Mixed flow pump impeller structure for reducing cavitation erosion of blade rims

Abstract

The invention provides a mixed flow pump impeller structure for reducing the cavitation erosion of blade rims. The mixed flow pump impeller structure comprises blades, an impeller hub and rim drainagepieces, wherein the blades are arranged on the impeller hub, and the rim drainage pieces are arranged on the blade rims and are located on one sides, where the inlet edges are located, of the blades.According to the mixed flow pump impeller structure, the rim drainage pieces are installed at the blade rims, so that bubbles generated by gap blowing-up vortexes of the blade rims are effectively isolated, moreover, bubbles generated by leakage vortex cavitation are killed in the areas away from the surfaces of the blades, then the cavitation erosion damage to the blade rims is reduced, and theservice life of an impeller is prolonged; and the rim drainage pieces are fixed at the blade rims through fastening screws, so that after the rim drainage pieces are damaged due to the cavitation erosion, the method that the rim drainage pieces are directly replaced can be also adopted, the whole impeller is not required to be disassembled, and then the whole life cycle cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of fluid machinery, and in particular relates to a mixed-flow pump impeller structure for improving blade rim cavitation. Background technique [0002] Mixed flow pump is a kind of hydraulic machinery with performance and structure between centrifugal pump and axial flow pump. It has the advantages of large flow, high efficiency and strong cavitation resistance. It is used in agricultural drainage, urban water supply and drainage, large water conservancy projects and nuclear power plants. Areas such as circulating water systems play an important role. Due to the special structure of the mixed flow pump, there is a gap between the rim of the impeller blade and the end wall of the runner chamber. During the rotation of the impeller, due to the large pressure difference between the pressure surface and the suction surface of the blade, the gap is prone to leakage flow, and Leakage flow and mainstream entrainme...

AI Technical Summary

Problems solved by technology

However, the impeller only moves the flow separation point backward, and the blade cavitation area only moves to the rear of the impeller, which does not significantly improve the cavitation performance of the pump.

Patent CN204610363U welds a chord strip with a width of 3% of the chord length and a height of 2% of the chord length on the back of the blade at a distance of 75% of the chord length from the water inlet, but this destroys the original flow surface of the impeller, causing hydraulic loss and reducing hydraulic performance

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