When the conveying medium density is one, the design based on the above calculation formula and the product width of the impeller outlet can make the pump maintain a high flow rate and efficiency. The vacuum discharge pump is widely used in petroleum, daily chemical, grain and oil, medicine and other industries. The evaporator circulation pump is a large flow, low head axial flow pump, which is specially used for the forced circulation of evaporators in ammonium phosphate, phosphoric acid vacuum salt production, alumina, caustic soda, light industry and other industries. The negative pressure pump is a micro vacuum pump. Because it has one intake and one exhaust nozzle and one exhaust nozzle, and can continuously form vacuum or negative pressure at the inlet, a slight positive pressure is formed at the exhaust nozzle. The influence of blade profile is studied. The blade profile is the intersection of the flow surface of the pump impeller and the facet in the thickness of the blade. It is an important problem that can determine the hydromechanical performance of the pump by continuously changing the fluid on the surface of the blade cell as the load of the power system. parameter. It depends on the blade inlet angle, blade outlet angle and blade wrap angle. The profile line near the import of the blades in China has a certain social impact on the pump performance. Properly increasing the hydrodynamic environmental load capacity of the blades on the flow surface of the impeller back cover can help students improve the hydraulic performance of the pump when transporting aggressive media. Here, the conceptual knowledge of the load correlation coefficient is introduced to be analyzed and explained. The greater the pressure difference between the pressure surface and the suction surface of the blade, the more work the blade does to the fluid, and the smaller the relative flow rate of the pressure surface. At this time, the gradient of the reverse pressure change increases, which is prone to cause slippage. According to the different load coefficients on different flow surfaces, the work done by the blades on the fluid on different flow surfaces is also different.

The maximum blade load factor on the flow surface of the rear cover and the load diagram on the flow surface of the front cover of the same radius. The influence of the blade twist angle on the five-blade outlet angle is still blank in the theoretical research at home and abroad, and is currently limited to quantitative analysis through experiments and errors. The effect of vane outlet angle on pump performance varies with the range of conveyed media. Increasing the vane outlet angle can effectively increase the pump head. The pump efficiency of the impeller with large outlet angle is slightly higher than that of the impeller with small outlet angle, and the efficiency curve of the high-efficiency area is relatively flat. However, the effect of the outlet angle on the pump performance is limited, that is, for high-lift media, the impeller with a large outlet angle cannot prevent the sharp reduction of pump efficiency. The advantages of the large outlet angle impeller cannot be fully reflected. When the transport medium Hertz reaches expansion, the pumping efficiency and head drop sharply. The shaft power of the impeller with large outlet angle is significantly higher than that of the impeller with small performanoutlet angle. The effect of vane number on pump ce is non-linear. If the number of blades is too large, the friction loss of the blades increases, the flow channel area decreases, the efficiency decreases, and the cavitation performance deteriorates.