June 2002 Gasification Archive

For more information to help people develop better stoves for cooking with biomass fuels in developing regions, please see our web site: http://www.bioenergylists.org

From Gavin at roseplac.worldonline.co.uk Sat Jun 1 06:57:14 2002
From: Gavin at roseplac.worldonline.co.uk (Gavin Gulliver-Goodall)
Date: Tue Aug 31 21:37:53 2004
Subject: Wonderful fans!
In-Reply-To: <000e01c2086c$c9dd2a00$511d66ce@default>
Message-ID: <MABBJLGAAFJBOBCKKPMGOEGHCFAA.Gavin@roseplac.worldonline.co.uk>

Has anyone investigated clockwork- like the clockwork radio. Or gravity -
like a pendulum clock escapement?
Something simple like an endless string loop going round a pulley- Pulley
connected via high gearing to a small fan. String has 3 knots in it equally
spaced- there are 2 weights which are slipped over string above knot at the
top of the loop and removed at the bottom so you get -say 3 minutes blow for
moving the weight once- no constant tending, no batteries, renewable fan
power?
I taught kids at a school where we used the falling weight driving a fan as
a simple timing device- the fan provided braking so the weight fell slowly
and they could time an egg with it.

Just a thought for you inventors with stoves to try if you fancy

Or a bicycle pump and a small storage tank- could be a foot pump and a car
inner tube-
How much air is needed for enough "blow" to cook a meal with efficient smoke
free combustion ?

Cheers
gavin
Gavin Gulliver-Goodall
3G Energi,

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

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

-----Original Message-----
From: Dean Still [mailto:dstill@epud.net]
Sent: Friday, May 31, 2002 7:31
To: stoves@crest.org
Subject: Re: Wonderful fans!

Dear Paul, Tom, and all,

Peter Scott, Ken Goyer and I have been trying for a while to add a small fan
to a sidefeed Rocket. The experiment that shows best promise is made from a
8" high two inch thick home made firebrick cylinder inside a coffee can. The
firebrick combustion chamber is pushed against the inside of the coffee can
leaving a crescent moon space on the opposite side... A 4" in diameter round
hole is cut through both the can and combustion chamber, (near the base of
each) into which sticks, on top of a shelf, are fed. The space between the
top of the combustion chamber cylinder and coffee can is filled with
fiberglass insulation. A 3" in diameter computer fan is used to blow air
into the space between the firebrick cylinder and coffee can. The air enters
the combustion chamber through 1/8th inch holes at the level of the shelf
except where the holes would blow air out the horizontal feed magazine. A
higher ring of similarly positioned 5/16" holes, two inches above the level
of the shelf, adds additional turbulence.

The stove shows very little smoke, most of the time the air is clear above
the stove. A pot used to boil water (38% efficiency) had no soot on it after
the test. The yellow flames are very excited, as can be imagined. I'll post
a picture soon. Aiming the jets of air away from the horizontal fuel
magazine allows wood to be introduced in the normal manner while the fan is
cleaning up smoke and blowing air up the chimney.

Tom, as usual, is right, I think...Air is the solution to pollution. In this
case, the air is even cold but the jets of air make for a very active fire
that does not want to smoke even when too much fuel is pushed into the fire.
In our last experiment, Ken rigged up a regulator to the air supply. When we
pushed way too much fuel into the combustion chamber adding even more air
immediately cleaned up the smoke. Now if we could only do this without a
fan!

Looks to me that a natural draft stove will not smoke if the operator does
not feed in too much wood but a fan allows the operator to be considerably
more cavalier. If the fan is reliable the chimney can be gotten rid of and
efficiency rises higher. Leaving a chimney above the fire lets the stove
function pretty well when the fan ceases to create its magic.

Best,

Dean

-
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>
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>
For information about CHAMBERS STOVES
>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm

From tombreed at attbi.com Sun Jun 2 04:41:32 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:53 2004
Subject: Wonderful fans!
In-Reply-To: <MABBJLGAAFJBOBCKKPMGOEGHCFAA.Gavin@roseplac.worldonline.co.uk>
Message-ID: <01e301c20a38$03791b30$0680fd0c@TOMBREED>

Dear All:

There is a great resistance to the battery operated fans by the tinkerers.
I lie awake nights thinking of alternatives and there are at least 20 other
means of supplying 3.6 kg of air to 600 g of wood per hour to make a 3 kW
cooking fire. Then I get up and proceed with the 1.5 V AA battery that
lasts 3 hours on high (fast boil) and 6 hours on simmer and costs $0.30 to
$1 retail.

We will also market a small solar charger and lithium ion battery for those
who are offended by disposable batteries.

Tom Reed BEF STOVEWORKS
----- Original Message -----
From: "Gavin Gulliver-Goodall" <Gavin@roseplac.worldonline.co.uk>
To: <stoves@crest.org>
Sent: Saturday, June 01, 2002 9:52 AM
Subject: RE: Wonderful fans!

> Has anyone investigated clockwork- like the clockwork radio. Or gravity -
> like a pendulum clock escapement?
> Something simple like an endless string loop going round a pulley- Pulley
> connected via high gearing to a small fan. String has 3 knots in it
equally
> spaced- there are 2 weights which are slipped over string above knot at
the
> top of the loop and removed at the bottom so you get -say 3 minutes blow
for
> moving the weight once- no constant tending, no batteries, renewable fan
> power?
> I taught kids at a school where we used the falling weight driving a fan
as
> a simple timing device- the fan provided braking so the weight fell slowly
> and they could time an egg with it.
>
> Just a thought for you inventors with stoves to try if you fancy
>
> Or a bicycle pump and a small storage tank- could be a foot pump and a car
> inner tube-
> How much air is needed for enough "blow" to cook a meal with efficient
smoke
> free combustion ?
>
> Cheers
> gavin
> Gavin Gulliver-Goodall
> 3G Energi,
>
> Tel +44 (0)1835 824201
> Fax +44 (0)870 8314098
> Mob +44 (0)7773 781498
> E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>
>
> The contents of this email and any attachments are the property of 3G
Energi
> and are intended for the confidential use of the named recipient(s) only.
> They may be legally privileged and should not be communicated to or relied
> upon by any person without our express written consent. If you are not an
> addressee please notify us immediately at the address above or by email at
> Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>. Any files attached to
> this email will have been checked with virus detection software before
> transmission. However, you should carry out your own virus check before
> opening any attachment. 3G Energi accepts no liability for any loss or
> damage that may be caused by software viruses.
>
> -----Original Message-----
> From: Dean Still [mailto:dstill@epud.net]
> Sent: Friday, May 31, 2002 7:31
> To: stoves@crest.org
> Subject: Re: Wonderful fans!
>
> Dear Paul, Tom, and all,
>
> Peter Scott, Ken Goyer and I have been trying for a while to add a small
fan
> to a sidefeed Rocket. The experiment that shows best promise is made from
a
> 8" high two inch thick home made firebrick cylinder inside a coffee can.
The
> firebrick combustion chamber is pushed against the inside of the coffee
can
> leaving a crescent moon space on the opposite side... A 4" in diameter
round
> hole is cut through both the can and combustion chamber, (near the base of
> each) into which sticks, on top of a shelf, are fed. The space between the
> top of the combustion chamber cylinder and coffee can is filled with
> fiberglass insulation. A 3" in diameter computer fan is used to blow air
> into the space between the firebrick cylinder and coffee can. The air
enters
> the combustion chamber through 1/8th inch holes at the level of the shelf
> except where the holes would blow air out the horizontal feed magazine. A
> higher ring of similarly positioned 5/16" holes, two inches above the
level
> of the shelf, adds additional turbulence.
>
> The stove shows very little smoke, most of the time the air is clear above
> the stove. A pot used to boil water (38% efficiency) had no soot on it
after
> the test. The yellow flames are very excited, as can be imagined. I'll
post
> a picture soon. Aiming the jets of air away from the horizontal fuel
> magazine allows wood to be introduced in the normal manner while the fan
is
> cleaning up smoke and blowing air up the chimney.
>
> Tom, as usual, is right, I think...Air is the solution to pollution. In
this
> case, the air is even cold but the jets of air make for a very active fire
> that does not want to smoke even when too much fuel is pushed into the
fire.
> In our last experiment, Ken rigged up a regulator to the air supply. When
we
> pushed way too much fuel into the combustion chamber adding even more air
> immediately cleaned up the smoke. Now if we could only do this without a
> fan!
>
> Looks to me that a natural draft stove will not smoke if the operator
does
> not feed in too much wood but a fan allows the operator to be considerably
> more cavalier. If the fan is reliable the chimney can be gotten rid of and
> efficiency rises higher. Leaving a chimney above the fire lets the stove
> function pretty well when the fan ceases to create its magic.
>
> Best,
>
> Dean
>
>
>
> -
> Stoves List Archives and Website:
> http://www.crest.org/discussion/stoves/200204/
> http://crest.org/discussiongroups/resources/stoves/
> >
> Stoves List Moderators:
> Ron Larson, ronallarson@qwest.net
> Elsen L. Karstad, elk@wananchi.com www.chardust.com
> >
> List-Post: <mailto:stoves@crest.org>
> List-Help: <mailto:stoves-help@crest.org>
> List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >
> Sponsor the Stoves List: http://www.crest.org/discuss3.html
> -
> Other Biomass Stoves Events and Information:
> http://www.bioenergy2002.org
> http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> For information about CHAMBERS STOVES
>
>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm
>
>
> -
> Stoves List Archives and Website:
> http://www.crest.org/discussion/stoves/200204/
> http://crest.org/discussiongroups/resources/stoves/
> >
> Stoves List Moderators:
> Ron Larson, ronallarson@qwest.net
> Elsen L. Karstad, elk@wananchi.com www.chardust.com
> >
> List-Post: <mailto:stoves@crest.org>
> List-Help: <mailto:stoves-help@crest.org>
> List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >
> Sponsor the Stoves List: http://www.crest.org/discuss3.html
> -
> Other Biomass Stoves Events and Information:
> http://www.bioenergy2002.org
> http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> For information about CHAMBERS STOVES
>
>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm
>

From psanders at ilstu.edu Sun Jun 2 07:30:40 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <000e01c2086c$c9dd2a00$511d66ce@default>
Message-ID: <4.3.1.2.20020602112444.018e4a20@mail.ilstu.edu>

Gavin and Tom and all,

I like the gravity idea. Assuming that FORCED air becomes recognized as an
important consideration, we will need to start amassing our info on the
ways to do it.

Perhaps there is a "Forced-Air List-Serve" that could assist us.

About your comment on the bicycle pump and a storage device (inner tube,
etc), that is the first think that I tried in April 2001 after I first met
Tom Reed and saw the prototype of the Turbo Stove with fan. My experiment
was a total flop. I eventually figured out (with Stoves list assistance)
that the actual volume of needed air is MUCH greater that what I could
conveniently put into an inner tube. I am quite sure that storage of air
under pressure is NOT a viable option.

(After that start I then I began work with briquettes with holes -- ala
Legacy Foundation -- and eventually to natural draft gasifiers, and now
with cautious interest in fans for forced air.)

Paul

At 04:52 PM 6/1/02 +0100, Gavin Gulliver-Goodall wrote:
>Has anyone investigated clockwork- like the clockwork radio. Or gravity -
>like a pendulum clock escapement?
>Something simple like an endless string loop going round a pulley- Pulley
>connected via high gearing to a small fan. String has 3 knots in it equally
>spaced- there are 2 weights which are slipped over string above knot at the
>top of the loop and removed at the bottom so you get -say 3 minutes blow for
>moving the weight once- no constant tending, no batteries, renewable fan
>power?
>I taught kids at a school where we used the falling weight driving a fan as
>a simple timing device- the fan provided braking so the weight fell slowly
>and they could time an egg with it.
>
>Just a thought for you inventors with stoves to try if you fancy
>
>Or a bicycle pump and a small storage tank- could be a foot pump and a car
>inner tube-
>How much air is needed for enough "blow" to cook a meal with efficient smoke
>free combustion ?
>
>Cheers
>gavin
>Gavin Gulliver-Goodall
>3G Energi,
>
>Tel +44 (0)1835 824201
>Fax +44 (0)870 8314098
>Mob +44 (0)7773 781498
>E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>

Paul S. Anderson, Ph.D., Fulbright Prof. to Mozambique 8/99 - 7/00
Rotary University Teacher Grantee to Mozambique >10 mo of 2001-2003
Dept of Geography - Geology (Box 4400), Illinois State University
Normal, IL 61790-4400 Voice: 309-438-7360; FAX: 309-438-5310
E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders

From Gavin at roseplac.worldonline.co.uk Sun Jun 2 11:40:16 2002
From: Gavin at roseplac.worldonline.co.uk (Gavin Gulliver-Goodall)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <01e301c20a38$03791b30$0680fd0c@TOMBREED>
Message-ID: <MABBJLGAAFJBOBCKKPMGAEGJCFAA.Gavin@roseplac.worldonline.co.uk>

Aha, thanks Tom,
3.6kg/hr airflow at ? pressure-people talk of PC ventilation fans is that
the right sort of size? I have a mind to make a model fan and weight device
so I would quite like some info on pressure and an idea of diameter and any
ductwork sizes so I make something relevant.
= 1 litre per sec.
My book says that you should get 1 l/s for 0.25W with an axial fan in a tube
24mm in diameter. This is the best performance in my book Is yours as
efficient Tom?
PC fans are in the 0.1-1.0 W range
1W =1j/sec
1j = Nm
so a 500g (5N) weight dropping 500mm gives 2.5Nm
If that were to take 20s that would be 0.125W
So 1kg dropping 1.5 min would deliver around 0.1W.

Lets think another way:

1.5V AA battery has a maximum of say 1.5ah.
that's 1.5v x 1.5a/3 on fast boil

=0.75W draw on the battery. If you are using every last drop of energy in
the battery. Is it an alkaline or Zinc battery?

Another thought on the Battery front.
My second-hand experience from friends who have worked in Africa is that
"technology " like batteries and chargers tend to walk so would not be a
secure method of ensuing efficient and clean stoves A simple mechanical
thing that's easily fixed (or made) from readily available waste (tin cans)
has far more chance of acceptance and use... I stand to be corrected here by
others with more direct experience.

From andrew.heggie at dtn.ntl.com Mon Jun 3 04:19:16 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <000e01c2086c$c9dd2a00$511d66ce@default>
Message-ID: <hjnmfukb2g3uoqcdh78i41utl9o2u9fr1q@4ax.com>

On Sat, 1 Jun 2002 16:52:08 +0100, "Gavin Gulliver-Goodall"
<Gavin@roseplac.worldonline.co.uk> wrote:

>Has anyone investigated clockwork- like the clockwork radio. Or gravity -
>like a pendulum clock escapement?

We looked at this previously, I posted message
hprottgltk9ualqj6gtvfrim11q3m350fa@4ax.com
28/10/01

>Something simple like an endless string loop going round a pulley- Pulley
>connected via high gearing to a small fan. String has 3 knots in it equally
>spaced- there are 2 weights which are slipped over string above knot at the
>top of the loop and removed at the bottom so you get -say 3 minutes blow for
>moving the weight once- no constant tending, no batteries, renewable fan
>power?

We did develop this but the power over time whilst cooking becomes
quite a lot of foot pounds of effort.

>I taught kids at a school where we used the falling weight driving a fan as
>a simple timing device- the fan provided braking so the weight fell slowly
>and they could time an egg with it.

I speculated that in this instance the cubical power requirement of
the fan acting as a regulator would also allow the clockwork to meter
the fuel.

I am still wondering if the legacy foundation briquettes could be
formed in the cobnut size range. I have higher hopes for forced air
with less than ideal fuel, which agri waste may be.
>
>Just a thought for you inventors with stoves to try if you fancy
>
>Or a bicycle pump and a small storage tank- could be a foot pump and a car
>inner tube-
>How much air is needed for enough "blow" to cook a meal with efficient smoke
>free combustion ?

Tom answered what mass of stoichiometric air you need, the real
question is what degree of turbulence you need to give sufficient
contact between reacting molecules to enable clean combustion AND best
approaching stoichiometric conditions.

AJH

From andrew.heggie at dtn.ntl.com Mon Jun 3 04:20:03 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <01e301c20a38$03791b30$0680fd0c@TOMBREED>
Message-ID: <nknmfuon4pdtcth1im6sbddug1204orj23@4ax.com>

On Sun, 2 Jun 2002 21:34:50 +0100, "Gavin Gulliver-Goodall"
<Gavin@roseplac.worldonline.co.uk> wrote:

>Aha, thanks Tom,
>3.6kg/hr airflow at ?

Unless your fuel is very good (like natural gas) or the stove has
excellent characteristics you will need more airflow than this to
cleanly burn 600g of biomass. This figure is the stoichiometric mass
of air necessary for combustion, with a typical wood fuel in a small
stove I suggest an exav of 1.5 would be more in keeping.

>pressure-people talk of PC ventilation fans is that
>the right sort of size? I have a mind to make a model fan and weight device
>so I would quite like some info on pressure and an idea of diameter and any
>ductwork sizes so I make something relevant.
>= 1 litre per sec.
>My book says that you should get 1 l/s for 0.25W with an axial fan in a tube
>24mm in diameter.

While the 24mm tube may imply a back pressure you have otherwise got
your dimensions a bit out. To derive a power figure you need
dimensions of force times distance over time. Pressure times volume
over time has the same dimensions, you have missed out the figure for
pressure. My stove works at 5mm of water gauge about a 5th of an inch.
I make this about 50pascals. I had better check my maths and
conversions as a quick calculation of moving 5m3 air/hour through a
back pressure of 50pascals yields 0.06W.

Perhaps if you come down from that cold wet country where men wear
skirts to visit me, you could bring a pitot tube and we could do some
meaningful measurements?

> This is the best performance in my book Is yours as
>efficient Tom?
>PC fans are in the 0.1-1.0 W range

electrical consumption or air throughput?

>1W =1j/sec
>1j = Nm
>so a 500g (5N) weight dropping 500mm gives 2.5Nm
>If that were to take 20s that would be 0.125W
>So 1kg dropping 1.5 min would deliver around 0.1W.

These figures seem to ignore the conversion of the electricity into
movement of air. IMO fans are not very efficient.
>
>Lets think another way:
>
>1.5V AA battery has a maximum of say 1.5ah.
> that's 1.5v x 1.5a/3 on fast boil
>
>=0.75W draw on the battery. If you are using every last drop of energy in
>the battery. Is it an alkaline or Zinc battery?

The point being that the battery has many external costs which haven't
been properly accounted?
>
>Another thought on the Battery front.
>My second-hand experience from friends who have worked in Africa is that
>"technology " like batteries and chargers tend to walk so would not be a
>secure method of ensuing efficient and clean stoves A simple mechanical
>thing that's easily fixed (or made) from readily available waste (tin cans)
>has far more chance of acceptance and use... I stand to be corrected here by
>others with more direct experience.
>From this discussion I think that a clockwork like the clockwork radio-
>direct drive for preference or charger/motor would give a sensible cooking
>time for maximum simplicity and minimum drain on the local economy.
>I believe wind up radios have been supplied and are in use in many parts of
>Africa for over 10 years now?

I am not at all against the principal, I just feel that most cooks
would consider expending a bit of their fuel to derive the forced air
rather than a lot of lifting or winding.
>Cheers
>Gavin
>Tom Reed Wrote
>Dear All:
>
>There is a great resistance to the battery operated fans by the tinkerers.

Blast, I been reduced to a tinkerer :-)

>I lie awake nights thinking of alternatives and there are at least 20 other

I listed the few I could think of last year, let's see how many anyone
can list and the scale of operation e.g. chimneys are an old
technology but only good for very small drafts without dumping all the
heat at a high temperature.

>means of supplying 3.6 kg of air to 600 g of wood per hour to make a 3 kW
>cooking fire. Then I get up and proceed with the 1.5 V AA battery that
>lasts 3 hours on high (fast boil) and 6 hours on simmer and costs $0.30 to
>$1 retail.

Is USD 0.30 per days cooking of 3kW(t) for 3 hours a bearable cost? Is
9kWhr(t) a realistic figure for a cooking unit?
>
>We will also market a small solar charger and lithium ion battery for those
>who are offended by disposable batteries.

Even lithium battery will be disposable after a finite number of
cycles, mind you this technology has improved fantastically.

I have said before, I have nothing against using electric fans, I had
just got th impression from users in the field that the infrastructure
was not available to support them nor could the economy afford them.
That is not to say I have any reason to believe my flash steam
monotube aspirator could be supported either. I have however suggested
it might open up access to fuels currently ignored or wasted.

AJH

PS is this a competition to see how many times you can get the CREST
sigfile repeated in a posting? :-)

>> -
>> Stoves List Archives and Website:
<snip>
>>
>> -
>> Stoves List Archives and Website:
<snip>
>-
>Stoves List Archives and Website:

From alyilmaz at anet.net.tr Mon Jun 3 09:01:51 2002
From: alyilmaz at anet.net.tr (ali yilmaz)
Date: Tue Aug 31 21:37:54 2004
Subject: GAS-L: MDF and energy
In-Reply-To: <007b01c1f6af$d3ca8860$6401a8c0@tommain>
Message-ID: <000b01c20b28$f3d33de0$59ab92d4@b0b2a8>

Hello all,

Does anyone has any experience about the
energy consumption / need of a continuous MDF plant with 500 m3
capacity.

I am trying to calculate an approximate energy
value for the followings ( but a little bit confused with differentr feedbacks I
got from my customer...)

- Energy spent in the presses
- Refiner
- Dryers

Any help or related weblinks will be
appreciated.

Thanks

Ali

From VHarris001 at aol.com Mon Jun 3 19:16:05 2002
From: VHarris001 at aol.com (VHarris001@aol.com)
Date: Tue Aug 31 21:37:54 2004
Subject: GAS-L: Re: Gasifier fundamental question
Message-ID: <140.f6c3884.2a2d9887@aol.com>

Tom, now that you are back, I thought I'd try reposting this question.

In a message dated 04/14/2002 6:33:29 PM Eastern Daylight Time, tombreed@attbi.com writes:

The air fuel ratio for volatiles in a dry fuel is about 1. For charcoal it
is 6!

Tom, would you be so kind as to elaborate? I gather that to burn the charcoal, the required air to fuel ratio is 6. But I'm not clear about what air to fuel ratio is required to gasify the wood. And what air to fuel ratio is then required to combust the pyrolysis gases?

Thanks
Vernon Harris

From Gavin at roseplac.worldonline.co.uk Mon Jun 3 23:29:00 2002
From: Gavin at roseplac.worldonline.co.uk (Gavin Gulliver-Goodall)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <nknmfuon4pdtcth1im6sbddug1204orj23@4ax.com>
Message-ID: <MABBJLGAAFJBOBCKKPMGMEGKCFAA.Gavin@roseplac.worldonline.co.uk>

Ok
More thoughts:
We? Stovers should be first looking at the needs of our customers- do they
want a new stove? Is smoke an issue to them? What functionality would they
like form thier stove. Cooking on a stove against an open fire is not only
more efficient but also offers alternative cooking techniques...

Then some money comparisons:
If an aid agency gives the stoves for free or the designs are passed freely
so that individuals or local tradespeople can make them easily.. What fuel
is available?
Lots of questions: Im sure you have all discussed them.

Briquettes with holes sound exiting dispense with the fan problem , but who
makes them and how much does this cost in labour and plant/materials does
this extra cost benefit the consumer (of the stove)

Here in the UK
Kerosene cost around 2p/kWh
Propane (Bulk) around 4p/kWh

An AA battery 30p -for 9kWh of cooking on Toms stove =3.1p/kWh
Not attractive

Can the guys on the spot give us a definitive- are batteries financially
viable and available for their target consumer?

This will surely answer the question so that we can address alternative
mechanical draught or an injector system or stick with flues or devise
cunning cheap to make briquettes etc. Or go for a simple fan assisted stove
and not worry?

Cheers
Gavin

-----Original Message-----
From: AJH [mailto:andrew.heggie@dtn.ntl.com]
Sent: Monday, June 03, 2002 14:14
To: stoves@crest.org
Subject: Re: Wonderful fans!

On Sun, 2 Jun 2002 21:34:50 +0100, "Gavin Gulliver-Goodall"
<Gavin@roseplac.worldonline.co.uk> wrote:

>Aha, thanks Tom,
>3.6kg/hr airflow at ?

Perhaps if you come down from that cold wet country where men wear
skirts to visit me, you could bring a pitot tube and we could do some
meaningful measurements?

> This is the best performance in my book Is yours as
>efficient Tom?
>PC fans are in the 0.1-1.0 W range

electrical consumption or air throughput?

>1W =1j/sec
>1j = Nm
>so a 500g (5N) weight dropping 500mm gives 2.5Nm
>If that were to take 20s that would be 0.125W
>So 1kg dropping 1.5 min would deliver around 0.1W.

The point being that the battery has many external costs which haven't
been properly accounted?
>
>Another thought on the Battery front.
>My second-hand experience from friends who have worked in Africa is that
>"technology " like batteries and chargers tend to walk so would not be a
>secure method of ensuing efficient and clean stoves A simple mechanical
>thing that's easily fixed (or made) from readily available waste (tin cans)
>has far more chance of acceptance and use... I stand to be corrected here
by
>others with more direct experience.
>From this discussion I think that a clockwork like the clockwork radio-
>direct drive for preference or charger/motor would give a sensible cooking
>time for maximum simplicity and minimum drain on the local economy.
>I believe wind up radios have been supplied and are in use in many parts of
>Africa for over 10 years now?

Blast, I been reduced to a tinkerer :-)

>I lie awake nights thinking of alternatives and there are at least 20 other

Even lithium battery will be disposable after a finite number of
cycles, mind you this technology has improved fantastically.

AJH

PS is this a competition to see how many times you can get the CREST
sigfile repeated in a posting? :-)

>> -
>> Stoves List Archives and Website:
<snip>
>>
>> -
>> Stoves List Archives and Website:
<snip>
>-
>Stoves List Archives and Website:

-
Stoves List Archives and Website:
http://www.crest.org/discussion/stoves/200204/
snip

From E.KITUYI at CGIAR.ORG Tue Jun 4 00:46:31 2002
From: E.KITUYI at CGIAR.ORG (Kituyi, Evans)
Date: Tue Aug 31 21:37:54 2004
Subject: charcoal stove
Message-ID: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>

Thanks
Mohamed, though i do not have an immediate answer. Perhaps someone on the
stovers list could assist!
Evans

-----Original Message-----From: Mohamed Mwondha
[mailto:mode@gt.co.ke]Sent: Thursday, May 30, 2002 1:18
PMTo: e.kituyi@cgiar.orgSubject: charcoal
stove

Mohamed Yusuf Mwondha
P.O.Box 5282-00506 Nyayo
NAIROBI
30.05.02
Mr.Evans Kituyi
African Centre for Technology
Studies,
Nairobi, Kenya.
Dear Sir,
RE:
FARM WASTE CHARCOAL STOVE
I commend your in your efforts in finding
cheap energy for the poor.
I would like to produce charcoal from farm
waste e.g. coffee husks and would really appreciate if you have any
information on how I could obtain a machine which could convert farm waste to
charcoal. I would also like to know the process of doing so.
Thank you
Yours faithfully,
M.Y.Mwondha

From kenboak at stirlingservice.freeserve.co.uk Tue Jun 4 01:12:57 2002
From: kenboak at stirlingservice.freeserve.co.uk (kenboak@stirlingservice.freeserve.co.uk)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful Fans/extra water
Message-ID: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>

Stovers,

Despite a period of absence from the list, I have been following your discussion regarding fans.

Might I suggest a simple idea using a jet of steam to entrap a greater volume of air up through a chimney and thus creating a forced draft using the steam ejector principle.

Alternatively using 2 computer fans mounted on a common shaft, one being driven by the jet of steam in turbine mode, the other used as a fan to create the draft. We used to make steam turbines as kids from old cocoa cans - before we had the luxury of computer fans with precision bearings.

On a completely different subject, when bone dry wood is "roasted" in an oxygen depleted atmosphere, and begins to pyrolise - will some of the byproducts of pyrolysis break down to create additional water vapour as a results of the chemical cracking of the cellulose material?

I recently observed a great deal of water vapour released from a "dry" wood sample - much more than I expected, and I wondered if other Stovers had had experience of this.

regards,

Ken Boak

From Gavin at roseplac.worldonline.co.uk Tue Jun 4 01:24:35 2002
From: Gavin at roseplac.worldonline.co.uk (Gavin Gulliver-Goodall)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful Fans/extra water
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <MABBJLGAAFJBOBCKKPMGEEGMCFAA.Gavin@roseplac.worldonline.co.uk>

Ken et al,

If we raise steam from our stove to create a forced draft then:
1) We will need an alternative forced draft during initial steam raising
2) We will need a SAFE steam boiler and a means of topping it up /auto
dowsing the fire to avoid boiling dry and explosion risk
3) We will use a proportion ??how much?? Of the heat from our stove to raise
the steam-

Will the added complication and expense justify the clean burning rather
than use of a flue?

Cheers
gavin

Gavin Gulliver-Goodall
3G Energi,

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

-----Original Message-----
From: kenboak@stirlingservice.freeserve.co.uk
[mailto:kenboak@stirlingservice.freeserve.co.uk]
Sent: Tuesday, June 04, 2002 11:11
To: stoves@crest.org
Subject: Re: Wonderful Fans/extra water

Stovers,

Despite a period of absence from the list, I have been following your
discussion regarding fans.

Might I suggest a simple idea using a jet of steam to entrap a greater
volume of air up through a chimney and thus creating a forced draft using
the steam ejector principle.

Alternatively using 2 computer fans mounted on a common shaft, one being
driven by the jet of steam in turbine mode, the other used as a fan to
create the draft. We used to make steam turbines as kids from old cocoa
cans - before we had the luxury of computer fans with precision bearings.

On a completely different subject, when bone dry wood is "roasted" in an
oxygen depleted atmosphere, and begins to pyrolise - will some of the
byproducts of pyrolysis break down to create additional water vapour as a
results of the chemical cracking of the cellulose material?

I recently observed a great deal of water vapour released from a "dry" wood
sample - much more than I expected, and I wondered if other Stovers had had
experience of this.

regards,

Ken Boak

From andrew.heggie at dtn.ntl.com Tue Jun 4 02:18:15 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful Fans/extra water
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <qm4pfu0bmdg7pg77j4r6hbqle38pg54j1c@4ax.com>

On Tue, 4 Jun 2002 10:10:51 +0000,
kenboak@stirlingservice.freeserve.co.uk wrote:

>Stovers,
>
>Despite a period of absence from the list, I have been following your discussion regarding fans.

Nice to hear from you again Ken, I lost you after my last e-mail.
Having now tried a couple of flash steam monotube boilers I could use
some analysis of my figures.
>
>Might I suggest a simple idea using a jet of steam to entrap a greater volume of air up through a chimney and thus creating a forced draft using the steam ejector principle.

I use my steam aspirator to provide the combustion air pressure for
two reasons.
1) A steam ejector as used on a steam engine requires a chimney, as
you have seen my burners work slightly pressurised and without a
chimney. The pan gets in the way of a chimney, though Rogerio and Dean
have posted on progress with sunken pots with flues.

2) With relatively poor heat exchange surfaces the cookstove rejects
heat at a relatively high temperature, this tends to mean induced
draft flue gas movers need considerably more power, though they act in
addition to a chimney effect.

>
>Alternatively using 2 computer fans mounted on a common shaft, one being driven by the jet of steam in turbine mode, the other used as a fan to create the draft. We used to make steam turbines as kids from old cocoa cans - before we had the luxury of computer fans with precision bearings.

Computer fans I have seen have plastic blades which potentially will
melt. An axial steam turbine coupled to a centrifugal fan could well
work and be formed from tincanium, bearings would be a problem. There
would be no need for a common shaft as such as they could be formed on
the same "propeller", like the bypass fan on a jet.

What price per watt will you be able to get one of your engines down
to?
>
>On a completely different subject, when bone dry wood is "roasted" in an oxygen depleted atmosphere, and begins to pyrolise - will some of the byproducts of pyrolysis break down to create additional water vapour as a results of the chemical cracking of the cellulose material?

Yes, Tom Reed has often posted in the past that the various stages of
"cooking" wood into charcoal are akin to removing water molecules from
the idealised "wood molecule". Consider that the wood was formed by
the tree taking water from the ground, carbon dioxide from the air and
using the energy from photons combining them to a sugar which is
further combined to make the collection of carbohydrates we know as
wood, expiring the oxygen as a by product. This is photosynthesis.

Pyrolysis is the splitting of this wood back into its constituent
parts, one part left in the absence of oxygen for complete combustion
is charcoal. This charcoal is the "fixed" charcoal of the original
sample of wood and comprises some 25-70% of the original carbon in the
wood depending on conditions in the carboniser.

If the char sample is pure you will see that the amount of water
vapour given of via pyrolysis is exactly the same as if the whole
sample had been burnt and will amount to about 50% of the dry weight
of the original wood.
>
>I recently observed a great deal of water vapour released from a "dry" wood sample - much more than I expected, and I wondered if other Stovers had had experience of this.

Be aware that with british hardwoods and uk climate it is unusual to
have a sample better than 15% mc wwb even if it has been stored under
cover.

AJH

From andrew.heggie at dtn.ntl.com Tue Jun 4 02:18:45 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: charcoal stove
In-Reply-To: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>
Message-ID: <376pfu0o66vvun8oi15c3cqnbj8vbv060i@4ax.com>

On Tue, 04 Jun 2002 02:42:28 -0700, "Kituyi, Evans"
<E.KITUYI@CGIAR.ORG> wrote:

>RE: FARM WASTE CHARCOAL STOVE
>
>I commend your in your efforts in finding cheap energy for the poor.
>
>I would like to produce charcoal from farm waste e.g. coffee husks and would
>really appreciate if you have any information on how I could obtain a
>machine which could convert farm waste to charcoal. I would also like to
>know the process of doing so.

I suggest you look through the archives linked from the CREST site
http://www.crest.org/discussion/stoves/current/ if you do not see this
reply on the list.

The two Karves in India have a simple system doing this from an
initial idea from Yury Yudkevich from Russia.

In essence the method is to pack dry agriwaste into drums and seal the
top except for a small vent. This is then loaded upside down into a
(preferably) enclosed large stove which is lit.

The heat from the stove brings the biomass in the stove up to
temperature at which point offgas is driven out of the drum at the
bottom and ignites, augmenting the heat from the stove and further
cooking the drum. Once evolution of offgas is finished the drum is
placed still upside down in sand to cool.

The offgas being forced to exit at the bottom of the drum means both
that its heat is used to heat unreacted biomass in the drum as it
passes down through it as well as the flame at the vent then heating
the drum above it.

A friend using one of my woodchip burners (internal capacity 700
litres) reports successfully making charcoal with seasoned wood by
this method, a 200ltre drum charred in 2 hrs.

Another method with dry particles which may be simpler for coffee
husks is a large idd kiln. Alex Engish did some work on this and I
have successfully used one up to 100 litres capacity. Whilst this
method has the advantage of needing no support fuel, yields are lower.

Both methods are cheap, fast and flare offgas cleanly.

AJH

From andrew.heggie at dtn.ntl.com Tue Jun 4 02:19:19 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful Fans/extra water
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <3g7pfuorlfq4qu85shj75ercaa8ooarbt2@4ax.com>

On Tue, 4 Jun 2002 11:18:29 +0100, "Gavin Gulliver-Goodall"
<Gavin@roseplac.worldonline.co.uk> wrote:

>Ken et al,
>
>If we raise steam from our stove to create a forced draft then:
>1) We will need an alternative forced draft during initial steam raising

Why? Steam raising doesn't take long and is part of the startup
process. I do have contingency for this by Teeing of air from the
reservoir to start but I do not think it will be necessary if a good
kindly is used.

>2) We will need a SAFE steam boiler and a means of topping it up /auto
>dowsing the fire to avoid boiling dry and explosion risk

Well sort of, the monotube boiler does not hold much water, so the
scope for an explosion on rupture is small. Also it is well within the
stove and shielded. Pressurising is simple by a small air pump of the
type seen on a primus stove. Boiling dry will probably not be a
problem with steel tube if we can live with low pressures.

>3) We will use a proportion ??how much?? Of the heat from our stove to raise
>the steam-

Interesting problem, I have theorised I "should" get away with an
insignificantly small amount of steam. Theory and practice have yet to
come together.
>
>Will the added complication and expense justify the clean burning rather
>than use of a flue?

Probably not with a decent fuel, please note flues are not necessarily
compatible with cookstove use.

Looks like Brits on a public holiday are hogging the list, bless her
;-).
AJH

From rstanley at legacyfound.org Tue Jun 4 07:30:43 2002
From: rstanley at legacyfound.org (Richard Stanley)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful fans!
In-Reply-To: <000e01c2086c$c9dd2a00$511d66ce@default>
Message-ID: <3CFC7A2E.9B7D6243@legacyfound.org>

Heres a fan power generating idea which combines the clock mechanism powered by
gravity and resolves the problem of the need top lower teh pot closer to the
embers as the burn progresses in a conventional wood fire.

. The gravity drive coul be the pot itself . As the flames die back to embers,
the full pot (as the kinetic energy source behind the gravity drive of the
clock fan mechanism ) is lowering into the embers -as the fan whirs away. Ser
it up right and the fan dies out as the pot bottoms out and hopefully the
flames are out and cooking is finished.

And will we be able to make this happen within the mass consummers of Africa or
just the stovers labs ?

Richard Stanley
AshlandOregon

From andrew.heggie at dtn.ntl.com Tue Jun 4 09:18:23 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:54 2004
Subject: Wonderful Fans/extra water
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <lk0qfu4g39jntst8jb63m0p4u9ejpboqat@4ax.com>

I have had a reply from Harmon Seaver which was meant for the list:

On Tue, Jun 04, 2002 at 12:12:17PM +0100, AJH wrote:

> melt. An axial steam turbine coupled to a centrifugal fan could well
> work and be formed from tincanium, bearings would be a problem. There
> would be no need for a common shaft as such as they could be formed on
> the same "propeller", like the bypass fan on a jet.
>
If a simple (cheap) bearing solution could be found, I think this
is by far the most excellent idea yet put forth. Think of the fans at
the bottom of the stove with the flash steam tube in the upper
secondary burn area -- designed right it would also avail a control
via the amount of water put in, i.e., the stove would self-reduce to a
simmer when the water ran out. Or a dab more water added later to burn
up the charcoal.
Perhaps even better, wouldn't the steam from the fans come up into
the coals and break down, adding H to the woodgas, as is done with
bigger gasifiers? Or would it dampen the fuel too much?

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

From tombreed at attbi.com Thu Jun 6 04:44:59 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:54 2004
Subject: GAS-L: Hand powered blower
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <00f601c20d5c$66a61d30$0680fd0c@TOMBREED>

Dear All:

On my visit to Paul Anderson last month he showed me a hand powered squirrel
cage blower made in China that he had purchased in SA for ~ $1. Worked
quite well for starting fires, augmenting woodgas stoves etc. It was black
plastic and about 20 cm long by 10 cm high.

Does anyone else know of this device and where I could see it on the web or
buy one?

TOM REED

-
Gasification List Archives:
http://www.crest.org/discussion/gasification/200202/

Gasification List Moderator:
Tom Reed, Biomass Energy Foundation, Reedtb2@cs.com
www.webpan.com/BEF
List-Post: <mailto:gasification@crest.org>
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http://www.crest.org/articles/static/1/1011975672_7.html Carbon

From dstill at epud.net Thu Jun 6 07:49:45 2002
From: dstill at epud.net (Dean Still)
Date: Tue Aug 31 21:37:54 2004
Subject: Lanny and Peter's sunken pot stove
Message-ID: <005e01c20d5a$bf97a780$491d66ce@default>

Dear Stovers,

I'm posting a series of pictures showing details of a prototype Rocket stove
that Lanny Hensen and Peter Scott built in Rome, Georgia where Lanny lives.
This stove is a sheet metal version of a sunken two pot stove with baking
oven that Peter is now taking with him to Africa where he is teaching a
course on stove making. Although this is only a prototype and we are not
sure of its longevity the photos show construction details that follow Larry
Winiarski's Rocket design principles. Further testing will determine where
in the stove home made refractory ceramic parts need to replace sheet metal.

The great advantage of sunken pot stoves is: greater pot surface area is
exposed to heat; therefore there is significantly increased fuel efficiency.

The heat contacts a pot first as it leaves the Rocket internal chimney. The
water or food in the pot keeps pot temperatures relatively cool so that pots
do not suffer degradation from heat and flame. If the same heat first
contacted a griddle it would get very hot and eventually wear away.

If the pot absorbs enough heat then secondary surfaces are not exposed to
high heat and last longer.

All smoke is obviously carried through the stove and out the chimney because
pots fit tightly into holes in the top of the stove.

In this prototype stove, five pounds of water in the first pot boiled in 9
minutes. Five pounds of water in the second pot boiled in 25 minutes. The
amount of heat that goes to each pot is determined by the placement of the
Rocket elbow. In this case, quick boiling in the first pot ( boils corn) and
less heat in the second pot (simmers sauce) was accomplished by directing
heat mostly at the first pot.

A guillotine door slides down between the two pots sending heat around the
oven in sheet metal ducts. The oven is surrounded by insulation on all sides
and has an insulated door. It bakes potatoes in an hour and stays around
350F. A griddle can be placed over the first hole to cook tortillas.

The disadvantage of the sunken pot stove is that only specific pots can be
used since the pot has to fit in the hole. Cooks need to be ok with using
pots that probably are sold with the stove. The advantage of the sunken pot
stove is that a Rocket style two pot stove, depending on pot size, amount of
water in pots, etc. will be 30% to 50% fuel efficient.

Lanny does such beautiful work. Those of us who think about stoves can
imagine the pleasure that having a professionally built model can give.
Thanks so much to Lanny for his help on this project! (Both this stove and
Lanny's Wok stove will be cooking food at the next ETHOS (Engineers in
Technical Humanitarian Opportunities of Service) stove conference, January
at Seattle University. All are welcome!)

Best,

Dean

From tmiles at trmiles.com Thu Jun 6 11:49:21 2002
From: tmiles at trmiles.com (Tom Miles)
Date: Tue Aug 31 21:37:54 2004
Subject: Lanny and Peter's sunken pot stove
In-Reply-To: <005e01c20d5a$bf97a780$491d66ce@default>
Message-ID: <016a01c20d9b$694de600$6501a8c0@tommain>

Can be seen at:
http://crest.org/discussiongroups/resources/stoves/Still/South%20Africa%202/
SAF2POT.html

Tom

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: <stoves@crest.org>
Sent: Thursday, June 06, 2002 5:59 AM
Subject: Lanny and Peter's sunken pot stove

> Dear Stovers,
>
> I'm posting a series of pictures showing details of a prototype Rocket
stove
> that Lanny Hensen and Peter Scott built in Rome, Georgia where Lanny
lives.
> This stove is a sheet metal version of a sunken two pot stove with baking
> oven that Peter is now taking with him to Africa where he is teaching a
> course on stove making. Although this is only a prototype and we are not
> sure of its longevity the photos show construction details that follow
Larry
> Winiarski's Rocket design principles. Further testing will determine where
> in the stove home made refractory ceramic parts need to replace sheet
metal.
>
> The great advantage of sunken pot stoves is: greater pot surface area is
> exposed to heat; therefore there is significantly increased fuel
efficiency.
>
> The heat contacts a pot first as it leaves the Rocket internal chimney.
The
> water or food in the pot keeps pot temperatures relatively cool so that
pots
> do not suffer degradation from heat and flame. If the same heat first
> contacted a griddle it would get very hot and eventually wear away.
>
> If the pot absorbs enough heat then secondary surfaces are not exposed to
> high heat and last longer.
>
> All smoke is obviously carried through the stove and out the chimney
because
> pots fit tightly into holes in the top of the stove.
>
> In this prototype stove, five pounds of water in the first pot boiled in 9
> minutes. Five pounds of water in the second pot boiled in 25 minutes. The
> amount of heat that goes to each pot is determined by the placement of the
> Rocket elbow. In this case, quick boiling in the first pot ( boils corn)
and
> less heat in the second pot (simmers sauce) was accomplished by directing
> heat mostly at the first pot.
>
> A guillotine door slides down between the two pots sending heat around the
> oven in sheet metal ducts. The oven is surrounded by insulation on all
sides
> and has an insulated door. It bakes potatoes in an hour and stays around
> 350F. A griddle can be placed over the first hole to cook tortillas.
>
> The disadvantage of the sunken pot stove is that only specific pots can be
> used since the pot has to fit in the hole. Cooks need to be ok with using
> pots that probably are sold with the stove. The advantage of the sunken
pot
> stove is that a Rocket style two pot stove, depending on pot size, amount
of
> water in pots, etc. will be 30% to 50% fuel efficient.
>
> Lanny does such beautiful work. Those of us who think about stoves can
> imagine the pleasure that having a professionally built model can give.
> Thanks so much to Lanny for his help on this project! (Both this stove and
> Lanny's Wok stove will be cooking food at the next ETHOS (Engineers in
> Technical Humanitarian Opportunities of Service) stove conference, January
> at Seattle University. All are welcome!)
>
> Best,
>
> Dean
>
>
> -
> Stoves List Archives and Website:
> http://www.crest.org/discussion/stoves/200204/
> http://crest.org/discussiongroups/resources/stoves/
> >
> Stoves List Moderators:
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> List-Post: <mailto:stoves@crest.org>
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> List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >
> Sponsor the Stoves List: http://www.crest.org/discuss3.html
> -
> Other Biomass Stoves Events and Information:
> http://www.bioenergy2002.org
> http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> For information about CHAMBERS STOVES
>
>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm
>
>

From psanders at ilstu.edu Thu Jun 6 14:48:50 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:54 2004
Subject: charcoal stove
In-Reply-To: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>
Message-ID: <4.3.1.2.20020606185309.01c514d0@mail.ilstu.edu>

Andrew,

Please tell us where there is info on your "woodchip burners"

AND also comment on the possibility of making use of the flared off-gas.

(Is this potentially a larger-volume "gasifier" -- loose use of the term?)

Paul

At 12:12 PM 6/4/02 +0100, AJH wrote:

>A friend using one of my woodchip burners (internal capacity 700
>litres) reports successfully making charcoal with seasoned wood by
>this method, a 200ltre drum charred in 2 hrs.
>
>Another method with dry particles which may be simpler for coffee
>husks is a large idd kiln. Alex Engish did some work on this and I
>have successfully used one up to 100 litres capacity. Whilst this
>method has the advantage of needing no support fuel, yields are lower.
>
>Both methods are cheap, fast and flare offgas cleanly.
>
>AJH

From tombreed at attbi.com Fri Jun 7 04:31:03 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:55 2004
Subject: Lanny and Peter's sunken pot stove
In-Reply-To: <005e01c20d5a$bf97a780$491d66ce@default>
Message-ID: <01c501c20e23$a1a032f0$0680fd0c@TOMBREED>

Dear Dean, Lanny, Peter and all:

Congratulations on your improved sunken pot stoves.

Actually the three stone fire began to be improved about 1750 when Ben
Franklin invented the box stove for home heating and then it was realized
that you could also cook on it. Most of our progenitors since 1850 cooked
on kitchen "ranges" which had nested rings for sunken pots, a nested oven,
and a nested water heater that all extracted heat from the wood/coal fire.

I lived with a kitchen range for a few years in an old farm house on Grand
Island New York (1954-56). Each morning I would revive the fire and shake
the grate - chuga chga chuga. That would wake up the rest of the family.
You can probably find pictures in old Sears or MW catalogues.

However their univeral availability they rested on mass production and good
cheap cast iron castings. But the principles are very similar to what many
are trying to develop now from sheet metal. Maybe it's time to revive the
old technology...

Yours for better cooking, TOM REED BEF STOVEWORKS

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: <stoves@crest.org>
Sent: Thursday, June 06, 2002 6:59 AM
Subject: Lanny and Peter's sunken pot stove

From kchisholm at ca.inter.net Fri Jun 7 05:48:27 2002
From: kchisholm at ca.inter.net (Kevin Chisholm)
Date: Tue Aug 31 21:37:55 2004
Subject: GAS-L: Re: Hand powered blower
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <3D00C707.25135B4B@ca.inter.net>

Dear Tom

I have some sources for such fans in China, and could inquire on a source of
supply for them.

The key thing in the fan is the required fan performance:
1: The required air flow
2: The required static pressure.

From andrew.heggie at dtn.ntl.com Sun Jun 9 04:19:18 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:55 2004
Subject: Wonderful Fans/extra water
In-Reply-To: <20020604101051.CAJR13372.fep02-svc.ttyl.com@localhost>
Message-ID: <lke6gukd7hmtki2me0o4lubdo718johrnn@4ax.com>

On Tue, 4 Jun 2002 08:11:12 -0500, Harmon Seaver
<hseaver@cybershamanix.com> wrote:

>On Tue, Jun 04, 2002 at 12:12:17PM +0100, AJH wrote:
>
>> melt. An axial steam turbine coupled to a centrifugal fan could well
>> work and be formed from tincanium, bearings would be a problem. There
>> would be no need for a common shaft as such as they could be formed on
>> the same "propeller", like the bypass fan on a jet.
>>
> If a simple (cheap) bearing solution could be found,

I have considered this, it seems within the realms of possibility for
the axial bearing to be using the steam to float on. Consider the
steam entering the bearing and venting at one end, the other being
blocked. The steam nozzle could then be a continuous slit which also
took up the thrust in the bearing, once rotating wear should be
minimal as it floats on the steam.

OTOH The fans should have little axial load so a bronze bush may last
for years.

>I think this is by far
>the most excellent idea yet put forth. Think of the fans at the bottom of the
>stove with the flash steam tube in the upper secondary burn area -- designed
>right it would also avail a control via the amount of water put in, i.e., the
>stove would self-reduce to a simmer when the water ran out. Or a dab more water
>added later to burn up the charcoal.

This could also be controlled by the relationship between the monotube
outlet jet size and the reservoir pressure.

> Perhaps even better, wouldn't the steam from the fans come up into the coals
>and break down, adding H to the woodgas, as is done with bigger gasifiers? Or
>would it dampen the fuel too much?

I have often mentioned this, the thing is the temperature in the co
generator phase of the gasifier is very high. In some car units like
the kalle exhaust gas was recirculated to keep this temperature down.
The thing is, as you note, adding steam to the producer gas reaction
to enable a bit of water gas reaction is highly endothermic AND
requires the temperature in the bed to stay above 700C (or maybe
higher). I think the ejector design will run on only 2% steam by
volume, so it should cause no problem.

I still prefer the aspirator if it can be configured properly, after
having made a few tests it looks like I need less coils than I
currently use.

Now this problem of steam getting into the combustion air need not be
a problem with the close coupled steam turbine and fan as the steam
can vent elsewhere. This is true also if they are made from a piece of
tincanium. The paddle of the centrifugal part is made by cutting them
from a flat sheet as petals on a flower. These being twisted at the
"spoke" that attaches them to the centre through 90 degrees. The steam
jet then playing on the twisted spokes (which become the axial
turbine) and passing straight out the other side, the air inlet for
the centrifugal part running coaxially and with the steam flow, the
outlet being on the perimeter.

I shall see if I can make one if I have a little time.

AJH

From andrew.heggie at dtn.ntl.com Sun Jun 9 04:20:29 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:55 2004
Subject: charcoal stove
In-Reply-To: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>
Message-ID: <koe6gu012hth3js1rutm59dvha5mdkb7ep@4ax.com>

On Thu, 06 Jun 2002 18:56:34 -0500, "Paul S. Anderson"
<psanders@ilstu.edu> wrote:

>Andrew,
>
>Please tell us where there is info on your "woodchip burners"

I can assure you all, and I mean all, relevant information has been
posted to stoves by myself. The precise composition of the whole is
proprietary and I welcome enquiries ;-).
>
>AND also comment on the possibility of making use of the flared off-gas.

The flared offgas is a high quality heat source, probably in the order
of 12 MJ/kg average, my colleagues are currently coupling a different
burner up to a simple gas turbine using this gas! I do not know the
exact relationship between the gas cv and flame temperature but in
general the temperature is related to the cv divided by the mass flow.

From tombreed at attbi.com Sun Jun 9 11:21:41 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:55 2004
Subject: charcoal stove
In-Reply-To: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>
Message-ID: <00d701c20fef$56ce5b80$0680fd0c@TOMBREED>

Dear Stovers and Gasifiers:

Typical producer gas produced in conventional downdraft gasifiers has a
heating value of 5 to 6 MJ/Nm3. Superficial velocity typically 0.1-0.3 m/s
(m3/s//m2).

In the inverted downdraft mode the gas velocity is much lower (0.01 - 0.05
m/s) because at higher velocities the charcoal upper layer blows out (unless
you put a grate over it). This lower intensity gives lower flaming
temperatures in the flaming pyrolysis zone and accounts for the MUCH higher
charcoal yields (0.2 to 0.25 rather than 0.05 - 0.1 for conventional
downdraft).

It requires typically < 1 kg of air to pyrolyse 1 kg of biomass to make
combustible volatiles from biomass, leaving behind 20% charcoal. It
requires 6 kg of air to gasify 1 kg of charcoal to CO. Therefore, when the
gasification process does not gasify the charcoal, there is much less
nitrogen in the offgas.

Andrew guesses inverted downdraft gas might be as much as 12 MJ/Nm3, and I
tend to agree with him. However, it is a difficult measurement to make
because the gas may have as much as 50% condensibles in addition to CO, H2
and rich hydrocarbons.

In any case, it is a great gas for all heat applications as long as you stay
above the dewpoint (300C???).

Onward, TOM REED BEF GASWORKS
----- Original Message -----
From: "AJH" <andrew.heggie@dtn.ntl.com>
To: <stoves@crest.org>
Sent: Sunday, June 09, 2002 7:17 AM
Subject: Re: charcoal stove

On Thu, 06 Jun 2002 18:56:34 -0500, "Paul S. Anderson"
<psanders@ilstu.edu> wrote:

>Andrew,
>
>Please tell us where there is info on your "woodchip burners"

From psanders at ilstu.edu Sun Jun 9 13:05:16 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:55 2004
Subject: Shell Foundation grants
Message-ID: <4.3.1.2.20020609170607.018ff790@mail.ilstu.edu>

Stovers,

In case you have not heard:
Message from Shell Foundation said that the results of the initial
screening of the proposals for the "Household Energy and Health" grants
will be MAILED from UK probably as of Monday 10 June. So we wait for the
mail each day!!! There were about 300 proposals.

I hope that those who are successful will inform all of the Stoves readers.

And those who are NOT successful might want to chat also to others who
might find ways to link together some aspects of the diverse project.

Best of luck (and skill) to all.

Paul
Paul S. Anderson, Ph.D., Fulbright Prof. to Mozambique 8/99 - 7/00
Rotary University Teacher Grantee to Mozambique >10 mo of 2001-2003
Dept of Geography - Geology (Box 4400), Illinois State University
Normal, IL 61790-4400 Voice: 309-438-7360; FAX: 309-438-5310
E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders

From dstill at epud.net Sun Jun 9 14:06:07 2002
From: dstill at epud.net (Dean Still)
Date: Tue Aug 31 21:37:55 2004
Subject: 'Complete' Rocketry Class
Message-ID: <001301c20fe5$9edff500$741d66ce@default>

Dear Stovers,

Syllabus for ten day Aprovecho stove class. Students will write up findings
for Crest, Hedon, and ETHOS.

Best,

Dean

Vernacular Stove Class
June 10 to 19, 2002
Aprovecho Research Center

Monday 10
Introductory Lecture by Dr. Larry Winiarski
Three Stone Fire Discussion
Three Stone Fire Efficiency Contest
Sam Baldwin’s Improved Three Stone Fire: Heat Transfer Efficiency
The Five Gallon Rocket and Skirt

Tuesday 11
“Mass and Insulation” by Dean Still
Design Discussion “Earthen Cooking Stoves in Ecuador”
Build Ecuador prototypes for Becky Bee/test
“Homemade Refractory Ceramics” by Ken Goyer
Making same

Wednesday 12 and 19
Sustainable Forestry with Matthew Hall

Thursday 13
Make the Pocket Rocket
“Multiple Pot Stoves” by Dean Still
Build South African 2 Pot Stoves
“Agricultural Drying with Wood” by Dr. Larry Winiarski
Build Large Scale Dryer

Friday 14
“Bread Ovens” by Dean Still
Design seminar
Build bread ovens
“The 6 Brick Insulative Ceramic Stove” by Ken Goyer
Make same

Saturday 15
Catch up
Reading
Testing
Write up results

Monday 17 (Morning with Mat in the Woods or:)
“Heating Water with Wood” by Dean Still
Design and Build a water heater
“The Dona Justa Griddle Stove" by Dean Still
Design and Build a Dona Justa

Tuesday 18
“Cleaning up Combustion” by Dean Still
A Day Exploring (Building and Testing) Solutions

From harrick01 at cwpanama.net Mon Jun 10 08:35:13 2002
From: harrick01 at cwpanama.net (BHarrick)
Date: Tue Aug 31 21:37:55 2004
Subject: Auke Koopmans
In-Reply-To: <4.3.1.2.20020502152728.018a6410@mail.ilstu.edu>
Message-ID: <004601c210a4$c1ee8330$0f00000a@beatriz>

Dear Sirs,
I would like communicate with Dr. Auke Koopmans . Could someone send me his
email, please.
Beatriz Harrick

From brunom1 at yucom.be Mon Jun 10 09:15:04 2002
From: brunom1 at yucom.be (Bruno M.)
Date: Tue Aug 31 21:37:55 2004
Subject: Auke Koopmans
In-Reply-To: <4.3.1.2.20020502152728.018a6410@mail.ilstu.edu>
Message-ID: <5.1.0.14.0.20020610195258.00a50d60@pop3.yucom.be>

At 12:32 10/06/2002 -0500, Harrick wrote:
>Dear Sirs,
>I would like communicate with Dr. Auke Koopmans . Could someone send me his
>email, please.
>Beatriz Harrick

hallo,

you mean this :

auke.koopmans@fao.org

Regards
Bruno M.

-----------------------------------------------------
Reply's to BrunoM1@yucom.be

From koopmans at loxinfo.co.th Mon Jun 10 13:34:54 2002
From: koopmans at loxinfo.co.th (Auke Koopmans)
Date: Tue Aug 31 21:37:55 2004
Subject: Auke Koopmans
In-Reply-To: <4.3.1.2.20020502152728.018a6410@mail.ilstu.edu>
Message-ID: <001901c210ce$e257afa0$e85892cb@xxxx>

The email adress auke.koopmans@fao.org is no longer valid as the Regional
Wood Energy Development Programme has been terminated after 16 years having
been active in the field of wood and biomass energy. My email address is now
koopmans@loxinfo.co.th

Best regards,

Auke Koopmans

----- Original Message -----
From: "BHarrick" <harrick01@cwpanama.net>
To: <stoves@crest.org>
Sent: 11 June 2002 00:32
Subject: Auke Koopmans

> Dear Sirs,
> I would like communicate with Dr. Auke Koopmans . Could someone send me
his
> email, please.
> Beatriz Harrick
>
>
>
> -
> Stoves List Archives and Website:
> http://www.crest.org/discussion/stoves/200204/
> http://crest.org/discussiongroups/resources/stoves/
> >
> Stoves List Moderators:
> Ron Larson, ronallarson@qwest.net
> Elsen L. Karstad, elk@wananchi.com www.chardust.com
> >
> List-Post: <mailto:stoves@crest.org>
> List-Help: <mailto:stoves-help@crest.org>
> List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >
> Sponsor the Stoves List: http://www.crest.org/discuss3.html
> -
> Other Biomass Stoves Events and Information:
> http://www.bioenergy2002.org
> http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> For information about CHAMBERS STOVES
>
>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm
>

From andrew.heggie at dtn.ntl.com Wed Jun 12 11:11:18 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:55 2004
Subject: charcoal stove
In-Reply-To: <FC788AB9771FD6118E6F0002A5AD7B8F7C7F24@icrafnttrain.icraf.cgiar.org>
Message-ID: <t5afguog9f3iftjrt5dkv9pgmn18r2vjf0@4ax.com>

On Sun, 9 Jun 2002 13:53:33 -0600, "Tom Reed" <tombreed@attbi.com>
wrote:

>Dear Stovers and Gasifiers:
>
>Typical producer gas produced in conventional downdraft gasifiers has a
>heating value of 5 to 6 MJ/Nm3. Superficial velocity typically 0.1-0.3 m/s
>(m3/s//m2).
Seeing as 3/4 of the air flow is nitrogen then these figures would be
up in the mid teens if oxygen blown?
>
>In the inverted downdraft mode the gas velocity is much lower (0.01 - 0.05
>m/s) because at higher velocities the charcoal upper layer blows out (unless
>you put a grate over it). This lower intensity gives lower flaming
>temperatures in the flaming pyrolysis zone and accounts for the MUCH higher
>charcoal yields (0.2 to 0.25 rather than 0.05 - 0.1 for conventional
>downdraft).
>
>It requires typically < 1 kg of air to pyrolyse 1 kg of biomass to make
>combustible volatiles from biomass, leaving behind 20% charcoal. It
>requires 6 kg of air to gasify 1 kg of charcoal to CO. Therefore, when the
>gasification process does not gasify the charcoal, there is much less
>nitrogen in the offgas.
>
This begins to address Vernon Harris' query of a few days ago,
unfortunately I have not had time to put my brain into gear to give
him a proper answer. In my analogy I have said carbohydrate takes the
form Cx(H20)y. Your idealised wood molecule C10H14O6 differs from this
a bit. David Beedie's quick calculation for purposes of calculating
air masses simply ignores the H2O fraction, because though there are
differing bond energies depending on whether C-O or C-H or H-O bonds
are being broken the H20 appears on both sides of the equation if
combustion is complete (though it never is). So for complete
combustion we need only calculate the O2 necessary to add to the
carbon and then add the weight of nitrogen associated with the air. I
cribbed a stoichiometric ratio of 5.72:1 from David for this.

>Andrew guesses inverted downdraft gas might be as much as 12 MJ/Nm3, and I
>tend to agree with him. However, it is a difficult measurement to make
>because the gas may have as much as 50% condensibles in addition to CO, H2
>and rich hydrocarbons.
>
>In any case, it is a great gas for all heat applications as long as you stay
>above the dewpoint (300C???).

I think we should also point out that there is also the sensible heat
in the gas to account for, the offgas from the downdraught will be at
1100C, that from the idd ~500C. This is why the Dasifier can smelt
bronze, the gases from the producer gas reaction of C=>CO are already
hot before they are further oxidised CO=>CO2. The overall equation
C=>CO2 is releasing ~30MJ per kg of fuel so has a much higher reaction
temperature than dry biomass with only ~20MJ/kg.

Tom, I hope you and Ronal are not getting too close a demonstration of
biomass combustion gone wild?

AJH

From adkarve at pn2.vsnl.net.in Tue Jun 18 16:02:18 2002
From: adkarve at pn2.vsnl.net.in (A.D. Karve)
Date: Tue Aug 31 21:37:55 2004
Subject: GAS-L: Sweet Chestnut Gasification
Message-ID: <000301c21730$3e085e00$e89ec7cb@adkarvepn2.vsnl.net.in>

Dear Paul,
in India, sorghum and maize fodder is chopped in a hand operated "chaff
cutter". The cheapest model consists of a single blade that is worked up
and down like the blade of a guillotine. We are working on modifying this
model in such a way, that the blade can be operated pedally instead of
manually. This would leave the hands free to manipulate the load of fodder
on the work platform. The more sophisticated ones have two blades, that
serve as the spokes of the wheel. When a handle, placed near the rim of the
wheel is rotated, it also activates a mechanism that pushes the fodder load
towards the wheel so that it gets caught in the blades on the spokes.
I can inquire about the prices and let you know, if you are interested in
such a contraption.
Dr.A.D.Karve
President
Appropriate Rural Technology Institute
Pune, India
-----Original Message-----
From: Paul S. Anderson <psanders@ilstu.edu>
To: Graeme Williams <graeme@powerlink.co.nz>; rebecca.heaton@bronzeoak.com
<rebecca.heaton@bronzeoak.com>
Cc: gasification@crest.org <gasification@crest.org>; bioenergy@crest.org
<bioenergy@crest.org>; stoves@crest.org <stoves@crest.org>
Date: Monday, June 17, 2002 11:28 PM
Subject: Re: GAS-L: Sweet Chestnut Gasification

>Dear Graeme and other "Gasifiers", (with copy to the Stoves list serve)
>
>I am new to this list serve, but have been active for a year on the Stoves
>List serve. I am working with Tom Reed on a domestic gasifier stove for
>cooking with biomass. My area of work is southern Africa, specifically in
>Mozambique and where it joins with Swaziland and South Africa. I head to
>Africa on 4 July for 3 months.
>
>My question is about "chippers". Graeme makes clear statements about drum
>chippers producing poor quality chips and screw-auger chippers producing
>good quality chips.
>
>Is there a good source of info about these chippers, especially regarding
>making fuel for gasifiers? I am especially interested in the least
>expensive, and I hope manually powered, but all info will be useful.
>
>Paul
>
>Paul S. Anderson (full signature block info should be at the end of this
>message.)
>
>At 03:34 PM 6/14/02 +1200, Graeme Williams wrote:
>>Hello Rebecca,
>>
>>Sweet Chestnut should not cause any problems if used for down draught
>>gasifiers. As with all woods used for gasification, the moisture content
>>should be as low as possible (15 - 20%) and you need to closely monitor
the
>>chip size.
>>
>>The big trap for most projects drawing wood from city forestry, is the use
>>of drum chippers which make a lot of fines and is very poor gasifier fuel.
I
>>am pretty sure there was a lot of chestnut chipped at Rural Generations
>>Brook Hall Project in Londonderry following Winter gales a couple of years
>>ago and there were no unusual problems, although it was mixed with other
>>hardwoods.
>>
>>Make sure you use a screw auger chipper with a medium size chip (50 x 25 x
>>5) and it should work fine.
>>
>>Problems with coppice willow gasification can be overcome with a correctly
>>designed gasifier, and again the correct cutting size of the chip. If you
>>haven't done so, you can read about our work with the fuel on the Fluidyne
>>Archive www.fluidynenz.250x.com
>>
>>Hope this helps
>>
>>Doug Williams
>>FLUIDYNE GASIFICATION
>>
>>
>>-
>>Gasification List Archives:
>>http://www.crest.org/discussion/gasification/200202/
>>
>>Gasification List Moderator:
>>Tom Reed, Biomass Energy Foundation, Reedtb2@cs.com
>>www.webpan.com/BEF
>>List-Post: <mailto:gasification@crest.org>
>>List-Help: <mailto:gasification-help@crest.org>
>>List-Unsubscribe: <mailto:gasification-unsubscribe@crest.org>
>>List-Subscribe: <mailto:gasification-subscribe@crest.org>
>>
>>Sponsor the Gasification List: http://www.crest.org/discuss3.html
>>-
>>Other Gasification Events and Information:
>>http://www.bioenergy2002.org
>>http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
>>http://www.crest.org/articles/static/1/1011975339_7.html Gasification
>>http://www.crest.org/articles/static/1/1011975672_7.html Carbon
>
>Paul S. Anderson, Ph.D., Fulbright Prof. to Mozambique 8/99 - 7/00
>Dept of Geography - Geology (Box 4400), Illinois State University
>Normal, IL 61790-4400 Voice: 309-438-7360; FAX: 309-438-5310
>E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders
>
>
>-
>Stoves List Archives and Website:
>http://www.crest.org/discussion/stoves/200204/
>http://crest.org/discussiongroups/resources/stoves/
>>
>Stoves List Moderators:
>Ron Larson, ronallarson@qwest.net
>Elsen L. Karstad, elk@wananchi.com www.chardust.com
>>
>List-Post: <mailto:stoves@crest.org>
>List-Help: <mailto:stoves-help@crest.org>
>List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
>List-Subscribe: <mailto:stoves-subscribe@crest.org>
>>
>Sponsor the Stoves List: http://www.crest.org/discuss3.html
>-
>Other Biomass Stoves Events and Information:
>http://www.bioenergy2002.org
>http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
>http://www.crest.org/articles/static/1/1011975339_7.html Gasification
>http://www.crest.org/articles/static/1/1011975672_7.html Carbon
>>
>For information about CHAMBERS STOVES
>>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.ht
m
>
>

From rstanley at legacyfound.org Tue Jun 18 18:08:18 2002
From: rstanley at legacyfound.org (Richard Stanley)
Date: Tue Aug 31 21:37:55 2004
Subject: GAS-L: Sweet Chestnut Gasification
In-Reply-To: <000301c21730$3e085e00$e89ec7cb@adkarvepn2.vsnl.net.in>
Message-ID: <3D0F92CB.5C1E2F5E@legacyfound.org>

Dear AD Karve and Paul Anderson,

We are always looking for a thresher masher gadget for the production of holey
briquettes too. Have more than a few designs accumilated and on test through
our various training groups andproducers. None of them yet employ a feeding
mechanism: This would be of great interest because it is bound to not only make
the materialprep process more efficient but far safer as well. We have to not
only chop the material but slightly defibrate it by beating or tearing it
through a set of combs (or between two closely positioned conical ginding
stones) to ensure sufficient fibers for binding after a subsequent fiber
softening process.

Richard Stanley
Legacy Foundation

"A.D. Karve" wrote:

> Dear Paul,
> in India, sorghum and maize fodder is chopped in a hand operated "chaff
> cutter". The cheapest model consists of a single blade that is worked up
> and down like the blade of a guillotine. We are working on modifying this
> model in such a way, that the blade can be operated pedally instead of
> manually. This would leave the hands free to manipulate the load of fodder
> on the work platform. The more sophisticated ones have two blades, that
> serve as the spokes of the wheel. When a handle, placed near the rim of the
> wheel is rotated, it also activates a mechanism that pushes the fodder load
> towards the wheel so that it gets caught in the blades on the spokes.
> I can inquire about the prices and let you know, if you are interested in
> such a contraption.
> Dr.A.D.Karve
> President
> Appropriate Rural Technology Institute
> Pune, India
> -----Original Message-----
> From: Paul S. Anderson <psanders@ilstu.edu>
> To: Graeme Williams <graeme@powerlink.co.nz>; rebecca.heaton@bronzeoak.com
> <rebecca.heaton@bronzeoak.com>
> Cc: gasification@crest.org <gasification@crest.org>; bioenergy@crest.org
> <bioenergy@crest.org>; stoves@crest.org <stoves@crest.org>
> Date: Monday, June 17, 2002 11:28 PM
> Subject: Re: GAS-L: Sweet Chestnut Gasification
>
> >Dear Graeme and other "Gasifiers", (with copy to the Stoves list serve)
> >
> >I am new to this list serve, but have been active for a year on the Stoves
> >List serve. I am working with Tom Reed on a domestic gasifier stove for
> >cooking with biomass. My area of work is southern Africa, specifically in
> >Mozambique and where it joins with Swaziland and South Africa. I head to
> >Africa on 4 July for 3 months.
> >
> >My question is about "chippers". Graeme makes clear statements about drum
> >chippers producing poor quality chips and screw-auger chippers producing
> >good quality chips.
> >
> >Is there a good source of info about these chippers, especially regarding
> >making fuel for gasifiers? I am especially interested in the least
> >expensive, and I hope manually powered, but all info will be useful.
> >
> >Paul
> >
> >Paul S. Anderson (full signature block info should be at the end of this
> >message.)
> >
> >At 03:34 PM 6/14/02 +1200, Graeme Williams wrote:
> >>Hello Rebecca,
> >>
> >>Sweet Chestnut should not cause any problems if used for down draught
> >>gasifiers. As with all woods used for gasification, the moisture content
> >>should be as low as possible (15 - 20%) and you need to closely monitor
> the
> >>chip size.
> >>
> >>The big trap for most projects drawing wood from city forestry, is the use
> >>of drum chippers which make a lot of fines and is very poor gasifier fuel.
> I
> >>am pretty sure there was a lot of chestnut chipped at Rural Generations
> >>Brook Hall Project in Londonderry following Winter gales a couple of years
> >>ago and there were no unusual problems, although it was mixed with other
> >>hardwoods.
> >>
> >>Make sure you use a screw auger chipper with a medium size chip (50 x 25 x
> >>5) and it should work fine.
> >>
> >>Problems with coppice willow gasification can be overcome with a correctly
> >>designed gasifier, and again the correct cutting size of the chip. If you
> >>haven't done so, you can read about our work with the fuel on the Fluidyne
> >>Archive www.fluidynenz.250x.com
> >>
> >>Hope this helps
> >>
> >>Doug Williams
> >>FLUIDYNE GASIFICATION
> >>
> >>
> >>-
> >>Gasification List Archives:
> >>http://www.crest.org/discussion/gasification/200202/
> >>
> >>Gasification List Moderator:
> >>Tom Reed, Biomass Energy Foundation, Reedtb2@cs.com
> >>www.webpan.com/BEF
> >>List-Post: <mailto:gasification@crest.org>
> >>List-Help: <mailto:gasification-help@crest.org>
> >>List-Unsubscribe: <mailto:gasification-unsubscribe@crest.org>
> >>List-Subscribe: <mailto:gasification-subscribe@crest.org>
> >>
> >>Sponsor the Gasification List: http://www.crest.org/discuss3.html
> >>-
> >>Other Gasification Events and Information:
> >>http://www.bioenergy2002.org
> >>http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> >>http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> >>http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> >Paul S. Anderson, Ph.D., Fulbright Prof. to Mozambique 8/99 - 7/00
> >Dept of Geography - Geology (Box 4400), Illinois State University
> >Normal, IL 61790-4400 Voice: 309-438-7360; FAX: 309-438-5310
> >E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders
> >
> >
> >-
> >Stoves List Archives and Website:
> >http://www.crest.org/discussion/stoves/200204/
> >http://crest.org/discussiongroups/resources/stoves/
> >>
> >Stoves List Moderators:
> >Ron Larson, ronallarson@qwest.net
> >Elsen L. Karstad, elk@wananchi.com www.chardust.com
> >>
> >List-Post: <mailto:stoves@crest.org>
> >List-Help: <mailto:stoves-help@crest.org>
> >List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> >List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >>
> >Sponsor the Stoves List: http://www.crest.org/discuss3.html
> >-
> >Other Biomass Stoves Events and Information:
> >http://www.bioenergy2002.org
> >http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> >http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> >http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >>
> >For information about CHAMBERS STOVES
> >>http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.ht
> m
> >
> >
>
> -
> Stoves List Archives and Website:
> http://www.crest.org/discussion/stoves/200204/
> http://crest.org/discussiongroups/resources/stoves/
> >
> Stoves List Moderators:
> Ron Larson, ronallarson@qwest.net
> Elsen L. Karstad, elk@wananchi.com www.chardust.com
> >
> List-Post: <mailto:stoves@crest.org>
> List-Help: <mailto:stoves-help@crest.org>
> List-Unsubscribe: <mailto:stoves-unsubscribe@crest.org>
> List-Subscribe: <mailto:stoves-subscribe@crest.org>
> >
> Sponsor the Stoves List: http://www.crest.org/discuss3.html
> -
> Other Biomass Stoves Events and Information:
> http://www.bioenergy2002.org
> http://www.crest.org/articles/static/1/1010424940_7.html Bioenergy
> http://www.crest.org/articles/static/1/1011975339_7.html Gasification
> http://www.crest.org/articles/static/1/1011975672_7.html Carbon
> >
> For information about CHAMBERS STOVES
> >http://www.repp.org/discussiongroups/resources/stoves/Chambers/Chambers.htm

From dstill at epud.net Tue Jun 18 20:04:09 2002
From: dstill at epud.net (Dean Still)
Date: Tue Aug 31 21:37:55 2004
Subject: Class Activities "Complete Rocketry"
Message-ID: <001301c21642$047c41e0$1d1d66ce@default>

Dear Friends,

Thought that it might be interesting for stovers to hear about the findings
of this Spring's two week stove class at Aprovecho. We've had a good time,
kept quite busy and report the following:

1.) Five outdoor tests of the three stone fire, after a lecture on
combustion in the open fire, resulted in an average of 23% efficiency. Pots
were large, ten to twelve inches in diameter, filled with 8,000 to 10,000
grams of water. Folks who want to, can do quite well using an open fire! (In
the field, most folks are not often this careful.) But, in the lab, we find
that admiring traditional technologies only helps to point out how to
improve further developments.

2.) We were asked by a group wanting to build stoves in Ecuador to design a
simple earthen stove with chimney that was as fuel efficient as possible.
Students, Jim Wilmes and Damon Ogle, helped to develop the design, build
prototypes and do the testing of the final stove. The students started with
Sam Baldwin's sheet metal cylinder around the fire cutting a five inch in
diameter fuel magazine hole near the base of the metal cylinder. A four inch
thick cylinder of earth was formed around the 1/2" lower sheet metal skirt
leaving a 3" annular air space between the parallel circular walls. The
sheet metal skirt surrounded the submerged pot leaving a 1/2" gap between
pot and sheet metal. The pot was supported five inches above the fire using
bent rebar...A 55 gallon drum lid fit on top of the earthen wall.

A tight hole cut in the lid allowed the pot to lower into the skirt until it
met the rebar pot support five inches above the fire. A chimney hole was cut
into the metal top as well opposite the arched entrance in the earthen wall
through which sticks enter the hole in the skirt. A hemispherical sheet
metal cone fills the gap between the holes in the sheet metal and earthen
cylinders and supports the earth above the arched opening. Hot flue gases
pass through the 1/2" space between the top of the skirt and the lid and
exit out of the chimney with gratifying speed... (I'll post a picture and
diagram soon.)

Tests show that this stove is 29% efficient. The 3 inches of trapped air
between the sheet metal and earthen wall acts as insulation. The six inch
high 1/2" annular gap between the pot and skirt creates a great chimney
above the fire, resulting in lots of draft. Smoke is removed by the chimney.
I think of this stove as one of the simplest Rocket stoves yet! We hope that
the design ideas are of some use to the team in Ecuador as they adapt local
input into a final design.

3.) Students created a new type of homemade insulative refractory brick by
replacing the sawdust in Ken Goyer's recipe ( two parts regular clay, one
part high fire clay, one part cement, four parts finely sifted sawdust) with
perlite. The bricks were fired in a brick kiln built by the students with
direction by Dr. Larry Winiarski. We plan to continue experiments with
pumice rock in place of combustible material.

4.) Students made five gallon Rocket stoves with three improvements: A.) a
sturdy sheet metal pot support in the shape of a railroad tie, B.) shelves
in the fuel magazine were lengthened toward the user and a support touching
the table top was added to keep the shelf level. C.) A hammer was used to
beat the top of the 5 gallon metal container into a bowl like shape which
helps keep the same cross sectional area beneath pots, assisting heat
transfer dramatically. Using ten to twelve inch pots and 8,000 to 10,000
grams of water these stoves scored an average of 38% efficiency.

5.) Students also helped Larry build his large wood fired agricultural dryer
which we plan to test soon. Lectures and group discussions usually preceded
building and testing designs.

The next one week stove training begins August 23 by which time Dean and
Larry and Ken will have recovered from this very active class!

Best,

Dean

From tombreed at attbi.com Wed Jun 19 01:57:40 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:55 2004
Subject: GAS-L: Fw: Chippers
Message-ID: <005101c2177c$2fd69210$0680fd0c@TOMBREED>

Dear All:

Being interested in chippy and chunky fuel for
gasifiers, I am naturally interested in chippers and chunkers.

Chippers, like pelletizers, are available
commercially, but can cost big $$$. Morbark (in Mich.) is a leader
in the field of whole tree chipping, and they make chippers from 4 inch diameter
to at least 20 inch, maybe more. Feed in a tree and 30 seconds later you
have chips. They are used commercially for paper making, so just buy
yourself a truck and chipper and you could supply ALL the biomass fuel needs of
any developing country.

On a smaller scale, there is a company, OLATHE in
Kansas City that I am very familiar with and they make horticultural
chippers.

Chunkers were developed by the U.S. Forest Service
in Houton Michigan and they make chunks several inches on a side. A cord
of wood takes a year to dry; a pile of chips never dries (air can't
circulate). A crib of chunks will dry in a month.

Be careful not to confuse chips with shards made by
a hammer mill pounding the wood to pieces. The chips have 37 degree (like
the beaver tooth) angles on both ends and are typically 1 inch X 3/4 inch by 1/4
inch. The shards are typically 3 inch by 1/2 inch by 1/2 inch.

If you REALLY want to know more about the latest in
this field, ask TOM MILES, our system moderator.

TOM
REED
BEF GASWORKS

From tombreed at attbi.com Wed Jun 19 02:27:52 2002
From: tombreed at attbi.com (Tom Reed)
Date: Tue Aug 31 21:37:55 2004
Subject: Please make new titles for new subjects
Message-ID: <009101c21780$6f5f1430$0680fd0c@TOMBREED>

Dear All:

Really now! Lately postings have been coming
through that have a title which refers to two or three steps backwards.

For those of us who keep track of the good
information flowing here, it is necessary (for the search engine) to have a
title that fits the subject.

PLEASE FIT...

Thanks,
TOM
REED
GASIFICATION MODERATOR

From psanders at ilstu.edu Mon Jun 24 05:05:25 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:55 2004
Subject: Shell (anyone)
Message-ID: <4.3.1.2.20020624160458.01c72100@mail.ilstu.edu>

Stovers,

Well, 2 full weeks after the announced sending of the results from the
first round of the Shell Foundation proposals, I have not received any
response.

Has anyone received a reply (either positive or negative) about their proposal?

The e-mail address that was given for contact was

sep@si.shell.com

I will let you know what I find out.

From robertoescardo at arnet.com.ar Wed Jun 26 22:45:56 2002
From: robertoescardo at arnet.com.ar (=?iso-8859-1?Q?Roberto_Escard=F3?=)
Date: Tue Aug 31 21:37:55 2004
Subject: Hy all!!
Message-ID: <008d01c21d84$f1c9d4a0$0100a8c0@pentium>

Hy
Stovers.
I was a “listener”
in the stoves list for some time; we (me and my group) are from now on full
participants.
A few words to
introduce my group, our project and myself. (We hope to have a web site running
in one or two months with more info)
Me: My name is
Roberto Escardó, 63, married for 35 years now, three children, all married, four
grand-children (Two pairs of female twins!!) I live in Buenos Aires, Argentina. I am
an Industrial Engineer, and my career was in Operations (manufacture,
construction), the last 15 years mainly as a Project Manager.
I was born and
raised in the Andean South (Patagonia) where I come back as frequently as
possible for trekking, horse riding and skiing.
Our group: Growing up!! A physician, (specialist in respiratory
diseases and epidemiology), an old (me) and two thirty-something engineers, one
Ph. D. (next week) in ecology, one Forest Engineer (The last two females), a
couple NGO´s interested in the protection of native forests. (The Patagonian
Andes forests are the only ones in temperate climate in the Southern
hemisphere), other people interested and ready to sign on.
Our project:
KUTRALDUM (Nice name: Kutraldum means “making fire” in mapundungun, the language
of Mapuche people)
Our mission: Made
available to the native and poor population in the Patagonian Andes efficient
wood stoves.
The Patagonian Andes
extends from Neuquen (38º S lat) to Ushuia (52º S lat), something like between
the south of Colorado to Calgary, in the Rockies, but in the southern
hemisphere: Same daylight, similar climate, a bit windier.
Some
facts:
1) Natives and poor
population (our objective) use three stones fires indoors for cocking, heating
and lighting. For some groups (mostly natives) wood is an abundant resource, for
others (urbanized poors) is scarce.
2) Respiratory
health is our main concern. We suspect IAP is similar to those measured in
Africa or India, but due to longer exposure times we have a greater risk of
COPD. We do not have strict epidemiological data, but available data confirms this
suspicion.
3) We must consider
both cocking and heating and solve, one way or other, the lighting aspect.
(Daylight in winter is less than eight hours and in winter 75% of time is
cloudy, > 6/8 of clouds) A wood gas light perhaps?
4) The Chilean
Patagonian Andes region has the same characteristics and the same native
population. We expect to work in collaboration with them.
We had done some
preliminary work: Some data collection and analysis, a pair of rockets stoves.
We are now concentrated in funding and plan to begin been “operational” in two
months.
END
NOTES:
1)
Thanks a lot to all Stovers, we have learned a lot just
browsing the list, and we are sure of your future help (A lot will be surely
asked)
2)
Special thanks to Dean Still for making available to us
Aprovecho literature, to Paul for her encouragement.
3)
A question: (candid answers requested) is my English easily
understood? (My sons speak English much better than me, I can made it corrected
if necessary)
4)
Second question: We are metric people: Do you bother if we
use only metric units or do you prefer we use English/American ones? (It is no
burden, I have a nice Java applet running in my PC capable of doing even the
most strangest unit conversions)
Yours
truly
Roberto E.
EscardóAraóz 2689 1425 Ciudad de Buenos AiresArgentinatel: +
54 11 4834 6190<A
href="mailto:robertoescardo@arnet.com.ar">robertoescardo@arnet.com.ar<?xml:namespace
prefix = o ns = "urn:schemas-microsoft-com:office:office"
/>

From ronallarson at qwest.net Thu Jun 27 08:28:28 2002
From: ronallarson at qwest.net (Ron Larson)
Date: Tue Aug 31 21:37:55 2004
Subject: Hy all!!
In-Reply-To: <008d01c21d84$f1c9d4a0$0100a8c0@pentium>
Message-ID: <005001c21dd4$1990fdc0$f2ee6541@ronallarson>

Roberto -

1. I am responding as the
nominal coordinator of "stoves" - and say on behalf of about 200 list members -
"welcome."

2. I have been quite
silent recently - having been out of town for the last three weeks and busy on
other topics as well. I will try to catch up and respond to other
interesting recent messages ASAP.

3. See more notes and
ideas below.
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
----- Original Message -----
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black">From:
<A href="mailto:robertoescardo@arnet.com.ar"
title=robertoescardo@arnet.com.ar>Roberto Escardó
To: <A href="mailto:stoves@crest.org"
title=stoves@crest.org>STOVES
Sent: Wednesday, June 26, 2002 8:47
PM
Subject: Hy all!!

Hy
Stovers.
I was a “listener”
in the stoves list for some time; we (me and my group) are from now on full
participants.
A few words to
introduce my group, our project and myself. (We hope to have a web site
running in one or two months with more info)

<snip here - but thanks for providing nice detail. I believe you are
the only list member in Argentina.>

3) We must
consider both cocking and heating and solve, one way or other, the lighting
aspect. (Daylight in winter is less than eight hours and in winter 75% of time
is cloudy, > 6/8 of clouds) A wood gas light perhaps?

 RWL4. We have had almost no discussion on this
list about lighting - I think demonstrating that we haven't tried enough and
that it is a difficult problem. Modern US stoves all (?) have a high
temperature ceramic "glass" to get some illumination out - but mostly to allow
a better view of the flames - for aesthetic reasons. Probably too
expensive for practical replacements for a 3-stone stove. I hope others
will suggest good options. Yours of using wood gas is well worth
pursuing - it has been mentioned by Tom Reed - but not integrated to any stove
that I am aware of.

 <snip>

3)
A question: (candid answers requested) is my English
easily understood? (My sons speak English much better than me, I can made it
corrected if necessary)

 (RWL): No problems for most of us, I am
sure. Not worth pointing out the small differences. (But "Paul" is
a masculine name.)

4)
Second question: We are metric people: Do you bother if we
use only metric units or do you prefer we use English/American ones? (It is no
burden, I have a nice Java applet running in my PC capable of doing even the
most strangest unit conversions)

(RWL): I personally try to use nothing but metric units and I
believe most list members try to do the same. Please do NOT yourself try
to return to "English" (American) units. Maybe you can help Americans
out of a terribly bad habit.

Yours
truly
Roberto E.
EscardóAraóz 2689 1425 Ciudad de Buenos AiresArgentinatel: +
54 11 4834 6190<A
href="mailto:robertoescardo@arnet.com.ar">robertoescardo@arnet.com.ar<?xml:namespace
prefix = o ns = "urn:schemas-microsoft-com:office:office"
/>

 (RWL): Again - Thanks for providing
this fine introduction. You have made some strong "stoves" connections
already and I assume will get more ideas - hopefully especially on
lighting. You will be helping a lot of us by asking questions
especially.

Ron

From dstill at epud.net Thu Jun 27 14:11:25 2002
From: dstill at epud.net (Dean Still)
Date: Tue Aug 31 21:37:55 2004
Subject: using excess air
Message-ID: <006701c21e9a$ed5eb900$281d66ce@default>

Dear Stovers,

Peter Scott who is presently teaching stove
design in South Africa commented on an interesting set of experiments performed
by Damon Ogle recently at the Aprovecho lab. We were playing around with Foseco
riser sleeves (Kalmin 64). We placed a type K thermocouple at one foot, two
foot, three foot and four foot intervals in a 4' high chimney made from the foot
high 5" in diameter riser sleeves placed on top of eachother. When we
started a fire at the bottom of the tube, there was about a 75 degree F
difference between all sensors, averaging around 1300F or so. But if the top
three riser sleeves were removed the temperature at the one foot level was
around 1600F. When we added the second sleeve at the two foot level the
temperature was around 1500. Adding the third decreased the exit temperature to
around 1400F and then down to 1300F or so when the fourth 12" high section
was added. The heat was not being absorbed by the riser sleeve but instead
excess air pulled into the fire by the increased draft of the taller chimneys
was dramatically lowering the exit temps. and internal chimney temps, as well.
Lower exit temperatures equals lower Delta T between heat and pot which results
in decreased efficiency.

Increasing internal chimney height above the fire is maybe the
easiest way to decrease emissions from the fire. A 24" high chimney
contains the fire for a longer time, no flames exit the top of the chimney. But
we have seen again and again how tall internal chimneys decrease heat transfer
efficiency, so the stove is less fuel efficient.

It would be nice to use the taller chimney but somehow use the
increased draft to a beneficial purpose. One approach is to decrease the gap
between pot skirt and pot when using taller internal chimneys. That seems perfectly reasonable to me but we are then using the gap as a
damper to reduce air flow. If there is an optimum rate of airflow which is
determined by highest temperatures hitting the pot combined with cleanest
emissions then the other common sense option to decrease air flow is to use a
smaller diameter fuel magazine.

But, there is perhaps a third best option. Larry Winiarski,
Damon Ogle and Jim Wilmes were not sure how exactly to do it but they'd like to
leave the increased airflow alone until it is slowed down by creating turbulence
in the fire. Creating a frenzied, jumpy fire like we see when using jets of air
from a fan, that used up the excess air at speed, would be a nice
trick.

Best,

Dean
<BLOCKQUOTE
style="BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: 5px">

From rmiranda at sdnnic.org.ni Thu Jun 27 18:37:37 2002
From: rmiranda at sdnnic.org.ni (Rogerio Miranda)
Date: Tue Aug 31 21:37:56 2004
Subject: KUTRALDUM
In-Reply-To: <008d01c21d84$f1c9d4a0$0100a8c0@pentium>
Message-ID: <3.0.5.32.20020627124418.01018cd0@205.218.248.130>

Hi Roberto:

Good to hear about your project. We have a similar project in Central
America called PROLEÑA, and our mission is to modernize the way people in
Honduras and Nicaragua use and produce wood energy.

Next month we are facing a new chalenge, since I will be moving to La Paz ,
Bolivia, where we also pretend to work in the same areas.

We have here in Managua a woodstove factory that produces about 100
Ecostoves per month in average. The Ecostove is based on the rocket stove
combustion system and uses a sealed system to pipe out all the smoke and
soot produced, resulting in nule indoor air pollution. You can see pictures
about the Ecostove on the stove list web site.

We have produced a low cost version of the ecostove, around 30US$ and that
is what I have in mind for the bolivian andes, as well.

I will be very interested in exchanging experiences with KUTRALDUM, and
perhaps we could visit you in Argentina some time, and vice-versa.

Best wishes

Rogerio Miranda

At 11:47 p.m. 26/06/02 -0300, Roberto Escardó wrote:
> Hy Stovers. I was a “listener” in the stoves list for some time; we
>(me and my group) are from now on full participants. A few words to
>introduce my group, our project and myself. (We hope to have a web site
>running in one or two months with more info) Me: My name is Roberto
>Escardó, 63, married for 35 years now, three children, all married, four
>grand-children (Two pairs of female twins!!) I live in Buenos Aires,
>Argentina. I am an Industrial Engineer, and my career was in Operations
>(manufacture, construction), the last 15 years mainly as a Project
>Manager. I was born and raised in the Andean South (Patagonia) where I
>come back as frequently as possible for trekking, horse riding and skiing.
>Our group: Growing up!! A physician, (specialist in respiratory diseases
>and epidemiology), an old (me) and two thirty-something engineers, one Ph.
>D. (next week) in ecology, one Forest Engineer (The last two females), a
>couple NGO´s interested in the protection of native forests. (The
>Patagonian Andes forests are the only ones in temperate climate in the
>Southern hemisphere), other people interested and ready to sign on. Our
>project: KUTRALDUM (Nice name: Kutraldum means “making fire” in
>mapundungun, the language of Mapuche people) Our mission: Made available
>to the native and poor population in the Patagonian Andes efficient wood
>stoves. The Patagonian Andes extends from Neuquen (38º S lat) to Ushuia
>(52º S lat), something like between the south of Colorado to Calgary, in
>the Rockies, but in the southern hemisphere: Same daylight, similar
>climate, a bit windier. Some facts: 1) Natives and poor population (our
>objective) use three stones fires indoors for cocking, heating and
>lighting. For some groups (mostly natives) wood is an abundant resource,
>for others (urbanized poors) is scarce. 2) Respiratory health is our
>main concern. We suspect IAP is similar to those measured in Africa or
>India, but due to longer exposure times we have a greater risk of COPD. We
>do not have strict epidemiological data, but available data confirms this
> suspicion. > 6/8 of clouds) A wood gas light perhaps? 4) The Chilean
>Patagonian Andes region has the same characteristics and the same native
>population. We expect to work in collaboration with them. We had done some
>preliminary work: Some data collection and analysis, a pair of rockets
>stoves. We are now concentrated in funding and plan to begin been
>“operational” in two months. END NOTES: 1) Thanks a lot to all
>Stovers, we have learned a lot just browsing the list, and we are sure of
>your future help (A lot will be surely asked) 2) Special thanks to
>Dean Still for making available to us Aprovecho literature, to Paul for
>her encouragement. 3) A question: (candid answers requested) is my
>English easily understood? (My sons speak English much better than me, I
>can made it corrected if necessary) 4) Second question: We are
>metric people: Do you bother if we use only metric units or do you prefer
>we use English/American ones? (It is no burden, I have a nice Java applet
>running in my PC capable of doing even the most strangest unit
>conversions) Yours truly Roberto E. Escardó
> 1425 Ciudad de Buenos Aires
>Argentina
> 6190
>robertoescardo@arnet.com.ar
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Rogério Carneiro de Miranda
Director, Ecofogones y Reposición Forestal
PROLEÑA/Nicaragua
Apartado Postal C-321
Managua, Nicaragua
TELEFAX (505) 249 0116
EMAIL: rmiranda@sdnnic.org.ni
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

From tmiles at trmiles.com Thu Jun 27 18:53:51 2002
From: tmiles at trmiles.com (Tom Miles)
Date: Tue Aug 31 21:37:56 2004
Subject: Prototype Ecuadorian earthen stove
Message-ID: <02ac01c21e2d$7daee250$6501a8c0@tommain>

See the Stoves page for a photo of a Prototype Ecuadorian earthen stove developed at the Aprovecho class
June 2002. Posted by Dean Still. Click the Photo for Dean's report on the
class.

<A
href="http://www.repp.org/discussiongroups/resources/stoves/">http://www.repp.org/discussiongroups/resources/stoves/

Tom Miles

From andrew.heggie at dtn.ntl.com Thu Jun 27 20:49:04 2002
From: andrew.heggie at dtn.ntl.com (AJH)
Date: Tue Aug 31 21:37:56 2004
Subject: using excess air
In-Reply-To: <006701c21e9a$ed5eb900$281d66ce@default>
Message-ID: <hlvmhug7fos4todvmq9jakraugak0blhic@4ax.com>

On Fri, 28 Jun 2002 04:56:34 -0700, "Dean Still" <dstill@epud.net>
wrote:

>
>But, there is perhaps a third best option. Larry Winiarski, Damon Ogle and Jim Wilmes were not sure how exactly to do it but they'd like to leave the increased airflow alone until it is slowed down by creating turbulence in the fire. Creating a frenzied, jumpy fire like we see when using jets of air from a fan, that used up the excess air at speed, would be a nice trick.

I concur with your analysis that given the same inlet conditions a
higher chimney will develop a higher depression at the inlet and thus
increase air supply.

Now, as excess air increases mass flow and decreases heat transfer,
you need to retune the inlet air to get back nearer to stoichiometric
conditions BUT as you now have higher draught you can convert some of
the power in the airflow to produce sufficient turbulence to both
increase residence time and reduce induction of excess air. The
classic way is to cause the incoming air to run counter current to the
flame, this provides mixing (turbulence) and consumes power to do so.

I wish I had met up with you when you were in London I could probably
have done a quick demo of this.

Now you are running with chimneys there is much more scope for better
combustion without recourse to fans.

I had meant to post on my steam aspirator, I have had it successfully
running but I feel like a poor version of Howard Hughes struggling to
get his spruce goose off the sea before an end to hostilities was
called (I believe his contract specified that), anyway whilst it
sustains combustion in a device that self extinguishes in the absence
of a fan, it needs much more fettling. In fact the steam content very
much modifies the flame, such that I do not think my monotube boiler
and nozzle are at all matched to the task. I have some jpegs I could
send.

I now think it would probably better suit when used to provide only
primary air or as an eductor. In essence I must be achieving very very
poor mass and power ratios on the aspirator, such that Ken Boak's
mechanical propeller could well have better conversion of the steam to
air motion.

BTW I have been following the thread on whether our little devices are
allowed to be termed gasifiers and (whilst interested in gasifiers) am
quite happy to let the purveyors of vapourware keep the term whilst
actual stoves that can be deployed in the field get designed and made.

AJH

From psanders at ilstu.edu Thu Jun 27 22:08:54 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:56 2004
Subject: Actual stoves using gasification Re: using excess air
In-Reply-To: <006701c21e9a$ed5eb900$281d66ce@default>
Message-ID: <4.3.1.2.20020627205556.018b6f00@mail.ilstu.edu>

At 11:03 PM 6/27/02 +0100, AJH wrote:
>snip...
>BTW I have been following the thread on whether our little devices are
>allowed to be termed gasifiers and (whilst interested in gasifiers) am
>quite happy to let the purveyors of vapourware keep the term whilst
>actual stoves that can be deployed in the field get designed and made.
>
>AJH

To Andrew (and others).

I am all smiles as I admit to being one of "the purveyors of
vapourware". I am glad that I can count on friendly and constructive
comments from the experts on the Stoves list as I (we) attempt to develop
an "actual stove" that is powered by gasification (AKA vapourware).

Note that I am NOT sending this message to the people on the Gasification
list serve mainly because the "chit chat" that we seem to enjoy with Stoves
is not evident in my short time on the Gasification list. But if Andrew's
and my comments leak out to them, perhaps they will be further motivated to
help develop "actual stoves" that utilize gasification. (I have 4
self-identified "gasifier people" who are not on Stoves list but have
indicated "small stove" interest. They are getting a copy.)

I will not ask for a definition of an "actual stove" but simply think of it
as being a useful stove that is sustainable (not donor subsidized) for many
people (at least 10,000) who are among the financially poor of this world.

From psanders at ilstu.edu Fri Jun 28 17:09:46 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:56 2004
Subject: Shell results
Message-ID: <4.3.1.2.20020628155249.01b3c830@mail.ilstu.edu>

Stovers (all of whom are my friends),

Let me be the first person to report the results of a proposal to the Shell
Foundation for the "Home Energy and Health" program.

The "Juntos Gasifier Stove...." proposal did not make it past this first
cut. They do not give much feedback (understandably because they had over
300 proposals). They did say that "It was felt that your project makes
a strong case for providing energy services and/or equipment. However, the
financing mechanism for service/product delivery is less developed." Shell
indicated that it wants geographic balance of the projects funded, and
pretty clear sustainability of the funded projects at the end of the 3 years.

Best wishes to those who are getting the invitation to continue with their
proposal. If you can see any link in which a small combustion chamber (as
is the Juntos gasifier) can be of POSSIBLE use to your project, please
contact me and I will supply inputs at no charge, and I might even do any
mutually agreed upon work at no charge.

I head to Africa on 4 July for 3 months. I just had to know the Shell
proposal results. So I sent an e-mail to the following address and
received a digital copy of their letter. I live in central USA, so
snail-mail delivery to me should be about as good as it gets (except for
those who live in Europe). I have no idea of when the actual letter will
arrive.

<SEP@si.shell.com>

By the way, I do have an approved US$10,000 grant from Rotary for
Gasifier/biomass stove work in southern Africa. I will be busy with stoves
work (plus my geography teaching work about maps). but on a more limited
budget than what Shell would have provided.

Again, best wishes to all of you who are still in the running. I hope
that you will keep the Stoves list serve informed. I believe that much
assistance for any project will come when people are openly discussing
their activities.

Sincerely,

From psanders at ilstu.edu Fri Jun 28 19:03:51 2002
From: psanders at ilstu.edu (Paul S. Anderson)
Date: Tue Aug 31 21:37:56 2004
Subject: GAS-L: Batch loaded gasifiers - small ones
Message-ID: <4.3.1.2.20020628175344.01b37210@mail.ilstu.edu>

Dear Gasifiers and Stovers,

My quite simple knowledge of gasifiers leaves me with some questions.

1. The Reed-Larson (1995) small gasifier stove and Tom Reed's "Wood-Gas
Campstove" (and what I am doing with the Juntos gasifier stoves) are "batch
loaded", not with continuous feed of the fuel. Are there in the commercial
world any batch loaded gasifiers? If yes, a few details of a web link
would be useful.

2. The above named small gasifiers drive off the gases and create
"char". Tom's stoves (combustion units) will then in a second phase burn
(consume) the char, leaving only ash. But Ron Larson and I like to remove
the batch of char, and then reload with fresh biomass fuel for more
gasification. Reasons: Ron wants to save char. I want to protect my
fragile stove from the "forge-like" heat of the burning of the
char. Question: What do the commercial gasifiers do about char
production? Do you consume it right on the spot, with either simultaneous
consumption of char while gasifying other fuel OR as a second phase of the
burning process? Or does anyone remove the char from the gasifier, and if
so, for what purposes?

Thanks in advance for your replies. I hope I hear from many on the
Gasifier list.

-
Gasification List Archives:
http://www.crest.org/discussion/gasification/200202/

From Carefreeland at aol.com Sat Jun 29 18:28:48 2002
From: Carefreeland at aol.com (Carefreeland@aol.com)
Date: Tue Aug 31 21:37:56 2004
Subject: using excess air
Message-ID: <46.29b38271.2a4f8e8f@aol.com>

Dean,
Early blastfurnaces in the hanging rock region of Ohio utilized
suction from a 30ft chimney, and the wind creating updraft over a
ridge(hill). The furnace was located at the base of a ridge, and the lift
from the venturi effect of the wind passing over the ridge would create a
powerful updraft. The air was drawn in from a high pressure area and
discharged in a lower pressure area.
These furnaces did not reach the high temperatures of the later steam
blasts, however the blast air was not preheated as much. The majority of the
blast effect was simple convection draw from a hot sandstone chimney and
burning hardwood char.
This system was developed over a thousand year period.
Dan Dimiduk

From jmdavies at xsinet.co.za Sun Jun 30 17:16:05 2002
From: jmdavies at xsinet.co.za (John Davies)
Date: Tue Aug 31 21:37:56 2004
Subject: GAS-L: Small Scale Gasifiers Defined
In-Reply-To: <4.3.1.2.20020626140200.0191f100@mail.ilstu.edu>
Message-ID: <066d01c2207a$1bb152a0$216a27c4@jmdavies>

Greetings to All,

I have been quietly listening recently without commenting. I find the
discussion on terminology quite puzzling.

1. Producer gas can only be manufactured in a gasifier, be it large or
small, stand alone or as a part of a cook stove.

2. When producer gas is burned, I can only consider it to be combustion, be
it large or small, stand alone or as a part of a cook stove.

In the railway world, the Argentinean locomotive engineer L D Porta called
the "Staged Gasification" or a "Close Coupled Gasifier" as adapted to steam
locomotives, " GAS PRODUCER COMBUSTION SYSTEM" or GPCS. This made it quite
clear that both processes were involved as opposed to straight combustion of
the fuel. Once again, I do not see any limitation to size in this
description.

I hope that this reference gives food for thought in the quest of finding a
suitable description for stoves using this process.

Regards,
John Davies.
Secunda,
South Africa.

> However, I must disagree with your conclusion. You wrote:
> Most lay people do not consider this close coupled system a gasifier.
> Therefore while we could call it "Staged Gasification" or a "Close Coupled
> Gasifier", we have elected to call it staged combustion.
>

BioEnergy Lists: Improved Biomass Cooking Stoves

June 2002 Biomass Cooking Stoves Archive