Ben and Judy's Sugarhouse in West Edmeston, NY had one of these at one time. I was there a few years ago for a Glen Goodrich tubing seminar. After the seminar we walked one of their sugarbushes. Mounted right at the back of a garage, behind the sugarhouse was a PVC contraption, likely 30' or so high. I asked what it was and they said they had used it as a releaser at one time. They explained it, but being so long ago I don't recall details. They did say that the vacuum would pull the sap up in the vertical tube and at some point it would get a slug of air in it, that let the sap all fall out into a barrel on the bottom. The barrel had a drain tube to drain the excess to a sap tank. Then the process would repeat. Sounded neat but sadly I din't even have vacuum at that time and didn't pay close enough attention to what Ben said.
Dave Klish, I recently bought 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.