Tuesday, March 8, 2011

Building the Gasifier

You're probably going read a lot of posts about this wood gasifier that I am building. This is a major project for me, and I will keep posting updates right here.

Today I began the actual cutting. I have spent plenty of time researching gasification, and settled on a customized design:

This is the hearth. Air comes through the pipes and into the reaction area. This part will get the hottest. All the gases will pass through the upside down cone (inverted V), ensuring that the tars are cracked at high temperatures. The top side of the inverted V will rapidly fill with ash, creating a very insulative layer. Ash will also form a reduction cone from the narrow part up, determined by the ash's angle of repose against the walls and the throat. Anyway, enough theory for now.  Here is the outer tank ready to be cut - an old 16" water heater.

This was a gas fired heater, meaning a flue pipe runs top to bottom, welded in at each end. This makes cutting the tank in half tricky. The pipe has to be freed, eventually at each end.

To make the cone, I need a piece of heavy steel cut to this pattern:

Traced and cut out from the remaining piece:

The perspective makes it look funny, but this is a very curly piece of metal. Not the right curl for my cone, though. I flattened it out:

Now I cut the other tank, in much the same manner. This one is the inner tank with a large opening in the bottom for the base of the cone:

One goes inside the other. There is a 3/4 inch gap all around for some air pipes, and for the gas to exit.
That's all for today. Stay tuned...