Working Principle And Structural Characteristics Of Centrifugal Pump

Apr 07, 2022

The structural characteristics of centrifugal pump are as follows: in a volute shaped pump shell, an impeller that can rotate rapidly is installed in the blade

There are 2 ~ 8 blades on the wheel. There are two interfaces on the pump casing. The inlet leading to the center of the impeller is connected with the suction pipeline; In pump

The tangent of the shell is the same as the outlet, which is connected with the discharge pipeline, as shown in Figure 1-12.

The main working part of centrifugal pump is impeller. The second is liquid suction chamber, pump body (pump shell), pump cover and shaft seal device (pump)《

And packing gland or mechanical seal), axial force balancing device, bearing, coupling, bracket, extrusion chamber, etc. When impeller I

When, the liquid can continuously suck people from the suction inlet and discharge from the discharge outlet, and make the liquid generate pressure and discharge to a high place:

Before starting, fill the pump casing and suction pipeline with liquid from the funnel. When the impeller rotates rapidly, the liquid in the impeller also rotates under the promotion of the blades in the impeller, so that the liquid obtains centrifugal force and moves outward from the center of the impeller along the blade channel, and then is thrown out from the end of the blade into the volute chamber or diffuser (or guide wheel) in the pump housing. When the liquid flows to the diffusion tube, due to the gradual expansion of the cross-sectional area of the liquid flow, the flow rate slows down, converting part of the kinetic energy into static energy head, increasing the pressure, and finally pressing out from the discharge tube. At the same time, in the center of the impeller, local vacuum is generated due to the liquid being thrown out, so the liquid in the suction pool is continuously sucked into the pump from the suction pipe under the action of liquid level pressure. The impeller rotates continuously to send the liquid from the suction tank to the high-level tank or pressure vessel.

Centrifugal pump can transport liquid by relying on the high-speed rotating impeller to make the liquid subject to the action of centrifugal force, so it is called centrifugal pump.

When the centrifugal pump is started, if there is no liquid in the pump body and suction pipe, it has no ability to pump liquid because of its suction capacity

When there is no liquid in the impeller but only air, the density of air is much smaller than that of liquid

No matter how the impeller rotates at high speed, the impeller inlet can not reach the vacuum required for liquid absorption, that is, the centrifugal force generated will be reduced

It is very small, so the low pressure formed in the central area of the impeller is not enough to suck the liquid in the liquid suction pool (storage tank) into the pump

Aspirate. This phenomenon that the centrifugal pump cannot absorb liquid due to air in the pump is called air binding, as shown in Figure 1-16.

Therefore, before starting the centrifugal pump, the pump body and suction pipe must be filled with liquid or air.