Re: "Worlds Fastest Stove" Contest Was: Re: LETS ADOPT A UNIVERSAL POT

["Paul S. Anderson" <psanders@ilstu.edu>]

Stovers,   RE contest and standardized "pot"

1.  The is no choice except to go metric!!   Says this
American fellow in Illinois.

2.  Three or four (or more) contests simultaneously would be great,
with an "overall" winner.

3.  This is the type of contest that attracts hundreds of entries
once the professors in universities like MIT and CalTech get wind of it
!!   But hard to "control" the issues of cost of
materials (One titanium ........ etc, vs one tin-can-ium.....) and other
variables (so many variables even to the temp of starting water and the
air-temp of the room or outside (with any breeze is a
factor).   So keep the stakes low and the fun high and lots of
"honorable mentions"!!

4.   About the pot size.  Let's get our variables under
control.  These are JUST SUGGESTIONS.!!!

        

A. 
quantity of water   (the standard MUST be metric.  
Anyone working in English measures must provide all of the conversions
and provide the results in the metric system.)

        

        

1. 
one (1) liter, and

        

        

2. 
six (6) liters  (about 1.5 gallons) (and 6 is more easily divisible
than 5)

        

B. 
Clean water, and start at 20 degree C.  sounds about right,

        

        

1. 
time needed to go to 90 degrees C AND

        

        

2. 
time needed to go to full boil (which is NOT 100 degrees C depending on
elevation / air pressure, so this is NOT standard).

        

        

3. 
Amount of water boiled away per time unit and or per unit of fuel.

        

C. 
Pot size   (pot to be of "typical-pot X-gauge" steel,
or is there a relatively acceptable conversion if someone uses an
aluminum pot or thick cast iron?.), with lid or cover:

        

        

1. 
small diameter = about 7 minches = 17.5 cm, but plus or minus 1 or 2 or 3
cm ) and

        

        

2. 
larger pot (to be discussed),

        

The
combination of A.1., B.2. (report your elevation), and C.1. should let
some of us get started if we can agree.

        

And the
combination of A.2, B.2, and C2 would probably be another reasonably
acceptable combination for those wanting larger quantities of water.

        

OTHER
variables are more related to the stove and the fuel and should be
reported, but are NOT part of the "standardized
pot".   Those other variables include:

        

D. 
Cold (not pre-fired) stove, and pre-heated stove

        

E. 
Environmental conditions

        

F. 
Fuels    and more 

AS FOR ME (and many others on this list serve), I do not even have a
suitable thermometer to go from 10 to 110 degrees C., much less some of
the other equipment that serious contenders/researchers/evaluators/judges
would need.  I will do my development work "in the rough"
and present it to the experts to make the final
evaluations/measurements.  If the results cannot be replicated
consistently by the experts, then the initial results cannot be relied
upon.

But I can get 2 appropriate-sized pots, plus a watch, plus a measuring
container for 1 and more liters.   And I can ship a stove (when
ready) to one or more points of evaluation.

So I have given by "2-cents" of opinion.  I know that ___
I ___ will not be making the decision on "standard pots", and I
await likes of Ron and Dean and Kevin to please work for some tentative
agreement.

Paul

P.S.  I could use the $100.     :-))

At 02:42 AM 1/6/02 -0400, Kevin Chisholm wrote:

Dear Tom
 
Given that 1 litre is a convenient water volume, and given that the test should be available universally, I would propose that the standard "pot" be the standard 1.36 litre "juice can" which measures about 7" (176 mm) by 4-2/8" (106 mm) outside dimensions. My assumption is that this is indeed a universally available can size.
 
A 1 litre measure would be at a height of 127.2 mm from the inside bottom.The can I have in front of me now just happens to rolled rings in it. The second ring from the top is almost exactly 127.2" from the inside bottom. This would serve as a very simple "fill level indicator." This can size also has about 50 mm of ullage or "head space" to prevent boil-over.
 
Note that this is a test system, and does not necessarily have to use a "real world cooking container."
 
A very interesting point was raised by Ron: Who has the "World's fastest stove?" If there was sufficient interest, my Company, Energy Engineering Ltd, would post a $100 First prize to the Contest entrant having the "Worlds Fastest Stove," using a maximum of 500 gms solid biomass fuel charge
 
Contest Rules could tentatively include:
 
1: The stove system must be at room temperature before start of the timing.
2:  The time clock starts when the fuel is lit.
3: Any "common solid biomass fuel" may be used.
4: A "common solid biomass fuel" is defined as any naturally occurring  solid non-fossil biomass material that is economically available to at least 1 million people throught the World. 
5: The stove system must be entirely self powered. Internal powering, such as would result from a thermopile and motor, or a Sterling engine system to provide forced draft or suction effects, is permissable, providing that their source of energy is the permitted fuel charge.
6: The container employed shall be a standard commercially available "juice can" with the top cut off with a standard can opener.The can shall not be modified to increase its surface area.The Judges can, at their slole discression, supply the Entrant with a "standard" can if they feel the entrant's can has been modified in any way.
7: The can shall have a snug fitting cover with a 10 mm hole in the top center, and a 2 mm hole to act as an air vent, 25mm away from the center of the cover..
8: Water content in the container shall be 1.0 kG of potable water, measured at 20.0 degrees C. Water temperatures more than 20.0 C shall be lowered to 20.0 starting tempreature with ice cubes..
9: A copper penny shall be placed over the 10 mm hole in the cover prior to the start of the test.
10 Timing will stop when the penny is seen to more as a result of steam created.
11: The winner shall be the entry whose penny moves as a result of steam generation in the shortest time.
 
Judging the stoves will be a bit more difficult, in that this is a potentially a  "World Class Event." If there is sufficient  interest, then Contest and Judging Details can be worked out.
 
I would tentatively propose that the Final Tests and Award of the Prize would take place no later than 1 Nov 2002
 
Perhaps the Stoves List, or some other suitable Organization could sanction the event, to give it stature?
 
Possibly we could discuss the Contest Concept on the Stoves List, to see if there is interest, and if so, to see if a practical way can be found to run the contest.
 
Kindest regards,
 
Kevin Chisholm
 
 

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

From: Reedtb2@cs.com

To: dstill@epud.net ; stoves@crest.org ; horizon@engr.colostate.edu ; bvanappel@yahoo.com ; ACousins@seattleu.edu ; kammen@princeton.edu ; dpennise@uclink4.berkeley.edu ; delaciebarney@yahoo.com ; entre16@intelnet.net.gt ; dononeal@fni.com ; elizabethb@itdg.org.uk ; fev@darkwing.uoregon.edu ; rudy@wehi.edu.au ; grant@ecoharmony.com ; jeff@hesperian.org ; jesldc@dante.lbl.gov ; krisab@oregon.uoregon.edu ; goyen@efn.org ; Peter.Kenmore@fao.org ; kmbryden@iastate.edu ; Kevin.Hallinan@notes.udayton.edu ; krksmith@uclink4.berkeley.edu ; lanny@roman.net ; larryw@proaxis.com ; childers@peak.org ; LButtner@winrock.org ; gandanga@dsl-only.net ; pattiflynn@hotmail.com ; apropeter@hotmail.com ; verhaarp@cqu.edu.au ; rdboyt@yahoo.com ; richardnjagu@yahoo.com ; rmiranda@sdnnic.org.ni ; ronallarson@qwest.net ; stuart@treeswaterpeople.org ; tami.bond@noaa.gov ; tempra@treeswaterpeople.org ; tmiles@trmiles.com

Sent: Saturday, January 05, 2002 8:51 PM

Subject: Re: LETS ADOPT A UNIVERSAL POT

Dear Dean and All:

I like the idea of a universal stove test with a prescribed pot size.  However, I was puzzled during my visit that you boiled 5 lb of water when so many other people (and therefore we do it) seem to use 1 liter.  

I vote for 1 liter because

The test is faster

It is enough to do most cooking since the steam condenses on the food (when there is a lid)

It is easier to divide by 1,000 cm3 than 5 lb or 2.72 liters.

Ron asked this morning whether 3 minutes to boil 1 liter was a record.  Possibly.  We most always boil in less than 7 minutes, sometimes 5 minutes on the various forced draft stoves. FOr water at 20 C boiling at 100 C, 5 minutes to boiling implies a heat transfer rate of (1 liter X 4.18 kJ/liter-degreeX80degrees/300 sec) 1.11 kJ/s = 1.11 kW, a respectable heat transfer.  (The small element on an electric stove consumes 1.5 kW, the large 2.5 kW).  

I hope you are taking a census on the answers, having asked a good question.

Yours truly,          TOM REED             BEF STOVEWORKS

In a message dated 1/5/02 12:25:15 PM Mountain Standard Time, dstill@epud.net writes:

Dear Lanny,

Glad to hear that you want to continue the Rocket Wok project. I'll try from

my end to use the stove as much as possible, get the students to use it and

give it a real try out. And I'll get you all the feedback. Also inform the

List.

I looked at your improved pot skirt and my two cents worth would be that

using a insulated Rocket combustion chamber under the pot gives us a lot of

draft so I wouldn't think that diminished draft would be a problem. Mark

Bryden who advises me about stoves, has the idea that increasing the force

with which hot flue gases contact the pot helps to punch through a still air

boundry layer so I wonder about the value of increasing dwell time, slowing

hot gases, as a big determinant of heat transfer. I don't know and the

perfect test might be to compare results from a straight skirt and your

spiral. I do know that the right sized gap has a tremendous effect on heat

transfer and that this gap is very small. Larry uses as a rule of thumb

keeping the same cross sectional area all through the stove so bigger pots

use smaller gaps.

Of course, the pot shape is a huge factor. A pot that touches more water

inside is better, therefore a large diameter pot with a little water in it

boils quickly. In our tests, big pots generally score higher than small

pots.

Could I then take this opportunity to forward a suggestion which Ron and I

tossed about on a train heading from Rugby to London? Let's form one center

of sanity in the bigger stove world here on the CREST list and all agree on

a pot size/amount of water that we all use in our tests! Then we can compare

results of tests. Until we do so, this factor will confound comparisons.

At Aprovecho we now use a nine inch in diameter steel pot that is five

inches high. We use five pounds of water in it. But I'm perfectly happy to

switch to liters!!

If we establish the UNIVERSAL POT SIZE FOR TESTING/AMOUNT OF WATER we will

have done something that the befuddled stove world has not accomplished in

decades! Let's do it and maybe we'll force the rest of the stove world to

follow...

Best,

Dean

Paul S. Anderson, Ph.D.,  Fulbright Prof. to Mozambique 8/99 - 7/00

Dept of Geography - Geology (Box 4400), Illinois State University

Normal, IL  61790-4400   Voice:  309-438-7360;  FAX:  309-438-5310

E-mail: psanders@ilstu.edu - Internet items: www.ilstu.edu/~psanders