Corn Fired Boiler

I've not seen plans. Many people in my area are using them. I've looked over all the units at the MN state fair three years running.

People are having trouble with the units that use the little rotating agitator finger idea. They are for sale cheap on the used market.

The best idea going right now is to have one left and one right hand auger made of cast iron to agitate and move the burn pile along. The screws sit inside a half round SS plenum that has many 1/8" holes drilled in it. A blower forces combustion air through the holes. I see no reason the augers can't be fabricated out of stainless steel, but they will require replacement when they burn up.

There's also a feed auger from the corn bin to just above the feed screws. Electrical controls determine how fast this auger runs and there's safeties for fire out and water too hot.

The heat exchanger is identical to a wood boiler right now. Just a double wall very large pipe. say one 18" and one 24". I think we'll see improvements in heat exchanger design. If I were to build today, I'd copy the old triple pass boiler design seen in coal boilers made of cast iron fifty to hundred years ago. Wish I had the one from my first house. I'd just insert the corn unit.

I plan on building one when I can no longer cut wood. And that day is getting near. I plan to just copy the best design I see.

karl

By this I assume you mean that there are two counter rotating augers, such that the corn is pushed along between them from one end towards the other.

Is the half round such that the augers set inside and there is a valley below the augers, or is it more of a wide U trough that they lay against the round edges with a flat between them?

What sort of size auger? 3", 4", smaller?

I have been thinking about this for awhile. Being a software engineer(working in HVAC conveniently enough), the controls for this would be simple(for me).

I agree. A triple pass system would seem better than the simple water jacket. Perhaps a combination system.

I hope to finally getting around to building one this year. I would like to supplement the house boiler with a corn system. Alpha/Beta version would probably be test run in the shop first as supplement to the hot water heat there.