Optimum Design With CAD For Main Parameters Of 3B33 Model Centrifugal Pump

Centrifugal pumps are general machinery which are mainly used for sending fluid, semi-fluid and thick liquid body. Centrifugal pumps have advantages such as high rotation speed, small, light, high pressure head, simple structure, steady performance, easy for operating and maintance. Centrifugal pumps are widely used in every departments of the national economy.The structure of 3B33 model centrifugal pump is complicated with more parts and large dimension, leakage is serious, center of gravity is unstable, efficiency of operation is low. This study is a project of Donggang city water pump factory.An all performance test-bed of Centrifugal pumps was set up with, advanced test instrument and equipment to carry out performance test for 3B33 centrifugal pumps. Experiment result were analyzed through regression and the optimal working performance parameter and flow range were determined for 3B33 centrifugal pumps. Performance equation of centrifugal pump and relations with factors were developed, considering actual working parameter range. The optimal working performance parameter of the pump and reasons of differing form rated parameters, were investigated. With modern design theory and current centrifugal pump research results both domestic and international, structure improvement and optimum design methods were put forward.In order to reduce impeller disc frictions lose. Optimum design for pump impeller exiting parameters was carried out. In order to reduce centrifugal pump vapor erode, impeller inlet parameters were optimized. Blades number and wrap angle were calculated according to formula, with Excel, two-dimension drawings by inputting data into Pro/E. Using impeller flow area optimization model, flow area of the pump was selected.With helicoids hell hydraulic lose model and diffusion pipe hydraulic lose model, helicoids hell 8th section was optimized, and other helicoids hell sections area were calculated, according to the sectional parameter. Using polar coordinates helicoids hell hydraulic curves, in different position were determined and drawn.The results of main parameter for 3B33 model pump through optimum design were as following: .Optimal rotational speed range was 2900rpm-3000rpm with the best rotational speed 2950rpm; optimal flow range was 30m3/h-40 m3/h with the best flow 35 m3/h; optimal pressure head was 27m-35m with the best pressure head 32m. Optimal efficiency range was 65.6%-67.4% with the best efficiency 66%; the best pipeline pressure was 0. 25MPa; the axle power of centrifugal pump was 4.34kW; the match power of the pump was 5.43kW. The results of optimum design for pump impeller were as following: Z=5,&1=26mm;β1=34°;D1 =76mm;b2=9.5mm; β2=18°; D2=164mm. Z=6;b1-27mm;β1=36°;D1 =74mm;b2=10rrun;β2=20°;D2=160mm.