Schematics needed

[Oddmott]

Hey all,

I recently collected 3 old wood furnaces. Hoping that one of them may work to turn into an evaporator and the other two will provide extra metal and fire-stop materials.

But, I'm having difficulty finding any good schematics... can anyone provide plans for an evaporator capable of at least 10gph, or point me in the right direction?

Thank you,
Matt

[maple flats]

I don't have schematics or drawings, but you want to plan about 12 sq. ft surface area if it is a flat pan, if part flat and part flues the area can be less. I suggest you start with 12 sq. ft flat and as you get more into it you can get a set made that has both. You want to design it with the fire on grates about 18-20" below the pan(s), with a large draft door under the grates. Make the first 1/3-1/2 at that depth, then ramp up to within 10-12" of the pans, and fill that space with vermiculite for insulation, cap with half bricks (fire brick about 1.25" thick) to leave about 1-1.5" under the pans until you get back to the stack. The extra space being filled with vermiculite for now, is for drop flues if you advance to that. Then you won't need to rebuild, you'll have the option of either raised or drop flues.. The 1-1.5" below the pans is to force the heat up to the pans. If you go raised flue in the future, the space reduces to about 1/2" max. The floor under the vermiculite can be plain sheet metal, that is what an official factory made basic evaporator is.