Difference between working principle of centrifugal pump and self-priming pump

From the working principle, the centrifugal pump is generally driven by a motor. Before starting the pump, the pump body and the suction pipeline are filled with liquid. When the impeller rotates at high speed, the impeller drives the liquid between the blades to rotate. Due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller, and the kinetic energy also increases. When the liquid enters the pump casing, as the flow passage in the volute casing gradually expands, the flow velocity of the liquid gradually decreases, and part of the kinetic energy is converted into static pressure energy, so that the liquid flows out along the discharge outlet with higher pressure. With the use of the velocity of water, the impeller drives the pump impeller to pump water to the bank. This type of pump can be pumped into the river, but it must be rushed or there is a gap.

The difference between the two is mainly that before the centrifugal pump is operated, the pump body and the inlet pipe must be filled with water and vacuumed. The water of the original water is pressed into the inlet pipe through the pipe network under the action of atmospheric pressure (or water pressure). Continuous pumping. Self-priming pumps do not require irrigation, which is the origin of self-priming pumps.

Centrifugal pumps are mainly used by the force of Lee's centrifugal force, while self-priming pumps mainly use an impulse of the current itself.