Rectangle gasifier

Has any body ever fooled around with a rectangle gasifier?
I built a square gasifier boiler i heat mt house and shop with.
It burns 18" wood I thought it would be nice if you could build an on demand rectangle gasifier so you could use stick wood
I thought about using Wayne’s design but i’m not sure about the air nozzles
Any thinks ?

Search “Hugh Wilson” on the Woodgas Yahoo Group. He was posting last year at this time. (June/July 2011) There are photos, too. i.e. hughnw_57 added 5 photos to the Rectangular Gasifier folder. There are hundreds of folders in the photo section of the Yahoo Woodgas Group. Sometimes it is easier to start at the last folder and back up to the “R’s”.

I had a concept unit a while back that had twin rectangular gasifiers. The concept was to use one at a time with automation. While one was in opperation it would flow into the other side and it would act as a filter. When the fuel would run out you then would fill it back up and then run the other side.

But its on the back burner for now.

Rectangular hopper ok, but hearth? The corners will allow pyrolysis gas to bypass, causing tarry gas. Rectangular boxes further downstream of the gasifier ask for additional strength to avoid implosions or flip-flop noise when dents are pulled in and released.


Would a rectangular “fire box” with a round opening in the bottom at the pyrolisys stage work? It would make things more space efficient as long as it still worked.

Depends on what you mean with “fire box”. We’re not talking about a stove. Pyrolysis zone is at and above of the nozzles. I would not build anything rectangular from four inches above the nozzles to the end of the grate. Even long protubing nozzles give me the creeps.

In WW2 some brands had rectangular gasifier hearths. Don’t know about their performance. They remained rare for some reason.


“Fire box” = “Rectangular fire tube”. :stuck_out_tongue: