This is a type of salt water distiller, that works well below the boiling point of water.
First, there's the salt water chamber, a thermally insulated, cylindrical chamber, with two heat exchanger coils in it, and an air bubbler at the bottom.
Salt water is pumped in at the bottom and is heated
as it rises.
Dry air is pumped in at the bottom through the bubbler; the air bubbles become humid on their way up, partly because the air is dry to start with, and partly because the water is warm near the top.
The bubbles remove enough moisture that the salt water becomes a concentrated brine by the time it reaches the top.
The warm brine, upon reaching the top, then flows down through one of the two heat exchanger coils in the chamber, giving most of it's heat back to the unconcentrated salt water.
The air, upon reaching the top, passes through a baffle that ensures no saltwater is mixed with the air, and then is compressed.
The hot, compressed, humid, air is then sent through the other heat exchanger coil, giving it's heat to the salt water.
After the air reaches the bottom, it goes through an expander, which air pressure into mechanical energy, which reduces the energy needed to compress the air in the first place.
Not only will some water condense out of the humid compressed air due to cooling while in the heat exchanger, but more water will condense due to the cooling of the air when the air is expanded.
After expansion, the air goes through a gas/liquid seperator, and the distilled water is pumped away.
The cold air then goes through a heat exchanger, where the waste brine (which was still warm) heats the air back up to it's starting temp.
Then the air goes back to the bubbler.