Air lift pumps

Pohle-1892-patent-air-lift-pump.gif An air lift pump consists of a vertical pipe immersed in a liquid, an air compressor, and a conduit to introduce the compressed air  into the bottom of vertical pipe. As air flows from the conduit  into the vertical pipe, a vertical flow of bubbles and liquid is created in the pipe.  The bouyancy of the air bubbles  lifts the liquid and ejects it from the upper end of the pipe above the surface of the liquid.

An air lift pump can lift a liquid to a height above the surface of the liquid equal to about 2/3 of the depth at which the air is injected into the bottom of the vertical pipe

Air lift pumps may have a number of applications in solar water heating.  12 volt DC air pumps are common and cheap, and may be powered directly by solar electric panels.

Here are three old patents for air lift devices.