[Stoves] Dung Berry Fireballs

[Crispin Pemberton-Pigott]

Dear Kobus

I confirm all you have written about the briquette burn, from my own 
observations.

In general, the briquettes burn better with preheated primary air though the 
burning process is the same.  Preheating is such a significant contributor 
to a good burn that with regard to moister fuels (which briquettes often 
are) the pilot flame can probably be stated not to be a 'need' but rather 
that is it 'helpful'.

Regards
Crispin

++++++++++

"The stack effect produced a yellow flame licking out
the top and igniting unburnt gases formed during the slow top-down flaming
pyrolysis burn on the outside of the stack, ultimately resulting in a
charred briquette stack which would then slowly start to 'burn'  (±25 min
into burn) to ash ±45 min later.  The internal 'pilot flame' required hot
secondary air upon reaching the mid-point of the top briquette and this was
supplied via holes cast into the base of the briquettes.  If the creep rate
of the internal flame is not arrested (primary air), it soon reaches the
base of the stack and eventually creeps around on to the outer rim of the
bottom briquette, as Richard rightly said.

Regards

Kobus