What is Centrifugal Pump?

To understand what is centrifugal pump, first we have to know what is pump. Pump is a machine that transfers mechanical energy from prime mover(motor or internal combustion engine, etc.) to hydrodynamic energy to make fluids move.

What is centrifuge? In fact, centrifuge is caused by the inertia of objects. For example, when you spin an umbrella slowly, the rain drops on it will spin along. That’s because the force of friction between rain drops and umbrella works as centripetal force. But if you spin the umbrella fast, the friction force will not be enough to keep the rain drops spinning along and they will run away from the umbrella and move outward. Just like you tie a stone with a rope, hold the rope and spin the stone in a circle. If you spin it very fast, the rope will break up and the stone will fly away in the radial direction. That is so-called centrifuge.

Centrifugal pump is designed by that principle. The high speed spinning impellers move water and throw it out for delivery. The centrifugal pump converts the mechanical energy from the prime mover to energy in a moving fluid through the rotating impellers. When the centrifugal pump starts working, its impellers filled with fluids will start to rotate. Under the centrifugal force, the fluid is whirled radially outward along flow channels between impellers. The fluid gains both velocity and pressure while passing through the impeller. Then it goes through the delivery chamber, where the flow is decelerated and the pressure is further increased. Finally, the fluids is sent out along discharge piping line. As the fluid is being discharged, the center of impeller will have low pressure or become vacuum. The fluids in suction tank will continuously flow through the suction tube into the center of the impeller under atmosphere pressure. In this way, the rotating impellers keep drawing in and draining out fluids.