[Stoves] combustion of char -- spontaneous and dangerous

[Crispin Pemberton-Pigott]

Dear Kevin

 

That is indeed a refuelling. The initial drop is the coal burning. Then it
is refuelled (jump up in mass) then it burns down again and eventually goes
out completely after some hours. 

 

The surprises are the shaking of the stove scale by the wind in the night,
and then the increase in the system mass. The curve moves up and down in a
manner surprisingly similar to the mass change charts of Battacharyya. This
was a traditional stove and the burning of coal near the edges of the
chamber is not all perfect.  How much O2 can char pick up in a few hours?
Is this real or an artifact of the wind?

 

Regards

Crispin

 

 

 

Dear Crispin

 

I don't understand the graph...

1: What are the units of the vertical scale? (Is it Grams weight?)

2: The weight (?) gain is virtually instantaneous.

 

Presuming the vertical axis is the weight of the stove system and contents
in grams, the instantaneous system weight gain would be 108,400 less 103,800
= 4,600 grams.

 

What could possibly explain such a large and instantaneous weight gain? Did
someone simply put more wood or coal on the fire?

 

Best wishes,

 

Kevin

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

From: Crispin Pemberton-Pigott <mailto:crispinpigott at gmail.com>  

To: 'Discussion of biomass cooking stoves'
<mailto:stoves at lists.bioenergylists.org>  

Sent: Monday, February 25, 2013 2:45 PM

Subject: Re: [Stoves] combustion of char -- spontaneous and dangerous

 

Dear Friends
 
Here is a mass profile, raw and smoothed with 21 point simple averaging
(minus 1000 to pull it down so you can see it).
 

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