I’ve been thinking about redesigning my vertical oriented retort into a horizontal one.
The retort works fine, but it is cumbersome to assemble. The outer barrels have to be stacked around the inner chamber holding the wood. Then a flue has to be placed on top. Then I have to place sheets of steel roofing around the barrels to insulate them Unloading is the reverse and then the vessel holding the charcoal has to be picked up and tilted on its side to be unload.
I had decided to rotate everything 90 degrees. That way a lid on the 200 liter drum could be opened to get access to the inner vessel that could then be opened to unload, already in a horizontal position. Everything else could remain untouched.
Then just now I came across this commercial design:
It is so elegant. It is easy to open and close, It is insulated for better efficiency. The burn chamber is made out of materials that should last a lifetime. Finally, the charcoal vessel is an easily replaceable steel drum.
The vessel I have is made from a propane tank. It is already beginning to spall after less then 10 burns. It is also much smaller than an oil drum so for the same amount of effort I could probably double the amount of charcoal produced with this other design.
One other advantage is that with multiple drums, you could start a another batch while the first is cooling, simply by changing the drums out. It will require a significant investment in steel and firebricks, but I think it is worth it. I will probably start designing and calculating material costs, etc.