Submersible pumps operate by pushing fluid to the surface, contrasting with jet pumps that rely on suction. A key advantage of submersible pumps is their resistance to cavitation, a significant issue in regular centrifugal pumps due to low suction pressure.
Here's a breakdown of how they work:
- Motor and Pump Integration: The pump and motor are tightly coupled, with the motor typically located directly beneath the pump. This configuration allows the entire unit to be submerged in the fluid.
- Sealed Motor: The motor is sealed in a watertight enclosure to prevent fluid ingress and electrical shorts.
- Impeller Design: Submersible pumps usually employ a centrifugal pump design. The impeller, driven by the motor, rotates at high speed.
- Fluid Intake and Discharge: Fluid enters the pump through an inlet screen, preventing large debris from entering and damaging the pump. The rotating impeller imparts kinetic energy to the fluid, increasing its velocity and pressure.
- Diffuser: After exiting the impeller, the fluid passes through a diffuser. The diffuser is designed to convert the fluid's kinetic energy into pressure energy, further increasing the pressure.
- Upward Flow: The high-pressure fluid is then discharged through an outlet at the top of the pump and flows upwards through a pipe or hose to the surface.
- Cavitation Prevention: Because the pump is submerged, the fluid pressure at the pump inlet is higher than atmospheric pressure, minimizing the risk of cavitation. According to the reference, cavitation is a major problem for regular centrifugal pumps because of low suction pressure. Submersible pumps avoid this problem.
In summary, submersible pumps effectively push fluids upwards, minimizing cavitation risk due to their submerged operation and sealed motor design.
