September 2003 Gasification Archive

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

+From dstill at EPUD.NET Mon Sep 1 01:46:44 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: Hayboxes again
Message-ID: <SUN.31.AUG.2003.224644.0700.DSTILL@EPUD.NET>

Dear Friends,

Bruce Stahlburg reminded us on ETHOS last week that the Haybox (an insulated
box that cooks with retained heat) achieves the best heat transfer
efficiency to the pot, dramatically increasing the effectiveness of cooking.
Bruce made the best Hayboxes that I've seen in Bolivia and he helps us
remember that this simple technology saves fuel and, because the fire is
used for a much shorter time, should help with emissions....I've been doing
a lot of experiments recently cooking one kilo of unsoaked pinto beans to
completion. Today I ran an experiment using the Haybox.

Here are the results:

A carefully tended three stone fire used an average of 1.8 kilos of oven
dried wood to cook a kilo of pinto beans in three tests. It took 40 minutes
to bring the beans and 5 litres of water to boil. Then the beans needed to
simmer for 90 minutes until soft. 812 grams of wood were used in the high
power phase. Simmering at around 98C required 1,032 grams of wood.

The Rocket stove used an average of 472 grams to bring the same amount of
water and beans to boil in 18 minutes. 614 grams of wood was used in the 90
minutes to complete the cooking task.

Using the Rocket stove/Haybox requires 4 litres water since there is less
evaporation. Bringing the water to boil and simmering the beans for 10
minutes used 490 grams of wood, today. Then I put the pot in the haybox.
Cooking took 28 minutes.

The Haybox/Rocket combination saved 1354 grams of wood compared to the open
fire and it saved one hour and forty minutes of time spent feeding the fire.
About 600 grams of wood were left unused by adding the Haybox to the Rocket
and again 90 minutes of the day were saved!

Cooking one kilo of dry pinto beans can be accomplished using about .5 kilo
of wood using one half hour of fire tending. Thanks Bruce for reminding me
how well the Haybox works!! I hope that we seriously consider a Haybox
project in places, like Mexico, where beans are cooked every day...

A Haybox is simple to design:

1.) needs R-7( well insulated) to cook beans
2.) the insulation has to be very light weight
3.) the box has to be as air tight as possible
4.) the insulation can't get wet from condensation
5.) test the Haybox by making sure that a pot full of water at 100C stays
above 95C for an hour or longer.
6.) a good Haybox does not require added hot mass to cook food.

All Best,

Dean

From tmiles at TRMILES.COM Mon Sep 1 00:06:52 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] Hayboxes again
Message-ID: <SUN.31.AUG.2003.210652.0700.TMILES@TRMILES.COM>

Dean,

What are they calling the haybox in Bolivia or Mexico? There is probably a
traditional equivalent.

Tom

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: "ethos" <ethos@vrac.iastate.edu>; <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, August 31, 2003 10:46 PM
Subject: [ethos] Hayboxes again

> Dear Friends,
>
> Bruce Stahlburg reminded us on ETHOS last week that the Haybox (an
insulated
> box that cooks with retained heat) achieves the best heat transfer
> efficiency to the pot, dramatically increasing the effectiveness of
cooking.
> Bruce made the best Hayboxes that I've seen in Bolivia and he helps us
> remember that this simple technology saves fuel and, because the fire is
> used for a much shorter time, should help with emissions....I've been
doing
> a lot of experiments recently cooking one kilo of unsoaked pinto beans to
> completion. Today I ran an experiment using the Haybox.
>
> Here are the results:
>
> A carefully tended three stone fire used an average of 1.8 kilos of oven
> dried wood to cook a kilo of pinto beans in three tests. It took 40
minutes
> to bring the beans and 5 litres of water to boil. Then the beans needed to
> simmer for 90 minutes until soft. 812 grams of wood were used in the high
> power phase. Simmering at around 98C required 1,032 grams of wood.
>
> The Rocket stove used an average of 472 grams to bring the same amount of
> water and beans to boil in 18 minutes. 614 grams of wood was used in the
90
> minutes to complete the cooking task.
>
> Using the Rocket stove/Haybox requires 4 litres water since there is less
> evaporation. Bringing the water to boil and simmering the beans for 10
> minutes used 490 grams of wood, today. Then I put the pot in the haybox.
> Cooking took 28 minutes.
>
> The Haybox/Rocket combination saved 1354 grams of wood compared to the
open
> fire and it saved one hour and forty minutes of time spent feeding the
fire.
> About 600 grams of wood were left unused by adding the Haybox to the
Rocket
> and again 90 minutes of the day were saved!
>
> Cooking one kilo of dry pinto beans can be accomplished using about .5
kilo
> of wood using one half hour of fire tending. Thanks Bruce for reminding me
> how well the Haybox works!! I hope that we seriously consider a Haybox
> project in places, like Mexico, where beans are cooked every day...
>
> A Haybox is simple to design:
>
> 1.) needs R-7( well insulated) to cook beans
> 2.) the insulation has to be very light weight
> 3.) the box has to be as air tight as possible
> 4.) the insulation can't get wet from condensation
> 5.) test the Haybox by making sure that a pot full of water at 100C stays
> above 95C for an hour or longer.
> 6.) a good Haybox does not require added hot mass to cook food.
>
>
> All Best,
>
> Dean
>
>
>
>
>

From dstill at EPUD.NET Mon Sep 1 06:01:45 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] Hayboxes again
Message-ID: <MON.1.SEP.2003.030145.0700.DSTILL@EPUD.NET>

Dear Tom,

In San Nicolas, BCS Mexico, where I lived for ten years, we called the
Haybox "La Caja Frijol"...

Best,

Dean

From tmiles at TRMILES.COM Mon Sep 1 14:12:02 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:35 2004
Subject: Fw: [ethos] Hayboxes again
Message-ID: <MON.1.SEP.2003.111202.0700.TMILES@TRMILES.COM>

----- Original Message -----
From: "AES" <aes@bitstream.net>
Sent: Monday, September 01, 2003 10:01 AM
Subject: Re: [ethos] Hayboxes again

> There are of course several names given to this techonology including
> haybox, fireless cooker, retained heat cooker. In Bolivia, we came up
with
> a Spanish translation of fireless cooker by calling it "Cocina Sin Fuego".
> Many of the participants in our projects also dubbed it the Magic Box
(Caja
> Magia) because of its mysterious ability to cook without fuel. Not sure
> what they call it in Mexico.
>
> I like this technology for several reasons not the least of which is the
> additional energy savings mentioned by Dean. It is easy to make, easy to
> use, can be made with local, cheap materials, and also saves time as it
does
> not have to be attended to. You can cook and be at the market in the same
> time.
>
> I recently put one together here in Minneapolis for demonstration purposes
> and it was, by all measures, not engineered perfectly. Made entirely of
> cardboard (no reflective material) put together for insulation and with
not
> a very tight fit. This model could have been improved yet still worked in
> cooking beans to perfection. My point is that this techonology is also
> fairly forgiving.
>
> In Bolivia, the ever talented Daniel Quispe made our "Cocina Sin Fuego"
with
> plywood, styrofoam and printing plates. Admittedly over engineered on our
> initial products it would keep food hot for hours. This model we sold in
> the market so it was painted and had a nice aesthetic look.
>
> This model was too expensive for the lower income population so for that
> model we used either cardboard/tinfoil or cardboard/tinfoil/lambs wool.
> Both worked beautifully. I have photos of each but decided not to send
them
> as the files may be too large for some. I can send them to anyone
> interested.
>
> Lastly, it seems like it would be easy to permanently build this
techonology
> into the kitchen. Next to the stove, consider a adobe or brick box for
the
> outer shell, then incorporate all the rules of a haybox cooker. It could
> even be part of a bench or seat. Beans go from the Rocket stove to the
> fireless cooker thus freeing up the space for another pot of food or to
heat
> water for coffee, washing, etc.
>
> Wilfred and I are on a committee to let us all ponder the ultimate goal of
> making less smoke and saving fuel. You can see with the various names of
> types of cookers that part of that work is coming up with the nomenclature
> so we all know what we are talking about. On a side note, in Bolivia a
> woman who used the Rocket Stove said to me that it should be called La
> Cocina de Poca Le?a (Little firewood cooker). That is what I called it
from
> that point after.
>
> Thanks to Dean for the testing of all these types of technologies. I have
> shown the refractory brick type Rocket Stove to several folks here in
> Minneapolis and they, as well as I, are truly amazed at how well it works.
> I just signed up for the conference in Boulder so will see you there.
>
> Perhaps more than you wanted to know,
>
> Bruce
>
> ----- Original Message -----
> From: "Tom Miles" <tmiles@trmiles.com>
> To: "Dean Still" <dstill@epud.net>; "ethos" <ethos@vrac.iastate.edu>;
> <STOVES@LISTSERV.REPP.ORG>
> Sent: Sunday, August 31, 2003 11:06 PM
> Subject: Re: [ethos] Hayboxes again
>
>
> > Dean,
> >
> > What are they calling the haybox in Bolivia or Mexico? There is probably
a
> > traditional equivalent.
> >
> > Tom
> >
> >
> > ----- Original Message -----
> > From: "Dean Still" <dstill@epud.net>
> > To: "ethos" <ethos@vrac.iastate.edu>; <STOVES@LISTSERV.REPP.ORG>
> > Sent: Sunday, August 31, 2003 10:46 PM
> > Subject: [ethos] Hayboxes again
> >
> >
> > > Dear Friends,
> > >
> > > Bruce Stahlburg reminded us on ETHOS last week that the Haybox (an
> > insulated
> > > box that cooks with retained heat) achieves the best heat transfer
> > > efficiency to the pot, dramatically increasing the effectiveness of
> > cooking.
> > > Bruce made the best Hayboxes that I've seen in Bolivia and he helps us
> > > remember that this simple technology saves fuel and, because the fire
is
> > > used for a much shorter time, should help with emissions....I've been
> > doing
> > > a lot of experiments recently cooking one kilo of unsoaked pinto beans
> to
> > > completion. Today I ran an experiment using the Haybox.
> > >
> > > Here are the results:
> > >
> > > A carefully tended three stone fire used an average of 1.8 kilos of
oven
> > > dried wood to cook a kilo of pinto beans in three tests. It took 40
> > minutes
> > > to bring the beans and 5 litres of water to boil. Then the beans
needed
> to
> > > simmer for 90 minutes until soft. 812 grams of wood were used in the
> high
> > > power phase. Simmering at around 98C required 1,032 grams of wood.
> > >
> > > The Rocket stove used an average of 472 grams to bring the same amount
> of
> > > water and beans to boil in 18 minutes. 614 grams of wood was used in
the
> > 90
> > > minutes to complete the cooking task.
> > >
> > > Using the Rocket stove/Haybox requires 4 litres water since there is
> less
> > > evaporation. Bringing the water to boil and simmering the beans for 10
> > > minutes used 490 grams of wood, today. Then I put the pot in the
haybox.
> > > Cooking took 28 minutes.
> > >
> > > The Haybox/Rocket combination saved 1354 grams of wood compared to the
> > open
> > > fire and it saved one hour and forty minutes of time spent feeding the
> > fire.
> > > About 600 grams of wood were left unused by adding the Haybox to the
> > Rocket
> > > and again 90 minutes of the day were saved!
> > >
> > > Cooking one kilo of dry pinto beans can be accomplished using about .5
> > kilo
> > > of wood using one half hour of fire tending. Thanks Bruce for
reminding
> me
> > > how well the Haybox works!! I hope that we seriously consider a Haybox
> > > project in places, like Mexico, where beans are cooked every day...
> > >
> > > A Haybox is simple to design:
> > >
> > > 1.) needs R-7( well insulated) to cook beans
> > > 2.) the insulation has to be very light weight
> > > 3.) the box has to be as air tight as possible
> > > 4.) the insulation can't get wet from condensation
> > > 5.) test the Haybox by making sure that a pot full of water at 100C
> stays
> > > above 95C for an hour or longer.
> > > 6.) a good Haybox does not require added hot mass to cook food.
> > >
> > >
> > > All Best,
> > >
> > > Dean
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>

From tmiles at TRMILES.COM Mon Sep 1 14:25:59 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:35 2004
Subject: CALL FOR VOLUNTEERS FOR DISCUSSION ABOUT LIST IMPROVEMENTS
Message-ID: <MON.1.SEP.2003.112559.0700.TMILES@TRMILES.COM>

Bioenergy List Participants

We've maintained the bioenergy lists on a mostly volunteer basis for almost 10 years. The lists and list software needs modification so that we can make the lists more responsive and more functionsl/

We're looking for volunteers who will join a discussion about improvements to the discussion lists at REPP. We're looking for people who have IT knowledge and in particular list server knowledge, to participate in discussions on how to fix the list deficiencies.

The first stage of volunteering is for discussion, brainstorming and problem solving only. From that pool of volunteers, once we have solutions, hopefully we can then get volunteers to implement the solutions.

If you are able and interested please send me an email at tmiles@trmiles.com

Thanks

Tom Miles

Bioenergy Lists Administrator

Discussion lists on REPP include:

BIOCONVERSION
The Bioconversion Discussion List (151 subscribers)
BIOENERGY
The Bioenergy Discussion List (433 subscribers)
DIGESTION
The Digestion Discussion List (297 subscribers)
GASIFICATION
The Gasification Discussion List (348 subscribers)
GREENBUILDING
The Greenbuilding Discussion List Managed by Buildinggreen.com (844 subscribers)
PVUSERS
The PV Users Discussion Group at REPP (188 subscribers)
STOVES
The Stoves Discussion List (216 subscribers)
STRAWBALE
The Strawbale Construction Discussion List at REPP.org (566 subscribers)
From aes at BITSTREAM.NET Mon Sep 1 19:06:51 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] Hayboxes again
Message-ID: <MON.1.SEP.2003.180651.0500.AES@BITSTREAM.NET>

Dean,

Did the Rocket Stove in this test you did have a skirt?

Just curious,

Bruce

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: "ethos" <ethos@vrac.iastate.edu>; <STOVES@LISTSERV.REPP.ORG>
Sent: Monday, September 01, 2003 12:46 AM
Subject: [ethos] Hayboxes again

From dstill at EPUD.NET Mon Sep 1 20:26:41 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] Hayboxes again
Message-ID: <MON.1.SEP.2003.172641.0700.DSTILL@EPUD.NET>

Dear Bruce,

The test was done using a pot sunken into a stove top with tight fit so the
smoke exits through an attached chimney. Forcing the heat to scrape against
the pot in the small gap dramatically increases heat transfer to the pot.

All Best,

Dean

From robertoescardo at ARNET.COM.AR Mon Sep 1 23:49:12 2003
From: robertoescardo at ARNET.COM.AR (=?iso-8859-1?Q?Roberto_Escard=F3?=)
Date: Tue Aug 10 18:30:35 2004
Subject: Turbo oven
Message-ID: <TUE.2.SEP.2003.004912.0300.ROBERTOESCARDO@ARNET.COM.AR>

Today I just catched the end of a CNN (in spanish) interview with Rene Nu?ez Suarez, an engineer from San Salvador who was showing his "turbo kitchen". All that I find about in a web search was a couple of news and a CV. As anyone heard about his "low temp combustion" ?

Roberto.

SAN SALVADOR - (Nov 2002) Salvadoran engineer Ren? N??ez-Su?rez received in New Delhi the individual prize of the Climate Technology Initiative (CTI) for the "turbo-oven", a process of low-temperature combustion that reduces greenhouse gas emissions, like carbon dioxide, associated with the burning of fuels.
The design entails a stainless steel cylinder with 10 air injectors, an internal ventilator and an air-regulating plate. With electricity and five 10-cm pieces of wood, it generates enough heat to cook meals three times a day.
The "turbo-oven" demonstrated a significant reduction in the consumption of wood compared to the traditional ovens based on fire alone. (What I see at CNN was a stove, not an oven)

From rmiranda at INET.COM.BR Tue Sep 2 07:15:01 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:35 2004
Subject: Turbo oven
In-Reply-To: <03be01c37106$19820640$0100a8c0@pentium>
Message-ID: <TUE.2.SEP.2003.081501.0300.RMIRANDA@INET.COM.BR>

Roberto: I did heard about it few years ago while in Nicaragua, but the
Rene apparently was very silent about it due property rights. Just
recently I found also an article which Tom Miles posted in the spanish
version of the stove site. Take a look there. rogerio

At 12:49 a.m. 02/09/03 -0300, Roberto Escard? wrote:
>Today I just catched the end of a CNN (in spanish) interview with Rene
>Nu?ez Suarez, an engineer from San Salvador who was showing his "turbo
>kitchen". All that I find about in a web search was a couple of news and a
>CV. As anyone heard about his "low temp combustion" ?
>
>Roberto.
>
>SAN SALVADOR - (Nov 2002) Salvadoran engineer Ren? N??ez-Su?rez received
>in New Delhi the individual prize of the Climate Technology Initiative
>(CTI) for the "turbo-oven", a process of low-temperature combustion that
>reduces greenhouse gas emissions, like carbon dioxide, associated with the
>burning of fuels.
>The design entails a stainless steel cylinder with 10 air injectors, an
>internal ventilator and an air-regulating plate. With electricity and five
>10-cm pieces of wood, it generates enough heat to cook meals three times a
>day.
>The "turbo-oven" demonstrated a significant reduction in the consumption
>of wood compared to the traditional ovens based on fire alone. (What I see
>at CNN was a stove, not an oven)

From dstill at EPUD.NET Wed Sep 3 02:07:03 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] matching firepower to pots
Message-ID: <TUE.2.SEP.2003.230703.0700.DSTILL@EPUD.NET>

Dear Stovers,

Help! We are trying to figure out how much firepower is needed in a stove designed to cook food in 100, 200, and 300 litre pots...Does anyone know how much wood needs to be burned per minute to deliver at say 30% heat transfer efficiency the optimum amount of heat to such big pots?

All Best,

Dean

From dstill at EPUD.NET Thu Sep 4 02:15:27 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: Fw: [ethos] matching firepower to pots
Message-ID: <WED.3.SEP.2003.231527.0700.DSTILL@EPUD.NET>

Dear Stovers,

From stoves at ECOHARMONY.COM Wed Sep 3 11:49:29 2003
From: stoves at ECOHARMONY.COM (Grant Ballard-Tremeer)
Date: Tue Aug 10 18:30:35 2004
Subject: [ethos] matching firepower to pots
In-Reply-To: <002e01c371e1$bb42bfc0$df1e6c0c@default>
Message-ID: <WED.3.SEP.2003.164929.0100.STOVES@ECOHARMONY.COM>

On Wednesday 03 September 2003 7:07 am, Dean Still wrote:
> Help! We are trying to figure out how much firepower is needed in a stove
> designed to cook food in 100, 200, and 300 litre pots...Does anyone know
> how much wood needs to be burned per minute to deliver at say 30% heat
> transfer efficiency the optimum amount of heat to such big pots?

Dean,

REDI (http://home.worldcom.ch/redi/) have a kerosene burner for institutional
kitchens of 18.5 kW, 45% fuel efficiency, suitable for 150-200 litre pots. It
should be fairly easy to work out typical wood burn rates from that.

Hope this helps

Grant

--
Grant Ballard-Tremeer PhD, CEng, MIMechE
Visit Eco on the web at http://ecoharmony.com
HEDON Household Energy Network http://hedon.info
SPARKNET Knowledge Network in Southern and East Africa
http://sparknet.info
-------------------

From psanders at ILSTU.EDU Wed Sep 3 13:47:07 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:35 2004
Subject: Useful stoves contacts such as REDI
In-Reply-To: <200309031649.29292.stoves@ecoharmony.com>
Message-ID: <WED.3.SEP.2003.124707.0500.PSANDERS@ILSTU.EDU>

Stovers,

My question relates to the probably-many others who work on stoves and are
unknown (or little known) to us. One example is REDI:

>At 04:49 PM 9/3/03 +0100, Grant Ballard-Tremeer wrote:

>REDI (http://home.worldcom.ch/redi/) have a kerosene burner for institutional
>kitchens of 18.5 kW, 45% fuel efficiency, suitable for 150-200 litre pots.

That was the first time I had heard of REDI. I visited the website and was
VERY pleased with what I saw and read about their stoves.

But why have I (we) heard so little about REDI and probably
others? Perhaps nobody from those groups has anyone reading the Stoves
List Serve messages.

Are there others working on stoves unknown to us? Any leads? Is the
stoves community too fragmented? Do we actually have contact via the
various networks such as Grant's HEDON and A.D. Karve's ARTI and the
southeast Asia group and ETHOS and other groups?

I doubt that we do have sufficient contact.

Comments and "solutions" are requested.

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 stoves at ECOHARMONY.COM Wed Sep 3 15:10:21 2003
From: stoves at ECOHARMONY.COM (Grant Ballard-Tremeer)
Date: Tue Aug 10 18:30:35 2004
Subject: Useful stoves contacts such as REDI
In-Reply-To: <4.3.1.2.20030903123518.01ca6b70@mail.ilstu.edu>
Message-ID: <WED.3.SEP.2003.201021.0100.STOVES@ECOHARMONY.COM>

On Wednesday 03 September 2003 6:47 pm, Paul S. Anderson wrote:
> Are there others working on stoves unknown to us? Any leads? Is the
> stoves community too fragmented? Do we actually have contact via the
> various networks such as Grant's HEDON and A.D. Karve's ARTI and the
> southeast Asia group and ETHOS and other groups?

Yes, in my opinion too fragmented, but many of us are working to overcome
these - including the good folks of REPP Stoves list... The ITDG Boiling
Point journal (http://www.itdg.org/html/energy/boilingpoint.htm) address list
covering thousands, and even that - I believe - is only the tip of the
iceberg!

> Comments and "solutions" are requested.

More (much more) of the same in my opinion. Paul, you are one of the best
stove evangelists... Keep it up!

Regards
Grant

PS. REDI were one of the founding members of HEDON Household Energy Network -
see http://www.hedon.info/whonwot.php

From crispin at NEWDAWN.SZ Wed Sep 3 17:49:22 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:35 2004
Subject: matching firepower to pots
Message-ID: <WED.3.SEP.2003.234922.0200.CRISPIN@NEWDAWN.SZ>

Dear Dean

I have been making a 330 litre 'industrial' wood fired pot for dyeing
operations (handicraft) for some years. It may be relevant. We claim a
nominal power of 30 kw but it might be as much as

It is wood-fired (non-pine usually) and has a grate measuring 750mm long,
150mm wide and 350mm deep. There is ample air supplied from below (to let
the ash fall down) and standard Tsotso-type preheating of secondary air fed
in through the sides.

This means that the grate sides, which are perforated with 12.5mm holes, are
enclosed on the outside by a stainless steel sheet (3mm 3CR12) at an angle
of, I would guess, 10-15 degrees. Cold air rises up the gap between the
outside sheet and grate wall, and enters the fire through the holes
(pre-heated secondary air).

Now it is difficult to know what the wood mass is at any time in it, but
they re-fill the grate (add more, rather than fill an empty grate) about
every 45-60 minutes. It is used to boil a large rectangular tank with a
capacity of 330 litres, which is almost never nearly full - perhaps 200
litres at a time. For food it might be a reasonable equivalent. Food needs
less heat than water as it burns on the outside if it is porridge-like
(can't conduct heat as well as water).

I am sorry to not be able to report an accurate efficiency to you on the
whole system, but it cut their wood consumption by a factor of 6 compared
with open fires with large logs on it boiling half-drums.

From tmiles at TRMILES.COM Wed Sep 3 23:55:11 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:35 2004
Subject: IEA Bioenergy Task29 - educational web site on biomass and
bioenergy
Message-ID: <WED.3.SEP.2003.205511.0700.TMILES@TRMILES.COM>

Velimir,

Biomass education is important and difficult work. Congratulations to IEA
Task 29 members for taking it on. I hope that everyone visits your draft
site at http://www.task29.epsilon.hr and comments. I have a couple of
observations and questions that may help you in developing the site:

1. Will the site be multilingual?
2. Who is the target audience? It is difficult to tell whether it is aimed
at adults or school children.
3. Do you have an estimate or definition of what the market or user of the
site will be?
4. How will your audience find the site?
5. Does your intended audience use the WWW for instructional purposes?
6. How will you measure or test the effectiveness or use of the site?
7. Will the site contents be available via CD or pdf for use in the
classroom?
8. Will there be instructional materials for teachers?
9. Will you include biomass use in cooking stoves which is the largest
consumer of biomass in quantity and in numbers of people around the world?
See http://www.repp.org/discussiongroups/resources/stoves/
10. Will you be showing comparisons with fossil fuels for each of the
biomass examples?

Kind regards,

Tom Miles
T R Miles Technical Consultants
Portland, OR
tmiles@trmiles.com
www.trmiles.com

Posted to Bioenergy@listserv.repp.org

> On Wed, 3 Sep 2003 11:28:12 +0200, Velimir Segon <vsegon@EIHP.HR> wrote:
>
> >Dear participants of the discussion list,
> >
> >IEA Bioenergy Task 29: Socio-economic drivers in implementing bioenergy
> >systems focuses its work very much on bioenergy education and promotion.
> >As one of the main activities within the task, we have developed an
> >educational website (still a draft) which can be visited at
> >www.task29.epsilon.hr . The intention is, apart of being a useful source
> >of information, the web site is meant to provide interactive learning
> >(see tools). Moreover, the web is also planned to be used as a tool to
> >generate a book in FAQ format. All reasonable questions and answers from
> >'ask-the-experts' will be stored in database and will be used to produce
> >a book entitled 'Frequently asked questions about biomass and
> >bioenergy'.
> >
> >I would like to kindly ask you to visit the web and forward the web
> >address to anyone you think might be interested, and send us any
> >comments and suggestions for improvement.
> >
> >
> >Best regards,
> >
> >Velimir Segon, M.Sc.
> >Researcher - BIOEN programme
> >Energy Institute 'Hrvoje Pozar'
> >Savska c. 163
> >10000 Zagreb
> >Croatia
> >
> >Tel: +385 1 6326 158
> >Fax: +385 1 6040 599
>

From jeff.forssell at CFL.SE Thu Sep 4 03:48:47 2003
From: jeff.forssell at CFL.SE (Jeff Forssell)
Date: Tue Aug 10 18:30:35 2004
Subject: IEA Bioenergy Task29 - educational web site on biomass and
bioenergy
Message-ID: <THU.4.SEP.2003.094847.0200.JEFF.FORSSELL@CFL.SE>

Unfortunately there's no mailadress to the person seeking feedback on the site.

One thing I like to check about sites is how will be be for a user that doesn't have a giant monitor.

If I go in with my 1024*768 screen it is completely filled.

"Gibble listed the two most popular screen resolutions...
800x600 - 47%
1024x768 - 46% "

Don't know who Gibble is or when that investigation was made but I'm sure that many of the people that site should want to reach will have small monitors, which means that about 30% of each page will have to be right-scrolled to reach =Terrible.

The layout dictators that made the site have also decided that everyone should have (besides giant screens) excellent eyesight so that you aren't allowed to increase the text size (for visibility) or decrease to fit into your screen (or printout). An intelligent css layout using ems rather than pixel size can make a layout size follow the size of the font (which you should never fix!)

Navigational alternatives could be better implemented. (tabbing not always possible because of javascripts without real functional value, accesskeys nonexistant {but that?s something the few sites have discovered}) Some links are just a tiny "<" or ">". No wonder so many colleagues are carrying their mouse arm in a sling!

Shockwave usage- Shockwave can produce some very nice instructional material and be quite compact. But it would be good it as much as possible is presented in simpler form. Boardband Internet is not available everywhere and especially where the needs are greatest. Consideration of that factor must influence choices of how to present material. (If possible with alternatives so broadband users can access good material, even if everybody can't.

How is "our" site?
http://www.repp.org/discussiongroups/resources/stoves/
It is more flexible: you can change font sizes.

On the opening page the only thing that makes it "too big" for 800*600 is that ther is a wide picture in the first column
http://www.repp.org/discussiongroups/resources/stoves/Oneil/nicaragua/riobravo.jpg
which is 400 px wide. I think it would be good to diminish or crop it to about 270.

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

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

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

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

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

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

> -----Original Message-----
> From: Tom Miles [mailto:tmiles@TRMILES.COM]
> Sent: Thursday, September 04, 2003 5:55 AM
> To: STOVES@LISTSERV.REPP.ORG
> Subject: Re: [STOVES] IEA Bioenergy Task29 - educational web site on
> biomass and bioenergy
>
>
> Velimir,
>
> Biomass education is important and difficult work.
> Congratulations to IEA
> Task 29 members for taking it on. I hope that everyone visits
> your draft
> site at http://www.task29.epsilon.hr and comments. I have a couple of
> observations and questions that may help you in developing the site:
>
> 1. Will the site be multilingual?
> 2. Who is the target audience? It is difficult to tell
> whether it is aimed
> at adults or school children.
> 3. Do you have an estimate or definition of what the market
> or user of the
> site will be?
> 4. How will your audience find the site?
> 5. Does your intended audience use the WWW for instructional purposes?
> 6. How will you measure or test the effectiveness or use of the site?
> 7. Will the site contents be available via CD or pdf for use in the
> classroom?
> 8. Will there be instructional materials for teachers?
> 9. Will you include biomass use in cooking stoves which is the largest
> consumer of biomass in quantity and in numbers of people
> around the world?
> See http://www.repp.org/discussiongroups/resources/stoves/
> 10. Will you be showing comparisons with fossil fuels for each of the
> biomass examples?
>
> Kind regards,
>
> Tom Miles
> T R Miles Technical Consultants
> Portland, OR
> tmiles@trmiles.com
> www.trmiles.com
>
> Posted to Bioenergy@listserv.repp.org
>
>
> > On Wed, 3 Sep 2003 11:28:12 +0200, Velimir Segon
> <vsegon@EIHP.HR> wrote:
> >
> > >Dear participants of the discussion list,
> > >
> > >IEA Bioenergy Task 29: Socio-economic drivers in
> implementing bioenergy
> > >systems focuses its work very much on bioenergy education
> and promotion.
> > >As one of the main activities within the task, we have developed an
> > >educational website (still a draft) which can be visited at
> > >www.task29.epsilon.hr . The intention is, apart of being a
> useful source
> > >of information, the web site is meant to provide
> interactive learning
> > >(see tools). Moreover, the web is also planned to be used
> as a tool to
> > >generate a book in FAQ format. All reasonable questions
> and answers from
> > >'ask-the-experts' will be stored in database and will be
> used to produce
> > >a book entitled 'Frequently asked questions about biomass and
> > >bioenergy'.
> > >
> > >I would like to kindly ask you to visit the web and forward the web
> > >address to anyone you think might be interested, and send us any
> > >comments and suggestions for improvement.
> > >
> > >
> > >Best regards,
> > >
> > >Velimir Segon, M.Sc.
> > >Researcher - BIOEN programme
> > >Energy Institute 'Hrvoje Pozar'
> > >Savska c. 163
> > >10000 Zagreb
> > >Croatia
> > >
> > >Tel: +385 1 6326 158
> > >Fax: +385 1 6040 599
> >
>

From tombreed at COMCAST.NET Thu Sep 4 05:28:12 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:35 2004
Subject: Reflective insulation
Message-ID: <THU.4.SEP.2003.032812.0600.TOMBREED@COMCAST.NET>

Dear Dean and all:

Insulation can work in two ways - by slowing the conduction of heat or by
stopping radiation of heat by reflecting the heat back to the source. The
second method is best where it can be employed. The radiation heat loss
increases as T^4 power, while conduction is only T^1 power, so reflective
insulation is particularly important in furnace design.
~~~~~~~~~~~
The simplest example of both is the thermos bottle. There is a vacuum
between the inner and outer glass to prevent CONDUCTION of heat through the
gas. There is a layer of silver on the inside of the glass to prevent
RADIATION.
~~~~~~~~~~~~~
While at MIT I developed a TRANSPARENT furnace that uses a layer of gold on
a Pyrex sleeve to reflect the heat back into the furnace. The gold is only
200 atoms thick so costs < $1 and the gold is transparent in the visible
region of the spectrum, but >99% reflective in the IR. See for instance

http://www.thermcraftinc.com/transtemp-furnaces.html

Our company, Transept sold these furnaces for 25 years and I received ~
$50,000 in royalties over that period. (MIT gave its inventors 5% of
royalties, industry gives nothing.) Now the company has been sold to others
and Bill King, President, is retired.

~~~~~~~~~~
There are many ways to stop radiation heat loss.

I was head of the crystal growth department at MIT (Lincoln Labs) and
developed many high temperature furnaces. One of the highest used similar
principles.

A tungsten heating element can achieve temperatures > 2500 C (4500 F), but
must be well insulated. We wrapped a 6 cm diameter by 10 cm high tungsten
element in a coil of ~10 layers of embossed tantalum foil. The embossing
kept contact between successive layers to a minimum.
~~~~~~~
So I would urge all of you to consider wrinkled foil as an insulation where
you can \keep it clean and where temperatures don't exceed the MP of
aluminum (~600 C).

Onward!

TOM REED BEF STOVEWORKS

Silver is the best IR reflector, Gold is one of the best, but aluminum foil
also have a very high reflectance.
Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: "ethos" <ethos@vrac.iastate.edu>
Sent: Tuesday, August 26, 2003 1:39 PM
Subject: [ethos] insulation

> Dear ETHOS:
>
> Lanny Hensen shares a great recipe for use in places where aluminum foil
> won't burn up...less than 700F, I think...
>
> I plan to add more plies of insulation to the inner
> sleeve which will be aluminum foil with sawdust and sugar water (all
common
> materials) wrapped in about 6 plies to build up about 1/2". The sawdust
and
> sugar burn to make a crusty spacer to keep the aluminum foil from touching
> itself. The aluminum foil is a good air barrier to block conduction,
> convection. I tried
> it on a camp stove, seems to work. This insulating method cheap, simple
and
> uses common materials if it proves to work.
>
> Peter Scott writes from Uganda:
>
> Just a couple of words. So I found my dream accomplice. This guy named
> George Sizoomu. He has been building stoves for years and he has already
> perfected an insulated brick in Uganda . 1 part rock dust , 1 part normal
> clay, 1 part kaolin and 1 part fine sawdust by weight. Works out to 4
parts
> sawdust , 1 part other by volume. incredibly light!We fired a couple of 6
> brick stoves using his mix and ours.
>
> Details to follow...By the way, I count 12 folks from ETHOS going to the
> conference in Boulder!
>
> All Best,
>
> Dean
>
>

From tombreed at COMCAST.NET Thu Sep 4 05:35:55 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:35 2004
Subject: Drying Formed Clay Shapes
Message-ID: <THU.4.SEP.2003.033555.0600.TOMBREED@COMCAST.NET>

Dear Richard and all:

You can also slow drying by putting object in icebox (also good for slow
drying wood). Maybe in the freezer, though possibly the tiny ice crystals
would help or hurt the process. (I hope someone experiments with
freeze/drying clays.)
Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Richard Boyt" <rdboyt@YAHOO.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, August 26, 2003 8:05 PM
Subject: [STOVES] Ceramics For Stoves: Drying Formed Clay Shapes

> Ceramics For Stoves: Drying Formed Clay Shapes
>
> Stovers:
>
> Just how and why does plastic clay change as it dries? I know just enough
to know that I don't know very much.
>
> Books tell me that tiny particles of clay are a bit like playing cards. In
a loose scattered stack, these platelets interlace and, if lubricated with
water, easily slide over each other. This is why clay can take and hold most
any shape you give it. This property is generally called "plasticity". Dry
the clay by removing the water, and the particles can no longer slide. The
drying clay now becomes hard and rigid, and loses its plasticity. Tests I
have recently made indicate that clay shrinks quite steadily as it dries. As
long as it retains its plasticity, rapid uneven drying does not present a
serious problem. However, as the clay loses plasticity, care must be taken
to dry it evenly, to prevent shrinkage stresses that can cause fractures in
the clay to occur. As long as all portions of the clay remain plastic, you
can safely air dry. Drying evenly usually means slow drying. This is
particularly important if an object made of clay has great differences in
thickness. Outside!
> surfaces
> tend to dry faster than inside surfaces. Thin sections tend to dry more
quickly than thick sections. Top surfaces tend to dry faster than bottoms.
>
> If you want to dry clay evenly, it is hard to beat putting it inside a
polyethylene plastic grocery bag with just a bit of an opening at the top, w
ell above the top of the clay. As water evaporates from the surface of the
clay, it cools and dampens the air in the bag surrounding the clay. The cool
damp air sinks, filling the plastic bag. The slightly open top permits a
very slow air exchange with warmer, drier outside air, and so the clay dries
and shrinks slowly, evenly, and thus with minimal stress. After the clay has
dried enough to loose plasticity, and to change to a lighter color, you can
usually finish drying it in the open air.
>
> So just how long should it take to dry a clay shape? It depends upon the
size, the shape, and the thickness of the clay object. The temperature and
humidity of the air, the openness (porosity) of the clay, the size and
position of the hole at the top of the plastic bag, and just how much water
the clay holds. How do you know when its dry? The most obvious clue is when
it becomes hard enough to resist a fingernail impression, and it changes
color, usually becoming a lighter shade. A typical coffee cup shape might
safely dry in a day or two. A 3" diameter solid clay ball might take a week
or two.
>
> If, in spite of all your efforts, for whatever reason, your clay fails, as
long as it hasn't been fired, you can reclaim it by re-mixing with water,
and start over.
>
>
>
> Good luck!
>
> Dick Boyt
>
>
>
> ---------------------------------
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free, easy-to-use web site design software
>

From jeff.forssell at CFL.SE Thu Sep 4 07:22:08 2003
From: jeff.forssell at CFL.SE (Jeff Forssell)
Date: Tue Aug 10 18:30:35 2004
Subject: Reflective insulation
Message-ID: <THU.4.SEP.2003.132208.0200.JEFF.FORSSELL@CFL.SE>

> While at MIT I developed a TRANSPARENT furnace that uses a
> layer of gold on
> a Pyrex sleeve to reflect the heat back into the furnace.
> The gold is only
> 200 atoms thick so costs < $1 and the gold is transparent in
> the visible
> region of the spectrum, but >99% reflective in the IR. See
> for instance
>
> http://www.thermcraftinc.com/transtemp-furnaces.html

If I check the site I find:
****
What about the gold mirror as insulation? How thick is the gold film?

From crispin at NEWDAWN.SZ Thu Sep 4 09:12:56 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:35 2004
Subject: Reflective insulation
Message-ID: <THU.4.SEP.2003.151256.0200.CRISPIN@NEWDAWN.SZ>

Dear Jeff

>From our estimate of the amount of gold deposited, ... would look
>like a series of gold islands with open spaces between islands.
>The heavier the film, the less space between the gold islands.
>
>It sounds strange that a layer way over 200 atoms would be so unconnected.

Gold tends to grow metal crystals so the 'islands' are expectable (high
affinity for itself). I understand that the nuggets in the rivers of both
South America and the Yukon actually grew in the same way from gold
atoms/molecules washing along the stream in the water.

Once the gaps between the islands is less than 1/4 of the wavelength of the
incident radiation, it should reflect quite well. In the case of the high
temperature ovens, the infra-red radiation (or most of it) was well below
the maximum reflecting frequency and got bounced whereas visible light (or
the higher end of it) could pass right through.

I am pretty sure the solar heating film works the same way: the visible
light and ultra-violet passes through into the house, hits something and is
converted to infra-red, then can't get out again. Any conductive/magnetic
grid or pattern of spots should give the same result.

Regards
Crispin

From crispin at NEWDAWN.SZ Thu Sep 4 08:50:42 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:35 2004
Subject: Reflective insulation
Message-ID: <THU.4.SEP.2003.145042.0200.CRISPIN@NEWDAWN.SZ>

Dear Tom

FIRST

>...Gold is one of the best, but aluminum foil also have a very high
reflectance.

Is there some reason why aluminum foil is not used more in Solar cookers? I
am mystified why something so cheap and available is not used on a
replaceable basis.

I take it from your description that reflecting heat would not be different,
or not substantially different, from reflecting the broad spectrum of normal
solar insolation.

I see people using anodized polished aluminum with a claimed 99%
reflectivity, at something like $6.50 a square metre (cost). It does resist
scratches quite well (surprisingly well) but for the money, it can be a lot
bigger and have replaceable foil stuck to it with a large net gain in power.
Commercial solar cookers are unaffordable.

Perhaps this is not mystical, people are just keen on high tech materials.

SECOND...

What is the reflectivity comparison between a 99% material and aluminum foil
when the incident angle of incoming radiation is not normal to the surface?

Can't I get a high reflectivity by taking a lower quality material like the
foil and get high performance at, say, 45 degrees? As-rolled stainless
steel is very reflective at a low angle.

Thanks!
Crispin

From rdboyt at YAHOO.COM Thu Sep 4 10:44:24 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:35 2004
Subject: Fwd: Ceramics for Stoves: Making Samples for Testing, Part 5A
Message-ID: <THU.4.SEP.2003.074424.0700.RDBOYT@YAHOO.COM>

Ceramics for Stoves: Making Samples for Testing, Part 5A

After a number of attempts to find an ideal shape for testing the properties of a locally found clay, I have come upon one that looks promising. It is a disk 1 cm thick and 7.2 cm in diameter. This odd diameter was determined by a tin can I chose to use as a cookie-cutter. With it, I cut numerous circular disks from a 1 cm thick slab of moldably plastic clay rolled out with a rolling pin supported at its ends by two 24cm long by 1 cm thick metal supports. In this way, I can cut many uniform disks quickly and efficiently, each with a volume of 40.7 cc and a top and bottom surface area of 40.7 square cm.

To make the cookie cutter, I cut out both ends of the tin can. The can top was cut out in the usual manner, but the bottom was cut by slanting the can opener as it cut so that it also removed the thick ring of metal surrounding the bottom. The now-sharp bottom end of the can was then filed to remove any burr that would catch and hold the clay and so make the disk difficult to remove. A bottle slightly smaller in diameter than the tin can was used to push the clay disk down and out of the can. I marked each side of the disk with an identifying number and with six short, shallow, thin marks across its diameter. These marks were made 1 cm apart so that I could later determine the shrinkage of the disk as it dries. By weighing each disk as I measure it, I could figure the relationship between drying and shrinking. A graph of this shows a slightly curved downsloping line that indicates that the rate of shrinkage slows slightly as weight loss due to drying progresses.

Even though you turn the disks over frequently as they dry, it is difficult to keep them flat. Whichever surface is on the top tends to dry (and shrink) faster, and so the edges curl upwards. This is the reason for marking both sides and then averaging the shrinkage measurements as the disk dries.

I made the disks and dried them in sets of ten, so that I could test individual disks for various properties as I heated them to different temperatures in a kiln. This allows me to test different clay mixes for strength, plasticity, porosity, shrinkage, weight, thermal shock resistance, heat transfer, specific gravity, abrasion resistance, and maybe some other properties that I invite you to suggest.

I use a drop test to measure plasticity, a digital scale to measure weight, a metric ruler to measure length, a small electric kiln to fire the disks to various temperatures, scales to measure force required to break, submersion in water to measure porosity, a propane torch to measure thermal shock resistance and heat transfer, and a silicon carbide grindstone to measure abrasion resistance.

I invite ideas on how to better set up these and other tests that you think might prove useful. It all takes time, but should help make decisions as I add non-clay materials to the clay to obtain desirable properties that would prove useful in designing ceramic components for stoves. I've made a drawing that I can send to anyone interested.

Dick Boyt

---------------------------------
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software

From pippo at IMRE.OC.UH.CU Thu Sep 4 14:20:26 2003
From: pippo at IMRE.OC.UH.CU (Dr. Walfrido Alonso Pippo)
Date: Tue Aug 10 18:30:35 2004
Subject: Unsubscribe
In-Reply-To: <4.3.1.2.20030903123518.01ca6b70@mail.ilstu.edu>
Message-ID: <THU.4.SEP.2003.142026.0400.PIPPO@IMRE.OC.UH.CU>

--
-------------------------------------------------------------------------
Dr. Walfrido Alonso Pippo
Instituto de Materiales y Reactivos.Universidad de La Habana
Zapata y G. Vedado. 10400 Ciudad de La Habana. Cuba
Telf: (53-7) 70 5707 FAX: (53-7) 794651
E-Mail: pippo@imre.oc.uh.cu
-------------------------------------------------------------------------

From psanders at ILSTU.EDU Thu Sep 4 14:56:35 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:35 2004
Subject: Haybox & hotbag and reflective insulation
In-Reply-To: <01ac01c372c6$dc7349e0$b5affd0c@TOMBREED>
Message-ID: <THU.4.SEP.2003.135635.0500.PSANDERS@ILSTU.EDU>

Stovers,

At a stoves conference in South Africa (March 2003, I believe), several of
us (Crispin, John Davies, Peter Scott, myself, and maybe others) received
from the sponsor GTZ a "haybox" that was actually a "hotbag". My wife
(Noeli) has used it several time and we have been doing some experiments in
Mozambique with alternative "hotbags/hayboxes". Here are some questions
and some comments:

1. The GTZ hotbag consisted of a simple "pocket-type" bag with the top and
bottom being made of a "sandwich" of "cloth, batting, mylar sheet, batting,
cloth". Total thickness of the top (or bottom) would be about 2 cm (quite
thin, especially if compared with layers of straw or hay). Works well for
finishing the cooking of rice.

2. We believe that the mylar sheet is a crucial element: No penetration
of vapor, and probably reflectance.

3. Many sheets of mylar seem to be "aluminized" (as in those birthday
balloons filled with helium.)

Question 1: How important is the metallic (aluminum?) coating? Or would
transparent plastic film do the same job?

4. In our quest for alternative materials, I found some "under the roof"
roofing material that is woven plastic (like in those tough woven plastic
sacks that are used for shipping many things) but with one side (or both
sides at higher price) aluminized. Very tough stuff, still roughly
flexible, can be stitched, great for making "bags or boxes" for haybox cooking.

Question 2: Is there any advantage or disadvantage relating to the cooking
issues (not regarding costs) of having thin layer of aluminum versus
thicker aluminum, even aluminum sheets?

Question 3: Is there any (or much) advantage to having a polished (shiny)
aluminum surface instead of a dull aluminum surface?

5. Going one step further, I have just started an experiment with another
source of aluminum-coated materials and I need some help understanding what
it would accomplish as far as the cooking process is concerned. First, the
material is FREE. Absolutely FREE. In fact, it is refuse material that
is literally thrown away by the thousands of square meters every day in
most cities of the developing world. I am referring to the paper-based
cartons for liquids like long-life UHT-treated milk and fruit juices.

These are usually one-liter containers the size of a slightly flattened and
widened brick. When opened, the resultant "sheet" is approximately 20 x 30
cm. The inside of the carton is aluminum covered. (I assume it is
aluminum, but I have no confirmation of that.) The outside is like
cardboard (not corrugated) usually with a wax or plastic-type coating.

The cartons are rinsed, cut & opened, and dried (3 steps in any
order). They can be joined by overlapping in at least two
ways: A. Contact glue seems to work wonderfully well, but I have not
tested how it stands up to the heat of the pot and to continual
usage. B. Stitch the sheets together like a shoe-repairman does with an
awl and thread (1 cm spacing of stitches seems good, but maybe an
industrial quality sewing machine with long stitches would also
work.). (Option C is to glue and stitch.).

6. Based on Tom Reed's comments to the Stoves List today 4 Sept, multiple
layers of any (and this) insulating material would have even better results
(but do not let the aluminum layers touch each other.)

I can imagine many shapes and sizes of "hayboxes" and "hotbags" at very low
prices. Several tests could be run (I have not had time for any thus far)
on the heat losses.

Comments are welcome.

Paul (back from Africa 2 weeks ago.)
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 crispin at NEWDAWN.SZ Thu Sep 4 17:17:25 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:35 2004
Subject: Haybox & hotbag and reflective insulation
Message-ID: <THU.4.SEP.2003.231725.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

I will try to add useful edges here and there:

1.
>...received from the sponsor GTZ a "haybox"
>that was actually a "hotbag".

This is made in townships around Johannesburg and is a layer of cotton (not
blend), thin quilting, a sheet of aluminized mylar present-wrapping sheet,
another layer of quilting and an outside layer which can be blend or cotton.
It was developed by Wendy Chandler wendy-chandler@mweb.co.za and sell for
up to $12.

2.
>We believe that the mylar sheet is a crucial element:
>No penetration of vapor, and probably reflectance.

It is the reflectance of the shiny surface, not particularly its insulating
value (which is low as the material is quite dense).

4.
>In our quest for alternative materials, I found some "under the roof"
>roofing material that is woven plastic

It is called 'Sisulation' and is available in three gradings of insulating
value sold as 400, 410 and 420 all of which have the same shiny aluminum
surfaces. It significantly reduces radiation of heat from the wretchedly
hot galvanized roof sheeting. It is reinforced with strands of sisal and
can span a 9-12 inch wide space (of great length) unsupported.

>Question 2: Is there any advantage ... having thin
>layer of aluminum

As Tom has built it, only a very thin layer is required. Remember the
aluminum is a lousy insulator so it only works well as a reflector.

>Question 3: Is there any (or much) advantage to having a polished (shiny)
>aluminum surface instead of a dull aluminum surface?

Yes. My question is rather, how much, and at what incident angle. The loss
for the rough surface is related to the surface roughness, the shape of the
roughening and the frequency of the radiation reaching it. If a surface
didn't look shiny, it would be because the light was being absorbed, so if
it reflects visible light well, it will (in nearly all cases you can think
of) reflect longer wavelengths as well or better. High frequencies like
X-rays pass through most things.

>5. Going one step further, ... I am referring to the paper-based
>cartons for liquids like long-life UHT-treated milk and fruit juices.

Another source in your area is the 5 litre wine containers which are made
from mylar: very strong and super flat surface, with very thin aluminum
coated on top of it. These are much larger surfaces per 'unit' and offering
a fee for them gives the dump scavengers something sell. They are far
shinier that the Tetra-Pak product.

>These are usually one-liter containers the size of a
>slightly flattened and widened brick.

Called Tetra-Pak or Tetra-Brick (same big international company). The
'shiny' is indeed aluminum.

>6. Based on Tom Reed's comments ... multiple
>layers of any (and this) insulating material would
>have even better results

Yes. Touching together will have little effect on them (the actual benefit
of a very small gap is mostly theoretical) because the insulating layer is
the cardboard part. Even tightly rolled into an insulating sleeve they are
pretty darned good.

>I can imagine many shapes and sizes of "hayboxes"
>and "hotbags" at very low prices.

I think the wine containers are best for the Hot Bags because of their large
size, flexible nature and stitchability. Perhaps they are not easy to find
in Maputo but you could get masses at any RSA urban centre's dump or
collected from friends.

They also make nice inflatable camping pillows!

Regards
Crispin

From tmiles at TRMILES.COM Thu Sep 4 23:19:58 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:35 2004
Subject: IEA Bioenergy Task29 - educational web site on biomass and
bioenergy
Message-ID: <THU.4.SEP.2003.201958.0700.TMILES@TRMILES.COM>

Jeff,

The author of the request to review http://www.task29.epsilon.hr is:

Velimir Segon vsegon@EIHP.HR
Researcher - BIOEN programme
Energy Institute 'Hrvoje Pozar'
Savska c. 163
10000 Zagreb
Croatia

Tel: +385 1 6326 158
Fax: +385 1 6040 599

Tom Miles

----- Original Message -----
From: "Jeff Forssell" <jeff.forssell@cfl.se>
To: "Tom Miles" <tmiles@TRMILES.COM>; <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, September 04, 2003 12:48 AM
Subject: RE: [STOVES] IEA Bioenergy Task29 - educational web site on biomass
and bioenergy

Unfortunately there's no mailadress to the person seeking feedback on the
site.

One thing I like to check about sites is how will be be for a user that
doesn't have a giant monitor.

If I go in with my 1024*768 screen it is completely filled.

"Gibble listed the two most popular screen resolutions...
800x600 - 47%
1024x768 - 46% "

Don't know who Gibble is or when that investigation was made but I'm sure
that many of the people that site should want to reach will have small
monitors, which means that about 30% of each page will have to be
right-scrolled to reach =Terrible.

The layout dictators that made the site have also decided that everyone
should have (besides giant screens) excellent eyesight so that you aren't
allowed to increase the text size (for visibility) or decrease to fit into
your screen (or printout). An intelligent css layout using ems rather than
pixel size can make a layout size follow the size of the font (which you
should never fix!)

Navigational alternatives could be better implemented. (tabbing not always
possible because of javascripts without real functional value, accesskeys
nonexistant {but that?s something the few sites have discovered}) Some
links are just a tiny "<" or ">". No wonder so many colleagues are carrying
their mouse arm in a sling!

Shockwave usage- Shockwave can produce some very nice instructional material
and be quite compact. But it would be good it as much as possible is
presented in simpler form. Boardband Internet is not available everywhere
and especially where the needs are greatest. Consideration of that factor
must influence choices of how to present material. (If possible with
alternatives so broadband users can access good material, even if everybody
can't.

How is "our" site?
http://www.repp.org/discussiongroups/resources/stoves/
It is more flexible: you can change font sizes.

On the opening page the only thing that makes it "too big" for 800*600 is
that ther is a wide picture in the first column
http://www.repp.org/discussiongroups/resources/stoves/Oneil/nicaragua/riobravo.jpg
which is 400 px wide. I think it would be good to diminish or crop it to
about 270.

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

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

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

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

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

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

From dstill at EPUD.NET Fri Sep 5 13:57:05 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:35 2004
Subject: 25 Quotes from Sam Baldwin
Message-ID: <FRI.5.SEP.2003.105705.0700.DSTILL@EPUD.NET>

Dear Friends,

Every time that I read "Biomass Stoves" I am reminded what a jewel of a book
it is. Here are " a few" examples why this is the best book written on wood
burning cooking stoves.

All Best,

Dean

25 Quotes From
?Biomass Stoves: Engineering Design,
Development and Dissemination:
By Samuel Baldwin, 1987

1.) The energy efficiency of a stove can be dramatically increased by making
use of the energy in this hot flue gas through improved convective heat
transfer to the pot. (Page 28)
2.) High power water boiling tests, for example, measure the thermal
efficiency. High/low power water boiling tests and cooking tests measure the
stove efficiency. (Page 31)
3.)
it is the surface resistance, not the resistance to heat transfer of
the material itself, that primarily determines the rate of heat loss through
the stove wall. (Page 34)
4.) In controlled cooking tests with aluminum pots, fuel savings were about
45% compared to using clay pots. (Page 35)
5.) Although a thick wall of dense high specific heat material may have
slightly lower heat loss than a thinner wall after several hours
it takes
many hours more for the eventual heat loss of the thick wall to compensate
for its much greater absorption of heat to warm up to this state. Thus, it
is always preferable to make the solid (non-insulator) portion of the wall
as thin and light as possible. Additionally, the use of lightweight
insulants such as fiberglass or double walled construction can dramatically
lower heat loss
Materials such as sand-clay or concrete, which have a high
specific heat and density, and which must be formed in thick sections to be
sufficiently strong to support or resist the fire, should therefore be
avoided. (Page 36)
6.) Water heating tests on hot massive stoves, however, have shown that only
0.6 to 1.3% of the energy released by the fire, of which perhaps one-third
was stored in the massive wall, could be recuperated
heating the water by
typically 18 to 19C
What is often thought to be heating or cooking by heat
recuperation is actually done by the remaining coals of the fire. (Page 36)
7.) Similarly, using stored heat to complete cooking is an extremely
inefficient technique compared to using a high efficiency lightweight stove
and possibly a ?haybox? cooker
(Page 36)
8.) Thus, lightweight walls have the intrinsic potential for much higher
performance than massive walls due to their lower thermal inertia. This does
not, however, necessarily mean that a lightweight stove will automatically
save energy or that a massive stove cannot. For a lightweight stove to save
energy its heat loss to the exterior must also be minimized and the
convective and radiant heat transfer to its pot must be optimized.
Conversely, massive stoves can and sometimes save energy if the convective
and radiant heat transfer to the pot is carefully optimized. (Page 38)
9.) To increase the heat transfer to the pot there are, in principle, three
things to do. First, the temperature of the hot gas can be increased
Second,
as much of the area of the pot should be exposed to the hot gas as
possible
The gas should be allowed to rise up around the pot and contact its
entire surface
. Third, the convective heat transfer coefficient should be
increased. This can be done by increasing the velocity of the hot gas as it
flows past the pot...In convective heat transfer, the primary resistance to
heat flow is not within the solid object (unless it is a very good
insulator), nor within the flowing hot gas. Instead, the primary resistance
is in the "?surface boundary layer"of very slowly moving gas immediately
adjacent to a wall
It is this surface boundary layer of stagnant gas that
primarily limits heat transfer from the flowing hot gas to the pot
To
improve the thermal efficiency of a stove, the thermal resistance of this
boundary layer must be reduced. This can be accomplished by (among others)
increasing the flow velocity of the hot gas over the surface boundary layer
and, thinner, the boundary layer of stagnant gas then offers less resistance
to conductive heat transfer across it to the pot
(Page 41 to 42)
10.) The flow velocity of the hot gas over the pot is increased by narrowing
the channel gap through which the gas must flow past the pot. (Page 42)
11.) For a 10cm long channel, the channel efficiency drops from 46% for an
8mm gap to 26% for a 10mm gap. (Page 45)
12.) For the 4mm gap, effectively all the energy in the gas can be
recuperated in the first 2cm length of the channel. Channels longer than 5cm
are useless. For the 6mm gap, the first 5cm length recuperates 57% of the
energy in the gas, the next 5cm recuperates an additional 16%, the next 5cm
an additional 8%, and so on. (Page 45)
13.) On page 48 Baldwin has two graphs that show optimum power of the stove
matched to gap length and width. Stove efficiency is shown as dependent on
these variables. ?At powers greater than the optimum the combustion gases
cannot all escape out the channel and instead must flow out the door or
perhaps suffocate the fire and lower the combustion quality. At powers below
the optimum, the gas flow through the channel will remain about the same but
will be at a lower temperature due to more entrained air
In either case the
efficiency drops. Experimental work has shown that for a variety of stoves
the efficiency has a maximum at a particular fire power
?(Page 49)
14.) It is rather arbitrarily recommended that the pot to grate distance be
no less than .4 times the pot diameter. (Page 54)
15.)
A metal wall with 2cm of fiberglass insulation can provide 50% more
radiant heat flux to the pot than a bare metal wall
For example, insulating
the exterior wall of a prototype channel stove increased the stove?s
efficiency from about 33% to about 41% and increased its predicted fuel
economy relative to the open fire from about 48% to about 57%
(Page 54)
16.) If a cold object, such as a pot, is placed close to the fire it will
cool and stop the combustion of some of these volatiles, leaving a thick
black smoke. (Page 59)
17.) The entire process uses about 5 meters cubed of air (at 20C and sea
level pressure) to completely burn 1 kg of wood. To completely burn 1 kg of
charcoal requires about 9 meters cubed of air. Thus, a wood fire burning at
a power level of 1 kW burns .0556 grams of wood/second and requires about
.278 liters of air per second. Additional, excess air is always present in
open stoves and is important to ensure that the combustion process is
relatively complete. (Page 59)
18.) Using a grate will often increase efficiency and may reduce emissions
as well
By injecting air below the fuel bed they provide better mixing of
air with both the fuelbed and the diffusion flames above
Grates with a high
density of holes (high fraction of open area) can also achieve high
firepowers due to the improved mixing of air with the fuelbed. (Page 60)
19.) Controlling excess air can increase efficiency but may also increase
emissions if too little oxygen enters the combustion chamber or if the
mixing is poor. (Page 60)
20.) Injecting secondary air into the diffusion flame may, in some cases,
allow more complete combustion than would otherwise be possible
Where an
open firebox is used, however, secondary air may lower efficiency by cooling
the hot gases. (Page 60)
21.) Preheating incoming air may also improve the quality of combustion and
the efficiency by raising average combustion chamber temperatures.
Preheating, however, can only be done in stoves where excess air is
controlled; otherwise the air will bypass the preheating ducts and flow
directly in the door. (Page 61)
22.) Optimizing the shape of the combustion chamber may affect the
combustion quality and stove efficiency in a number of ways. (Page 61)
23.) Insulating the combustion chamber raises interior temperatures and can
reduce emissions. (Page 61)
24.) How well the fire is tended can strongly influence fuel use. Page 62)
25.) One of the most important factors determining field performance of a
stove is the firepower it is run at during the simmering phase. Because
simmering times tend to be long, quite modest increases in firepower above
the minimum needed can greatly increase fuel consumption. (Page 63)

From rstanley at LEGACYFOUND.ORG Fri Sep 5 12:49:05 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and coffee-smoked sausages
Message-ID: <FRI.5.SEP.2003.194905.0300.>

Its a bit rainy these days in Kampala. I had the inspiration to just sit outside
on the front stoop around a briquette fire(of course) and roast some sausages for
a snack. It also offered the opportunituy to see how our firsat batch of test
blends here in Uganda would fare. we are using varoius mixtures of sawdust, coffee
husks, miscl. leaves and grasses.

Well let me tell you, if you have never had coffee smokes pork sausages you are
missing something ! Mmmmm.

I also had the chance to observe burn location and migration in direct answer a
long standing question. Ron and others have often asked me to tell them if the
holey briquette burns from the top down (and if it can be made to do so) or from
the bottom. I can now say that it definately burns up from the bottom through the
core.

Trying to top lite in a free standing position, using parafin but with no attempt
at air control of any sort, was not possible. Once ignited, (from the bottom)
the flames will first carbonise the core then radiate up through the core and out
to some of the top surface but by this time we are beginning to realise a blue
to transparent flame in a white hot zone which seems to start and remain well down
into the core through the duration of the burn. The whole mass eventually
becomes one friable cylinder of ash covered glowing coals, the heat having most
definately emmanated out and up from the lower interior surface of the core.

I have just posted three photos (via Tom Miles --thanks in advance for that Tom,
), showing this effect in a top, an oblique and a side view of a stacked array of
two briquettes --at about 45 minutes into the burn.
I have also added a not particularly heroic human hand, holding the naturally
insulated exterior of same briquettes about 20 minutes into the same burn. You
cannot normally hold the exteriour after 30 minutes but much depends upon the
blend of the briquette.

Back to that sausage: its all relative....

Richard Stanley

From keith at JOURNEYTOFOREVER.ORG Fri Sep 5 15:45:03 2003
From: keith at JOURNEYTOFOREVER.ORG (Keith Addison)
Date: Tue Aug 10 18:30:36 2004
Subject: Methane Digesters For Fuel Gas and Fertilizer,
With Complete Instructions For Two Working Models
Message-ID: <SAT.6.SEP.2003.044503.0900.KEITH@JOURNEYTOFOREVER.ORG>

Greetings

Just to announce a new addition to the Biofuels online library that
should be of interest:

http://journeytoforever.org/biofuel_library.html#methanefry
Methane Digesters For Fuel Gas and Fertilizer, With Complete
Instructions For Two Working Models -- by L. John Fry, Santa Barbara,
Calif. 93103, ? 1973, Eighth Printing (out of print). Excellent
manual on making and using methane -- biogas. Fry developed his
techniques while running a pig farm in South Africa, designing the
first full scale displacement methane plant. Good information on
integrating biogas production with gardening and farming, and with
pond-culture food production. Designs for a Sump Digester using
55-gal oil drums and an Inner Tube Digester. With thanks to Kirk
McLoren.
DjVu version: This file requires the DjVu plug-in reader, available
as a free download (about 1Mb) for Windows, Linux, Solaris and
Macintosh. View online or download the file for offline viewing.
http://journeytoforever.org/biofuel_library/MethaneDigesters.djvu
Download DjVu here:
http://www.lizardtech.com/download/?f=0&d=1
DjVu FAQ here:
http://www.lizardtech.com/support/faq/general_djvu.php

Table of Contents

1 Background
Methane-Gas Plant: Synergy at Work

2 History

3 Biology of Digestion
Bio-Succession in the Digester
pH and the Well-Buffered Digester
Temperature

4 Raw Materials
Digestible Properties of Organic Matter
Amount of Manure Collectable
Manure Production and the Livestock Unit
Carbon to Nitrogen Ratio (C/N)
Calculating C/N Ratios

5 The Gas
Composition
Fuel Value
Amount of Gas From Different Wastes

6 Digesters
Basic Digester Design
Raw Materials and Digester Design
Loading Rate, Detention Time and Digester Size
Heating Digesters
Insulating Digesters

7 Using Gas
Properties of Methane
Uses of Methane
Efficiency of Digestion

8 Using Sludge
Sludge as a Fertilizer
Sludge Gardening and Farming
Sludge-Pond Cultures

9 Building a Sump Digester
Making Starter Brew

10 Building an Inner Tube Digester
Inner Tube Digester Parts List
1. Main Chamber of the Digester
2. The Plastic Insert
3. Attaching the Cylinder to the Inner Tube
4. Inlet Fittings and Attachment of the Slurry (Feeding) Bucket
5. Fitting the Effluent Pipe
6. Fitting the Gas Outlet
7. The Scum Collector
8. Gas Yield Indicator
9. Pressure Release Bottle
10. Inner Tube Storage
11. Burner
12. Temperature
13. The Bacterial Brew
14. Feeding
15. Removing Scum and Effluent
16. Safety Precautions
17. Lighting the Flame
18. pH

11 Necessity is the Mother of Invention
Design of the First Full Scale Displacement Methane Plant
Digester Description

12 References

Biofuels Library contents

* Mother Earth Alcohol Fuel
* The Manual for the Home and Farm Production of Alcohol Fuel
* The Sunflower Seed Huller and Oil Press
* Fuel From Sawdust
* The UC Davis biodiesel study
* Straighter-than-straight vegetable oils as diesel fuels
* Palm Oil as a Fuel for Agricultural Diesel Engines: Comparative
Testing against Diesel Oil
* Kinetics of Palm Oil Transesterification in a Batch Reactor
* The Butterfield Still -- Farm-scale ethanol fuel production plant
* The Fats and Oils: a General View
* Put a chicken in your tank
* Methane Digesters For Fuel Gas and Fertilizer -- With Complete
Instructions For Two Working Models
* Micro Cogeneration: 21st Century Independent Power -- How to Design
and Construct Your Own Independent Power System
* Optimization of a Batch Type Ethyl Ester Process
* Production and Testing of Ethyl and Methyl Esters
* Transesterification Process to Manufacture Ethyl Ester of Rape Oil
* Making and Testing a Biodiesel Fuel Made From Ethanol and Waste
French-Fry Oil
* Intensive Field Trial of Ethanol/Petrol Blend in Vehicles
* NIR Helps Turn Vegetable Oil into High-Quality Biofuel
* Rapid Monitoring of Transesterification and Assessing Biodiesel
Fuel Quality by Near-infrared Spectroscopy Using a Fiber-Optic Probe
* Monitoring a Progressing Transesterification Reaction by
Fiber-Optic Near Infrared Spectroscopy with Correlation to 1H Nuclear
Magnetic Resonance Spectroscopy
* Cornmeal Adsorber for Dehydrating Ethanol Vapors
* Separating Ethanol From Water
* Apparatus for the Continuous Manufacture of Absolute Alcohol
* Absolute Alcohol Using Glycerine
* Wood Alcohol
* Wood-to-Oil Process
* Liquefaction
* Biochemical Sources of Fuels

Best wishes

Keith Addison
Journey to Forever
Handmade Projects
Ichijima, Japan
http://journeytoforever.org/

From crispin at NEWDAWN.SZ Fri Sep 5 18:27:47 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and coffee-smoked sausages
Message-ID: <SAT.6.SEP.2003.002747.0200.CRISPIN@NEWDAWN.SZ>

Dear Stanley

You didn't mention what sort of device you are using to do the burning in.
Is it just a little pile or in a 'device'?

Thanks
Crispin

----- Original Message -----
From: "Richard Stanley" <rstanley@legacyfound.org>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, September 05, 2003 6:49 PM
Subject: Re: [STOVES] holey briquettes and coffee-smoked sausages

Its a bit rainy these days in Kampala. I had the inspiration to just sit
outside
on the front stoop around a briquette fire(of course) and roast some
sausages for
a snack. It also offered the opportunituy to see how our firsat batch of
test
blends here in Uganda would fare. we are using varoius mixtures of sawdust,
coffee
husks, miscl. leaves and grasses.
[snip]

From adkarve at PN2.VSNL.NET.IN Fri Sep 5 23:16:34 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:36 2004
Subject: [Fwd: [STOVES] Haybox & hotbag and reflective insulation]
Message-ID: <SAT.6.SEP.2003.084634.0530.ADKARVE@PN2.VSNL.NET.IN>

In India we can buy various sizes of aluminium containers with lids.
The containers are cylindrical, without handles, and the lids are flat
without knobs. A small container fits easily inside a larger one. By
using two such containers and sawdust to fill the space between them, we
made a hot box. It was not only cheap and durable, but it also gave the
desirable results.
Polystyrene foam sheets are available in various thicknesses in hobby
shops in India. As they can be easily cut with any sharp blade, they are
a hot favorite among those who want to make temporary decorations for
birthday parties or letterings for office functions etc. I used to have
a cheap metal container for keeping ice cubes. It was extremely well
insulated so that the cubes would remain intact for several hours. Later
the metal rusted and before throwing the contraption away, I cut it open
to look at the insulating material, and was surprised that it was just
polystyrene foam. It could also be used in a hot box.
We also made a hot box that was built into a clay stove. It was just a
hole next to the firebox of the stove. The hole is lined with any
suitable insulating material (hay, straw, coconut husk, cotton etc.) and
it has a wooden lid. The pot with half cooked food is taken off the
fire, put into the hole and covered with the lid.
A.D.Karve

From tmiles at TRMILES.COM Fri Sep 5 23:13:20 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and coffee-smoked sausages
Message-ID: <FRI.5.SEP.2003.231320.0400.TMILES@TRMILES.COM>

Richard's pictures of briquettes can be seen linked to the Stoves page and
at:

http://www.repp.org/discussiongroups/resources/stoves/Stanley/briqburn.html

The top view reminds me of a stove we used to make that friends in the
Peace Corps more than 20 years ago called a "Ghana stove". Sawdust was
packed tightly in a can or tube with a hole formed in the middle and an
air hole at the bottom. The stove was lit and allowed to burn from the
inside out as it heated food in a pot.

Thanks Richard

Tom

From kenboak at STIRLINGSERVICE.FREESERVE.CO.UK Sat Sep 6 05:07:51 2003
From: kenboak at STIRLINGSERVICE.FREESERVE.CO.UK (Ken Boak)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and modern domestic waste?
Message-ID: <SAT.6.SEP.2003.100751.0100.KENBOAK@STIRLINGSERVICE.FREESERVE.CO.UK>

Richard & Stovers,

I read with interest your recent postings about holey briquettes and having
followed the links, seen the pictures on the Legacy Foundation Website.

Your proposal for a briquetting machine, aimed at the US and Western World
for reducing paper and card waste - especially junk mail, and providing a
fuel for fireplaces, barbeques etc is an excellent one, and I should like to
learn more of your progress in this direction.

I live in suburban south-east England about 20 miles south of London, where
our local authority runs a scheme for recycling newspaper and card, and
offers a weekly home collection service. They also run a collection site
where garden waste is shredded and converted into compost. Collecting waste
for recycling is only good if there is a market for the end product - and
your briquettes could offer a suitable solution for paper and garden waste.
Briquettes could be manufactured on a commercial scale and sold through
garden centres, filling stations and local shops, there being a summer
market for barbeques and a winter market for open fireplaces.

I noted that one of your briquette recipies was made from 10% shredded
plastic bags, 50% paper and card and 40% agri-waste. Is this a viable mix?
What is the effect on the burn/smoke if the product contains 10% plastic
(polythene) waste?

The effect of the hole in producing a white hot zone at the top of the
briquette was of interest, and this high temperature combustion may play an
important part in the thermal reduction of the plastic compounds into more
benign substances.

In the densely populated parts of the UK, domestic waste is becoming an ever
increasing problem, landfill sites becoming rapidly exhausted and huge
public opposition to any form of municipal incineration plant. Gone are the
days of coal fires in every home, where most of the food and packaging waste
(mostly paper and card) was burnt on the open fireplace, and it was only the
ashes that were carried away by the "dustbin-man" once a week.

As a result of changing packaging technology and practices, our domestic
waste contains a high percentage of plastic waste including food wrappers,
plastic bags and plastic drinks bottles. There is currently no market for
this type of waste and so most of it adds to the input to the remaining
landfill sites.

I believe that suitably shredded, a certain percentage of plastic waste
could be added toother combustible waste, using your holey briquetting
method and that could be used as a domestic heating fuel.

If anyone has knowledge of the combustion processes involved in burning
plastic in a bio-fuel mix, and the implications to the pollutants contained
within the gaseous products of combustion, please share your comments.

regards,

Ken Boak

From crispin at NEWDAWN.SZ Sat Sep 6 05:47:55 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:36 2004
Subject: 25 Quotes from Sam Baldwin
Message-ID: <SAT.6.SEP.2003.114755.0200.CRISPIN@NEWDAWN.SZ>

Dear Dean

Thanks for that thought-provoking list of quotes from Sam. It is
interesting to think of /in toto/ and if this represents the basis of
APROVECHO training it explains why my conversations with people from there
have been so animated and indeed seminal. Fifteen years later, this list
should be perhaps reviewed for accuracy (or generality) in the light of
developments with gasifiers and controlled air stoves (non-fuel metered
stoves) that have come along in the meantime.

I was pondering drafting a set of stove design principles for my website so
people could make things themselves to experiment with or manufacture around
the world. As my design criteria are sometimes similar and sometimes quite
different from Sam's it might add some fuel to the stove debate fire.

This post is pushing me to do it sooner while the idea is hot. The thing is
I don't want it to be a reactive essay, it should rather be a set of design
principles from another school of thought. Some people feel there isn't or
can't or shouldn't be another such school (truth being truth and principles
being principles) and others are omnivorous. I am at the omnivore end.

People have different ways of describing reality (and physics) and that
communication can mislead or obfuscate or elucidate or enlighten others
depending on how they interpret the words used and understand the physics
and people involved.

One example is the /defacto/ presentation of convective heat transfer _not_
being a form of radiation of energy from one body to another. A second
(though not in the list) is the idea that there is such a thing as a 'coal
gasifier' when all coal fires are gas fires, perhaps even more obviously
than the fact the all wood fires are gas fires. Terminology matters when
describing science.

My point is that how we talk about what is going on tends to get people on
certain paths and not others. This can work as a mental block and prevent
other avenues being explored. This is worst then one is, through training,
self-censoring.

An example of something left out of the list is the idea of heat-recycling
stoves. Everything relates to the idea of keeping heat in rather than
bringing it back. Something brought back is not lost. Principles for
stoves designed in this fashion do not agree with a number of the principles
in Sam's list, comprehensive though it is for 'normal' stoves. I wonder if
'gasifiers' are also deviant.

I think it is in everyone's interest to have a comprehensive list(s) of
design guidelines from different schools of thought available for the whole
world to gain from and this list, with its open archives, is probably the
best, neutral place to store it.

What do you say, folks?

Towards better stoves and understanding!
Crispin

From rstanley at LEGACYFOUND.ORG Sat Sep 6 07:32:28 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and modern domestic waste?
Message-ID: <SAT.6.SEP.2003.143228.0300.>

Ken and Stovers,

Thanks for the interest : There are a few points I'd just like to clarify:

1) With reference to the plastic combustion, it is indeed reported in the
Swedish and British environmental science community that polyethylene bag
material in particular is safely incinerated at temperatures above 200 deg.
centigrade. This does NOT at least fo our purposes, apply to other forms of
plastic such as the polystyrenes (the insulated packaging for everything from
cups to trays for food, and the corn flake shapes used for packaging, and the
poly vinyl chlorates and probably dozens of others way beyond my limited
knowledge. All we are pursuing is the possible admixture of a plastic consumer
shopping bag to an agro residue based briquette. At 5 to 7 grams per bag and
one bag per briquette, This constitutes about 7/135 or roughly 5% by weight.
We have tried two bags / briquette and that can work well provided the bag is
very well shredded but that's another issue.

Some of the sources of our interest in the combustion of polyethylene bags are
mentioned in an article by David Harrison of the London Daily Telegraph on
March 4, 2003 , titled "Time to throw out 'myth' of recycling"
he writes:

Throw away the green and blue bags and forget those trips to
return bottles - recycling household waste is a load of, well,
rubbish, say leading environmentalists and waste campaigners.

In a reversal of decades-old wisdom, they argue
that burning
cardboard, plastics and food leftovers is better
for the
environment and the economy than recycling.

They dismiss household trash separation
- a practice
encouraged by the green lobby - as a waste of
time and money.
The assertions, likely to horrify many
environmentalists, are made
by five campaigners from Sweden, a country
renowned for its concern
for the environment and advanced approach to
waste.
They include Valfrid Paulsson, a former
director-general
of the government's environmental protection
agency; Soren
Norrby, the former campaign manager for Keep
Sweden
Tidy, and the former managing directors of
three
waste-collection companies.
The Swedes' views are shared by many
British local
authorities, who have drawn up plans to build
up to 50
incinerators in an attempt to tackle a
growing waste mountain
and cut the amount of garbage going to
landfills.
"For years, recycling has been held up
as the best way to
deal with waste. It's time that myth was
exploded," said one
deputy council leader in southern England.
A spokesman for East Sussex County
Council, which
plans to build an incinerator, said, "It's
idealistic to think that
everything can be recycled. It's just not
possible. Incineration
has an important role to play."
The Swedish group said that the "vision
of a recycling
market booming by 2010 was a dream 40 years
ago and is
still just a dream."
The use of incineration to burn
household waste -
including packaging and food - "is best for
the environment,
the economy and the management of natural
resources," they
wrote in an article for the newspaper Dagens
Nyheter.
Technological improvements have made
incineration
cleaner, the article said, and the process
could be used to
generate electricity, cutting dependency on
oil.
Mr. Paulsson and his co-campaigners said
that collecting
household cartons was "very unprofitable."
Recycled bottles cost glass companies
twice as much as
the raw materials, and recycling plastics was
uneconomical,
they said. "Plastics are made from oil and
can quite simply be
incinerated."
The Swedes stressed that the collection
of dangerous
waste, such as batteries, electrical
appliances, medicines,
paint and chemicals "must be further
improved."
They added, "Protection of the
environment can mean
economic sacrifices, but to maintain the
credibility of
environmental politics the environmental
gains must be worth
the sacrifice."
The Environmental Services Association,
representing the
British waste industry, agreed that the
benefits of incineration
had been largely ignored.
Andrew Ainsworth, its senior policy
executive, said, "This
is a debate that we need to have in this
country. Recycled
products have got to compete in a global
market, and
sometimes recycling will not be economically
viable or
environmentally sustainable."
A spokesman for the government's
Department for
Environment, Food and Rural Affairs said
incineration was
"way down the list" because "it causes
dangerous emissions,
raises public concern and sends out a
negative message about
reuse."

The notion that the ubiquitous polethylene plastic shopping bag is relatively
safe to incinerate, is also supported by several of our own well qualified
Stovers. I would recommend in particular, the further insights of Stovers,
Peter Verhaart and Kevin Chisholm.
It appears that the polyvinyl plastic bag can be incinerated in a commercial,
regulated setting. However, this may be a far cry from consumer consumption at
least in situations where there are viable alternatives and its use does not
represent a survival issue, such as face the poor in the marginal environments
of the developing nations. What if for example it a plastic bag blend were to
be burned wet or without adequate venting in your community there ? . We know
what happens in terms of wood smoke under such conditions but what about the
effect of the plastic ? We can revert to the classic "cover ourselves legally"
mentality, but well beyond such defensive and costly, short term and
deconstructive tactics, is the larger and more sticky issue of environmental
and health impact. A lot more has to be known before anyone jumps into
promoting large scale combustion of at least a consumer product which
incorporates this material where other safer alternatives are within reach.

2) On the lighter and more immediately practical side, is the end use of
unwanted and unsought commercial advertisements via the post. I do not pretend
to know the figures for the UK but in the US of the Americas, this "Junk mail"
arrives at the doorstep of the average family at the rate of about 0.6 kg per
day. Assuming on average, a daily supply of your yard wastes of three times
this amount and you have a workable blend and volumes for production of good
quality briquettes, of sufficient numbers to meet most if not all of your
hearth or wood stove-based heating and summer barbecue fuel requirements.
Another "free" catalogue anyone ?

3) The mechanism for accomplishing the briquette production at the small
community to household level exits -- and indeed works at the prototype level
now. As a small top loading washing machine-sized mechanism, it will have to be
scaled up considerably to handle any sizeable community. However anyone of us
who has invented anything, to discover that it works on the first go round,
can't help but to share the enthusiasm we have in now "pressing on" with its
full development into a market ready product. We are eager to discuss this,
with interested financial and technical partners !

Thanks for your interest Ken. I will be posting notes on our progress as we
proceed.

Richard Stanley
Kampala

From kchisholm at CA.INTER.NET Sat Sep 6 09:06:02 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:36 2004
Subject: Magnesium, Alzheimer's,
and Aluminum Cooking Pots. Was:Re: [STOVES] [Fwd: [STOVES] Haybox
& hotbag and reflective insulation]
Message-ID: <SAT.6.SEP.2003.100602.0300.KCHISHOLM@CA.INTER.NET>

Dear AD

As I get older, I become increasingly concerned about Alzheimer's Disease.
Aluminum deposition in the brain is associated with Alzheimer's.

It appears to me that the prime mechanism of Aluminum accumulation is lack
of Magnesium in the diet. Apparently Magnesium and Aluminum are
interchangeable in certain enzyme systems causing harm. Additionally,
apparently Aluminums can replace Magnesium in the brain, allowing calcium to
flood in, causing cell death. (Andrasi E et al., "Disturbances of Magnesium
Concentrations in various brain areas in Alzheimer's Disease." Magnes. Res.,
vol 13, no. 3, pp. 189-196, 2000)

Similarly, with Parkinson's Disease aluminums can be a contributing factor
in central nervous system degeneration. In one autopsy study, calcium and
aluminums were elevated in the brains of victims of Parkinson's Disease, as
compared to people with normal brains. (Yasui M et al., "Calcium, magnesium
and Aluminium concentrations in Parkinson's Disease.", Neurotoxicology, vol
13, no. 3, pp 593-600, 1992)

We should all be careful about using aluminums cookware if our diets are low
in magnesium. In Third World Countries where successful diets and eating
habits have been developed prior to the introduction of aluminums cookware,
there may not be sufficient magnesium in the diet to protect against
Aluminium entry into the body.

Your suggestion of using nesting pots for heat conservation is excellent.
Are there similar pots made with stainless steel? A safe way to proceed
would be to use an Aluminium pot as the exterior pot, and to use a stainless
inner pot that contacts the food.

Kindest regards,

Kevin Chisholm

----- Original Message -----
From: "A.D. Karve" <adkarve@PN2.VSNL.NET.IN>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Saturday, September 06, 2003 12:16 AM
Subject: [STOVES] [Fwd: [STOVES] Haybox & hotbag and reflective insulation]

> In India we can buy various sizes of aluminium containers with lids.
> The containers are cylindrical, without handles, and the lids are flat
> without knobs. A small container fits easily inside a larger one. By
> using two such containers and sawdust to fill the space between them, we
> made a hot box. It was not only cheap and durable, but it also gave the
> desirable results.

From dstill at EPUD.NET Sat Sep 6 16:29:13 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:36 2004
Subject: 25 Quotes from Sam Baldwin
Message-ID: <SAT.6.SEP.2003.132913.0700.DSTILL@EPUD.NET>

Dear Crispin,

Batch loaded stoves open up a whole new wonderful set of possibilities for
cook stoves. Baldwin didn't consider this subset of stoves in his book.
Gasifiers and controlled air stoves (non-fuel metered stoves), as you say,
operate differently and it would be great to see design principles for
successful stoves. I build one occasionally and tried quite a few with Dr.
Anderson and Ron Larson in June.

Dr. Larry Winiarski, as I've written, studied and built many gasifiers
before turning back to metered fuel burning. Larry is the Technical Director
at Aprovecho. He is an expert in gasification and ran a gasified truck at
the Design Seminar in June. Larry has concentrated on direct optimized
burning because it seemed the simplest solution to getting vernacular
improved cookstoves to the millions who need them...

When we train folks here we try to get them ready to build stoves for NGO's
who ask for technical assistance. Since stoves need to meet local needs the
consultant has to be able to design and develop stoves with local women who
will approve the final adaption. Learning design principles is important but
knowing how to use available materials is also necessary. We want
consultants to know thermodynamics and to be familiar with solar, wood
stoves and retained heat cookers.

Larry has a list of 10 design principles that are very much in line with
Baldwin, although Larry has found ways to optimize heat transfer with
cleaner burning. Baldwin, Micuta had effective heat transfer to the pot in
their stoves but had not worked out an improved combustion chamber. Larry
did all this starting from 1982. His work influenced the folks at Eindhoven,
I think, when they started experimenting with his downdraft/downfeed
combustion chamber arrangements.

I believe that Winiarski, Baldwin, Micuta, Prasad, Veerhaart, Visser and
others would have lots of shared agreements regarding metered burning
stoves. I hope to be pointing out some of these areas of possible consensus
exerpted from their books.

I wish you all the best luck and am very interested and supportive of
similar efforts with gasifier and non-fuel metered stoves.

All Best,

Dean

From rdboyt at YAHOO.COM Sat Sep 6 15:19:39 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
Message-ID: <SAT.6.SEP.2003.121939.0700.RDBOYT@YAHOO.COM>

Subject: Stoves for Space Heating

Stovers all:

It is not uncommon for the temperature to dip into the low twenties and teens during winter where we live, in far southwest Missouri. Our primary source of space heat is a cast iron, no-grate box stove connected to a brick chimney by a six-inch diameter flue pipe, about ten feet long.

We generally experience warm ceilings and cold floors, so several years ago, I fashioned a reverse-flow heat exchanger by encasing the six-inch diameter flue inside an eight inch diameter stove pipe. A thermostatically controlled squirrel cage blower picks up cold air from the floor, runs it upward to the stove pipe near to where the flue connects to the chimney. This floor air then flows over and down along the hot six-inch flue pipe all the way back to just above the stove, where it exits into the room flowing down and out over the hot top surface of the stove. This is better explained by a sketch I will send to anyone requesting it.

It worked very well, but there was a surprise. After only a few months of operation, we found that the flue to the chimney was not drawing properly. We discovered a creosote build-up in the six inch flue pipe that reduced its effective diameter to about three inches, right at the place where the cold floor air from the blower struck the outside of the hot stove flue pipe. Easy to remove, easy to clean, lightweight, and at least that creosote/soot was deposited before it could get into the brick chimney itself, where it would be difficult to remove, and would be a set-up for a dangerous flue fire. A thermostatically controlled ceiling fan above the stove pushes warm ceiling air down toward the floor.

The design is reasonably failsafe. If the electricity goes off nothing gets too hot. The ceiling fan and the squirrel cage blower make a little noise, but that is actually reassuring when you wake up at night and know you've got a good fire going in the stove. If you don't hear any noise, you know your fire may need re-stoking.

Dick Boyt

rdboyt@yahoo.com

---------------------------------
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software

From rdboyt at YAHOO.COM Sat Sep 6 15:25:22 2003
From: rdboyt at YAHOO.COM (Richard Boyt)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Vertical Shaft Charcoal Kiln
Message-ID: <SAT.6.SEP.2003.122522.0700.RDBOYT@YAHOO.COM>

Subject: Vertical Shaft Charcoal Kiln

Stovers:

I am fascinated by Tom Jones's description of the Chinese vertical shaft brick kiln. I pity those poor fellows who must load the unfired brick while working directly in the hot plume of upwelling coal-fired exhaust gasses. Unfortunate that no temperatures of firing were given. I suspect that the maximum brick firing temperatures may have been rather low, perhaps even as low as 400 degrees C (750 degrees F), which would produce a soft brick, but would have the advantage of maintaining the strength and prolonging the life of the steel supporting rods.

The vertical shaft brick kiln being tested in Nicaragua has reported difficulties in getting the fire started. Was the problem ever solved? If so, how did they do it?

I built a very small much-modified version of the vertical shaft kiln to see if I could fire sawdust to char. Five tin cans with crimped tops were filled with sawdust and stacked to form a tower. The top can had a loose lid inserted on top of the sawdust. The tower was placed inside a stove, and a fire was maintained in the space surrounding the tower. Once the tower got hot enough to pyrolize the sawdust, the resulting gasses formed lovely blue crowns of flame, as they exited through the crimped top ends of each can. In this way, each can helps in supplying the heat to help pyrolize the sawdust in the cans above. This is a variation of the innovative char making retorts reported by A.D. Karve. When cooled down, all of the sawdust had been converted to char except the bottom one, which had been converted only at the top half. Once going good, no smoke came out of the tin can chimney I added to stimulate combustion.

None of the sawdust char went to ash. A lot of work for not much char, but if it were scaled up, maybe. I think it could be built so that you could lower the chimney by removing cool char cans at the bottom of the tower, then raise the tower by adding unfired sawdust cans at the top. I've got a drawing that I'll send if anyone is interested.

Dick Boyt

rdboyt@yahoo.com

---------------------------------
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software

From ventfory at IAFRICA.COM Sat Sep 6 15:57:00 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and modern domestic waste?
Message-ID: <SAT.6.SEP.2003.215700.0200.VENTFORY@IAFRICA.COM>

Richard S, Ken Boak and Stovers

I am also impressed with Richard Stanley's unique briquette making technique and the use of non-woody biomass material, mixed in with waste paper in a water slurry. I am totally convinced that he has a winning combination here. The system he proposes is far more cost effective than mechanized screw extruding or piston press systems when aimed at small scale community upliftment programs for example. It has a low capital equipment acquisition cost and lower running- and equipment maintenance/breakdown costs. The process is more labour intensive by design and is aimed at creating jobs, which also offers entrepreneurs countless business opportunities.

On to plastics:
With regards to using plastics in said briquettes, new evidence now points to this practice actually being environmentally friendly. Just a word of caution, that the burning of plastics leaves a sticky deposit on the inside of stove chimneys/flue pipes, which could lead to excessive smoke release just after lighting the next fire (or lead to chimney fires?). This evidence was found in a field trial report prepared and funded for by the National Energy Council of South Africa in 1990, later published in a working paper called "The Development of a Low-Cost Fuel-Efficient Wood-Burning stove". The presence of plastic deposits in the flue pipes were attributed to the usage of plastic bags for kindling during start-up (40% of users in the KwaBiyela district). It has to be said that this problem probably only occurred due to low combustion temperatures (less than 200?C) of the primitive cast iron stoves used in the trials, so how much this evidence relates to modern stoves or the use of plastics in briquettes will be for someone else to address. It might also be advisable then perhaps to use chimneyless stoves when burning plastics, no?

Regards

Kobus

----- Original Message -----
From: Ken Boak <kenboak@STIRLINGSERVICE.FREESERVE.CO.UK>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Saturday, September 06, 2003 11:07 AM
Subject: [STOVES] holey briquettes and modern domestic waste?

> Richard & Stovers,
>
> I read with interest your recent postings about holey briquettes and having
> followed the links, seen the pictures on the Legacy Foundation Website.
>
> Your proposal for a briquetting machine, aimed at the US and Western World
> for reducing paper and card waste - especially junk mail, and providing a
> fuel for fireplaces, barbeques etc is an excellent one, and I should like to
> learn more of your progress in this direction.
>
> I live in suburban south-east England about 20 miles south of London, where
> our local authority runs a scheme for recycling newspaper and card, and
> offers a weekly home collection service. They also run a collection site
> where garden waste is shredded and converted into compost. Collecting waste
> for recycling is only good if there is a market for the end product - and
> your briquettes could offer a suitable solution for paper and garden waste.
> Briquettes could be manufactured on a commercial scale and sold through
> garden centres, filling stations and local shops, there being a summer
> market for barbeques and a winter market for open fireplaces.
>
> I noted that one of your briquette recipies was made from 10% shredded
> plastic bags, 50% paper and card and 40% agri-waste. Is this a viable mix?
> What is the effect on the burn/smoke if the product contains 10% plastic
> (polythene) waste?
>
> The effect of the hole in producing a white hot zone at the top of the
> briquette was of interest, and this high temperature combustion may play an
> important part in the thermal reduction of the plastic compounds into more
> benign substances.
>
> In the densely populated parts of the UK, domestic waste is becoming an ever
> increasing problem, landfill sites becoming rapidly exhausted and huge
> public opposition to any form of municipal incineration plant. Gone are the
> days of coal fires in every home, where most of the food and packaging waste
> (mostly paper and card) was burnt on the open fireplace, and it was only the
> ashes that were carried away by the "dustbin-man" once a week.
>
> As a result of changing packaging technology and practices, our domestic
> waste contains a high percentage of plastic waste including food wrappers,
> plastic bags and plastic drinks bottles. There is currently no market for
> this type of waste and so most of it adds to the input to the remaining
> landfill sites.
>
> I believe that suitably shredded, a certain percentage of plastic waste
> could be added toother combustible waste, using your holey briquetting
> method and that could be used as a domestic heating fuel.
>
> If anyone has knowledge of the combustion processes involved in burning
> plastic in a bio-fuel mix, and the implications to the pollutants contained
> within the gaseous products of combustion, please share your comments.
>
>
> regards,
>
>
> Ken Boak

From kenboak at STIRLINGSERVICE.FREESERVE.CO.UK Sat Sep 6 16:29:34 2003
From: kenboak at STIRLINGSERVICE.FREESERVE.CO.UK (Ken Boak)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Vertical Shaft Charcoal Kiln
Message-ID: <SAT.6.SEP.2003.212934.0100.KENBOAK@STIRLINGSERVICE.FREESERVE.CO.UK>

Dick & Stovers,

Last summer I had the opportunity to try the retort method of charcoal
making on a slightly larger scale using a 210 litre oil drun packed with
hazel offcuts up to 50mm in diameter. A central pipe ensured that the
pyrolisis products could escape from the drum in a controlled manner, yet
prevent air for combustion entering the barrel.

The barrel was loaded into a 1m diameter x 1m deep cylindrical stove and
fired with woodchips and forestry waste. After a burn period of
approximately 3 hours and 1 hour cooling, the stove was opened and the
contents of the drum investigated. There were a few "brown ends" but the
majority of the hazel had succesfully been converted to charcoal.

This method ensures that a batch of charcoal can be produced in a much
shorter priod of time, the heat being supplied from a sacrificial fuel such
as woodchips combined with the pyrolisis gases of the charcoal/wood payload.

regards

Ken Boak

From hseaver at CYBERSHAMANIX.COM Sun Sep 7 21:53:21 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
In-Reply-To: <20030906191939.93826.qmail@web13206.mail.yahoo.com>
Message-ID: <SUN.7.SEP.2003.205321.0500.HSEAVER@CYBERSHAMANIX.COM>

On Sat, Sep 06, 2003 at 12:19:39PM -0700, Richard Boyt wrote:
> Subject: Stoves for Space Heating
>
(snip)

> It worked very well, but there was a surprise. After only a few months of operation, we found that the flue to the chimney was not drawing properly. We discovered a creosote build-up in the six inch flue pipe that reduced its effective diameter to about three inches, right at the place where the cold floor air from the blower struck the outside of the hot stove flue pipe. Easy to remove, easy to clean, lightweight, and at least that creosote/soot was deposited before it could get into the brick chimney itself, where it would be difficult to remove, and would be a set-up for a dangerous flue fire. A thermostatically controlled ceiling fan above the stove pushes warm ceiling air down toward the floor.
>
You need to feed some of that preheated air back into the stove up near
where the flue exits the firebox, thus providing sufficient secondary air to
burn up all those combustibles before they hit the flue, or at least keep the
combustion going up into the flue.
Most wood heating stoves are pretty poorly designed, but can be modified with
a little thought and effort to become a clean burning gasifying stove.

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

From dstill at EPUD.NET Mon Sep 8 04:24:27 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
Message-ID: <MON.8.SEP.2003.012427.0700.DSTILL@EPUD.NET>

Harmon wrote:
> You need to feed some of that preheated air back into the stove up near
>where the flue exits the firebox, thus providing sufficient secondary air
to
>burn up all those combustibles before they hit the flue, or at least keep
the
>combustion going up into the flue.
> Most wood heating stoves are pretty poorly designed, but can be modified
with
>a little thought and effort to become a clean burning gasifying stove.
>
Dear Harmon,

How do you make sure that flame is always present to ignite the gases?

Best,

Dean

From crispin at NEWDAWN.SZ Mon Sep 8 03:52:07 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
Message-ID: <MON.8.SEP.2003.095207.0200.CRISPIN@NEWDAWN.SZ>

Dear Richard

I agree with Harmon: masses of creosote and soot in the pipe is a sign of
poor combustion or deliberate air starvation. It might be accumulating only
when the stove is cold, or when it is 'banked down' (starved of air) for the
night, or simply all the time because the air supply is so poor.

Try to avoid introducing the hot air at the exit of the stove or else you
will have a fire going in the pipe. A catalytic converter is also a
possibility.

Regards
Crispin

++++++++
>
You need to feed some of that preheated air back into the stove up near
where the flue exits the firebox, thus providing sufficient secondary air to
burn up all those combustibles before they hit the flue, or at least keep
the
combustion going up into the flue.
Most wood heating stoves are pretty poorly designed, but can be modified
with
a little thought and effort to become a clean burning gasifying stove.

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

From fmartirena_add at YAHOO.ES Mon Sep 8 05:52:13 2003
From: fmartirena_add at YAHOO.ES (Fernando Martirena)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and coffee-smoked sausages
Message-ID: <MON.8.SEP.2003.115213.0200.FMARTIRENAADD@YAHOO.ES>

Interesting what's been donde with the holey briquettes!!!

In separate message am sending you (Tom) pictures of our recent development
in the field of clay bound briquettes. We have -after a hint from the stoves
list, shifted to a holey sawdust briquette which burns far better than our
previous versions. We have also re-engineered the machine, which now is more
productive...

Greetings from Germany, where I am doing a post doctoral research till end
of oktober

fernando martirena
_____________________________
Jos? Fernando Martirena Hern?ndez (Prof. PhD Ing.)
University Gh Kassel
Fachbereich 14 Bauingeneurwesen
FG Werkstoffe des Bauwesens
M?nchebergstr. 7 D-34109 Kassel
tel: ++49 (0) 561 804-3967
fax: ++ 49 (0) 5 61 8 04-2662
e-mail: fmartirena@yahoo.es
website: www.ecosur.org

----- Original Message -----
From: "Tom Miles" <tmiles@TRMILES.COM>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Saturday, September 06, 2003 5:13 AM
Subject: Re: [STOVES] holey briquettes and coffee-smoked sausages

> Richard's pictures of briquettes can be seen linked to the Stoves page and
> at:
>
>
http://www.repp.org/discussiongroups/resources/stoves/Stanley/briqburn.html
>
> The top view reminds me of a stove we used to make that friends in the
> Peace Corps more than 20 years ago called a "Ghana stove". Sawdust was
> packed tightly in a can or tube with a hole formed in the middle and an
> air hole at the bottom. The stove was lit and allowed to burn from the
> inside out as it heated food in a pot.
>
> Thanks Richard
>
> Tom

From fmartirena_add at YAHOO.ES Mon Sep 8 06:08:56 2003
From: fmartirena_add at YAHOO.ES (Fernando Martirena)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Vertical Shaft Charcoal Kiln
Message-ID: <MON.8.SEP.2003.120856.0200.FMARTIRENAADD@YAHOO.ES>

Dear Richard

Thanks for your interest in VSBK. I will insert a few comments direct on
your text.

regards, fernando martirena

(ecosur Cuba-Nicaragua)

----- Original Message -----

From: "Richard Boyt" <rdboyt@YAHOO.COM>

To: <STOVES@LISTSERV.REPP.ORG>

Sent: Saturday, September 06, 2003 9:25 PM

Subject: [STOVES] Subject: Vertical Shaft Charcoal Kiln

> Subject: Vertical Shaft Charcoal Kiln
>
> Stovers:
>
> I am fascinated by Tom Jones's description of the Chinese vertical shaft
brick kiln. I pity those poor fellows who must load the unfired brick while
working directly in the hot plume of upwelling coal-fired exhaust gasses.
Unfortunate that no temperatures of firing were given. I suspect that the
maximum brick firing temperatures may have been rather low, perhaps even as
low as 400 degrees C (750 degrees F), which would produce a soft brick, but
would have the advantage of maintaining the strength and prolonging the life
of the steel supporting rods.

(FM1) Firing temperature must be higher, I'd rather say 900 C, otherwise the
brick will not be burnt thorughly. I must say, however, that temperatures at
the top of the kiln are not so high -though yet high enough as to make the
workers unconfortable- because the burnig chamber is in the middle of the
shaft. The process takes advance of the hot gases going upwards from the
burning chamber, which will prepare the green bricks for the burning
(drying)

> The vertical shaft brick kiln being tested in Nicaragua has reported
difficulties in getting the fire started. Was the problem ever solved? If
so, how did they do it?

(FM2) The problem was basically a mechanical one. The bolt press that would
supposedly bear and bring the loading platform up and down got
jammed -basically because of the weight of the bricks- and it was therefore
difficult to move the platform up and down. This unfortunately limited the
possibilities of regulating the firing time and some bricks resulted
underfired. This problem is currently being solved

From rstanley at LEGACYFOUND.ORG Mon Sep 8 02:21:29 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
Message-ID: <MON.8.SEP.2003.092129.0300.>

Dean,

You have always been a bit silent when it comes to gassifying. I noted your
reference to Larry's earlier-and extensive- gassification work but then your
institutes subsequent decision to stay with what I understand as 'direct
combustion'. I ask this not as a reporter looking for contest but rather
because fellow stover, Kobus Venter and I are making a gassifier stove
specifically for the briquette (actually he is doing the brunt of the design
and fabrication work and I am advising on it from the briquette production
standpoint).
My interest was sparked because of hte hoigher efficiency they offer and
because the by product lends itself to charcoal enriched briquettes which
command a far higher price for the local producers in their local markets. It
also appears that seems that gassifers depend highly upon consistency in the
kind, shape and thermal values of the fuel load - and these are feaatures
which local biomass producerrs can and do control quite regularly in their
production of the holey briquette. For these reasons then it makes sense for
us but when the wood stove gurus like youself and Larry hold back on
gassification it gives me some reason for concern.

Your Rocket stove design is, while excellent, would appear to be somewhat setup
for function as a gassifier; Ie., it controls the fuel burn rate through
restriction of the burn to just thte ends of a limited size of fuel. Why
therefore, do you not take it the final step and consider secondary air feed ?
Is the gassification process to finnicky or costly or unreliable for the added
benefit the user would receive ?

You questioned Harmon Seaver (below) when he suggested such, about the source
of the flame (apparently to keep the combustion of the volatiles going through
his proposed secondary air feed. I am puzzled by this as would the flame not
already be within the combustion chamber -- Perhaps this the reason you do not
pursue the idea of gassification ?

Curiously and with kind regards

Richard Stanley
Kamapla

Dean Still wrote:

> Harmon wrote:
> > You need to feed some of that preheated air back into the stove up near
> >where the flue exits the firebox, thus providing sufficient secondary air
> to
> >burn up all those combustibles before they hit the flue, or at least keep
> the
> >combustion going up into the flue.
> > Most wood heating stoves are pretty poorly designed, but can be modified
> with
> >a little thought and effort to become a clean burning gasifying stove.
> >
> Dear Harmon,
>
> How do you make sure that flame is always present to ignite the gases?
>
> Best,
>
> Dean

From hseaver at CYBERSHAMANIX.COM Mon Sep 8 08:49:37 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
In-Reply-To: <000d01c375e2$aafef480$9b1e6c0c@default>
Message-ID: <MON.8.SEP.2003.074937.0500.HSEAVER@CYBERSHAMANIX.COM>

On Mon, Sep 08, 2003 at 01:24:27AM -0700, Dean Still wrote:
> Dear Harmon,
>
> How do you make sure that flame is always present to ignite the gases?
>

It's hard to imagine a fire burning in a parlor-sized box stove where the
flame wouldn't always be present to ignite the gases. By the time the fire
burned down low enough that the flames were smaller and near the bottom of the
stove, few if any combustibles would be going up the flue, right? Figuring out
exactly where to feed in the secondary air to achieve the best burn might take
some experimentation, but I know that the better designed old-time heating
stoves had a secondary air inlet right below the collar for the flue pipe, which
we always opened after the fire got burning well and the primary air feed was
closed down. This had a two-fold effect, one in that it fed air from on top of
the fire, helping to burn the gases, and secondly to reduce the power of the
draft from the hot chimmney which tended to suck air into the stove from all
over in those old non-airtight stoves.
And, of course, building the fire to burn from the top down when first
started would also help alleviate the creosote problem.

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

From hseaver at CYBERSHAMANIX.COM Mon Sep 8 09:09:18 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: Stoves for Space Heating
In-Reply-To: <004201c375de$766f48e0$2a47fea9@md>
Message-ID: <MON.8.SEP.2003.080918.0500.HSEAVER@CYBERSHAMANIX.COM>

On Mon, Sep 08, 2003 at 09:52:07AM +0200, Crispin wrote:
> Dear Richard
>
> I agree with Harmon: masses of creosote and soot in the pipe is a sign of
> poor combustion or deliberate air starvation. It might be accumulating only
> when the stove is cold, or when it is 'banked down' (starved of air) for the
> night, or simply all the time because the air supply is so poor.

He's cooling off the stove pipe by extracting heat from it, which is why the
creosote is being deposited right there -- normally with that sort of stove
design it would be deposited higher up in the chimney especially where it
exited the roof.

>
> Try to avoid introducing the hot air at the exit of the stove or else you
> will have a fire going in the pipe. A catalytic converter is also a
> possibility.
>

I don't think a fire in the pipe is a problem, we normally would see our
stove pipe glowing red during Winter when it was seriously cold and we had the
stove running wide open. Better to be burning those gases in the pipe than
allowing the creosote to accumulate in the chimney, then, after building up a
thick layer, igniting in an extremely hot, chimney destroying blaze.
Of course, and even better idea would be to add a more substantial secondary
burning chamber to the top of the stove made from something like a 20l or 56l
drum. And then add a refractory lining to the firebox in the stove to enhance
combustion.
Or get a better designed stove with a built-in secondary burning chamber like
the Vermont Castings models. Still, even those are perfect since the firechamber
walls are also the heat exchanger, which, as we know, reduces combustion
efficiency, which is why they all come with a cat converter now.

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

From rstanley at LEGACYFOUND.ORG Mon Sep 8 15:43:08 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:36 2004
Subject: Reflective insulation
Message-ID: <MON.8.SEP.2003.224308.0300.>

Kobus et al..

Interesting. Wonder is anyone has ever mixed in / coated the inner surface of the clay liner with / Mica or ?? to create a more relfective surface ?? Higher surface reflectance means by definition , lower rate of transmission of heat through the body which if everything else is equal, translates to lower operating temperatures of the liner body and probably a longer life.
Short o some other breakthrough, imagine Dean and George's refractory clay liner with Lenny's aluminum foil /sugar water sawdust liner

Richard Stanley
Nagaseru, Kampala

Dean, pls pass this to George:
Sebu, where in Uganda are you/were you working and are you planning to return ?

Kobus wrote:

> Richard S,
>
> You said:
> > Did you read this from guru Tom Reed
> > What if you coated the sleeve with a reflective material, or, you added a
> > liner inside the sleeve, (we talked about a 1/4" wire mesh to protect the your
> > sleeve or a plain insulative clay liner: what about making this out of a
> > reflective material one which could be removed and cleaned periodically. ..
>
> My reason for using refractory ceramics (riser sleeves) from the start as opposed to using steel or clays was due to the insulative and reflective nature of these ceramics. As Tom R says "Insulation can work in two ways - by slowing the conduction of heat or by stopping radiation of heat by reflecting the heat back to the source". Risers do both very well and being almost snow white in colour (does not get dirty at all) it reflects and radiates infra-red light/heat exceptionally well.
>
> Adding a wire mesh to "protect" the riser from wear and tear sounds good, but would have to be made of titanium or something? The alternative is to use cheap wire mesh, which is replaced from month to month. Richard, also bear in mind that the fuel briquettes are not in contact with the side of the riser in the briquette gasifying stove, so I do not envisage any damage caused by scrapes in any case. As far as long term wear of risers or clays go, I would think risers would eventually wear out (lightly carcinogenic in other words) just like metal combustion chambers wear through. I am not sure on the life expectancy of say a 5mm thick steel cylindrical combustion chamber (Crispin, perhaps you could come in here), but a riser sleeve with a wall thickness of 20mm, used every day, should last 2 years burning charcoal or 4 years burning biomass. Perhaps someone else could give their thoughts on the wear rate of clays (used in a JIKO for instance). Mine are only educated guesses and
> going on what the manufacturers claim, and I am using a special silicon hardener to increase its durability.
>
> I would consider switching to non-refractory specific clays if someone manages to make white clay combustion chambers and it has good insulative properties.
>
> Regards
>
> Kobus
>
> ----- Original Message -----
> From: Richard Stanley <rstanley@legacyfound.org>
> To: Kobus Venter / HBGS <ventfory@iafrica.com>
> Sent: 04 September 2003 15:47
> Subject: [Fwd: [STOVES] Reflective insulation]
>
> > Kobus,
> > Did you read this from guru Tom Breed
> > What if you coated the sleeve with a reflective material, or, you added a
> > liner inside the sleeve, (we talked about a 1/4" wire mesh to protect the your
> > sleeve or a plain insulative clay liner: what about making this ot of a
> > reflective material one which could be removed and cleaned periodically. ..
> > Cannot ignore the power of four...
> > Thoughts for the moment anyway ,
> > anon,
> > Richard
> >
> > tombreed wrote:
> >
> > > Dear Dean and all:
> > >
> > > Insulation can work in two ways - by slowing the conduction of heat or by
> > > stopping radiation of heat by reflecting the heat back to the source. The
> > > second method is best where it can be employed. The radiation heat loss
> > > increases as T^4 power, while conduction is only T^1 power, so reflective
> > > insulation is particularly important in furnace design.
> > > ~~~~~~~~~~~
> > > The simplest example of both is the thermos bottle. There is a vacuum
> > > between the inner and outer glass to prevent CONDUCTION of heat through the
> > > gas. There is a layer of silver on the inside of the glass to prevent
> > > RADIATION.
> > > ~~~~~~~~~~~~~
> > > While at MIT I developed a TRANSPARENT furnace that uses a layer of gold on
> > > a Pyrex sleeve to reflect the heat back into the furnace. The gold is only
> > > 200 atoms thick so costs < $1 and the gold is transparent in the visible
> > > region of the spectrum, but >99% reflective in the IR. See for instance
> > >
> > > http://www.thermcraftinc.com/transtemp-furnaces.html
> > >
> > > Our company, Transept sold these furnaces for 25 years and I received ~
> > > $50,000 in royalties over that period. (MIT gave its inventors 5% of
> > > royalties, industry gives nothing.) Now the company has been sold to others
> > > and Bill King, President, is retired.
> > >
> > > ~~~~~~~~~~
> > > There are many ways to stop radiation heat loss.
> > >
> > > I was head of the crystal growth department at MIT (Lincoln Labs) and
> > > developed many high temperature furnaces. One of the highest used similar
> > > principles.
> > >
> > > A tungsten heating element can achieve temperatures > 2500 C (4500 F), but
> > > must be well insulated. We wrapped a 6 cm diameter by 10 cm high tungsten
> > > element in a coil of ~10 layers of embossed tantalum foil. The embossing
> > > kept contact between successive layers to a minimum.
> > > ~~~~~~~
> > > So I would urge all of you to consider wrinkled foil as an insulation where
> > > you can \keep it clean and where temperatures don't exceed the MP of
> > > aluminum (~600 C).
> > >
> > > Onward!
> > >
> > > TOM REED BEF STOVEWORKS
> > >
> > > Silver is the best IR reflector, Gold is one of the best, but aluminum foil
> > > also have a very high reflectance.
> > > Yours truly,
> > >
> > > Dr. Thomas Reed
> > > tombreed@comcast.com
> > > www.woodgas.com
> > > ----- Original Message -----
> > > From: "Dean Still" <dstill@epud.net>
> > > To: "ethos" <ethos@vrac.iastate.edu>
> > > Sent: Tuesday, August 26, 2003 1:39 PM
> > > Subject: [ethos] insulation
> > >
> > > > Dear ETHOS:
> > > >
> > > > Lanny Hensen shares a great recipe for use in places where aluminum foil
> > > > won't burn up...less than 700F, I think...
> > > >
> > > > I plan to add more plies of insulation to the inner
> > > > sleeve which will be aluminum foil with sawdust and sugar water (all
> > > common
> > > > materials) wrapped in about 6 plies to build up about 1/2". The sawdust
> > > and
> > > > sugar burn to make a crusty spacer to keep the aluminum foil from touching
> > > > itself. The aluminum foil is a good air barrier to block conduction,
> > > > convection. I tried
> > > > it on a camp stove, seems to work. This insulating method cheap, simple
> > > and
> > > > uses common materials if it proves to work.
> > > >
> > > > Peter Scott writes from Uganda:
> > > >
> > > > Just a couple of words. So I found my dream accomplice. This guy named
> > > > George Sizoomu. He has been building stoves for years and he has already
> > > > perfected an insulated brick in Uganda . 1 part rock dust , 1 part normal
> > > > clay, 1 part kaolin and 1 part fine sawdust by weight. Works out to 4
> > > parts
> > > > sawdust , 1 part other by volume. incredibly light!We fired a couple of 6
> > > > brick stoves using his mix and ours.
> > > >
> > > > Details to follow...By the way, I count 12 folks from ETHOS going to the
> > > > conference in Boulder!
> > > >
> > > > All Best,
> > > >
> > > > Dean
> > > >
> > > >
> >

From tmiles at TRMILES.COM Mon Sep 8 21:25:14 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:36 2004
Subject: holey briquettes and coffee-smoked sausages
Message-ID: <MON.8.SEP.2003.182514.0700.TMILES@TRMILES.COM>

See Fernando's press and briquettes on the Stoves web pages at:
http://www.repp.org/discussiongroups/resources/stoves/Martirena/briqpress.html

Tom
----- Original Message -----
From: "Fernando Martirena" <fmartirena_add@yahoo.es>
To: "Tom Miles" <tmiles@TRMILES.COM>
Cc: "Stoves List" <stoves@crest.org>
Sent: Monday, September 08, 2003 2:52 AM
Subject: Re: [STOVES] holey briquettes and coffee-smoked sausages

> Interesting what's been donde with the holey briquettes!!!
>
> In separate message am sending you (Tom) pictures of our recent
development
> in the field of clay bound briquettes. We have -after a hint from the
stoves
> list, shifted to a holey sawdust briquette which burns far better than our
> previous versions. We have also re-engineered the machine, which now is
more
> productive...
>
> Greetings from Germany, where I am doing a post doctoral research till end
> of oktober
>
> fernando martirena
> _____________________________
> Jos? Fernando Martirena Hern?ndez (Prof. PhD Ing.)
> University Gh Kassel
> Fachbereich 14 Bauingeneurwesen
> FG Werkstoffe des Bauwesens
> M?nchebergstr. 7 D-34109 Kassel
> tel: ++49 (0) 561 804-3967
> fax: ++ 49 (0) 5 61 8 04-2662
> e-mail: fmartirena@yahoo.es
> website: www.ecosur.org
>
>
> ----- Original Message -----
> From: "Tom Miles" <tmiles@TRMILES.COM>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Saturday, September 06, 2003 5:13 AM
> Subject: Re: [STOVES] holey briquettes and coffee-smoked sausages
>
>
> > Richard's pictures of briquettes can be seen linked to the Stoves page
and
> > at:
> >
> >
>
http://www.repp.org/discussiongroups/resources/stoves/Stanley/briqburn.html
> >
> > The top view reminds me of a stove we used to make that friends in the
> > Peace Corps more than 20 years ago called a "Ghana stove". Sawdust was
> > packed tightly in a can or tube with a hole formed in the middle and an
> > air hole at the bottom. The stove was lit and allowed to burn from the
> > inside out as it heated food in a pot.
> >
> > Thanks Richard
> >
> > Tom
>
>
>

From dstill at EPUD.NET Mon Sep 8 17:25:05 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: gasification
Message-ID: <MON.8.SEP.2003.142505.0700.DSTILL@EPUD.NET>

Dear Richard,

As you know, this is a touchy subject. As Crispin points out there seem to
be "two camps" here on STOVES. Studying how to make good $5 stoves for
people in poorer countries is my job here at Aprovecho. I'm lucky enough to
have a lab and with a team consisting of Dr. Larry Winiarski, Ken Goyer,
Damon Ogle, Peter Scott and Mike Hatfield here in Oregon we try to develop
materials and designs that are used by teams in Central America and Africa
to make stoves. I introduce my answer in this way because we help to make
stoves as well as researching about them. Metered burning is dictated by
cooks who are used to this pattern of combustion.

Dr. Winiarski studied gasification for more than a decade but then looked
for other answers because gasification was "finicky". His opinion is that
gasifying stoves are intriguing but that they require too much fiddling to
operate. So he turned his attentions to metered fuel solutions which, in his
opinion, are simpler, and more adaptable to the people with whom we work.
The open fire is operated in the same way as the Rocket stove. The
traditional stove used in Mexico is used in the same way as a Rocket stove,
sticks are pushed into the fire as they are consumed.

A basic tenant of Appropriate Technology is that any device needs to be
adapted to the situation. For the same reason, I'm sure that there is a
place for gasifying stoves. I'd love to cook with the Chinese straw gas
stove, for example. If I wasn't busy trying to improve the Rocket stove it
would be great to experiment with other approaches. Any effort made in
either 'camp' is well spent, in my opinion...

I do think, Richard, that there is a misunderstanding about adding secondary
air. It works wonders in batch loaded systems but not necessarilly in
metered combustion systems. I wish that just adding preheated secondary air
solved problems in the way that Harmon suggested as regards heating stoves.
"The WoodBurner's Encyclopedia" has a chapter on the futility of adding
preheated secondary air in many heating stoves because there isn't
sufficient flame, too. If you look in a 4 inch in diameter tube with a fire
at the bottom, you'll see that even such a small space isn't filled with
flame. Smoke escapes because the flame only fills a part of the space. In a
larger space, like a heating stove, flame fills a fraction of the interior
and smoke isn't combusted. Unfortunately adding preheated air only helps if
there is good mixing of fuel, air, spark, as in a top burning batch loaded
fire...

Baldwin in Biomass Stoves writes, " Injecting secondary air into the
diffusion flame may, in some cases, allow more complete combustion than
would otherwise be possible
Where an open firebox is used, however,
secondary air may lower efficiency by cooling the hot gases."
(Page 60)

The heat in a metered fuel stove comes from the fire in the combustion zone.
Using some of this heat to warm air cools the combustion zone. But we want
the combustion zone to be as hot as possible, in a metered fuel stove, to
assist clean burning. In the insulated Rocket combustion chamber
temperatures are very high everywhere, right up to the pot. There is also
oxygen everywhere in the combustion chamber . So adding preheated air would
only cool the Rocket type combustion zone and would serve no real beneficial
purpose. Unless pushed by a fan the force of secondary air does not
substantially improve mixing, unfortunately.

This is not true in a top lit, batch fire. There may not be enough oxygen
above the fire and the solution is to add secondary air. But the cleaning
up it creates does not necessarily occur in a non gasifying stove. A Rocket
stove is cleaned up by mixing fuel, air and spark. Adding preheated air does
not do in it what happens in a top burning batch fed combustion system.

By the way, simple folks like myself, find it easier to define gasification
as a system that combusts the smoke made in one vessel in a separate burner,
like the Chinese stove. Larry's gasified truck makes smoke near the bed of
the vehicle and burns it in the engine. Calling top or bottom lit batch
combustion gasification sure complicates our discussions, doesn't it?

All Best,

Dean

From crispin at NEWDAWN.SZ Tue Sep 9 07:31:28 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:36 2004
Subject: Subject: gasification
Message-ID: <TUE.9.SEP.2003.133128.0200.CRISPIN@NEWDAWN.SZ>

Dear Dean and Richard and all Interested Parties

I can't cover everything on this subject in one post and I feel that so many
things need attention that it might be best to discuss principles only so
that the most readers can get either benefit, elicidation or lost.

As Dean says, Aprovecho studies how to make $5 stoves. Well... they have
other stoves too that cost far more than that but there is an ideology in
place that seeks to bring low cost stoves to people all over the show.
Good.

As everyone is aware, this goal is hardly unique: India has make projects
with the same goal, Christa Roth in Malawi, Agnes Klingshirn, Ewert in
Namibia, Paul in Normal Ill., potters in Ethiopia and so on. There are a
lot of interested paties and Aprovecho is a well known one (and for good
reason).

There is no qualification to enter into this field of service, me being a
prime example with a background in AT of all sorts, but stoves was for me so
minor that it didn't even surface publicly for more than 15 years after
getting going on them. I truly knew nothing at all about stoves when I got
started at the Transkei Appropriate Technololgy Unit (now called ECATU) in
the early 80's. In the meantime I have collected design principles and
anecdotes to support them so that a 'significant leap' technology might one
day emerge. It was David Hancock who really pushed me to do something
concrete.

Dean mentions a 'touchy subject' and I am not sure this noble goal should
have such a thing. I find that when I say something with good intentions,
or when I 'speak the truth' as I see it, I can't know how that will be taken
by other people and what there reaction will be. I am trying to build a
scientifically rooted consensus on how to deliver more stoves that work well
to more people.

When there are serious disagreements as to what is going on in a stove in
terms of how it works, or how it should work, it can usually be resolved by
all parties having careful discussions on agreed terms so that scientific
truth, as it is understandable at the time, results.

The same cannot be said of ideological commitments to certain approaches to
people, technologies or intervention styles. When one takes an ideological
position on technologies, there both are plusses and minuses. One sounds
more 'committed' but one may miss a boat or two in passing. I feel that
open-mindedness is a prerequisite to discovering truth, and that independent
investigation of the truth is a prerequisite to establish what the truth is.
These two things, open-mindedness and independent investigation, are
separate things. Some people champion one more than the other, some
neither.

When seeking knowledge of how to approach the 'repair' of an existing
technology, the wood stove with the choked pipe, for example, one is best
equipped to deal with the range of possible solutions when both the above
principles are in full effect:

Close not thine eyes to alternatives, and
Know of thine own knowledge.

This list, like most internet groups dealing in technology, is full of
people who 'sell things'. Sometimes it is a product, or training, or egos,
or positions, or influence, or a place in history. I see nothing wrong with
that as the best way to get progress with stoves it to have people who are
committed to the subject give forth on their views and approaches. I think
it would be wrong to say about another, "He only says that because he has
something to sell." We are all selling something and the only possible way
to be fair is to declare your interest. There is no such thing as an
objective person who has not declared their interest. This is brilliantly
explained in William S Hatcher's recent book _Minimalism_ if you want to
know more.

I will start with Dean's statement, "Metered burning is dictated by cooks
who are used to this pattern of combustion."

In my experience, cooks will use anything that works well and is convenient
so I won't start off in my stove research with a commitment to metered
burning. But that is _my_ approach. Others may find something else. My
experience is largely limited to Southern Africa but Indians seem to be as
adaptable as Africans.

Fuel metering is a social interaction with the technology because people
have to do it, the stove does not do it by itself (well... very few do).
One must be careful not to make a technology decision based on a social
assessment: don't make a grate from cast iron because people cook porrige at
8 in the morning. One must separate how stoves work from how people work
with them, and wholism is the governing integrator. Arguments mustn't
confuse stove criteria, only integrate them.

As fuel metering is often mentioned in this group, it is worth looking at
the implications of different levels of interaction between the user and the
technology. A traditional three stone fire can indeed be described as a
fuel metered event. The user, in our region, must attend to the fire
approximately once in 20 to 40 minutes (average 30 minutes). The fire can
be left cooking beans for half an hour without attention. This has
developed into a requirement of the society. There are many things to do at
that time of day.

Social considerations are, in my view, predominant in the acceptance of a
technology. If the 30 minute rule was applied by a stove selection
committee, certain technologies would emerge as favourites: the Reed
Gasifier being one of them as the re-fueling interval suits what people
already do - light, then attend the fire every 30 minutes or so.

It may be that asking people to attend to the fire every 3 minutes (10 times
the amount of attention) is as significant a deviation from the norm as
asking people to use a completely different fuel or to cook a different
food. Changing some aspect of the technology by an order of magnitude (10)
is a very, very large change, even if in principle, the 'method of use' is
roughly identical. On the other hand, I hold that the three stone fire is
more analgous to a batch system than a continuous feed system because it can
be left along for long periods of time with a reasonable constant heat
level.

Dean correctly notes: "A basic [tenet] of Appropriate Technology is that any
device needs to be adapted to the situation." The question arises: what is
the situation to which we are adapting? Another is, are we adapting the
people to the technology or the technology to the people? As AD Karve
points out, people adapt all the time, and significantly too, when the
occasion warrants it. We must study people's reaction to proposed changes
and observe what people say, do, like and dislike. It would be wrong to
propose that a technology is not going to be acceptable because it requires
people to adapt. People do the strangest things when they want to.

I agree with Tom and Paul and the Chinese that there is a place for
gasifying stoves. Why? Because the closer I get to making one, the more I
can adapt the stove to suit multiple fuels and multiple cooking patterns all
while reducing the attention the cook must pay to the stove's operation.

Again I agree with Dean: "...there is a misunderstanding about adding
secondary air." The discussion about adding secondary air always seems to
be taken in isolation from other aspects of the stove's functioning (in my
experience of it). If the conclusion, after an exposition on cooling and
lack of flame to ignite and so on, is that _in principle_ secondary air
should not be introduced, then something is seriously wrong with the
argument. I agree there is a misunderstanding, but we do not agree on what
that misunderstanding is.

I described some time ago to this group how adding pre-heated secondary to a
Rocket stove might be done, and the immediate benefit thereof: well burned
fuel with much longer combustion chamber life (if made of metal). I won't
repeat it now. Pre-heated secondary air is not only about combustion, it
affects the stove life.

Secondary air does not have to be added above and away from the primary
combustion in the way a gasifier burns gasses away from the smokey fuel.
Put air jets where they do the most good. That 'good' may include cooling
the outer surface, driving good mixing above the primary fire, cooling the
combustion chamber, stirring air here and there, burning coals and ash and
so on. Make no mistake, Rocket stoves and sheltered fires have secondary
air provision. In the Rocket it goes under the shelf, over the coals,
around the sticks and up the sides of the combustion chamber where it mixes
with unburned gases, combusting them.

Tom's camping stove is a true batch loader. Stoves like the Vesto (if there
are any others) are in part fuel metered. They burn hotter when there is a
greater amount of fuel (or more accurately, burning surface area) so one can
regulate the heat by putting in more or less fuel. The main difference
between sheltered fires (like the Rocket) and air controlled fires (like
most wood stoves) is that the air going to the fire can be controlled. This
is a difference in approach that is fundamental: fuel metering only v.s.
fuel /and/ air metering. There are a lot of good reasons for controlling
the air to a fire, but principally they are power control and clean
combustion.

Wood stoves and the average gasifiers are described as 'batch loaders' - you
put in wood and burn it for a long time then add more fuel. It is very
convenient and is a natural extension of the three stone fire: wood+match,
cook for a while, add wood. I find it odd that these devices can be
characterized otherwise, and simultaneously the Rocket stove be described
as being essentially the same as a three stone fire, whether in Mexico or
elsewhere. A three stone fire has the same use pattern as a batch loader.
You push in some wood and it burns for a while, then you push in some more -
a batch. A more accurate division of stove type might be batch-fed and
continuous-fed, this deriving from the amount of attention or frequency the
stove requires to add fuel. I can think of several stoves in each category.
There is thus no agreement on how to even characterize the stoves, let alone
how they work.

Let me continue: In Dean's final paragraphs that start, "The heat in a
metered fuel stove comes from the fire in the combustion zone..." there is
nearly no single phrase with which I agree, but there isn't space to deal
with it all here. Listing the statements (beliefs) it contains is to list
the reasons why the Rocket stove has not had a leap forward in performance
or emissions in the past decade. As far as I can see, you can't improve
significantly on the performance or convenience of a Rocket stove until you
start to add air control. I am not saying people should not build and use
Rocket stoves if they want to, but Dean's analysis of what and why and where
things are or even can or cannot happen in the stove does not match my
experience of reality. I will give only one simple example: When I add a
pre-heated (uncontrolled, REALLY simple) secondary air supply to the Rocket
stove, it doubles the attention interval from 3 minutes to 6 minutes or more
because more fuel can be fed in at once. I encourage people to try it and
report to the group.

I have little more to add at this time beyond this: I don't think it is an
accident that every large producer of wood stoves in the world, good, bad or
indifferent, has some form of air control on the device.

Sincere regards
Crispin

From adkarve at PN2.VSNL.NET.IN Fri Sep 12 11:32:00 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:36 2004
Subject: Failure of Improved stoves programme in India
Message-ID: <FRI.12.SEP.2003.210200.0530.ADKARVE@PN2.VSNL.NET.IN>

The National Programme on Improved Cookstoves (NPIC) was terminated by
the Government of India in the year 2002, because it failed to make any
significant impact. There exist various explanations as to why this
programme failed, but the fact remained that the housewives did not
accept the stoves that were offered to them under this programme. The
period during which the NPIC and also the national biogas programme were
implemented by the Government of India coincided with the period during
which Liquified Petroleum Gas (LPG) made tremendous advances in the
urban areas, without any propaganda on the part of the Government.
Currently, you would find hardly a household in the cities without LPG.
We, at Appropriate Rural Technology Institute, feel that NPIC failed
because the implementing agencies failed to take note of the changed
aspirations of the rural housewives. The village life in India
underwent drastic changes in the last two decades of the 20th century.
Bullock power was replaced by tractors, waterpumps, threshers, and
motorised vehicles. Villagers have T.V.s. There are telephones in the
villages having world-wide connectivity. People are wearing nylons and
terylenes instead cotton clothing, and using detergents to wash them.
The housewives are using plasticware, chinaware and stainless steel pots
and pans in the kitchen. On this background, and on the threshhold of
the 21st century, the Government of India wanted the rural housewife to
continue using dung cakes, cotton stalks, maize cobs and tree loppings
as fuel. She wanted more modern and user friendly fuels and cooking
systems. We are having great success in our own state in propagating
charcoal burning stoves that use charcoal produced from agricultural
waste (more eco-friendly, as no trees are cut for making charcoal). The
demand for the briquettes has outstripped the supply, which has
momentarily stopped due to the rainy season. We are still in the process
of refining our new compact biogas plant, which runs on waste starch,
but people are greatly interested in it and I am sure that it too would
be sold in large numbers, once the model has been standardised and we
start mass producing it.
A.D.Karve

From adkarve at PN2.VSNL.NET.IN Fri Sep 12 11:32:45 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:36 2004
Subject: Magnesium, Alzheimer's,
and Aluminum Cooking Pots. Was:Re: [STOVES] [Fwd: [STOVES] Haybox
& hotbag and reflective insulation]
Message-ID: <FRI.12.SEP.2003.210245.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Kevin,
thanks for the warning about aluminium. The aluminium containers that I
mentioned in my mail are not cookpots but just containers in which
grain, flour, cookies, atc. are stored. In the particular use that I
suggested, the containers would be used only for making the hotbox, in
which the cookpots would be kept. In India, we generally do not have
pots with handles. We use a pair of tongs similar to those used by
blacksmiths in Western cowboy movies, for lifting and holding the pots.
Being without hanldes, the pots can be easily nested into each other.
Yours A.D.Karve

Kevin Chisholm wrote:

>Dear AD
>
>As I get older, I become increasingly concerned about Alzheimer's Disease.
>Aluminum deposition in the brain is associated with Alzheimer's.
>
>It appears to me that the prime mechanism of Aluminum accumulation is lack
>of Magnesium in the diet. Apparently Magnesium and Aluminum are
>interchangeable in certain enzyme systems causing harm. Additionally,
>apparently Aluminums can replace Magnesium in the brain, allowing calcium to
>flood in, causing cell death. (Andrasi E et al., "Disturbances of Magnesium
>Concentrations in various brain areas in Alzheimer's Disease." Magnes. Res.,
>vol 13, no. 3, pp. 189-196, 2000)
>
>Similarly, with Parkinson's Disease aluminums can be a contributing factor
>in central nervous system degeneration. In one autopsy study, calcium and
>aluminums were elevated in the brains of victims of Parkinson's Disease, as
>compared to people with normal brains. (Yasui M et al., "Calcium, magnesiumand Aluminium concentrations in Parkinson's Disease.", Neurotoxicology, vol
>13, no. 3, pp 593-600, 1992)
>
>We should all be careful about using aluminums cookware if our diets are low
>in magnesium. In Third World Countries where successful diets and eating
>habits have been developed prior to the introduction of aluminums cookware,
>there may not be sufficient magnesium in the diet to protect against
>Aluminium entry into the body.
>
>Your suggestion of using nesting pots for heat conservation is excellent.
>Are there similar pots made with stainless steel? A safe way to proceed
>would be to use an Aluminium pot as the exterior pot, and to use a stainless
>inner pot that contacts the food.
>
>Kindest regards,
>
>Kevin Chisholm
>
>
>----- Original Message -----
>From: "A.D. Karve" <adkarve@PN2.VSNL.NET.IN>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Saturday, September 06, 2003 12:16 AM
>Subject: [STOVES] [Fwd: [STOVES] Haybox & hotbag and reflective insulation]
>
>
>> In India we can buy various sizes of aluminium containers with lids.
>>The containers are cylindrical, without handles, and the lids are flat
>>without knobs. A small container fits easily inside a larger one. By
>>using two such containers and sawdust to fill the space between them, we
>>made a hot box. It was not only cheap and durable, but it also gave the
>>desirable results.
>>
>
>

From solar1 at ZUPER.NET Fri Sep 12 19:37:31 2003
From: solar1 at ZUPER.NET (Sobre la Roca: Energ=?ISO-8859-1?B?7Q==?=a Solar para el
Desarrollo)
Date: Tue Aug 10 18:30:36 2004
Subject: [ethos] Hayboxes again
In-Reply-To: <001101c370aa$b171ead0$259ef3d8@D289YG11>
Message-ID: <FRI.12.SEP.2003.193731.0400.SOLAR1@ZUPER.NET>

Hi all,
Sorry I am jumping in so late on this thread but my trusty G3 was in the
compu hospital and I just now have managed to get back into the loop.

I don't remember the times for the Colorado event but hope we don't cross
wires and I hope that this arrives before then.

By the way I am writing from Bolivia. We have the distinction of having
made the most solar cookers, retained heat cookers and efficient wood
cookers in the country. Based on our user surveys we believe we can
demonstrate the best usage rate and technology transfer any where.

We call our project Ecological Cookers because it uses a combination of the
3 - solar, efficient wood and retained heat! That combination has helped us
overcome many earlier objections and problems in solar cooking course and
tech transfer.

Since the year 2000 we have participated in capacitating users of more than
1400 cookers. ok not much by some standards but then again we have some
interesting data to back us up.

Let me take a moment to say hello to Bruce Stalberg. Thanks to Bruce there
are hundreds of Solar cookers in Bolivia today. I say thanks to Bruce
because it was he who lit my fuse. Not only that but during 1999 his much
needed economical support was the key to us not drowning in oblivia. (play
on words). MUCHO THANKS BRUCE

Bruce wrote about Daniel Quispe. Well Daniel didn't last long on his own
and he came back to work for Sobre la Roca: Energia Solar para el Desarrollo
in 2001. Since then he has been part of our 3 to 5 man team, although
Daniel has mostly worked in the carpentry shop fabricating the "kits" we use
in our hands on ecological cooker courses. Daniel's brother Felix has
proven more adept at technology transfer than Daniel. It was Felix who
helped us in the Courses in North Potosi we did with Wilfred and Rotary
International. Through us Wilfred learned of Aprovecho and boy I'm glad he
did cuz he is one fire ball of enthusiasm and we understand Aprovecho style
stoves are now the vogue in Africa in part to his getting Larry to accompany
him there.

Even though I have been a renewable's bug since the mid seventies, it was
Bruce that brought solar cooking and retained heat cooking back to my
horizon. While he was in Bolivia Bruce taught a handful of courses and also
was instrumental in involving SOS Aldeas in Solar cooking. Bruce's courses
were among those I studied in developing our methodology that is currently
being used in our Ecological cooker courses.

Bruce, remember those cookers you found on the Island of the Sun in lake
Titicaca, being used for tool boxes after your course there! Bruce learned
about the Rocket stove from us thanks to the persistence of Dean Still who
keep sending me books until one finally got here. Bruce took a Rocket we
had given him to Argentina and then one to Paraguay. Later we saw results
of those seeds when we visited CEDESOL Paraguay last year. They had made
their own refinements but Bruce was the spark!

Let me regress to naming the Bolivian "hay box". Although Bruce's round
model was great and very efficient, we made ours square. That allowed the
use of several size pots, including those with handles. We like he, used
Styrofoam as the insulation. However our most recent and most popular model
is just a woven basket, some plastic woven burlap type bags and sheep's wool
sown in. More folks are amazed at how that combination can cook. it was
during our Bolivia Inti course that Jonathan Herve from France and I made
one in the north jungas of La Paz in 2002.

Even when we teach folks to make "the hay box" from jute bags, a basket and
wool, we use the term thermal cooker or retained heat cooker. We never use
the term Cocina magica or magic cooker. The last thing we want in
technology transfer is invoking images of "the white man" bringing "magic".
Besides, God's Word say He abhors magic.

I conferred with Dra. Esther Balboa , the vice president of our recently
formed Foundation called CEDESOL (as a result of agreements made during my
time in Paraguay with the ULOG engineer who taught Bruce solar cooking).
She suggested to use the term THERMAL COOKER or RETAINED HEAT COOKER instead
of cocinas sin fuego Fireless cooker or Magic Cooker.

Esther is an indigenous woman Doctored in Anthropology and mastered in
Sociology who speaks seven languages and was vice-presidential candidate
representing an indigenous party in Bolivia during the last elections.

So we urge you all to consider using THERMAL COOKER or RETAINED HEAT COOKER.
In Spanish it would be Cocina T?rmica o Cocina de Retenci?n de Calor.
Although "hay box" is the most historically correct, we have found that
using our terms helps in the technology transfer.

One reason why is because they are not magic. Another reason is that every
time you say their name, you are reinforcing the mind in why the cookers
work. that helps make the technology common. We have found that once it
becomes "theirs" it is much faster to propagate, and then THEY can do it.

We use the ULOG style box cooker in our course and we teach that when the
sun is not shinning or it is night or raining, use the retained heat mode
(Modelo de Retenci?n de Calor) to cook in the solar cooker. That has helped
our course participants average a 65% fuel savings, with 97% of the
participants using the solar cookers 3 times or more a week,

Our project demonstrates that solar cookers can be assimilated into the
Bolivian culture, resulting in a High usage rate.

97% of those surveyed used the solar cookers 3 times or more a week.
89% use the cookers 5 to 7 days a week. (In 2001 77% were in this category)
46% use the cookers 7 days a week.
81% used the solar cookers to prepare 2 or more meals a day.
14% cooked 3 meals a day in the solar cookers.
95% heated water for washing dishes or bathing in their solar cooker.
54% pasteurized water in their alternative cooking devices.
The participants developed a significant variety of uses for the solar
cookers.
These uses were disseminated to others through participation in the follow
up meetings (every 15 days during the six months).
The course results validate the methodology utilized throughout the course.

Even though we don't have the financing to build Rocket stoves and Retained
heat cookers with every solar cooker participant, we teach and demonstrate
their use during the 5 day hands on part of our courses, explaining how and
why they work and giving drawings and instructions so that those motivated
can make their own. - teaching to fish - many do go on to build their own
and that is our success. IT BECOMES THEIR TECHNOLOGY

Thanks for permitting us to participate in this discussion. We look forward
to one day sitting down and breaking bread with you all. mean time -
Thanks Bruce for your inspiration and much needed economical support. Just
look what has sprung from those seeds.

Wilfred - you wont believe this but I think Sak'ani really is the best
course we've done in the many dozens over these 5 years. I just got back
from there and soon Rotary will have a first class report on their use. I
got some fantastic pictures of Indigenous women doing traditional weavings
beside their solar cooker. All are very greatfull to Rotary!!!

Dean your constant fine tuning and encouragement has been a wonderful
inspiration to many but especially to me. God Bless you.

have a good time all in Colorado.
un abrazo caloroso
David and Ruth Whitfield

in a previous message, AES on 9/1/03 13:01 at aes@bitstream.net wrote:

>> Dean,
>>
>> What are they calling the haybox in Bolivia or Mexico? There is probably a
>> traditional equivalent.
>>
>> Tom
>>
>
>>> Dear Friends,
>>>
>>> Bruce Stahlburg reminded us on ETHOS last week that the Haybox (an
>> insulated
>>> box that cooks with retained heat) achieves the best heat transfer
>>> efficiency to the pot, dramatically increasing the effectiveness of
>> cooking.
>>> Bruce made the best Hayboxes that I've seen in Bolivia and he helps us
>>> remember that this simple technology saves fuel and, because the fire is
>>> used for a much shorter time, should help with emissions.
>>> All Best,
>>>
>>> Dean
>>>
--
"Just remember we have enlisted for the duration in service to the truth."
Chuck Colson's friend

David Whitfield

solar1@zuper.net
aguaviva@zuper.net
dewv@yahoo.com

http://www.solarcooking.org/media/broadcast/whitfield/bio-whitfield.htm
http://www.quickinfo247.com/86196/FCS
http://www.thehungersite.com

From crispin at NEWDAWN.SZ Sun Sep 14 15:18:18 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:36 2004
Subject: Failure of Improved stoves programme in India
Message-ID: <SUN.14.SEP.2003.211818.0200.CRISPIN@NEWDAWN.CO.SZ>

Dear A.D.

I note your comments on the spread of LPG without government assistance.
Paraffin is widely used here in Southern Africa.

We have recently received the results of a professionally conducted
marketing survey of 500 people on the acceptance the Vesto as a cooking
device. One remarkable output which was completely unexpected was that 52%
of those interviewed who routinely use paraffin - normally considered a
transitional fuel and a progression up from wood or coal - rated their
approval of the fuel as 1 out of 5, i.e. "highly unsatisfied". Only 15%
rated themselves as highly satisfied with paraffin: 5 out of 5.

Paraffin was widely claimed to be a dangerous fuel and is known to be the
cause the deaths of hundreds of people per year and the poisoning of
thousands of children who accidentally drink it from glass bottles.

While wood stoves are normally targeted at people who currently use wood,
there is clearly an opportunity to get people to switch from non-renewable
paraffin to renewable biofuels.

With best regards
Crispin

----- Original Message -----
From: "A.D. Karve" <adkarve@PN2.VSNL.NET.IN>
Sent: Friday, September 12, 2003 5:32 PM
Subject: [STOVES] Failure of Improved stoves programme in India

The National Programme on Improved Cookstoves (NPIC) was terminated by
the Government of India in the year 2002, because it failed to make any
significant impact.[snip]

From psanders at ILSTU.EDU Sun Sep 14 16:17:19 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:36 2004
Subject: Boulder meeting info please
Message-ID: <SUN.14.SEP.2003.151719.0500.PSANDERS@ILSTU.EDU>

Would someone please sent the info on the meeting in early October 2003 in
Boulder, Colorado, USA. Dates, objectives, and agenda. (and any intending
participants.)

Thanks.

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 psanders at ILSTU.EDU Sun Sep 14 16:36:40 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:36 2004
Subject: Small rotary chopper for larger chips
Message-ID: <SUN.14.SEP.2003.153640.0500.PSANDERS@ILSTU.EDU>

Stovers,

For fuels the small gasifiers (and other uses), I want to make "chips" from
twigs and thin branches up to 2 cm diameter, with 1 to 4 cm lengths. (Not
product the small "wood chips" that are everywhere in the USA and
elsewhere) In Mozambique we are attempting to make a guillotine-type
chopper (ala the diagram that Graham at Fluidyne has on his website.)

But I want to have a faster process.

1. Perhaps a modified rotary-lawn-mower. Consider a hole in the top of
the blade cover of the mower. Insert a stick into it an it gets wacked
off. Not a very standardized chip, and potentially dangerous use of the
mower. So what could I put onto the powered vertical shaft of the engine
that would better produce the chuncky pieces that I desire?

2. Another posibility is a modified rear wheel of a bicycle that is
stationary (supported with braces to keep it off the ground.) The power
person pedals at modest speed, uses the gear-shift to get the rear wheel
rotating at some appropriate speed. But instead of a tyre, (tire), the
rear unit is to have some chopper device that is spinning on the horizontal
axis.

Issues include the weight of the spinning "thing" and the positioning of
the stick so that it gets chopper or broken or ?? to make the appropriate
size pieces.

Anyone with ideas?

Thanks in advance.

From lanny at ROMAN.NET Sun Sep 14 18:30:30 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:36 2004
Subject: Small rotary chopper for larger chips
Message-ID: <SUN.14.SEP.2003.183030.0400.LANNY@ROMAN.NET>

Hey Paul,
There is a larger machine common around furniture manufactures that is
called a "Hog".
It is a hammer mill that shatters scrap wood into pieces about the size you
mentioned. I am not sure that you could scale it down but it may be worth a
look.
With any low powered chopper you will need a good flywheel for momentum.
Lanny

----- Original Message -----
From: Paul S. Anderson <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, September 14, 2003 4:36 PM
Subject: [STOVES] Small rotary chopper for larger chips

> Stovers,
>
> For fuels the small gasifiers (and other uses), I want to make "chips"
from
> twigs and thin branches up to 2 cm diameter, with 1 to 4 cm lengths. (Not
> product the small "wood chips" that are everywhere in the USA and
> elsewhere) In Mozambique we are attempting to make a guillotine-type
> chopper (ala the diagram that Graham at Fluidyne has on his website.)
>
> But I want to have a faster process.
>
> 1. Perhaps a modified rotary-lawn-mower. Consider a hole in the top of
> the blade cover of the mower. Insert a stick into it an it gets wacked
> off. Not a very standardized chip, and potentially dangerous use of the
> mower. So what could I put onto the powered vertical shaft of the engine
> that would better produce the chuncky pieces that I desire?
>
> 2. Another posibility is a modified rear wheel of a bicycle that is
> stationary (supported with braces to keep it off the ground.) The power
> person pedals at modest speed, uses the gear-shift to get the rear wheel
> rotating at some appropriate speed. But instead of a tyre, (tire), the
> rear unit is to have some chopper device that is spinning on the
horizontal
> axis.
>
> Issues include the weight of the spinning "thing" and the positioning of
> the stick so that it gets chopper or broken or ?? to make the appropriate
> size pieces.
>
> Anyone with ideas?
>
> Thanks in advance.
>
> 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 ronallarson at QWEST.NET Sun Sep 14 18:59:04 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:37 2004
Subject: Boulder meeting info please
Message-ID: <SUN.14.SEP.2003.165904.0600.RONALLARSON@QWEST.NET>

Paul:

Look at: http://www.sustainableresources.org/sr2003/program/schedule.html

and http://www.sustainablevillage.com/

which leads you to http://www.carebridge.info/sr2003/index.html

I leave on Friday AM for a prior commitment with my wife - but chair a
session with Dean Still and Mark Bryden on Thursday PM. I hope others
coming (maybe a dozen in all) will sign in on "stoves" as well.

Ron

----- Original Message -----
From: Paul S. Anderson <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, September 14, 2003 2:17 PM
Subject: Boulder meeting info please

> ---------------------- Information from the mail
header -----------------------
> Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
> Poster: "Paul S. Anderson" <psanders@ILSTU.EDU>
> Subject: Boulder meeting info please
> --------------------------------------------------------------------------
-----
>
> Would someone please sent the info on the meeting in early October 2003 in
> Boulder, Colorado, USA. Dates, objectives, and agenda. (and any
intending
> participants.)
>
> Thanks.
>
> 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 adkarve at PN2.VSNL.NET.IN Mon Sep 15 00:53:29 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <MON.15.SEP.2003.102329.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Crispin,
what exactly is paraffin? Is it the same as kerosene? It was used
extensively in India and it was the fuel of choice of the urban poor
because its price was subsidised to stop people from using wood or wood
charcoal. But after India joined the WTO, subsidies are being reduced.
So kerosene that used to cost Rs. 4 per litre now costs about 20. A
family using kerosene as cookifuel, requires daily about 1 litre of
kerosene. A rich family, using LPG uses daily only Rs. 10 worth of gas.
Using our charcoal made from agricultural waste and the special stove
and pots that we have designed, a family would need daily only about Rs.
5 worth of charcoal. The rural poor generally get their fuel free of
cost, and therefore they are reluctant to buy processed fuel. We are now
designing a kiln by which an individual family can convert its own
agricultural waste into charcoal and would thus have a pollution free
fuel. The charcoal made by the conventional process has about 20%
volatiles, and therefore it produces smoke and soot while burning,
whereas our charcoal, made by using our own kiln burns cleanly.
A.D.Karve

From adkarve at PN2.VSNL.NET.IN Mon Sep 15 00:53:48 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:37 2004
Subject: machine for cutting sticks and twigs
Message-ID: <MON.15.SEP.2003.102348.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Paul,
there exists a machine called a chaff cutter, which is used for chopping
fodder sorghum and millets into small pieces. It is regularly used in
India and is therefore available in stores selling agricultural
machinery. The machine comes both as a hand operated and electrically
driven model. It has a system by which the rate of feeding the material
can be controlled, so that you can get pieces of any desired length.
With sticks and twigs, the amount to be fed into the machine would have
to be smaller than green fodder, but it should work. The hand operated
model has a heavy flywheel.
Yours A.D.Karve

From elk at WANANCHI.COM Mon Sep 15 00:55:37 2003
From: elk at WANANCHI.COM (Elsen Karstad)
Date: Tue Aug 10 18:30:37 2004
Subject: Small rotary chopper for larger chips
Message-ID: <MON.15.SEP.2003.075537.0300.ELK@WANANCHI.COM>

Paul;

Forage choppers come in a variety of sizes and configurations, from
hand-powered rotary cutting blades suitable for chopping green Napier Grass
and green corn stalk/leaf through heavier powered versions of the same &
right up to robust 10hp choppers capable of taking the sort of tough
material you describe.

I've a 5 hp 3-phase chopper that I bought 'off the shelf' here in Nairobi.
It's made in India, but I've seen similar locally-made versions. It has an
approx. 15 kg. flywheel and tough angled cutting blades set at on a heavy
70cm dia.steel disk rotating at 1440 rpm.) There are slots in the
disk....... material fed into the side-mounted feeding chute is chopped by
the blades in a scissor action against hard steel set in the mouth of the
chute. The slots in the rotating disk allow the chopped material to pass
through to the other side of the disk where flat paddles fixed to the disk
propel the chips forward and out a chute at the front of the machine's
cowling (which fits over all moving parts).

It seems to be very efficient- fast and noisy. Output seems to be in the
range of a ton per hour wet weight. I've chopped coconut husk (keep the
blades sharp!) and quite a lot of rose flower trimmings for my
carbonisation experiments. I'll be testing a variety of other course
material soon- pineapple tops, small branches, dry corn stalk etc. Chopping
and drying allows a host of materials to be carbonised via my open-pit
downdraught system, and would be handy for your work with 'holey briquettes'
as well, I'm sure.

rgds;
elk

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, September 14, 2003 11:36 PM
Subject: [STOVES] Small rotary chopper for larger chips

From rstanley at LEGACYFOUND.ORG Mon Sep 15 03:38:17 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:37 2004
Subject: Boulder meeting info please
Message-ID: <MON.15.SEP.2003.103817.0300.>

Paul,

Sustainable Village conference
I'm presenting a workshop for the pre-conference with Engineers Without Borders
on Tues Sept 30th (1-5pm) and at the end of the conference; Sat Oct 04 (10 -
12 am). Tom Miles kindly poosted the conference information a while back for
the Stoves group but its the same link as Ron also provided. It looks like a
good place for many of us to meet and put faces to the virtual fraternity we
have developed. Can you make it out there ?

Reinventing the wheel:

On your thinking about chopping up wood. Here are a few thoughts based on some
previous experience in Tanzania.-- and again reinforced in observation of a
french machine in Bamako Mali. The bicycle wheel--as used in tact, on a bike,
is not the way to go for hard impact chopping as you propose. There is not
enough mass (rotational momentum) in the wheel ( even at its maximum rotational
veloicity --say 450 rpm--to provide the shear forces necessary for chopping,
nor is the axel strong enough to support the added weight of the required
concrete to create the necessary mass. Concrete cast into the wheel with a
(panga ?) blade inset could do for a while, but then the wheel bearings ad
relatively miniscule shaft dia. will not tolerate the increased load much less
the impact forces you will be imposing. It also ties up the bike for this
dedicated purpose.

If your purpose is for the lab I would go with Lanny's suggestion.

If you want it for ready replication in / by the village fundi, then cast a
separate wheel (using the same bike wheel dimensions but not the wheel parts)
in concrete about a dedicated shaft of say 20 mm dia (minimum) running through
sealed ball bearings. The panga (?) blade should be cast, not in a direct
radial configuration but at a curved radial pattern to "shear" rather than
"whack" off the wood. The use of sealed ball bearings is recommended to allow
you to adjust and hold a tight tolerance between the blade and the sheariing
plate(another chunk of same panga firmly mounted onto the frame. Best if this
can all be set up on the vertical (ie., disk rotates on the"flat" with shaft on
the vertical) such that the sticks can be fed by gravity through a feed chute
which insures straight feed into --and on through--the rotating blade,
hitting a stop which you will have mounted on the frame beneath the blade
"port" at the desired length. This imlies that you allow for an oval opening in
front of the blade to allow the sticks to fall through.

This kind of configuration works well with a simple under mounted crank /
connecting rod / treadle link to a foot pedal and allows you to easily
translate foot treadle motion into rotation of said vertical shaft. You could
go with a chain or rope drive but you do no want a high rotating velocity
Though if my undergrad physics is correct, it would garner far more energy you
will have the problem of far greater wear and tear on the machine, the problem
of balancing the wheel and more than anything, ensuring a consistent stick
length, as this depends upon gravity flow of same through the mentioned port
in front of rotating blade and on into the stop behind same. (Speed up the
wheel and the stick cannot fall rapidly enough to reach the stop --you
literally behead the process). "Slow-with-mass" is the way to go with hand
operated gadgets like this.

Given a suggested dia of a bike wheel using about 25kg /55 lbs of concrete
(which you hopefully invest mostly in the outer diameter), you may want to
also consider use of a thrust bearing at the bottom of the shaft (used clutch
throughout bearing off a manual shift car/truck is fine as long as you keep it
clean). All this well predates access to digital imagery and email back into
the 70's and the AT center we once ran in Arusha but unless my recollection is
faulty, it should still work. But not to reinvent th wheel, there are several
well proven Indian, Irish and French designs (which of course implys that
there are probably scads of others out there) which work on very similar
principles.

Aluta Coninua,
Richard Stanley
Kampala

From rstanley at LEGACYFOUND.ORG Mon Sep 15 06:51:22 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:37 2004
Subject: Small rotary chopper for larger chips
Message-ID: <MON.15.SEP.2003.135122.0300.>

Paul, Elsen et al.

We also have available, a recently built and field tested thresher masher
chopper (the "TMC-1") device which is hand or foot operated but it is too
light for the kind of wood chopping you are into. It could handle 20 mm
diameters of green wood at most but even this if far too large for use as a
feedstock for the holey briquette. The TMC does howeverr do wonders for most
eveything else (agro residues, plastic ployethelene shopping bags, paper ,
carton board etc.) as feedstock for the holey briquette.

I did not think it was quite appropriate for the Stoves site per se but if
there is interest, I will ask Tom Miles to kindly post it up on our 'photos'
section of the Stoves site.

Richard Stanley

From crispin at NEWDAWN.SZ Mon Sep 15 08:08:25 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <MON.15.SEP.2003.140825.0200.CRISPIN@NEWDAWN.SZ>

Dear A.D.

>what exactly is paraffin? Is it the same as kerosene?

Yes.

I asked the staff what they thought of paraffin and apparently the stoves
only last about a year, and require maintenance after 4 months so there is a
real gap in the market. The cost of buying aand maintaining a stove, fuel
included, for 3 years is about 3500 Rands which is simlar to a coal user
cooking with an 'mbaula' (open 25 litre paint can).

It is my hope to bring that total down to R1500 (device and fuel for 3
years) with mass production.

>We are now designing a kiln by which an individual
>family can convert its own agricultural waste into charcoal

I think this is a good interim approach. I hope that eventually a gasifier
will appear which can take the raw material directly and give a useful,
controllable flame.

Regards
Crispin

From steve at SUSTAINABLEVILLAGE.COM Mon Sep 15 08:54:47 2003
From: steve at SUSTAINABLEVILLAGE.COM (Steve Troy)
Date: Tue Aug 10 18:30:37 2004
Subject: STOVES - Boulder meeting info please
In-Reply-To: <200309150400.h8F404515228@ns1.repp.org>
Message-ID: <MON.15.SEP.2003.065447.0600.STEVE@SUSTAINABLEVILLAGE.COM>

>From: "Paul S. Anderson" <psanders@ILSTU.EDU>
>Would someone please sent the info on the meeting in early October
>2003 in Boulder, Colorado, USA. Dates, objectives, and agenda.
>(and any intending participants.)

Hi Paul,
The Boulder conference is October 1-4. Here's information on one of
the sessions most interesting for this list. For more details, see
http://www.sustainableresources.org and/or email me
<steve@sustainableresources.org>. Steve

Session 10: Feeding the World
Thursday October 2, 3:15 - 5:15 p.m.
Chair: Ron Larson, American Solar Energy Society, Boulder, CO

* Twenty Five Years Developing Vernacular Stoves
Dean Still, Aprovecho Research Center, Cottage Grove, OR

* An Arranged Marriage: Solar Cookers and Fuel-Efficient Stoves
Barbara Knudson, Walden University, Minneapolis, MN

* One Solar Cooking Technology: Success and Expanded Applications
Margaret Owino, Solar Cookers International, Sacramento, CA

* The Integrated Cooking Method - a Report from Rwanda
Wilfred and Marie Pimentel, Fresno, CA

* Simplicity, Efficiency, Effectiveness: A Case for Engineering Design of
Biomass Cookstoves in Developing Nations
Kenneth Bryden, Iowa State University, Ames, IA

===============================================================
Sustainable Resources 717 Poplar Ave.
Boulder, CO 80304
email: steve@sustainableresources.org web site:
http://www.sustainableresources.org
voice 303-998-1323 ext. 100, fax 303-449-1348

From ronallarson at QWEST.NET Mon Sep 15 13:08:10 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <MON.15.SEP.2003.110810.0600.RONALLARSON@QWEST.NET>

Crispin, A.D. (cc "stoves"):

Today you followed this comment from A.D. Karve
>
> >We are now designing a kiln by which an individual
> >family can convert its own agricultural waste into charcoal

with your "hope" as follows:

>
> I think this is a good interim approach. I hope that eventually a
gasifier
> will appear which can take the raw material directly and give a useful,
> controllable flame.
>
> Regards
> Crispin
>

Here are a few additions to your hope - with which I concur:

RWL:

1. I strongly urge not calling any such device a "gasifier" - but
rather call it a "pyrolyzer" - as the word "gasifier" typically means
striving for minimum charcoal production.

2. On this list we have discussed many ways to produce charcoal - but
typically the "kiln" approach does not do what you ask for - a "useful and
controllable flame".

3. To do what you suggest, I feel it is necessary to have top lighting
and controllable primary air and a separate (not necessarily controllable)
secondary air inlet. I first said this in late 1995 on the bioenergy list
in

http://www.repp.org/discussion/bioenergy/199512/msg00069.html

4. Many aspects of the design, including a "sketch", were continued by
me a few weeks later in
http://www.repp.org/discussion/bioenergy/199601/msg00028.html

5. At the urging of Tom Miles. the "stoves" list started up in February of
1996, with quite a few persons adding that they had successfully tested the
basic concepts - see http://www.repp.org/discussion/stoves/199602/ and
following.
I believe most who tried made it work - but especially recall testing
done by Tom Duke and Alex English. Alex got to pretty large sizes using
straws. I personally have had luck with raspberry stalks and pine cones -
but in general I was testing only with small "branches". At Approvecho this
past year, I successfully used corn cobs. Always little visible smoke - but
more teting still needs to be done.

6. I think that those trying to produce charcoal (with the qualifications
you have placed) at the household level from ag wastes will benefit by going
back to those discussions from 7 + years ago. There have been probably a
hundred messages since on what I think you are asking for.

Ron

From psanders at ILSTU.EDU Mon Sep 15 15:07:15 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: machine for cutting sticks and twigs
In-Reply-To: <3F6545DC.4060300@pn2.vsnl.net.in>
Message-ID: <MON.15.SEP.2003.140715.0500.PSANDERS@ILSTU.EDU>

Thanks to all who provided info about the "chopper".

A.D., could you please send more info (maybe a manufacturer's web site or
where I could get pictures) about what you described? Thanks,

Paul

At 10:23 AM 9/15/03 +0530, A.D. Karve wrote:
> Dear Paul,
>there exists a machine called a chaff cutter, which is used for chopping
>fodder sorghum and millets into small pieces. It is regularly used in
>India and is therefore available in stores selling agricultural
>machinery. The machine comes both as a hand operated and electrically
>driven model. It has a system by which the rate of feeding the material
>can be controlled, so that you can get pieces of any desired length.
>With sticks and twigs, the amount to be fed into the machine would have
>to be smaller than green fodder, but it should work. The hand operated
>model has a heavy flywheel.
>Yours A.D.Karve

From psanders at ILSTU.EDU Mon Sep 15 16:44:34 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: Boulder meeting info please
In-Reply-To: <3F656C3D.D3B47547@legacyfound.org>
Message-ID: <MON.15.SEP.2003.154434.0500.PSANDERS@ILSTU.EDU>

Stovers,

I may or may not see you in Boulder. Who will be there Friday afternoon
and later? Because I MUST teach a night class until 9:00 PM on Thursday in
central Illinois, and it will take 15 to 18 hours to drive to Boulder (on
my way to Utah by Tues 7 October). My wife and I can drive it, but not
arrive before Friday PM.

Ron wrote earlier that he is leaving Boulder Friday AM, but now Richard
wrote about a Saturday workshop. There was no info on the website that I
saw about Saturday or later activities.

Well, Richard is coming from Uganda, and Tom Reed lives in Denver area and
will be available, and others are from Boulder, and Dean and Mark might be
staying over on Friday evening. So, that could make for a great Friday
gathering (almost a mini-workshop) or something on Saturday AM or PM (or
even Sunday or Monday for me, but not for many others).

As for my contribution, I would have with me my "quite-finalized" version
of the Juntos Biomass Gasifier. I have started production in Mozambique of
25 of them, and am preparing the designs/pictures/descriptions for the
"USA-Europe-style" of home user who can shop at Home Depot or Menards or
Lowes or almost any decent hardware store.

So, should I hasten to Boulder (which I am very willing to do if justified
by meeting Stovers), or just casually arrive in Denver to see Tom R. on
Sunday or Monday?

Richard, please tell us the topic of your workshop on Saturday (and is it
different from you workshop on Tuesday?

And when and how much of the conference will really be about stoves
issues? Specifics, please !!!

Paul

At 10:38 AM 9/15/03 +0300, Richard Stanley wrote:
>Paul,
>
>Sustainable Village conference
>I'm presenting a workshop for the pre-conference with Engineers Without
>Borders on Tues Sept 30th (1-5pm) and at the end of the conference;
>Sat Oct 04 (10 - 12 am). Tom Miles kindly poosted the conference
>information a while back for the Stoves group but its the same link as Ron
>also provided. It looks like a good place for many of us to meet and put
>faces to the virtual fraternity we have developed. Can you make it out there ?

From psanders at ILSTU.EDU Mon Sep 15 16:53:54 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <002a01c37b0f$cee759a0$77387f41@oemcomputer>
Message-ID: <MON.15.SEP.2003.155354.0500.PSANDERS@ILSTU.EDU>

Stovers,

Richard Stanley sent an excellent item, but under the Subject of the
Boulder Meeting. So I have copied Richard's message below.

This is the basic info I thought might be out there among the
Stovers. Others, please comment. Richard, can you please provide any
photos or drawings or more specifications and info about your earlier
experiences? (Then in Boulder on Saturday 4 Oct we could discuss the fine
points of implementation.)

Paul

**** below is Richard's earlier message ***** (nothing added by me below
this line) **

Reinventing the wheel:

On your thinking about chopping up wood. Here are a few thoughts based on
some previous experience in Tanzania.-- and again reinforced in observation
of a french machine in Bamako Mali. The bicycle wheel--as used in tact, on
a bike, is not the way to go for hard impact chopping as you propose. There
is not enough mass (rotational momentum) in the wheel ( even at its maximum
rotational velocity --say 450 rpm--to provide the shear forces necessary
for chopping, nor is the axal strong enough to support the added weight of
the required concrete to create the necessary mass. Concrete cast into the
wheel with a (panga ?) blade inset could do for a while, but then the
wheel bearings ad relatively miniscule shaft dia. will not tolerate the
increased load much less the impact forces you will be imposing. It also
ties up the bike for this dedicated purpose.

If your purpose is for the lab I would go with Lanny's suggestion.

If you want it for ready replication in / by the village fundi, then cast a
separate wheel (using the same bike wheel dimensions but not the wheel
parts) in concrete about a dedicated shaft of say 20 mm dia (minimum)
running through sealed ball bearings. The panga (?) blade should be cast,
not in a direct radial configuration but at a curved radial pattern to
"shear" rather than "whack" off the wood. The use of sealed ball bearings
is recommended to allow you to adjust and hold a tight tolerance between
the blade and the sheariing plate(another chunk of same panga firmly
mounted onto the frame. Best if this can all be set up on the vertical
(ie., disk rotates on the"flat" with shaft on the vertical) such that the
sticks can be fed by gravity through a feed chute which insures straight
feed into --and on through--the rotating blade, hitting a stop which you
will have mounted on the frame beneath the blade "port" at the desired
length. This imlies that you allow for an oval opening in front of the
blade to allow the sticks to fall through.

This kind of configuration works well with a simple under mounted crank /
connecting rod / treadle link to a foot pedal and allows you to easily
translate foot treadle motion into rotation of said vertical shaft. You
could go with a chain or rope drive but you do no want a high rotating
velocity Though if my undergrad physics is correct, it would garner far
more energy you will have the problem of far greater wear and tear on the
machine, the problem of balancing the wheel and more than
anything, ensuring a consistent stick length, as this depends upon
gravity flow of same through the mentioned port in front of rotating blade
and on into the stop behind same. (Speed up the wheel and the stick cannot
fall rapidly enough to reach the stop --you literally behead the process).
"Slow-with-mass" is the way to go with hand operated gadgets like this.

Given a suggested dia of a bike wheel using about 25kg /55 lbs of concrete
(which you hopefully invest mostly in the outer diameter), you may want to
also consider use of a thrust bearing at the bottom of the shaft (used
clutch throughout bearing off a manual shift car/truck is fine as long as
you keep it clean). All this well predates access to digital imagery and
email back into the 70's and the AT center we once ran in Arusha but
unless my recollection is faulty, it should still work. But not to reinvent
th wheel, there are several well proven Indian, Irish and French designs
(which of course implys that there are probably scads of others out there)
which work on very similar principles.

Aluta Coninua,
Richard Stanley
Kampala

From psanders at ILSTU.EDU Mon Sep 15 16:57:55 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <3F659950.61116DFE@legacyfound.org>
Message-ID: <MON.15.SEP.2003.155755.0500.PSANDERS@ILSTU.EDU>

Richard,

Please send me the specifications. I am involved with briquettes in
Mozambique. Yes. please have the info posted at the website.

Paul

At 01:51 PM 9/15/03 +0300, Richard Stanley wrote:
>Paul, Elsen et al.
>
>We also have available, a recently built and field tested thresher masher
>chopper (the "TMC-1") device which is hand or foot operated but it is too
>light for the kind of wood chopping you are into. It could handle 20 mm
>diameters of green wood at most but even this if far too large for use as a
>feedstock for the holey briquette. The TMC does howeverr do wonders for most
>eveything else (agro residues, plastic ployethelene shopping bags, paper ,
>carton board etc.) as feedstock for the holey briquette.
>
>I did not think it was quite appropriate for the Stoves site per se but if
>there is interest, I will ask Tom Miles to kindly post it up on our 'photos'
>section of the Stoves site.
>
>Richard Stanley

From crispin at NEWDAWN.SZ Mon Sep 15 18:09:04 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:37 2004
Subject: machine for cutting sticks and twigs
Message-ID: <TUE.16.SEP.2003.000904.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

I have access to two different machines you could have a look at here in
Swaziland. One is from Uganda which is dreadful in execution but reasonable
in layout. The other is a roller-feed unit with a flywheel - very nice but
I didn't want to make it because of the right hand drive gears it has.

Gimme a call...

Regards
Crispin

From psanders at ILSTU.EDU Mon Sep 15 22:54:02 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: Haybox bibliography - additions please
Message-ID: <MON.15.SEP.2003.215402.0500.PSANDERS@ILSTU.EDU>

Stovers:

One of my students has put together the start of a bibliography about
Hayboxes. She has not yet finished. Many are on the Web. Two are by
Dean, but I do not recognize the other authors. I have NOT had a chance to
look them over yet.

Anyone have any additional items that should be included? Please send them
to me and I will get them onto the list.

Thanks.

Paul

****************** Bibliography (initial draft) about "Hayboxes **************

Bambrick, Frank and Hurley, Brian (1977). The haybox the energy saving
cooker. Dublin,
Ireland: Low Energy Systems.

Becker, Sheryl (n.d.) City Slicker Hayboxes. Retrieved September 5, 2003,
from Yahoo
Search Website: http://www.guidezone.skl.com/haybox.htm

Be environmentally friendly and use a hot bag for cooking with retained
heat-. [Brochure].
(n.d.) (Source: ProBEC stoves conference in South Africa )

Bridgwater, Mike (n.d.) Heat retention cooking vs.solar
cooking. Retrieved September 5, 2003,
from The Solar Cooking Archive, The Solar Cookers International Website:
http://www.solarcooking.org/wonderbaskets.htm

Cooking on Camp. (n.d.) Retrieved September 5, 2003, from the Camping and
Outdoor
Activities Website: http://indigo.ie/~rpmurphy/camping/Cooking.html

Cooking Primitive. (n.d.) Retrieved September 5, 2003, from The Inquiry
Net! Website:
http://www.inquiry.net/outdoor/skills/b-p/wb/cooking.htm

Cleovoulou, Mario (1997, January/February). Introducing fuel-saving
cooking methods in
southern Tamil Nadu. Social Change and Development. Retrieved from
http://www.cleovoulou.com/fuelsave.htm

De Lissa, N R (1919). En Casserole and haybox; the best cooking with least
fuel and utility
recipes (additional). London: Simpkin, Marshall, Hamilton, Kent & Co. Ltd.

Goldstein, Olga (1977). Solar food warmer and insulated cooker. Ste. Anne
de Bellevue,
Quebec: Brace Research Institute.

Haybox Cookery. (1997). Retrieved September 5, 2003, from The Centre for
Alternative Technology Website:
http://www.cat.org.uk/catpubs/tipsheet.tmpl?sku=05

Hayboxes. (1999 Spring/Summer). Talking Leaves. Retrieved September 5,
2003 from Lost
Valley Educational Center from the World Wide Web:
http://www.lostvalley.org/haybox1.html

Heath, Ambrose (1976). Haybox cookery. London: Barrie and Jenkins.

Retained Heat Cooking. (n.d.) Retrieved September 5, 2003, from The Solar
Cooking Archive,
The Solar Cookers International Website: http://solarcooking.org/ret-heat.htm

Rohde, Eleanour Sinclair (1939). Haybox cookery. London: G. Routledge.

Roth, Chris (2003, Spring). The Haybox: Why every household needs
one. Talking Leaves.
Retrieved September 8, 2003 from the World Wide Web:
http://www.talkingleaves.org/s03haybox.htm

Still, Dean (2001, September 13). Designing vernacular cooking stoves: A
quick summary for
the Shell Foundation discussions. Retrieved from Aprovech Research Center
on September 5, 2003 on the World Wide
Web:
http://www.shellfoundation.org/dialogues/household_energy/downloads/cooking.pdf

Still, D., Kness, J., Billetsen, B., Cox, G., Espenan, M., Nael, J.B.,
Nicholas, D., Subramanian,
M., & Zettler, D.F. (1996, July 3). Fuel Efficient Wood Stoves and
Hayboxes: Efficiency of Combustion, Operator Expertise, and Heat Transfer
Effeciency. Aprovecho Research Center. Retrieved September 8, 2003, from
http://www.efn.org/~apro/AT/stove96.html

The pots and the haybox. (2000). Retrieved September 11, 2003 from the
World Wide Web:
http://www.cc.jyu.fi/~hvirtane/cooker/node25.html

Welcome to the wonderful world of ULOG. (1998). Retrieved September 5,
2003, from
ULOG Website: http://www.ulog.ch/english/u_hay.html

************************ end ******************
Misc.
http://solarcooking.vjungle.com/mike_bridgwater1.asf (interview with Mike
Bridgwater)

From psanders at ILSTU.EDU Mon Sep 15 23:14:37 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
In-Reply-To: <01e201c37bad$1b0b7440$08630443@net>
Message-ID: <MON.15.SEP.2003.221437.0500.PSANDERS@ILSTU.EDU>

Stovers,

As usual, Ron has very good content in his message (repeated below.). I
have seen and hope to eventually include references to many of those very
early messages when I write a history of the development of these new type
of "gasifiers".

I will comment on one thing he said:

> 1. I strongly urge not calling any such device a "gasifier" - but
> rather call it a "pyrolyzer" - as the word "gasifier" typically means
> striving for minimum charcoal production.

Paul says:

A. When speaking to the general citizen (and the poorly educated in some
communities), the word "pyrolysis" and "pyrolyzer" are not well
understood. A "gasifier" is much more easily understood.

B. In my Juntos gasifier that is developing well (and will have a major
message within 5 weeks), developments are moving that will ALLOW (user
option) the burning of a much greater portion of the charcoal than was the
case in the initial Reed - Larson IDD stoves. That would pull the name
back toward use of "gasifier" instead of "pyrolyzer." The people for whom
A.D. Karve is producing charcoal from agro-wastes will not need to produce
or use much charcoal if (a big IF that is getting smaller) they can use the
agro-wastes directly for their cooking.

C. INHO, It is still too early to lock onto one name for this relatively
very new type of biomass-using stove.

Paul

At 11:08 AM 9/15/03 -0600, Ron Larson wrote:
>Crispin, A.D. (cc "stoves"):
>
> Today you followed this comment from A.D. Karve
> >
> > >We are now designing a kiln by which an individual
> > >family can convert its own agricultural waste into charcoal
>
> with your "hope" as follows:
>
>
> >
> > I think this is a good interim approach. I hope that eventually a
>gasifier
> > will appear which can take the raw material directly and give a useful,
> > controllable flame.
> >
> > Regards
> > Crispin
> >
>
> Here are a few additions to your hope - with which I concur:
>
> RWL:
>
> 1. I strongly urge not calling any such device a "gasifier" - but
>rather call it a "pyrolyzer" - as the word "gasifier" typically means
>striving for minimum charcoal production.
>
> 2. On this list we have discussed many ways to produce charcoal - but
>typically the "kiln" approach does not do what you ask for - a "useful and
>controllable flame".
>
> 3. To do what you suggest, I feel it is necessary to have top lighting
>and controllable primary air and a separate (not necessarily controllable)
>secondary air inlet. I first said this in late 1995 on the bioenergy list
>in
>
>http://www.repp.org/discussion/bioenergy/199512/msg00069.html
>
> 4. Many aspects of the design, including a "sketch", were continued by
>me a few weeks later in
>http://www.repp.org/discussion/bioenergy/199601/msg00028.html
>
>5. At the urging of Tom Miles. the "stoves" list started up in February of
>1996, with quite a few persons adding that they had successfully tested the
>basic concepts - see http://www.repp.org/discussion/stoves/199602/ and
>following.
> I believe most who tried made it work - but especially recall testing
>done by Tom Duke and Alex English. Alex got to pretty large sizes using
>straws. I personally have had luck with raspberry stalks and pine cones -
>but in general I was testing only with small "branches". At Approvecho this
>past year, I successfully used corn cobs. Always little visible smoke - but
>more teting still needs to be done.
>
>6. I think that those trying to produce charcoal (with the qualifications
>you have placed) at the household level from ag wastes will benefit by going
>back to those discussions from 7 + years ago. There have been probably a
>hundred messages since on what I think you are asking for.
>
>Ron

From messinger.roth at AFRICA-ONLINE.NET Tue Sep 16 02:37:54 2003
From: messinger.roth at AFRICA-ONLINE.NET (Christa Roth)
Date: Tue Aug 10 18:30:37 2004
Subject: Haybox bibliography - additions please
Message-ID: <TUE.16.SEP.2003.083754.0200.MESSINGER.ROTH@AFRICAONLINE.NET>

Dear Paul, Thanks for the effort to start a bibliography on hayboxes. The
african version of the hayboxes, which we call 'fireless cookers' or
'foodwarmers' is made out of an old basket and dry banana leaves. A
step-by-step picture instruction on how to do it is found on
http://ecoharmony.net/hedon/howto.php
Christa Roth, Food and Household Energy Advisor to the Integrated Food
Security Programme Mulanje, Malawi

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, September 16, 2003 4:54 AM
Subject: [STOVES] Haybox bibliography - additions please

> Stovers:
>
> One of my students has put together the start of a bibliography about
> Hayboxes. She has not yet finished. Many are on the Web. Two are by
> Dean, but I do not recognize the other authors. I have NOT had a chance
to
> look them over yet.
>
> Anyone have any additional items that should be included? Please send
them
> to me and I will get them onto the list.
>
> Thanks.
>
> Paul
>
> ****************** Bibliography (initial draft) about "Hayboxes
**************
>
> Bambrick, Frank and Hurley, Brian (1977). The haybox the energy saving
> cooker. Dublin,
> Ireland: Low Energy Systems.
>
> Becker, Sheryl (n.d.) City Slicker Hayboxes. Retrieved September 5,
2003,
> from Yahoo
> Search Website: http://www.guidezone.skl.com/haybox.htm
>
> Be environmentally friendly and use a hot bag for cooking with retained
> heat-. [Brochure].
> (n.d.) (Source: ProBEC stoves conference in South Africa )
>
> Bridgwater, Mike (n.d.) Heat retention cooking vs.solar
> cooking. Retrieved September 5, 2003,
> from The Solar Cooking Archive, The Solar Cookers International Website:
> http://www.solarcooking.org/wonderbaskets.htm
>
> Cooking on Camp. (n.d.) Retrieved September 5, 2003, from the Camping
and
> Outdoor
> Activities Website: http://indigo.ie/~rpmurphy/camping/Cooking.html
>
> Cooking Primitive. (n.d.) Retrieved September 5, 2003, from The Inquiry
> Net! Website:
> http://www.inquiry.net/outdoor/skills/b-p/wb/cooking.htm
>
> Cleovoulou, Mario (1997, January/February). Introducing fuel-saving
> cooking methods in
> southern Tamil Nadu. Social Change and Development. Retrieved from
> http://www.cleovoulou.com/fuelsave.htm
>
> De Lissa, N R (1919). En Casserole and haybox; the best cooking with
least
> fuel and utility
> recipes (additional). London: Simpkin, Marshall, Hamilton, Kent & Co.
Ltd.
>
> Goldstein, Olga (1977). Solar food warmer and insulated cooker. Ste.
Anne
> de Bellevue,
> Quebec: Brace Research Institute.
>
> Haybox Cookery. (1997). Retrieved September 5, 2003, from The Centre for
> Alternative Technology Website:
> http://www.cat.org.uk/catpubs/tipsheet.tmpl?sku=05
>
> Hayboxes. (1999 Spring/Summer). Talking Leaves. Retrieved September 5,
> 2003 from Lost
> Valley Educational Center from the World Wide Web:
> http://www.lostvalley.org/haybox1.html
>
> Heath, Ambrose (1976). Haybox cookery. London: Barrie and Jenkins.
>
> Retained Heat Cooking. (n.d.) Retrieved September 5, 2003, from The
Solar
> Cooking Archive,
> The Solar Cookers International Website:
http://solarcooking.org/ret-heat.htm
>
> Rohde, Eleanour Sinclair (1939). Haybox cookery. London: G. Routledge.
>
> Roth, Chris (2003, Spring). The Haybox: Why every household needs
> one. Talking Leaves.
> Retrieved September 8, 2003 from the World Wide Web:
> http://www.talkingleaves.org/s03haybox.htm
>
> Still, Dean (2001, September 13). Designing vernacular cooking stoves:
A
> quick summary for
> the Shell Foundation discussions. Retrieved from Aprovech Research Center
> on September 5, 2003 on the World Wide
> Web:
>
http://www.shellfoundation.org/dialogues/household_energy/downloads/cooking.
pdf
>
>
> Still, D., Kness, J., Billetsen, B., Cox, G., Espenan, M., Nael, J.B.,
> Nicholas, D., Subramanian,
> M., & Zettler, D.F. (1996, July 3). Fuel Efficient Wood Stoves and
> Hayboxes: Efficiency of Combustion, Operator Expertise, and Heat Transfer
> Effeciency. Aprovecho Research Center. Retrieved September 8, 2003, from
> http://www.efn.org/~apro/AT/stove96.html
>
> The pots and the haybox. (2000). Retrieved September 11, 2003 from the
> World Wide Web:
> http://www.cc.jyu.fi/~hvirtane/cooker/node25.html
>
> Welcome to the wonderful world of ULOG. (1998). Retrieved September 5,
> 2003, from
> ULOG Website: http://www.ulog.ch/english/u_hay.html
>
> ************************ end ******************
> Misc.
> http://solarcooking.vjungle.com/mike_bridgwater1.asf (interview with Mike
> Bridgwater)
>
>
>
>
>
>
>
> 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 steve at SUSTAINABLEVILLAGE.COM Tue Sep 16 04:46:51 2003
From: steve at SUSTAINABLEVILLAGE.COM (Steve Troy)
Date: Tue Aug 10 18:30:37 2004
Subject: Boulder meeting info please
In-Reply-To: <200309160400.h8G40j505711@ns1.repp.org>
Message-ID: <TUE.16.SEP.2003.024651.0600.STEVE@SUSTAINABLEVILLAGE.COM>

>As for my contribution, I would have with me my "quite-finalized"
>version of the Juntos Biomass Gasifier.

Paul,
In case you make it early, we have a big exhibit hall and about 160
exhibitors so far, entertainment and we expect a big turn-out of
people beyond those attending the conference. It would be great to
have your Juntos on display. We're giving free "poster board" spaces
to non-profits, charging for larger 5x10 and 10x10 areas (between
$400 and $850). We could give a free larger space to this Stoves
group though if you'd like to put a display together.
Steve
--

===============================================================
The Sustainable Village, LLC 717 Poplar Ave.
Boulder, CO 80304
email: steve@sustainablevillage.com web site:
www.sustainablevillage.com
voice 303-998-1323 ext. 100, 888-317-1600 fax 303-449-1348
Sustainable Resources 2003 <www.sustainableresources.org>
"Resources for the Developing World"

From aes at BITSTREAM.NET Tue Sep 16 22:41:25 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:37 2004
Subject: Haybox bibliography - additions please
Message-ID: <TUE.16.SEP.2003.214125.0500.AES@BITSTREAM.NET>

Paul,

Thanks for putting this together. It is quite an extensive list. I see
some references to Solar Cookers International but am not sure if included
is a book that Wilfred sent me on Haybox cooking in hard format. I don't
know if it is online or not. Wilfred, is it available electronically? If
so, it could be added to the list. It is called:

A Resource Book on Fire-Less Cookers/Cooking (The Hay Basket) Compiled by
Solar Cookers Int. (EA)

One thing to remember about these cookers is that there is not any one way
to build them and that, perhaps more importantly, they can be of very simple
and inexpensive design. They work as well as those engineered like a
Mercedes Benz.

See you in Boulder,

Bruce

From ronallarson at QWEST.NET Tue Sep 16 23:00:58 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <TUE.16.SEP.2003.210058.0600.RONALLARSON@QWEST.NET>

Stovers:

Today, Paul Anderson noted that I had said:
>
> > 1. I strongly urge not calling any such device a "gasifier" - but
> > rather call it a "pyrolyzer" - as the word "gasifier" typically means
> > striving for minimum charcoal production.
>
and Paul says:
>
> A. When speaking to the general citizen (and the poorly educated in some
> communities), the word "pyrolysis" and "pyrolyzer" are not well
> understood. A "gasifier" is much more easily understood.

RWL: I doubt this. Almost every culture will translate "pyrolysis" as
"charcoal making" (and get the concept right away) - and you will find that
I usually use this term ("charcoal-making" - not "pyrolysis") when talking
about a top-lit stove. On this list, I think it safe to talk about
pyrolysis and the distinction between it and gasification.

If you use "gasifier", I think the translation is apt to come out as
something very foreign to what we are talking about. Anyone out there in a
position to check my claim with some group that has never seen a "gasifier"?

>
> B. In my Juntos gasifier that is developing well (and will have a major
> message within 5 weeks), developments are moving that will ALLOW (user
> option) the burning of a much greater portion of the charcoal than was the
> case in the initial Reed - Larson IDD stoves. That would pull the name
> back toward use of "gasifier" instead of "pyrolyzer." The people for whom
> A.D. Karve is producing charcoal from agro-wastes will not need to produce
> or use much charcoal if (a big IF that is getting smaller) they can use
the
> agro-wastes directly for their cooking.

RWL: Note that A.D. and Crispin are asking how to make charcoal at the
household level - not how to consume it.
I'm anxious to see how efficient your charcoal combustion is within the
original charcoal-maker. My prediction is that it will be close to zero -
i.e. not able to keep at a boiling water temperature - the combustion of the
charcoal being too far from the pot. That has been the experience of
others.

Ron

> C. INHO, It is still too early to lock onto one name for this relatively
> very new type of biomass-using stove.
>
> Paul
>
RWL: Understood your position - but think it wrong. Still think there
are big problems in calling a charcoal-making stove a "gasifier" - where
minimum charcoal production seems to be a goal.
I have no problem with having "gasifier" stoves - but much prefer that
the name "gasifier" not be used for stoves intended to make charcoal - as
A.D. and Crispin seem to desire.

Ron

From psanders at ILSTU.EDU Tue Sep 16 23:18:49 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: Stoves booths at Boulder meeting!!!!
In-Reply-To: <a0521062cbb8c7bafea78@[10.0.1.2]>
Message-ID: <TUE.16.SEP.2003.221849.0500.PSANDERS@ILSTU.EDU>

Stovers,

How about presenting our stoves stuff at the Boulder meeting? My actions
are below in this message, but first I reprint Steve's comments, in case
you missed them:

At 02:46 AM 9/16/03 -0600, Steve Troy wrote:

>Paul,
>In case you make it early, we have a big exhibit hall and about 160
>exhibitors so far, entertainment and we expect a big turn-out of
>people beyond those attending the conference. It would be great to
>have your Juntos on display. We're giving free "poster board" spaces
>to non-profits, charging for larger 5x10 and 10x10 areas (between
>$400 and $850). We could give a free larger space to this Stoves
>group though if you'd like to put a display together.
>Steve
> The Sustainable Village, LLC 717 Poplar Ave. Boulder, CO 80304
> email: steve@sustainablevillage.com web site: www.sustainablevillage.com
> voice 303-998-1323 ext. 100, 888-317-1600 fax
> 303-449-1348
> Sustainable Resources 2003
> <www.sustainableresources.org>
> "Resources for the Developing World"

Too good an offer to pass up. Here is what has been approved and what is
possible (but not promised until Steve says it is arranged.)

A small booth (5 x 10) will be provided for the small
gasifiers/pyrolyzers. Paul Anderson is coordinating this booth and needs
contacts and approvals of some content by the others who could have inputs
(sorry for the short notice to Tom and Ron and John and others). The booth
will feature the work of Tom Reed, Ron Larson, Paul Anderson, John Davies,
and any others who have worked on these new gasifiers.

Steve said that Legacy Foundation (Richard Stanley) will have a booth about
briquettes.

If others have a booth or a poster, please tell us ASAP. Steve said that
posters could be up-graded to booths if needed.

We Stovers COULD have an additional 5 x 10 booth (or booths???) if SOON
(meaning THIS week) the contacts are made with Steve. Do NOT delay until
Friday. Get you thoughts out to appropriate people ASAP.

Dean Still told me tonight that transport from Oregon to Colorado is one
difficulty for Aprovecho to take a booth (and the need to have reasonable
coverage of the booth by a person who could answer questions.) But perhaps
others could assist with transport or coverage. Contact Dean.

And/or could there be an ETHOS booth??? (So I am sending this message
also to the ETHOS list serve -- sorry for double delivery to those who are
on both lists.)

Any other ideas??

Steve said that the booths are likely to be placed close to each other
because of similar interests. That could assist us with some issues of
coverage of the needed times.

We Stovers are truly blessed to have Steve Troy as a subscriber to our list
serve.
Thanks, Steve, for helping us with contacts to this conference.

(Until today I thought that I could not attend because of my teaching
schedule, but I have made arrangements to be able to attend the conference
as of mid-afternoon on Wednesday 1 October through to the very end. Much
to do before then.)

Paul

From dstill at EPUD.NET Tue Sep 16 04:18:57 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:37 2004
Subject: Testing Cookstoves
Message-ID: <TUE.16.SEP.2003.011857.0700.DSTILL@EPUD.NET>

Testing Cookstoves
By
Dean Still and Damon Ogle
Aprovecho Research Center

In June of 2003, approximately twenty people met at the Aprovecho Research
Center near Eugene, Oregon to compare various wood burning cooking stoves
most of which are now used in either Central America or Africa. The stoves
were tested using a Water Boiling Test. This test has been used at Aprovecho
for many years. Energy in the fire heats water up to boiling and by
measuring the sensible (by rise in water temperature) and latent heat (by
amount of steam generated) the thermal efficiency of the stove is
determined. The amount of heat entering the pot divided by the total of heat
released from the burning wood results in a percentage. Higher percentages
indicate a stove that has improved thermal efficiency. This test is
frequently called Percent Heat Utilized (PHU).

After comparing the performance of many stoves side by side, doubts about
the approach forced a re-examination of the literature on testing. In the
Aprovecho tests stoves that burned at high power exclusively, using up fuel
quickly, scored higher than other stoves that boiled food as quickly but
then simmered the water at slightly less than full boil for much longer time
periods. The same amount of wood was used in all tests and it seemed
reasonable to expect that the stove that kept food at near boiling
temperatures for the longest time would be the most fuel efficient when
cooking food. Somehow the PHU test did not seem to be predictive of success
at cooking food.

Rereading Baldwin, Prassad, Visser and the VITA 1985 International
Standards, an undivided wall of opinion confronted the bemused Aprovecho
testers. The books and articles explained that the PHU test does not
accurately predict success at cooking, even though the use of the test
continues to be almost universal. The VITA International Standards, for
example, are based on an entirely different approach to testing stoves that
determines the wood used in high and low power operation of the cooking
stove. As the literature points out, knowing the rate of wood used at high
power (when the water is being quickly brought to boil) and at low power
(when the water temperature is kept steady while simmering) can be used to
more accurately predict fuel use for different cooking tasks.

Stoves that produce a lot of steam score higher on the PHU test. When
cooking, however, the production of excess steam is just a waste of energy.
Considerably more steam is made at 100C than at 98C so the stove that
maintains the water temperature at 98C does not score well although that
same stove will probably use less wood when cooking beans, for example. The
rewarding of the production of excessive steam in the PHU test seems obvious
when contemplated. But testing is a complex subject and the alternative
method, (Specific Consumption) although promoted by the best-known authors
in the field, and adapted at an international conference, has not become
well known.

The use of PHU over the years may have masked the importance of adequate
turn down in stoves. Prassad and Visser have explained repeatedly that only
a small part of the energy used in bringing water quickly to boil is
necessary to keep water simmering, when replacing the energy lost from the
pot. Stoves that do not have the ability to deliver small amounts of heat
will not simmer food efficiently. Much of cooking is simmering, which can
occur for an hour or two. Scoring well on the PHU test requires producing
excess energy during the entire burn. A test that does not reward successful
turndown in a stove ignores a reality of cooking.

Reading about testing exposes the reader to the vast, thoughtful expertise
of the researchers who spent decades studying cooking stoves. Two
unfortunate problems become apparent. In some way, the suggested transition
to a more predictive testing method has not penetrated into general
awareness. The benefits of the alternative testing methods could assist the
entire field to create stoves that more successfully reduce fuel
consumption. And, while a great deal of agreement exists in the literature
concerning how to improve both heat transfer and combustion efficiency, this
hard won knowledge does not seem to have resulted in a generation of stoves
with the improved characteristics. The apparent consensus that defined good
engineering practice may not have reached the ears and minds of stove
builders.

A technological revolution, the Internet, brings the diverse, worldwide
community of stove makers into closer contact. Lists of people interested in
stoves allow for very satisfactory, rapid information exchange. Consultants
in Africa can draw on assistance from groups of hundreds of professionals
who are eager to help create improved cooking technologies. Perhaps this
brave new world will facilitate the real communication that may have been
more difficult even ten years ago. Making best use of the invaluable body of
knowledge, from authors such as Baldwin, Prassad, Visser, et al., that could
benefit those in need, seems more likely, today. Hopefully, the retarded
passage of knowledge into practice adds a momentum to some degree fueled by
twenty years of missed opportunity.

From crispin at NEWDAWN.SZ Wed Sep 17 06:18:16 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <WED.17.SEP.2003.121816.0200.CRISPIN@NEWDAWN.SZ>

Dear Ron

I hope, a couple of clarifications:

Paul
>>>1. I strongly urge not calling any such device a "gasifier" - but
>>>rather call it a "pyrolyzer" - as the word "gasifier" typically means
>>>striving for minimum charcoal production.

I think we need to look at this definition closely. I agree with it because
if I am making a grass gasifier, I don't expect there to be anything left at
the end. Although the 'burning' of charcoal was mentioned further down, I
am still thinking of gasifying it - i.e. driving off the carbon as CO and
burning it close to the pot with some distance, perhaps, between the carbon
and the pot.

and Paul says:
>>A. When speaking to the general citizen (and the poorly
>>educated in some communities), the word "pyrolysis" and
>>"pyrolyzer" are not well understood.

I certainly agree there. I haven't met anyone outside this group who knows
what the words mean at all.

>>A "gasifier" is much more easily understood.

I agree with this in principle as 'gas' is knows to be just that: 'Handigas'
or 'propane' or 'natural gas' or 'methane' or 'biogas'. A 'wood gasifier'
gives one the idea that the wood is turned into gas. A 'pyrolyzer' that
turns wood into gas with a slightly different co-intention is still a type
of gasifier: it turns wood into gas.

In Swaziland there is the additional complication that 'gezi' which is the
word for 'gas' also means electricity as all lighting used to be piped gas
and 'gezi' came to mean 'light' and fitting electricity is of course adding
'lights' to your house. The best local name would be 'wood-gas stove'.

>RWL: Note that A.D. and Crispin are asking how to make
>charcoal at the household level - not how to consume it.

Actually it was my unexpressed vision that the fuel be totally consumed as
in a Vesto. This happens in two stages at a low power setting: wood is
largely charcoaled then the charcoal is burned by opening the air supply. I
was thinking of a gasifier in which there is a physical separation between
the initial combustion and production of gases and the subsequent burning of
them. I think Paul described this definition first.

>RWL: I'm anxious to see how efficient your charcoal combustion is
>within the original charcoal-maker.

This differs from my vision of the gasifying device. If the charcoal is
burned to CO2 somewhere in the gas-producing chanber, it might be difficult
to deliver the heat to the pot unless it is well insulated or entrained in a
vortex passing through a reflective pipe, or moving the whole fire towards
the pot.

>RWL: My prediction is that it will be close to zero -
>i.e. not able to keep at a boiling water temperature - the
>combustion of the charcoal being too far from the pot.
>That has been the experience of others.

Well...OK,...but maybe others will have different approaches to getting the
heat to the pot, or else will be able to create CO at a reasonable
efficiency and deliver the (very hot) CO to the pot 'burner' and reduce it
to CO2 giving a useful heat output. One might also be able to lift the
charcoal produced towards the pot with a lever and burn it directly to CO2.
It seems unwise to limit a designer too much by saying that the charcoal is
'too far from the pot' and therefore a stove of that type can't be made to
work usefully.

I feel that this name splitting are really semantical and not based on a
technical analysis because if challenged theoretically, one can put up a
good case that all fires are gas fires, thus all stoves are wood or coal or
charcoal 'gasifiers'. These definitions sound arbitrary, especially when
one gets innovative about the layout and function.

I can't defend the division of products into stove groups based on the
amount of charcoal left. If it has, say, 15% charcoal production, then a
Welcome Dover coal stove with wood burning in it would be classified as a
pyrolyzer, as it produces more % charcoal than many semi-professional
Mo?ambicano 'charcoal makers' working in the forest.

I am worried that handy definitions that apply to particular situations or
constructions will lend people to think that other layouts will not provide
better or workable stoves.

One example I can give, sourced from this list, is the idea that _only_ a
high hot gas velocity past the pot can give better heat transfer rates.
This is frequently mentioned and ideas about scrubbing and boundary layers
are cited, as well as good quality emperical data from tests to show the
idea correct. However this is only one man's view of the elephant.

Feeding hot gases past the pot at a very low speed is also an effective way
to very high heat transfer. Thus to say that the _only_ way to get higher
heat transfer (implying that this is true under all conditions) is to speed
up the gas flow past the pot, limits ones approach to heat transfer and
therefore stove design problems. This limitation and the statement creating
it are rooted in an inaccurate conceptualization of how heat transfers from
molecule to molecule in gases. I mentioned this before: all heat transfer
from gas to pot is by radiation, not 'conduction' (unless the gas
temporarily becomes attached to the crystal structure of the pot).
Bascially there is no such thing as 'conduction' of heat between fire
combustion products and the pot though we tolerate the term in discussion.

Given a 'normal' stove with a certain amount of heat being transferred,
there are two ways to increase the heat transfer efficiency: close the gap
and increase the speed of gas flow, or close the gap and _reduce_ the speed
of gas flow. At very low speeds, one might not need to reduce the gap to
get an increase. This is 'apples'.

This analysis says nothing about the losses one might have in the stove body
between the fire and heat transfer zone which is a completely separate issue
('oranges') and is related to the device, not the theory and practice of
heat transfer. It would be incorrect to reply to my argument, "The losses to
the stove body would reduce the _overall_ efficiency of the device if the
gas flow is reduced." So what. That may or may not be true depending on
the device - you could design your way around it.

Having a cute statement about or name for a practical truth in an average
situation may not illuminate a student about the theory underlying it and
therefore poses the risk of railroading stove builders into certain ways of
thinking about what is possible. Such cute statements are like charts: an
inaccurate representation of a partially understood truth.

Gasifier? Pyrolyzer? To the average user it is still just a stove.

Thanks for the opportunity to ruminate
Crispin

From rstanley at LEGACYFOUND.ORG Wed Sep 17 06:59:35 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:37 2004
Subject: Stoves booth: CU at Boulder ?
Message-ID: <WED.17.SEP.2003.135935.0300.>

Fellow Stovers,

The idea of a dedicated Stoves booth at the forthcoming Sustainable
Village conference in
Boulder (1 - 4 Oct), placed right in our soot filled hands, is tempting
indeed.
I'm planning on bringing in a briquette gassifier stove prototype made
by fello stover, Kobus Venter, if Ugandan, moreso, US Customs does not brand
it a retort for refining "dangerous materials"---but that may be
nothing, compared to what they are probably going to say about
an unaccompanied guniea sack of briquettes.

Hope to meet as many of you there as possible. For our two cents we
will be
running a hands-on and theroetical workshop on the 30th Sept (Tues) and again
on the 4th Oct in the "CU" Lab.

CU there

Richard Stanley
Kampala

From dstill at EPUD.NET Wed Sep 17 15:48:44 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:37 2004
Subject: making insulative bricks for combustion chambers
Message-ID: <WED.17.SEP.2003.124844.0700.DSTILL@EPUD.NET>

Dear Friends,

Just a quick note about making sawdust/clay insulative firebrick. Yesterday
the Aprovecho class made a production line and timed brick making using the
following recipes:

500 grams sawdust (fine only)
1000 grams ball clay (dry)
1600 grams water

This was our light mix.

The heavy mix was:

500 grams sawdust
1200 grams clay
1800 grams water

Since the water and sawdust are consumed in the firing process the weight of
the brick is the weight of the dry clay minus 14%, the weight of water of
hydration. We aim for bricks that are about half the weight of an equal
volume of water.

It was easy for the class to make a brick per minute, individually preparing
the mix for each brick. One group sifted sawdust, another measured
ingredients into bowls, another hand mixed. Then others added water and
mixed. The bowl was then handed to another station that filled molds. The
molds had paper liners. The wet brick was immediately dropped gently out of
the mold onto drying boards which were taken to the wood fired dryer.

We agreed that this operation could be fine tuned to produce two to three
times more bricks per minute. If a cement mixer was used the process would
be much faster. We are now drying the bricks and I'll bring some to Boulder.

All Best,

Dean

From psanders at ILSTU.EDU Thu Sep 18 00:21:42 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:37 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
In-Reply-To: <3F68CCC2.CF2E4D8F@treeswaterpeople.org>
Message-ID: <WED.17.SEP.2003.232142.0500.PSANDERS@ILSTU.EDU>

Stuart and Dean and others.

Maybe the booths will be close together.

Steve Troy is providing us with a second 5ft wide by 10 ft deep booth to be
beside the one for the small gasifiers. That second one will have
additional stoves and stoves-related items. I need to make sure that it is
well utilized, so anyone can send me info. For example, Crispin's Vesto
stove has been sent to Steve, so it could go in there also.

Concerning any Aprovecho or other stove, I think the source of the stove
should decide if they want someone else to bring one of their stoves. That
is, Dean and his group will need to tell you if they want the
"funky-looking" stove to be shown, painted or not painted. Perhaps there
is some way you could assist Aprovecho to transport some Rocket stove
materials to Boulder.

Another use for the second booth could be a place to show the Legacy
Foundation briquette-making materials (or some of them) on the Thurs and
Friday between the Wed and Sat workshops.

A couple of guidelines if anyone wants to put something in the second booth:
1. Fairness of display and space for all who use it.
2. Provide signs or info or something to tell what it is.
3. Do NOT put valuables in the booth, because there might not be
a person to supervise the booth for every hour.
4. Be sure you have thought of what will be done with the items
at the end of the show.
5. I (Paul Anderson) have offered to coordinate the use of the
second booth, so please provide me with information and do NOT expect that
I have assumed responsibility for what you are placing in the booth.

Finally, these three (and perhaps more) booths might become a convenient
meeting and message point for all the stove-focused people.

This is all turning out very nicely so far.

Thanks again to Steve Troy.

Paul

At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
>Hi Paul and others,
>
>Trees, Water & People will have a booth at the Boulder conference and we
>will have
>an EcoStove (the metal version of the Justa stove) there on display, along
>with
>posters of our stove and reforestation projects. I have a Rocket stove that is
>funky looking (made from 5 gallon paint can), but functional. if you want
>that
>stove that for the stoves display/booth, I can bring that down. I can even
>paint it
>up to look more presentable.
>
>Actually, that's a good by-line for Aprovecho "funky, but functional".
>
>Stuart

From tombreed at COMCAST.NET Thu Sep 18 01:29:10 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:37 2004
Subject: paraffin
Message-ID: <WED.17.SEP.2003.232910.0600.TOMBREED@COMCAST.NET>

Dear Crispin, Paul, Stoves and Gasifiers:

Here's the elephant and the blind men again trying to agree on a single
definition for pyrolysis products and uses. I hope we can agree on
acceptable terminology, even if we choose to use different terms in
different situations.

We have been over this a number of times before. Since pyrolysis produces
1/3 charcoal, 1/3 combustible gas and 1/3 volatile tars, also combustible.
It is unfortunate that pyrolysis can't make up it's mind, but that's the way
it is! You will call a pyrolyser a charcoal producer, a gas producer or a
liquid producer, depending on what you do with the products.

Since a pyrolysis stage is necessary for both gasification and combustion,
there is a continuum between pyrolysis and gasification and combustion and a
continuum between the uses for heat, fuel and chemical uses. But words
don't like continuums. Let's stop insisting on rigid categories and just be
more specific and polite about what we are talking about.

Our gasifier stove produces 2/3 of the energy as a combustible gas on the
first downward pass, leaving 1/3 of the energy in the charcoal. Continuing
the supply of the same primary air to the charcoal then produces charcoal
gas which also burns beautifully if the A/F ratios are right. SO, WE ARE
CALLING IT A GASIFIER STOVE. It produces gas, then supplies the CORRECT
amount of air to burn the gas. The main purpose is cooking. If you want to
stop after the first phase, it is also an efficient charcoal producer,
provided you use dry biomass.

When Ron Larson called me in 1995 asking how can we use the gases coming
from making charcoal, we collaborated on the
natural-draft-woodgas-cooking-charcoal-producer. But He saw it as a
charcoal producer with cooking as a by product, I saw it as a stove with
charcoal as a potential by product. He has always resisted my names;
currently toplit updraft gasifier, or tar burning char making gasifier
(previously upsidedowndraft, inverted downdraft gasifier) and I have
resisted his names (toplit charcoal producer). But we still manage to talk
to each other.

Back to work!

TOM REED
Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Crispin" <crispin@newdawn.sz>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 17, 2003 4:18 AM
Subject: [STOVES] RE :paraffin

> Dear Ron
>
> I hope, a couple of clarifications:
>
> Paul
> >>>1. I strongly urge not calling any such device a "gasifier" - but
> >>>rather call it a "pyrolyzer" - as the word "gasifier" typically means
> >>>striving for minimum charcoal production.
>
> I think we need to look at this definition closely. I agree with it
because
> if I am making a grass gasifier, I don't expect there to be anything left
at
> the end. Although the 'burning' of charcoal was mentioned further down, I
> am still thinking of gasifying it - i.e. driving off the carbon as CO and
> burning it close to the pot with some distance, perhaps, between the
carbon
> and the pot.
>
> and Paul says:
> >>A. When speaking to the general citizen (and the poorly
> >>educated in some communities), the word "pyrolysis" and
> >>"pyrolyzer" are not well understood.
>
> I certainly agree there. I haven't met anyone outside this group who
knows
> what the words mean at all.
>
> >>A "gasifier" is much more easily understood.
>
> I agree with this in principle as 'gas' is knows to be just that:
'Handigas'
> or 'propane' or 'natural gas' or 'methane' or 'biogas'. A 'wood gasifier'
> gives one the idea that the wood is turned into gas. A 'pyrolyzer' that
> turns wood into gas with a slightly different co-intention is still a type
> of gasifier: it turns wood into gas.
>
> In Swaziland there is the additional complication that 'gezi' which is the
> word for 'gas' also means electricity as all lighting used to be piped gas
> and 'gezi' came to mean 'light' and fitting electricity is of course
adding
> 'lights' to your house. The best local name would be 'wood-gas stove'.
>
> >RWL: Note that A.D. and Crispin are asking how to make
> >charcoal at the household level - not how to consume it.
>
> Actually it was my unexpressed vision that the fuel be totally consumed as
> in a Vesto. This happens in two stages at a low power setting: wood is
> largely charcoaled then the charcoal is burned by opening the air supply.
I
> was thinking of a gasifier in which there is a physical separation between
> the initial combustion and production of gases and the subsequent burning
of
> them. I think Paul described this definition first.
>
> >RWL: I'm anxious to see how efficient your charcoal combustion is
> >within the original charcoal-maker.
>
> This differs from my vision of the gasifying device. If the charcoal is
> burned to CO2 somewhere in the gas-producing chanber, it might be
difficult
> to deliver the heat to the pot unless it is well insulated or entrained in
a
> vortex passing through a reflective pipe, or moving the whole fire towards
> the pot.
>
> >RWL: My prediction is that it will be close to zero -
> >i.e. not able to keep at a boiling water temperature - the
> >combustion of the charcoal being too far from the pot.
> >That has been the experience of others.
>
> Well...OK,...but maybe others will have different approaches to getting
the
> heat to the pot, or else will be able to create CO at a reasonable
> efficiency and deliver the (very hot) CO to the pot 'burner' and reduce it
> to CO2 giving a useful heat output. One might also be able to lift the
> charcoal produced towards the pot with a lever and burn it directly to
CO2.
> It seems unwise to limit a designer too much by saying that the charcoal
is
> 'too far from the pot' and therefore a stove of that type can't be made to
> work usefully.
>
> I feel that this name splitting are really semantical and not based on a
> technical analysis because if challenged theoretically, one can put up a
> good case that all fires are gas fires, thus all stoves are wood or coal
or
> charcoal 'gasifiers'. These definitions sound arbitrary, especially when
> one gets innovative about the layout and function.
>
> I can't defend the division of products into stove groups based on the
> amount of charcoal left. If it has, say, 15% charcoal production, then a
> Welcome Dover coal stove with wood burning in it would be classified as a
> pyrolyzer, as it produces more % charcoal than many semi-professional
> Mo?ambicano 'charcoal makers' working in the forest.
>
> I am worried that handy definitions that apply to particular situations or
> constructions will lend people to think that other layouts will not
provide
> better or workable stoves.
>
> One example I can give, sourced from this list, is the idea that _only_ a
> high hot gas velocity past the pot can give better heat transfer rates.
> This is frequently mentioned and ideas about scrubbing and boundary layers
> are cited, as well as good quality emperical data from tests to show the
> idea correct. However this is only one man's view of the elephant.
>
> Feeding hot gases past the pot at a very low speed is also an effective
way
> to very high heat transfer. Thus to say that the _only_ way to get higher
> heat transfer (implying that this is true under all conditions) is to
speed
> up the gas flow past the pot, limits ones approach to heat transfer and
> therefore stove design problems. This limitation and the statement
creating
> it are rooted in an inaccurate conceptualization of how heat transfers
from
> molecule to molecule in gases. I mentioned this before: all heat transfer
> from gas to pot is by radiation, not 'conduction' (unless the gas
> temporarily becomes attached to the crystal structure of the pot).
> Bascially there is no such thing as 'conduction' of heat between fire
> combustion products and the pot though we tolerate the term in discussion.
>
> Given a 'normal' stove with a certain amount of heat being transferred,
> there are two ways to increase the heat transfer efficiency: close the gap
> and increase the speed of gas flow, or close the gap and _reduce_ the
speed
> of gas flow. At very low speeds, one might not need to reduce the gap to
> get an increase. This is 'apples'.
>
> This analysis says nothing about the losses one might have in the stove
body
> between the fire and heat transfer zone which is a completely separate
issue
> ('oranges') and is related to the device, not the theory and practice of
> heat transfer. It would be incorrect to reply to my argument, "The losses
to
> the stove body would reduce the _overall_ efficiency of the device if the
> gas flow is reduced." So what. That may or may not be true depending on
> the device - you could design your way around it.
>
> Having a cute statement about or name for a practical truth in an average
> situation may not illuminate a student about the theory underlying it and
> therefore poses the risk of railroading stove builders into certain ways
of
> thinking about what is possible. Such cute statements are like charts: an
> inaccurate representation of a partially understood truth.
>
> Gasifier? Pyrolyzer? To the average user it is still just a stove.
>
> Thanks for the opportunity to ruminate
> Crispin

From adkarve at PN2.VSNL.NET.IN Thu Sep 18 10:16:30 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:37 2004
Subject: charcoal and biogas
Message-ID: <THU.18.SEP.2003.194630.0530.ADKARVE@PN2.VSNL.NET.IN>

We are agressively marketing the idea of using processed fuel, i.e.
charcoal and biogas, in order to save the Indian rural households from
indoor air pollution. The charcoal produced by using our oven and retort
process burns without any smoke or soot. It is thus of a much better
quality than the charcoal produced by the traditional kilns. Secondly,
we can use even light biomass for making charcoal, because in our
process, our char remains within the retort and does not get mixed with
the ash. The Sarai stove-and-cooker system, developed by us for use with
our briquettes is also selling very brisquely. With increasing number of
Sarai stove users, the demand for char briquettes is also increasing.
Many species of agrowaste are today burned by the farmers in the field
itself, in order to clear the field for the next crop. Our commercial
kiln contains seven retorts. We are now developing an oven and retort
kiln having a single retort, which a farmer would use for converting his
own agrowaste into char. He briquettes it, using our briquette mold. A
rural family would require in a year about 200 kg of charcoal. About a
week's work with our kiln, after harvesting his crop, would provide him
with all the charcoal that he would need in a year.
Our compact biogas plant based on waste starch is giving fantastic
results. A student of my daughter's analysed the gas produced in our
biogas plant by a titration method. She bubbled it through KOH solution
and then by titrated the solution with HCl. She reported that our gas
contained only 4% carbon dioxide. This is just unbelievable, but the
chemistry professor in the collecge supervised the entire operation. The
analyses were done on 4 consecutive days and the results varied from
about 3% to 4% carbon dioxide. If this were to be true, we can sell this
gas as automobile fuel.
A.D.Karve, President,
Appropriate Rural Technology Institute
Pune, India

From jmdavies at XSINET.CO.ZA Thu Sep 18 03:50:29 2003
From: jmdavies at XSINET.CO.ZA (John Davies)
Date: Tue Aug 10 18:30:37 2004
Subject: Termonology of combustion
Message-ID: <THU.18.SEP.2003.095029.0200.JMDAVIES@XSINET.CO.ZA>

Greetings Stovers,

The terminology used and proposed on this list is fine for technical
discussion.

According to my understanding.

The term PYROLYSIS is the action of reducing the fuel to carbon by way of
applying external heat in an oxygen starved atmosphere, in other words none
of the Carbon content is allowed to be reduced by oxygen and the volatile
content at the temperature involved is driven off as a Gas.

GASIFICATION, as has been done for more than a century in industry, is the
process where the fuel is partly reacted with oxygen to produce CO, CO2,
H2, and volatile gasses as produced by PYROLYSIS. So there is a degree of
pyrolysis taking place in gasification.

By my reasoning, if any reaction with oxygen takes place in the fuel bed, it
cannot be referred to as pyrolysis,

I must agree with Crispin in the area of introducing our stoves to the user.
In the larger sense we must adopt terms which are meaningful to the user who
in the most part has never heard of technical terms. Even the late steam
locomotive developer Eng.. L D Porta who was producing a product for
technical orientated customers, referred to his gasification process of fuel
in a locomotive firebox as a, GAS PRODUCER COMBUSTION SYSTEM.

If we are to give the user a meaningful description of a stoves combustion
qualities we must use terms which are understandable to the user, and
explain in simple terms why this is beneficial.

Each stove manufacturer must develop terms which will explain the merits of
a stove to the user. i.e. SAVES FUEL BY PRODUCING A CLEAN BURNING FLAME AT
THE BEST DISTANCE FROM THE POT.

Likewise my smoke free gasifier coal stove, could be promoted as, THE COAL
STOVE THAT USES LESS FUEL BY BURNING THE SMOKE. This would be followed by a
simple explanation, that smoke is actually small particles of unburned fuel
released into the air.

A TRUE STORY
I had an amusing incident at a stoves workshop. After top lighting my COAL
stove, the smokey flames were exiting the pot hole at the top of the stove.
When the pot was placed on the stove, smoke was seen exiting the chimney for
a few seconds, after which the smoke disappeared. A Lady from a 3rd world
background promptly proclaimed that the fire had gone out. The pot was
lifted to show the smokey flame and the process was repeated several times.
Once the pot was boiling vigorously, and no visible smoke had been produced
in the process, she asked the question. How can a coal fire burn with not
even a little smoke.
On explaining that the stove was designed to burn the smoke, she shook her
head and said, " I do not understand this, but I have seen it happen.

So we can carry on debating between ourselves, technical terms for the
combustion process in our stoves, but it means nothing to the users. We have
to develop a totally different terminology for marketing.

Keep the fires burning,
Hot and clean,

John Davies.

From tombreed at COMCAST.NET Fri Sep 19 01:29:28 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:37 2004
Subject: "Combustor", Gasifier" or Pyrolyser"
Message-ID: <THU.18.SEP.2003.232928.0600.TOMBREED@COMCAST.NET>

All Stovers (and gasification):

The premier biomass thermal conversion lab in India is the Pyrolysis,
Gasification, Combustion, the PGC lab at IISC, Bangalore of Prof. Mukunda.
You can't do gasification of solid fuels without initial pyrolysis; you
can't do combustion without initial gasification. So the three are sister
technologies, and anyone interested in one should be interested in all
three.

Yesterday I gave a number of reason to call stoves that burn the gas
separately from the pyrolysis stage "gasifiers". Here are two more.

Ron says below that most people can recognize "pyrolyser" from its roots.
OK, maybe. However, by the same token they will recognize "gasifier" from
its roots. While many people might be able to derive "pyrolyser", the word
has no association with cooking. The billions of people now burning methane
and propane at high cost will be led to burning WoodGas through association
of the words.

AND its roots are deeply into modern technology where every city had
(usually coal) gasifiers supplying city gas, often by a process of pyrolysis
to make coke as a co-product. So we are doing the same thing at a smaller
scale, and the charcoal is a co-product while the majority product is the
gas.

And in the case of our stoves, the PURPOSE of the stove is to make a gas for
CLEAN combustion because it is very difficult to simultaneously burn the
gas/vapors and the charcoal. If you choose to stop the process half way
through and take the charcoal as a by-product, fine, but the PURPOSE is
still "cooking with gas".

Finally, note that we don't have a "Pyrolysis" section here at REPP, but we
do have a "Gasification" section, so that newcomers will find information on
the processes involved.
~~~~~~~~
So, I hope that I can get Ron Larson to at least use the names "gasifier"
and "pyrolyser" together.
Most gasifiers need to have their names modified, as in "tar burning, char
making gasifier" = "updraft gasifier", .... etc. so I'd recommend the
longer name top be "PYROLYSIS GASIFIER" if it will make Ron happy and
terminate this interminable discussion.

Onward to better "cooking with gas",

TOM REED (Gasification list moderator)

Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Ron Larson" <ronallarson@QWEST.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, September 16, 2003 9:00 PM
Subject: Re: [STOVES] paraffin

> Stovers:
>
> Today, Paul Anderson noted that I had said:
> >
> > > 1. I strongly urge not calling any such device a "gasifier" - but
> > > rather call it a "pyrolyzer" - as the word "gasifier" typically
means
> > > striving for minimum charcoal production.
> >
> and Paul says:
> >
> > A. When speaking to the general citizen (and the poorly educated in
some
> > communities), the word "pyrolysis" and "pyrolyzer" are not well
> > understood. A "gasifier" is much more easily understood.
>
> RWL: I doubt this. Almost every culture will translate "pyrolysis"
as
> "charcoal making" (and get the concept right away) - and you will find
that
> I usually use this term ("charcoal-making" - not "pyrolysis") when talking
> about a top-lit stove. On this list, I think it safe to talk about
> pyrolysis and the distinction between it and gasification.
>
> If you use "gasifier", I think the translation is apt to come out as
> something very foreign to what we are talking about. Anyone out there in
a
> position to check my claim with some group that has never seen a
"gasifier"?
>
>
> >
> > B. In my Juntos gasifier that is developing well (and will have a major
> > message within 5 weeks), developments are moving that will ALLOW (user
> > option) the burning of a much greater portion of the charcoal than was
the
> > case in the initial Reed - Larson IDD stoves. That would pull the name
> > back toward use of "gasifier" instead of "pyrolyzer." The people for
whom
> > A.D. Karve is producing charcoal from agro-wastes will not need to
produce
> > or use much charcoal if (a big IF that is getting smaller) they can use
> the
> > agro-wastes directly for their cooking.
>
> RWL: Note that A.D. and Crispin are asking how to make charcoal at
the
> household level - not how to consume it.
> I'm anxious to see how efficient your charcoal combustion is within
the
> original charcoal-maker. My prediction is that it will be close to zero -
> i.e. not able to keep at a boiling water temperature - the combustion of
the
> charcoal being too far from the pot. That has been the experience of
> others.
>
> Ron
>
> > C. INHO, It is still too early to lock onto one name for this
relatively
> > very new type of biomass-using stove.
> >
> > Paul
> >
> RWL: Understood your position - but think it wrong. Still think
there
> are big problems in calling a charcoal-making stove a "gasifier" - where
> minimum charcoal production seems to be a goal.
> I have no problem with having "gasifier" stoves - but much prefer that
> the name "gasifier" not be used for stoves intended to make charcoal - as
> A.D. and Crispin seem to desire.
>
> Ron

From kchisholm at CA.INTER.NET Fri Sep 19 10:30:25 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:37 2004
Subject: "Combustor", Gasifier" or Pyrolyser"
Message-ID: <FRI.19.SEP.2003.113025.0300.KCHISHOLM@CA.INTER.NET>

Dear Tom

The "interminable discussion" is probably such, simply because there is
considerable divergence on understanding of terms. This divergence on
understanding leads to confusion. If people "in the trade" are not fully
satisfied with terminology, then it will be very difficult to communicate
desired meanings to the average stove/gasifier/pyrolizer/furnace/combustor
user. I would suggest that it is thus important that this confusion be "run
to ground."

----- Original Message -----
From: "tombreed" <tombreed@COMCAST.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, September 19, 2003 2:29 AM
Subject: [STOVES] "Combustor", Gasifier" or Pyrolyser"

> All Stovers (and gasification):
>
> The premier biomass thermal conversion lab in India is the Pyrolysis,
> Gasification, Combustion, the PGC lab at IISC, Bangalore of Prof. Mukunda.
> You can't do gasification of solid fuels without initial pyrolysis;

That is very true, but pyrolysis does not imply gasification: the pyrolysis
process can stop at the Torrification level.

you
> can't do combustion without initial gasification.

That is true also, but you may not wish to use the gases for combustion
(they may be intended as a feedstock for a chemical reactor) or for stove
purposes (it may be intended for combustion in an engine.)

So the three are sister
> technologies, and anyone interested in one should be interested in all
> three.

Well, the three girls could be sisters, but they may also only be
girl friends. :-) Obviously a person operating a wood gasifier for
production of wood gas for use in an engine does not have to be interesated
in stoves fueled with wood gas.
>
> Yesterday I gave a number of reason to call stoves that burn the gas
> separately from the pyrolysis stage "gasifiers". Here are two more.
>
> Ron says below that most people can recognize "pyrolyser" from its roots.
> OK, maybe. However, by the same token they will recognize "gasifier" from
> its roots.

OK...

While many people might be able to derive "pyrolyser", the word
> has no association with cooking.

True. However, these millions don't need to know about pyrolysis any more
than they need to know how an engine works in order to drive a car.
Howwever, the pyrolysis term is very important to stove and gasifier system
designers and builders.

The billions of people now burning methane
> and propane at high cost will be led to burning WoodGas through
association
> of the words.

OK.... in this case it could simply be called a "Wood Gas Stove"
>
> AND its roots are deeply into modern technology where every city had
> (usually coal) gasifiers supplying city gas, often by a process of
pyrolysis
> to make coke as a co-product. So we are doing the same thing at a smaller
> scale, and the charcoal is a co-product while the majority product is the
> gas.

Tat is different. That would be a "Charcoal Producing Wood Gas Stove"
>
> And in the case of our stoves, the PURPOSE of the stove is to make a gas
for
> CLEAN combustion because it is very difficult to simultaneously burn the
> gas/vapors and the charcoal. If you choose to stop the process half way
> through and take the charcoal as a by-product, fine, but the PURPOSE is
> still "cooking with gas".

I would suggest that a device intended to make a fuel gas for cooking and to
make charcoal at the same time is a very special case. I would suggest that
the terminology should be set up to handle more general and common cases.
Note also, that the use of the gas may not be for cooking... In Dr. Karve's
case, it is used for process heat, but it could also be used in an engine.
>
> Finally, note that we don't have a "Pyrolysis" section here at REPP, but
we
> do have a "Gasification" section, so that newcomers will find information
on
> the processes involved.

I would suggest that you don't need a "Pyrolysis Section" If you did, that
would suggest that the desired objective was "pyrolysis", rather than
"Charcoal" or "Gasification" or "Stoves" or "Combustion"
> ~~~~~~~~
> So, I hope that I can get Ron Larson to at least use the names "gasifier"
> and "pyrolyser" together.
> Most gasifiers need to have their names modified, as in "tar burning, char
> making gasifier" = "updraft gasifier", .... etc.

OK, but would that be a "top lit updraft gasifier", or a "bottom lit updraft
gasifier" :-)
so I'd recommend the
> longer name top be "PYROLYSIS GASIFIER" if it will make Ron happy and
> terminate this interminable discussion.

The "pyrolysis" term is redundant. If it was a "cooking device using biomass
fuel that was pyrolized to yield a wood gas fuel for burning in situ", why
not simply call it a "wood stove"?

Note that a "wood gas stove", to be consistent with a "propane gas stove" or
a "natural gas stove" implies that a "prepared gas fuel" is supplied to the
stove. The mess and bother associated with wood is separated from the stove
function.
>
> Onward to better "cooking with gas",
>
Yes, indeed!!

Kindest regards,

Kevin Chisholm

From crispin at NEWDAWN.SZ Fri Sep 19 07:48:31 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:37 2004
Subject: Dick's stove
Message-ID: <FRI.19.SEP.2003.134831.0200.CRISPIN@NEWDAWN.SZ>

Dear Dick

Thanks for the drawing and complete description. It is clear to me that
your combustion isn't too good and that is why it continues to smoke and
leage so much uncombusted volatile material coated on the chimney.

I am wondering if your stove has a door which isopened to load wood and then
is close for the burn. It you were to leave this door open, does it brun so
quickly and hot that it is uncomfortable? Do you have a flue damper?

If you could leave the door open to allow more air to get to the top of the
fire (providing thereby secondary combustion above the wood) AND close the
flue damper slightly, you would be able to balance the draft with the air
need. I think you would find that allowing the air to get at the fire
through the open door owuld clean up (and make more efficient) your
combustion. Result: smaller fire, same heat, clean chimney.

From andrew.heggie at DTN.NTL.COM Sat Sep 20 16:37:00 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:37 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <4.3.1.2.20030914151727.01cc6270@mail.ilstu.edu>
Message-ID: <SAT.20.SEP.2003.213700.0100.>

On Sun, 14 Sep 2003 15:36:40 -0500, Paul S. Anderson wrote:

I posted details of a PTO driven rotary shear some while back.
Unfortunately I cannot find the reference now.

I have seen a more modern version the Bilke. The one I initially
described was imported into UK from US. It was a large sprocket wheel
driven by a small sprocket on the pto. A slot, wide enough to take the
log diameter, was cut in about 60 degrees of the disc. A Vee shaped
anvil was set against the disc to shear the log between the disc and
the Vee. I guess it rotated about 1rpm, so a 10:1 reduction via the
chain and sprockets. The wood was pushed through the slot and sheared
off at the vee.

I could see a smaller unit with higher reduction gearing being
feasible using a lawn mower engine. In fact the chap at Bilke's
importers told me yesterday that they test the machines with a 2kW
electric motor geared down.

The earlier chain driven (the Bilke uses cogs) one had a further
feature in that the disc had a spike in the trailing edge of the slot,
this effectively split the log just before it was sheared, the
operator, who was quite severely thrown about by holding onto the log,
could rotate the billet by 90 degrees as he fed it in between cuts, to
produce quartered logs.

AJH

From psanders at ILSTU.EDU Sun Sep 21 12:54:20 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <kqdpmv8apkfp4ubnoeefoelmalh9idsu7k@4ax.com>
Message-ID: <SUN.21.SEP.2003.115420.0500.PSANDERS@ILSTU.EDU>

Andrew,

Very interesting and useful. Any pictures you could send to me (off-list
because of file size)?

Only 1 rpm (or even 2 or 5 rpm) is very slow, so the power needed to make
the cuts must have been very great.

As Richard Stanley wrote before, there is a great trade-off between speed
and mass. Here are some of my "thoughts" (from a NON-engineer):

1. 600 rpm would be 10 rps (revolutions per second). (and lawn mower
engines are much faster, I believe.) And there could be multiple cutting
edges/blades on the revolving piece, which would multiply the number of
cuts per revolution.

That would still be much too fast to be able to thrust 1 cm of a
small-diameter stick (0.5 to 2 cm ) through a hole and then sheer off the
end of the stick.

So, how does a "fast" machine make chunks bigger that the little chips that
are so common?

2. Richard's comments about a heavy fly-wheel were very
interesting. Consider: Instead of the bicycle wheel (too weak), what
about half of the rear axle of an automobile? Most wrecked vehicles have
this as almost-free "junk". Be sure to include the "wheel" (the metal that
normally would hold the rubber tire in place) and include as much of the
axle as is needed to support the wheel. (If the differential and drive
shaft are included, you have a 90 degree angle for ease of mounting.) (And
if the vehicle engine still functions, then there is even a great power
supply!!!!!)

As I write, this item # 2 is taking two directions: One is for the HEAVY
but slow moving chopper using just part of the rear wheel and axle that
could be manually powered.

The other is for a "chopper device" that is attached to the rear (drive)
wheel of a vehicle (fully functional or even not functional for
transportation) that is raised (jacked up) so that the operating engine is
simply spinning one wheel (or both for a "double" unit). Arrangements to
attach and detach the chopper unit to the rotating axle are easy and
numerous. (This is something link a PTO [Power Take Off ] that tractors
have, but available using common passenger vehicles.)

[[ Please remember that I usually think in terms of impoverished developing
societies where tractors are uncommon, but some form of motorized vehicle
can be found if needed. ]]

So, "power" is now considered to be available. Maybe Richard's or other's
ideas for the chopper can be implemented.

See you (Richard and some others) at the Sustainable Resources conference
in Boulder on 1 - 4 October.

Paul

At 09:37 PM 9/20/03 +0100, Andrew Heggie wrote:
>On Sun, 14 Sep 2003 15:36:40 -0500, Paul S. Anderson wrote:
>
> >Stovers,
> >
> >For fuels the small gasifiers (and other uses), I want to make "chips" from
> >twigs and thin branches up to 2 cm diameter, with 1 to 4 cm lengths. (Not
> >product the small "wood chips" that are everywhere in the USA and
> >elsewhere) In Mozambique we are attempting to make a guillotine-type
> >chopper (ala the diagram that Graham at Fluidyne has on his website.)
>
>I posted details of a PTO driven rotary shear some while back.
>Unfortunately I cannot find the reference now.
>
>I have seen a more modern version the Bilke. The one I initially
>described was imported into UK from US. It was a large sprocket wheel
>driven by a small sprocket on the pto. A slot, wide enough to take the
>log diameter, was cut in about 60 degrees of the disc. A Vee shaped
>anvil was set against the disc to shear the log between the disc and
>the Vee. I guess it rotated about 1rpm, so a 10:1 reduction via the
>chain and sprockets. The wood was pushed through the slot and sheared
>off at the vee.
>
>I could see a smaller unit with higher reduction gearing being
>feasible using a lawn mower engine. In fact the chap at Bilke's
>importers told me yesterday that they test the machines with a 2kW
>electric motor geared down.
>
>The earlier chain driven (the Bilke uses cogs) one had a further
>feature in that the disc had a spike in the trailing edge of the slot,
>this effectively split the log just before it was sheared, the
>operator, who was quite severely thrown about by holding onto the log,
>could rotate the billet by 90 degrees as he fed it in between cuts, to
>produce quartered logs.
>
>AJH

From andrew.heggie at DTN.NTL.COM Sun Sep 21 16:25:00 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <4.3.1.2.20030921110331.01cde700@mail.ilstu.edu>
Message-ID: <SUN.21.SEP.2003.212500.0100.>

On Sun, 21 Sep 2003 11:54:20 -0500, Paul S. Anderson wrote:

>
>Very interesting and useful. Any pictures you could send to me (off-list
>because of file size)?

No but a search in google on bilke should get results.
>
>Only 1 rpm (or even 2 or 5 rpm) is very slow, so the power needed to make
>the cuts must have been very great.

I think you are confusing force with power.
>
>As Richard Stanley wrote before, there is a great trade-off between speed
>and mass. Here are some of my "thoughts" (from a NON-engineer):

No there isn't.
>
>1. 600 rpm would be 10 rps (revolutions per second).

Standard tractor pto is 540 or 1000 rpm for maximum power, you may
well vary this to give maximum economy or minimise wear and tear.

> (and lawn mower
>engines are much faster, I believe.)

3600rpm seems to be the standard.

>And there could be multiple cutting
>edges/blades on the revolving piece, which would multiply the number of
>cuts per revolution.
>
>That would still be much too fast to be able to thrust 1 cm of a
>small-diameter stick (0.5 to 2 cm ) through a hole and then sheer off the
>end of the stick.
>
>So, how does a "fast" machine make chunks bigger that the little chips that
>are so common?

As I said you gear it down, in doing so you increase the torque,
torque is the rotary force needed to overcome the twig's resistance to
shearing ( power limits the number of times you can do this in a given
time). As this torque is only required for a small proportion of the
cutter's rotation and the input is available for the whole rotation
then if the rotationg mass is increased some of the input is "stored"
as inertia, this is then available when the resistance of the stem is
incurred.

Consider also the commercial chipper blows chips into a container,
this uses a lot of extra power, so a more appropriate technology might
well just allow the chunks to drop into a container.

AJH

From tombreed at COMCAST.NET Sun Sep 21 19:45:13 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:38 2004
Subject: [GASL] gasification syntax
Message-ID: <SUN.21.SEP.2003.174513.0600.TOMBREED@COMCAST.NET>

Dear Joel:

Thanks for your thoughtful analysis and preferences and semantic comments
below. While our words are necessary to our thoughts, we are also their
prisoners. Nature presents us with a continuum of data and we try to
quantify it as best we can. We escape from this prison by doing experiments
which may disagree without presumptions - then we learn.

Yours truly,

TOM REED

From: "Joel Florian" <joflo@YIFAN.NET>
To: <GASIFICATION@LISTSERV.REPP.ORG>
Sent: Thursday, September 18, 2003 11:48 AM
Subject: [GASL] gasification syntax

> Dear Tom,
>
> Thank you for encouraging polite dialogue about terminology.
>
> Confusion can be the reader's (or listener's) fault as much as the
writer's
> (or speaker's). Certainly when we chose a word or name to convey an idea,
> we should choose it with the idea of communicating an idea. But we have
no
> control over people's associations with a particular word. Different
types
> of people have different associations with words, and indeed different
> reasons for using words. For example, politicians have different motives
> for choosing a word than say a lawyer or an engineer. I think you get my
> point without elaborating further.
> I've interspersed a few comments below.
>
> At 11:29 PM 9/17/2003 -0600, tombreed wrote:
> >Dear Crispin, Paul, Stoves and Gasifiers:
> >
> >Here's the elephant and the blind men again trying to agree on a single
> >definition for pyrolysis products and uses. I hope we can agree on
> >acceptable terminology, even if we choose to use different terms in
> >different situations.
>
> To carry your analogy further, if those blind men were on radio (or had an
> blind audience) each one of their descriptions would have conjured up a
> different image in each listener's mind. Consider the blind man who was
> holding the elephant's leg and said "An Elephant is a Tree!" There are
> about as many varieties, shapes, sizes, textures, etc of trees as there
are
> different kinds of biomass. Even if we don't agree on terminology, we
> should agree that a word is only a tool for communication and as such, it
> is only as effective as its use matches the recipient's comprehension.
>
> <snip>
> >Our gasifier stove produces 2/3 of the energy as a combustible gas on the
> >first downward pass, leaving 1/3 of the energy in the charcoal.
Continuing
> >the supply of the same primary air to the charcoal then produces charcoal
> >gas which also burns beautifully if the A/F ratios are right. SO, WE ARE
> >CALLING IT A GASIFIER STOVE. It produces gas, then supplies the CORRECT
> >amount of air to burn the gas. The main purpose is cooking. If you want
to
> >stop after the first phase, it is also an efficient charcoal producer,
> >provided you use dry biomass.
>
> I believe the inventor and developer have naming rights. There's no way
> one single name could encompass every possible use. Duct tape has
hundreds
> of uses other than sealing "ducts".
>
>
>
> >When Ron Larson called me in 1995 asking how can we use the gases coming
> >from making charcoal, we collaborated on the
> >natural-draft-woodgas-cooking-charcoal-producer. But He saw it as a
> >charcoal producer with cooking as a by product, I saw it as a stove with
> >charcoal as a potential by product. He has always resisted my names;
> >currently toplit updraft gasifier, or tar burning char making gasifier
> >(previously upsidedowndraft, inverted downdraft gasifier) and I have
> >resisted his names (toplit charcoal producer). But we still manage to
talk
> >to each other.
> >
> >Back to work!
>
> Tom, I really like your original name -- the upsidedowndraft gasifier.
It
> works for me. It helps me remember that it works similarly to the
> historically significant downdraft gasifier yet it is lit from the
> top. Therefore it burns most of the tars yet doesn't need a high
> temperature grate or throat (can't think of the right word, sorry) and can
> be conveniently lit from the top. The best of downdraft as well as
updraft
> technology. Plus it's a catchy name. Inverted downdraft is almost as good
> but it is a little longer and doesn't imply the advantages of the
> updraft. It's really hard to name something based on the desired output
> because different people want different things.
>
> I operate a piece of heating equipment that I call a "sawdust boiler."
It
> burns sawdust, woodchips, and hog fuel (I even burned some moldy pinto
> beans in it --- PHEW). I suppose it operates on what could be termed
> "close-coupled thermal gasification" since it has two chambers and (at
> least theoretically) two stages of combustion. I suppose some might even
> argue with the term "boiler" since the
> 3-pass-return-tube-hot-gas-to-glycol/water-heat-exchanger only makes hot
> water and the water never "boils".
>
> The word is not the thing.
>
> So Tom, go ahead and name your "babies" what you want to name them. If
we
> don't understand, we'll ask what you mean. In the dialogue, we might
learn
> something.
>
> Joel Florian, Alaska
>
>
> >TOM REED
> >Yours truly,
> >
> >Dr. Thomas Reed
> >tombreed@comcast.com
> >www.woodgas.com
> >----- Original Message -----
> >From: "Crispin" <crispin@newdawn.sz>
> >To: <STOVES@LISTSERV.REPP.ORG>
> >Sent: Wednesday, September 17, 2003 4:18 AM
> >Subject: [STOVES] RE :paraffin
> >
> >
> > > Dear Ron
> > >
> > > I hope, a couple of clarifications:
> > >
> > > Paul
> > > >>>1. I strongly urge not calling any such device a "gasifier" - but
> > > >>>rather call it a "pyrolyzer" - as the word "gasifier" typically
means
> > > >>>striving for minimum charcoal production.
> > >
> > > I think we need to look at this definition closely. I agree with it
> >because
> > > if I am making a grass gasifier, I don't expect there to be anything
left
> >at
> > > the end. Although the 'burning' of charcoal was mentioned further
down, I
> > > am still thinking of gasifying it - i.e. driving off the carbon as CO
and
> > > burning it close to the pot with some distance, perhaps, between the
> >carbon
> > > and the pot.
> > >
> > > and Paul says:
> > > >>A. When speaking to the general citizen (and the poorly
> > > >>educated in some communities), the word "pyrolysis" and
> > > >>"pyrolyzer" are not well understood.
> > >
> > > I certainly agree there. I haven't met anyone outside this group who
> >knows
> > > what the words mean at all.
> > >
> > > >>A "gasifier" is much more easily understood.
> > >
> > > I agree with this in principle as 'gas' is knows to be just that:
> >'Handigas'
> > > or 'propane' or 'natural gas' or 'methane' or 'biogas'. A 'wood
gasifier'
> > > gives one the idea that the wood is turned into gas. A 'pyrolyzer'
that
> > > turns wood into gas with a slightly different co-intention is still a
type
> > > of gasifier: it turns wood into gas.
> > >
> > > In Swaziland there is the additional complication that 'gezi' which is
the
> > > word for 'gas' also means electricity as all lighting used to be piped
gas
> > > and 'gezi' came to mean 'light' and fitting electricity is of course
> >adding
> > > 'lights' to your house. The best local name would be 'wood-gas
stove'.
> > >
> > > >RWL: Note that A.D. and Crispin are asking how to make
> > > >charcoal at the household level - not how to consume it.
> > >
> > > Actually it was my unexpressed vision that the fuel be totally
consumed as
> > > in a Vesto. This happens in two stages at a low power setting: wood
is
> > > largely charcoaled then the charcoal is burned by opening the air
supply.
> >I
> > > was thinking of a gasifier in which there is a physical separation
between
> > > the initial combustion and production of gases and the subsequent
burning
> >of
> > > them. I think Paul described this definition first.
> > >
> > > >RWL: I'm anxious to see how efficient your charcoal combustion is
> > > >within the original charcoal-maker.
> > >
> > > This differs from my vision of the gasifying device. If the charcoal
is
> > > burned to CO2 somewhere in the gas-producing chanber, it might be
> >difficult
> > > to deliver the heat to the pot unless it is well insulated or
entrained in
> >a
> > > vortex passing through a reflective pipe, or moving the whole fire
towards
> > > the pot.
> > >
> > > >RWL: My prediction is that it will be close to zero -
> > > >i.e. not able to keep at a boiling water temperature - the
> > > >combustion of the charcoal being too far from the pot.
> > > >That has been the experience of others.
> > >
> > > Well...OK,...but maybe others will have different approaches to
getting
> >the
> > > heat to the pot, or else will be able to create CO at a reasonable
> > > efficiency and deliver the (very hot) CO to the pot 'burner' and
reduce it
> > > to CO2 giving a useful heat output. One might also be able to lift
the
> > > charcoal produced towards the pot with a lever and burn it directly to
> >CO2.
> > > It seems unwise to limit a designer too much by saying that the
charcoal
> >is
> > > 'too far from the pot' and therefore a stove of that type can't be
made to
> > > work usefully.
> > >
> > > I feel that this name splitting are really semantical and not based on
a
> > > technical analysis because if challenged theoretically, one can put up
a
> > > good case that all fires are gas fires, thus all stoves are wood or
coal
> >or
> > > charcoal 'gasifiers'. These definitions sound arbitrary, especially
when
> > > one gets innovative about the layout and function.
> > >
> > > I can't defend the division of products into stove groups based on the
> > > amount of charcoal left. If it has, say, 15% charcoal production,
then a
> > > Welcome Dover coal stove with wood burning in it would be classified
as a
> > > pyrolyzer, as it produces more % charcoal than many semi-professional
> > > Mo?ambicano 'charcoal makers' working in the forest.
> > >
> > > I am worried that handy definitions that apply to particular
situations or
> > > constructions will lend people to think that other layouts will not
> >provide
> > > better or workable stoves.
> > >
> > > One example I can give, sourced from this list, is the idea that
_only_ a
> > > high hot gas velocity past the pot can give better heat transfer
rates.
> > > This is frequently mentioned and ideas about scrubbing and boundary
layers
> > > are cited, as well as good quality emperical data from tests to show
the
> > > idea correct. However this is only one man's view of the elephant.
> > >
> > > Feeding hot gases past the pot at a very low speed is also an
effective
> >way
> > > to very high heat transfer. Thus to say that the _only_ way to get
higher
> > > heat transfer (implying that this is true under all conditions) is to
> >speed
> > > up the gas flow past the pot, limits ones approach to heat transfer
and
> > > therefore stove design problems. This limitation and the statement
> >creating
> > > it are rooted in an inaccurate conceptualization of how heat transfers
> >from
> > > molecule to molecule in gases. I mentioned this before: all heat
transfer
> > > from gas to pot is by radiation, not 'conduction' (unless the gas
> > > temporarily becomes attached to the crystal structure of the pot).
> > > Bascially there is no such thing as 'conduction' of heat between fire
> > > combustion products and the pot though we tolerate the term in
discussion.
> > >
> > > Given a 'normal' stove with a certain amount of heat being
transferred,
> > > there are two ways to increase the heat transfer efficiency: close the
gap
> > > and increase the speed of gas flow, or close the gap and _reduce_ the
> >speed
> > > of gas flow. At very low speeds, one might not need to reduce the gap
to
> > > get an increase. This is 'apples'.
> > >
> > > This analysis says nothing about the losses one might have in the
stove
> >body
> > > between the fire and heat transfer zone which is a completely separate
> >issue
> > > ('oranges') and is related to the device, not the theory and practice
of
> > > heat transfer. It would be incorrect to reply to my argument, "The
losses
> >to
> > > the stove body would reduce the _overall_ efficiency of the device if
the
> > > gas flow is reduced." So what. That may or may not be true depending
on
> > > the device - you could design your way around it.
> > >
> > > Having a cute statement about or name for a practical truth in an
average
> > > situation may not illuminate a student about the theory underlying it
and
> > > therefore poses the risk of railroading stove builders into certain
ways
> >of
> > > thinking about what is possible. Such cute statements are like
charts: an
> > > inaccurate representation of a partially understood truth.
> > >
> > > Gasifier? Pyrolyzer? To the average user it is still just a stove.
> > >
> > > Thanks for the opportunity to ruminate
> > > Crispin
>

From Carefreeland at AOL.COM Sun Sep 21 22:33:29 2003
From: Carefreeland at AOL.COM (Carefreeland@AOL.COM)
Date: Tue Aug 10 18:30:38 2004
Subject: Scam Warning for E-mail friends
Message-ID: <SUN.21.SEP.2003.223329.EDT.>

Dear E-mail Friends,
The following E-mail was sent to my address. This is a scam. I have
reported it to aol and have been informed that it is being investigated. I
almost clicked on the blue link instinctively in anger at the false billing. I
changed the "click here" and the addresses, from blue to black type by
deleting and rewriting. Then I cut and pasted this current letter to this warning
letter.
Please be warned and if anything like this is sent to you, please
report to the person you are supposedly being billed by as well as your ISP. DO
NOT click on the link. Thank you, the computer you save may be yours.

Subj: Your Order Confirmation Response:?
Date: 9/21/03 4:37:28 PM Eastern Daylight Time
From: Koosh925
BCC: Carefreeland

Dear AOL member,

There has been a purchase added to your AOL billing method. This purchase
took place at 1-800-FLOWERS.com. If this order was unauthorized and you would
like to cancel or review this order Please click here
Below is listed information about your order.
Produce - Chocolate-Covered Strawberries in Velvet Heart Box

Price - $89.99
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From dstill at EPUD.NET Tue Sep 23 03:56:02 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:38 2004
Subject: [GASL] gasification syntax
Message-ID: <TUE.23.SEP.2003.005602.0700.DSTILL@EPUD.NET>

Dear Tom,

I'm having a sign made for the Aprovecho lab quoting you...We did a three
day seminar this weekend for 25 students, bright and eager, from Humboldt
State. Their professor, Melanie Williams, who promises to come to Seattle
January 31 for the ANNUAL ETHOS MEETING, used the word 'reify' a couple of
times. It's a word I adore that Webster defines as, " to convert into or
regard as a concrete thing".

My conceptions of stove reality have certainly misled as much as guided me.
With Carl Jung, I very much believe in the scientific method. More than half
the time experiments end up challenging my suppositions. When I start to
wonder about how something works, my partner Damon quietly moves to the
testing bench, reminding me about the worth of speculation.

That dog you got for your birthday is only "yours" if it follows you
around...

All Best,

Dean

From jmdavies at XSINET.CO.ZA Tue Sep 23 10:19:51 2003
From: jmdavies at XSINET.CO.ZA (John Davies)
Date: Tue Aug 10 18:30:38 2004
Subject: New Address
Message-ID: <TUE.23.SEP.2003.161951.0200.JMDAVIES@XSINET.CO.ZA>

Greetings to Tom and Stovers.

Please note that with immediate effect , my e-mail address will be changing.

Tom would you please change my address on the stove site, and change the set
up for me so that I receive messages sent by me, instead of a message
stating that my mail has been accepted.

My new e-mail address is jmdavies@telkomsa.net

Thanking you,
John Davies

From psanders at ILSTU.EDU Tue Sep 23 18:53:38 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
In-Reply-To: <3F70CAD2.F154A12F@treeswaterpeople.org>
Message-ID: <TUE.23.SEP.2003.175338.0500.PSANDERS@ILSTU.EDU>

Stuart,

I assume you checked with Dean about what you will bring. I suggest that
some brochure or handout be available, if possible.

Yes, there should be space in the booth areas. Being a portable Rocket, I
assume it is one made from metal cans.

I do not yet have the designation of the booth areas, but please arrange
for the Rocket to arrive at the exhibit area between 3 and 5 PM on Wed 1
October when I should be there setting things up. If you get there before
I do, it is probably safe to leave it in the booth area for me to find.

Steve Troy: Do you have one of Crispin's Vesto stoves?
Any other stoves coming to be shown? I will arrange the booth according
to what arrives.

See you in Boulder.

Paul

At 04:36 PM 9/23/03 -0600, Stuart Conway wrote:
>HI Paul,
>
>I'll go ahead and paint the Rocket stove this weekend and bring it down
>next week
>to Boulder for the conference. Sounds like you have plenty of space on the
>second
>table/booth for stoves.
>
>Stuart
>
>"Paul S. Anderson" wrote:
>
> > Stuart and Dean and others.
> >
> > Maybe the booths will be close together.
> >
> > Steve Troy is providing us with a second 5ft wide by 10 ft deep booth to be
> > beside the one for the small gasifiers. That second one will have
> > additional stoves and stoves-related items. I need to make sure that it is
> > well utilized, so anyone can send me info. For example, Crispin's Vesto
> > stove has been sent to Steve, so it could go in there also.
> >
> > Concerning any Aprovecho or other stove, I think the source of the stove
> > should decide if they want someone else to bring one of their stoves. That
> > is, Dean and his group will need to tell you if they want the
> > "funky-looking" stove to be shown, painted or not painted. Perhaps there
> > is some way you could assist Aprovecho to transport some Rocket stove
> > materials to Boulder.
> >
> > Another use for the second booth could be a place to show the Legacy
> > Foundation briquette-making materials (or some of them) on the Thurs and
> > Friday between the Wed and Sat workshops.
> >
> > A couple of guidelines if anyone wants to put something in the second
> booth:
> > 1. Fairness of display and space for all who use it.
> > 2. Provide signs or info or something to tell what it is.
> > 3. Do NOT put valuables in the booth, because there might not be
> > a person to supervise the booth for every hour.
> > 4. Be sure you have thought of what will be done with the items
> > at the end of the show.
> > 5. I (Paul Anderson) have offered to coordinate the use of the
> > second booth, so please provide me with information and do NOT expect that
> > I have assumed responsibility for what you are placing in the booth.
> >
> > Finally, these three (and perhaps more) booths might become a convenient
> > meeting and message point for all the stove-focused people.
> >
> > This is all turning out very nicely so far.
> >
> > Thanks again to Steve Troy.
> >
> > Paul
> >
> > At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
> > >Hi Paul and others,
> > >
> > >Trees, Water & People will have a booth at the Boulder conference and we
> > >will have
> > >an EcoStove (the metal version of the Justa stove) there on display, along
> > >with
> > >posters of our stove and reforestation projects. I have a Rocket stove
> that is
> > >funky looking (made from 5 gallon paint can), but functional. if you want
> > >that
> > >stove that for the stoves display/booth, I can bring that down. I can even
> > >paint it
> > >up to look more presentable.
> > >
> > >Actually, that's a good by-line for Aprovecho "funky, but functional".
> > >
> > >Stuart
> >
> > 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 aes at BITSTREAM.NET Tue Sep 23 22:02:19 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
Message-ID: <TUE.23.SEP.2003.210219.0500.AES@BITSTREAM.NET>

Clarification on "Stoves"...would a haybox cooker fit in at your booth or
are you keeping it to strictly biomass stoves? I could bring one, with an
explanation but only if you all think it would be a good idea.

Bruce

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, September 23, 2003 5:53 PM
Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!

> Stuart,
>
> I assume you checked with Dean about what you will bring. I suggest that
> some brochure or handout be available, if possible.
>
> Yes, there should be space in the booth areas. Being a portable Rocket, I
> assume it is one made from metal cans.
>
> I do not yet have the designation of the booth areas, but please arrange
> for the Rocket to arrive at the exhibit area between 3 and 5 PM on Wed 1
> October when I should be there setting things up. If you get there before
> I do, it is probably safe to leave it in the booth area for me to find.
>
> Steve Troy: Do you have one of Crispin's Vesto stoves?
> Any other stoves coming to be shown? I will arrange the booth according
> to what arrives.
>
> See you in Boulder.
>
> Paul
>
> At 04:36 PM 9/23/03 -0600, Stuart Conway wrote:
> >HI Paul,
> >
> >I'll go ahead and paint the Rocket stove this weekend and bring it down
> >next week
> >to Boulder for the conference. Sounds like you have plenty of space on
the
> >second
> >table/booth for stoves.
> >
> >Stuart
> >
> >"Paul S. Anderson" wrote:
> >
> > > Stuart and Dean and others.
> > >
> > > Maybe the booths will be close together.
> > >
> > > Steve Troy is providing us with a second 5ft wide by 10 ft deep booth
to be
> > > beside the one for the small gasifiers. That second one will have
> > > additional stoves and stoves-related items. I need to make sure that
it is
> > > well utilized, so anyone can send me info. For example, Crispin's
Vesto
> > > stove has been sent to Steve, so it could go in there also.
> > >
> > > Concerning any Aprovecho or other stove, I think the source of the
stove
> > > should decide if they want someone else to bring one of their stoves.
That
> > > is, Dean and his group will need to tell you if they want the
> > > "funky-looking" stove to be shown, painted or not painted. Perhaps
there
> > > is some way you could assist Aprovecho to transport some Rocket stove
> > > materials to Boulder.
> > >
> > > Another use for the second booth could be a place to show the Legacy
> > > Foundation briquette-making materials (or some of them) on the Thurs
and
> > > Friday between the Wed and Sat workshops.
> > >
> > > A couple of guidelines if anyone wants to put something in the second
> > booth:
> > > 1. Fairness of display and space for all who use it.
> > > 2. Provide signs or info or something to tell what it is.
> > > 3. Do NOT put valuables in the booth, because there might
not be
> > > a person to supervise the booth for every hour.
> > > 4. Be sure you have thought of what will be done with the
items
> > > at the end of the show.
> > > 5. I (Paul Anderson) have offered to coordinate the use of
the
> > > second booth, so please provide me with information and do NOT expect
that
> > > I have assumed responsibility for what you are placing in the booth.
> > >
> > > Finally, these three (and perhaps more) booths might become a
convenient
> > > meeting and message point for all the stove-focused people.
> > >
> > > This is all turning out very nicely so far.
> > >
> > > Thanks again to Steve Troy.
> > >
> > > Paul
> > >
> > > At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
> > > >Hi Paul and others,
> > > >
> > > >Trees, Water & People will have a booth at the Boulder conference and
we
> > > >will have
> > > >an EcoStove (the metal version of the Justa stove) there on display,
along
> > > >with
> > > >posters of our stove and reforestation projects. I have a Rocket
stove
> > that is
> > > >funky looking (made from 5 gallon paint can), but functional. if you
want
> > > >that
> > > >stove that for the stoves display/booth, I can bring that down. I can
even
> > > >paint it
> > > >up to look more presentable.
> > > >
> > > >Actually, that's a good by-line for Aprovecho "funky, but
functional".
> > > >
> > > >Stuart
> > >
> > > 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
>
> 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 psanders at ILSTU.EDU Tue Sep 23 22:27:38 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
In-Reply-To: <001301c3823f$ee835200$a9b90443@D289YG11>
Message-ID: <TUE.23.SEP.2003.212738.0500.PSANDERS@ILSTU.EDU>

Bruce,

Sure, bring it. Please write (off list) to describe it. I can bring one
that is the "hot bag" type from ProBEC in Africa.

Paul

At 09:02 PM 9/23/03 -0500, AES wrote:
>Clarification on "Stoves"...would a haybox cooker fit in at your booth or
>are you keeping it to strictly biomass stoves? I could bring one, with an
>explanation but only if you all think it would be a good idea.
>
>Bruce
>
>
>----- Original Message -----
>From: "Paul S. Anderson" <psanders@ILSTU.EDU>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Tuesday, September 23, 2003 5:53 PM
>Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!
>
>
> > Stuart,
> >
> > I assume you checked with Dean about what you will bring. I suggest that
> > some brochure or handout be available, if possible.
> >
> > Yes, there should be space in the booth areas. Being a portable Rocket, I
> > assume it is one made from metal cans.
> >
> > I do not yet have the designation of the booth areas, but please arrange
> > for the Rocket to arrive at the exhibit area between 3 and 5 PM on Wed 1
> > October when I should be there setting things up. If you get there before
> > I do, it is probably safe to leave it in the booth area for me to find.
> >
> > Steve Troy: Do you have one of Crispin's Vesto stoves?
> > Any other stoves coming to be shown? I will arrange the booth according
> > to what arrives.
> >
> > See you in Boulder.
> >
> > Paul
> >
> > At 04:36 PM 9/23/03 -0600, Stuart Conway wrote:
> > >HI Paul,
> > >
> > >I'll go ahead and paint the Rocket stove this weekend and bring it down
> > >next week
> > >to Boulder for the conference. Sounds like you have plenty of space on
>the
> > >second
> > >table/booth for stoves.
> > >
> > >Stuart
> > >
> > >"Paul S. Anderson" wrote:
> > >
> > > > Stuart and Dean and others.
> > > >
> > > > Maybe the booths will be close together.
> > > >
> > > > Steve Troy is providing us with a second 5ft wide by 10 ft deep booth
>to be
> > > > beside the one for the small gasifiers. That second one will have
> > > > additional stoves and stoves-related items. I need to make sure that
>it is
> > > > well utilized, so anyone can send me info. For example, Crispin's
>Vesto
> > > > stove has been sent to Steve, so it could go in there also.
> > > >
> > > > Concerning any Aprovecho or other stove, I think the source of the
>stove
> > > > should decide if they want someone else to bring one of their stoves.
>That
> > > > is, Dean and his group will need to tell you if they want the
> > > > "funky-looking" stove to be shown, painted or not painted. Perhaps
>there
> > > > is some way you could assist Aprovecho to transport some Rocket stove
> > > > materials to Boulder.
> > > >
> > > > Another use for the second booth could be a place to show the Legacy
> > > > Foundation briquette-making materials (or some of them) on the Thurs
>and
> > > > Friday between the Wed and Sat workshops.
> > > >
> > > > A couple of guidelines if anyone wants to put something in the second
> > > booth:
> > > > 1. Fairness of display and space for all who use it.
> > > > 2. Provide signs or info or something to tell what it is.
> > > > 3. Do NOT put valuables in the booth, because there might
>not be
> > > > a person to supervise the booth for every hour.
> > > > 4. Be sure you have thought of what will be done with the
>items
> > > > at the end of the show.
> > > > 5. I (Paul Anderson) have offered to coordinate the use of
>the
> > > > second booth, so please provide me with information and do NOT expect
>that
> > > > I have assumed responsibility for what you are placing in the booth.
> > > >
> > > > Finally, these three (and perhaps more) booths might become a
>convenient
> > > > meeting and message point for all the stove-focused people.
> > > >
> > > > This is all turning out very nicely so far.
> > > >
> > > > Thanks again to Steve Troy.
> > > >
> > > > Paul
> > > >
> > > > At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
> > > > >Hi Paul and others,
> > > > >
> > > > >Trees, Water & People will have a booth at the Boulder conference and
>we
> > > > >will have
> > > > >an EcoStove (the metal version of the Justa stove) there on display,
>along
> > > > >with
> > > > >posters of our stove and reforestation projects. I have a Rocket
>stove
> > > that is
> > > > >funky looking (made from 5 gallon paint can), but functional. if you
>want
> > > > >that
> > > > >stove that for the stoves display/booth, I can bring that down. I can
>even
> > > > >paint it
> > > > >up to look more presentable.
> > > > >
> > > > >Actually, that's a good by-line for Aprovecho "funky, but
>functional".
> > > > >
> > > > >Stuart
> > > >
> > > > 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
> >
> > 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 rstanley at LEGACYFOUND.ORG Wed Sep 24 01:19:47 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
Message-ID: <WED.24.SEP.2003.081947.0300.>

Paul,

I am bringing in a prototype briquette gassifier made by fellow stover, Kobus
Venter . If you have space we can demo it there
We will also be demonstrating it at our own Briquette booth. in a preconerence
aqnd end of conference workshop. I look fwd to meeting you.

Richard Stanley,
Kampala

"Paul S. Anderson" wrote:

> Bruce,
>
> Sure, bring it. Please write (off list) to describe it. I can bring one
> that is the "hot bag" type from ProBEC in Africa.
>
> Paul
>
> At 09:02 PM 9/23/03 -0500, AES wrote:
> >Clarification on "Stoves"...would a haybox cooker fit in at your booth or
> >are you keeping it to strictly biomass stoves? I could bring one, with an
> >explanation but only if you all think it would be a good idea.
> >
> >Bruce
> >
> >
> >----- Original Message -----
> >From: "Paul S. Anderson" <psanders@ILSTU.EDU>
> >To: <STOVES@LISTSERV.REPP.ORG>
> >Sent: Tuesday, September 23, 2003 5:53 PM
> >Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!
> >
> >
> > > Stuart,
> > >
> > > I assume you checked with Dean about what you will bring. I suggest that
> > > some brochure or handout be available, if possible.
> > >
> > > Yes, there should be space in the booth areas. Being a portable Rocket, I
> > > assume it is one made from metal cans.
> > >
> > > I do not yet have the designation of the booth areas, but please arrange
> > > for the Rocket to arrive at the exhibit area between 3 and 5 PM on Wed 1
> > > October when I should be there setting things up. If you get there before
> > > I do, it is probably safe to leave it in the booth area for me to find.
> > >
> > > Steve Troy: Do you have one of Crispin's Vesto stoves?
> > > Any other stoves coming to be shown? I will arrange the booth according
> > > to what arrives.
> > >
> > > See you in Boulder.
> > >
> > > Paul
> > >
> > > At 04:36 PM 9/23/03 -0600, Stuart Conway wrote:
> > > >HI Paul,
> > > >
> > > >I'll go ahead and paint the Rocket stove this weekend and bring it down
> > > >next week
> > > >to Boulder for the conference. Sounds like you have plenty of space on
> >the
> > > >second
> > > >table/booth for stoves.
> > > >
> > > >Stuart
> > > >
> > > >"Paul S. Anderson" wrote:
> > > >
> > > > > Stuart and Dean and others.
> > > > >
> > > > > Maybe the booths will be close together.
> > > > >
> > > > > Steve Troy is providing us with a second 5ft wide by 10 ft deep booth
> >to be
> > > > > beside the one for the small gasifiers. That second one will have
> > > > > additional stoves and stoves-related items. I need to make sure that
> >it is
> > > > > well utilized, so anyone can send me info. For example, Crispin's
> >Vesto
> > > > > stove has been sent to Steve, so it could go in there also.
> > > > >
> > > > > Concerning any Aprovecho or other stove, I think the source of the
> >stove
> > > > > should decide if they want someone else to bring one of their stoves.
> >That
> > > > > is, Dean and his group will need to tell you if they want the
> > > > > "funky-looking" stove to be shown, painted or not painted. Perhaps
> >there
> > > > > is some way you could assist Aprovecho to transport some Rocket stove
> > > > > materials to Boulder.
> > > > >
> > > > > Another use for the second booth could be a place to show the Legacy
> > > > > Foundation briquette-making materials (or some of them) on the Thurs
> >and
> > > > > Friday between the Wed and Sat workshops.
> > > > >
> > > > > A couple of guidelines if anyone wants to put something in the second
> > > > booth:
> > > > > 1. Fairness of display and space for all who use it.
> > > > > 2. Provide signs or info or something to tell what it is.
> > > > > 3. Do NOT put valuables in the booth, because there might
> >not be
> > > > > a person to supervise the booth for every hour.
> > > > > 4. Be sure you have thought of what will be done with the
> >items
> > > > > at the end of the show.
> > > > > 5. I (Paul Anderson) have offered to coordinate the use of
> >the
> > > > > second booth, so please provide me with information and do NOT expect
> >that
> > > > > I have assumed responsibility for what you are placing in the booth.
> > > > >
> > > > > Finally, these three (and perhaps more) booths might become a
> >convenient
> > > > > meeting and message point for all the stove-focused people.
> > > > >
> > > > > This is all turning out very nicely so far.
> > > > >
> > > > > Thanks again to Steve Troy.
> > > > >
> > > > > Paul
> > > > >
> > > > > At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
> > > > > >Hi Paul and others,
> > > > > >
> > > > > >Trees, Water & People will have a booth at the Boulder conference and
> >we
> > > > > >will have
> > > > > >an EcoStove (the metal version of the Justa stove) there on display,
> >along
> > > > > >with
> > > > > >posters of our stove and reforestation projects. I have a Rocket
> >stove
> > > > that is
> > > > > >funky looking (made from 5 gallon paint can), but functional. if you
> >want
> > > > > >that
> > > > > >stove that for the stoves display/booth, I can bring that down. I can
> >even
> > > > > >paint it
> > > > > >up to look more presentable.
> > > > > >
> > > > > >Actually, that's a good by-line for Aprovecho "funky, but
> >functional".
> > > > > >
> > > > > >Stuart
> > > > >
> > > > > 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
> > >
> > > 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
>
> 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 crispin at NEWDAWN.SZ Wed Sep 24 03:41:46 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:38 2004
Subject: Stoves booths at Boulder meeting!!!!
Message-ID: <WED.24.SEP.2003.094146.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

Steve will probably get a Vesto today via Adam Barrow in Texas. David
Driver is also getting one.

Regards
Crispin

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 12:53 AM
Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!

Stuart,

[snip]
Steve Troy: Do you have one of Crispin's Vesto stoves?
Any other stoves coming to be shown? I will arrange the booth according
to what arrives.

See you in Boulder.

Paul

From crispin at NEWDAWN.SZ Wed Sep 24 03:48:47 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:38 2004
Subject: Stoves booths at Boulder meeting!!!!
Message-ID: <WED.24.SEP.2003.094847.0200.CRISPIN@NEWDAWN.SZ>

Just a reminder that the Hot Bag referred to is not a ProBEC initiative but
a creation of

Wendy Chandler
Hot Bags Project
Home: 0711-792-8675
Mobile: 0783-539-5192
E-Mail: wendy-chandler@mweb.co.za

Thanks
Crispin

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 4:27 AM
Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!

Bruce,

Sure, bring it. Please write (off list) to describe it. I can bring one
that is the "hot bag" type from ProBEC in Africa.

Paul

[snip]

From mchambwera at WWF.ORG.ZW Wed Sep 24 06:19:24 2003
From: mchambwera at WWF.ORG.ZW (mchambwera@WWF.ORG.ZW)
Date: Tue Aug 10 18:30:38 2004
Subject: Unsubscribe
Message-ID: <WED.24.SEP.2003.121924.0200.>

Hi there,

Could someone please assist me with information on how to
unsubscribe from the stoves and bioenergy lists?

Muyeye

From steve at SUSTAINABLEVILLAGE.COM Wed Sep 24 05:39:12 2003
From: steve at SUSTAINABLEVILLAGE.COM (Steve Troy)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
In-Reply-To: <200309240402.h8O42Y523623@ns1.repp.org>
Message-ID: <WED.24.SEP.2003.033912.0600.STEVE@SUSTAINABLEVILLAGE.COM>

>Steve Troy: Do you have one of Crispin's Vesto stoves? Any other
>stoves coming to be shown? I will arrange the booth according to
>what arrives.

Paul
It hasn't arrived yet but received a message that it was sent. We
also have two types of Volcano stoves if you'd like to display them.
We put a revised exhibit hall map on
http://www.sustainableresources.org/sr2003/exhibits/map.html and have
the booths assigned now.
Michael Lupton sent a message about Richard Stanley's pre-conference
briquetting workshop on Tuesday afternoon,
http://www.sustainableresources.org/sr2003/pre-conf/stanley.html.
They would really like to test-burn some of their briquettes in
various stoves. If any of you will be here that early, please bring
your stoves!
Steve

From yark at UIUC.EDU Wed Sep 24 10:33:39 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <4.3.1.2.20030915154523.01cc1790@mail.ilstu.edu>
Message-ID: <WED.24.SEP.2003.093339.0500.YARK@UIUC.EDU>

Dear Stovers,

On chopping up wood: Small chips for briquetting are one application.
Another potential application is getting wood to the small sizes that burn
better in stoves. For example, the Rocket stove might burn clean with small
wood and not with large branches. If I were a busy homemaker, I might be
tempted to skip the size-reduction step. It is difficult and annoying to
split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
bicycle-wheel and other ideas provide community wood chopping, for cleaner
burning wood?

Tami

From snkm at BTL.NET Wed Sep 24 11:18:17 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.091817.0600.SNKM@BTL.NET>

If I had market for short parts of wood here and was interested in
production I would simply put cane cutters to it with their machetes.

In fact -- they would roam the bush looking for dry dead branches -- chop
them to the right size -- fill bags with them -- and deliver these to the
"station" where they would be inspected -- weighed and paid for.

But then -- here we try to stay labor intensive -- as we have no social
blankets -- and everyone needs a "work".

Apparently people in other 3rd world countries on this list are rich -- and
have no workers needing work -- so can play around designing a machine to
do this.

Like india!!

Surprising how rich India is all of a sudden. Hard for me to believe.

In real work this would never work because they are all out their roaming
the bush with their machetes now -- to get their fire wood -- anyway.

Your trying to convince them that they can exert less labor by using less
wood by "buying" (and they have not much money for beyond basics) your
stoves because these stoves are more efficient -- but you have to cut the
wood into perfect little tiny parts -- etc.

Meanwhile my neighbors are still cooking using lengthy wood in Maya style
fire hearths -- and certainly -- I would want this increase in efficiency
well proved before changing that system!

They regulate their heat by pushing the long sticks in --

India makes a fine rotary chopper for preparing gasifier fuel:

http://aewgasifiers.netfirms.com/

Browse around -- you'll find it there -- as well as some other useful devices.

But it takes very little time for a person proficient with a machete to
chop up enough stick for a daily cooking -- if they had to -- which they do
not.

Peter Singfield -- Belize

At 09:33 AM 9/24/2003 -0500, Tami Bond wrote:
>Dear Stovers,
>
>On chopping up wood: Small chips for briquetting are one application.
>Another potential application is getting wood to the small sizes that burn
>better in stoves. For example, the Rocket stove might burn clean with small
>wood and not with large branches. If I were a busy homemaker, I might be
>tempted to skip the size-reduction step. It is difficult and annoying to
>split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
>bicycle-wheel and other ideas provide community wood chopping, for cleaner
>burning wood?
>
>Tami
>

From dstill at EPUD.NET Thu Sep 25 01:18:21 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.221821.0700.DSTILL@EPUD.NET>

Dear Peter Singfield,

What is the average diameter of sticks pushed into stoves where you live in
Belize?

Best,

Dean

From psanders at ILSTU.EDU Wed Sep 24 12:04:00 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: [ethos] Stoves booths at Boulder meeting!!!!
In-Reply-To: <3F71296D.5FD03B02@legacyfound.org>
Message-ID: <WED.24.SEP.2003.110400.0500.PSANDERS@ILSTU.EDU>

Richard,

Great !!!! Please send me some indication of the size / space needed to
show it. Any short written material would also be appreciated.

Paul

At 08:19 AM 9/24/03 +0300, Richard Stanley wrote:
>Paul,
>
>I am bringing in a prototype briquette gassifier made by fellow stover, Kobus
>Venter . If you have space we can demo it there
>We will also be demonstrating it at our own Briquette booth. in a
>preconerence
>aqnd end of conference workshop. I look fwd to meeting you.
>
>Richard Stanley,
>Kampala
>
>"Paul S. Anderson" wrote:
>
> > Bruce,
> >
> > Sure, bring it. Please write (off list) to describe it. I can bring one
> > that is the "hot bag" type from ProBEC in Africa.
> >
> > Paul
> >
> > At 09:02 PM 9/23/03 -0500, AES wrote:
> > >Clarification on "Stoves"...would a haybox cooker fit in at your booth or
> > >are you keeping it to strictly biomass stoves? I could bring one, with an
> > >explanation but only if you all think it would be a good idea.
> > >
> > >Bruce
> > >
> > >
> > >----- Original Message -----
> > >From: "Paul S. Anderson" <psanders@ILSTU.EDU>
> > >To: <STOVES@LISTSERV.REPP.ORG>
> > >Sent: Tuesday, September 23, 2003 5:53 PM
> > >Subject: Re: [STOVES] [ethos] Stoves booths at Boulder meeting!!!!
> > >
> > >
> > > > Stuart,
> > > >
> > > > I assume you checked with Dean about what you will bring. I
> suggest that
> > > > some brochure or handout be available, if possible.
> > > >
> > > > Yes, there should be space in the booth areas. Being a portable
> Rocket, I
> > > > assume it is one made from metal cans.
> > > >
> > > > I do not yet have the designation of the booth areas, but please
> arrange
> > > > for the Rocket to arrive at the exhibit area between 3 and 5 PM on
> Wed 1
> > > > October when I should be there setting things up. If you get there
> before
> > > > I do, it is probably safe to leave it in the booth area for me to find.
> > > >
> > > > Steve Troy: Do you have one of Crispin's Vesto stoves?
> > > > Any other stoves coming to be shown? I will arrange the booth
> according
> > > > to what arrives.
> > > >
> > > > See you in Boulder.
> > > >
> > > > Paul
> > > >
> > > > At 04:36 PM 9/23/03 -0600, Stuart Conway wrote:
> > > > >HI Paul,
> > > > >
> > > > >I'll go ahead and paint the Rocket stove this weekend and bring it
> down
> > > > >next week
> > > > >to Boulder for the conference. Sounds like you have plenty of space on
> > >the
> > > > >second
> > > > >table/booth for stoves.
> > > > >
> > > > >Stuart
> > > > >
> > > > >"Paul S. Anderson" wrote:
> > > > >
> > > > > > Stuart and Dean and others.
> > > > > >
> > > > > > Maybe the booths will be close together.
> > > > > >
> > > > > > Steve Troy is providing us with a second 5ft wide by 10 ft deep
> booth
> > >to be
> > > > > > beside the one for the small gasifiers. That second one will have
> > > > > > additional stoves and stoves-related items. I need to make
> sure that
> > >it is
> > > > > > well utilized, so anyone can send me info. For example, Crispin's
> > >Vesto
> > > > > > stove has been sent to Steve, so it could go in there also.
> > > > > >
> > > > > > Concerning any Aprovecho or other stove, I think the source of the
> > >stove
> > > > > > should decide if they want someone else to bring one of their
> stoves.
> > >That
> > > > > > is, Dean and his group will need to tell you if they want the
> > > > > > "funky-looking" stove to be shown, painted or not painted. Perhaps
> > >there
> > > > > > is some way you could assist Aprovecho to transport some Rocket
> stove
> > > > > > materials to Boulder.
> > > > > >
> > > > > > Another use for the second booth could be a place to show the
> Legacy
> > > > > > Foundation briquette-making materials (or some of them) on the
> Thurs
> > >and
> > > > > > Friday between the Wed and Sat workshops.
> > > > > >
> > > > > > A couple of guidelines if anyone wants to put something in the
> second
> > > > > booth:
> > > > > > 1. Fairness of display and space for all who use it.
> > > > > > 2. Provide signs or info or something to tell what it is.
> > > > > > 3. Do NOT put valuables in the booth, because there might
> > >not be
> > > > > > a person to supervise the booth for every hour.
> > > > > > 4. Be sure you have thought of what will be done with the
> > >items
> > > > > > at the end of the show.
> > > > > > 5. I (Paul Anderson) have offered to coordinate the
> use of
> > >the
> > > > > > second booth, so please provide me with information and do NOT
> expect
> > >that
> > > > > > I have assumed responsibility for what you are placing in the
> booth.
> > > > > >
> > > > > > Finally, these three (and perhaps more) booths might become a
> > >convenient
> > > > > > meeting and message point for all the stove-focused people.
> > > > > >
> > > > > > This is all turning out very nicely so far.
> > > > > >
> > > > > > Thanks again to Steve Troy.
> > > > > >
> > > > > > Paul
> > > > > >
> > > > > > At 03:06 PM 9/17/03 -0600, Stuart Conway wrote:
> > > > > > >Hi Paul and others,
> > > > > > >
> > > > > > >Trees, Water & People will have a booth at the Boulder
> conference and
> > >we
> > > > > > >will have
> > > > > > >an EcoStove (the metal version of the Justa stove) there on
> display,
> > >along
> > > > > > >with
> > > > > > >posters of our stove and reforestation projects. I have a Rocket
> > >stove
> > > > > that is
> > > > > > >funky looking (made from 5 gallon paint can), but
> functional. if you
> > >want
> > > > > > >that
> > > > > > >stove that for the stoves display/booth, I can bring that
> down. I can
> > >even
> > > > > > >paint it
> > > > > > >up to look more presentable.
> > > > > > >
> > > > > > >Actually, that's a good by-line for Aprovecho "funky, but
> > >functional".
> > > > > > >
> > > > > > >Stuart
> > > > > >
> > > > > > 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
> > > >
> > > > 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
> >
> > 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 kchisholm at CA.INTER.NET Wed Sep 24 12:02:19 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.130219.0300.KCHISHOLM@CA.INTER.NET>

Dear Tami

The cruel fact is that chopping, slicing, splitting, or smashing wood is
very energy intensive. If the device is powered by an engine, one needs a
significant sized engine . If powered by hand, it is hard work.

Chopping: Cutting the wood approximately perpendicular to the direction of
growth, ie, across the grain
Splitting: Cutting the wood parallel to the direction of growth, i.e. with
the grain
Slicing: Cutting the wood at a significant angle to the direction of growth.
"Smashed Wood": This would be wood that went through a hammer mill or some
such device. It is reduced to a very small size, with very high "surface
area per pound." The product is "wood fluff."

The energy required is proportional to "the new surface produced." Chopping,
splitting, and slicing and smashing have different energy constants, i.e.,
"foot-pounds of energy per each square foot of new surface area produced."

In general, chopping is the most energy intensive, splitting is the least,
and slicing is somewhere in-between. Smashing has a very much higher energy
requirement.

In general also, sliced wood is "better" as a fuel in that invariably, there
is internal shearing, or "internal surface" created, and this enables the
wood to dry better. However, sliced wood generally performs poorly in a
combustor system designed for dry split wood.

Wood "choppers" cut sticks into short lengths. This is good for drying, in
that there can be an axial flow of moisture, and the wood can dry, even when
the bark is unbroken. There is a critical length for various woods to permit
axial drying. For example, White Birch sticks about 18" long can actually
rot before they dry, because of their waterproof bark.

Your "Community Wood Processor" is a good idea. However, it must be able to
process the wood in a way that it meets the requirements for the stoves in a
community.

There must be a match between the fuel available, and the combustor design.
The combustor can be designed to meet the circumstances of wood
availability, OR, the wood must be processed to make it suitable for the
combustor.

The size and strength of the processor depend on the forces involved. The
forces in general, are dependant on the amount of new surface being created
at any given instant. Obviously, a dull cutter or chipper requires more
force than a sharp tool.

Another factor of concern to the designer of a chipper, chopper, slicer or
smasher, is how the wood is to be fed into the system. This is a dangerous
job, and it is best done with automatic feed or self feeding systems.
Consider a tree with its branches still on. For example, a Xmas Tree. It
might be 3" at the butt, and say 8' long the branches must be chopped off
beforehand, OR a "grabber system" of some sort must be included to bend the
branches and pull the tree into the cutters. The trimmed stem can be fed
vertically into a hopper, and it can "self feed" by its weight.

A powered chipper is "a dangerous piece of work". It must be of a relatively
robust design. It needs an engine, and purchased fuel, unless a wood gas
engine is employed.

So, this sort of gets back to a manual system.... wood can be chopped to
length with an axe, it can be split with an axe, and it can be sliced with
an axe. Larger sections of wood should be sawn with a chain saw, but then,
this requires mixed gasoline fuel, and "a machine from away."

There are an enormous number of variables associated with "a wood chipper."
Nobody in the world can design a "Universal Wood
Chipper/Chopper/Slicer/Smasher" However, if someone could come up with a
meaningful specification for a specific application, then there are many
people who could configure a suitable design.

One of my many faults is that if you ask me what time it is, I tell you how
to build a watch. :-)

Best wishes,

Kevin
----- Original Message -----
From: "Tami Bond" <yark@UIUC.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 11:33 AM
Subject: Re: [STOVES] Small rotary chopper for larger chips

> Dear Stovers,
>
> On chopping up wood: Small chips for briquetting are one application.
> Another potential application is getting wood to the small sizes that burn
> better in stoves. For example, the Rocket stove might burn clean with
small
> wood and not with large branches. If I were a busy homemaker, I might be
> tempted to skip the size-reduction step. It is difficult and annoying to
> split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
> bicycle-wheel and other ideas provide community wood chopping, for cleaner
> burning wood?
>
> Tami

From psanders at ILSTU.EDU Wed Sep 24 13:34:23 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <00c901c382b5$5a867ac0$fa9a0a40@kevin>
Message-ID: <WED.24.SEP.2003.123423.0500.PSANDERS@ILSTU.EDU>

Kevin,

Please tell me how to build a "watch" (chipper) that will give me chunky
pieces. I do NOT want smashed, and the type of wood would be generally too
too thin to split (keep to 2.5 cm = inch diameter and less). A diagonal
slice would be fine; no need to have perpendicular cuts.

Desired size is about 2 to 3 cm long and the diameter of the wood. If the
wood is over 2 cm in diameter, it would be fine if the chips came out about
1 cm thick, but that is not a main issue. But I do NOT want the "fluff"
or the small chips that are used for yard/lawn cover. Small stuff tends to
pack too tightly for the TLUD (top-lit up-draft) gasifiers that require air
to come up through the loaded fuel (chips).

For example, corn cobs when dry are about 1 to 1.5 cm in diameter. I
prefer lengths of 2 to 5 cm, but I do not bother to cut or break them.

I do NOT want a motorized operation (except maybe for the
developed-world-model that could be powered by a motor from a small lawn
mower.) A hand crank and a fly-wheel would seem appropriate.

I do NOT want to make chips out of larger-diameter branches (not at
present, anyway.) I want to use the "junk wood."

Andrew correctly pointed out that I do not have a firm grasp of the
"mechanics" needed for the chipper. I am open to all suggestions.

To Peter: I certainly understand your comment about hand chopping. In
Mozambique I paid a local fellow to get me a sack of "small-branch
chips". Burned VERY well. And when I see people earning their living
making gravel out of larger stones with only a hammer as their tool, I know
that people can earn a living doing this manual labor. But I guess I am
looking for a SLIGHTLY better way than a machete.

Kevin (and others), please recall my earlier note that almost every
"junked" vehicle can provide almost free 4 heavy-duty ball-bearing rotors
from its 4 wheels.

Thanks for your assistance.

Paul

At 01:02 PM 9/24/03 -0300, Kevin Chisholm wrote:
>Dear Tami
>
>The cruel fact is that chopping, slicing, splitting, or smashing wood is
>very energy intensive. If the device is powered by an engine, one needs a
>significant sized engine . If powered by hand, it is hard work.
>
>Chopping: Cutting the wood approximately perpendicular to the direction of
>growth, ie, across the grain
>Splitting: Cutting the wood parallel to the direction of growth, i.e. with
>the grain
>Slicing: Cutting the wood at a significant angle to the direction of growth.
>"Smashed Wood": This would be wood that went through a hammer mill or some
>such device. It is reduced to a very small size, with very high "surface
>area per pound." The product is "wood fluff."
>
>The energy required is proportional to "the new surface produced." Chopping,
>splitting, and slicing and smashing have different energy constants, i.e.,
>"foot-pounds of energy per each square foot of new surface area produced."
>
>In general, chopping is the most energy intensive, splitting is the least,
>and slicing is somewhere in-between. Smashing has a very much higher energy
>requirement.
>
>In general also, sliced wood is "better" as a fuel in that invariably, there
>is internal shearing, or "internal surface" created, and this enables the
>wood to dry better. However, sliced wood generally performs poorly in a
>combustor system designed for dry split wood.
>
>Wood "choppers" cut sticks into short lengths. This is good for drying, in
>that there can be an axial flow of moisture, and the wood can dry, even when
>the bark is unbroken. There is a critical length for various woods to permit
>axial drying. For example, White Birch sticks about 18" long can actually
>rot before they dry, because of their waterproof bark.
>
>Your "Community Wood Processor" is a good idea. However, it must be able to
>process the wood in a way that it meets the requirements for the stoves in a
>community.
>
>There must be a match between the fuel available, and the combustor design.
>The combustor can be designed to meet the circumstances of wood
>availability, OR, the wood must be processed to make it suitable for the
>combustor.
>
>The size and strength of the processor depend on the forces involved. The
>forces in general, are dependant on the amount of new surface being created
>at any given instant. Obviously, a dull cutter or chipper requires more
>force than a sharp tool.
>
>Another factor of concern to the designer of a chipper, chopper, slicer or
>smasher, is how the wood is to be fed into the system. This is a dangerous
>job, and it is best done with automatic feed or self feeding systems.
>Consider a tree with its branches still on. For example, a Xmas Tree. It
>might be 3" at the butt, and say 8' long the branches must be chopped off
>beforehand, OR a "grabber system" of some sort must be included to bend the
>branches and pull the tree into the cutters. The trimmed stem can be fed
>vertically into a hopper, and it can "self feed" by its weight.
>
>A powered chipper is "a dangerous piece of work". It must be of a relatively
>robust design. It needs an engine, and purchased fuel, unless a wood gas
>engine is employed.
>
>So, this sort of gets back to a manual system.... wood can be chopped to
>length with an axe, it can be split with an axe, and it can be sliced with
>an axe. Larger sections of wood should be sawn with a chain saw, but then,
>this requires mixed gasoline fuel, and "a machine from away."
>
>There are an enormous number of variables associated with "a wood chipper."
>Nobody in the world can design a "Universal Wood
>Chipper/Chopper/Slicer/Smasher" However, if someone could come up with a
>meaningful specification for a specific application, then there are many
>people who could configure a suitable design.
>
>One of my many faults is that if you ask me what time it is, I tell you how
>to build a watch. :-)
>
>Best wishes,
>
>Kevin
>----- Original Message -----
>From: "Tami Bond" <yark@UIUC.EDU>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Wednesday, September 24, 2003 11:33 AM
>Subject: Re: [STOVES] Small rotary chopper for larger chips
>
>
> > Dear Stovers,
> >
> > On chopping up wood: Small chips for briquetting are one application.
> > Another potential application is getting wood to the small sizes that burn
> > better in stoves. For example, the Rocket stove might burn clean with
>small
> > wood and not with large branches. If I were a busy homemaker, I might be
> > tempted to skip the size-reduction step. It is difficult and annoying to
> > split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
> > bicycle-wheel and other ideas provide community wood chopping, for cleaner
> > burning wood?
> >
> > Tami

From kchisholm at CA.INTER.NET Wed Sep 24 14:47:17 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.154717.0300.KCHISHOLM@CA.INTER.NET>

Dear Paul
----- Original Message -----
From: "Paul S. Anderson" <psanders@ilstu.edu>
To: "Kevin Chisholm" <kchisholm@ca.inter.net>; <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 2:34 PM
Subject: Re: [STOVES] Small rotary chopper for larger chips

> Kevin,
>
> Please tell me how to build a "watch" (chipper) that will give me chunky
> pieces.

Were you intending to buy them from me, or did you simply require a proven
prototype so that you or others could make them ? What "price window" would
you think would be appropriate for the final system? How many would you
require?

> I do NOT want smashed, and the type of wood would be generally too
> too thin to split (keep to 2.5 cm = inch diameter and less). A diagonal
> slice would be fine; no need to have perpendicular cuts.
>
OK....

> Desired size is about 2 to 3 cm long and the diameter of the wood. If the
> wood is over 2 cm in diameter, it would be fine if the chips came out
about
> 1 cm thick, but that is not a main issue. But I do NOT want the "fluff"
> or the small chips that are used for yard/lawn cover. Small stuff tends
to
> pack too tightly for the TLUD (top-lit up-draft) gasifiers that require
air
> to come up through the loaded fuel (chips).

OK... one man turns the crank, one man feeds the sticks.
>
> For example, corn cobs when dry are about 1 to 1.5 cm in diameter. I
> prefer lengths of 2 to 5 cm, but I do not bother to cut or break them.
>
OK... this is different... corn cobs would be easier to cut. However,
because of short length, and danger of hands near cutters, the cobs should
be handled with tongs.

> I do NOT want a motorized operation (except maybe for the
> developed-world-model that could be powered by a motor from a small lawn
> mower.) A hand crank and a fly-wheel would seem appropriate.

A hand crank and flywheel would work. However, power output would be
somewhat limited, and as a consequence capacity would be limited. How many
pounds per hour would you have in mind?
>
> I do NOT want to make chips out of larger-diameter branches (not at
> present, anyway.) I want to use the "junk wood."
>
> Andrew correctly pointed out that I do not have a firm grasp of the
> "mechanics" needed for the chipper. I am open to all suggestions.

OK... looks like you want to chop branches up to about 3 cm diameter, with
the ratio of the length to the thickness about 2. What kind of wood would
you be planning on using? More specifically, would you have some "energy
index", such as "foot pounds of energy required to produce 1 square inch of
new surface?" Also, it would be necessary to know how many pounds per hour
you wished to produce.
>
> To Peter: I certainly understand your comment about hand chopping. In
> Mozambique I paid a local fellow to get me a sack of "small-branch
> chips". Burned VERY well. And when I see people earning their living
> making gravel out of larger stones with only a hammer as their tool, I
know
> that people can earn a living doing this manual labor. But I guess I am
> looking for a SLIGHTLY better way than a machete.

There are a lot of good things to be said about a machette, two of which
are: it is cheap, and it works.
>
> Kevin (and others), please recall my earlier note that almost every
> "junked" vehicle can provide almost free 4 heavy-duty ball-bearing rotors
> from its 4 wheels.

Are junked vehicles actually available in the area where you want the
chopper to be operated? Front or rear wheel drive?The use of a car rear end
could open some possibilities.

Best wishes,

Kevin

From psanders at ILSTU.EDU Wed Sep 24 15:19:32 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <010701c382cc$7565f020$fa9a0a40@kevin>
Message-ID: <WED.24.SEP.2003.141932.0500.PSANDERS@ILSTU.EDU>

Kevin,

Not wanting a proven prototype nor the development costs. Mainly want the
ideas/concepts. The disadvantaged people are eventually the one who would
be making this item, which is clearly much more simple than making a
"watch". You wrote about "how to make a watch" and not about making a
watch for me or others.

Not cutting the corn cobs. I was not totally clear, sorry. I want to cut
the branches.

If 3 cm seems big, then even 2 or 1.5 cm would be of interest to be
cut/chopped.

I have NO idea about the "power" or the "foot pounds of energy" to which
you refer.

Amount of production of the "chips:" How about 3 to 5 liters per day of
chopped pieces per family. An hour on the "machine" could produce 1 to 7
days supply for a household. (These are just guess-timents.

Yes, a two-person effort. One for power and one for feeding the branches
into the device.

Sorry I am of so little help on those issues.

But I can say that when I use my hatchet or machete to chop branches, the
pieces fly all over the place, the effort of repeatedly chopping (instead
of some rotational force) seem high for the meager results, the lengths are
totally irregular (lack of chopping talent on my part) and I am looking for
a different way.

And the commercially available "choppers" (like that nice one from India to
which Peter directed us) are FAR too sophisticated. 5 HP motor, high
volume of output, and a price tag above what would be reachable for those
who I hope could be using my gasifier stove.

Yes, there are junk rear axles around in many many places. Some are rusted
beyond use, but others could be useful.

Looking forward to your ideas.

Paul

At 03:47 PM 9/24/03 -0300, Kevin Chisholm wrote:
>Dear Paul
>----- Original Message -----
>From: "Paul S. Anderson" <psanders@ilstu.edu>
>To: "Kevin Chisholm" <kchisholm@ca.inter.net>; <STOVES@LISTSERV.REPP.ORG>
>Sent: Wednesday, September 24, 2003 2:34 PM
>Subject: Re: [STOVES] Small rotary chopper for larger chips
>
>
> > Kevin,
> >
> > Please tell me how to build a "watch" (chipper) that will give me chunky
> > pieces.
>
>Were you intending to buy them from me, or did you simply require a proven
>prototype so that you or others could make them ? What "price window" would
>you think would be appropriate for the final system? How many would you
>require?
>
>
> > I do NOT want smashed, and the type of wood would be generally too
> > too thin to split (keep to 2.5 cm = inch diameter and less). A diagonal
> > slice would be fine; no need to have perpendicular cuts.
> >
>OK....
>
> > Desired size is about 2 to 3 cm long and the diameter of the wood. If the
> > wood is over 2 cm in diameter, it would be fine if the chips came out
>about
> > 1 cm thick, but that is not a main issue. But I do NOT want the "fluff"
> > or the small chips that are used for yard/lawn cover. Small stuff tends
>to
> > pack too tightly for the TLUD (top-lit up-draft) gasifiers that require
>air
> > to come up through the loaded fuel (chips).
>
>OK... one man turns the crank, one man feeds the sticks.
> >
> > For example, corn cobs when dry are about 1 to 1.5 cm in diameter. I
> > prefer lengths of 2 to 5 cm, but I do not bother to cut or break them.
> >
>OK... this is different... corn cobs would be easier to cut. However,
>because of short length, and danger of hands near cutters, the cobs should
>be handled with tongs.
>
> > I do NOT want a motorized operation (except maybe for the
> > developed-world-model that could be powered by a motor from a small lawn
> > mower.) A hand crank and a fly-wheel would seem appropriate.
>
>A hand crank and flywheel would work. However, power output would be
>somewhat limited, and as a consequence capacity would be limited. How many
>pounds per hour would you have in mind?
> >
> > I do NOT want to make chips out of larger-diameter branches (not at
> > present, anyway.) I want to use the "junk wood."
> >
> > Andrew correctly pointed out that I do not have a firm grasp of the
> > "mechanics" needed for the chipper. I am open to all suggestions.
>
>OK... looks like you want to chop branches up to about 3 cm diameter, with
>the ratio of the length to the thickness about 2. What kind of wood would
>you be planning on using? More specifically, would you have some "energy
>index", such as "foot pounds of energy required to produce 1 square inch of
>new surface?" Also, it would be necessary to know how many pounds per hour
>you wished to produce.
> >
> > To Peter: I certainly understand your comment about hand chopping. In
> > Mozambique I paid a local fellow to get me a sack of "small-branch
> > chips". Burned VERY well. And when I see people earning their living
> > making gravel out of larger stones with only a hammer as their tool, I
>know
> > that people can earn a living doing this manual labor. But I guess I am
> > looking for a SLIGHTLY better way than a machete.
>
>There are a lot of good things to be said about a machette, two of which
>are: it is cheap, and it works.
> >
> > Kevin (and others), please recall my earlier note that almost every
> > "junked" vehicle can provide almost free 4 heavy-duty ball-bearing rotors
> > from its 4 wheels.
>
>Are junked vehicles actually available in the area where you want the
>chopper to be operated? Front or rear wheel drive?The use of a car rear end
>could open some possibilities.
>
>Best wishes,
>
>Kevin

From snkm at BTL.NET Wed Sep 24 15:24:23 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.132423.0600.SNKM@BTL.NET>

Dear Dean

Anywhere from 1/2 to 3 inch diameter -- and 24 to 36 inch long.

As far as I have seen -- this same system in Mexico (at least southern) --
Guatemala, Honduras, El Salvador and Nicaragua.

Basically -- in terms that the list can visualize -- a 3 stone stove on a
platform -- no chimney --

Cooking of beans is a big deal -- and it is hard to beat the efficiency of
this system for that. Short hot start -- long slow simmer.

And very seldom does one see smoke or smell burning wood in these villages.
As that can occur only when they start their fires -- but normally they are
burning -- or being "kept" -- 24 hours per day. And when burning -- they
are very clean.

Mind you -- generations of skill developed to do all of this right.

The stoves are housed in special structures called out-door kitchens. Also
of a design dating 1000's of years.

However -- if people get rich enough -- they can't convert to butane stoves
quick enough -- for obvious reasons.

But to get them to spend money on an "improved" wood burning stove --
seriously folks -- I don't believe so.

They can replace their cooking needs with butane for around $7.50 or less
per month.

Butane sells here for $1.50 per gallon.

Peter

At 10:18 PM 9/24/2003 -0700, Dean Still wrote:
>Dear Peter Singfield,
>
>What is the average diameter of sticks pushed into stoves where you live in
>Belize?
>
>Best,
>
>Dean
>

From kchisholm at CA.INTER.NET Wed Sep 24 15:52:55 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.165255.0300.KCHISHOLM@CA.INTER.NET>

Dear Paul
Subject: Re: [STOVES] Small rotary chopper for larger chips

> Kevin,
>
> Not wanting a proven prototype nor the development costs. Mainly want the
> ideas/concepts. The disadvantaged people are eventually the one who would
> be making this item, which is clearly much more simple than making a
> "watch". You wrote about "how to make a watch" and not about making a
> watch for me or others.
>
OK... what would "the permissable cost of the finished product, ready for
production?"

...del...
>
> I have NO idea about the "power" or the "foot pounds of energy" to which
> you refer.

This is important... it determines the force that must be applied, and that
determines gear ratios or lever lengths.
>
> Amount of production of the "chips:" How about 3 to 5 liters per day of
> chopped pieces per family. An hour on the "machine" could produce 1 to 7
> days supply for a household. (These are just guess-timents.
>
3 litres in one hour to 7x5=35 litres in one hour is a broad range. It is
rather difficult for me to make estimates, in that I don't know what kind of
wood you will be using, where it will be used, worker diligence and stamina,
etc.

> Yes, a two-person effort. One for power and one for feeding the branches
> into the device.
>
OK
> Sorry I am of so little help on those issues.
>
I am sure you can appreciate that if you want a chipper to work in a given
application, the designer needs to know the relevant parameters.

> But I can say that when I use my hatchet or machete to chop branches, the
> pieces fly all over the place, the effort of repeatedly chopping (instead
> of some rotational force) seem high for the meager results, the lengths
are
> totally irregular (lack of chopping talent on my part) and I am looking
for
> a different way.

OK... with your hatchet, how many cuts could you make an hour? Whether it is
a hand held hatchet or a machine guided blade, one person of equivalent
diligence and stamina (D&S) can do about the same number of cuts per hour in
with similar wood. If the nature of the wood and the are such that you could
do 10 cuts per minute, then that would be roughly 600 cuts per hour. The
machine will not materially increase production, because it is "energy
limited.". All it will do is make the cuts more uniform, and leave the
choppings in one pile.
>
> And the commercially available "choppers" (like that nice one from India
to
> which Peter directed us) are FAR too sophisticated. 5 HP motor, high
> volume of output, and a price tag above what would be reachable for those
> who I hope could be using my gasifier stove.

A 5 HP chopper would have an output about 100 times as great as a manually
hand cranked chopper.
>
> Yes, there are junk rear axles around in many many places. Some are
rusted
> beyond use, but others could be useful.

Unless there are lots of them around, and in good working order, it would
not be a good idea to depend on their availability. I woud guess that you
are looking for a system with broad application.
>
> Looking forward to your ideas.
>
One thing you might consider is drilling a hole in one end of a machette,
and then spiking it to the side of a saw horse type structure. The Operator
simply moves the machette up and down to to cut the branches to the desired
length.

Is that the sort of thing that would seem to be applicable to your
circumstances?

Kevin
>
> At 03:47 PM 9/24/03 -0300, Kevin Chisholm wrote:
> >Dear Paul
> >----- Original Message -----
> >From: "Paul S. Anderson" <psanders@ilstu.edu>
> >To: "Kevin Chisholm" <kchisholm@ca.inter.net>; <STOVES@LISTSERV.REPP.ORG>
> >Sent: Wednesday, September 24, 2003 2:34 PM
> >Subject: Re: [STOVES] Small rotary chopper for larger chips
> >
> >
> > > Kevin,
> > >
> > > Please tell me how to build a "watch" (chipper) that will give me
chunky
> > > pieces.
> >
> >Were you intending to buy them from me, or did you simply require a
proven
> >prototype so that you or others could make them ? What "price window"
would
> >you think would be appropriate for the final system? How many would you
> >require?
> >
> >
> > > I do NOT want smashed, and the type of wood would be generally too
> > > too thin to split (keep to 2.5 cm = inch diameter and less). A
diagonal
> > > slice would be fine; no need to have perpendicular cuts.
> > >
> >OK....
> >
> > > Desired size is about 2 to 3 cm long and the diameter of the wood. If
the
> > > wood is over 2 cm in diameter, it would be fine if the chips came out
> >about
> > > 1 cm thick, but that is not a main issue. But I do NOT want the
"fluff"
> > > or the small chips that are used for yard/lawn cover. Small stuff
tends
> >to
> > > pack too tightly for the TLUD (top-lit up-draft) gasifiers that
require
> >air
> > > to come up through the loaded fuel (chips).
> >
> >OK... one man turns the crank, one man feeds the sticks.
> > >
> > > For example, corn cobs when dry are about 1 to 1.5 cm in diameter. I
> > > prefer lengths of 2 to 5 cm, but I do not bother to cut or break them.
> > >
> >OK... this is different... corn cobs would be easier to cut. However,
> >because of short length, and danger of hands near cutters, the cobs
should
> >be handled with tongs.
> >
> > > I do NOT want a motorized operation (except maybe for the
> > > developed-world-model that could be powered by a motor from a small
lawn
> > > mower.) A hand crank and a fly-wheel would seem appropriate.
> >
> >A hand crank and flywheel would work. However, power output would be
> >somewhat limited, and as a consequence capacity would be limited. How
many
> >pounds per hour would you have in mind?
> > >
> > > I do NOT want to make chips out of larger-diameter branches (not at
> > > present, anyway.) I want to use the "junk wood."
> > >
> > > Andrew correctly pointed out that I do not have a firm grasp of the
> > > "mechanics" needed for the chipper. I am open to all suggestions.
> >
> >OK... looks like you want to chop branches up to about 3 cm diameter,
with
> >the ratio of the length to the thickness about 2. What kind of wood would
> >you be planning on using? More specifically, would you have some "energy
> >index", such as "foot pounds of energy required to produce 1 square inch
of
> >new surface?" Also, it would be necessary to know how many pounds per
hour
> >you wished to produce.
> > >
> > > To Peter: I certainly understand your comment about hand chopping.
In
> > > Mozambique I paid a local fellow to get me a sack of "small-branch
> > > chips". Burned VERY well. And when I see people earning their living
> > > making gravel out of larger stones with only a hammer as their tool, I
> >know
> > > that people can earn a living doing this manual labor. But I guess I
am
> > > looking for a SLIGHTLY better way than a machete.
> >
> >There are a lot of good things to be said about a machette, two of which
> >are: it is cheap, and it works.
> > >
> > > Kevin (and others), please recall my earlier note that almost every
> > > "junked" vehicle can provide almost free 4 heavy-duty ball-bearing
rotors
> > > from its 4 wheels.
> >
> >Are junked vehicles actually available in the area where you want the
> >chopper to be operated? Front or rear wheel drive?The use of a car rear
end
> >could open some possibilities.
> >
> >Best wishes,
> >
> >Kevin
>
> 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 kchisholm at CA.INTER.NET Wed Sep 24 16:01:21 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:38 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.170121.0300.KCHISHOLM@CA.INTER.NET>

Dear Peter
...del...>
> But to get them to spend money on an "improved" wood burning stove --
> seriously folks -- I don't believe so.
>
> They can replace their cooking needs with butane for around $7.50 or less
> per month.
>
> Butane sells here for $1.50 per gallon.
>
Very interesting!! Is this $US or $Bz? While $7.50 per month may not sound
like much, it may be a very significant percentage of their monthly cash
income. Roughly, what would be the monthly income of such a family? (i.e.,
burning stick wood now, and considering going to Butane?

Kindest regards,

Kevin
>

From snkm at BTL.NET Wed Sep 24 20:38:58 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.183858.0600.SNKM@BTL.NET>

Dear Kevin;

Basically -- those that can afford the $7.50 US per month -- do -- those
that can't -- do not -- but some just prefer cooking with wood -- even
though they can afford butane.

And some deprive themselves of food to pay for butane!

Capital investment for a butane stove and regulator is around $25 US --

In my house here the women insist on cooking beans -- at least once per
week -- on the fire hearth. Just for the extra flavor.

I like mine pre-soaked for 24 hours (partially sprouting) then pressure
cooked at 15 psi over a small butane flame for 45 minutes.

I also like to add some molasses to the beans -- a habit which drives them
nuts here. but as I always have some home made molasses at hand -- and it
is so healthy -- and so traditional in French Quebec for beans -- I do.

In short Kevin -- there is no "law" to cooking of food -- no "rules" -- it
is also up to taste -- and other difficult to define parameters.

Like woman visiting in outdoor kitchen minding the fire hearth while
minding the beans.

When I lived in town (Corozal) a few years ago -- one ton of dried firewood
was $10 US --

I regard with as much pleasure -- well splitting wood with an axe -- as
most North Americans do sitting and watching sports on TV.

Be careful folks not to automatically apply North american "monoculture"
attitudes to the rest of this world's kitchens.

That is automation of basic life style physical activities to give more
time to the household to watch TV???

Because that is what usually occurs.

Peter

At 05:01 PM 9/24/2003 -0300, Kevin Chisholm wrote:
>Dear Peter
>...del...>
>> But to get them to spend money on an "improved" wood burning stove --
>> seriously folks -- I don't believe so.
>>
>> They can replace their cooking needs with butane for around $7.50 or less
>> per month.
>>
>> Butane sells here for $1.50 per gallon.
>>
>Very interesting!! Is this $US or $Bz? While $7.50 per month may not sound
>like much, it may be a very significant percentage of their monthly cash
>income. Roughly, what would be the monthly income of such a family? (i.e.,
>burning stick wood now, and considering going to Butane?
>
>Kindest regards,
>
>Kevin
>>
>

From adkarve at PN2.VSNL.NET.IN Wed Sep 24 21:33:24 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.070324.0530.ADKARVE@PN2.VSNL.NET.IN>

Peter made a reference to the fact that the rural Indians were rich.
In fact they are so rich that they use electricity for cooking their
meals. In the state of Maharashtra, where I reside, every single
village is connected to the grid. Because the electricity is supplied
through naked wires strung on overhead poles, anybody can tap the
electricity using a metal hook attached to the end of a bamboo pole, and
a wire (insulated) leading from the hook to the house. One can buy in
any rural electric shop cheap electric stoves (naked coils of the
heating element fitted into a ceramic plate) and copper hooks attached
to lengths of wire. The shopkeeper would even teach you, how to fit the
hook on a bamboo pole and how to use this contraption for stealing
electricity from the public grid. Stealing electricity is not a
cognisable offence (i.e. the police would not interfere unless the owner
files an official complaint). The person appointed by the Government of
Maharashtra to maintain the electric line is called the linesman. It is
his duty to report the theft, but he would be the last person to do so,
because he would then not be able to collect bribes from the thieves.
A.D.Karve

>>
>>
>

From snkm at BTL.NET Wed Sep 24 22:25:21 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <WED.24.SEP.2003.202521.0600.SNKM@BTL.NET>

At 07:03 AM 9/25/2003 +0530, A.D. Karve wrote:
>>>>
Peter made a reference to the fact that the rural Indians were rich. In
fact they are so rich that they use electricity for cooking their meals. In
the state of Maharashtra, where I reside, every single village is
connected to the grid. Because the electricity is supplied through naked
wires strung on overhead poles, anybody can tap the electricity using a
metal hook attached to the end of a bamboo pole, and a wire (insulated)
leading from the hook to the house. One can buy in any rural electric shop
cheap electric stoves (naked coils of the heating element fitted into a
ceramic plate) and copper hooks attached to lengths of wire. The
shopkeeper would even teach you, how to fit the hook on a bamboo pole and
how to use this contraption for stealing electricity from the public grid.
Stealing electricity is not a cognisable offence (i.e. the police would not
interfere unless the owner files an official complaint). The person
appointed by the Government of Maharashtra to maintain the electric line is
called the linesman. It is his duty to report the theft, but he would be
the last person to do so, because he would then not be able to collect
bribes from the thieves.
A.D.Karve

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

For the rest of the list --

A.D. Karve and I are doing a little tongue in cheek.

For many of the poorer villages in India they have no sticks to chop for
cooking fuel.

Here in Central America -- even the poorest village can find sufficient
fire wood for cooking purposes.

However -- in both places -- India and Central America -- when climate
fails the crop growing season people need no fuel at all -- and they starve.

Belize has been "blessed" these past 15 years and allowed to run a huge
deficit (comparatively -- per capita) compared to our neighbors. This
influx of "false" wealth has led to a huge loss of basic skills in survival
-- as full bellies make for lazy people.

A.D. -- has this occurred in India??

I fear that a balancing of accounts will be due one day. No more deficit
spending manna -- and then we will sing to a different tune.

In this village of Xaibe -- it is the older people that stay loyal to the
fire hearth and even still plant food around their houses.

The younger all use butane -- except for some of the very poor -- and now
grow lawns around their houses -- and control those with lawn mowers.

My house is still surrounded with food plants -- mainly plantain -- and we
use machete to "clean" the ground. Grass of any form is not tolerated at all.

It is in this shifting world that you stovers are trying to introduce a
better system -- but all is not as it seems.

Population pressures are much greater today -- we exist at such a level
only to the grace of petroleum products.

It reminds me of yeast in a fresh brew -- feasting on a single asset --
carbohydrates -- like there is no end in sight.

Could it be possible we are but champagne to the Gods?? Or just plain beer??

Can CO2 be an agent of exhilaration for such as these??

Can our toxic wastes be beneficial vitamins?

Have we -- the "yeast" passed our point of no return?

It seems to me that dominant societies of earth abandoned alternative means
(of survival) a while ago -- now it's full speed ahead -- damned be our
future.

Denial -- rather than hope -- rules.

Another "gem" for small manual "chipper" --

Ever see a cable cutter??

It is a chisel in a die -- you pass the thick (to one inch!!) steel cable
through the die hole and slam down with a sledge on the contained chisel --
while the entire unit sits on a solid base.

The chisel is riding on a coil spring -- so is returned to top position
after each strike.

I believe you will find a lighter -- though larger (diameter die hole)
design such as this -- ideal for your present purposes.

That is simply -- and uniformly -- converting any tubular biomass of
variable diameters to equal, short lengths, of any desired form.

One man pushes the stick though till it hits a set point stopper -- the
other man swings the sledge. The shortened stick drops into bag or bucket.
Then stick pushed again --

Bang -- bang -- bang -- ad finum.

You might want to prototype this using a wide carpenter's wood chisel and a
guillotine style rack made of hard wood. Pretend its the French revolution.

Indeed -- a guillotine would probably work well -- the cutting through the
human neck probably being equivelent to chopping a stick. Ergo -- a good
meat clever --weighted -- or an axe head with a spring return in a hard
wood frame. Or the blade of any hand planer.

Kevin -- you might want to rig up one of the above designs to make fuel for
the Chinee Gasifier stove???

Peter Singfield
Belize

From dstill at EPUD.NET Thu Sep 25 06:13:06 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.031306.0700.DSTILL@EPUD.NET>

Dear Peter,

Very glad that you are not seeing smoke when folks use the traditional
stove. Where I lived in Mexico for ten years there was a lot of smoke made
when cooking using the same system. In the lab even when I am careful fires
make smoke. There was a species of wood in the desert that didn't smoke much
(palo fiero) but it had been generally used up. Many of the kids in my
village had asthma and older folks had breathing problems, coughs, as well.

The folks I lived with had an old truck and a propane stove. Both worked
about one third of the time. The fishing and ranching families could afford
big purchases when they saved up or had a good year. You should have seen
some of the coming out parties for the 15 year old girls! Mules were a back
up for the truck, a row boat backed up the motorboat and the traditional
three stone fire on a platform backed up the propane stove. Propane was not
available most trips to town. Firewood was free.

Putting a chimney on the traditional cooking system would go a long way to
solving the medical problems created by exposure to smoke. Cutting right
sized holes in the lid of a drum into which fit the family pots allows the
smoke to exit out of a chimney placed through the back wall of the fogon
tradicional. When folks aren't breathing smoke they save money spent on
treating illness. We rushed my poor little asthmatic godson many times to
the doctor which took us a day's nerve wracking travel...It is also possible
to improve the traditional cooking system so that folks use half the wood or
less. Replace the earthen walls with insulative brick walls made locally.
Use a skirt around the pots. Not expensive or demanding great adjustments.
Even where I lived in Mexico, 80k from the closest town of 8,000, getting
wood was a lot of work, so using half had advantages that were obvious to
everyone. A really good cooking stove can be made and sold for ten dollars
and up. Not so much money when balanced against the advantages...

Try to get a good wood burning stove away from a village woman who finally
has one...You might be taking away something she really values. To make sure
that a stove is an improvement, though, I think that it has to be designed
and tested by local women who adjust it until they are satisfied. This
process took quite a while with the wildly successful HELPS stove. The stove
has to be an improvement TO COOKS. It is the female cooks who convince their
friends to try a better cooking method...

If the women are not involved in the whole process the stove, insulative
wall, skirt, chimney, etc. may not be "an improvement". Pepsi doesn't create
a new product without doing a lot of consumer testing first, you bet. I
agree that to change the traditional pattern of pushing long sticks into the
fire is going to be a challenge if it requires more work...Traditional
methods are evolutionarily tested, very well adapted to the situation.

Do you see smoke where folks have used up the preferred firewood species?

All Best,

Dean

From psanders at ILSTU.EDU Wed Sep 24 23:44:36 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
In-Reply-To: <014401c382d5$cf614850$fa9a0a40@kevin>
Message-ID: <WED.24.SEP.2003.224436.0500.PSANDERS@ILSTU.EDU>

Kevin,

As we can all see, there are so many unknowns that we reach blockages in
our efforts. I do not have answers to the various questions raised.

I remain very interested in the "large chips" issue, but right now I must
devote my time to the Boulder conference, my Juntos Stove, and other issues.

I hope that some experimentation might eventually move this issue forward.

All efforts are appreciated.

Paul

At 04:52 PM 9/24/03 -0300, Kevin Chisholm wrote:
>Dear Paul
>Subject: Re: [STOVES] Small rotary chopper for larger chips
>
>
> > Kevin,
> >
> > Not wanting a proven prototype nor the development costs. Mainly want the
> > ideas/concepts. The disadvantaged people are eventually the one who would
> > be making this item, which is clearly much more simple than making a
> > "watch". You wrote about "how to make a watch" and not about making a
> > watch for me or others.
> >
>OK... what would "the permissable cost of the finished product, ready for
>production?"
>
>...del...
> >
> > I have NO idea about the "power" or the "foot pounds of energy" to which
> > you refer.
>
>This is important... it determines the force that must be applied, and that
>determines gear ratios or lever lengths.
> >
> > Amount of production of the "chips:" How about 3 to 5 liters per day of
> > chopped pieces per family. An hour on the "machine" could produce 1 to 7
> > days supply for a household. (These are just guess-timents.
> >
>3 litres in one hour to 7x5=35 litres in one hour is a broad range. It is
>rather difficult for me to make estimates, in that I don't know what kind of
>wood you will be using, where it will be used, worker diligence and stamina,
>etc.
>
> > Yes, a two-person effort. One for power and one for feeding the branches
> > into the device.
> >
>OK
> > Sorry I am of so little help on those issues.
> >
>I am sure you can appreciate that if you want a chipper to work in a given
>application, the designer needs to know the relevant parameters.
>
> > But I can say that when I use my hatchet or machete to chop branches, the
> > pieces fly all over the place, the effort of repeatedly chopping (instead
> > of some rotational force) seem high for the meager results, the lengths
>are
> > totally irregular (lack of chopping talent on my part) and I am looking
>for
> > a different way.
>
>OK... with your hatchet, how many cuts could you make an hour? Whether it is
>a hand held hatchet or a machine guided blade, one person of equivalent
>diligence and stamina (D&S) can do about the same number of cuts per hour in
>with similar wood. If the nature of the wood and the are such that you could
>do 10 cuts per minute, then that would be roughly 600 cuts per hour. The
>machine will not materially increase production, because it is "energy
>limited.". All it will do is make the cuts more uniform, and leave the
>choppings in one pile.
> >
> > And the commercially available "choppers" (like that nice one from India
>to
> > which Peter directed us) are FAR too sophisticated. 5 HP motor, high
> > volume of output, and a price tag above what would be reachable for those
> > who I hope could be using my gasifier stove.
>
>A 5 HP chopper would have an output about 100 times as great as a manually
>hand cranked chopper.
> >
> > Yes, there are junk rear axles around in many many places. Some are
>rusted
> > beyond use, but others could be useful.
>
>Unless there are lots of them around, and in good working order, it would
>not be a good idea to depend on their availability. I woud guess that you
>are looking for a system with broad application.
> >
> > Looking forward to your ideas.
> >
>One thing you might consider is drilling a hole in one end of a machette,
>and then spiking it to the side of a saw horse type structure. The Operator
>simply moves the machette up and down to to cut the branches to the desired
>length.
>
>Is that the sort of thing that would seem to be applicable to your
>circumstances?
>
>Kevin
> >
> > At 03:47 PM 9/24/03 -0300, Kevin Chisholm wrote:
> > >Dear Paul
> > >----- Original Message -----
> > >From: "Paul S. Anderson" <psanders@ilstu.edu>
> > >To: "Kevin Chisholm" <kchisholm@ca.inter.net>; <STOVES@LISTSERV.REPP.ORG>
> > >Sent: Wednesday, September 24, 2003 2:34 PM
> > >Subject: Re: [STOVES] Small rotary chopper for larger chips
> > >
> > >
> > > > Kevin,
> > > >
> > > > Please tell me how to build a "watch" (chipper) that will give me
>chunky
> > > > pieces.
> > >
> > >Were you intending to buy them from me, or did you simply require a
>proven
> > >prototype so that you or others could make them ? What "price window"
>would
> > >you think would be appropriate for the final system? How many would you
> > >require?
> > >
> > >
> > > > I do NOT want smashed, and the type of wood would be generally too
> > > > too thin to split (keep to 2.5 cm = inch diameter and less). A
>diagonal
> > > > slice would be fine; no need to have perpendicular cuts.
> > > >
> > >OK....
> > >
> > > > Desired size is about 2 to 3 cm long and the diameter of the wood. If
>the
> > > > wood is over 2 cm in diameter, it would be fine if the chips came out
> > >about
> > > > 1 cm thick, but that is not a main issue. But I do NOT want the
>"fluff"
> > > > or the small chips that are used for yard/lawn cover. Small stuff
>tends
> > >to
> > > > pack too tightly for the TLUD (top-lit up-draft) gasifiers that
>require
> > >air
> > > > to come up through the loaded fuel (chips).
> > >
> > >OK... one man turns the crank, one man feeds the sticks.
> > > >
> > > > For example, corn cobs when dry are about 1 to 1.5 cm in diameter. I
> > > > prefer lengths of 2 to 5 cm, but I do not bother to cut or break them.
> > > >
> > >OK... this is different... corn cobs would be easier to cut. However,
> > >because of short length, and danger of hands near cutters, the cobs
>should
> > >be handled with tongs.
> > >
> > > > I do NOT want a motorized operation (except maybe for the
> > > > developed-world-model that could be powered by a motor from a small
>lawn
> > > > mower.) A hand crank and a fly-wheel would seem appropriate.
> > >
> > >A hand crank and flywheel would work. However, power output would be
> > >somewhat limited, and as a consequence capacity would be limited. How
>many
> > >pounds per hour would you have in mind?
> > > >
> > > > I do NOT want to make chips out of larger-diameter branches (not at
> > > > present, anyway.) I want to use the "junk wood."
> > > >
> > > > Andrew correctly pointed out that I do not have a firm grasp of the
> > > > "mechanics" needed for the chipper. I am open to all suggestions.
> > >
> > >OK... looks like you want to chop branches up to about 3 cm diameter,
>with
> > >the ratio of the length to the thickness about 2. What kind of wood would
> > >you be planning on using? More specifically, would you have some "energy
> > >index", such as "foot pounds of energy required to produce 1 square inch
>of
> > >new surface?" Also, it would be necessary to know how many pounds per
>hour
> > >you wished to produce.
> > > >
> > > > To Peter: I certainly understand your comment about hand chopping.
>In
> > > > Mozambique I paid a local fellow to get me a sack of "small-branch
> > > > chips". Burned VERY well. And when I see people earning their living
> > > > making gravel out of larger stones with only a hammer as their tool, I
> > >know
> > > > that people can earn a living doing this manual labor. But I guess I
>am
> > > > looking for a SLIGHTLY better way than a machete.
> > >
> > >There are a lot of good things to be said about a machette, two of which
> > >are: it is cheap, and it works.
> > > >
> > > > Kevin (and others), please recall my earlier note that almost every
> > > > "junked" vehicle can provide almost free 4 heavy-duty ball-bearing
>rotors
> > > > from its 4 wheels.
> > >
> > >Are junked vehicles actually available in the area where you want the
> > >chopper to be operated? Front or rear wheel drive?The use of a car rear
>end
> > >could open some possibilities.
> > >
> > >Best wishes,
> > >
> > >Kevin
> >
> > 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 crispin at NEWDAWN.SZ Thu Sep 25 05:01:17 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.110117.0200.CRISPIN@NEWDAWN.SZ>

Dear Friends

What is the energy content of butane (MJ/Kg)?

Thanks
Crispin

From tombreed at COMCAST.NET Thu Sep 25 08:51:37 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.065137.0600.TOMBREED@COMCAST.NET>

Dear Stovers:

Good list from Kevin below on the difference of chopping, splitting etc.

One more to add, and I hope Tom Miles will add more info.

Tom's father certainly understood and may have been involved with the
origins of "CHIPPING". Chipping is what the beaver does, cutting diagonally
across the grain at, as I remember, 38 degrees, which minimizes the energy
required for Mr. Beaver, and surely for producing non splintery pieces.

Hammer milling tends to produce what I call "shards" with fibers sticking
out all over that prevent feeding. Chipping produces pieces almost as good
as wood blocks.

Comments from TOM I hope.

Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Kevin Chisholm" <kchisholm@ca.inter.net>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 10:02 AM
Subject: Re: [STOVES] Small rotary chopper for larger chips

> Dear Tami
>
> The cruel fact is that chopping, slicing, splitting, or smashing wood is
> very energy intensive. If the device is powered by an engine, one needs a
> significant sized engine . If powered by hand, it is hard work.
>
> Chopping: Cutting the wood approximately perpendicular to the direction of
> growth, ie, across the grain
> Splitting: Cutting the wood parallel to the direction of growth, i.e. with
> the grain
> Slicing: Cutting the wood at a significant angle to the direction of
growth.
> "Smashed Wood": This would be wood that went through a hammer mill or some
> such device. It is reduced to a very small size, with very high "surface
> area per pound." The product is "wood fluff."
>
> The energy required is proportional to "the new surface produced."
Chopping,
> splitting, and slicing and smashing have different energy constants, i.e.,
> "foot-pounds of energy per each square foot of new surface area produced."
>
> In general, chopping is the most energy intensive, splitting is the least,
> and slicing is somewhere in-between. Smashing has a very much higher
energy
> requirement.
>
> In general also, sliced wood is "better" as a fuel in that invariably,
there
> is internal shearing, or "internal surface" created, and this enables the
> wood to dry better. However, sliced wood generally performs poorly in a
> combustor system designed for dry split wood.
>
> Wood "choppers" cut sticks into short lengths. This is good for drying, in
> that there can be an axial flow of moisture, and the wood can dry, even
when
> the bark is unbroken. There is a critical length for various woods to
permit
> axial drying. For example, White Birch sticks about 18" long can actually
> rot before they dry, because of their waterproof bark.
>
> Your "Community Wood Processor" is a good idea. However, it must be able
to
> process the wood in a way that it meets the requirements for the stoves in
a
> community.
>
> There must be a match between the fuel available, and the combustor
design.
> The combustor can be designed to meet the circumstances of wood
> availability, OR, the wood must be processed to make it suitable for the
> combustor.
>
> The size and strength of the processor depend on the forces involved. The
> forces in general, are dependant on the amount of new surface being
created
> at any given instant. Obviously, a dull cutter or chipper requires more
> force than a sharp tool.
>
> Another factor of concern to the designer of a chipper, chopper, slicer or
> smasher, is how the wood is to be fed into the system. This is a dangerous
> job, and it is best done with automatic feed or self feeding systems.
> Consider a tree with its branches still on. For example, a Xmas Tree. It
> might be 3" at the butt, and say 8' long the branches must be chopped off
> beforehand, OR a "grabber system" of some sort must be included to bend
the
> branches and pull the tree into the cutters. The trimmed stem can be fed
> vertically into a hopper, and it can "self feed" by its weight.
>
> A powered chipper is "a dangerous piece of work". It must be of a
relatively
> robust design. It needs an engine, and purchased fuel, unless a wood gas
> engine is employed.
>
> So, this sort of gets back to a manual system.... wood can be chopped to
> length with an axe, it can be split with an axe, and it can be sliced with
> an axe. Larger sections of wood should be sawn with a chain saw, but then,
> this requires mixed gasoline fuel, and "a machine from away."
>
> There are an enormous number of variables associated with "a wood
chipper."
> Nobody in the world can design a "Universal Wood
> Chipper/Chopper/Slicer/Smasher" However, if someone could come up with a
> meaningful specification for a specific application, then there are many
> people who could configure a suitable design.
>
> One of my many faults is that if you ask me what time it is, I tell you
how
> to build a watch. :-)
>
> Best wishes,
>
> Kevin
> ----- Original Message -----
> From: "Tami Bond" <yark@UIUC.EDU>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Wednesday, September 24, 2003 11:33 AM
> Subject: Re: [STOVES] Small rotary chopper for larger chips
>
>
> > Dear Stovers,
> >
> > On chopping up wood: Small chips for briquetting are one application.
> > Another potential application is getting wood to the small sizes that
burn
> > better in stoves. For example, the Rocket stove might burn clean with
> small
> > wood and not with large branches. If I were a busy homemaker, I might be
> > tempted to skip the size-reduction step. It is difficult and annoying to
> > split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
> > bicycle-wheel and other ideas provide community wood chopping, for
cleaner
> > burning wood?
> >
> > Tami

From tombreed at COMCAST.NET Thu Sep 25 09:00:13 2003
From: tombreed at COMCAST.NET (tombreed)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.070013.0600.TOMBREED@COMCAST.NET>

Dear Stovers:

Further thoughts on size reduction.

1) Peter: Will a machete, designed to cut wet cane, easily cut dry wooden
sticks? Don't they need to be well supported to make inch length pieces?

2) Much of the wood in the world occurs as very large chunks and so is
suitable for 3 stone stoves. However, a lot of biomass occurs as small
pieces - nut hulls, acorns, seeds, cobs, ... and so is only suitable for
certain stoves. Nice to have this option.

One of the nicest "natural pellets" I have come across is the Eucalyptus
nut. They burn very poorly in most stoves, and give off an oily, astringent
smoke. However, they are quite dense and burn beautifully in our WoodGas
Stoves. A few trees would supply a families cooking needs for year. There
are many other small biomass forms that have no use in conventional cooking
and would be great for WoodGas stoves.

Onward............ TOM REED

Yours truly,

Dr. Thomas Reed
tombreed@comcast.com
www.woodgas.com
----- Original Message -----
From: "Peter Singfield" <snkm@BTL.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Wednesday, September 24, 2003 9:18 AM
Subject: Re: [STOVES] Small rotary chopper for larger chips

> If I had market for short parts of wood here and was interested in
> production I would simply put cane cutters to it with their machetes.
>
> In fact -- they would roam the bush looking for dry dead branches -- chop
> them to the right size -- fill bags with them -- and deliver these to the
> "station" where they would be inspected -- weighed and paid for.
>
> But then -- here we try to stay labor intensive -- as we have no social
> blankets -- and everyone needs a "work".
>
> Apparently people in other 3rd world countries on this list are rich --
and
> have no workers needing work -- so can play around designing a machine to
> do this.
>
> Like india!!
>
> Surprising how rich India is all of a sudden. Hard for me to believe.
>
> In real work this would never work because they are all out their roaming
> the bush with their machetes now -- to get their fire wood -- anyway.
>
> Your trying to convince them that they can exert less labor by using less
> wood by "buying" (and they have not much money for beyond basics) your
> stoves because these stoves are more efficient -- but you have to cut the
> wood into perfect little tiny parts -- etc.
>
> Meanwhile my neighbors are still cooking using lengthy wood in Maya style
> fire hearths -- and certainly -- I would want this increase in efficiency
> well proved before changing that system!
>
> They regulate their heat by pushing the long sticks in --
>
> India makes a fine rotary chopper for preparing gasifier fuel:
>
> http://aewgasifiers.netfirms.com/
>
> Browse around -- you'll find it there -- as well as some other useful
devices.
>
> But it takes very little time for a person proficient with a machete to
> chop up enough stick for a daily cooking -- if they had to -- which they
do
> not.
>
> Peter Singfield -- Belize
>
> At 09:33 AM 9/24/2003 -0500, Tami Bond wrote:
> >Dear Stovers,
> >
> >On chopping up wood: Small chips for briquetting are one application.
> >Another potential application is getting wood to the small sizes that
burn
> >better in stoves. For example, the Rocket stove might burn clean with
small
> >wood and not with large branches. If I were a busy homemaker, I might be
> >tempted to skip the size-reduction step. It is difficult and annoying to
> >split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
> >bicycle-wheel and other ideas provide community wood chopping, for
cleaner
> >burning wood?
> >
> >Tami
> >
>

From jmdavies at TELKOMSA.NET Thu Sep 25 09:18:52 2003
From: jmdavies at TELKOMSA.NET (John Davies)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.151852.0200.JMDAVIES@TELKOMSA.NET>

Greetings,

An idea.

Now that we have a flywheel weighted rotary cutting blade, turning at
relatively slow RPM, driven by whatever, here is an idea for feeding.

The branches to be cut are about 20mm diameter, but the cutting power will
be dependant on the wetness, thickness and age of these branches. If they
are produced by a coppiced mini plantation these branches would be
relatively straight, but could be quite long.

For such a fuel supply one could mount 50mm plastic tubes at an angle
sufficient for the branches to slide down the tube by gravity after each
cut, against a variable positioned plate. Maybe up to six tubes could be
mounted with their feed holes, staggered around the circumference in such a
way that only one branch is cut at a time. So we feed six tubes for soft wet
thinner branches and reduce the number of tubes loaded as the branches
become thicker or harder. This will utilize the available power to the
optimum, with the production being a variable relative to the power
requirement per cut.

N.B. WHATEVER SYSTEM IS USED, DONT FORGET EYE PROTECTION. YOU WOULD HATE
SOMEONE TO HAVE AN EYE INJURY.

Regards,
John Davies.

From psanders at ILSTU.EDU Thu Sep 25 18:04:29 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:39 2004
Subject: Early TLUD (ala Tom Reed) gasifiers
Message-ID: <THU.25.SEP.2003.170429.0500.PSANDERS@ILSTU.EDU>

Stovers and ETHOS readers (sorry for duplicates, but I do not want to miss
anyone with this message.)

For the "History of the TLUD Gasifiers," I would like to know names and
places and dates of those who made such a device in the early years, and in
recent years.

TLUD refers to Top-Lit Up-Draft gasifiers, also known as

IDD (inverted down draft)
Reed-Larson 1995
Juntos-type (Paul Anderson)
charcoal-making pyrolyzers
etc.

The story says that Tom Reed thought it up in 1985. I am asking Tom for
early diagrams or photos, but others might have some documentation also.

1995 Peko Pe stove in Denmark by Norwegian Paal Wendelbo (

In 1995 - 96 Tom and Ronal Larson do work together and the result is the
1996 conference paper (on the web now) and the Reed-Larson 1995 unit that I
have and will bring to Boulder next week.

1997 - 98 Richard Boyd does his Ten Can stove !! (I recently RE-found
my printout of his work. You should see it
at http://www.ikweb.com/enuff/public_html/Tencan.htm The T must be
capitalized in the word /Tencan .) Dick, how many did you
build? What other details can you tell us.

2001 Paul Anderson gets started after meeting Tom Reed.
We also know of John Davies (TLUD gasifier of coal)
And now Kobus and Stanley have a TLUD gasifier of charcoal (to be seen at
Boulder meeting)

But I think there was also some units built by Alex English and
by Andrew Heggie, and
by Agua Das, and
perhaps others?

Something done in China??? Hardly ever any information from there. No
evidence that it is actually TLUD gasification.

And the "J" stove? Tom R, can you give more info? (see you in Boulder)

And is the Z-stove really a TLUD gasifier?

Anybody else?

Please be as specific as you can, and be sure it gets sent to the whole
stoves list. (ETHOS readers who want this should be sure that they get the
Stove messages or have someone forward the replies.

Thanks,

Paul

From snkm at BTL.NET Thu Sep 25 19:54:56 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:39 2004
Subject: Small rotary chopper for larger chips
Message-ID: <THU.25.SEP.2003.175456.0600.SNKM@BTL.NET>

At 07:00 AM 9/25/2003 -0600, tombreed wrote:
>Dear Stovers:
>
>Further thoughts on size reduction.
>
>1) Peter: Will a machete, designed to cut wet cane, easily cut dry wooden
>sticks? Don't they need to be well supported to make inch length pieces?
>

Actually -- the machete designed specifically for cutting cane is not
popular here. They use only the more general purpose one.

In the actual practice of chopping wood with a machete -- the blade is
introduced at a slight angle -- never directly 90 deg. to the fiber line --
say at least 15 deg -- one side or the other. It is quite tricky. And takes
years of practice to master.

Still -- it is a given in the villages here that every male over the age of
12 (at least) can -- and many woman as well.

Further -- if you place a stick on a solid surface -- then yes -- a machete
can chop clean through surprisingly thick hard wood -- even using a direct
blow.

A solid surface being such as a large block of wood -- a splitting block if
you will.

>2) Much of the wood in the world occurs as very large chunks and so is
>suitable for 3 stone stoves. However, a lot of biomass occurs as small
>pieces - nut hulls, acorns, seeds, cobs, ... and so is only suitable for
>certain stoves. Nice to have this option.
>
>One of the nicest "natural pellets" I have come across is the Eucalyptus
>nut. They burn very poorly in most stoves, and give off an oily, astringent
>smoke. However, they are quite dense and burn beautifully in our WoodGas
>Stoves. A few trees would supply a families cooking needs for year. There
>are many other small biomass forms that have no use in conventional cooking
>and would be great for WoodGas stoves.

Good point Tom!!

We have a very common palm nut tree here -- cohune palm -- which is a
simply incredible source of energy rich fuel pellets.

A few of those can supply cooking oil and cooking fuel for any family easily.

But they do not burn well in a 3 stone design.

Now -- there is a real project -- designing the stove for this fuel.

Mother natures absolutely best "pellet" --

I have all kinds of specs on this from a biomass power plant study that was
supposed to be built using just this fuel. It so closely approximates coal.

Comes in a uniform size -- and is dry -- plus rich in vegetable oil -- what
more can one ask for??

I wonder if normal palm tree nuts could not be used for these same purposes??

Peter

>
>Onward............ TOM REED
>
>
>Yours truly,
>
>Dr. Thomas Reed
>tombreed@comcast.com
>www.woodgas.com
>----- Original Message -----
>From: "Peter Singfield" <snkm@BTL.NET>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Wednesday, September 24, 2003 9:18 AM
>Subject: Re: [STOVES] Small rotary chopper for larger chips
>
>
>> If I had market for short parts of wood here and was interested in
>> production I would simply put cane cutters to it with their machetes.
>>
>> In fact -- they would roam the bush looking for dry dead branches -- chop
>> them to the right size -- fill bags with them -- and deliver these to the
>> "station" where they would be inspected -- weighed and paid for.
>>
>> But then -- here we try to stay labor intensive -- as we have no social
>> blankets -- and everyone needs a "work".
>>
>> Apparently people in other 3rd world countries on this list are rich --
>and
>> have no workers needing work -- so can play around designing a machine to
>> do this.
>>
>> Like india!!
>>
>> Surprising how rich India is all of a sudden. Hard for me to believe.
>>
>> In real work this would never work because they are all out their roaming
>> the bush with their machetes now -- to get their fire wood -- anyway.
>>
>> Your trying to convince them that they can exert less labor by using less
>> wood by "buying" (and they have not much money for beyond basics) your
>> stoves because these stoves are more efficient -- but you have to cut the
>> wood into perfect little tiny parts -- etc.
>>
>> Meanwhile my neighbors are still cooking using lengthy wood in Maya style
>> fire hearths -- and certainly -- I would want this increase in efficiency
>> well proved before changing that system!
>>
>> They regulate their heat by pushing the long sticks in --
>>
>> India makes a fine rotary chopper for preparing gasifier fuel:
>>
>> http://aewgasifiers.netfirms.com/
>>
>> Browse around -- you'll find it there -- as well as some other useful
>devices.
>>
>> But it takes very little time for a person proficient with a machete to
>> chop up enough stick for a daily cooking -- if they had to -- which they
>do
>> not.
>>
>> Peter Singfield -- Belize
>>
>> At 09:33 AM 9/24/2003 -0500, Tami Bond wrote:
>> >Dear Stovers,
>> >
>> >On chopping up wood: Small chips for briquetting are one application.
>> >Another potential application is getting wood to the small sizes that
>burn
>> >better in stoves. For example, the Rocket stove might burn clean with
>small
>> >wood and not with large branches. If I were a busy homemaker, I might be
>> >tempted to skip the size-reduction step. It is difficult and annoying to
>> >split a 9-cm diameter chunk down to 2-3 cm diameter. Can these neat
>> >bicycle-wheel and other ideas provide community wood chopping, for
>cleaner
>> >burning wood?
>> >
>> >Tami
>> >
>>
>
>

From dstill at EPUD.NET Fri Sep 26 20:28:32 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:39 2004
Subject: The Hanson Two Pot with Oven Stove
Message-ID: <FRI.26.SEP.2003.172832.0700.DSTILL@EPUD.NET>

Dear Friends,

Today I had the great pleasure of testing Lanny Hanson's newest contribution
to the Rocket stove family. Larry Winiarski has developed 10 design
principles which result in better combustion and improved heat transfer to
the pot(s). We used Larry's design principles in this new stove...Lanny and
I have worked together on a couple of projects and I've learned a lot from
Lanny who is an expert in slow cooking, making one of the world's best
charcoal barbecue cookers.

Lanny has added his special touch to this new stove...There are at least two
Lanny inventions incorporated in this stove that make it perform differently
compared to other Rocket stoves...
1.) the external chimney rotates matching openings to side vents in the pot
skirts enveloping the two submerged pots. Rotating the chimney controls the
amount of heat entering pot one, pot two, or the large oven included under
the pots. Heat can be directed wherever desired!
2.) The stove is designed to be shut down after bringing the pots to boil.
Shutting the sliding door over the fuel magazine and blocking the chimney
allows only enough air to enter the combustion chamber, keeping the produced
charcoal burning. The charcoal simmers the pots of food to completion...

Today I burnt 1.1 kilo of air dried Douglas fir in Lanny's stove. The first
pot 2/3rds full with 5 liters of water boiled after 17.5 minutes. The second
same sized pot, also with 5 liters of water, boiled at 20 minutes. At this
time, 20 minutes after starting the fire, the oven was at 500 degrees
F...The stove was shut down and the water in both pots continued to rapidly
boil for 60 more minutes. After the hour the oven was opened again and the
internal temperature was at 435 F...

Lanny learned from making barbecues how to get a lot of work from a small
fire, first as it burns and then using the produced charcoal to simmer the
food. The stove seems magically fuel efficient;
my students eventually surrounded the stove as it continued without
additional wood to rapidly boil the 10 liters of water on and on...We'll
post photos when Tom Miles returns from Russia.

Best,

Dean

From aes at BITSTREAM.NET Fri Sep 26 23:58:32 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:39 2004
Subject: [ethos] The Hanson Two Pot with Oven Stove
Message-ID: <FRI.26.SEP.2003.225832.0500.AES@BITSTREAM.NET>

Dean,

Wow, how exciting. Are you bringing this to Boulder? Photos? Sounds
incredible. And simple, the best kind of technology available.

Bruce

----- Original Message -----
From: "Dean Still" <dstill@epud.net>
To: "ethos" <ethos@vrac.iastate.edu>; <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, September 26, 2003 7:28 PM
Subject: [ethos] The Hanson Two Pot with Oven Stove

> Dear Friends,
>
> Today I had the great pleasure of testing Lanny Hanson's newest
contribution
> to the Rocket stove family. Larry Winiarski has developed 10 design
> principles which result in better combustion and improved heat transfer to
> the pot(s). We used Larry's design principles in this new stove...Lanny
and
> I have worked together on a couple of projects and I've learned a lot from
> Lanny who is an expert in slow cooking, making one of the world's best
> charcoal barbecue cookers.
>
> Lanny has added his special touch to this new stove...There are at least
two
> Lanny inventions incorporated in this stove that make it perform
differently
> compared to other Rocket stoves...
> 1.) the external chimney rotates matching openings to side vents in the
pot
> skirts enveloping the two submerged pots. Rotating the chimney controls
the
> amount of heat entering pot one, pot two, or the large oven included under
> the pots. Heat can be directed wherever desired!
> 2.) The stove is designed to be shut down after bringing the pots to boil.
> Shutting the sliding door over the fuel magazine and blocking the chimney
> allows only enough air to enter the combustion chamber, keeping the
produced
> charcoal burning. The charcoal simmers the pots of food to completion...
>
> Today I burnt 1.1 kilo of air dried Douglas fir in Lanny's stove. The
first
> pot 2/3rds full with 5 liters of water boiled after 17.5 minutes. The
second
> same sized pot, also with 5 liters of water, boiled at 20 minutes. At this
> time, 20 minutes after starting the fire, the oven was at 500 degrees
> F...The stove was shut down and the water in both pots continued to
rapidly
> boil for 60 more minutes. After the hour the oven was opened again and the
> internal temperature was at 435 F...
>
> Lanny learned from making barbecues how to get a lot of work from a small
> fire, first as it burns and then using the produced charcoal to simmer the
> food. The stove seems magically fuel efficient;
> my students eventually surrounded the stove as it continued without
> additional wood to rapidly boil the 10 liters of water on and on...We'll
> post photos when Tom Miles returns from Russia.
>
> Best,
>
> Dean
>

From dstill at EPUD.NET Sat Sep 27 02:09:31 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:39 2004
Subject: See Lanny's 2 Pot/Oven stove
Message-ID: <FRI.26.SEP.2003.230931.0700.DSTILL@EPUD.NET>

Dear Friends,

Bruce Stahlburg asks to see the photos of Lanny's stove before Tom returns
from Russia...See the photos: hssa.jpg ; hss06 ,07,08,15,16,17,18,19,20 and
hss21.jpg
> >> >Just go to the link and change the number and go to the other photos.
> >> >http://www.lanny.us/hssa.jpg
> >> >http://www.lanny.us/hss06.jpg

All Best,

Dean

From psanders at ILSTU.EDU Mon Sep 29 13:01:38 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:39 2004
Subject: [ethos] & [STOVES] The Hanson Two Pot with Oven Stove
In-Reply-To: <000b01c3848e$4b9b5780$b81e6c0c@default>
Message-ID: <MON.29.SEP.2003.120138.0500.PSANDERS@ILSTU.EDU>

Stovers,

The Hanson 2-pot+oven stove is REALLY nice, in my opinion.

Note that it is "stove STRUCTURE" or "APPLICATION of heat" and is NOT
focused on how to make the heat. Therefore, Lanny's stove is highly
important to those who are working on the heat production because it shows
us some innovative ways to utilize the heat.

The "external chimney rotates matching openings to side vents in the pot
skirts enveloping the two submerged pots" is a very nice "twist". simple
concept that has many applications.

Also, a useful oven is a "plus" for a stove.

The cost is/could be an issue. This is not a stove for refugee camps and
the extremely poor people. But we all know that as people attain better
incomes, they desire stoves with more functions. (and they eventually
progress from this type of improved stove to stoves with even more
functions and higher costs.)

Lanny's talents with metal work are again evident! I would like to try to
connect my Juntos gasifier combustion chamber to a stove like this !!!!!

If we could eventually have some more details, including overall dimensions
and the inner workings of rotating chimney and the flow of the flue gases,
that would be appreciated.

Also, the photos do not show on which side and in what position is the
entry of the fuel for the Rocket "fire-box/combustion chamber."

Congratulations on your good work!!!!!!!!!!!!!!

Paul

At 05:28 PM 9/26/03 -0700, Dean Still wrote:
>Dear Friends,
>
>Today I had the great pleasure of testing Lanny Hanson's newest contribution
>to the Rocket stove family. Larry Winiarski has developed 10 design
>principles which result in better combustion and improved heat transfer to
>the pot(s). We used Larry's design principles in this new stove...Lanny and
>I have worked together on a couple of projects and I've learned a lot from
>Lanny who is an expert in slow cooking, making one of the world's best
>charcoal barbecue cookers.
>
>Lanny has added his special touch to this new stove...There are at least two
>Lanny inventions incorporated in this stove that make it perform differently
>compared to other Rocket stoves...
>1.) the external chimney rotates matching openings to side vents in the pot
>skirts enveloping the two submerged pots. Rotating the chimney controls the
>amount of heat entering pot one, pot two, or the large oven included under
>the pots. Heat can be directed wherever desired!
>2.) The stove is designed to be shut down after bringing the pots to boil.
>Shutting the sliding door over the fuel magazine and blocking the chimney
>allows only enough air to enter the combustion chamber, keeping the produced
>charcoal burning. The charcoal simmers the pots of food to completion...
>
>Today I burnt 1.1 kilo of air dried Douglas fir in Lanny's stove. The first
>pot 2/3rds full with 5 liters of water boiled after 17.5 minutes. The second
>same sized pot, also with 5 liters of water, boiled at 20 minutes. At this
>time, 20 minutes after starting the fire, the oven was at 500 degrees
>F...The stove was shut down and the water in both pots continued to rapidly
>boil for 60 more minutes. After the hour the oven was opened again and the
>internal temperature was at 435 F...
>
>Lanny learned from making barbecues how to get a lot of work from a small
>fire, first as it burns and then using the produced charcoal to simmer the
>food. The stove seems magically fuel efficient;
>my students eventually surrounded the stove as it continued without
>additional wood to rapidly boil the 10 liters of water on and on...We'll
>post photos when Tom Miles returns from Russia.
(Below is info from Dean about photos: (VERY Useful, says Paul)
Bruce Stahlburg asks to see the photos of Lanny's stove before Tom returns
from Russia...See the photos: hssa.jpg ; hss06 ,07,08,15,16,17,18,19,20 and
hss21.jpg
> >> >Just go to the link and change the number and go to the other photos.
> >> >http://www.lanny.us/hssa.jpg
> >> >http://www.lanny.us/hss06.jpg

>Best,
>
>Dean

From psanders at ILSTU.EDU Tue Sep 30 17:26:06 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:39 2004
Subject: Bibliography for Hayboxes
In-Reply-To: <BAY5-F36H2zqXA0QbRI00019b63@hotmail.com>
Message-ID: <TUE.30.SEP.2003.162606.0500.PSANDERS@ILSTU.EDU>

Stovers,

The following is STILL a draft. Needs reference to the lady in South
Africa with the Hot Bags, plus any other items that you can still send
directly to Brandy Wilken at

BRANDY WILKEN <brandeewine74@msn.com> I will post the final
bibliography plus her report to the Stoves list.

Anderson

At 02:47 AM 9/30/03 +0000, BRANDY WILKEN wrote:

Bibliography of Hayboxes / Hot Bags
(Draft version - 30 September 2003)
(A report about these and final sources will be available by November 2003.)
(N.K.A = No Known Author) & (n.d = not dated).
Compiled by Student Brandy Wilken for Professor Paul S. Anderson
psanders@ilstu.edu

Bambrick, Frank and Hurley, Brian (1977). The haybox the energy saving
cooker. Dublin,
Ireland: Low Energy Systems.

Becker, Sheryl (n.d.) City Slicker Hayboxes. Retrieved September 5, 2003,
from Yahoo
Search Website: http://www.guidezone.skl.com/haybox.htm

Cleovoulou, Mario (1997, January/February). Introducing fuel-saving
cooking methods in
southern Tamil Nadu. Social Change and Development. Retrieved from
http://www.cleovoulou.com/fuelsave.htm

De Lissa, N R (1919). En Casserole and haybox; the best cooking with least
fuel and utility
recipes (additional). London: Simpkin, Marshall, Hamilton, Kent & Co. Ltd.

Goldstein, Olga (1977). Solar food warmer and insulated cooker. Ste. Anne
de Bellevue,
Quebec: Brace Research Institute.

Heath, Ambrose (1976). Haybox cookery. London: Barrie and Jenkins.

(N.K.A), (n.d - 1). Be environmentally friendly and use a hot bag for
cooking with retained
heat-. [Brochure].

(N.K.A), (n.d - 2). Cooking on Camp. Retrieved September 5, 2003, from
the Camping
and Outdoor Activities
Website: http://indigo.ie/~rpmurphy/camping/Cooking.html

(N.K.A), (n.d - 3). Cooking Primitive. Retrieved September 5, 2003, from
The Inquiry
Net! Website: http://www.inquiry.net/outdoor/skills/b-p/wb/cooking.htm

(N.K.A), (n.d - 4). Making the Pounds Meet the Ends. Retrieved September
12, 2003,
from http://www.poundsmeetends.co.uk/articles/haybox.htm

(N.K.A), (n.d - 5). Retained Heat Cooking. (n.d.) Retrieved September 5,
2003, from The Solar
Cooking Archive, The Solar Cookers International
Website: http://solarcooking.org/ret-heat.htm

(N.K.A), (n.d - 6). Home Heating and Cooking. Retrieved September 12,
2003, from Dancing
Rabbit Ecovillage Website: http://www.dancingrabbit.org/energy/heating.html

(N.K.A), (n.d 7) HRC's for the UK - Haybox Cookery. Retrieved September
12, 2003, from
Sunseed Tanzania Trust
Website: http://www.sunseedtanzania.org/HRC/HRCS_UK.html

(N.K.A), (n.d 8) The Haybox. Retrieved September 12, 2003, from Working
Group on
Development Techniques
Website: http://www.wot.utwente.nl/wot/us/field/sun/haybox.html

(N.K.A), (n.d 9) The Prepared Home. Making the most of scarce fuel when
cooking by using a hay box.
Retrieved September 5, 2003, from The Prepared Home
Website: http://www.preparedhome.co.uk/articles/haybox.htm

(N.K.A), (n.d 10) Action Plan: Global Warming. Retrieved September 12,
2003, from
Ninelives Website: http://www.ninelives.tv/9skills/s_warming.htm

(N.K.A), (n.d 11) Conserving electricity at home. Retrieved September 12,
2003, from
BirdLife South Africa
Website: http://www.birdlife.org.za/resources/sustainable/energy/84_85.htm

(N.K.A), (n.d 12) How to make a food warmer/fireless cooker. Retrieved
September 16, 2003,
from Hedon Household Energy Network
Website: http://ecoharmony.net/hedon/howto.php

(N.K.A), (n.d - 13) Aprovecho's Guide to Hay Boxes and Fireless
Cooking. [Brochure]

(N.K.A), (1977) Low Energy Systems. [Pamplet] Retrieved September 12,
2003, from Village
Earth
Website:
http://www.villageearth.org/atnetwork/atsourcebook/chapters/energygeneral.htm#The%20Haybox

(N.K.A), (1997). Haybox Cookery. Retrieved September 5, 2003, from The
Centre for
Alternative Technology Website:
http://www.cat.org.uk/catpubs/tipsheet.tmpl?sku=05

(N.K.A), (1998). Hayboxes. Retrieved September 5, 2003, from ULOG Website:
http://www.ulog.ch/english/u_hay.html

(N.K.A), (1999 Spring/Summer), Hayboxes. Talking Leaves. Retrieved
September 5,
2003 from Lost Valley Educational Center from the World Wide Web:
http://www.lostvalley.org/haybox1.html

(N.K.A), (2000-a). Biomass Technology Examples. Retrieved September 12,
2003 from
Energy Saving Now
Website: http://www.energy.saving.nu/biomass/technology.shtml

(N.K.A), (2000-b). The pots and the haybox. Retrieved September 11, 2003
from the
World Wide Web: http://www.cc.jyu.fi/~hvirtane/cooker/node25.html

(N.K.A), (Summer 2000) The Haybox Cooker. Communities Magazine
#115. Retrieved
September 12, 2003, from Communities Magazine Back Issues, 2000s
Website: http://store.ic.org/products/communities-issues-2000s.html

Pierce, Anne (n.d.) Simply Living: The story of Compassion and the
Wonderbox. Essex: Box
Publications.

Rohde, Eleanour Sinclair (1939). Haybox cookery. London: G. Routledge.

Roth, Chris (2003, Spring). The Haybox: Why every household needs
one. Talking Leaves.
Retrieved September 8, 2003 from the World Wide Web:
http://www.talkingleaves.org/s03haybox.htm

Shrestha, Sama & Munankami, Rajeev (1999, March 1) Haybox
Cooker. Retrieved September
12, 2003 from Centre for Rural Technology, Nepal from World Wide
Website: http://www.panasia.org.sg/nepalnet/crt/haybox.htm

Solar Cookers International (n.d.). Fire-Less Cookers/Cooking (The Hay
Basket). No
Publication Information.

BioEnergy Lists: Improved Biomass Cooking Stoves

September 2003 Biomass Cooking Stoves Archive