The impeller is the core part of the pump and the main influence factor on the working efficiency.

Pump impeller basic introduction

Centrifugal pump impeller mainly has the following four forms, closed, front half open, after half open, open these four types.

1. Closed impeller: it is composed of blade and front and rear cover plates. The closed impeller is more efficient and difficult to manufacture. It is used most in centrifugal pump. Suitable for conveying clean water, solution and other viscosity small clean liquid without particles.

2. Half-open impeller: there are generally two structures: one is the front half-open impeller, which is composed of the rear cover plate and the blade. The impeller efficiency of this structure is relatively low. The efficiency is basically the same as that of the closed impeller, and in addition to conveying liquid, the blade also has the sealing function of the back blade or the auxiliary impeller. The semi-open impeller is suitable for conveying liquid containing suspended solids and fibers. The semi-open impeller is less difficult to manufacture, lower cost, and has strong adaptability. In recent years, it has been gradually applied in the centrifugal pump used in oil refining and chemical industry, and used for conveying clean water and near-clean water liquid.

3, open impeller: only the blade and blade reinforcement, no front and rear cover plate impeller. The number of blades of open impeller is less than 2-5. Pump impeller low efficiency, less application, mainly used for conveying viscous liquid and slurry liquid.

The impeller blade of centrifugal pump impeller is generally back-curved blade. There are two kinds of blades: cylindrical blade and twisted blade. The application of twisted blade can reduce the load of the blade, improve the suction ability of centrifugal pump and improve the cavitation resistance. Pump impeller centrifugal pump for refining and chemical industry requires impeller to be cast or welded integral pump impeller. Welding pump impeller is developed in recent years, more used for casting poor performance of metal materials, such as iron and its alloy, the manufacture of chemical special centrifugal pump. The geometric accuracy and surface finish of the welded pump impeller are better than that of the cast impeller, which is beneficial to improve the efficiency of the centrifugal pump.