[Stoves] Organic Solid Fuel Classification System
Jeff Davis
jeff0124 at velocity.net
Sun Oct 1 13:45:06 CDT 2006
Dear All,
I have been prodded, several times, to expel on my below comment (EXHIBIT A).
In addition to being a "stove lister" I am also a "gasification lister" so I
also have prime movers on my mind and at the time of writing "EXHIBIT A" I
was pondering about the days of my MEN gasifier experience (EXHIBIT D). That
was were I learned that the fuel was as important if not MORE important than
the energy convertion device. I also found that my IHC 345 (truck engine) was
only too happy to show me how good my fuel was.
I was also thinking about the Bisschop and wondering if RPM would infer flame
speed (% of hydrogen?), non-compression engine between stove and compression
engine, car engines sensors attached to the Bisschop, power developed
(generator) and heat generated.
I was writing to the stove list so I should NOT have wrote about prime movers
testing fuel and should have re-posted EXHIBIT B and C.
So we have two aspects of testing fuel: 1. A very thorough method (Kevin) and
2. A simple method (David). Kevin has a good point for being thorough and
exact, after all we study quarks, neutrinos and black-holes. First I would
check to see if this was already done. I remember reading about town-gas and
fuels and they said that at that time there was no lab test to predict how
the fuel would work so the best test was to just gasify it or in our case
just burn it.
IMHO:
I would vote for a simple test for the many. The first stove would be a
standard stove to test local fuels for the many not the few. So, a person at
location A could test his/her fuel and give this data to a stove designer in
location B. This stove designer in location B can now produce a similar fuel
to aid in his/her design work. It seems to me without a standard stove to
test fuels we are just having fun with tin cans.
Warm wishes,
Jeff
+++++EXHIBIT A+++++
Dear Kevin,
> Does all that sort of hang together? :-)
>
> Best wishes,
>
> Kevin
I think I'll just let the Bisschop be the judge.
Your friend,
Jeff
++++++end of EXHIBIT A++++++
+++++EXHIBIT B+++++
Jeff wrote:
Dear All,
How about a stove that has an adjustable fuel to air ratio. First adjust the
stove so that it is burning good. The emissions hood would also be nice here.
How about an O2 sensor?
Next start over with a new batch of fuel and measure the amount of air
consumed (air fuel ratio), fuel consumed, remaining ash and how much water
was boiled away.
If we know the air/fuel ratio, how clean it burns, Joules/g (Btu's) and
remaining ash what more do we really need?
Jeff
+++++end of EXIBIT B+++++
+++++EXIBIT C+++++
Dear List,
If we use a standard fuel to test stoves, why not use a standard stove to test
fuels?
Jeff
+++++end of EXIBIT C+++++
+++++EXIBIT D+++++
http://www.repp.org/discussiongroups/resources/gasification/davis/davisMENgasifier.html
+++++end of EXIBIT D+++++
Kevin wrote:
>The first thing that would be nice to know are the fuel properties for which
>the stove was designed, and the properties of the fuel to be tested. If
>there was a significant mismatch, then it could be a waste of time to even
> start the test. Clearly, it would not be worthwhile to try and burn rice
> husks in a
> stove designed for forced air flow through a bed of wood chips, or in a
> stove designed for pellets, or in a stove designed for split cordwood. For
> example, a Jotul Stove that works well on split cordwood would probably not
> be the best stove for burning fireballs. Most
> stoves that can burn anything would be expected to burn only few fuels well.
>
> It would be nice to know the range of fuel moisture contents, for which the
> stove is intended to burn. Relatively wet fuels with low unit surface area
> should probably have a fuel chamber with relatively large "floor area," to
> give the maximum potential for drying by back radiation. On the other hand,
> relatively dry fuels with large surface area should perhaps have a
> relatively low floor area exposed to flame radiation, to minimize runaway
> pyrolysis.
>
> It may be advantageous or necessary to vary the air/fuel ratio, depending on
> whether the fuel is wet or dry. Wet fuels may require a higher apparent
> primary air flow to bring the fire closer to the wet bed, as a way to assist
> in drying adequately so that combustion can be sustained.
>
> It would be nice to know the permissible superficial velocity of Primary Air
> into the fuel bed, to get a feel for whether fuel or ash would tend to
> fluidize, or carry over to the secondary combustion zone. If particulate
> matter carryover is a concern because of the nature of the fuel or ash, it
> would be nice to know if the stove design contained a "settlement chamber
> effect" to allow the particulate carryover to settle out before it reached
> the living space.
>
> It would be nice to know the characteristics of air flow through the bed, to
> determine if the available fan pressure or natural draft was sufficient to
> support effective primary combustion.
>
> Once the low range Air/Fuel ratio was set, it would be nice to have a
> secondary air control. Depending on fuel characteristics, it might be
> advantageous to have a variable Air Fuel Ratio. For example, a stove
> designed for burning wet fuel should perhaps have a high Air/Fuel Ratio,
> when operated at a lower percentage of rated capacity, but as the burning
> rate was increased, then it may be desirous to reduce the Air/Fuel ratio in
> the primary combustion zone, and increase the air flow to the secondary
> combustion zone.
>
> etc....
>
> As "The Fireball Man", you would be very aware of the differences that
> starting materials, size, smoothness, uniformity of size, and moisture
> content would have on burning characteristics. You might be able to make
> Fireballs with 5 or 10 or 30 significantly different burning
> characteristics. Another way to say that is "Some fireballs are better than
> others." It would thus seem to me that some stoves would be better for some
> fireballs than others.
>
> Does all that sort of hang together? :-)
>
> Best wishes,
>
> Kevin
>
*
On Sunday 17 September 2006 01:45 pm, frank at compostlab.com wrote:
> I think we can come up with a classification system for solid, organic
> fuels that will be able to predict the burning characteristics of a fuel
> and aid in forming bricks of materials that will perform the way we want.
**************************************************************
****************************************************************
Kevin wrote:
***************************************************************
> Dear Jeff
>
> > Dear List,
> >
> > If we use a standard fuel to test stoves, why not use a standard stove to
> > test
> > fuels?
>
> That is similar to saying: "Lets use a standard engine to test fuels." If I
> give you a diesel engine and ask you to test #6 oil, you may or may not get
> good results. Or, if I give you a spark ignition engine set up for high
> octane gasoline, you will get very different results when you use hydrogen,
> low octane gasoline, CO, propane, Natural gas, biogas or kerosene.
>
> More specifically, a "Standard Fuel" is an excellent idea for comparing
> stoves designed to burn this standard fuel. Similarly, a "Standard Stove"
> would be an excellent way to test fuels which were said to be within a
> standard property and performance range. I would suggest that it is not
> possible to build one stove to test all fuels, but you could have a range
> of "Standard Test Stoves" for a range of "Standard Fuels."
>
> For example, if there was a pellet stove optimized for burning 1/4"x1/2"
> long pellets to deliver say 10 kW to warm air, then you could easily
> determine how well your fireballs burned in a stove designed for wood
> pellets. However, this test may, or may not, be a meaningful evaluation of
> your fireballs as a fuel. It may show that you need a different stove
> design to burn your fireballs optimally. For example, your fireballs could
> have different density, different moisture content, different% volatiles,
> different surface area per gram of fuel, different size, different gas flow
> characteristics, different feeding characteristics, and different
> requirements for primary and secondary air.
>
> Science is about standardization and repeatability. If we start with an
> identical stove and an identical fuel, then science says we should get
> identical results. If you get better results than I, that would be because
> you were more proficient in the art of running a stove. If you can document
> the procedures you employed, and if I am then able to repeat the run using
> your procedure, you have converted art into science.
>
> Frank sought to simply define relevant properties of various fuels. His
> proposed work had nothing directly to do with stove design, but rather
> simply to describe the fuels. The Stove Designer would take over from there
> and design a stove in a manner that was optimal for that specific fuel.
>
> Best wishes,
>
> Kevin
>
> Kevin,
> let me just say that from your comments it appears to me that you live
> in an unrealistic sterile world condition. Much like the USA State
> Department. Now I LOVE north America but over the years of living
> outside of her borders, I have seem some very stupid policy come from
> government representatives and policy makes. It seems to me that you
> have much in common with them.
>
> Decisions here in the field are not made from the criteria you suggest.
>
> We do not lack skilled designers not skilled thinkers here in the third
> world. The biggest problem third world people encounter is people that
> try to impose their way of thinking over others, much like your examples
> of how you think.
>
> If you bother to add 1 plus 1 then you might notice that we have
> designed stoves to meet the perceived need here in Bolivia. 2 of those
> designs are already posted on the bioenergy list. just look under
> videos and CEDESOL. For years we have exchanged information and applied
> the current body of knowledge to the problems and within the scope of
> solar, retained heat and efficient biomass cookers *we have developed
> solutions*. Not by our selves but with many collaborators, including Dr.
> Anderson. Now let me ask you a specific question.
>
> Kevin, in all the time on this list that you have been posting comments
> how many of them have been selected to be included into the body of
> *solutions* applied to the world's problems related to indoor air
> pollution and household energy?
>
> Can you please give me one concrete specific example. From the years of
> learning here and applying the shared knowledge I have acquired and
> freely shared with others, I can't observe once, in you case. Please
> correct me if I am in error.
>
> My opinion is that playing "devil's advocate" is useful in some cases
> but can be carried to far and for me you often reach that point.
>
> Unless you can show me a specific example then please don't continue to
> confuse the issues with BS. Ok. Thank you Kevin. - -- - - -
>
> Now concerning testing methods. and discounting Kevin's comments that
> so far do not contain substance on this issue.
> - - - -- - - - - -
> Let's keep working towards, standardized lab methods that any of us may
> apply in not very equipped lab situations, combined with the field test
> of cooking and user adaptability. And let's please remember the KISS
> principle - keep it simple S.
>
> looking at the Phillips stove or the T- lud, if the cook is not
> interested in making little pieces of fuel then regardless of how
> efficient those technologies are, they will not be widely implemented.
> I suggest that that is the "bottom line", sand we must work forward from
> there.
>
> So, please lets discuss this point of view a bit. From my experience,
> we can change the users habits if the benefits to them is sufficient
> compared to keeping the habit. For example, in the case of solar cooker
> use, no one has started out with that habit but when the users chose to
> adopt it we have been able to document about a 65% fuel savings.
>
> In the case of our current project, GTZ did not include solar or
> retained heat until the possible users demanded them. and then we must
> build on increasing user awareness. This is a variable that must be
> incorporated into the design equation. The user's habits.
>
> I agree that having simplified data on energy value for fuel types is
> valuable as a point of reference as Frank is suggesting, but experience
> has shown me that it is not practical, conclusive data, because in
> different countries the fuel needs are so diverse.
>
> However if we can recognize the need to educate the user in applying the
> same principals we have employed in designing the stoves, their use is
> more probable.
>
> So as we move forward, looking at all of the possible answers, I suggest
> we maintain in mind the needs and habits of the users as an active part
> of the equation and testing methods.
>
> un abrzo a todos
>
> David Whitfield
> CEDESOL Foundation
>
Kevin Chisholm wrote:
> Dear David
> ----- Original Message ----- From: "CEDESOL Foundation lists"
> <lists.cedesol at gmail.com>
> To: "Kevin Chisholm" <kchisholm at ca.inter.net>
> Cc: <frank at compostlab.com>; "Tessa Vlaanderen"
> <tessa.vlaanderen at gmail.com>; <stoves at listserv.repp.org>
> Sent: Friday, September 29, 2006 11:00 PM
> Subject: Re: [Stoves] Stove testing methods
>
>
>> Dear Kevin,
>> I don't know what world you live in but it sure is different than
>> mine. ;-)
>
> We are indeed in violent agreement on that one!! :-)
>>
>> We are not an NGO that looks at the problem and then tries to find an
>> "off the shelf" solution as you suggested in the latter part of your
>> post. Also we do not look to import solutions since the importation
>> and transportation would cost more than the product! And therefore
>> would not be a solution.
>
> I am quite aware of Distribution Costs. You should clarify "Imported
> Solution" by realizing that an "Imported Solution" could be "Imported
> Hardware" or an "Imported Design". It might be to your advantage to
> consider importing a suitable design, if local designers are not
> sufficiently skilled.
>>
>> Your replies depict the root problem with some of these suggestions,
>> and also relate to what prompted my request for simple solutions.
>
> If you can define your requirements, I am sure there are people on
> this List that can provide an optomised solution, if a solution is
> possible. If you have a complex set of requirements, then a simple
> solution may not be possible. I hereby pose a challenge to you: You
> post a sensible Stove Specification to the Stoves List, and I will
> assure you that you will get a sensible solution.
>
> Let's
>> drop down to your "contribution".
>>
>
>
>> Kevin Chisholm wrote:
>>> Dear David
>>>
>>> With all due respect, I would suggest that you have the cart before
>>> the horse....
>>>
>>> The fundamental problem is to design a good stove in the first
>>> place. If stoves are designed to meet the conditions required of
>>> them, the test results are guaranteed to be superior than if someone
>>> puts together a "neat stove" without considering all the features it
>>> must deliver to the end user.
>>>
>> all I can say here is "duh" Who in the real world would ever
>> consider designing a neat stove without considering the end user.
>> Perhaps that is the norm in your world, if not then your reply is
>> just antagonistic dribble.
>
> I would guess that many Organizations acquired neat looking stoves
> that failed miserably in the Field. Indeed, a number of recent
> postings allude to the significantly reduced field performance of
> stoves that looked pretty neat in the lab.
>
>>> Consider if you order an "electric generator", and don't tell
>>> Supplier "X" your complete requirements. He sends you a 3 kW
>>> generator, 110 VAC 60 Hz, fueled by natural gas, good for emergency
>>> use. What you really need might have been 30 kW, 220 VAC, 50 Hz,
>>> fueled with diesel fuel, good for prime power. When you test the
>>> generator from "Supplier "X", you will not be pleased.
>> How can you really expect some trumped up example like this is
>> possible in the real world?
>
> In my opinion, selecting a stove without a clear fuel specification is
> in the same league as the above example.
>>
>> In your world you might face that situation or so might a person
>> sitting comfortably in an armchair before his computer with no
>> realization of what the field really is and thinks he is smart enough
>> to intimidate anyone else with his replies.
>>>
> Are you intimidated by my suggestion that you get a comprehensive
> Stove Specification?
>
>>> It is the same with stoves... you can get the right results the
>>> first time if you order a stove that was designed for your intended
>>> application.
>
>> Let me ask you to order a stove for yareta, llama dung and tolla that
>> could also be used with various types of firewood and degrees of
>> humidity, with a chimney.
>
> What you are asking for here is the Stove Equivalent of my generator
> example above.
>>>
>>> For example, Paul Anderson mentioned that a stove test with which he
>>> was associated failed miserably because he was required to use a
>>> fuel for which the stove was not designed.
>> Paul is an extremely hard working, intelligent individual who really
>> gets out there and explores real solutions. He is not stumped by
>> challenges and he persistently looks for ways to move forward. You
>> can learn a great deal from his example. Paul is not "an armchair
>> quarterback". He is in my opinion an applied scientist. And he has
>> been in this part of the field several times and has earned my
>> respect as well as the respect of many ETHOS volunteers who have
>> worked with him, experimenting and tinkering to fine tune the "right
>> combinations".
>
> I am not at all criticising Paul. Indeed, I am very sympathetic to the
> situation he described. He volunteered to help a competitor, but
> regrettably, the rules required that the Competitor use the fuel that
> was selected as "standard" for the test, but the fuel was
> inappropriate for what seemed to be an otherwise good stove.
>
>>> This is a vivid proof of the importance of matching the stove design
>>> to the fuel. What Frank is proposing is to assemble a list of
>>> various fuels, and do test work to present their important properties.
>>>
>> What I an saying is that the picture you paint is not probable
>> because in the real world of applications there are too many varibles
>> to testing the fuel. You have no control how the fuel is used or
>> gathered or stored and it is not usually mass produced
>
> The picture I paint is indeed probable for the very reasons you list.
> It is impossible to design a stove that accomplishes teh desired
> functions unless the Stove Designer has a clear specification. How can
> one possibly expect consistent results from a stove if the fuel
> conditions vary as much as you suggest? If you specify a reasonable
> range of fuel conditions, then the Stove Designer can probably deal
> well with them.
>
>>> As an NGO person wishing to acquire stoves for the people you work
>>> with, here is how the Work that Frank proposes could be helpful to you:
>> If you analyze the word *ass u me* do you know what happens? Seems
>> that your remarks are full of assumptions.
>>>
> Certainly, they are full of assumptions! Which of the assumptions do
> you find to be substantially in error?
>
>>> You could identify the fuel available to your people, include other
>>> relevant specifications, and then send out an Inquiry to various
>>> Stove Manufacturers or Designers, and ask: "Will your stove meet the
>>> required specifications when operating on Fuel #XXX as described in
>>> Frank's Fuel Book?"
>> Here I have to just break down, drop all niceties and say HOW
>> STUPID. Do you think people don't take these things into
>> consideration as a matter of course? Is that the type of people you
>> are used to dealing with?
>
> Your stove evaluating criteria, as listed below, would seem to be
> deficient.
>
> Well save me some air space and don't make those assumptions or
>> at least please don't write about those assumptions related to my
>> posts. i am looking for serious replies.
>
> I am attempting to help you get serious replies. If you put out a
> serious specification, then you should get serious replies. I would
> suggest that a specification based on your "3 basic things are
> important..." is not enough. All you have to do is elaborate fully on
> "...plus how is the stove
> accepted by the actual users...." :-)
>>>
> Best wishes,
>
> Kevin
>
>>>
>>> ----- Original Message ----- From: "CEDESOL Foundation lists"
>>> <lists.cedesol at gmail.com>
>>> To: <frank at compostlab.com>
>>> Cc: "Tessa Vlaanderen" <tessa.vlaanderen at gmail.com>;
>>> <stoves at listserv.repp.org>
>>> Sent: Friday, September 29, 2006 5:36 PM
>>> Subject: Re: [Stoves] Stove testing methods
>>>
>>>
>>>> Dear Stovers et al.,
>>>>
>>>> From the point of view of someone in the field, in a developing
>>>> country, actively involved in stove dissemination, design and testing;
>>>> more elaborate testing of fuels and such is not what is needed.
>>>>
>>>> Simplified testing procedures that can be reproduced in the lab in
>>>> developed countries, in the lab in developing countries, combined with
>>>> tests cooking local foods, combined with tests by actual users under
>>>> their "normal" conditions is more practical for us. That coupled with
>>>> the scaling up suggestions offered by Don Oneal about a year ago is
>>>> the
>>>> most practical way to have a "generic" stove procedure.
>>>>
>>>> There are too many variables to take into consideration other
>>>> wise. As
>>>> I insinuated in my last post, with different cooking needs, fuel needs
>>>> and cultures you just can not mechanize stoves and fuels so easily as
>>>> some seem to be trying to do.
>>>>
>>>> 3 basic things are important to compare stoves. How much pollution is
>>>> produced and how much energy gets into the pot over time, plus how is
>>>> the stove accepted by the actual users. In the final analysis, the
>>>> last
>>>> variable is the most critical to getting stoves out of the designing
>>>> labs and into the hands of the cooks.
>>>>
>>>> As a user in the field of the testing methods we welcome
>>>> simplification
>>>> on how to demonstrate combustion efficiency and heat transfer
>>>> efficiency. From there it is our responsibility to adapt to the
>>>> users.
>>>>
>>>> thanks for the suggestions
>>>>
>>>> David Whitfield
>>>> Cochabamba Bolivia
>>>>
>
>
--
Jeff Davis
Somewhere 20 miles south of Lake Erie, USA
http://www.velocity.net/~jeff0124
More information about the Stoves
mailing list