[Stoves] Broken Brick Mixed with Charcoal

[Paul S. Anderson]

Dear John, Tom R., Crispin and all,

Very interesting topic.

Yes, we would like to reduce the radiation of heat downward (and protect the
grate at the same time), and somehow use that heat at the level of the 
pot. Does the brick/stone/lava-rock accomplish this?  If so, how does 
that heat at
the bottom become useful at the pot level above?  Is it really based on having
plenty of insulation around the bottom, including simply having space 
below the
hot charcoal to reduce heat loss to the soil, etc.?

John, the comments about making CO from CO2 plus hot C are correct, but is the
benefit of the brick pieces based on allowing air to flow through the char, or
is it because the brick pieces help give the needed height (thickness 
of layer)
of the hot char with which the CO2 can react?  Your taught me years ago 
that we
need about 15 layers of the fuel-partical size above the hot coals for the CO
creation to best take place.  Perhaps the brick is simply helping to have that
height.

Too many charcoal fires are with a thin layer of charcoal (briquettes or
pieces).  In that case, the main reaction is to make CO2, which releases much
heat but is somewhat further from the place of use of the heat (unless the pot
is placed very close to the coals).  So, in the initially-mentioned case of
improved heat capture (or heat output), was it actually because of combustion
of the CO near the pot being better than the CO2 reaction further down, 
and the
brick pieces had helped to cause this advantage?

Paul
-- 
Paul S. Anderson, Ph.D., Geography professor - Emeritus
Telephone:  USA-309-452-7072 (residence and office)
Internet site:  www.ilstu.edu/~psanders
For my gasifier stoves info, go to:
http://bioenergylists.org/contributors#Paul_Anderson



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