I was inspired by Abner's giant retort to try and upsize our retort a little bit. I am following a design somewhat similar to his.
In a nutshell, I have a 55 gallon drum on its side, with a burner pipe coming out of the barrel and wrapping under it to heat the barrel with the wood gas.
This assembly will be placed inside my BBQ pit. The BBQ pit is 4 feet wide by 6 feet long by 2 feet high concrete block.
The pit will be filled with slab wood and set ablaze.
It will be covered with a "Quonset hut" style roof, with a chimney in the middle.
Here is the stand for the 55 gallon drum.
Here is a side view of the retort.
Here is a view from the end. As you can see, I have placed a valve on the burner pipe so that I can make the thing completely airtight when it is done.
The biggest unknown right now is how big and how many jets to place in the burner pipe. Right now, I have 17 3/16" holes drilled in the pipe. Here is a close-up view of that.
I am afraid that if I make the holes too big or too numerous, the gas won't make it to the far end of the pipe. But if I make them too small or too infrequent, I risk over-pressuring the vessel.
Any thoughts on this?
Will post pictures of the outer assembly after I move it into the BBQ pit.