Has anyone tried this?
As I understand it, a milking machine needs around 15psi of vacuum. A
water column 34 feet high would create a vacuum of about 15 psi (atmospheric pressure). Imagine you had a sealed tank, full of water, elevated 40 or so feet up. The elevated tank has a pipe descending from it, the bottom end of which is immersed in water in a tank that is open to the air, such that the difference in height between the surface of the water in the tank at the bottom is 34 feet below the elevated tank. This
should create a vacuum in the elevated tank. You would then plumb a vacuum line from the top of the elevated tank to your milking parlor. When you ran the milking machine, the level of the water in the elevated tank would drop, and in the bottom tank it would rise, but if the volume of the elevated tank were large compared to the volume of
milk, and to the volume of air required by the pulsator (and, of
course, to the air that inevitably leaks in when you are attaching and removing the milking cups), it should be possible to supply an appropriate volume of vacuum for the duration of the milking operation.
At the end, or before starting the next milking cycle, you would refill the elevated tank by pumping water back into it, preferably with a hand or bicycle operated pressure pump.
What I'm trying to do, here, is make a system that does not require electricity.
