Main Components And Working Principles Of Agricultural Centrifugal Pump

Agricultural Centrifugal Pump is mainly composed of an impeller, shaft, pump casing, shaft seal, and sealing ring. Generally, the pump casing should be filled with liquid before starting the centrifugal pump. When the prime mover drives the pump shaft and the impeller to rotate, the liquid moves in a circular motion with the impeller on the one hand, and on the other hand, it is thrown out from the center of the impeller to the periphery under the action of centrifugal force. The impeller gains pressure energy and velocity energy. When the liquid flows through the volute to the discharge port, part of the velocity energy will be converted into static pressure energy. When the liquid is thrown from the impeller, the central part of the impeller creates a low-pressure area, which forms a pressure difference with the pressure of the suction liquid surface, so the liquid is continuously sucked in and discharged with a certain pressure. Below, let's take a look at the main components of the centrifugal pump:

(1) Pump casing
There are two types of pump casings: axial split type and radial split type. The casing of most single-stage pumps is volute type, and the radially split casing of multi-stage pumps is generally annular casing or circular casing. The liquid thrown from the impeller is collected and directed to the diffuser tube to the pump outlet. The pump casing withstands the full operating pressure and thermal load of the liquid.

(2) Impeller
The impeller is the only working part, and the pump does work on the liquid through the impeller. There are three types of impellers: closed, open, and semi-open. The closed impeller consists of blades, a front cover, and a rear cover. The semi-open impeller consists of blades and a rear cover. The open impeller has only blades and no front and rear cover plates. Closed impellers are more efficient, and open impellers are less efficient.

(3) Sealing ring

The function of the sealing ring is to prevent internal leakage and external leakage of the pump. The sealing ring made of wear-resistant material is inlaid on the front and rear cover plates of the impeller and the pump casing and can be replaced after wear.

(4) Shaft and bearing
The impeller is fixed at one end of the pump shaft, and the coupling is installed at the other end. According to the size of the pump, rolling bearings and sliding bearings can be selected as bearings.

(5) Shaft seal
There are generally two types of shaft seals: mechanical seals and packing seals. Generally, pumps are designed to be equipped with both packing seals and mechanical seals.