1. Closed impeller:
And before and after the cover is composed of blades. The efficiency of the closed impeller is higher and the production is more difficult. In the centrifugal pump application. Suitable for transporting water, solution, and other small particles of the viscosity of the cleaning liquid.
2. Semi open impeller:
Generally have two kinds of structure of semi open and is composed of a rear cover plate and blades, the structure, the efficiency of the impeller lower, to improve efficiency for equipped with can adjust clearance seal ring another half open, is composed of a front cover plate and blades, because can be applied with a closed type water pump impeller as the sealing ring? Efficiency and closed impeller is basically the same as blades, and apart from the transport of fluids, also has: back vane, and the Deputy impeller sealing effect. The semi open impeller is suitable for transporting liquid containing solid particles, fibers, etc.. Semi open impeller production is difficult, low cost, and adaptability, in recent years in the oil refining and chemical industry with a gradual increase in the application, and for the delivery of water and water approximation of the liquid.
3. Open impeller:
Only blades and blades are reinforced, without a front and back cover plate of the impeller. Open impeller blade number less 2-5. Impeller pump impeller efficiency is low, the application is less, mainly used for transporting high viscosity liquid and slurry liquid.
The impeller of the centrifugal pump impeller is generally backward curved blade. There are two kinds of cylindrical and twisted, the application of twisted blades can reduce the load of the blade, and can improve the suction performance of the centrifugal pump, improve the ability to resist cavitation, but the production is more difficult, the cost is higher. Centrifugal pump impeller for pump impeller, the whole pump impeller is required for the casting or whole welding seam welding. Welding pump impeller is developed in recent years, more for poor casting performance of metal materials, such as iron and its alloys, the production of special centrifugal pump chemical. The geometric accuracy and surface finish of welding pump impeller are superior to casting impeller, which is beneficial to improve the efficiency of centrifugal pump.
