerman, suggested this should be
about a 6 mm gap, but I don't have the book handy. Perhaps at the 6 cm
cookpot height, there is a better optimum gap width.
Having a cylindrical rather than conical (frustum) outer wall also
might help in heat transfer to the cookpot.

Elsen:
>2). Flame Holding: seems O.K. & is at the rim as well as over the top of
>the fuel cell, but I'm looking for improvement. Maybe my flame holding
>problems toward the end of the burn are a result of secondary air becoming
>too hot as the pyrolisis zone reaches the bottom of the fuel cell.

(RWL): I wonder if a blunt interior body might help. You have a pretty
large space to get air to. I have used a "disk" of metal just sitting on
the charcoal that seemed to help.

Elsen:
>I seem stuck on the idea of pre-heating secondary air...is it advantageous?
>Comments?

(RWL): Seems like a useful approach to me, but I have no numbers to
support the effort.

Elsen:
>At the end of the session, it's a joy to simply bend back a few tabs on the
>lower lid, drop the whole bottom out including the fuel cell, and smother
>the smoldering charcoal in the cell by inverting yet another (unmodified)
>paint can over the bottom lid/fuel cell assembly. Maybe this should be
>called the 4can stove if the extinguishing can is counted in?

(RWL): I like the concept. It sure sounds easier than what I have been doing.
>
Elsen
>4) No reason why this design couldn't be followed using sheet steel- but
>the advantages of using cheap used mass produced paint cans are obvious,
>and the 'mating' between lid and can would have to be re-thought, no?

(RWL): Yes.
I'm wondering if an interior tripod approach would allow the outer
sheet metal approach to be cheaper, where old large cans are not available.
Cheaper because the shield wouldn't have to support anything except itself.
The 'mating' may also then not have to be very good, since the secondary
air is all coming from the bottom anyway and is not supporting any weight.
>
Elsen:
>5) I've given up on the sand as a primary air control device- no 'sex
>appeal' if y'know what I mean? Unconventional, inconvenient, and messy in
>the rainy season. I've put the entire stove on three legs now that hold it
>several cm above the ground to allow free primary air access. A wide stance
>gives the necessary stability when stirring heavy maize meal porridge.

(RWL): This last point is very important I think. My supports would never
withstand vigorous stirring. Could you describe this base a little more?
What are the three legs attached to?

Great work!! Glad your vacation is over.

Regards Ron

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

From rteretap at nbnet.co.ke Thu Aug 28 09:08:24 1997
From: rteretap at nbnet.co.ke (R.T.E & RETAP)
Date: Tue Aug 31 21:35:32 2004
Subject: Inclusion in the Stoves Bulletin
Message-ID: <3.0.1.16.19970828153502.199f3d78@nbnet.co.ke>

Renewable Energy Technology Assistance Programme (RETAP) is an indigenous
NGO Registered in Kenya to promote the use of efficient energy technologies
within Eastern Africa. We are writing to request you to place us on your
stoves E-Mail Bulletin. If there is anything we are supposed to do before
being placed on it,
we would be glad to oblige.

Thanking you in advance.

Enos

For: Charles M. Gitundu
Executive Chairman
Renenewable Energy Technology Assistance Programme

From krksmith at uclink4.berkeley.edu Thu Aug 28 12:10:46 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:32 2004
Subject: Network on health impacts of indoor air pollution from cookstoves
Message-ID: <199708281612.JAA16024@uclink4.berkeley.edu>

Dan, You may want to contact the editor of Boiling Point (Elizabeth Bates,
<elizabethb@itdg.org.uk>) to have her put a notice about your new network in
the next issue (which happens to be focused on health). Best/K

At 10:21 AM 8/22/97 +0500, you wrote:
>Dear Colleagues:
>
>The USAID sponsored Environmental Health Project (EHP) is establishing an
>information network on the health impacts of indoor air pollution caused by
>cookstoves. One major objective of the network is to link the health and
>energy sectors to stimulate interest in health education and the prevention of
>respiratory diseases in existing and future stove programs.
>
>Please contact me if you would like additional information.
>
>Sincerely,
>Dan Campbell
>EHP
>1611 North Kent St, #300
>Arlington, Virginia 22209 USA
>www.access.digex.net/~ehp
>
>
>
>
>Date: 22 Aug 97 12:21:00
>From:"E. L. Karstad" <owner-stoves@crest.org>
>To: stoves@crest.org
>Subject: Still Here!
>Reply-to: stoves@crest.org
>X-Authentication-Warning: solstice.crest.org: majordom set sender to
owner-stoves@crest.org using -f
>X-Orcl-Application: Mime-Version: 1.0
>X-Orcl-Application: Content-Type: text/plain; charset="us-ascii"
>X-Orcl-Application: Sender: owner-stoves@crest.org
>X-Orcl-Application: Precedence: bulk
>X-Orcl-Application: content-length: 950
>
>
>I'm still here & monitoring the traffic in the group. I don't think I'll
>sidetrack to the fruit drier project- I'm doing daily trials on a 3can
>charcoal making stove at the moment. I'll come forward with more
>information once there's either something to report or I've lost the plot &
>need group guidance.
>
>At this rate, I should submit results to the group early next month.
>
>Still manually churning out charcoal briquettes at the rate of 100 kg/day
>using vendors waste (discarded unsaleable fines & powder). This is a neat
>viable little method- please forward any interested parties my way, as I
>think this can now be considered field tested & should be promoted.
>
>I'm pleased to see that photos of the briquetter are still at Alex's site
>http://www1.kingston.net/~english/Stoves.html
>
>Regards;
>
>
>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 Aug 28 13:01:41 1997
From: elk at arcc.or.ke (Elsen L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: Article extract- 'Daily Nation' Nairobi
Message-ID: <m0x47yC-0006e0C@arcc.or.ke>

Stovers; and excerpt from todays paper & a chance to practice my typing skills.

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

Kitchen Escapes Attention in Pollution War. Daily Nation, Kenya 28/8/97.

........A 1996 study on the influence of improved stoves on Acute
Respiratory Infection, Conjunctivitis, and Accidental burns by Dr. Margaret
Makumi Kinyanjui in Kiambu district found that 38% of women below 60 who
used three-stone fireplaces had ARI. In households with the improve
'Maendeleo' stove, the percentage dropped to 13.5. Kinyanjui says that 12
percent of women using three-stone fireplaces are likely to suffer from
conjunctivitis.... This percentage reduces to 0.4% in households using the
improved stove.

...... Small children who stay at their mother's side while the mothers cook
in smoke filled rooms are also affected. In Kiambu, 59.1 percent of these
children had ARI.......

.... In Kenya 95% of rural kitchens use either wood or charcoal. With a
decreasing resource base of high quality fuel, women switch from wood to
lower quality fuels such as softwood, agricultural residues and animal dung.
Thes products smoke extensively, emitting soot and tar.

Although Kinyanjui's study found a reduction in ARI, and conjunctivitis,
studies done at the Univ. of Witwatersrand in South Africa found that
although enclosed stoves all have greater heat transfer efficiencies than
open fires, their emission levels of carbon monoxide and other poisonous
gasses is twice as high.

"This study contradicts most of the major works that have been done in this
area around the world. We would have to examine the stoves themselves and
see under what conditions the study was done." Says Kinyanjui, Deputy
Reproductive Health Manager, Division of Primary Health Care of the Ministry
of Health.

A two-year study on Domestic Air Pollution by Dr. Amelia Mutere in Kiambu
between 1988 -1990, for example, found that CO concentration at the cooks
stirring position for the traditional 3-stone stove was 212 ppm, while for
the Maendeleo stove it was 88 ppm. The average total suspended particles are
4459 mg/m3 and 1723 mg/m3. Both levels are above the WHO standards put at
100-150 mg/m3 over 8 hours.

From phoenix at transport.com Thu Aug 28 13:55:51 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:32 2004
Subject: Ronald & Others on Stoves@crest.org
Message-ID: <199708281759.KAA31980@brutus.transport.com>

Enos brings up a good point and perhaps you have addressed it before I
joined your group. Stoves has collected a wide range of talented
individuals who contribute to the website. Would it be possible (and
acceptable to the group) to publish a list of the names and e-mail
addresses of all the participants such that we can correspond directly on
specific matters which might go beyond Stoves information?

Thanks!
Art

----------
> From: R.T.E & RETAP <rteretap@nbnet.co.ke>
> To: Stoves@crest.org
> Subject: Inclusion in the Stoves Bulletin
> Date: Thursday, August 28, 1997 8:35 AM
>
> Renewable Energy Technology Assistance Programme (RETAP) is an indigenous
> NGO Registered in Kenya to promote the use of efficient energy
technologies
> within Eastern Africa. We are writing to request you to place us on your
> stoves E-Mail Bulletin. If there is anything we are supposed to do
before
> being placed on it,
> we would be glad to oblige.
>
> Thanking you in advance.
>
> Enos
>
> For: Charles M. Gitundu
> Executive Chairman
> Renenewable Energy Technology Assistance Programme

From larcon at sni.net Fri Aug 29 09:01:10 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list (Re: Ronald & Others on Stoves@crest.org)
Message-ID: <v01540b02b02bf6427406@[204.133.251.23]>

Art:
This issue has come up on several other crest lists - and the lists
are not published without specific permission being given. The only
information that list coordinators have (and you don't) is the list of
e-mail addresses (without names to go with them).

I would be glad to start creating an alphabeticized list. I think
it should be safe to assume that anyone regularly putting their full name
and address and phone numbers into their messages don't mind being on the
list. Therefore, please contact me if you don't want to be on this list
(that will be published once in a awhile, and will be available to anyone
who asks).

Others who would like to be on the list should let me know (Art,
your address was not on your message, nor was the full address for Enos nor
Charles M. Gitundu).

Art - I think you have a good idea (especially because we have some
very good talent listening in), but before I do anything, I hope we can
hear what the downside might be (presumably some more junk mail).

Regards Ron

>Enos brings up a good point and perhaps you have addressed it before I
>joined your group. Stoves has collected a wide range of talented
>individuals who contribute to the website. Would it be possible (and
>acceptable to the group) to publish a list of the names and e-mail
>addresses of all the participants such that we can correspond directly on
>specific matters which might go beyond Stoves information?
>
>Thanks!
>Art
>
>----------
>> From: R.T.E & RETAP <rteretap@nbnet.co.ke>
>> To: Stoves@crest.org
>> Subject: Inclusion in the Stoves Bulletin
>> Date: Thursday, August 28, 1997 8:35 AM
>>
>> Renewable Energy Technology Assistance Programme (RETAP) is an indigenous
>> NGO Registered in Kenya to promote the use of efficient energy
>technologies
>> within Eastern Africa. We are writing to request you to place us on your
>> stoves E-Mail Bulletin. If there is anything we are supposed to do
>before
>> being placed on it,
>> we would be glad to oblige.
>>
>> Thanking you in advance.
>>
>> Enos
>>
>> For: Charles M. Gitundu
>> Executive Chairman
>> Renenewable Energy Technology Assistance Programme

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

From larcon at sni.net Fri Aug 29 09:01:36 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: Article extract- Denver Post
Message-ID: <v01540b06b02c0948ec40@[204.133.251.23]>

Elsen said:

>Stovers; an excerpt from todays paper & a chance to practice my typing skills.

<snip>

Your types of health excerpts don't appear in our paper too often,
but they reminded me to report that last week our local paper reported that
the charcoal kilns in the USA state of Missouri, which produce 80% of US
"natural" charcoal, had been told by state and national environmental
groups (our EPA) to clean up their act - no more venting. I'm trying to
learn more.

Regards Ron

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

From elk at arcc.or.ke Fri Aug 29 10:12:53 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: More 3can Charcoal-Making Stove trials
Message-ID: <v01510103b02c73269447@[199.2.222.150]>

Too hot! The flames are at times visible along the edge of the cooking pot
and produce some black soot.

Miserable FOM of .85 over 1hr35min cooking time with 5.5kg wood. The good
news is a charcoal conversion of 23%. I used half bone-dry and half fresh
acacia- toplit with kindling. I thought the inclusion of fresh (green) wood
would slow down the burn, but it evidently didn't, though an improvement in
charcoal yield above the previous 18% may be attributable to higher fuel
mosture content.

Now, while I'm constructing a new version of pyrolising stove incorporating
a much smaller fuel cell and 'direct injection' secondary air (trials
commence Monday), I am following Ronal's advice on further modifications to
the 3can. I intend to follow up on this stove, as it's simplicity and low
cost is very attractive. We just need better performance (sounds simple, eh
Alex?).

On today's trial I put restrictors on both the fuel cell, by placing a
star-shaped metal cover over the wood after ignition and by reducing the
gap between pot and stove to 5mm with the insertion of a flat ring of sheet
metal.

Again, half green and half dry wood is used.

Before the results, as the trial is now underway- a few answers to Ronal's
questions of 26/8:

Refractory cement is expensive. I've put approx. 8 kg on at a cost of USD
equiv. $8.00. This is obviously not a method of insulation that could be
recommended for a commercial version of the stove. Sheet metal sounds
better.

Gap spacing between cook pot and stove has been rather roughly determined
by triangular star-shaped upturned tabs of metal (part of can's lid), and
was in the order of 1.2 cm I'd say. As mentioed above, this has been
reduced, and now is 5mm. Why is this gap so important Ronal? Is is simply
due to it's control on chiney flue draw? The cook pot is 11 cm deep by 23
cm inside diam.

Secondary air is now through 97 5mm holes in a ring 8 cm above the bottom
of the stove.

I hav'nt tried the inner sleeve you recommend Ronal, Do I assume that this
would simply raise the combustion zone closer to the pot's bottom? I've
noted that if flame actually touches the pot, soot is produced. My present
problem is flames that are too high. Too much fuel? Fuel cell too hot &
pyrolisis to quick?

The base is made of 4mm by 4 cm wide flat bar bolted onto the stove 2/3rds
of the way up. Two bolts for each leg. Legs extend at a 45' angle from the
stove. The basal diameter is 60 cm (encompassing the three legs), and the
stove bottom is 10 cm above the ground. Added stability is provided by
individual wire struts running horizontally from the bottom of the stove to
each leg ('buttoned' through small holes drilled in stove & legs). This
seems to provide ample stability for stirring a stiff maizemeal mixture,
though all trials to date have been with water.

O.K.- The results are in- improved controllability; I'd say a turndown rate
of slightly better than 3. Excellent slow boil. Flame holding is good; from
the cell edges tapering up centrally over the cell, only one outage with
lots of smoke, but the stove re-lit quickly with the primary air half open
(primary air was closed immediately after ignition when the star-shaped
plate was placed on top of the fuel cell.

No soot or visible flame jetting up along the side of the pot. The rate of
burn has been pretty effectively controlled now.

FOM at .64 ( 5.5 kg wood to boil off 3.5 kg water).
Burn duration: 1 hr 45 min in gusty conditions outdoors.
Charcoal production 23% (1.26 kg from 5.5 kg wood)

I find the poor FOM puzzling. This should be much better. Maybe the slow
boil over a longer period of time evaporates less water proprtionally than
a fast boil over a short time?

I'll seat the pot deeper into the stove for the next trial.

All for now- It's Friday & there's a cold brew waiting somewhere!

elk

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

From elk at arcc.or.ke Fri Aug 29 10:14:25 1997
From: elk at arcc.or.ke (E. L. Karstad)
Date: Tue Aug 31 21:35:32 2004
Subject: Article in 'Daily Nation' 28/8/97
Message-ID: <v01510102b02c648223b6@[199.2.222.150]>

There may be some confusion- I did not write the article I quoted from
yesterday. I omitted to include the reporter's name- Evaline Were.

Sorry for any confusions

elk

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

From phoenix at transport.com Fri Aug 29 10:25:24 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list (Re: Ronald & Others on Stoves@crest.org)
Message-ID: <199708291427.HAA11630@s.transport.com>

Please allow me to correct my own fax pas regarding my address.

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

Some of the "silent contributors" might only live a few miles apart even
though this is a world wide forum.

Thank you!

Art
----------
> From: Ronal W. Larson <larcon@sni.net>
> To: stoves@crest.org
> Subject: Re: a stoves mailing list (Re: Ronald & Others on
Stoves@crest.org)
> Date: Friday, August 29, 1997 6:06 AM
>
> Art:
> This issue has come up on several other crest lists - and the
lists
> are not published without specific permission being given. The only
> information that list coordinators have (and you don't) is the list of
> e-mail addresses (without names to go with them).
>
> I would be glad to start creating an alphabeticized list. I
think
> it should be safe to assume that anyone regularly putting their full name
> and address and phone numbers into their messages don't mind being on the
> list. Therefore, please contact me if you don't want to be on this list
> (that will be published once in a awhile, and will be available to anyone
> who asks).

From REEDTB at compuserve.com Fri Aug 29 12:51:47 1997
From: REEDTB at compuserve.com (Tom Reed)
Date: Tue Aug 31 21:35:32 2004
Subject: Prasad message on "Smoke and Corn"
Message-ID: <199708291252_MC2-1E97-484@compuserve.com>

Dear Prasad:

I don't think you have been listening closely, or you are burned out on
stoves.

We havn't been talking about "wood stoves" mostly - we are talking about
"wood-gas stoves", descended in part from the "J" stove of PV, but much
simpler. So if you havn't built one and tried it you are in no position to
say we have made little progress.

Just finished the 3rd Biomass of the Americas conference ( on plane going
home). Spent many hours talking stoves with Alex English and Mukunda.

Regards, TOM REED

From larcon at sni.net Sat Aug 30 00:15:40 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list
Message-ID: <v01540b06b02d39681379@[204.133.251.9]>

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

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 larcon at sni.net Sat Aug 30 00:15:52 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: More 3can Charcoal-Making Stove trials
Message-ID: <v01540b07b02d3ab36137@[204.133.251.9]>

Summary: A few more comments and questions in response to Elsen's
continued research.

>Too hot! The flames are at times visible along the edge of the cooking pot
>and produce some black soot.
>
(RWL): Presumably this has been solved below by going to a smaller
fuel can (or maybe just a star shaped "disk" on the charcoal) (or both?)?
We need some tabulations or nomograms to show "best" fuel cell diameters
and fuel depths for various pot sizes and cooking tasks.

>Miserable FOM of .85 over 1hr35min cooking time with 5.5kg wood. The good
>news is a charcoal conversion of 23%. I used half bone-dry and half fresh
>acacia- toplit with kindling. I thought the inclusion of fresh (green) wood
>would slow down the burn, but it evidently didn't, though an improvement in
>charcoal yield above the previous 18% may be attributable to higher fuel
>mosture content.

(RWL) - I gather that you felt moisture had little effect - at least when
half of the fuel was dry - half wet. I've never tried this intentionally
(probably unintentionally), but the result seems surprising. I have had
trouble with wet wood. I'll bet that this FOM is higher than anything you
could get with any other (wood-burning) stove.

>Now, while I'm constructing a new version of pyrolising stove incorporating
>a much smaller fuel cell and 'direct injection' secondary air (trials
>commence Monday),

(RWL): Direct injection secondary air means your "3can" geometry (with its
type of preheating)?

> I am following Ronal's advice on further modifications to
>the 3can. I intend to follow up on this stove, as it's simplicity and low
>cost is very attractive. We just need better performance (sounds simple, eh
>Alex?).
>
>On today's trial I put restrictors on both the fuel cell, by placing a
>star-shaped metal cover over the wood after ignition and by reducing the
>gap between pot and stove to 5mm with the insertion of a flat ring of sheet
>metal.
>
>Again, half green and half dry wood is used.
>
>Before the results, as the trial is now underway- a few answers to Ronal's
>questions of 26/8:
>
>Refractory cement is expensive. I've put approx. 8 kg on at a cost of USD
>equiv. $8.00. This is obviously not a method of insulation that could be
>recommended for a commercial version of the stove. Sheet metal sounds
>better.

(RWL): This may be a good spot for Paul Hait to tell us about his work on
his lower cost similar product - if he is ready.

>
>Gap spacing between cook pot and stove has been rather roughly determined
>by triangular star-shaped upturned tabs of metal (part of can's lid), and
>was in the order of 1.2 cm I'd say. As mentioed above, this has been
>reduced, and now is 5mm. Why is this gap so important Ronal? Is is simply
>due to it's control on chiney flue draw? The cook pot is 11 cm deep by 23
>cm inside diam.

(RWL): The why is a good question. It comes from the theory of convective
heat transfer - which is not my area. I am pretty sure that the theory
does not involve chimney flue draw - which is clearly going to be
influenced. Any theorists out there want to wade in?

Is this the same cook pot? What is the full volume and your volume
of water in the cook pot?
>
>Secondary air is now through 97 5mm holes in a ring 8 cm above the bottom
>of the stove.
>
>I hav'nt tried the inner sleeve you recommend Ronal, Do I assume that this
>would simply raise the combustion zone closer to the pot's bottom?

(RWL): Maybe you have tried it - I was just suggesting a way to get
variable gap widths (like your 12 and 5 mm) - but all in one test. If the
intensity of boiling increases, you are moving in the right direction,

> I've
>noted that if flame actually touches the pot, soot is produced. My present
>problem is flames that are too high. Too much fuel? Fuel cell too hot &
>pyrolisis to quick?

(RWL): I'd say too much fuel - and/or too much primary air ("pyrolysis too
quick") - and/or not enough space from top of fuel cell to bottom of pot.
I doubt the "Fuel cell too hot". Any other thoughts from others on
sooting? One time (and only one time - long ago) I produced copious
amounts of soot - and I don't know what I did and haven't been able to
reproduce it.
>
>The base is made of 4mm by 4 cm wide flat bar bolted onto the stove 2/3rds
>of the way up. Two bolts for each leg. Legs extend at a 45' angle from the
>stove. The basal diameter is 60 cm (encompassing the three legs), and the
>stove bottom is 10 cm above the ground. Added stability is provided by
>individual wire struts running horizontally from the bottom of the stove to
>each leg ('buttoned' through small holes drilled in stove & legs). This
>seems to provide ample stability for stirring a stiff maizemeal mixture,
>though all trials to date have been with water.

(RWL): Thanks - sounds good (and important).
>
>O.K.- The results are in- improved controllability; I'd say a turndown rate
>of slightly better than 3. Excellent slow boil. Flame holding is good; from
>the cell edges tapering up centrally over the cell, only one outage with
>lots of smoke, but the stove re-lit quickly with the primary air half open
>(primary air was closed immediately after ignition when the star-shaped
>plate was placed on top of the fuel cell.

(RWL): I suggest trying to start the pyrolysis with the star shaped piece
already in place (kindling beneath) and primary air wide open at first. I
think what is happening with the star shaped piece (how big a gap - min and
max?) is that the extra gas near the secondary air makes for better flame
holding there and more complete combustion at lower heights.
>
>No soot or visible flame jetting up along the side of the pot. The rate of
>burn has been pretty effectively controlled now.
>
>FOM at .64 ( 5.5 kg wood to boil off 3.5 kg water).
>Burn duration: 1 hr 45 min in gusty conditions outdoors.
>Charcoal production 23% (1.26 kg from 5.5 kg wood)
>
>I find the poor FOM puzzling. This should be much better. Maybe the slow
>boil over a longer period of time evaporates less water proprtionally than
>a fast boil over a short time?

(RWL): I think you may be right - and I know nothing about this area (of
how to maximize evaporation). Trying a series of smaller depths of water
might work also - filling up the pot part way several times.
>
>I'll seat the pot deeper into the stove for the next trial.

(RWL) I believe this is unequivocally the right thing to do. Varying the
height of the shield above the top of the pot will possibly change the rate
of boil also.
>
>All for now- It's Friday & there's a cold brew waiting somewhere!
>
(RWL): Also still Friday here. I head out tomorrow for our famous 3-day
Labor day weekend - the end of summer. I think there's a cold brew waiting
out there for me too (a camping vacation in the little Colorado town of
Crestone).
>
>elk
>
>_____________________________
>Elsen Karstad
>P.O Box 24371 Nairobi, Kenya
>Tel:254 2 884437
>E-mail: elk@arcc.or.ke
>______________________________

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

From larcon at sni.net Sat Aug 30 10:52:22 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: a (k) stoves mailing list
Message-ID: <v01540b00b02de53f3c25@[204.133.251.1]>

This has got to stop!! Ron

>In a message dated 8/30/97 7:11:26 AM, you wrote:
>
>>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
>
>Ron
>
>Looks good to me:
>
>C. A. Kezar
>1807 Clovermeadow Dr. Vienna VA 22182 USA
>Tele:703-255-3325
>E mail: ckezar34@aol.com

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

From larcon at sni.net Sat Aug 30 10:55:44 1997
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list
Message-ID: <v01540b03b02de5e061ea@[204.133.251.2]>

Just in - another message from my friend Chuck Kezar (emphasize "K"). This
has to stop!! Ron

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

From phoenix at transport.com Sat Aug 30 12:31:22 1997
From: phoenix at transport.com (Art Krenzel)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list
Message-ID: <199708301635.JAA13626@brutus.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
>
>
> 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 rmiranda at sdnnic.org.ni Sun Aug 31 15:52:15 1997
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:35:32 2004
Subject: a stoves mailing list
In-Reply-To: <v01540b06b02d39681379@[204.133.251.9]>
Message-ID: <3.0.2.16.19970830132949.258fec88@ns.sdnnic.org.ni>

Ron: Perhaps we could include just the name of the organization in which we
work for, if it is the case, and also main areas of interest as key
words.?????????

Rogerio K. Miranda

At 10:21 PM 8/29/97 -0600, you wrote:
>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
>
>
>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
>
>
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
ATP/PROLENA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
telefax (505) 276 2015
EM <rmiranda@sdnnic.org.ni>
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BioEnergy Lists: Improved Biomass Cooking Stoves

August 1997 Biomass Cooking Stoves Archive