Take two on the charcoal retort in an attempt to get the burn temperature higher and complete the process of charcoal formation.
The first attempt was promising but seemed to take too long to get to operating temperature and did not stay there long enough. So rather than stand the drum on the ground, I built a new base using three logs and some angle iron. The plan was to provide more heat below the drum, allow fuel to be added from the bottom as well as the top, and to allow more air into the combustion chamber.
After a slow start, again due to wet fuel wood, a good operating temperature was reached in about an hour. This time, the base was much hotter and the wood gas was being produced in larger volumes.
However, the raised base design introduced new flaws of its own. In the original design, the air was drawn in solely through the triangular holes, mixed with the wood gas, and fed directly into the combustion chamber over the coals. But in this configuration, there was a much larger volume of air coming in from several different places which allowed some of the wood gas to escape and burn outside the drum. Also, though the draft was as strong as before, the air was pulled through without being fed into the coals at the base. This meant that the some of the wood gas heat was lost externally and the base fire was not as hot as it should have been.
The next day I was happy to find a retort about two-thirds full of beautiful, shiny, light, softwood charcoal. The rest was well on its way but still brown, heavy, and hard so it will be first in on the next batch.
We sorted and chopped most of it but couldn’t wait to make a fire so we spent the afternoon at the anvil. This was my first time to forge with charcoal but I didn’t have much trouble adapting. It feels like it burns faster than coal so we will need a bit more of it, and I also noticed that the fire collapses much easier than with coal and takes a bit more raking to keep piled up and concentrated. It was very clean and hot and I look forward to using charcoal as long as I can streamline the retort function and production side of things.
Find out about the construction and operation of our new and improved charcoal kiln: Charcoal Kiln V.3