Air Lift Pumps
The Air Lift Pump is a type of deep well pump, sometimes used to remove water from mines. It can also be used to pump a slurry of sand and water or other "gritty" solutions.
In its most basic form this pump has NO moving parts, other than an air compressor. The efficiency of the air compressor is a prime factor in determining the overall efficiency of the pump.
Increased efficiency in the pump itself can be achieved - but with added complexity. Shown here is a simple Air Lift Pump.
Compressed air is piped down a shaft. The air then returns up a Discharge Pipe carrying water with it. The pump works by "aerating" the water in the discharge pipe.
The added air lowers the specific gravity of the fluid mixture. Since it is lighter than the surrounding water, it is pushed upwards.
This type of pump can lift 20 to 2000 gallons per minute, up to about 750 feet. The discharge pipe must be placed deep into the water, from 70% of the height of the pipe above the water level (for lifts to 20 feet) down to 40 percent for higher lifts. Air Lift Pump