[Stoves] Magh Smoke Burner Stove

[AJH]

On Mon, 09 Apr 2007 17:10:42 -0500, Paul S. Anderson wrote:

>
>Quoting Thomas Reed <tombreed at comcast.net>:
>>
>> So, if you are willing to use only the volatiles and use the charcoal
>> for terra pretta (or mix it back in with the next batch of wood), you
>> can avoid stainless.

Taken to the ultimate conclusion the stove would simply choke up with
ash, if you sift out the ash then you can recycle the char a number of
times. When john Davies posted about getting the high sulphur offgas
from bitumous coal to burn (in ~2000 he reported people left the stove
outside to drive off unburnt offgas and only used it once the fossil
coal was reduced to burning coke)I found one way to get around the
problem was a tlud burn but recycling sifted coke back alongside or on
top of the fresh coal. Ronal and I had to eat a cold fish supper
because we stayed outside playing with it too long.

>The above refers to TLUDs.  And IF the use is ONLY for the pyrolysis gases,
>there is no reason to put the charcoal back into the next batch of wood 
>because
>there are no sources of pyrolysis gases in that char.

There will still be some Paul but the char will still burn tlud, have
a try, from memory the downward rate of spread of the fire is much
faster as the fire front only has to heat dry char to its ignition
temperature.

A simple experiment would be to fill a 1m by 150mm diameter flue pipe
and mark the outside with a fixed length crayon mark, the speed of
progress of the fire downward could be timed.

One of the things I never resolved about a long stack tlud fire was
how the air supply varied as the column of hot gases above the fire
lengthened and the column of fuel (and its resistance to air and
offgas) shrank. I think there is a need for an experiment with a
constant mass air supply.

The other thing I didn't do yet is to run comparable experiments with
inclined tubes to see how far off vertical the tube would still
function in tlud mode. This of course is more of interest in the
production of char rather than a functional cookstove. It's a shame
your visit was brief and only in London, you may have enthused me to
have a go!

AJH