[Stoves] RE Central channel combustion stoves. WasRE:HensonCenterFiure Burner System

[Tom Miles]

Paul,

Aprovecho uses the Water Boiling Test to measure stove performance as
described at ETHOS in 
http://bioenergylists.org/stovesdoc/ETHOS2006/Still/StillETHOS2006.pdf

Every second they measure the concentration (parts per million or mg per
Normal cubic meter of gas) of the pollutant, say CO, in the gas drawn from
the hood. The mass which changes over time is tabulated in a spreadsheet.
That gives them the mass (grams) of pollutant emitted during the test.

To calculate the total emission in grams from the concentration in PPM or
mg/Nm3 you need to measure the mass flow of the stack gas, which they do in
the portable and fixed test hoods.

The mass of pollutant is related to the amount of water (5L) boiled so you
get grams of CO for the test divided by the 5L. It's an average for cook.   

The CO is a result of not enough air being mixed with the high concentration
of CO at the beginning of the cook, so it spikes at the beginning and
declines during the cook as you see in the graph made from measurements
every second. That's what the graph is built from.

You'll note in the 2005 stoves camp report they report the amount of CO in
different terms and separate out the CO for cook and CO for simmer. They use
g/L even though they used 5L in the cook.
http://bioenergylists.org/stovesdoc/ethos/2005camp/camps2005.htm  

They will not doubt include the calculations in the forthcoming "Comparing
Cookstoves" which they promise is due out soon, likely before Stoves Camp. 

I hope this helps. 

Regards,

Tom 

-----Original Message-----
From: psanders at ilstu.edu [mailto:psanders at ilstu.edu] 
Sent: Thursday, June 15, 2006 8:07 PM
To: Tom Miles
Cc: 'Stoves'; 'Ananda Weerakkody - Sri Lanka - Philippines'
Subject: RE: [Stoves] RE Central channel combustion stoves.
WasRE:HensonCenterFiure Burner System

Dear Tom,

THANKS!!   Very helpful!!

Is there a way to compare data that says "CO to cook = xx g"  and
"CO to cook is yyy ppm"?  The graph of the Rocket charcoal stove shows
continuous measurements, with spikes and declines.  But how is such as graph
interpreted as a single number reading of ppm (the visual average of 
the line?)
and how is that converted to grams?

I feel like I should know this, but I have not mastered the topic.  For 
example,
all of the "CO to cook" measurements from Stove Camp 2005 data have 
readings of
about 1 to 6 grams per liter.  Is the reported value of "12" for the Rocket
charcoal stove based on grams of CO for one liter or for all 5 liters of
water
boiled + simmered?

Puzzled!

Paul


Quoting Tom Miles <tmiles at trmiles.com>:

> Paul,
>
> Find the data in Dean's post and pdf at:
> http://bioenergylists.org/en/node/506
> http://bioenergylists.org/en/node/551
> And linked to
>
http://bioenergylists.org/stovesdoc/Aprovecho/charcoalstove/Aprovecho_Charco
> al_Rocket_Stove.pdf
>
> CO chart at http://bioenergylists.org/en/node/546
>
> Tom Miles
>
> -----Original Message-----
> From: stoves-bounces at listserv.repp.org
> [mailto:stoves-bounces at listserv.repp.org] On Behalf Of Paul S. Anderson
> Sent: Monday, June 12, 2006 9:21 AM
> To: Dean Still
> Cc: Ananda Weerakkody - Sri Lanka - Philippines; 'Stoves'
> Subject: RE: [Stoves] RE Central channel combustion stoves. Was
> RE:HensonCenterFiure Burner System
> -----
> What are the comparable figures from tests of charcoal stoves for boil and
> simmer and total?  If already posted, please direct me to them.
>
> Paul
>
>
>



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