Airlift pump
An airlift pump is a simple pump which is powered by compressed air.
Utilization
Airlift pumps are often used in deep dirty wells where sand would quickly abrade mechanical parts. (The compressor is on the surface and no mechanical parts are needed in the well). However airlift wells must be much deeper than the water table to allow for submergence. Air is generally pumped at least as deep under the water as the water is to be lifted. (If the water table is 50 ft below, your air should be pumped 100 feet deep).
It is also sometimes used in part of the process on a wastewater treatment plant if a small head is required (typically around 1 foot head).
Method of Operation
Typically, the compressed air is pumped down a pipe into a well and bubbles into another larger diameter pipe. The air bubbles return to the surface in the larger pipe. Since the resulting air-water mixture is less dense than the surrounding water, it rises and a fizzy spurting flow of air and water results.