Here is a sketch of what I have in my head. None of this actually exists yet, as I am currently calculating material cost. But, before I nail down too many details, I’d like to run it by those who may have swum in these waters before.
I’m using a 55-gallon Gilmore-style retort, just as Gary has described. It sits inside a cinder block housing underneath the oven. The weight of the oven is supported by the steel plate which has one 12” hole in the center, and as many 1” holes as necessary to supply pre-heated secondary air to the inside of the oven chamber. The pyrolysis gases exit the retort and pass through a 12” clay pipe to the underside of the soapstone oven floor, supported by a loose layer of firebricks, the layer being open on the sides and back. The hot gases flow out toward the side and back openings, where the secondary air nozzles are located. The gases ignite and should completely combust inside the oven chamber, transferring most of their heat into the thermal mass of the oven.
I am also planning to mount wheels on the bottom of my retort, and put in some type of steel rail on my concrete base to safely roll the hot, loaded retort in and out as necessary.
Comments/crticisms are all welcome.