April 2003 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 adkarve at PN2.VSNL.NET.IN Tue Apr 1 00:15:37 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:20 2004
Subject: receipt of messages
Message-ID: <TUE.1.APR.2003.104537.0530.ADKARVE@PN2.VSNL.NET.IN>

I have started geting messages from STOVES@LISTSERV.REPP.ORG. Thanks
A.D.Karve

From crispin at NEWDAWN.SZ Wed Apr 2 13:25:05 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: lids Re: Stove testing - Vivienne Abbott
Message-ID: <WED.2.APR.2003.202505.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

I was discussing this lids-on lids-off issue with Vivienne and she has the
following sage advice:

+++++++++

In order to decide whether or not to use a lid in testing, one needs to
decide the purpse of the test. Clearly a basic water boiling test (in which
the heat of vapourisation of the water is included as useful heat) is best
done without a lid, as the primary purpose is to test combustion efficiency
and heat transfer efficiency.

Although the pots used may not be pressure cookers, some additional pressure
can build up if the lid fits well and condensing steam creates a seal.
Bellerive found considerable fuel savings using reasonably well fitting lids
with a stone place on top. Lids vary considerably, and even the same lid may
achieve a better fit in one position for one test than in other
positions/tests - hence the increased scatter Sam found in his tests.
Another variation, was that some testers used to use a lid in the first (to
boil) phase, and then remove it for the simmering phase.

A simulated or controlled cooking test should be carried out using the
instructions given to cooks to obtain the most efficient use of their fuel,
i.e. use a lid (if that is at all appropriate to the cooking procedure and
local situation.

+++++++++

So I also see merit in the lid on to boil and lid off to continue boiling,
lid on if it is a simmering test. Interesting combination. Perhaps that is
the best of both approaches.

It is more of a challenge to keep a stove simmering after a fast boil and is
perhaps a good test of a stove's flexibility: can the efficiency remain high
when the fuel is withdrawn (fuel metered) or when the air is closed off (air
controlled)?

Regards
Crispin

From nariphaltan at SANCHARNET.IN Fri Apr 4 03:32:36 2003
From: nariphaltan at SANCHARNET.IN (nariphaltan)
Date: Tue Aug 10 18:30:20 2004
Subject: Hello!
Message-ID: <FRI.4.APR.2003.140236.0530.NARIPHALTAN@SANCHARNET.IN>

Dear Stovers,

You might enjoy reading the following article on cooking and lighting for rural areas.

http://education.vsnl.com/nimbkar/housenergy.html

Cheers.

Anil K. Rajvanshi
Director
Nimbkar Agricultural Research Institute
P.O.Box 44, Phaltan-415523
Maharashtra, India
Ph: 91-2166-222396/220945
Fax: 91-2166-221328
E-mail: nariphaltan@sancharnet.in

http://nariphaltan.virtualave.net
http://www.nariphaltan.org

From dstill at EPUD.NET Fri Apr 4 22:28:58 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: Using Pumice to Make Lightweight Ceramics in El Salvador
Message-ID: <FRI.4.APR.2003.192858.0800.DSTILL@EPUD.NET>

Dear Stovers:

The following report from Damon Ogle details his recent experience with
refractory ceramics in El Salvador. He describes how to make pumice/clay
bricks for use in combustion chambers. There are five recently developed
recipes that we hope to share in the near future. They are: pumice/clay,
vermiculite/clay, sawdust/clay, perlite/clay and charcoal/clay.

The three photos that will follow Damon's excellent paper show 1.)
tilemakers in Central America making "baldosa" a floor tile used in the
combustion chamber of the Dona Justa stove built with assistance from Trees,
Water and People and in the HELPS stove, project managed by Don O'Neal. 2.)
six pumice/clay bricks that create an insulated combustion chamber 3.) a
kiln in El Salvador for firing bricks.

Best,

Dean Still
Aprovecho Research Center

Using Pumice to Make Lightweight Ceramics in El Salvador

March 31, 2003

Damon Ogle

In work for the Aprovecho Research Center, other researchers and I have
recently developed several types of insulative ceramics. We wanted to see if
it was possible to produce similar materials elsewhere. The following
report describes methods for making parts for combustion chambers using
materials and processes available in and around the community of El Coco in
El Salvador.

El Coco is a community of 800 people located in a volcanic area near the
Guatemalan border. Pumice deposits in the area are typical of deposits found
in many areas of the world. The nearby town of Chalchuapa is a small
agricultural community with a market, hardware stores, pottery operations
and several brick kilns, which supply the needs of the area.
.
Pumice

Several natural deposits of pumice are found around El Coco. These deposits
consist of layers of loose material from ? to 5 meters thick. The maximum
size of particles in each deposit varied with location and ranged from as
much as 3 cm down to 1 cm in size. At first glance, the density of these
deposits seemed to be about the same. When we screened samples of these
deposits into their component sizes and weighed them we found significant
differences in the densities of different sizes. Larger pieces of pumice
all tended to be lighter (0.25 to 0.35 gr./cc). Smaller sand-sized portions
varied in density from 0.31 gr./cc to 1.13 gr./cc depending on the deposit
from which they came. Finding that smaller particles of pumice are denser
than larger particles in the same deposit is consistent with findings from
pumice deposits in Oregon.

We needed to use only lightweight components in the ceramics in order to end
up with a finished product that had low density. It simplifies the task to
use a portion of pumice from all component sizes. We found two methods to
achieve the desired result. 1.) Combine the lighter sand portion from one
deposit with larger particles from another deposit. 2.) Screen out and
discard the heavy sand?sized material from a coarse deposit and then crush
some of the larger pieces to manufacture some finer, less dense material.
Both approaches proved workable.

Clay

Clay was obtained from a potter in nearby Chalchuapa. The potter processed
this clay himself from local sources. This clay was almost identical to the
mix used by the brick maker in the same neighborhood. He mixed 1 part
?barro negro?(dug from the neighbor?s yard) and about ? part ?barro rojo?
(trucked in from the countryside nearby) with water. He then screened and
dried the resulting thin mud in a large shallow pond. When the mud had
dried to the desired consistency, it was mixed with a small amount of
?tierra blanca? (which I believe to be fine volcanic ash) and used to make a
variety of earthenware pots.
The brick maker used a similar recipe (proportions are often ?eyeballed?
rather than measured exactly) but did not bother to screen the material. He
also added a small amount (5%-10%) of horse manure to the mix for bricks and
?baldosas? or floor tiles.
Terms like ?barro negro? (black clay), ?barro rojo?(red clay), and ?tierra
blanca?(white earth) are used by potters and masons throughout Central
America, but do not necessarily signify identical materials. It?s important
to note that potters or brick makers in a particular area will have
developed their own ?recipes? which produce good ceramics using local
materials.

Brick Kilns

The design of brick kilns varied from country to country. All the kilns we
saw were wood fired. We measured temperatures in various kilns using
pyrometric cones. Kilns in Honduras incorporated a chimney in their ?arched
tunnel? design and reached a temperature in excess of 1050 C. Kilns in El
Salvador were without chimneys and vented through the top of the carefully
constructed stack of bricks. We measured temperatures as low as 700 C in
some parts of these kilns. Temperatures in the center of these kilns were
950 C. In spite of these variations in temperature, good durable bricks
were produced in all cases.

Fabrication of Pumice/Clay Bricks

A ?gradation? of pumice was prepared by screening the raw pumice over a
simple two-deck hand screen to separate the material into three different
sizes, and then recombining measured amounts of each size to produce the
proper mix. The upper screen had an opening of 4.75 mm (#4 sieve) and the
screen below it had an opening of 2.36mm (#8 sieve). Both were mounted on a
simple wooden frame. Using pumice with a maximum natural size of about 12.5
mm (1/2?) produced screened sizes of 12.5 mm to 4.75 mm for the largest
size, 4.75 mm to 2.36 mm for the intermediate size, and 2.36 mm and smaller
for the finest size. These sizes were then recombined by volume as follows:
two parts of the largest size, one part of the intermediate size, four parts
of the smallest size. A large amount of this pumice aggregate was prepared
for use in all bricks.

Trapezoidal molds having a volume of 2075 cc were used to form bricks, which
were about 29 cm long and 6.8 cm thick. After some experimentation we
settled on a formulation of 2725 cc of pumice aggregate, 480 cc of damp
clay, and 750 cc of water to make each brick. Materials were mixed, tamped
into molds and compacted by hand. Molds were removed immediately and the
?green? bricks were allowed to dry in the sun for at least three days.

Pumice bricks were fired with a batch of regular bricks in the kiln at
Chalchuapa. Firing took 24 hours and reached a temperature of 950 C (cone
08). Fired bricks were dark red in color and appeared to be strong enough
for use in stoves. Density of the fired bricks was 0.81 gr./cc. One of
these bricks was brought back from El Salvador and is currently undergoing
laboratory testing. Other bricks were used in the construction of a ?six
brick? rocket stove that is now being field-tested by a family in El Coco.

Cement/Pumice Bricks

Six bricks were made from pumice gradation using cement instead of clay as a
binder. Mike Hatfield of Aprovecho developed several combinations of pumice
and cement. All combinations produced usable lightweight bricks, which did
not require firing in a kiln. One sample formulation was: 2750cc of pumice
aggregate, 500 cc of cement, 900 cc of water. Mike also created a nice
?bucket stove? using local materials, which incorporated these bricks in its
design.

Controversy surrounds the use of cement in refractory ceramics.
Knowledgeable ceramists present convincing arguments why cement is
detrimental. Nonetheless, cement has been an ingredient in recipes for
making castable or insulative bricks or kilns. Ken Goyer of Aprovecho
developed an excellent formula for making lightweight, refractory bricks
from sawdust and a mixture of ? cement and ? clay. A Rocket stove made from
this material has been in regular use for more than a year at temperatures
of around 900 C, and shows no apparent signs of deterioration.

I have made several ceramic materials that incorporated cement along with
clay in the fabrication and have not noted any short-term adverse effects.
I prefer clay without cement but only because cement produces a slightly
heavier material than fired clay.
The big advantage of using cement instead of clay is that it sets up rapidly
and obtains full strength in about three days. No firing in a kiln is
necessary, so it would be easier, and less expensive, to manufacture simple
?market? stoves using this method. Cement/pumice bricks may well have a
limited durability, however. Hopefully, tests to be done at the University
of Dayton will establish how long a cement based brick lasts when exposed to
the higher temperatures in a Rocket type combustion chamber.

?Self-Firing Bricks?

A single experiment was conducted to see if it was possible to ?self fire?
green pumice/clay bricks in place in a rocket-stove combustion chamber. A
pumice/clay brick was inserted in place of one of the cement/pumice bricks
in the ?bucket stove? described above. A fire was started in the stove and
run at ?normal? temperatures for one hour. Using a digital thermometer,
temperatures of 800 C to 850 C were observed in the Rocket combustion
chamber. For the next two hours we attempted to produce the highest
temperatures possible in the stove to ?fire? the bricks. The bottom
portion of the combustion chamber got hot enough to glow orange and appear
translucent from the inside. The highest temperature measured during this
period was 927 C.
After three hours, the temperature on the inside wall of the clay/pumice
brick was measured at 786 C. A thin layer of loose pumice, between the
bricks and the bucket that contained them, prevented outside air from
cooling the outside of the brick. The thin galvanized bucket that contained
the stove got too hot to hold onto comfortably, but not hot enough to cause
a serious burn. The galvanized coating on the bucket was unaffected. The
fire was extinguished and water was poured onto the hot bricks to cool them.
The cement/pumice bricks seemed undamaged by the test. The pumice/clay
brick was fired to a red color only in the inside 2-cm of the brick. The
outside of the same brick was unchanged. The brick as a whole, seemed
sturdy enough to be used in a stove.
Two lessons were learned from this test firing:
1. It is difficult to completely fire a clay/pumice brick in place.
2. Clay/pumice bricks seem to be good insulators.

Conclusions and Recommendations

It is possible to make serviceable insulative refractory ceramics in
countries like El Salvador having natural sources of pumice. Care should be
taken to locate and use the lightest possible pumice available to
manufacture the pumice aggregate to be used in the process. Screening out
and discarding (scalping) heavy sand components from the pumice deposit will
probably be necessary. Pumice pieces larger than 12.5 mm in diameter can be
reduced by crushing the ?scalped? material between two heavy steel cylinders
set approximately 8 mm apart. The resulting product can then be screened and
recombined to produce the pumice aggregate portion of the mix.

Local clay formulations and firing processes could be utilized to make the
bricks. Regardless of the clay formulations or firing temperatures
involved, locally successful ceramic technology should work well to bind the
pumice aggregate together. Pumice/clay stove parts greater than 5 cm in
thickness will probably not require any further insulation and can be
incorporated directly into high mass mud or masonry stove bodies. Using this
or a similar process may make it possible to produce low cost portable
stoves, which not only save fuel but also burn cleaner.

I would like to express my thanks to Stuart Conway of Trees, Water People
and to Patrick Flynn who runs the stove project in El Coco for their help
with this research.

From dstill at EPUD.NET Mon Apr 7 18:14:01 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: Thinking About Wood
Message-ID: <MON.7.APR.2003.151401.0700.DSTILL@EPUD.NET>

Dear Stovers,

Here minus the photos is a description of wood use in El Salvador by Ken
Goyer, stove consultant with Aprovecho. Sending the text with photos to Tom
Miles for inclusion on the webpage.

All Best,

Dean

Thinking About Wood
By Ken Goyer
March, 2003

If you live in a place where wood is your main form of energy you think a
lot about wood. Much of your time is spent gathering, handling, and using
wood, or money is spent to buy it.
In El Salvador, the main unit of wood is the pante. This is a stack of wood
70 centimeters wide, one meter high and four meters long. In the United
States we measure wood by the cord. This is a stack of wood four feet wide,
four feet high, and eight feet long. A pante is about equal to a cord of
wood. ( You can do the math.)
A pante is divided into either 10 or 12 cargas. A carga is determined by how
much your bestia (horse, mule, or donkey) can haul. If you have an old,
small, or worn out bestia you have to make more trips to get a pante.
Carga, think cargo of an animal.
A carga is divided into two large, or three small tercios depending on who
you are talking too. A large bestia can carry three tercios. One on each
side and another on the top. A smaller bestia hauls two tercios. If you
don't have a bestia then you carry one tercio on your back if you are a man,
or on your head if you are a woman. The statistics on neck and back injuries
would be interesting but as they say in the commercials, "Don't try this at
home." Later, I was talking with the health promoter and he says that there
aren't any statistics because neck and back injuries are a way of life here.
Everybody has them.
My friend, Esperanza, summarizes this as follows:
1 pante = 10 cargas
1 carga = 2 large tercios

Esperanza believes that a carga should weigh 2 quintales (200 lbs.) so a
tercio weighs 100 lbs. At 20 tercios per pante this would make a pante weigh
2000 lbs. If you overload a Toyota pickup truck in El Salvador, (The
standard mechanical bestia) you can haul a pante. So 2000 lbs. for a pante
sounds about right. I recall that you cannot haul a full cord of wood in the
United States on an average pickup truck so there is a disparity of
information here. A strong person can carry 100 lbs. So a tercio at 100 lbs.
seems about right.
People agree that a pante costs about C250 (Colones). And a tercio costs
about C20. That puts a premium on a small amount of wood. Esperanza says
that when Miguel gets desperate for money, he will sell her a tercio for $1
(a dollar).
$1 = C8.75 (colones)
C250 = $28.57
The streets of San Salvador have become the dollar store of the country
since the dollar became the legal tender of El Salvador. Everything costs a
"dollar". The other unit of exchange has become the "cuoda". We call it a
quarter. Much confusion has been created by this monetary change to the
dollar and many traditional commodities such as firewood are still valued in
colones even though colones are almost nonexistent.
It takes two days to cut a pante of wood and two more days to make 10 or 12
trips with a bestia to deliver it to your home or a place where it can be
sold, usually near a road. So a hard working, enterprising, healthy, strong
individual can make $7 a day cutting and hauling firewood.
Fidel reminisces about his youth -the years between 1970 and 1978. The only
way that he could make money was to cut and deliver firewood to
Chalatenango. He was paid one colon per carga, which he carried on his back,
since he had no bestia. With 5 colones he could buy a shirt and with 8 to 10
colones he could buy a pair of shoes.
Esperanza says that she uses as much as 5 pantes per year. Three her nephew
cuts, and two she buys. This seems like a lot to me and I thought another
year she told me she used 3 pantes, which she bought by selling a pig she
raised, if it didn't die from "el accidente". I sometimes see her walking
down the road carrying a large branch that she has collected herself, even
though she is eighty years old. For now let's assume that she uses 5 pantes
per year. 5 pantes times 10 cargas/pante times 2 tercios/carga = 100 tercios
per year. Or one tercio every three or four days. So if all of this is true,
she uses 25 or 30 pounds of le?a (firewood) per day. Elena says that she
uses a tercio in three days. Since this is the dry season and there is
little work in the milpa (corn field), many people are putting up their
year's supply of firewood. Three to five pantes is not an uncommon number
for a household.
I had 2000 bricks made for "Estufa Larry," (the six brick stove). The brick
maker used 2 pantes to fire the bricks for three days in the kiln. Only 1700
bricks survived the kiln and as many as 500 more may be defective. So using
4000 lbs. of le?a to make 1200 bricks which will make 200 stoves equals 20
lbs. of le?a per stove. This seems like a good deal considering that this
much wood could be rapidly recovered by the efficient stove. Say in about
one week
All firewood is not equal. A serious turning point in my stove construction
came when I realized that the fire did not thrive in the stove. It turned
out that I had selected some le?a that was "bad". I set about to learn more
about firewood. Short of having a botanical interest one shouldn't try and
learn too much about le?a. There must be about thirty kinds of trees. Only
the old timers know most of them. The younger people will misname them.
Sometimes there are two or more names for the same tree. There is some
firewood that is considered "good" and other that is considered "bad".
"Good" or "bad" may be applied to wood for what we would consider strange
reasons- it has a pretty core, or it's ugly. Some wood is punky and
considered bad, but it burns really good. Some wood is impossible to split.
Much wood has a very high ash content. Some wood is easy to split and burns
with a clean, hot flame. This is the wood that you want to use when you are
demonstrating a stove for the first time, but your audience will know that
you are using good wood. There is nothing more frustrating than showing off
your pride and joy and then not being able to light a fire in it. Still some
wood is so bad it isn't even considered for cooking. It's sold to the brick
makers for use in their kilns. A good stove should be able to successfully
burn bad wood, not to mention wet wood or other fuels such as corn cobs.
Now for the bad news. Since wood is a commodity, it is bought and sold in
the marketplace. If you save wood in an energy efficient stove you can sell
it to somebody else for money. And when you are desperately poor that's
exactly what you do, you sell your assets. I heard of a man selling his
Model T Ford during the depression for five dollars so he could buy food.
Just like Miguel will cut and deliver a tercio of wood for a penny a pound.
Times are hard right now and wood which is the available commodity is being
cut and sold a fast as possible
The good side is that at least the person gets a little bit of money instead
of just burning up the wood. More wood will be cut anyway because there is
still a demand for it. When energy efficient stoves are plentiful enough to
reverse the demand for wood, (or more likely when the supply of wood runs
out), campesinos will grumble about it, the same way they grumble now about
the low price of corn. Energy efficient stoves are a good idea, there just
aren't enough of them (yet) to reverse the devastation that is taking place.

From dstill at EPUD.NET Wed Apr 9 05:44:05 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: Vermiculite/Clay & Charcoal/Clay Refractory Insulative Materials
Message-ID: <WED.9.APR.2003.024405.0700.DSTILL@EPUD.NET>

Dear Friends,

Inspired by the work done by Ken Goyer and Damon Ogle, we've been
experimenting with other recipes at the Aprovecho lab.

400 to 700 grams of moist clay
300 grams of vermiculite
900cc of water

makes a 2100cc trapazoidal brick as shown in the slide show of the 6 brick
Rocket stove. Vermiculite bricks seem to be strong and they weigh less than
two pounds depending on the amount of clay used. Lighter, more insulative
bricks made with 400 grams of moist clay would not stand up to abrasion but
might serve as tunnels of a Lorena stove, for example.

900 grams of moist clay
550 grams of finely ground charcoal
800 cc of water

makes another sturdy, light weight brick weighing one and a half pounds. The
charcoal burns out leaving air holes, resulting in a lighter brick.

Both vermiculite and charcoal bricks were fired at cone 03 or 1060C. about
100 degrees C higher than the operating temperatures of a Rocket stove. The
charcoal/clay recipe was suggested by Dick Boyt a couple of years ago. I
hope that charcoal/clay is as durable as it seems because both of these
materials are common place.

Test samples of both the vermiculite and charcoal mixes are being sent to
Dr. Pinnell and Dr. Andreatta who are analyzing them.

Mix moist clay and water first until the clay is suspended in the water, no
lumps! Then add dry material, mix very well and tamp into molds. After two
days the brick falls out of the mold and after further drying is fired.

All Best,

Dean

From crispin at NEWDAWN.SZ Thu Apr 10 04:20:39 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Vermiculite/Clay & Charcoal/Clay Refractory Insulative
Materials
Message-ID: <THU.10.APR.2003.102039.0200.CRISPIN@NEWDAWN.SZ>

Dear Dean

Regarding the second mix:

>900 grams of moist clay
>550 grams of finely ground charcoal
>800 cc of water

Do you have an idea about the final mass, or alternatively, the dry clay
content? I can't work out how much clay there is from these figures.

Do you think all the charcoal burned out? Would the final weight have no
charcoal content left?

Thanks
Crispin

From dstill at EPUD.NET Fri Apr 11 00:51:33 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: Vermiculite/Clay & Charcoal/Clay Refractory Insulative
Materials
Message-ID: <THU.10.APR.2003.215133.0700.DSTILL@EPUD.NET>

Dear Crispin,

The total weight of a experimental charcoal/clay brick is around 700 grams.
Almost all of the charcoal is burned out so most of the remainder is clay
full of air holes. I'll be writing up a complete report soon on all the
recipes. I think that it is important to finely grind up the charcoal.

Best,

Dean

From tmiles at TRMILES.COM Fri Apr 11 13:16:23 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:20 2004
Subject: Stoves Website Update
Message-ID: <FRI.11.APR.2003.101623.0700.TMILES@TRMILES.COM>

It's a full time job to keep the web site up to date with our active
stovers.

See: http://www.repp.org/discussiongroups/resources/stoves/

Try the Find! search utility on the site. It indexes the site every day so
all recent web pages, documents and pdf files (80 MB) are indexed.

Sjoerd Nienhuys has provided his Research Report on BACIP Wood Stoves for
High Mountain Areas, Pakistan

Ken Goyer writes about fuel use in El Salvador in Thinking About Wood

Damon Ogle gives us more tips about insulating firebrick in his Using Pumice
to Make Lightweight Ceramics in El Salvador

Dean Still has added notes to Aprovecho's Making Insulative Clay Combustion
Chambers

Dean has provided us with a paper on The Effect of Material Choice on the
Combustion Chamber of a Rocket Cooking Stove

Kobus Venter has provided pictures and a description of a charcoal stove he
is developing for Southern Africa. And John Davies is developing a new coal
stove.

We still look forward to reports from the Probec meeting in South Africa and
the Asian (ARECOP) meeting in the Phillipines.

Kind regards,

Tom Miles

From tmiles at TRMILES.COM Fri Apr 11 14:01:05 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:20 2004
Subject: Regional Workshop on Sustainable Improved Cookstove
Dissemination, Cebu PHillipines
Message-ID: <FRI.11.APR.2003.110105.0700.TMILES@TRMILES.COM>

See www.arecop.org for report and presentations

Regional Workshop on Sustainable Improved Cookstove Dissemination with
Special Emphasis on Commercialisation.
Cebu, Philippines 15-18 February 2003
Organised by : Asia Regional Cookstove Program Secretariat (Indonesia) &
APPROTECH Asia (Philippines)

Thirty four participants from 10 countries in Asia and from outside the
region (Brazil, South Africa and Zimbabwe) attended the workshop, held in
Cebu Midtown Hotel, Cebu City.

Ms. Teresita Borra, Director of Energy Utilisation and Management Bureau,
Department of Energy Philipine, delivered the inaugural speech for the
workshop. Keynote speech of the workshop was delivered by Mr. Auke Koopman,
formerly the Chief Technical Advisor of Regional Wood Energy Development
Program - FAO.

The four-day workshop was divided into several sessions : approaches and
strategies to ICS dissemination, ICS commercialisation, technical issues
(design production and quality control), working through markets and roles
of institutions in ICS commercialisation. Each session consisted of paper
presentation and group discussions. Field visits were conducted on the
second day, to an ICS production center (Cebu Pottery Craft & Trade Center)
and ICS retailer, in Carcar district, Cebu. In addition, there was also a
simulation, "ICS Producer, Retailer and Buyer Game", conducted on the second
day. The workshop concluded with participants working out a framework for
ICS commercialisation

From clarky90 at YAHOO.CO.NZ Sun Apr 13 03:49:21 2003
From: clarky90 at YAHOO.CO.NZ (Marc Levine)
Date: Tue Aug 10 18:30:20 2004
Subject: Tin hobo stoves
Message-ID: <SUN.13.APR.2003.034921.0400.CLARKY90@YAHOO.CO.NZ>

Hello all
I am doing post graduate work at the Design Department at the University of Otago,
Dunedin New Zealand. Two years ago I did a research project about tin stoves. I
was inspired by the tin stoves that the New Zealand POWs designed and built in the
Benghazi, Syria POW camp during WW2. There was almost no fuel in the camp so
they deconstructed their huts (turned the 2x8s into 2x4s, removed as much stuctural
timber as possible from the floors and ceilings and turned it into wood chips). They
built forced draft (hand cranked centrifical blowers). I found some drawings in a 1946
NZ govt publication about the POWs. Their were actually quite a few designs. They
were made of kerosene tins and cans from their Red Cross parcels. They were
boiling a liter of water in under 2 minutes! There is nothing like a nice cup of tea.
I am also interested in the old "hobo stoves" made out of the #10 tin cans- the sort
that institutional kitchens get baked beans and stewed tomatos in. You cut a "rat
hole" in the bottom 1/4 and put a series of triangular holes (using the old beer can
opener that no one uses anymore) just below the top rim of the can. They are
stunning little stoves. They cost nothing to make, burn forest litter and are very
efficient. I used one to cook for my wife and two kids on a six week camping holiday
around the South Island 3 years ago. Faster than the gas stove- even having to
rumage around finding bark and twigs to fuel it!
kind regards Marc Levine

From crispin at NEWDAWN.SZ Sun Apr 13 16:16:49 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: New testing protocols for semi-gasifying stoves required
Message-ID: <SUN.13.APR.2003.221649.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

Further to the email I sent a couple of weeks ago about lid-off continuous
boiling tests, I have done a few tests with the lid on to see what issues
came up.

To review, I previously commented on the issues in efficiency testing that
can arise when looking for 'missing water' as the measure of PHU with the
lid on and also system efficiency drops when the lid is on a simmering pot,
which might in act be a characteristic of the stove not burning well at
lower power.

I found something quite unexpected when doing these tests that points out a
real need to immediately review the way in which tests of certain types of
stove are done, in particular semi-gasifiers and gasifiers. If standard
testing protocols are followed there now remains no doubt in my mind that
highly misleading results may be obtained.

Presented here are some figures obtained during continuous boiling tests
with a pot covered with a lid. The pot was brought to a boil first and the
measurements are the time, the water remaining and the fuel still in the
grate. The stove and pot used is the same one in the previous report: a
Vesto with a flat bottomed 230mm dia aluminum pot. The fuel is a low
density hardwood something like poplar. All the tests involve small amounts
of fuel. The wood is assumed to have a heat content of 16 MJ/Kg.

Section 1, Water already boiling

TIME WATER MASS FUEL REMAINING PHU
20:21 3396gm 204gm
20:24 3306 170
20:27 3252 144 Avg 33.9%
Wood largely charcoaled, little flame
20:30 3212 132
20:34 3184 120
20:36 3174 116 Avg 39.4%

Apart from the likelihood of some heat coming from a lowering of the stove's
temperature, there is a significant difference in the PHU when the fire was
older than when is was new. Remembering that this stove is a batch loaded
and air supply-controlled device. The volatiles in the wood burn off prior
to the burning of the charcoal. These two 'fractions' of the wood have very
different heat contents.

Note what happened when only charcoal was burning:

Section 2, Very small amount of fuel
20:42 3070 104
20:45 3024 86
20:48 2996 82 Avg 47.5% eff

I assumed this was at least partly retained heat from the stove body.
Alerted to this significant variation, I refuelled with a single piece of
wood and waited for it to light properly and put the pot back on. These are
the numbers:

Section 3, New wood added
TIME WATER MASS FUEL REMAINING PHU
20:54 2956 216
20:58 2802 132
21:00 2738 112
21:02 2698 104
21:05 2656 96 Avg 35.3%

The 96 grammes left was of course mostly charcoal. One might assume the
test is a reasonable one, partly because the PHU is high and partly because
more than half of the wood was burned. It appears representative. However,
let us divide the 11 minutes in half and look again:

20:54 2956 216
20:58 2802 132
21:00 2738 112 Avg 29.6%

21:00 2738 112
21:02 2698 104
21:05 2656 96 Avg 72.4%

This gives a very different picture. It may be that much more heat is being
wasted when the fire is larger, though an average of 17 gm per minute cannot
be considered unreasonably large or inefficient a fire. Some heat may have
been invested in the steelwork when the fire was larger and recovered as the
burning rate
reduced. On balance through, it appears that the burning of the 'volatiles'
in the wood first does lower the calculated efficiency. Some of that which
is volatile is water and unfortunately I was not able to deduce the 'cost'
of that from the fuel value. But all things considered, it appears that in
principle the point is
demonstrated: early fuel burning is not charcoal in a stove of this type and
the heat value per Kg is not always 16MJ.

If, for example, one were to assign a heat content of 12 MJ/Kg for the
volatiles, and 28MJ/Kg to the (bone dry) charcoal and recalculate the above
PHU figures, we find a PHU of 39.5% for the first 6 minutes and 41% for the
next 5 minutes - about constant. What the heat content figures are is not
as important at this time as understanding the principle involved. Perhaps
someone can provide something far more accurate.

During the first 6 minutes the actual PHU was probably 1/3 higher than it
appeared to be using an average 'heat content of wood' figure. This is a
proportion so large that any test done without observing the condition of
the wood is basically meaningless. During a rapid boiling test of 2 litres
of water, it might only take 6 or 7 minutes and the apparent PHU would be
very misleading. The only thing I can propose at this time is to try to
make sure the fire has some charcoal and some new wood in it during the
whole test.

The effect of retained heat in the stove can clearly be seen in the results
of this tiny charcoal fire burning 1gm per minute:

Section 4, Charcoal only
TIME WATER MASS FUEL REMAINING PHU
21:07 2636 92
21:09 2620 90 113%
21:11 2606 88 98.9%
21:13 2594 86 84.8%
21:15 2584 84 70.6%
21:17 2575 83 127%
Avg
95.7%

Clearly this is impossible.The declining rate of water being boiled off each
minute indicates that the heat input is reducing steadily, even as the
charcoal burning rate was held constant. This is consistent with a cooling
stove body. If the PHU was, for example, 35%, then the boiling rate
indicates an average cooling over the ten minutes of 88 decrees C (the stove
body weighs 6.3 Kg). Obviously the interior would cool more than the
exterior but the average is a pretty constant 8.8 deg per minute.

Taking the test from 20:54 to 21:17, the PHU appears to be 40.5 but one must
remember that heat was invested in the stove body before the test started
and recovered before the end so the calculation gives a number slightly
higher than it really is.

Conclusion

Semi-gasifier stoves like the Vesto and all wood gasifiers which use air
control as the heat regulating mechanism, at least in general terms, tend to
burn the volatiles first and the charcoal later. This can lead to
significant inaccuracies during rapid boiling and initial lighting tests or
if there is a significant amount of unburned charcoal still burning in the
grate at the end of the test.

The real influence of retained heat and water in the wood boiling out before
the charcoal burning gets well under way remains to be assessed.

Sincerely,
Crispin

From dan.asplund at JSP.FI Mon Apr 14 03:49:35 2003
From: dan.asplund at JSP.FI (Dan Asplund)
Date: Tue Aug 10 18:30:20 2004
Subject: International Nordic BIOENERGY2003 Conference.Programme available
Message-ID: <MON.14.APR.2003.034935.0400.DAN.ASPLUND@JSP.FI>

International Nordic BIOENERGY2003 Conference
2-5, September 2003, in City Jyvaskyla in FINLAND

Nordic BIOENERGY2003 Conference with Technical Tours and Bioenergy2003
Exhibition will be held in Finland on September 2nd-5th, 2003
(www.finbioenergy.fi/bioenergy2003).

The most updated and important bioenergy event in the field in the year!
Conference is international and the language is English.

? Conference
? Over 70 oral presentations from all over Europe
? Technical Study Tours
? Poster viewings
? Bioenergy Technology Exhibition
? Wood and Forest 2003 Exhibition
? Social Programmes
.

The Conference is an excellent highway and opportunity into the modern
bioenergy business and technologies used in Finland and Nordic countries.
And it?s more! It?s global like energy itself. Over 70 oral presentations
from all over Europe and also poster viewing guarantee that. You can update
and concrete your knowledge about the modern biomass-based power, heating
and CHP systems, plants and technologies and also the multi-scale
procurement systems and newest R&D-results during the Conference.

Main-organizer is FINBIO with its 100 member companies and organisations in
close co-ordination with SVEBIO (Sweden), DANBIO (Denmark) and NOBIO
(Norway) and also ITEBE (France) and ABA (Austria).

Nordic Bioenergy Conference has been held every second or third year by a
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place in the heart of bioenergy - in Central-Finland in City Jyvaskyla and
arroundings. In Central Finland you can see more bioenergy harvesting
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You can see also information about The BIOENERGY2003 via internet.
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How to register, what hotels, how to go and Conference prices.
See the internet-address: www.finbioenergy.fi/bioenergy2003

From tombreed at ATTBI.COM Mon Apr 14 09:18:12 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:20 2004
Subject: New testing protocols for semi-gasifying stoves required
Message-ID: <MON.14.APR.2003.071812.0600.TOMBREED@ATTBI.COM>

Dear Crispin and All:

First, my compliments to Crispin on getting some science into both the
questions and the answers. Nothing beats scratching your head over results
that seem puzzling, and a lot of things about wood heat are puzzling.

(I remember tests by Jay Shelton showed 10% moisture wood burned
significantly more efficiently than "bone dry" wood in heating stoves.
Reason: In bone dry wood pyrolysis took place in the whole piece, releasing
more volatiles than could be burned in that stove. With 10% moisture the
pyrolysis is localized to the high air combustion area.)

Your comments on lid-on vs lid-off testing are very much on the mark. The
heat of vaporization of water is SO large compared to the energy required
for pyrolysis, that results can be counterintuitive in both the burning and
the boiling. I presume the reality is that competent cooks usually try to
boil away as little water (and flavor and vitamins) as possible, so favor
simmering using lid wherever possible.

~~~~~~~
Here's a suggestion for revising the tests.

An electric stove has very high efficiency (neglecting the 70% loss in
generation/transmission), and the power level can be controlled much better
than any wood or even WoodGas stove. One stove I examined lately used 1.9
kW on the large heating element and 1 kW on the small when they were full
on. (Unfortunately, control at lower levels is maintained by varying the
time that the element is on with a Robertshaw control, but a clip on ammeter
or any voltage sensor would enable you to time the pulses.)
the elements

I hope someone will measure power required to maintain a lid off high boil
and low boil and then incipient boil (simmer) with closed lid. I'll bet
the simmer is 1/10th the power of high boil.

Onward with knowledge instead of guesses... Hope we can agree on a
"realistic stove testing protocol".

~~~~~~~~
I have calculated the heat required for pyrolysis as a function of moisture
content and final temperature, and also the heat required for torrefaction
(pyrolysis below 300 C). I would be happy to send my Excel file to anyone
interested.

Yours truly, TOM REED

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Crispin" <crispin@newdawn.sz>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, April 13, 2003 2:16 PM
Subject: [STOVES] New testing protocols for semi-gasifying stoves required

> Dear Stovers
>
> Further to the email I sent a couple of weeks ago about lid-off continuous
> boiling tests, I have done a few tests with the lid on to see what issues
> came up.
>
> To review, I previously commented on the issues in efficiency testing that
> can arise when looking for 'missing water' as the measure of PHU with the
> lid on and also system efficiency drops when the lid is on a simmering
pot,
> which might in act be a characteristic of the stove not burning well at
> lower power.
>
> I found something quite unexpected when doing these tests that points out
a
> real need to immediately review the way in which tests of certain types of
> stove are done, in particular semi-gasifiers and gasifiers. If standard
> testing protocols are followed there now remains no doubt in my mind that
> highly misleading results may be obtained.
>
> Presented here are some figures obtained during continuous boiling tests
> with a pot covered with a lid. The pot was brought to a boil first and
the
> measurements are the time, the water remaining and the fuel still in the
> grate. The stove and pot used is the same one in the previous report: a
> Vesto with a flat bottomed 230mm dia aluminum pot. The fuel is a low
> density hardwood something like poplar. All the tests involve small
amounts
> of fuel. The wood is assumed to have a heat content of 16 MJ/Kg.
>
> Section 1, Water already boiling
>
> TIME WATER MASS FUEL REMAINING PHU
> 20:21 3396gm 204gm
> 20:24 3306 170
> 20:27 3252 144 Avg 33.9%
> Wood largely charcoaled, little flame
> 20:30 3212 132
> 20:34 3184 120
> 20:36 3174 116 Avg 39.4%
>
> Apart from the likelihood of some heat coming from a lowering of the
stove's
> temperature, there is a significant difference in the PHU when the fire
was
> older than when is was new. Remembering that this stove is a batch loaded
> and air supply-controlled device. The volatiles in the wood burn off
prior
> to the burning of the charcoal. These two 'fractions' of the wood have
very
> different heat contents.
>
> Note what happened when only charcoal was burning:
>
> Section 2, Very small amount of fuel
> 20:42 3070 104
> 20:45 3024 86
> 20:48 2996 82 Avg 47.5% eff
>
> I assumed this was at least partly retained heat from the stove body.
> Alerted to this significant variation, I refuelled with a single piece of
> wood and waited for it to light properly and put the pot back on. These
are
> the numbers:
>
> Section 3, New wood added
> TIME WATER MASS FUEL REMAINING PHU
> 20:54 2956 216
> 20:58 2802 132
> 21:00 2738 112
> 21:02 2698 104
> 21:05 2656 96 Avg 35.3%
>
> The 96 grammes left was of course mostly charcoal. One might assume the
> test is a reasonable one, partly because the PHU is high and partly
because
> more than half of the wood was burned. It appears representative.
However,
> let us divide the 11 minutes in half and look again:
>
> 20:54 2956 216
> 20:58 2802 132
> 21:00 2738 112 Avg 29.6%
>
> 21:00 2738 112
> 21:02 2698 104
> 21:05 2656 96 Avg 72.4%
>
> This gives a very different picture. It may be that much more heat is
being
> wasted when the fire is larger, though an average of 17 gm per minute
cannot
> be considered unreasonably large or inefficient a fire. Some heat may
have
> been invested in the steelwork when the fire was larger and recovered as
the
> burning rate
> reduced. On balance through, it appears that the burning of the
'volatiles'
> in the wood first does lower the calculated efficiency. Some of that
which
> is volatile is water and unfortunately I was not able to deduce the 'cost'
> of that from the fuel value. But all things considered, it appears that
in
> principle the point is
> demonstrated: early fuel burning is not charcoal in a stove of this type
and
> the heat value per Kg is not always 16MJ.
>
> If, for example, one were to assign a heat content of 12 MJ/Kg for the
> volatiles, and 28MJ/Kg to the (bone dry) charcoal and recalculate the
above
> PHU figures, we find a PHU of 39.5% for the first 6 minutes and 41% for
the
> next 5 minutes - about constant. What the heat content figures are is not
> as important at this time as understanding the principle involved.
Perhaps
> someone can provide something far more accurate.
>
> During the first 6 minutes the actual PHU was probably 1/3 higher than it
> appeared to be using an average 'heat content of wood' figure. This is a
> proportion so large that any test done without observing the condition of
> the wood is basically meaningless. During a rapid boiling test of 2
litres
> of water, it might only take 6 or 7 minutes and the apparent PHU would be
> very misleading. The only thing I can propose at this time is to try to
> make sure the fire has some charcoal and some new wood in it during the
> whole test.
>
> The effect of retained heat in the stove can clearly be seen in the
results
> of this tiny charcoal fire burning 1gm per minute:
>
> Section 4, Charcoal only
> TIME WATER MASS FUEL REMAINING PHU
> 21:07 2636 92
> 21:09 2620 90 113%
> 21:11 2606 88 98.9%
> 21:13 2594 86 84.8%
> 21:15 2584 84 70.6%
> 21:17 2575 83 127%
> Avg
> 95.7%
>
> Clearly this is impossible.The declining rate of water being boiled off
each
> minute indicates that the heat input is reducing steadily, even as the
> charcoal burning rate was held constant. This is consistent with a
cooling
> stove body. If the PHU was, for example, 35%, then the boiling rate
> indicates an average cooling over the ten minutes of 88 decrees C (the
stove
> body weighs 6.3 Kg). Obviously the interior would cool more than the
> exterior but the average is a pretty constant 8.8 deg per minute.
>
> Taking the test from 20:54 to 21:17, the PHU appears to be 40.5 but one
must
> remember that heat was invested in the stove body before the test started
> and recovered before the end so the calculation gives a number slightly
> higher than it really is.
>
> Conclusion
>
> Semi-gasifier stoves like the Vesto and all wood gasifiers which use air
> control as the heat regulating mechanism, at least in general terms, tend
to
> burn the volatiles first and the charcoal later. This can lead to
> significant inaccuracies during rapid boiling and initial lighting tests
or
> if there is a significant amount of unburned charcoal still burning in the
> grate at the end of the test.
>
> The real influence of retained heat and water in the wood boiling out
before
> the charcoal burning gets well under way remains to be assessed.
>
> Sincerely,
> Crispin

From jmdavies at XSINET.CO.ZA Mon Apr 14 08:37:59 2003
From: jmdavies at XSINET.CO.ZA (John Davies)
Date: Tue Aug 10 18:30:20 2004
Subject: Probec Workshop - March 10 to 14 2003
Message-ID: <MON.14.APR.2003.143759.0200.JMDAVIES@XSINET.CO.ZA>

Greetings to all Stovers,

This account is my personal view of the workshop.

This workshop organized by Probec, was the second of 2 workshops, and hosted
by the Vaal Triangle Technicon at Vanderbyl Park, close to Johannesburg in
South Africa. The theme was "Efficient use of biomass in stoves and
marketing, in the Southern parts of Africa". I was indeed privileged to
attend this event.

The workshop started off with a welcome, introduction of participants, and
an introduction to efficient
burning of biomass, outlining how biomass burns, and the basic principles
that need to be addressed by the stove developer.

The workshop then got underway, and followed the evolution of the cooking
fire in Africa with each presentation representing improved technology and
how it implemented in different geographical areas. The technology covered
the spectrum from containing the simple fire, and concentrating the heat, in
an enclosure, through to improved combustion
techniques, and right up to full blown gasifier technology. Each
presentation included the features of each stove, how it improved life for
the user, fuel saved.and how it was manufactured and marketed.

Next came practical demonstrations of the stoves on display, with the
delegates moving from stove to stove, exchanging ideas and discussing the
merits of different features.

The final day, was an open day with visitors from government agencies and
other interested parties visiting this event. We were honored to have a
visit from the SADAC minister of "mineral and energy affairs".

This workshop was certainly an eye opener to all delegates, irrespective of
the level of technology they are currently involved with. The people of
Probec are to be commended, for the way in which they brought people
together from sub-Saharan Africa, for 5 days of sharing and learning.

I left the conference with the feeling that there is so much still to be
done, and that only a very small part of this large region was represented,
but of course it would have been impossible to include everybody.

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

Some observations Made.

In each case the results were, that fuel savings of 50% and better were
being achieved as opposed to the traditional methods of the area. A
remarkable aspect of all these stove projects was that the cost to the user
was affordable relative to the socio-economic position of the communities.
Some of the stove applications cost as little as $1.50 , ranging up to $40.

The stoves presented fell into 3 categories.

1 conventional burning, enclosed fire. Believed to be 12 to 15% efficient.

These included mud stoves which are built into the house and various
portable metal and clay, bucket type stoves.

My impression that these stoves, make almost as much smoke as an open fire,
per unit of fuel burned, and rely on the skill of the operator to minimize
this. But do contain and direct the heat to where it is needed. This allows
savings of scarce firewood ranging from 50 to 80 %. The higher figure made
possible by adding biomass waste which would not be practical with an open,
or 3 stone fire.

2. Improved combustion models by way of improved air flow and
increased combustion chamber temperature , which is achieved by, double
walls, insulation and multi layer construction. . Believed to be about 20%
efficient.

These stoves showed reduced smoke, and in many cases were relatively clean
burning once the fire was established. Included the various Toto stoves,
the Rocket types and Eco stove.

3 Stoves with controlled air flows, including gasifier stoves. Believed to
be 25 to 30% efficient.
The application of the technology unfortunately brings these stoves into the
higher price bracket.

These stoves showed really good combustion with bright yellow/ white flames,
only the true gasifier models being virtually smokeless throughout the burn
cycle. The 3 versions present all having some form of air preheat. And air
flow control.

a. VESTO from New Dawn Engineering. This stove has the ability to direct
preheated air to where it is needed in the combustion chamber, in what
appears to be a normal type of fire. We saw this stove operated with a clean
flame varying from a half meter in height to one small enough to simmer a
pot, in all cases clean and bright. Crispin has a winner here.

Gasifier Units – these use a densely packed bed of fuel and are top lit –
with the fuel charge being determined to match the job in hand.

b. Juntos Gasifier Combustion Unit. Paul Anderson demonstrated this
technology burning a variety of biomas. Always had a clean yellow/white
flame, irrespective of the size. Paul has yet to develop this into a stove.

c. My coal Gasifer Stove. This was really the odd one out at a biomass
workshop, but it was designed for a coal burning area with a smoke pollution
problem, where biomass is scarce and has to be transported great distances,
making it expensive. This stove will contribute to conserving trees in an
area where they do not grow naturally.

The stove is top lit and designed for use with a chimney, which is necessary
for indoor use. and gives virtually smoke free combustion throughout the
burn, and instant and fairly constant heat from the initial lighting. This
stove is in the process of commercialization, details of the stove are not
available. Some photos and information will soon be on the stoves web-site.

Conclusion,. Great advancement can be made to the stoves in category 1 and
2 by including some of the more advanced technology. It was observed that
the clay stoves, and those with various refractory linings have a great
potential for advancement without increasing the cost.

My lasting impressions were that all the different projects were equally
successful, in reducing biomass usage. In many cases the smoke emissions
into a building are still far from the ideal, but the participants have
gained new knowledge, which in many cases can be implemented to improve many
stoves. It must be borne in mind that technology can only be implemented if
it is affordable. I am convinced that in many cases affordable ways will be
found to apply this new knowledge.

Regards from South Africa,

John Davies.

From rmiranda at INET.COM.BR Mon Apr 14 19:40:03 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:20 2004
Subject: Regional Workshop on Sustainable Improved Cookstove
Dissemination, Cebu PHillipines
In-Reply-To: <00f801c30054$54299510$6701a8c0@OFFICE3>
Message-ID: <MON.14.APR.2003.204003.0300.RMIRANDA@INET.COM.BR>

Tom and all:

I was present on this workshop, although my ability to full participation
was limited due a strong and weird flue like illness ( I still have
doubts that my illness could have been SARS, since I got it flying from
Hong Kong to Manila).

The workshop was a gathering of stove practitioners from Asia, and my
impression was that most of the people managed very well the topic of the
workshop. This regional common knowledge is mostly due to the long term
regional project support on stoves networking and technological transfer,
by the late RWEDP and actually by ARECOP.

The proceeding of this workshop (which is expected to be available in the
ARECOP web page in a few months) probably will look like a textbook about
stoves commercialization, since it was discussed in deep by the participants.

My impression about the stove technology being promoted in the region, is
that they are focusing in the very low cost stoves (US$ 1 to 3 range), such
as the chimneyless ceramic "anagi stove", the "bucket stove" (charcoal and
wood) and "mud stove". Flue stoves presented were the mud molded like the
indian "chulha stove". Also there was the impressive VESTO from New Dawn
Engineering.

Everyone is claiming 50 to 70% fuel saving, but seems to be mostly based on
anedoctal reports from users.

The chimney less stoves such the Anagi and Mud stoves still generated lots
of smoke, which made me wonder how effective are they if Indoor Air
Pollution is a key concern?

No doubt that at this very low costs and with the commercialization
strategies being used throughout the region, improved cookstoves are much
more popular and accessible to the many in need in Asia.

I personally,coming from Latin America, learned a lot about
commercialization strategies (since we are just starting into this
approach), and as well about manufacturing very low cost stoves. However I
believe Asia countries should learned more about possibly integrating the
"higher efficiency and lower emission" rocket stove burner into their low
cost stoves, and also marketing higher cost/higher quality stoves for more
demanding customers.

Unfortunately in Latin America we haven`t had yet a regional strong stoves
support project, to exchange information, technology, networking and
training, as ProBec (GTZ) has done for Southern African and RWEDP (FAO) and
ARECOP (Dutch) has done for Asia. Only in Central America that Trees, Water
and People has played that role of expanding knowledge, when comes to
woodstoves.

Rogerio

At 11:01 a.m. 11/04/03 -0700, Tom Miles wrote:
>See www.arecop.org for report and presentations
>
>Regional Workshop on Sustainable Improved Cookstove Dissemination with
>Special Emphasis on Commercialisation.
> Cebu, Philippines 15-18 February 2003
> Organised by : Asia Regional Cookstove Program Secretariat (Indonesia) &
>APPROTECH Asia (Philippines)
>
> Thirty four participants from 10 countries in Asia and from outside the
>region (Brazil, South Africa and Zimbabwe) attended the workshop, held in
>Cebu Midtown Hotel, Cebu City.
>
> Ms. Teresita Borra, Director of Energy Utilisation and Management Bureau,
>Department of Energy Philipine, delivered the inaugural speech for the
>workshop. Keynote speech of the workshop was delivered by Mr. Auke Koopman,
>formerly the Chief Technical Advisor of Regional Wood Energy Development
>Program - FAO.
>
> The four-day workshop was divided into several sessions : approaches and
>strategies to ICS dissemination, ICS commercialisation, technical issues
>(design production and quality control), working through markets and roles
>of institutions in ICS commercialisation. Each session consisted of paper
>presentation and group discussions. Field visits were conducted on the
>second day, to an ICS production center (Cebu Pottery Craft & Trade Center)
>and ICS retailer, in Carcar district, Cebu. In addition, there was also a
>simulation, "ICS Producer, Retailer and Buyer Game", conducted on the second
>day. The workshop concluded with participants working out a framework for
>ICS commercialisation

From tmiles at TRMILES.COM Mon Apr 14 22:08:48 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:20 2004
Subject: Stoves Website Update
Message-ID: <MON.14.APR.2003.220848.0400.TMILES@TRMILES.COM>

Thanks to John Davies and Rogerio Miranda for their observations about the
Probec and ARECOP conferences, respectively.

John's coal gasifier stove can be seen on the Stoves pages. Look under New
> Combustion Chambers for "Gasifier Coal Stove John Davies South Africa
April 2003"

Kobus Venter has provided flame pictures of charcoal combustion in his
prototype stove. Find the link to his page below John's.

We've also added links to some of the papers from the ARECOP/Cebu
conference on the Stoves, Country, and Dissemination pages. You will see
the significance of Rogerio's comments as you read the papers from
Cambodia, Laos and Nepal.

http://www.repp.org/discussiongroups/resources/stoves/

Web browsers viewed more than 12,000 stoves pages on REPP/CREST during
March. About 8,200 views were to the Stoves web pages. The remainder were
to current and past stoves archives. A reminder that the stove discussion
archives are now on the web at
http://listserv.repp.org/archives/stoves.html

Tom

From Visser at BTGWORLD.COM Tue Apr 15 04:19:55 2003
From: Visser at BTGWORLD.COM (Piet Visser)
Date: Tue Aug 10 18:30:20 2004
Subject: Stove testing and lids
Message-ID: <TUE.15.APR.2003.101955.0200.VISSER@BTGWORLD.COM>

Dear stovers,

Crispin,

You are right that the volatiles burn of first and the charcoal burns
later, where the rate of the burning of the charcoal depends to a large
extend of the airation of the fuelbed (primary air). At WSG in Eindhoven we
have done a lot of experiments on weightlosses of the fuelbedf under
different conditions, where we have measured the weightloss every 10 seconds.

Based on the work of Brame and King (1967) we have assumed a 80% volatile
20% carbon breakdown of the wood during combustion, resulting, for oven dry
white fir, in 15.2 MJ/kg for the volatiles and 33 MJ/kg for the carbon,
based on 18.73 MJ/kg for the wood.

If you use this model, the power calculated from the weightloss curves
shows a peak during the burning of the volatiles, but the efficiency is
roughly constant (as you have concluded also).

For practical experiments I think it is OK to use the combustion value of
the fuelwood, with a correction for the remaining charcoal, to calculate
the average power and the average efficiency for both the high power and
the low power phase of the waterboiling experiment.

A summary of these weightloss experiments is presented on the cookstove.net
website.

www.btgworld.com

click "links", then

www.cookstove.net

click "final design", then
click "R&D labs"

Best regards,

Piet Visser
_____________________________________________________________

Piet Visser
BTG biomass technology group B.V.
c/o University of Twente
Postal address : P.O. Box 217, 7500 AE Enschede, The Netherlands
Physical address : Drienerlolaan 5, 7522 NB Enschede, The Netherlands

Phone : +31 53 489 2897
Direct : +31 53 489 2889
Fax : +31 53 489 3116
E-mail : Office@btgworld.com
Direct : visser@btgworld.com

==> Visit our website at <http://www.btgworld.com> <==
==> Visit our website at <http://www.ecogas.nl> <==
==> Visit the stove website at <http://www.cookstove.net> <==
_____________________________________________________________

From ventfory at IAFRICA.COM Thu Apr 17 07:35:50 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:20 2004
Subject: Charcoal burning - Pictures & references
Message-ID: <THU.17.APR.2003.133550.0200.VENTFORY@IAFRICA.COM>

Dear Stovers,

Would anyone care to comment on the photo's taken of the flames emitted from my prototype charcoal gasifying stove? I believe that pictures can speak volumes, as words are not always translated into the same mental pictures formed by the readers.
.
The URL is:

http://crest.org/discussiongroups/resources/stoves/Venter/Venterstove/Venterstove.html

As for the absence of the total stove from these pictures (stove body etc) I'd like to quote what Tom Reed said:

>"....I find that most stove tinkerers tend to focus on materials of >construction first and principles last....AIR CONTACT IS THE MOST >IMPORTANT PART OF STOVE DESIGN....So, in stove design, first focus >on the principles - how the pyrolysis will occur, how the resulting gases
>will access oxygen, then worry about....fuel, combustion chamber, >physical structure, and cooking....So, principles first, application second >will get us to a new generation of cookstoves!"

I would like to thank Tom for his wise words here, he has inspired me to tinker till I'm blue (or is that tinker till the flame is blue?). He has also helped me tremendously off-list as well. It may also be interesting to some to note that I have applied in practice, some ideas listed in postings to the list by other stovers. They have all selflessly made comments to help others achieve efficient charcoal burning and I would like to thank them as well, even without them necessarily making a reference to charcoal. They were:

Daniel Dimiduk 1-March, 2002
2-March, 2002

Andrew JH 1-March, 2002
24 May, 2002

Dr. Larry Winiarski/Dean Still
9-April, 2002
22 April, 2002
7-May, 2002
25 May, 2002
20 July, 2002

A.D.Karve 14 April, 2002
8-May, 2002
21 September, 2002

Paul S. Anderson 15-April, 2002
26 October, 2002

Harmon Seaver 15 April, 2002

Kevin Chisholm 14 April, 2002
16 April, 2002
7-May, 2002

Tom Miles 23 May, 2002

Peter Verhaart 25 April, 2002
24 May, 2002

Tom Reed 15 April, 2002
3 May, 2002
24 May, 2002
3 August, 2002
21 September, 2002

John Davies 29 September, 2002

Elsen L. Karstad 15-February, 2002

Steve Layton 11-March, 2002

Tami Bond 7-March, 2002

Grant Ballard-Tremeer 2 May, 2002

Kirk Smith 5 May, 2002

Crispin 25 May, 2002
19 March, 2003
23 March, 2003

I have in fact benefited from all active/participating members, and will continue to do so into the future. The above reference list is mainly for those interested in charcoal burning by households. The archives contain all these postings which corresponds with the dates listed.

The next vital step I feel is to obtain scientific analysis of the flames, and then focus on materials.

Also food for thought -

Charcoal (carbon) - produced by gasification contains much less volatiles than charcoals produced by conventional (polluting) kilns - right? - is this the reason why charcoal gasification is low key on both the stove list and gasification list?

Charcoal gasification could benefit who? - perhaps areas where charcoals are made in a polluting manner, but that is in contrast with the aims of pro-biomass gasification groups advocating means and ways of trying to conserve the air and the natural vegetation.

Simplified - are there biomass pyrolysing systems that could benefit both the environment (less polluting), yet still retain enough volatiles (for blue flame burning) to benefit users of charcoal gasifying stoves?

If not, then at least until large scale clean burning pyrolysing practices are in place the charcoal gasifier could play a major role in reducing indoor pollution in homes where charcoal is the preferred fuel for whatever reason.

Kobus
ventfor@iafrica.com

From psanders at ILSTU.EDU Thu Apr 17 05:09:34 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:20 2004
Subject: Tin hobo stoves
In-Reply-To: <LISTSERV%2003041303492112@LISTSERV.REPP.ORG>
Message-ID: <THU.17.APR.2003.100934.0100.PSANDERS@ILSTU.EDU>

Marc

If the unit you describe was top lighted and actually burned the smoke that
was generated, you are dealing with an important piece of history, what has
become known as an inverted downdraft gasifier (IDD) or a "counter-draft
gasifier".

Please answer about the top lighting and send more information.

I am seldom on line while in Africa, so I hope I will receive your reply.
Please send to the Stoves list serve, not just to me.

Paul
--
Paul S. Anderson, Ph.D.
(In Mozambique until early May)

Quoting Marc Levine <clarky90@YAHOO.CO.NZ>:

> Hello all
> I am doing post graduate work at the Design Department at the University of
> Otago,
> Dunedin New Zealand. Two years ago I did a research project about tin stoves.
> I
> was inspired by the tin stoves that the New Zealand POWs designed and built
> in the
> Benghazi, Syria POW camp during WW2. There was almost no fuel in the camp so
> they deconstructed their huts (turned the 2x8s into 2x4s, removed as much
> stuctural
> timber as possible from the floors and ceilings and turned it into wood
> chips). They
> built forced draft (hand cranked centrifical blowers). I found some drawings
> in a 1946
> NZ govt publication about the POWs. Their were actually quite a few designs.
> They
> were made of kerosene tins and cans from their Red Cross parcels. They were
> boiling a liter of water in under 2 minutes! There is nothing like a nice cup
> of tea.
> I am also interested in the old "hobo stoves" made out of the #10 tin cans-
> the sort
> that institutional kitchens get baked beans and stewed tomatos in. You cut a
> "rat
> hole" in the bottom 1/4 and put a series of triangular holes (using the old
> beer can
> opener that no one uses anymore) just below the top rim of the can. They are
> stunning little stoves. They cost nothing to make, burn forest litter and are
> very
> efficient. I used one to cook for my wife and two kids on a six week camping
> holiday
> around the South Island 3 years ago. Faster than the gas stove- even having
> to
> rumage around finding bark and twigs to fuel it!
> kind regards Marc Levine
>

------------------------------------------------------------
Illinois State University Webmail https://webmail2.ilstu.edu

From crispin at NEWDAWN.SZ Thu Apr 17 14:48:15 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Tin hobo stoves
Message-ID: <THU.17.APR.2003.204815.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

I want to remind you of your own definition of gasifiers in that the 'gas'
should be burned somewhere not immediately adjacent to the pyrolizing area.

By that definition I am not sure that top lighting qualifies something as a
'gasifier'. You could top light anything. That is one way of lighting a
pile of crop residue (in a stove) so that it smokes the least.

What do you think? Isn't it just an "updraft" fire? Or just a 'fire'?

Regards
Crispin

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, April 17, 2003 11:09 AM
Subject: Re: [STOVES] Tin hobo stoves

Marc

Please answer about the top lighting and send more information.

I am seldom on line while in Africa, so I hope I will receive your reply.
Please send to the Stoves list serve, not just to me.

Paul
--
Paul S. Anderson, Ph.D.
(In Mozambique until early May)

Quoting Marc Levine <clarky90@YAHOO.CO.NZ>:

> Hello all
> I am doing post graduate work at the Design Department at the University
of
> Otago,
> Dunedin New Zealand. Two years ago I did a research project about tin
stoves.

From psanders at ILSTU.EDU Fri Apr 18 20:35:35 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:20 2004
Subject: Tin hobo stoves
In-Reply-To: <005f01c30512$424871a0$3149fea9@home>
Message-ID: <SAT.19.APR.2003.013535.0100.PSANDERS@ILSTU.EDU>

Quoting Crispin <crispin@newdawn.sz>:

> Dear Paul
>
> I want to remind you of your own definition of gasifiers in that the 'gas'
> should be burned somewhere not immediately adjacent to the pyrolizing area.

Crispin
the burning can be "immediately adjacent to the pyrolizing area", but should
not be intermingled with it in an indistinguishable and non-separable way. Tom
Reed uses the term "close coupled combustion". Some timed it is VERY close,
but it is separable.

>
> By that definition I am not sure that top lighting qualifies something as a
> 'gasifier'. You could top light anything. That is one way of lighting a
> pile of crop residue (in a stove) so that it smokes the least.

"smokes the least" is not the same as "burns the smoke." And the smoldering
residue is not with controls over the burning of the smoke, even if it is
burning when all is hot enough to sustain the combustion of the smoke.

>
> What do you think? Isn't it just an "updraft" fire? Or just a 'fire'?
>
> Regards
> Crispin
>
--
Paul S. Anderson, Ph.D.
(In Mozambique until early October)

------------------------------------------------------------
Illinois State University Webmail https://webmail2.ilstu.edu

From crispin at NEWDAWN.SZ Sat Apr 19 06:42:12 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Stove testing and lids - Piet
Message-ID: <SAT.19.APR.2003.124212.0200.CRISPIN@NEWDAWN.SZ>

Dear Piet

Thanks for this contribution. Real figures!

Supposing I have air-dried 15% moisture wood, with all the water boiling off
in the pre-charcoal stage. How would the calculation look then?

If I have 240 gm of wood and burn it with relatively little primary air I
might have 80gm of what looks like charcoal left after a time. It seems to
me that the reduction in heat value for the first (half?) of the burn is
quite significant.

The first half of the weight loss goes quite a bit faster than the second
half, time-wise. The PHU figures I have been calculating are going to be
thrown all over the place.

Regards
Crispin

----- Original Message -----
From: Piet Visser <Visser@BTGWORLD.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, April 15, 2003 10:19 AM
Subject: [STOVES] Stove testing and lids

Dear stovers,

Crispin,

If you use this model, the power calculated from the weightloss curves
shows a peak during the burning of the volatiles, but the efficiency is
roughly constant (as you have concluded also).

A summary of these weightloss experiments is presented on the cookstove.net
website.

www.btgworld.com

click "links", then

www.cookstove.net

click "final design", then
click "R&D labs"

Best regards,

Piet Visser
_____________________________________________________________

Piet Visser
BTG biomass technology group B.V.
c/o University of Twente

From crispin at NEWDAWN.SZ Sat Apr 19 16:59:36 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: New testing protocols for semi-gasifying stoves required
Message-ID: <SAT.19.APR.2003.225936.0200.CRISPIN@NEWDAWN.SZ>

Dear Tom

I noticed in reading "Developments in Thermochemical Biomass Conversion"
Conference, Banff, Canada, 20-24 May, 1996 you have the following:

>Power: The heat content of the gas is ~ 18kJ/g, so
>consumption of 4-10 g/m produces 1.2-3.0 kWt .

This is a very different figure for the 'volatiles' reported by Piet quoting
the 1967 source. Is the resulting drop compared with the bone dry wood
because of the 7.8% moisture content? 33 and 18 MJ/Kg are really different
numbers.

>I have calculated the heat required for pyrolysis as a function of moisture
>content and final temperature, and also the heat required for torrefaction
>(pyrolysis below 300 C). I would be happy to send my Excel file to anyone
>interested.

Please send me the file, OK?

Many thanks
Crispin

From crispin at NEWDAWN.SZ Sat Apr 19 17:24:02 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Pyrolysis v.s. Gasification
Message-ID: <SAT.19.APR.2003.232402.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

I am sure this is the right place to ask:

From crispin at NEWDAWN.SZ Sat Apr 19 17:59:43 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Pyrolysis v.s. Gasification
Message-ID: <SAT.19.APR.2003.235943.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

From adkarve at PN2.VSNL.NET.IN Sun Apr 20 22:12:22 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:20 2004
Subject: Pyrolysis v.s. Gasification
Message-ID: <MON.21.APR.2003.074222.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Crispin,
definition is one thing and usage of a word is another. In wood
gasification, the material to be gasified is ignited, but the oxygen supply
is so regulated, that only a part of it burns. The heat generated by the
burning part of the biomass causes the rest of the biomass to pyrolyse.
However, because both the processes occur in the same container, the gas
also contains a lot of nitrogen and carbon monoxide, in addition to the
distillates of wood. In pyrolysis, the woody material is heated in a closed
vessel, without allowing oxygen to enter the vessel. I therefore suggest
that the two processes should be differentiated not by the presence or
absence of water, but by the presence or absence of oxygen.
A.D.Karve
-----Original Message-----
From: Crispin <crispin@newdawn.sz>
To: STOVES@LISTSERV.REPP.ORG <STOVES@LISTSERV.REPP.ORG>
Date: Sunday, April 20, 2003 2:55 AM
Subject: [STOVES] Pyrolysis v.s. Gasification

>Dear Stovers
>
>I am sure this is the right place to ask:
>
>>From http://wwwscience.murdoch.edu.au/teach/n210/lects/fuel/biomas2.pdf
>
>"Gasification: partial combustion of wood in presence of steam to give a
>mixture of CO2, CO and H2
>Pyrolysis: heating of biomass in absence of O2 to give solid char, liquid
>distillate and gases."
>
>I have seen several references to 'pyrolysis fronts' and gasification. Is
>there general agreement on the above definitions?
>
>It seems to me that with real wood containing water, there is a presence of
>steam. Is this enough steam to qualify for a true 'gasification' process
in
>a wood burning stove with inadequate primary air for full combustion? What
>would the liquid distillates be in the absence of steam?
>
>There is even talk of "fast pyrolysis".
>
>I am getting more confused the more I read.
>
>Regards
>Crispin
>

From crispin at NEWDAWN.SZ Mon Apr 21 12:49:09 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: Pyrolysis v.s. Gasification - AD
Message-ID: <MON.21.APR.2003.184909.0200.CRISPIN@NEWDAWN.SZ>

Dear AD

>In wood gasification, the material to be gasified is
>ignited, but the oxygen supply is so regulated,
>that only a part of it burns.

I would say that a charcoal producing stove in is this category, were it
producing a lot less that the 'normal' amount of charcoal.

>In pyrolysis, the woody material is heated in a closed
>vessel, without allowing oxygen to enter the vessel.

Well, as you said, there is pyrolysis going on even in the gasification
process. I am not comitted to any answer here, it is just that when one
builds a stove that has only a 2mm hole as an air supply it tantamount to a
retort - almost. I supposed that almost none of the char is gassed off in
that circumstance. I was wondering why that is not called a 'pyrolyzer'
instead of a gasifier.

It matters if one is looking at putting in a fan on a stove to promote
combustion. If you knew in advance that a pyrolyzer will benefit from a fan
more than a gasifier, one starts off on a different tack when doing the
design. If the products of pyrolysis are significantly different from
gasifier products, then one would expect a different response to puttin a
blower into the system. The one with heavier vaporized liquids will benefit
more, I think.

Tami says that coal gases are not fundamentally different from wood gases in
that they are pretty light (I am not suggesting they are the same gases
chemically). If coal was pyrolyzed instead of gasified it would be quite a
different combustion problem.

I therefore suggest that the gases one is trying to burn in the 'visible
flame' section of a stove would fall into two categories, as you suggest,
with and (substantially) without oxygen.

Clearly wood or coal pyrolyzes away from the intense heat and those products
are re-heated as they get closer to the flames (or hot coals) and
re-constituted or vaporized into 'gasses' and then burned directly, feeding
heat back to continue the reaction chain.

If the separate addition of secondary air is required to complete combustion
then one could argue that the stove is a gasifier as it is producing a lot
of incompletely combusted products/gases below the secondary air injection
stage. On the other hand, unless this was not contained in a combustion
chamber (an open fire) the seconday air is free to join in at any stage up
the flame ladder.

I am still convinced that all fires are gas fires, that some stoves are
gasifiers, and that some 'gasifiers' are pyrolyzers, and also that some
'gasifiers' in name are, on analysis, simply stoves.

As for the steam angle, perhaps that is just a cheap and controllable method
of heating wood to drive out gases, though I do follow the chemical reaction
produced by the steam.

Thanks!
Crispin

From tombreed at ATTBI.COM Mon Apr 21 15:35:28 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:20 2004
Subject: Charcoal burning - Pictures & references
Message-ID: <MON.21.APR.2003.133528.0600.TOMBREED@ATTBI.COM>

Dear Kobus;

Beautiful pictures, worth at least 10,000 words.

The world needs a good charcoal burning cookstove as much as a good
woodburning one. It would be nice to combine both at once, but this
requires control over the air fuel ratios, as well as total air. You are on
the right track and I applaud the use of the riser sleeves at this point.

The pictures look somewhat like our "inverted downdraft" stoves look burning
the charcoal after the wood is gone. The problem for us is that at this
stage it is necessary to increase primary air and decrease secondary air.
Your two 3/4 inch holes seem to be burning the CO nicely, but I would
recommend more smaller holes with the same area.

It is also useful to limit the flow of gases upward with a bluff body so
that you get a ring of heat and better draft. The gases from that area of
charcoal can't fill the upper chamber, and so result in instability as some
gases rise and others fall.

I hope you'll keep us posted on future progress...

Yours truly, TOM REED
BEF STOVEWORKS

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Kobus" <ventfory@IAFRICA.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, April 17, 2003 5:35 AM
Subject: [STOVES] Charcoal burning - Pictures & references

Dear Stovers,

http://crest.org/discussiongroups/resources/stoves/Venter/Venterstove/Venter
stove.html

As for the absence of the total stove from these pictures (stove body etc)
I'd like to quote what Tom Reed said:

>"....I find that most stove tinkerers tend to focus on materials of
>construction first and principles last....AIR CONTACT IS THE MOST
>IMPORTANT PART OF STOVE DESIGN....So, in stove design, first focus >on the
principles - how the pyrolysis will occur, how the resulting gases
>will access oxygen, then worry about....fuel, combustion chamber, >physical
structure, and cooking....So, principles first, application second >will get
us to a new generation of cookstoves!"

I would like to thank Tom for his wise words here, he has inspired me to
tinker till I'm blue (or is that tinker till the flame is blue?). He has
also helped me tremendously off-list as well. It may also be interesting to
some to note that I have applied in practice, some ideas listed in postings
to the list by other stovers. They have all selflessly made comments to
help others achieve efficient charcoal burning and I would like to thank
them as well, even without them necessarily making a reference to charcoal.
They were:

Daniel Dimiduk 1-March, 2002
2-March, 2002

Andrew JH 1-March, 2002
24 May, 2002

Dr. Larry Winiarski/Dean Still
9-April, 2002
22 April, 2002
7-May, 2002
25 May, 2002
20 July, 2002

A.D.Karve 14 April, 2002
8-May, 2002
21 September, 2002

Paul S. Anderson 15-April, 2002
26 October, 2002

Harmon Seaver 15 April, 2002

Kevin Chisholm 14 April, 2002
16 April, 2002
7-May, 2002

Tom Miles 23 May, 2002

Peter Verhaart 25 April, 2002
24 May, 2002

Tom Reed 15 April, 2002
3 May, 2002
24 May, 2002
3 August, 2002
21 September, 2002

John Davies 29 September, 2002

Elsen L. Karstad 15-February, 2002

Steve Layton 11-March, 2002

Tami Bond 7-March, 2002

Grant Ballard-Tremeer 2 May, 2002

Kirk Smith 5 May, 2002

Crispin 25 May, 2002
19 March, 2003
23 March, 2003

I have in fact benefited from all active/participating members, and will
continue to do so into the future. The above reference list is mainly for
those interested in charcoal burning by households. The archives contain
all these postings which corresponds with the dates listed.

The next vital step I feel is to obtain scientific analysis of the flames,
and then focus on materials.

Also food for thought -

Charcoal (carbon) - produced by gasification contains much less volatiles
than charcoals produced by conventional (polluting) kilns - right? - is this
the reason why charcoal gasification is low key on both the stove list and
gasification list?

Charcoal gasification could benefit who? - perhaps areas where charcoals
are made in a polluting manner, but that is in contrast with the aims of
pro-biomass gasification groups advocating means and ways of trying to
conserve the air and the natural vegetation.

Simplified - are there biomass pyrolysing systems that could benefit both
the environment (less polluting), yet still retain enough volatiles (for
blue flame burning) to benefit users of charcoal gasifying stoves?

If not, then at least until large scale clean burning pyrolysing practices
are in place the charcoal gasifier could play a major role in reducing
indoor pollution in homes where charcoal is the preferred fuel for whatever
reason.

Kobus
ventfor@iafrica.com

From crispin at NEWDAWN.SZ Wed Apr 23 07:30:04 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:20 2004
Subject: The gas heat value question to Tom Reed
Message-ID: <WED.23.APR.2003.133004.0200.CRISPIN@NEWDAWN.SZ>

Dear Tom

I was thinking about the post the other day in which I asked about the heat
value of the gases. I was making typos and thinking backwards at least part
of the time. Sorry about that.

Let me put it this way:

The heat value of gas you quoted in your 1996 paper was about 18MJ/Kg. The
one cited by Piet was 15.2. That is the difference I was asking about.

Is there general agreement on the carbon content of wood(s) and therefore
the volatiles content? The man in Hawaii making charcoal under pressure
said, I recall, something about it being a 45% yield of a 'high volatiles'
charcoal or something to that effect. I am sure that doesn't mean it was a
wood with a 45% carbon content, but more that it looked and worked like
charcoal.

If you get 20-25% yield of charcoal in a gasifier, what does that mean about
the original proportion that was carbon?

I am drafting a general case formula for calculating the heat yielded during
a test of a semi-gasifier like the Vesto or a gasifier where there is
significant charcoal left in the combustion chamber at the end. How much of
the original wood is charcoal and how much is carbon?

The water has to be gone by the time the charcoal appears, so there is a
loading of the detrimental effect of wood moisture to the front of the burn.
I want to get this into the calculation. Whenever there is charcoal left
after a test burn, it should be included in the calculation as dry charcoal,
that than 'wood'.

Regards
Crispin

From dstill at EPUD.NET Thu Apr 24 21:00:17 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: Fw: Great grates?
Message-ID: <THU.24.APR.2003.180017.0700.DSTILL@EPUD.NET>

Dear Friends,

Damon Ogle and Mike Hatfield observed in their recent trip to Central
America that the shelf placed in the fuel magazine of the Rocket stoves
which lifts the sticks of wood up off the floor of the combustion chamber)
was frequently put aside by users who first placed sticks of wood directly
on the floor of the combustion chamber and then after a while, on top of the
glowing coals.

Damon and Mike wondered whether including a shelf was important. Luckily,
researchers become opinionated only if they get lazy...Damon set up a test
stove in the lab and he and I ran nine one hour water boiling tests. The
same stove was tested three times with 1.) a horizontal sheet metal shelf
2.) then without it, 3.) then with a solid brick shelf in the feed magazine
that blocked air from passing under the shelf and allowed primary air to
feed
the fire in the combustion chamber from underneath a metal grate in the
floor
of the combustion chamber. Air was drawn directly up through the fire. Check
out a drawing of the shelf concept in the Rocket combustion chamber on the
Aprovecho stove page at www.efn.org/~apro

After averaging the results from the three tightly grouped series of tests,
the simple shelf improved efficiency by 14%. The solid shelf with under fire
air improved efficiency by 35.7 %.

The amazing Sam Baldwin, in the best book yet written on cookstoves,
"BIOMASS STOVES: ENGINEERING DESIGN, DEVELOPMENT, AND DISSEMINATION"
reported improving efficiency from 18% to 25% by using a grate on a
"malgache" metal stove. This represents an improvement of 38.8%, which
parallels our findings.

Grates that allow air to pass under and up through the burning sticks can
have a significant positive effect on efficiency.

Both Damon and I also observed that fewer coals are produced by using a
shelf or grate. But further testing is needed to determine the extent of the
difference. More hours staring into the fire!

All Best,

Dean Still
Damon Ogle

From dstill at EPUD.NET Thu Apr 24 22:27:53 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:20 2004
Subject: experiments vs opinions
Message-ID: <THU.24.APR.2003.192753.0700.DSTILL@EPUD.NET>

Dear Friends,

My energetic friend Damon, who is around 50 years old like me, answers many
questions about stoves with the simple reply: "Let's test it! And be sure!"

Like him, I think that finding out the truth is usually just a lot of simple
work. Experiments take time and it's necessary to repeat and repeat the
work for accuracy...

Education which is not based on experimental observation is often the
reading of others work, and historical summaries. What percentage of the
work is faulty? Who knows what part of books is truth or fiction? I find
that many of the books about cooking stoves are incorrect in vital ways.
Summaries in Scientific American are not entirely accurate. Garbage in,
garbage out, you know...

In my opinion, the quickest way to answer a question is to perform a test of
it. True for psychology, true for engineering. Experimental education is the
fastest route to useable knowledge even if it takes a long time. At least
you make progress...A lot of university education has very smart folks
reading many books, but I end up thinking that to a large extent this is an
unfortunate waste of time. The garbage in books is carefully hidden and can
only be identified by experimentation, which, in my experience, is far too
tedious and boring for most younger folks to endure.

It's so much easier and fun to be opinionated. The love of a subject can
take years to develop. Older folks, who hopefully have jumped through
thousands of trees and enough bedrooms, are usually the ones ready to settle
down and do a bit of hard work. Younger folk, and rightly so, have a lot of
very important things to do, to invent themselves. At least at Aprovecho, it
is usually the grey haired crew who fall in love with a certain aspect of
nature, and are motivated to do the careful observing necessary to try to
uncover, for example, secrets of fire.

I have to drink a lot of coffee to pay attention, these days. I'm glad that
Damon is around!

All Best,

Dean

From yark at U.WASHINGTON.EDU Fri Apr 25 03:17:19 2003
From: yark at U.WASHINGTON.EDU (Tami Bond)
Date: Tue Aug 10 18:30:20 2004
Subject: [ethos] experiments vs opinions
In-Reply-To: <002101c30ad2$5ebc1420$401e6c0c@default>
Message-ID: <FRI.25.APR.2003.001719.0700.YARK@U.WASHINGTON.EDU>

Dear Dean,

first you say:
> In my opinion, the quickest way to answer a question is to perform a test of
> it. True for psychology, true for engineering. Experimental education is the
> fastest route to useable knowledge even if it takes a long time.

and then:
> It's so much easier and fun to be opinionated. The love of a subject can
> take years to develop.

Why, your whole message was an opinion! :-)

I think you have fallen in love with testing and that's great. YES we need
more stove testing! But all of chemistry, physics, and meteorology was
initiated by passionate observationalists who then made the next leap-- to
simple laws that could be communicated with the simple language of
mathematics. That admittedly has become overblown, but don't sneeze at
shortcuts to knowledge when they present themselves. Time is short, after
all...

> Older folks, who hopefully have jumped through
> thousands of trees and enough bedrooms, are usually the ones ready to settle
> down and do a bit of hard work.

You're saying that swinging between trees and partners must precede stove
experimentation? My oh my, what's on schedule for the next ETHOS meeting?
;-)

Tami

From Gavin at AA3GENERGI.FORCE9.CO.UK Fri Apr 25 03:09:26 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:21 2004
Subject: experiments vs opinions
In-Reply-To: <002101c30ad2$5ebc1420$401e6c0c@default>
Message-ID: <FRI.25.APR.2003.080926.0100.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Dean,
As a practical man I agree. And within the "black art" that is stove design
experimental verification is necessary and isn't "playing with matches" when
Mom isn't looking half the reason were all doing this (here in the electric
range west at least?)
However for the development of humankind ( in a technical sense:- how to
blow ourselves up and destroy the world in the quickest time kinda thing) we
would all still be experimenting to be sure that a round wheel was best if
we don't accept given knowledge.
For instance my grandfathers PhD paper in Physical science was a teaching
resource for my high school- except it was out of date and superceded by the
time I studied.

To move forward we need to understand first (and second) principles but
don't need to demonstrate them al the time.

Keep up the good work and really relevant postings

Gavin (the haggis hunter!)
Gavin Gulliver-Goodall
3G Energi,

Tel +44 (0)1835 824201
Fax +44 (0)870 8314098
Mob +44 (0)7773 781498
E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>

The contents of this email and any attachments are the property of 3G Energi
and are intended for the confidential use of the named recipient(s) only.
They may be legally privileged and should not be communicated to or relied
upon by any person without our express written consent. If you are not an
addressee please notify us immediately at the address above or by email at
Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>. Any files attached to
this email will have been checked with virus detection software before
transmission. However, you should carry out your own virus check before
opening any attachment. 3G Energi accepts no liability for any loss or
damage that may be caused by software viruses.

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
Of Dean Still
Sent: Friday, April 25, 2003 3:28
To: STOVES@LISTSERV.REPP.ORG
Subject: [STOVES] experiments vs opinions

Dear Friends,

My energetic friend Damon, who is around 50 years old like me, answers many
questions about stoves with the simple reply: "Let's test it! And be sure!"

Like him, I think that finding out the truth is usually just a lot of simple
work. Experiments take time and it's necessary to repeat and repeat the
work for accuracy...

I have to drink a lot of coffee to pay attention, these days. I'm glad that
Damon is around!

All Best,

Dean

From dstill at EPUD.NET Fri Apr 25 04:33:50 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:21 2004
Subject: experiments vs opinions
Message-ID: <FRI.25.APR.2003.013350.0700.DSTILL@EPUD.NET>

Dear Friends,

I don't know many folks who really use all that math and extensive
preparation when they are designing, developing a simple tool to help poor
folks. Larry Winiarski may be the exception but he will be the first to tell
you that a lot of the most important stuff he has learned came from his Boy
Scout instructor.

Let's think about stoves for example...Who would develop the best stove
more quickly: a serious student with a library and computer or a serious
student who made prototypes and tested them as evidence suggested better
evolutions? The serious student with the computer wouldn't know when an
assumption was faulty without experimentation and so far the models are not
accurate. Making prototypes of simple things can happen pretty quickly.

Perhaps more importantly, the hardest part of inventing is development which
can only happen by experimentation/feedback. Is it fair to say that
DESCRIPTION FOLLOWS LEARNING when we're talking about tools?

Shall I be really radical and suggest that the prepared mind can be just as
troubled, slowed, confounded by accepted errors as the unprepared mind,
beginning the study, is by having to learn how to observe? Most AT designers
still believe that earth is good insulation. They read that in books
published by ITDG/VITA. Reading books can be hazardous to progress!

Who would start the study in a more evolved state: the student who read
books, half of which are wrong, or the student who walked around villages
that had nearly run out of firewood, observing stoves?

I believe that someone like Mark Bryden will eventually complete a accurate
mathematical model of a cookstove. Won't he be able to do so by describing
what some experimentalist observed through trial and error? In that golden
age, of accurate mathematical models, university learning will be of direct
use to poor folks but so far, to the best of my knowledge, accurate models
that create best vernacular tools do not yet exist. University testing,
describing what occurs, helps in the here and now.

IMO, if the goal of learning is to reduce human suffering, then experimental
education starting from direct observation of the tool to be evolved, as it
is used in practice, will produce most efficient progress. Could be
wrong...but in my defense remember that I see naive humanists at Aprovecho
every week who do things like double the efficiency of a wood fired
dehydrator by playing with it, and noting when fruit dries faster. After a
month of drying fruit, the poetry spouting, ragged, math hating children of
god tell me that for the first time in their life they understand a machine.
From tmiles at TRMILES.COM Fri Apr 25 14:05:27 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] Re: experiments vs opinions
Message-ID: <FRI.25.APR.2003.110527.0700.TMILES@TRMILES.COM>

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
>Most AT designers still believe that earth is good insulation. They read
that in books published by ITDG/VITA. Reading books can be hazardous to
progress!

To paraphase Will Rogers (See Will Rogers says http://www.willrogers.org/) :
"All I know is what I read on the Internet."

So if we tell the right story on the Internet maybe we can make some
progress.

Tom

From dstill at EPUD.NET Fri Apr 25 18:03:22 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:21 2004
Subject: great grates?
Message-ID: <FRI.25.APR.2003.150322.0700.DSTILL@EPUD.NET>

Dear Friends,

A diagram showing the shelf in the Rocket combustion chamber can be found
at:

http://www.efn.org/~apro/AT/atrocketpage.html

Is the improvement in efficiency sufficient reason to reinforce efforts to
include shelves in the Rocket? I agree with Laurie Childers (on ETHOS) that
shelves are thrown away for good reasons. It's an interesting topic of
conversation...

Best,

Dean

Best,

Dean

From Carefreeland at AOL.COM Sat Apr 26 01:08:23 2003
From: Carefreeland at AOL.COM (Carefreeland@AOL.COM)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] experiments vs opinions
Message-ID: <SAT.26.APR.2003.010823.EDT.>

In a message dated 4/25/03 3:19:55 AM Eastern Daylight Time,
yark@U.WASHINGTON.EDU writes:

>
> You're saying that swinging between trees and partners must precede stove
> experimentation? My oh my, what's on schedule for the next ETHOS meeting?
> ;-)
>
> Tami
>

DD It's all about "free radicals" bouncing around in the firebox anyway isn't
it? Maybe if we studied monkeys behavior at a ballroom dance, we would
understand combustion chemistry better anyhow. ;-)

DD As far as combustion chambers made of dirt? It all depends who's dirt we
are using. I study dirt for a living, and I can assure you that one man's
dirt can make a much better combustion chamber than another. Maybe the book
wasn't wrong, it was just a comment based on local studies. Start by asking
how wet the dirt was when the fire was lit? Just food for thought.

DD I made a rather clean burning fire today in the dump during a rainshower.
I burned several cubic yards of damp rotting discarded construction lumber,
by alternating drier cut honeysuckle brush between thin layers of lumber.
You could say it was like a 3 stone fire, except that the stones in this case
were a pile of discarded chunks of concrete slabs the size of boulders.
Metal reclaimed from the rotten wood piles will also be recycled.
DD I top lit the fire, and burned a ragged polyethylene tarp over the wood to
rapidly establish a high temperature and coals. Once the concrete heated up,
the fire became much cleaner burning. The honeysuckle brush formed an
afterburner helping to flare the unburned gas and smoke. The rain acted as
my final smoke scrubber, bringing the particles, CO2 and fly ash back down to
earth to fertilize the inert reclaimed ground. Rain also protected the rest
of the area from the real risk of a wildfire in the dump. Part of the goal
here is to establish firebreaks.
DD I can't say I was happy to waste the energy, but I doubt that I could have
burned that damp rotten wood as cleanly in any small woodstove. The benefit
in this case is reclaimed landfill space now ready for a final covering of
clean discarded earth from a construction site. The future use of this space
is for growing seedling trees in containers. I didn't pollute the site, and
can only benefit the earth by cleaning it up as efficiently as possible. That
is more useful land where a dump once stood, and land is a valuable resource
too.
DD By clean burning this wood, I am also substituting CO2 production for
natural methane production. This is a net plus for greenhouse gas reduction.

DD The point of this, is that knowledge is where we find it, and cookstoves
aren't the only use of good combustion knowledge. Sometimes I get lost on
this list in cookstove testing "statistic heaven." I wish I could go back to
watching blastfurnaces, burning twigs to cook hamburgers, and playing with
matches in the garden. I'll have to settle for cleaning up part of a 40 year
old dump for today, all I get out of it is land to grow trees on, but that's
just an opinion.
Dan Dimiduk

From tombreed at ATTBI.COM Sat Apr 26 08:32:29 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:21 2004
Subject: Ice ages and Humans? Earth Day
Message-ID: <SAT.26.APR.2003.063229.0600.TOMBREED@ATTBI.COM>

Dear Cu Lynn:

You said...

>I tend to believe the more positive views:
that Mother Earth is very strong and very smart and can heal herself, as
she does everyday, in combination with the sun.

~~~~~~~~
Right on! We tend to assume responsibility for all the ills of the world,
whereas it existed quite nicely, thank you, before humans arrived and will
probably bumble along after we leave (or are thrown out).

Here's a new thought. Humans began to develop from simians about 3 million
years ago. The first ice age was about 2 million years ago and we've had a
dozen since then. A mile deep pile of ice across the continents really
tears up the landscape. Coincidence?

Uncle TOM

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: "Lynne D. Duesenberg" <LDuesenberg@compuserve.com>
To: "Tom Reed" <tombreed@attbi.com>
Sent: Sunday, April 20, 2003 10:30 AM
Subject: Re: Earth Day

Tom,

Thanks for your input. I looked at the Arapahoe library site and they have
1 of the three books, one copy checked out and one on the shelf. I agree,
the environmentalists have gone way overboard. Makes you wonder at the
intelligence of some of the people that buy the more absurd things they
say! I think they're so intent on finding something negative, they'll
believe anything sometimes!! I tend to believe the more positive views:
that Mother Earth is very strong and very smart and can heal herself, as
she does everyday, in combination with the sun.

See you soon!
Love, Cuz Lynne

From rstanley at LEGACYFOUND.ORG Sat Apr 26 10:46:55 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:21 2004
Subject: experiments vs opinions
Message-ID: <SAT.26.APR.2003.174655.0300.>

Out here in the as yet to be globalised world, I have found some of the best
and most innovative practical thinkers to be amongst the simple ubiquitos,
development- invisible population of street fundis (small shop tinkerers) who
have little more than their imagination and scrap to work with in resolving
daily problems..

A dozen such kids given the support and encouragement to focus on real life
technical development problems, with exposure to other's experience globally
(through such basic access to such conducive and rich information exchange
environments as provided stoves group !) and a no frills digital camera, and
you have one of the best locally applied r&d bases you can hope for.

Tammy suggeste we take advantage of the principles which have accumilated from
experience. I interpert that here as mentored discussion&debate over
observations of infomation gained through focused internet access and
relevent site visits locally. Dean suggests we stick to immedaite hands on
expeimentation: thats certainly a foundation to the process that one cannot
ignore but it should not and need not happen in isolation.

I feel that both of you are right if you take the process iteratively and with
a sence of humility in a working environment which allows the feedom to make
mistakes efficiently and which provides for practical information access and
exchange.

But that is not what is happening in the development game: Directed by those
with notmuch more than paper degrees and little or no field expeience,
innovation is (as the enemy of institutional thinking ) subverted and boxed
into a corner of regulations to make life safe, consistent , secure. (this
begins to sound a lot like George's world but I wont go there). How many of
the polytechs and engineering labs and development institutes host the
philosophy that the student must not begin their research until the subject is
fully understood !

We must learn as the teachers have learned, not as they teach. Accumilated
foundations in the sciences and internet email contact can either greatly
benefit this approach or it can snuff it out:

Outside the bubble,

Richard Stanley

Gavin Gulliver-Goodall wrote:

> Dean,
> As a practical man I agree. And within the "black art" that is stove design
> experimental verification is necessary and isn't "playing with matches" when
> Mom isn't looking half the reason were all doing this (here in the electric
> range west at least?)
> However for the development of humankind ( in a technical sense:- how to
> blow ourselves up and destroy the world in the quickest time kinda thing) we
> would all still be experimenting to be sure that a round wheel was best if
> we don't accept given knowledge.
> For instance my grandfathers PhD paper in Physical science was a teaching
> resource for my high school- except it was out of date and superceded by the
> time I studied.
>
> To move forward we need to understand first (and second) principles but
> don't need to demonstrate them al the time.
>
> Keep up the good work and really relevant postings
>
> Gavin (the haggis hunter!)
> Gavin Gulliver-Goodall
> 3G Energi,
>
> Tel +44 (0)1835 824201
> Fax +44 (0)870 8314098
> Mob +44 (0)7773 781498
> E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>
>
> The contents of this email and any attachments are the property of 3G Energi
> and are intended for the confidential use of the named recipient(s) only.
> They may be legally privileged and should not be communicated to or relied
> upon by any person without our express written consent. If you are not an
> addressee please notify us immediately at the address above or by email at
> Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>. Any files attached to
> this email will have been checked with virus detection software before
> transmission. However, you should carry out your own virus check before
> opening any attachment. 3G Energi accepts no liability for any loss or
> damage that may be caused by software viruses.
>
> -----Original Message-----
> From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
> Of Dean Still
> Sent: Friday, April 25, 2003 3:28
> To: STOVES@LISTSERV.REPP.ORG
> Subject: [STOVES] experiments vs opinions
>
> Dear Friends,
>
> My energetic friend Damon, who is around 50 years old like me, answers many
> questions about stoves with the simple reply: "Let's test it! And be sure!"
>
> Like him, I think that finding out the truth is usually just a lot of simple
> work. Experiments take time and it's necessary to repeat and repeat the
> work for accuracy...
>
> Education which is not based on experimental observation is often the
> reading of others work, and historical summaries. What percentage of the
> work is faulty? Who knows what part of books is truth or fiction? I find
> that many of the books about cooking stoves are incorrect in vital ways.
> Summaries in Scientific American are not entirely accurate. Garbage in,
> garbage out, you know...
>
> In my opinion, the quickest way to answer a question is to perform a test of
> it. True for psychology, true for engineering. Experimental education is the
> fastest route to useable knowledge even if it takes a long time. At least
> you make progress...A lot of university education has very smart folks
> reading many books, but I end up thinking that to a large extent this is an
> unfortunate waste of time. The garbage in books is carefully hidden and can
> only be identified by experimentation, which, in my experience, is far too
> tedious and boring for most younger folks to endure.
>
> It's so much easier and fun to be opinionated. The love of a subject can
> take years to develop. Older folks, who hopefully have jumped through
> thousands of trees and enough bedrooms, are usually the ones ready to settle
> down and do a bit of hard work. Younger folk, and rightly so, have a lot of
> very important things to do, to invent themselves. At least at Aprovecho, it
> is usually the grey haired crew who fall in love with a certain aspect of
> nature, and are motivated to do the careful observing necessary to try to
> uncover, for example, secrets of fire.
>
> I have to drink a lot of coffee to pay attention, these days. I'm glad that
> Damon is around!
>
> All Best,
>
> Dean

From dstill at EPUD.NET Sun Apr 27 03:33:04 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:21 2004
Subject: Stove Testing and Design Seminar June 2 to 6
Message-ID: <SUN.27.APR.2003.003304.0700.DSTILL@EPUD.NET>

Dear Stovers:

So far we have in the Aprovecho lab: the most recent Vesto stove, a Juntos
stove, a Jiko stove, and a Rocket stove for testing. I'm hoping to have a
Turbo stove as well.

We're building the new hood and set up. The Enerac 3000E combustion analyzer
is working , we also have the PICO working for temperatures and a separate
set up room measurement of CO using the HOBO monitor. My plan is to do 3
tests of each stove (Monday, Tuesday) revolving the teams between two
stations. A third station will be various lectures and things like
insulative brick making, etc.) My hope is that we are finished with testing,
water boiling and emissions after two days. Then we can get down to the fun
part of building prototypes and seeing how our changes improve stoves. The
last day, Friday, I see as a general discussion of what we've learned
followed by plans for continuing research.

We have about 7 folks signed up now with room for say three more. I'd like
to do this Stove Testing and Design Seminar every year to give our stove
community shared experience.

All Best,

Dean

From hseaver at CYBERSHAMANIX.COM Sat Apr 26 13:55:26 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:21 2004
Subject: Ice ages and Humans? Earth Day
In-Reply-To: <01ad01c30bef$e717c5d0$c281fd0c@TOMBREED>
Message-ID: <SAT.26.APR.2003.125526.0500.HSEAVER@CYBERSHAMANIX.COM>

On Sat, Apr 26, 2003 at 06:32:29AM -0600, Tom Reed wrote:
> Dear Cu Lynn:
>
> You said...
>
> >I tend to believe the more positive views:
> that Mother Earth is very strong and very smart and can heal herself, as
> she does everyday, in combination with the sun.
>
> ~~~~~~~~
> Right on! We tend to assume responsibility for all the ills of the world,
> whereas it existed quite nicely, thank you, before humans arrived and will
> probably bumble along after we leave (or are thrown out).

Well, you're absolutely correct there -- this world would be a veritable
paradise were it not for humans. SARS will likely, as currently projected, only
kill one in seven -- what's really needed is a 50-75% reduction.

--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From tmiles at TRMILES.COM Sat Apr 26 14:09:01 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] Stove Testing and Design Seminar June 2 to 6
Message-ID: <SAT.26.APR.2003.110901.0700.TMILES@TRMILES.COM>

Dean,

It looks like a great program.

> So far we have in the Aprovecho lab: the most recent Vesto stove, a Juntos
> stove, a Jiko stove, and a Rocket stove for testing. I'm hoping to have a
> Turbo stove as well.

Doesn't it make sense to add an improved clay stove of the kind you
discussed with Paul Mushamba some weeks ago?
See: Energy Saving Stoves in Southern Africa
http://www.repp.org/discussiongroups/resources/stoves/GTZ/Mushamba_Still.htm
l

Tom Miles

From tombreed at ATTBI.COM Sun Apr 27 08:29:35 2003
From: tombreed at ATTBI.COM (Tom Reed)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
Message-ID: <SUN.27.APR.2003.062935.0600.TOMBREED@ATTBI.COM>

Dear Family and Friends:

The Email below reminds me: There is a new type of can opener on the market (hand operated ~$10, electric Hamilton Beach~$20 at Bed Bath and Beyond). It unseals the can on the OUTSIDE of the rim, allowing you to lift the lid off and use it as a cover for the food if you put part back in the frig. It does NOT cut the inside of the lid and drop it into the can contents.

I was first attracted to it because we can then use the can tops in making our WoodGas stoves for developing countries.
~~~~~~~
The warning below could possibly save your life and the remediation is simple. Wash/rinse your cans, even if they look "clean". AND/OR use the new can openers.

Your friend and scout,

TOM REED BEF STOVEWORKS

Dr. Thomas B. Reed
1810 Smith Rd., Golden, CO 80401
tombreed@attbi.com; 303 278 0558 Phone; 303 265 9184 Fax
----- Original Message -----
From: Herbert Bruch
Sent: Saturday, April 26, 2003 7:56 AM
Subject: FW: safety tip

-----Original Message-----
From: chuck thomas [mailto:cthomas2000@4edisp.net]
Sent: Friday, April 25, 2003 5:54 PM
Subject: safety tip

IMPORTANT

A stock clerk was sent to clean up a storeroom in Maui, Hawaii. When he got

back, he was complaining that the storeroom was really filthy and that he

had noticed dried mouse or rat droppings in some areas.

A couple of days later, he started to feel like he was coming down with a

stomach flu, complained of sore joints and headaches, and began to vomit.

He went to bed and never really got up again. Within two days he was

severely ill and weak. His blood sugar count was down to 66, and his face

and eyeballs were yellow. He was rushed to the emergency at Pali-Momi,
where

he was diagnosed to be suffering from massive organ failure. He died
shortly

before midnight.

No one would have made the connection between his job and his death, had it

not been for a doctor who specifically asked if he had been in a warehouse

or exposed to dried rat or mouse droppings at any time. They said there is
a

virus (much like the Hanta virus) that lives in dried rat and mouse

droppings. Once dried, these droppings are like dust and can easily be

breathed in or ingested if a person does not wear protective gear or fails

to wash face and hands thoroughly.

An autopsy was performed on the clerk to verify the doctor's suspicions.

This is why it is extremely important to ALWAYS carefully rinse off the
tops

of canned sodas or foods, and to wipe off pasta packaging, cereal boxes,
and

so on.

Almost everything you buy in a supermarket was stored in a warehouse at one

time or another, and stores themselves often have rodents.

Most of us remember to wash vegetables and fruits but never think of boxes

and cans.

The ugly truth is, even the most modern, upper-class, super store has rats

and mice. And their warehouse most assuredly does!

Whenever you buy any canned soft drink, please make sure that you wash the

top with running water and soap or, if that is not available, drink with a

straw.

The investigation of soda cans by the Center for Disease Control in Atlanta

discovered that the tops of soda cans can be encrusted with dried rat's

urine, which is so toxic it can be lethal. Canned drinks and other

foodstuffs are stored in warehouses and containers that are usually
infested

with Rodents, and then they get transported to retail outlets without being

properly cleaned. Please forward this message to the people you care about.

(I JUST DID!)

From robertoescardo at ARNET.COM.AR Sun Apr 27 13:19:17 2003
From: robertoescardo at ARNET.COM.AR (=?iso-8859-1?Q?Roberto_Escard=F3?=)
Date: Tue Aug 10 18:30:21 2004
Subject: About AAC
Message-ID: <SUN.27.APR.2003.141917.0300.ROBERTOESCARDO@ARNET.COM.AR>

Some time ago we investigated in depht AAC. Gonzalo, a young engineer of our team (now working in a gas field in Bolivia) was in contact with the Hebel support enginer here (trained in Germany). I think it will be prudent to recheck it.
Roberto.

----- Original Message -----
From: Roberto Escard?
To: stoves@crest.org ; Peter Verhaart
Cc: ethos
Sent: Thursday, September 26, 2002 10:51 PM
Subject: [ethos] Re: Re: A note in AAC

Peter:
Mas vale tarde que nunca. (Translation: It?s better late than never)
The HEBEL support engineer here gave as the following info:
All cement-based materials are vulnerable to the attack of atmospheric carbon dioxide In concrete due to the scarce diffusion of gas in their interior; the effect is only superficial. AAC is a lot more permeable to air and it absorbs carbon dioxide easily, then the hydrated lime, either from the cement free lime or from the Si and Al hydrates reacts with the CO2 forming calcium carbonate:

Ca(OH)2 + CO2--------CO3Ca + H2O

Carbonatization causes a decrease of volume, denominated "carbonatization contraction". If CO2 concentration is high, or the exposure time is enough long, the contraction originates fissures. In AAC during the curing Ca hydrates react with the sand Si forming highly stable tebermorite so "carbonatization contraction" tends to be small. The risk from atmospheric CO2 contamination is very low, but is not the case in a combustion chamber or chimney.

HEBEL of Germany recommends coating chimneys or smoking conduits with refractory bricks to avoid carbonisation.

Other point in combustion chambers is permanent exposure to flames. AAC resists a flame temp of 1000 ?C 240 minutes without any loss of stability. If exposure time is much longer, the combined water of moisturized cement will evaporate, degrading the material
Regards
Roberto.

----- Original Message -----
From: Peter Verhaart
To: stoves@crest.org
Sent: Tuesday, September 03, 2002 3:01 AM
Subject: Fwd: Re: A note in AAC

Date: Tue, 03 Sep 2002 15:59:55 +1000
To: Roberto Escard? <robertoescardo@arnet.com.ar>
From: Peter Verhaart <pverhaart@optusnet.com.au>
Subject: Re: A note in AAC

Maybe you should do a test. Did the man tell you what chemical reactions you could expect?

Peter Verhaart

At 18:56 02/09/02 -0300, you wrote:

Autoclaved Aerated Concrete (AAC)

There was a thread about AAC some weeks ago: An young engineer workinkg with us contacted last week a local maker (under a licence from Hebel in Germany) The sales technician was very collaborative and he quickly discouraged us about using it for combustion chambers: AAC is atacked by CO2!!!
(Big note in Manuals: carefully protect any chimney made with AAC bricks with refractory bricks - AAC dose not stand CO2 exposure) Pitty, it sounded as a nice material for combustion chambers!!
Roberto Escard?

From tmiles at TRMILES.COM Mon Apr 28 21:05:39 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] Fw: Great grates?
Message-ID: <MON.28.APR.2003.180539.0700.TMILES@TRMILES.COM>

Do people remove the shelf in the Rocket stove so they can burn larger
pieces of fuel?

Instead of a shelf I would put a fulcrum at the entrance to the combustion
chamber that would hold the tip of the fuel up off the floor of the
combustor. That way air could flow in and around the fuel without the
inconvenience of the fuel-efficient shelf. You might regain part of the lost
efficiency.

Something like that could form part of a modification to the combustion
chamber of the Maendelao or Upesi stoves that would make them more fuel
efficient. As I look at the long sticks feeding the Maendaleo I have to
think that part of the attraction of that design is feeding larger sticks of
fuel.

See Christa Roth's photos of the Chitetezo Mbaula clay stove (photo 1), mud
stoves (photo 3) and mud stoves with liners (photos 7 and 8) at:
http://ecoharmony.net/hedon/malawistoves.php
You can see a rest for the firewood at the rear of the mud stove (Photo 4).
That would serve a similar purpose to the fulcrum or the shelf although the
geometry of the firebox is different in these Maendaleo stoves.

Tom Miles

----- Original Message -----
From: "Stuart Conway" <stuart@treeswaterpeople.org>
To: "Dean Still" <dstill@epud.net>; "ethos" <ethos@vrac.iastate.edu>
Sent: Monday, April 28, 2003 3:30 PM
Subject: Re: [ethos] Fw: Great grates?

> Dean et al,
>
> Thanks for sending out the results of the tests on the efficacy of the
shelves
> for the combustion chambers on the Rockets and other fuel efficient
stoves. I
> have noticed many people not using the shelves on my visits To Central
America
> as well. I will keep insisting that people keep using them, especially now
armed
> with this new information on the shelfs effect on fuel efficiency. Ahh,
the
> power of numbers.
>
> Stuart Conway
>
> Dean Still wrote:
>
> > Dear Friends,
> >
> > Damon Ogle and Mike Hatfield observed in their recent trip to Central
> > America that the shelf placed in the fuel magazine of the Rocket stoves
> > which lifts the sticks of wood up off the floor of the combustion
chamber)
> > was frequently put aside by users who first placed sticks of wood
directly
> > on the floor of the combustion chamber and then after a while, on top of
the
> > glowing coals.
> >
> > Damon and Mike wondered whether including a shelf was important.
Luckily,
> > researchers become opinionated only if they get lazy...Damon set up a
test
> > stove in the lab and he and I ran nine one hour water boiling tests. The
> > same stove was tested three times with 1.) a horizontal sheet metal
shelf
> > 2.) then without it, 3.) then with a solid brick shelf in the feed
magazine
> > that blocked air from passing under the shelf and allowed primary air
to
> > feed
> > the fire in the combustion chamber from underneath a metal grate in the
> > floor
> > of the combustion chamber. Air was drawn directly up through the fire.
Check
> > out a drawing of the shelf concept in the Rocket combustion chamber on
the
> > Aprovecho stove page at www.efn.org/~apro
> >
> > After averaging the results from the three tightly grouped series of
tests,
> > the simple shelf improved efficiency by 14%. The solid shelf with under
fire
> > air improved efficiency by 35.7 %.
> >
> > The amazing Sam Baldwin, in the best book yet written on cookstoves,
> > "BIOMASS STOVES: ENGINEERING DESIGN, DEVELOPMENT, AND DISSEMINATION"
> > reported improving efficiency from 18% to 25% by using a grate on a
> > "malgache" metal stove. This represents an improvement of 38.8%, which
> > parallels our findings.
> >
> > Grates that allow air to pass under and up through the burning sticks
can
> > have a significant positive effect on efficiency.
> >
> > Both Damon and I also observed that fewer coals are produced by using a
> > shelf or grate. But further testing is needed to determine the extent of
the
> > difference. More hours staring into the fire!
> >
> > All Best,
> >
> > Dean Still
> > Damon Ogle
>
>
>
>

From jeff.forssell at CFL.SE Tue Apr 29 02:29:44 2003
From: jeff.forssell at CFL.SE (Jeff Forssell)
Date: Tue Aug 10 18:30:21 2004
Subject: Fw: Great grates?
Message-ID: <TUE.29.APR.2003.082944.0200.JEFF.FORSSELL@CFL.SE>

Am I the only having difficulty picturing what this looks like?:

>3.) then with a solid brick shelf
> in the feed
> magazine
> > > that blocked air from passing under the shelf and
> allowed primary air
> to
> > > feed
> > > the fire in the combustion chamber from underneath a
> metal grate in the
> > > floor
> > > of the combustion chamber. Air was drawn directly up
> through the fire.

because there is no drawing about that here:
> Check
> > > out a drawing of the shelf concept in the Rocket
> combustion chamber on
> the
> > > Aprovecho stove page at www.efn.org/~apro

Jeff Forssell (tv? s)
SWEDISH AGENCY FOR FLEXIBLE LEARNING (CFL)
Box 3024
SE-871 03 H?RN?SAND /Sweden

<http://www.cfl.se/english/index.htm>
+46(0)611-55 79 48 (Work) +46(0)611-55 79 80 (Fax Work)
+46(0)611-22 1 44 (Home) ( mobil: 070- 35 80 306; [070-4091514])

residence:
Gamla Karlebyv?gen 14 / SE-871 33 H?rn?sand /Sweden

e-mail: every workday: jeff.forssell@cfl.se <mailto:jeff.forssell@cfl.se>
(travel, visiting: jeff_forssell@hotmail.com & MSMessenger)

Personal homepage: <http://www.torget.se/users/i/iluhya/index.htm>
My village technology page: http://home.bip.net/jeff.forssell

Instant messengers Odigo 792701 (ICQ: 55800587; NM/MSM use hotmail address)

From dstill at EPUD.NET Mon Apr 28 05:49:44 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:21 2004
Subject: Fw: Great grates/HTE
Message-ID: <MON.28.APR.2003.024944.0700.DSTILL@EPUD.NET>

Dear Jeff,

Very sorry for my poor description of the improved shelf in the Rocket stove
experiment. Is this any better?

Imagine the shelf made from solid ceramic material. The shelf rests on the
floor of the fuel magazine filling the lower third of the fuel magazine...
Sticks lay on top of the solid ceramic block. All air passes over the shelf.

In the bottom of the Rocket combustion chamber in the internal vertical
chimney there is a grate with holes in it. Air is sucked up through this
grate, through the coals, up into the chimney. Having air pulled through the
coals was responsible for the 35 % increase in efficiency. I imagine that
there was less cooling of combustion with this pattern.

I imagine that in the Rocket stove where the coals are far away from the pot
most heat transfer is by convection. The velocity of the hot flue gases
(faster is better) and the temperature at the pot (hotter is better)
predominantly determine heat transfer efficiency to the pot... The pot size
and shape, of course, how much of the pot is contacted by fast moving hot
flue gases , forcing hot flue gases to scrape against the pot surface in
small 5mm to 10mm ducts is also very important. Improvements in heat
transfer to the pot result in much greater improvements in percent of heat
utilized compared to improvements in combustion efficiency. Force fast
moving very hot flue gases to scrape against the entire outer surface of the
big pot full of water and efficiencies sharply rise into the 40 to 50%
range.

Best,

Dean

From tmiles at TRMILES.COM Wed Apr 30 01:15:51 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: Spanish Language Stoves Website
Message-ID: <TUE.29.APR.2003.221551.0700.TMILES@TRMILES.COM>

Stuart, Lisa

Picking up an old thread: do we have anyone willing to spend some time on
Spanish language content for the stoves web site? I can manage, organize or
present Spanish and Portuguese files but I don't have time to generate any
content. I can also provide the English language files for anyone who wants
to translate them. It would be great to have Spanish language content coming
from native speakers in the project areas. I can set up a parallel site that
is linked to the main site.

We could start with some of the content from the workshops like the gender
workshop that Winrock hosted. More to the point I think is the practical
content like Jim Wilmes has prepared and Spanish versions of the fuel and
stove construction issues. We can also add an interactive Spanish discussion
and link Rogerio's bioenergia discussion.

Someone needs to volunteer to start contributing articles or translations.

Saludos

Tom

----- Original Message -----
From: "Stuart Conway" <stuart@treeswaterpeople.org>
To: "Lisa Buttner" <LButtner@winrock.org>
Cc: "ethos" <ethos@vrac.iastate.edu>
Sent: Wednesday, January 08, 2003 4:20 PM
Subject: Re: [ethos] Re: MIS faculty seeking projects

> Hi Lisa et al,
> I agree that having the information in Spanish on the stove website would
be a good thing for spreading the stove technology into Latin America. We
could even think about making an interactive decision tree (like Jim Welch
did for TNC) strictly for stoves, so that people could decide which stove is
the best for their area, given the type of foods cooked, available
materials, cost considerations, ect. We can discuss these ideas further in
a few days.
>
> See you soon.
>
> Stuart Conway
>
>
> Lisa Buttner wrote:
>
> > Tom et al,
> >
> > I would like to add to the wish list: information in Spanish to reach
our Latin American partners. I think a modest amount of information would
be a useful resource to help project implementers make more informed choices
in the field. Potential topics might include: basics of efficiency
principles; materials characteristics, options, cost comparisions;
variations in cooking needs and associated design adjustments;
considerations for standardization, mass production and commercialization;
examples and comparisons of existing models and related experiences by
country/region; introduction of haybox principles and potential additional
fuel savings; etc.
> >
> > This raises the question of audience for the website discussion; I would
guess that we might define more than one priority group.
> >
> > Looking forward to the discussions!
> >
> > Lisa B?ttner

From crispin at NEWDAWN.SZ Wed Apr 30 05:09:03 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:21 2004
Subject: Great grates? - Tom M
Message-ID: <WED.30.APR.2003.110903.0200.CRISPIN@NEWDAWN.SZ>

Dear Tom

The point of the Maendeleo stove floor shape was raised at at the
Vereeniging conference. Apparently they sometimes put a narrow clay shelf
across the _front_ to hold the fuel up off the floor of coals slightly.
This is not an approximation of the layout of a Rocket but it does keep the
wood off the cold floor when starting off. It seems like a good idea.

Regards
Crispin

++++++++++

Tom Miles

From rmiranda at INET.COM.BR Wed Apr 30 09:07:45 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] Spanish Language Stoves Website
In-Reply-To: <035401c30ed7$945d0ef0$a82367ce@tomslaptop>
Message-ID: <WED.30.APR.2003.100745.0300.RMIRANDA@INET.COM.BR>

Tom: If I can be of help in this matter, let's do it. Although my spanish
is not perfect, I can get the message trough. Portuguese no problem.

Rogerio

At 10:15 p.m. 29/04/03 -0700, Tom Miles wrote:
>Stuart, Lisa
>
>Picking up an old thread: do we have anyone willing to spend some time on
>Spanish language content for the stoves web site? I can manage, organize or
>present Spanish and Portuguese files but I don't have time to generate any
>content. I can also provide the English language files for anyone who wants
>to translate them. It would be great to have Spanish language content coming
>from native speakers in the project areas. I can set up a parallel site that
>is linked to the main site.
>
>We could start with some of the content from the workshops like the gender
>workshop that Winrock hosted. More to the point I think is the practical
>content like Jim Wilmes has prepared and Spanish versions of the fuel and
>stove construction issues. We can also add an interactive Spanish discussion
>and link Rogerio's bioenergia discussion.
>
>Someone needs to volunteer to start contributing articles or translations.
>
>Saludos
>
>Tom
>
>
>----- Original Message -----
>From: "Stuart Conway" <stuart@treeswaterpeople.org>
>To: "Lisa Buttner" <LButtner@winrock.org>
>Cc: "ethos" <ethos@vrac.iastate.edu>
>Sent: Wednesday, January 08, 2003 4:20 PM
>Subject: Re: [ethos] Re: MIS faculty seeking projects
>
>
> > Hi Lisa et al,
> > I agree that having the information in Spanish on the stove website would
>be a good thing for spreading the stove technology into Latin America. We
>could even think about making an interactive decision tree (like Jim Welch
>did for TNC) strictly for stoves, so that people could decide which stove is
>the best for their area, given the type of foods cooked, available
>materials, cost considerations, ect. We can discuss these ideas further in
>a few days.
> >
> > See you soon.
> >
> > Stuart Conway
> >
> >
> > Lisa Buttner wrote:
> >
> > > Tom et al,
> > >
> > > I would like to add to the wish list: information in Spanish to reach
>our Latin American partners. I think a modest amount of information would
>be a useful resource to help project implementers make more informed choices
>in the field. Potential topics might include: basics of efficiency
>principles; materials characteristics, options, cost comparisions;
>variations in cooking needs and associated design adjustments;
>considerations for standardization, mass production and commercialization;
>examples and comparisons of existing models and related experiences by
>country/region; introduction of haybox principles and potential additional
>fuel savings; etc.
> > >
> > > This raises the question of audience for the website discussion; I would
>guess that we might define more than one priority group.
> > >
> > > Looking forward to the discussions!
> > >
> > > Lisa B?ttner

From tmiles at TRMILES.COM Wed Apr 30 13:55:41 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:21 2004
Subject: [ethos] Re: Spanish Language Stoves Website
Message-ID: <WED.30.APR.2003.105541.0700.TMILES@TRMILES.COM>

Stuart and all,

Thank you for the positive response for the Spanish stoves site. Unless
there is a more appropriate term I'll set up the site under the URL
http://www.repp.org/discussiongroups/resources/estufas/

So far we have offers from:

Cuba, Jos? Fernando Martirena Hern?ndez
Central America, Jim Wilmes
Columbia, Bernardo Sanchez
Brazil, South America, Rogerio Miranda
Argentina, Roberto Escard?

Where terms differ in Central/Andes or South America we can put alternate
terms in brackets in the translation.

Documents that we now have in Spanish online include:
Stove Construction:
Visual Guide to Assembling the Justa Stove Jim Wilmes, Trees Water and
People and Aprovecho, February 2003 English and Spanish
Guia para construir estufa justa (pdf 1200 kb)
Mantenimiento Ecofogon o Justa (pdf 200 kb)

I'll create a Spanish home page, that someone can edit, and start with these
stove construction and maintenance documents then we can build from there.

(The criteria I use for content is usually that if something is of interest
and use to me I assume that it will be useful to others. So all my web sites
have been like personal notebooks that are shared in public.)

Graphic presentations like power point can be very useful and are easily
converted to web pages if anyone has those in Spanish.

Regards,

Tom

----- Original Message -----
From: "Stuart Conway" <stuart@treeswaterpeople.org>
To: "Tom Miles" <tmiles@trmiles.com>
Cc: "ethos" <ethos@vrac.iastate.edu>
Sent: Wednesday, April 30, 2003 9:46 AM
Subject: [ethos] Re: Spanish Language Stoves Website

> Hi Tom,
>
> I have a native speaker from Columbia, Bernardo Sanchez, who is willing to
do
> some translations of the stove documents. I think that we should start
with the
> stove construction plans, as the most important ones, and then go from
there.
> Aprovecho already had someone translate the Justa stove plans into
Spanish. How
> about the Rocket stove plans? Have those been translated into Spanish yet?
>
> Stuart
>
> Tom Miles wrote:
>
> > Stuart, Lisa
> >
> > Picking up an old thread: do we have anyone willing to spend some time
on
> > Spanish language content for the stoves web site? I can manage, organize
or
> > present Spanish and Portuguese files but I don't have time to generate
any
> > content. I can also provide the English language files for anyone who
wants
> > to translate them. It would be great to have Spanish language content
coming
> > from native speakers in the project areas. I can set up a parallel site
that
> > is linked to the main site.
> >
> > We could start with some of the content from the workshops like the
gender
> > workshop that Winrock hosted. More to the point I think is the practical
> > content like Jim Wilmes has prepared and Spanish versions of the fuel
and
> > stove construction issues. We can also add an interactive Spanish
discussion
> > and link Rogerio's bioenergia discussion.
> >
> > Someone needs to volunteer to start contributing articles or
translations.
> >
> > Saludos
> >
> > Tom
> >
> > ----- Original Message -----
> > From: "Stuart Conway" <stuart@treeswaterpeople.org>
> > To: "Lisa Buttner" <LButtner@winrock.org>
> > Cc: "ethos" <ethos@vrac.iastate.edu>
> > Sent: Wednesday, January 08, 2003 4:20 PM
> > Subject: Re: [ethos] Re: MIS faculty seeking projects
> >
> > > Hi Lisa et al,
> > > I agree that having the information in Spanish on the stove website
would
> > be a good thing for spreading the stove technology into Latin America.
We
> > could even think about making an interactive decision tree (like Jim
Welch
> > did for TNC) strictly for stoves, so that people could decide which
stove is
> > the best for their area, given the type of foods cooked, available
> > materials, cost considerations, ect. We can discuss these ideas further
in
> > a few days.
> > >
> > > See you soon.
> > >
> > > Stuart Conway
> > >
> > >
> > > Lisa Buttner wrote:
> > >
> > > > Tom et al,
> > > >
> > > > I would like to add to the wish list: information in Spanish to
reach
> > our Latin American partners. I think a modest amount of information
would
> > be a useful resource to help project implementers make more informed
choices
> > in the field. Potential topics might include: basics of efficiency
> > principles; materials characteristics, options, cost comparisions;
> > variations in cooking needs and associated design adjustments;
> > considerations for standardization, mass production and
commercialization;
> > examples and comparisons of existing models and related experiences by
> > country/region; introduction of haybox principles and potential
additional
> > fuel savings; etc.
> > > >
> > > > This raises the question of audience for the website discussion; I
would
> > guess that we might define more than one priority group.
> > > >
> > > > Looking forward to the discussions!
> > > >
> > > > Lisa B?ttner
>
>
>

From robertoescardo at ARNET.COM.AR Wed Apr 30 13:59:20 2003
From: robertoescardo at ARNET.COM.AR (=?iso-8859-1?Q?Roberto_Escard=F3?=)
Date: Tue Aug 10 18:30:21 2004
Subject: Fw: [STOVES] Spanish Language Stoves Website
Message-ID: <WED.30.APR.2003.145920.0300.ROBERTOESCARDO@ARNET.COM.AR>

I forgot to copy the message to Tom to the lists, so here it is, with Tom
return included.
Regards.
Roberto.

----- Original Message -----
From: "Tom Miles" <tmiles@trmiles.com>
To: "Roberto Escard?" <robertoescardo@arnet.com.ar>
Sent: Wednesday, April 30, 2003 2:18 PM
Subject: Re: [STOVES] Spanish Language Stoves Website

> Roberto,
>
> Thank you for the offer. I think we can actually cover the major regions
of
> Spanish among members on the list: Where terms are different we can do
what
> the machine translators do and put alternate terms in brackets in the
> translation.
>
> I too am pleased with the discussion. Good content and interest.
>
> Thanks
>
> Tom
>
>
>
> ----- Original Message -----
> From: "Roberto Escard?" <robertoescardo@arnet.com.ar>
> To: "Tom Miles" <tmiles@TRMILES.COM>
> Sent: Wednesday, April 30, 2003 8:11 AM
> Subject: Re: [STOVES] Spanish Language Stoves Website
>
>
> > Tom:
> > I can put some hours a week in the spanish content, at least till next
> > spring (South) I will be back at home next monday, where I have more
time
> > and resources.
> > I think it will be useful to have a "priority list" to begin with.
> > Latin-american spanish is not very homogeneous and even that I have some
> > experience in writing in "neutral" spanish I think it will be necessary
to
> > cross-check translations between areas (Central America, Central Andean,
> > South)
> > Get in touch next week.
> > Best regards
> > Roberto,
> >
> > Lots of activity in the Stoves list and very interesting threads.
Cheers!!
> >
> >
> >
> > ----- Original Message -----
> > From: "Tom Miles" <tmiles@TRMILES.COM>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Wednesday, April 30, 2003 2:15 AM
> > Subject: [STOVES] Spanish Language Stoves Website
> >
> >
> > > Stuart, Lisa
> > >
> > > Picking up an old thread: do we have anyone willing to spend some time
> on
> > > Spanish language content for the stoves web site? I can manage,
organize
> > or
> > > present Spanish and Portuguese files but I don't have time to generate
> any
> > > content. I can also provide the English language files for anyone who
> > wants
> > > to translate them. It would be great to have Spanish language content
> > coming
> > > from native speakers in the project areas. I can set up a parallel
site
> > that
> > > is linked to the main site.
> > >
> > > We could start with some of the content from the workshops like the
gend
> er
> > > workshop that Winrock hosted. More to the point I think is the
practical
> > > content like Jim Wilmes has prepared and Spanish versions of the fuel
> and
> > > stove construction issues. We can also add an interactive Spanish
> > discussion
> > > and link Rogerio's bioenergia discussion.
> > >
> > > Someone needs to volunteer to start contributing articles or
> translations.
> > >
> > > Saludos
> > >
> > > Tom
> > >
> > >
> > > ----- Original Message -----
> > > From: "Stuart Conway" <stuart@treeswaterpeople.org>
> > > To: "Lisa Buttner" <LButtner@winrock.org>
> > > Cc: "ethos" <ethos@vrac.iastate.edu>
> > > Sent: Wednesday, January 08, 2003 4:20 PM
> > > Subject: Re: [ethos] Re: MIS faculty seeking projects
> > >
> > >
> > > > Hi Lisa et al,
> > > > I agree that having the information in Spanish on the stove website
> > would
> > > be a good thing for spreading the stove technology into Latin America.
> We
> > > could even think about making an interactive decision tree (like Jim
> Welch
> > > did for TNC) strictly for stoves, so that people could decide which
> stove
> > is
> > > the best for their area, given the type of foods cooked, available
> > > materials, cost considerations, ect. We can discuss these ideas
further
> > in
> > > a few days.
> > > >
> > > > See you soon.
> > > >
> > > > Stuart Conway
> > > >
> > > >
> > > > Lisa Buttner wrote:
> > > >
> > > > > Tom et al,
> > > > >
> > > > > I would like to add to the wish list: information in Spanish to
> reach
> > > our Latin American partners. I think a modest amount of information
> would
> > > be a useful resource to help project implementers make more informed
> > choices
> > > in the field. Potential topics might include: basics of efficiency
> > > principles; materials characteristics, options, cost comparisions;
> > > variations in cooking needs and associated design adjustments;
> > > considerations for standardization, mass production and
> commercialization;
> > > examples and comparisons of existing models and related experiences by
> > > country/region; introduction of haybox principles and potential
> additional
> > > fuel savings; etc.
> > > > >
> > > > > This raises the question of audience for the website discussion; I
> > would
> > > guess that we might define more than one priority group.
> > > > >
> > > > > Looking forward to the discussions!
> > > > >
> > > > > Lisa B?ttner
> >
> >
> >
>
>

From crispin at NEWDAWN.SZ Mon Apr 28 01:56:13 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:21 2004
Subject: New Can opener &safety tip
Message-ID: <MON.28.APR.2003.075613.0200.CRISPIN@NEWDAWN.SZ>

Dear Stoves and can recyclers

Some of you might be old enough to rememebr that before and after WWII
people kept the cans, filled them with food they wanted to store and put on
new tops. The cans slowly get shorter and shorter until they look like tuna
cans after a number of uses.

I wonder if the lids and hand-operated re-sealer is still available.

Regards
Crispin

BioEnergy Lists: Improved Biomass Cooking Stoves

April 2003 Biomass Cooking Stoves Archive