[Stoves] Crispin´s kiln-was Re: Traditional Charcoal Making

[AJH]

On Sun, 08 Jul 2007 15:03:30 -0300, Kevin Chisholm wrote:

>Dear David
>
>If Crispin has a volume market, the best would probably be a Three Kiln 
>System operating in rotation:
>1: Loading
>2: Drying
>3: Firing

You forget cooling. One of the problems seems to be that cooling needs
to be slow and uniform, to avoid stresses from differential
contraction as the stove body cools below it plastic state but quick
enough to allow handling out of the kiln.

I think there may be some scope for limited preheating outside the
kiln, to say 120C and then the first  ramp up to 200C could use the
heat from the third chamber cooling. Crispin would need to post
figures for the mass of a stove body to see if the sensible heat in
cooling from 1170C to 120C is worth conserving. 
>
>That way, he can run in a continuous cycle.

Continuous doesn't need three chambers just one long chamber with
produce moving through it. This doesn't suit a small operation as it
implies continuous 3 shift 24hr working. The batch sequential working
would aim to retain as much heat in the system in the ~16hr period
there was no one in attendance with the major ramp up to 1170 targeted
for a time when there was someone on hand.

Again from Ken Goyer's article it looks like there may well be a need
for a more efficient kiln suited to the small producer of 1000 bricks
a day. The temperatures for this appear well within the capabilities
of a pyrolysis offgas flame.

BTW has anyone with access to a cone 3 and a tlud device with premixed
flame  actually seen if it can reach the 1168C temperature?

AJH