posted 4 hours ago
I tried this Monday. It was partly inspired by the likes of Trace Oswald and others' experiments. I didn't tilt the barrel, but I started it half full. I couldn't really replicate Trace's version, because his had no holes in the bottom of the barrel. Mine has holes. Holes in metal are hard to put back.
The main motivation was that it seemed that often, I will start a biochar burn and at some point, the fire wants to choke and go out. My main interpretation of this is that there is condensation that builds up too much and the combo of water vapor and smoke makes the fire go out.
I have made some steps to decrease this effect. I went from a 5" wide chimney to a 10" one. That helped a lot. When I have the chimney on, I also now usually lift the chimney to place the wood in quickly. Then I let the chimney down quickly and let it start to burn before adding another one. I also took Douglas Alpenstock's idea of a metal bar connecting the bottom to the top, so that air can always travel from the bottom to the top and vice versa. All of those helped but I would still get sputtering after awhile-maybe 45 minutes to an hour.
My theory was too much smoke and condensation at that 45 minute time. For my new experiment, I would start with mostly skinny sticks and only about 1/2 full. There is less condensation in skinny sticks and they burn quickly. I have done this a few times now. Because they burn quickly, I have to actively add a lot more wood at the beginning. There is a period of about 45 minutes now, when I am adding wood, a bit by bit, until I can actually fill the 55 gallon barrel.
It is more work, but so far, I have not experienced a choking from smoke and condensation. It seems that starting this way may prevent the sputtering from condensation and smoke.
John S
PDX OR
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