I want to try making a down draft gasifier since my first simple fire gasifier is almost complete and working.
As I showed in my simple fire thread, I’m starting with a propane tank.
I estimated wrong and this is the same diameter as the 20# tank I used as a filter so this one might be a 30#.
I filled it with water 3 times and then cut the bottom off leaving the top ring as a possible stand.
Now I’m not sure how to continue.
I have a brake rotor that almost fits and there’s a ridge near the bottom that might hold it in place but not sure if I should have the dish up or down.
I could cut the center out completely or add a plate with more holes and call that my grate.
Another choice is a smaller brake rotor.
But there would be gaps around the outside of I put it at the ridge or very little space for the outlet pipe if I just set it on the bottom.
This might be what I go with unless I get some better ideas before I do it. Grind the outside to make a ring that will sit on the ridge on the big rotor using it as the grate and put the smaller one on top leaving a ring to hold ashes or charcoal as insulation.
Also, I’m not sure about the nozzle(s). If I remember right, there should be 4 to 6 inches between the nozzle and the grate.
This will be charcoal but I’d be lying if I said I don’t plan to at least try some “rocket fuel” or at least feed it some charcoal that didn’t fully convert. This will be for small engines possibly a lawn mower but the first test will likely be the generator that I currently run off the simple fire because it’s already set up.
I had planned to just take it apart and dump it to clean it but might try to put an ash clean out port at the bottom.
Being the first Down Draft gasifier I’ve ever tried to build I might be doing it wrong. I’m not afraid to fail but if anyone sees any problems with my plans I’m not afraid to change my plans.