BioEnergy Lists: Improved Biomass Cooking Stoves

From REEDTB at compuserve.com Sat Mar 1 18:32:38 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:04 2004
Subject: GAS-L: Knowledge of Lambiotte continuous retorts?
Message-ID: <199703011839_MC2-11E5-F15E@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Myles:

I have long known OF the Lambiotte (or SIFIC) charcoal maker. It recycles
heat from the gases given off and requires no external heat source. Makes
over 30% charcoal.

There are 5 pages of description of Lambiotte in "Industrial Charcoal
Making", FAO Forestry Paper No. 63, obtainable from FAO (c 1985), ISBN
92-5-102307-7.

If you find out anything more, please forward to me.

Yours truly, TOM REED

 

From sail at why.net Mon Mar 3 17:36:37 1997
From: sail at why.net (ronald coleman)
Date: Tue Aug 31 21:35:04 2004
Subject: Chambers cookstove
Message-ID: <1.5.4.32.19970303224027.006718ec@why.net>

Sorry to bother but if you could point me toward some information on
Chambers cookstoves I would appreciate it.
Thanks
ron

 

 

From verhaarp at janus.cqu.edu.au Mon Mar 3 17:59:28 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:04 2004
Subject: Indian Rope Trick
Message-ID: <1.5.4.32.19970303230435.0067a390@janus.cqu.edu.au>

To Tom Reed and the other Stovers,

About the Indian Rope Trick.

I finally managed to dig up an article I thought I had. It is about
stabilising the combustion zone in a vertical cylindrical pipe of constant
cross section by controlling the downward airflow rate. The experiments were
done by Tony Bridgwater and David Earp at Aston University, Birmingham, UK,
starting sometime in 1986.

I was hoping to find the actual downward velocity of the air in the fuelbed,
but that was not calculated and data are insufficient to work it out here. I
am fairly sure I corresponded about it but it may be quite a while before I
find that correspondence

What we are talking about is Open Core Downdraft Gasification, this term may
have been coined by David M.
Earp and Anthony V. Bridgwater of Aston University Birmingham U.K.
They presented papers at both the 1987 Orleans and the 1989 Lisbon EC
conference on Biomass for Energy and
Industry. Subject was gasification of wood in a very simple reactor,
consisting of a vertical quartz pipe of 75
mm internal (I presume) diameter.

Looking at their figures:

Pipe diameter: 75 mm
Specific capacity: 290...415 kg/(m2.hr) dry wood
Feedstock woodchips (actually 1/4" and 3/16" dowels cut into short pieces,
according to David Earp)
Airflow rate: 850...1050 Nm3/(m2.hr)

For the above setup this gives (if I didn't make my usual calculation mistakes):
Feed rate: 0.356 ... 0.509 g/s
Airflow 1.146 ... 1.416 l/s;
and a velocity: 0.26 ... 0.32 m/s through the empty pipe.

We need to know the void fraction (how many m3 of wood per m3 of space) to
get the actual velocity of the
air through the fuel.
According to my experience with the downdraft stove no realistic chimney
height can achieve enough draft to
satisfy the above conditions.

David and his mates could keep the combustion zone at a set location by
varying the airflow. If the fire tended
to creep upward, the flow was increased (they had a suction pump downstream,
after a cooler). Not having to
worry about pressure losses they could maintain a layer of char of any
thickness downstream of the combustion
zone, where the combustion gases were partially reduced to H2, CO and CH4.

The title of the article is: "Research into a Transparent Open Core
Downdraft Gasifier", and two of the five
references are to Tom Reed and M. Markson.

The gas has a higher heating value of 3.3 MJ/Nm3. Is that something you can
design a burner for, in a domestic
size? For 1 kW you need about 1.1 m3 per hour.

The feed rate is equivalent with 6.764 ... 9.671 kW; for the WSG downdraft
stove, with a grate diameter of 120 mm that would be equivalent with
(120/75)2 * 6.764 = 17.3 kW for the lowest feed rate. Our downdraft stove
produced a maximum heat output rate of 8 kW. Etienne correct me if I am wrong?
Would that mean a chimney of more than 4 m tall?

I see that somehow I forgot to send the original message so it won't hurt to
add my latest thoughts (Prasad always says I think as slow as I drink).

If what I said is true then a conical fuel container with the narrowest
section at the grate can only have the combustion zone smack on top of the
grate. If the air velocity falls below the critical value the fire will
creep upward and nothing can stop it. The only configuration with inherent
stability would be one with the base of the cone at the bottom end. In that
way the combustion zone would be stabilised where the flow velocity has the
right value. It cannot creep upward because of the increasing air velocity.

Nature is a bitch.

Cheers and NOx,

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

 

 

From REEDTB at compuserve.com Tue Mar 4 16:25:21 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:04 2004
Subject: Tarless Gasifier Demo
Message-ID: <199703041630_MC2-121A-1D71@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Stovers and Gasifierers(?):

Glad to hear from Pete concerning the rate of propogation of the "flaming
pyrolysis" zone in a pile of woodchips. While the discussion applied to
"gasifier stoves", it applies even more in the "GASIFICATION" node, so I'm
responding in both.

Just as "burning velocity" of gas/air mixtures is central to understanding
the use of gaseous fuels in Bunsen and other burners, Markson and I in 1982
discovered that the "propogation velocity" of a burning "flaming pyrolysis
zone" is central to understanding the behavior of the "stratified downdraft
gasifier". (I believe it was Ali Kaupp and maybe Bob Reines at UCDavis who
coined the name "open core" gasifier as an alternative to "stratified
downdraft" about 1984. I have never understood what an "open core" was - I
hope someone can enlighten me.) Incidentally, the propogation velocity is
very difficult to predict, but obviously depends a great deal on moisture
content, which is probably why downdraft gasifiers require <20%MC for good
operation. Other early names associated with this work are Wallawender at
Kansas State, the Buck Rogers Co. and the very earliest the Chinese rice
hull gasifier.

The term "stratified downdraft" (as opposed to Imbert/nozzle stabilized
downdraft) comes from the plug flow of the fuel, first through the "flaming
pyrolysis" zone, making CO/H2 rich combustion gases, then as char through
the reduction zone with the gases passing the same way at about 0.2-1 m/sec
(superficial velocity).

The "Transparent Gasifier" was first built at NREL/SERI about 1982, based
on a patent of mine from MIT. Thin gold, 20 nm thick, insulates as well as
an inch of Fibrefrax. We market a transparent furnace that will go to
1100C. Cost <$1,000. We built several transparent gasifiers and have a
lot of video footage showing the flaming pyrolysis and reduction zones.

We originated the term "flaming pyrolysis" by analogy to "flaming
combustion", a very old term. FC is the combustion of gases in an excess
of air, as in a match or candle flame, where the products are largely CO2
and H2O. FP is the combustion of gases (from pyrolysis) in an excess of
fuel, where the products include a lot of CO and H2 as well. Glad to see
the term is surviving without dilution.

All of this was covered when it was still fresh in my mind in disgusting
detail in our "Handbook of BIomass Downdraft Gasifier Engine Systems",
(Reed and Das, 1988, Chapters 4 and 5, available from the BEF Press). (End
of commercial).

There is to be an energy fair in Boulder (People's Republic of) in May this
year and Das and I believe it is possible to make a gasifier with low
enough tar to run a Honda 3kW generator with NO scrubbing. I gave him a
copy of Bhatacharya's Two Stage (Tarless) gasifier paper yesterday. Any
suggestions (other than it ain't possible)?

Best to all, especially PETE, who starte this train of thought ... TOM
REED

 

From les.gornall at dial.pipex.com Tue Mar 4 19:37:37 1997
From: les.gornall at dial.pipex.com (Dr. Les. Gornall)
Date: Tue Aug 31 21:35:04 2004
Subject: ashes to ashes - smoke to smoke
Message-ID: <331CC38D.1C0A@dial.pipex.com>

My problem- smoke in the kitchen. I need a solution.

Background. I have built a solar powered house
which is described on my web page

http://dspace.dial.pipex.com/town/terrace/ae198/ SolarHouse.html

It is located in Northern Ireland, sub-arctic tundra, wind speeds
highest in Europe, winter sun for 5 -10 weeks of the year is minimal.
Even with the best insulation (12-18" all round) if there is no sun,
occupational heat of 2 adults, 3 children = 12deg.C internal
temperature. We need 18 minimum or the kids won't do their homework!
Answer- a Yotul 118 woodstove in the kitchen - takes two foot logs. We
grow ash (fraxinus sp.) and by the time we retire, we will have fixed
enough carbon to justify burning the trees grown for the purpose to heat
us without a cash requirement - ashes to ashes!

Two weeks ago I fitted the Yotul stove into the solar house kitchen
which has been built with a conventional 20ft high, 6" nominal bore
pottery flue in a concrete block chimney. The base of the chimney is
offset about 12" by means of two 90degree bends ending vertically. The
stove was lit and 'the dragon', as the stove is affectionately called,
filled the kitchen with acrid smoke. Tar streamed down through cracks
in the headers of the alcove in which the dragon sits. A storm appeared,
the tar was washed down the chimney - about two pints had to be mopped
up and the top of the stove became a tar pyrolysis unit. We tried
again, the dragon did its bit, pouring smoke into the kitchen. When
the windows in the kitchen are opened on the windward side the smoking
is reduced, however, any gust of wind on the house (typically 45mph +)
sends more smoke into house. This is our first attempt at burning wood
- what amazes me is how keen you guys are!!! We must be doing something
wrong. The chimney has been checked and it is clear of debris.

The sun shone both yesterday and today, and the house temperature is
back up to 22 C. But what of the dragon, should I call for St. George
to slay the monster, rebuild the chimney, cap it with a gizmo or build a
wind turbine?

I would value the assistance of experts.

Best regards

--
Dr. Les. Gornall
Director
Practically Green
(Environmental Services)
Solar House
Magherafelt
Co. Londonderry
Northern Ireland
BT45 6HW

+44 1648 32615
les.gornall@dial.pipex.com

 

From J.J.Todd at geog.utas.edu.au Wed Mar 5 02:15:41 1997
From: J.J.Todd at geog.utas.edu.au (J.J.Todd@geog.utas.edu.au)
Date: Tue Aug 31 21:35:04 2004
Subject: ashes to ashes - smoke to smoke
Message-ID: <199703050723.SAA01672@corinna.its.utas.edu.au>

Dr Les Gornall requested ideas for preventing smoke blow-back from a wood
fuelled cooking stove.
The reason smoke enters the room instead of going up the flue is that the
air pressure in the room is lower than the pressure in the flue. This
could happen in a well sealed house with roof vents because the warm house
behaves like a chimney itself and, until the stove's chimney is hot, the
room pressure will be less than the pressure in the stove chimney.
My suggestions are:
1. Open some windows in the kitchen, turn off any exhaust fans, and burn
half a dozen sheets of crumpled newspaper in the stove (no wood at this
stage) to warm the flue. When the paper has burned, set the fire and light
it and then close the windows.
2. If this does not work, extend the height of the chimney, use some 6 inch
pipe (anything, even galvanised, will do to first see if this solves the
problem). I think roughly a 6 foot extension would be worth trying. Then
repeat step 1. If this does seem to solve the problem then a more robust
chimney extension could be tried.
The flue draft is a function of the flue gas temperature and the height of
the flue. As soon as the flue draft (i.e. air pressure in the flue) is
below the air pressure in the room the flue should draw.
If you do get everything working, I would strongly suggest a smoke alarm in
the kitchen in case smoke and CO start to enter the room at night when you
are asleep.
Good luck!
Dr John Todd
University of Tasmania, Australia

 

 

From les.gornall at dial.pipex.com Wed Mar 5 02:40:15 1997
From: les.gornall at dial.pipex.com (Dr. Les. Gornall)
Date: Tue Aug 31 21:35:04 2004
Subject: Re. Ashes to Ashes , Smoke to Smoke.
Message-ID: <331D26B3.E0B@dial.pipex.com>

Dr John Todd kindly replied to my call for help!

> The reason smoke enters the room instead of going up the flue is that the
> air pressure in the room is lower than the pressure in the flue.

I agree - the evidence is chokingly visible!
This
> could happen in a well sealed house with roof vents because the warm house
> behaves like a chimney itself and, until the stove's chimney is hot, the
> room pressure will be less than the pressure in the stove chimney.

This is most illuminating - the chimney is not quite as high as the roof ridge - I
think I will have words with a certain engineer and the builder!

> My suggestions are:
> 1. Open some windows in the kitchen, turn off any exhaust fans,

I have an air to air heat exchanger fitted with both exhaust and inlet fans. If I turn
these off, then I loose the benefit of the house which recovers 85% of the heat in the
exhaust air. However, I should be able to arrange a positive differential pressue by
means of increasing the voltage on one fan via a stepped transformer. Thanks!

and burn
> half a dozen sheets of crumpled newspaper in the stove (no wood at this
> stage) to warm the flue. When the paper has burned, set the fire and light
> it and then close the windows.

I did that - the trouble begins even before the window is closed.

> 2. If this does not work, extend the height of the chimney, use some 6 inch
> pipe (anything, even galvanised, will do to first see if this solves the
> problem). I think roughly a 6 foot extension would be worth trying. Then
> repeat step 1. If this does seem to solve the problem then a more robust
> chimney extension could be tried

- I will try this soon !

> The flue draft is a function of the flue gas temperature and the height of
> the flue. As soon as the flue draft (i.e. air pressure in the flue) is
> below the air pressure in the room the flue should draw.

I accept this, but the wind is so strong in this area that I fear no matter how high
the flue is, the wind will always drive the hot flue gases downwards, is there such a
thing as a wind proof flue, bearing in mind that gust of over 100mph occur in the
winter occasionally, 60mph frequently and generally the site has a 6m/second average
windspeed?

> If you do get everything working, I would strongly suggest a smoke alarm in
> the kitchen in case smoke and CO start to enter the room at night when you
> are asleep.

This might explain my headache!

 

> Good luck!

Thanks!

> University of Tasmania, Australia

--
Dr. Les. Gornall
Director
Practically Green
(Environmental Services)
Solar House
Magherafelt
Co. Londonderry
Northern Ireland
BT45 6HW

+44 1648 32615
les.gornall@dial.pipex.com

 

From verhaarp at janus.cqu.edu.au Wed Mar 5 06:23:39 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:04 2004
Subject: ashes to ashes - smoke to smoke
Message-ID: <1.5.4.32.19970305113042.0068dcac@janus.cqu.edu.au>

>From Piet Verhaart

At 00:51 5/03/97 +0000, you wrote:

>My problem- smoke in the kitchen. I need a solution.

Hardly daring to suggest it, but does your dragon draw its combustion air
from the room to be heated? If so, the problem might be that the house is so
well built that there are insufficient air leaks to supply the stove.
There are stoves that draw their combustion air from outside (from the air
space between inner and outer wall, for instance) and that kind would be
better suited.

Hoping your problem will be solved soon, by fair means or foul.

Regards,

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

 

 

From E.Moerman at stud.tue.nl Wed Mar 5 06:52:38 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:04 2004
Subject: Indian Rope Trick
Message-ID: <46565.s335192@popserver.tue.nl>

Peter Verhaart <verhaarp@janus.cqu.edu.au> writes:

> The feed rate is equivalent with 6.764 ... 9.671 kW; for the WSG downdraft
> stove, with a grate diameter of 120 mm that would be equivalent with
> (120/75)2 * 6.764 = 17.3 kW for the lowest feed rate. Our downdraft stove
> produced a maximum heat output rate of 8 kW. Etienne correct me if I am
> wrong? Would that mean a chimney of more than 4 m tall?

If you want a CO/CO2 ratio below 0.1% then 8kW is about the maximum power
output. If you don't care about the combustion quality then you can get up
to over 10kW.

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

 

From mheat at mha-net.org Wed Mar 5 08:11:20 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:04 2004
Subject: Re. Ashes to Ashes , Smoke to Smoke.
Message-ID: <199703051318.IAA14650@nic.ott.hookup.net>

Dr. Les Gornall wrote:

>
>This is most illuminating - the chimney is not quite as high as the roof
ridge - I
>think I will have words with a certain engineer and the builder!
>
------reply separator-----------------

Here's another one: With the strong wind, the short chimney, and the unknown
roof orientation, the chimney exit may be located in a postive pressure zone
(relative to inside) created by wind effects interacting with your roof
geometry.

One solution that works for strong wind gusts is the "Vacu-stack" chimney
cap, manufactured by

Improved Consumer Products, Inc.
P.O. Box 1264
Attleboro Falls
MA 02763 (USA)
(508)695-7000
FAX 695-4209
----------------------------------------------------------
Norbert Senf -----------------email: mheat@mha-net.org
Masonry Stove Builders -------website: www.mha-net.org
RR 5 Shawville----------------fax: 819.647.6082
Quebec J0X 2Y0----------------voice: 819.647.5092

 

 

From bedwards at iastate.edu Thu Mar 6 01:36:05 1997
From: bedwards at iastate.edu (William A Edwards)
Date: Tue Aug 31 21:35:04 2004
Subject: re smoky stove
Message-ID: <9703060643.AA17168@isum2.iastate.edu>

(snip)
> Two weeks ago I fitted the Yotul stove into the solar house kitchen
> which has been built with a conventional 20ft high, 6" nominal bore
> pottery flue in a concrete block chimney. The base of the chimney is
> offset about 12" by means of two 90degree bends ending vertically. The
> stove was lit and 'the dragon', as the stove is affectionately called,
> filled the kitchen with acrid smoke. Tar streamed down through cracks
> in the headers of the alcove in which the dragon sits. A storm appeared,
> the tar was washed down the chimney - about two pints had to be mopped
> up and the top of the stove became a tar pyrolysis unit. We tried
> again, the dragon did its bit, pouring smoke into the kitchen. When
> the windows in the kitchen are opened on the windward side the smoking
> is reduced, however, any gust of wind on the house (typically 45mph +)
> sends more smoke into house. This is our first attempt at burning wood
> - what amazes me is how keen you guys are!!! We must be doing something
> wrong. The chimney has been checked and it is clear of debris.

(snip)

> Dr. Les. Gornall
> Director
> Practically Green
> (Environmental Services)
> Solar House
> Magherafelt
> Co. Londonderry
> Northern Ireland
> BT45 6HW
>
> +44 1648 32615
> les.gornall@dial.pipex.com

How cold is it in the house when you start the fire? Close to the temperature
outside? My brother-in-law has had a yotul, though a smaller model, and has
had some trouble getting it started when the house cold. How dry is your
wood? Maybe not dry enough? How high ABOVE THE ROOF does your chimney extend?
I had a similar problem with the propane furnace in a mobile home; added
chimney height cured it. I really think added chimney height will cure the
smoke problem. The rest of this addresses the other problem. Install the pipe
that connects to the chimney with the female ends up and the male ends down
and make sure that the horizontal section has some slope toward the stove,
this plus dry wood and warm chimney should cure creosote ("tar") problem.
It also might help if (once you get a fire going) as long as you need the
supplemental heat don't let the fire go out and especially don't let the
chimney get cold. Hope this helps

Bill

---
------------------------------------------------------------------------------
William A (Bill) Edwards | It's you and me against the world.
bedwards@iastate.edu | When do we attack?
If these aren't my very own views I want to know who the heck's responsible!
------------------------------------------------------------------------------

 

From Morten.Fossum at energy.sintef.no Thu Mar 6 02:44:38 1997
From: Morten.Fossum at energy.sintef.no (Morten Fossum)
Date: Tue Aug 31 21:35:04 2004
Subject: New member and 2 questions
Message-ID: <3.0.16.19970306085023.4777dd64@mail.trd.sintef.no>

Hello list members.

Beeing new on this list let me start with a short presentation. My name is
Morten Fossum and I'm working in SINTEF, located in Trondheim Norway. I
guess those of you that is intereseted in skiing now that we just had the
world championship competitions here in Trondheim. I work as a research
scientist ( since 1987)mainly with biomass, but I have also worked on
natural gas, waste, oil and coal. On biomass I have been involved with
projects related to combustion and pyrolysis. For the last couple of years
I also have been working on gasification of biomass as a part of my PhD
studies. For more information about SINTEF, please visit our homepage
http://www. sintef.no.

Now my 2 questions.

1. Self-heating of charcoal.

We have just done some tests on self-heating of charcoal according to the
procedures given by IMO BC-CODE. Have any of you any experience with this
test or knowledge of other investigations on self-heating of charcoal?

2. Sulfur balance for the pyrolysis process.
This may be strange because sulfur is not regarded as a major pollutant in
terms of the utilisation of biomass but nevertheless.

The metallurgical industry in Norway use charcoal as a feedstock and are
now looking at the potential to increase the use of charcoal. As a part of
the investigations they also are interested to look at the effects on terms
of sulfur emissions (thats a tax question). So, have any of you put up a
sulfur balance for the pyrolysis process? Will the sulfur stay in the solid
phase?

Regards

Morten Fossum
SINTEF Energy, Dep. of Thermal Energy and Hydropower
N-7934 Trondheim
Tel.: +47 73 59 25 14
Fax.: +47 73 59 28 89
E-mail: Morten.Fossum@energy.sintef.no

 

From E.Moerman at stud.tue.nl Thu Mar 6 09:07:43 1997
From: E.Moerman at stud.tue.nl (E.Moerman)
Date: Tue Aug 31 21:35:04 2004
Subject: Re. Ashes to Ashes , Smoke to Smoke.
Message-ID: <54565.s335192@popserver.tue.nl>

"Dr. Les. Gornall" <les.gornall@dial.pipex.com> writes:

> I accept this, but the wind is so strong in this area that I fear no matter
> how high the flue is, the wind will always drive the hot flue gases
> downwards, is there such a thing as a wind proof flue, bearing in mind
> that gust of over 100mph occur in the winter occasionally, 60mph
> frequently and generally the site has a 6m/second average windspeed?
>

I am not an expert in chimney equipment, but as far as I know there exists a
rotating cap that should be placed on top of the chimney. If the wind is
blowing the cap starts rotating. I think this reduced the pressure in the
chimney, so it should improve the draft. However I think you might get
problems with soot etc. Perhaps you should contact a chimney sweep.

Good luck.

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

 

From tmiles at teleport.com Thu Mar 6 11:04:23 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:04 2004
Subject: Re. Ashes to Ashes , Smoke to Smoke.
Message-ID: <3.0.32.19970306081240.00bc68b0@mail.teleport.com>

At 03:09 PM 3/6/97 +0100, Etienne Moerman wrote:
>I am not an expert in chimney equipment, but as far as I know there exists a
>rotating cap that should be placed on top of the chimney. If the wind is
>blowing the cap starts rotating. I think this reduced the pressure in the
>chimney, so it should improve the draft. However I think you might get
>problems with soot etc. Perhaps you should contact a chimney sweep.

A chimney cap used here in the Northwest swivels with the wind presumably
reducing turbulence and increasing draft. Our neighor has one. When he
fires up his wood stove even in light winds the cap has the effect of
directing his smoke right into our house. But for him it helped solve the
kind of problem you describe.

Tom

 

From REEDTB at compuserve.com Sat Mar 8 07:49:55 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:04 2004
Subject: stoves-digest V1 #108
Message-ID: <199703080756_MC2-124A-80C5@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Mort:

Self heating charcoal manufacture: You can find any result you want on
this subject in the literature. Antal has published figures on the "heat
of pyrolysis", showing it can vary from several hundred + to several
hundred - kJ (kcal?).

The reasons for the diversity are many - come visit for more. The
principle reason is that SLOW pyrolysis of MASSIVE wood produces minimum
volatiles, maximum charcoal, which is the exothermic part of pyrolysis.
(Vaporization of the tars and PLA is endothermic.)

The most convincing evidence for self heating is the experience of the
charcoal industry itself. If you put a carload of scrap wood in a kiln and
monitor the temperature of the kiln and the center of the wood pile,
initially the woodpile lags behind the kiln - to about 275C. At this point
the TC in the pile catches up with the kiln and passes it, reaching about
425 C, even if you turn the kiln off.

We make a product, Sea Sweep, an oil absorbent from wood. An important
part of our process is quenching the wood before pyrolysis is finished to
preserve the structure.

On the other hand, at high heat transfer rates, the surface of each
particle can be incandescent while the center is still cold!. Under these
conditions the outer regions of the charcoal are gassified by the emerging
CO2/H2O and char yields are very low.

So you can see your question opens a large CAN OF WORMS, much of which is
not yet explored.

2) Sulfure. I have no proof, but I don't think the miniscule sulfur will
stay in the charcoal during metal reduction. It sure doesn't during
gasification.

 

From tduke at igc.apc.org Sat Mar 8 19:01:01 1997
From: tduke at igc.apc.org (Thomas Duke)
Date: Tue Aug 31 21:35:04 2004
Subject: Measuring stove airflow.
In-Reply-To: <Pine.3.89.9702210702.A20073-0100000@teal.csn.net>
Message-ID: <3321FE4E.5F8F@igc.apc.org>

Hi,

I have a peace corps volunteer friend in Nepal. She is living with some
villagers. Their house is filled with smoke because of cooking on an open
fire inside the house. She is concerned about the effect of smoke on the
small children. So, I sent a copy of the drawing of the original stove (two
one gallon tin cans) and said I post a message to you (Stoves group) because
I know a lot of thinking and developing has taken place after we did our
initial work.

I will send any suggestions you have for her to her. It is a long and
difficult journey by foot for her to get to a telephone. However her father
is sending her some things shortly. So, please let me know what you think
will help.

Sincerely,

Tom

 

From verhaarp at janus.cqu.edu.au Sun Mar 9 07:19:39 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:04 2004
Subject: Measuring stove airflow.
Message-ID: <1.5.4.32.19970309122641.006753cc@janus.cqu.edu.au>

>From Piet Verhaart

At 18:03 8/03/97 -0600, you wrote:
>Hi,
>
>I have a peace corps volunteer friend in Nepal. She is living with some
>villagers. Their house is filled with smoke because of cooking on an open
>fire inside the house. She is concerned about the effect of smoke on the
>small children. So, I sent a copy of the drawing of the original stove (two
>one gallon tin cans) and said I post a message to you (Stoves group) because
>I know a lot of thinking and developing has taken place after we did our
>initial work.
>
>I will send any suggestions you have for her to her. It is a long and
>difficult journey by foot for her to get to a telephone. However her father
>is sending her some things shortly. So, please let me know what you think
>will help.
>

I just learnt there is a portable metal stove on the market in India by the
name of Swosthee. The stove is made in a 1 and a 2 kW version. For more
information E-mail Mrs Gayathri V. on <gayathri@aero.iisc.ernet.in>.
Mrs G. just sent me an article on that stove that appeared in Sadhana
(Engineering version of the Quarterly Journal of the Indian Institute of
Sciences in Bangalore) in NINETEEN EIGHTY EIGHT. I can't stop thinking why I
didn't see that article in 1988. It appears to be the answer to a maiden's
prayer (if the maiden happens to be Cinderella). It has a high efficiency,
low emissions and is easy to run. I am going to make one myself.

Hoping this will help.
Best regards,

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

 

 

From REEDTB at compuserve.com Sun Mar 9 09:02:23 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:04 2004
Subject: Measuring stove airflow.
Message-ID: <199703090909_MC2-124E-384B@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Tom Duke, Stovers and Gasifiers all:

Tom Duke said:

"I have a peace corps volunteer friend in Nepal. She is living with some
villagers. Their house is filled with smoke because of cooking on an open
fire inside the house. She is concerned about the effect of smoke on the
small children."
~~~~~
Tom, what a tragic tale of smoke and woe you tell for your friend. The
village women will cough out their lungs & burn out their eyes before they
are forty, burning wet wood, straw and dung in closed huts. (Ask Kirk
Smith the consequences of breathing the equivalent of ten packs of
cigarettes per cooked meal!) Sad to say, these conditions apply to over
half the women in the world. This is "THE WORLD COOKING PROBLEM". (If men
did the cooking maybe they would try to improve cooking conditions or the
fuel or the technology.)

I've had some personal experience being exposed to smoke and spending a
season hacking and coughing. I'm no longer devil-may-care about breathing
smoke. My occasional co-author, Agua Das is working on a charcoal project.
Last time I saw him he was hacking and coughing. I asked if it could be
smoke .....could be! Any other personal experiences out there? H&C are
the hazards of combustion/gasification research. Beware!

Twelve years ago at a conference in South Africa (with Tom Miles Jr., our
webmaster) I saw the palls of smoke that hang over the black homelands. I
decided to work on "gasification for cooking". The inverted downdraft (aka
charcoal producing stove) is one result which Ron and I hope will lead to
cleaner cooking. Village gasifiers (Shandong, China, see Ralph Overend)
may also help solve the problem.

The more I get to know about the golden triangle of
pyrolysis/gasification/combustion, the more I feel there is a simple
affordable solution for these problems. But predictions and papers are
plentiful, significant experiments few and far between. I spend ten hours
at this computer for every hour I can scarf off to run a new test. There
is no money available to solve the world cooking problem and most
scientists haven't a clue about the fundamentals of PGC.

So I hope we can continue to make forward progress in this most important
area. Meanwhile, Tom, I hope you will get feedback from your Peace Corps
volunteer so we can appreciate the magnitude and dimensions of the problem.

Yours faithfully, TOM REED

 

From tmiles at teleport.com Sun Mar 9 13:33:23 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:04 2004
Subject: GAS-L: Re: Measuring stove airflow.
Message-ID: <3.0.32.19970309104152.00728298@mail.teleport.com>

>Tom Duke said:
>"I have a peace corps volunteer friend in Nepal. She is living with some
>villagers. Their house is filled with smoke because of cooking on an open
>fire inside the house. She is concerned about the effect of smoke on the
>small children."

That has long been a recognized concern and there is work in progress. I
think an excerpt from a message from Daniel Kammen earlier this year is
appropriate:

"my research group has been doing a number of village and some large
studies of
fuel switching in both e. africa and mexico. we are writing up parts of it
all now, but some of the themes that have proved fascinating (beyond the
emission inventories and epidemiology: we typically do [CO], [CO2], [NOx],
[SOx], TSP/RSP, and health surveys with local doctors) have been:

1. improvements in economic status not translating to any
improvement in the kitchen area

2. stove innovation and design changes in areas that go from
collecting wood to fuelwood markets

3. the differing impression of the benefit of stoves between men
and women.

The other angle that we are gearing up to do. . . follows a theme carried
by Prasad and Piet: charcoal. In addition to the need for more work on
charcoal pyrolysis
efficiency (particularly for small-scale production) is the local
ecological impact: changes in the soil microbiology, resistance to erosion,
changes in plant species, etc. ...in areas intensively harvested."

TR: Regarding the South Africa trip, I also remember palls of smoke in the
conference rooms, especially after Tom Reed gave his cigarette
demonstration of the principles of gasification (or was that just an excuse
to light up? I know, you didn't inhale!).

It hasn't been that long (20 years?) since America, in particular, has been
evangelical about health effects of smoke. When we hosted an international
residential solid fuels conference in Portland in 1979 it amazed me to see
people leave a lecture on health effects that included some particularly
horrid photos lung damage, to step out for a smoke.

At that same conference speakers from Norway were advocating the use of
charcoal - "biocoal" - for residential heating.

Perhaps someone knows of a recent bibliography of health effects of cooking.

Tom Miles, Jr.

----------------------------------------------------------------------------
-------
Tom Miles, Jr. Thomas R. Miles
tmiles@teleport.com Consulting Design
Engineer
http://www.teleport.com/~tmiles/ 5475 SW Arrowwood Lane
Tel (503) 292-0107 Fax (503) 292-2919 Portland, Oregon, USA 97225-1353

 

From rmiranda at sdnnic.org.ni Mon Mar 10 14:45:31 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:04 2004
Subject: Measuring stove airflow.
Message-ID: <199703101351.NAA02510@ns.sdnnic.org.ni>

 

"I have a peace corps volunteer friend in Nepal. She is living with some
>villagers. Their house is filled with smoke because of cooking on an open
>fire inside the house. She is concerned about the effect of smoke on the
>small children. "

We in PROLENA (a specific wood energy development NGO in central America)
are developing projects to disseminate improved woodstoves among the urban
household at first. Our main concernes are the impact of woodsmoke on the
health of women and children, the hight cost of fuelwood (> US$ 80ton), and
the deforestation impact from the fuelwood demand.

To aware the women for those impacts we tell them that:

. the wood smoke that their family inhales causes accute respiratory
infections, eyes irritation, and for pregnant women that are indications
that child birth weight is in average 70 grs less than for no exposed mothers.

. the accumulation of tar that she sees in her roof, is as well being
accumulated in her lungs (this has been very effective in making them aware,
and willing to change).

. She could reduce the impact of fuelwood cost in the family budget,
aproximately 25%.

To facilitate them to acquire an improved woodstove we do:

. train one or two women in the community as stovers, since she can be
specialized in building stoves, and also can earn a living from this profession.

. identify cheaper sources of material (bricks and metal sheets)

. offer microcredit loans to them( US$20 to 40), in order to buy the
material and labor to acquire a new stove

Also we do:

. conferences, radio talk and article in the press awarening the population
and the governemnt authorities (forestry, environment, health and energy
ministries), about the impacts of traditional wood stoves, what can be done,
and each one responsability.

OBS: There is still a great need for further research on the impact of
biomass smoke to human health. Also, credit and services to acquire improved
stoves is in great need in the developing countries.

It is amazing that we are in the door of the 21st century, we have gone to
the moon, but still at least 2/5 of the world are using 1st century wood
combustion technology for cooking.

Hope this info can be of help

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

 

 

From mheat at mha-net.org Mon Mar 10 16:21:29 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:04 2004
Subject: Measuring stove airflow.
Message-ID: <3.0.32.19970310163006.007e8100@mha-net.org>

At 01:51 PM 10/03/97 GMT, Rogerio Carneiro de Miranda wrote:
>
(snip)>
>OBS: There is still a great need for further research on the impact of
>biomass smoke to human health.

A website with a very extensive bibliography on the health effects of
woodsmoke is located at

http://www.imaja.com/imaja/bi/BurningIssues.html

The lady who runs it is a bit extreme, since she's dedicated to eradicating
woodburning from the face of the earth (which in her case probably only
extends to the borders of the U.S.). I think she may have some chemical
sensitivity or health problems and may have had a very rude neighbour with
a stinky fireplace. Anyway, it is a very useful site.
-----------------------------------------
Norbert Senf--------------------email:---mheat@mha-net.org
Masonry Stove Builders-------------------mheat@hookup.net
RR 5, Shawville-----------------website: http://mha-net.org/msb
Quebec J0X 2Y0------------------fax:-----819.647.6082
--------------------------------voice:---819.647.5092

 

 

 

From bhatta at ait.ac.th Mon Mar 10 20:19:22 1997
From: bhatta at ait.ac.th (Prof. S.C. Bhattacharya)
Date: Tue Aug 31 21:35:04 2004
Subject: No Subject
In-Reply-To: <199703041630_MC2-121A-1D71@compuserve.com>
Message-ID: <Pine.SOL.3.91.970311081823.6584B-100000@rccsun>

 

H. Michael-Kim (EFEU GmbH, R & D for Energy and Environment, D-5830
Schwelm) reported development of "Three-phase wood gasifier system
EASIMOD" some time ago. His gasifier design was claimed to produce "tar-free"
gas.

Does any body know about the status of this gasifier or the email address
(or fax number) of Mr. Michel-Kim?

S.C. Bhattacharya

-------------------------------------------------------------------
S. C. Bhattacharya Voice : (66-2) 524 5403 (Off) Professor 524 5913 (Res)
Asian Institute of Technology Fax : (66-2) 524 5439 GPO Box 2754, Bangkok
10501 516 2126 Thailand e-mail: bhatta@ait.ac.th
-------------------------------------------------------------------

On Tue, 4 Mar 1997, Thomas Reed wrote:

> Thomas B. Reed 303 278 0558 V Colorado School of Mines
> 1810 Smith Rd., 303 278 0560 FX Department Chem Eng
> Golden, CO 80401 ReedTB@Compuserve.com
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Stovers and Gasifierers(?):
>
> Glad to hear from Pete concerning the rate of propogation of the "flaming
> pyrolysis" zone in a pile of woodchips. While the discussion applied to
> "gasifier stoves", it applies even more in the "GASIFICATION" node, so I'm
> responding in both.
>
> Just as "burning velocity" of gas/air mixtures is central to understanding
> the use of gaseous fuels in Bunsen and other burners, Markson and I in 1982
> discovered that the "propogation velocity" of a burning "flaming pyrolysis
> zone" is central to understanding the behavior of the "stratified downdraft
> gasifier". (I believe it was Ali Kaupp and maybe Bob Reines at UCDavis who
> coined the name "open core" gasifier as an alternative to "stratified
> downdraft" about 1984. I have never understood what an "open core" was - I
> hope someone can enlighten me.) Incidentally, the propogation velocity is
> very difficult to predict, but obviously depends a great deal on moisture
> content, which is probably why downdraft gasifiers require <20%MC for good
> operation. Other early names associated with this work are Wallawender at
> Kansas State, the Buck Rogers Co. and the very earliest the Chinese rice
> hull gasifier.
>
> The term "stratified downdraft" (as opposed to Imbert/nozzle stabilized
> downdraft) comes from the plug flow of the fuel, first through the "flaming
> pyrolysis" zone, making CO/H2 rich combustion gases, then as char through
> the reduction zone with the gases passing the same way at about 0.2-1 m/sec
> (superficial velocity).
>
> The "Transparent Gasifier" was first built at NREL/SERI about 1982, based
> on a patent of mine from MIT. Thin gold, 20 nm thick, insulates as well as
> an inch of Fibrefrax. We market a transparent furnace that will go to
> 1100C. Cost <$1,000. We built several transparent gasifiers and have a
> lot of video footage showing the flaming pyrolysis and reduction zones.
>
> We originated the term "flaming pyrolysis" by analogy to "flaming
> combustion", a very old term. FC is the combustion of gases in an excess
> of air, as in a match or candle flame, where the products are largely CO2
> and H2O. FP is the combustion of gases (from pyrolysis) in an excess of
> fuel, where the products include a lot of CO and H2 as well. Glad to see
> the term is surviving without dilution.
>
> All of this was covered when it was still fresh in my mind in disgusting
> detail in our "Handbook of BIomass Downdraft Gasifier Engine Systems",
> (Reed and Das, 1988, Chapters 4 and 5, available from the BEF Press). (End
> of commercial).
>
> There is to be an energy fair in Boulder (People's Republic of) in May this
> year and Das and I believe it is possible to make a gasifier with low
> enough tar to run a Honda 3kW generator with NO scrubbing. I gave him a
> copy of Bhatacharya's Two Stage (Tarless) gasifier paper yesterday. Any
> suggestions (other than it ain't possible)?
>
> Best to all, especially PETE, who starte this train of thought ... TOM
> REED
>
>
>

 

From RMetro4891 at aol.com Mon Mar 10 20:26:40 1997
From: RMetro4891 at aol.com (RMetro4891@aol.com)
Date: Tue Aug 31 21:35:04 2004
Subject: antique stove 1922 joy
Message-ID: <970310203323_447578945@emout20.mail.aol.com>

i would like to know if you carry parts for this antique stove

 

From krksmith at uclink4.berkeley.edu Tue Mar 11 19:37:11 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:04 2004
Subject: A plea for assistance
Message-ID: <199703120044.QAA14900@uclink4.berkeley.edu>

Greetings,

As some of you know, we have been engaged in an extensive study of emissions
from cookstoves in India and China. Although funded by the USEPA greenhouse
gas program, since we are measuring some 60 airborne species (including CO2,
CO, CH4, N2O, PM, and many individual hydrocarbons, including benzene, 1,3
butadiene, etc.) the result will have substantial interest from a health
standpoint as well. Currently we are just finishing monitoring the 30 most
common stove-fuel combinations in each country; involving stoves run on
several species of wood, several crop residues, dung, several coals,
kerosene, and various gases. Also, in Thailand, we have been monitoring the
same set of emissions in five kinds of traditional charcoal kilns, which, as
you know, tend to be quite polluting. After being cleaned up and published,
this 65 by 60 spreadsheet (which will also include data on fuel and ash
composition and stove efficiency) will be useful for a number of purposes.
When it becomes available (we hope by summer), I will make an announcement
on this listserver.

My current question, however, relates to a potential continuation of funding
for this work. We are proposing to extend our effort to encompass not only
the current stove-fuel combinations in actual use, but also those improved
devices and fuels being promoted or developed in either developed or
developing countries, but with potential application in developing-country
settings. This will allow calculation of the potential greenhouse-gas and
health benefits of policies to promote improved stoves or fuels.

As part of our effort to justify this new funding, however, I need your
help. We need to include a list of organizations/people doing work on
improved stoves and/or fuels who would, in principle, be willing and able to
submit their systems for testing within the next 18 months or so. We do not
ask for a firm commitment, but only that there is a reasonable likelihood.

Thus, my plea: Could you let me know if you, or anyone else you know, might
have an improved device or fuel in this category (existing or in
development) and be willing to have it tested?

Obviously, we have interest in such devices or fuels anywhere in the world.
Given the politics of EPA funding, however, it would be particularly helpful
to have some to list from the USA that might have potential Third World
application.

Needed would be Company name, person's name, device/fuel name, brief
description including characteristics that make it "improved," address,
contact numbers. Copies of any relevant literature would be much
appreciated (see address below).

Many thanks for any leads. Best/K

Kirk R. Smith, Ph.D.
Professor of Environmental Health Sciences
(Associate Director for International Programs
Center for Occupational and Environmental Health)
140 Warren Hall, MC 7360
University of California
Berkeley, CA 94720
Phone: 510 643 0793; Fax: 510 642 5815
krksmith@uclink4.berkeley.edu
http://ehs.sph.berkeley.edu

email: krksmith@uclink4.berkeley.edu

 

 

From verhaarp at janus.cqu.edu.au Tue Mar 11 19:56:47 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:04 2004
Subject: A plea for assistance
Message-ID: <1.5.4.32.19970312010415.006854fc@janus.cqu.edu.au>

>From Piet Verhaart

Dear Kirk,

At 16:44 11/03/97 -0800, you wrote:
>Greetings,
>
>As some of you know, we have been engaged in an extensive study of emissions
>from cookstoves in India and China. Although funded by the USEPA greenhouse
etc, and..
>Needed would be Company name, person's name, device/fuel name, brief
>description including characteristics that make it "improved," address,
>contact numbers. Copies of any relevant literature would be much
>appreciated (see address below).
>
Here is the (E-mail) address of Mrs. Gayathri of the Biomass Users Network
in Bangalore India.. They are very active in Biomass burning devices and
appear very conscious of emissions.

<gayathri@aero.iisc.ernet.in>

Mrs.Gayathri V BIOMASS USERS NETWORK - INDIA
Project Engineer
Combustion Gasification and Propulsion Lab.
Dept. of Aerospace Engineering
IISc . Bangalore 560 012 Phone :(off) +91-80-3092338 or 3348536

Hoping this is of some use to you,
Best Regards,
Peter Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail: verhaarp@janus.cqu.edu.au

 

 

From kammen at phoenix.Princeton.EDU Tue Mar 11 21:57:11 1997
From: kammen at phoenix.Princeton.EDU (Daniel M. Kammen)
Date: Tue Aug 31 21:35:04 2004
Subject: A plea for assistance
Message-ID: <v01530513af4b86a2a994@[128.112.44.150]>

hi kirk,
feel free to list me as someone willing and happy to submit several improved
stoves used in Kenya and Mexico for testing.

>From Kenya:

KCJ
Kuni mbili stove (2 models)
Traditional metal grate stove

>From Mexico
traditional elevated stove
Lorena stove

- dan

 

 

From tmiles at teleport.com Wed Mar 12 00:49:45 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:04 2004
Subject: A plea for assistance
Message-ID: <3.0.32.19970311215824.00751844@mail.teleport.com>

Kirk,

The commercial cookstoves made by Pyromid should be candidates for this.
Paul Hait of Pyromid should still be on this list. He has a distribution
system via Care, I believe.

Tom
----------------------------------------------------------------------------
-------
Tom Miles, Jr. Thomas R. Miles
tmiles@teleport.com Consulting Design
Engineer
http://www.teleport.com/~tmiles/ 5475 SW Arrowwood Lane
Tel (503) 292-0107 Fax (503) 292-2919 Portland, Oregon, USA 97225-1353

 

From SMOUSE at lynx.petc.doe.gov Wed Mar 12 07:30:17 1997
From: SMOUSE at lynx.petc.doe.gov (Scott Smouse)
Date: Tue Aug 31 21:35:04 2004
Subject: A plea for assistance -Reply
Message-ID: <s3265c57.080@lynx.petc.doe.gov>

FYI

 

From larcon at lynx.sni.net Wed Mar 12 23:48:50 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
Message-ID: <v01540b01af4d395674c9@[204.133.251.11]>

 

Stovers:

The following three part exchange was initated by Art yesterday.
Can anyone help with his request for assistance?

Part 1.
>
>Hi Ron! We had spoken on the phone about charcoal stoves earlier last
>week. This is just a note to ask you if you have heard of a wood chip
>powered water heater made in Australia? It had been made by Everyday
>Mfg. until about six years ago and is no longer available on the
>market. I was wondering if you might have any photo's or drawings of
>the stove's construction.
>
>Please contact me at: Phoenix@triax.com

Part 2: Ronal W. Larson wrote:
>
> Hi - Unless I hear differently in the next day or so from you, I am going
> to just send this out to the stoves list and ask for their help. I don't
> have any of the data. There was some information on a similar wood-fired
> hot water heater in Sweden about a year ago. Moreover, we have several
> list members who are in stove manufacture and another several in Australia
> - so we might get an answer.

Part 3: from Art:

I contacted Everyday Manufacturing in Sidney, Australia today. They
stopped
building the chip hot water heater two years ago. The person I spoke
with
said the owner was in California trying to market a very efficient wood
stove.
By their own claim, they are manufacturing the most efficient stove
available
in Australia and were going to market worldwide. I asked the person who
answered
the phone to leave a message for the owner to call me in Oregon about
getting some
plans, drawings or photos so we could analyze the design. Hope to hear
from him
soon.

Thanks for putting the question out on the stoves list and letting the
rest of the
group take a crack at getting the design of the chip water heater
combustion box.

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

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From J.J.Todd at geog.utas.edu.au Thu Mar 13 03:23:28 1997
From: J.J.Todd at geog.utas.edu.au (J.J.Todd@geog.utas.edu.au)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
Message-ID: <199703130558.QAA02433@corinna.its.utas.edu.au>

Discussion on hot water chip heaters (Ron Larson, Art Krenzel).

We (at the University of Tasmania) are just about to start some tests on a
chip heater (for water heating) which was developed at the Appropriate
Technology Centre in Alice Springs, Australia. This is a heater which has
been used in Aboriginal communities, but apparently is not very efficient.
Our testing is aimed at suggesting improvements in design.
I think there might also be a Western Australian manufacturer of a domestic
sized chip heater. I will try to track down a name and address and post it
on this list next week.
John Todd

 

 

From verhaarp at janus.cqu.edu.au Thu Mar 13 06:19:31 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
Message-ID: <1.5.4.32.19970313112703.0067b154@janus.cqu.edu.au>

>From Piet Verhaart.

There was a message in reply to Kirk's request, very short and
incomprehensible to me. None of my business, of course, but always curious
about things I am too young to understand, I would like to know the meaning
of <FYI>.
Being in capitals, it might be a so-called Flame, something in the spirit of
"Confound Your Impudence", the best I could come up with.

There is talk about woodchip water heaters. Can anybody tell me anything
about the average size of those chips? They might be suitable for my BBQ
(with Flaming combustion).

Today I received a PhD thesis about Stabilisation of Laminar Premixed Flames
(I seem to be talking of flames all the time tonight), by Roel M.M. Mallens.
Eindhoven 1996.
It could be useful for woodstovers trying to fix premixed flames on a
burner. Probably obtainable from the Group Secretary, Rian Tielemans, E-mail
address <rian@wop.wtb.tue.nl>.

Mrs Gayathri V. has asked me to write an article (for BUN). If I get it
written in time it will be about developments in woodburning cookstoves in
our List, or on the various ways we try to achieve our aims.

That is it for now, have to get back to my article.

Cheers,

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

 

 

From les.gornall at dial.pipex.com Thu Mar 13 21:19:13 1997
From: les.gornall at dial.pipex.com (Dr. Les. Gornall)
Date: Tue Aug 31 21:35:05 2004
Subject: Ashes to Ashes, smoke to smoke
Message-ID: <332863AC.89D@dial.pipex.com>

I thank everyone for their assistance with the smokey wood burner
problem. For your information here is the action plan:

We will
1. Backfill the gap between the ceramic flue and concrete chimney with
micafil insulation.

2. Raise the chimney height to 18" above the ridge of the roof.

3. Revise the flue cap - I may re model the existing unit to provide
a vaccum effect when the wind is blowing.

5. Provide a better seal between the stove alcove roof and chimney.

4. Test the burner to see if the above arrangement is compatible with
the existing air to air heat exchanger with fans on and fans off. This
system has centrifugal fans of open architecture and should provide a
clear air way to the outside without the need for an additional pipe
through the wall when there is a power cut.

5. Fit a CO warning siren to the kitchen.

OK this leaves me with only one puzzle regarding smoke in the kitchen.
Has anyone analysed the efficiency of a wood stove installation after
drawing the boundary of the system so as to include the air changes
needed to clear small amounts of residual smoke?

My interest here is stimulated by a piece of research I did on H2S odour
pollution. Dilutions 1,000 or 10,000 to 1 or more were needed to remove
odour to below odour threshold levels. If we equate odour with
'unhealthy chemicals' then I wonder if we need to consider dilutions of
kitchen air in the above range. If that is so, then the energy cost of
heating, say 10,000 litres of winter air at 5 degrees C to disperse 1
litre of smoke, then the overall efficiency of the stove reduces
somewhat.

In the light of ever more stringent health and safety considerations
some hard facts and numbers about system efficiency would be most
useful. If health and safety litigators became sensitised to problems
of smoke in kitchens (and we only have to look at recent events in the
cigarette story for likely action,) such problems may become important
financially and structurally and we may have to consider wood burners in
remote out buildings only.

What do the experts say on this matter?

 

Thanks again to all those contributing for your assistance,

Les. Gornall

--
Dr. Les. Gornall
Director
Practically Green
(Environmental Services)
Solar House
Magherafelt
Co. Londonderry
Northern Ireland
BT45 6HW

+44 1648 32615
les.gornall@dial.pipex.com

 

From phoenix at triax.com Sat Mar 15 10:26:05 1997
From: phoenix at triax.com (phoenix)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
In-Reply-To: <1.5.4.32.19970313112703.0067b154@janus.cqu.edu.au>
Message-ID: <332AC009.3536@triax.com>

Peter Verhaart wrote:
>
> >From Piet Verhaart.
>
> There was a message in reply to Kirk's request, very short and
> incomprehensible to me. None of my business, of course, but always curious
> about things I am too young to understand, I would like to know the meaning
> of <FYI>.
> Being in capitals, it might be a so-called Flame, something in the spirit of
> "Confound Your Impudence", the best I could come up with.
>
> There is talk about woodchip water heaters. Can anybody tell me anything
> about the average size of those chips? They might be suitable for my BBQ
> (with Flaming combustion).
>
> Today I received a PhD thesis about Stabilisation of Laminar Premixed Flames
> (I seem to be talking of flames all the time tonight), by Roel M.M. Mallens.
> Eindhoven 1996.
> It could be useful for woodstovers trying to fix premixed flames on a
> burner. Probably obtainable from the Group Secretary, Rian Tielemans, E-mail
> address <rian@wop.wtb.tue.nl>.
>
> Mrs Gayathri V. has asked me to write an article (for BUN). If I get it
> written in time it will be about developments in woodburning cookstoves in
> our List, or on the various ways we try to achieve our aims.
>
> That is it for now, have to get back to my article.
>
> Cheers,
>
> Piet Verhaart
> Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
> Phone: +61 79 331761 Fax: +61 79 331761 or 332112
> E-mail: verhaarp@janus.cqu.edu.au
FYI means "For Your Information"
Are you currently working on any small scale stove designs?
Wood chips can be produced by several mechanical means. The most
popular machines are used in the forest and can produce several tons per
hour of chips. Wood chips do not have a specific dimension such as
charcoal briquettes might since each machine that produces wood chips
can produce a range of sizes depending upon the technology used to make
them. The sizes range from approximately 1 inch X 1 inch X 1/8 inch to
2 X 2 X 1/4 inch. The size of the chip depends upon the species of wood
being chipped, moisture content, the chipper head design, the angle and
pressure of feed, the speed of the disc, blade sharpness, etc. A large
tree chipper produces a reasonable range of particle sizes during
during production.
There are smaller chippers which are home sales products which use a
hammer mill design to reduce long cuttings into a wide range of particle
sizes applicable for use as mulch but not for serious use in combustion.
Art Krenzel

 

 

From phoenix at triax.com Sat Mar 15 10:26:30 1997
From: phoenix at triax.com (phoenix)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
In-Reply-To: <199703130558.QAA02433@corinna.its.utas.edu.au>
Message-ID: <332ABD1C.746B@triax.com>

J.J.Todd@geog.utas.edu.au wrote:
>
> Discussion on hot water chip heaters (Ron Larson, Art Krenzel).
>
> We (at the University of Tasmania) are just about to start some tests on a
> chip heater (for water heating) which was developed at the Appropriate
> Technology Centre in Alice Springs, Australia. This is a heater which has
> been used in Aboriginal communities, but apparently is not very efficient.
> Our testing is aimed at suggesting improvements in design.
> I think there might also be a Western Australian manufacturer of a domestic
> sized chip heater. I will try to track down a name and address and post it
> on this list next week.
> John Todd
Hi John!

Thank you for your reply. The chip water heater I was referred to was
made by Everyday Manufacturing near Sidney. They still have not called
so I have no further information. Do you have any drawings of the chip
stove you are testing? When you say "aboriginal", do you mean fashioned
from natural materials or fabricated by pioneering English settlers in
the outback. Do you have one of these stoves in your possession that
you might sketch a plan of the combustion chamber and approximate
dimensions?

Looking forward to your reply.
Art Krenzel

 

 

From phoenix at triax.com Sat Mar 15 16:44:18 1997
From: phoenix at triax.com (phoenix)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
In-Reply-To: <199703130558.QAA02433@corinna.its.utas.edu.au>
Message-ID: <332B0310.5923@triax.com>

phoenix wrote:
>
> J.J.Todd@geog.utas.edu.au wrote:
> >
> > Discussion on hot water chip heaters (Ron Larson, Art Krenzel).
> >
> > We (at the University of Tasmania) are just about to start some tests on a
> > chip heater (for water heating) which was developed at the Appropriate
> > Technology Centre in Alice Springs, Australia. This is a heater which has
> > been used in Aboriginal communities, but apparently is not very efficient.
> > Our testing is aimed at suggesting improvements in design.
> > I think there might also be a Western Australian manufacturer of a domestic
> > sized chip heater. I will try to track down a name and address and post it
> > on this list next week.
> > John Todd
> Hi John!
>
Another thought - do you have the e-mail address for the Appropriate
Technology Center in Alice Springs? Perhaps I could get some
information on the stove from them. Or do you have other sites in
Australia which I might find information on chip stoves?

Thanks!
Art

 

 

From al443003 at mail.mty.itesm.mx Sat Mar 15 20:41:03 1997
From: al443003 at mail.mty.itesm.mx (EDGARDO PAREDES)
Date: Tue Aug 31 21:35:05 2004
Subject: Hello from a developing country
Message-ID: <332B5141.19F0@mail.mty.itesm.mx>

I am student from Mexico.
And I am developing in a school project a investigation about the
production and comercialization of charcoal. Waht I have found is that we
have a growing demand and a decreasing sense of the tree. So we are
presenting a posible solution involucrating the government-reforestation
community-workers and the entrepeuner-new process.

Here in this new process, I think, you can help alot!!!!!!! I understand that
you develope a stove to increase efficiency in the production.

My opinion fo the debate is that we (developing countries) can still
produce charcoal only taking care of the environment.

Thankyou

 

From phoenix at triax.com Sun Mar 16 11:25:45 1997
From: phoenix at triax.com (phoenix)
Date: Tue Aug 31 21:35:05 2004
Subject: Hello from a developing country
In-Reply-To: <332B5141.19F0@mail.mty.itesm.mx>
Message-ID: <332C216A.7443@triax.com>

EDGARDO PAREDES wrote:
>
> I am student from Mexico.
> And I am developing in a school project a investigation about the
> production and comercialization of charcoal. Waht I have found is that we
> have a growing demand and a decreasing sense of the tree. So we are
> presenting a posible solution involucrating the government-reforestation
> community-workers and the entrepeuner-new process.
>
> Here in this new process, I think, you can help alot!!!!!!! I understand that
> you develope a stove to increase efficiency in the production.
>
> My opinion fo the debate is that we (developing countries) can still
> produce charcoal only taking care of the environment.
>
> Thankyou
The manufacturing of charcoal can be done more efficiently at a variety
of levels. There is a great deal of interest in the efficient use of
wood to produce cooking heat and, as a byproduct, produce a small amount
of charcoal which can be used in preparing the next meal. The stove
designs can be enlarged such that the amount of excess charcoal produced
can be marketed locally for use as charcoal for cooking. Another
larger, more efficient design would allow for the production of even
larger amounts of charcoal which could be marketed in a village
perhaps. The goal of all the stoves is, through higher temperature,
insulated combustion, more efficiently consume the tar components of
wood decompostition and utilize some of the energy to produce charcoal
as well as cook and heat.
I think biomass in general, and the tree in particular, should receive
recognition as perhaps the best choice of "energy battery" for the
storage of solar energy for the common citizens of the world. A
"VOLKSBATTERY" perhaps.
I would appreciate hearing your plan to reduce the impact of humanity on
the environment.
Art Krenzel
phoenix@triax.com

 

 

From tmiles at teleport.com Sun Mar 16 12:50:28 1997
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:35:05 2004
Subject: Hello from a developing country
Message-ID: <3.0.32.19970316095608.00b07760@mail.teleport.com>

At 08:35 AM 3/16/97 -0800, you wrote:
>EDGARDO PAREDES wrote:
>> My opinion fo the debate is that we (developing countries) can still
>> produce charcoal only taking care of the environment.

ART KRENZEL wrote:
>designs can be enlarged such that the amount of excess charcoal produced
>can be marketed locally for use as charcoal for cooking. Another

Edgardo and Art,

Buena onda. Useful thoughts.

A technical solution must work in a social context. Go to the Sierra or the
desert and you cannot ignore a social reality: making charcoal is a way for
people to turn their labor into cash. We call it "sweat equity"; there they
call it survival. The demand for charcoal and the need for cash puts an
unrelenting pressure on the forest resource. Nowhere is this pressure more
intense than in the sierra of Mexico where a very large quantity of forest
has disappeared during the economic crises of the last 20 years.

An efficient stove can conserve a resource and produce a charcoal
byproduct. The amounts of charcoal produced are not impressive. It is a
small but continuous activity. What has been the experience in Mexico of
attempts to promote or use more efficient stoves? Where else have
charcoal-making stoves been tried?

The next level is more efficient industrial production. Using a higher
level of technology requires running a business - individual, communal or
state - and takes the control and benefits of charcoal production away from
the individual or family. Community businesses, empresas ejidales, of this
kind have rarely succeeded in Mexico. There was a proposal to do this in
Durango six or seven years ago using the Mark IV kiln from the FAO. Have
there been others? Where in the world is communal charcoal production
succeeding to provide environmental, social and economic benefits?

Saludos,

Tom Miles, Jr.

----------------------------------------------------------------------------
-------
Tom Miles, Jr. Thomas R. Miles
tmiles@teleport.com Consulting Design
Engineer
http://www.teleport.com/~tmiles/ 5475 SW Arrowwood Lane
Tel (503) 292-0107 Fax (503) 292-2919 Portland, Oregon, USA 97225-1353

 

From krksmith at uclink4.berkeley.edu Sun Mar 16 13:48:29 1997
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal
Message-ID: <199703161856.KAA28138@uclink4.berkeley.edu>

Last week, there was some communication on this listserver about improved
stove programs in Nepal and so I thought there might be some interest in the
following.

In late Feb., I was in Nepal with my family on a short revisit. We had a
chance to see the results of an improved stove program in a village area
some 40 km from Kathmandu, up in the hills above the valley. Although
showing some progress, it was sadly reminiscent of many such efforts over
the past 15 years in developing countries. (In the early 1990s, I was
involved in a "Global Review of Improved Stove Programs" in which we
examined well over a hundred programs in different parts of the world,
including the two largest -- the national programs of India and China.)

These mud stoves had enclosed combustion chambers, baffles, two pot holes,
and a flue -- no door or damper. Unlike what has often been the case in
such programs, the flues extended only about 5 feet high before turning out
through the wall. Taller flues that go through the roof tend to increase
the draft so much that fuel efficiency declines substantially. The flues
were made of local materials and thus saved money on what can be an
expensive part of the system if made of metal or asbestos.

Unfortunately, however, the stoves too were made entirely of a local mixture
of mud, dung, and sand offering no significant advance in materials over
what is used in the traditional open stove bodies in the area. After only 2
weeks, many were cracking. Daily stress induced by the heavy pots and
extreme temperature changes were already causing the interior dimensions
(baffle - pot distances, etc.) to soften and fuzz into what would be little
different from the traditional situation before long.

In an attempt to strengthen the stoves, a metal tripod had been built into
the mud of the chamber, but with such different thermal expansion
characteristics the mud and metal were separating.

The women were already complaining that the stoves were too fragile to take
the weight of the large pots they need to use every few days to cook animal
fodder.

I did not have monitoring equipment, but the stoves were clearly releasing
substantial smoke into the houses. Opinions about fuel and time savings varied.

It is difficult to identify any improved stove program that has been
successful over a large scale that has relied solely on local materials and
skills. Indeed, it is somewhat patronizing to think that outsiders could
somehow come up with an improved way of doing what the villagers have been
doing for centuries under the same restraints. The most successful
programs, in my experience, have been those that recognized the need to
develop stoves that used advanced materials and skills so that the resulting
devices could retain their improved performance over long periods.
"Advanced," here, does not mean made in Silicon Valley, but made by artisans
who have the skills to deal with metals and ceramics that can take abuse and
heat stress.

It is unlikely to be efficient and effective to teach villagers how to make
such stoves if they are to make only one every two years or so. The skills
can only be retained by an artisan who frequently uses them. This is not to
say that villagers cannot understand, repair, and maintain such devices,
only that it may be a waste of their time to learn how to make them as a
sideline to their main occupations. Think of the bicycle. It is
appropriate technology, understandable and maintainable by any householder.
But it cannot be efficiently made at the household level using local materials.

The history of technology is one of specialization. Those who propose
stoves that are somehow better but still use local skills and materials must
argue against history.

The most successful stove program, China's, is also the largest with some
150 million households covered (surely one of the largest development
projects in history in terms of number of people affected). Among the
things that set them off from many of the other stove programs was an
initial recognition of the need for artisan involvement. They basically
helped create hundreds of "rural energy companies," which, among other
products, manufactured the critical combustion chamber parts out of good
quality ceramics. These were then easily shipped to households, where the
bricks and other less important structural materials could be built around
them. Thus, costs were kept down, but quality assurance was possible in the
critical components.

It is a big world, with millions of different household situations. Thus,
there is likely to be a niche for almost any approach. Particularly in the
poorest areas where fuel is gathered and stoves must essentially be
costless, there are appropriate places for self-made stove programs. For
large-scale long-term dissemination, however, skills and materials
specialization are probably needed/K

Kirk R. Smith
UC Berkeley

 

 

From larcon at lynx.sni.net Sun Mar 16 22:23:13 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: FYI
Message-ID: <v01540b00af5261027c91@[204.133.251.1]>

 

1. For Peter Verhaart: (per your message of a few days ago) "FYI" equates
to "For Your Information" (not a flame). FYI is used with short "heads up"
type memos - usually intended for one other person.

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From larcon at lynx.sni.net Sun Mar 16 23:59:11 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: PAREDES, Krenzel, and Miles comments on charcoal production
Message-ID: <v01540b02af526d70684b@[204.133.251.16]>

1. Edgardo Paredes raised the subject of charcoal production in Mexico.
(Edgardo - I have signed you up for our stoves list and forwarded the next
two responses - to make sure that you received them. I'm not sure you
would have otherwise; I apologize if you receive them twice.) I would also
like to forward some earlier material on small scale charcoal production
with a charcoal-making stove - that still needs much development.
Unfortunately, I have recently modified my e-mail and inadvertently lost
this material from January 1996. If anyone saved them, I'd appreciate
receiving copies back (I believe Jan 3 and 6).

2. Art Krenzel indicated the possibility of improved charcoal production
while cooking. I also signed up Krenzel fairly recently,and also would
like to send the same material on charcoal-producing stoves. I hope Art
will expand on his remarks about charcoal-making stoves per Tom Miles'
request. Art, I doubt that anyone on the list knows what you were referring
to.

3. Tom Miles said today:
"An efficient stove can conserve a resource and produce a charcoal
byproduct. The amounts of charcoal produced are not impressive. It is a
small but continuous activity. What has been the experience in Mexico of
attempts to promote or use more efficient stoves? Where else have
charcoal-making stoves been tried?"

Tom is generally correct on the non-impressiveness of conventional
charcoal production, but the charcoal-making stove that Tom Reed and I have
been promoting achieves about 25% conversion by weight (40+% by energy)
with no loss of the waste gases that are found in almost all other charcoal
production. 25% seems to exceed the conversion efficiency of most rural
charcoal production, as I understand the literature. Other:
a. Our charcoal is a co-product - not a by-product.
b. A charcoal-making stove can be cleaner and more efficient and
controllable than conventional combustion stoves. It therefore seems
possible that cooks will prefer to use wood in such a stove and thus drive
inefficient rural charcoal production out of existence. I agree with Tom's
generally negative comments about present charcoal production.
c. I echo Tom's hope to hear of other charcoal-making stove work.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From rmiranda at sdnnic.org.ni Mon Mar 17 08:53:16 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal
Message-ID: <199703170759.HAA02779@ns.sdnnic.org.ni>

Dear Kirk Smith:

At 10:56 AM 3/16/97 -0800, you wrote:
> "(In the early 1990s, I was
>involved in a "Global Review of Improved Stove Programs" in which we
>examined well over a hundred programs in different parts of the world,
>including the two largest -- the national programs of India and China.) "

>(snip)>
>It is unlikely to be efficient and effective to teach villagers how to make
>such stoves if they are to make only one every two years or so. The skills
>can only be retained by an artisan who frequently uses them. This is not to
>say that villagers cannot understand, repair, and maintain such devices,
>only that it may be a waste of their time to learn how to make them as a
>sideline to their main occupations. Think of the bicycle. It is
>appropriate technology, understandable and maintainable by any householder.
>But it cannot be efficiently made at the household level using local materials.
>
>The most successful stove program, China's, is also the largest with some
>150 million households covered (surely one of the largest development
>projects in history in terms of number of people affected). Among the
>things that set them off from many of the other stove programs was an
>initial recognition of the need for artisan involvement. They basically
>helped create hundreds of "rural energy companies," which, among other
>products, manufactured the critical combustion chamber parts out of good
>quality ceramics. These were then easily shipped to households, where the
>bricks and other less important structural materials could be built around
>them. Thus, costs were kept down, but quality assurance was possible in the
>critical components.
>
==============================
Dear kirk: I enjoyed reading your message. Before PROLENA/Honduras initiated
its woostove dissemination pilot project in Tegucigalpa, I did a quick
literature review to find out more about commom mistakes in woodtoves
dissemination projects in latin America. Although it wasn't writen, but I
understood that most projects that failed were also incentivating each women
to built its own stove. From what you exactly explained above we decided to
adopt a new approach in which just one or two women were trainned as stovers
in the community. So far, it is working with our project.

Others unwritten failures that I captured were:

Lack of credit to acquire a new improved woodstove, and

Focus mostly in the environmental conservation aspects of fuelwood.

Then, based in our own perceptions, we decided to adopt the three basic
approachs:

1. Train few women as stovers builters, so they can do better each time, and
make a living from it;

2. Give great importance to the health aspects during the motivation
program. We found it very effective, and mainly when we explained to the
women that "their lungs could be dark as their kitchen roof".

3. Created a microcredit fund, so the women could acess it, and repay based
in what they save from less fuelwood comsumption and her economic capacity.

Recently, in our Second Woodenergy Congress of Honduras, during the woostove
discussion group, it was enphasized that also it is very important to
address the whole family during the motivation campaign, mainly the man,
because he in many situations hold the power of decision.

I believe that many woodstoves dissemination projects designed here in
Central America, didn't took in consideration what works and what don't
works. I think that we need to share more with developers the experiences
of sussceful approaches.

Regards

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

 

 

From owner-stoves at crest.org Mon Mar 17 11:18:44 1997
From: owner-stoves at crest.org (by way of Tom Miles <tmiles@teleport.com>)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal
Message-ID: <3.0.32.19970317082729.0070cd84@mail.teleport.com>

From: prasad@tn7.phys.tue.nl (prasad)
Message-Id: <9703171523.AA08718@tn7.phys.tue.nl>
Subject: Re: Reminiscences on a Stove Program in Nepal

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

To:Kirk Smith, Rogerio Miranda and other stovers

Sub: Kirk's reminiscences on Nepal trip

I was absent for two weeks being away in India. It looked like I missed Kirk
in Delhi.

At any rate, I felt like chuckling in one breath and sad in another
breath on reading the posting of Kirk. Many a moon back I prepared a report
for
ILO on Stoves ("Woodburning Stoves: Their Technology, economics and
deployment",
Working paper, World Employment Programme Research, ILO, Geneva, March 1983).
The paper discusses in length the defects of mud stoves in general and in
particular the two-pan stove. I'm sure Pete Verhaart will share my feelings
on
the subject. It seems as though time seems to have stood still as far as
stove
technology goes in many parts of the world.

At a minimum we should be graduating to bricks from mud (if people believe
that metal stoves are no go in the rural areas). Rogerio's thought of
training women stove builders and involving the entire family in the
persuasion process of accepting improved stoves.

That is it for now.

Prasad

 

 

From REEDTB at compuserve.com Mon Mar 17 16:05:14 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal
Message-ID: <199703171611_MC2-12BB-7678@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kirk, G &S:

I very much appreciated Kirk's comments on the Nepalese stoves and, as an
inventor, I would like to add a few caveats.

Yes, invention is often inevetable when new materials or other fabrication
technologies become available, witness graphite clubs, rackets,
rockets,....; the internet building on PCs building on chips building on
the transistor,..... .

HOWEVER: Sometimes the missing link is a vision or an accident or better
understanding. I have always wondered why the hula-hoop was invented in
the 1950s when hoops had been around hundreds of years.

I invented a GOLD FURNACE which uses a 20 nanometer layer of "transparent
in the visible and >99% reflective in the IR to replace an INCH of fibrous
insulation. The key link was my realization that the radiative losses are
100 times higher than the convective losses, so reflecting radiation makes
the furnace possible. There are several thousand of these around (made by
TransTemp) in Chelsea Mass.

The top ignited stove that Ron and I work with is (a) not obvious and (b)
clean and steady relative to conventional bottom ignition. It came from
lying awake at 3 AM in South Africa in 1955.

So..........While there is a great deal of truth in what Kirk says, there
is NO SUBSTITUTE for understanding and thinking and puzzling and reading
and cogitating.

Cheers, think, TOM REED

 

From REEDTB at compuserve.com Mon Mar 17 16:04:55 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: chip stoves
Message-ID: <199703171611_MC2-12BB-7679@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Art and Stovers:

To add to what Art said about chippers:

Hammer mills also make "chips", but they should more properly be called
"stringers" or "sliver" since there is little cross grain cutting.

Yesterday Ron Larson and I were talking about the undknown effect of chip
size on combustion rate and speculating that a pile of 1/2" chips would
burn a lot faster than a pile of 2" chips. For the last two years I have
been working from a few bushels of 1/2" chips from NREL. They are gone and
I am having a hard time finding more. I have gone to nurseries etc. and
they tend to have more stringers than chips. (Costs money to cut vs
smash).

Yesterday, while on a hike on the HIGHLINE CANAL with my wife we saw a
small pile of perfect chips and took a sample. I'm thinking of visiting
the park administrators to find where that chipper is in use.

A world expert on chipping is TOM MILES Jr. - Senior claims to have
invented the perfect angle for cutting, derived from the beavers teeth. Is
that correct TOM?

More thoughts, sources? TOM REED

 

From mheat at mha-net.org Mon Mar 17 19:25:48 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal]
Message-ID: <332DD50C.99E@mha-net.org>

Thomas Reed wrote:
> >(snip)
> >
> > The top ignited stove that Ron and I work with is (a) not obvious and (b)
> > clean and steady relative to conventional bottom ignition. It came from
> > lying awake at 3 AM in South Africa in 1955.
> >
> (snip)
>
For another interesting take on top ignition, check out:
http://www.wood-heat.com/topdown.htm
--
--------------------------------------------------------
Norbert Senf email: mheat@mha-net.org
Masonry Stove Builders mheat@hookup.net
RR 5, Shawville website: http://mha-net.org/msb
Quebec J0X 2Y0 fax: 819.647.6082
voice: 819.647.5092

--
--------------------------------------------------------
Norbert Senf email: mheat@mha-net.org
Masonry Stove Builders mheat@hookup.net
RR 5, Shawville website: http://mha-net.org/msb
Quebec J0X 2Y0 fax: 819.647.6082
voice: 819.647.5092

 

From verhaarp at janus.cqu.edu.au Tue Mar 18 04:19:50 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:05 2004
Subject: Reminiscences on a Stove Program in Nepal
Message-ID: <1.5.4.32.19970318092720.0068d5ac@janus.cqu.edu.au>

>From Piet Verhaart

At 08:27 17/03/97 -0800, you wrote:
>From: prasad@tn7.phys.tue.nl (prasad)
>Message-Id: <9703171523.AA08718@tn7.phys.tue.nl>
>Subject: Re: Reminiscences on a Stove Program in Nepal
>
>From:K.Krishna Prasad
>TUE, EIndhoven <prasad@tn7.phys.tue.nl>
>
>To:Kirk Smith, Rogerio Miranda and other stovers
>
>Sub: Kirk's reminiscences on Nepal trip
>
>I was absent for two weeks being away in India. It looked like I missed Kirk
>in Delhi.
>
>At any rate, I felt like chuckling in one breath and sad in another
>breath on reading the posting of Kirk. Many a moon back I prepared a report
>for
>ILO on Stoves ("Woodburning Stoves: Their Technology, economics and
>deployment",
>Working paper, World Employment Programme Research, ILO, Geneva, March 1983).
>The paper discusses in length the defects of mud stoves in general and in
>particular the two-pan stove. I'm sure Pete Verhaart will share my feelings
>on
>the subject. It seems as though time seems to have stood still as far as
>stove
>technology goes in many parts of the world.
>
>At a minimum we should be graduating to bricks from mud (if people believe
>that metal stoves are no go in the rural areas). Rogerio's thought of
>training women stove builders and involving the entire family in the
>persuasion process of accepting improved stoves.
>
>That is it for now.
>
>Prasad
>

Yes, Prasad, it was a very 'Deja vue' experience or an 'Aha Erleebnis'. It
did put the problems very clearly and it will probably do some good.

So you were in India, why didn't you make a hop to Brisbane, after letting
us know so wee'd be ready to abduct you to Gracemere?

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

 

 

From REEDTB at compuserve.com Tue Mar 18 08:18:55 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: Hello from a developing country
Message-ID: <199703180825_MC2-12C0-152C@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Edgardo:

Here's a simple experiment. Make a few hole in the bottom of a 2 liter tin
can. Fill it with DRY wood chips. Light it ON THE TOP. It will make a
lot of smoke which will burn above the pile. With the right equipment it
can burn clean.

After about an hour the combustion will stop. Immediately stop the air
holes. You should have a charcoal yield of 25% by weight.

This principle works whether you use a 2 l can or a 55 gallon drum. But
you need to find a use for the 60% gas that you have burned. In small
units it is good for cooking; in large ones for baking or brickmaking.

Yours truly, TOM REED

 

From REEDTB at compuserve.com Wed Mar 19 16:38:43 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: Top down gasification
Message-ID: <199703191645_MC2-12D6-DFFC@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear John Gulland:

Norbert Senf (at Masonry Stoves) allerted me to your "top down" article on
the WWW at http://www.wood-heat.com/topdown.htm. I'll recommend it to all
our CREST stove and gasification people. I read it and printed it out to
show my wife. Then I saw your main page. Great. Do you have any
objections to my putting your "Top Down" article in our STOVE node? I'll
wait for your OK.

Here is a poem I sent out to CREST members a year ago. Feel free to add to
your list:
~~~~~~~~~
Here is a poem I came across in my files - it was our Christmas card in the
palmy days of renewable energy.

WOOD HEAT
Beech wood fires are bright and clear
If the logs are kept a year.
Chestnuts only good, they say
If for long its laid away.
But ash wood new or ash wood old
Is fit for a queen with a crown of gold.
Birch and fir logs burn too fast,
Blaze up bright and do not last.
Is by the Irish said
Hawthorn bakes the sweetest bread.
Elm wood burns like churchyard mould -
Een the very flames are cold;
But ash wood green and ash wood brown
Is fit for a queen with a golden crown.
Poplar gives a bitter smoke,
Fills your eyes and makes you choke.
Apple wood will scent your room
With an incense like perfume.
Oaken logs if dry and old
Keep away the winter cold.
But ash wood wet and ash wood dry
A king shall warm his slippers by.

Oak logs will warm you well,
If theyre warm and dry.
Larch logs of pine wood smell
But sparks will fly.
Beech logs for Christmas time;
Yew logs heat well.
Scotch logs its a crime
For anyone to sell.
Birch logs will burn too fast,
Chestnut scarce at all.
Hawthorn logs are good to last,
If cut in the fall.
Holly logs will burn like wax,
You should burn them green.
Elm logs like smouldering flax;
No flames to be seen.
Pear logs and apple logs,
They will scent your room.
Cherry logs across the dogs
Smell like flowers in bloom.
But ash logs all smooth and gray,
Burn them green or old,
Buy up all that come you way,
Theyre worth their weight in gold.
From Tree farm by John Estabrook
*****
(However, remember, all wood has the same (+/- 5%) heating value on a DRY,
ASH FREE basis. )

Does anyone have any modern comments on the advice of this piece?
~~~~~~~~~
Sad to say, no one had any comments.

My field is gasification. I "discovered" the top burning advantages for
gasification in 1985 and have been developing improved cooking stoves for
third world countries since then. We finally got a "blue" cooking flame
last year.

Nice to know the principles of science --- and wood burning --- apply
across the board to gasification and combustion and ......everything.

Keep up the good work -----if you're ever in Denver, look us up....

Yours truly, TOM REED

 

From verhaarp at janus.cqu.edu.au Thu Mar 20 00:55:41 1997
From: verhaarp at janus.cqu.edu.au (Peter Verhaart)
Date: Tue Aug 31 21:35:05 2004
Subject: Top down gasification
Message-ID: <1.5.4.32.19970320060301.0069b874@janus.cqu.edu.au>

>From Piet Verhaart

At 16:44 19/03/97 -0500, you wrote:
>Thomas B. Reed 303 278 0558 V Colorado School of Mines
>1810 Smith Rd., 303 278 0560 FX Department Chem Eng
>Golden, CO 80401 ReedTB@Compuserve.com
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Dear John Gulland:
>
>Norbert Senf (at Masonry Stoves) allerted me to your "top down" article on
>the WWW at http://www.wood-heat.com/topdown.htm. I'll recommend it to all
>our CREST stove and gasification people. I read it and printed it out to
>show my wife. Then I saw your main page. Great. Do you have any
>objections to my putting your "Top Down" article in our STOVE node? I'll
>wait for your OK.
>
>Here is a poem I sent out to CREST members a year ago. Feel free to add to
>your list:
> ~~~~~~~~~
>Here is a poem I came across in my files - it was our Christmas card in the
>palmy days of renewable energy.
>
> WOOD HEAT
> Beech wood fires are bright and clear
> If the logs are kept a year.
> Chestnuts only good, they say
> If for long its laid away.
> But ash wood new or ash wood old
> Is fit for a queen with a crown of gold.
> Birch and fir logs burn too fast,
> Blaze up bright and do not last.
> Is by the Irish said
> Hawthorn bakes the sweetest bread.
> Elm wood burns like churchyard mould -
> Een the very flames are cold;
> But ash wood green and ash wood brown
> Is fit for a queen with a golden crown.
> Poplar gives a bitter smoke,
> Fills your eyes and makes you choke.
> Apple wood will scent your room
> With an incense like perfume.
> Oaken logs if dry and old
> Keep away the winter cold.
> But ash wood wet and ash wood dry
> A king shall warm his slippers by.
>
> Oak logs will warm you well,
> If theyre warm and dry.
> Larch logs of pine wood smell
> But sparks will fly.
> Beech logs for Christmas time;
> Yew logs heat well.
> Scotch logs its a crime
> For anyone to sell.
> Birch logs will burn too fast,
> Chestnut scarce at all.
> Hawthorn logs are good to last,
> If cut in the fall.
> Holly logs will burn like wax,
> You should burn them green.
> Elm logs like smouldering flax;
> No flames to be seen.
> Pear logs and apple logs,
> They will scent your room.
> Cherry logs across the dogs
> Smell like flowers in bloom.
> But ash logs all smooth and gray,
> Burn them green or old,
> Buy up all that come you way,
> Theyre worth their weight in gold.
> From Tree farm by John Estabrook
> *****
>(However, remember, all wood has the same (+/- 5%) heating value on a DRY,
>ASH FREE basis. )
>
>Does anyone have any modern comments on the advice of this piece?
> ~~~~~~~~~
>Sad to say, no one had any comments.
>
>My field is gasification. I "discovered" the top burning advantages for
>gasification in 1985 and have been developing improved cooking stoves for
>third world countries since then. We finally got a "blue" cooking flame
>last year.
>
>Nice to know the principles of science --- and wood burning --- apply
>across the board to gasification and combustion and ......everything.
>
>Keep up the good work -----if you're ever in Denver, look us up....
>
>Yours truly, TOM REED
>
>Great, Tom. Actually the combustion in the downdraft stove is top down
combustion turned upside down (if anyone can still follow the argument). In
both modes heat is kept away from fuel not in the immediate vicinity of the
combustion zone.
Lets keep thinking uninhibitedly, very hard indeed.
Cheers,
Piet Verhaart
Peter Verhaart 6 McDonald St Gracemere Q 4702 Australia
Phone: +61 79 331761 Fax: +61 79 331761 or 332112
E-mail: verhaarp@janus.cqu.edu.au

 

 

From john at gulland.ca Fri Mar 21 16:31:52 1997
From: john at gulland.ca (John Gulland)
Date: Tue Aug 31 21:35:05 2004
Subject: Top down gasification
In-Reply-To: <199703191645_MC2-12D6-DFFC@compuserve.com>
Message-ID: <33332A7F.D9@gulland.ca>

Thomas Reed wrote:
>
> Norbert Senf (at Masonry Stoves) allerted me to your "top down" article on
> the WWW at http://www.wood-heat.com/topdown.htm. I'll recommend it to all
> our CREST stove and gasification people. I read it and printed it out to
> show my wife. Then I saw your main page. Great. Do you have any
> objections to my putting your "Top Down" article in our STOVE node? I'll
> wait for your OK.
>

Good to hear from you Tom.
I am pleased that you liked what you saw when you visited
wood-heat.com. My intention and that of those who sponsor me in hosting
the site is that everything there is in the public domain and we
encourage people to grab what they like and adapt it for their own use.
We do like to be listed as the source, so more people are encouraged to
visit and use the site. So, by all means, have a go.

>
> Here is a poem I sent out to CREST members a year ago. Feel free to add to
> your list:
>

You left an opening for comments on the poem. As any of my colleagues
will confirm, I have an opinion on absolutely everything that has to do
with wood heating.

>
> Apple wood will scent your room
> With an incense like perfume.
>

These days, we refer to this as indoor air pollution.

>
> Burn them green or old,
>

Ahem, we like to suggest that all species be cut and split and stored
under cover for at least the full summer before burning. Some very hard
species like Oak need a longer period of seasoning and all species take
longer in damp, maritime climates. My particular spin on the wood pile
is that the uglier the better and the more environmentally appropriate.
Ugly stacks are made up of the crooked, malformed trees and deadfalls
that are useless for other purposes. I promote the use of less
desirable softwood species for spring and fall use. Personally, I use a
lot of Poplar and really like it for the "shoulder" seasons, provided it
is properly seasoned. You can use enough of it to get a decent fire
burning without overheating the house in relatively mild weather. I
like to tell people that in the coldest climates (like the frozen
Canadian north) there is no hardwood, so people use Spruce and Jack Pine
and seem to make out just fine.

>
> My field is gasification. I "discovered" the top burning advantages for
> gasification in 1985 and have been developing improved cooking stoves for
> third world countries since then. We finally got a "blue" cooking flame
> last year.
>

I would love to hear more about a blue flame cooking range.

>
> Nice to know the principles of science --- and wood burning --- apply
> across the board to gasification and combustion and ......everything.
>

The January/February issue of the Canadian magazine Harrowsmith Country
Life had an article about me titled, believe it or not, Mr. Wood Heat
Builds His Dream Home, in which there was a sidebar on the top down
burn. I was swamped with mail as a result and much of it was from
people who, despite being sceptical, tried the top down technique and
were utterly amazed how well it worked. They noted a great reduction in
smoke and in wood consumption and in ignition time. One fanatic claimed
it changed her life! Wood heat people are an interesting bunch all
right.

I am currently playing with a tiny downdraft gasifier in my workshop and
really enjoying it after a decade of wanting to get my hands on one and
never finding the time. I am still debugging, so there is much work to
do.

Norbert is a great professional friend of mine and it was he who tipped
me to the Crest stove list. I'm glad he did.

Good to hear from you. I suspect you and I will be corresponding again.

Regards,
John

This is for business: http://www.gulland.ca
This is for pleasure: http://www.wood-heat.com

 

From mheat at mha-net.org Sat Mar 22 07:07:22 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:05 2004
Subject:
Message-ID: <3.0.32.19970322071617.007cbe40@mha-net.org>

At 04:32 PM 21/03/97 -0800, you wrote:
>Norbert
>A few weeks back you had talked about the "do's and Don'ts" could you
>explain to me about the "not having the chimney up the exterior wall
>portion" I was hoping to give the reason to a client. I am amazed at all
>the data from the list and especially fascinated by the positive and
>negative pressure issues. With pilot lights and other gas appl. being in
>more and more homes today it could be really dangerous if some one did not
>calc things out. Anyway thanks for your time. Darrin
>Thanks again,
>
>Darrin Thornton @ Polysteel Alternative Building Systems, Inc.
>664 Hillandale Circle
>Eagle Point, Oregon 97524
>Office 541-830-FORM (3676) Fax 541-830-3611
>EMAIL: epsform@cdsnet.net
>www.cdsnet.net/Business/Polysteel
>That's about all the electronic leashes I want!!
>

Lots of reasons, depends on the specifics. For wood stoves, you need all
the help you can get, so you don't want to do anything to cool the stack
down. With a cooler stack you will get:

- cooler stack temps, therefore less draft, therefore:

- Startup problems

- Will start to spill sooner under negative pressure, possibly poisoning
you to death with CO at night while you sleep

- lower efficiency (if the chimney is outside the house, obviously you are
losing some heat to the outside with it)

- if your are burning in smoldering mode (which you shouldn't), a cooler
stack will cause more condensation of creosote in the flue, rather than
into the atmosphere. Therefore a higher likelyhood of chimney fire and
burning your house down. A lot of people think having the chimney outside
the house is safer (it's not.)

- for R-2000 houses in Canada, we've made it illegal.

Best......Norbert

-----------------------------------------
Norbert Senf--------------------email:---mheat@mha-net.org
Masonry Stove Builders-------------------mheat@hookup.net
RR 5, Shawville-----------------website: http://mha-net.org/msb
Quebec J0X 2Y0------------------fax:-----819.647.6082
--------------------------------voice:---819.647.5092

 

 

 

From REEDTB at compuserve.com Mon Mar 24 07:54:56 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: Woodchips and spit
Message-ID: <199703240800_MC2-132B-DA85@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Anouk and all:

I was hoping you would ask!

My deceased colleague, (Harry LaFontaine, ne Jensen) was a member of the
Danish underground and had 1,000 stories - (some of them possibly fables
like from his GGGrandFather, mother's side).

Early in the war Denmark made gasifiers to operate trucks, fishing boats
etc. They were fueled with wood blocks, but if the blocks had more than
20% moisture the gas would be weak and tarry. The government set up a
squad of "wood block inspectors", complete with uniforms, epaulets etc.
They would go to the stores selling bags of wood blocks, pull out their
resistivity meters, and if the blocks had too much water they could fine
the store owners or shut them down.

Wood is like a bunch of drinking straws lined up together, and above 20%
moisture these straws are full of water. After a year or so it was
discovered that if you spit on one end of the block and blew through the
other end you would see bubbles - if the straws were empty. If they were
full of water, you couldn't blow bubbles.

Overnight the squad of inspectors was disbanded. Too bad for bureaucracy,
good for gasification.

Try it! And don't be caught buying or burning wet wood!

Tom Reed

 

From REEDTB at compuserve.com Mon Mar 24 12:02:53 1997
From: REEDTB at compuserve.com (Thomas Reed)
Date: Tue Aug 31 21:35:05 2004
Subject: Water in biomass
Message-ID: <199703240801_MC2-132B-DA89@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Anders et al:

I believe bone dry wood requires so little heat to pyrolyze that the whole
mass "smokes", while the air supply can only keep up with one part. 10% or
more water localizes the action.

I have seen this effect in both combustion and gasification. In any case,
bone dry wood is very rare except in plywood plants.

This discussion of water in wood has been most interesting. Have we hit
bottom yet?

Tom Reed

 

From bryden at cae.wisc.edu Mon Mar 24 15:13:37 1997
From: bryden at cae.wisc.edu (Ken Bryden)
Date: Tue Aug 31 21:35:05 2004
Subject: Water in biomass
Message-ID: <199703242015.OAA21353@cae.wisc.edu>

Tom,
you wrote
>I believe bone dry wood requires so little heat to pyrolyze that the whole
>mass "smokes", while the air supply can only keep up with one part. 10% or
>more water localizes the action.
>
I can't visualize what you mean. Do you mean that under conditions of
natural convection you can't get enough O2 into the reaction zone or does
this hold also for forced convection?

As you note bone dry wood is rare enough I always start my thinking (and
calcs) with 8% moisture as the lowest.

Mark Bryden

 

 

From KCShuttle at aol.com Mon Mar 24 15:31:03 1997
From: KCShuttle at aol.com (KCShuttle@aol.com)
Date: Tue Aug 31 21:35:05 2004
Subject: want to sell stoves
Message-ID: <970324153748_1849283687@emout12.mail.aol.com>

We have a few older gas and electric stoves - where do you suggest we should
post them?

Thanks

 

From rmiranda at sdnnic.org.ni Mon Mar 24 16:08:37 1997
From: rmiranda at sdnnic.org.ni (Rogerio Carneiro de Miranda)
Date: Tue Aug 31 21:35:05 2004
Subject: IMPROVED STOVES COMPANY
Message-ID: <199703241513.PAA05985@ns.sdnnic.org.ni>

Dear stovers:

Here we are trying to develop a small wood stoves construction company that
will sell their services to low income population of Tegucigalpa, Honduras.
>From our pilot project we detected that there is a great need to improve
wood stoves technology among most of urban residents of Tegucigalpa. We also
detected that making the housewifes aware of the hazards from indoors air
polution, the savings opportunities, and credit acess, most of them will
decide to acquire a new improved wood stove.

We now want to make it as business, in which the profits will be used to
finance further research and to cover our NGO (PROLENA) operation costs. We
are asking a loan from a renewable energy credit foundation to start a small
company, which will market the new improved wood stove, construct it from a
mix of pre-manufactured and/or local materials, train the housewife its
operation and loan them the cash to acquire it. We are now gathering info
to prepare our proposal, and we would like to ask you the following:

1. Do you know of any similar experience of this kind of business in other
countries ?
Where and how susscefull it is ?

2. What would be the acceptance of higher quality stoves (more durability)
with of course higher prices, in relation to a more artesanal model with
local available materials and lower prices ? If you facilitate them a
credit, would they them decide by a better looking and longer lasting stove ?

Thanks in advance for your time and attention.

 

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

 

 

From tduke at igc.apc.org Tue Mar 25 08:37:48 1997
From: tduke at igc.apc.org (Thomas Duke)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal II
In-Reply-To: <199703240801_MC2-132B-DA89@compuserve.com>
Message-ID: <3337D5EA.B52@igc.apc.org>

Dear Stovers,

I am writing to report my research concerning the situation where my peace
corps friend in Nepal is living in a home where smoke fills the house every
time they cook. This research has broadened out to include fields of religion
and social interaction. So, I will give some illustrations to show what I am
finding.

I have had the opportunity to see (by way of video tape) the building of a
grass suspension bridge by a South American community of Inca descent. There
are many aspects of their social orginization and their religious convictions
that apply to our stoves problem in Nepal. So, I will describe some of it
here.

It was known that these people still knew how to build a rope suspension
bridge about 150 feet long across a gorge about 60 feet deep. That they could
build it entirely out of grass and do it in just three days. These are
remarkable claims for a pre-industrial society. So, their ability to achieve
such a tremendous feat so quickly with no modern tools or machines has
bearing on how to solve the smoke in the home of our Nepal friends.

This bridge is made of 7,000 yards (21,000 feet) of 1/2 inch diameter coya
grass rope. The actual construction of the bridge begins the day before they
begin to assemble the finished product. The day before they get together to
build the bridge a woman goes to the hill side and collects enough grass to
twist up 150 feet of 1/2 inch dia. rope. One hundred and forty women are
doing the same thing in their own villages scattered around the area. During
construction these strands of 1/2 inch dia. rope will be twisted into cables
of 24 strands each. Three cables will then be braided into a major bridge
rope. Four of these bridge ropes will be the foot path of the bridge. Two of
the major bridge ropes will be the hand rails. These ropes are strung across
the gorge on the second day. On the third day they lace the foot path ropes
together and the hand rails to the foot path, placing mats of grass on the
foot path. So, you see with simple materials and simple organization they are
able to accomplish a remarkable feat.

This is all done under the guidance and sanction of the local religious
leader. He calls forth the earth's blessing on the building of the bridge.
This is very important to the spiritual condition of the people envolved in
building the bridge. So, I see involvement of the spiritual leader of the
community as necessary to ridding the Nepal homes of cooking smoke.

Also every person who worked on the bridge was paid. Note that the bridge is
a community project. It benefits the whole community. However the bridge
builders are paid, and a strict account of who worked on the bridge is kept.
So, I see it necessary to find ways to pay the workers who build the systems
that are used to provide these Nepal homes with smokeless heat, and cooking.

The bridge building activity is a community get-together, like a fair, or
festival, there is excitement and fun, it is like a vacation activity. So, I
feel that this festival mood is essential to a stove building, chimney
building, or perhaps even bigger gassifier building, project in Nepal.

There was a bridge master. He is responsible for the building of the bridge.
perhaps responsible for its maintenence later and its removal when it has
served its usefull life. So, I believe there must be a stove master or
gassifier master in the village who is responsible.

The use of native material (coya grass) from the Puna Grassland speaks to me
of local creativity. This makes me feel that we need to tap the creative
power of the native people, the people of Nepal, to find materials to work
with. So, I suggest we look at how they successfully achieve other local
projects, like building temples. What role the religeous leaders play, how
they organize, how they raise funds, what mood the building project is done
in, then I feel we will see the way to successfully removing the dreadful
smoke from the village homes where it infects the lungs and burns the eyes.

I have sent copies of all your comments and suggestions to the father of my
friend in Nepal. He has access to a computer at school (where he works) and
they have internet capability. So, I hope he joins in the discussion.

Please respond with all comments and criticism. This will help us discover
the path to success. Let us look steadfastly to the goal of the best interest
of our friends in Nepal.

Sincerely,

Tom Duke

 

From larcon at lynx.sni.net Wed Mar 26 00:56:48 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal II
Message-ID: <v01540b00af5e6d028ef2@[204.133.251.11]>

Stovers -

Tom Duke impresses me greatly. I hope he is still as enthusiastic as a
year ago when he came up with several nice modifications of the
charcoal-making stove.

Tom:

I think you have offered a very convincing parallel - in the 3 day
bridge building example.

Let me know how you think I could help. I'm afraid our problem is
money to get the right modifications for Nepal.

Ron Larson

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From tduke at igc.apc.org Fri Mar 28 09:32:26 1997
From: tduke at igc.apc.org (Thomas Duke)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal III
In-Reply-To: <v01540b00af5e6d028ef2@[204.133.251.11]>
Message-ID: <333BD6DE.38FD@igc.apc.org>

Hi Ron,

Good to hear from you! Yes I am still enthusiastic. I need to make another
report to you and the group about my research. This one is on the work I have
been doing with direct solar, and Stirling engines. Basically what prompted
this branch in my research is this: That from my crude calculations direct
solar is about 1,000 times more efficient then growing a tree and burning the
wood. So, I have done some exploring of this field and find we can probably
benefit both from using some direct solar and some Stirling engines. However
I must attend to some other work this morning and will have to wait till this
evening before I can make a more detailed report. So, by for now, and thanks
for the kind words.

Sincerely,

Tom Duke

Ronal W. Larson wrote:
>
> Stovers -
>
> Tom Duke impresses me greatly. I hope he is still as enthusiastic as a
> year ago when he came up with several nice modifications of the
> charcoal-making stove.
>
> Tom:
>
> I think you have offered a very convincing parallel - in the 3 day
> bridge building example.
>
> Let me know how you think I could help. I'm afraid our problem is
> money to get the right modifications for Nepal.
>
> Ron Larson
>
> Ronal W. Larson, PhD
> 21547 Mountsfield Dr.
> Golden, CO 80401
> 303/526-9629

 

From mheat at mha-net.org Fri Mar 28 10:43:56 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal III
Message-ID: <3.0.32.19970328105253.007cc720@mha-net.org>

At 08:34 AM 28/03/97 -0600, Thomas Duke wrote:
>Hi Ron,
>
>Good to hear from you! Yes I am still enthusiastic. I need to make another
>report to you and the group about my research. This one is on the work I
have
>been doing with direct solar, and Stirling engines. Basically what prompted
>this branch in my research is this: That from my crude calculations direct
>solar is about 1,000 times more efficient then growing a tree and burning
the
>wood. So, I have done some exploring of this field and find we can probably
>benefit both from using some direct solar and some Stirling engines. However
>I must attend to some other work this morning and will have to wait till
this
>evening before I can make a more detailed report. So, by for now, and thanks
>for the kind words.

Hi Tom:

I'd be interested in finding out about specific models of Stirling engines
that you have experience with. We've had some small involvement
investigating the possibility of domestic scale co-generation with cordwood
by using a Stirling engine coupled to a cookstove or to a masonry heater,
initially proposed by Toronto engineer Greg Allen for the CMHC Healthy
House in Toronto. They went with a gasifier instead, unsuccessfully so far,
I might add. One of the impossible specifications to meet was the
requirement for off-the-shelf technology.

At the time, we investigated a 500W unit developed for third-world use by
Sunpower in Ohio. One problem with it was a very narrow power band (in the
500 C range), with a factory refit required if the safety valve blew.

Greg is currently investigating a couple of other units, but I don't have
any details yet.

Best.......Norbert Senf
-----------------------------------------
Norbert Senf--------------------email:---mheat@mha-net.org
Masonry Stove Builders-------------------mheat@hookup.net
RR 5, Shawville-----------------website: http://mha-net.org/msb
Quebec J0X 2Y0------------------fax:-----819.647.6082
--------------------------------voice:---819.647.5092

 

 

 

From tduke at igc.apc.org Fri Mar 28 22:16:02 1997
From: tduke at igc.apc.org (Thomas Duke)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal III A
In-Reply-To: <v01540b00af5e6d028ef2@[204.133.251.11]>
Message-ID: <333C8994.6F19@igc.apc.org>

Hi Ron and all,

This is to be a little report on my findings about solar and Stirling
engines. As I mentioned in "Nepal III" my crude calculations show that direct
solar is about 1,000 times more efficient then growing a tree and burning the
wood. So, here are some more details.

It is probably no supprise to most of you that direct solar is so much more
efficient then growing a tree. I suspected that it was, however the magnitude
of difference is what got my attention. So, I will tell here how I made the
estimation. One square meter recieves about 1,000 watts of power for about 8
hours per day, for a little over 100 days here in Iowa. This estimate is a
little conservative, however it is adequate to illustrate the point. That is
800,000 watt hours of energy. If we assume about 1,000 watt hours per pound
of wood, the square meter is equivelent to about 800 pounds of wood. It was
this consideration that caused me to explore the field of direct solar.

I am using today some very simple solar ovens to heat water for my early
garden. The warm water warms the soil making the plants think it is later in
the year. Also when there is enough moisture on my little garden, I simply
put the warm jugs of water under a clouche to help keep the soil warm at
night. This system is very simple to use. So, I feel that when the sun is
available, it can be used to warm water, dry wood, and so on saving
completely that amount of wood, and preventing that amount of smoke.

I am also aware that there are times when rotating shaft power would be very
beneficial. Electric photovoltaic panels are very expensive for many remote
villages, so, I first started thinking about using stirling engines with the
stoves to produce some electric power. However when I discovered that direct
solar is so much more efficient then burning wood I started looking for
Stirling engines that will run directly from solar input. The first truly
exciting engines I found are designed by Bomin of Germany. From two square
meters of collector they produce 120 watts of rotating shaft power. As I
explored around I found that there is a rather large variety of Stirling
engines that operate at very low temperature. Most of these are models,
however it proves the concept.So, I am thinking of ways small solar Stirling
engines and small wood powered Stirling engines can contribute to the best
interest of people. There are places around the world where yarn is still
spun by using a drop spindle. A small engine would work very nicely for this
job.

It was the value of land that prompted me to ask the question about how much
energy we can get per square meter. I considered the corn we grow out here.
We grow about 5 stalks of corn per square meter. We recieve about 1 penny per
ear of corn we grow. That is about 5 cents per square meter. If we burn that
corn to cook a meal, we will burn up all the energy captured and stored from
1 square meter, for one meal. However enough sunlight energy radiates on that
square meter to cook about 800 meals. So, that is when I began thinking that
I need to consider using direct solar energy in any way I can, for cooking,
preheating water, drying wood, heating other things, perhaps even combustion
air, and so on.

There is an interesting thing about Stirling engines that allows them to be
used as heat pumps, for heating and for cooling. This seems significant to me
because in some remote sites it is very difficult to keep medical supplies
cool. Also a heat pump could be used for cooking and house heating or
cooling. So, as I think of the problems of smoke in the homes of our friends
in Nepal, I think about ways of getting heat into the house without getting
smoke in there also.

What do you think about putting the stove outside of the house and conduct
the heat into the house for use there? I built a wood burning (down draft)
stove to heat our house for a couple of winters. I built it outside the house
and piped hot water in the house to heat it. It worked very well, lowered our
heating bill so much the propane delivery man ask about our wood stove. The
Romans used to heat their "Baths" with wood fires out side of the bath area,
and piped the heat under the floors and in the walls. I think they used stone
or concrete heat ducts. So, I wonder if there are simple ways we can keep the
smoke out of the homes and burn our wood very efficiently.

I have studied some chemistry and know that carbon is a very versitile atom.
It has bonding that allows for the production of organic molecuels. So, I am
wondering if they can use their charcoal to make something. Something
chemical besides gun power (charcoal, saltpeter, sulfur). Also I am wondering
if they grind their charcoal into a fine powder, can we make a stove that
burns fine charcoal power efficently. The generating plant down here drops
powered coal into the fire near the top of the chamber with good combustion
results.

Let me know what you think.

Sincerely,

Tom Duke

 

From tduke at igc.apc.org Sat Mar 29 22:16:11 1997
From: tduke at igc.apc.org (Thomas Duke)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal III (Stirling)
In-Reply-To: <3.0.32.19970328105253.007cc720@mha-net.org>
Message-ID: <333DDBC3.1DE1@igc.apc.org>

Hi Norbert,

There are several. Some ready for commercial use. Some that you could
probably get. So I will give you a list starting with the ready for
commercial use ones, and working down. Let me know what power output you
want, and what temperature range you are wanting to use. And I can give you
some guidelines and explain the field a little.

Bomin Solar http://www.tiac.net/users/pcag/solar/
South power http://www.southpower.co.nz/whisp.htm
Tamin http://www.tamin.com/tese001.html
Andy Ross 1660 W. Henderson Rd., Columbus, Ohio, 43220
Japanese University http://www.mech.saitama-u.ac.jp/kiriki/home.html
Ecoboy-SCM81 http://www.bekkoame.or.jp/khirata/ecoboyn/index.htm
Bob Bailey baileys@vax2.rain.gen.no.us

Bob Baily offers an excellent, comprehensive video tape "An Introduction to
Hot Air Engines." There are many engines shown in this video, including the
Tamin engine, and several Andy Ross engines.

Andy Ross built a 100 watt 300cc engine under a DOE appropriate technology
grant. It produced 112.4 watts at 1,150 rpm, atmospheric. He ran this engine
on a wood stove for demonstrations. He eventually sold it to the University
of Calgary.

Dr. James R. Senft of the University of Wisconsin has done some excellent
work with low temperature Stirling engines. He has one that runs on a
temperature difference of only one degree f. He is in the math department at
River falls. His books are published by Moriya Press, PO Box 384, River
Falls, WI 54022

The low temperature engines are easier to build and cheaper. They take up
more space and are less efficient. However, when using the heat off of the
cool side of the engine to heat a house, efficency may not be a question. The
Bomin solar engines run at temperatures below 100 degrees C. and produce
about 60 watts per square meter.

There are more sites where Stirling engine information is available. However
this may get you started, because you can usually find links to other sites.
So, let me know how it goes and I will be glad to explain what I know.

I have designed and built some engines. I am designing a solar powered engine
now and am thinking of making it out of pvc pipe (very cheap). So, I can give
you some suggestions and dimentions if you want to design your own engine.

Sincerely,

Tom Duke

Norbert Senf wrote:

> Hi Tom:
>
> I'd be interested in finding out about specific models of Stirling engines
> that you have experience with. We've had some small involvement
> investigating the possibility of domestic scale co-generation with cordwood
> by using a Stirling engine coupled to a cookstove or to a masonry heater,
> initially proposed by Toronto engineer Greg Allen for the CMHC Healthy
> House in Toronto. They went with a gasifier instead, unsuccessfully so far,
> I might add. One of the impossible specifications to meet was the
> requirement for off-the-shelf technology.
>
> At the time, we investigated a 500W unit developed for third-world use by
> Sunpower in Ohio. One problem with it was a very narrow power band (in the
> 500 C range), with a factory refit required if the safety valve blew.
>
> Greg is currently investigating a couple of other units, but I don't have
> any details yet.
>
> Best.......Norbert Senf
> -----------------------------------------
> Norbert Senf--------------------email:---mheat@mha-net.org
> Masonry Stove Builders-------------------mheat@hookup.net
> RR 5, Shawville-----------------website: http://mha-net.org/msb
> Quebec J0X 2Y0------------------fax:-----819.647.6082
> --------------------------------voice:---819.647.5092
>
>
>

 

From mheat at mha-net.org Sun Mar 30 08:21:38 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:35:05 2004
Subject: Nepal III (Stirling)
Message-ID: <3.0.32.19970330083033.007cf9f0@mha-net.org>

At 09:19 PM 29/03/97 -0600, Thomas Duke wrote:
>Hi Norbert,
>
>There are several. Some ready for commercial use. Some that you could
>probably get. So I will give you a list starting with the ready for
>commercial use ones, and working down. Let me know what power output you
>want, and what temperature range you are wanting to use. And I can give you
>some guidelines and explain the field a little.

Hi Tom:

Thanks very much for the leads. I will check them out. There are some
rumblings about starting this project up again as a commercial venture, so
we will see.

A second idea that has come up is to use heat pipe technology for one-way
transfer of heat during a masonry heater batch burn to heat up an insulated
mass ( a "heat battery") that could provide longer term heat for cooking.
Any leads in this area that you or any of the list members could provide
would be appreciated as well.

Best......Norbert
-----------------------------------------
Norbert Senf--------------------email:---mheat@mha-net.org
Masonry Stove Builders-------------------mheat@hookup.net
RR 5, Shawville-----------------website: http://mha-net.org/msb
Quebec J0X 2Y0------------------fax:-----819.647.6082
--------------------------------voice:---819.647.5092

 

 

 

From larcon at lynx.sni.net Mon Mar 31 12:54:07 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: Biomass energy
Message-ID: <v01540b02af65a82751a3@[204.133.251.23]>

Stovers: Can anyone on the stoves list supply some help to Charlie Cary
in this message I am forwarding? This is somewhat pertinent to the recent
communication from Tom Duke (which I have started a separate reply to).

Ron

>Date: Sat, 29 Mar 1997 16:11:16 -0600 (CST)
>From: crcary@ix.netcom.com (Charlie Cary)
>Subject: Biomass energy
>To: larcon@csn.net
>
>I have been selling industrial wood fired boilers to the American
>forest products industry for eleven years and am very interested in
>putting together a small (50kw to 150) village power system. The
>components are off the shelf now that coppus-Murray has come out with a
>small turbine system.
>
>My Company is too small (less than 2million a year in sales) to take the
>lead on putting this sytem together. Do you know of anyone,
>organization or business which would be interested in packaging off the
>shelf biomass combustion technology?
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From larcon at lynx.sni.net Mon Mar 31 12:53:22 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: Stirlings and Nepal III A remarks from Tom Duke
Message-ID: <v01540b04af63082b7cc1@[204.133.251.4]>

Stovers - this is an open reply to Tom - trying to make the reply mostly on
stoves. I have tried to shorten Tom's original as much as I could, to avoid
getting too long. You may have to re-read Tom's original to understand his
views.

Tom: >solar is about 1,000 times more efficient then growing a tree and
burning the wood.

Ron: I think the ratio is closer to 100, depending on the quality of
energy we are talking about - electricity or thermal energy, and especially
on what part of the world. I just spent four days covering a PV conference
for Solar Today magazine (see the next issue) and Tom has given me a chance
to add a bit to the little bit of technical data in my half page report
there.

Tom on annual energy level: >800,000 watt hours of energy (per sq m per year)

Ron: Dividing by 8766 gives about 91 watts - whereas the usual tropics
number is about 250 watts (rarely more than 300 watts annual average almost
anywhere). Tom was considering a corn growing season of 100 days only.

Tom: > If we assume about 1,000 watt hours per pound (for wood, or 2.2kW/kg)

Ron: At 18 MJ/kg one gets exactly 5 kWh/kg, or 2.273 kWh/pound (wood
consumption of 1 kG/hr gives 5kW power level release)

Tom: >the square meter is equivelent to about 800 pounds of wood.

Ron: Tom is dividing 800 (kWh/sqm-yr) by 1 (kWh/lb) = 800 (lb/sqm-yr). I
would get 250 (W) * 8.766 (kh/yr) / 5 (kWh/kg) = 438 kg/sqm-yr = 964
(lb/sqm-yr). (about 20% higher than Tom's value.)
If one could find a spot where the tree grew with an energy
conversion efficiency of 1%, then the tree weight gain (again using 5
kWh/kg) should be

.01 * 250 * 8.766 (kWh/sqm-yr) / 5 (kwh/kg) = 4.38 (kg/sqm-yr)

which shows we need about 100 square meters of trees (or have to wait 100
years) to get the sustainable equivalent solar energy input (which was the
meaning of the 1% efficiency). Unfortunately, trees are rarely that
efficient - although some other plants approach 3%.

With PV electricity at 10% conversion efficiency, the ratio is only
10 - but we shouldn't compare energy in the form of electricity and trees.
Where trees are converting solar energy at an annual lifetime rate of only
0.1% - then Tom is correct about the ratio of 1000 - but one still needs to
throw in some conversion efficiency to capture the incoming solar energy in
a form as convenient as wood.

 

It was
>this consideration that caused me to explore the field of direct solar.
>
>I am using today some very simple solar ovens to heat water for my early
>garden. The warm water warms the soil making the plants think it is later in
>the year. Also when there is enough moisture on my little garden, I simply
>put the warm jugs of water under a clouche to help keep the soil warm at
>night. This system is very simple to use. So, I feel that when the sun is
>available, it can be used to warm water, dry wood, and so on saving
>completely that amount of wood, and preventing that amount of smoke.
>
>I am also aware that there are times when rotating shaft power would be very
>beneficial. Electric photovoltaic panels are very expensive for many remote
>villages, so, I first started thinking about using stirling engines with the
>stoves to produce some electric power. However when I discovered that direct
>solar is so much more efficient then burning wood I started looking for
>Stirling engines that will run directly from solar input. The first truly
>exciting engines I found are designed by Bomin of Germany. From two square
>meters of collector they produce 120 watts of rotating shaft power. As I
>explored around I found that there is a rather large variety of Stirling
>engines that operate at very low temperature. Most of these are models,
>however it proves the concept.So, I am thinking of ways small solar Stirling
>engines and small wood powered Stirling engines can contribute to the best
>interest of people. There are places around the world where yarn is still
>spun by using a drop spindle. A small engine would work very nicely for this
>job.
>
>It was the value of land that prompted me to ask the question about how much
>energy we can get per square meter. I considered the corn we grow out here.
>We grow about 5 stalks of corn per square meter. We recieve about 1 penny per
>ear of corn we grow. That is about 5 cents per square meter. If we burn that
>corn to cook a meal, we will burn up all the energy captured and stored from
>1 square meter, for one meal. However enough sunlight energy radiates on that
>square meter to cook about 800 meals. So, that is when I began thinking that
>I need to consider using direct solar energy in any way I can, for cooking,
>preheating water, drying wood, heating other things, perhaps even combustion
>air, and so on.
>
>There is an interesting thing about Stirling engines that allows them to be
>used as heat pumps, for heating and for cooling. This seems significant to me
>because in some remote sites it is very difficult to keep medical supplies
>cool. Also a heat pump could be used for cooking and house heating or
>cooling. So, as I think of the problems of smoke in the homes of our friends
>in Nepal, I think about ways of getting heat into the house without getting
>smoke in there also.
>
>What do you think about putting the stove outside of the house and conduct
>the heat into the house for use there? I built a wood burning (down draft)
>stove to heat our house for a couple of winters. I built it outside the house
>and piped hot water in the house to heat it. It worked very well, lowered our
>heating bill so much the propane delivery man ask about our wood stove. The
>Romans used to heat their "Baths" with wood fires out side of the bath area,
>and piped the heat under the floors and in the walls. I think they used stone
>or concrete heat ducts. So, I wonder if there are simple ways we can keep the
>smoke out of the homes and burn our wood very efficiently.
>
>I have studied some chemistry and know that carbon is a very versitile atom.
>It has bonding that allows for the production of organic molecuels. So, I am
>wondering if they can use their charcoal to make something. Something
>chemical besides gun power (charcoal, saltpeter, sulfur). Also I am wondering
>if they grind their charcoal into a fine powder, can we make a stove that
>burns fine charcoal power efficently. The generating plant down here drops
>powered coal into the fire near the top of the chamber with good combustion
>results.
>
>Let me know what you think.
>
>Sincerely,
>
>Tom Duke

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629

 

 

From larcon at lynx.sni.net Mon Mar 31 18:02:35 1997
From: larcon at lynx.sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:35:05 2004
Subject: Last message
Message-ID: <v01540b00af65f5a464d6@[204.133.251.20]>

I didn't mean to send the last message yet on Tom Duke's computations.
I'll clean up the mess tomorrow. Sorry to all. Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401
303/526-9629