Unless there is something missing in your picture, your design is flawed. For one thing, with all of the tubing in the steam but having no drain tray to catch the large amount of condensation, you may not see any net gain. With cold sap flowing thru the long tubing it will sweat big time. That will then drip back into the pan to be boiled again and again. Yes, the sap will warm but at a huge loss of potential because of the condensation going back into the pans.
Does your hood set down on the raised flue pan? If not is should, also, it should not be out in the open over the syrup pan, and the stack on the flue hood should have a damper. To use it for the best gain, when you are boiling hard, close the damper slowly, just until steam begins the leak out of any leak spots, the lock it in that position.
You will do far better if you design a parallel flow, even 2 tiers, all in the flue pan portion of the hood, with the hood setting down on the flue pan. Each section (whether 1-2 or even more) of the parallel design should rise from one end to the other. Then the entire system of tubes should join into 1, from there it could exit to the float box, or turn and rise again thru another like the first. With the rise the warming sap climbs the slope(mine is just 1.0" rise in a 54" long preheater, which then goes up to another level and then rises another inch to over the point where the first sap entered and from there it flows to the float box supply pipe).
Under the set of parallel tubes is a catch tray, which is also sloped and it drains of into the hood gutter and out, it also is under the steam stack, catching that condensate too.
If I have missed something I'm sorry if I misjudged it, I just called it as I saw it.
Last edited by maple flats; 03-03-2019 at 07:31 PM.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.