A submersible pump uses a motor in a watertight housing to drive a pumping mechanism that pushes a column of liquid to move to another location. The sealed housing allows the pump and motor to be placed inside the fluid it pumps without damaging the electric motor.
The submersible pump includes a series of impellers that are stacked to lift the water. When the motor starts, these impellers turn like a boat propeller to force the water to move. Because the fluid is pushed, the submersible pump moves fluids over large differences in vertical height. To further improve the lift, it is possible to include additional submersible pumps along the line.
Submersible pumps have use in many applications other than supplying water. Single-stage pumps with specially designed impellers pump sewage, sludge and drainage. They also offer an effective means of mining petroleum from a deep well.
Most shallow wells use jet pumps. These pumps create a suction by evacuating air from the pipe. The weight of air on top of the water at the bottom of the well pushes the water into the evacuated area and moves it to the surface. Atmospheric pressure limits jet pumps to a 25-foot depth.