October 1999 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 ticu at rdsor.ro Sun Oct 3 19:23:30 1999
From: ticu at rdsor.ro (Cornel Ticarat)
Date: Tue Aug 31 21:36:23 2004
Subject: Producing charcoal.
Message-ID: <199910032323.TAA11427@solstice.crest.org>

Dear Sirs,

We are a Romanian company interested in producing charcoal and we need information to
establish a plant. Will You kindly let us have that infornation and tell us what are Your terms of co-operation.
We mention we would like to use "pyrolsis method".

Our address:
S.C. MANNA COM PLUS S.R.L.
Bd. Decebal, no. 5
Bl. P 18, ap. 13
Oradea, 3700, Romania
Tel: +40.59.160.372
Fax: +40.59.479.002
E-mail: ticu@rdsor.ro

With our best thanks,

Director,
Cornel Ticarat

Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Mon Oct 4 22:11:18 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:23 2004
Subject: Forward a request on sawdust-burning stoves
Message-ID: <v01540b00b41f0b016310@[204.131.233.15]>

Wendy and Jim: There are quie a few references in stoves literature to
stoves specifically designed for sawdust. They typically start with a
suitable - sized cylindrical metal can with a single smallish outside hole
near the bottom of the outer wall. One puts a wooden horizontal pipe
"mandrel" through this hole and another vertical one from the top that
meets the first near the bottom.

The operator packs sawdust around both and then removes both
mandrels. The fire is started at the bottom. I have never built or used
one.

I think that in a few days you will find some diagrams on a site
maintained by alex english (address <english@adan.kingston.net>) called:

Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html

You might also look back at our archives - since I am sure we have
mentioned it several times:

http://solstice.crest.org/renewables/stoves-list-archive/

This is a somewhat unusual request. Can you further explain the
circumstances behind it?

Care to join our list?

Stovers: I don't recall this subject coming up in detail. How about
someone sending the necessary detailed plans to Alex. Obviously anyone
with detailed knowledge on how to use these stoves should communicate with
Wendy as well (hopefully through the list).

Ron

>Date: Mon, 4 Oct 1999 08:59:12 -0600
>To: Stoves@crest.org
>From: standley@sol.racsa.co.cr (Jim Standley & Wendy Rockwell)
>
>Dear Sirs,
>
>I am interested in obtaining plans for a sawdust burning stove.
>
>Cordially
>Wendy Rockwell
>
>Jim Standley
>Wendy Rockwell
>506-645-5147
>506-645-5551
>apto. 37-5655
>Santa Elena Puntarenas
>

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

From larcon at sni.net Thu Oct 7 08:24:48 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:23 2004
Subject: Forwarding Khouri on starch vs clay binders
Message-ID: <v01540b03b42242b31102@[204.131.233.31]>

Ramzi - I hope Elsen Karstad will also comment on your detailed questions-
but I know he believes there is virtue in clay being cheaper and having a
benficial effect in slowing the burn of charcoal. Look up Elsen's past
comments in our archives.

Ron

>
>Dear all.
>
>I have noticed that in all documentation's the clay has been added as a
>binder. The following WWW states that starch is more commonly used with 5%
>starch. http://nt1.frim.gov.my/charcoal.html
>
>I am looking into setting up my fabrication plant to produce charcoal
>briquettes. I am studying the best binder to use and method of application.
>
>I will be interested in knowing the following:
>1) what do you think of Starch as a binder?
>2) if clay is used what is the kind of clay used?
>3) is clay completely odorless and burns to ash?
>4) what pressure is used in fabricating charcoal briquettes?
>5) What kind or binders do commercial brands use?
>6) Process of commercially producing charcoal briquettes, pressures,
>temperatures etc..
>
>I would very much appreciate some answers.
>
>Thank you. Your mailing lists are interesting and full of info..
>
>Ramzi Khouri.
<ramzikhouri@hotmail.com>

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

From elk at net2000ke.com Thu Oct 7 09:50:56 1999
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:23 2004
Subject: Charcoal Briquette Binders
Message-ID: <199910071358.QAA29511@net2000ke.com>

Ramzi Khouri asks;>1) what do you think of Starch as a binder?Starch as a binder introduces an unburnt organic material to the charcoal briquette which produces some smell (varies with starch origin), some smoke (particularly during lighting) and does not significantly increase ash- this may or may not be desirable. Starch is usually derived from grain, and it's use could be considered as a diversion of a human food resource for use as a fuel component. It is probably a slightly superior binder than clay, though in my experience, differences are minimal. Both clay and starch are water soluble, and briquettes disintegrate when wet. I suspect (someone correct me if I'm wrong please) that starch binds best when subjected to high pressures, and allows for larger particle sizes to be effectively amalgamated into the briquette- the resultant briquette can be bulkier (lighter) and lower ash- quick to light. Clay works well under lower pressures with finer charcoal particle size, resulting in a dense briquette- harder to light & with a longer burning time. You may want to determine what the market requirement is in terms of burning time and lightability & select your binders accordingly.>2) if clay is used what is the kind of clay used?I use a Bentonite clay of volcanic origin- very common here in Nairobi, but would expect that most clays would exhibit similar binding effect.>3) is clay completely odorless and burns to ash?Yes. The briquette ash is of a reddish-brown colour.>4) what pressure is used in fabricating charcoal briquettes?I've not measured the pressure in my extruders- resistance is primarily determined by the length of the die-pipe that forms and extrudes the cylindrical briquette. See the stoves web-page for a photo of the extruder.>5) What kind or binders do commercial brands use?Often both starch and clay plus 'secret' ingredients. This is proprietary information and you won't get it from most commercial producers voluntarily.... >6) Process of commercially producing charcoal briquettes, pressures,>temperatures etcSorry- I have little information on standard processes, having developed my own... undoubably re-inventing a currently or previously used method. I do sympathize with the lack of readily available information of charcoal briquette manufacture. Possibly the agricultural engineering dept,. of a large university would have more specific information for you.elk~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Elsen L. Karstad , P.O. Box 24371 Nairobi Kenyaelk@net2000ke.com tel/fax (+ 254 2) 884437

From Reedtb2 at cs.com Fri Oct 8 10:14:17 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:23 2004
Subject: Harvesting biomass
Message-ID: <0.449f702b.252f5711@cs.com>

Dear All:

At the risk of repeating some of the previous messages on this subject, I'll
add my 2 c worth.

Mother Nature is the greatest recycler of all, but even she makes mistakes.
If she had better recycling we wouldn't have peat swamps - and oil - and
coal, and there would be a lot more CO2 in the air and we'd be back in the
middle of the paleozoic.

When I first became intersted in biomass as a RENEWABLE energy source, I
worried a lot about the same things bothering Toni and others.

There may still be some worries unaccounted for, but

1) Mature trees are 95% stored dead lignocellulosic material - no nitrogen or
phosphorus, so tree mulch isn't very good fertilizer. All of the good stuff
is stored in the leaves and dropped on the forest floor for recycle.

2) Roots and particularly tree roots are continually releasing useful
minerals locked up in clays. So we have hurricanes every 30 years or so to
topple the trees and bring up this rich stuff.

3) Our harvesting of the food or wood part of biomass leaves lots of
residues to be recycled.

4) If you are worried about the nitrogen content, use the energy in the
residues to make urea and nitrates - that's why humans were created.

So, I'll continue to work on the conversion end of biomass, knowing that
there's lots of biomass to be recycled that surely won't bother our long
range prospects. I'll keep my eye out for those that do.

Onward.... TOM REED BEF

In a message dated 10/7/99 2:23:00 PM Mountain Daylight Time, Davost@aol.com
writes:

<<
<< Even the fastest growing biomass still depletes
soils and aquifers and hampers future generations ability to meet their
needs. >>

Toni, the above statement is not even close to the truth. By establishing
perennial crops, say trees, the record shows increases in soil fertility
rather than the other way around, the reason being soil mineralization by
root-produced organic acids and leaf recycling. You may want to find out
what happens to farmed ground when it's planted back to trees. There is all
kinds of data on this but you may want to study the land put in to farming
in
SE Asia and Brazil. According to your statement, sterile Minnesota corn
ground could never grow trees without fertilization. I invite you to come
and look for yourself.
>>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From karve at wmi.co.in Fri Oct 8 23:33:40 1999
From: karve at wmi.co.in (karve)
Date: Tue Aug 31 21:36:23 2004
Subject: Charcoal Briquette Binders
In-Reply-To: <199910071358.QAA29511@net2000ke.com>
Message-ID: <37FEB8EB.609FA305@wmi.co.in>

Dear Stovers,
Just a few words to add to what Mr. Karstad has written.
I have found that polyvinyl alcohol (PVA) is a very good binder. It
comes in the form of a white powder, which when mixed with water and
heated, forms a colourless liquid. As it cools down it forms a gummy
gelatenous substance. One can heat it back to the liquid form before
adding to the char dough. Even a small quantity of PVA (about 1% by wt.
or so) gives very tough briquettes. I found that even hand pressed char
balls can be rendered unbreakable on sun drying if PVA is used as
binder. In my project, the economics did not turn out to be favourable
for use of PVA, but I feel that if the briquettes are to be mass
produced and transported over long distances, PVA can bring the loss due
to breakage down to almost 0%.
We generally use a mixture of clay + cowdung or paste of waste
grain, etc. Clay not only acts as a binder but it also influences the
burning rate. I have used black cotton soil (vertisol) which is formed
by weathering of basalt.
Another interesting organic binder is liquid jaggery. It is a fairly
good binder and the briquette gives a nice caramelly smell on burning.
With regards,
Priyadarshini Karve

Elsen Karstad wrote:

> Ramzi Khouri asks;
>
> >1) what do you think of Starch as a binder?
>
> Starch as a binder introduces an unburnt organic material to the
> charcoal briquette which produces some smell (varies with starch
> origin), some smoke (particularly during lighting) and does not
> significantly increase ash- this may or may not be desirable. Starch
> is usually derived from grain, and it's use could be considered as a
> diversion of a human food resource for use as a fuel component. It is
> probably a slightly superior binder than clay, though in my
> experience, differences are minimal. Both clay and starch are water
> soluble, and briquettes disintegrate when wet.
>
> I suspect (someone correct me if I'm wrong please) that starch binds
> best when subjected to high pressures, and allows for larger particle
> sizes to be effectively amalgamated into the briquette- the resultant
> briquette can be bulkier (lighter) and lower ash- quick to light.
> Clay works well under lower pressures with finer charcoal particle
> size, resulting in a dense briquette- harder to light & with a longer
> burning time. You may want to determine what the market requirement is
> in terms of burning time and lightability & select your binders
> accordingly.
>
> >2) if clay is used what is the kind of clay used?
>
> I use a Bentonite clay of volcanic origin- very common here in
> Nairobi, but would expect that most clays would exhibit similar
> binding effect.
>
> >3) is clay completely odorless and burns to ash?
>
> Yes. The briquette ash is of a reddish-brown colour.
>
> >4) what pressure is used in fabricating charcoal briquettes?
>
> I've not measured the pressure in my extruders- resistance is
> primarily determined by the length of the die-pipe that forms and
> extrudes the cylindrical briquette. See the stoves web-page for a
> photo of the extruder.
>
> >5) What kind or binders do commercial brands use?
>
> Often both starch and clay plus 'secret' ingredients. This is
> proprietary information and you won't get it from most commercial
> producers voluntarily....
>
> >6) Process of commercially producing charcoal briquettes, pressures,
> >temperatures etc
>
> Sorry- I have little information on standard processes, having
> developed my own... undoubably re-inventing a currently or previously
> used method. I do sympathize with the lack of readily available
> information of charcoal briquette manufacture. Possibly the
> agricultural engineering dept,. of a large university would have more
> specific information for you.
>
> elk
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Elsen L. Karstad , P.O. Box 24371 Nairobi Kenya
> elk@net2000ke.com tel/fax (+ 254 2) 884437

begin:vcard
n:Karve;Priyadarshini
tel;fax:-
tel;home:91 020 233258
tel;work:91 020 342217/4390348/4392284
x-mozilla-html:FALSE
url:http://members.tripod.com/ARTI_India/index.html
org:Appropriate Rural Technology Institue (ARTI)
version:2.1
email;internet:karve@wmi.co.in
title:Member
note:ARTI is an NGO undertaking research projects to study, develop, standardise, implement, commercialise and popularise innovative appropriate rural technologies with special emphasis on making traditional rural enterprises more profitable and generating new employment opportunities through introduction of novel business possibilities in rural areas.
adr;quoted-printable:;;2nd Floor, Maninee Apartments,=0D=0AOpposite Pure Foods Co., Dhayarigaon,;Pune,;Maharashtra;411 041;India
fn:Dr. Priyadarshini Karve
end:vcard

From larcon at sni.net Tue Oct 12 15:53:30 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:23 2004
Subject: Forwarding: Greetings from Hohenheim
Message-ID: <v01540b00b4294134916f@[204.131.233.4]>

Stovers:
The following is a nice introduction from two new subscribers.

Dr.Dr. h.c. W. Muehlbauer and Elmar:
Please do say hello to Dr. El Fadil. If you ever find a way to
communicate with him (now in Sudan) via e-mail, we on this list would much
appreciate obtaining that address as well
A convenient way to spread your interesting new work described
below is to send anything further in electronic form to Alex English, who
maintains a "stoves" webpage for us:

Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html

Alex can be reached at <english@adan.kingston.net>

Can you say anything at this time about the relative economics
and/or health impacts of your plant oils stove vs conventional (kerosene)
or soood stoves.

Again welcome to "stoves", and especially for your fine first
introductory message. Ron

>
>Dear Ron Larson:
>
>Thank you very much for your e-mail and also for giving us the chance of
>introducing our work to the mailing group. Actually, El Fadil did his Ph.D. at
>our institute and was working in the office right next to me (it's a small
>world, isn't it?). Do you have any message for him?
>
>We are looking forward being a part of the mailing list group!
>
>Thanks again!
>
>Sincerely,
>Elmar
>
>
>Development of a plant oil cooking stove
>
>Dear Stovers:
>
>We are very pleased being a part of the Stoves Mailing List and would like to
>take the chance to introduce us and our work shortly.
>
>Our Institute for Agricultural Engineering in the Tropics and Subtropics at
>Hohenheim University in Stuttgart, Germany develops applied technologies for
>developing countries and provides expertise on conservation tillage, water and
>energy saving irrigation systems, drying of agricultural products and solar
>energy utilization in rural areas.
>
>In one project we are developing a household cooking stove which can be fueled
>by pure plant oils only. As you all know, utilization of plant oils as cooking
>fuel is connected with numerous ecological, economic, and sociological
>benefits.
>
>
>The basic functioning of the stove is quite similar to the pressure kerosene
>stoves. Nevertheless, since physical and chemical properties of plant oils
>differ substantially from kerosene, a completely new design of the stove is
>required. For example, a new vaporizer was developed which enhances the
>retention time of the fuel within the flame taking into account the high
>ignition points of plant oil. A new start-up device adapted for plant oils was
>designed as well.
>
>We have already developed a preliminary stove which can be operated
>continuously
>with different pure plant oils. Right now we are working on the design of a
>prototype which can be tested within a developing country within the next
>year.
>
>For measuring the parameters and emissions of the stove a test bench is set up
>at our institute. Moreover we are working on basic investigations regarding the
>behavior of plant oils at high temperatures.
>
>If anyone of you has any further questions or ideas about our project please
>feel free to contact us any time. We would also be pleased to provide you more
>detailed information.
>
>Sincerely,
>Werner Muehlbauer
>Elmar Stumpf
>
>
>
>Prof. Dr.-Ing. Dr. h.c. W. Muehlbauer
>Dipl.-Ing. Elmar Stumpf, M.Sc.
>Institute for Agricultural Engineering in the Tropics and Subtropics
>University of Hohenheim (495)
>Garbenstr. 9
>70599 Stuttgart, Germany
>Tel.: +49 - 711 - 459 2840
>Fax: +49 - 711 - 459 3298
>e-mail: stumpf@ats.uni-hohenheim.de
>

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

From larcon at sni.net Tue Oct 12 17:15:48 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:23 2004
Subject: Forwarding Claudio Sbaraglio on charcoal prohibitions
Message-ID: <v01540b02b429484d3c6a@[204.131.233.32]>

Stovers (especially Rogerio):

The following message is in response to an earlier exchange in
which Claudio asked:

>>Is it true that since January 2001 it will be not possible to export wood
>>charcoal if wood is not from re plant?

I asked for more detail, after which I received this following
message. I wonder if anyone (maybe especially Rogerio - who might pass
this message on to the Bioenergia list) knows of any forthcoming
prohibitions on charcoal export (unless from a reforestation project) -
especially in Brazil or Argentina. Thanks in advance.

Ron

>Dear Ronal,
>
>thank you for your reply. I'm just asking because one brasilian
>exporter/producer of wood charcoal told me that since 1st January 2000 it
>will be proibited to export charcoal that comes from not re forestation.
>He referred especially to Argentina where there is not a re forestation
>program.
>
>If you could know something more please referre me. So I will do.
>
>Kind Regards
>Claudio
> "WLT Co." <wlt.co.@iname.com>

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

From larcon at sni.net Thu Oct 14 17:17:40 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding Prof. Grover long report - part 1
Message-ID: <v01540b03b42bf3fd5fce@[204.131.233.2]>

Stovers: The following document is sufficiently long that it is coming in
two parts. Professor Grover is a new member of "stoves" - but exceedingly
well known in the world of stoves, based on many years of outstanding stove
research and teaching in India.

This has also been sent to Alex English for putting on his web site
with better formatting (but I am sending this on without knowing if Alex
will be able to handle the better version. Give Alex a few days to get
word back on what he was able to accomplish.

Professor Grover: Thank you for a most interesting and large first report
from you. (I am sending it on quickly - and will comment also later after
having more time to read it.)

It is wonderful to have your first submission to the 160+ persons
now on this list. Welcome to our group.

Ron (The remainder is all from Professor Grover.)

14th Oct. 1999

Dear Stovers,

I am sending a concept of high performance stoves a you to a evaluate. =
If possible may construct a prototype and let me have the feed back. =
This concept was presented at FAO consultative meet of RWEDP at Phuket =
(7-9 Oct. 1999). I shall be pleased to provide any more details required =
by you.

Regards P.D. Grover
Address:
IRP Energy Consultants
44, Community Centre
East of Kailash
New Delhi - 110 065
Tele: 623 5026
Fax : 91-11-621 8273

COST ESTIMATES FOR A =91DREAM STOVE=92 FOR ASIA

PROF. P. D. GROVER*

1.0 INTRODUCTION

The role of adopting biomass fueled improved cook stoves in providing =
comparative convenience to users, control of indoor emissions in =
domestic sector and fuel savings is well recognized. This is evident =
from the fact that almost every country in Asia has their own programme =
of developing and disseminating improved cook stoves (ICS) amongst =
several million of households who cannot afford the modern clean and =
efficient fuels. As an example, India with its National Programme on =
Improved Chulhas, implemented since 1985-86, has so far promoted 28.50 =
million stoves against an estimated potential of covering 120 million =
rural and semi-urban households (1). A survey study has shown that an =
improved chulha saved fuel material equivalent to 210 kg of coal/soft =
coke, valued at Rs. 388 per year. In terms of kerosene, the savings work =
out to about 40 litres per chulhas per year, valued at Rs. 343 per =
household.=20

So far the thermal efficiency of these improved stoves has approached 25 =
to 35 percent, compared to 6 to 10 percent for traditional stoves. This =
implies that these stoves are still 65-75 percent inefficient and =
account for a tremendous energy wastage, considering the gigantic number =
of such appliances deployed in the domestic sector. The question that =
arises at this stage is whether these indicative efficiency and =
inefficiency numbers can be reversed. Presently, the answer may be an =
elusive one but the fact remains that the efficiencies have to be =
improved if we aim at sustainable development and take into =
consideration the negative role of green house gases being generated by =
these inefficient ICS. By any wood energy projection model, the fact =
remains that the wood energy is here to stay. Many people in Asia and in =
the world will continue to depend on wood to fuel their energy needs. =
Therefore, there is a need to maximize its utilization through efficient =
appliances. One is optimistic as high efficiencies have been obtained in =
similar industrial systems. For instance, a steam generation plant with =
88% thermal efficiency has been reported working on rice husk producting =
10 TPH of high pressure steam with 2000 kg/hr. of rice husk, at SEDA =
Distillery in Saluzzo (Italy), operational since 1983 (2).=20

Even at domestic level, a typical multipurpose wood fueled appliance, =
known as =91thermo kitchen=92, providing cooking, space heating and =
utility hot water can reach an overall thermal efficiency of 75-80%. A =
large variety of such models are being used in the villages of Europe, =
some of them using direct flame combustion while others have the =
inverted flame (down draft) combustion system (2).

However, these appliances are very large in their thermal output and =
also very expensive. The need is, therefore, to scale down these =
technologies used in such appliances and bring them to play their role =
in cookstoves at reasonable and affordable costs. The future cookstove =
development

programmes should be directed in this direction so as to have a stove in =
near future with an overall high performance. At present, such a stove =
may be termed as a "Dream Stove".

* Ex. I.I.T. Delhi

IRP Energy Consultants

44, Community Centre

East of Kailash, New Delhi - 45 India

2.0 REVIEW OF STOVE DEVELOPMENT

The developmental approach to cookstove design has been shifting between =
fuel efficient to emission efficient stoves. Between this shift, one of =
the development strategies adopted on a large scale was to improve their =
heat transfer efficiency and provide a chimney to take away the smoke. =
Although this approach helps in improving the indoor air quality but the =
quality of combustion still remains questionable in most of the designs. =
Incomplete combustion in such stoves not only tends to deposit products =
of incomplete combustion, mostly carbon soot and tars, in the flue =
ducting and chimney but also those products which remain undeposited =
escape into the atmosphere and are potential green house gases. The time =
has arrived that we should further improve these stoves and move up the =
energy ladder from presently developed ICS to high performance cook =
stoves (HPC).

A HPC stove should be both fuel and emission efficient. Both these =
aspects are so inter-related that an emission efficient stove will =
inherently have an efficient consumption of fuel. In other words, a high =
performance stove implies that other than CO2 and water vapours as =
unavoidable emissions of complete combustion, the associated undesirable =
emissions as products of incomplete combustion (PIC) should be minimized =
or totally eliminated. These also include avoidance of thermal emissions =
(called thermal pollution) and particulate emissions. The traditional =
cookstoves, because of their very low efficiency, emit more than 10% of =
their carbon as PIC comprising varying amount of tars. In addition, =
about 100 to 180 g of carbon monoxide and 7.7 g of particulate matter =
are also emitted per kg. of wood. In comparison, one kg of charcoal used =
for cooking in metal stoves emits 250 - 350 g of carbon monoxide, but =
less (2.4 g) of particulate matter. These PIC emissions do increase when =
loose biomass or cowdung are deployed for cooking in these stoves.=20

Furthermore, it should be understood that the efficient use of wood is =
much more eco-friendly than the use of more efficient and convenient =
fuels, such as kerosene and LPG, so far as emission of carbon dioxide is =
concerned which is the principal source of global warming. The CO2 =
emission factor for fuel wood is placed as 5.1 kg CO2/GJ compared with =
corresponding figures of LPG of 76.6 kg CO2/GJ and for natural gas as =
49.5 CO2/GJ (3).

3.0 STRATEGY FOR DEVELOPMENT

The development approach for HPC requires a directed focus towards the =
production of emission efficient stoves, irrespective of whether the =
emissions take place either indoor or into the outdoor atmosphere. =
Emissions are emissions and must be prevented to safeguard the =
environment. This approach will automatically provide a large saving of =
fuels. For sustainable development, this becomes mandatory because wood =
consumption for energy is going to stay with us whether we want it or =
not. According to FAO report,(3) the wood fuel consumption in Asia is =
projected to go upto 11,600 PJ in 2010 from 8,304 PJ in 1994 at the =
prevailing consumption growth rate of averaging 2.1% per annum. The =
stove development strategy should, therefore, be primarily directed =
towards getting complete combustion of fuel to avoid emissions along =
with maximum reduction of heat losses to the atmosphere, unless these =
heat losses are needed towards space heating as an additional utility. =
These process conditions would provide clean and total combustion of =
biomass leading to the development of high performance stoves. A stove =
with these features is being termed as a =91Dream Stove=92.=20

Understanding the combustion process provides the ability to manipulate =
it for maximum thermal efficiency and minimum pollution production. =
Before the concept of a "Dream Stove" is initiated it is pertinent to =
review the related aspects of biomass combustion.

4.0 BIOMASS COMBUSTION

The combustion of solid fuel encompasses a series of complex reactions =
whereby carbon and hydrogen in the fuel chemically react with =
atmospheric oxygen to form CO2 and H2O while liberating usable heat. The =
mechanisms of combustion include:

particle heating and drying, pyrolysis, gas phase precombustion =
reactions, combustion reactions, char oxidation reactions and =
post-combustion reactions. Without going into their details we will =
consider only a general model as shown in figure - 1 comprising stages =
of wood heating and drying, solid particle pyrolysis, gas phase =
reactions and char oxidation reactions.

Stage - 1 Heating and Drying

Initially the wet biomass fuel particle is heated to the point when its =
pyrolysis begins. This stage of heating and drying is dominated by =
physical reactions and greatly influenced by the fuel moisture content. =
Higher moisture content reduces the energy availability of the fuel but =
enhances the heating process due to higher fuel thermal conductivity.

Stage - 2 Pyrolysis

Once the fuel particle is dried and heated to temperatures approaching =
225 - 3250 C, thermal breakdown (pyrolysis) of hemicellulose starts =
continuing to pyrolyse other biomass constituents (cellulose and lignin) =
as the temperature reaches towards 5000 C. Pyrolysis releases volatiles =
and gaseous products and solid char, the proportion of these heavily =
depends upon particle size, ultimate temperature, and rate and time of =
heating.=20

Stage - 3 Gas Phase Reactions

The volatiles produced during pyrolysis are a vast array of products and =
undergo complex array of sequential reactions in order to achieve their =
total combustion. In order to initiate and sustain clean and total =
combustion of these volatiles, the larger molecular constituents of =
these volatiles have to be fragmented into lower order molecules by =
maintaining high temperatures, turbulence and residence time in the =
combustion chamber. Normally in a typical stove these processes are left =
to the geometry of its combustion chamber and flue gas pathways. Before =
completion of these processes if these flaming gases are quenched by =
taking away heat by a cook pot, these volatiles remain unreacted and =
produce smoky flame. Therefore, providing proper conditions or =
incorporating any additional facility in the stove for fragmentation of =
these large molecules (tars etc.) is the key to getting clean and total =
combustion.

Stage - 4 Char Oxidation reactions

During pyrolysis char is also produced which gets combusted with air by =
surface reactions. Initially as CO and H2 are generated which inturn =
provide clean burning. The char oxidation reactions are much slower than =
the gas phase flaming reactions. This hot char can also be utilized for =
the thermal cracking or fragmentation of tarry volatiles to obtain clean =
combustible gases as practiced in down draft gasifiers.

5.0 COMBUSTION CONCEPT IN A =91DREAM STOVE=92

The purpose of reviewing the combustion mechanism is to try to =
incorporate separate stages of combustion in a stove. Instead of having =
only one combustion chamber to allow all the competing reactions of =
various stages to take place, the proposal is to incorporate more than =
one stages in a stove to manipulate total combustion. Furthermore, this =
conceptual stove should have only minimum number of stages so as not to =
complicate its design and operation. The concept being proposed is not =
new but it is similar to a system comprising a combination of downdraft =
gasifier and gaseous burner, both combined in a single cookstove. =
Accordingly, for a "Dream Stove" a combination of only two stages is =
proposed. First stage is for heating, drying and pyrolysis of fuel with =
minimum amount of air followed by a second stage in which the gaseous =
pyrolytic products are thermally cracked and then burnt clean with =
additional secondary air. The thermal cracking of tars is facilitated by =
passing the volatiles over hot and burning charcoal kept in the second =
stage. This implies that this stove is first started as charcoal stove =
in the second stage, with left over charcoal by the previous operation, =
followed by initiating controlled combustion in the pyrolysis chamber, =
stage - 1. Though it may seem slightly complicated but the advantages =
obtained in overall performance over weigh this extra effort as one is =
expected to get clean charcoal fire in a wood fired stove. Conceptually =
the process is shown in Figure - 2.

Charcoal Cooking

Fuel Flue

Primrary air Secondary air

Figure - 2. Concept of combustion in a "Dream Stove"

Stage - I . Heading, Drying & Pyrolysis Stage - I I .Thermal Cracking of =
Tar and Clean Combustion.

The advantages of staged combustion are many. Because of destruction of =
tars and other larger molecules of volatiles the combustion obtained is =
clean and PIC are eliminated. Apart from clean and complete combustion, =
the other main benefit of stage combustion is the reduction of emissions =
especially those of particulates. Junge, (4) has demonstrated that =
particulate carry over in biomass combustion is minimized during staged =
combustion. Staged combustion amounts to the using of sub-stoichiometric =
quantities of air in pyrolytic stage with excess air being introduced as =
secondary air. The optimum percentage of air introduced as over fire or =
secondary air appears to be in 55 - 60% of total air range. The effect =
of overfire air on carry over of particulates in Industrial applications =
is given in figure - 3.

(End of section 5 - Sections 6-11 are in Part 2 of this forwarded message)

From larcon at sni.net Thu Oct 14 17:17:50 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding Prof. Grover long report - part 2
Message-ID: <v01540b05b42bf66ef2a3@[204.131.233.2]>

Stovers: The following is the second and last part of a report from Prof.
Grover. See also (hopefully) a more readable version at the Alex English
web site:
http://www.ikweb.com/enuff/public_html/Stoves.html

(The rest (Sections 6-11) is from Professor Grover. Ron)

6.0 EXPECTED THERMAL EFFICIENCY OF A =91DREAM STOVE=92

In order to arrive at a reasonable value of thermal efficiency of a =
"Dream Stove" it is desirable to first calculate the maximum theoretical =
efficiency possible under ideal and pseudo practical conditions. The =
data of such an exercise is presented below:

EXERCISE - I=20

BASIS:

(a) Wood fuel with 15% moisture and 3% ash.

(b) No losses other than heat losses from the flue gases.

(d) Heating value of wood is taken as 4800 kcal (=BB 20 MJ) per kg on =
dry basis or 4080 kcal/kg with 15 percent moisture.

Table - I Loss of Heat with Flue Gases

Percentage Excess air

(%)
Percentage Heat taken away by flue gases at 1500 C

(Sensible heat + latent)
Stove efficiency

(%)
=20
(Stoichiometric)

0
14.4
85.6
=20
30
16.2
83.8
=20
50
17.3
82.7
=20
100
20.2
79.8
=20
=20

Table - I shows that with control of excess air about 80 percent thermal =
efficiency of a stove can be obtained. It may be mentioned that staged =
combustion system would need lesser excess air than that required for a =
conventional single stage stove. Apart from major losses through the =
flue gases, there are other heat losses which cannot be eliminated but =
can be minimized by taking up appropriate measures. In order to quantify =
other various losses, the data developed by Sharma (5) and reproduced as =
Table - I I is taken into consideration.. Analyzing this data, it can be =
concluded that the major heat losses in ICS are the unknown losses =
amounting to as high as 40 percent for a single pot stove. These are =
basically due to incomplete combustion. Other major losses are due to =
sensible heat gained by multipot stoves amounting to as high as 39 =
percent when the useful heat component varies from 25 to 29 percent. =
Apart from achieving complete combustion, it is also desired to minimize =
these losses which can be achieved by using proper light-weight and =
effective insulation. For this insulation an optimum use of ceramic =
fibre blanket of 25 mm thick is recommend for a "Dream Stove".

Ceramic fibre blankets have very low thermal conductivity, about 16% of =
any dense refractory material, are light weight (65 - 192 kg/m3) and =
extremely cost effective. The relative cost of ceramic fibre blanket of =
25mm thickness is about 20 percent of an equivalent 135 mm dense =
refractory. Ceramic fibres can withstand temperatures up to 13000 C =
compared to mineral wool upto 7000 C and glass fibre upto 4500 C. Use of =
ceramic fibre can drastically improve the performance of a cookstove.

Table I I Results of the thermal performance of various stoves(5)

Considering the data given in Tables I & I I and based on experience =
gained with Industrial furnaces working on wood, it is possible to =
restrict the various heat losses from cook stoves to the values given in =
Table I I I . Also the techniques that are deployable to attain these =
values are provided.

Table - I I I Maximum limits of Heat losses expected from A "Dream =
Stove"

Avenue of heat losses
Percentage=20
Techniques Deployable
=20
Flue gases
=20
20=20
Minimize excess air=20

Maximize heat transfer

Gases outlet temp. =BB 1500 C
=20
Radiation losses from stove body
=20
4
Proper insulation with enclosed fire
=20
Sensible heat gained by stove
=20
5
Minimizing the stove weight and use of effective and light =
weight insulation around hot zones.
=20
Heat losses through ash and charcoal handling
=20
2
Minimized by enclosed operation and preheating the air over =
hot ash
=20
Unknown losses
4
Minimized by careful operation
=20
Useful heat=20
65
Balance
=20

This above mentioned value of 65% thermal efficiency can also be =
justified by comparing a "Dream Stove" with a combined system of a =
gasifier (80 - 85% efficiency) and gas combustion burner with cooking =
efficiency of 80%, providing an overall efficiency in the range of 64 to =
68 percent. Compared to present ICS efficiency of about 25-30 percent, =
this may seem like a dream but with innovative approach it should be =
achievable. Detailed analysis of existing stoves, design of stoves with =
staged combustion, intensive prototype and extensive fields testing =
programmes have to be continued to develop this "Dream Stove".

7.0 PROPOSED DESIGN OF A "DREAM STOVE"

Many design configurations of "Dream Stove" are possible. Some of these =
are conceptualized and given in figure-4. All of these may not initially =
give desired thermal efficiencies but one fact is clear that they will =
provide complete combustion and a significant reduction of PIC. Multipot =
approach (figure - 4b) should provide efficiencies approaching the =
anticipated values compared to the single pot stoves (figure - 4a).

In all these configurations, chamber I is meant for drying and pyrolysis =
of biomass operating under starved air producing pyrolysis gases and =
wood charcoal. The pyrolysis gases are allowed to pass through chamber - =
I I which is basically a charcoal burning chamber meant to crack the =
volatiles before these are combusted.

The stove operation is first started in the chamber I I using left over =
charcoal from from the previous operation using any suitable ignitor and =
cooking operation is initiated. Immediately afterwards pieces of wood =
are added into the chamber I and ignited with small pieces of wood. A =
damper is needed for chamber I to minimize the ingression of primary =
air. Another damper for secondary air will also be a useful addition. =
Once the cooking operation is complete, the dampers are closed to stop =
the pyrolysis process and the charcoal produced is not allowed to burn =
but retained for the next operation. In case the cooking operation is =
required for a lengthy period of time a part of hot charcoal from =
chamber - I can be manually transfered to chamber - I I . At the end of =
cooking, quenching of charcoal can also be done by a mild sprinkling of =
water.

Along with charcoal some refractory pieces should also be added which =
will offer additional surface area for the cracking of volatiles. The =
quantity and sizes of these refractory pieces can be optimized by the =
developers to provide clean and complete burning of volatiles. It may be =
reiterated that the proposed "Dream Stove" is to provide absolute clean =
combustion similar to the one experienced by the burning of L.P.G. with =
minimum manipulation by the users.

In case loose biomass is utilized as fuel, configuration (4-c) is an =
ideal design. Since the char produced in this stove shall be in powder =
form, this will have to be briquetted using 30 percent moist clay into =
lumps or as beehive briquettes using hand moulds. Any type of convenient =
operation or design can be adopted but the basic requirement of any =
stove is that two chambers have to be provided to get clean and complete =
combustion.

8.0 COST ESTIMATION

Out of three configurations proposed in figure - 4, the single pot =
vertical (4-a) and multipot horizontal stoves (4-b) can be built in =
traditional materials coupled with modern insulating materials. =
Accordingly, these are comparatively cheaper than the single pot-radial =
stove for loose biomass which has to be built in metal. Since A "Dream =
Stove" has to be not only efficient but should also be made available at =
affordable costs, the cost estimates for only single and multipot =
configurations have been carried out.

The cost estimation of any new appliance is normally based on the cost =
of similar systems for which sufficient experience is available. =
Accordingly, in this particular case the cost of a multi-pot stove is =
based on a similar three pot ICS known as "Rohini" which is fairly =
popular in India (6). The proposed two pot "Dream Stove" is similar to =
"Rohini" model, given in figure -5 except for the following =
modifications. The modified "Rohini" stove converted into a Two Pot =
"Dream Stove" is shown in Figure - 6.

Modifications:

1. The first pot chamber of "Rohini" stove is converted into Stage - 1 =
of the "Dream Stove" mean for pyrolysis of wood by providing a proper =
side damper, closing the top end with an insulated enclosure and =
providing a suitable grate for proper distribution of primary air.

2. The second pot chamber of Rohini stove is converted into stage - I I =
of the "Dream Stove" meant for cracking and combustion of pyrolytic =
gases by providing a charcoal grate and used as first chamber for =
cooking.

3. The pot three of Rohini stove acts as the second pot for cooking in =
the "Dream Stove".

4. To conserve heat losses, all stages I , I I , I I I and intermediate =
flue ductings are fitted with 20 mm thick fired clay liners backed by =
25mm thickness of ceramic fibre blanket. This technique would avoid the =
heating of stove body and considerably reduce the sensible heat losses =
to heat up the large mass of the stove.

5. Holes for secondary air entrance with damper are provided between =
stage I and I I . The main body of the stove can be constructed in three =
possible types of material. These are:

(i) Entirely made from local clay as in Rohini model

(ii) Made in cement mortar construction for longer life and low =
maintenance

(iii) Made in local clay with outer body cladding of 1.5 mm thick steel =
for enhanced life and clean appearance

(iv) Made in cement mortar with cladding of 1.5mm thick m.s. plate for =
maintenance free operation.

Based on the dimensions of the two pot "Dream Stove" shown in figure - =
6, the quantities of different materials deployed for construction and =
their unit costs are given in Table I =D1=20

Table I =D1 Materials of Construction and Costs

Material
Quantity
Density

kg/m3
Unit Cost

Rs./Kg.
Material Cost

(Rs.)*
=20
Clay (Mud)
0.047 m3
1,800
0.40
35
=20
Cement Concrete
0.047 m3
2,300
1.25
135
=20
Fire clay=20

liners 20 mm thick
0.009 m3
2,200
10
200
=20
Blanket 25 mm thick

(ceramic fibre)
0.45 m2
65 - 192
=BB 325/ m2
150
=20
Steel Casing 1.5 mm thick
1.2 m2
7800
=BB 30
420
=20
Chimney Steel
7.5 =C6 x 350 L
7800
30
400
=20
Chimney ceramic
7.5 =C6 x 350 L x 2 TH
-
-
300
=20
=20
*(Based on Indian Cost Data. US $ =3D Rs. 43.5)

In addition, the stove shall have two air dampers; one each for primary =
and secondary air and two grates for the stages I - I I . The estimated =
costs of these accessories is around Rs. 50. Having inventoried the =
materials required (Table I =D1 ) for the construction of two pot stove, =
the cost estimates for various options are now provided in Table - =D1=20

Table - =D1 Cost Estimates Of Two Pot "DREAM STOVE"

Stove
Material Cost

(Rs.)
Labour

(Rs.)
Total

(Rs.)
=20
clay body, ceramic pipe chimney without ms casing
735
125
860

(US $ =3D 20)
=20
cement body ceramic pipe chimney without ms casing
835
125
960

(US $ =3D 22)
=20
Extra ms casing
-
-
420

(US $ =3D 9.70)
=20
=20

8.1 SINGLE-POT-STOVE

The cost of a two pot stove is rather high and is unaffordable by =
majority of users. In that situation a single pot stove without ms =
casing and chimney will be cheaper and so desirable to develop. =
Accordingly, the quantities and type of materials required for a single =
pot stove, based on the design given in Figure-4a, have also been =
determined and are given in Table - =D1 I .

Table: VI Material Costs for Single Pot =91DREAM STOVE=92

Materials
Quantity
Material Costs
=20
Fire clay liners
0.0047 m3
105
=20
Ceramic fibre blanket
0.24 m2 (25 mm thick)
80
=20
Clay
0.01 m3
10
=20
Cement
0.01 m3
40
=20
Steel casing (1.5 mm Th.)
0.4 m2 (optional)
140
=20
Two dampers and one charcoal grate
-
50
=20
=20

The overall cost of single pot stove of various options is given in =
Table - VII.

Table - =D1 I I Cost Estimates of Single Pot Stoves

Stove
Material Costs

(Rs.)
Labour

(Rs.)
Total

(Rs.)
=20
Stove in clay with ceramic liners
245
100
345

(US $ 8.00)
=20
Stove in cement with ceramic liners
275
100
375

(US $ 8.62)
=20
ms casing (optional)
140
-
140

(US $ 3.25)
=20
=20

The single pot "Dream Stove" could be made available at a cost ranging =
from $ 8.0 to $ 12.0 a piece. Like any other items, this cost can be =
reduced by having mass production and using local materials having the =
same thermal and mechanical properties. So the development activities =
should also be directed towards selecting cheaper materials for =
construction without sacrificing their essential properties to restrict =
heat losses. The heat losses directly affect the desired temperatures =
within the stoves which in turn have direct bearing on the quality of =
combustion. The main emphasis for the development of "Dream Stove" has =
to be on the core aspect of quality combustion and its related fallout =
on emission quality.

9.0 DESIGN OF COOKING POT

Another major aspect in cookstove development is to have a cooking pot =
which can offer optimum surface area for heat transfer and can cook more =
than two food items in multiple sub-compartments. These separate food =
compartments are arranged in such a manner that the steam evolved from =
the bottom most compartment can condense on the upper compartment =
thereby providing fuel economy in a similar manner as in multi-effect =
evaporators in Industry. This is another area of development which is =
important and should be adopted as an integral part of "Dream Stove" =
development.

10.0 CONCLUSIONS

By any stretch of dreaming and imagination, it is not impossible to have =
a biomass cook stove with total combustion and an approachable =
efficiency of around 65 percent, and also made available at an =
affordable cost. The basic concept to be adopted is to aim for total =
fuel combustion. The total fuel operation, desirable for micro and macro =
level control of atmospheric pollution, leading to better life for all =
the inhabitants of this universe.

11.0 REFERENCES:

1. Ministry of Non-Conventional Energy Sources, Govt. of India, Annual =
Rep., 1998-99.

2. Biomass Combustion Technologies, CNRE guideline No. 1, pp.66-68, FAO =
publication, 1988.

3. Trossero, Miguel. A, Ed., The role of wood energy in asia, FAO =
working paper, FOPW/97/2, Nov., 1997.

4. Junge, D.C, Design Guideline Handbook for Industrial Boilers Fired =
with Wood and Bark residue fuels, Oregon St. uni., Corvallis, Oregon, =
1979.=20

5. Sharma, S.K, Improved Solid Biomass Burning Cookstoves, RWEDP, Field =
Document No. 44, pp.66, Sept., 1993.

6. Sharma, S.K. Improved Solid Biomass Burning Cookstoves, RWEDP, Field =
Document No.44,pp.88,Sept.1993.

From Alex.English at adan.kingston.net Fri Oct 15 22:44:27 1999
From: Alex.English at adan.kingston.net (*.english)
Date: Tue Aug 31 21:36:24 2004
Subject: Prof. Grover's Paper
Message-ID: <199910160248.WAA03660@adan.kingston.net>

Dear Stovers,
Prof. Grover's paper,
COST ESTIMATES FOR A `DREAM STOVE' FOR ASIA
can be found in the New section of the Stoves webpage.

Alex
Alex English
RR 2 Odessa, Ontario, Canada
K0H2H0 613-386-1927
Fax 613-386-1211
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Fri Oct 15 23:52:02 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding request on hay-burning (older, US) stove
Message-ID: <v01540b00b42da73c8d3b@[204.131.233.19]>

Stovers - This sounds like a problem for anyone with a technology history
background. Anyone able to help?

There have been some past discussions on this list about the use of
straw in some developing country stoves - anyone have some ideas from
modern usage that might be pertinent as well.

Millard - Your address came through with only one "l" - so I am responding
both ways. Please clarify. Feel free to send us more information on your
reason for writing.

Ron

>To: stoves@crest.org
>Subject: Hay Burner
>Content-Type: text/plain; charset=us-ascii
>Content-Transfer-Encoding: 7bit
>
>Having e-mail address problems so BE SURE the "l" is in dbleagle. Now
>for the request, I'm seeking a source for information on a type of
>heating/cook stove called a "Hay Burner" it was apparently used
>primarily in the plains states and of course the primary fuel was
>twisted up hay and grasses.
>Thank you
>Millard
>Anchorage AK
>

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

From larcon at sni.net Sat Oct 16 21:53:47 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding Donnay on effects of CO
Message-ID: <v01540b01b42eaa0cb5f4@[204.131.233.19]>

Stovers: I saw the following on the IAQ list and thought our list might
find it intriguing. I asked the author, Albert Donnay, for a bit more
information to which Albert responded:

>
>thanks for your interest. please do forward this to your list and request
>comment. mcs= multiple chemical sensitivity
>cfs=chronic fatigue syndrome
>hope this helps.
>--albert
>ps. worst indoor coal gas problems in the world are in China.
>
Anyone have any first-hand data on the medical impacts of CO
exposure (from stoves) to pass on back to Mr. Donnay?

Ron

The following is what appeared on "IAQ"

>> Date: Tue, 12 Oct 1999 16:47:46 -0400
>> From: Albert Donnay <adonnay@bcpl.net>
>> Subject: Poe Suffered MCS&CFS from CO Poisoning
>>
>> In a paper given at the International Edgar Allan Poe Conference in
>> Richmond VA on 9 October 1999, I presented evidence in support of my
>> hypothesis that Poe may have suffered from MCS and CFS as a result of
>> carbon monoxide poisoning from his occupational and residential
>> exposures to illuminating gas. (In the 1830s and 1840s when Poe was
>> exposed, illuminating gas was made from coal and contained 5% or
>> 50,000ppm CO; automobile exhaust, in comparison, contains 1% to 10% CO,
>> depending on the age and condition of the car.)
>>
>> The evidence for this hypothesis includes:
>>
>> * the many symptoms Poe describes in his letters, all consistent with CO
>> poisoning, MCS and CFS.
>>
>> * the many symptoms Poe describes in 14 of his tales and 3 of his
>> poems. Examples from the 6 tales in which these symptoms are central to
>> the story are posted at <A
>> HREF="http://www.mcsrr.org/poe/symptoms.html">http://www.mcsrr.org/poe/sympt
>> oms.html</A>. The
>> Fall of the House of Usher alone describes a total of 30 symptoms, and
>> MCS patients whose illness began with a documented chronic CO exposure
>> (lasting weeks to months) report experiencing an average of 27 of these
>> in the last month, compared to healthy controls who report an average of
>> only 2. (I'd like to hear from anyone *with MCS due to CO poisoning*
>> who scores below 20, and anyone *without MCS or CO poisoning* who scores
>> above 20)
>>
>> * the diagnoses made of Poe during his lifetime and on his deathbed by
>> medical professionals, all of which are consistent with CO poisoning
>> (heart disease, nervous exhaustion and brain congestion)
>>
>> * 15 of the 20 theories proposed in the 20th century to explain Poe's
>> illness also are consistent with CO poisoning.
>>
>> * unequivocal evidence that at least one of his homes (on 7th St in
>> Philadelphia, now a National Park Service museum) was originally built
>> with illuminating gas, and evidence suggesting some of the publishers'
>> offices in which he worked in Philadelphia and New York as well as the
>> hospital in which he died in Baltimore also may have been gas-lit.
>>
>> * daguerreotypes of Poe that show one of his eyes drooping lower than
>> the other, while his mouth droops slightly on the other side (note this
>> is not Bell's Palsy, in which the droops would both be on the same
>> side). Poe's unusual abnormality is a clear sign of some kind of
>> neurological injury, and it is also seen today in some people today with
>> MCS, but it is not reported in any neurology textbooks and none of the
>> neurologists I spoke with about this had ever heard of it.
>>
>> In order to increase public awareness of CO poisoning -- still the
>> largest source of accidental toxic death and injury in North America --
>> I created a poster with Poe's image (courtesy of the Maryland Historical
>> Society) entitled "The Tell-Tale Face of Carbon Monoxide Poisoning" that
>> lists CO symptoms, populations at risk, sources, effects and
>> treatments. It was unveiled at the Poe Museum in Richmond on the
>> opening night of the International Poe Conference, 7 October 1999, the
>> 150th anniversary of Poe's death, and will remain on permanent display
>> there.
>>
>> The 11x17 poster also is being distributed free (with a long list of
>> references) to all emergency rooms in the US and Canada by CO Referral &
>> Resources (a new project of MCS Referral & Resources), thanks to a grant
>> from AIM Safe Air Products, a Canadian manufacturer of CO alarms
>> (1-800-ASK-4-AIM). A thumbnail of the poster may be seen at
>> www.mcsrr.org, and free copies are
>> available.
>>
>> Newspaper articles about my Poe hypothesis appeared October 9 in the
>> Toronto Star and other Canadian papers, and the Baltimore Sun discussed
>> it in a feature story on October 11. A <A
>> HREF="http://www.reutershealth.com/cgi-bin/ssi/framethis?catalog=eline&file=
>> 1999101117.html">ReutersHealth wire story</A> was released October 12
>>
>> --Albert Donnay, MHS
>> President, MCS Referral & Resources
>> (and now also CO Referral & Resources)
>> adonnay@mcsrr.org
>> 410-362-6400, fax 362-6401
>> 508 Westgate Rd, Baltimore MD 21229
>>
>> Ronal W. Larson, PhD
>> 21547 Mountsfield Dr.
>> Golden, CO 80401, USA
>> 303/526-9629; FAX same with warning
>> larcon@sni.net
>
>
>
>--
>
>-- Albert Donnay, MHS
>President, MCS Referral & Resources, Inc.
>adonnay@mcsrr.org, www.mcsrr.org
>508 Westgate Rd, Baltimore MD 21229
>410-362-6400, fax 362-6401
>

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

From dstill at epud.org Mon Oct 18 01:55:28 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:24 2004
Subject: reply to Dream Stove paper
Message-ID: <000701befd2b$1b43c5c0$da0e66d1@default>

First, let me express thanks to Professor Grover for such a pleasant
article. It was a pleasure to read and has stimulated much animated
discussion.

I certainly do not wish to be brash but I am moved to state contrary
opinions. I believe that there is a flaw in the reasoning behind Professor
Gover's explanation of how to produce a 65% efficient wood stove for
cooking. In my opinion, the stove movement often overemphasizes the gains to
be made from improved combustion while underestimating the limitations of
the pot as a poor heat exchanger.

I believe that Professor Dan Kammen made the same mistake in his article
summarizing progress in woodstoves for "Scientific American". The idea that
improvement in stoves comes from improving combustion is, I believe, a
paradigm that while commonly accepted does not lead to the most fruitful
work.

Professor Grover states, "Analyzing this data (Sharma), it can be concluded
that the major heat losses in the improved cook stoves are the unknown
losses amounting to as high as 40 percent for a single pot stove. These are
basically due to incomplete combustion." He goes on to very rightly point
out the usefullness of insulation in thermally isolating the stove body from
the heat flow path, reducing absorption into the mass. But, our tests
contradict his assumption that improving combustion is the component that
greatly increases overall stove efficiency.

System efficiency is dramatically improved by increasing the efficiency of
the least efficient component. Combustion efficiency in a smoldering fire
can be about 60 to 70 percent. That percentage of the stored BTU's become
heat. It is relatively easy to encourage 90 percent and above combustion
efficiency. Metering the fuel, insulating the combustion chamber, and making
a hot, fierce fire achieve almost complete combustion. One can also go the
route of gasification. Or make a good, experty tended, three stone fire.

But, the pot is a terrible heat exchanger. So only a small percentage of
heat actually gets into the water and food. The percent of heat that makes
it into the food can be increased by exposing more of the pot surface area
to hot flue gases, optimizing heat absorption at the pot surface, using
multiple pots, etc.

For example, the bigger the pot, the greater the heat transfer efficiency.
Full pots score better than half full pots. A skirt around the pot
dramatically improves efficiency. Covered pots save fuel.

Professor Grover ends his report by including a paragraph on pot design. I
heartily agree with him that a new pot, designed to increase surface area to
volume ratio, and that forces heat to rub against the pot surface would
dramatically improve fuel economy. Effort spent in improving the pot as heat
exchanger is many times more likely to improve cooking stove efficiency than
improving the combustion side of the equation.

Complete combustion reduces exposure to harmful smoke. All stoves should be
designed to reduce such exposure. But complete combustion, in my opinion,
does not greatly increase the overall efficiency of the improved cook stove.
To dramatically reduce fuel use, instead improve heat transfer to the pot or
better yet, use a retained heat cooker (haybox).

With best regards,

Dean Still

From larcon at sni.net Mon Oct 18 14:46:40 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Following up on Dean Still reply to Dream Stove paper
Message-ID: <v01540b01b43106a2b3b3@[204.131.233.25]>

Dean said:
<snip>
>In my opinion, the stove movement often overemphasizes the gains to
>be made from improved combustion while underestimating the limitations of
>the pot as a poor heat exchanger.

This is mainly to provide strong support for Dean's comments on the
importance of optimizing the heat transfer to the cook pot.

Dean:
<snip>
> It is relatively easy to encourage 90 percent and above combustion
>efficiency. Metering the fuel, insulating the combustion chamber, and making
>a hot, fierce fire achieve almost complete combustion. One can also go the
>route of gasification. Or make a good, experty tended, three stone fire.
>
Ron:
I still am in the process of getting my own response to Professor
Grover's article, but want to add a bit on the value of pyrolysis vs
gasification. I am pretty sure those of us working on charcoal-making
stoves are always seeing something well above 99% combustion efficiency -
we measure almost no CO and experience essentially no odor. (Alex - I hope
you can confirm this with more quantitative results.)

But I see a main value of charcoal-making stoves in being able to
drive ordinary charcoal-makers out of business. Their usual combustion
efficiency is close to 0% (of the emitted gases - with value remaining only
in the charcoal). When they emit CO2, they are losing their main product.

I do not believe that Professor Grover is aware of the past
discussion on this list of this new approacah to pyrolysis stoves. In
particular - it is not necessary to have a down-draft design to achieve
pyrolysis.

Dean, continued:
>But, the pot is a terrible heat exchanger. So only a small percentage of
>heat actually gets into the water and food. The percent of heat that makes
>it into the food can be increased by exposing more of the pot surface area
>to hot flue gases, optimizing heat absorption at the pot surface, using
>multiple pots, etc.
>
>For example, the bigger the pot, the greater the heat transfer efficiency.
>Full pots score better than half full pots.

Ron:
Dean - can you add any experimental data you might have about
efficiency as a function of the size of the pot. It would seem that there
might be an optimum size (for a given cooking (ie weight of water) job) -
as the surface area will increase radiation losses from a very wide pan.

Has anyone else on the list ever seen such data or conducted tests
where the only variable was the size of the cook pot?

Dean:
> A skirt around the pot
>dramatically improves efficiency. Covered pots save fuel.

Ron:
The best analytical (which doesn't include experimental) work I
have seen on "skirts" is in list-member Sam Baldwin's PhD thesis. I think
I got close to 50% efficiency once when I was using a double metal sleeve
with apparently the right dimensions. Dean has previously reported that
the optimum gap is less than a centimeter (and such separation numbers also
depend on the height of the pot).

In the early days of the "stoves" list we also sometimes referred
to a stove figure of merit - the ratio of the weight of water that could be
boiled away (pot top off in this experimental study environment) for a
given weight of wood (where a credit would of course be given for making
charcoal). In the charcoal-making case, I recall we were talking about
getting about an FOM of 1 - and that wasn't easy experimentally. I'll try
to find my efficiency computations on what an FOM = 1 means in efficiency
terms - but I think it is around 50% (with credit given for the charcoal -
which is usually 25% by weight).

Dean:
>Professor Grover ends his report by including a paragraph on pot design. I
>heartily agree with him that a new pot, designed to increase surface area to
>volume ratio, and that forces heat to rub against the pot surface would
>dramatically improve fuel economy. Effort spent in improving the pot as heat
>exchanger is many times more likely to improve cooking stove efficiency than
>improving the combustion side of the equation.

Ron:
Professor Grover was encouraging also more development work on the
concept of vertical stacking of cook pots - which seems to be done in
China. Are there any list members who can comment on how much efficiency
improvement is to be found with vertical pot stacking? The capture of the
energy in that evaporated water is of course well worth striving for.

The modern gas-fired water heater efficiency is well above 65%.
This is achieved by having a very tall narrow design with only a narrow
interior heat transfer surface. (The last (failed) one of mine that I
could look at had one interesting interior long "wavy" vane also). The
nearest cookpot equivalent of which I am aware is the Russian samovar
design - on which we have had considerable discussion - but no concrete
efficiency numbers. Anyone able to supply any experimental data on the
efficiency gains of putting the hot flame gases through the middle of the
pot rather than around it?

I am afraid that a major problem will occur with making pots with
such a shape - but there is no sense even worrying about this if the
efficiency improvement is not good. Any data? I have a test in mind, but
no time to carry it out.

Dean:
>Complete combustion reduces exposure to harmful smoke. All stoves should be
>designed to reduce such exposure. But complete combustion, in my opinion,
>does not greatly increase the overall efficiency of the improved cook stove.
>To dramatically reduce fuel use, instead improve heat transfer to the pot or
>better yet, use a retained heat cooker (haybox).
>
>With best regards,
>
>Dean Still
>
Dean - Thanks for reminding us of this important (I agree is now
the most efficiency important) aspect of cook-stove (through pot/sleeve)
design. I doubt that Professor Grover will disagree with your remarks as
they apply to efficiency.

But I don't think you at Approvecho have yet reported on any work
with Pyrolysis-type stoves - which I took to be a main thrust of Prof.
Grover's paper (in order especially to improve combustion efficiency for
reasons of health). Have you all yet constructed and experimented with any
such stove? I am not suggesting the down-draft approach or gasification -
but rather what Elsen, Alex, several Toms, and I have reported on in a
simple cheap "updraft" design - what Tom Reed calls an Inverted down draft
design.

I repeat that I have not absorbed the full Grover paper - as I
still have had access only to the e-mailed version. More after I see the
full paper with figures and tables that are understandable

Ron

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

From jon at jonrouse.freeserve.co.uk Mon Oct 18 17:59:05 1999
From: jon at jonrouse.freeserve.co.uk (Jon Rouse)
Date: Tue Aug 31 21:36:24 2004
Subject: Jon Rouse - New Member Introduction
Message-ID: <008201bf19b4$7cdc8e20$d881883e@jonr>

Stoveys,

I have been subscribed to the 'stoves list' for some months now as a
'listener' only, but have finally got round to introducing myself.

I am English, live in London, and have just completed a Masters in Rural
Development at the University of Sussex. I studied quite a broad range of
subjects from theoretical to practical, including environmental &
sustainable development issues in rural, urban and refugee settings. My
particular interests are in the technical and social aspects of improved
stoves and in microcredit / microenterprise schemes. I subscribed to this
list originally as a result of my general interest in fuel-efficient /
improved biomass stoves in the developing world. It was also to immerse
myself in 'stove issues' whilst researching my dissertation. My dissertation
was entitled 'Improved Biomass Cookstove Programmes: Fundamental Criteria
for Success'. The Abstract (for those who are interested) is shown below in
full. In brief, the paper drew together technical design features of stoves
and aspects of accompanying programmes that could be applied as broadly as
possible. It centred around the principle of balancing 'technical
perfection' with user needs (they seem often to work against one another),
and examined ways in which the compromising of both could be minimised.
Certain specific design details were proposed to this end.

My background is in Applied Physics - though my interest in stoves, like my
interest in the process of 'development' itself is entirely practical. I
have worked in Pakistan, Indonesia and Uganda on a variety of projects, and
intend to visit India in the new year. There I plan to pursue (even
combine?!) my interest in microenterprise and improved stoves.

I would be happy to discuss further my ideas for stove improvements.

Thank you for this stimulating arena for discussion.

Jon Rouse

IMPROVED BIOMASS COOKSTOVE PROGRAMMES: FUNDAMENTAL CRITERIA FOR SUCCESS.
ABSTRACT
'This paper examines the design of improved biomass cookstoves and the
content of
programmes that facilitate their effective use and dissemination. The
primary aim of improved
cookstove programmes is to improve the overall efficiency of the cooking
process.
Fundamental technical and practical methods of achieving this are discussed
and consolidated
in this paper. Conflicts resulting from balancing technical perfection and
user needs are also explored. Finally, a number of the author's ideas are
proposed as further improvements to the effectiveness of stove programmes.
This paper is primarily a technical piece of writing. It is intended to have
the potential for adaptation to a guide relating to the fundamentals of
stove design and programme planning.'

--------------------------------------------
Jon Rouse
jon@jonrouse.freeserve.co.uk
--------------------------------------------

From rmiranda at sdnnic.org.ni Mon Oct 18 22:24:30 1999
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:36:24 2004
Subject: Jon Rouse - New Member Introduction
Message-ID: <3.0.5.32.19991018202541.0099f1e0@ns.sdnnic.org.ni.>

Hi Jon: We in PROLEÑA/Honduras have tried to start a microcredit fund in a
communitty in Tegucigalpa to pay for the Plancha Stove. From my last visit
there last week, it seems that this programm does not goes well due the
presence of other woodstoves dissemination projects thats just give away
100% of the stove cost. So there are not reason to borrow, if you can get
it for free.

I still like and believe in this concept, and we will continue to try this
idea in other communitty, in which there are not unfair competition.

rogerio
PROLEÑA/Nicaragua

>Reply-To: "Jon Rouse" <jon@jonrouse.freeserve.co.uk>
>From: "Jon Rouse" <jon@jonrouse.freeserve.co.uk>
>To: <stoves@crest.org>
>Subject: Jon Rouse - New Member Introduction
>Date: Mon, 18 Oct 1999 22:03:14 +0100
>X-MSMail-Priority: Normal
>X-Mailer: Microsoft Outlook Express 5.00.2014.211
>X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211
>Sender: owner-stoves@crest.org
>
>Stoveys,
>
>I have been subscribed to the 'stoves list' for some months now as a
>'listener' only, but have finally got round to introducing myself.
>
>I am English, live in London, and have just completed a Masters in Rural
>Development at the University of Sussex. I studied quite a broad range of
>subjects from theoretical to practical, including environmental &
>sustainable development issues in rural, urban and refugee settings. My
>particular interests are in the technical and social aspects of improved
>stoves and in microcredit / microenterprise schemes. I subscribed to this
>list originally as a result of my general interest in fuel-efficient /
>improved biomass stoves in the developing world. It was also to immerse
>myself in 'stove issues' whilst researching my dissertation. My dissertation
>was entitled 'Improved Biomass Cookstove Programmes: Fundamental Criteria
>for Success'. The Abstract (for those who are interested) is shown below in
>full. In brief, the paper drew together technical design features of stoves
>and aspects of accompanying programmes that could be applied as broadly as
>possible. It centred around the principle of balancing 'technical
>perfection' with user needs (they seem often to work against one another),
>and examined ways in which the compromising of both could be minimised.
>Certain specific design details were proposed to this end.
>
>My background is in Applied Physics - though my interest in stoves, like my
>interest in the process of 'development' itself is entirely practical. I
>have worked in Pakistan, Indonesia and Uganda on a variety of projects, and
>intend to visit India in the new year. There I plan to pursue (even
>combine?!) my interest in microenterprise and improved stoves.
>
>I would be happy to discuss further my ideas for stove improvements.
>
>Thank you for this stimulating arena for discussion.
>
>Jon Rouse
>
>IMPROVED BIOMASS COOKSTOVE PROGRAMMES: FUNDAMENTAL CRITERIA FOR SUCCESS.
>ABSTRACT
>'This paper examines the design of improved biomass cookstoves and the
>content of
>programmes that facilitate their effective use and dissemination. The
>primary aim of improved
>cookstove programmes is to improve the overall efficiency of the cooking
>process.
>Fundamental technical and practical methods of achieving this are discussed
>and consolidated
>in this paper. Conflicts resulting from balancing technical perfection and
>user needs are also explored. Finally, a number of the author's ideas are
>proposed as further improvements to the effectiveness of stove programmes.
>This paper is primarily a technical piece of writing. It is intended to have
>the potential for adaptation to a guide relating to the fundamentals of
>stove design and programme planning.'
>
>--------------------------------------------
>Jon Rouse
>jon@jonrouse.freeserve.co.uk
>--------------------------------------------
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
Asesor Tecnico Principal
PROLEÑA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
TELEFAX (505) 276 2015, 270 5448
EMAIL: rmiranda@sdnnic.org.ni
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From kchishol at fox.nstn.ca Mon Oct 18 22:35:48 1999
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding Prof. Grover long report - part 1
In-Reply-To: <v01540b03b42bf3fd5fce@[204.131.233.2]>
Message-ID: <380BDAD2.1F3CF032@fox.nstn.ca>

"Ronal W. Larson" wrote:

> Stovers: The following document is sufficiently long that it is coming in
> two parts. Professor Grover is a new member of "stoves" - but exceedingly
> well known in the world of stoves, based on many years of outstanding stove
> research and teaching in India.

I would like to comment on the above report as follows...

Two Kinds of Efficiency:

The point was made by Prof. Grover and others about the importance of
differentiating between:
A: Combustion Efficiency, and B: Heat Recovery Efficiency.

This is a very important step, to ensure that fundamentally sound "stove systems"
can be designed and built economically.

Regrettably, I could not see drawings of the Stove Concept on the Home Page, but I
would like to pass the following comments:

1: Carbon burning from C to CO liberates only 4,000 BTU/Lb, while the CO burning
from CO to CO2 liberates 10,000 BTU per pound carbon. It is thus very important to
separate the combustion zone from the heat recovery zone, to prevent quenching of
the combustion reaction and loss of combustion efficiency.

2: Heat transfer to the cooking pots is very important, obviously. The mechanisms
are primarily convection and radiation. In the regime of natural convection, a
typical Heat Transfer Coefficient is 1 BTU per Hour per Square Foot per degree F.
When boiling water, the pot surface would hardly ever get above 225 deg. F.
Combustion gases at say 1,225 degrees F would thus be able to transfer only 1,000
BTU per hour per square foot of pot area, by natural convection alone. A stove
burning 1 pound of dry wood atabout 80% combustion efficiency would liberate about
6,500 BTU per hour. This suggests that with natural convection alone, the area of
the cooking pot would have to be in the order of about 6.5 square feet!! However,
it gets worse.....as the hot gases initially lose their energy, their temperature
drops, and at the "cool end," the total heat transfer per square foot falls,
necessitating even greater area.

Two factors can be changed, to improve convective heat transfer:
1: Increase the effective area of the pot, by adding fins. This is probably quite
practical with cast iron pots.

2: Find ways to increase the velocity of the products of combustion, so that
Forced Convection heat transfer rates apply. Even with mild "forced convection",
the average heat transfer coefficients can be increased to 3 to 5 BTU/Hour per
square foot per degree F.

Radiation Heat Transfer.

This varies as the 4th power of the temperature difference. It is important to
create conditions where radiation contributes significantly to the transfer of
heat to the pot. Consider a case where there was a pot with an area of 1 sq. foot
sitting in a "radiation pot" with a surface temperature of 1,225 degrees F. With
the standard formula for heat transfer by radiation:

Q = K*e*(T2^4-T1^4)

we get a heat transfer rate of about 12,000 BTU/Hour per square foot of pot area.
The nominal effect is to reduce the required pot area to 1/12 of the area required
if free convection alone was the only heat transfer mechanism at play.

The implications here are that the stove MUST be designed to promote radiation
heat transfer. If not, cooking pot area must be excessive, if good heat transfer
is to be attained. To attain this in practise, I would suggest the following
concept:

Construct a "radiation chamber" into which the bottom portion of a finned cast
iron pot was placed. Introduce the fully pre-combusted gases into the radiation
chamber in a spiral manner, so that they first heated the walls of the chamber,
and then went on to contact the fins on the underside of the pot.

This should accomplish several things:

1: Combustion, by definition, is "pre-completed" and thus permits maximum
combustion efficiency, while minimizing the tendancy of soot formation on a
relatively cold surface. (The bottom of the pot.)

2: It will permit a very significant radiation heat transfer effect, which reduces
pot area requirements.

3: It moves the convective heat transfer toward the forced convection regime,
reducing the requirement for pot area.

I hope this is helpful.

Kindest regards,

Kevin Chisholm

From kchishol at fox.nstn.ca Mon Oct 18 22:46:21 1999
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:24 2004
Subject: OT: Special Purpose Charcoals.
Message-ID: <380BDD4A.D7D25425@fox.nstn.ca>

I realize this is a bit Off Topic, but perhaps someone would have some
insight into the following questions:

1: I have heard that charcoal made from alder wood is especialy good for
the manufacture of gunpowder. This is sort of a dying market, but I was
wondering if anyone has any experience with charcoal made from Speckled
alder? If so, does it have any special or unique properties?

2: Are there any woods that would be particularily good for
manufacturing charcoal sticks for use by artists, for making charcoal
drawings? Are there any special charcoaling techniques that should be
employed to make such a charcoal?

Thanks very much.

Kevin Chisholm

From karve at wmi.co.in Tue Oct 19 00:09:18 1999
From: karve at wmi.co.in (karve)
Date: Tue Aug 31 21:36:24 2004
Subject: Jon Rouse - New Member Introduction
In-Reply-To: <3.0.5.32.19991018202541.0099f1e0@ns.sdnnic.org.ni.>
Message-ID: <380BF06C.4182430@wmi.co.in>

Dear Dr. Miranda,
Perhaps it would be a better idea to try financing local stove makers to establish
workshops so that a standardised product can be made in the vicinity of the users.
This serves a two-fold purpose. One, it introduces a new income generating activity in
the rural locality and two, the users get an easy access to the improved stove models
at a reasonable cost. In India, we have found that this approach is highly
successful, definitely more successful than giving a direct subsidy/finace to the
stove buyers.
With regards,
Priyadarshini Karve

Rogerio Miranda wrote:

> Hi Jon: We in PROLEÑA/Honduras have tried to start a microcredit fund in a
> communitty in Tegucigalpa to pay for the Plancha Stove. From my last visit
> there last week, it seems that this programm does not goes well due the
> presence of other woodstoves dissemination projects thats just give away
> 100% of the stove cost. So there are not reason to borrow, if you can get
> it for free.
>
> I still like and believe in this concept, and we will continue to try this
> idea in other communitty, in which there are not unfair competition.
>
> rogerio
> PROLEÑA/Nicaragua
>
> >Reply-To: "Jon Rouse" <jon@jonrouse.freeserve.co.uk>
> >From: "Jon Rouse" <jon@jonrouse.freeserve.co.uk>
> >To: <stoves@crest.org>
> >Subject: Jon Rouse - New Member Introduction
> >Date: Mon, 18 Oct 1999 22:03:14 +0100
> >X-MSMail-Priority: Normal
> >X-Mailer: Microsoft Outlook Express 5.00.2014.211
> >X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2014.211
> >Sender: owner-stoves@crest.org
> >
> >Stoveys,
> >
> >I have been subscribed to the 'stoves list' for some months now as a
> >'listener' only, but have finally got round to introducing myself.
> >
> >I am English, live in London, and have just completed a Masters in Rural
> >Development at the University of Sussex. I studied quite a broad range of
> >subjects from theoretical to practical, including environmental &
> >sustainable development issues in rural, urban and refugee settings. My
> >particular interests are in the technical and social aspects of improved
> >stoves and in microcredit / microenterprise schemes. I subscribed to this
> >list originally as a result of my general interest in fuel-efficient /
> >improved biomass stoves in the developing world. It was also to immerse
> >myself in 'stove issues' whilst researching my dissertation. My dissertation
> >was entitled 'Improved Biomass Cookstove Programmes: Fundamental Criteria
> >for Success'. The Abstract (for those who are interested) is shown below in
> >full. In brief, the paper drew together technical design features of stoves
> >and aspects of accompanying programmes that could be applied as broadly as
> >possible. It centred around the principle of balancing 'technical
> >perfection' with user needs (they seem often to work against one another),
> >and examined ways in which the compromising of both could be minimised.
> >Certain specific design details were proposed to this end.
> >
> >My background is in Applied Physics - though my interest in stoves, like my
> >interest in the process of 'development' itself is entirely practical. I
> >have worked in Pakistan, Indonesia and Uganda on a variety of projects, and
> >intend to visit India in the new year. There I plan to pursue (even
> >combine?!) my interest in microenterprise and improved stoves.
> >
> >I would be happy to discuss further my ideas for stove improvements.
> >
> >Thank you for this stimulating arena for discussion.
> >
> >Jon Rouse
> >
> >IMPROVED BIOMASS COOKSTOVE PROGRAMMES: FUNDAMENTAL CRITERIA FOR SUCCESS.
> >ABSTRACT
> >'This paper examines the design of improved biomass cookstoves and the
> >content of
> >programmes that facilitate their effective use and dissemination. The
> >primary aim of improved
> >cookstove programmes is to improve the overall efficiency of the cooking
> >process.
> >Fundamental technical and practical methods of achieving this are discussed
> >and consolidated
> >in this paper. Conflicts resulting from balancing technical perfection and
> >user needs are also explored. Finally, a number of the author's ideas are
> >proposed as further improvements to the effectiveness of stove programmes.
> >This paper is primarily a technical piece of writing. It is intended to have
> >the potential for adaptation to a guide relating to the fundamentals of
> >stove design and programme planning.'
> >
> >--------------------------------------------
> >Jon Rouse
> >jon@jonrouse.freeserve.co.uk
> >--------------------------------------------
> >
> >Stoves List SPONSORS and ARCHIVES:
> >http://solstice.crest.org/renewables/stoves-list-archive/
> >Stoves Webpage
> >http://www.ikweb.com/enuff/public_html/Stoves.html
> >For information about CHAMBERS STOVES
> >http://www.ikweb.com/enuff/public_html/Chamber.htm
> >
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> Rogerio Carneiro de Miranda
> Asesor Tecnico Principal
> PROLEÑA/Nicaragua
> Apartado Postal C-321
> Managua, Nicaragua
> TELEFAX (505) 276 2015, 270 5448
> EMAIL: rmiranda@sdnnic.org.ni
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm

From heat-win at cwcom.net Tue Oct 19 07:12:57 1999
From: heat-win at cwcom.net (T J Stubbing)
Date: Tue Aug 31 21:36:24 2004
Subject: OT: Special Purpose Charcoals.
In-Reply-To: <380BDD4A.D7D25425@fox.nstn.ca>
Message-ID: <380C5450.363E580C@cwcom.net>

Dear Kevin and 'Stoves',

Kevin Chisholm wrote:

Snip:

> I realize this is a bit Off Topic, but perhaps someone would have some
> insight into the following questions:
>
> 1: I have heard that charcoal made from alder wood is especialy good for
> the manufacture of gunpowder. This is sort of a dying market, but I was
> wondering if anyone has any experience with charcoal made from Speckled
> alder? If so, does it have any special or unique properties?

The alder growing along the banks of the river Clun in Shropshire, UK, was
harvested to support a clog making industry and to make gunpowder charcoal.

When these demands ceased the alder was neglected for many years but is now
being restored by cutting out the old wood and encouraging new growth.

The cut-outs are being converted to barbecue charcoal being widely sold
through petrol stations and similar local outlets in a mobile 'Viking'
charcoal maker by the Shropshire Hills Countryside Unit where my contact is
Andy Grundy who is running the project and can be reached at
<anyone@shropshills.prestel.co.uk>

He might be able to answer your questions about 'Speckled alder', etc.

Regards,

Thomas (Stubbing)

P.S. The 'Viking' claims a 5 ton/week charcoal output and costs £35,000 to
£40,000. We think we can double that output and improve quality with a
machine being quoted for £30,000 which is based on our airless drying
technology, see <http://www.dryers-airless.mcmail.com>.

From Reedtb2 at cs.com Tue Oct 19 08:48:47 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:24 2004
Subject: CO, Gasifiers, and Wood-gas Stoves
Message-ID: <0.480922a9.253dc379@cs.com>

Dear all...

I have been working in laboratories with producer gas which ALWAYS contains
>10% CO for 25 years now and can't say for sure I have ever had any CO
poisoning symptoms. I'm equally sure I have had small doses. So I was very
interested to read Albert Donnay's recent posting and will acquire the poster
and post it in our new BEF and CPC labs.

Under my BEF PRESS publication hat, I feel a sense of responsibility to
anyone using producer gas and we ALWAYS publish CO warnings in our books.
When wood gasifiers first came into use during WW II there were quite a few
deaths from CO .... then none. There is a long chapter on CO in our
"GEN-GAS" book.

However, I feel equally responsible to put the toxicity of CO in context.
(Remember, I not not an MD, but have collected info for 25 years). Yes, 2
full breaths will kill you and until 1940 when natural gas came into use, the
suicide's best friend was his/her oven. Lots of CO suidices were featured in
old movies! Now instead of the desired suicide, you blow up the house if you
attempt suicide with a natural gas oven. If you try to use your ultra clean
car in a sealed garage for suicide, you die of CO2 suffication which requires
> 5% CO2. So make sure you start with a full tank.

Don't forget, most of the cities of the world (including Poe's Richmond) had
gas light by 1900. So, we have lived safely with CO in the past and can do
it safely again. Humans have lived with lesser amounts of CO from day 1 in
their cooking and heating fires. Wood combustion is almost never ideal and
is sure to leave lots of CO. Smokers intentionally breathe enough CO to keep
their blood level about 100 ppm (?), similarly traffic policemen on busy
corners.

When I first began working on wood-gas stoves, Agua Das was horrified at the
idea of having a CO generator in the home. (Every fire is a CO generator to
some degree, so if we give up CO entirely we will have to give up all
combustion.) However, I quickly realized that the gasifier-stove generates
so much volatile material along with the CO that one is instantly warned if
the fire should go out. These volatiles are like the odourant's they put in
propane, natural gas and manufactured gas to warn of a gas leak. We
recommend that every woodgas stove have a vent, but you should have that
anyway to take the cooking odors out of the house. I regularly burn my
woodgas stove indoors without a vent, now that I know what I am doing. No
odor.

Charcoal combustion and gasification is the real culprit, not wood
gasification. Wood has its built in odorant, but charcoal generated CO is
odorless. Our Turbo stove can also be used in the charcoal mode and that's
where you really need the warning.

So, we who are doing experiments should all have a Nighthawk (?) CO meter in
our labs. (Cost $40-$60). Robb Walt and I once set off it's 200 ppm CO
alarm while developing the Stirling gasifier. Generally however I record 0
CO during my stove tests unless I put the meter directly over the flame and
even then only 0-10 ppm.

Considering the health risks of NOT using producer gas stoves in developing
countries I'm willing to risk the stove, but keep warning everyone involved.

Not being a world expert in CO poisoning, I hope this will generate lots of
comments.

Yours for a long, happy low CO life.... TOM REED BEF
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From Reedtb2 at cs.com Tue Oct 19 08:48:51 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:24 2004
Subject: RESPONSIBLE Harvesting of Biomass
Message-ID: <0.47d6fee7.253dc37c@cs.com>

Dear Gasification and Stoves:

In my book, Kermit Schlansker (posting below) has the right attitude and
Sierra has gone off the track. Responsible use of biomass is infinitely
sustainable and greatly augmentable. Of course "responsible" is the key
work, but humans are getting slowly more responsible as they get more
civilized. (Fewer children, cleaner rivers and air, more protection of
forests,....)

In the 1940's there was hardly a tree left in China and Korea and they
suffered the "sand dragon". Now both countries are 10% forested and growing.
The U.S. East of the Mississippi probably has two to 3 times the number of
trees of 1900.

Keep cutting.... responsibly. It's called "stewardship" and we all must
practice it.

TOM REED BEF

In a message dated 10/15/99 1:36:25 PM Mountain Daylight Time,
kssustain@provide.net writes:

<< Re: Harvesting Biomass

There have been so many messages on this subject that I can't keep
track of them so must speak in general terms.
It is unfortunate that the Sierra Club has taken a position against
harvesting biomass because in the end, we must. When the fossil fuels are
gone then wood will be cut as a means of staying warm and there may be no
possibility of controlling such cutting. It is my belief that oil will be at
very low levels within 50 years and that gas will also become scarce. If
there is going to be any future then we must make realistic plans.
The important thing we must do right now is to plant several billion
trees. We can say that this is for nature, Global Warming, lumber, or fuel
for our grandchildren. In order to do this we must create a Civilian
Conservation Corps, use prisoners, use children, use people on welfare, and
use volunteers in order to get the job done. We need to plant all species in
any location where it appears they will have a chance to grow. Since there is
a 50 year lead time in tree growth we must start immediately. The mass
planting program is an antidote for monoculture, erosion, and unemployment.
Although I am in favor of spending massive sums on solar and wind,
preferably with money from energy taxes, I do not believe that either of
these will provide enough energy to satisfy our needs. High costs of
production, storage, and conversion to vehicular fuel will prevent them from
coming close to replacing fossil fuels. What I can see as being possible is
that about 10% of present use could come from solar, 10% from wind, and about
15% from biomass. For the rest, we will have to learn to do without. Biomass
is by far the cheapest alternate fuel and is the only one which can in raw
state be used to power trains and tractors. If forests are fertilized with
nitrogen, ashes, and sewage then they truly become solar energy. Forget about
the airplanes and cars.
It is my belief that Solar Powered Boilers with Steam Engines may
be cheaper and more useful than Solar Electric Cells. An ultimate project for
solar energy would be a nitrogen fertilizer factory in the desert. Without
this fertilizer there would be mass starvation. Presently nitrogen fertilizer
is made using large amounts of energy and natural gas. The desert factory
would need only sun, air, and water as inputs. The output would be essential
fertilizer which could be easily shipped.
Another thing that is essential is to develop and put into mass
production small steam engines driving alternators which can be used for
Combined Heat and Power and Combined Heat and Manufacturing. There are and
will be tremendous amounts of waste wood and clean solid waste which should
be changed to energy and fertilizer. Every bit of waste burned saves coal
from being burned. Wood stoves, fireplaces, and coal are more polluting than
wood and clean waste burned in well designed installations with good
pollution controls.
The unfortunate thing about solar power junkies like the Sierra
club and A Novelli is that their arguments work against mass tree planting
and the development of means to use waste fuels. In the future we will need
every bit of energy we can get in order to forestall mass starvation.
Conservation is our best tool against Unsustainability. I have a
web page on the subject at http://www.provide.net/~kssustain. There is a good
oil reference at http://dieoff.org/page140.htm. Thanks to Jay Hanson for
publishing so many good references.

Kermit Schlansker PE kssustain@provide.net

>>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Tue Oct 19 11:47:49 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: OT: Special Purpose Charcoals.
Message-ID: <v01540b05b431b7034e54@[204.131.233.4]>

Kevin - several years ago, because we had mentioned the word "charcoal"
quite a bit on "stoves", we received several hits from persons interested
in your two topics (because of the efficiency of search engines). (And I
am a little worried about your latest return to the topic - since when I
have gone searching on "charcoal" I still find our site quite often mixed
in with these oother applications for charcoal. The biggest other
subculture is charcoal for barbequeing.)

Thanks a lot more for your excellent analysis of pot heat transfer
- which I will respond to separately.

See more below.

>I realize this is a bit Off Topic, but perhaps someone would have some
>insight into the following questions:
>
>1: I have heard that charcoal made from alder wood is especialy good for
>the manufacture of gunpowder. This is sort of a dying market, but I was
>wondering if anyone has any experience with charcoal made from Speckled
>alder? If so, does it have any special or unique properties?

No real help here - but you might find something by searching under
"fireworks" and/or "pyrotechnics"

>
>2: Are there any woods that would be particularily good for
>manufacturing charcoal sticks for use by artists, for making charcoal
>drawings? Are there any special charcoaling techniques that should be
>employed to make such a charcoal?

In our earlier "stoves" dialog on this (or maybe it was off list),
I found people using grape vine segments.

The standard techniqe for artists seems to be to place the pieces
in a can like a paint can - with a lid that can be tightly put in place.
Then, with a single small hole in the lid, the entire can is placed in a
simple fireplace fire. The can is removed when the "offgases" can no
longer be seen to be burning.

Hope that others can add more.

Ron

>
>Thanks very much.
>
>Kevin Chisholm

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

From larcon at sni.net Tue Oct 19 23:25:10 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding request on CHARCOAL-MAKING STOVES
Message-ID: <v01540b00b4324737051c@[204.131.233.43]>

Stovers - This is to make public a letter to Bhutan that turned from
private to public. Your comments are welcome

Chhimi:

Almost everything you read about on "stoves" is being offered
without fee. However, there are several strong list members who also
provide consulting services - and who therefore are not so free to provide
free information . Yours is a request that could go either way - and
therefore I am turning your personal letter to me into a request to the
full "stoves" list. Here are some of my thoughts:

1. I have heard excellent things about the environmental ethic
preesnt in Bhutan and your letter confirms that. Congratulations on
searching out better ways to do things. If you hear what you like as a
result of your request, I hope you will let me know if I should sign you up
(for free) so you can easily keep us informed of your progress.

2. Most of our discussion on this list refers only to small
single-family stoves. As part of that list thrust, there has been a
continuing thread related to small charcoal-making stoves. Moreover,
because much charcoal making relates to charcoal for cook-stoves and there
is no other list working on charcoal-making - we seem to have ended up a
site for larger scale charcoal - making, which seems to be your interest.
On the other hand, maybe you really are interested in smaller
charcoal-makers, so I must ask for clarification on what might be best for
Bhutan.

3. Assuming you are interested in making use of some of your waste product
stream in making charcoal in small charcoal-making stoves, I urge you to
look at some of the literature on our two web sites maintained by CREST and
Alex English:

>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html

Those who have tried the approach have generally had success. You
need to use dry fuel, to control primary air, to light at the top, to have
tight fuel packing, and have a sufficiently tall
"chimney/combustion-chamber" so as to have both a good draft and complete
combustion. There is no alternative to giving it a try. Many of us can
send a sample, but I think it will be better to adapt local materials and
have a local tinkerer get involved early. Manyon the list can give
guidance if you have problems.

The key to success will be getting a unit that does a good job for
local cooking needs - and so you will have to tell us more about such
items as the types of food being cooked, and the length of time for
cooking.

The big advantages will be that the cook has a new source of
income, there will be more healthfull cooking, and there will be much less
waste from both traditional charcoal-making and in normal cooking.

I would not recommend this approach unless these items are
important in Bhutan. This is not an appropriate technology in the United
States.

We have had a few dialogues about using sawdust for cooking.

4. Now turning to much larger forms of charcoal making: First look back
in our websites for work by Elsen Karstad on turning sawdust to charcoal.
Unfortunately Elsen is generally not using the waste heat - but the sawdust
is otherwise being wasted.
Look also at work by Alex English on some larger scale units using
a geometry much like that for cooking. Elsen's interest is in heating.

Several others have reported on making charcoal in proprietary
design while using the waste heat in part for pre-drying both lumber and
the scrap material being turned into charcoal. I hope they will contact
you off-list if they find your letter of interest.

5. I hope that you will find this brief information useful and will give
us more background on what you are attempting to accomplish in Bhutan. We
need items like waste tons/week, whether you are in an urban or rural
environment, what you are now doing with the waste, etc.

Ron

>BHUTAN BOARD PRODUCTS LTD
>POST BOX - 91
>TALA ; PHUENTSHOLING
>BHUTAN
>
>PH - 00975-5-272606
>FX - 00975-5-272608
>--------------------------------------------
>
>MR. CHHIMI THENDUP.
>WORKS DIRECTOR
>BHUTAN BOARD PRODUCTS LTD
>POST BOX - 91
>TALA ; PHUENTSHOLING
>BHUTAN
>
>PH - 00975-5-272606
>FX - 00975-5-272608
>--------------------------------------------
>
>DEAR MR. LARSON,
>
> WE HAVE COME ACROSS IN FOREST ENERGY FORUM NO. 4 JUNE 1999
>ISSIE, CHARCAOL MAKING STOVE. AS WE ARE THE ONLY COMPANY IN OUR COUNTRY
>MANUFACTURE PARTICLE BOARD OUT OF WOOD, AS WE HAVE EXCESS WASTE GENERATE IN
>THE PROCESS AND LIKE TO CONVERT TO VALUE ADDED PRODUCT. WHAT ARE THE SIZES
>OF YOUR CHARCOAL-MAKING STOVE AND PER HOURS WOOD WASTE IS REQUIRED. WE
>APPRECIATED IF YOU SENT US YOUR OFFER.
>
>
>REGARDS,
>
>
>CHHIMI THENDUP

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

From dstill at epud.org Wed Oct 20 00:26:52 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:24 2004
Subject: reply to Ronal Larson
Message-ID: <002001befe38$5bfd4060$a60e66d1@default>

Dear Ronal,

I'm hoping that this Thursday's class can create some useful data as regards
optimal size of the cooking pot for a particular task. My general impression
is that cooking stoves burn wood too fast, which is supported by Kevin
Chisholm's wonderful comments. It's this kind of helpful dialogue that makes
the stove list so great!

His comments reinforced a seemingly contradictory conclusion we pondered
after talking to Professor Mark Bryden and testing the Zip stove with
battery that increasing speed of hot flue gases increases heat transfer.

Generally, since we don't go smaller than 4" in diameter feed
magazine/combustion chamber (since people don't seem to accept it) the
higher the surface area to volume ratio the better in pots. Getting the low
mass, insulated skirt red hot helps to increase efficiency.

As far as new developments in top burning or gasification go, we would love
to see a working model. When Alex visited we couldn't keep the stove lit,
wood was probably too wet. Would someone take pity on us and send a model
that we could test?

Dr. Winiarski, Aprovecho engineer, spent more than a decade building lots of
stoves along these lines. After this experience, his opinion was that
successful designs were too finicky for use in the places Aprovecho was
visiting. So, he developed the Rocket style of stove that aims for complete
initial combustion. However, we are always hoping that someone will come up
with great new approaches!

Best to all,

Dean Still

From elk at net2000ke.com Wed Oct 20 02:03:26 1999
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:24 2004
Subject: CO poisoning- first-hand observations
Message-ID: <199910200612.JAA02217@net2000ke.com>

From pdg at del2.vsnl.net.in Thu Oct 21 03:03:54 1999
From: pdg at del2.vsnl.net.in (P D Grover)
Date: Tue Aug 31 21:36:24 2004
Subject: Dream Stove-Asia-Comments by Dean Still
Message-ID: <000101bf1b94$118fa6c0$746236ca@cms.pdgdel2.vsnl.net.in>

21th Oct. 1999

To
Stovers

Subject: Dream Stove-Asia-Comments by Dean Still

First, let me thank members of Stove Group for their reactions
to the proposed stove concept. The very fact that the reactions have been
generated, the major purpose of the paper is served.

One paper cannot solve all the problems of having a high
overall efficiency with cost effective measures(I would not call them low level
technology). There are many grey areas which have not been addressed. The
emphasis in this paper has been to cater for complete combustion to take care of
emissions (both indoor and outdoor). Charcoal based volatile cracker for getting
clean combustion from volatiles is the key feature of this note: How to achieve
this is for the Stovers to try in actual practice and then share their
experiences. We have tried this concept in metallic stoves with loose biomass
and it works.

For example: If you try to burn coal/coke beehive briquette by
igniting it from top end with 100-150 grams of charcoal or with an ignited
beehive briquette, you will have zero smoke. On the other hand the normal way of
igniting these briquettes by burning the ignitor from below you get an intensive
smoking period of 20-35 minutes. We have done these tests in Myanmar for burning
of pet coke beehive briquettes with very successful results.

Cook pot designs integrated with stove are equally important.
Overall efficiency of any combustion appliance (small or industrial) is the
product of combustion efficiency and heat transfer efficiency to
utility/utilities. Some tests in this direction using multi effect pots carried
out by Dr. Pandit of Chem. Eng. Dept. of UDCT Matunga Bombay have resulted in
saving of 60% fuel. His fax No. 91-22-4145614.

With best of luck with stove testing and innovative pot
design.

Prof. P.D. Grover

From pdg at del2.vsnl.net.in Thu Oct 21 04:19:46 1999
From: pdg at del2.vsnl.net.in (P D Grover)
Date: Tue Aug 31 21:36:24 2004
Subject: No Subject
Message-ID: <000201bf1b9e$bb1a29e0$8b6236ca@cms.pdgdel2.vsnl.net.in>

21th Oct. 1999

To
Stovers

Subject: Dream Stove-Asia-Comments by Dean Still

First, let me thank members of Stove Group for their reactions
to the proposed stove concept. The very fact that the reactions have been
generated, the major purpose of the paper is served.

With best of luck with stove testing and innovative pot
design.

Prof. P.D. Grover

From pdg at del2.vsnl.net.in Thu Oct 21 05:09:17 1999
From: pdg at del2.vsnl.net.in (P D Grover)
Date: Tue Aug 31 21:36:24 2004
Subject: No Subject
Message-ID: <001401bf1ba5$9a59e680$be6236ca@cms.pdgdel2.vsnl.net.in>

21th Oct. 1999

To
Stovers

Subject: Dream Stove-Asia-Comments by Dean Still

First, let me thank members of Stove Group for their reactions
to the proposed stove concept. The very fact that the reactions have been
generated, the major purpose of the paper is served.

With best of luck with stove testing and innovative pot
design.

Prof. P.D. Grover

From Reedtb2 at cs.com Thu Oct 21 08:44:10 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:24 2004
Subject: New Stove Lab and Stove Books
Message-ID: <0.5c46967b.25406566@cs.com>

Dear Ron et al:

The Biomass Energy Foundation has set up a 500 ft2 stove laboratory at the
corner of Quaker and Old Golden Rd in Pleasant View (Golden) CO. I have two
students from the Colorado School of Mines doing research on forced
convection stoves, a fabrication shop, laboratory equipment, and of course a
CO meter. My stove work was getting to be too much for my home lab (garage
sized).

Ron, I loaned you a number of books on stoves, stove testing etc. from my
library. I would like to shelve them in the new lab, so please go through
your piles and return them. I hope you might also like to come see the new
lab. Any other stovers coming to town will also be taken to the lab.

Yours truly, TOM REED BEF
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From rmiranda at sdnnic.org.ni Thu Oct 21 20:37:53 1999
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:36:24 2004
Subject: New Stove Lab and Stove Books
In-Reply-To: <0.5c46967b.25406566@cs.com>
Message-ID: <3.0.5.32.19991021173255.0093c810@ns.sdnnic.org.ni.>

Dear Tom:

Right now we are budgeting a stove lab which we will ask IDB to finance it
for the National Energy Commission of Nicaragua. Can you tell me how much
it did cost in terms of equipments?

Thanks

Rogerio

At 08:47 a.m. 21/10/99 EDT, you wrote:
>Dear Ron et al:
>
>The Biomass Energy Foundation has set up a 500 ft2 stove laboratory at the
>corner of Quaker and Old Golden Rd in Pleasant View (Golden) CO. I have two
>students from the Colorado School of Mines doing research on forced
>convection stoves, a fabrication shop, laboratory equipment, and of course a
>CO meter. My stove work was getting to be too much for my home lab (garage
>sized).
>
>Ron, I loaned you a number of books on stoves, stove testing etc. from my
>library. I would like to shelve them in the new lab, so please go through
>your piles and return them. I hope you might also like to come see the new
>lab. Any other stovers coming to town will also be taken to the lab.
>
>Yours truly, TOM REED BEF
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
Asesor Tecnico Principal
PROLEÑA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
TELEFAX (505) 276 2015, 270 5448
EMAIL: rmiranda@sdnnic.org.ni
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Thu Oct 21 23:51:01 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: Forwarding Donnay#2 on CO, Gasifiers, and Wood-gas Stoves
Message-ID: <v01540b00b4353d7aa25b@[204.131.233.16]>

Stovers: The following second message from Albert Donnay is just in -
responding to a message from Tom Reed.

Albert: A few more questions:

1. Do you have any other CO statistics - especially in developing
countries - and especially from stove use?

2. Any comments on the near-fatality story from Elsen Karstad? (Just sent
to Albert recently)

3. Andrew Heggie in another private off-list conversation said (and I
wonder if you could comment):
> I usually quote
>the report that King Philip 2nd of Spain was found pink like a lobster
>after he was left in a sealed bed chamber with a charcoal brazier.

4. Apparently there is a US national register for your CO fatality
statistics. Where is that registry and is there anything similar on an
international scale?

5. I called your 1-800 number listed below and had a short conversation
with a "Chris" - learning that the price for your digital output unit is
about $45 - but drops to $33 for a dozen. His explanation for having a
three-year warranty (4-5 year expected life) for a disposable (no battery
replacement possible) unit was not quite clear. He is sending more
literature - from which I suppose I can learn something about the various
possible ranges of CO (in ppm).
But my interest is more on how you think such a unit can be used by
stoves researchers. Most of us on this list would like very much to use a
simple hand-held unit with accurate output in which we could modify the
stove performance to minimize CO output (as quantitatively measured). Are
you aware of any use of your digital output model in this way? Or should
we expect that the ranges (ppm) would not be appropriate for for a bad
charcoal-burner?

6. Any other guidance for the stove world - on how to make stoves with
lower CO output.?

Thanks again for repsonding and thanks in advance for answers you might be
able to provide for the above. . Ron

(The remainder of this message is all from Albert.)

This was forwarded to me from the Stoves list, because of my interest in CO.
Please see that my comments make it back to the list. Thanks -- Albert Donnay.

I want to correct some of the potentially lethal misinformation that Tom posted
about CO:

First, accidental CO poisoning still kills more people--about 1500 per year in
USA-- than all other toxins combined. Another 2000 kill themselves
intentionally
with CO. Many deaths are caused by people using a gas oven as a heat
source (Tom
is right that if you just run the gas without lighting it, you get an explosion
hazard, but many people also are made sick by the natural gas itself
--methane--and/or the "odorant" --ethyl mercaptan-- that is added to it.

But he is not correct in saying that:

>If you try to use your ultra clean
>car in a sealed garage for suicide, you die of CO2 suffication which requires
> 5% CO2. So make sure you start with a full tank.

There are no ultra clean cars except electric ones. Any gasoline combustion
engine run in a closed garage will kill you from CO buildup long before any CO2
buildup. Your death will come fastest on a cold day with a cold engine,
but even
a warm engine on a warm day will do the deed.

With respect to gas light, most cities had it by 1875, and by 1900 many were
already in the midst of switching over to electric light. Unfortunately,
the same
manufactured gas (from coal) was then used for another 50years as utility
gas for
heating, cooking, refrig. and other appliances until the widespread intro of
natural gas in the 1950s. We did NOT live safely with gas in the last
century--it was a leading cause of death and illness then too--and we are not
living safely with it today either, mostly because we still allow the use of
unvented gas appliances indoors (ovens, ranges, space heaters, etc) and, even
worse, because we allow tightly sealed homes to be built with attached and
tuck-under garages.

Smokers and others routinely exposed to high levels of CO actually adapt to this
relative oxygen debt quite well (just like people who live at altitude). It is
non-smokers who are at greatest risk from CO because they are much more
sensitive
to low levels. (Notice how when smokers and non-smokers go skiing at high
altitude, say for a week in Colorado, the non-smokers are gasping for air while
the smokers do just fine). The COHb level in non-smokers (from the body's own
production of CO) is normally less than 2%. But in smokers this may be 5% to
15%. CO may also be measured in exhaled breath. Here non-smokers are about
6ppm, smokers are 10 to 70 ppm.

Of greatest concern is Tom's comment that:
> I regularly burn my woodgas stove indoors without a vent, now that I know what
I am
> doing. No odor.

If he does this, and if thinks that because he can't smell any volatiles there
also is no CO, then he most certainly does not know what he is doing. Any
combustion produces CO to some degree, and there may be an odor that he simply
can't detect or can no longer detect (the phenomenon of sensory habituation
allows us to tune out sensory input after they are recognized: the best example
is H2S or hydrogen sulfide, the gas that smells like rotting eggs when you first
smell it but within minutes most people can't smell it at all). Please folks,
don't take any stupid chances -- if you burn any fuel indoors, use a vent!

And get a good CO Alarm. The Nighthawk brand he mentions was recalled earlier
this year for problems with it failing to go off fast enough or at all. Since I
also am the medical director of AIM Safe Air Products, I of course want to
recommend ours-- it's portable and comes with batteries that last 3 years,
don't
need replacing and can't be removed. It also has a memory function that stores
the peak CO level for up to 8 days and shows how many hours have elapsed since,
which is very useful when investigating CO leaks.

You can order directly from AIM (I won't be profiting personally) by calling
1-800-220-0121.

--Albert Donnay, MHS
adonnay@mcsrr.org

Tom Reed, Reedtb2@cs.com wrote:

> Dear all...
>
> I have been working in laboratories with producer gas which ALWAYS contains
> >10% CO for 25 years now and can't say for sure I have ever had any CO
> poisoning symptoms. I'm equally sure I have had small doses. So I was very
> interested to read Albert Donnay's recent posting and will acquire the poster
> and post it in our new BEF and CPC labs.
>
>
> However, I feel equally responsible to put the toxicity of CO in context.
> (Remember, I not not an MD, but have collected info for 25 years). Yes, 2
> full breaths will kill you and until 1940 when natural gas came into use, the
> suicide's best friend was his/her oven. Lots of CO suidices were featured in
> old movies! Now instead of the desired suicide, you blow up the house if you
> attempt suicide with a natural gas oven. If you try to use your ultra clean
> car in a sealed garage for suicide, you die of CO2 suffication which requires
> > 5% CO2. So make sure you start with a full tank.
>
> Don't forget, most of the cities of the world (including Poe's Richmond) had
> gas light by 1900. So, we have lived safely with CO in the past and can do
> it safely again. Humans have lived with lesser amounts of CO from day 1 in
> their cooking and heating fires. Wood combustion is almost never ideal and
> is sure to leave lots of CO. Smokers intentionally breathe enough CO to keep
> their blood level about 100 ppm (?), similarly traffic policemen on busy
> corners.
>
> When I first began working on wood-gas stoves, Agua Das was horrified at the
> idea of having a CO generator in the home. (Every fire is a CO generator to
> some degree, so if we give up CO entirely we will have to give up all
> combustion.) However, I quickly realized that the gasifier-stove generates
> so much volatile material along with the CO that one is instantly warned if
> the fire should go out. These volatiles are like the odourant's they put in
> propane, natural gas and manufactured gas to warn of a gas leak. We
> recommend that every woodgas stove have a vent, but you should have that
> anyway to take the cooking odors out of the house. I regularly burn my
> woodgas stove indoors without a vent, now that I know what I am doing. No
> odor.
>
> Charcoal combustion and gasification is the real culprit, not wood
> gasification. Wood has its built in odorant, but charcoal generated CO is
> odorless. Our Turbo stove can also be used in the charcoal mode and that's
> where you really need the warning.
>
> So, we who are doing experiments should all have a Nighthawk (?) CO meter in
> our labs. (Cost $40-$60). Robb Walt and I once set off it's 200 ppm CO
> alarm while developing the Stirling gasifier. Generally however I record 0
> CO during my stove tests unless I put the meter directly over the flame and
> even then only 0-10 ppm.
>
> Considering the health risks of NOT using producer gas stoves in developing
> countries I'm willing to risk the stove, but keep warning everyone involved.
>
> Not being a world expert in CO poisoning, I hope this will generate lots of
> comments.
>
> Yours for a long, happy low CO life.... TOM REED BEF

From larcon at sni.net Thu Oct 21 23:51:43 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:24 2004
Subject: comments on Prasad, Miranda, Karve and Rouse recent messages
Message-ID: <v01540b02b43582ecf332@[204.131.233.16]>

Stovers:

The follosing is a mishmash of responses to the three recent
messages triggered by the Jon Roush introdcutory message

A. Re Rogerio's response - dealing mostly with microcredit

Since I happened to have been with Rogerio outside Managua, I can
say that the large Plancha type stoves used in Niicaragua must be built
on-site, whereever thay are to be introduced. As Dean Still has argued on
this list, this is a very heavy and not very efficient unit. But it does
come with a chimney and polluton release is lower - as Rogerio has
reported. As I reported last spring, Rogerio is doing great work, but I
see many chances to improve the Plancha (my favorite being to use the
insulating volcanic slab material that is so plentiful).

I hope that Rogerio and Priyadarshini will enter in again on the
issues of both gifts vs loans - and also on the issue of local production.
Without further discussion, I am afraid we will not get at the important
points that Prasad is raising.

Rogerio - would you prefer to see a combination of cost buy-down
and loans? Have you discussed this with those who are providing the free
stoves? Are they Plancha type stoves - or is there a big difference in
type of stoves? Is the free stove an adequate stove? How wide-spread is
the give-away?

B. Re Priyadarshini's contribution - that dealt mainly with local
production - an aspect of Rogerio's message.

Priyadarshini - My guess is that your village-created stove option
is ceramic and quite small - very unlike that of Rogerio. Your issue of
local production responded well to the production side of Jon Rouse'
message - but not on the microcreidt issue raised by Jon and Rogerio. What
are your thoughts on microcredit when coupled with stoves?

C. Re Prasad's Message today:

Prasad - your message was silent on the subject of microcredit. Do
you see a relationship with type of stove?

All - under what circumstances do you see something other than
local manufacture (and local dissemination) as being the best approach ?

D. Re Jon's original message:

Jon: Welcome to stoves!!.

Congratulations for having started this provocative three-way
discussion. Further dialog will certainly help us to learn a lot more -
and maybe especially about your own thesis.

a. Your introductory message of the 18th only gave the abstract
for your master's thesis. If it is to your advantage, I hope that you will
send tell us how to read the whole document. One way is to send it to Alex
English - much as we have recently been able to read all of Professor
Grover's recent report for FAO. Talk first with Alex at
<english@adan.kingston.net>

b. Do you have any reaction to the three messages that have
followed yours?

c. I have been a fan of microcredit - but see it as a means of
investment - not as something to normally be used for household articles
(such as stoves normally). On the other hand something that saves time and
improves health certainly has an economic payback as well. Have you been
looking at microcredit in this way? Are you aware of locations where
microcredit has worked for stoves purchase?

d. You will have noticed our sometimes discussion of
charcoal-making stoves - which do have income generation potential (with
investment payback in a few months). Have you any thoughts on this
difference - and the way lenders and borrowers might react to this
difference?

e. Now something off-topic - but I'd like your thoughts on this.
When I was last in Kafa, Ethiopia, I met a gentleman who had given out (not
loaned) a very small amount of money. I think it was $25.00 each to eight
groups of 4 or 5 women. He did this after considerable training and
discussion on how the women would save the income from investment - mostly
done for products for quick resale. Except for not worrying about
repayment, the operations are much like the Grameen Bank Each group had
doubled their cash in about 6 months (and I am now out of date by 6 months
- but presume growth is continuing). The women worked as teams.
The person who did this (the implementer - using money from a third
party donor) believed this was a superior approach to borrowing - for a
range of reasons that I better not get into here. When I have mentioned
this to local microcredit experts - they are aghast - saying that one
cannot give money to a poor person (the same story Mohammed Yunus heard
about lending money). What are your thoughts on this?

Anyway - thanks for a very provocative first introduction - and
again welcome. Speaking for many on the list, I am sure, we look forward
to more of what you have learned in your academic studies.

Anyone else want to weigh in on this return to a few of the
dissemination topics from our past? Or on different types of stoves?

Ron

From pdg at del2.vsnl.net.in Fri Oct 22 01:37:29 1999
From: pdg at del2.vsnl.net.in (P D Grover)
Date: Tue Aug 31 21:36:24 2004
Subject: Fw:
Message-ID: <000001bf1c50$e01817e0$73cec5cb@cms.pdgdel2.vsnl.net.in>

-----Original Message-----From: P
D Grover <<A
href="mailto:pdg@del2.vsnl.net.in">pdg@del2.vsnl.net.in>To: <A
href="mailto:stoves@crest.org">stoves@crest.org <<A
href="mailto:stoves@crest.org">stoves@crest.org>Date: Friday,
October 22, 1999 1:19 AM

21th Oct. 1999

To
Stovers

Subject: Dream Stove-Asia-Comments by Dean Still

First, let me thank members of Stove Group for their reactions
to the proposed stove concept. The very fact that the reactions have been
generated, the major purpose of the paper is served.

With best of luck with stove testing and innovative pot
design.

Prof. P.D. Grover

From karve at wmi.co.in Fri Oct 22 10:06:03 1999
From: karve at wmi.co.in (karve)
Date: Tue Aug 31 21:36:24 2004
Subject: [Fwd: comments on Prasad, Miranda, Karve and Rouse recent messages]
Message-ID: <38106FCE.AA2BB8A6@wmi.co.in>

To: "Ronal W. Larson" <larcon@sni.net>
Subject: Re: comments on Prasad, Miranda, Karve and Rouse recent messages
From: karve <karve@wmi.co.in>
Date: Fri, 22 Oct 1999 19:37:22 +0530
References: <v01540b02b43582ecf332@[204.131.233.16]>

Stovers,
This is indeed a tricky issue and very much dependent on the ground
realities in any given situation. However, I still feel that it is much more
useful to encourage local manufacturing of the stoves, irrespective of size and
extent of technological input involved. I agree with Dr. Prasad's observation
that the density of manufacturers should be such that each can earn a
comfortable living and the supply is sufficient to fulfill the demands of all
potential users.
I personally think that self help groups formed by the local people
themselves (groups that generate their own funds and give loans to members of
the group) is a much better form of microcredit than making the poor people
indebted to some banking organisation. The concept of self help group is
becoming popular in India, especially among rural women and the loan may be
taken either for starting an enterprise or for getting over some domestic
problem. It is remarkable but in most groups the recovery of loan is 100%. In
such a set up there will not be any problem in getting a loan for buying an
improved stove, provided the other members of the group could be convinced of
the need.
In India, I don't think there is a need to consider microcredit for
purchase of improved stoves. Firstly the clay stove prices are affordable and
secondly there is a government subsidy on certain models, the subsidy amount
depending on the social and financial status of the beneficiary. However the
subsidy can be availed of just once, while the life of a clay stove is not more
than 2 years in an ordianry rural household. If the household is then reverting
back to the traditional stove, then the whole programme of stove dissemination
should be deemed a failure. In our surveys we found that people may acquire the
first improved stove just because some government official forces them to, to
achive his designated 'target' of number of stoves to be distributed under the
subsidy programme. After using the stove for an year or two, the users
themselves realise its utility. When the time comes for them to replace their
old stove, they are more than willing to spend some extra money and get another
improved stove. At this juncture it is very much essential that they should
have an easy access to an improved stove manufacturer. Otherwise, they will be
forced to go back to the traditional stove. That is why in the long run it is
much more effective to spend some resources in ensuring that there are properly
trained improved stove manufacturers in each administrative block of the rural
part of the country.
This also has the highly desirable side effect of creating a new income
generating activity in rural areas. At present we have about 50 potters in this
business in Maharashtra state and all of them are earning Rs.1,00,000 or more
annualy which is a good income for a rural enterprise. One of the potters once
told our trainers that if it had not been for this income, he would have had no
option but to marry off his daughter after her school education, at 18 years of
age. But since he could afford it, she was able to go for college education. I
think that comment is self explanatory.
Besides training, the stove manufacturers require seed money to start their
business. What I was suggesting in my earlier message was that it is worthwhile
to create microcredit/finance schemes aimed at helping such rural
entrepreneurs.
I am strongly opposed to the concept of 'gift'. Our experience has shown
that it is important to make the stove users pay some money for their improved
stoves. Wherever stoves (or anything for that matter) were given absolutely
free, a very high percentage of people did not use them at all. The reasons are
more psychological than anything else.
I would certainly love to get some input from Mr. Rouse on the issue in
view of his field of specialisation.
Regards,
Priyadarshini Karve.

"Ronal W. Larson" wrote:

> Stovers:
>
> The follosing is a mishmash of responses to the three recent
> messages triggered by the Jon Roush introdcutory message
>
> A. Re Rogerio's response - dealing mostly with microcredit
>
> Since I happened to have been with Rogerio outside Managua, I can
> say that the large Plancha type stoves used in Niicaragua must be built
> on-site, whereever thay are to be introduced. As Dean Still has argued on
> this list, this is a very heavy and not very efficient unit. But it does
> come with a chimney and polluton release is lower - as Rogerio has
> reported. As I reported last spring, Rogerio is doing great work, but I
> see many chances to improve the Plancha (my favorite being to use the
> insulating volcanic slab material that is so plentiful).
>
> I hope that Rogerio and Priyadarshini will enter in again on the
> issues of both gifts vs loans - and also on the issue of local production.
> Without further discussion, I am afraid we will not get at the important
> points that Prasad is raising.
>
> Rogerio - would you prefer to see a combination of cost buy-down
> and loans? Have you discussed this with those who are providing the free
> stoves? Are they Plancha type stoves - or is there a big difference in
> type of stoves? Is the free stove an adequate stove? How wide-spread is
> the give-away?
>
> B. Re Priyadarshini's contribution - that dealt mainly with local
> production - an aspect of Rogerio's message.
>
> Priyadarshini - My guess is that your village-created stove option
> is ceramic and quite small - very unlike that of Rogerio. Your issue of
> local production responded well to the production side of Jon Rouse'
> message - but not on the microcreidt issue raised by Jon and Rogerio. What
> are your thoughts on microcredit when coupled with stoves?
>
> C. Re Prasad's Message today:
>
> Prasad - your message was silent on the subject of microcredit. Do
> you see a relationship with type of stove?
>
> All - under what circumstances do you see something other than
> local manufacture (and local dissemination) as being the best approach ?
>
> D. Re Jon's original message:
>
> Jon: Welcome to stoves!!.
>
> Congratulations for having started this provocative three-way
> discussion. Further dialog will certainly help us to learn a lot more -
> and maybe especially about your own thesis.
>
> a. Your introductory message of the 18th only gave the abstract
> for your master's thesis. If it is to your advantage, I hope that you will
> send tell us how to read the whole document. One way is to send it to Alex
> English - much as we have recently been able to read all of Professor
> Grover's recent report for FAO. Talk first with Alex at
> <english@adan.kingston.net>
>
> b. Do you have any reaction to the three messages that have
> followed yours?
>
> c. I have been a fan of microcredit - but see it as a means of
> investment - not as something to normally be used for household articles
> (such as stoves normally). On the other hand something that saves time and
> improves health certainly has an economic payback as well. Have you been
> looking at microcredit in this way? Are you aware of locations where
> microcredit has worked for stoves purchase?
>
> d. You will have noticed our sometimes discussion of
> charcoal-making stoves - which do have income generation potential (with
> investment payback in a few months). Have you any thoughts on this
> difference - and the way lenders and borrowers might react to this
> difference?
>
> e. Now something off-topic - but I'd like your thoughts on this.
> When I was last in Kafa, Ethiopia, I met a gentleman who had given out (not
> loaned) a very small amount of money. I think it was $25.00 each to eight
> groups of 4 or 5 women. He did this after considerable training and
> discussion on how the women would save the income from investment - mostly
> done for products for quick resale. Except for not worrying about
> repayment, the operations are much like the Grameen Bank Each group had
> doubled their cash in about 6 months (and I am now out of date by 6 months
> - but presume growth is continuing). The women worked as teams.
> The person who did this (the implementer - using money from a third
> party donor) believed this was a superior approach to borrowing - for a
> range of reasons that I better not get into here. When I have mentioned
> this to local microcredit experts - they are aghast - saying that one
> cannot give money to a poor person (the same story Mohammed Yunus heard
> about lending money). What are your thoughts on this?
>
> Anyway - thanks for a very provocative first introduction - and
> again welcome. Speaking for many on the list, I am sure, we look forward
> to more of what you have learned in your academic studies.
>
> Anyone else want to weigh in on this return to a few of the
> dissemination topics from our past? Or on different types of stoves?
>
> Ron
>
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Fri Oct 22 12:19:49 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding another CO reference
Message-ID: <v01540b02b43637f251ee@[204.131.233.17]>

Stovers: This message just in from "stoves" list member Cathy Flanders
(who is also manager for the very active IAQ e-mail list). (Thanks very
much Cathy - please keep these coming.)

The remainder is from Cathy (Rkfabf@aol.com):

IAQ List Subscribers -

The Oct. 23rd issue of the British Medical Journal contained an editorial
article which I thought would be of interest to a number of IAQ List
subscribers. I have included everything except the extensive
acknowledgments & references which contain hyperlinks to sources. They can
be found at the end of the article on the BMJ website.

-------------Begin Text--------------------------------------------------

BMJ 1999;319:1082-1083 ( 23 October )
Editorials

<H2><A HREF="http://www.bmj.com/cgi/content/full/319/7217/1082">Carbon monoxide
poisoning</A></H2>
Is still an underrecognised problem</b>

The onset of autumn and cooler weather traditionally heralds the start of
another season in the northern hemispherethe peak incidence of unintentional
deaths from carbon monoxide. Each year around 50 people in the United Kingdom
die from carbon monoxide poisoning, and a year ago the chief medical officer
warned again of the dangers.1 As yet there is no evidence that the population
is at any lesser risk.

Humans have been poisoned by carbon monoxide since they first discovered
hydrocarbon fuels, incomplete combustion of which is the usual cause of
poisoning. Napoleon's surgeon, Larrey, saw soldiers with carbon monoxide
induced myonecrosis when billeted in huts heated by woodburning stoves. And
over 60 years ago American physicians were warned that chronic carbon
monoxide exposure could mimic many neurological conditions, such as "cerebral
haemorrhage, encephalitis, multiple sclerosis, spastic paraplegia, chorea and
tetany."2 Throughout the world people continue to die unnecessarily from
carbon monoxide exposure or to survive their encounter with disabling
symptoms whose cause is misdiagnosed.

Carbon monoxide famously binds to haemoglobin over 200 times more strongly
than oxygen, a strange evolutionary quirk explained by the tiny amounts of
carbon monoxide produced naturally in the body by haem oxygenase and the need
to have an efficient scavenging system for such a toxic substance.3 Although
the carboxyhaemoglobin which results from inhaling the gas is an indicator of
exposure, clinical features may persist or begin long after the disappearance
of measurable carboxyhaemoglobin, which has a half life of only four to five
hours when clean air is breathed. Displacement of oxygen from haemoglobin is
merely the best known property of carbon monoxide, which poisons the body in
many more subtle and complex ways.

Carbon monoxide interferes with other ferroproteins such as myoglobin and
various enzymes including members of the cytochrome family.4 Studies suggest
that endogenous carbon monoxide may share properties with nitric oxide, such
as smooth muscle relaxation and altered platelet aggregation, and be
intimately linked with nitric oxide dependent reactions, which if unregulated
can lead to cellular death. Oxidative damage to neurovascular epithelium
produced by carbon monoxide causes increased leucocyte adherence and
subsequent peroxidation of brain lipid. 5 6

The central nervous system is thus especially vulnerable, with areas at
arterial "watersheds"such as the medulla and basal gangliaat particular
risk.1 The damage can be shown radiologically.7 Isolated neurological
symptoms such as gesture apraxia and single seizures have been ascribed to
carbon monoxide poisoning, as has "winter headache." A delayed neurological
syndrome,8 which may mimic almost any neuropsychiatric complaint, though
impaired motor control is usually a prominent feature, has been reported up
to 80 days after carbon monoxide exposure. Yet this syndrome is both
preventable and treatable if the true cause is recognised.9

Economics and geography, as much as pathology and biochemistry, determine
someone's susceptibility to carbon monoxide poisoning. Korea's population is
slightly smaller the United Kingdom's, yet 20 years ago there were around
3000 deaths and a million admissions a year,10 and by 1982, 300 hospitals
were equipped with hyperbaric oxygen facilities. Korean houses are still
commonly heated by a large coal brick dropped into a space beneath the living
area. Horizontal "chimneys" pass under other rooms in the house to provide
heat, and several dwellings often share a final common flue.

In Chesterfield recently a family of four and their elderly neighbour died
because the common chimney to their housesbuilt of porous materialsbecame
blocked, venting fumes from a gas boiler into both homes.11 All five deaths
would almost certainly have been prevented by a domestic carbon monoxide
alarm. More modern house design brings its own problems, however. In a well
insulated home the negative pressure created by a bathroom extractor fan can
be enough to cause retrograde flow in an otherwise normal chimney. Most
people think of engine exhaust as a means of deliberate self poisoning, but
in Quebec it is the commonest cause of unintentional carbon monoxide deaths,
when engines are left running in enclosed spaces, for warmth or when being
repaired.

Numbers of cases sublethal exposure to carbon monoxide in Britain are
traditionally quoted as 200 a year, but up 250 000 gas appliances are
condemned annually. Even assuming that as few as 10% of these appliances were
giving off significant amounts of carbon monoxide, and discounting exposure
from other domestic sources, this suggests that as many as 25 000 people
every year may be exposed to the effects of carbon monoxide within the home.
Whatever the actual number, the overwhelming majority of cases go
unrecognised, unreported, and untreated. Chronic carbon monoxide exposure is
misdiagnosed. A survey carried out by the charity Carbon Monoxide Support
showed that in only one case out of 77 was exposure correctly identified on
the basis of symptoms alone.12

The early symptoms of carbon monoxide poisoning are usually said to be flu
like, which, though arguably true, also encourages the wrong diagnosis. As a
result a doctor's most likely response when faced with more than one member
of a household exhibiting similar symptoms is to think of a vague microbial
cause (a diagnosis never tested) when in reality a far more prosaic cause may
exist. Symptoms may initially be mild, often include gastrointestinal upset
more in children, and usually bear a temporal relation to occupancy of a
particular building or room. Classically, several family members (including
pets) are affected. Testing for carboxyhaemoglobin is straightforward and
will pick up exposure in its early stages. Oximetry on a sample of blood has
long been the only useful immediate investigation, but breath meters,
originally developed as smoking cessation aids, are now available.13 Most of
the time no one thinks to do the test.

Perhaps the most tragic consequence of a missed diagnosis is that patients
may be discharged to the very environment that is poisoning them. When deaths
are investigated it is not uncommon to find that the victim sometimes even
several members of the same family had visited a doctor with symptoms of
carbon monoxide toxicity in the days before death. With a simple,
non-invasive testing device the chances of such tragedies could be
dramatically lessened. But to achieve this we must also see increased
awareness of the problem, among both patients and their doctors.

Ed Walker, staff grade practitioner.
Accident and Emergency Department, Dewsbury District Hospital, Dewsbury WF13
4HS (ed@limeland.demon.co.uk)

Alastair Hay, reader in chemical pathology.
Molecular Epidemiology Unit, University of Leeds LS2 9JT

-----------------------End Text---------------------------------------------

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material is distributed without profit for personal, research
and educational uses. **
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<b>*INTERESTING LINK FOR THE WEEK:</b>

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A partnership program of resources formed by the EPA, Montana State
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From Alex.English at adan.kingston.net Fri Oct 22 22:53:06 1999
From: Alex.English at adan.kingston.net (*.english)
Date: Tue Aug 31 21:36:25 2004
Subject: Dream Stove Paper
Message-ID: <199910230257.WAA28134@adan.kingston.net>

Dear Stovers,
The figures which were missing from the webpage version of the paper,
are now included.

From larcon at sni.net Sun Oct 24 22:52:01 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding request on charcoal retorts
Message-ID: <v01540b00b439785f3b54@[204.131.233.16]>

>Dear Sirs,
>
>I have heard there is some "Sonocarb" type retort which can process FRESH
>CUTTED WOOD (moisture: 50-60 %) into charcoal. Is that true? If so, please
>let me know the address of the company producing it. If not, please let me
>know another type of retort which can process fresh cutted wood into
>charcoal and the company producing it.
>
>My address:
>
>Cornel Ticarat
>Bd. Decebal, no. 5
>Bl. P 18, ap. 13
>Oradea, 3700
>Romania
>Tel: +40.59.160.372
>Fax: +40.59.479.002
>E-mail: ticu@rdsor.ro
>
>My best thanks in advance.
>
>Sincerely yours,
>
>Cornel Ticarat

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

From heat-win at cwcom.net Mon Oct 25 02:30:18 1999
From: heat-win at cwcom.net (T J Stubbing)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding request on charcoal retorts
In-Reply-To: <v01540b00b439785f3b54@[204.131.233.16]>
Message-ID: <3813FB28.644E4039@cwcom.net>

Dear Ronal, Stovers and Cornel Ticarat,
Regarding Cornel's:
>I have heard there is some "Sonocarb" type retort
which can process FRESH
>CUTTED WOOD (moisture: 50-60 %) into charcoal. Is that true? If so,
please
>let me know the address of the company producing it. If not, please
let me
>know another type of retort which can process fresh cutted wood into
>charcoal and the company producing it.
On 4th October I included the following in a message he may not have received
at the time:
"If you look at our web site <http://www.dryers-airless.mcmail.com>
you will see that we have developed an energy-efficient superheated steam
drying process.
Using that process we are now drying wood and converting it to charcoal
in only three to four hours and our licensee is now offering to supply
transportable, approximately1 tonne moist weight capacity machines for
£30,000 ex works in the UK which can produce upwards of 10 tonnes/week
of charcoal depending on how moist the wood is, how large the pieces and
how many hours/week the machine is in use."
The wood can easily "process FRESH CUTTED WOOD (moisture: 50-60 %) into
charcoal".
I have never heard of "Sonocarb" and would be interested to learn about
it if anyone can provide information on it.
Regards,
Thomas (J Stubbing)

From rmiranda at sdnnic.org.ni Tue Oct 26 01:55:02 1999
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:36:25 2004
Subject: D. Justa, plancha stove
Message-ID: <3.0.5.32.19991025235335.009c0da0@ns.sdnnic.org.ni.>

Dear Ron and all:

Just to report that 3 weeks ago I went to Tegucigalpa and visited 3 houses
in which they are using the new Plancha stove called now "Doña Justa" or
Mrs. Justa stove.

This stove is a combination of the plancha developed by PROLEÑA and the
rocket stove by APROVECHO. This combination job was done by APROVECHO
people last year in Honduras with some $ help from Forest, People and
Water-FPW another US (Colorado)! based NGO.

I just want to tell this list that I was very impresed by the new D. justa
stove.

Basicaly, it has a central combustion chamber made of ceramic (the concept
of the rocket stove!) surrounded by ash, inside a square box or wall of mud
brick. It is then totaly covered by the 1/8 inch, 50 by 50 cm metal plate
(plancha stove concept!), and with a chimney made of a thin metal tube that
goes outside the roof.

My fisrt impresion was "=how nice it looks=", it is well done and takes
away the normal vision of traditional woodstoves in central america, which
is :3 stones or semi-open fires, with black walls and roof, dirt kichten,
dirt pots, big pieces of firewood, e.g. an ugly ambient.

talking with the women, they all seem very happy about it, and I
investigated why, and the reasons were first the cleanliness of the
kitchen, with no smoke, no black wall or roof, no black pots, not ashes,
not big peaces of firewood.

second they told me that it really saves energy. I had my doubts about
that, because the big plancha radiating energy, but they did insiste that
it really save lots of firewood. This D. justa stove uses small pieces of
wood, since it is much more efficient, and only allows small piece of wood
into it. Althoug the efficient gain with the rocket combustion camera could
be lost by the large plancha, all 3 women and their husbands told me that
they do use less firewood, one even said 50% less.

>From the manufacturer manual( APROVECHOS report on it), it should be around
16% efficiency, not much more than an open fire that can produce 14%, but
now I am confused after the women testimony. I recommended
PROLEÑA>/Honduras to run a test on it and confirme the women report.

What I liked most about this stove was that it produces a clean ambient,
which is the number one concern for women in our region. It also gives a
new status to the family, a feeling of progress and development.

The second think is the practice of it, since the womnen can cook
tortillas, meat, eggs and pancakes direct on it, besides not giving extra
work to the women to clean out the bottom of the pots after the cooking is
done. Someone told me that at nite they close the chimney and the fire box
mouth, and it keeps the plancha warm all nite long, and they put the
firewood on top of it(plancha)!, and the firewood will be dry and ready
for the breakfast.

Also, The metal chimney allows a fast cleaning if you hit it with a wood
stick and collect the tar ash from the bottom of the chimney, troughtout a
side opening specialy designed by the D. Justa (the first women to receive
the plancha stove in tegucigalpa back in 1995)

The third I like this stove is the savings, although the theory may say
not, but testimonies are saying yes. We have to look it again with more
detailes.

The fourth think I liked about it, is that it requires to be manufacture by
skilled people of the 3 main parts: the ceramic fire box, the metal plate
or plancha, and the metal chimney. it is good because allows mass
production with lower costs and garantee better quality parts with better
perfomance. (Prasad and I discussed the advantages of this approach
extensively in our non-virtual, face to face discussion over 1 1/2 years
ago in Germany)

The price was reported by Saul Guzman, PROLEÑA>/Honduras executive director
as 30 to 40 USD, while people from APROVECHO resports 25 USD. Perrhaps
mass production can keep it lower ?

In resume, I felt quite happy that finally it seems that we are approaching
the "today´s dream stove". It is about time, to give firewood users a
better way to cook and live, making the changes from 15 century
technologies to 19 century tech.

Early next year we here in Nicaragua are expecting APROVECHO´s people
(peter scott and larry winiarsky)! to come down for a month or two, and
work with us developing a similar stove for Nicaragua.

One of the thinks I would like to try then is to investigate the efficiency
in more detaile and perhaps reduce the area of the plancha, without losing
its ability to be practical.

Ron, I must say that this progress has only being made thanks to the stove
list, which put PROLEÑA, FPW and APROVECHO in contact, producing this
beautiful result.

Greetings to everyone

rogerio miranda

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogerio Carneiro de Miranda
Asesor Tecnico Principal
PROLEÑA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
TELEFAX (505) 276 2015, 270 5448
EMAIL: rmiranda@sdnnic.org.ni
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From heat-win at cwcom.net Tue Oct 26 05:55:40 1999
From: heat-win at cwcom.net (T J Stubbing)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding request on charcoal retorts
In-Reply-To: <v01540b00b439785f3b54@[204.131.233.16]>
Message-ID: <38157CC8.E933071B@cwcom.net>

On the 25th I wrote:
Dear Ronal, Stovers and Cornel Ticarat,
Regarding Cornel's:
>I have heard there is some "Sonocarb" type retort
which can process FRESH
>CUTTED WOOD (moisture: 50-60 %) into charcoal. Is that true? If so,
please
>let me know the address of the company producing it. If not, please
let me
>know another type of retort which can process fresh cutted wood into
>charcoal and the company producing it.
On 4th October I included the following in a message he may not have received
at the time:
"If you look at our web site <http://www.dryers-airless.mcmail.com>
you will see that we have developed an energy-efficient superheated steam
drying process.
Using that process we are now drying wood and converting it to charcoal
in only three to four hours and our licensee is now offering to supply
transportable, approximately1 tonne moist weight capacity machines for
£30,000 ex works in the UK which can produce upwards of 10 tonnes/week
of charcoal depending on how moist the wood is, how large the pieces and
how many hours/week the machine is in use."
The wood can easily "process FRESH CUTTED WOOD (moisture: 50-60 %) into
charcoal".
Sorry, but that sentence should of course have read:
The machine can easily "process FRESH CUTTED WOOD (moisture:
50-60 %) into charcoal".
Incidentally, if anyone is having difficulty in accessing my web site
<http://www.dryers-airless.mcmail.com>, though it can still be accessed
there my server says that using <http://www.dryers-airless.cwc.net>
may be more reliable.
Regards,
Thomas (J Stubbing)

From woodcoal at mailbox.alkor.ru Tue Oct 26 07:06:22 1999
From: woodcoal at mailbox.alkor.ru (Woodcoal)
Date: Tue Aug 31 21:36:25 2004
Subject: simple furnace ( mail Ronal W. Larson 09.19.99)
Message-ID: <01bf1f97$8d946a60$LocalHost@22>

Dear Peter Wong and all,
The most simple furnace is a pot from burnt clay. The wall near of bottom has
4 or 8 holes on a circumference. The clay circle with holes costs inside on a
support above than holes in walls. Coal or the chips lay on this circle and set
fire. On a pot it is possible to pose food. The pot is possible to take out and
to plot food not in the house. The thick walls of a pot store heat long. When
fire will go out, the pot can be brought in the house for heat. The food can
remain ardent long in a pot.
Sincerely yours, Yury Yudkevitch, Dr., ass.
Prof. Department of Forest Chemical Technology, St.-Petersburg Forest
Technical Academy(Russia)

From Reedtb2 at cs.com Tue Oct 26 09:57:30 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:25 2004
Subject: CO meters, smoke meters et al
Message-ID: <0.ae345225.25470e1b@cs.com>

Dear Albert Donnay, Stovers and Gasifiers...:

My thanks to Ron and Albert for opening this important issue, and here are a
few more thoughts and rebuttals.

1) The Nighthawk digital meter seems to come in a variety of models. Is the
criticism for slow response applicable to all models? I have been using it
with mixed feeling for three years. Yes, it is slow, but WOW it has a great
alarm. Woke me up at midnight a year ago.

2) Is there a webpage for the AIM meter? Can anyone post a brochure.

~~~~~~~~~~~
I would like to defend and inform myself on what Albert calls my "potentially
lethal misinformation". I am not setting myself up to be an expert, so I
throw the following out to the experts in hopes of learning from the
discussion.

I was taken to task for saying that I burned the Turbo stove indoors without
a vent. Robb Walt and I have demonstrated it on the desks of many
bureaucrats and NGO's around the world to show that there are NO emissions
when wood is properly burned. (Typically the stove does not register ANY CO
on the Nighthawk suspended 3 feet above the fire.)

My point was NOT, that we should ignore CO in biomass combustion. It was
that when burning wood, the smoke acts as a natural "odorant" much more
powerful than the mercaptans added to natural gas. I have suffered from
smoke inhalation several times, but did not show CO symptoms. Kirk Smith
regularly warns us of the health effects of biomass cooking - smoke, not CO.
So it is my current belief that when cooking with wood, the smoke is more
toxic than the CO. I hope I can get a debate going between Andrew and Kirk.

The real killer is CHARCOAL. No odorant left in the fuel. So, the wood
burning country folk die of smoke related diseases while the city folk (who
burn charcoal) die of CO poisoning.

Last Saturday I illustrated this to my student in the Turbo stove. In the
initial stage, the volatiles burn and leave charcoal. (NO CO registered
during volatile combustion). After the volatiles have all burned, the stove
becomes a CO generator. OK if you burn it in situ; lethal if not. We blew
out the CO flame and quickly saw 350 ppm on our Nighthawk directly over the
stove and turned off the stove. Khris was impressed!

SO in summary, .... we believe that all biomass stove installations should
have a "cooking vent". Who wants the grease and garlic condensing on the
walls (and lungs)? And, this will also take out any combustion emissions,
smoke or CO that occur. If the STOVES list is trying to improve the cooking
lot of 3 billion people, they should make this a policy cornerstone.

~~~~~~~
If humans were less tolerant to CO and smoke, civilization would probably
never have developed. SO, living with smoke and CO is the penalty we pay for
burning fossil and renewable fuels.

In the last decades smoke alarms have become ubiquitous in the developed
world, while CO alarms are relatively rare. Is it too much to hope that AIM
or NIGHTHAWK will make a combination SMOKE/CO alarm?
~~~~~

There are no ultra clean cars except electric ones. Any gasoline combustion
engine run in a closed garage will kill you from CO buildup long before any
CO2
buildup. Your death will come fastest on a cold day with a cold engine,
but even a warm engine on a warm day will do the deed.

Maybe Andrew has a pre-1985 car with no oxygen sensor. When I have my car
tested (at idle) it puts out less than 5 ppm CO, and probably 13% CO2. 5 ppm
CO is less than you find on a busy street corner in Tokyo. Why does Andrew
claim that you will still die of CO poisoning rather than CO2 suffocation?
Humans can tolerate up to 5% CO2 in their air (for instance on submarines),
but 13% is lethal (Lake Nios in Africa killed 1900 citizens and 10,000 cows
by belching a CO2 cloud).
~~~~~
I was glad to hear that smokers "adapt" to CO poisoning (and high altituge).
No doubt they produce more hemoglobin - is this confirmed. I have long
suspected that when interviewing people to work on gasification one should
choose smokers over non-smokers. Could it be that by giving up smoking, we
weaken our capacity to deal with CO and smoke from other sources? Maybe
second hand smoke is a good thing.

It is Autumn here in Colorado - very colorful - and I miss the smell of
burning leaves, associated with my youth. The leaf smell is quite different
from the wood smoke smell. I attribute it to the nitrogen left in the
leaves. The smell of a good cigar is quite different from that of a
cigarette too, but that's a different subject.

So, for the foreseeable future we had better educate ourselves, our clients
and our children on the dangers of smoke and CO, but not make them so afraid
that they die of worry.

Yours for a better, safer, renewable future, TOM REED BEF

In a message dated 10/21/99 10:00:34 PM Mountain Daylight Time,
larcon@sni.net writes:

<<

This was forwarded to me from the Stoves list, because of my interest in CO.
Please see that my comments make it back to the list. Thanks -- Albert
Donnay.

I want to correct some of the potentially lethal misinformation that Tom
posted
about CO:

First, accidental CO poisoning still kills more people--about 1500 per year
in
USA-- than all other toxins combined. Another 2000 kill themselves
intentionally
with CO. Many deaths are caused by people using a gas oven as a heat
source (Tom
is right that if you just run the gas without lighting it, you get an
explosion
hazard, but many people also are made sick by the natural gas itself
--methane--and/or the "odorant" --ethyl mercaptan-- that is added to it.

But he is not correct in saying that:

>If you try to use your ultra clean
>car in a sealed garage for suicide, you die of CO2 suffication which
requires
> 5% CO2. So make sure you start with a full tank.

There are no ultra clean cars except electric ones. Any gasoline combustion
engine run in a closed garage will kill you from CO buildup long before any
CO2
buildup. Your death will come fastest on a cold day with a cold engine,
but even
a warm engine on a warm day will do the deed.

With respect to gas light, most cities had it by 1875, and by 1900 many were
already in the midst of switching over to electric light. Unfortunately,
the same
manufactured gas (from coal) was then used for another 50years as utility
gas for
heating, cooking, refrig. and other appliances until the widespread intro of
natural gas in the 1950s. We did NOT live safely with gas in the last
century--it was a leading cause of death and illness then too--and we are not
living safely with it today either, mostly because we still allow the use of
unvented gas appliances indoors (ovens, ranges, space heaters, etc) and, even
worse, because we allow tightly sealed homes to be built with attached and
tuck-under garages.

Smokers and others routinely exposed to high levels of CO actually adapt to
this
relative oxygen debt quite well (just like people who live at altitude). It
is
non-smokers who are at greatest risk from CO because they are much more
sensitive
to low levels. (Notice how when smokers and non-smokers go skiing at high
altitude, say for a week in Colorado, the non-smokers are gasping for air
while
the smokers do just fine). The COHb level in non-smokers (from the body's own
production of CO) is normally less than 2%. But in smokers this may be 5% to
15%. CO may also be measured in exhaled breath. Here non-smokers are about
6ppm, smokers are 10 to 70 ppm.

Of greatest concern is Tom's comment that:
> I regularly burn my woodgas stove indoors without a vent, now that I know
what
I am
> doing. No odor.

If he does this, and if thinks that because he can't smell any volatiles
there
also is no CO, then he most certainly does not know what he is doing. Any
combustion produces CO to some degree, and there may be an odor that he
simply
can't detect or can no longer detect (the phenomenon of sensory habituation
allows us to tune out sensory input after they are recognized: the best
example
is H2S or hydrogen sulfide, the gas that smells like rotting eggs when you
first
smell it but within minutes most people can't smell it at all). Please
folks,
don't take any stupid chances -- if you burn any fuel indoors, use a vent!

And get a good CO Alarm. The Nighthawk brand he mentions was recalled
earlier
this year for problems with it failing to go off fast enough or at all.
Since I
also am the medical director of AIM Safe Air Products, I of course want to
recommend ours-- it's portable and comes with batteries that last 3 years,
don't
need replacing and can't be removed. It also has a memory function that
stores
the peak CO level for up to 8 days and shows how many hours have elapsed
since,
which is very useful when investigating CO leaks.

You can order directly from AIM (I won't be profiting personally) by calling
1-800-220-0121.

--Albert Donnay, MHS
adonnay@mcsrr.org

Tom Reed, Reedtb2@cs.com wrote:
>>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From Reedtb2 at cs.com Tue Oct 26 09:57:36 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:25 2004
Subject: New Stove Lab and Stove Books
Message-ID: <0.7b857785.25470e1c@cs.com>

Dear Rogerio et al:

In response to your question on the cost of our stove lab, less than $2,000
spent over the last decade. I presume you mean wood stoves, not heating
stoves.

You can however, spend as much or as little as you like, depending on whether
it is your money (my case) or some agency. You should have (in approximate
order and suggested costs for standard items)

A vented hood to operate the stove under
A CO and SMOKE meter ($200)
An oven for drying biomass and testing moisture content ($50-$500)
A balance for weighing fuel; preferably that you can mount the stove on while
it is burning to test burn rate
A microbalance for working with smaller samples
A fabrication facility including sheet metal bending, rolling and shearing
Other things more specific to your needs....

Hope this helps,

TOM REED BEF/CPC

In a message dated 10/21/99 6:46:06 PM Mountain Daylight Time,
rmiranda@sdnnic.org.ni writes:

<<
Dear Tom:

Right now we are budgeting a stove lab which we will ask IDB to finance it
for the National Energy Commission of Nicaragua. Can you tell me how much
it did cost in terms of equipments?

Thanks

Rogerio
>>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From dstill at epud.org Tue Oct 26 12:17:27 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:25 2004
Subject: Following up on Dean Still reply to Dream Stove paper
Message-ID: <000e01beff54$11bbab00$eb0e66d1@default>

Dear Ronal,

We are working on the question of an optimal pot shape. Making the plancha
in a Honduran stove into a shallow "pot" with 6 feet of surface area but
only 1" depth did increase efficiency to around 20% but losses from the
large surface area kept water from boiling. Not great!

As we ponder the question, a Thought Experiment occurred to us that I am
moved to share since I think it sheds light on the performance of cooking
stoves:

How much heat should contact the pot for optimal performance?

Imagine the pot with a candle underneath it. All of the heat is absorbed by
the pot so that your hand above the pot feels no elevated temperatures. That
equals something like100% heat transfer.

Isn't one answer to the above question then: Increase heat under pot and
skirt surrounding pot until excess heat emerges from the top of the pot?
Excess heat overwhelms pot's ability to absorb heat and is wasted.

Would water boil in such a stove? Are very low powered stoves acceptable?

We're starting a test.

Best,

Dean
Aprovecho

From kmbryden at iastate.edu Tue Oct 26 12:19:18 1999
From: kmbryden at iastate.edu (mark bryden)
Date: Tue Aug 31 21:36:25 2004
Subject: New Stove Lab and Stove Books
In-Reply-To: <0.7b857785.25470e1c@cs.com>
Message-ID: <4.1.19991026110328.00bc9890@kmbryden.mail.iastate.edu>

Rogerio,

I have working on outfitting a stoves lab for approximately the past year
and I agree with Tom's list but I think the first question you need to
answer is if you intend to have a research lab or if you are looking for
something different. If you are going to outfit a research lab the cost
will be significantly higher than $2000. An analytical balance alone can
cost $3000. With that said, how much you spend is of course related to your
funding sources and your needs.

I am working on developing detailed computational models of stoves and so
my needs may be different than yours. My minimum list looks like:

Hoods
CO alarm (safety use only)
drying oven
ashing furnace
analytical balance
2 precision balances with data aquisition capability (differing ranges to
measure mass vs.time)
Thermocouples and thermocouple readers
Data Aquisition equipment
Computer for data aquisition
digital anemometer

Gas analyzer - CO, CO2, O2, HC (I don't have this yet but need it)
and of course there are always other wants (an IR based digital temperature
detector like Dean Still's for example) and needs that arise.

Good luck.

Mark Bryden

At 10:01 AM 10/26/99 -0400, you wrote:
>Dear Rogerio et al:
>
>In response to your question on the cost of our stove lab, less than $2,000
>spent over the last decade. I presume you mean wood stoves, not heating
>stoves.
>
>You can however, spend as much or as little as you like, depending on whether
>it is your money (my case) or some agency. You should have (in approximate
>order and suggested costs for standard items)
>
>A vented hood to operate the stove under
>A CO and SMOKE meter ($200)
>An oven for drying biomass and testing moisture content ($50-$500)
>A balance for weighing fuel; preferably that you can mount the stove on while
>it is burning to test burn rate
>A microbalance for working with smaller samples
>A fabrication facility including sheet metal bending, rolling and shearing
>Other things more specific to your needs....
>
>Hope this helps,
>
>TOM REED BEF/CPC
>
>
>In a message dated 10/21/99 6:46:06 PM Mountain Daylight Time,
>rmiranda@sdnnic.org.ni writes:
>
><<
> Dear Tom:
>
> Right now we are budgeting a stove lab which we will ask IDB to finance it
> for the National Energy Commission of Nicaragua. Can you tell me how much
> it did cost in terms of equipments?
>
>
> Thanks
>
> Rogerio

___________________________________________________________
Mark Bryden, Ph.D. Assistant Professor
kmbryden@iastate.edu Iowa State University
ph: 515-294-3891 3030 Black Engineering Bldg
fax: 515-294-3261 Ames, Iowa 50011-2161
Stoves List SPONSORS and ARCHIVES:
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http://www.ikweb.com/enuff/public_html/Chamber.htm

From jon at jonrouse.freeserve.co.uk Tue Oct 26 17:33:35 1999
From: jon at jonrouse.freeserve.co.uk (Jon Rouse)
Date: Tue Aug 31 21:36:25 2004
Subject: Stoves; microcredit, 'microgifts' and microenterprise
Message-ID: <00a301bf1ffa$46d34840$a777883e@jonr>

Ron, Karve, Rogerio & Stovers...

Thanks very much for your responses. Here are some responses to some of the
many issues raised.

Firstly, I fear one aspect of my last message was misunderstood - that
relating to the integration of microcredit into improved stove programmes.
My interest in this is related to the starting of small enterprises through
a loan rather than loans designed to enable people to purchase stoves. In
fact, the example cited by Rogerio of giving loans to help pay for stoves in
Honduras was the first such example I had heard about. I have read a fair
bit about projects that have involved giving away the stoves or offering
heavy subsidy, and I had heard that such projects often struggled. This has
clearly been the experience of Karve, and as he said, the most likely
reasons for their failure are associated with the psychology of gifts .v.
products worked for / bought / earned. However, it is interesting that
Karve's experience is that an initial (small?) subsidy can be a very
positive thing as it encourages people to take the plunge. A good idea for
getting people to buy their first stove where otherwise they would remain
unconvinced. Naturally, the success of this working relies on the product
actually being effective, attractive and useful or time saving - so that
people really will keep using it and in the case of ceramic stoves, replace
it when necessary.

I see many good reasons for keeping stove manufacture local. While I don't
believe the bottom line of everything is money, I do think a stove project
needs to be economically viable and capable of generating profit, and hence
incomes, for local people. In addition to the livelihood provision, this
also serves to enhance the sustainability of the project. If the
programme is genuinely financial viable, then it need not rely on external
support and will perpetuate itself. In order to get small businesses up and
running in poorer areas, initial capital is the problem, and it is here that
small loans some into play. It is a project like this that I would like to
get involved with in India.

My work on microenterprise has mainly been involved with the concept (and
basic design / testing) of a spreadsheet that is capable of modelling a
small economy. The idea was born out of a notion that there must be optimum
loan amounts for given situations. It turns out that, according to basic
testing, there are certain values of loans from which an individual most
benefits. Benefits are measured in two ways;
1) How much cash the borrower has at the end of the year
2) What proportion of the year the borrower has a given amount of cash
sufficient to invest (perhaps in a stove manufacture or small agricultural
project).
The optimum loan amount constitutes the loan size for which the borrower
ends up with the most money at the end of the year, or for which the
borrower has the maximum amount of money for the most time in the year.

The spreadsheet takes into account seasonal income, seasonal ad-hoc expenses
(medicine, funerals etc.), interest rates and 'cross financing'. Cross
financing is
the common scenario wherein people resort to short-term high interest
'informal sector' (moneylender) loans to finance repayments. It is this last
thing
that often draws people into 'debt traps'. The spreadsheet calculates
the need for cross financing automatically. Finally, the spreadsheet is
capable
of taking into account the profits and costs of a small enterprise. The
model
can run over a number of years.

The spreadsheet suggests that there certainly is an optimum loan size, and
that the results of lending more or less than that amount can lead to
significantly less desirable situations at the end of the year for the
scenarios I modelled. (I got the scenarios from various Participatory Rural
Appraisal reports. It really needs field testing though!) It also showed
that there are best times to lend the money within the year, and
(particularly interesting to me) optimum repayment schemes. Optimum
repayment schemes are those whereby the lender still gets all money repaid
within the given period, but the borrower gets to repay when he / she is
most capable. For example, repayments could be higher just after harvest,
and lower during leaner periods of the year. Or, rather than spreading
repayments equally throughout a year, they could become greater towards
the end of a year when a business has been established and begins to
generate some income. This is an excellent way of minimising the need for
cross financing.

Ron mentioned an interesting project in Ethiopia wherein instead of being
leant money, groups of women (wholly more trustworthy than men!) were given
a small sum, which was successfully invested. I see gifts of money for
investment as slightly different from gifts of money to buy something like a
stove. Anyway - I also looked into the use of this spreadsheet for
calculating minimum useful gift sizes; both for simply helping to get people
through lean periods to avoid the debt cycle, and for helping people get a
small business up and running. It may well be - though I am undecided -
that there are circumstances wherein a gift may do more good than a loan. I
would be interested in knowing more about just why the implementer of the
Ethiopian project felt this was such a good idea.

Apologies - this message is rather too long. I hope you got this far.

I could wax lyrical about this idea more - but I am aware that it is
slightly off the subject for this newsgroup. However, I would love to know
people's comments / thoughts / ideas. I would love to take this idea further
and make it work for real people. But how?

Regarding my dissertation (and some examples of this microfinance /
enterprise spreadsheet in action?) I am intending to post some stuff up on
the WWW relatively soon.

Best regards,

Jon Rouse

From Alex.English at adan.kingston.net Tue Oct 26 22:32:06 1999
From: Alex.English at adan.kingston.net (*.english)
Date: Tue Aug 31 21:36:25 2004
Subject: reply to Dream Stove paper
In-Reply-To: <000701befd2b$1b43c5c0$da0e66d1@default>
Message-ID: <199910270236.WAA04840@adan.kingston.net>

Hi Dean,
You wrote;
> Complete combustion reduces exposure to harmful smoke. All stoves should be
> designed to reduce such exposure. But complete combustion, in my opinion,
> does not greatly increase the overall efficiency of the improved cook stove.

I have recently seen some evidence to the contrary albeit with a
high tech turbo type stove.

With the good gas mixing that forced air offers, excess air levels
can be reduced significantly. This pushes the hot mix temperatures up
400 degrees F. Going back to what Kevin said about radiant heat
transfer varying with the fourth power of the temperature difference,
I see this being a senario where a .5% improvement in combustion
efficiency, from 99.0% to 99.5 % could yield a greater net
increase in heat transfer efficiency. That is the part which I
haven't measured, yet.

Till later, Alex

>
> With best regards,
>
> Dean Still
>
>
>
>
>
>
>
> Stoves List SPONSORS and ARCHIVES:
> http://solstice.crest.org/renewables/stoves-list-archive/
> Stoves Webpage
> http://www.ikweb.com/enuff/public_html/Stoves.html
> For information about CHAMBERS STOVES
> http://www.ikweb.com/enuff/public_html/Chamber.htm
>
>
Alex English
RR 2 Odessa, Ontario, Canada
K0H2H0 613-386-1927
Fax 613-386-1211
Stoves List SPONSORS and ARCHIVES:
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http://www.ikweb.com/enuff/public_html/Chamber.htm

From Alex.English at adan.kingston.net Tue Oct 26 22:32:06 1999
From: Alex.English at adan.kingston.net (*.english)
Date: Tue Aug 31 21:36:25 2004
Subject: Following up on Dean Still reply to Dream Stove paper
In-Reply-To: <v01540b01b43106a2b3b3@[204.131.233.25]>
Message-ID: <199910270236.WAA04846@adan.kingston.net>

Dear Ron, Dean and .....

> Ron:
> I am pretty sure those of us working on charcoal-making
> stoves are always seeing something well above 99% combustion efficiency -
> we measure almost no CO and experience essentially no odor. (Alex - I hope
> you can confirm this with more quantitative results.)

I can't confirm the statement above.. What I have found is that the
combustion efficiency of some charcoal making, top lit, pyrolyser
stoves is quite variable. There is no magic here. Pyrolysis releases
combustible products and if the air/fuel mix is to lean or to rich,
or poorly mixed, or quenched, the combustion efficiency suffers. What
I feel I can confirm is that the combustion efficiency with this type
of stove can be very good. How does 99.9% sound? The same
stove, without the benefit of instrumentation, can be easily
operated with no visible smoke in the mid 90's.

My best measured estimate of the combustion efficiency of Elsen's
Can Stove Charcoal maker would be about 98%. Eindhoven's research
put their experimental down draft stove up around 99% and their
experimental updraft stove around 94-95%. Data from Grant
Ballard-Tremeer's thesis shows so called improved stoves below 95%,
with open fires slightly higher than 95%.

Even if all these numbers came from the same test methods, which they
don't, correlating combustion efficiency with harmful emissions
would be problematic. The CO emissions are the largest potion of the
losses. Yet it is the hydrocarbon emissions that seem to be the
greatest concern . There is no consistent correlation between the two
for combustion efficiencies in the mid 90s %. For combustion
efficiencies over 99% the correlation is better.

So although combustion efficiency is a good quantitative measure of
undesirable emissions and lost potential, it can be an unreliable
qualitative measure.

Having said that, it does appear that virtually all practical
cooking stoves operate at well below 98% combustion efficiency with
the production of significant quantities of toxic emissions. It may
seem like a small increment, but I think Prof. Grover has tried to go
the extra difficult step and design a significantly cleaner stove
that would be over 99% , with very low levels of hydrocarbon
emissions.

I look forward to data about the combustion efficiency and actual
emissions of the char-top stoves that Prof. Grover has described.

Regards, Alex English

From karve at wmi.co.in Tue Oct 26 22:57:53 1999
From: karve at wmi.co.in (karve)
Date: Tue Aug 31 21:36:25 2004
Subject: Stoves; microcredit, 'microgifts' and microenterprise
In-Reply-To: <00a301bf1ffa$46d34840$a777883e@jonr>
Message-ID: <38166A67.3745843F@wmi.co.in>

Stovers,
This is in response to the following part of a very useful message from Mr.
Rouse.

Jon Rouse wrote:
.... However, it is interesting that
Karve's experience is that an initial (small?) subsidy can be a very
positive thing as it encourages people to take the plunge. A good idea for
getting people to buy their first stove where otherwise they would remain
unconvinced. Naturally, the success of this working relies on the product
actually being effective, attractive and useful or time saving - so that
people really will keep using it and in the case of ceramic stoves, replace
it when necessary.

I think it should be clarified that just giving a subsidy is not enough. As
long as the improved stove dissemination programme involves just giving away the
stove models as per the availability of models and the convenience of the
government officials, the programme fails miserably. However, this is the way we
now try to go about the distribution of the subsidised stoves.
First a meeting is organised with the people in the village. In this meeting
a trainer from the Technical Back up Unit (TBU) explains the various models
available under the subsidy programme, their advantages over the traditional
models, the relative merits and demerits, etc. He also explains the proper ways
to use the different stoves. The people are encouraged to choose the models (one
pot hole, two pot holes, fixed, portable, etc.) that they think are suitable for
their households. The TBU also conducts user feedback surveys. This serves as an
inspection of the supplied stoves, the surveyor too can remove any
doubts/misconceptions that the user may have about the stove, and the feedback
collected is useful in design improvement.
Of course, this works only where the TBU is an active participant and
dedicated to making the programme a success.
When the stoves were being supplied without any active involvement of the
users in the programme, even when the user's had paid some amount for it, the
stoves would remain unused. Many times this was because the supplied model was
not suitable to the family's requirement. But the most important reason was a
negative feeling towards something developed by 'educated' people ('What do
these people who live in the comfort of their modern houses know about cooking
in a hut? Their fancy appliances will never work here. What right do they have
to tell us that the methods developed by our ancestors through experience are
wrong?').
Therefore even the subsidy run programme is successful only if their is
active involvement of the user's themselves. It also helps a great deal to
involve a local NGO who has established itself as a group of local peole truly
dedicated to the development of their own village.
Regards,
Priyadrshini Karve

From dstill at epud.org Tue Oct 26 23:40:45 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:25 2004
Subject: Fitting flame to pot
Message-ID: <000e01beff63$f1f282c0$9b0e66d1@default>

As we were slogging around, and chatting, in the ankle deep mud today,
building the foundation for two more handicapped accessable bathrooms to be
added to the dorm, a couple of numbers coincided in what seemed possibly to
be a related fashion.

This is just for fun and contemplation, I'm not sure if it's true or not.

Our cooking stoves use something like 2 pounds of wood per hour.
That's around 17,600 BTU's.

The good stoves operate at around 30% efficiency.

One third of 2 pounds is .66 pounds of wood.

Maybe we should be only pushing .66 pounds of wood through that stove per
hour because the pot in that configuration does not absorb the excess heat.
(We are getting close to 100% combustion and use insulation to reduce heat
loss into the stove body.) .66 pounds of wood is about 5,600 BTU's.

What will happen Thursday when the class tests the following stove: pot is
insulated to greatly reduce losses. Heat is introduced at a rate calculated
to not exceed pot's ability to absorb heat, say 1/2 pound per hour.
Combustion occurs in a smaller, well insulated combustion chamber.

(By the way, it's probably wrong, but we figure radiation to be more like 4
to 5 times better than convection at 1,000 degrees F difference, not 12. Can
others chime in on this question?)

If one square foot of the pot is contacting heat then maybe 1,000BTU/hour is
getting through by convection and between 4 and 5 thousand/hour by
radiation. That adds up pretty close to our original number of 5600.

If this is a good number, which is doubtful anyway, is this a support for
burning .66 pounds of wood per hour maximum in this stove?

Will we get some very high % Thursday?

I'll report back Thursday night.

Best,

Dean

From woodcoal at mailbox.alkor.ru Wed Oct 27 09:59:56 1999
From: woodcoal at mailbox.alkor.ru (Woodcoal)
Date: Tue Aug 31 21:36:25 2004
Subject: New Stove Design
Message-ID: <01bf2064$33bff5e0$LocalHost@22>

Dear Richard,
I have read at http://www.chrbo.com about chrbo. It is necessary to do the
precise deduction on a delineation or on the stove in a nature. But that I
have seen, it was pleasant to me. It is very similar to a Japanese pot,
which one I always advocated, but is made modern, beautifully, accurate. I
think, chrbo waits the good future. I wish to you success. I can be the
expert, if you want to advocate chrbo in Russia.

Sincerely yours, Yury Yudkevitch, Dr., ass. Prof.
Department of Forest Chemical Technology,
St.-Petersburg Forest Technical Academy(Russia)

<Richard Boetcker <rboetcke@bitcorp.net>
To: Rogerio Miranda <rmiranda@sdnnic.org.ni>; Woodcoal
<woodcoal@mailbox.alkor.ru>
26.10.1999 18:44 New Stove Design >

>Dear Sirs:
>
>I have been a member of the stoves list for a few months and have, on my
>own, developed a very unusual stove. The price could be dropped to half
>if tooling was in place. Presently the stoves are being made on
>punching machines and it is very slow and labor intensive. Please visit
>my web site at http://www.chrbo.com and tell me what you think. Alex
>English in Canada and Elsen Karstad in Africa have stoves and are
>helping me by running tests for efficiency and emissions.
>Sincerely,
>Richard C. Boetcker
>Sandy, Utah
>
>

From kchishol at fox.nstn.ca Wed Oct 27 10:20:46 1999
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:25 2004
Subject: Fitting flame to pot
In-Reply-To: <000e01beff63$f1f282c0$9b0e66d1@default>
Message-ID: <38170C45.9DDCECCC@fox.nstn.ca>

Dear Dean

I like your common sense, empirical approach!! :-) Nothing is as humbling to a
good theory as a reality check!!

Basically, the problem between "theory" and "practise" is not that the theory is
wrong..... the assumptions are wrong. "Practise" is reality. The difference
between them is a measure of the potential for improvement.

My first guess to explain the difference between theory and your observed
results is that the effective temperature for radiation is lower than assumed.
Do you have access to a radiation pyrometer, where you can measure the effective
temperature of the radiating surfaces which "see the pot"? This would be very
helpful. Gas temperatures per se are relatively meaningless without knowing the
radiation charactistics of the gases. Air at 1000 degrees differential has very
different characteristics than a luminous flame with the same gas temperature.

Best wishes in your interesting search!!

BTW.... I'll leave you with an interesting thought:
"2+2 = 5.....the Answer is right, but the Question is wrong." :-)

Kevin Chisholm

Dean Still wrote:
..del...

> This is just for fun and contemplation, I'm not sure if it's true or not.
>
> Our cooking stoves use something like 2 pounds of wood per hour.
> That's around 17,600 BTU's.
>
> The good stoves operate at around 30% efficiency.
>
> One third of 2 pounds is .66 pounds of wood.
>
> Maybe we should be only pushing .66 pounds of wood through that stove per
> hour because the pot in that configuration does not absorb the excess heat.
> (We are getting close to 100% combustion and use insulation to reduce heat
> loss into the stove body.) .66 pounds of wood is about 5,600 BTU's.
>
> What will happen Thursday when the class tests the following stove: pot is
> insulated to greatly reduce losses. Heat is introduced at a rate calculated
> to not exceed pot's ability to absorb heat, say 1/2 pound per hour.
> Combustion occurs in a smaller, well insulated combustion chamber.
>
> (By the way, it's probably wrong, but we figure radiation to be more like 4
> to 5 times better than convection at 1,000 degrees F difference, not 12. Can
> others chime in on this question?)
>
> If one square foot of the pot is contacting heat then maybe 1,000BTU/hour is
> getting through by convection and between 4 and 5 thousand/hour by
> radiation. That adds up pretty close to our original number of 5600.
>
> If this is a good number, which is doubtful anyway, is this a support for
> burning .66 pounds of wood per hour maximum in this stove?
>
> Will we get some very high % Thursday?
>
> I'll report back Thursday night.
>

From english at adan.kingston.net Wed Oct 27 19:31:23 1999
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding a response from Prasad
Message-ID: <199910272335.TAA13013@adan.kingston.net>

To:Prof.Grover, Dean Still, Ron Larson and other stove folk

From: Prasad

> Subject: Following up on Dean Still reply to Dream Stove paper

Before going any further, I would like to commend the work of
Prof.Grover on his "dream stove". I have not looked at the paper with
adequate attention. But my first impression is that it is far too
expensive and my gut feeling quite cumbersome to oerate. I shall
comment on these aspects in a later mail, But I'll restrict myself
now to the comments of Dean and Ron.

>
> Dean said:
> <snip>
> >In my opinion, the stove movement often overemphasizes the gains to
> >be made from improved combustion while underestimating the limitations of
> >the pot as a poor heat exchanger.
>
> This is mainly to provide strong support for Dean's comments on the
> importance of optimizing the heat transfer to the cook pot.
>
Prasad.

The question is : Is combustion efficiency achieved at the expense of
heat transfer? Kirk Smith and others state that heat transfer
efficiency is often achieved at the expense of combustion quality.
One point needs to be remembered in this connection. You may have 90%
combustion efficiency. That last 10% can make all the difference
between a healthy indoor and a deadly place.

My argument is that it is possible to achieve both by careful design.
I shall come to these points at a later date.

> Dean:
> <snip>
> > It is relatively easy to encourage 90 percent and above combustion
> >efficiency. Metering the fuel, insulating the combustion chamber, and making
> >a hot, fierce fire achieve almost complete combustion. One can also go the
> >route of gasification. Or make a good, experty tended, three stone fire.
> >
> Ron:
> I still am in the process of getting my own response to Professor
> Grover's article, but want to add a bit on the value of pyrolysis vs
> gasification. I am pretty sure those of us working on charcoal-making
> stoves are always seeing something well above 99% combustion efficiency -
> we measure almost no CO and experience essentially no odor. (Alex - I hope
> you can confirm this with more quantitative results.)
>
> But I see a main value of charcoal-making stoves in being able to
> drive ordinary charcoal-makers out of business. Their usual combustion
> efficiency is close to 0% (of the emitted gases - with value remaining only
> in the charcoal). When they emit CO2, they are losing their main product.
>
> I do not believe that Professor Grover is aware of the past
> discussion on this list of this new approacah to pyrolysis stoves. In
> particular - it is not necessary to have a down-draft design to achieve
> pyrolysis.
>

Prasad:

It is not proper to state that downdraft combustion achieves better
pyrolysis. My claim is that downdraft stove achieves better quality
of combustion, at least that is what we can say on the basis of our
work at Eindhoven.

>
> Dean, continued:
> >But, the pot is a terrible heat exchanger. So only a small percentage of
> >heat actually gets into the water and food. The percent of heat that makes
> >it into the food can be increased by exposing more of the pot surface area
> >to hot flue gases, optimizing heat absorption at the pot surface, using
> >multiple pots, etc.
> >
> >For example, the bigger the pot, the greater the heat transfer efficiency.
> >Full pots score better than half full pots.
>
> Ron:
> Dean - can you add any experimental data you might have about
> efficiency as a function of the size of the pot. It would seem that there
> might be an optimum size (for a given cooking (ie weight of water) job) -
> as the surface area will increase radiation losses from a very wide pan.
>

The heat transfer to the pot is a bear indeed. I am afraid you guys
will respond: here he goes again. You guys need to read all of our
work at Eindhoven. Heat transfer to pan can be increased by providing
a shield around the pan and matching the pan size with the power of
the fire. These have been discussed by us and we have various types
of results that support these claims. For a starter you can consult
Woodstove Compendium and the article in Advances in Heat Transfer.

> Has anyone else on the list ever seen such data or conducted tests
> where the only variable was the size of the cook pot?
>
> Dean:
> > A skirt around the pot
> >dramatically improves efficiency. Covered pots save fuel.
>
>
> Ron:
> The best analytical (which doesn't include experimental) work I
> have seen on "skirts" is in list-member Sam Baldwin's PhD thesis. I think
> I got close to 50% efficiency once when I was using a double metal sleeve
> with apparently the right dimensions. Dean has previously reported that
> the optimum gap is less than a centimeter (and such separation numbers also
> depend on the height of the pot).
>
> In the early days of the "stoves" list we also sometimes referred
> to a stove figure of merit - the ratio of the weight of water that could be
> boiled away (pot top off in this experimental study environment) for a
> given weight of wood (where a credit would of course be given for making
> charcoal). In the charcoal-making case, I recall we were talking about
> getting about an FOM of 1 - and that wasn't easy experimentally. I'll try
> to find my efficiency computations on what an FOM = 1 means in efficiency
> terms - but I think it is around 50% (with credit given for the charcoal -
> which is usually 25% by weight).
>
> Dean:
> >Professor Grover ends his report by including a paragraph on pot design. I
> >heartily agree with him that a new pot, designed to increase surface area to
> >volume ratio, and that forces heat to rub against the pot surface would
> >dramatically improve fuel economy. Effort spent in improving the pot as heat
> >exchanger is many times more likely to improve cooking stove efficiency than
> >improving the combustion side of the equation.
>
> Ron:
> Professor Grover was encouraging also more development work on the
> concept of vertical stacking of cook pots - which seems to be done in
> China. Are there any list members who can comment on how much efficiency
> improvement is to be found with vertical pot stacking? The capture of the
> energy in that evaporated water is of course well worth striving for.
>
> The modern gas-fired water heater efficiency is well above 65%.
> This is achieved by having a very tall narrow design with only a narrow
> interior heat transfer surface. (The last (failed) one of mine that I
> could look at had one interesting interior long "wavy" vane also). The
> nearest cookpot equivalent of which I am aware is the Russian samovar
> design - on which we have had considerable discussion - but no concrete
> efficiency numbers. Anyone able to supply any experimental data on the
> efficiency gains of putting the hot flame gases through the middle of the
> pot rather than around it?
>
> I am afraid that a major problem will occur with making pots with
> such a shape - but there is no sense even worrying about this if the
> efficiency improvement is not good. Any data? I have a test in mind, but
> no time to carry it out.
>
> Dean:
> >Complete combustion reduces exposure to harmful smoke. All stoves should be
> >designed to reduce such exposure. But complete combustion, in my opinion,
> >does not greatly increase the overall efficiency of the improved cook stove.
> >To dramatically reduce fuel use, instead improve heat transfer to the pot or
> >better yet, use a retained heat cooker (haybox).
> >
> >With best regards,
> >
> >Dean Still
> >
> Dean - Thanks for reminding us of this important (I agree is now
> the most efficiency important) aspect of cook-stove (through pot/sleeve)
> design. I doubt that Professor Grover will disagree with your remarks as
> they apply to efficiency.
>
> But I don't think you at Approvecho have yet reported on any work
> with Pyrolysis-type stoves - which I took to be a main thrust of Prof.
> Grover's paper (in order especially to improve combustion efficiency for
> reasons of health). Have you all yet constructed and experimented with any
> such stove? I am not suggesting the down-draft approach or gasification -
> but rather what Elsen, Alex, several Toms, and I have reported on in a
> simple cheap "updraft" design - what Tom Reed calls an Inverted down draft
> design.
>
> I repeat that I have not absorbed the full Grover paper - as I
> still have had access only to the e-mailed version. More after I see the
> full paper with figures and tables that are understandable
>
> Ron
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401, USA
> 303/526-9629; FAX same with warning
> larcon@sni.net
>
>
Prasad:
I don't care for pans with fins etc. For such a small device that
sounds too esoteric. I am still of the opinion that one could build a
stove that costs much less than what Grover is suggesting. I believe
the gasification stove is also quite complicated to operate.
Collection of charcoal, its storage and then marketing demands too
much from the harassed woman who happens to be the cook we need to
cater to.

The kind of production system Priyadarshini is envisaging will put
the Eindhoven downdraft stove, Ron's gasifier stove and the dream
stove in the category of yet another dream.

What should be such a stove? I shall try my hand at that next time I
write.

Yours
Prasad

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>

From english at adan.kingston.net Wed Oct 27 19:31:25 1999
From: english at adan.kingston.net (*.English)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding comments from Prasad
Message-ID: <199910272335.TAA13021@adan.kingston.net>

Dear Ron, Rogerio, Karve, and Rouse

> Date: Thu, 21 Oct 1999 22:01:31 -0600
> To: stoves@crest.org
> From: larcon@sni.net (Ronal W. Larson)
> Subject: comments on Prasad, Miranda, Karve and Rouse recent messages

> Stovers:
>
> The follosing is a mishmash of responses to the three recent
> messages triggered by the Jon Roush introdcutory message
>
>
>
> C. Re Prasad's Message today:
>
> Prasad - your message was silent on the subject of microcredit. Do
> you see a relationship with type of stove?
>
> All - under what circumstances do you see something other than
> local manufacture (and local dissemination) as being the best approach ?
>
>
Well, I ran out of time that day. Thus my silence on microcredit.The
international enthusiasm about microcredit, as far as I can gather,
arises from the success story of Grameen Bank in Bangladesh. I cannot
suppress a chuckle at this awareness.It also will provide a neat line
for Sanjeev Bhaskar in that delightful comedy programme of BBC called
"Goodness Gracious Me!" I don't know how many readers of this
list have watched this programme. Mr.Bhaskar will dismiss microcredit
by saying: "We knew it in India long time back, man."

Let me quote from my personal experience. My father worked in a steel
plant in South India. My mother was a member of the Ladies Club
there. Some of the members of the club organized themselves into what
was called chit fund. They were clever and limited the membership to
twelve. Each member contributed, if my memory is right, half a rupee
per month. As soon as the kitty was full they put the names of the
women on individual pieces of a paper (of course folded) in a small
vessel. The vessel was shaken and one piece of paper was picked. The
person whose name was on that paper took the kitty for the month. The
person who got the money the first month, needless to say, had to pay
for the rest of the 11 months and on the second month there were
only 11 pieces of paper and so on. It worked very well and what is
more, nobody reneged on payment and there was no argument as to the
methodology. I remember my getting a pair of slippers and such
things. She used it on things she wanted to use it. My father had no
say in the matter! As far as I can remember it went on for at least 6
years at which time I left the town for college in Bangalore. That
was 50 odd years back.

The point here is that these ladies had no CEO of a Grameen
Bank urging them to do it. As far as I can gather it is simply
similar to a kid's piggy bank. I know very many variations on the
theme exist. There is something like auctioneering. Most of these are
male inventions. It is common knowledge that invariably these have
ended up in a mess. Even in the case of Grameen Bank, women have been
bulk of their clients. I sincerely believe that is the reason why the
scheme has worked so sucessfully. Thus I was not also surprised to
hear Priyadarshini saying we don't need it in India.

Now, Ron, coming to your comment/query, this was too long a yarn to
weave that day. Now to the question. In theory it should work for any
stove design. For the heavy stoves, since they have to be built in
situ, it requires a trained person (I really don't buy the idea of
owner-built stoves; it would be nice to hear Dean's views on it since
Approvecho "sold" Lorena stoves on that basis) to collect materials
and build it. She/he has to be paid for it. Micro credit is a neat
way of providing it. There are several bugs in the system. If the
builder has to make a living out of building stoves, he/she would
have to have a large number of customers. That would be too large a
group for peer pressure to work. Thus grameen bank loans are
negotiated to small groups of women - I have heard a number of
five. For the builder this is too small a group. Thus several such
groups need to be put together. An organizational structure of
the type Grameen Bank then becomes necessary. Note there is a major
difference between my mother's chit fund group and these groups.
The former is a voluntary group and there was no condition how the
money should be spent. The latter is an altogether a different kettle
of fish. Thus the costs of running the programme will be much higher
than the interest rates we pay for a bank loan. No doubt it will be
much smaller than the usurious interests charged by the proverbial
local moneylender.

That is where a one-pan metal stove scores. These can be produced on
an "industrial" scale and sold through "commercial" channels. These
vendors can provide the credit, but that entirely depends on the
trust the vendor has in the buyer. My bet is that such a trust is an
honest to goodness dream, not the"dream stove".

Thus it requires great deal of work to persuade people to (a) buy the
stove, (b) organize them to jointly make sure the payments occur
regularly and (c) to "sell" the system to producers and vendors.

It places enormous demands on the organizational skills of the person
in charge of the operation. Remember that this person has to operate
on the ground and not from an office in the IMF headquarters at
Washington DC. This is where an institution of the type of Grameen
Bank is imperative. Obviously they have invested heavily on people
who are required to do the necessary work on the ground. They have
presumably selected people with some level of commitment and I am
sure they are adequately compensated for their labours.

I have not heard of a stove programme that has done this type of
work. There is a great deal of talk about Chinese stove programmes
but unfortunately these seem to be less well documented than the
Grameen Bank programmes. Thus one shrugs one's shoulders when people
ask:why can't people follow the Chinese example? There simply is a
large hole in the details which are essential for a stove programme
to work.

Ron, I think I have earned my place in the group after a long
silence!

Prasad

From Reedtb2 at cs.com Thu Oct 28 10:00:30 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:25 2004
Subject: Radiation from small flames
Message-ID: <0.baa37110.2549b1f0@cs.com>

Dear Stovers, Robb et al:

There is an understandable confusion in the field of combustion flames
concerning the role of radiation.

Clean flames are relatively transparent and radiate very poorly = have very
low emissivity. However, if they are a few meters thick, they radiate quite
well.

Thus, it is possible to put your finger 1 cm to the side of a Bunsen burner,
Meeker burner flame or even a candle flame and feel NO heat. (Don't however
put your finger IN the flame: the convection from the 1400 to 2000 C flame
will cause a bad burn.)

However, that same flame in an open hearth furnace 3 meters thick becomes the
principle source of heat transfer to the melt!

So, in cooking flames the radiation is almost certainly less than 1% of the
heat transfer.

In a message dated 10/27/99 11:17:19 AM Mountain Daylight Time,
Robbcpc@aol.com writes:

<< This is food for thought: The temperature of a gas vs its radiation
properties. How are radiation properties measured (characterized)? Do we
have such a measurement device on our wish list of equipment for the Stove
Lab?? If not, perhaps we should add it (?).

Robb
-----------------
Forwarded Message:
Subj: Re: Fitting flame to pot
Date: 10/27/99 8:27:11 AM Mountain Daylight Time
From: kchishol@fox.nstn.ca (Kevin Chisholm)
Sender: owner-stoves@crest.org
To: stoves@crest.org

Dear Dean

I like your common sense, empirical approach!! :-) Nothing is as humbling to
a
good theory as a reality check!!

Basically, the problem between "theory" and "practise" is not that the
theory is
wrong..... the assumptions are wrong. "Practise" is reality. The difference
between them is a measure of the potential for improvement.

My first guess to explain the difference between theory and your observed
results is that the effective temperature for radiation is lower than
assumed.
Do you have access to a radiation pyrometer, where you can measure the
effective
temperature of the radiating surfaces which "see the pot"? This would be very
helpful. Gas temperatures per se are relatively meaningless without knowing
the
radiation charactistics of the gases. Air at 1000 degrees differential has
very
different characteristics than a luminous flame with the same gas
temperature.

Best wishes in your interesting search!!

BTW.... I'll leave you with an interesting thought:
"2+2 = 5.....the Answer is right, but the Question is wrong." :-)
>>
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From Reedtb2 at cs.com Thu Oct 28 10:01:10 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:25 2004
Subject: Inverted downdraft stove research
Message-ID: <0.d7c1c0ed.2549b1f7@cs.com>

Dear Alex et al:

We are finally getting around to doing better research on the Turbo (inverted
downdraft top burning charcoal making volatile burning) stove.

I have a student here at the Colorado School of Mines, Khris Kircher, who is
doing the work for his EPICS class. We have built a Turbo stove in which the
pyrolysis air (= fuel production rate) and the combustion air are separately
controlled by flowmeters. We expect to be able to measure optimum flame
conditions as a function of fuel production rate. We are also developing a
"heat meter" to measure the available heat from the flame and will correlate
it to the "heat transfer" to the the pot.

Keep tuned for further developments....

Yours truly, TOM REED and KHRIS KIRCHER

In a message dated 10/26/99 8:39:07 PM Mountain Daylight Time,
Alex.English@adan.kingston.net writes:

<<
> Ron:
> I am pretty sure those of us working on charcoal-making
> stoves are always seeing something well above 99% combustion efficiency -
> we measure almost no CO and experience essentially no odor. (Alex - I hope
> you can confirm this with more quantitative results.)

I can't confirm the statement above.. What I have found is that the
combustion efficiency of some charcoal making, top lit, pyrolyser
stoves is quite variable. There is no magic here. Pyrolysis releases
combustible products and if the air/fuel mix is to lean or to rich,
or poorly mixed, or quenched, the combustion efficiency suffers. What
I feel I can confirm is that the combustion efficiency with this type
of stove can be very good. How does 99.9% sound? The same
stove, without the benefit of instrumentation, can be easily
operated with no visible smoke in the mid 90's.

My best measured estimate of the combustion efficiency of Elsen's
Can Stove Charcoal maker would be about 98%. Eindhoven's research
put their experimental down draft stove up around 99% and their
experimental updraft stove around 94-95%. Data from Grant
Ballard-Tremeer's thesis shows so called improved stoves below 95%,
with open fires slightly higher than 95%.

Even if all these numbers came from the same test methods, which they
don't, correlating combustion efficiency with harmful emissions
would be problematic. The CO emissions are the largest potion of the
losses. Yet it is the hydrocarbon emissions that seem to be the
greatest concern . There is no consistent correlation between the two
for combustion efficiencies in the mid 90s %. For combustion
efficiencies over 99% the correlation is better.

So although combustion efficiency is a good quantitative measure of
undesirable emissions and lost potential, it can be an unreliable
qualitative measure.

Having said that, it does appear that virtually all practical
cooking stoves operate at well below 98% combustion efficiency with
the production of significant quantities of toxic emissions. It may
seem like a small increment, but I think Prof. Grover has tried to go
the extra difficult step and design a significantly cleaner stove
that would be over 99% , with very low levels of hydrocarbon
emissions.

I look forward to data about the combustion efficiency and actual
emissions of the char-top stoves that Prof. Grover has described.

Regards, Alex English

>>
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From larcon at sni.net Thu Oct 28 12:18:29 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding Prasad: Following up on Dream Stove paper
Message-ID: <v01540b00b43e27ae098c@[204.131.233.15]>

Stovers: This was delayed 3 days by confusion on my part.

Prasad: Sorry for the delay - caused by my getting both a personal copy
and the bounced version from "stoves". Shall we add your new e-mail
address to the list?

The rest all from Prasad:

To:Prof.Grover, Dean Still, Ron Larson and other stove folk

From: Prasad

> Date: Mon, 18 Oct 1999 12:56:17 -0600
> To: stoves@crest.org
> From: larcon@sni.net (Ronal W. Larson)
> Subject: Following up on Dean Still reply to Dream Stove paper

My argument is that it is possible to achieve both by careful design.
I shall come to these points at a later date.

Prasad:

The kind of production system Priyadarshini is envisaging will put
the Eindhoven downdraft stove, Ron's gasifier stove and the dream
stove in the category of yet another dream.

What should be such a stove? I shall try my hand at that next time I
write.

Yours
Prasad

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

From larcon at sni.net Thu Oct 28 15:33:50 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:25 2004
Subject: Prasad comments on microcredit
Message-ID: <v01540b02b43e2e78a1e6@[204.131.233.17]>

Stovers:

Thanks to Alex for passing on the two messages from Prasad, but
sorry that you all received a duplicate. I am adding Prasad's new address
to the list.

Last night I read an article in the November (latest) issue of
Scientific American by Mohamed Yunus - the Bangladeshi Economics Professor
who began the whole successful Grameen Bank program. I heard Yunus in
Denver a few years ago and went to a Denver microcredit fund-raiser a few
days ago.

Denver now has about 100 borrowers - paying 1% per month on the
unpaid balance (balances which would astound Bangaldeshi - but needed to
help the poor here). Only one Denver group has defaulted - apparently in
premeditated fashion - but overall, this is considered a success as well.
Yunus comments on the need for early financial management support for the
bank (and doesn't mention a lot of help from volunteers on business
techniques.) We're off on a non-stove tangent perhaps, but dissemination
is a key interest of this list - so it is welcome to have Prasad's
additional wisdom on this topic.

At the end of this latest message, Prasad says:

" Ron, I think I have earned my place in the group after a long
silence!"

To which I think we all will agree that it is great to have
Prasad's wisdom with us always and at any time. To those who have come to
this list lately, they should know that Prasad led the prestigious
Eindhoven University stove work beginning more than 20 years ago (but now
unfunded). Prasad has a wonderful store of stoves knowledge.

Ron

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

From kevinmloftus at hotmail.com Thu Oct 28 15:41:14 1999
From: kevinmloftus at hotmail.com (Kevin Loftus)
Date: Tue Aug 31 21:36:25 2004
Subject: Remove me!
Message-ID: <19991028194519.98819.qmail@hotmail.com>

Please could I, Kevinmloftus@hotmail.com be removed from your mailing list. I thank you for the useful mail which I have recieved, but What I now recieve is of no use to me. Thank You.

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From larcon at sni.net Fri Oct 29 18:06:51 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:25 2004
Subject: Forwarding Donnay Re CO meters, smoke meters et al
Message-ID: <v01540b00b43fcc72675a@[204.131.233.6]>

Stovers: This is to forward a response from Albert Donnay to a response
message from Tom Reed:

Albert - Thanks for your continued attention to the small world of stoves

Ron (The rest all as coming from Albert)

> >From: Reedtb2@cs.com
> >Date: Tue, 26 Oct 1999 10:00:59 EDT
> >Subject: CO meters, smoke meters et al
> >To: larcon@sni.net, stoves@crest.org, gasification@crest.org
> >MIME-Version: 1.0
> >
> >Dear Albert Donnay, Stovers and Gasifiers...:
>

> >
> >2) Is there a webpage for the AIM meter? Can anyone post a brochure.
>

AIM is at www.aimsafety.com

> >I was taken to task for saying that I burned the Turbo stove indoors without
> >a vent. Robb Walt and I have demonstrated it on the desks of many
> >bureaucrats and NGO's around the world to show that there are NO emissions
> >when wood is properly burned. (Typically the stove does not register ANY CO
> >on the Nighthawk suspended 3 feet above the fire.)
>

what you describe is not a reliable test method, and the Nighthawk is not a
suitable test instrument. You would need to set up a flue that went fully
around
the stove top and measure for CO in the flue gas with a metal probe attached to
your detector. AIM's model 450 and other professional models usually come
with this
attachment, but cost $400 and up.

> >So it is my current belief that when cooking with wood, the smoke is more
> >toxic than the CO. I hope I can get a debate going between Andrew and Kirk.
> >

If not a debate between them, than with me. Wood smoke contains many toxic
gases,
but the CO in it will kill you faster than anything else.

> >
> >SO in summary, .... we believe that all biomass stove installations should
> >have a "cooking vent". Who wants the grease and garlic condensing on the
> >walls (and lungs)? And, this will also take out any combustion emissions,
> >smoke or CO that occur. If the STOVES list is trying to improve the cooking
> >lot of 3 billion people, they should make this a policy cornerstone.
> >
>

we agree ! Now if only we could get all natural gas stove installations to
include
a vent ...

> >In the last decades smoke alarms have become ubiquitous in the developed
> >world, while CO alarms are relatively rare. Is it too much to hope that AIM
> >or NIGHTHAWK will make a combination SMOKE/CO alarm?
> > ~~~~~
> >

AIM's will be available in 2000.
-- Albert Donnay, MHS
President, MCS Referral & Resources, Inc.
Medical Director, AIM Safe Air Products, 1-800-ASK-4-AIM
adonnay@mcsrr.org, www.mcsrr.org
508 Westgate Rd, Baltimore MD 21229
410-362-6400, fax 362-6401

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

From dstill at epud.org Sat Oct 30 02:19:02 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:25 2004
Subject: Results of a few simple tests
Message-ID: <002e01beffc6$2c60c720$9c0e66d1@default>

I'm looking forward to the day when the cooking stove is understood, when it
can be modelled successfully. Then we will understand why certain approaches
are more or less efficient. Until that day, we keep plugging along making
stoves and testing them, like shooting arrows into a black box. Fascinating,
all the same!

Here, for entertainment purposes only, are this week's results from students
tests of their prototype stoves.

Our test uses a small, uncovered pot which is filled 4/5 full with 5 pounds
of water. Two pounds of dry wood is burned in the stove at a moderate rate.
We use 17,200 BTU's as a guess for the BTU's contained in the two pounds of
wood.

Measuring both sensible and latent heat, from loss of steam, we figure the
percent of heat that made it into the pot.

Test One

A three stone fire four inches under the pot. The pot is surrounded by
insulation on the sides and top. 26%

Test Two

A vertical stove with two pots. Using a low mass, insulated Rocket elbow and
short chimney under the first pot. The second pot heats from flue gases that
pass the first pot. Both pots are inside a low mass, insulated chimney. 38%

Test Three

A 2" thick cement plancha stove in which heat passes in a narrow gap beneath
the plancha (griddle). The 2 pots sit on the plancha above large openings.
Smoke exits from a chimney. 14%

General Conclusions:1.) low mass, insulated stoves that expose the greatest
amount of pot surface area to the heat perform well.2.) Heat needs to be
made to contact pot surface directly. 3.)High mass materials absorb heat
that could assist cooking. 4.)Even with multiple pots, 40% efficiency
usually demands covering so much of the pot that the stove becomes an oven.

Best,

Dean

From AlanPengelly at compuserve.com Sat Oct 30 14:28:14 1999
From: AlanPengelly at compuserve.com (Alan Pengelly)
Date: Tue Aug 31 21:36:25 2004
Subject: Remove me please
Message-ID: <199910301430_MC2-8B07-C229@compuserve.com>

Please remove my name from your stoves mailing list. I have found a lot of
the mail recieved to be marginally interesting but it is not in my main
field of interest. Incidentally, I think that the technical content is a
bit low level from the enthusiastic stovers and that there is far too much
gratuitous polemics from the two sides of the green war; most of whose
soldiers seem to be far too well qualified to waste their time and other's
on such waffle.

Thanks for past service

Alan Pengelly
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BioEnergy Lists: Improved Biomass Cooking Stoves

October 1999 Biomass Cooking Stoves Archive