Performance And Application Of The Partial-flow Pump

The partial flow pump which is also named tangent pump is a kind of new type centrifugal pump for transporting the liquid of small-capacity and high-head. Compared with generally centrifugal pump, its head-discharge curve is flat, Then it can attain to the result of changing flow but keep the constant pressure. Resolved super pressure problem at small discharge with generally centrifugal pump.So far, the theories system of the partial flow pump is dispersion, it's apply scope is restricted for the limiting of the hydraulic design method. but the high building, extfeniely high building within city flow out in great quantities now, to the fire fight pump which have the strict request for the problem of small discharge super press, and the type choosing for new item of chemistry industry and petroleum industry, the expanding to permit of old machine sets, the all needing the function scope extended partial flow pump which have big-capacity and high-head characteristics. Another, The water supply system of the city and other domains which have economy energy request and need the characteristics of changing flow but keep the constant pressure, The multiple class partial flow pump should be used .The theories of the partial flow pump is summarized based on exist literature, data and other's investigation results, make it become a perfect system, the method of hydraulic design is enlarged based on experiment and research, extended widely the usage scope and the structure forms of the partial flow pump, and got the actual usage in the engineering, bringing considerable economy and society value.Based on the results of the investigation, the following conclusions can be made:1. partial flow pump with big-capacity and high-head:(1)The coefficient selection of the larynx current velocity should be low in 0.6.(2)It is suitable that the impeller with blade number Z=8 go together with rectangular section spiral casing.(3)It is not obviously lifting efficiency by using of rectangular section spiral casing, But it can raise no-discharge pump head clearly, make the characteristics curve tend in the flatness.2. multiple class partial flow pump:(1)The head coefficient value should be low in the single class partial flow pump.(2)The total area of larynx wicket gate should be 200% the single class's larynx area.