The second half of the load construction cut offs donated by Tim and his crew at Bayshore Construction were just enough to fill the retort and fuel a round of charcoal making. Though the lid and support bars were very warped from the last burn, the lid was hammered flat and new bars were cut from heavier scrap angle iron rather than starting from scratch. The major variable this time around was packing the charcoal wood much more loosely inside the retort as per the recommendation on Daniel’s site.
Massive flames entirely from burning wood gas coming out around the edges of the lower lid, igniting, and getting sucked up the combustion chamber.
The burn went relatively quickly, burned very hot upon reaching the off-gassing stage, and may used less fuel wood than before. This was also the first time that the drum was hot enough to turn black over almost all of the surface. After the burn was complete, steel scrap, wood, and soil was used to seal off the drum as much as possible while cooling overnight.
The sorted and chopped yield, the few brown pieces at lower right.
The next morning there was a small amount of ash in the retort but most of the wood had turned to charcoal as planned. The amount of brown wood (incomplete charcoal) was much smaller than in previous tests. I would say that, though less wood was processed, the return was higher by far than when the barrel was more tightly packed. I mailed some of this batch to Pierre and he said it was still too overcooked for tanren, tabled for a future kiln design.
Another shot of the dancing dragon (or is it a jelly fish?), burning wood-gas in the combustion chamber opening.
Find out about the construction and operation of our new and improved charcoal kiln: Charcoal Kiln V.3