The Airlift pump, sometimes called a mammoth pump, is easy to construct from common materials. Invented around 1797 by Carl Emanuel Löscher.
Air is injected in to the lower end of an open pipe, which is immersed in the liquid, pumping liquid up. Often this idea is used in boreholes, but can also be used for dredging or collecting scientific specimens.
- An open pipe that is immersed in the liquid
- Compressed air (blower, compressor)
- A sieve, to collect sand or other objects you want to either collect or sepparate from the liquid, depending on what you want to collect.
Not much is needed to build an airlift pump, that is the main advantage of these pumps, but to operate one, you should keep in mind that the immersion length is bigger than halve the length of the pipe. The compressed air will produce a forth of air and water, which has a lower density than water itself.
The density of this air/water mixture is about halve the density of water alone, which means you can get this mixture to rise approximately equal to the immersed depth of the pipeline. This means that if the water level drops below a certain point (immersed level is less than halve the length of the risisng main) no water can be transferred from the well this way. For a “steady” supply of water usually the immersion lenght is twice that of the length above the water level.
Joseph F has had success using this model, a 40W ZOIC Commercial Air Pump, to drive water up 3' of head (3' of pipe submerged under water level). Similar to this setup: