December 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 yark at UIUC.EDU Mon Dec 1 02:19:18 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:42 2004
Subject: 17 Excerpts from Woodburning Cookstoves
In-Reply-To: <20031122022512.90326CBA@telchar.epud.net>
Message-ID: <MON.1.DEC.2003.011918.0600.YARK@UIUC.EDU>

Dean,
Thanks for yet another message from the greats.

>8.) Values for temperatures of the gases are 1260K and 950K for a
>volatile excess air factor of 1.5 and 2.5 respectively. (Page 43)

This is interesting. I did some (very crude) modeling a few years ago on
oxidation rates of soot. You have a chance of consuming it in the exhaust,
only if you keep the temperature above about 1200K. Have not confirmed that
with measurements.

We have all heard 'time, temperature, turbulence' but haven't put numbers
on it, to my knowledge. Does this mean that we must limit excess air to
~1.7 in order to keep temperatures high enough to consume the particles?
(And we must get rid of them prior to heat contacting the pot.) This is, of
course, assuming that there's only one combustion zone-- not a 'gasifying'
stove.

Tami

From crispin at NEWDAWN.SZ Mon Dec 1 16:37:12 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:42 2004
Subject: World Bank Extractive Industry Review Final Report
Message-ID: <MON.1.DEC.2003.233712.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

This will be of interest to many.

Regards
Crispin

+++++++

Attached is an extract from the World Bank Extractive Industry Review
report, WB Extractive Industry Review Final Report.doc which calls for the
phasing out of investments in coal and oil and strongly supports renewables
and energy efficiency.

The full report can be downloaded from the following
http://www.eireview.net/finalreport.htm

Sourced from

Khamarunga G. Banda
Gender and Energy
Minerals & Energy Policy Centre
Mintek Building
200 Hans Strijdom Drive
Randburg
2125
South Africa
+27 (0)11 709 4018
+27 (0)11 709 4595 (fax)

++++++++++

ACTIVELY PROMOTE SUSTAINABLE ENERGY POLICIES, ENERGY EFFICIENCY, RECYCLING,
AND CLEANER FUELS, ESPECIALLY RENEWABLES

Oil, gas, and coal are produced not as ends in themselves but as a means to
provide energy that is beneficial for poverty alleviation. To meet the need
for sustainable development, however, energy that is generated by fossil
fuels must take into account the release of greenhouse gases and their
contribution to climate change, with its negative impact on agriculture and
food production in developing countries.

While recognizing that it is each country's right to set its own energy
strategy, IBRD and IDA should position themselves to help governments adopt
sustainable energy strategies that address the energy needs of the poor and
that minimize climate change, which will disproportionately affect the poor.
Countries should be helped to remove subsidies from carbon-based fuels,
taking due account of the potential impacts on the poor, by shifting
subsidies to meet the basic needs of the poor and by ensuring mitigating
plans. And WBG lending should concentrate on aggressively promoting the
transition to renewable energy and endorsing natural gas as a bridging
fuel-building new pipelines and renovating leaking ones.

The WBG should apply carbon shadow value analysis systematically to its
cost-benefit analysis and rate of return calculations in order to
internalize the currently externalized costs of all energy projects, such as
greenhouse gas emissions, as a follow-up to its carbon back-casting as input
for its strategies to encourage investment in low and no-carbon energy
alternatives. Shadow pricing should internalise both local costs, like
pollution, and global costs, such as climate change.

On this basis the WBG should phase out investments in oil production by
2008, the year of the first commitment period under the Kyoto Protocol, and
devote its limited scarce resources to investments in renewable energy
resource development, emissions-reducing projects, clean energy technology,
energy efficiency and conservation, and other efforts that de-link energy
use from greenhouse gas emissions. During this phasing out period, WBG
investments in oil should be exceptional, limited only to poor countries
with few alternatives. Meanwhile, the WBG should build local capacities of
developing countries to help them negotiate better deals from foreign
companies, with the funds used for poverty alleviation through sustainable
development.

The WBG has for the last few years not invested in new coal mining
development. This should continue. The WBG should concentrate its lending on
activities that reduce pollution and greenhouse gas emissions, such as
lending to replace coal-fired power plants with gas-fired ones. It should
also promote clean technology and help replace old polluting infrastructure
with newer technologies, updating inefficient coal generators.

IBRD and IDA should accelerate the help given to countries to phase out
uneconomic and environmentally unsound coal mining by helping them address
any negative economic impacts of a phase-out and bridge a transition to
cleaner energies. Mine closure strategies should recognize the high
dependence of mining communities on this source of income and employment and
should provide adequate compensation, job creation, and training to affected
workers and communities beforehand. Any such strategies should be designed
and implemented with the participation of local governments and workers.

When a mine is to close, a "just transition fund" could be created to
finance programs for community development, retraining, and social safety
nets. The fund could be supported by trust funds from industrial countries,
in light of their contribution to climate change problems. This model could
also be explored to help countries address the social and economic impacts
on the poor of removing subsidies to carbon-based fuels.

Using materials more than once is another form of efficiency, and the WBG
should help governments develop economic instruments, policies, and
incentive systems that promote materials recovery and recycling through
effective collection systems and the creation of markets, education, and
incentives for waste separation. Recycling needs to be regulated to ensure
it is conducted in a way that is both socially and environmentally
responsible.

The WBG should make funds available through the Global Environment Facility
or other body to promote renewable energy vigorously. It should develop a
robust portfolio for renewable energy, aggressively increasing investments
in renewable energies by about 20 percent annually and thereby moving toward
a better balance between support for fossil fuel projects, currently 94
percent of the energy portfolio, and renewables projects, currently just 6
percent. The promotion of renewable energy that is needed in poverty
alleviation efforts and in response to climate change should be done
by setting up a specialized WBG unit or team for renewables and energy
conservation. It should support country teams by proactively identifying
possible energy conservation and renewables projects or programs, assessing
country capacity to produce and service renewables and energy conservation,
and identifying ways to build up that capacity, as well as by assessing
lending capacity for renewables and energy conservation and ways to
strengthen that capacity.

The WBG can help tackle global imbalances in energy production and use by
promoting dialogue and partnerships to discuss ways to deal with climate
change, such as through technology transfer. It should publicize research on
climate change as a public information good and should publicly "name and
shame" countries or companies with irresponsible policies and practices.

And finally, the WBG should take the initiative to coordinate various
research activities throughout the world to focus on a combined global
effort of striving for sustainable energy development that could contribute
significantly to poverty alleviation through sustainable development.

From psanders at ILSTU.EDU Tue Dec 2 13:57:53 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:42 2004
Subject: Chimney problems and solutions
In-Reply-To: <00c901c3b781$8d7316e0$85387f41@oemcomputer>
Message-ID: <TUE.2.DEC.2003.125753.0600.PSANDERS@ILSTU.EDU>

Lanny and all.

Good observations, and a call for action. Please tell us more of what you
envision as

>a simple manual machine made from common parts that you would find at a
scrap metal place.
> This device needs to do all the steps necessary to make and seam chimney
pipe from flat sheet metal.

In Mozambique my tin-smiths take flat steel (0.35 or 0.6 mm) and beat it
over a steel pipe (about 5 cm diameter) to make chimney pipe at about 7.5
cm (3 inch) diameter, and with good seams. Labor intensive, but a nice
product.

However, I almost suspect that the metal cost to them for the flat steel is
almost the same as the whole price of the industrially produced 3 inch rain
down-spout pipe, labor included (because of lower metal price for larger
purchases of the originally flat steel, but with cost increases because of
transport and storage and overhead.)

I am all in favor of the creation of a "chimney pipe" industry close to the
sites of installation and with lots of jobs. But we also need to bring
down the price.

Dick Boyd has a nice description on the repp.org/resources web page about
making chimney pipe our of old tin cans. Assuming that enough cans of the
appropriate diameter can be found (in the dumpsters of the cities), should
we even consider going down that road of "tin-can-ium?" So many studies
point out that pride-of-ownership (including appearance) is extremely
important, even more than the price factor for many of even the poorest people.

So, how do we get many many meters of 75 mm = 3 inch diameter chimney
pipe? (anyone want 4 inch, which to me is too big)? And is it agreed that
there is no substitute for galvanized mild steel?

Paul

At 03:34 PM 11/30/03 -0500, Lanny Henson wrote:
>Dear Stove Friends,
>Looks like chimneys need our attention!
>
> From your comments some of the problems with chimneys are:
>1x- The cost of chimney parts or the parts are not available, or the lack
>of tools, equipment, methods and skills to build the parts.
>2x- The lack of skills, tools and rigging to install the chimney parts.
>3x- Water leaks at roof or wall penetration are a common problem.
>4x- Safety is an issue. There is a fire hazard with chimneys. There needs to
>be clearance from a chimney pipe to combustible materials.
>5x- Chimney cleaning is another complaint.
>6x- Excess draft from a too tall chimney can suck all the heat out of your
>stove this is especially bad when you are in low power and hay box modes.
>7x- The thermal mass of the chimney and or its r factor can be a problem.
>8x- The stack head (vent caps) are expensive to buy and can create static
>pressure that restricts the flow from the low powered flow generated by
>draft.
>
>Some thoughts on how to solve these problems:
>
>A- We need to design a simple manual machine made from common parts that you
>would find at a scrap metal place. This device needs to do all the steps
>necessary to make and seam chimney pipe from flat sheet metal.
>B- We also will need a method to build a special tool to set the pipe seam.
>C- We will need a simple method to build a roof/wall flashing that is leak
>proof and fire safe, built with only hand tools, no power tools.
>D- We will also need a way to prevent excess draft.
>E- We will need a chimney design that is very easy to clean.
>F- We will also need a simple vent cap that is easy to build with hand
>tools.
>G- In case there is no electricity, the chimney building methods should be
>manual not needing power tools.
>H- The methods to build the chimney making equipment should take only hand
>held power tools and a jig.
>I- We would also need a training manual that can be understood from the
>photos because of language barriers. The manual should show how to build the
>equipment to fabricate the round chimney duct pipe and how to use the
>equipment and hand tools to design and build a complete chimney system from
>flat sheet metal.
>
>Is there anything that I need to add to this wish lists or the problem list?
>
>Lanny Henson
>
>----- Original Message -----
>From: AES <aes@BITSTREAM.NET>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Saturday, November 29, 2003 6:31 PM
>Subject: Re: [STOVES] [ethos] BBC NEWS Science-Nature Indoor smoke 'kills
>millions'
>
>
> > Many of the improved stoves I saw in Guatemala utilize both improvements:
> > increase efficiency of wood use and include a chimney. The inclusion of a
> > chimney is not as straightforward as it seems to a simple solution. In
>one
> > case, the chimney was rotted from a rain water leak at the roof...a simple
> > fix yet not done by the owner and the stove was then not used (except as a
> > table). In another example where the chimney leaked it was fixed on the
> > spot before major damage to the metal pipe and the owner was educated on
>how
> > to correct any leaks should they happen in the future. Without that site
> > visit, hard to know if the chimney would have met the same fate as in the
> > previous example. In yet another example, the chimney was plugged with
> > carbon material and not functioning, thus resulting in a smoke filled
> > kitchen. With each component of a stove adds one more system that adds
>more
> > complexity. While it seems that a chimney is a simple and effective
> > addition, that is not always the case.
> >
> > Back to the basics of development work: each application should be
>decided
> > locally and with much input from the users. Including a chimney where
> > cooking is done outside would add cost and additional maintenance with
> > relatively little benefit. Rather than looking down a pipe that only
>views
> > one type of technology, having various tools to offer, from use of the sun
> > to cook/preheat water to fireless cooking to increasing the efficiency of
> > the stove (including a skirt when feasible), all will reduce the amount of
> > smoke created from cooking.
> >
> > I realize with each type of technology adds cost and complexity but
>exposing
> > the users to each at least allows them to decide which of them they would
> > like to use.
> >
> > I appreciate any and all further comments on this topic.
> >
> > Bruce Stahlberg
> >
> >
> > ----- Original Message -----
> > From: "Ron Larson" <ronallarson@QWEST.NET>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Saturday, November 29, 2003 3:04 PM
> > Subject: Re: [STOVES] [ethos] BBC NEWS Science-Nature Indoor smoke 'kills
> > millions'
> >
> >
> > > Kevin (cc stoves):
> > >
> > > Today, you stated/asked:
> > >
> > > > K: It boggles me that this is still a problem when there is such a
> > simple
> > > > solution: a chimney.
> > > >
> > > > Attempting to build a better stove so that the products of combustion
> > can
> > > be
> > > > vented inside the living space is a well meaning non-solution.
> > > >
> > > > What are the reasons why chimneys are not accepted as a solution to
>this
> > > > problem?
> > > >
> > > > Kindest regards,
> > > >
> > > > Kevin Chisholm
> > > >
> > >
> > > RWL:
> > >
> > > 1. One analysis I have seen comes from ITDG - and as I recall
>(hoping
> > > others will chime in) the main reason for non acceptance of chimneys has
> > > been cost. This is probably compounded by simple wood stove users not
> > > being well informed on the health hazards of smoke and of the relatively
> > > good economics of avoiding illness, etc.
> > >
> > > 2. I have seen at least one paper (now forgotten where - but see
> > > http://www.trmiles.com/stoves/Boyt/chimney/chimney.html) about users
>being
> > > able to build a quite well-functioning, almost-zero-cost chimney from
> > > piecing used metal cans together.
> > >
> > > 3. I think ITDG concluded that a cheap preferred alternative to
> > > chimneys was a vent hood - somewhat lighter perhaps and able to be above
>a
> > > well functioning (more efficient, embedded cookpot, etc) stove of any
> > type.
> > >
> > > 4. Of course some places prefer to cook outdoors or in separate well
> > > vented area - and htis works against the use of chimneys as well.
> > >
> > > 5. And putting all the smoke outside is not necessarily a good idea
> > in
> > > a crowded urban environment - a justification for improving stove
> > > performance regardless of using a chimney.
> > >
> > > 6. Kevin has raised an important point and I hope others will chime
>in.
> >
> >

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 Tue Dec 2 15:22:53 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
Message-ID: <TUE.2.DEC.2003.162253.0400.KCHISHOLM@CA.INTER.NET>

Dear Paul
----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, December 02, 2003 2:57 PM
Subject: Re: [STOVES] Chimney problems and solutions

I was very impressed with Lanny's assessment of the steps of the problem
that had to be adressed.

Do you think ther is a way that some appropriate Funding Agency could get
him a few dollars to deal with all the very relevant issues he identified?

Possibly there could be funding for Technology Transfer?

What would you suggest as a way for Lanny to proceed to get a bit of Support
Funding?

Kindest regards,

Kevin
> > This device needs to do all the steps necessary to make and seam
chimney
> pipe from flat sheet metal.
>
> In Mozambique my tin-smiths take flat steel (0.35 or 0.6 mm) and beat it
> over a steel pipe (about 5 cm diameter) to make chimney pipe at about 7.5
> cm (3 inch) diameter, and with good seams. Labor intensive, but a nice
> product.
>
> However, I almost suspect that the metal cost to them for the flat steel
is
> almost the same as the whole price of the industrially produced 3 inch
rain
> down-spout pipe, labor included (because of lower metal price for larger
> purchases of the originally flat steel, but with cost increases because of
> transport and storage and overhead.)
>
> I am all in favor of the creation of a "chimney pipe" industry close to
the
> sites of installation and with lots of jobs. But we also need to bring
> down the price.
>
> Dick Boyd has a nice description on the repp.org/resources web page about
> making chimney pipe our of old tin cans. Assuming that enough cans of the
> appropriate diameter can be found (in the dumpsters of the cities), should
> we even consider going down that road of "tin-can-ium?" So many studies
> point out that pride-of-ownership (including appearance) is extremely
> important, even more than the price factor for many of even the poorest
people.
>
> So, how do we get many many meters of 75 mm = 3 inch diameter chimney
> pipe? (anyone want 4 inch, which to me is too big)? And is it agreed that
> there is no substitute for galvanized mild steel?
>
> Paul
>

From psanders at ILSTU.EDU Tue Dec 2 16:12:27 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <00fe01c3b912$14aa4980$8d9a0a40@kevin>
Message-ID: <TUE.2.DEC.2003.151227.0600.PSANDERS@ILSTU.EDU>

Kevin, Lanny and all,

At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:

>I was very impressed with Lanny's assessment of the steps of the problem
>that had to be adressed.
I do not see those comments as "steps" but as "pieces". and many of the
pieces have some good solutions that need to be compiled (as could be done
on our Stoves List Serve). For example, There are ways to pull apart a
stove pipe to have access to clean it. and there are caps and wind-vanes
that can cover the tops of the chimneys. And different types of "dampers"
exist, and ways to prevent leaks at the passage points through roofs and
walls. I do not foresee funding for that compilation. (more below)

>Do you think ther is a way that some appropriate Funding Agency could get
>him a few dollars to deal with all the very relevant issues he identified?
>
>Possibly there could be funding for Technology Transfer?
>
>What would you suggest as a way for Lanny to proceed to get a bit of Support
>Funding?
Lanny mentioned some "simple manual machine". Does he have something in
mind? What would it take to test the basics of such a machine? Does it
work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
could undertake to try to make such a device? Perhaps Lanny, but he would
need to explain more.

Assume for a moment that a simple device could pull from the end a piece of
Pre-cut-to-width mild steel and then by turning a crank out comes a
respectable 3 inch diameter tube that could be already closed or could
require some reasonable "assembly" to become a chimney pipe. (in the USA
we can see such pieces in a hardware stove in the "ducting" section,
crimped at one end and ready to "snap" together.) And "seamless gutters"
of any lengths for roofs are made out of aluminium "on the spot" at the
residences where the gutters are being installed. Starts flat and comes
out in gutter shape. Anyone know about that process? Is it relevant to
our needs? COULD we use aluminium after we get far enough away from the
high heat areas? (or could a chimney fire literally melt and consume the
entire aluminium chimney !!! ??)

Lanny has made some IMPRESSIVE stove items in the past. But I do not know
if he has the resources (time and money) to make a prototype "chimney
maker".

I would undertake to make a device in Africa if convinced that it has a
reasonable chance to be successful. I have already done this type of
"replication and modification" on the briquette-making presses that Richard
Stanley advocates and shares with us. WHEN we are successful with the type
of briquette press that meets our needs, I am sure that we will be making
several of them. And I believe in the importance of chimneys and the need
to make them easier and with less expense.

Separate question: Is the 3 inch (75 mm) diameter chimney appropriate for
most of us? The Pakistani BACIE stove use 3 inch. I use 3 inch, John
Davies uses 3 inch, and I believe that the stove/oven (not Vesto) that I
bought from Crispin uses 3 inch diameter chimney. What about Aprovecho
with the Rocket stoves? If the 75 mm (3-inch) size is widely accepted,
then that makes our task easier.

Paul

From aes at BITSTREAM.NET Tue Dec 2 16:20:06 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
Message-ID: <TUE.2.DEC.2003.152006.0600.AES@BITSTREAM.NET>

In making the older style metal Rocket stoves, we used to fabricate the
metal tubing on site by folding over the edges in a S type fashion so they
would hook together. Between the pressure of the metal tube and pinching the
folds, it held together. This metal was much thicker than would be needed
for a chimney so a thinner metal would be easier to work with in the field.

While having a major manufacturing process would be great for producing
larger quantity, an on-site, low tech and easily done system already exists
for locations where a chimney is desired but piping is not available.

Cost still remains a question.

Bruce

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, December 02, 2003 3:12 PM
Subject: Re: [STOVES] Chimney problems and solutions

> Kevin, Lanny and all,
>
> At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:
>
> >I was very impressed with Lanny's assessment of the steps of the problem
> >that had to be adressed.
> I do not see those comments as "steps" but as "pieces". and many of the
> pieces have some good solutions that need to be compiled (as could be done
> on our Stoves List Serve). For example, There are ways to pull apart a
> stove pipe to have access to clean it. and there are caps and wind-vanes
> that can cover the tops of the chimneys. And different types of "dampers"
> exist, and ways to prevent leaks at the passage points through roofs and
> walls. I do not foresee funding for that compilation. (more below)
>
> >Do you think ther is a way that some appropriate Funding Agency could get
> >him a few dollars to deal with all the very relevant issues he
identified?
> >
> >Possibly there could be funding for Technology Transfer?
> >
> >What would you suggest as a way for Lanny to proceed to get a bit of
Support
> >Funding?
> Lanny mentioned some "simple manual machine". Does he have something in
> mind? What would it take to test the basics of such a machine? Does it
> work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> could undertake to try to make such a device? Perhaps Lanny, but he would
> need to explain more.
>
> Assume for a moment that a simple device could pull from the end a piece
of
> Pre-cut-to-width mild steel and then by turning a crank out comes a
> respectable 3 inch diameter tube that could be already closed or could
> require some reasonable "assembly" to become a chimney pipe. (in the USA
> we can see such pieces in a hardware stove in the "ducting" section,
> crimped at one end and ready to "snap" together.) And "seamless gutters"
> of any lengths for roofs are made out of aluminium "on the spot" at the
> residences where the gutters are being installed. Starts flat and comes
> out in gutter shape. Anyone know about that process? Is it relevant to
> our needs? COULD we use aluminium after we get far enough away from the
> high heat areas? (or could a chimney fire literally melt and consume the
> entire aluminium chimney !!! ??)
>
> Lanny has made some IMPRESSIVE stove items in the past. But I do not know
> if he has the resources (time and money) to make a prototype "chimney
> maker".
>
> I would undertake to make a device in Africa if convinced that it has a
> reasonable chance to be successful. I have already done this type of
> "replication and modification" on the briquette-making presses that
Richard
> Stanley advocates and shares with us. WHEN we are successful with the
type
> of briquette press that meets our needs, I am sure that we will be making
> several of them. And I believe in the importance of chimneys and the need
> to make them easier and with less expense.
>
> Separate question: Is the 3 inch (75 mm) diameter chimney appropriate for
> most of us? The Pakistani BACIE stove use 3 inch. I use 3 inch, John
> Davies uses 3 inch, and I believe that the stove/oven (not Vesto) that I
> bought from Crispin uses 3 inch diameter chimney. What about Aprovecho
> with the Rocket stoves? If the 75 mm (3-inch) size is widely accepted,
> then that makes our task easier.
>
> 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 Tue Dec 2 16:46:38 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <009f01c3b91a$0f741560$39b70443@D289YG11>
Message-ID: <TUE.2.DEC.2003.154638.0600.PSANDERS@ILSTU.EDU>

Bruce,

Thanks for the message and info.

By "S-type fashion", what exactly do you mean?

One side could "hook" to the outside and the other could hook to the
inside, so when rolled they could grab each other. Then could be pounded
onto each other.

Are you saying that simply "hand roll" the metal will get the round
shape? No pounding? What diameter were you obtaining on the finished
tubes? 3-inch is a rather tight roll even with thin metal.

I am sure you know how it can be done, but I have not yet grasped the
details of how "I" could do it. When I can do it, then I know I can
explain it to those who work with me in Africa. Sorry I am so
dense. :-)) More details please.

Paul

At 03:20 PM 12/2/03 -0600, AES wrote:
>In making the older style metal Rocket stoves, we used to fabricate the
>metal tubing on site by folding over the edges in a S type fashion so they
>would hook together. Between the pressure of the metal tube and pinching the
>folds, it held together. This metal was much thicker than would be needed
>for a chimney so a thinner metal would be easier to work with in the field.
>
>While having a major manufacturing process would be great for producing
>larger quantity, an on-site, low tech and easily done system already exists
>for locations where a chimney is desired but piping is not available.
>
>Cost still remains a question.
>
>Bruce
>
>
>----- Original Message -----
>From: "Paul S. Anderson" <psanders@ILSTU.EDU>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Tuesday, December 02, 2003 3:12 PM
>Subject: Re: [STOVES] Chimney problems and solutions
>
>
> > Kevin, Lanny and all,
> >
> > At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:
> >
> > >I was very impressed with Lanny's assessment of the steps of the problem
> > >that had to be adressed.
> > I do not see those comments as "steps" but as "pieces". and many of the
> > pieces have some good solutions that need to be compiled (as could be done
> > on our Stoves List Serve). For example, There are ways to pull apart a
> > stove pipe to have access to clean it. and there are caps and wind-vanes
> > that can cover the tops of the chimneys. And different types of "dampers"
> > exist, and ways to prevent leaks at the passage points through roofs and
> > walls. I do not foresee funding for that compilation. (more below)
> >
> > >Do you think ther is a way that some appropriate Funding Agency could get
> > >him a few dollars to deal with all the very relevant issues he
>identified?
> > >
> > >Possibly there could be funding for Technology Transfer?
> > >
> > >What would you suggest as a way for Lanny to proceed to get a bit of
>Support
> > >Funding?
> > Lanny mentioned some "simple manual machine". Does he have something in
> > mind? What would it take to test the basics of such a machine? Does it
> > work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> > could undertake to try to make such a device? Perhaps Lanny, but he would
> > need to explain more.
> >
> > Assume for a moment that a simple device could pull from the end a piece
>of
> > Pre-cut-to-width mild steel and then by turning a crank out comes a
> > respectable 3 inch diameter tube that could be already closed or could
> > require some reasonable "assembly" to become a chimney pipe. (in the USA
> > we can see such pieces in a hardware stove in the "ducting" section,
> > crimped at one end and ready to "snap" together.) And "seamless gutters"
> > of any lengths for roofs are made out of aluminium "on the spot" at the
> > residences where the gutters are being installed. Starts flat and comes
> > out in gutter shape. Anyone know about that process? Is it relevant to
> > our needs? COULD we use aluminium after we get far enough away from the
> > high heat areas? (or could a chimney fire literally melt and consume the
> > entire aluminium chimney !!! ??)
> >
> > Lanny has made some IMPRESSIVE stove items in the past. But I do not know
> > if he has the resources (time and money) to make a prototype "chimney
> > maker".
> >
> > I would undertake to make a device in Africa if convinced that it has a
> > reasonable chance to be successful. I have already done this type of
> > "replication and modification" on the briquette-making presses that
>Richard
> > Stanley advocates and shares with us. WHEN we are successful with the
>type
> > of briquette press that meets our needs, I am sure that we will be making
> > several of them. And I believe in the importance of chimneys and the need
> > to make them easier and with less expense.
> >
> > Separate question: Is the 3 inch (75 mm) diameter chimney appropriate for
> > most of us? The Pakistani BACIE stove use 3 inch. I use 3 inch, John
> > Davies uses 3 inch, and I believe that the stove/oven (not Vesto) that I
> > bought from Crispin uses 3 inch diameter chimney. What about Aprovecho
> > with the Rocket stoves? If the 75 mm (3-inch) size is widely accepted,
> > then that makes our task easier.
> >
> > 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 aes at BITSTREAM.NET Tue Dec 2 16:50:00 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
Message-ID: <TUE.2.DEC.2003.155000.0600.AES@BITSTREAM.NET>

Paul,

Good questions and yes, it was a 4 inch tube which makes rolling it easier.
We used to roll it around a log to give it the roundness but a 3" tube would
be harder to do. The S type system is by folding a small lip on one side,
doing the same on the other but in the opposite direction so they hook
together. If the metal was thinner (than the tubes used in the combustion
chamber of the older metal Rocket stoves) then it would be easier to work
with. I have not tried this when trying to make a 3" pipe. Sorry about the
lack of detail in my technical writing. Does this help any?

Bruce

----- Original Message -----
From: "Paul S. Anderson" <psanders@ilstu.edu>
To: "AES" <aes@bitstream.net>; <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, December 02, 2003 3:46 PM
Subject: Re: [STOVES] Chimney problems and solutions

> Bruce,
>
> Thanks for the message and info.
>
> By "S-type fashion", what exactly do you mean?
>
> One side could "hook" to the outside and the other could hook to the
> inside, so when rolled they could grab each other. Then could be pounded
> onto each other.
>
> Are you saying that simply "hand roll" the metal will get the round
> shape? No pounding? What diameter were you obtaining on the finished
> tubes? 3-inch is a rather tight roll even with thin metal.
>
> I am sure you know how it can be done, but I have not yet grasped the
> details of how "I" could do it. When I can do it, then I know I can
> explain it to those who work with me in Africa. Sorry I am so
> dense. :-)) More details please.
>
> Paul
>
> At 03:20 PM 12/2/03 -0600, AES wrote:
> >In making the older style metal Rocket stoves, we used to fabricate the
> >metal tubing on site by folding over the edges in a S type fashion so
they
> >would hook together. Between the pressure of the metal tube and pinching
the
> >folds, it held together. This metal was much thicker than would be
needed
> >for a chimney so a thinner metal would be easier to work with in the
field.
> >
> >While having a major manufacturing process would be great for producing
> >larger quantity, an on-site, low tech and easily done system already
exists
> >for locations where a chimney is desired but piping is not available.
> >
> >Cost still remains a question.
> >
> >Bruce
> >
> >
> >----- Original Message -----
> >From: "Paul S. Anderson" <psanders@ILSTU.EDU>
> >To: <STOVES@LISTSERV.REPP.ORG>
> >Sent: Tuesday, December 02, 2003 3:12 PM
> >Subject: Re: [STOVES] Chimney problems and solutions
> >
> >
> > > Kevin, Lanny and all,
> > >
> > > At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:
> > >
> > > >I was very impressed with Lanny's assessment of the steps of the
problem
> > > >that had to be adressed.
> > > I do not see those comments as "steps" but as "pieces". and many of
the
> > > pieces have some good solutions that need to be compiled (as could be
done
> > > on our Stoves List Serve). For example, There are ways to pull apart
a
> > > stove pipe to have access to clean it. and there are caps and
wind-vanes
> > > that can cover the tops of the chimneys. And different types of
"dampers"
> > > exist, and ways to prevent leaks at the passage points through roofs
and
> > > walls. I do not foresee funding for that compilation. (more below)
> > >
> > > >Do you think ther is a way that some appropriate Funding Agency could
get
> > > >him a few dollars to deal with all the very relevant issues he
> >identified?
> > > >
> > > >Possibly there could be funding for Technology Transfer?
> > > >
> > > >What would you suggest as a way for Lanny to proceed to get a bit of
> >Support
> > > >Funding?
> > > Lanny mentioned some "simple manual machine". Does he have something
in
> > > mind? What would it take to test the basics of such a machine? Does
it
> > > work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> > > could undertake to try to make such a device? Perhaps Lanny, but he
would
> > > need to explain more.
> > >
> > > Assume for a moment that a simple device could pull from the end a
piece
> >of
> > > Pre-cut-to-width mild steel and then by turning a crank out comes a
> > > respectable 3 inch diameter tube that could be already closed or could
> > > require some reasonable "assembly" to become a chimney pipe. (in the
USA
> > > we can see such pieces in a hardware stove in the "ducting" section,
> > > crimped at one end and ready to "snap" together.) And "seamless
gutters"
> > > of any lengths for roofs are made out of aluminium "on the spot" at
the
> > > residences where the gutters are being installed. Starts flat and
comes
> > > out in gutter shape. Anyone know about that process? Is it relevant
to
> > > our needs? COULD we use aluminium after we get far enough away from
the
> > > high heat areas? (or could a chimney fire literally melt and consume
the
> > > entire aluminium chimney !!! ??)
> > >
> > > Lanny has made some IMPRESSIVE stove items in the past. But I do not
know
> > > if he has the resources (time and money) to make a prototype "chimney
> > > maker".
> > >
> > > I would undertake to make a device in Africa if convinced that it has
a
> > > reasonable chance to be successful. I have already done this type of
> > > "replication and modification" on the briquette-making presses that
> >Richard
> > > Stanley advocates and shares with us. WHEN we are successful with the
> >type
> > > of briquette press that meets our needs, I am sure that we will be
making
> > > several of them. And I believe in the importance of chimneys and the
need
> > > to make them easier and with less expense.
> > >
> > > Separate question: Is the 3 inch (75 mm) diameter chimney appropriate
for
> > > most of us? The Pakistani BACIE stove use 3 inch. I use 3 inch,
John
> > > Davies uses 3 inch, and I believe that the stove/oven (not Vesto) that
I
> > > bought from Crispin uses 3 inch diameter chimney. What about
Aprovecho
> > > with the Rocket stoves? If the 75 mm (3-inch) size is widely
accepted,
> > > then that makes our task easier.
> > >
> > > 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
>
> 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 Dec 2 17:26:17 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <00b601c3b91e$3cd81f20$39b70443@D289YG11>
Message-ID: <TUE.2.DEC.2003.162617.0600.PSANDERS@ILSTU.EDU>

Bruce,

Yes, very useful.

How did you make the folds at the edges? Some large hardware stores have a
about 12 inch by 5 inch "double-piece plate" that has a small gap on the
edge of the long sides. The metal to be bent slips in easily, and then can
be bent quite nicely. I am sure that overseas I can get such a thing made
that would be a meter long or even more. So the edge folding could be easy
enough in a "locally specific manually mass produced" effort to make 50 or
100 meters of chimney pipe for 20 to 50 houses, and to do that every week
for as long as the demand continues.

About the rolling on a log (or pipe). I think this is where some
improvement could be made. How to roll a meter or more of flat metal into
a reasonable near-cylinder.???? Anyone have any ideas? Could we push it
through a fat long "funnel" starting at about 8 inch diameter and exiting
at about 3 inch diameter (and allow the future chimney to spring open a
little after exit). Note that the flat metal is only about 10 inches wide
(2 pi r = circumference = d pi = 3 inches x 3.1415 plus some
overlap for the folds that become the hooks.)

(It is nice to be back home where I have good e-mail access to my Stoves
friends.)

Paul

At 03:50 PM 12/2/03 -0600, AES wrote:
>Paul,
>
>Good questions and yes, it was a 4 inch tube which makes rolling it easier.
>We used to roll it around a log to give it the roundness but a 3" tube would
>be harder to do. The S type system is by folding a small lip on one side,
>doing the same on the other but in the opposite direction so they hook
>together. If the metal was thinner (than the tubes used in the combustion
>chamber of the older metal Rocket stoves) then it would be easier to work
>with. I have not tried this when trying to make a 3" pipe. Sorry about the
>lack of detail in my technical writing. Does this help any?
>
>Bruce
>
>
>----- Original Message -----
>From: "Paul S. Anderson" <psanders@ilstu.edu>
>To: "AES" <aes@bitstream.net>; <STOVES@LISTSERV.REPP.ORG>
>Sent: Tuesday, December 02, 2003 3:46 PM
>Subject: Re: [STOVES] Chimney problems and solutions
>
>
> > Bruce,
> >
> > Thanks for the message and info.
> >
> > By "S-type fashion", what exactly do you mean?
> >
> > One side could "hook" to the outside and the other could hook to the
> > inside, so when rolled they could grab each other. Then could be pounded
> > onto each other.
> >
> > Are you saying that simply "hand roll" the metal will get the round
> > shape? No pounding? What diameter were you obtaining on the finished
> > tubes? 3-inch is a rather tight roll even with thin metal.
> >
> > I am sure you know how it can be done, but I have not yet grasped the
> > details of how "I" could do it. When I can do it, then I know I can
> > explain it to those who work with me in Africa. Sorry I am so
> > dense. :-)) More details please.
> >
> > Paul
> >
> > At 03:20 PM 12/2/03 -0600, AES wrote:
> > >In making the older style metal Rocket stoves, we used to fabricate the
> > >metal tubing on site by folding over the edges in a S type fashion so
>they
> > >would hook together. Between the pressure of the metal tube and pinching
>the
> > >folds, it held together. This metal was much thicker than would be
>needed
> > >for a chimney so a thinner metal would be easier to work with in the
>field.
> > >
> > >While having a major manufacturing process would be great for producing
> > >larger quantity, an on-site, low tech and easily done system already
>exists
> > >for locations where a chimney is desired but piping is not available.
> > >
> > >Cost still remains a question.
> > >
> > >Bruce
> > >
> > >
> > >----- Original Message -----
> > >From: "Paul S. Anderson" <psanders@ILSTU.EDU>
> > >To: <STOVES@LISTSERV.REPP.ORG>
> > >Sent: Tuesday, December 02, 2003 3:12 PM
> > >Subject: Re: [STOVES] Chimney problems and solutions
> > >
> > >
> > > > Kevin, Lanny and all,
> > > >
> > > > At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:
> > > >
> > > > >I was very impressed with Lanny's assessment of the steps of the
>problem
> > > > >that had to be adressed.
> > > > I do not see those comments as "steps" but as "pieces". and many of
>the
> > > > pieces have some good solutions that need to be compiled (as could be
>done
> > > > on our Stoves List Serve). For example, There are ways to pull apart
>a
> > > > stove pipe to have access to clean it. and there are caps and
>wind-vanes
> > > > that can cover the tops of the chimneys. And different types of
>"dampers"
> > > > exist, and ways to prevent leaks at the passage points through roofs
>and
> > > > walls. I do not foresee funding for that compilation. (more below)
> > > >
> > > > >Do you think ther is a way that some appropriate Funding Agency could
>get
> > > > >him a few dollars to deal with all the very relevant issues he
> > >identified?
> > > > >
> > > > >Possibly there could be funding for Technology Transfer?
> > > > >
> > > > >What would you suggest as a way for Lanny to proceed to get a bit of
> > >Support
> > > > >Funding?
> > > > Lanny mentioned some "simple manual machine". Does he have something
>in
> > > > mind? What would it take to test the basics of such a machine? Does
>it
> > > > work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> > > > could undertake to try to make such a device? Perhaps Lanny, but he
>would
> > > > need to explain more.
> > > >
> > > > Assume for a moment that a simple device could pull from the end a
>piece
> > >of
> > > > Pre-cut-to-width mild steel and then by turning a crank out comes a
> > > > respectable 3 inch diameter tube that could be already closed or could
> > > > require some reasonable "assembly" to become a chimney pipe. (in the
>USA
> > > > we can see such pieces in a hardware stove in the "ducting" section,
> > > > crimped at one end and ready to "snap" together.) And "seamless
>gutters"
> > > > of any lengths for roofs are made out of aluminium "on the spot" at
>the
> > > > residences where the gutters are being installed. Starts flat and
>comes
> > > > out in gutter shape. Anyone know about that process? Is it relevant
>to
> > > > our needs? COULD we use aluminium after we get far enough away from
>the
> > > > high heat areas? (or could a chimney fire literally melt and consume
>the
> > > > entire aluminium chimney !!! ??)
> > > >
> > > > Lanny has made some IMPRESSIVE stove items in the past. But I do not
>know
> > > > if he has the resources (time and money) to make a prototype "chimney
> > > > maker".
> > > >
> > > > I would undertake to make a device in Africa if convinced that it has
>a
> > > > reasonable chance to be successful. I have already done this type of
> > > > "replication and modification" on the briquette-making presses that
> > >Richard
> > > > Stanley advocates and shares with us. WHEN we are successful with the
> > >type
> > > > of briquette press that meets our needs, I am sure that we will be
>making
> > > > several of them. And I believe in the importance of chimneys and the
>need
> > > > to make them easier and with less expense.
> > > >
> > > > Separate question: Is the 3 inch (75 mm) diameter chimney appropriate
>for
> > > > most of us? The Pakistani BACIE stove use 3 inch. I use 3 inch,
>John
> > > > Davies uses 3 inch, and I believe that the stove/oven (not Vesto) that
>I
> > > > bought from Crispin uses 3 inch diameter chimney. What about
>Aprovecho
> > > > with the Rocket stoves? If the 75 mm (3-inch) size is widely
>accepted,
> > > > then that makes our task easier.
> > > >
> > > > 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
> >
> > 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 Tue Dec 2 17:17:19 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
Message-ID: <TUE.2.DEC.2003.181719.0400.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: Tuesday, December 02, 2003 5:12 PM
Subject: Re: [STOVES] Chimney problems and solutions

I would think that if a specific task was put to Lanny, he could configure a
complete plan to meet the requirements of the Funding Agency.
>
> >Do you think ther is a way that some appropriate Funding Agency could get
> >him a few dollars to deal with all the very relevant issues he
identified?
> >
> >Possibly there could be funding for Technology Transfer?
> >
> >What would you suggest as a way for Lanny to proceed to get a bit of
Support
> >Funding?
> Lanny mentioned some "simple manual machine". Does he have something in
> mind? What would it take to test the basics of such a machine? Does it
> work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> could undertake to try to make such a device? Perhaps Lanny, but he would
> need to explain more.

If he was in contact with a Funding Agency, I am sure they could work out
all the details between themselves. However, Lanny impresses me as a
"tinman", and I am sure he knows what can't be done, what can be done, and
how to do it.
>
> Assume for a moment that a simple device could pull from the end a piece
of
> Pre-cut-to-width mild steel and then by turning a crank out comes a
> respectable 3 inch diameter tube that could be already closed or could
> require some reasonable "assembly" to become a chimney pipe. (in the USA
> we can see such pieces in a hardware stove in the "ducting" section,
> crimped at one end and ready to "snap" together.) And "seamless gutters"
> of any lengths for roofs are made out of aluminium "on the spot" at the
> residences where the gutters are being installed. Starts flat and comes
> out in gutter shape. Anyone know about that process? Is it relevant to
> our needs? COULD we use aluminium after we get far enough away from the
> high heat areas? (or could a chimney fire literally melt and consume the
> entire aluminium chimney !!! ??)

I am sure that Lanny could address all these questions.
>
> Lanny has made some IMPRESSIVE stove items in the past. But I do not know
> if he has the resources (time and money) to make a prototype "chimney
> maker".

I don't know if he does, or if he doesn't, but I am sure that with suitable
and appropriate funding he could do the job.
>
> I would undertake to make a device in Africa if convinced that it has a
> reasonable chance to be successful. I have already done this type of
> "replication and modification" on the briquette-making presses that
Richard
> Stanley advocates and shares with us. WHEN we are successful with the
type
> of briquette press that meets our needs, I am sure that we will be making
> several of them. And I believe in the importance of chimneys and the need
> to make them easier and with less expense.

You would appear to have the resources, and Lanny would appear to have the
knowledge and skills necessary to make a program work. Could be a potential
for a successful project here!!
>
Best Wishes,

Kevin

From psanders at ILSTU.EDU Tue Dec 2 17:55:06 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <018001c3b923$0e822530$8d9a0a40@kevin>
Message-ID: <TUE.2.DEC.2003.165506.0600.PSANDERS@ILSTU.EDU>

Kevin and all,

About your very last comment, sorry if I gave the incorrect impression that
I have the resources to fund someone's efforts. I have some funds (about
US$4000 remaining) from Rotary to do a stoves project in Mozambique, but
that does not include salaries for anyone in or from a developed country
(nor for transportation or any of my personal expenses to be in Africa).

I have not yet found how to tap into the Funding Agencies regarding
stoves. (By profession I am a professor of geography with a maps specialty
that has taken me to Africa in the past 5 years. And I am retiring from
teaching this semester, which means more available time to do things with
about half of my previous income level. So I, too, and on the lookout for
some funding, but not for me for this current topic of making chimneys.)

Paul

At 06:17 PM 12/2/03 -0400, 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: Tuesday, December 02, 2003 5:12 PM
>Subject: Re: [STOVES] Chimney problems and solutions
>
>
> > Kevin, Lanny and all,
> >
> > At 04:22 PM 12/2/03 -0400, Kevin Chisholm wrote:
> >
> > >I was very impressed with Lanny's assessment of the steps of the problem
> > >that had to be adressed.
> > I do not see those comments as "steps" but as "pieces". and many of the
> > pieces have some good solutions that need to be compiled (as could be done
> > on our Stoves List Serve). For example, There are ways to pull apart a
> > stove pipe to have access to clean it. and there are caps and wind-vanes
> > that can cover the tops of the chimneys. And different types of "dampers"
> > exist, and ways to prevent leaks at the passage points through roofs and
> > walls. I do not foresee funding for that compilation. (more below)
>
>I would think that if a specific task was put to Lanny, he could configure a
>complete plan to meet the requirements of the Funding Agency.
> >
> > >Do you think ther is a way that some appropriate Funding Agency could get
> > >him a few dollars to deal with all the very relevant issues he
>identified?
> > >
> > >Possibly there could be funding for Technology Transfer?
> > >
> > >What would you suggest as a way for Lanny to proceed to get a bit of
>Support
> > >Funding?
> > Lanny mentioned some "simple manual machine". Does he have something in
> > mind? What would it take to test the basics of such a machine? Does it
> > work for the thin metal (0.35 mm)? and for 0.6 or 0.8 mm metal? Who
> > could undertake to try to make such a device? Perhaps Lanny, but he would
> > need to explain more.
>
>If he was in contact with a Funding Agency, I am sure they could work out
>all the details between themselves. However, Lanny impresses me as a
>"tinman", and I am sure he knows what can't be done, what can be done, and
>how to do it.
> >
> > Assume for a moment that a simple device could pull from the end a piece
>of
> > Pre-cut-to-width mild steel and then by turning a crank out comes a
> > respectable 3 inch diameter tube that could be already closed or could
> > require some reasonable "assembly" to become a chimney pipe. (in the USA
> > we can see such pieces in a hardware stove in the "ducting" section,
> > crimped at one end and ready to "snap" together.) And "seamless gutters"
> > of any lengths for roofs are made out of aluminium "on the spot" at the
> > residences where the gutters are being installed. Starts flat and comes
> > out in gutter shape. Anyone know about that process? Is it relevant to
> > our needs? COULD we use aluminium after we get far enough away from the
> > high heat areas? (or could a chimney fire literally melt and consume the
> > entire aluminium chimney !!! ??)
>
>I am sure that Lanny could address all these questions.
> >
> > Lanny has made some IMPRESSIVE stove items in the past. But I do not know
> > if he has the resources (time and money) to make a prototype "chimney
> > maker".
>
>I don't know if he does, or if he doesn't, but I am sure that with suitable
>and appropriate funding he could do the job.
> >
> > I would undertake to make a device in Africa if convinced that it has a
> > reasonable chance to be successful. I have already done this type of
> > "replication and modification" on the briquette-making presses that
>Richard
> > Stanley advocates and shares with us. WHEN we are successful with the
>type
> > of briquette press that meets our needs, I am sure that we will be making
> > several of them. And I believe in the importance of chimneys and the need
> > to make them easier and with less expense.
>
>You would appear to have the resources, and Lanny would appear to have the
>knowledge and skills necessary to make a program work. Could be a potential
>for a successful project here!!
> >
>Best Wishes,
>
>Kevin

From solar1 at ZUPER.NET Tue Dec 2 18:00:27 2003
From: solar1 at ZUPER.NET (Sobre la Roca: Energ=?ISO-8859-1?B?7Q==?=a Solar para el
Desarrollo)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <00b601c3b91e$3cd81f20$39b70443@D289YG11>
Message-ID: <TUE.2.DEC.2003.190027.0400.SOLAR1@ZUPER.NET>

Bruce, Paul
Good comments on the chimney situation.

Bruce if you like we can try to duplicate that tube in thin gauge say 28 or
26 sheet metal, in a three inch tube. Another alternative could be change
size from 3 inch to 4 inch.

Bruce, We are making rockets with 6 sawdust cement and clay bricks instead
of sheet metal tubes because the tubes burnt up in about 6 months especially
in the tropics.

I think the basic start of this thread was a good push by Bruce to think
past where we are. I believe he had observed many problems with the chimney
installations. Most seemed to do with maintenance or clogging.

I recall another part of his observations that hasn't been picked up yet.
Solar cookers and fireless cookers. Is it possible that "we" stovers have
not gained experience in using solar or fireless cookers and for that reason
can't comment? We have demonstrated that solar and fireless cooking when
worked at from a socialogical base instead of technological base can be
assimilated into developing culture.
http://www.she-inc.org/article.php?id=23 This can give a glimpse of what we
have been able to document.

Perhaps Bruce is also trying to generate discussion concerning what we could
term "integrated" cooking systems.

Bruce I support that discussion. And believe that if one is training a
"new" technology such as fireless cooking, it is easier to add the training
necessary of some form of follow up maintenance program to cover the chimney
use transfer.

What do you think?
in a previous message, AES on 12/2/03 17:50 at aes@BITSTREAM.NET wrote:

> Paul,
>
> Good questions and yes, it was a 4 inch tube which makes rolling it easier.
> We used to roll it around a log to give it the roundness but a 3" tube would
> be harder to do. The S type system is by folding a small lip on one side,
> doing the same on the other but in the opposite direction so they hook
> together. If the metal was thinner (than the tubes used in the combustion
> chamber of the older metal Rocket stoves) then it would be easier to work
> with. I have not tried this when trying to make a 3" pipe. Sorry about the
> lack of detail in my technical writing. Does this help any?
>
> Bruce
>
>
> ----- Original Message -----
> From: "Paul S. Anderson" <psanders@ilstu.edu>
> To: "AES" <aes@bitstream.net>; <STOVES@LISTSERV.REPP.ORG>
> Sent: Tuesday, December 02, 2003 3:46 PM
> Subject: Re: [STOVES] Chimney problems and solutions
>
>
--
"It is always the simple that produces the marvelous" Amelia Barr

David Whitfield
Bolivia

http://www.repp.org/discussiongroups/resources/stoves/#David_Whitfield
http://www.solarcooking.org/media/broadcast/whitfield/bio-whitfield.htm

From hseaver at CYBERSHAMANIX.COM Tue Dec 2 18:24:49 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:43 2004
Subject: Compact Biogas Plant
Message-ID: <TUE.2.DEC.2003.172449.0600.HSEAVER@CYBERSHAMANIX.COM>

I'm really interested in building one of Dr. Karve's biogas units, and I'm
wondering why it wouldn't work even better if it had a higher nitrate input,
such as cat and dog feces, or even human? And also had the idea that since some
brands of "kitty litter" sold in the US are made of wheat, wouldn't that work
quite well also, along with the cat feces?

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

From monogle at OREGONCOAST.COM Tue Dec 2 20:38:59 2003
From: monogle at OREGONCOAST.COM (Damon Ogle)
Date: Tue Aug 10 18:30:43 2004
Subject: 17 Excerpts from Woodburning Cookstoves
Message-ID: <TUE.2.DEC.2003.173859.0800.MONOGLE@OREGONCOAST.COM>

Dean, Tami and all,

Your comments about excess air factors and temperatures got me to
thinking about the down-draft stove which was built at Eindhoven. I
looked up the paper "Clean Combustion of Wood:Part II" by Hasan Kahn.
They did, as you know , get very clean combustion (0.078% CO/CO2) and
this "sweet spot"occured exactly when the excess air factor was at 1.75.

They didn't measure temperatures in the hottest part of the
combustion zone, but did measure it at the bottom of the chimney (772 C
or 1045 K). I suspect that temperatures in the "guts" of the stove were
somewhat higher,as they were complaining about the entire stove becoming
red hot and corroding quickly. They ran out of funding before they
solved the materials problem.
I suspect that looking at the excess air factor would be a good tool
for achieving the high temperatures (1200 K or 927 C) we need to get
clean combustion. I just haven't figured out a simple way to measure it
yet. Any suggestions?
I have been experimenting here with a couple of variations of the
Eindhoven down-draft stove made from light weight ceramics. I found
that I also have a materials problem. My grates keep melting. I have,
however noticed that temperatures in the down draft seem to run about
100 C higher than in other experimental stoves. The highest temperature
I have observed so far is 1128 C or 1401 K. It certainly seems feasible
to me to achieve a steady 1200 K (927 C) in some sort of improved stove.

Tami asked "-must we get rid of (the particles of soot) prior to
heat contacting the pot?". I think yes. Once the gases cool down (and
this happens very quickly when they meet the pot) we are "dead in the
water", so to speak.
Does anyone out there know anything about the down-draft "J" stove
that was worked on at the University of Hawaii in the early '80s? I
think it might have been developed by "Islam" and/or "Antol". Haven't
been able to get any details. It was also supposed to be very clean
burning.
Damon

From crispin at NEWDAWN.SZ Wed Dec 3 04:16:56 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
Message-ID: <WED.3.DEC.2003.111656.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

How about coming by? I know you probaly can't but I could show you how to
makea seam on a small diameter chimney. I have borrowed a very verys econd
hand seam roller from a neighbour as I might have to make 4000 lengths of
chimney and I will certainly do it 'by hand' from pre-cut strips. They winn
be, as you thought, 3 inch.

The main deal is to pre-form the edge that will be seamed before you roll
it.

All the tools required to make it quickly and by handa re very easy to make
from some pipe and flat bar. The same equipment can also make eaves troughs.

Regards
Crispin

----- Original Message -----
From: "Paul S. Anderson" <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, December 02, 2003 11:46 PM
Subject: Re: [STOVES] Chimney problems and solutions

Bruce,

Thanks for the message and info.

By "S-type fashion", what exactly do you mean?

One side could "hook" to the outside and the other could hook to the
inside, so when rolled they could grab each other. Then could be pounded
onto each other.

Are you saying that simply "hand roll" the metal will get the round
shape? No pounding? What diameter were you obtaining on the finished
tubes? 3-inch is a rather tight roll even with thin metal.

Paul

From adkarve at PN2.VSNL.NET.IN Wed Dec 3 19:10:15 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:43 2004
Subject: mud chimney
Message-ID: <THU.4.DEC.2003.054015.0530.ADKARVE@PN2.VSNL.NET.IN>

We make stoves out of mud and use a mold for it, so that the
dimensions are adhered to. The stoves are generally made by a local
artisan, in the same village where they are installed. Formerly, the
chimney pipe used to be the costliest item.We used to use a 3.5 meter
length of asbestos cement pipe as a chimney, but nowdays such pipes are
no longer available. Therefore, we have also made a mold for the
chimney. It produces oblong hollow pieces of mud, each about 75 cm long
and about 25 cm wide, having a lumen of 8 to 10 cm diameter, running
vertically in the centre. By stacking the pieces one on top of the other
vertically, one can form a continuous tube. The stoves are generally
situated near one of the walls in the kitchen. The same wall serves as
a support for the chimney pieces. Only the last section of the chimney,
which sticks out of the roof, and which has to stand without any
support, is made of metal tubing. We are still testing this concept and
have not yet started using such chimneys on a large scale, but the
preliminary tests have given positive results. Being made locally, using
local clay, they are cheaper than a metallic chimney.
Dr.A.D.Karve, President,
Appropriate Rural Technology Institute,
Pune, India.

From english at KINGSTON.NET Wed Dec 3 20:29:21 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:43 2004
Subject: chimney problems
Message-ID: <WED.3.DEC.2003.202921.0500.>

Hi all,
I remember Elizabeth Bates of Boiling Point magazine forcefully
explaining that cooking stoves with chimneys had failed everywhere
that she knew of.

Does anyone know about the Chinese experience with chimneys?

The eco rocket stove has been around for a while now in Central
America. What is the experience there?

Where ever a short duration small fire is required for family cooking
with an efficient stove you will inevitably have problems with the gasses
being cooled to much,( after the cooking pot by an uninsulated pipe)
causing deposition of the condensing products of incomplete
combustion which plug up the chimney and water which promotes
corosion.

The physics of vent hoods is less problematic for small output
combustion.

Alex

From krishnakumar_07 at YAHOO.CO.UK Thu Dec 4 03:41:48 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:43 2004
Subject: NDG
Message-ID: <THU.4.DEC.2003.084148.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

i would like to know the draft required inside the
stove to produce the gas, which could seperately taken
to burner for combustion.

=====
krish

________________________________________________________________________
Download Yahoo! Messenger now for a chance to win Live At Knebworth DVDs
http://www.yahoo.co.uk/robbiewilliams

From snienhuys at SNV.ORG.NP Thu Dec 4 04:27:46 2003
From: snienhuys at SNV.ORG.NP (Sjoerd Nienhuys)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions /Re: [STOVES] [ethos] BBC
NEWS Science-Nature Indoor smoke 'kills millions'
In-Reply-To: <00c901c3b781$8d7316e0$85387f41@oemcomputer>
Message-ID: <THU.4.DEC.2003.151246.0545.SNIENHUYS@SNV.ORG.NP>

Chimney vent and roof passage.

Please see my paper on Pakistan stoves for the vent cap. The stoves website,
http://www.repp.org/discussiongroups/resources/stoves/

Regards,

Sjoerd Nienhuys
Senior Renewable Energy Advisor SNV-Nepal
Tel: 5523444, extension 137.
snienhuys@snv.org.np

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
Behalf Of Lanny Henson
Sent: Monday, December 01, 2003 2:20 AM
To:
Subject: [STOVES] Chimney problems and solutions /Re: [STOVES] [ethos]
BBC NEWS Science-Nature Indoor smoke 'kills millions'

Dear Stove Friends,
Looks like chimneys need our attention!

From hrickard at NBNET.NB.CA Thu Dec 4 11:06:03 2003
From: hrickard at NBNET.NB.CA (Harry J. Rickard)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney probelms - indoor smoke reduction
Message-ID: <THU.4.DEC.2003.110603.0500.HRICKARD@NBNET.NB.CA>

Hi Folks,

We developed a solid fuel that reduces pm by 84% and CO by 94% using waste
materials normally destined for landfills. No mater what country we live
in we all have waste materials that we can convert into fuel for cooking,
heating and energy.

The fuel we developed can be configured into various sizes and shapes such
as pellets, bricks, and logs.

The 14,000+ BTUs per lb results in a more complete burn therefor reducing
emissions harmful to the environment as a whole, as well as reduces buildup
in the chimney.

Check out the website. http://cei.bravehost.com/

Best Regards

Harry J. Rickard

CREEATIVE ENERGY INC.
6415 RTE 10
UPPER SALMN CREEK, NB
E4A 1E4

CANADA

From hseaver at CYBERSHAMANIX.COM Thu Dec 4 13:43:44 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney probelms - indoor smoke reduction
In-Reply-To: <LISTSERV%2003120411060333@LISTSERV.REPP.ORG>
Message-ID: <THU.4.DEC.2003.124344.0600.HSEAVER@CYBERSHAMANIX.COM>

On Thu, Dec 04, 2003 at 11:06:03AM -0500, Harry J. Rickard wrote:
> Hi Folks,
>
> We developed a solid fuel that reduces pm by 84% and CO by 94% using waste
> materials normally destined for landfills. No mater what country we live
> in we all have waste materials that we can convert into fuel for cooking,
> heating and energy.
>
> The fuel we developed can be configured into various sizes and shapes such
> as pellets, bricks, and logs.
>
> The 14,000+ BTUs per lb results in a more complete burn therefor reducing
> emissions harmful to the environment as a whole, as well as reduces buildup
> in the chimney.
>
> Check out the website. http://cei.bravehost.com/
>

Can you give us more info on your process? What is the feedstock and what
sort of machinery is used to make them?

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

From psanders at ILSTU.EDU Thu Dec 4 18:15:15 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: J stove
In-Reply-To: <3FCD3EB3.28FE0705@oregoncoast.com>
Message-ID: <THU.4.DEC.2003.171515.0600.PSANDERS@ILSTU.EDU>

At 05:38 PM 12/2/03 -0800, Damon Ogle wrote:
>Dean, Tami and all,
>(snip)
> Does anyone out there know anything about the down-draft "J" stove
>that was worked on at the University of Hawaii in the early '80s? I
>think it might have been developed by "Islam" and/or "Antol". Haven't
>been able to get any details. It was also supposed to be very clean
>burning.
> Damon

Tom Reed has spoken to me a little about it. I think he saw it. J stove
is somewhat related to the IDD (Inverted Down Draft) aka TLUD (top-lit up
draft) that is the basis of Tom's WoodGas Campstove and my Juntos gasifier
stove and John Davies' coal gasifier. In all cases the clean-ness of the
burn is outstanding. After all, we are burning the gases separately from
the creation of those gases by pyrolysis and some gasification of the char.

So this is a note to prompt Tom to reply to Damon's question.

Paul

From psanders at ILSTU.EDU Thu Dec 4 18:36:26 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney problems and solutions
In-Reply-To: <005301c3b993$07efe840$2a47fea9@md>
Message-ID: <THU.4.DEC.2003.173626.0600.PSANDERS@ILSTU.EDU>

Crispin,

Yes, I could very well be into Swaziland on my next trip to Africa, which
will begin in February.

Is the seam roller also called a "jenny"? My Mozambique tin smith has one
(can be found when needed). If the seam roller is something like a
jenny, perhaps a simple and specific jenny could be made specifically for
the seam and for the size of the stove pipes. (good jenny's are adjustable
in several way that make them more expensive than if the device was for a
specific purpose.

I liked A.D. Karve's comment about ceramic (fired clay) segments to make a
chimney.

Paul

At 11:16 AM 12/3/03 +0200, Crispin wrote:
>Dear Paul
>
>How about coming by? I know you probaly can't but I could show you how to
>makea seam on a small diameter chimney. I have borrowed a very verys econd
>hand seam roller from a neighbour as I might have to make 4000 lengths of
>chimney and I will certainly do it 'by hand' from pre-cut strips. They winn
>be, as you thought, 3 inch.
>
>The main deal is to pre-form the edge that will be seamed before you roll
>it.
>
>All the tools required to make it quickly and by handa re very easy to make
>from some pipe and flat bar. The same equipment can also make eaves troughs.
>
>Regards
>Crispin
>
>----- Original Message -----
>From: "Paul S. Anderson" <psanders@ILSTU.EDU>
>To: <STOVES@LISTSERV.REPP.ORG>
>Sent: Tuesday, December 02, 2003 11:46 PM
>Subject: Re: [STOVES] Chimney problems and solutions
>
>
>Bruce,
>
>Thanks for the message and info.
>
>By "S-type fashion", what exactly do you mean?
>
>One side could "hook" to the outside and the other could hook to the
>inside, so when rolled they could grab each other. Then could be pounded
>onto each other.
>
>Are you saying that simply "hand roll" the metal will get the round
>shape? No pounding? What diameter were you obtaining on the finished
>tubes? 3-inch is a rather tight roll even with thin metal.
>
>I am sure you know how it can be done, but I have not yet grasped the
>details of how "I" could do it. When I can do it, then I know I can
>explain it to those who work with me in Africa. Sorry I am so
>dense. :-)) More details please.
>
>Paul

From pverhaart at OPTUSNET.COM.AU Fri Dec 5 05:22:05 2003
From: pverhaart at OPTUSNET.COM.AU (Peter Verhaart)
Date: Tue Aug 10 18:30:43 2004
Subject: downdraft stoves
In-Reply-To: <3FCF9F47.6C16F1E3@oregoncoast.com>
Message-ID: <FRI.5.DEC.2003.202205.1000.PVERHAART@OPTUSNET.COM.AU>

Damon,

Thank you for your mail. What you write about the stove's
behaviour is exactly as I remember it. The stove needs some time to develop
the fire after which the flue gas is odourless. My barbecue has a slight
smell remiscent of the exhaust of LPG burning car engines. There is a
slight deposit of soot under the gridle. This can be explained by assuming
the reaction is prevented to go to completion because of the relative cool
surface of the griddle.
The Eindhoven downdraft stove deposited a thin layer of ash on the pan and
there was too much heat lost on the way for it to be efficient.

Good news about the gas analysis equipment. If I come over I will see if I
can bring a bag of flue gas from my BBQ. If our local University has them I
can probably get a friend to borrow one.

At 12:55 4/12/2003 -0800, you wrote:
>Peter, so nice to hear from you,
> 1300 C is getting right up there. That should do the job.
> I have not been able to do any emissions tests on the stoves I have been
>working with.

snip

> I have made two experimental stoves , and in both versions I tried to
>follow the basic geometry of your down draft stove ( with 62 cm chimney).
>One version was made of ceramic fiber (riser sleeves)which proved to be much
>too fragile.

My bbq has a grate of steel strips (25 * 3 mm) and they have stood up well.
They can be replaced easily but so far there has been no need.

Temperatures at the top of the chimney seem to be in the 700 C to 800 C
>range. There is no visible smoke and (as you described in your experiments
>at Eindhoven) no smell. The only exception being the strong smell of burning
>mustache on one occasion.

And of nostril hair when one tries to smell it directly instead of guiding
a whiff to the nose with a hand.

> This is only intended to be an experimental stove and is not intended as
>a practical cooking device.

For clean burning the gas tightness must not be interrupted so the only
possibility is as a hot plate. I did a water boiling test on the bbq which
I mailed to the List. I don't remember the figures, not spectacular but the
pans remained clean on the outside. A specially designed dd hot plate would
perform better.
Another problem is the feeding. As you found out it can produce poison gas
if you put in too much fuel.

With kind regards,

Peter Verhaart

From rmiranda at INET.COM.BR Fri Dec 5 08:24:38 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:43 2004
Subject: chimney problems
In-Reply-To: <3FCE47A1.10832.8382BA9@localhost>
Message-ID: <FRI.5.DEC.2003.112438.0200.RMIRANDA@INET.COM.BR>

Alex and colleagues:

" deposition of the condensing products of incomplete combustion which
plug up the chimney and water which promotes corrosion " are commonly seem
in Nicaragua with the Ecostove. Frequent cleaning is a must, so we need to
educate the user about it. We made calendar posters with the "10
commandments " for proper Ecostove maintenance as way to remind users.
Thicker (26 calibrer) and wider (4 inches) galvanize tubes helps to
increase chimney life and reduces cleaning frequency. For instance,
tortillas business makers who operate the Ecostove from 06:00 to 19:00
hs, the chimney must be replaced about every year (US$ 10 each chimney)
and clean one or two times a week, depending on the firewood. Whiter
firewood requires less frequent cleaning than darker firewood.

Rog?rio

At 08:29 p.m. 03/12/03 -0500, english@kingston.net wrote:
>Hi all,
>I remember Elizabeth Bates of Boiling Point magazine forcefully
>explaining that cooking stoves with chimneys had failed everywhere
>that she knew of.
>
>Does anyone know about the Chinese experience with chimneys?
>
>The eco rocket stove has been around for a while now in Central
>America. What is the experience there?
>
>Where ever a short duration small fire is required for family cooking
>with an efficient stove you will inevitably have problems with the gasses
>being cooled to much,( after the cooking pot by an uninsulated pipe)
>causing deposition of the condensing products of incomplete
>combustion which plug up the chimney and water which promotes
>corosion.
>
>The physics of vent hoods is less problematic for small output
>combustion.
>
>Alex

From english at KINGSTON.NET Sat Dec 6 21:36:51 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:43 2004
Subject: chimney problems
In-Reply-To: <4.3.2.7.0.20031205111108.00bf5f00@inet.com.br>
Message-ID: <SAT.6.DEC.2003.213651.0500.>

Rogerio,
Thank you for your detailed "old testament" response.

Are you satisfied with your educational solution?
What portion of the chimney pipe plugs or deteriorates first?

Wood stoves in the Northern contries have had the same chimney problems in the past.
However our solutions are too expensive. So if the Eco stove doesn't depend on a tall
chimeny, let me propose an experiment that would not be acceptable for wood stoves
here. Although it is used for gas and oil appliances for different reasons.

It is possible that dillution, inspite of lowering stack temperature could also reduce the
dew point of the condensible gasses and their deposition rate for a net improvement in
chimney life with reduced maintainance.

It is a simple matter of setting up a long term experiment. For example; end the stove
chimney 1.5 meters above the stove and insert it into a larger diameter portion that
extends the rest of the way. Optimum sizeing would have to be worked out.

Call it a hybrid.

Alex

for > Alex and colleagues:
>
> " deposition of the condensing products of incomplete combustion which
> plug up the chimney and water which promotes corrosion " are commonly seem
> in Nicaragua with the Ecostove. Frequent cleaning is a must, so we need to
> educate the user about it. We made calendar posters with the "10
> commandments " for proper Ecostove maintenance as way to remind users.
> Thicker (26 calibrer) and wider (4 inches) galvanize tubes helps to
> increase chimney life and reduces cleaning frequency. For instance,
> tortillas business makers who operate the Ecostove from 06:00 to 19:00
> hs, the chimney must be replaced about every year (US$ 10 each chimney)
> and clean one or two times a week, depending on the firewood. Whiter
> firewood requires less frequent cleaning than darker firewood.
>
> Rog?rio
>
>
> At 08:29 p.m. 03/12/03 -0500, english@kingston.net wrote:
> >Hi all,
> >I remember Elizabeth Bates of Boiling Point magazine forcefully
> >explaining that cooking stoves with chimneys had failed everywhere
> >that she knew of.
> >
> >Does anyone know about the Chinese experience with chimneys?
> >
> >The eco rocket stove has been around for a while now in Central
> >America. What is the experience there?
> >
> >Where ever a short duration small fire is required for family cooking
> >with an efficient stove you will inevitably have problems with the gasses
> >being cooled to much,( after the cooking pot by an uninsulated pipe)
> >causing deposition of the condensing products of incomplete
> >combustion which plug up the chimney and water which promotes
> >corosion.
> >
> >The physics of vent hoods is less problematic for small output
> >combustion.
> >
> >Alex
>
>
>

From dstill at EPUD.NET Sat Dec 6 23:55:00 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:43 2004
Subject: 18 Excerpts from Biofuels, Air Pollution and Health, K. Smith
Message-ID: <SAT.6.DEC.2003.205500.0800.DSTILL@EPUD.NET>

18 Excerpts from Chapter 8, Reducing Exposures: Fuels and Stoves from
"Biofuels, Air Pollution, and Health: A Global Review" by Kirk. R. Smith,
1987

1.) A purpose of this book.is to promote a third generation of improved
stoves, one that explicitly recognizes the possibilities and benefits of
reducing smoke exposure as well as fuel use. (259)

2.) There are three approaches in stove design for achieving exposure
reduction.The most obvious is to incorporate a flue or other method of
guiding the smoke from the room to the outside. The second approach is to
rely on efficiency improvements to reduce emissions..the use of less fuel
per meal will mean less emissions. The third approach is to utilize a
stove/fuel combination in which the combustion conditions lead to lower
emission factors. Ideally it is possible to consider combining two or even
all three of these approaches. (260)

3.) The average composition of dry wood is 51-52% carbon, 41-42% oxygen,
6% hydrogen and 0.5-1% nitrogen, sulfur, and ash. (264)

4.) Essentially all woods have gross energy contents (high heat value on
a moisture free basis) within 5% of 20MJ/kg (4780kcal or 8,600BTU/lb). .For
most purposes involving simple stoves, it is appropriate to use 18.6 MJ/kg,
which is the net energy or low heat value on a moisture free value. (267)

5.) .decreases in the moisture content of biofuels can sometimes lead to
increased emissions factors. .Extremely dry fuel produces elevated emissions
because the presence of some moisture is needed to suppress the onset and
extent of pyrolysis. (271)

6.) . the optimum moisture content for overall efficiency (about 19 %) is
significantly different than that for combustion efficiency (about 29%).
(272)

7.) .small decreases in burn rate can apparently produce large increases
in emission factors.this emissions threshold occurs above 2kg/h for
particulates, CO and total hydrocarbons. (276)

8.) Evidence indicates that emissions are lowest with small charges.The
reason for this effect is that with smaller charges there is less fuel in
the combustion chamber and thus a lower amount of pyrolysis in that part of
the fuel not directly in the combustion zone. Much of the fuel in a large
charge will be near enough to the combustion zone to undergo extensive
pre-burning pyrolysis and thus release materials into a region where space
and char burning has not yet commenced. In addition, quenching by cold fuel
is less likely with a small fuel charge.traditional cooking stoves are
generally fueled by frequent additions of small amounts of fuel, a factor
favorable to low emissions. (286)

9.) Apparently, combustion of larger pieces of fuel (larger volume to
surface ratios) result in lower emission factors.The reason for this effect
is the same as that which favors small fuel charges. Heat may take a
relatively short time to penetrate into the inner parts of fuel pieces with
small volume to surface ratios. .with larger pieces, much of the interior of
the fuel is protected from pyrolysis until such time as space and char
burning have been established nearby to consume the pyrolysis products. Of
course this ratio cannot be too large.(288).2-5cm.size is optimum.(290)

10.) .the increase in efficiency attained by
enclosing combustion in a chamber is also likely to result in an increase in
emission factors. This is undoubtedly due principally to lower turbulence
and, in the case of some stoves, reduction of the air/fuel ratio.

11.) One of the revelations of the recent research on
cookstoves has been that the open fire cookstove can be quite efficient by
many standards (Prasad, 1980; Joseph and Shanahan, 1981) With simple
modifications involving the introduction of a grate and optimizing
fuel-to-pan distance it is possible to achieve efficiencies approaching the
best that many "improved cookstoves" offer, i.e., 30%. (294)

12.) .it is best to monitor exposures rather than
area concentrations. (298)

13.) Evidence from laboratory studies indicate that
total organic emissions are temperature dependent.emissions seem to peak at
about 600C and decrease at temperatures above 900C.In general, the higher
the temperature, the lower the emission factors for all important biomass
combustion pollutants except NOx. (299)

14.) Complete combustion is sometimes defined to be
when less than 3% of the original carbon is found as CO and less than 0.5%
as simple organic compounds. Approximately 1100C is required to reach this
level (Leppa and Saarmi, 1982) (300)

15.) .the principle method by which burn rate has
been decreased has been to close down the airflow, i.e., reduce excess
airflow. .this action can greatly lower combustion efficiency and thus
increase emissions.it would be far better to increase the air flow velocity
aimed directly into the combustion region itself. .Even with much higher
rates of excess air, the high turbulence provided by forced air systems can
lower emission rates by factors of two or more (Allen and Cooke, 1981).
(300)

16.) Preheated primary air can decrease emissions by
increasing combustion efficiency. .It may result in the reverse effect
however in typical side or updraft cooking stoves because of early
volatilization and pyrolysis that may be induced.Secondary air, which is
introduced into the stove after the fuel bed in order to combust escaping
volatiles can in principle induce nearly complete combustion. In practice,
however, it is difficult to maintain the correct primary and secondary air
flow rates such that there is sufficient combustible material and
temperature for spontaneous combustion at the point where secondary air
enters (Verhaart, 1982). An alternative is to provide an ignition
source.(302)

17.) Short cooking times make the uninsulated metal
stove more efficient but longer cooking times may favor the high mass stove.
Better than either at any cooking time from this standpoint would be the
insulated metal stove. .high mass stoves can also be expected to produce
higher emissions at the beginning of the burn.(302)

18.) The most disconcerting result of this
examination of the woodstove emissions literature is that some of the
changes made to improve overall energy efficiency and convenience of
operation also tend to increase emission factors. The basic message,
however, is an optimistic one: there is no theoretical reason why the two
goals cannot be achieved together; incomplete combustion is the enemy both
of good efficiency and clean effluents. Indeed, the very richness and
variety of parameters involved in stove design and use offer the promise of
innovative solutions yet to come. (316)

From crispin at NEWDAWN.SZ Sun Dec 7 03:45:45 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:43 2004
Subject: chimney problems
Message-ID: <SUN.7.DEC.2003.104545.0200.CRISPIN@NEWDAWN.SZ>

Dear Roggerio and Alex

> insert it into a larger diameter portion that
>extends the rest of the way

>It is possible that dillution, inspite of lowering
>stack temperature could also reduce the
>dew point of the condensible gasses and
>their deposition rate for a net improvement in
>chimney life with reduced maintainance.

I like this suggestion because it allows a couple of other things to be done
as well. One is that you can use a top hood to create extra draft when
there is a wind, which might maintain a higher updraft speed and keep
suspended particles moving instead of settling on the walls.

Another is that there can be a short parallel chimney pipe below the
widening point which is open to the outside air on the bottom and opens into
the chimney at the top.

This can provide cold air that will be drawn upwards by the top hood. Thus
one basically gives up on trying to maintain a temperature high enough to
prevent condensation past the point where the chimney widens and instead
relies on updraft and turbulence to take the condensates and particles
through to the top. The updraft is powered by heat from the fire and wind
draft around the hood. When there is little wind, heat predominates.

This breaking of the draft may also help some stoves which struggle to burn
properly or manageably when connected to, say, 4 or more metres of chimney.
The stove designer is left with only trying to manage the exhaust
temperature and particles for 1.5 metres of stack.

The result may be a less frequent cleaning requirement and replacement of
the 'chimney' would be the 1.5 metre pipe, not the whole thing.

I still say this is a combustion problem, not a chimney design problem.
There is frequent mention on this list of a "$5 to $7 stove" yet apparently
people are connecting these to $10 chimneys which require replacement
annually. Not so?

Whither common sense?

Wouldn't it be better to spend $20 to $30 on a stove that burns the clogging
particles and complex gases that would otherwise precipitate into
chimney-eating chemicals?

Sincerely
Crispin

From lanny at ROMAN.NET Sun Dec 7 07:55:05 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney Draft Diverters For Small Cook Stoves
Message-ID: <SUN.7.DEC.2003.075505.0500.LANNY@ROMAN.NET>

A draft diverter prevents excessive draft and prevents back draft.
They are used on gas hot water heaters.
A draft diverter would be a good place to have access to the chimney for
cleaning.

A bucket diverter/small hood could accommodate more than one stove and would
have easy access for cleaning.

Another good idea and Alex mentioned this first, to telescope the stoves
chimney into a larger diameter chimney. He called it a hybrid.

Crispin made a good point I thought, to invest in a better stove and reduce
chimney cost/ maintenance.
The draft diverter drawings are very small about 50KB.
http://www.lanny.us/chimdd.html

I believe we can make chimneys work!
Lanny Henson

From crispin at NEWDAWN.SZ Sun Dec 7 11:47:44 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney Draft Diverters For Small Cook Stoves
Message-ID: <SUN.7.DEC.2003.184744.0200.CRISPIN@NEWDAWN.SZ>

Dear Lanny

Thanks for that link. It seems to me that putting the last device, the one
called a telescoping diverter, into a kitchen would (in a warm climate) be a
good way of getting pollutants out of the rooms as well as it is bound to
take air from the upper part of the room up the chimney.

It is sort of like a turbocharged hood. Not simply a hood, but a hood with
induced draft using the stove pipe as a driver.

Regards
Crispin

----- Original Message -----
From: "Lanny Henson" <lanny@ROMAN.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, December 07, 2003 2:55 PM
Subject: [STOVES] Chimney Draft Diverters For Small Cook Stoves

[snip]

Another good idea and Alex mentioned this first, to telescope the stoves
chimney into a larger diameter chimney. He called it a hybrid.

[snip]

From lanny at ROMAN.NET Mon Dec 8 05:24:08 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney Draft Diverters For Small Cook Stoves
Message-ID: <MON.8.DEC.2003.052408.0500.LANNY@ROMAN.NET>

Dear Crispin,
I had not thought of that. You could use the exhaust from a cook stove as a
draft inducer and you could move some stale air that way. Even if you have a
chimney type stove, it would be good to remove some air from the ceiling
area. You could also boost a hoods flow that way. A short chimney type stove
sitting under a hood with the stove's chimney extending into the hoods
exhaust duct could cause the hood to flow in a dead air situation.
Good thinking, it could apply!
Lanny Henson

----- Original Message -----
From: Crispin Pemberton-Pigott <crispin@newdawn.sz>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Sunday, December 07, 2003 11:47 AM
Subject: [STOVES] RE : Chimney Draft Diverters For Small Cook Stoves

> Dear Lanny
>
> Thanks for that link. It seems to me that putting the last device, the
one
> called a telescoping diverter, into a kitchen would (in a warm climate) be
a
> good way of getting pollutants out of the rooms as well as it is bound to
> take air from the upper part of the room up the chimney.
>
> It is sort of like a turbocharged hood. Not simply a hood, but a hood
with
> induced draft using the stove pipe as a driver.
>
> Regards
> Crispin
>
> ----- Original Message -----
> From: "Lanny Henson" <lanny@ROMAN.NET>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Sunday, December 07, 2003 2:55 PM
> Subject: [STOVES] Chimney Draft Diverters For Small Cook Stoves
>
> [snip]
>
> Another good idea and Alex mentioned this first, to telescope the stoves
> chimney into a larger diameter chimney. He called it a hybrid.
>
> [snip]
>

From krishnakumar_07 at YAHOO.CO.UK Mon Dec 8 06:24:53 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:43 2004
Subject: NDG
In-Reply-To: <002b01c3bce5$1a4889c0$45dc55d4@home>
Message-ID: <MON.8.DEC.2003.112453.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

I have fabricated the natural draft gasifier
with conrete and coated inside with clay.

I have made a trail run of it and it worked
satisfactorlly.The flame reached to a height of
1-1.25ft above the top of the stove.

Then i tried with clossing the top of the stove
with a lid and taking the gas seperately and burning
it through a burner. but i was unsuccesful in burning
the gas,
The gas came out through the primairy air port
and it did not gasify the wood inside.

i would like to know about the chimney effect
and draft to create the gas to come out of the pipe.

=====
krish

________________________________________________________________________
BT Yahoo! Broadband - Save ?80 when you order online today. Hurry! Offer ends 21st December 2003. The way the internet was meant to be. http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk

From hseaver at CYBERSHAMANIX.COM Mon Dec 8 09:41:00 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:43 2004
Subject: Biomass Densification
In-Reply-To: <00dc01c3ba9d$288ac240$8285b3cf@EasternFire>
Message-ID: <MON.8.DEC.2003.084100.0600.HSEAVER@CYBERSHAMANIX.COM>

Harry,
This sounds like a great idea. I would think that an even better
idea than making the fuel and selling it would be for someone to start
manufacturing small home or village size presses to make pellets.
Something about on the scale of the common wood splitter, with a 7-10hp
engine. There has been a lot of interest in this subject on the stoves
list. I would encourage you to write more about your process and
machinery to the list.
The world is in serious need of better methods of biomass
densification.

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

hrickard wrote:
> Hi Marmon,
>
> The feedstock is fibrous materials, or more commonly known as secondary
> biomass. Material that is rejected by recycling companies that is 100%
> biodegradable and originates from plant life. The process is that the
> material is "cleaned" to remove plastics, metals, and other undesirable
> objects that would contaminate the fuel. The fuel is then processed to be
> formed in a press and extruded to whatever configuration is desired. Manual
> presses can be used and would be feasible for small operations to
> manufacture fuel for household use, however we have designed a piece of
> equipment that will extrude high volumes of the fuel for commercialization.
>
> We would consider working with, and sharing the technology with any group or
> organization that meets our criteria.
>
> Best Regards
>
> Harry
> ----- Original Message -----
> From: "Harmon Seaver" <hseaver@CYBERSHAMANIX.COM>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Thursday, December 04, 2003 2:43 PM
> Subject: Re: [STOVES] Chimney probelms - indoor smoke reduction
>
>
>
>>On Thu, Dec 04, 2003 at 11:06:03AM -0500, Harry J. Rickard wrote:
>>
>>>Hi Folks,
>>>
>>>We developed a solid fuel that reduces pm by 84% and CO by 94% using
>
> waste
>
>>>materials normally destined for landfills. No mater what country we
>
> live
>
>>>in we all have waste materials that we can convert into fuel for
>
> cooking,
>
>>>heating and energy.
>>>
>>>The fuel we developed can be configured into various sizes and shapes
>
> such
>
>>>as pellets, bricks, and logs.
>>>
>>>The 14,000+ BTUs per lb results in a more complete burn therefor
>
> reducing
>
>>>emissions harmful to the environment as a whole, as well as reduces
>
> buildup
>
>>>in the chimney.
>>>
>>>Check out the website. http://cei.bravehost.com/
>>>
>>
>> Can you give us more info on your process? What is the feedstock and
>
> what
>
>>sort of machinery is used to make them?
>>
>>
>>--
>>Harmon Seaver
>>CyberShamanix
>>http://www.cybershamanix.com
>
>

From crispin at NEWDAWN.SZ Mon Dec 8 10:31:32 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:43 2004
Subject: Chimney Draft Diverters For Small Cook Stoves
Message-ID: <MON.8.DEC.2003.173132.0200.CRISPIN@NEWDAWN.SZ>

Dear Lanny

I have always been impressed with the simplicity of a stove hood as since
there is heat about, who not use it?

There is some good data on reduction of indoor air pollution using a hood,
but what if there was a stove piped stove with a piped stove pipe?

That might reduce the CO exposure to nearly nil in a regular warm climate
kitchen.

Regards
Crispin

++++++++
>...You could use the exhaust from a cook stove as a draft inducer ...

From Gavin at AA3GENERGI.FORCE9.CO.UK Mon Dec 8 11:30:01 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:43 2004
Subject: Biomass Densification
In-Reply-To: <3FD48D7C.4010701@cybershamanix.com>
Message-ID: <MON.8.DEC.2003.163001.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Hamon ,
There is a swedish designed small scale pelletiser - around 250kg/hr using
30kW electric drive-the basic unit would fit in a 20' container but poke
through the roof.
Unfortunately they don't have a website yet.

Personally I don't think it will be the answer to third world energy but it
is interesting and relevant to your comment.
If I find a way to post the brochure in the web I will let you all know.
Kind regards
gavin

Gavin Gulliver-Goodall
3G Energi,

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

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

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
Of Harmon Seaver
Sent: Monday, December 08, 2003 14:41
To: STOVES@LISTSERV.REPP.ORG
Subject: [STOVES] Biomass Densification

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

hrickard wrote:
> Hi Marmon,
>
> The feedstock is fibrous materials, or more commonly known as secondary
> biomass. Material that is rejected by recycling companies that is 100%
> biodegradable and originates from plant life. The process is that the
> material is "cleaned" to remove plastics, metals, and other undesirable
> objects that would contaminate the fuel. The fuel is then processed to be
> formed in a press and extruded to whatever configuration is desired.
Manual
> presses can be used and would be feasible for small operations to
> manufacture fuel for household use, however we have designed a piece of
> equipment that will extrude high volumes of the fuel for
commercialization.
>
> We would consider working with, and sharing the technology with any group
or
> organization that meets our criteria.
>
> Best Regards
>
> Harry
> ----- Original Message -----
> From: "Harmon Seaver" <hseaver@CYBERSHAMANIX.COM>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Thursday, December 04, 2003 2:43 PM
> Subject: Re: [STOVES] Chimney probelms - indoor smoke reduction
>
>
>
>>On Thu, Dec 04, 2003 at 11:06:03AM -0500, Harry J. Rickard wrote:
>>
>>>Hi Folks,
>>>
>>>We developed a solid fuel that reduces pm by 84% and CO by 94% using
>
> waste
>
>>>materials normally destined for landfills. No mater what country we
>
> live
>
>>>in we all have waste materials that we can convert into fuel for
>
> cooking,
>
>>>heating and energy.
>>>
>>>The fuel we developed can be configured into various sizes and shapes
>
> such
>
>>>as pellets, bricks, and logs.
>>>
>>>The 14,000+ BTUs per lb results in a more complete burn therefor
>
> reducing
>
>>>emissions harmful to the environment as a whole, as well as reduces
>
> buildup
>
>>>in the chimney.
>>>
>>>Check out the website. http://cei.bravehost.com/
>>>
>>
>> Can you give us more info on your process? What is the feedstock and
>
> what
>
>>sort of machinery is used to make them?
>>
>>
>>--
>>Harmon Seaver
>>CyberShamanix
>>http://www.cybershamanix.com
>
>

From hseaver at CYBERSHAMANIX.COM Mon Dec 8 11:49:36 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:43 2004
Subject: Biomass Densification
In-Reply-To: <MABBJLGAAFJBOBCKKPMGEEKIDCAA.Gavin@aa3genergi.force9.co.uk>
Message-ID: <MON.8.DEC.2003.104936.0600.HSEAVER@CYBERSHAMANIX.COM>

Oh, that's much too big. That's a fairly average commercial size, isn't
it? We need something the size of the ubiquitous (in the northern US and Canada,
at least) wood splitter. They're only about 5hp-8hp, at most maybe 16hp for a
really big one. Something you tow behind the pickup. Or run off the tractor's
hydraulics. With all the pellet stoves being sold in NA and Euro these days, I'd
think there would be an excellent market, and I'd think it would also be
something quite attractive to 3rd world markets as well, especially if it was
dual purpose, able to extrude briquets as well as pellets.
But do post the address and info from the company too -- I was trying awhile
back to get prices of smaller pelletizers from a couple of companies in the US
and got no real response.

On Mon, Dec 08, 2003 at 04:30:01PM -0000, Gavin Gulliver-Goodall wrote:
> Hamon ,
> There is a swedish designed small scale pelletiser - around 250kg/hr using
> 30kW electric drive-the basic unit would fit in a 20' container but poke
> through the roof.
> Unfortunately they don't have a website yet.
>
> Personally I don't think it will be the answer to third world energy but it
> is interesting and relevant to your comment.
> If I find a way to post the brochure in the web I will let you all know.
> Kind regards
> gavin
>
> Gavin Gulliver-Goodall
> 3G Energi,
>
> Tel +44 (0)1835 824201
> Fax +44 (0)870 8314098
> Mob +44 (0)7773 781498
> E mail Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>
>
> The contents of this email and any attachments are the property of 3G Energi
> and are intended for the confidential use of the named recipient(s) only.
> They may be legally privileged and should not be communicated to or relied
> upon by any person without our express written consent. If you are not an
> addressee please notify us immediately at the address above or by email at
> Gavin@3genergi.co.uk <mailto:Gavin@3genergi.co.uk>. Any files attached to
> this email will have been checked with virus detection software before
> transmission. However, you should carry out your own virus check before
> opening any attachment. 3G Energi accepts no liability for any loss or
> damage that may be caused by software viruses.
>
> -----Original Message-----
> From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
> Of Harmon Seaver
> Sent: Monday, December 08, 2003 14:41
> To: STOVES@LISTSERV.REPP.ORG
> Subject: [STOVES] Biomass Densification
>
> Harry,
> This sounds like a great idea. I would think that an even better
> idea than making the fuel and selling it would be for someone to start
> manufacturing small home or village size presses to make pellets.
> Something about on the scale of the common wood splitter, with a 7-10hp
> engine. There has been a lot of interest in this subject on the stoves
> list. I would encourage you to write more about your process and
> machinery to the list.
> The world is in serious need of better methods of biomass
> densification.
>
>
> --
> Harmon Seaver
> CyberShamanix
> http://www.cybershamanix.com
>
>
> hrickard wrote:
> > Hi Marmon,
> >
> > The feedstock is fibrous materials, or more commonly known as secondary
> > biomass. Material that is rejected by recycling companies that is 100%
> > biodegradable and originates from plant life. The process is that the
> > material is "cleaned" to remove plastics, metals, and other undesirable
> > objects that would contaminate the fuel. The fuel is then processed to be
> > formed in a press and extruded to whatever configuration is desired.
> Manual
> > presses can be used and would be feasible for small operations to
> > manufacture fuel for household use, however we have designed a piece of
> > equipment that will extrude high volumes of the fuel for
> commercialization.
> >
> > We would consider working with, and sharing the technology with any group
> or
> > organization that meets our criteria.
> >
> > Best Regards
> >
> > Harry
> > ----- Original Message -----
> > From: "Harmon Seaver" <hseaver@CYBERSHAMANIX.COM>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Thursday, December 04, 2003 2:43 PM
> > Subject: Re: [STOVES] Chimney probelms - indoor smoke reduction
> >
> >
> >
> >>On Thu, Dec 04, 2003 at 11:06:03AM -0500, Harry J. Rickard wrote:
> >>
> >>>Hi Folks,
> >>>
> >>>We developed a solid fuel that reduces pm by 84% and CO by 94% using
> >
> > waste
> >
> >>>materials normally destined for landfills. No mater what country we
> >
> > live
> >
> >>>in we all have waste materials that we can convert into fuel for
> >
> > cooking,
> >
> >>>heating and energy.
> >>>
> >>>The fuel we developed can be configured into various sizes and shapes
> >
> > such
> >
> >>>as pellets, bricks, and logs.
> >>>
> >>>The 14,000+ BTUs per lb results in a more complete burn therefor
> >
> > reducing
> >
> >>>emissions harmful to the environment as a whole, as well as reduces
> >
> > buildup
> >
> >>>in the chimney.
> >>>
> >>>Check out the website. http://cei.bravehost.com/
> >>>
> >>
> >> Can you give us more info on your process? What is the feedstock and
> >
> > what
> >
> >>sort of machinery is used to make them?
> >>
> >>
> >>--
> >>Harmon Seaver
> >>CyberShamanix
> >>http://www.cybershamanix.com
> >
> >

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

From rmiranda at INET.COM.BR Mon Dec 8 12:00:27 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:43 2004
Subject: chimney problems
In-Reply-To: <3FD24BF3.13179.FC9095@localhost>
Message-ID: <MON.8.DEC.2003.150027.0200.RMIRANDA@INET.COM.BR>

Alex et al:

Our educational posters seems to worked out, although we did discontinue it
after one year due lack of funds. Those who follow its instructions, had a
better performed stove. The instructions continue to be in the stove
owners manual, however few really read it or even remind of consult it.

The parts of the chimney that deteriorated first was the insert into the
stove body, and also the insert into the roof. The roof part deteriorated
is the one which is out side, not inside, perhaps due the cooling process
outdoors?

Your suggestion seem to be a good one, however what to do when you have a
back draft indoors due wind? would not make more sense to install the
wider tube just out side above the roof, instead of indoors?

We now use an anticorrosion paint inside the chimney tube, which increased
chimney life, delaying deterioration.

Rogerio

At 09:36 p.m. 06/12/03 -0500, english@kingston.net wrote:
>Rogerio,
>Thank you for your detailed "old testament" response.
>
>Are you satisfied with your educational solution?
>What portion of the chimney pipe plugs or deteriorates first?
>
>Wood stoves in the Northern contries have had the same chimney problems in
>the past.
>However our solutions are too expensive. So if the Eco stove doesn't
>depend on a tall
>chimeny, let me propose an experiment that would not be acceptable for
>wood stoves
>here. Although it is used for gas and oil appliances for different reasons.
>
>It is possible that dillution, inspite of lowering stack temperature could
>also reduce the
>dew point of the condensible gasses and their deposition rate for a net
>improvement in
>chimney life with reduced maintainance.
>
>It is a simple matter of setting up a long term experiment. For example;
>end the stove
>chimney 1.5 meters above the stove and insert it into a larger diameter
>portion that
>extends the rest of the way. Optimum sizeing would have to be worked out.
>
>Call it a hybrid.
>
>Alex
>
>
>
>
>for > Alex and colleagues:
> >
> > " deposition of the condensing products of incomplete combustion which
> > plug up the chimney and water which promotes corrosion " are commonly
> seem
> > in Nicaragua with the Ecostove. Frequent cleaning is a must, so we
> need to
> > educate the user about it. We made calendar posters with the "10
> > commandments " for proper Ecostove maintenance as way to remind users.
> > Thicker (26 calibrer) and wider (4 inches) galvanize tubes helps to
> > increase chimney life and reduces cleaning frequency. For instance,
> > tortillas business makers who operate the Ecostove from 06:00 to 19:00
> > hs, the chimney must be replaced about every year (US$ 10 each chimney)
> > and clean one or two times a week, depending on the firewood. Whiter
> > firewood requires less frequent cleaning than darker firewood.
> >
> > Rog?rio
> >
> >
> > At 08:29 p.m. 03/12/03 -0500, english@kingston.net wrote:
> > >Hi all,
> > >I remember Elizabeth Bates of Boiling Point magazine forcefully
> > >explaining that cooking stoves with chimneys had failed everywhere
> > >that she knew of.
> > >
> > >Does anyone know about the Chinese experience with chimneys?
> > >
> > >The eco rocket stove has been around for a while now in Central
> > >America. What is the experience there?
> > >
> > >Where ever a short duration small fire is required for family cooking
> > >with an efficient stove you will inevitably have problems with the gasses
> > >being cooled to much,( after the cooking pot by an uninsulated pipe)
> > >causing deposition of the condensing products of incomplete
> > >combustion which plug up the chimney and water which promotes
> > >corosion.
> > >
> > >The physics of vent hoods is less problematic for small output
> > >combustion.
> > >
> > >Alex
> >
> >
> >

From mantal at HAWAII.EDU Mon Dec 8 12:21:27 2003
From: mantal at HAWAII.EDU (Michael J. Antal, Jr.)
Date: Tue Aug 10 18:30:43 2004
Subject: J stove
In-Reply-To: <4.3.1.2.20031204170731.01f7fad0@mail.ilstu.edu>
Message-ID: <MON.8.DEC.2003.072127.1000.MANTAL@HAWAII.EDU>

The J stove was a joint project of Dr. Kirk Smith and me that supported an
MSE student (Nazrul Islam as I recall). His thesis should be available from
the UH library. Alternatively, Kirk may have a copy of it. As I recall the
stove worked quite well, but there was no interest or support for subsequent
research of this kind here.

Regards, Michael Antal.

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
Behalf Of Paul S. Anderson
Sent: Thursday, December 04, 2003 1:15 PM
To: STOVES@LISTSERV.REPP.ORG
Subject: [STOVES] J stove

So this is a note to prompt Tom to reply to Damon's question.

Paul

From cree at DOWCO.COM Mon Dec 8 13:43:26 2003
From: cree at DOWCO.COM (john olsen)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
Message-ID: <MON.8.DEC.2003.104326.0800.CREE@DOWCO.COM>

I believe that the "holey" briquette ( in my biased way), is the answer to
third World fuel, and the use of the "renewable" abundant Biomass, available
from forests, agriculture, etc.
Pellets are efficient, but, they need electricity to drive the screw, to
load them into the "burn box" of the Stove.
regards
John Olsen
www.heatloginc.com

From rstanley at LEGACYFOUND.ORG Sun Dec 7 11:35:02 2003
From: rstanley at LEGACYFOUND.ORG (rjstanley)
Date: Tue Aug 10 18:30:44 2004
Subject: Chimney problems and solutions
Message-ID: <SUN.7.DEC.2003.203502.0400.RSTANLEY@LEGACYFOUND.ORG>

Lenny Paul and Kevin,
Quick thought on chimney design: Am thinking a bit out of the box on this one(
more accurately perhaps out of the roll) : but do you recall what it was like when
you as a kid or bored adult or at anytime, out of simple error, surprise or
frustration, ever try to laterally pull apart or align a poorly wrapped roll of
paper, or other sheet rolled material. Recal how it forms a long tube of spiraled
overlapping layers ? What if the material was a roll of 10 to 15 cm (4 to 6 inch)
wide thin galvanised sheet metal and what if the overlap was controlled through a
series of sheet metal screws in holes which were punched / drilled set in with a
simple template ?
One would have their chimney to any desired length with little waste material.
Do not have any ideas about the ceiling / wall flange yet...
Richard Stanley

"Paul S. Anderson" wrote:

> Lanny and all.
>
> Good observations, and a call for action. Please tell us more of what you
> envision as
>
> >a simple manual machine made from common parts that you would find at a
> scrap metal place.
> > This device needs to do all the steps necessary to make and seam chimney
> pipe from flat sheet metal.
>
> In Mozambique my tin-smiths take flat steel (0.35 or 0.6 mm) and beat it
> over a steel pipe (about 5 cm diameter) to make chimney pipe at about 7.5
> cm (3 inch) diameter, and with good seams. Labor intensive, but a nice
> product.
>
> However, I almost suspect that the metal cost to them for the flat steel is
> almost the same as the whole price of the industrially produced 3 inch rain
> down-spout pipe, labor included (because of lower metal price for larger
> purchases of the originally flat steel, but with cost increases because of
> transport and storage and overhead.)
>
> I am all in favor of the creation of a "chimney pipe" industry close to the
> sites of installation and with lots of jobs. But we also need to bring
> down the price.
>
> Dick Boyd has a nice description on the repp.org/resources web page about
> making chimney pipe our of old tin cans. Assuming that enough cans of the
> appropriate diameter can be found (in the dumpsters of the cities), should
> we even consider going down that road of "tin-can-ium?" So many studies
> point out that pride-of-ownership (including appearance) is extremely
> important, even more than the price factor for many of even the poorest people.
>
> So, how do we get many many meters of 75 mm = 3 inch diameter chimney
> pipe? (anyone want 4 inch, which to me is too big)? And is it agreed that
> there is no substitute for galvanized mild steel?
>
> Paul
>
> At 03:34 PM 11/30/03 -0500, Lanny Henson wrote:
> >Dear Stove Friends,
> >Looks like chimneys need our attention!
> >
> > From your comments some of the problems with chimneys are:
> >1x- The cost of chimney parts or the parts are not available, or the lack
> >of tools, equipment, methods and skills to build the parts.
> >2x- The lack of skills, tools and rigging to install the chimney parts.
> >3x- Water leaks at roof or wall penetration are a common problem.
> >4x- Safety is an issue. There is a fire hazard with chimneys. There needs to
> >be clearance from a chimney pipe to combustible materials.
> >5x- Chimney cleaning is another complaint.
> >6x- Excess draft from a too tall chimney can suck all the heat out of your
> >stove this is especially bad when you are in low power and hay box modes.
> >7x- The thermal mass of the chimney and or its r factor can be a problem.
> >8x- The stack head (vent caps) are expensive to buy and can create static
> >pressure that restricts the flow from the low powered flow generated by
> >draft.
> >
> >Some thoughts on how to solve these problems:
> >
> >A- We need to design a simple manual machine made from common parts that you
> >would find at a scrap metal place. This device needs to do all the steps
> >necessary to make and seam chimney pipe from flat sheet metal.
> >B- We also will need a method to build a special tool to set the pipe seam.
> >C- We will need a simple method to build a roof/wall flashing that is leak
> >proof and fire safe, built with only hand tools, no power tools.
> >D- We will also need a way to prevent excess draft.
> >E- We will need a chimney design that is very easy to clean.
> >F- We will also need a simple vent cap that is easy to build with hand
> >tools.
> >G- In case there is no electricity, the chimney building methods should be
> >manual not needing power tools.
> >H- The methods to build the chimney making equipment should take only hand
> >held power tools and a jig.
> >I- We would also need a training manual that can be understood from the
> >photos because of language barriers. The manual should show how to build the
> >equipment to fabricate the round chimney duct pipe and how to use the
> >equipment and hand tools to design and build a complete chimney system from
> >flat sheet metal.
> >
> >Is there anything that I need to add to this wish lists or the problem list?
> >
> >Lanny Henson
> >
> >----- Original Message -----
> >From: AES <aes@BITSTREAM.NET>
> >To: <STOVES@LISTSERV.REPP.ORG>
> >Sent: Saturday, November 29, 2003 6:31 PM
> >Subject: Re: [STOVES] [ethos] BBC NEWS Science-Nature Indoor smoke 'kills
> >millions'
> >
> >
> > > Many of the improved stoves I saw in Guatemala utilize both improvements:
> > > increase efficiency of wood use and include a chimney. The inclusion of a
> > > chimney is not as straightforward as it seems to a simple solution. In
> >one
> > > case, the chimney was rotted from a rain water leak at the roof...a simple
> > > fix yet not done by the owner and the stove was then not used (except as a
> > > table). In another example where the chimney leaked it was fixed on the
> > > spot before major damage to the metal pipe and the owner was educated on
> >how
> > > to correct any leaks should they happen in the future. Without that site
> > > visit, hard to know if the chimney would have met the same fate as in the
> > > previous example. In yet another example, the chimney was plugged with
> > > carbon material and not functioning, thus resulting in a smoke filled
> > > kitchen. With each component of a stove adds one more system that adds
> >more
> > > complexity. While it seems that a chimney is a simple and effective
> > > addition, that is not always the case.
> > >
> > > Back to the basics of development work: each application should be
> >decided
> > > locally and with much input from the users. Including a chimney where
> > > cooking is done outside would add cost and additional maintenance with
> > > relatively little benefit. Rather than looking down a pipe that only
> >views
> > > one type of technology, having various tools to offer, from use of the sun
> > > to cook/preheat water to fireless cooking to increasing the efficiency of
> > > the stove (including a skirt when feasible), all will reduce the amount of
> > > smoke created from cooking.
> > >
> > > I realize with each type of technology adds cost and complexity but
> >exposing
> > > the users to each at least allows them to decide which of them they would
> > > like to use.
> > >
> > > I appreciate any and all further comments on this topic.
> > >
> > > Bruce Stahlberg
> > >
> > >
> > > ----- Original Message -----
> > > From: "Ron Larson" <ronallarson@QWEST.NET>
> > > To: <STOVES@LISTSERV.REPP.ORG>
> > > Sent: Saturday, November 29, 2003 3:04 PM
> > > Subject: Re: [STOVES] [ethos] BBC NEWS Science-Nature Indoor smoke 'kills
> > > millions'
> > >
> > >
> > > > Kevin (cc stoves):
> > > >
> > > > Today, you stated/asked:
> > > >
> > > > > K: It boggles me that this is still a problem when there is such a
> > > simple
> > > > > solution: a chimney.
> > > > >
> > > > > Attempting to build a better stove so that the products of combustion
> > > can
> > > > be
> > > > > vented inside the living space is a well meaning non-solution.
> > > > >
> > > > > What are the reasons why chimneys are not accepted as a solution to
> >this
> > > > > problem?
> > > > >
> > > > > Kindest regards,
> > > > >
> > > > > Kevin Chisholm
> > > > >
> > > >
> > > > RWL:
> > > >
> > > > 1. One analysis I have seen comes from ITDG - and as I recall
> >(hoping
> > > > others will chime in) the main reason for non acceptance of chimneys has
> > > > been cost. This is probably compounded by simple wood stove users not
> > > > being well informed on the health hazards of smoke and of the relatively
> > > > good economics of avoiding illness, etc.
> > > >
> > > > 2. I have seen at least one paper (now forgotten where - but see
> > > > http://www.trmiles.com/stoves/Boyt/chimney/chimney.html) about users
> >being
> > > > able to build a quite well-functioning, almost-zero-cost chimney from
> > > > piecing used metal cans together.
> > > >
> > > > 3. I think ITDG concluded that a cheap preferred alternative to
> > > > chimneys was a vent hood - somewhat lighter perhaps and able to be above
> >a
> > > > well functioning (more efficient, embedded cookpot, etc) stove of any
> > > type.
> > > >
> > > > 4. Of course some places prefer to cook outdoors or in separate well
> > > > vented area - and htis works against the use of chimneys as well.
> > > >
> > > > 5. And putting all the smoke outside is not necessarily a good idea
> > > in
> > > > a crowded urban environment - a justification for improving stove
> > > > performance regardless of using a chimney.
> > > >
> > > > 6. Kevin has raised an important point and I hope others will chime
> >in.
> > >
> > >
>
> 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 contacto at CALIPSO.COM.CO Mon Dec 8 16:11:35 2003
From: contacto at CALIPSO.COM.CO (Contactos Mundiales)
Date: Tue Aug 10 18:30:44 2004
Subject: Chimney problems and solutions
Message-ID: <MON.8.DEC.2003.161135.0500.CONTACTO@CALIPSO.COM.CO>

Dear Stanley:

Yes, the process works pretty good and it also has a commercial
name, known particularly in the air conditioning world: Spiroducts.

You can make a metal tube of any lenght and any diameter you
wish.

Anyone using a pop-rivet plier can meet the challenge.

Best regards,

Luis R. Calzadilla
Cali, Colombia
contacto@calipso.com.co

From lanny at ROMAN.NET Mon Dec 8 17:38:29 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:44 2004
Subject: NDG
Message-ID: <MON.8.DEC.2003.173829.0500.LANNY@ROMAN.NET>

Hey Krishna,
Your project sounds very interesting. To create draft or air flow I would
suggest a minimum of 1 meter of draft. Measure the draft height by measuring
from air intake to the top of the exhaust chimney, that is if the system is
sealed (air tight).
Tell us more as you go.
Where are you located? How did you become interested in stoves?
Lanny Henson

----- Original Message -----
From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Monday, December 08, 2003 6:24 AM
Subject: [STOVES] NDG

> I have fabricated the natural draft gasifier
> with conrete and coated inside with clay.
>
> I have made a trail run of it and it worked
> satisfactorlly.The flame reached to a height of
> 1-1.25ft above the top of the stove.
>
> Then i tried with clossing the top of the stove
> with a lid and taking the gas seperately and burning
> it through a burner. but i was unsuccesful in burning
> the gas,
> The gas came out through the primairy air port
> and it did not gasify the wood inside.
>
> i would like to know about the chimney effect
> and draft to create the gas to come out of the pipe.
>
>
>
> =====
> krish
>
> ________________________________________________________________________
> BT Yahoo! Broadband - Save ?80 when you order online today. Hurry! Offer
ends 21st December 2003. The way the internet was meant to be.
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
>
>

From ronallarson at QWEST.NET Mon Dec 8 18:11:59 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:44 2004
Subject: NDG
Message-ID: <MON.8.DEC.2003.161159.0700.RONALLARSON@QWEST.NET>

Krishna:

I fear giving advice without knowing more of your design. Please send
to either this list or, if photographic to mailto:tmiles@trmiles.com

My experience with what might be similar is that the combustion chamber
(which also serves as a chimney) needs to be about 150% as high as the
diameter. If too short, combustion will not be complete (as you appear to
be observing) and the pyrolysis gases will leave too much soot on surfaces
you (I hope) are trying to heat up. Also with too short a
combustion/chimney region, you will not develop a sufficiently good pressure
difference and not draw enough primary air through your fuel supply (which I
hope you are lighting from the top).

If the combustion area/chimney is too long, you are probably losing more
useful energy than you need to. If you are not planning something useful
for the pyrolysis gases, the chimney can be very tall.

Ron

----- Original Message -----
From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Monday, December 08, 2003 4:24 AM
Subject: NDG

> ---------------------- Information from the mail
header -----------------------
> Sender: The Stoves Discussion List <STOVES@LISTSERV.REPP.ORG>
> Poster: =?iso-8859-1?q?krishna=20kumar?=
<krishnakumar_07@YAHOO.CO.UK>
> Subject: NDG
> --------------------------------------------------------------------------
-----
>
> I have fabricated the natural draft gasifier
> with conrete and coated inside with clay.
>
> I have made a trail run of it and it worked
> satisfactorlly.The flame reached to a height of
> 1-1.25ft above the top of the stove.
>
> Then i tried with clossing the top of the stove
> with a lid and taking the gas seperately and burning
> it through a burner. but i was unsuccesful in burning
> the gas,
> The gas came out through the primairy air port
> and it did not gasify the wood inside.
>
> i would like to know about the chimney effect
> and draft to create the gas to come out of the pipe.
>
>
>
> =====
> krish
>
> ________________________________________________________________________
> BT Yahoo! Broadband - Save ?80 when you order online today. Hurry! Offer
ends 21st December 2003. The way the internet was meant to be.
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
>

From english at KINGSTON.NET Mon Dec 8 21:43:31 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:44 2004
Subject: chimney problems
In-Reply-To: <003001c3bca2$69b37bc0$0100007f@home>
Message-ID: <MON.8.DEC.2003.214331.0500.>

> I still say this is a combustion problem, not a chimney design problem.

Crispin,
I have missed a lot, do you have a long stick stove?
Alex

From english at KINGSTON.NET Mon Dec 8 21:43:30 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:44 2004
Subject: chimney problems
In-Reply-To: <4.3.2.7.0.20031208131419.00e0c520@inet.com.br>
Message-ID: <MON.8.DEC.2003.214330.0500.>

what to do when you have a
> back draft indoors due wind? would not make more sense to install the
> wider tube just out side above the roof, instead of indoors?

Rogerio,
Perhaps outside would be better, but likely more difficult to support.
A large over- lap would contain a brief pack puff. Some one will have to
do some trials to see what works, or doesn't.
Alex

From crispin at NEWDAWN.SZ Tue Dec 9 03:53:05 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:44 2004
Subject: chimney problems - Alex
Message-ID: <TUE.9.DEC.2003.105305.0200.CRISPIN@NEWDAWN.SZ>

Dear Alex

Well, that made me think...

No, I don't think so. We have a very large Tsotso-style boiler (30-40kw
range) which can take 750mm logs but I don't think that is what you mean.

All our stoves are batch burners for fairly small pieces 200mm long x 100
dia max and preferably 150 long, or charcoal or biomass briquettes.

Regards
Crispin

>> I still say this is a combustion problem, not a chimney design problem.

>I have missed a lot, do you have a long stick stove?

From K.Prasad at TUE.NL Tue Dec 9 07:01:00 2003
From: K.Prasad at TUE.NL (Prasad, K.)
Date: Tue Aug 10 18:30:44 2004
Subject: 17 Excerpts from Woodburning Cookstoves
Message-ID: <TUE.9.DEC.2003.130100.0100.K.PRASAD@TUE.NL>

Dear Tami

I don't know where to start. First let me say "Thank you" for your opening
sentence. Of course, more importantly, "thanks" to Dean Still who works with
Approvecho Institute that became famous with "Lorena Stove" that I have
criticized rather quite severely. ( See my report "Woodburning Stoves: Their
technology, economics and deployment", Working paper for the World
Employment Programme Research, International Labour Office, Geneva, 1983).

Vis-a-vis your question about soot, to put it mildly, our group never looked
at the problem of burning soot. As far as I can remember our "attitude" was
that if we could burn wood cleanly, there ain't going to be no soot. I'm
sorry if this sounds frivolous. Really speaking soot formation and its
presence in exhaust gases from a combustion system is a product of
incomplete combustion. Incomplete combustion could be due to low
temperatures (presumably due to too much heat loss from the combustion
space, maybe too much air being supplied or due to poor mixing between
combustibles and air).

Soot combustion is a tricky subject of study. Your statement that it can be
eliminated if the exhaust temperature is above 1200K. It probably is right,
but the catch is that you would like to keep the exhaust temperatures as low
as possible for reasons of efficiency. This point is illustrated in Fig.23
of the article in "Advances in Heat transfer" from which Dean got his
excerpts. I'm afraid I haven't seen your modelling efforts but I take it
that it resembles the work on pulverized fuel combustion. Sorry to say we
never pursued this line of study. I must say here that when we were busy
with work on woodstoves we were supported by the Directorate General for
International Development Assistance in Holland and we were located in the
Department of Applied Physics at the Eindhoven University of
Technology(names have changed now!!). We were trying to tread a virtually
undefined line between fundamental work and what can be used in a rural
kitchen. Much credit for the publication in "Advances in Heat Transfer"
should go to my friend Jim Hartnett who pushed us at the International Heat
Transfer Conference in Munich in 1982 to write. It took some 30 months
before it appeared in print!! I guess that is how the proverbial old boy
school network works - I did my Ph.D. at the University of Illinois at
Urbana and Jim was head of the Department of Mechanical Engineering at the
University of Illinois in Chicago. Needless to say that I knew him for
twentyfive odd years before the publication!!

One last remark. Gasifying stove. According to one of the mails, A dear
friend of mine, Liz Bates, is supposed to have said that a chimney srove has
never worked in a rural kitchen. At least as far as I can understand a
gasifying stove is far more complex system than a chimney!!!!

I hope that Lisa Buttner and Dean Still succeed in getting me to Seattle in
Jan-Feb 2004 and hope that you will br there to pursue this discussion
face-to-face.

Yours
Prasad

-----Original Message-----
From: Tami Bond [mailto:yark@UIUC.EDU]
Sent: Monday, December 01, 2003 8:19 AM
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] 17 Excerpts from Woodburning Cookstoves

Dean,
Thanks for yet another message from the greats.

>8.) Values for temperatures of the gases are 1260K and 950K for aut I
take it
>volatile excess air factor of 1.5 and 2.5 respectively. (Page 43)

Tami

From rmiranda at INET.COM.BR Tue Dec 9 07:42:16 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
In-Reply-To: <DKEKJFDEBAHEFLPFIOFOIEBICJAA.mantal@hawaii.edu>
Message-ID: <TUE.9.DEC.2003.104216.0200.RMIRANDA@INET.COM.BR>

Paul and others: There is an article in portuguese at :

http://www.repp.org/discussiongroups/resources/estufas/fogao%20a%20lenha/fogao_a_lenha_limpia.pdf

about a J stove construction.

rogerio

At 07:21 a.m. 08/12/03 -1000, Michael J. Antal, Jr. wrote:
>The J stove was a joint project of Dr. Kirk Smith and me that supported an
>MSE student (Nazrul Islam as I recall). His thesis should be available from
>the UH library. Alternatively, Kirk may have a copy of it. As I recall the
>stove worked quite well, but there was no interest or support for subsequent
>research of this kind here.
>
>Regards, Michael Antal.
>
>-----Original Message-----
>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>Behalf Of Paul S. Anderson
>Sent: Thursday, December 04, 2003 1:15 PM
>To: STOVES@LISTSERV.REPP.ORG
>Subject: [STOVES] J stove
>
>
>At 05:38 PM 12/2/03 -0800, Damon Ogle wrote:
> >Dean, Tami and all,
> >(snip)
> > Does anyone out there know anything about the down-draft "J" stove
> >that was worked on at the University of Hawaii in the early '80s? I
> >think it might have been developed by "Islam" and/or "Antol". Haven't
> >been able to get any details. It was also supposed to be very clean
> >burning.
> > Damon
>
>Tom Reed has spoken to me a little about it. I think he saw it. J stove
>is somewhat related to the IDD (Inverted Down Draft) aka TLUD (top-lit up
>draft) that is the basis of Tom's WoodGas Campstove and my Juntos gasifier
>stove and John Davies' coal gasifier. In all cases the clean-ness of the
>burn is outstanding. After all, we are burning the gases separately from
>the creation of those gases by pyrolysis and some gasification of the char.
>
>So this is a note to prompt Tom to reply to Damon's question.
>
>Paul
>
>
>
>Paul S. Anderson, Ph.D., Fulbright Prof. to Mozambique 8/99 - 7/00
>Rotary University Teacher Grantee to Mozambique >10 mo of 2001-2003
>Dept of Geography - Geology (Box 4400), Illinois State University
>Normal, IL 61790-4400 Voice: 309-438-7360; FAX: 309-438-5310
>E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders

From dstill at EPUD.NET Tue Dec 9 12:05:49 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:44 2004
Subject: No subject
Message-ID: <TUE.9.DEC.2003.090549.0800.DSTILL@EPUD.NET>

Dear Stovers,

Just an obvious reminder that chimneys are used in the 5,000 HELPS and
Trees, Water, & People griddle stoves that are being made and used in
Central America. While Liz Bates works in areas that have not yet used
chimneys, slightly richer areas have known and used chimneys for decades.

All Best,

Dean

From crispin at NEWDAWN.SZ Mon Dec 8 15:53:40 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:44 2004
Subject: Chimney problems and solutions
Message-ID: <MON.8.DEC.2003.225340.0200.CRISPIN@NEWDAWN.SZ>

Dear Richard

Good idea:
>What if the material was a roll of 10 to 15 cm (4 to 6 inch)
>wide thin galvanised sheet metal and what if the overlap
>was controlled through a series of sheet metal screws in
>holes which were punched / drilled set in with a
>simple template ?

Two problems: getting a long strip of galv (it would have to be slit from a
long large roll 1.25 metres wide) and the amount of overlap is longer on a
coil than a straight seam (less efficient use of material).

If it is a rolled seam (cheaper) there is more overlap. If it is a screwed
seam (most work = more cost and slower) there is less total overlap. In
both cases there is more seam on the helix than on a straight seam (about
40% more).

The minimum large roll size is 5 tons - about $8000. Slit into 150mm strips
it would give 8 km of strip. That would be the minimum 'buy'. You would
have to be interesting in a seriously large amount of chimney piping.

Are you?? :)

Regards
Crispin

From Gavin at AA3GENERGI.FORCE9.CO.UK Tue Dec 9 15:19:25 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <001801c3bdbb$2a95cbe0$4b0e640a@VALUEDCB7D4C82>
Message-ID: <TUE.9.DEC.2003.201925.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Actually John,
I'm sure you could make a clockwork pellet stove - like the clockwork radio.
But since pellets are energy intensive to make also they are only viable in
urban situations where transport and storage economics come into effect.

I think the list has discussed clockwork id fans with regard to stoves and
tom makes one with a tiny battery for efficient camp cooking
Cheers
gavin
-----Original Message-----
From: john olsen [mailto:cree@dowco.com]
Sent: Monday, December 08, 2003 18:43
To: STOVES@LISTSERV.REPP.ORG
Cc: Gavin Gulliver-Goodall
Subject: third world energy

From monogle at OREGONCOAST.COM Tue Dec 9 14:03:30 2003
From: monogle at OREGONCOAST.COM (Damon Ogle)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
Message-ID: <TUE.9.DEC.2003.110330.0800.MONOGLE@OREGONCOAST.COM>

Rogerio, Paul and others,
This "Fogao de Lenha de Combustao Limpa" is a very interesting design. I having some success
trying to decipher the text.
Do you know if it was ever produced in large numbers? If so, how did people like it? Did they
ever run any performance and/or emission tests on it?
In September of '96 Kirk Smith sent a letter to the Stoves Group on "Downdraft stoves down through
history". He makes reference to a 17th century stove which was capable of burning "cats-pifs" soaked
fuel without emitting odor. This must have been similar to the "J" stoves.
Thanks for all the good leads. Hope to see you in Seattle.

Damon

Rogerio Carneiro de Miranda wrote:

> Paul and others: There is an article in portuguese at :
>
> http://www.repp.org/discussiongroups/resources/estufas/fogao%20a%20lenha/fogao_a_lenha_limpia.pdf
>
> about a J stove construction.
>
> rogerio
>
> At 07:21 a.m. 08/12/03 -1000, Michael J. Antal, Jr. wrote:
> >The J stove was a joint project of Dr. Kirk Smith and me that supported an
> >MSE student (Nazrul Islam as I recall). His thesis should be available from
> >the UH library. Alternatively, Kirk may have a copy of it. As I recall the
> >stove worked quite well, but there was no interest or support for subsequent
> >research of this kind here.
> >
> >Regards, Michael Antal.
> >
> >-----Original Message-----
> >From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
> >Behalf Of Paul S. Anderson
> >Sent: Thursday, December 04, 2003 1:15 PM
> >To: STOVES@LISTSERV.REPP.ORG
> >Subject: [STOVES] J stove
> >
> >
> >At 05:38 PM 12/2/03 -0800, Damon Ogle wrote:
> > >Dean, Tami and all,
> > >(snip)
> > > Does anyone out there know anything about the down-draft "J" stove
> > >that was worked on at the University of Hawaii in the early '80s? I
> > >think it might have been developed by "Islam" and/or "Antol". Haven't
> > >been able to get any details. It was also supposed to be very clean
> > >burning.
> > > Damon
> >
> >Tom Reed has spoken to me a little about it. I think he saw it. J stove
> >is somewhat related to the IDD (Inverted Down Draft) aka TLUD (top-lit up
> >draft) that is the basis of Tom's WoodGas Campstove and my Juntos gasifier
> >stove and John Davies' coal gasifier. In all cases the clean-ness of the
> >burn is outstanding. After all, we are burning the gases separately from
> >the creation of those gases by pyrolysis and some gasification of the char.
> >
> >So this is a note to prompt Tom to reply to Damon's question.
> >
> >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 hseaver at CYBERSHAMANIX.COM Tue Dec 9 11:25:27 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <MABBJLGAAFJBOBCKKPMGOELGDCAA.Gavin@aa3genergi.force9.co.uk>
Message-ID: <TUE.9.DEC.2003.102527.0600.HSEAVER@CYBERSHAMANIX.COM>

On Tue, Dec 09, 2003 at 08:19:25PM -0000, Gavin Gulliver-Goodall wrote:
> Actually John,
> I'm sure you could make a clockwork pellet stove - like the clockwork radio.
> But since pellets are energy intensive to make also they are only viable in
> urban situations where transport and storage economics come into effect.

While they may be energy intensive to produce, they are still cheaper to
heat with (in the US) than natural gas, fuel oil, or electricity. And certainly
a lot more pleasant to use than firewood, if you use woodheat. I can attest to
the fact, having heated exclusively with wood for many years that it becomes
tiresome, even if you buy it and have it delivered. The constant tending that a
woodfired boiler, furnace, or parlor stove requires is time consuming and, even
worse, prohibits staying away from home drastically during the real cold
periods.
So pellet burners, especially those which also burn corn, etc., are
naturally becoming very popular in the US, Canada, and Europe. Also, in many
areas in the US, firewood as cordwood is becoming increasingly difficult to
get. Pellets are commonly made from sawdust and other forest product residues at
present, but there are other much more productive crops, like cattails and
switchgrass, which would be more cost effective, and also a lot more
environmentally sustainable.
Sure, briquettes make more sense for cooking in the 3rd world, but we
desperately need to develop sustainable (and clean) energy everywhere. Pellets
are an excellent fit for that -- and a small, personal scale pellet maker would
be very desirable. My heat and utility costs at present equal or exceed my
mortgage payments, and that's only going to worsen -- but think if I could
provide all my own heating fuel simply from pelletizing the leaves that people
pile on their curbs every Fall -- which, of course, the cities very expensively
have to gather and haul away.
Pellets could be made much more cheaply in decentralized
small-scale operations, since a big cost is trucking the sawdust to the pellet
mills, then trucking the pellets across the country. With 2-3 acres of cattail
marsh, for example, I could have enough fuel for heat forever. And another two
acres of canola and I'd have all the fuel I needed for my vehicles. 8-)

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

From krishnakumar_07 at YAHOO.CO.UK Wed Dec 10 01:57:58 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:44 2004
Subject: NDG
In-Reply-To: <026a01c3bde0$af628820$49600443@net>
Message-ID: <WED.10.DEC.2003.065758.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

I am final year stdent doing my Post graduation
in (Energy Engineering) in Anna University.
I completed my graduation in Mechanical Engineering
Madras University.I am staying in the city of Madras
in India.

I was on for a project for solar home ligthing in
unelectrified villages of the state,where i found that
almost all the villages is in dark and poverty.
People living here not having money and all are
uneducated.

There i found that there is abundance of
firewood(Juliflora), which they cut and use for the
cooking purpose.the method adopted by them is open
fire cooking which was very inefficient and produced a
lot of smoke.

Hence i thought of doing my project in developing
the stove which gives out less smoke burns the fuel in
an efficient manner.

The people donot have electricity so they cannot go
for woodcutter. hence they have to use the wood as
such choped from the forest hence i am trying to
develop a natural draft gasifier based stove which
burn fuel of greater size
and not of briquetted or pelletted fuels.

I am trying to develop one such design such that the
maximum size up to which the the fuel can be burned in
a efficient manner.

I am staying in such a place where i could not get
any guidance or i donot have proper instruments to
monitor them.

--- Ron Larson <ronallarson@QWEST.NET> wrote: >
Krishna:
>
> I fear giving advice without knowing more of
> your design. Please send
> to either this list or, if photographic to
> mailto:tmiles@trmiles.com
>
> My experience with what might be similar is that
> the combustion chamber
> (which also serves as a chimney) needs to be about
> 150% as high as the
> diameter. If too short, combustion will not be
> complete (as you appear to
> be observing) and the pyrolysis gases will leave too
> much soot on surfaces
> you (I hope) are trying to heat up. Also with too
> short a
> combustion/chimney region, you will not develop a
> sufficiently good pressure
> difference and not draw enough primary air through
> your fuel supply (which I
> hope you are lighting from the top).
>
> If the combustion area/chimney is too long, you
> are probably losing more
> useful energy than you need to. If you are not
> planning something useful
> for the pyrolysis gases, the chimney can be very
> tall.
>
> Ron
>
> ----- Original Message -----
> From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
> To: <STOVES@LISTSERV.REPP.ORG>
> Sent: Monday, December 08, 2003 4:24 AM
> Subject: NDG
>
>
> > ---------------------- Information from the mail
> header -----------------------
> > Sender: The Stoves Discussion List
> <STOVES@LISTSERV.REPP.ORG>
> > Poster: =?iso-8859-1?q?krishna=20kumar?=
> <krishnakumar_07@YAHOO.CO.UK>
> > Subject: NDG
> >
>
--------------------------------------------------------------------------
> -----
> >
> > I have fabricated the natural draft gasifier
> > with conrete and coated inside with clay.
> >
> > I have made a trail run of it and it worked
> > satisfactorlly.The flame reached to a height of
> > 1-1.25ft above the top of the stove.
> >
> > Then i tried with clossing the top of the stove
> > with a lid and taking the gas seperately and
> burning
> > it through a burner. but i was unsuccesful in
> burning
> > the gas,
> > The gas came out through the primairy air port
> > and it did not gasify the wood inside.
> >
> > i would like to know about the chimney effect
> > and draft to create the gas to come out of the
> pipe.
> >
> >
> >
> > =====
> > krish
> >
> >
>
________________________________________________________________________
> > BT Yahoo! Broadband - Save ?80 when you order
> online today. Hurry! Offer
> ends 21st December 2003. The way the internet was
> meant to be.
>
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> >

=====
krish

From Gavin at AA3GENERGI.FORCE9.CO.UK Wed Dec 10 04:24:10 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <20031209162527.GA5994@cybershamanix.com>
Message-ID: <WED.10.DEC.2003.092410.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Harman,
I see where you are coming from,
However making pellets manually , or on a small scale is not (here in
Europe) economic due to the labour requirements.
I would dispute whether replacing the fire tending duties for the third
world housewife with pellet making: grinding and drying the biomass before
reforming into pellets would appeal. Maybe if the men were to do it....

Also,
While wood makes excellent, clean burning pellets, However leaves and
grasses have a high ash content and low ash melting point so pellets from
these raw materials will not work as well as those you and I use in our
pellet stoves.

Briquettes, which I also use for heating in a traditional log-stove are also
excellent but labour intensive to make.

I like the idea of holey briquettes made from efficiently produced char as I
can see a simple , cheap easy to control stove with good heat output being
compatible with these briquettes.

Onward (as Tom says)

Gavin

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On Behalf
Of Harmon Seaver
Sent: Tuesday, December 09, 2003 16:25
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] third world energy

On Tue, Dec 09, 2003 at 08:19:25PM -0000, Gavin Gulliver-Goodall wrote:
> Actually John,
> I'm sure you could make a clockwork pellet stove - like the clockwork
radio.
> But since pellets are energy intensive to make also they are only viable
in
> urban situations where transport and storage economics come into effect.

While they may be energy intensive to produce, they are still cheaper to
heat with (in the US) than natural gas, fuel oil, or electricity. And
certainly
a lot more pleasant to use than firewood, if you use woodheat. I can attest
to
the fact, having heated exclusively with wood for many years that it becomes
tiresome, even if you buy it and have it delivered. The constant tending
that a
woodfired boiler, furnace, or parlor stove requires is time consuming and,
even
worse, prohibits staying away from home drastically during the real cold
periods.
So pellet burners, especially those which also burn corn, etc., are
naturally becoming very popular in the US, Canada, and Europe. Also, in many
areas in the US, firewood as cordwood is becoming increasingly difficult to
get. Pellets are commonly made from sawdust and other forest product
residues at
present, but there are other much more productive crops, like cattails and
switchgrass, which would be more cost effective, and also a lot more
environmentally sustainable.
Sure, briquettes make more sense for cooking in the 3rd world, but we
desperately need to develop sustainable (and clean) energy everywhere.
Pellets
are an excellent fit for that -- and a small, personal scale pellet maker
would
be very desirable. My heat and utility costs at present equal or exceed my
mortgage payments, and that's only going to worsen -- but think if I could
provide all my own heating fuel simply from pelletizing the leaves that
people
pile on their curbs every Fall -- which, of course, the cities very
expensively
have to gather and haul away.
Pellets could be made much more cheaply in decentralized
small-scale operations, since a big cost is trucking the sawdust to the
pellet
mills, then trucking the pellets across the country. With 2-3 acres of
cattail
marsh, for example, I could have enough fuel for heat forever. And another
two
acres of canola and I'd have all the fuel I needed for my vehicles. 8-)

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

From hseaver at CYBERSHAMANIX.COM Wed Dec 10 05:42:12 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
In-Reply-To: <MABBJLGAAFJBOBCKKPMGOELJDCAA.Gavin@aa3genergi.force9.co.uk>
Message-ID: <WED.10.DEC.2003.044212.0600.HSEAVER@CYBERSHAMANIX.COM>

On Wed, Dec 10, 2003 at 09:24:10AM -0000, Gavin Gulliver-Goodall wrote:
> Harman,
> I see where you are coming from,
> However making pellets manually , or on a small scale is not (here in

I'm certainly not suggesting making them manually. Using a small hammermill
type shredder and then feeding that into a screwpress extruder, or perhaps a
hydraulic ram press run by a 10hp engine. A screwpress might even be usuable to
squeeze oil from seed as well.

> Europe) economic due to the labour requirements.

> I would dispute whether replacing the fire tending duties for the third
> world housewife with pellet making: grinding and drying the biomass before
> reforming into pellets would appeal. Maybe if the men were to do it....

No, I'm not suggesting pellets for a third world application, especially
for cooking.

>
> Also,
> While wood makes excellent, clean burning pellets, However leaves and
> grasses have a high ash content and low ash melting point so pellets from
> these raw materials will not work as well as those you and I use in our
> pellet stoves.

I'll trade more ash removal for not having to kill trees. Or for not having
to wait 20 years for the trees to grow big enough for firewood.

>
> Briquettes, which I also use for heating in a traditional log-stove are also
> excellent but labour intensive to make.
>
Not with a good extruder. Briquettes would work if you had an old stoker fed
coal-fired boiler, but those are hard to come by these days, whereas pellet
boilers aren't, and with nicer controls and cleaner burning designs as well.

(snip)

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

From snkm at BTL.NET Wed Dec 10 10:58:23 2003
From: snkm at BTL.NET (Peter Singfield)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
Message-ID: <WED.10.DEC.2003.095823.0600.SNKM@BTL.NET>

At 04:42 AM 12/10/2003 -0600, Harmon Seaver wrote:

>A screwpress might even be usuable to
>squeeze oil from seed as well.
>

I can vouch for this -- if I adjust me screw press a little to tight I end
up with very hard coconut trash pellets!

So yes -- a screw press would probably work.

The one I have comes from Sri Lanka and costs $1250.

I operate that using a 12 HP -- two cylinder -- old style Lister diesel --
turning 650 rpm max.

I use old engine oil as fuel and lubrication.

I do not burn coconut trash pellets -- they do make excellent chicken and
turkey feed.

You can see this equipment at:

http://www.turneffecoconut.com

Browse around -- full pictures are there.

The chimney for the long flat plate drier (fuels by coconut shell) is a 16
ft long sheet of galvanized roofing material -- rolled around a log -- then
pop riveted.

This is then mounted on an old butane tank which is the exhaust receiver.

Works very well indeed.

I have just reproduced this same design of chimney for my cane juice boiler.

Also -- came up with an interesting solution to fire walling the fire box
area. I used 22 gauge sheet stainless spot welded to a grid of steel rebar
-- then a four inch thick casting of white marl with a little cement behind
that.

Pan boiling capacity is 125 gallons -- fuel is Bagasse -- which when dry --
burns like gasoline!!

More later -- after it has operated a year or two -- as indeed -- has the
flat plate drier -- now.

Peter -- doing it now -- in Belize -- and no Grants!!

Necessity is the mother of innovation -- grants is the depressant!!

From Gavin at AA3GENERGI.FORCE9.CO.UK Wed Dec 10 12:12:02 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
In-Reply-To: <20031210104212.GA8627@cybershamanix.com>
Message-ID: <WED.10.DEC.2003.171202.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

On Wed, Dec 10, 2003 at 09:24:10AM -0000, Gavin Gulliver-Goodall wrote:
> Harman,
> I see where you are coming from,
> However making pellets manually , or on a small scale is not (here in

I'm certainly not suggesting making them manually. Using a small
hammermill
type shredder and then feeding that into a screwpress extruder, or perhaps a
hydraulic ram press run by a 10hp engine. A screwpress might even be usuable
to
squeeze oil from seed as well.
[GGG] So where does the gas come from to drive the engine?
> Europe) economic due to the labour requirements.

As compared to all the work preparing and using regular firewood?
Cutting
15 cords (40 tons) of wood is no small job in itself, then of course you
have to
split it, then load it in the truck or wagon, haul it, unload and stack it.
Then
wait a year for it to dry, then carry it in the house to burn, armload after
armload, all day, and even getting up in the middle of the night to
replenish
the fire.
[GGG] Yep, but you need to do all this, plus dry the stuff down to below 15%
moisture then run it through your hammermill and extruder.
There are very efficient cordwood burners that will run your heating all day
and all night on a single charge of fuel
However they are not suitable for 3rd world at all.
> I would dispute whether replacing the fire tending duties for the third
> world housewife with pellet making: grinding and drying the biomass before
> reforming into pellets would appeal. Maybe if the men were to do it....

No, I'm not suggesting pellets for a third world application,
especially
for cooking.

I'll trade more ash removal for not having to kill trees. Or for not
having
to wait 20 years for the trees to grow big enough for firewood.
[GGG] Efficient burners + less firewood. Increased fossil fuel consumption
to produce manufactured fuel to burn in appliances with no greater
efficiencies = wasteful? No?
>
> Briquettes, which I also use for heating in a traditional log-stove are
also
> excellent but labour intensive to make.
>
Not with a good extruder. Briquettes would work if you had an old stoker
fed
coal-fired boiler, but those are hard to come by these days, whereas pellet
boilers aren't, and with nicer controls and cleaner burning designs as well.
[GGG] Yep, can burn briquettes in modern biomass stoker burners of say over
300kW rated output. Having converted several "old coal fired boilers " to
pellet burning and also replaces some old coal fired boilers with new pellet
boilers I can say categorically that the payback for boiler replacement -in
higher efficiency (lower fuel consumption) and lower maintenance is always
shorter than the "remaining life of the coal boiler-these thing can only
manage about 60% efficiency when they are clean and newly set up and degrade
terribly/ also they need regular manual cleaning.
These things are already happening in Europe but arn't appropriate in 3rd
worlds as yet due to capital ,and technical requirements of the equipment.
Cheers
Gavin
www.3genergi.co.uk
(snip)

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

From rmiranda at INET.COM.BR Wed Dec 10 12:51:22 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
In-Reply-To: <3FD61C81.AA5072A3@oregoncoast.com>
Message-ID: <WED.10.DEC.2003.155122.0200.RMIRANDA@INET.COM.BR>

Damon and others:

The "Fogao de queima limpa" author?s, Thomaz Borges can be contacted at:
thomazborges@uol.com.br

Rog?rio

At 11:03 a.m. 09/12/03 -0800, Damon Ogle wrote:
>Rogerio, Paul and others,
> This "Fogao de Lenha de Combustao Limpa" is a very interesting
> design. I having some success
>trying to decipher the text.
> Do you know if it was ever produced in large numbers? If so, how
> did people like it? Did they
>ever run any performance and/or emission tests on it?
> In September of '96 Kirk Smith sent a letter to the Stoves Group on
> "Downdraft stoves down through
>history". He makes reference to a 17th century stove which was capable of
>burning "cats-pifs" soaked
>fuel without emitting odor. This must have been similar to the "J" stoves.
> Thanks for all the good leads. Hope to see you in Seattle.
>
> Damon
>
>
>
>Rogerio Carneiro de Miranda wrote:
>
> > Paul and others: There is an article in portuguese at :
> >
> >
> http://www.repp.org/discussiongroups/resources/estufas/fogao%20a%20lenha/fogao_a_lenha_limpia.pdf
> >
> > about a J stove construction.
> >
> > rogerio
> >
> > At 07:21 a.m. 08/12/03 -1000, Michael J. Antal, Jr. wrote:
> > >The J stove was a joint project of Dr. Kirk Smith and me that supported an
> > >MSE student (Nazrul Islam as I recall). His thesis should be
> available from
> > >the UH library. Alternatively, Kirk may have a copy of it. As I
> recall the
> > >stove worked quite well, but there was no interest or support for
> subsequent
> > >research of this kind here.
> > >
> > >Regards, Michael Antal.
> > >
> > >-----Original Message-----
> > >From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
> > >Behalf Of Paul S. Anderson
> > >Sent: Thursday, December 04, 2003 1:15 PM
> > >To: STOVES@LISTSERV.REPP.ORG
> > >Subject: [STOVES] J stove
> > >
> > >
> > >At 05:38 PM 12/2/03 -0800, Damon Ogle wrote:
> > > >Dean, Tami and all,
> > > >(snip)
> > > > Does anyone out there know anything about the down-draft "J" stove
> > > >that was worked on at the University of Hawaii in the early '80s? I
> > > >think it might have been developed by "Islam" and/or "Antol". Haven't
> > > >been able to get any details. It was also supposed to be very clean
> > > >burning.
> > > > Damon
> > >
> > >Tom Reed has spoken to me a little about it. I think he saw it. J stove
> > >is somewhat related to the IDD (Inverted Down Draft) aka TLUD (top-lit up
> > >draft) that is the basis of Tom's WoodGas Campstove and my Juntos gasifier
> > >stove and John Davies' coal gasifier. In all cases the clean-ness of the
> > >burn is outstanding. After all, we are burning the gases separately from
> > >the creation of those gases by pyrolysis and some gasification of the
> char.
> > >
> > >So this is a note to prompt Tom to reply to Damon's question.
> > >
> > >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 redbeard at XMISSION.COM Wed Dec 10 12:52:52 2003
From: redbeard at XMISSION.COM (Dan Maker)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
Message-ID: <WED.10.DEC.2003.105252.0700.REDBEARD@XMISSION.COM>

Rogerio Carneiro de Miranda said:
>
> Paul and others: There is an article in portuguese at :
>
> http://www.repp.org/discussiongroups/resources/estufas/fogao%20a%20lenha/fogao_a_lenha_limpia.pdf
>
> about a J stove construction.

This same PDF seems to be avaliable in html here:
http://www.geocities.com/bemdosol/fogbest.html

And can be translated here:
http://world.altavista.com/

The translation isn't the best but for those of us that do not read portuguese,
it's a big help.

Dan
--
Jack of all trades, master of none.
Fiber Artist - Genealogist - Kilt Maker - Linux Geek - Piper - Woodworker
http://www.xmission.com/~redbeard

From psanders at ILSTU.EDU Wed Dec 10 13:10:35 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:44 2004
Subject: Uses of heat - into new boilers, etc.
In-Reply-To: <MABBJLGAAFJBOBCKKPMGKEMADCAA.Gavin@aa3genergi.force9.co.uk >
Message-ID: <WED.10.DEC.2003.121035.0600.PSANDERS@ILSTU.EDU>

Dear Gavin, (also known as GGG, which can become "G3" or "G-cubed")

I appreciate your comment copied below. Can you please tell me more about
"new pellet boilers." My interest is in CAPTURING THE HEAT IN USABLE
FORMS. I am NOT really interested in the "pellet-aspects" of the devices,
but in the boiler aspects.

Are the boilers for space heating or for what other uses?

Can these new boilers be realistically considered for applications in any
(or many) of the variety of Third World settings that we need to consider?

Assume the availability of sufficient heat that is at least as good as the
heat from the pellets.

At 05:12 PM 12/10/03 +0000, Gavin Gulliver-Goodall wrote:
>Having converted several "old coal fired boilers " to
>pellet burning and also replaces some old coal fired boilers with new pellet
>boilers I can say categorically that the payback for boiler replacement -in
>higher efficiency (lower fuel consumption) and lower maintenance is always
>shorter than the "remaining life of the coal boiler-these thing can only
>manage about 60% efficiency when they are clean and newly set up and degrade
>terribly/ also they need regular manual cleaning.

From psanders at ILSTU.EDU Wed Dec 10 13:43:40 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <001801c3bdbb$2a95cbe0$4b0e640a@VALUEDCB7D4C82>
Message-ID: <WED.10.DEC.2003.124340.0600.PSANDERS@ILSTU.EDU>

Dear John and all.

At 10:43 AM 12/8/03 -0800, john olsen wrote:
>I believe that the "holey" briquette ( in my biased way), is the answer to
>third World fuel, and the use of the "renewable" abundant Biomass, available
>from forests, agriculture, etc.
>Pellets are efficient, but, they need electricity to drive the screw, to
>load them into the "burn box" of the Stove.
>regards
>John Olsen
>www.heatloginc.com

Your comment could lead to some confusion of terminology, so I offer this
comment.

Compaction is not the same as densification.

Your densified "logs" (with holes or without) require substantial equipment
and energy for production. Your excellent product is akin to pellets, with
a major difference in sizes. I would not want to use the term "briquette"
to describe your product.

Richard Stanley's "briquettes" (with holes or without) are made from
"human-driven" simple presses. There is no densification (compression of
cell structures, etc.) of the biomass. And the resultant briquettes are
lighter (burn faster and require more space in transportation). But they
can be made locally. In Mozambique I and my associates are working on and
with presses for domestic use.

One of the other recent contributors to the discussion was mentioning local
production, but without distinguishing between low-pressure compression of
junk biomass versus high(er) pressure densification.

Personally, I believe that the low-pressure methods will become useful and
very localized, even becoming a community or even household process to
product usable fuel (not "great" fuel, but certainly worthy of being
used). Today, some affluent households have "trash compactors". (Trash
becomes more compact, but not more densified.) Interestingly, the
households of the impoverished societies could well have the briquette fuel
making presses and products before such methods become of interest to the
affluent societies.

Paul

From ronallarson at QWEST.NET Wed Dec 10 13:45:37 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:44 2004
Subject: NDG
Message-ID: <WED.10.DEC.2003.114537.0700.RONALLARSON@QWEST.NET>

Krishna:

Today you said, in response to my request for more information of a few
days ago:

<stet>
> I was on for a project for solar home ligthing in
> unelectrified villages of the state,where i found that
> almost all the villages is in dark and poverty.
> People living here not having money and all are
> uneducated.

RWL: I take the most important word here is "lighting" - but most of
your later discussion seems to be related to cooking. If you are really
looking at lighting - I suggest placing the large flame you previously
described inside a glass "tube" as used for kerosene lanterns. There have
been very few messages on this list about lighting applications with wood -
but before we go further down that path, you should clarify more on the
importance of lighting in your project.

> There i found that there is abundance of
> firewood(Juliflora), which they cut and use for the
> cooking purpose.the method adopted by them is open
> fire cooking which was very inefficient and produced a
> lot of smoke.

RWL: I am somewhat surprised that there is this abundance, but glad
there is. You might also want to look at ag residues which others from
India have been looking at for making charcoal. Those pyrolysis gases could
perhaps be very well used for lighting.

>
> Hence i thought of doing my project in developing
> the stove which gives out less smoke burns the fuel in
> an efficient manner.

RWL: Above, you talk about lighting. Could you clarify if you want to
do both cooking and lighting.

>
> The people donot have electricity so they cannot go
> for woodcutter. hence they have to use the wood as
> such choped from the forest hence i am trying to
> develop a natural draft gasifier based stove which
> burn fuel of greater size
> and not of briquetted or pelletted fuels.
>
RWL: This is a tougher job. I would say we have not been hearing of
any small gasifiers working with large wood.
My experience is that you will have considerable difficulty in doing what
you desire.

I will await further information before going further - but hope others
will jump in if they feel they have some ideas

> I am trying to develop one such design such that the
> maximum size up to which the the fuel can be burned in
> a efficient manner.

RWL: One solution, where there is plentiful wood, is to work with more
of a "plantation" approach, where the wood is gathered smaller - and at an
optimum size - which I am guessing is around 2-3 cm - for your (perceived)
application(s).

>
> I am staying in such a place where i could not get
> any guidance or i donot have proper instruments to
> monitor them.

RWL: Even in the US, there is a terrible shortage of good
instrumentation. But you can learn a lot if you concentrate on energy
efficiency mesauements - which only require a scale for measuring the
weights of water boiled away and the input biomass and produced
charcoal/ash.

Ron
>
>
> --- Ron Larson <ronallarson@QWEST.NET> wrote: >
> Krishna:
> >
> > I fear giving advice without knowing more of
> > your design. Please send
> > to either this list or, if photographic to
> > mailto:tmiles@trmiles.com
> >
> > My experience with what might be similar is that
> > the combustion chamber
> > (which also serves as a chimney) needs to be about
> > 150% as high as the
> > diameter. If too short, combustion will not be
> > complete (as you appear to
> > be observing) and the pyrolysis gases will leave too
> > much soot on surfaces
> > you (I hope) are trying to heat up. Also with too
> > short a
> > combustion/chimney region, you will not develop a
> > sufficiently good pressure
> > difference and not draw enough primary air through
> > your fuel supply (which I
> > hope you are lighting from the top).
> >
> > If the combustion area/chimney is too long, you
> > are probably losing more
> > useful energy than you need to. If you are not
> > planning something useful
> > for the pyrolysis gases, the chimney can be very
> > tall.
> >
> > Ron
> >
> > ----- Original Message -----
> > From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Monday, December 08, 2003 4:24 AM
> > Subject: NDG
> >
> >
> > > ---------------------- Information from the mail
> > header -----------------------
> > > Sender: The Stoves Discussion List
> > <STOVES@LISTSERV.REPP.ORG>
> > > Poster: =?iso-8859-1?q?krishna=20kumar?=
> > <krishnakumar_07@YAHOO.CO.UK>
> > > Subject: NDG
> > >
> >
> --------------------------------------------------------------------------
> > -----
> > >
> > > I have fabricated the natural draft gasifier
> > > with conrete and coated inside with clay.
> > >
> > > I have made a trail run of it and it worked
> > > satisfactorlly.The flame reached to a height of
> > > 1-1.25ft above the top of the stove.
> > >
> > > Then i tried with clossing the top of the stove
> > > with a lid and taking the gas seperately and
> > burning
> > > it through a burner. but i was unsuccesful in
> > burning
> > > the gas,
> > > The gas came out through the primairy air port
> > > and it did not gasify the wood inside.
> > >
> > > i would like to know about the chimney effect
> > > and draft to create the gas to come out of the
> > pipe.
> > >
> > >
> > >
> > > =====
> > > krish
> > >
> > >
> >
> ________________________________________________________________________
> > > BT Yahoo! Broadband - Save ?80 when you order
> > online today. Hurry! Offer
> > ends 21st December 2003. The way the internet was
> > meant to be.
> >
> http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> > >
>
> =====
> krish
>
> ________________________________________________________________________
> BT Yahoo! Broadband - Save ?80 when you order online today. Hurry! Offer
ends 21st December 2003. The way the internet was meant to be.
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
>

From hseaver at CYBERSHAMANIX.COM Wed Dec 10 08:54:04 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
In-Reply-To: <MABBJLGAAFJBOBCKKPMGKEMADCAA.Gavin@aa3genergi.force9.co.uk>
Message-ID: <WED.10.DEC.2003.075404.0600.HSEAVER@CYBERSHAMANIX.COM>

On Wed, Dec 10, 2003 at 05:12:02PM -0000, Gavin Gulliver-Goodall wrote:
> On Wed, Dec 10, 2003 at 09:24:10AM -0000, Gavin Gulliver-Goodall wrote:
> > Harman,
> > I see where you are coming from,
> > However making pellets manually , or on a small scale is not (here in
>
> I'm certainly not suggesting making them manually. Using a small
> hammermill
> type shredder and then feeding that into a screwpress extruder, or perhaps a
> hydraulic ram press run by a 10hp engine. A screwpress might even be usuable
> to
> squeeze oil from seed as well.
> [GGG] So where does the gas come from to drive the engine?

Veggie oil -- Gavin, are you actually reading what I'm writing? "squeeze oil
from seed" ????

> > Europe) economic due to the labour requirements.
>
> As compared to all the work preparing and using regular firewood?
> Cutting
> 15 cords (40 tons) of wood is no small job in itself, then of course you
> have to
> split it, then load it in the truck or wagon, haul it, unload and stack it.
> Then
> wait a year for it to dry, then carry it in the house to burn, armload after
> armload, all day, and even getting up in the middle of the night to
> replenish
> the fire.
> [GGG] Yep, but you need to do all this,

No, you definitely aren't reading my post. Going out on a tractor and mowing
a few acres with a forage chopper and wagon is no way equivalent to cutting,
splitting, hauling and stacking all that wood.

> plus dry the stuff down to below 15%
> moisture

And it takes a good year to dry the cordwood. With cattails I can dry them
much more easily, and use biomass to fuel the dryer as well.

> then run it through your hammermill and extruder.
> There are very efficient cordwood burners that will run your heating all day
> and all night on a single charge of fuel

Not in this climate, and certainly not for the house we presently live in.

> However they are not suitable for 3rd world at all.

No, but neither am I talking about 3rd world applications at this point.

> > I would dispute whether replacing the fire tending duties for the third
> > world housewife with pellet making: grinding and drying the biomass before
> > reforming into pellets would appeal. Maybe if the men were to do it....
>
> No, I'm not suggesting pellets for a third world application,
> especially
> for cooking.
>
> >
> > Also,
> > While wood makes excellent, clean burning pellets, However leaves and
> > grasses have a high ash content and low ash melting point so pellets from
> > these raw materials will not work as well as those you and I use in our
> > pellet stoves.
>
> I'll trade more ash removal for not having to kill trees. Or for not
> having
> to wait 20 years for the trees to grow big enough for firewood.
> [GGG] Efficient burners + less firewood. Increased fossil fuel consumption
> to produce manufactured fuel to burn in appliances with no greater
> efficiencies = wasteful? No?

What fossil fuels? If the tractor runs on veggie oil, the extruder runs on
veggie oil (or a gasifier fueled cogen unit running the electric motor) -- all
fuel produced right on the farm.

> >
> > Briquettes, which I also use for heating in a traditional log-stove are
> also
> > excellent but labour intensive to make.
> >
> Not with a good extruder. Briquettes would work if you had an old stoker
> fed
> coal-fired boiler, but those are hard to come by these days, whereas pellet
> boilers aren't, and with nicer controls and cleaner burning designs as well.
> [GGG] Yep, can burn briquettes in modern biomass stoker burners of say over
> 300kW rated output. Having converted several "old coal fired boilers " to
> pellet burning and also replaces some old coal fired boilers with new pellet
> boilers I can say categorically that the payback for boiler replacement -in
> higher efficiency (lower fuel consumption) and lower maintenance is always
> shorter than the "remaining life of the coal boiler-these thing can only
> manage about 60% efficiency when they are clean and newly set up and degrade
> terribly/ also they need regular manual cleaning.
> These things are already happening in Europe but arn't appropriate in 3rd
> worlds as yet due to capital ,and technical requirements of the equipment.
> Cheers

Do you have home sized stoker boilers that work with briquettes in
Europe? 300kw must be for large commercial buildings, schools, etc.

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

From hseaver at CYBERSHAMANIX.COM Wed Dec 10 09:02:23 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <4.3.1.2.20031210121726.01f42260@mail.ilstu.edu>
Message-ID: <WED.10.DEC.2003.080223.0600.HSEAVER@CYBERSHAMANIX.COM>

On Wed, Dec 10, 2003 at 12:43:40PM -0600, Paul S. Anderson wrote:
> Dear John and all.
>
> At 10:43 AM 12/8/03 -0800, john olsen wrote:
> >I believe that the "holey" briquette ( in my biased way), is the answer to
> >third World fuel, and the use of the "renewable" abundant Biomass,
> >available
> >from forests, agriculture, etc.
> >Pellets are efficient, but, they need electricity to drive the screw, to
> >load them into the "burn box" of the Stove.
> >regards
> >John Olsen
> >www.heatloginc.com
>
> Your comment could lead to some confusion of terminology, so I offer this
> comment.
>
> Compaction is not the same as densification.
>
> Your densified "logs" (with holes or without) require substantial equipment
> and energy for production. Your excellent product is akin to pellets, with
> a major difference in sizes. I would not want to use the term "briquette"
> to describe your product.

No, his extruder makes either logs or briquettes. But it's definitely a
commercial scaled unit.

I'm definitely only interested in densification. Manual compaction is useful
for the small amounts needed for cooking, but of no use for the amounts needed
for heating in really cold climates. Nor would they work well in stoker units,
since they'd easily crumble and jam the stoker.

>
> Personally, I believe that the low-pressure methods will become useful and
> very localized, even becoming a community or even household process to
> product usable fuel (not "great" fuel, but certainly worthy of being
> used). Today, some affluent households have "trash compactors". (Trash
> becomes more compact, but not more densified.) Interestingly, the
> households of the impoverished societies could well have the briquette fuel
> making presses and products before such methods become of interest to the
> affluent societies.

Just wait awhile. The US will be a 3rd world economy before you know it.

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

From Gavin at AA3GENERGI.FORCE9.CO.UK Wed Dec 10 14:15:12 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:44 2004
Subject: Uses of heat - into new boilers, etc.
In-Reply-To: <4.3.1.2.20031210120032.00e4df00@mail.ilstu.edu>
Message-ID: <WED.10.DEC.2003.191512.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Hi Paul,
Basically, see my website and the links from it.
The boilers I represent in the UK are gasifying boilers with very distinct
and separate pyrolysis and burn out zones. They achieve very high combustion
efficiency and effective heat exchange giving a net efficiency of up to 90%.

To achieve theses high performance figures they use forced or induced draft
conditions with electronically controlled air inlet valves. They also use
lambda (oxygen sensors) in the flue gas.
The key part is that they do not try to modulate, rather they burn fast and
clean until there is no fuel left. For space heating they use large heat
storage tanks to store very hot water until required at point of use.

These appliances could be appropriate to displace fossil fuel consumption in
third world cities but would not be appropriate for the rural homestead that
is the subject of much discussion on the Stoves list.

Modern pellet boilers are similar in combustion control but have a metered
feed of pellets so are able to modulate to match the boiler load.

All these products have been developed for the European "hydronic" hot water
heating systems and for heating water for pools etc. they are not available
as a stand alone combustor for other heating purposes. They are the result
of intensive R&D and as such have patents on critical components or
processes.
I guess the nearest Stoves-list equipment is Toms camp stove with its tiny
battery providing forced draft and hence much better fuel-air mix and flame
control.

Pellets have good heat output for 2 reasons: 1) they are very dry. 2) you
can make a small controllable (adjustable for size)fire with them so you
only burn the fuel you need to make the heat you want.
High density also means you can store lots of energy in a comparatively
small space- compared to say twigs.

I hope this helps

Kind regards
Gavin

(3G)

Dear Gavin, (also known as GGG, which can become "G3" or "G-cubed")

Are the boilers for space heating or for what other uses?

Can these new boilers be realistically considered for applications in any
(or many) of the variety of Third World settings that we need to consider?

Assume the availability of sufficient heat that is at least as good as the
heat from the pellets.

At 05:12 PM 12/10/03 +0000, Gavin Gulliver-Goodall wrote:
>Having converted several "old coal fired boilers " to
>pellet burning and also replaces some old coal fired boilers with new
pellet
>boilers I can say categorically that the payback for boiler replacement -in
>higher efficiency (lower fuel consumption) and lower maintenance is always
>shorter than the "remaining life of the coal boiler-these thing can only
>manage about 60% efficiency when they are clean and newly set up and
degrade
>terribly/ also they need regular manual cleaning.

From psanders at ILSTU.EDU Wed Dec 10 14:27:02 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
In-Reply-To: <5.0.0.25.2.20031208154217.031aa880@128.32.25.39>
Message-ID: <WED.10.DEC.2003.132702.0600.PSANDERS@ILSTU.EDU>

Kirk,

I am interested in those research results from Nazrul. Please tell me the
general topics and the format and quantity of items so we can discuss if I
want and how I could have access. Will you be going to the ETHOS (and
Partnership for Clean Air) meeting in Seattle on 31 Jan to 3 Feb 2004?

I went back to the Stoves archives and read (and copied) your September
1996 comments about the clean stove of the 1600's. You wrote that you have
unearthed the source document by Justell. I would be very interested in
obtaining a copy of that article.

One other item that you have seen is a gasifier in China. A picture was
posted, but did not show the bottom of the stove and I could not tell how
it worked. Any info on that would also be appreciated.

Several of us who are actively working on the current generation of very
small gasfiers are making significant progress. But to be successful
requires ALL of the 4 essential issues (fuels, combustion, heat use, and
human factors) to be in place, so there are still some delays.

Paul

At 03:43 PM 12/8/03 -0800, Kirk R. Smith wrote:
>I do still have some research results from Nazrul's work, if anyone is
>interested/lk
>
>
>
>At 07:21 AM 12/8/2003 -1000, Michael J. Antal, Jr. wrote:
>
>>The J stove was a joint project of Dr. Kirk Smith and me that supported an
>>MSE student (Nazrul Islam as I recall). His thesis should be available from
>>the UH library. Alternatively, Kirk may have a copy of it. As I recall the
>>stove worked quite well, but there was no interest or support for subsequent
>>research of this kind here.
>>
>>Regards, Michael Antal.
>>
>>-----Original Message-----
>>From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
>>Behalf Of Paul S. Anderson
>>Sent: Thursday, December 04, 2003 1:15 PM
>>To: STOVES@LISTSERV.REPP.ORG
>>Subject: [STOVES] J stove
>>
>>
>>At 05:38 PM 12/2/03 -0800, Damon Ogle wrote:
>> >Dean, Tami and all,
>> >(snip)
>> > Does anyone out there know anything about the down-draft "J" stove
>> >that was worked on at the University of Hawaii in the early '80s? I
>> >think it might have been developed by "Islam" and/or "Antol". Haven't
>> >been able to get any details. It was also supposed to be very clean
>> >burning.
>> > Damon
>>
>>Tom Reed has spoken to me a little about it. I think he saw it. J stove
>>is somewhat related to the IDD (Inverted Down Draft) aka TLUD (top-lit up
>>draft) that is the basis of Tom's WoodGas Campstove and my Juntos gasifier
>>stove and John Davies' coal gasifier. In all cases the clean-ness of the
>>burn is outstanding. After all, we are burning the gases separately from
>>the creation of those gases by pyrolysis and some gasification of the char.
>>
>>So this is a note to prompt Tom to reply to Damon's question.
>>
>>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 Gavin at AA3GENERGI.FORCE9.CO.UK Wed Dec 10 14:30:46 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
In-Reply-To: <20031210135404.GA9089@cybershamanix.com>
Message-ID: <WED.10.DEC.2003.193046.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Harmon,

<snip> Veggie oil -- Gavin, are you actually reading what I'm writing?
"squeeze oil
from seed" ????
[GGG] Point taken

<snip>
[GGG]
No, you definitely aren't reading my post. Going out on a tractor and
mowing
a few acres with a forage chopper and wagon is no way equivalent to cutting,
splitting, hauling and stacking all that wood.

[GGG] Sorry I was on the third world mindset at that point.
However forage harvested "stuff" is actually difficult to dry and mill on a
small scale- I have been physically and commercially involved in a number of
forage harvester/biomass trials and have developed a dryer for chipped
biomass. But it isn't economic at a farm scale- much too labour and capital
intensive. Unless you are a determined "greenie" or completely out of work
you are better off economically in the UK earning mioney and buying
aprocessed fuel - Pellets if you are into biomass.

> plus dry the stuff down to below 15%
> moisture

And it takes a good year to dry the cordwood. With cattails I can dry
them
much more easily, and use biomass to fuel the dryer as well.

> then run it through your hammermill and extruder.
> There are very efficient cordwood burners that will run your heating all
day
> and all night on a single charge of fuel

Not in this climate, and certainly not for the house we presently live
in.
[GGG] We can do a single burn log boiler to run a "hydronic" (water
/radiator or underfloor ) heating ssystem up to 150 kW nominal (1/2 million
btus)output that s over 600 kWh of heat per day youmust sure have a big
leaky house if that's not enough! Ever thought of investing in
draughtproofing and insulation? Sheeps wooll is good and organic insulating
material.

> However they are not suitable for 3rd world at all.

No, but neither am I talking about 3rd world applications at this point.
[GGG] Now I know...

<snip> Cheers

Do you have home sized stoker boilers that work with briquettes in
Europe? 300kw must be for large commercial buildings, schools, etc.
[GGG] no small stoker boilers (around 40kW ) need nice dry small , even
chips. Pellet burners start at 2-5kW as you know.
Bigger chip boilers with oversize feed augers can take briquettes these are
fairly common in Europe- some commercial organisations will buy fuel on the
spot market- briquettes or chips according to price and availability. Boiler
makers recommend you stick to one class of fuel for best reliability.

[GGG] cheers
Gavin

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

From larch at KOOTENAY.COM Wed Dec 10 15:17:09 2003
From: larch at KOOTENAY.COM (David Strom)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
Message-ID: <WED.10.DEC.2003.131709.0700.>

I'm from the affluent west, working like I'm in the third world, and
would be happy to be practising either technology on the piles of fine
shavings I make in my small flooring operation. But it's just a small
family business, and I can't go spending US$20,000 to make my waste
smaller.

Paul, can low-pressure briquettes be burned in residential woodstoves?

David

>
> Richard Stanley's "briquettes" (with holes or without) are made from
> "human-driven" simple presses. There is no densification (compression of
> cell structures, etc.) of the biomass. And the resultant briquettes are
> lighter (burn faster and require more space in transportation). But they
> can be made locally. In Mozambique I and my associates are working on and
> with presses for domestic use.
>
> One of the other recent contributors to the discussion was mentioning
> local
> production, but without distinguishing between low-pressure compression of
> junk biomass versus high(er) pressure densification.
>
> Personally, I believe that the low-pressure methods will become useful and
> very localized, even becoming a community or even household process to
> product usable fuel (not "great" fuel, but certainly worthy of being
> used). Today, some affluent households have "trash compactors". (Trash
> becomes more compact, but not more densified.) Interestingly, the
> households of the impoverished societies could well have the briquette
> fuel
> making presses and products before such methods become of interest to the
> affluent societies.
>
> 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 Wed Dec 10 16:15:59 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <3FD77F45.3040002@kootenay.com>
Message-ID: <WED.10.DEC.2003.151559.0600.PSANDERS@ILSTU.EDU>

David,

I am quite sure you can burn low-pressure briquettes in a residential
woodstove. In Mozambique we have burned them very successfully in some
NON-gasifier stoves in a regular combustion mode.

You will want to decide on a certain range of briquette sizes that are
acceptable to your stove (size of firebox, size of door, way to put in the
briquettes (by hand or by small shovel), and the type of heat intensity
that you want -- fast but frequent refueling vs. slow and longer lasting
combustion.)

The expert on briquettes in Richard Stanley. I am just a disciple.

You mention "fine shavings" and I imagine some curly wood shaving. Sawdust
is a different material. BOTH can be incorporated into briquettes.

A "binder" is needed to hold the materials together. A good one (and easy
for many of us) is newspaper. Soak it, and mash it back to a slurry of
paper pulp that is very fluid. Then mix pulp with sawdust (plus some
shavings?). About 30 % pulp should be sufficient, but you can go to 100%
pulp. (We have mixed in charcoal fines to make a great fuel.) Grab a
handful of the "mash" and squeeze. If it sticks together and shows the
configuration from inside your fist, then the mixture will probably be good
for making briquettes.

To form briquettes, there are several types of acceptable presses. I hope
to report in the near future about a simple one being tested in Mozambique
currently. Squeeze out the water and let the briquette air dry for a few days.

Be sure to visit the www.legacyfoundation.org web site for info from
Richard.

David, where are you located?

Paul

At 01:17 PM 12/10/03 -0700, David Strom wrote:
>I'm from the affluent west, working like I'm in the third world, and
>would be happy to be practising either technology on the piles of fine
>shavings I make in my small flooring operation. But it's just a small
>family business, and I can't go spending US$20,000 to make my waste
>smaller.
>
>Paul, can low-pressure briquettes be burned in residential woodstoves?
>
>David
>
>
>>
>>Richard Stanley's "briquettes" (with holes or without) are made from
>>"human-driven" simple presses. There is no densification (compression of
>>cell structures, etc.) of the biomass. And the resultant briquettes are
>>lighter (burn faster and require more space in transportation). But they
>>can be made locally. In Mozambique I and my associates are working on and
>>with presses for domestic use.
>>
>>One of the other recent contributors to the discussion was mentioning
>>local
>>production, but without distinguishing between low-pressure compression of
>>junk biomass versus high(er) pressure densification.
>>
>>Personally, I believe that the low-pressure methods will become useful and
>>very localized, even becoming a community or even household process to
>>product usable fuel (not "great" fuel, but certainly worthy of being
>>used). Today, some affluent households have "trash compactors". (Trash
>>becomes more compact, but not more densified.) Interestingly, the
>>households of the impoverished societies could well have the briquette
>>fuel
>>making presses and products before such methods become of interest to the
>>affluent societies.
>>
>>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 Wed Dec 10 19:10:03 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
Message-ID: <THU.11.DEC.2003.054003.0530.ADKARVE@PN2.VSNL.NET.IN>

I followed with interest the messages about the J stove but I could
not get any useful information. Is it shaped like the letter J? I can
imagine that if one filled wood pellets into the shorter arm of the J
and ignited them from above, the draft produced by the longer arm would
pull the smoke up the longer arm. This smoke could then be ignited as it
emerged from the longer arm. However this is only my imagination working
and the real thing could be quite different. Would anybody please
explain, in plain language, how it worked?
Dr.A.D.Karve, President,
Appropriate Rural Technology Institute
Pune, India.

Michael J. Antal, Jr. wrote:

>The J stove was a joint project of Dr. Kirk Smith and me that supported an
>MSE student (Nazrul Islam as I recall). His thesis should be available from
>the UH library. Alternatively, Kirk may have a copy of it. As I recall the
>stove worked quite well, but there was no interest or support for subsequent
>research of this kind here.
>
>Regards, Michael Antal.
>
>

From english at KINGSTON.NET Wed Dec 10 22:04:28 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:44 2004
Subject: Chimneys
In-Reply-To: <20031209170522.7610B7B6@telchar.epud.net>
Message-ID: <WED.10.DEC.2003.220428.0500.>

Dean,
Liz was not talking about imaginary chimneys. Granted, there are
significant differences between the circumstances surrounding her
comment and the Central American experience.

So if I can infer that you feel that stoves with chimneys in Central
America have been a success, the question remains, what factors are
responsible for the failure of some, and the success of others? What
does the literature say?

Kevin Chisholm implied that chimenys were a mind boggleingly simple
solution to indoor air pollution. Is it?

Alex

> Dear Stovers,

> Just an obvious reminder that chimneys are used in the 5,000 HELPS and
> Trees, Water, & People griddle stoves that are being made and used in
> Central America. While Liz Bates works in areas that have not yet used
> chimneys, slightly richer areas have known and used chimneys for decades.
>
>
>
> All Best,
>
>
>
> Dean
>

From hseaver at CYBERSHAMANIX.COM Wed Dec 10 18:06:07 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: third world energy
In-Reply-To: <4.3.1.2.20031210145849.01fa8520@mail.ilstu.edu>
Message-ID: <WED.10.DEC.2003.170607.0600.HSEAVER@CYBERSHAMANIX.COM>

On Wed, Dec 10, 2003 at 03:15:59PM -0600, Paul S. Anderson wrote:
> David,
>
> I am quite sure you can burn low-pressure briquettes in a residential
> woodstove. In Mozambique we have burned them very successfully in some
> NON-gasifier stoves in a regular combustion mode.
>
> You will want to decide on a certain range of briquette sizes that are
> acceptable to your stove (size of firebox, size of door, way to put in the
> briquettes (by hand or by small shovel), and the type of heat intensity
> that you want -- fast but frequent refueling vs. slow and longer lasting
> combustion.)

If you just want to use heatlogs in a conventional woodstove or boiler (or
even a nice gasifying one like a Kuenzel or Tarm), Paul's technique here could
be easily adapted to a slightly modified hydraulic woodsplitter, which rammed
out heatlogs thru a die. You could even make it fairly automatic, feeding the
mix from a hopper.
I've thought a lot about doing this, and using them in a masonry stove that
only needs feeding once or twice a day, and is probably a route I'd follow
especially if we end up building a new house.

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

From hseaver at CYBERSHAMANIX.COM Wed Dec 10 18:32:36 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:44 2004
Subject: Pellets (was third world energy)
In-Reply-To: <MABBJLGAAFJBOBCKKPMGIEMEDCAA.Gavin@aa3genergi.force9.co.uk>
Message-ID: <WED.10.DEC.2003.173236.0600.HSEAVER@CYBERSHAMANIX.COM>

On Wed, Dec 10, 2003 at 07:30:46PM -0000, Gavin Gulliver-Goodall wrote:
> [GGG] Sorry I was on the third world mindset at that point.
> However forage harvested "stuff" is actually difficult to dry and mill on a
> small scale- I have been physically and commercially involved in a number of
> forage harvester/biomass trials and have developed a dryer for chipped
> biomass. But it isn't economic at a farm scale- much too labour and capital
> intensive. Unless you are a determined "greenie" or completely out of work
> you are better off economically in the UK earning mioney and buying
> aprocessed fuel - Pellets if you are into biomass.
>

Yes, well, both of the above, plus I'd very much rather spend my time out of
doors doing something for myself rather than go spend time away from home in
some drudgery. And having to pay taxes on it besides.

(snip)

> [GGG] We can do a single burn log boiler to run a "hydronic" (water
> /radiator or underfloor ) heating ssystem up to 150 kW nominal (1/2 million
> btus)output that s over 600 kWh of heat per day youmust sure have a big
> leaky house if that's not enough!

Well, it would be nice if Kuenzel would start importing over here. Could go
Tarm, I guess, but they don't seem as efficient.

> Ever thought of investing in
> draughtproofing and insulation? Sheeps wooll is good and organic insulating
> material.

We've got a fairly large, all masonry house at present, no way to put
insulation in the walls, they're just brick with hollow tile inside then lath
and plaster. No studs in the outside walls at all. Once they get cold they stay
cold for a long time. Once Winter really sets in, the walls feel quite cold to
the touch most of the time. Hydronic heat. But we'll soon move and rent this to
students.
--
Harmon Seaver
CyberShamanix
http://www.cybershamanix.com

From pverhaart at OPTUSNET.COM.AU Thu Dec 11 06:03:30 2003
From: pverhaart at OPTUSNET.COM.AU (Peter Verhaart)
Date: Tue Aug 10 18:30:44 2004
Subject: J stove
In-Reply-To: <3FD7B5DB.8020604@pn2.vsnl.net.in>
Message-ID: <THU.11.DEC.2003.210330.1000.PVERHAART@OPTUSNET.COM.AU>

At 10:10 11/12/2003, you wrote:
> I followed with interest the messages about the J stove but I could
>not get any useful information. Is it shaped like the letter J? I can
>imagine that if one filled wood pellets into the shorter arm of the J
>and ignited them from above, the draft produced by the longer arm would
>pull the smoke up the longer arm. This smoke could then be ignited as it
>emerged from the longer arm. However this is only my imagination working
>and the real thing could be quite different. Would anybody please
>explain, in plain language, how it worked?
>Dr.A.D.Karve, President,
>Appropriate Rural Technology Institute
>Pune, India.

Dear Dr. Karve,

I had exactly the same idea, the smoke could be ignited.
Reality was different, when it is operated with a thin fuelbed, the draft
pulls air through the combustion zone and reacts with the volatiles
downstream from the grate. The result is a remarkable clean combustion.
What emerges from the chimney is clear and has no smell, analysis of the
flue gases showed an extremely low CO/CO2 ratio, below that considered
admisible for open kerosene burning appliances.
We think it works because the charcoal on the grate is burning vigorously,
above the charcoal fresh wood is being charred and the volatiles are drawn
through the burning charcoal. This leaves the volatiles little time to
combine into nasties, on the contrary, larger molecules are probably broken
down. These mixed with excess air are intimately mixed because of the
turbulence. The result is demonstrable clean combustion.
That is our explanation, we have no proof, were unable to analyse gas
anywhere in the reaction zone, so stand to be corrected as to the actual
reactions taking place.
We worked mostly with a chimney of 1 m which induced quite a good draft. On
a grate of 12 * 12 cm we could obtain a heat output rate of over 10 kW if
memory serves.
My downdraft barbecue also has a 12 * 12 cm grate and a 1 m chimney.
Probably because of heat losses to the griddle and flow resistance, I have
only been able to get 8.8 kW.
Here is a stove with a chimney that can be used indoors. For tests I have
lit it outside and as soon as the fire was established wheeled it indoors
to conduct water boiling tests.
I hope this has clarified things to some extent.

With kind regards,

Peter Verhaart

From dstill at EPUD.NET Thu Dec 11 11:45:49 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:44 2004
Subject: Chimneys
In-Reply-To: <3FD7986C.24355.FDD156@localhost>
Message-ID: <THU.11.DEC.2003.084549.0800.DSTILL@EPUD.NET>

Dear Alex,

I talked to Larry Winiarski last night about chimneys. He says that thin
sheet metal galvanized chimneys only last about a year or less in Central
America. A better answer is ceramic. Ceramic liners are used here in the
U.S. in fireplaces. Or maybe there are paints that protect the thin metal.

Light weight ceramic chimneys would not be too hard to make and Larry thinks
that we should make them as well when, with Trees, Water, & People, we start
a commercial stove project in Honduras this spring. We aim to sell a very
inexpensive insulative ceramic stove made in parts by a brick maker. We'll
try to make prototype insulative ceramic chimneys as well. We'll also follow
up leads on inexpensive protective paints like what Rogerio is using.

Folks need to clean the chimneys and replace them which is a maintenance
issue. But in my opinion the training to do maintenance is well repaid with
a safe interior environment. A chimney attached to a tight stove takes
unsafe emissions out of the room. In tests at Aprovecho we saw only 3 ppm of
CO in a very small chamber when running both the HELPS and TWP Justa stoves.
The unhealthy stuff polluted outside air, not the test kitchen.

We received a $25,000 grant to buy really good emission testing equipment. I
hope that when we have the Enerac 3000E and nephelometer hooked up to the
new hood here at Aprovecho that how to make a clean burning stove will
become more obvious. There are lots of hints in the literature. So far as I
know no one has tried all the hints. But that's what Damon Ogle and I will
be doing this winter. We'll also test the gasification approaches.

But no matter how clean we can get a wood burning stove to run operator
error easily creates unhealthy conditions. I'd sure like my mother to have a
chimney in her kitchen. Wood burning cooking and heating stoves used in the
U.S. have chimneys and with a small amount of maintenance they protect us
from harm.

All Best,

Dean

From crispin at NEWDAWN.SZ Thu Dec 11 14:26:16 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:44 2004
Subject: Partnership for Clean Indoor Air Pilot Projects
Message-ID: <THU.11.DEC.2003.212616.0200.CRISPIN@NEWDAWN.SZ>

Dear Stovers

I am pleased to announce that the Renewable Energy Association of Swaziland,
an NGO sheltered until this year at the offices of New Dawn Engineering and
boosted by years of continued support from the Energy Section of the
Swaziland Ministry of Natural Resources and the EU has made it through round
one with the United States Environmental Protection Agency's (USEPA)
Partnership for Clean Indoor Air Pilot Projects Grant Program for the coming
year. This is a global competition.

REASWA was joined by the very capable Hannah Routh (Skillshare) from the UK
this year. The team she put together for the project includes, in no
particular order:

Ms Feziwe Matsebula
Ms Hannah Routh
Dr Irma Allen
Mr Jonathan Curren
Dr Mduduzi Mathunjwa
Ms Phindi Zwane
and yours truly

The proposals were read and evaluated by a six-member panel of experts from
the USEPA, the United States Agency for International Development, the World
Health Organization, the Italian Ministry of Environment, and the Shell
Foundation.

REASWA's proposal includes establishing a baseline and evaluating the
improvements made to indoor air quality through the introduction of improved
cooking devices in rural Swaziland (hoods, chimneys, stoves, ventilation
etc). A recent survey in homesteads by REASWA showed that some households
in Swaziland have CO and PIC's in the kitchen 5 to 40 times the WHO limits.

I think it is great that the 'big guys' can listen to us 'little guys' on
such important matters!

Go team!

Best regards
Crispin

From psanders at ILSTU.EDU Thu Dec 11 18:13:51 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: third world energy
In-Reply-To: <20031210230607.GA9601@cybershamanix.com>
Message-ID: <THU.11.DEC.2003.171351.0600.PSANDERS@ILSTU.EDU>

Harmon,

Thanks for the tip. As far as I know, you are the first person to suggest
using a hydraulic woodspliter. Makes a lot of sense.

Anyone on the list serve have much experience with such woodspliters and
would care to "tinker" with some designs intended EITHER for the developed
societies OR for the developing societies (probably very different end
product devices for the needs of those societies). Richard Stanley and I
(and others) can assist with info on the materials to press through the device.

Crispin's briquette maker is hydraulic (and makes fine briquettes) but not
with the "continuous feed" and extrusion aspects nor with a (I believe)
"commodity" piece of equipment such as a wood splitter.

Paul

At 05:06 PM 12/10/03 -0600, Harmon Seaver wrote:
>On Wed, Dec 10, 2003 at 03:15:59PM -0600, Paul S. Anderson wrote:
> > David,
> >
> > I am quite sure you can burn low-pressure briquettes in a residential
> > woodstove. In Mozambique we have burned them very successfully in some
> > NON-gasifier stoves in a regular combustion mode.
> >
> > You will want to decide on a certain range of briquette sizes that are
> > acceptable to your stove (size of firebox, size of door, way to put in the
> > briquettes (by hand or by small shovel), and the type of heat intensity
> > that you want -- fast but frequent refueling vs. slow and longer lasting
> > combustion.)
>
> If you just want to use heatlogs in a conventional woodstove or
> boiler (or
>even a nice gasifying one like a Kuenzel or Tarm), Paul's technique here could
>be easily adapted to a slightly modified hydraulic woodsplitter, which rammed
>out heatlogs thru a die. You could even make it fairly automatic, feeding the
>mix from a hopper.
> I've thought a lot about doing this, and using them in a masonry
> stove that
>only needs feeding once or twice a day, and is probably a route I'd follow
>especially if we end up building a new house.
>
>
>
>Harmon Seaver
>CyberShamanix
>http://www.cybershamanix.com

From psanders at ILSTU.EDU Thu Dec 11 18:37:15 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: Partnership for Clean Indoor Air Pilot Projects
In-Reply-To: <008c01c3c025$c585a960$7adc55d4@home>
Message-ID: <THU.11.DEC.2003.173715.0600.PSANDERS@ILSTU.EDU>

To Crispin and the Swaziland team,

CONGRATULATIONS !!!!!!!!!!!!

Best wishes on the next round of the selection process (and eventually with
the grant, we hope !!!!!)

Please keep us posted via the Stoves List Serve. Perhaps some of us
Stovers can be of assistance once we know more about the proposal and
activities.

Again, CONGRATULATIONS !!!!!!

Paul (and also certainly for all of the Stovers)

At 09:26 PM 12/11/03 +0200, Crispin Pemberton-Pigott wrote:
>Dear Stovers
>
>I am pleased to announce that the Renewable Energy Association of Swaziland,
>an NGO sheltered until this year at the offices of New Dawn Engineering and
>boosted by years of continued support from the Energy Section of the
>Swaziland Ministry of Natural Resources and the EU has made it through round
>one with the United States Environmental Protection Agency's (USEPA)
>Partnership for Clean Indoor Air Pilot Projects Grant Program for the coming
>year. This is a global competition.
>
>
>REASWA was joined by the very capable Hannah Routh (Skillshare) from the UK
>this year. The team she put together for the project includes, in no
>particular order:
>
>Ms Feziwe Matsebula
>Ms Hannah Routh
>Dr Irma Allen
>Mr Jonathan Curren
>Dr Mduduzi Mathunjwa
>Ms Phindi Zwane
>and yours truly
>
>The proposals were read and evaluated by a six-member panel of experts from
>the USEPA, the United States Agency for International Development, the World
>Health Organization, the Italian Ministry of Environment, and the Shell
>Foundation.
>
>REASWA's proposal includes establishing a baseline and evaluating the
>improvements made to indoor air quality through the introduction of improved
>cooking devices in rural Swaziland (hoods, chimneys, stoves, ventilation
>etc). A recent survey in homesteads by REASWA showed that some households
>in Swaziland have CO and PIC's in the kitchen 5 to 40 times the WHO limits.
>
>I think it is great that the 'big guys' can listen to us 'little guys' on
>such important matters!
>
>Go team!
>
>Best regards
>Crispin

From andrew.heggie at DTN.NTL.COM Thu Dec 11 19:22:07 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:45 2004
Subject: third world energy
In-Reply-To: <4.3.1.2.20031211170522.01f52100@mail.ilstu.edu>
Message-ID: <FRI.12.DEC.2003.002207.0000.>

On Thu, 11 Dec 2003 17:13:51 -0600, Paul S. Anderson wrote:

>Harmon,
>
>Thanks for the tip. As far as I know, you are the first person to suggest
>using a hydraulic woodspliter.

I know of an attempt at this.

>Makes a lot of sense.

Not really, aside form hydraulic power transmission not being
particularly efficient you need to consider what happens when you
attempt to compress the fibre/sawdust in the breach. Try just pushing
the material through a tube, unless it is well lubricated to the
consistency of raw pastry the friction of the tube sides and the
bridging tendency of the feedstock "arch" in the tube and this arch
effectively transmits all the applied force into the wall of the tube.

Gav will verify that the way round this is to have a short die and
feed in small wads of material. There is probably a mathematical
equation that dictates the depth of the wad versus the diameters. I'll
venture the guess that friction losses become enormous once the wad
depth approaches the diameter of the tube.

With the screw press the shearing action of the screw overcomes this.
With ram presses the momentum in the press adds force, pinch roller
presses work on very many thin wads per revolution. Also their
relative high power input is beneficial in creating heat to aid
plasticising the lignin with wood pellets, animal feed pellets seem to
rely on natural oils to act as binders and so need not such high
powers.

I have some charcoal briquettes bought in France that have all the
appearance of having been forged and wonder what this approach has to
offer. The die is obviously tapered to allow the briquette to be
ejected.

Remember in using motive power to compact (or densify but densify is
only necessary if you need specific performance from your
pellet/briquette) you are using a high exergy energy source to produce
a lower one. So even on the large scale where the energy to produce
pellets is in the order of 2.5% of their fuel value, it has probably
cost 7.5% of their calorific value in a fossil fuel (biodiesels
excepted).
>
>Anyone on the list serve have much experience with such woodspliters and
>would care to "tinker" with some designs intended EITHER for the developed
>societies OR for the developing societies (probably very different end
>product devices for the needs of those societies). Richard Stanley and I
>(and others) can assist with info on the materials to press through the device.
>
>
I have sketched some designs for an alternative technology pelletting
device ( intended for use in small joinery workshops for their waste)
which I will discuss privately, with the understanding that I expect
to be becoming free from commercial obligations within a few months
and then if it works......

AJH

From andrew.heggie at DTN.NTL.COM Thu Dec 11 19:22:12 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:45 2004
Subject: third world energy
In-Reply-To: <4.3.1.2.20031210121726.01f42260@mail.ilstu.edu>
Message-ID: <FRI.12.DEC.2003.002212.0000.>

On Wed, 10 Dec 2003 12:43:40 -0600, Paul S. Anderson wrote:

>"human-driven" simple presses. There is no densification (compression of
>cell structures, etc.) of the biomass.

Seems fair enough, compaction is the attempt to remove interstitial
spaces between particle, densification is the attempt to remove voids
in the cell structure by modifying the cell walls permanently. We
could maybe get a handle on power requirement for the actual
densification, as opposed to the power lost in friction as particles
moving over each other with the knowledge that *dense* biomass is 1.5
time heavier than water and oven dry wood is in the order of 0.5 the
density of water.

> And the resultant briquettes are
>lighter (burn faster and require more space in transportation). But they
>can be made locally.

And local consumption of local produce is a good thing, but variety is
the spice of life.
>
>Personally, I believe that the low-pressure methods will become useful

I do also, indeed I think this can be extended into the harvesting
arena, we need modest compaction to make the raw agri waste amenable
to further downstream processing, without necessarily reaching the
250kg/m3 densities required for commercial road transport.

AJH

From andrew.heggie at DTN.NTL.COM Thu Dec 11 19:27:54 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:45 2004
Subject: Partnership for Clean Indoor Air Pilot Projects
In-Reply-To: <008c01c3c025$c585a960$7adc55d4@home>
Message-ID: <FRI.12.DEC.2003.002754.0000.>

On Thu, 11 Dec 2003 21:26:16 +0200, Crispin Pemberton-Pigott wrote:

Congratulations, well done.

AJH

From mantal at HAWAII.EDU Thu Dec 11 19:16:00 2003
From: mantal at HAWAII.EDU (Michael J. Antal, Jr.)
Date: Tue Aug 10 18:30:45 2004
Subject: J stove
In-Reply-To: <6.0.1.1.2.20031211204556.039eaeb0@mail.optusnet.com.au>
Message-ID: <THU.11.DEC.2003.141600.1000.MANTAL@HAWAII.EDU>

My initial idea that got Nazrul started was that the bed would be ignited on
the bottom and serve as a downdraft gasifier (as Peter describes below).
The long end of the J would provide the needed draft, as well as room for a
heat exchanger that would deliver hot air to a room needing heat. My
initial idea was not aimed at cooking; rather the heating of homes. Also, I
intended to make the short end of the J (or a portion thereof) transparent
to add some visual excitement to the apparatus. But here in Hawaii no one
needs heat for their homes, so the initial idea lacked staying power.
Nevertheless, Nazrul showed that it worked well. Kirk and Nazrul may have
expanded the research to include other approaches that I have forgotten.
Regards, Michael.

Michael J. Antal, Jr.
Coral Industries Distinguished Professor of Renewable Energy Resources
Hawaii Natural Energy Institute
School of Ocean and Earth Science and Technology (SOEST)
1680 East-West Rd., POST 109
University of Hawaii at Manoa
Honolulu, HI 96822

Phone: 808/956-7267
Fax: 808/956-2336
http://www.hnei.hawaii.edu

-----Original Message-----
From: The Stoves Discussion List [mailto:STOVES@LISTSERV.REPP.ORG]On
Behalf Of Peter Verhaart
Sent: Thursday, December 11, 2003 1:04 AM
To: STOVES@LISTSERV.REPP.ORG
Subject: Re: [STOVES] J stove

Dear Dr. Karve,

With kind regards,

Peter Verhaart

From adkarve at PN2.VSNL.NET.IN Thu Dec 11 19:37:05 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:45 2004
Subject: NDG
Message-ID: <FRI.12.DEC.2003.060705.0530.ADKARVE@PN2.VSNL.NET.IN>

Dear Mr. Krishna Kumar,
there can be number of ready made soultions for solving the problem of
smoke filled kitchens in rural India. I enclose a list of rural
household technologies developed by us. You may find either the one or
the other useful in your case.
.
Rural energy from agrowaste: The fraction of the total crop biomass,
that is economically not useful, is called agrowaste. Its proportion can
vary from 20 to 70% of the total biomass.It is estimated that
agriculture in India generates annually about 500 million tonnes of
agrowaste. ARTI has developed a number of technologies to utilise the
agrowaste as domestic fuel. They are as follows:
Improved cookstoves: Woody agrowaste such as stalks of cotton and
pegionpea are burnt directly in a woodburning cookstove. A traditional
rural cookstove, made of unfired clay, has a very low efficiency, it
produces a lot of smoke and soot and it has a life of just a couple of
years. The cookstoves developed by ARTI not only have a high efficiency
of about 25%, but they also reduce the indoor air pollution. Being made
of cement concrete, they last for at least 5 years.
Fuel briquettes from light Agrowaste: Because most agricultural species
are herbaceous, agricultural waste is generally in the form of leaves
and thin stems. The act of threshing also results in generating powdery
agrowaste. Agrowaste in these forms cannot be used as fuel in a wood
burning stove, but it can be converted into charcoal briquettes by using
a charring kiln based on the oven and retort system. The charcoal
produced in this kiln can be easily powdered, and mixed with a suitable
binder, it can be extruded into char briquettes.
Sarai stove-and-cooker system: This is an assembly, which is capable of
cooking a meal for a family of five using just 100 g of char briquettes.
A housewife, using a traditional wood-burning cookstove, would have to
use about 3 kg wood for cooking the same amount of food.
User friendly biogas technology: The traditional biogas technology,
based on cattle dung, is useful only to families having at least 6 to 8
heads of cattle. Because of the low rate of gas generation per unit mass
of dung, and long retention time of about 40 days, the smallest domestic
digester has a volume of about 2000 litres. Feeding daily about 40 kg
cattle dung into the digester and disposing of daily about 80 kg of
effluent slurry is a great bother. The new biogas plant developed by
ARTI is much more user friendly. Having a capacity of 400 litres, it
uses daily just 2 kg of starchy agrowaste (e.g. rhizomes of banana,
canna, nutgrass), non-edible seeds (e.g. Leucaena, Sesbania, tamarind,
mango kernels, spoilt grain), oilcake of nonedible oilseeds (Pongamia,
Madhuka, castor), or leftover food. Its reaction time is just a few
hours. It produces just a couple of litres of watery effluent that is
easy to dispose of.
Yours sincerely
Dr.A.D.Karve, President,
Appropriate Rural Technology Institute
Pune, India.

krishna kumar wrote:

> I am final year stdent doing my Post graduation
>in (Energy Engineering) in Anna University.
> I completed my graduation in Mechanical Engineering
>Madras University.I am staying in the city of Madras
> in India.
>
> I was on for a project for solar home ligthing in
>unelectrified villages of the state,where i found that
>almost all the villages is in dark and poverty.
>People living here not having money and all are
>uneducated.
>
> There i found that there is abundance of
>firewood(Juliflora), which they cut and use for the
>cooking purpose.the method adopted by them is open
>fire cooking which was very inefficient and produced a
>lot of smoke.
>
> Hence i thought of doing my project in developing
>the stove which gives out less smoke burns the fuel in
>an efficient manner.
>
> The people donot have electricity so they cannot go
>for woodcutter. hence they have to use the wood as
>such choped fro
>m the forest hence i am trying to
>develop a natural draft gasifier based stove which
>burn fuel of greater size
>and not of briquetted or pelletted fuels.
>
> I am trying to develop one such design such that the
>maximum size up to which the the fuel can be burned in
>a efficient manner.
>
> I am staying in such a place where i could not get
>any guidance or i donot have proper instruments to
>monitor them.
>
>
>
>

From psanders at ILSTU.EDU Thu Dec 11 20:27:49 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: third world energy
In-Reply-To: <mf2itv8fg64qtupvkseduvlc1mh14j1ng5@4ax.com>
Message-ID: <THU.11.DEC.2003.192749.0600.PSANDERS@ILSTU.EDU>

Andrew and Stovers,

THANKS for the great information. I know that Apolinario (my associate in
Mozambique) and Richard Stanley will also find the information to be
valuable. What you wrote makes great sense concerning the challenges we
have for the manually powered vertical press for biomass briquettes that we
are making.

WHEN our press works (or if we must abandon the attempt), then we will be
saying the details about it to the Stoves List Serve.

Andrew, for myself I agree to confidentiality concerning what you might be
willing to discuss about your new device to make pellets (and perhaps it
would work for making briquettes). Please contact me "off-list" for
discussion on this.

Paul

At 12:22 AM 12/12/03 +0000, Andrew Heggie wrote:
>On Thu, 11 Dec 2003 17:13:51 -0600, Paul S. Anderson wrote:
>
> >Harmon,
> >
> >Thanks for the tip. As far as I know, you are the first person to suggest
> >using a hydraulic woodspliter.
>
>I know of an attempt at this.
>
> >Makes a lot of sense.
>
>Not really, aside form hydraulic power transmission not being
>particularly efficient you need to consider what happens when you
>attempt to compress the fibre/sawdust in the breach. Try just pushing
>the material through a tube, unless it is well lubricated to the
>consistency of raw pastry the friction of the tube sides and the
>bridging tendency of the feedstock "arch" in the tube and this arch
>effectively transmits all the applied force into the wall of the tube.
>
>Gav will verify that the way round this is to have a short die and
>feed in small wads of material. There is probably a mathematical
>equation that dictates the depth of the wad versus the diameters. I'll
>venture the guess that friction losses become enormous once the wad
>depth approaches the diameter of the tube.
>
>With the screw press the shearing action of the screw overcomes this.
>With ram presses the momentum in the press adds force, pinch roller
>presses work on very many thin wads per revolution. Also their
>relative high power input is beneficial in creating heat to aid
>plasticising the lignin with wood pellets, animal feed pellets seem to
>rely on natural oils to act as binders and so need not such high
>powers.
>
>I have some charcoal briquettes bought in France that have all the
>appearance of having been forged and wonder what this approach has to
>offer. The die is obviously tapered to allow the briquette to be
>ejected.
>
>Remember in using motive power to compact (or densify but densify is
>only necessary if you need specific performance from your
>pellet/briquette) you are using a high exergy energy source to produce
>a lower one. So even on the large scale where the energy to produce
>pellets is in the order of 2.5% of their fuel value, it has probably
>cost 7.5% of their calorific value in a fossil fuel (biodiesels
>excepted).
> >
> >Anyone on the list serve have much experience with such woodspliters and
> >would care to "tinker" with some designs intended EITHER for the developed
> >societies OR for the developing societies (probably very different end
> >product devices for the needs of those societies). Richard Stanley and I
> >(and others) can assist with info on the materials to press through the
> device.
> >
> >
>I have sketched some designs for an alternative technology pelletting
>device ( intended for use in small joinery workshops for their waste)
>which I will discuss privately, with the understanding that I expect
>to be becoming free from commercial obligations within a few months
>and then if it works......
>
>AJH

From psanders at ILSTU.EDU Thu Dec 11 20:39:09 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
In-Reply-To: <mf2itv8fg64qtupvkseduvlc1mh14j1ng5@4ax.com>
Message-ID: <THU.11.DEC.2003.193909.0600.PSANDERS@ILSTU.EDU>

Stovers,

Can anyone please explain to me the heat value (calorific value) of paper
(such as newspaper) in comparison with that of wood (such as common-grade
firewood or even the wood used to make the paper pulp)?

Here is why: I can make a briquette or "paper log" out of discarded
newspaper and it will burn quite nicely in my gasifier (and probably in
other stoves). And if I have a kilogram of paper fuel (versus a kg of
stick-wood or wood chips), what amount of energy can I expect (especially
in comparison with the wood.)?

Or in other words, if I have a kg of newspapers delivered to my home (I pay
for the printed information and end up with the kg of paper in my garage),
what is the energy value and how does that compare with purchasing (or
going out to collect) a kg of wood?

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 tmiles at TRMILES.COM Thu Dec 11 23:14:11 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:45 2004
Subject: Fw: agroforestry in Nicaragua
Message-ID: <THU.11.DEC.2003.201411.0800.TMILES@TRMILES.COM>

MessageStovers,

This request from Peter Ojamaa (Petero@nimbusprojects.com) came to our Latin American Trade Council of Oregon but I think it is more appropriate for the biomass cookstoves discussion group stoves@listserv.repp.org .

Stuart, Rogerio, Dean can you reply to Peter?

Thanks

Tom Miles
tmiles@trmiles.com
Biomass Cookstoves Discussion
Renewable Energy Policy Project
http://www.repp.org/discussiongroups/resources/stoves/
http://listserv.repp.org/archives/stoves.html

----- Original Message -----
From: Peter Ojamaa
Sent: Thursday, December 11, 2003 1:48 PM
Subject: agroforestry in Nicaragua

Dear Tom:

I'll be very brief if somewhat overly so! Just back from 1st visit to northern Nica. Valley of the Rio Santa Maria near Praderas, NE of Jinotega.

Disturbed at land denudation and cultivation of very, very steep slopes. Seeming firewood needs has denuded even upper elevation slopes.

My thoughts go to managed agroforestry as a community project to provide cooking wood. Could you assist with any references to past research? Any thoughts would be appreciated.

Peter Ojamaa, Infotech Services,
Calgary, Alberta, Canada

PS: I'm a soils consultant with a strong biophysical background.

From elk at WANANCHI.COM Fri Dec 12 01:00:53 2003
From: elk at WANANCHI.COM (Elsen Karstad)
Date: Tue Aug 10 18:30:45 2004
Subject: Partnership for Clean Indoor Air Pilot Projects
Message-ID: <FRI.12.DEC.2003.090053.0300.ELK@WANANCHI.COM>

Well done & congratulations Crispin (& team).

I'm sure you'll make it through to the award- from what I've seen, you're on
precisely the right track.

Regards;
elk
--------------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi, Kenya

----- Original Message -----
From: "Crispin Pemberton-Pigott" <crispin@newdawn.sz>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, December 11, 2003 10:26 PM
Subject: [STOVES] Partnership for Clean Indoor Air Pilot Projects

> Dear Stovers
>
> I am pleased to announce that the Renewable Energy Association of
Swaziland,
> an NGO sheltered until this year at the offices of New Dawn Engineering
and
> boosted by years of continued support from the Energy Section of the
> Swaziland Ministry of Natural Resources and the EU has made it through
round
> one with the United States Environmental Protection Agency's (USEPA)
> Partnership for Clean Indoor Air Pilot Projects Grant Program for the
coming
> year. This is a global competition.
>
>
> REASWA was joined by the very capable Hannah Routh (Skillshare) from the
UK
> this year. The team she put together for the project includes, in no
> particular order:
>
> Ms Feziwe Matsebula
> Ms Hannah Routh
> Dr Irma Allen
> Mr Jonathan Curren
> Dr Mduduzi Mathunjwa
> Ms Phindi Zwane
> and yours truly
>
> The proposals were read and evaluated by a six-member panel of experts
from
> the USEPA, the United States Agency for International Development, the
World
> Health Organization, the Italian Ministry of Environment, and the Shell
> Foundation.
>
> REASWA's proposal includes establishing a baseline and evaluating the
> improvements made to indoor air quality through the introduction of
improved
> cooking devices in rural Swaziland (hoods, chimneys, stoves, ventilation
> etc). A recent survey in homesteads by REASWA showed that some households
> in Swaziland have CO and PIC's in the kitchen 5 to 40 times the WHO
limits.
>
> I think it is great that the 'big guys' can listen to us 'little guys' on
> such important matters!
>
> Go team!
>
> Best regards
> Crispin
>
>

From pverhaart at OPTUSNET.COM.AU Fri Dec 12 05:03:51 2003
From: pverhaart at OPTUSNET.COM.AU (Peter Verhaart)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
In-Reply-To: <4.3.1.2.20031211192815.00b8ff00@mail.ilstu.edu>
Message-ID: <FRI.12.DEC.2003.200351.1000.PVERHAART@OPTUSNET.COM.AU>

Paul,

I don't think you could go very wrong if you assumed 18 MJ/kg for
oven dry paper.

Peter Verhaart

At 11:39 12/12/2003, you wrote:
>Stovers,
>
>Can anyone please explain to me the heat value (calorific value) of paper
>(such as newspaper) in comparison with that of wood (such as common-grade
>firewood or even the wood used to make the paper pulp)?
>
>Here is why: I can make a briquette or "paper log" out of discarded
>newspaper and it will burn quite nicely in my gasifier (and probably in
>other stoves). And if I have a kilogram of paper fuel (versus a kg of
>stick-wood or wood chips), what amount of energy can I expect (especially
>in comparison with the wood.)?
>
>Or in other words, if I have a kg of newspapers delivered to my home (I pay
>for the printed information and end up with the kg of paper in my garage),
>what is the energy value and how does that compare with purchasing (or
>going out to collect) a kg of wood?
>
>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 koopmans at LOXINFO.CO.TH Fri Dec 12 05:36:01 2003
From: koopmans at LOXINFO.CO.TH (Auke Koopmans)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
Message-ID: <FRI.12.DEC.2003.173601.0700.KOOPMANS@LOXINFO.CO.TH>

Paul, Peter,

The information stored in my database gives the following values:
Paper 20702 kJ/kg db and waste paper as 19685 kJ/kg db. These values come
from the PHYLLIS database at www.ecn.nl/phyllis. The same site gives Ash
content as 8.6 and 7.9% respectively and both chemically contain around 49%
C.

Hope that this helps,

Auke Koopmans

----- Original Message -----
From: "Peter Verhaart" <pverhaart@OPTUSNET.COM.AU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, December 12, 2003 5:03 PM
Subject: Re: [STOVES] Comparing paper with wood as fuel.

> Paul,
>
> I don't think you could go very wrong if you assumed 18 MJ/kg for
> oven dry paper.
>
> Peter Verhaart
>
>
>
> At 11:39 12/12/2003, you wrote:
> >Stovers,
> >
> >Can anyone please explain to me the heat value (calorific value) of paper
> >(such as newspaper) in comparison with that of wood (such as common-grade
> >firewood or even the wood used to make the paper pulp)?
> >
> >Here is why: I can make a briquette or "paper log" out of discarded
> >newspaper and it will burn quite nicely in my gasifier (and probably in
> >other stoves). And if I have a kilogram of paper fuel (versus a kg of
> >stick-wood or wood chips), what amount of energy can I expect (especially
> >in comparison with the wood.)?
> >
> >Or in other words, if I have a kg of newspapers delivered to my home (I
pay
> >for the printed information and end up with the kg of paper in my
garage),
> >what is the energy value and how does that compare with purchasing (or
> >going out to collect) a kg of wood?
> >
> >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 andrew.heggie at DTN.NTL.COM Fri Dec 12 05:46:00 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
In-Reply-To: <6.0.1.1.2.20031212200205.02c29850@mail.optusnet.com.au>
Message-ID: <FRI.12.DEC.2003.104600.0000.>

On Fri, 12 Dec 2003 20:03:51 +1000, Peter Verhaart wrote:

>Paul,
>
> I don't think you could go very wrong if you assumed 18 MJ/kg for
>oven dry paper.

Just a quick post to agree that. Some of the pulp processes remove
lignin which will depress the overall figure but I think newsprint is
usually pulped entirely mechanically. Be aware that other papers,
particularly the glossies contain large amount of fillers (clay) which
must be subtracted from the dry matter before the calculation, not to
mention the clay effectively stifles decent combustion of the layers
of paper.

AJH

From krishnakumar_07 at YAHOO.CO.UK Fri Dec 12 06:35:29 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:45 2004
Subject: NDG
In-Reply-To: <026a01c3bde0$af628820$49600443@net>
Message-ID: <FRI.12.DEC.2003.113529.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

I would really thank you Dr.Ron & Dr.Lanny
for providing useful information.

Basically my project is using the Natural Draft
Gasifier for cooking and thermal application.

Actually I was on a survey for solar home lighting
and street lighting, on visiting many places in the
villages I found that on improving the cooking
standards in the villages in Tamil Nadu.Thats how I
got the idea.

I have seen in manual dyeing units the tempreture
of water is around 60- 80 degree centigrade.They use
open fire for their operation,which produces a lot of
smoke and workers feel it difficult to stand beside
and work.Hence I would like to use this NDG over there
also.

=====
krish

From krishnakumar_07 at YAHOO.CO.UK Fri Dec 12 06:39:46 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:45 2004
Subject: NDG
In-Reply-To: <LISTSERV%2003121206355308@LISTSERV.REPP.ORG>
Message-ID: <FRI.12.DEC.2003.113946.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

>
> I would really thank you Dr.Ron & Dr.Lanny
> for providing useful information.
>
> Basically my project is using the Natural Draft
> Gasifier for cooking and thermal application.
>
> Actually I was on a survey for solar home lighting
> and street lighting, on visiting many places in the
> villages I found that on improving the cooking
> standards in the villages in Tamil Nadu.Thats how I
> got the idea.
>
> I have seen in manual dyeing units the tempreture
> of water is around 60- 80 degree centigrade.They use
> open fire for their operation,which produces a lot
> of
> smoke and workers feel it difficult to stand beside
> and work.Hence I would like to use this NDG over
> there
> also.
>
>
>
>
> --- Ron Larson <ronallarson@QWEST.NET> wrote: >
> Krishna:
> >
> > I fear giving advice without knowing more of
> > your design. Please send
> > to either this list or, if photographic to
> > mailto:tmiles@trmiles.com
> >
> > My experience with what might be similar is
> that
> > the combustion chamber
> > (which also serves as a chimney) needs to be about
> > 150% as high as the
> > diameter. If too short, combustion will not be
> > complete (as you appear to
> > be observing) and the pyrolysis gases will leave
> too
> > much soot on surfaces
> > you (I hope) are trying to heat up. Also with too
> > short a
> > combustion/chimney region, you will not develop a
> > sufficiently good pressure
> > difference and not draw enough primary air through
> > your fuel supply (which I
> > hope you are lighting from the top).
> >
> > If the combustion area/chimney is too long,
> you
> > are probably losing more
> > useful energy than you need to. If you are not
> > planning something useful
> > for the pyrolysis gases, the chimney can be very
> > tall.
> >
> > Ron
> >
> > ----- Original Message -----
> > From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Monday, December 08, 2003 4:24 AM
> > Subject: NDG
> >
> >

=====
krish

From adkarve at PN2.VSNL.NET.IN Fri Dec 12 09:00:12 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:45 2004
Subject: Gasifier stove too tall for Indian Housewife.
Message-ID: <FRI.12.DEC.2003.193012.0530.ADKARVE@PN2.VSNL.NET.IN>

Thanks, Peter, for the information about the J-stove. Gasifier stoves
are too tall for the typical Indian rural housewife, who performs her
cooking sitting down on the floor. The cookstoves she uses are always
less than about 20 cm in height. The kind of gasifier stove described by
you would be too tall even for somebody who cooks standing up, because
the average height of the Indian housewife is barely 150 cm. We have,
in the past, constructed stoves for temples, where thousands of pilgrims
are fed every day. In this case, the stove and the pot sitting on it,
have a total height of about 250 cm. In such cases, we provide the cook
with an elevated platform, so that he can walk around the cookpot to
stir its contents. There is a chute having its opening at the same level
as the platform so that the cook can drop firewood through it. The
firewood falls on the grate. The ash removal is done from underneath
the platform.
Yours
A.D.Karve

Peter Verhaart wrote:

> At 10:10 11/12/2003, you wrote:
>
>> I followed with interest the messages about the J stove but I could
>> not get any useful information. Is it shaped like the letter J? I can
>> imagine that if one filled wood pellets into the shorter arm of the J
>> and ignited them from above, the draft produced by the longer arm would
>> pull the smoke up the longer arm. This smoke could then be ignited as it
>> emerged from the longer arm. However this is only my imagination working
>> and the real thing could be quite different. Would anybody please
>> explain, in plain language, how it worked?
>> Dr.A.D.Karve, President,
>> Appropriate Rural Technology Institute
>> Pune, India.
>
>
>
> Dear Dr. Karve,
>
> I had exactly the same idea, the smoke could be ignited.
> Reality was different, when it is operated with a thin fuelbed, the
> draft pulls air through the combustion zone and reacts with the
> volatiles downstream from the grate. The result is a remarkable clean
> combustion. What emerges from the chimney is clear and has no smell,
> analysis of the flue gases showed an extremely low CO/CO2 ratio, below
> that considered admisible for open kerosene burning appliances.
> We think it works because the charcoal on the grate is burning
> vigorously, above the charcoal fresh wood is being charred and the
> volatiles are drawn through the burning charcoal. This leaves the
> volatiles little time to combine into nasties, on the contrary, larger
> molecules are probably broken down. These mixed with excess air are
> intimately mixed because of the turbulence. The result is demonstrable
> clean combustion.
> That is our explanation, we have no proof, were unable to analyse gas
> anywhere in the reaction zone, so stand to be corrected as to the
> actual reactions taking place.
> We worked mostly with a chimney of 1 m which induced quite a good
> draft. On a grate of 12 * 12 cm we could obtain a heat output rate of
> over 10 kW if memory serves.
> My downdraft barbecue also has a 12 * 12 cm grate and a 1 m chimney.
> Probably because of heat losses to the griddle and flow resistance, I
> have only been able to get 8.8 kW.
> Here is a stove with a chimney that can be used indoors. For tests I
> have lit it outside and as soon as the fire was established wheeled it
> indoors to conduct water boiling tests.
> I hope this has clarified things to some extent.
>
> With kind regards,
>
> Peter Verhaart
>
>
>

From rmiranda at INET.COM.BR Fri Dec 12 10:16:30 2003
From: rmiranda at INET.COM.BR (Rogerio Carneiro de Miranda)
Date: Tue Aug 10 18:30:45 2004
Subject: Fw: agroforestry in Nicaragua
In-Reply-To: <00f301c3c066$67d38b20$6501a8c0@tomslaptop>
Message-ID: <FRI.12.DEC.2003.131630.0200.RMIRANDA@INET.COM.BR>

Peter:

I believe your best bet will be consulting with CATIE in Costa Rica
(perhaps www.catie.org.cr ?) as regional agriculture research center, CATIE
has extensive work around central america and including agroforestry x
fuelwood.

suerte

rog?rio

At 08:14 p.m. 11/12/03 -0800, Tom Miles wrote:
>MessageStovers,
>
>This request from Peter Ojamaa (Petero@nimbusprojects.com) came to our
>Latin American Trade Council of Oregon but I think it is more appropriate
>for the biomass cookstoves discussion group stoves@listserv.repp.org .
>
>Stuart, Rogerio, Dean can you reply to Peter?
>
>Thanks
>
>Tom Miles
>tmiles@trmiles.com
>Biomass Cookstoves Discussion
>Renewable Energy Policy Project
>http://www.repp.org/discussiongroups/resources/stoves/
>http://listserv.repp.org/archives/stoves.html
>
>
>----- Original Message -----
>From: Peter Ojamaa
>Sent: Thursday, December 11, 2003 1:48 PM
>Subject: agroforestry in Nicaragua
>
>
>Dear Tom:
>
>I'll be very brief if somewhat overly so! Just back from 1st visit to
>northern Nica. Valley of the Rio Santa Maria near Praderas, NE of Jinotega.
>
>Disturbed at land denudation and cultivation of very, very steep
>slopes. Seeming firewood needs has denuded even upper elevation slopes.
>
>My thoughts go to managed agroforestry as a community project to provide
>cooking wood. Could you assist with any references to past research? Any
>thoughts would be appreciated.
>
>Peter Ojamaa, Infotech Services,
>Calgary, Alberta, Canada
>
>PS: I'm a soils consultant with a strong biophysical background.

From dstill at EPUD.NET Fri Dec 12 12:40:59 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:45 2004
Subject: Design Guidlines for Cookstoves
Message-ID: <FRI.12.DEC.2003.094059.0800.DSTILL@EPUD.NET>

Looking for Consensus

Thematic excerpts from the following:

Biomass Stoves: Engineering Design, Development, and Dissemination by Samuel
Baldwin, 1987

Woodburning Cookstoves, Prassad, Sangen, Visser, 1984

Biofuels, Air Pollution, and Health: A Global Review, Smith, 1987

Rocket Stove Design Principles by Dr. Larry Winiarski

I have tried to organize the excerpts from Baldwin, Prassad, Smith, and
Winiarski at points of agreement. There are many areas of consensus in the
stove literature. I hope that what has been discovered by engineers will
help to create a better generation of improved cook stoves. Identifying
design principles is especially important with vernacular stoves because
cultural requirements necessitate many various adaptations.

The excerpts refer to intermittently fed stoves that do not aim to gasify
batches of wood but try to achieve "complete" initial combustion. I think
that it would be very helpful if experts in gasifying stoves could create a
list of design principles like these for a direct burning stove.

All Best,

Dean

1.) Insulate particularly the combustion chamber with low mass, heat
resistant materials in order to keep the fire as hot as possible and not to
heat the higher mass of the stove body. Winiarski

Short cooking times make the un-insulated metal stove more efficient but
longer cooking times may favor the high mass stove. Better than either at
any cooking time from this standpoint would be the insulated metal stove.
.high mass stoves can also be expected to produce higher emissions at the
beginning of the burn.(302) Smith

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) Baldwin

Insulating the combustion chamber raises interior temperatures and can
reduce emissions. (Page 61) Baldwin

2.) Within the stove body, above the combustion chamber, use an insulated,
upright chimney of a height that is about two or three times the diameter
before extracting heat to any surface (griddle, pots, etc.). Winiarski

3.) Heat only the fuel that is burning (and not too much). Burn the tips of
sticks as they enter the combustion chamber, for example. The object is NOT
to produce more gasses or charcoal than can be cleanly burned at the power
level desired. Winiarski

Evidence indicates that emissions are lowest with small charges.The reason
for this effect is that with smaller charges there is less fuel in the
combustion chamber and thus a lower amount of pyrolysis in that part of the
fuel not directly in the combustion zone. Much of the fuel in a large charge
will be near enough to the combustion zone to undergo extensive pre-burning
pyrolysis and thus release materials into a region where space and char
burning has not yet commenced. In addition, quenching by cold fuel is less
likely with a small fuel charge.traditional cooking stoves are generally
fueled by frequent additions of small amounts of fuel, a factor favorable to
low emissions. (286) Smith

4.) Using more or less sticks of wood, burning at the tips, creates high and
low power. Adjust the amount of burning wood to suit the cooking task.
Winiarski

.an ideal burner design with the power output ranging from 2.64KW to
0.44KW.fuel economy is dependent on three factors, namely, the efficiency
(as a function of power output), the maximum power output, and the ratio of
maximum to minimum power outputs. (Pages 108-109) Prassad

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) Baldwin

5.) Maintain a good air velocity through the fuel. The primary Rocket stove
principle and feature is using a hot, insulated, vertical chimney within the
stove body, above the fire, that increases draft. Winiarski

The annular space between pan and shield is an important part of the
shielded fire. It is the major zone for convective heat transfer to the pan
and the design tries to increase this heat transfer by increasing the flue
gas velocity. Therefore, the gap must be made as small as possible, with an
increasing flow resistance as a consequence. (Page 76) Prassad

.the principle method by which burn rate has been decreased has been to
close down the airflow, i.e., reduce excess airflow. .this action can
greatly lower combustion efficiency and thus increase emissions.it would be
far better to increase the air flow velocity aimed directly into the
combustion region itself. .Even with much higher rates of excess air, the
high turbulence provided by forced air systems can lower emission rates by
factors of two or more (Allen and Cooke, 1981). (300) Smith

.. 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) Baldwin

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) Baldwin

6.) Do not allow too much or too little air to enter the combustion chamber.
We strive to have stoichiometric (chemically ideal) combustion: in practice
there should be the minimum excess of air supporting clean burning.
Winiarski

Per kg of wood the stoichiometric amount of air is 4.48 m3, subdivided in
2.70 m3 and 1.78 m3 for volatiles and charcoal respectively; assuming that
20% of the wood is burned as charcoal. (Page 41) Prassad

Values for temperatures of the gases are 1260K and 950K for a volatile
excess air factor of 1.5 and 2.5 respectively. (Page 43)Prassad

Of the flow control methods, control of combustion air is to be preferred.
(Verhaart) (Page 77) Prassad

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) Baldwin

7.) The cross sectional area (perpendicular to the flow) of the combustion
chamber should be sized within the range of power level of the stove.
Experience has shown that roughly twenty-five square inches will suffice for
home use (four inches in diameter or five inches square). Commercial size is
larger and depends on usage. Winiarski

The power level of a cookstove with reasonable efficiency need be no more
than 2 to 4KW at the primary fuel level. (Page 4)Prassad

Evidence from laboratory studies indicate that total organic emissions are
temperature dependent.emissions seem to peak at about 600C and decrease at
temperatures above 900C.In general, the higher the temperature, the lower
the emission factors for all important biomass combustion pollutants except
NOx. (299) Smith

Optimizing the shape of the combustion chamber may affect the combustion
quality and stove efficiency in a number of ways. (Page 61) Baldwin

8.) Elevate the fuel and distribute airflow around the fuel surfaces. When
burning sticks of wood, it is best to have several sticks close together,
not touching, leaving air spaces between them. Particle fuels should be
arranged on a grate. Arrange the fuel so that air largely flows through the
glowing coals. Too much air passing above the coals cools the flames and
condenses oil vapors. Winiarski

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)
Baldwin

9.) Throughout the stove, any place where hot gases flow, insulate from the
higher mass of the stove body, only exposing pots, etc. to direct heat.
Winiarski

.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) Baldwin

10.) Transfer the heat efficiently by making the gaps as narrow as possible
between the insulation covering the stove body and surfaces to be heated but
do this without choking the fire. Estimate the size of the gap by keeping
the cross sectional area of the flow of hot flue gases constant. EXCEPTION:
When using an external chimney or fan the gaps can be substantially reduced
as long as adequate space has been left at the top of the internal short
chimney for the gasses to turn smoothly and distribute evenly. This is
tapering of the manifold. In a common domestic griddle stove with external
chimney, the gap under the griddle can be reduced to about one half inch for
optimum heat transfer. Winiarski

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) Baldwin

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) Baldwin

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) Baldwin

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) Baldwin

From lanny at ROMAN.NET Fri Dec 12 21:19:32 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:45 2004
Subject: NDG
Message-ID: <FRI.12.DEC.2003.211932.0500.LANNY@ROMAN.NET>

Dear Krishna,
Thanks for telling us about your work to improve cook stoves in Tamil Nadu
and other villages in India.
Can you give me more information?
What kind of pots are used?
Is cooking done indoors?
Is yes: What materials and how is the roof constructed?
What size is the room? and ceiling height?
Is the cook stove also used for heating the house?
How far to the nearest electrical source to use power tools to build stoves
and chimneys?
What raw materials are available to use for building stoves? Drums? buckets?
kiln for ceramics/fire clay/ fire bricks? sheet metals? insulation? metal
roofing?
What are you drying in the manual drying units?
Lanny Henson

----- Original Message -----
From: krishna kumar <krishnakumar_07@yahoo.co.uk>
To: Ron Larson <ronallarson@QWEST.NET>
Cc: <STOVES@LISTSERV.REPP.ORG>; <lanny@ROMAN.NET>
Sent: Friday, December 12, 2003 6:35 AM
Subject: Re: [STOVES] NDG

> I would really thank you Dr.Ron & Dr.Lanny
> for providing useful information.
>
> Basically my project is using the Natural Draft
> Gasifier for cooking and thermal application.
>
> Actually I was on a survey for solar home lighting
> and street lighting, on visiting many places in the
> villages I found that on improving the cooking
> standards in the villages in Tamil Nadu.Thats how I
> got the idea.
>
> I have seen in manual dyeing units the tempreture
> of water is around 60- 80 degree centigrade.They use
> open fire for their operation,which produces a lot of
> smoke and workers feel it difficult to stand beside
> and work.Hence I would like to use this NDG over there
> also.
>
>
>
>
> --- Ron Larson <ronallarson@QWEST.NET> wrote: >
> Krishna:
> >
> > I fear giving advice without knowing more of
> > your design. Please send
> > to either this list or, if photographic to
> > mailto:tmiles@trmiles.com
> >
> > My experience with what might be similar is that
> > the combustion chamber
> > (which also serves as a chimney) needs to be about
> > 150% as high as the
> > diameter. If too short, combustion will not be
> > complete (as you appear to
> > be observing) and the pyrolysis gases will leave too
> > much soot on surfaces
> > you (I hope) are trying to heat up. Also with too
> > short a
> > combustion/chimney region, you will not develop a
> > sufficiently good pressure
> > difference and not draw enough primary air through
> > your fuel supply (which I
> > hope you are lighting from the top).
> >
> > If the combustion area/chimney is too long, you
> > are probably losing more
> > useful energy than you need to. If you are not
> > planning something useful
> > for the pyrolysis gases, the chimney can be very
> > tall.
> >
> > Ron
> >
> > ----- Original Message -----
> > From: krishna kumar <krishnakumar_07@YAHOO.CO.UK>
> > To: <STOVES@LISTSERV.REPP.ORG>
> > Sent: Monday, December 08, 2003 4:24 AM
> > Subject: NDG
> >
> >
> > > ---------------------- Information from the mail
> > header -----------------------
> > > Sender: The Stoves Discussion List
> > <STOVES@LISTSERV.REPP.ORG>
> > > Poster: =?iso-8859-1?q?krishna=20kumar?=
> > <krishnakumar_07@YAHOO.CO.UK>
> > > Subject: NDG
> > >
> >
> --------------------------------------------------------------------------
> > -----
> > >
> > > I have fabricated the natural draft gasifier
> > > with conrete and coated inside with clay.
> > >
> > > I have made a trail run of it and it worked
> > > satisfactorlly.The flame reached to a height of
> > > 1-1.25ft above the top of the stove.
> > >
> > > Then i tried with clossing the top of the stove
> > > with a lid and taking the gas seperately and
> > burning
> > > it through a burner. but i was unsuccesful in
> > burning
> > > the gas,
> > > The gas came out through the primairy air port
> > > and it did not gasify the wood inside.
> > >
> > > i would like to know about the chimney effect
> > > and draft to create the gas to come out of the
> > pipe.
> > >
> > >
> > >
> > > =====
> > > krish
> > >
> > >
> >
> ________________________________________________________________________
> > > BT Yahoo! Broadband - Save ?80 when you order
> > online today. Hurry! Offer
> > ends 21st December 2003. The way the internet was
> > meant to be.
> >
> http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> > >
>
> =====
> krish
>
> ________________________________________________________________________
> BT Yahoo! Broadband - Save ?80 when you order online today. Hurry! Offer
ends 21st December 2003. The way the internet was meant to be.
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
>

From kchisholm at CA.INTER.NET Sun Dec 14 00:37:48 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:45 2004
Subject: chimney problems
Message-ID: <SUN.14.DEC.2003.013748.0400.KCHISHOLM@CA.INTER.NET>

Dear Crispin

...del...>

> I still say this is a combustion problem, not a chimney design problem.
> There is frequent mention on this list of a "$5 to $7 stove" yet
apparently
> people are connecting these to $10 chimneys which require replacement
> annually. Not so?
>
> Whither common sense?
>
> Wouldn't it be better to spend $20 to $30 on a stove that burns the
clogging
> particles and complex gases that would otherwise precipitate into
> chimney-eating chemicals?
>
You are "bang on". There would be no sooting and tar build-up problems if
the soot and tar were burned in the first place.

The best way to cure a problem is to prevent it from happening in the first
place.

Kindest regards,

Kevin

From Gavin at AA3GENERGI.FORCE9.CO.UK Sun Dec 14 06:05:31 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:45 2004
Subject: chimney problems
In-Reply-To: <04dc01c3c204$8b38d080$de9a0a40@kevin>
Message-ID: <SUN.14.DEC.2003.110531.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

Dear Crispin

...del...>

> I still say this is a combustion problem, not a chimney design problem.
> There is frequent mention on this list of a "$5 to $7 stove" yet
apparently
> people are connecting these to $10 chimneys which require replacement
> annually. Not so?
>
> Whither common sense?
>
> Wouldn't it be better to spend $20 to $30 on a stove that burns the
clogging
> particles and complex gases that would otherwise precipitate into
> chimney-eating chemicals?
>
I think Crispin, you have it in a nutshell,
[GGG] I though this was predominantly a British phenomenon but maybe it is
much more widespread human nature.
Thinking long term, thinking wholistically, is beyond most people most of
the time- I will include myself in this matter- particularly when spending
money- which is always in short supply.

So: you need a new stove(car/hifi/shopping bag/washing machine) you have
limited cash this week/month /year so you buy the best you can afford/nicest
colour etc. whole life costs/ environmental benefits etc - even if you
lecture in them.. go out the window.

Later. .your chimney, (brakes/Cdplayer/bag etc.) needs replacing- same
happens..

In my experience some rich people are able to spend their way out of this
conundrum and then save money- buy the best , it lasts- (clothes, cars,
domestic appliances etc) so over time they can save day to day expenditure
and be richer.

The rest of us just struggle ... meanwhile "society" (i.e. advertising etc.)
encourages us to buy more crap to chuck away next week.
A truly sustainable society is not a material society and the earth would
not support the large population of humans currently living on it. -most of
whom would not appreciate the way of life they would have to adopt!
Sorry- no answers only cynical observations shared with those who already
know!
Happy winter solstice
gavin

From crispin at NEWDAWN.SZ Sun Dec 14 10:00:21 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:45 2004
Subject: RE third world energy
Message-ID: <SUN.14.DEC.2003.170021.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

>Crispin's briquette maker is hydraulic ...

In fact that process is manual - the hydraulic press you saw was us
investigating whether or not there is any point in pressing massively on a
paper+wood chip briquette (there isn't).

We have two systems available - the old rectangular box 'Paper Brick Maker'
as on our website (download the slide show) and the high capacity system
that makes 16 per drop 68x68x45mm. That makes about 1500 units per hour
wihout no power except from the humans running it.

To save you a lot of time checking this out, soak your newspaper for 4 days
or more before using it is a binder. Mu-u-uch better.... And thus you
don't have to add bleach to break the paper up if you are patient.

Regards
Crispin

From crispin at NEWDAWN.SZ Sun Dec 14 10:00:08 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
Message-ID: <SUN.14.DEC.2003.170008.0200.CRISPIN@NEWDAWN.SZ>

Dear Paul

>Can anyone please explain to me the heat value (calorific
>value) of paper (such as newspaper) in comparison with
>that of wood

What is known as 'mechanical paper' is bashed up wood and as such, newspaper
has the same heat value as wood per kg.

Regards
Crispin

From crispin at NEWDAWN.SZ Sun Dec 14 14:18:38 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:45 2004
Subject: chimney problems
Message-ID: <SUN.14.DEC.2003.211838.0200.CRISPIN@NEWDAWN.SZ>

Dear Kevin

>There would be no sooting and tar build-up problems if
>the soot and tar were burned in the first place.

I think improved combustion is a necessary facet of a discussion on
chimneys.

I will be in Toronto for the next 3 weeks. Whitby actually. If anyone from
that region wants to talk face to face about stoves'n'things they are
welcome to give me a call at 905-668-5950 or leave a message at
905-665-7674.

One possible topic of a good conversation would the many new stove design
parameters that have emerged in the 16 years since the 1987 appearance of
"Biofuels, Air Pollution, and Health: A Global Review" by Kirk. R. Smith.
Essentially that book covers what was already done or believed (it is a
'review') and while Dean did note that it will not cover gassifiers, it also
has many 'design parameters' which are served up as 'givens'. On closer
analysis they refer only to a specific device with a certain set of
dimensions. Many of the truisms in Smiths book are device-specific. A lot
of understanding has emerged since 1987.

If it were possible it would be good to discuss with Toronto area people
what _general principles_ should be promulgated so that people building any
stove on a continuum from direct combustion to gasifier will be able to
effectively reduce pollution, exposure, consumption and working life.

BTT! (burn that tar!)
Crispin

From andrew.heggie at DTN.NTL.COM Sun Dec 14 14:54:17 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:45 2004
Subject: third world energy
In-Reply-To: <20031209162527.GA5994@cybershamanix.com>
Message-ID: <SUN.14.DEC.2003.195417.0000.>

On Tue, 9 Dec 2003 10:25:27 -0600, Harmon Seaver wrote:

> While they may be energy intensive to produce, they are still cheaper to
>heat with (in the US) than natural gas, fuel oil, or electricity.

Pellets are still not an economic fuel in UK, though there are
definitely niches for them.

> So pellet burners, especially those which also burn corn,

As I am over 200km from the nearest pellet plant I mostly burn wheat
screenings in mine.

>provide all my own heating fuel simply from pelletizing the leaves that people
>pile on their curbs every Fall -- which, of course, the cities very expensively
>have to gather and haul away.

Over 30 years ago I used to walk into the local library with my
daughter in a pram, as I kicked through the dry leaves I made exactly
the same observation to my wife (mind I did not think of pellets as I
was unaware of the concept of densification then), I still have never
seen a fuel pellet incorporating fallen leaves.

> Pellets could be made much more cheaply in decentralized
>small-scale operations, since a big cost is trucking the sawdust to the pellet
>mills, then trucking the pellets across the country.

I agree, local use of local production is a sound idea. Like you I see
no great reason not to make fuel from all these resources, however I
don't think you need to go the whole process of densification for a
local fuel pellet. Indeed I would go for a holistic integrated fuel
pellet, incorporating your cattail, the canola straw ( I think canola
is a proprietary name for the oil, in uk we abbreviate the name of the
crop to osr to save confusion with its common name) with the wood to
prevent clinker formation. I also would be happy to use some of those
wastes presently banned from fuel pellets, like the ink resins and
even waste polythene bags as a binder.

AJH

From english at KINGSTON.NET Sun Dec 14 17:27:36 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:45 2004
Subject: Chimneys
In-Reply-To: <20031211164522.AB7E8D3F@telchar.epud.net>
Message-ID: <SUN.14.DEC.2003.172736.0500.>

Dean,
Its great to here about the new technology that you will soon be using.
I sure hope you can share the results.

I sense from your, and Rogerio's, comments that for your stoves in Central America,
chimney performance is not a "show stopper". I take it that users are not becoming
frustrated, and abandoning the new stoves to go back to their old open fires or
chimneyless stoves as has happened in some other parts of the world. This has resulted
in the unfortunate situation of mothers having a chimney in the kitchen that isn't being
used, while new stoves and chimneys become associated with failure. There are
probably several factors at work here, but I have never seen them examined.

Clean combustion is a noble goal, and may well have as large an educational
component as chimney maintenance. It was not that long ago that chimney
recommendations for very clean gas appliances were significantly changed. This only
happened after a significant amount of careful research into the performance of
chimneys for that application in our environment.

I am wondering if anyone has tried to measure the surface temperatures of small
cooking stove chimneys. Where are the guide-lines that will helps stove designers avoid
problems in the field?

Setting "Perfect world combustion" to the side, I suspect that a realistically clean
simmering fire in an efficient family cookstove will need a very carefully designed
chimney/stove combination to avoid routinely reducing the effectiveness of the stove or
increasing the maintenance cost.

So which is farther from optimal, the stove or the chimney?

Good work Dean, your certainly in it for the long run.

Alex

>
> All Best,
>
> Dean
>

From english at KINGSTON.NET Sun Dec 14 22:30:25 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:45 2004
Subject: chimney problems
Message-ID: <SUN.14.DEC.2003.223025.0500.>

Dear Crispin, Kevin,

> >There would be no sooting and tar build-up problems if
> >the soot and tar were burned in the first place.

Yes.
>
> I think improved combustion is a necessary facet of a discussion on
> chimneys.

It is not. The conditions for good combustion will not always exist.

Lets suppose that we can design a chimney/vent that minimizes problems associated
with venting poor combustion. How much would we change it for venting good
combustion?

Is it easier to reduce chimney problems by improving combustion or by
adjusting chimney design? Surely that depends on the fuel and cultural
habits.

Surely both should be optimized.

I think Kirk Smith has significant evidence that improved venting is a "necessary facet of
a discussion" on meeting WHO guide-lines for indoor air pollution when using biomass
fuels. Contrary evidence may still be pending.

Alex

------- End of forwarded message -------

From elk at WANANCHI.COM Mon Dec 15 04:46:52 2003
From: elk at WANANCHI.COM (Elsen Karstad)
Date: Tue Aug 10 18:30:45 2004
Subject: biomass densification (WAS third world energy)
Message-ID: <MON.15.DEC.2003.124652.0300.ELK@WANANCHI.COM>

Stovers;

I've been following the correspondence on densification uncarbonised biomass
with interest. Andrew's informed communication (appended here) is of
particular help to me. We (Chardust) are importing a tubular inclined flash
drier to Kenya from India to pre-dry bagasse prior to carbonisation at out
Western Kenya 'CaneCoal' plant. This will-hopefully- remove the last
bottleneck to our production goal of achieving 5000 kg per day charcoal
briquette output.

Hopefully...... we are just under 1t/day now, and damp feedstock is our
major problem.

Anyway- this flash drier is supposed to be fed hot gasses from a simple
brick furnace burning 'baled' fresh bagasse (50% moisture content when
collected straight from the factory). We've been offered a baler with the
drier, but I reckon we can make one here. I'm trying to get the relevant
dimensions and maybe even pressure info from the supplier... who may or may
not cooperate.

The flash drier is designed to produce 1500 kg/hour dried bagasse at 5 to 7%
moisture the wet feedstock. Air/gas input temps are between 300 & 350 C, and
I assume that this is direct from the combustor & not via a heat exchange
system. Indian equipment is generally very simple- just the way I like it.

I've got a pretty massive hydraulic ram here, leftover from a fishmeal plant
I used to operate. I'm planning to use this as a ram compactor of some type-
should be fairly straightforward. It's got a pretty long stroke though- over
1 meter. I'll start some tests on this soon.

I don't envision producing a true 'log' via extremely high heat &
temperature- just a baler of some type, maybe even bound slightly with
molasses. Optimally, I'd use the wet factory-fresh bagasse & de-water
somewhat during compression. My first decision would be whether to design
this as a single stroke system producing one 'log' per stroke (maybe 4 inch
dia by 6 inch long) or a tapered die outlet where the cylinder exit remains
open.

Any suggestions on how a densifier of this type should be made would be
appreciated. I'll start my usual trial & error engineering process here in
the new year..........

rgds;
elk

----- Original Message -----
From: "Andrew Heggie" <Andrew.heggie@dtn.ntl.com>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Friday, December 12, 2003 3:22 AM
Subject: Re: [STOVES] third world energy

> On Thu, 11 Dec 2003 17:13:51 -0600, Paul S. Anderson wrote:
>
> >Harmon,
> >
> >Thanks for the tip. As far as I know, you are the first person to
suggest
> >using a hydraulic woodspliter.
>
> I know of an attempt at this.
>
> >Makes a lot of sense.
>
> Not really, aside form hydraulic power transmission not being
> particularly efficient you need to consider what happens when you
> attempt to compress the fibre/sawdust in the breach. Try just pushing
> the material through a tube, unless it is well lubricated to the
> consistency of raw pastry the friction of the tube sides and the
> bridging tendency of the feedstock "arch" in the tube and this arch
> effectively transmits all the applied force into the wall of the tube.
>
> Gav will verify that the way round this is to have a short die and
> feed in small wads of material. There is probably a mathematical
> equation that dictates the depth of the wad versus the diameters. I'll
> venture the guess that friction losses become enormous once the wad
> depth approaches the diameter of the tube.
>
> With the screw press the shearing action of the screw overcomes this.
> With ram presses the momentum in the press adds force, pinch roller
> presses work on very many thin wads per revolution. Also their
> relative high power input is beneficial in creating heat to aid
> plasticising the lignin with wood pellets, animal feed pellets seem to
> rely on natural oils to act as binders and so need not such high
> powers.
>
> I have some charcoal briquettes bought in France that have all the
> appearance of having been forged and wonder what this approach has to
> offer. The die is obviously tapered to allow the briquette to be
> ejected.
>
> Remember in using motive power to compact (or densify but densify is
> only necessary if you need specific performance from your
> pellet/briquette) you are using a high exergy energy source to produce
> a lower one. So even on the large scale where the energy to produce
> pellets is in the order of 2.5% of their fuel value, it has probably
> cost 7.5% of their calorific value in a fossil fuel (biodiesels
> excepted).
> >
> >Anyone on the list serve have much experience with such woodspliters and
> >would care to "tinker" with some designs intended EITHER for the
developed
> >societies OR for the developing societies (probably very different end
> >product devices for the needs of those societies). Richard Stanley and I
> >(and others) can assist with info on the materials to press through the
device.
> >
> >
> I have sketched some designs for an alternative technology pelletting
> device ( intended for use in small joinery workshops for their waste)
> which I will discuss privately, with the understanding that I expect
> to be becoming free from commercial obligations within a few months
> and then if it works......
>
> AJH
>
>

--------------------------------
Elsen L. Karstad
elk@wananchi.com
www.chardust.com
Nairobi, Kenya

From dstill at EPUD.NET Tue Dec 16 02:37:14 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:45 2004
Subject: Chimneys
In-Reply-To: <3FDC9D88.24697.18AE208@localhost>
Message-ID: <MON.15.DEC.2003.233714.0800.DSTILL@EPUD.NET>

Dear Alex,

Our intention at Aprovecho is always to share all information and we hope
that beginning this winter we can generate some accurate numbers for various
stoves. We received the $8,000 Enerac 3000E today! Should give us good
readings of CO, CO2, O2, hydrocarbons...Thanks to the Murdock Foundation...

I look at chimneys in a very positive light because the cost is low and the
cure to indoor air pollution, for all practical purposes, complete. Here in
Oregon, we heat with wood, many folks use wood stoves as their only heating
source. Chimneys here need to be cleaned often, more often if the stove
burns badly as most do, some monthly. It is important to make the chimney
easy to clean. The metal chimney in my house is twenty years old. The 55
gallon barrel stove that heats our lab is more than twenty years old.
Chimneys are the answer to IAP; the only question is how to fund their
installation.

The best combustion chamber can be easily defeated by operator error.
Although fans and 1,000F preheated primary air are much harder to defeat
than stoves relying on natural draft. I love blast furnace heating stoves
coupled to big heat exchangers! But simple cooking stoves without fans are
usually stuffed full of too much fuel, green as an apple. A chimney guards
the operator from their actions. Just have to clean it once in a while. Buy
good stuff...

Larry wants us to make light weight chimneys out of ceramic. Ken Goyer
extruded a beauty a while back...

All Best,

Dean

From kchisholm at CA.INTER.NET Tue Dec 16 09:39:38 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:45 2004
Subject: Chimneys
Message-ID: <TUE.16.DEC.2003.103938.0400.KCHISHOLM@CA.INTER.NET>

Dear Dean
----- Original Message -----
From: "Dean Still" <dstill@EPUD.NET>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: Tuesday, December 16, 2003 3:37 AM
Subject: Re: [STOVES] Chimneys

> I look at chimneys in a very positive light because the cost is low and
the
> cure to indoor air pollution, for all practical purposes, complete. Here
in
> Oregon, we heat with wood, many folks use wood stoves as their only
heating
> source. Chimneys here need to be cleaned often, more often if the stove
> burns badly as most do, some monthly. It is important to make the chimney
> easy to clean.

The fact that they need to be cleaned often is simply a result of the fact
that chimneys are being supplied with gases that allow them to dirty
themselves quickly.

The metal chimney in my house is twenty years old. The 55
> gallon barrel stove that heats our lab is more than twenty years old.
> Chimneys are the answer to IAP; the only question is how to fund their
> installation.

Now we are getting close to the heart of the matter: do we want a cure to
IAP, or do we want a low cost appliance? I would suggest that up until now,
appliance cost considerations are more important than Indoor Air Quality
considerations.
>
> The best combustion chamber can be easily defeated by operator error.

Sure. But at least control of the problem is in the hands of the operator,
with a good stove. To re-arrange the famous quote "Guns don't kill people;
people kill people" quotation, "Good stoves and chimneys don't make IAP; bad
operators of good systems make IAP"

> Although fans and 1,000F preheated primary air are much harder to defeat
> than stoves relying on natural draft. I love blast furnace heating stoves
> coupled to big heat exchangers! But simple cooking stoves without fans are
> usually stuffed full of too much fuel, green as an apple.

As an interesting aside, I took great personal pride in being able to spot a
home that was being heated by a "Suburban Woodmaster" stove, while driving
down the road at 60 miles per hour. All I had to do was look for the liquid
creosote draining out the ashpit door of the external chimney. :-) The
Suburban Woodmaster was a lovely looking "parlour stove" that had a grate
and ash drawer. All the wood was placed on the grate and all the combustion
air came up through grate. It is a wonderful example of what not to do when
the goal is to build a wood stove that has low emissions.

A chimney guards
> the operator from their actions. Just have to clean it once in a while.
Buy
> good stuff...
>
The major advantage of a chimney, as I see it, is that it gives the designer
an opportunity to design a stove that will not plog the chimney. :-)

Kindest regards,

Kevin

From psanders at ILSTU.EDU Tue Dec 16 11:32:26 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: Comparing paper with wood as fuel.
In-Reply-To: <005001c3c253$73e57ec0$2a47fea9@md>
Message-ID: <TUE.16.DEC.2003.103226.0600.PSANDERS@ILSTU.EDU>

Thanks to all who responded about paper and wood.

The numbers (calorific value) of wood and paper are a close match, and
Crispin sums it up very well (below.) (My question came because I thought
that the process of making paper might have removed some significant
material/component of the wood. Seems like it does not.)

THEREFORE,
Paper is DENSIFIED wood. A sheet of paper will sink in water. As one
person wrote, the specific gravity of water is 1.0, of wood is about 0.5,
and of paper is about 1.5 (all numbers are very approximate because of
different types of wood and of paper.)

SO
We are experimenting with making sheet-paper (specifically newspaper) into
"briquettes", but WITHOUT mushing it up to become paper pulp again (which
un-does the "densification" of the pulp when it is pressed into thin sheets.)

[Note: The "We" refers to myself and my oldest (age 28) daughter
Lily. She has finished her university degree and will be going with me to
Africa in February for several months for stoves work. Her address is in
the header of this message, but I will also relay to her any replies from
the Stoves List Serve.]

We have been wetting sheets of newspaper and then experimenting on how to
make them stick together. Several ways do not work well.

One way that seems promising is to work with a whole "section" of a
newspaper (about 10 "pages" as they are numbered, but actually about 5
"sheets" as they are printed and then folded once to become a section of a
newpaper.) Wet them together in a large-enough shallow tray, and then
roll the entire section. (we roll from the top or bottom (short width)
and not from the sides (longer length or height).

We have tried rolling both with and without a "stick" in the center. The
stick makes it much easier to begin and complete the roll. It acts like a
rolling pin (but on the inside of the dough). I used a drumstick (from a
drum, not a chicken). When rolled, I hit it downward on the workbench to
remove the stick. Then place the roll to dry.

A yet-to-be-perfected "trick" is to get the stick out of the roll. We have
made but not yet tried a slightly tapered stick. Should work better.

Best might be a hollow tube (but should be tapered) with some small holes
in it to let the center water get pressed through the holes into the tube
and then removed.

Drying in frigid Illinois in winter (-5 to +5 degrees C) could be a
problem. But the easy solution was to set the basket with the damp
briquettes over a vent for the warm air from the central heating
system. In addition to drying the briquettes, I am able to "humidify" my
home (a valid reason in the cold climates).

We made some inch-thick (2.5 cm) briquettes without hollow cores, and they
were slow to dry. 2+ cm is too big a diameter unless hollow.

When rolled without hollow centers (therefore, as solid briquettes), we
were able to easily twist the wet long roll to break off the desired length
of briquette. VERY easy.

But with the hollow center, we cannot twist the hollow roll. So we let
them dry (about 15 inches long = ~40 cm). Then we took the dry roll, and
whacked it with a hatchet and the job was done. (other cutters would be
better, but the doubts about cutting to desired sizes were resolved.)

Yesterday we took one of the short, hollow briquettes and placed it into a
jar of water. Even before it soaked up much water, it only floated about
25% of its height above the water line. I think that would indicate about
0.66 or 0.72 specific gravity. So the newspaper briquette can compete with
a "stick" of equal weight as a reasonable biomass fuel.

WHY DO THIS?
1. Newspaper in bulk smoothers fires or, as loose sheets, flames too
fast. To be useful as a fuel it needs to be compatible with the stove.

2. In the developed world, the actual paper of the newspaper is free if
you consider that the payment was for the information that is superceded
the next day. A subscription will result in "x" kilos of paper delivered
to one's doorstep each week. Please note that this is NOT intended as a
fuel in the impoverished societies.

3. Yes, I believe in recycling newspaper. But is the heat value greater
than the recycle value into toilet paper (or other paper) that requires
energy and materials to be produced? AT LEAST THE PAPER should not go to
the land-fill, which is what many people do with it.

4. Remember, I am a developer of small gasifier stoves. Good heat, clean
combustion, and good control. But fuels in a suitable size, etc, are
important. And this is an excellent fuel for a gasifier!!!!!!.

PROBLEMS:
The ink gets on your hands.
It does take some time.

But, if newspaper briquettes are someday viewed as desirable fuel, there
will be some nice machine (small for the home, or larger for the production
facility) that will take flat stacks of newspaper in at one end and yield
nice briquettes at the other end.

*******
Perhaps others have already done all of this and have gone far beyond our
work. Whatever the case, your comments will be greatly appreciated.

Thanks for working on stoves.

Paul and Lily
.
At 05:00 PM 12/14/03 +0200, Crispin wrote:
>Dear Paul
>
> >Can anyone please explain to me the heat value (calorific
> >value) of paper (such as newspaper) in comparison with
> >that of wood
>
>What is known as 'mechanical paper' is bashed up wood and as such, newspaper
>has the same heat value as wood per kg.
>
>Regards
>Crispin

From frank at COMPOSTLAB.COM Tue Dec 16 12:45:51 2003
From: frank at COMPOSTLAB.COM (Frank Shields)
Date: Tue Aug 10 18:30:45 2004
Subject: optimizing stoves
Message-ID: <TUE.16.DEC.2003.094551.0800.FRANK@COMPOSTLAB.COM>

Hi all,

I've been reading and enjoying the discussions.

It seems even the best designed stove will not be designed for soot free
exhaust under all conditions. For example when the stove starts up or the
fire gradually cools off and when adding more wood or poor quality wood.
Perhaps a combination fuels like a source of quick burners like pellets, dry
sawdust, rooled newsprint etc. and split wood might work better.

Perhaps loading the stove with wood but starting with newspaper and blown
pellets to get a quick, hot fire. The wood finally burns hot and the pellets
are then held back, perhaps until the stove starts to cool off when more
pellets are introduced until more wood is added. If no more wood is added
after a certain amount of time the pellets are shut off and the stove
quickly cools. Something like that.

I think a nepholometer, timer and temperature controller at the right
locations could run the pellet machine. Turn it on when the particles are
high and off when the temperature heats up(?).

Frank

Frank Shields
Soil Control Lab
42 Hangar Way
Watsonville CA 95076
(831) 724-5422 tel
(831) 724-3188 fax
frank@compostlab.com
www.compostlab.com

From psanders at ILSTU.EDU Tue Dec 16 13:14:45 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:45 2004
Subject: Gasifier stove too tall for Indian Housewife.
In-Reply-To: <3FD9C9EC.1020206@pn2.vsnl.net.in>
Message-ID: <TUE.16.DEC.2003.121445.0600.PSANDERS@ILSTU.EDU>

At 07:30 PM 12/12/03 +0530, A.D. Karve wrote:

Snip

> Gasifier stoves
>are too tall for the typical Indian rural housewife, who performs her
>cooking sitting down on the floor. The cookstoves she uses are always
>less than about 20 cm in height.

AD,

Thanks for the very useful information. This gives us all some "targets"
to meet.

Please note:
1. Tom Reed's WoodGas CampStove is less than 20 cm tall. (but not
designed for the developing societies.

2. I (with others) am working on a gasifier that can put out the heat at a
height below 20 cm. But nothing yet to report.

3. IF the J stove had a place to locate a pot that was basically SEALED to
a horizontal section of the chimney (what is actually done on many stoves
that allow sunken pots to be placed into holes in the stove cooking
surface), the height could still be less than the height of a pot that is
on top of a 20 cm high stove in India. Sealed is important to maintain the
draft that is essential in a J stove.

Paul

From psanders at ILSTU.EDU Tue Dec 16 14:02:51 2003
From: psanders at ILSTU.EDU (Paul S. Anderson)
Date: Tue Aug 10 18:30:46 2004
Subject: chimney problems
In-Reply-To: <04dc01c3c204$8b38d080$de9a0a40@kevin>
Message-ID: <TUE.16.DEC.2003.130251.0600.PSANDERS@ILSTU.EDU>

Stovers,

With all of the discussion about chimneys, the "gasifier folks" have been
quite quiet. I cannot speak for all of us, but I can say the following
from my experiences and contacts with others:

1. We do not have build-up of soot or other stuff in our chimneys. We
COULD have soot, etc, of if the gasifier stoves were improperly used or has
bad fuel. But our entire combustion arrangement is intended to create the
gases (smoke) and then burn it very completely. From ignition to the end
of pyrolysis, our entire operation is "smoke-burning."

2. Note that Tom Reed's campstove has no chimney at all. 2.5 years ago,
when I first met Tom and saw an early prototype that got me involved with
stoves, he lit that stove on a kitchen table inside an American
home. Absolutely impressive. No smoke. No problems. I would rather be
in an enclosed room with Tom's functioning gasifier than in the same room
with someone smoking tobacco for the same amount of time. Note that Tom
has forced air, so he has more control, and no need for a chimney to get
natural draft.

3. Most of us "gasifier-people" are using natural draft. For us, the
chimney is primarily for the draft, and not for the removal of gases. BUT
the removal of the limited amount of undesirable gases, etc. via a chimney
IS a nice feature.

4. We do not have years and years of usage of small gasifiers for cooking
stoves, so we cannot give hard data about build-up of soot, etc. So we
cannot (and do not want to) make any great claims at present. But we are
following the discussion and we are alert to the issues.

Keep on stovin'

From solar1 at ZUPER.NET Tue Dec 16 15:59:52 2003
From: solar1 at ZUPER.NET (Sobre la Roca: Energ=?ISO-8859-1?B?7Q==?=a Solar para el
Desarrollo)
Date: Tue Aug 10 18:30:46 2004
Subject: Clean air proposal Announcement - BOLIVIA
Message-ID: <TUE.16.DEC.2003.165952.0400.SOLAR1@ZUPER.NET>

Dear Stovers,

It was so wonderful to read Crispin's news the other day concerning his
invitation to submit a proposal for EPA's Clean Air grant. I had traveled
from 3 towns away to find the only jungle internet caf?. Turns out they
only had one machine and I had to wait more than an hour while someone else
like me from far away used it at a cost 5 times what one pays in the city.

Fully a week later, back in La Paz, sluggish and with a head ache because of
the change from 600 meters above sea level to 3,600 meters within a few
hours, I was cleaning my emails and wham! Notice from EPA arrived to us too!

We hope this will interest the list.

The notice states - ----------------
Thank you for applying for the United States Environmental
Protection Agency?s (USEPA) Partnership for Clean Indoor Air Pilot
Projects Grant Program. EPA received concept proposals in
response to the Request For Proposals (RFP) representing household
energy programs from throughout the world. I am pleased to announce
that the review panel has selected your organization to submit a full
proposal.

In order to proceed to the next phase of submitting a full
proposal, applicants had to adequately demonstrate the health outcomes
of their past or current household energy programs. In addition, they
had to propose a comprehensive household energy program (addressing
social/behavioral issues, market development, technology design and
performance, and exposure/health effects monitoring) which is likely to
increase the use of improved home cooking and/or heating practices and
reduce people's exposure to indoor air pollutants in homes. Your
concept proposal met this criteria. We look forward to receiving your full
proposal by January 15, 2004.
---------
Here is an excerpt from the Concept proposal. CEDESOL in English means
Center for Development with Solar Energy . . . .

As a new Foundation, CEDESOL cannot claim measurable results from past
programs except that recently at least 4 countries included improved
cook-stoves in their country?s energy policy, possibly as a result of
information we presented at the recent GVEP conference, July 2003 at Santa
Cruz, Bolivia. However, our founders and staff bring impressive
implementation experiences from diverse programs and we apply these
synergistic individual successful practices to help the poor, protect the
environment, increase gender equality, and realize sustainable development
through applying appropriate technologies, alternative education, and good
management practices as a strategy to achieve social justice.

For example, applying methodology developed by David and Ruth Whitfield,
1,500 solar cookers have been incorporated into the Bolivian and southern
Peruvian cultures in diverse climate zones and social levels since 2000.
Solid scientific data validate the effectiveness of the approach and
methodology utilized.

Increased health, better nutrition and an overall higher quality of life are
measurable major benefits from their usage, which also affect sustainable
development. What distinguishes this use of existing technologies is the
unique way in which several technologies were combined into one system, each
complimenting the others and eliminating many of the previous barriers that
prevented incorporation of these technologies into developing cultures.
Respondents to surveys suggest 65% fuel reduction, recuperation of about 11
productive hours a week and better nutrition are the results of utilizing
these household energy delivery systems (implying better health and safer
cooking conditions while reducing CO2 by about 2.5 tons per year per
family).
http://www.repp.org/discussiongroups/resources/stoves/#David_Whitfield
http://www.she-inc.org/whitfield.htm ,
http://www.she-inc.org/article.php?id=23 ,
Our vision of improved stoves is integrated use of efficient biomass,
retained heat and solar cooking.

Part of CEDESOL?s stated corporate purpose is to foment micro businesses,
especially in rural areas in order to empower disenfranchised persons in
sustainable development activities. Some of the course participants have
already developed cottage industries to supply these devices within their
geographical areas. The for profit Bolivian business owned and administered
by Ruth de Whitfield, Sobre la Roca is now perusing commercialization of
improved stoves, working through folks that had participated in the hands on
courses.

PROJECT OVER VIEW
We believe a decentralized distribution system is necessary to facilitate
the appropriation of this technology by the needy so that their use becomes
incorporated into the culture beyond the project?s funding period.

Two critical factors traditionally receive least funding prospects; public
awareness, and business development. Rather than focus on stove
dissemination (although this is an element in the project), this project
will develop new business models, identify seed capital resources for
implementing the new enterprises, educate public, government and civil share
holders to health impacts and interventions and promote the implementation
of these practices. The project design and initial implementation (to
establish model viability) will be accomplished during the 2 - year pilot
phase, while the project?s timeline is approximately 5 years.

This project proposes to inform 1 million households, help create 30 - 50
small regional businesses and deliver through micro credit operations 15,000
integrated cooking systems to families (impacting directly approximately
68,000 people), in 3 distinct climate zones, representative, not only of
Bolivia but South America as a whole.

National and international universities will partner with national health
agencies to monitor existing and mitigation effects. Results will be
published and disseminated nationally and internationally.

OUR PROJECT TEAM INCLUDES
David Whitfield, Executive Director of CEDESOL Foundation, educated in
social and environmental sciences brings technological and practical
development experience into the organization.

Pedro Beccar, Financial Director, has a strong business administration and
international relations background, with grant managing experience. He is
responsible for overseeing administration of the Foundation, its projects
and enlaces with government.

Dr. Esther Balboa, Educational Director, - an anthropologist, has extensive
experience in alternative energies, publications, elaboration of didactical
material and communications. She was the vice presidential candidate for an
indigenous party during the last Bolivian elections and is internationally
respected for her integrity and understanding of rural cultures. She speaks
3 native languages. Part of her contribution is volunteered.

Gonzalo Terceros R., Projects Coordinator, a sociologist and ex Mayor of
Cochabamaba, has extensive experience in project management, team building,
grant implementation, governmental relations and problem solving. He
partially works as a volunteer.

Ilse Gisela Revollo, Administrative Coordinator, has a background in
business administration and works with micro enterprise development.

Jose Luis Rivero, Coordinator General, specializes in communication and
alternative education. He coordinates planning, radio and video
productions, organizational and managerial development and training.

Mery Norma Montalvo, a systems engineer is responsible for internal
communications, information flow and will be publishing project activities
on the Web.

Mario Ortu?o is auditor and accountant under the Financial Director. He
also helps in teaching micro enterprise accounting. He speaks Quechua and
some Aymara.

We have 5 ecological cooker trainers and construction technicians, who speak
either Quechua or Aymara.

Other human resources are added as required, but we try to work with support
from specialty organizations to reduce full time employees and make use of
talent already developed within these external organizations.

Please join us in hoping that both Crispin's organization and ours receive
final grant approval.

If Crispin in South Africa was excited about the little guys being listened
to, imagine how we feel here in Bolivia! ;-)

We welcome your advice and experience.
Un abrazo
David

--
How do I work. I grope. -- Albert Einstein (1879-1955)

David Whitfield
Director
CEDESOL
P.O. Box 4723
La Paz Bolivia South America
591-2-2414882 office 591 715 16356 cellular
591 4 4258093 Cochabamba 591 774 24269

solar1@zuper.net
aguaviva@zuper.net
dewv@yahoo.com
http://www.solarcooking.org/media/broadcast/whitfield/bio-whitfield.htm

http://www.thehungersite.com

From hseaver at CYBERSHAMANIX.COM Wed Dec 17 01:25:24 2003
From: hseaver at CYBERSHAMANIX.COM (Harmon Seaver)
Date: Tue Aug 10 18:30:46 2004
Subject: Chimneys
In-Reply-To: <004d01c3c3e2$86914b40$f19a0a40@kevin>
Message-ID: <WED.17.DEC.2003.002524.0600.HSEAVER@CYBERSHAMANIX.COM>

On Tue, Dec 16, 2003 at 10:39:38AM -0400, Kevin Chisholm wrote:

(snip)
>
> As an interesting aside, I took great personal pride in being able to spot a
> home that was being heated by a "Suburban Woodmaster" stove, while driving
> down the road at 60 miles per hour. All I had to do was look for the liquid
> creosote draining out the ashpit door of the external chimney. :-) The
> Suburban Woodmaster was a lovely looking "parlour stove" that had a grate
> and ash drawer. All the wood was placed on the grate and all the combustion
> air came up through grate. It is a wonderful example of what not to do when
> the goal is to build a wood stove that has low emissions.
>

I was going down the highway late one night, came by a house literally
enveloped in a thick cloud of smoke which extended out across the
highway. Thinking that the house was one fire, and seeing no lights on, I turned
around and went back to alert the owners or neighbors or someone. Then I saw
they had one of the infamous "outside wood boilers" in the back yard.

(snip)

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

From kchisholm at CA.INTER.NET Wed Dec 17 13:23:08 2003
From: kchisholm at CA.INTER.NET (Kevin Chisholm)
Date: Tue Aug 10 18:30:46 2004
Subject: Chimneys
Message-ID: <WED.17.DEC.2003.142308.0400.KCHISHOLM@CA.INTER.NET>

Dear Harmon
del....
> I was going down the highway late one night, came by a house literally
> enveloped in a thick cloud of smoke which extended out across the
> highway. Thinking that the house was one fire, and seeing no lights on, I
turned
> around and went back to alert the owners or neighbors or someone. Then I
saw
> they had one of the infamous "outside wood boilers" in the back yard.
>
They are indeed a wonderful lesson on how not to build a wood stove or
boiler. They employ the same basic principles as the Suburban Woodmaster:
1: Much of combustion air comes in through the grate on which a large
quantity of fuel is stored.
2: Products of combustion pass up through the wood fuel
3: Some of these boilers have "secondary air", but most do not. When the do
have secondary air, it is only supplied when the boiler is operating on
"high fire."
3: They have a "chilled surface" in the firebox area, that is wonderfully
effective in chilling the combustion process.

"Outside boilers" like this give woodburning a bad name.

Kevin

From english at KINGSTON.NET Thu Dec 18 07:07:31 2003
From: english at KINGSTON.NET (english@KINGSTON.NET)
Date: Tue Aug 10 18:30:46 2004
Subject: Chimneys
In-Reply-To: <004d01c3c3e2$86914b40$f19a0a40@kevin>
Message-ID: <THU.18.DEC.2003.070731.0500.>

Kevin,
Discussions about improved combustion have swirled around this list for
almost a decade now. The challenge is significant out in the field.
A work in progress to be sure.

I sense that chimneys, simple as they seem, have not been discussed on the same
level. There are some technical aspects to venting that are being taken for granted, that
are a kin to setting highway speed limits based on dry road conditions.

Education will always be a partial solutio as will good technical design.

So in the wordy absence of numbers let me through some out there, that others in the
field might report back in kind.

When my heating stove has an internal stack temperature of 450F the external surface
temperature of the single walled stove pipe (1.5 m abouve the stove) drops below the
boiling point of water (212F). A second layer, or double wall, creating a radiant sheild
and reducing convective losses, raises that temperature 50F.

Just a beginning, Alex
PS. The major advantage of a good stove is that it gives the designer a chance to
to design a chimney that will minimize the costs of operator error. :-)
> The major advantage of a chimney, as I see it, is that it gives the designer
> an opportunity to design a stove that will not plog the chimney. :-)
>
> Kindest regards,
>
> Kevin
>

From krishnakumar_07 at YAHOO.CO.UK Thu Dec 18 07:31:42 2003
From: krishnakumar_07 at YAHOO.CO.UK (=?iso-8859-1?q?krishna=20kumar?=)
Date: Tue Aug 10 18:30:46 2004
Subject: NDG
In-Reply-To: <007401c3c11f$cefdeac0$81387f41@oemcomputer>
Message-ID: <THU.18.DEC.2003.123142.0000.KRISHNAKUMAR07@YAHOO.CO.UK>

Sir,
The queries you have asked me are

1.Can you give me more information?

I am yet to start the detailed readings on this i
have noted the flame tempreture to be 677 deg
centigrade and the bed tempreture was 1044 deg
centigrade. I have yet to set the thermocouples for
the detailed readings.

What kind of pots are used?
I am using alluminium pots.

Is cooking done indoors?
At present i am doing it on the open space

Is yes: What materials and how is the roof
constructed?
What size is the room? and ceiling height?
NA

Is the cook stove also used for heating the house?
I could get you.

How far to the nearest electrical source to use power
tools to build stoves and chimneys?

Is the place of installation for a village it is of
5-10 km away.

What raw materials are available to use for building
stoves? Drums? kiln for ceramics/fire clay/ fire
bricks? sheet metals? insulation?
metal
roofing?

buckets?
Clay is available in plenty,
because the houses here all are mud houses.
Hence the materials i have made of concrete.
And fired clay can also be used.

What are you drying in the manual drying units?
No, in manual dyeing units for the colouring of the
threads that are used in cloths making because there
plenty here in my state which is around 400 km from
the place i live.

thank you

--- Lanny Henson <lanny@ROMAN.NET> wrote: > Dear
Krishna,
> Thanks for telling us about your work to improve
> cook stoves in Tamil Nadu
> and other villages in India.
> Can you give me more information?
> What kind of pots are used?
> Is cooking done indoors?
> Is yes: What materials and how is the roof
> constructed?
> What size is the room? and ceiling height?
> Is the cook stove also used for heating the house?
> How far to the nearest electrical source to use
> power tools to build stoves
> and chimneys?
> What raw materials are available to use for building
> stoves? Drums? buckets?
> kiln for ceramics/fire clay/ fire bricks? sheet
> metals? insulation? metal
> roofing?
> What are you drying in the manual drying units?
> Lanny Henson
>
>
>
>
> ----- Original Message -----
> From: krishna kumar <krishnakumar_07@yahoo.co.uk>
> To: Ron Larson <ronallarson@QWEST.NET>
> Cc: <STOVES@LISTSERV.REPP.ORG>; <lanny@ROMAN.NET>
> Sent: Friday, December 12, 2003 6:35 AM
> Subject: Re: [STOVES] NDG
>
>
> > I would really thank you Dr.Ron & Dr.Lanny
> > for providing useful information.
> >
> > Basically my project is using the Natural
> Draft
> > Gasifier for cooking and thermal application.
> >
> > Actually I was on a survey for solar home
> lighting
> > and street lighting, on visiting many places in
> the
> > villages I found that on improving the cooking
> > standards in the villages in Tamil Nadu.Thats how
> I
> > got the idea.
> >
> > I have seen in manual dyeing units the
> tempreture
> > of water is around 60- 80 degree centigrade.They
> use
> > open fire for their operation,which produces a lot
> of
> > smoke and workers feel it difficult to stand
> beside
> > and work.Hence I would like to use this NDG over
> there
> > also.
> >
> >
> >
> >
> > --- Ron Larson <ronallarson@QWEST.NET> wrote: >
> > Krishna:
> > >
> > > I fear giving advice without knowing more of
> > > your design. Please send
> > > to either this list or, if photographic to
> > > mailto:tmiles@trmiles.com
> > >
> > > My experience with what might be similar is
> that
> > > the combustion chamber
> > > (which also serves as a chimney) needs to be
> about
> > > 150% as high as the
> > > diameter. If too short, combustion will not be
> > > complete (as you appear to
> > > be observing) and the pyrolysis gases will leave
> too
> > > much soot on surfaces
> > > you (I hope) are trying to heat up. Also with
> too
> > > short a
> > > combustion/chimney region, you will not develop
> a
> > > sufficiently good pressure
> > > difference and not draw enough primary air
> through
> > > your fuel supply (which I
> > > hope you are lighting from the top).
> > >
> > > If the combustion area/chimney is too long,
> you
> > > are probably losing more
> > > useful energy than you need to. If you are not
> > > planning something useful
> > > for the pyrolysis gases, the chimney can be very
> > > tall.
> > >
> > > Ron
> > >
> > > ----- Original Message -----
> > > From: krishna kumar
> <krishnakumar_07@YAHOO.CO.UK>
> > > To: <STOVES@LISTSERV.REPP.ORG>
> > > Sent: Monday, December 08, 2003 4:24 AM
> > > Subject: NDG
> > >
> > >
> > > > ---------------------- Information from the
> mail
> > > header -----------------------
> > > > Sender: The Stoves Discussion List
> > > <STOVES@LISTSERV.REPP.ORG>
> > > > Poster: =?iso-8859-1?q?krishna=20kumar?=
> > > <krishnakumar_07@YAHOO.CO.UK>
> > > > Subject: NDG
> > > >
> > >
> >
>
--------------------------------------------------------------------------
> > > -----
> > > >
> > > > I have fabricated the natural draft
> gasifier
> > > > with conrete and coated inside with clay.
> > > >
> > > > I have made a trail run of it and it
> worked
> > > > satisfactorlly.The flame reached to a height
> of
> > > > 1-1.25ft above the top of the stove.
> > > >
> > > > Then i tried with clossing the top of the
> stove
> > > > with a lid and taking the gas seperately and
> > > burning
> > > > it through a burner. but i was unsuccesful in
> > > burning
> > > > the gas,
> > > > The gas came out through the primairy air
> port
> > > > and it did not gasify the wood inside.
> > > >
> > > > i would like to know about the chimney
> effect
> > > > and draft to create the gas to come out of
> the
> > > pipe.
> > > >
> > > >
> > > >
> > > > =====
> > > > krish
> > > >
> > > >
> > >
> >
>
________________________________________________________________________
> > > > BT Yahoo! Broadband - Save ?80 when you order
> > > online today. Hurry! Offer
> > > ends 21st December 2003. The way the internet
> was
> > > meant to be.
> > >
> >
>
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> > > >
> >
> > =====
> > krish
> >
> >
>
________________________________________________________________________
> > BT Yahoo! Broadband - Save ?80 when you order
> online today. Hurry! Offer
> ends 21st December 2003. The way the internet was
> meant to be.
>
http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> >

=====
krish

________________________________________________________________________
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From ventfory at IAFRICA.COM Thu Dec 18 08:52:47 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:46 2004
Subject: chimney problems
Message-ID: <THU.18.DEC.2003.155247.0200.VENTFORY@IAFRICA.COM>

Paul,

I agree with your rationale that small gasifying stoves burn the smoke and unless we are dealing with a "bad fuel" or have "improper usage" there should not be much soot.

Tom's campstove (based on his earlier IDD stove) emits almost negligent amounts of visible smoke, but I surmise also little CO too which indicates complete combustion. He has achieved this without the need for a chimney in his initial designs, but due to the need to change the airflow through the stove to efficiently burn the resultant char he added the fan - hence a complete and smokeless burn from start to finish.

Instead of adding a fan it could be possible to achieve simultaneous pyrolysis of the biomass and gasification of resultant char by increasing the airflow through the stove by adding an external chimney to allow for complete biomass and char burning. One would have to raise combustion temperatures beyound 900?C (when charcoal gases off). This is theoretically possible - by improving on chamber insulation techniques. Failing that, the external chimney could remain, but is only opened/activated at the start of the char burning phase to consume the higher CO gases now being released. The chimney will last long this way as charcoal does not give off much soot - right?.

--------------

----- Original Message -----
From: Paul S. Anderson <psanders@ILSTU.EDU>
To: <STOVES@LISTSERV.REPP.ORG>
Sent: 16 December 2003 21:02
Subject: Re: [STOVES] chimney problems

> Stovers,
>
> With all of the discussion about chimneys, the "gasifier folks" have been
> quite quiet. I cannot speak for all of us, but I can say the following
> from my experiences and contacts with others:
>
> 1. We do not have build-up of soot or other stuff in our chimneys. We
> COULD have soot, etc, of if the gasifier stoves were improperly used or
has
> bad fuel. But our entire combustion arrangement is intended to create the
> gases (smoke) and then burn it very completely. From ignition to the end
> of pyrolysis, our entire operation is "smoke-burning."
>
> 2. Note that Tom Reed's campstove has no chimney at all. 2.5 years ago,
> when I first met Tom and saw an early prototype that got me involved with
> stoves, he lit that stove on a kitchen table inside an American
> home. Absolutely impressive. No smoke. No problems. I would rather be
> in an enclosed room with Tom's functioning gasifier than in the same room
> with someone smoking tobacco for the same amount of time. Note that Tom
> has forced air, so he has more control, and no need for a chimney to get
> natural draft.
>
> 3. Most of us "gasifier-people" are using natural draft. For us, the
> chimney is primarily for the draft, and not for the removal of gases. BUT
> the removal of the limited amount of undesirable gases, etc. via a chimney
> IS a nice feature.
>
> 4. We do not have years and years of usage of small gasifiers for cooking
> stoves, so we cannot give hard data about build-up of soot, etc. So we
> cannot (and do not want to) make any great claims at present. But we are
> following the discussion and we are alert to the issues.
>
> Keep on stovin'
>
> 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 ventfory at IAFRICA.COM Thu Dec 18 09:01:24 2003
From: ventfory at IAFRICA.COM (Kobus)
Date: Tue Aug 10 18:30:46 2004
Subject: Feedback - briquette gasifier stove
Message-ID: <THU.18.DEC.2003.160124.0200.VENTFORY@IAFRICA.COM>

Hi all,

Just a quick report back on progress made by myself and Richard on the development of a briquette gasifying stove. Our more practical process-of-elimination-approach has prompted us to explore all possibilities and experiment with various different airflow speeds through, placements inside and quantities supplied into the combustion chamber. What we have discovered is that the combustion chamber height was most crucial, then position and direction of the air inlets and lastly quantity of air drawn into the reaction. The position of the air inlets refer to both primary and secondary air.

More surprisingly perhaps we had to alter the briquette shape (height of briquette and width of centre hole in particular) which evolved in conjunction with the placement and quantity of primary and secondary air. The centre hole in the briquette started to play a more pivotal role as it acted as a mini chimney, mini combustion chamber and departure point of the pot licking flame. We have it set up now so that the primary air feeds the centre hole and secondary air aiding the flame height (much like a candle) as well as gasifying the outside of the briquette.

We have tested our stove for CO (ppm) with my new HOBO CO datalogger and discovered that a 90 gram briquette (60% paper, 40% Eucalyptus sawdust) gave off an average ppm count of 17 (CO) for a gas burn length lasting 15 min and 50 seconds. The charcoal burn lasted for another 23 minutes giving off an average ppm count of 53 (CO) for that period. We advise removing the pyrolysed briquette before the char burn commences.

More later on the CO ppm count from my charcoal gasifier stove and I have news on the local development of an Ethanol stove.
------------

From lanny at ROMAN.NET Fri Dec 19 04:56:14 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:46 2004
Subject: NDG
Message-ID: <FRI.19.DEC.2003.045614.0500.LANNY@ROMAN.NET>

Dear Krishna,
Thank you for your answers to my questions. I Have a few more if that is OK.
How much do the cooking pots hold?
How many pots are used to cook a meal?
What foods are cooked in poor areas, rice? corn? beans? wheat?
If electric power is within 10 to 20Km, that is not too far to transport a
stove. So practical stove design could use electricity in the construction.
Steel drums can be cut and used to make stoves and NDG outer shells. Are
drums avaliable?
How many liters are you heating in the dyeing tanks? Is there room to get a
NDG under the drying units or do you need to flow into the side or down
under the unit?
Lanny Henson

----- Original Message -----
From: krishna kumar <krishnakumar_07@yahoo.co.uk>
To: Lanny Henson <lanny@ROMAN.NET>
Cc: <STOVES@LISTSERV.REPP.ORG>
Sent: Thursday, December 18, 2003 7:31 AM
Subject: Re: [STOVES] NDG

> Sir,
> The queries you have asked me are
>
> 1.Can you give me more information?
>
> I am yet to start the detailed readings on this i
> have noted the flame tempreture to be 677 deg
> centigrade and the bed tempreture was 1044 deg
> centigrade. I have yet to set the thermocouples for
> the detailed readings.
>
> What kind of pots are used?
> I am using alluminium pots.
>
> Is cooking done indoors?
> At present i am doing it on the open space
>
> Is yes: What materials and how is the roof
> constructed?
> What size is the room? and ceiling height?
> NA
>
> Is the cook stove also used for heating the house?
> I could get you.
>
> How far to the nearest electrical source to use power
> tools to build stoves and chimneys?
>
> Is the place of installation for a village it is of
> 5-10 km away.
>
> What raw materials are available to use for building
> stoves? Drums? kiln for ceramics/fire clay/ fire
> bricks? sheet metals? insulation?
> metal
> roofing?
>
> buckets?
> Clay is available in plenty,
> because the houses here all are mud houses.
> Hence the materials i have made of concrete.
> And fired clay can also be used.
>
> What are you drying in the manual drying units?
> No, in manual dyeing units for the colouring of the
> threads that are used in cloths making because there
> plenty here in my state which is around 400 km from
> the place i live.
>
> thank you
>
>
>
>
> --- Lanny Henson <lanny@ROMAN.NET> wrote: > Dear
> Krishna,
> > Thanks for telling us about your work to improve
> > cook stoves in Tamil Nadu
> > and other villages in India.
> > Can you give me more information?
> > What kind of pots are used?
> > Is cooking done indoors?
> > Is yes: What materials and how is the roof
> > constructed?
> > What size is the room? and ceiling height?
> > Is the cook stove also used for heating the house?
> > How far to the nearest electrical source to use
> > power tools to build stoves
> > and chimneys?
> > What raw materials are available to use for building
> > stoves? Drums? buckets?
> > kiln for ceramics/fire clay/ fire bricks? sheet
> > metals? insulation? metal
> > roofing?
> > What are you drying in the manual drying units?
> > Lanny Henson
> >
> >
> >
> >
> > ----- Original Message -----
> > From: krishna kumar <krishnakumar_07@yahoo.co.uk>
> > To: Ron Larson <ronallarson@QWEST.NET>
> > Cc: <STOVES@LISTSERV.REPP.ORG>; <lanny@ROMAN.NET>
> > Sent: Friday, December 12, 2003 6:35 AM
> > Subject: Re: [STOVES] NDG
> >
> >
> > > I would really thank you Dr.Ron & Dr.Lanny
> > > for providing useful information.
> > >
> > > Basically my project is using the Natural
> > Draft
> > > Gasifier for cooking and thermal application.
> > >
> > > Actually I was on a survey for solar home
> > lighting
> > > and street lighting, on visiting many places in
> > the
> > > villages I found that on improving the cooking
> > > standards in the villages in Tamil Nadu.Thats how
> > I
> > > got the idea.
> > >
> > > I have seen in manual dyeing units the
> > tempreture
> > > of water is around 60- 80 degree centigrade.They
> > use
> > > open fire for their operation,which produces a lot
> > of
> > > smoke and workers feel it difficult to stand
> > beside
> > > and work.Hence I would like to use this NDG over
> > there
> > > also.
> > >
> > >
> > >
> > >
> > > --- Ron Larson <ronallarson@QWEST.NET> wrote: >
> > > Krishna:
> > > >
> > > > I fear giving advice without knowing more of
> > > > your design. Please send
> > > > to either this list or, if photographic to
> > > > mailto:tmiles@trmiles.com
> > > >
> > > > My experience with what might be similar is
> > that
> > > > the combustion chamber
> > > > (which also serves as a chimney) needs to be
> > about
> > > > 150% as high as the
> > > > diameter. If too short, combustion will not be
> > > > complete (as you appear to
> > > > be observing) and the pyrolysis gases will leave
> > too
> > > > much soot on surfaces
> > > > you (I hope) are trying to heat up. Also with
> > too
> > > > short a
> > > > combustion/chimney region, you will not develop
> > a
> > > > sufficiently good pressure
> > > > difference and not draw enough primary air
> > through
> > > > your fuel supply (which I
> > > > hope you are lighting from the top).
> > > >
> > > > If the combustion area/chimney is too long,
> > you
> > > > are probably losing more
> > > > useful energy than you need to. If you are not
> > > > planning something useful
> > > > for the pyrolysis gases, the chimney can be very
> > > > tall.
> > > >
> > > > Ron
> > > >
> > > > ----- Original Message -----
> > > > From: krishna kumar
> > <krishnakumar_07@YAHOO.CO.UK>
> > > > To: <STOVES@LISTSERV.REPP.ORG>
> > > > Sent: Monday, December 08, 2003 4:24 AM
> > > > Subject: NDG
> > > >
> > > >
> > > > > ---------------------- Information from the
> > mail
> > > > header -----------------------
> > > > > Sender: The Stoves Discussion List
> > > > <STOVES@LISTSERV.REPP.ORG>
> > > > > Poster: =?iso-8859-1?q?krishna=20kumar?=
> > > > <krishnakumar_07@YAHOO.CO.UK>
> > > > > Subject: NDG
> > > > >
> > > >
> > >
> >
> --------------------------------------------------------------------------
> > > > -----
> > > > >
> > > > > I have fabricated the natural draft
> > gasifier
> > > > > with conrete and coated inside with clay.
> > > > >
> > > > > I have made a trail run of it and it
> > worked
> > > > > satisfactorlly.The flame reached to a height
> > of
> > > > > 1-1.25ft above the top of the stove.
> > > > >
> > > > > Then i tried with clossing the top of the
> > stove
> > > > > with a lid and taking the gas seperately and
> > > > burning
> > > > > it through a burner. but i was unsuccesful in
> > > > burning
> > > > > the gas,
> > > > > The gas came out through the primairy air
> > port
> > > > > and it did not gasify the wood inside.
> > > > >
> > > > > i would like to know about the chimney
> > effect
> > > > > and draft to create the gas to come out of
> > the
> > > > pipe.
> > > > >
> > > > >
> > > > >
> > > > > =====
> > > > > krish
> > > > >
> > > > >
> > > >
> > >
> >
> ________________________________________________________________________
> > > > > BT Yahoo! Broadband - Save ?80 when you order
> > > > online today. Hurry! Offer
> > > > ends 21st December 2003. The way the internet
> > was
> > > > meant to be.
> > > >
> > >
> >
> http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> > > > >
> > >
> > > =====
> > > krish
> > >
> > >
> >
> ________________________________________________________________________
> > > BT Yahoo! Broadband - Save ?80 when you order
> > online today. Hurry! Offer
> > ends 21st December 2003. The way the internet was
> > meant to be.
> >
> http://uk.rd.yahoo.com/evt=21064/*http://btyahoo.yahoo.co.uk
> > >
>
> =====
> krish
>
> ________________________________________________________________________
> Yahoo! Messenger - Communicate instantly..."Ping"
> your friends today! Download Messenger Now
> http://uk.messenger.yahoo.com/download/index.html
>

From andrew.heggie at DTN.NTL.COM Fri Dec 19 17:39:44 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: Comparing paper with wood as fuel.
In-Reply-To: <4.3.1.2.20031216092852.0230c160@mail.ilstu.edu>
Message-ID: <FRI.19.DEC.2003.223944.0000.>

On Tue, 16 Dec 2003 10:32:26 -0600, Paul S. Anderson wrote:

> A sheet of paper will sink in water.

Yes, I admit I was a bit surprised as I had never tried it,

> As one
>person wrote, the specific gravity of water is 1.0, of wood is about 0.5,
>and of paper is about 1.5 (all numbers are very approximate because of
>different types of wood and of paper.)

Here I think you are getting over enthusiastic, I think the 1.5 figure
is an ideal piece of biomass with no air spaces. I doubt most
densification processes go this far, as the cost would be too great.

As a little experiment after testing the assertion that newspaper
sinks I measured a newspaper and weighed it. I made a thickness of 16
sheets to be 1.2mm and the weight about 90g.

This gave me a total volume of 0.000138m3 for a weight of 0.00009
tonnes or .654 tonnes/m3, in UK I suspect we use mainly spruce pulp,
the basic density of spruce is about .33tonne/m3. So the mechanical
pulping does reduce the volume between fibers but does not even reach
the density of water. Please recheck these figures as it was a quick
after supper experiment.

So why does the paper sink? I did not see any air bubbles as the paper
became saturated but think that the pulping process damages the cells
sufficiently for capillary attraction to enable them to become
saturated with water, so instead of the paper being biomass cell walls
with air spaces in between, giving a total density of .65 in air once
saturated the density of the biomass less air spaces was greater than
1. Or have I made a basic mistake?

>
>SO
>We are experimenting with making sheet-paper (specifically newspaper) into
>"briquettes", but WITHOUT mushing it up to become paper pulp again (which
>un-does the "densification" of the pulp when it is pressed into thin sheets.)

On my visit to a pulp mill making kraft paper ( some thermochemical de
lignification involved) there was no pressing done, rather the pulp
was sprayed onto a fast moving web which had a vacuum dewatering
system, after the web the ,by now recognisable but weak, paper ran
over a series of perforated drums which were heated by direct natural
gas flames, the drying was all that was needed to bond the fibers into
paper.

AJH

From crispin at NEWDAWN.SZ Mon Dec 22 10:42:48 2003
From: crispin at NEWDAWN.SZ (Crispin)
Date: Tue Aug 10 18:30:46 2004
Subject: ] Feedback - briquette gasifier stove - Kobus
In-Reply-To: <004a01c3c56f$88ca31e0$48271ec4@kobus>
Message-ID: <MON.22.DEC.2003.104248.0500.>

Dear Kobus

Thanks for your report on the emissions. I wish I had at least one of
your pieces of testing hardware!

A couple of things come to mind:

Have you any way to get a CO:CO2 ratio figure? We are supposed to reach
1:50 to meet the SABS standard.

Something else is that I hope you get a chance to burn one or both of
the briquette sizes in a standard Vesto and tell me how it goes. It
will char the briquettes first and then (if you open the air) burn the
char pretty well. With a hot stove and very little (remnant) charcoal
our normal advice is to lift the stove body off its base to allow free
air flow to the last little bit or else there is a CO spike at the end
of the burn.

I have been reading the SABS test report on the wick-type paraffin stove
and it is pretty horrific. The CO/CO2 ratio is 75:1000 once it gets
going (worse before that).

Can you switch that logger back and forth between CO and CO2 levels to
get a ratio?

Happy Winter Solstice!
Crispin in Whitby Ontario for a change = cold!

From dstill at EPUD.NET Wed Dec 24 12:19:13 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:46 2004
Subject: Happy Holidays!
Message-ID: <WED.24.DEC.2003.091913.0800.DSTILL@EPUD.NET>

Dear Friends,

Winter sun is as lazy as I feel these mornings, peaking up out of the
covers, maybe looking forward to a great stiff cup of coffee as much as me.
Drinking huge yardsticks of lemonade were an upside to the heat in the
Mexican desert, the comfort of hot coffee is certainly enhanced by winter in
the grey Willamette valley.

Eneagram folks in the church say that personality strength is also one?s
inherent weakness. Winter offers a perfect example that an abiding
characteristic, the cold, can be appreciated or feared.

At NOLS in the desert we had to teach freezing students how to take care of
themselves. College students would sit, teeth chattering, wretched, too
lethargic to put on the clothing that would conserve their heat, allow them
to live outdoors. Did you know that Outward Bound and then NOLS were started
because young soldiers died next to older soldiers who lived in the cold, in
the heat? The weather was in context for the older guys but new and
frightening to the na?ve.

O yes, there I am, doing all that same me stuff again
The Norwegians? say
that there is no such thing as bad weather
only bad clothing. So, I pull on
my stupid looking stocking cap that always makes my teenage boys laugh, wear
the thick socks and coat and aim to be at peace with the weather, at peace
with who I am, sipping Christmas coffee.

Wishing us the best of the season and the best from life!

Dean

From andrew.heggie at DTN.NTL.COM Wed Dec 24 18:22:28 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: ] Feedback - briquette gasifier stove - Kobus
In-Reply-To: <3FE710F8.2040505@newdawn.sz>
Message-ID: <WED.24.DEC.2003.232228.0000.>

On Mon, 22 Dec 2003 10:42:48 -0500, Crispin wrote:

>
>Have you any way to get a CO:CO2 ratio figure? We are supposed to reach
>1:50 to meet the SABS standard.

Is this a mass ratio or volume ratio? If you have CO and excess air
measurements you can derive CO2 from knowing the fuel chemistry. Each
time I ,infrequently, go back to the chemistry of combustion I have to
clear away 35 years of cobwebs as I have no texts here. A 1:50 volume
ratio of CO to CO2 would mean, using an idealised biomass of C6H10O5,
that for every:

C6H10O5+3O2+12N2=>5H2O+6CO+12N2

there would be

50 C6H10O5+6O2+24N2=>5H2O+6CO2+24N2

reactions

Now a quick play with the spreadsheet suggests this is a mass ratio of
about 3000 parts per million and a volume ratio of a bit more on the
total flux. So either my calculations are way out or this is not a
hard target to meet.

I had hoped there would be a bit more on list comment on Tami's
comments about attaining critical temperatures in the burn, this is
highly related to both moisture content in the fuel and excess air
(which themselves have a positive relationship). Now any one know's
that burning wet wood is bad but this mass flow relationship explains
why wet wood is unlikely to burn completely. In effect there is a
large negative feedback if pics are discharged as their heat value is
lost from the combustion region. Recent reports suggest that as well
as the problems of sub 10 micron class particles emitted as pics
damaging lungs they are a bigger than expected cause of global
warming, through both direct absorbtion of radiation as well as
effects on the albedo of snow covered areas.

Merry Christmas all

AJH

From andrew.heggie at DTN.NTL.COM Wed Dec 24 18:22:32 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: Low-cost briquette press
In-Reply-To: <009801c3c7d6$34018730$c20cc13f@ROD>
Message-ID: <WED.24.DEC.2003.232232.0000.>

On Sun, 21 Dec 2003 22:17:35 +0700, Robert Deutsch wrote:

>Dear Andrew and Harmon and all,
>
>I'm wondering if the manual lever arm press described at www.echonet.org

Sorry couldn't see it on the page and haven't had time to search the
site. Paul Sanderson and I have discussed the cinva "lever arm block
maker" I suggested this could be modified to form holes and allow
drainage, with a bit of extra compression at the end of travel
provided by a roller cam. This should aid in dewatering the briquette
and hence drying.

>could be motorized with a small horse power electric motor driving a cam or
>crank shaft through a belt drive reduction. It wouldn't put much travel in
>the lever arm, but energy consumption should be low and the mold could be
>progressively advanced towards the pivot point through several cycles until
>the required compression is achieved. Any thoughts?

My thoughts for this subject are fairly basic, the amount of work put
into the compressing consists of the force time distance of moving the
fibres together plus the friction losses in doing so. Once compressed
the fibers need to be retained in the compressed state, if the
compression achieves permanent deformation (as I suspect happens in
Richard Stanley's mushy briquette) then no binding is necessary, if
not then there is a loss of compression energy as the fibers spring
back against whatever retaining medium (string, wire etc) is used.
Each relaxation as the pivot point changed would be a loss of energy.
This is no big deal if the power comes from a fossil fueled engine,
not acceptable if some poor grunt is doing the work.

With woody types of biomass there is typically a high length to
diameter ratio which makes conventional balers unsuitable.

In uk we had a number of manual "baling engines" that woodland workers
used to achieve the result of a portable bundle of reasonable bulk
density. One of my neighbours still has the remains of a pimp engine
his father used to use to make kindling bundles for sale to local
shops in the 50s. More recently I have seen the large, forwarder
based, balers from Scandinavia to facilitate the uplift and onward
transport of sausage shaped bales for use in heating and power plants.

AJH

From andrew.heggie at DTN.NTL.COM Wed Dec 24 18:22:38 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: Uncarbonised biomass densification ( was third world energy)
In-Reply-To: <00c801c3c2eb$78397380$3341083e@toshibauser>
Message-ID: <WED.24.DEC.2003.232238.0000.>

On Mon, 15 Dec 2003 10:37:26 +0300, Elsen Karstad wrote:

>
>Anyway- this flash drier is supposed to be fed hot gasses from a simple
>brick furnace burning 'baled' fresh bagasse (50% moisture content when
>collected straight from the factory). We've been offered a baler with the
>drier, but I reckon we can make one here. I'm trying to get the relevant
>dimensions and maybe even pressure info from the supplier... who may or may
>not cooperate.

I take it this is a concurrent flow device?

The baling is necessary only in order to ensure enough mass is in the
burner without needing constant stoking?
>
>The flash drier is designed to produce 1500 kg/hour dried bagasse at 5 to 7%
>moisture the wet feedstock. Air/gas input temps are between 300 & 350 C, and
>I assume that this is direct from the combustor & not via a heat exchange
>system. Indian equipment is generally very simple- just the way I like it.

So the flue of the burner is mixed with dilution air before meeting
the wet feedstock?
>
>I've got a pretty massive hydraulic ram here, leftover from a fishmeal plant
>I used to operate. I'm planning to use this as a ram compactor of some type-
>should be fairly straightforward. It's got a pretty long stroke though- over
>1 meter. I'll start some tests on this soon.

How far have you got?
>
> I don't envision producing a true 'log' via extremely high heat &
>temperature- just a baler of some type, maybe even bound slightly with
>molasses. Optimally, I'd use the wet factory-fresh bagasse & de-water
>somewhat during compression.

I would expect the moisture content to be well above 50% if you can
readily squeeze water out of it, it may still be a worthwhile trade
off of power versus heat energy to dry.

>My first decision would be whether to design
>this as a single stroke system producing one 'log' per stroke (maybe 4 inch
>dia by 6 inch long) or a tapered die outlet where the cylinder exit remains
>open.
>
>Any suggestions on how a densifier of this type should be made would be
>appreciated. I'll start my usual trial & error engineering process here in
>the new year..........

You have confused me, I cannot see the benefit in densifying a low
value fuel for your dryer, it strikes me as an unnecessary step and
wasteful of motive power. I can see the need for compacting a bundle
of agriwaste to facilitate onward handling.

It's cold and wet here, perhaps I should come over for a chat ;-)

AJH

From ronallarson at QWEST.NET Fri Dec 26 00:22:08 2003
From: ronallarson at QWEST.NET (Ron Larson)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
Message-ID: <THU.25.DEC.2003.222208.0700.RONALLARSON@QWEST.NET>

Tami (cc stoves)

1. Happy Holidays to you and all stovers (a bit belatedly).

2. I thought of you and "stoves" today as our local Denver Post carried a story about global warming and a recently reported large relationship (especially to ice-melting which adds to GW) to soot. I also heard this story on our local public radio a few days ago and Googleing shows it has been widely reported. The download citation (which was free for me) is at

http://www.pnas.org/cgi/content/full/100/11/6319?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=hansen&andorexactfulltext=and&searchid=1072414606188_2724&stored_search=&FIRSTINDEX=0&resourcetype=1

The key thought in here for me was toward the end where Jim Hansen and other authors said:

"Despite the uncertainties in the several climate forcings associated with actions designed to reduce aerosols, meaningful implications can be drawn for both developing and developed countries. The large emissions of soot aerosols in developing countries have negative impacts on human health, agricultural productivity, regional climate, and global warming. Reductions of soot emissions from cook-stoves, polluting industries, and vehicles thus would have multiple benefits. "

So Tami - this is to ask you to give us a bit more background on this new report - is this really new or just better understood and accepted? Does this all agree with your own work?

Also, in your conversations with Hansen or others on this, has there been any indication of how the stove communtiy could make application for funds to reduce this quite large (25% of the CO2 impact) GW impact? When this is coupled with release of CH4, CO, H2, etc - has there yet been any estimate of how much the stoves contribution is in total to GW?

3. Also back in October, you raised the issue of temperature being an indicator of poor emissions. I wonder if you or anyone can report on anything experimental on this relationship? Isn't this mostly a statement about excess air?

Ron

From yark at UIUC.EDU Fri Dec 26 12:10:27 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
Message-ID: <FRI.26.DEC.2003.111027.0600.YARK@UIUC.EDU>

Ron,

Merry Christmas, Happy Holidays and the like!

> So Tami - this is to ask you to give us a bit more background on this
new report -
> is this really new or just better understood and accepted? Does this
all agree with your own
> work?

The new report by Jim Hansen discusses the impact of black carbon or 'soot'
on snow albedo. 'Albedo' means basically brightness, reflectivity. Soot
makes snow less reflective. If more light is absorbed by the surface, more
energy stays in the system. This is an average warming of climate.

Jim's calculation of the contribution of soot to the albedo of snow, and
its impact on climate forcing, is a new estimate. However, the impact of
black carbon on snow albedo has been studied for a couple of decades. I
haven't done any modeling on surface albedo so I can't comment on
agreement. My job is mainly figuring out how much soot comes out so I can
provide that information to climate models. (The Hansen models are not yet
using my numbers, which are still being inspected by reviewers.)

> Also, in your conversations with Hansen or others on this, has there
been any
> indication of how the stove communtiy could make application for funds
to reduce
> this quite large (25% of the CO2 impact) GW impact? When this is
coupled with
> release of CH4, CO, H2, etc - has there yet been any estimate of how
much the stoves
> contribution is in total to GW?

I believe the CH4 contribution is quite small, and that is the only
'Kyoto-gas'-- the only one for which credit is currently available (if
that). Stoves contribution to CO2 is negligible. I believe Kirk Smith's
work showed that the major gaseous impact of stove emissions was from the
CO (correct me, Kirk, if you are listening). CO is not a greenhouse gas,
but it has indirect effects on climate because it changes some of the
chemistry and allows the non-CO2 greenhouse gases to stay in the atmosphere
longer. However, only gases with direct effects were included in the Kyoto
agreement.

Is there any indication of how to get $$ for Stoves? No, this issue is
still quite contentious, and it may be a while before the idea is accepted,
if ever. By my estimate, stoves put out about 25% of the 'black carbon'
(BC) globally. That's a lot! But that is not the whole picture. When BC is
emitted from stoves, it's also accompanied by other aerosols (the white
smoke) that contributes to cooling. So looking at just 'soot'-- the black
stuff-- doesn't give you a good idea of whether a particular technology,
like stoves, has a warming or cooling effect on climate.

> 3. Also back in October, you raised the issue of temperature being an
indicator of
> poor emissions. I wonder if you or anyone can report on anything
experimental on
> this relationship? Isn't this mostly a statement about excess air?

It's not necessarily excess air, but that has a lot to do with it. I was
talking about how post-combustion dilution, in addition to excess air,
prevents any pollutants from being burned out. Once the air is cold, the
particles no longer like to react with oxygen. Experimental values are
available for soot oxidation, from the combustion literature.

My idea is this: 'Have good combustion, and don't make the particles. But
you will make them anyway; your combustion will fail, at least on an
episodic basis. Then, better make darn sure you have a way to burn them out.'

Tami

From tmiles at TRMILES.COM Fri Dec 26 21:35:33 2003
From: tmiles at TRMILES.COM (Tom Miles)
Date: Tue Aug 10 18:30:46 2004
Subject: NDG
Message-ID: <FRI.26.DEC.2003.213533.0500.TMILES@TRMILES.COM>

I've developed a reference page on the Biomass Cooking Stoves website
around Krishna Kumar's discussion of a natural draft gasifier stove.

http://www.repp.org/discussiongroups/resources/stoves/kumar/ndg.htm

Tom Miles

From lanny at ROMAN.NET Sat Dec 27 08:58:49 2003
From: lanny at ROMAN.NET (Lanny Henson)
Date: Tue Aug 10 18:30:46 2004
Subject: NDG
Message-ID: <SAT.27.DEC.2003.085849.0500.LANNY@ROMAN.NET>

Krishna,
You mentioned connecting a gasifier to a dye tank.
I have some suggestions to 1- reduce heat loss and to 2- improve the fire.

1-Reduce heat loss.
http://www.lanny.us/kk2c.jpg 17K
a-Cover the top of the tank when possible
b-Insulate the sides of the tank.
c-Line the trough with ashes for insulation.
Tell me more about the process. How long does the tank stay hot? Continuous?
Once a day? Once a week?

2- Improve the efficiency of the burn.
Seal the tank to the floor and wall and chimney with mud to maximize the
pressure of the draft.
http://www.lanny.us/kk1c.jpg 17K
http://www.lanny.us/kk3c.jpg 23K

Use this draft to pull the flow from your gasifier.
The draft should be sufficient to pull the flow down and up like siphoning.
There should be enough draft pulling to lay the gasifier on its side.
Also try using a fire cover over the trough to focus the supply air.
The draft should increase the velocity and create a blasting effect.
Back burn the wood as you feed it in.
Keep a small hot fire and keep a watch on your chimney exhaust.
Line the trough with ashes for insulation.
If this works design a horizontal gasifier to fit in the trough.

Lanny Henson

From aes at BITSTREAM.NET Fri Dec 26 12:50:56 2003
From: aes at BITSTREAM.NET (AES)
Date: Tue Aug 10 18:30:46 2004
Subject: [ethos] Happy Holidays!
Message-ID: <FRI.26.DEC.2003.115056.0600.AES@BITSTREAM.NET>

Happy Holidays and a new year filled with many positive changes.

Does anyone have hotel information for the Seattle Conference? A selection of hotels in the area would be nice if anyone has that information.

Thanks,

Bruce

----- Original Message -----
From: Dean Still
To: ethos@vrac.iastate.edu ; STOVES@LISTSERV.REPP.ORG ; 'Aprovecho Research Center' ; 'Bernard Amadei' ; 'meera' ; bvanappel@yahoo.com ; NBecker@IWKAPacSystems.com
Sent: Wednesday, December 24, 2003 11:19 AM
Subject: [ethos] Happy Holidays!

Dear Friends,

Winter sun is as lazy as I feel these mornings, peaking up out of the covers, maybe looking forward to a great stiff cup of coffee as much as me. Drinking huge yardsticks of lemonade were an upside to the heat in the Mexican desert, the comfort of hot coffee is certainly enhanced by winter in the grey Willamette valley.

Eneagram folks in the church say that personality strength is also one's inherent weakness. Winter offers a perfect example that an abiding characteristic, the cold, can be appreciated or feared.

At NOLS in the desert we had to teach freezing students how to take care of themselves. College students would sit, teeth chattering, wretched, too lethargic to put on the clothing that would conserve their heat, allow them to live outdoors. Did you know that Outward Bound and then NOLS were started because young soldiers died next to older soldiers who lived in the cold, in the heat? The weather was in context for the older guys but new and frightening to the na?ve.

O yes, there I am, doing all that same me stuff again.The Norwegians' say that there is no such thing as bad weather.only bad clothing. So, I pull on my stupid looking stocking cap that always makes my teenage boys laugh, wear the thick socks and coat and aim to be at peace with the weather, at peace with who I am, sipping Christmas coffee.

Wishing us the best of the season and the best from life!

Dean

From rstanley at LEGACYFOUND.ORG Sat Dec 27 01:44:30 2003
From: rstanley at LEGACYFOUND.ORG (Richard Stanley)
Date: Tue Aug 10 18:30:46 2004
Subject: Low-cost briquette press
Message-ID: <SAT.27.DEC.2003.104430.0400.>

Dear Andrew et al.,

You are getting close: The missing part is to soften the fibers BEFORE
compressing them. To do this in the field with rural groups, we usually
partially decompose them but just as often the would be production teams will
depending upon resources available etc., , opt to use a mortar and pestle at
one end, or a 5 hp hammer l mill with a 25 mm dia screen openings --on the
other.

Compression using a wet slurry ( not more than 35% solids in fact ) can not
easily be done using a press which generates much beyond 30 bars of pressure
with the wet process, before the slurry mass starts to immediately heat up and
generates a steam cannon. The other negative effect of heating is to destroy
fiber integrity and greatly limit the market for the technology away from the
real local employment ans skill generation need in low incom,e areas. Thats not
to say that a mechanised version cannot find applicaiton in the more urban
markets but its just not our main focus --not for another 6 months at any rate.

My two shillings in a nutshell: If you are attempting wet process (use of any
moisture at all as a "fluidiser/mixing /chopping mashing medium ", Stay wet,
stay at ambient temp, do not go above 25 bars in the cylinder, and focus more
on mastering the art of partial decomposition and blending of pithy and
granular materials to optimise densification mass and you are on the right
track .

Echo's briquette press derives from their exposure to our inital intriduction
of the technology in Haiti three years ago. Seems that many are now into
trying out different press designs. There must be at least half a dozen out
there now. The original compound lever manual "Bryant press" is hardly the
only or most cost effective solution for every situation) but in fact, no
matter what design derives, we should not be deluded into thinking that high
pressure is not the critical element to effective "wet-process" biomass fuel
briquetting.

Richard Stanley

Andrew Heggie wrote:

> On Sun, 21 Dec 2003 22:17:35 +0700, Robert Deutsch wrote:
>
> >Dear Andrew and Harmon and all,
> >
> >I'm wondering if the manual lever arm press described at www.echonet.org
>
> Sorry couldn't see it on the page and haven't had time to search the
> site. Paul Sanderson and I have discussed the cinva "lever arm block
> maker" I suggested this could be modified to form holes and allow
> drainage, with a bit of extra compression at the end of travel
> provided by a roller cam. This should aid in dewatering the briquette
> and hence drying.
>
> >could be motorized with a small horse power electric motor driving a cam or
> >crank shaft through a belt drive reduction. It wouldn't put much travel in
> >the lever arm, but energy consumption should be low and the mold could be
> >progressively advanced towards the pivot point through several cycles until
> >the required compression is achieved. Any thoughts?
>
> My thoughts for this subject are fairly basic, the amount of work put
> into the compressing consists of the force time distance of moving the
> fibres together plus the friction losses in doing so. Once compressed
> the fibers need to be retained in the compressed state, if the
> compression achieves permanent deformation (as I suspect happens in
> Richard Stanley's mushy briquette) then no binding is necessary, if
> not then there is a loss of compression energy as the fibers spring
> back against whatever retaining medium (string, wire etc) is used.
> Each relaxation as the pivot point changed would be a loss of energy.
> This is no big deal if the power comes from a fossil fueled engine,
> not acceptable if some poor grunt is doing the work.
>
> With woody types of biomass there is typically a high length to
> diameter ratio which makes conventional balers unsuitable.
>
> In uk we had a number of manual "baling engines" that woodland workers
> used to achieve the result of a portable bundle of reasonable bulk
> density. One of my neighbours still has the remains of a pimp engine
> his father used to use to make kindling bundles for sale to local
> shops in the 50s. More recently I have seen the large, forwarder
> based, balers from Scandinavia to facilitate the uplift and onward
> transport of sausage shaped bales for use in heating and power plants.
>
> AJH

From dstill at EPUD.NET Sat Dec 27 15:08:51 2003
From: dstill at EPUD.NET (Dean Still)
Date: Tue Aug 10 18:30:46 2004
Subject: accomodations for ETHOS/PCIA Meetings
In-Reply-To: <001801c3cc99$a62c9cb0$26af0443@D289YG11>
Message-ID: <SAT.27.DEC.2003.120851.0800.DSTILL@EPUD.NET>

Bruce,

I'll send complete directions/information this week but there are rooms
booked at the Kirkland Inn Best Western, like last year. Tell them you are
with ETHOS/Partnership for Clean Indoor Air. Complete details to follow
soon. Looking forward to seeing everyone!

Best,

Dean

From adkarve at PN2.VSNL.NET.IN Sun Dec 28 05:27:01 2003
From: adkarve at PN2.VSNL.NET.IN (A.D. Karve)
Date: Tue Aug 10 18:30:46 2004
Subject: Seattle Conference
Message-ID: <SUN.28.DEC.2003.155701.0530.ADKARVE@PN2.VSNL.NET.IN>

Stovers,
Both my daughter, Dr. Priyadarshini Karve and myself are planning to
attend the ETHOS conference and the following EPA workshop at Seattle.
Hope to see you all there. I am keen to meet all of you personally, so
that I can put faces to names.
Wishing you all a happy new year.
Yours
Dr.A.D.Karve, President,
Appropriate Rural Technology Institute
Pune, India.

From andrew.heggie at DTN.NTL.COM Sun Dec 28 17:31:48 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
In-Reply-To: <5.2.0.9.2.20031226110641.03600e80@staff.uiuc.edu>
Message-ID: <SUN.28.DEC.2003.223148.0000.>

On Fri, 26 Dec 2003 11:10:27 -0600, Tami Bond wrote:

>Is there any indication of how to get $$ for Stoves? No, this issue is
>still quite contentious, and it may be a while before the idea is accepted,
>if ever. By my estimate, stoves put out about 25% of the 'black carbon'
>(BC) globally. That's a lot!

How much for wildfires?

> But that is not the whole picture. When BC is
>emitted from stoves, it's also accompanied by other aerosols (the white
>smoke) that contributes to cooling.

Some of this white smoke will be condensed water vapour, some
pics/offgas. I think the black carbon as a sol will appear blue
because the of the way the distribution of the particles is dictated
by their physics.

>It's not necessarily excess air, but that has a lot to do with it. I was
>talking about how post-combustion dilution, in addition to excess air,
>prevents any pollutants from being burned out.

In the absence of any formal learning, I think I need to know your
definition of what we are referring the excess air to. If we mean that
% of air that is in the massflow in excess of a stoichiometric amount
then poor combustion will be exhibited by both pics and O2 in the flue
gas. The point is that if poor combustion has occurred because
critical temperatures have not been reached then not only has the
excess air quenched the reaction but also the full calorific value of
the fuel has not been realised, hence further reducing the
temperature.

> Once the air is cold, the
>particles no longer like to react with oxygen.

Yes the temperature, time, turbulence rule are all to do with
increasing the chance an oxygen atom has of mating with a fuel gas.
There are also the thresholds of fuel:air ratios in gaseous phases,
flame holding (and in its absence spontaneous combustion temperatures)
as well as the limit on attainable temperature being set by the
calorific value divided by the massflow. Mass flow being chiefly to do
with the combustion air but frequently fuel moisture will have as
great an effect as the fuel on this.

> Experimental values are
>available for soot oxidation, from the combustion literature.
>
>My idea is this: 'Have good combustion, and don't make the particles. But
>you will make them anyway; your combustion will fail, at least on an
>episodic basis. Then, better make darn sure you have a way to burn them out.'

Which is why I have tended to an insulated combustion chamber rather
than depend on flame holding.

AJH

From yark at UIUC.EDU Mon Dec 29 01:05:19 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:46 2004
Subject: AJH: excess air
In-Reply-To: <87kuuv49mp1u6tjuo54vjpphioq6kakrsq@4ax.com>
Message-ID: <MON.29.DEC.2003.000519.0600.YARK@UIUC.EDU>

>In the absence of any formal learning, I think I need to know your
>definition of what we are referring the excess air to.

Okay, my comment was very loose, and written in *complete* absence of
formal learning. I just meant to say that excess air that came in the inlet
and went through the combustion lowers the temperature; so does air that
comes in after any combustion has taken place. You may call this 'secondary
air,' but at some point it never had a chance of participating in what we
consider a flame, and so I think of it as dilution. I think the terminology
doesn't matter so much.

>The point is that if poor combustion has occurred because
>critical temperatures have not been reached then not only has the
>excess air quenched the reaction but also the full calorific value of
>the fuel has not been realised, hence further reducing the
>temperature.

Yup. Two bad things about incomplete combustion.
However, at SOME POINT we have to get the heat out-- and into the pot or
the room. So we have to finish up the burn before it hits the pot.

>Yes the temperature, time, turbulence rule are all to do with
>increasing the chance an oxygen atom has of mating with a fuel gas.

... and WANTING to react with it; forgive the analogy, but you can put two
people in a bed and if they're both exhausted, nothing will happen!

>Which is why I have tended to an insulated combustion chamber rather
>than depend on flame holding.

I agree with the rest of your comments so I didn't comment.

But now you have got me thinking about designing to allow some amount of
bad combustion. Are there simple feedbacks we can put in a stove that would
prevent the burn from going 'over the cliff' or catch it if it does? Hmmmm.
I'm sure people already tried this.

Tami

From yark at UIUC.EDU Mon Dec 29 09:39:28 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
In-Reply-To: <87kuuv49mp1u6tjuo54vjpphioq6kakrsq@4ax.com>
Message-ID: <MON.29.DEC.2003.083928.0600.YARK@UIUC.EDU>

>How much for wildfires?

Maybe ~50% for open fires if you count *everything* (Northern forests,
savanna in Africa, rain forests, crop stubble etc.) All of these numbers
are really uncertain.

>Some of this white smoke will be condensed water vapour, some
>pics/offgas.

Right, I wasn't counting the condensed water vapor, but it does get sort of
counted when you model the impact on light. The water vapor condenses on
the existing particles. Same with clouds (usually).

>I think the black carbon as a sol will appear blue
>because the of the way the distribution of the particles is dictated
>by their physics.

I think the white smoke appears blue. The black carbon absorbs so much
light that it actually looks black. Color has a lot to do with the eye's
interpretation, where the light is coming from, and what's behind the
smoke. You can make particles that are NOT black look black, but it's hard
to make really black stuff look anything BUT black. It's also hard to see--
which is one reason I think we have to measure PM (particulate matter)
instead of completely relying on the eye test.

Excess air in next post.

Tami

From andrew.heggie at DTN.NTL.COM Mon Dec 29 20:16:02 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: AJH: excess air
In-Reply-To: <5.2.0.9.2.20031228233655.0239a3a8@staff.uiuc.edu>
Message-ID: <TUE.30.DEC.2003.011602.0000.>

On Mon, 29 Dec 2003 00:05:19 -0600, Tami Bond wrote:

>
>Okay, my comment was very loose, and written in *complete* absence of
>formal learning. I just meant to say that excess air that came in the inlet
>and went through the combustion lowers the temperature;

I am uneasy with this as it assumes that you can achieve
stoichiometric combustion. Now I think this is near enough true with a
good fuel like natural gas, I suspect it is not with a biomass fuel
with realistic moisture content. I would like to hear of practical or
measured experiments. To my mind the highest temperature is achieved
at stoichiometric air, however I wonder if there are cases were
combustion cannot ensure enough oxygen molecules react with fuel
molecules. In this case the loss of calorific value in pics may be
sufficient to reduce temperatures, I cite the example of a glowing
log, it never attains enough heat to ignite the pyrolysis gas until
you blow on it and it bursts into flame.

> so does air that
>comes in after any combustion has taken place.

OK what term are we to put on this non combustion air?

> You may call this 'secondary
>air,'

Nope, to me secondary air is very specifically that air that is
necessary to burn the various offgases (both pyrolysis and CO
generated in the firebed) generated by primary combustion. In fact
with good fuels this secondary air may be staged into tertiary and
more phases to reduce the risk of NOx formation.

> but at some point it never had a chance of participating in what we
>consider a flame, and so I think of it as dilution. I think the terminology
>doesn't matter so much.

I agree the semantics don't matter as long as we have conveyed what we
mean correctly. I actually think of dilution air as that air that is
entrained with the combustion products for a specific purpose, most
likely to reduce flue temperatures below a point where they may damage
downstream components, either by temperature or allowing flue products
(like alkali metals) to react with them.
>
>>The point is that if poor combustion has occurred because
>>critical temperatures have not been reached then not only has the
>>excess air quenched the reaction but also the full calorific value of
>>the fuel has not been realised, hence further reducing the
>>temperature.
>
>Yup. Two bad things about incomplete combustion.
>However, at SOME POINT we have to get the heat out-- and into the pot or
>the room. So we have to finish up the burn before it hits the pot.

Totally agreed the pot should be above the flame, even though this
means it experiences a lower delta T.
>
>>Yes the temperature, time, turbulence rule are all to do with
>>increasing the chance an oxygen atom has of mating with a fuel gas.
>
>... and WANTING to react with it; forgive the analogy, but you can put two
>people in a bed and if they're both exhausted, nothing will happen!

I think the turbulence term covers this ;-)

>
>But now you have got me thinking about designing to allow some amount of
>bad combustion. Are there simple feedbacks we can put in a stove that would
>prevent the burn from going 'over the cliff' or catch it if it does? Hmmmm.
>I'm sure people already tried this.

I am not sure what you mean, the expedient of flue gas recirculation
is sometimes used to reduce the heat in the primary combustion zone.
Prior to fuel injection it was a technique used to reduce NOx
emissions in SI engines.

AJH

From andrew.heggie at DTN.NTL.COM Mon Dec 29 20:16:09 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
In-Reply-To: <5.2.0.9.2.20031228232505.0228d018@staff.uiuc.edu>
Message-ID: <TUE.30.DEC.2003.011609.0000.>

On Mon, 29 Dec 2003 08:39:28 -0600, Tami Bond wrote:

>>I think the black carbon as a sol will appear blue
>>because the of the way the distribution of the particles is dictated
>>by their physics.
>
>I think the white smoke appears blue. The black carbon absorbs so much
>light that it actually looks black.

It's too long ago for me to remember why sols appear white or blue,
something to do with back scatter and the weak repulsive forces
between the particles, its the reason the sky appears blue on a clear
day. I'd like to see some experimental results of the smoke from a
stack. I had assumed for you to be able to see black smoke the soot
particles were dense enough to have conglomerated in some way, the
blue smoke indicating a true sol rather than a suspension.

AJH

From kgoyer at COMCAST.NET Tue Dec 30 01:38:40 2003
From: kgoyer at COMCAST.NET (ken goyer)
Date: Tue Aug 10 18:30:46 2004
Subject: Question on Hansen new report
In-Reply-To: <5.2.0.9.2.20031228232505.0228d018@staff.uiuc.edu>
Message-ID: <MON.29.DEC.2003.223840.0800.KGOYER@COMCAST.NET>

Dear Tami, I love it when you guys talk dirty. Generally I try to avoid
posting to the lists because I am afraid of being sucked into the black
hole. Last fall, my wife, Ellen, and I went on vacation to Hong Kong.
Flying along at 40,000 feet, crossing the international date line, way
out in the middle of the Pacific ocean, about the latitude of Kamchatka,
the temperature was -40 degrees F.& C., somewhere between the
troposphere and the stratosphere, way above all the clouds, looking out
the window I see this black band above us. Some time later it becomes
two black bands, all the way to Japan. Now I know that you know all
about this. But to actually see it is very scary. I'm glad we are all
trying to do something about it. I'm glad you like insulated combustion
chambers. I think it's sad that the North Pole is melting and Santa
Clause is going to drown.
Everyone have a happy new year and see you at Ethos, Regards, Ken

Tami Bond wrote:

>> How much for wildfires?
>
>
> Maybe ~50% for open fires if you count *everything* (Northern forests,
> savanna in Africa, rain forests, crop stubble etc.) All of these numbers
> are really uncertain.
>
>> Some of this white smoke will be condensed water vapor, some
>> pics/offgas.
>
>
> Right, I wasn't counting the condensed water vapor, but it does get
> sort of
> counted when you model the impact on light. The water vapor condenses on
> the existing particles. Same with clouds (usually).
>
>> I think the black carbon as a sol will appear blue
>> because the of the way the distribution of the particles is dictated
>> by their physics.
>
>
> I think the white smoke appears blue. The black carbon absorbs so much
> light that it actually looks black. Color has a lot to do with the eye's
> interpretation, where the light is coming from, and what's behind the
> smoke. You can make particles that are NOT black look black, but it's
> hard
> to make really black stuff look anything BUT black. It's also hard to
> see--
> which is one reason I think we have to measure PM (particulate matter)
> instead of completely relying on the eye test.
>
> Excess air in next post.
>
> Tami
>

From Gavin at AA3GENERGI.FORCE9.CO.UK Tue Dec 30 04:40:49 2003
From: Gavin at AA3GENERGI.FORCE9.CO.UK (Gavin Gulliver-Goodall)
Date: Tue Aug 10 18:30:46 2004
Subject: AJH: excess air
In-Reply-To: <hoj1vv0ghrfga6fpd37snno5qc4vfgd7rh@4ax.com>
Message-ID: <TUE.30.DEC.2003.094049.0000.GAVIN@AA3GENERGI.FORCE9.CO.UK>

We get very near stoichiometric on commercial woodchip boilers with
electronic combustion monitoring and for that matter on similar log boilers.
I doubt that the technology would scale and simplify to suit the Stoves
requirements. Mind- you... I have an idea ;-)
gavin

[GGG] snip
I am uneasy with this as it assumes that you can achieve
stoichiometric combustion. Now I think this is near enough true with a
good fuel like natural gas, I suspect it is not with a biomass fuel
with realistic moisture content. I would like to hear of practical or
measured experiments. To my mind the highest temperature is achieved
at stoichiometric air, however I wonder if there are cases were
combustion cannot ensure enough oxygen molecules react with fuel
molecules. In this case the loss of calorific value in pics may be
sufficient to reduce temperatures, I cite the example of a glowing
log, it never attains enough heat to ignite the pyrolysis gas until
you blow on it and it bursts into flame.

[GGG] GGG

AJH

From crispin at NEWDAWN.SZ Tue Dec 30 12:09:04 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:46 2004
Subject: AJH: excess air
Message-ID: <TUE.30.DEC.2003.120904.0500.CRISPIN@NEWDAWN.SZ>

Dear Gavin, Andrew and All

AJH wrote
>I cite the example of a glowing log, it never
>attains enough heat to ignite the pyrolysis gas until
>you blow on it and it bursts into flame.

Well that got me to thinking. Suppose you were burning 4 gm per minute of
carbon from the glowing log. There would be smoke or a lot of CO, as I
think he describes it.

Then you blow on it increasing the amount of O2 hitting some part of the
combustion zone. This (presumably) creates a higher temperature locally and
the resulting flame jumps along the available hot pyrolysis gases floating
from other parts of the log.

Things to think about:

1. In the initial condition, does the presence of a large amount of cold
excess air prevent it igniting without being blown on?

2. Would the flame spontaneously appear if the log were enclosed in a
small, reflective or insulated [cylinder/box/chamber] and the excess air
limited to some amount slightly above the 'bare air' requirement? If so,
then insulated or poorly-conducting chambers should improve things.

3. If the heat from the hot smoke were used to preheat the primary air
hitting the log, and that heat continued to further heat the smoke which in
turn heated the new primary air even more, would a flame emerge
spontaneously without it being blown on? If so, then heat recycling stoves
should improve things.

4. Does the placing of a flame on the smoke (so to speak) increase the
rate of burn from 4 gm/min?

Regards
Crispin

From andrew.heggie at DTN.NTL.COM Tue Dec 30 18:38:40 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:46 2004
Subject: AJH: excess air
In-Reply-To: <020c01c3cef8$4b66deb0$75cd3c43@MARGARET>
Message-ID: <TUE.30.DEC.2003.233840.0000.>

On Tue, 30 Dec 2003 12:09:04 -0500, Crispin Pemberton-Pigott wrote:

>Dear Gavin, Andrew and All
>
>AJH wrote
>>I cite the example of a glowing log, it never
>>attains enough heat to ignite the pyrolysis gas until
>>you blow on it and it bursts into flame.
>
>Well that got me to thinking. Suppose you were burning 4 gm per minute of
>carbon from the glowing log. There would be smoke or a lot of CO, as I
>think he describes it.

OK we can spend a little time playing with this but that was not the
intent of my query. I was interested in how Tami and others viewed
excess air, I mooted this posibility to illustrate that if combustion
conditions were poor, even in the presence of (but not reacting)
stoichiometric amounts of air, that not only would there still be
large amounts of oxygen in the flue gas but also the effects of pics
in the flue gas meant a large part of the calorific value of the fuel
was discharged up the flue, thus reducing heat release in the
combustion chamber. As the heat flux in the combustion chamber divided
by the massflow is what dictates adiabatic temperature the
temperature in the combustion chamber might never get high enough.

An opposite example might be a stove configured to burn at a certain
rate say x kg(odw)/hr, so we might arrange to supply it with
stoichiometric air at about 6x kg/hr. If the ratio of the air supplied
as primary air is too high then we end up with a CO generator and
discharge this as a pic.
>
>Then you blow on it increasing the amount of O2 hitting some part of the
>combustion zone. This (presumably) creates a higher temperature locally and
>the resulting flame jumps along the available hot pyrolysis gases floating
>from other parts of the log.

I think the point is that the log will happily burn its fixed carbon
content flamelessly and below 400C, so if either the air flow keeps it
this cool AND/Or it radiates sufficient heat to limit the temperature
AND/OR the loss of heat to vapourising moisture content does the same
plus any other conductive losses to fuel and stove then the
temperature will stay below the spontaneous ignition temperature of
the offgas. Blowing on the ember creates a high enough local
temperature coupled with increasing the offgas, once some 600C is
reached and there are areas where the offgas and air are in the right
proportion then a flame will start.
>
>Things to think about:
>
>1. In the initial condition, does the presence of a large amount of cold
>excess air prevent it igniting without being blown on?

See above, IMO the moisture content is likely to have the highest
effect, of course any draught is dependant on the chimney effect and
this cannot happen until the flue gas is hot.
>
>2. Would the flame spontaneously appear if the log were enclosed in a
>small, reflective or insulated [cylinder/box/chamber] and the excess air
>limited to some amount slightly above the 'bare air' requirement? If so,
>then insulated or poorly-conducting chambers should improve things.

Definitely but allow for the fact that evolving offgas and steam
"interfere" with the fuel to air interface.
>
>3. If the heat from the hot smoke were used to preheat the primary air
>hitting the log, and that heat continued to further heat the smoke which in
>turn heated the new primary air even more, would a flame emerge
>spontaneously without it being blown on? If so, then heat recycling stoves
>should improve things.

Pass but anything that gets the offgas up to temperature will do, of
course if the offgas and air are in the right ratio (and in a diffuse
flame they will be somewhere on the interface) then a spark of
sufficient energy will set it away.
>
>4. Does the placing of a flame on the smoke (so to speak) increase the
>rate of burn from 4 gm/min?

Almost certainly as the flame signifies that offgas is burning, this
will increase draught by convection (chimney effect) and radiate heat
back to the fuel.

AJH

From pverhaart at OPTUSNET.COM.AU Wed Dec 31 05:12:27 2003
From: pverhaart at OPTUSNET.COM.AU (Peter Verhaart)
Date: Tue Aug 10 18:30:47 2004
Subject: AJH: excess air
In-Reply-To: <020c01c3cef8$4b66deb0$75cd3c43@MARGARET>
Message-ID: <WED.31.DEC.2003.201227.1000.PVERHAART@OPTUSNET.COM.AU>

At 12:09 30/12/2003 -0500, you wrote:
>Dear Gavin, Andrew and All
>
>AJH wrote
> >I cite the example of a glowing log, it never
> >attains enough heat to ignite the pyrolysis gas until
> >you blow on it and it bursts into flame.
>
>Snip

>Things to think about:
>
>1. In the initial condition, does the presence of a large amount of cold
>excess air prevent it igniting without being blown on?

It can also be a problem of low gas velocities. The cloud of smoke prevents
air from reaching the burning carbon in a sufficient rate to increase the
burning rate and hence the tepmerature.

>2. Would the flame spontaneously appear if the log were enclosed in a
>small, reflective or insulated [cylinder/box/chamber] and the excess air
>limited to some amount slightly above the 'bare air' requirement? If so,
>then insulated or poorly-conducting chambers should improve things.

No, see above.

>3. If the heat from the hot smoke were used to preheat the primary air
>hitting the log, and that heat continued to further heat the smoke which in
>turn heated the new primary air even more, would a flame emerge
>spontaneously without it being blown on? If so, then heat recycling stoves
>should improve things.

There is not enough primary air hitting the log, the air temperature
probably not significant.

>4. Does the placing of a flame on the smoke (so to speak) increase the
>rate of burn from 4 gm/min?

Probably. For 2 reasons. One, radiation from the flame would increase the
temperature. Two and more importantly, the flaming smoke has a much higher
bouyancy and so increases the flow, drawing smoke from the burning char and
enabling more air to reach it.

Peter Verhaart

From yark at UIUC.EDU Wed Dec 31 08:17:26 2003
From: yark at UIUC.EDU (Tami Bond)
Date: Tue Aug 10 18:30:47 2004
Subject: AJH: excess air
In-Reply-To: <75u3vvkb2dfbki1knc8cuujdlcmc7h96qi@4ax.com>
Message-ID: <WED.31.DEC.2003.071726.0600.YARK@UIUC.EDU>

AJH wrote:

>not only would there still be
>large amounts of oxygen in the flue gas but also the effects of pics
>in the flue gas meant a large part of the calorific value of the fuel
>was discharged up the flue, thus reducing heat release in the
>combustion chamber.

Yes but I think that the primary reason temperature loss is from heat
removal and not from incomplete combustion. That is, the PICs are best
looked at as a symptom and not a cause.

I have steered away from answering 'how I view excess air' because I have a
hard time defining excess air for non-premixed flames. The pyrolysis gas is
mixing with air and burning at the same time. In that case, the definition
of 'enough' air to accomplish the combustion depends on mixing as well as
nibbling away H and C with O2 (stoichiometry).

> >Then you blow on it increasing the amount of O2 hitting some part of the
> >combustion zone. This (presumably) creates a higher temperature locally and
> >the resulting flame jumps along the available hot pyrolysis gases floating
> >from other parts of the log.

This sounds right to me, summarized like this:
- combustion is a runaway reaction
hotter = faster reaction = more heat = faster reaction
- heat from the reaction has a choice:
(a) radiated or carried away vs
(b) heat up fuel & air
- if there's too much (a), can't get to (b) and hence to the runaway
...before ignition point, limited by *heat* availability (so keep the
heat)
...after, limited by *reactant* availability (so mix well)

>I think the point is that the log will happily burn its fixed carbon
>content flamelessly and below 400C, so if <snipped lots of contributing
>factors> then the temperature will stay below the spontaneous ignition
>temperature of the offgas.

** bingo! ** :-)

This brings up another point. We are speaking of the Stove or the Firebox
as if there's one single optimization point: THE airflow, THE burn rate.
But a really lovely challenge is getting a good, clean turndown or simmer
rate. A combustion chamber that works great at keeping heat for your
starting burn has a completely different character when you reduce the burn
rate by x4. Eight sticks are cozy and hot compared with two in the same
space. We have a scaling problem. This holds not only for different phases
of cooking, but also for different kinds (coffee vs beans, say).

Tami

From crispin at NEWDAWN.SZ Wed Dec 31 09:36:22 2003
From: crispin at NEWDAWN.SZ (Crispin Pemberton-Pigott)
Date: Tue Aug 10 18:30:47 2004
Subject: AJH: excess air
Message-ID: <WED.31.DEC.2003.093622.0500.CRISPIN@NEWDAWN.SZ>

Dear Andrew

Many thanks for taking the time to reply in detail. We seem to agree on
this in every respect.

My motive in all this is to examine in more detail the options available to
someone wanting to improve the combustion of a cooking stove, or any fire
for that matter.

There are times in any fire I have seen, certainly my own, when the
smouldering conditions you describe exist. When the consultation turns to
improving this condition, it is my observation that usually the only
solution discussed is using 'insulated combustion chambers'.

That's the participants' choice I guess...it will help some things, but by
my calculation, it will not improve combustion as much as bringing lost heat
(exhaust heat or heat conducted through the stove body) to the primary air.

For example, the likelihood of the smouldering fire spontaneously bursting
into flame solely through the use of a light ceramic insulating combustion
chamber appears to be lower than if the heat emerging from the stove is used
to increase the incoming air temperature. As you say: "...once some 600C
is reached and there are areas where the offgas and air are in the right
proportion then a flame will start."

Now, I know from Tom Reed that the actual temperature of the reacting
molecules is high, but as you noted the offgassing temperature of the log is
probably near 400C. That would be a condition where there is a fairly large
amount of excess air (as the stove is usually thought to be 'open' to air
flow and designed for a larger flame than a smouldering log) hitting and
chilling the reaction. The velocity of the new air would give some fanning
of the flame, but not as much, as you note, as when the fire is going
'normally'.

Insulating the chamber will not change these conditions much at all. With
the smouldering log: once the temperature inside a perfectly insulated
combustion chamber stabilizes (at perhaps 500?), it will be at a condition
(balance) where the incoming air chills the reaction to the point where it
still cannot reach 600C without an operator intervention (puffing on the
smoulding log).

Recycling heat from the smouldering log - which is an unnatural phenomenon -
tends to cause a flame to emerge, without intervention, every time. Heat
from any available reaction in the log, at whatever draft prevails, can in
part be directed to preheating the primary air. If it were perfectly
recycled, the reaction on the log would rapidly reach spontaneous flame
ignition, however like trying to build a perfectly insulated chamber, it
isn't possible.

However, it can easily be demonstrated that even with a small percentage of
the heat being recycled, the smouldering conditions transform into flame
conditions without operator intervention.

The importance of this is _not_ that smouldering logs will spontaneously
re-ignite but that the will not fall into that condition in the first place.
In any stove that does not recycle heat, there is a significantly higher
risk of a log falling into a smouldering condition than with a stove that
does. At the very end of any burn, I think the condition is nearly
unavoidable, however that will happen far later in a heat recycling stove
than in one without such a heat path.

Dean Still and others have pointed out that improving combustion from 98 to
99% only gives a 1% improvement in stove performance whereas shrouding the
pot can bring 10 or 20 times that benefit. Similarly, making insulated
combustion chambers does not seem to hold the same potential benefits which
are theoretically available from heat recycling. Even if the goal was to
get a very clean emissions figure, the flame conditions which can take
advantage of the insulated environment only exist part of the time. On the
other hand, the flame conditions (including the moisture content issues you
raised) which can benefit from preheated primary air almost always exist.
Combustion conditions which will _not_ benefit from having hot, dry (low
Rel.H.) air fed in are rare. Trying to burn oven-dried gum-bearing wood
would be one of them. Burning a highly volatile fuel like gasoline might be
another.

People burning wood dried in a damp, tropical environment would probably
benefit the most from a heat recycling approach to stove construction and
there are probably more than a 100 million homes like that.

Best regards for the New Year!
Crispin

From andrew.heggie at DTN.NTL.COM Wed Dec 31 15:26:56 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:47 2004
Subject: AJH: excess air
In-Reply-To: <5.2.0.9.2.20031230223601.0111da68@staff.uiuc.edu>
Message-ID: <WED.31.DEC.2003.202656.0000.>

On Wed, 31 Dec 2003 07:17:26 -0600, Tami Bond wrote:

>Yes but I think that the primary reason temperature loss is from heat
>removal and not from incomplete combustion. That is, the PICs are best
>looked at as a symptom and not a cause.

Yes

>
>I have steered away from answering 'how I view excess air' because I have a
>hard time defining excess air for non-premixed flames.

OK, just identifying the problem is "defining excess air for non
premixed flames" is a leap forward. There is little doubt any oxygen
surviving passing through a premixed flame must be excess air.
Premixing does not necessarily mean absence of pics though.

>
>> >Then you blow on it increasing the amount of O2 hitting some part of the
>> >combustion zone. This (presumably) creates a higher temperature locally and
>> >the resulting flame jumps along the available hot pyrolysis gases floating
>> >from other parts of the log.
>
>This sounds right to me, summarized like this:
>- combustion is a runaway reaction

OK there is positive feedback. Biggest in the case of the updraught
fire.
> hotter = faster reaction = more heat = faster reaction
>- heat from the reaction has a choice:
> (a) radiated or carried away vs
> (b) heat up fuel & air

Yes, noting that there are upper bounds put on either by the caloric
value. Radiation between fuel particles is an important mechanism for
transferring heat.

>- if there's too much (a), can't get to (b) and hence to the runaway
> ...before ignition point, limited by *heat* availability (so keep the
>heat)
> ...after, limited by *reactant* availability (so mix well)

Seems good, there are two different ignition points though, the flash
point depends on flame holding to sustain the burn. I would like to
hear more about the mechanisms of flame holding.

>This brings up another point. We are speaking of the Stove or the Firebox
>as if there's one single optimization point: THE airflow, THE burn rate.
>But a really lovely challenge is getting a good, clean turndown or simmer
>rate. A combustion chamber that works great at keeping heat for your
>starting burn has a completely different character when you reduce the burn
>rate by x4. Eight sticks are cozy and hot compared with two in the same
>space. We have a scaling problem. This holds not only for different phases
>of cooking, but also for different kinds (coffee vs beans, say).

I cannot add anything to this apart from the analogy that one can
understand how an engine works but there are an awful lot of different
sorts of cars.

Well Peter Verhaart, who made similar points with a differing
conclusion from mine, will have celebrated the start of the new year
already, some of you in the new world will be celebrating a few hours
after me. Either way a happy and prosperous new year to you all, with
a special mention to an old dog who may well be pulling on his skirt
for the Hogmanay party oop north of me ;-).

AJH

From andrew.heggie at DTN.NTL.COM Wed Dec 31 15:27:00 2003
From: andrew.heggie at DTN.NTL.COM (Andrew Heggie)
Date: Tue Aug 10 18:30:47 2004
Subject: AJH: excess air
In-Reply-To: <029f01c3cfab$79c6ba10$75cd3c43@MARGARET>
Message-ID: <WED.31.DEC.2003.202700.0000.>

On Wed, 31 Dec 2003 09:36:22 -0500, Crispin Pemberton-Pigott wrote:

>There are times in any fire I have seen, certainly my own, when the
>smouldering conditions you describe exist. When the consultation turns to
>improving this condition, it is my observation that usually the only
>solution discussed is using 'insulated combustion chambers'.
>
>That's the participants' choice I guess...it will help some things, but by
>my calculation, it will not improve combustion as much as bringing lost heat
>(exhaust heat or heat conducted through the stove body) to the primary air.

I don't think I can add much more, to my mind the insulated combustion
chamber allows you to keep the combustion temperature above the
spontaneous ignition point. So I agree with you, it does not
necessarily aid combustion because you can achieve the same thing by
keeping a flame present. Now in my large burner I have almost no
insulation and I do preheat air, both for different reasons.

http://homepage.dtn.ntl.com/andrew.heggie/agwaste/chipburner.html
>
>For example, the likelihood of the smouldering fire spontaneously bursting
>into flame solely through the use of a light ceramic insulating combustion
>chamber appears to be lower than if the heat emerging from the stove is used
>to increase the incoming air temperature. As you say: "...once some 600C
>is reached and there are areas where the offgas and air are in the right
>proportion then a flame will start."

but holding that flame without the gas flow blowing it off is the
problem,
>
>Now, I know from Tom Reed that the actual temperature of the reacting
>molecules is high, but as you noted the offgassing temperature of the log is
>probably near 400C. That would be a condition where there is a fairly large
>amount of excess air (as the stove is usually thought to be 'open' to air
>flow and designed for a larger flame than a smouldering log) hitting and
>chilling the reaction. The velocity of the new air would give some fanning
>of the flame, but not as much, as you note, as when the fire is going
>'normally'.
>
>Insulating the chamber will not change these conditions much at all. With
>the smouldering log: once the temperature inside a perfectly insulated
>combustion chamber stabilizes (at perhaps 500?),

No much higher, up to 1200C with high mc, I forget the adiabatic flame
temperature for dry wood in air but would guess above 1600C.
Now as you might imagine this can have serious effects in a batch
loaded device, especially with small bits of wood as they quickly
reach a runaway condition and even if you reduce primary air to zero
you may not be able to meet the need for secondary air.

> it will be at a condition
>(balance) where the incoming air chills the reaction to the point where it
>still cannot reach 600C without an operator intervention (puffing on the
>smoulding log).
>
>Recycling heat from the smouldering log - which is an unnatural phenomenon -
>tends to cause a flame to emerge, without intervention, every time. Heat
>from any available reaction in the log, at whatever draft prevails, can in
>part be directed to preheating the primary air. If it were perfectly
>recycled, the reaction on the log would rapidly reach spontaneous flame
>ignition, however like trying to build a perfectly insulated chamber, it
>isn't possible.

You are mixing two differing points here, either spontaneous or flame
ignition. I am fairly confident that the spark ignition point of wood
gas would fall to a low temperature (difficult to measure as
condensible tars will fall out of the stream as it cools). You could
heat a dry piece of wood to 270C and the offgas would sustain a flame
well I suspect the offgas would have to have a calorific value of
>2MJ/kg to sustain a flame in free air, I don't know what significance
the 250C above ambient would have nor whether the offgas would be rich
enough at this point.

I still have not found out the relationship of flame speeds in
mixtures of gases or flash points.
>
>However, it can easily be demonstrated that even with a small percentage of
>the heat being recycled, the smouldering conditions transform into flame
>conditions without operator intervention.

I believe you but have not seen it done nor can imagine how to do it
without a chimney or fan, in essence you are increasing the enthalpy
of the gas mix.
<snip>

>Dean Still and others have pointed out that improving combustion from 98 to
>99% only gives a 1% improvement in stove performance whereas shrouding the
>pot can bring 10 or 20 times that benefit.

Which is one reason the list discussion has concentrated on this and I
have not had the experience to join in. Tami's recent figure about
stoves contribution to black particulates make me feel that
compromising a good burn out by attempting to maximise heat transfer
is a mistake. Here I would cite the example of a diesel engine, it has
a maximum fuel control which is generally sealed. If you open this up
you can increase the power at the cost of worse economy AND vast
increase in particulates.

AJH

BioEnergy Lists: Improved Biomass Cooking Stoves

December 2003 Biomass Cooking Stoves Archive