Compared with other types of pumps, centrifugal pumps have many advantages, such as centrifugal pumps have uniform flow, stable operation, low vibration, high speed, low equipment installation and maintenance costs, and a wide range of applications (including flow, head, and adaptability to the nature of the medium). Therefore, the centrifugal pump is an extremely widely used pump in industrial production.
In petroleum and petrochemical production enterprises, various centrifugal pumps are widely used, and centrifugal pumps are also widely used in other sectors of the national economy.
The centrifugal pump is generally driven by an electric motor. Before starting the pump, the pump body and the suction pipe are filled with liquid. When the impeller rotates at high speed, the impeller drives the liquid between the blades to rotate together. Due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller (the flow rate can be increased to 15-25m/s), and the kinetic energy also increases. When the liquid enters the pump casing, as the flow channel in the volute-shaped pump casing gradually expands, the flow rate of the liquid gradually decreases, and part of the kinetic energy is converted into static pressure energy, so the liquid flows out along the discharge port at a higher pressure.
At the same time, a certain vacuum is formed at the center of the impeller because the liquid is thrown out, and the pressure Pa at the liquid level is higher than that at the center of the impeller. Therefore, the liquid sucked into the pipeline enters the pump under the action of the pressure difference. The impeller keeps rotating, and the liquid is continuously sucked and pressed out. The centrifugal pump is called a centrifugal pump because it can transport liquid mainly by centrifugal force.