Centrifugal impeller and pump apparatus

Abstract

The centrifugal impeller includes a plurality of blades (3), a plurality of fluid paths (P) for delivering a fluid from an impeller inlet (1) to an impeller outlet (2), and a shroud (4) and a hub (5) for forming the fluid paths (P). Each of the fluid paths (P) is formed between adjacent two of the blades (3). A curved line (L3) of the shroud (4) curves so as to project toward the hub (5) in a region from a blade inlet (A) to a predetermined position (C) of the blade (3), and the curved line (L3) curves so as to project toward the opposite side of the hub (5) in a region from the predetermined position (C) to a blade outlet (B).

Description

technical field [0001] The present invention relates to a centrifugal impeller and a pump device, in particular to a centrifugal impeller used in a centrifugal pump, such as a volute tubular centrifugal pump, to pressurize the fluid by applying kinetic energy to the fluid through centrifugal force, In particular, it also relates to a pump device having such a centrifugal impeller. Background technique [0002] In the centrifugal impeller shown in Figures 1A and 1B, the inlet width B of the blade 110 can be adjusted 1 and outlet width B 2 , The inlet diameter D of the centrifugal impeller 0 and outlet diameter D 2 , and the inlet angle β of the blade 110 1 and exit angle β 2 Design to meet desired flow rate and desired pump head. In a conventional centrifugal impeller, it is necessary to change the width of the blade 110 from the inlet width B 1 Gradually change to outlet width B 2 , it is also necessary to change the angle of the blade 110 from the inlet angle β 1 G...

AI Technical Summary

Problems solved by technology

[0004] However, as shown in FIGS. 2A and 2B , if a curve L1 or a straight line L2 is formed at the wheel housing 120, the flow path 140 will not be able to flow if the flow rate of the centrifugal impeller is small and the pump head is high, that is, the specific speed (Ns) is small. The meridional length of will become longer, and the width of the entire flow path 140 in the meridian plane cross-section will become smaller

As a result, the relative velocity of the fluid flowing through the flow path 140 becomes large, and thus the friction loss in the flow path 140 increases, which reduces impeller performance.

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