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Anyone make biochar?
I finished building a kiln today. Took me five revisions before I got it running right. I found it extremely frustrating that all the information I could find about them was from disorganized hippie minds. Surely someone could come up with some kind of guidelines for ventilation. There are easy to find formulas you can use when ventilating a water heater or an attic, for example.
Anyway, it's a Top Lit UpDraft (TLUD) design utilizing a 55gal barrel. I have 36 1/2" holes drilled in the bottom of the barrel. 180 1/2" holes drilled around the rim of the barrel. A 12" diameter chimney. Results of the most recent test firing seemed satisfactory, though I suspect I may want to add slightly more ventilation around the rim.
Earlier iterations involved a 6" diameter chimney, which was inadequate although very effective as a smoke generator, as well as fewer air intake holes around the rim, which also resulted in excess smoke, as well as backdrafting that created amusing clouds of smoke rings puffing out of the holes in the rim of the barrel.
I advise against drilling holes in the rim. Once I realized how much ventilation is required at the top, I would not have continued drilling if I had been able to find my jigsaw.
