preheater question

[cur dog]

Has anyone here ever experimented with running a section of stainless pipe thru their smoke stack? I'm sure if the sap were to sit very long it would become gas, or scorch. If it was kept flowing, I would think it would be a very efficient way to super heat your sap. Any thoughts, or designs out there?

[Vermonner]

I think that would depend on stack temps. If she's glowing red and your stack temp is > 750, I bet it would scorch pretty rapidly. I saw a homemade copper preheater (they're all over this site) in operation this year, placed just above the 218 degree steam and the sap in the preheater which was at 40F on the way in, hit the pan at about 170F. This had their drawoff running pretty consistently and the depth of sap in the pans remained consistent. The more I think about it, the more I think Stack temps would scorch the sap.

Maybe try playing around with it? 6" of SS pipe in the stack @ 600+Farenheit = 3 feet of copper over 218 deg F steam? Who knows? Good luck