[Stoves] Personal history on charcoal-makingstoves.(notnecessarily same as TLUD)

[Crispin Pemberton-Pigott]

Dear All

Ron Rote:
>I can tell you for sure though that above a certain moisture level,
>there is no chance of igniting the pyrolysis gases - just too
>much moisture there.

And Jeff Jotted:
>...I would also look outside of the stove in order to
> increase efficiency by exploring methods of drying the fuel.

This turns out to be a major issue with charcoal burning stoves.  The Maputo 
Ceramic Stove, which looks like a vertical cylinder with hips, has a handy 
way of using heat lost through the upper cylindrical portion.  A tray can be 
made from a large tin or new/recycled material that has a hole the diameter 
of the upper section of the MCS.

The charcoal to be use in future is placed in hte tray.  It has a diameter 
or about 225 ID and whatever you like OD, with a height of about 100mm.  The 
temperature of the outside of the stove in that area is something like 200. 
This is enough to dry the charcoal without setting it alight.

We found that people in Maputo do try to dry their fuel by putting it in the 
sun, revealing that there is an understanding about loss cause by moisture.

Or, they may recognize that it is harder to light.

Either way, we now have a 'free' method of drying charcoal when cooking.

I did some math on the heat loss from moisture in the charcoal and it was 
rather more lossy than I hoped.  Keep your powder dry!  When extrapolating 
backwards to the amount of forest felled to drive the moisture out of the 
charcoal once it is wet, the impact of drying is impressive.

Regards
Crispin