Working principle of centrifugal pump and common flow regulation methods?

Working principle of centrifugal pump: When the centrifugal pump works, the liquid gains energy under the action of inertial centrifugal force and increases the pressure. Before the centrifugal pump works, the pump body and inlet pipeline must be filled with liquid medium to prevent cavitation. When the impeller rotates rapidly, the blades promote the medium to rotate rapidly, and the rotating medium flies out of the impeller under the action of centrifugal force. After the water in the pump is thrown out, the central part of the impeller forms a vacuum zone. While continuously inhaling the liquid, it constantly gives the inhaled liquid a certain amount of energy and discharges the liquid. Centrifugal pump works continuously.

Common flow regulation methods of centrifugal pump;

1) the method of changing the characteristic curve of the pump;

A. change the speed of the pump with frequency converter. The higher the speed, the greater the flow.

B, cutting the excircle of the impeller and changing the diameter of the impeller.

2) Change the pipeline characteristic curve: The most common method is to adjust the opening of the outlet valve of centrifugal pump. The valve opening becomes smaller, the local resistance of the pipeline increases, the characteristic curve of the pipeline becomes steeper, the working point moves to the left, and the flow rate of the pump decreases. On the contrary, the valve opening becomes larger and the pump flow increases.