First, the main working principle of centrifugal pump

(1) The centrifugal pump impeller is rotated by the pump shaft to work on the fluid between the blades. The fluid is subjected to centrifugal force and is thrown to the periphery by the center of the impeller. When the centrifugal pump fluid reaches the periphery of the impeller, the flow rate is very high.

(2) The centrifugal pump casing collects the liquid that is thrown from between the blades. These liquids flow in the direction of the volute-shaped passage in the casing, which converts the kinetic energy of the fluid into static pressure energy and reduces energy loss. Therefore, the function of the centrifugal pump casing is not only to collect liquid, but also an energy conversion device.

(3) Centrifugal pump liquid suction principle: The centrifugal pump relies on the impeller to rotate at a high speed, forcing the liquid in the center of the centrifugal pump impeller to be thrown away at a high speed, thereby forming a low pressure in the center of the impeller, and the liquid in the lower tank is thus continuously Suck up. Centrifugal pump air-binding phenomenon: If the centrifugal pump is filled with gas before starting, the impeller center gas can not be formed into a sufficient vacuum when it is thrown after starting, so that the liquid in the tank cannot be sucked up.

This phenomenon is called air binding. In order to prevent the air pumping phenomenon of the centrifugal pump, the space inside the pump casing should be filled with external liquid before the centrifugal pump starts. This step is called a pump. In order to prevent the liquid poured into the pump casing from flowing into the lower tank due to gravity, a check valve (bottom valve) is installed at the inlet of the suction line of the centrifugal pump; if the position of the centrifugal pump is lower than the liquid level in the tank, when starting No need to pump.

(4) The guide wheel is installed on the outer circumference of the centrifugal pump impeller to make the liquid energy conversion efficiency in the pump high. The guide wheel is a fixed bladed ring located on the periphery of the centrifugal pump impeller.

The bending direction of the blade is opposite to the bending direction of the impeller blade, and the bending angle is exactly adapted to the direction in which the liquid flows out from the impeller, guiding the liquid to smoothly change direction in the pump casing passage, thereby minimizing energy loss and dynamic pressure energy. The efficiency of conversion to static pressure energy is high.

(5) The balance hole on the rear cover of the centrifugal pump eliminates the axial thrust. The pressure of the liquid leaving the periphery of the impeller is already high, and some of it will seep into the back side of the impeller rear cover, while the liquid inlet at the front side of the centrifugal pump impeller is low pressure, thus creating an axial thrust that pushes the impeller toward the inlet side of the centrifugal pump. .

This tends to cause wear of the centrifugal pump impeller in contact with the pump casing of the centrifugal pump, and vibration is generated in severe cases. The balance hole leaks a part of the high pressure liquid to the low pressure zone, reducing the pressure difference between the front and rear of the impeller. However, this will also reduce the efficiency of the centrifugal pump.

(6) Centrifugal pump shaft seal device ensures normal and efficient operation of the centrifugal pump. In the fluoroplastic centrifugal pump, the pump shaft rotates and the shell does not move. If the annulus between them is not sealed or sealed badly, the outside air will seep into the low pressure zone at the center of the impeller, which will reduce the flow and efficiency of the pump. In severe cases, the flow is zero - air binding. Typically, a mechanical seal or a packing seal can be used to seal between the centrifugal pump shaft and the centrifugal pump casing.

Shandong Deyuan Pump Co., Ltd. is a professional manufacturer of pump products. Users who want to know more about the information are welcome to visit the official website of Shandong Deyuan Pump Co., Ltd. or call us, we will sincerely serve you.