The pump impeller is made of cast iron. The blades on the pump impeller play a major role. The shape and size of the pump impeller are closely related to the pump performance. Generally, the pump impeller can be divided into single suction type and double suction type. The single suction type impeller absorbs water unilaterally, and the small flow pump impeller is mostly of this type. The double suction impeller absorbs water from both sides, and the large flow pump impeller adopts the double suction impeller.
Dalian casting impeller is the core component of water pump and the main influencing factor of working efficiency Under certain working conditions, if the impeller is not well designed, hydraulic loss and clearance loss will occur at the pump inlet and blade Then we must choose a professional pump impeller manufacturer in terms of selection.
Centrifugal pump impellers mainly have the following four forms: closed, front semi open, rear semi open and open.
1. Closed impeller: composed of blades and front and rear cover plates. The closed impeller has high efficiency and is difficult to manufacture. It is widely used in centrifugal pumps. It is suitable for conveying clean water, solution and other clean liquids without particles with small viscosity.
2. Semi open impeller: generally, there are two kinds of structures. One is the front semi open impeller, which is composed of a rear cover plate and blades. The impeller of this structure has low efficiency. In order to improve efficiency, a sealing ring with adjustable clearance is required. The other is the rear semi open impeller, which is composed of a front cover plate and blades. Because the same sealing ring as the closed water pump impeller can be used? The efficiency is basically the same as that of the closed impeller, and the blade not only conveys liquid, but also has the sealing function of back blade or auxiliary impeller. Semi open impeller is suitable for conveying liquid containing suspended solids such as solid particles and fibers. Semi open impeller is less difficult to manufacture, lower in cost, and has strong adaptability. In recent years, it has been increasingly used in centrifugal pumps for oil refining and chemical industry, and is used to transport clean water and liquid similar to clean water.
3. Open impeller: an impeller with only blades and blade stiffeners and no front and rear cover plates. The number of open impeller blades is less than 2-5. The pump impeller has low efficiency and few applications. It is mainly used to transport high viscosity liquid and slurry liquid.
The blades of centrifugal pump impeller are generally backward curved blades. There are two types of blades: cylindrical and twisted. The application of twisted blades can reduce the load of blades, improve the suction performance of centrifugal pumps and improve the anti cavitation ability, but it is difficult to manufacture and the cost is high. Pump impeller centrifugal pump for oil refining and chemical industry requires that the impeller be a cast or welded integral pump impeller. Welded water pump impeller is developed in recent years. It is mainly used for casting metal materials with poor performance, such as iron and its alloys, to manufacture special chemical centrifugal pumps. The geometric accuracy and surface finish of welded pump impeller are better than that of cast impeller, which is beneficial to improve the efficiency of centrifugal pump.
