[Stoves] RE: Central channel combustion stoves. Was RE: Henson CenterFiure Burner System

[Crispin Pemberton-Pigott]

Dear Nordica

This relates to the part you write about charcoal burning.

>I've also been learning some interesting things
>about charcoal while testing two stoves from
>Africa this past week...

It appears you have been learning about those two stoves more than about 
charcoal burning.  The devices definitely respond differently from other 
stoves using the same fuel.  For example, if you close the little door 
cutting off the air and the CO does not go up it means either the stove is 
leaky and allows air in somewhere else (like at the top of the stove) or 
else you are using a fuel that does not require air to burn.

>Both the CO/CO2 ratio (between 8% and 15%)
>and emission factors were actually slightly less during simmering,

This suggests that the fuel is starved of air when the burn rate is higher 
(typically 4 to 8 gm per minute).  This is a classic problem with the JIKO. 
The air hole is not large enough to feed the fire.  The CO is higher than 
when the fuel is mostly burned _and the door is still open_.

When you have a door that does not seal off the air, then air is getting to 
the fuel bed by another route.  That could give you the result of having no 
major increase in CO when the air supply is supposed to be nearly shut off.

If the CO remains basically the same, where is the air coming from?

Best regards
Crispin