# Gasification plans/homemade



## trydave

I wood like to build a gasification boiler or convert my outdoor wood boiler.  I am getting way to much smoke and want to reduce woode usage.  I have seen plans for a seton gasification boiler but thay want $700.  Does anyone have plans or expierence that can help me.  Thnaks


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## Nofossil

My brother built one from scratch with stainless heat exchangers. Came out nice, but it was a whole summer project. The controller can be a problem if you don't have the tools and experience to roll your own.

Basic theory is simple, materials can be a challenge. The combustion chamber sees over 2200F, which is more than many refractory materials can handle. Gaskets must be perfect. The slightest leak in the gas generation chamber is a real problem.

The gas generation chamber must be pressurized by a fan - preferably variable speed. He used a unit out of a pickup truck heater, and replaced the speed control switch with a set of relays. A portion of the air from the blower must be introduced into the combustion nozzle, and that fraction must be adjustable. Some sort of control system must manage the fan, circulation pump, and a recirculation loop that helps get the inlet above condensation temperatures quickly.

If you copied the nozzle dimensions and geometry from a 'known good' design, you'd probably be all right.

In summary, it's doable but it's a big project with some special challenges. Get a few friends with different skills to help. I can provide more details about what we did if you decide to go forward.

Here's a link to some pictures of my brother's boiler as it was being built.


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## Eric Johnson

What that guy did just blows my mind when I think about it and look at those pictures. What a satisfying project.


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## Eric Johnson

If you could turn an OWB into a gasifier with a $700 retrofit, then there wouldn't be any more OWBs sold.

The design differences are fundamental. I don't see how you could do it.

I tried something similar with an add-on cat combustor to a conventional wood-fired boiler. I got the required stack temps (600+) but was never able to cut my smoke output, even though I suspect the cat was working to some extent. The first $100 takes the cat add-on.


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## slowzuki

I've seen some plans a fellow had for casting / building a gasification/higher efficiency liner for a OWB.  It had a section connecting to the stack, and the wood was up on a ceramic bed.


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## rsnider

Go to woodheat.org and in the owb page you can find a reply were a guy changed his owb to a more efficient boiler. It looks to me he had a classic "central boiler" and added firebrick and a fan on exhaust (he gives his data on wood usage and less smoke).

hope this helps.


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## antknee2

The boiler is a absolute marvel of American ingenuity  please keep us updated on amazing machine . Thanks Anthony


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