Volute Design For Lower Manufacturing Cost and Radial Load Reduction

Abstract

A volute for a pump featuring a volute or casing having a pump inlet for receiving a fluid being pumped, a pump discharge for providing the fluid, and a volute or casing vane forming double volutes therein. The volute has an upper cutwater farthest from the pump discharge defining an upper cutwater throat area and an end of passage for the upper cutwater, and also has a lower cutwater closest to the pump discharge defining a lower cutwater throat and a corresponding end of passage for the lower cutwater. The upper cutwater throat area is dimensioned to be greater than and not equal to the lower cutwater throat area so the upper cutwater throat area and the lower cutwater throat area provide substantially equal flow velocity at both the upper cutwater and the lower cutwater in response to an angular sweep of the fluid being pumped. The end of passage for the upper cutwater is dimensioned with an upper cutwater passage area that is greater than and not equal to a corresponding lower cutwater passage area of the corresponding end of passage for the lower cutwater so that upper and lower cutwater passage areas at the pump discharge are balanced as a function of differing rates of flow of the fluid being pumped therein and so that the fluid being pumped from associated ends of the upper and lower cutwater passage areas meets at the pump discharge with a substantially equal velocity.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims benefit to provisional patent application Ser. No. 62 / 213,739, filed 3 Sep. 2015, which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a volute for a pump; and more particularly relates to a pump having an improved volute design.[0004]2. Brief Description of Related Art[0005]FIG. 1 shows a normal or conventional dual volute Vpa having a volute wall Vwall with a pump inlet represented by the label i and a pump outlet or discharge represented by the label o. The conventional dual volute Vpa includes a casing vane CVpa formed therein, which has a lower cutwater c1 and an upper cutwater c2 that are arranged on an axis Ac1, c2 on opposite sides of the volute wall Vwall and about 180° apart in a radial separation, e.g., consistent with that shown in FIG. 1. In FIG. 1, the radial degrees of 0°, 90°, 180°, 270° are indicate...

AI Technical Summary

Benefits of technology

The present invention provides a new design for a volute in a rotodynamic pump that reduces the load on the impeller and improves casting quality. This is achieved through an improved pressure balance and minimizing fluid friction. The design also reduces the length of the passage and increases the size of its associated passage, while in a split case pump, simplifying the design and reducing manufacturing costs.

Problems solved by technology

One disadvantage of the known volute design Vpa, e.g., like that shown in FIG. 1, is that the development of the opposed casing tongues results in a long passage length for cutwater farthest away from the pump discharge o, otherwise know as the upper cutwater C2.

This long length adds complexity to the casing and increases the difficulty to properly clean the casting.

This results in additional costs, and if not properly cast and cleaned will result in loss of pump performance.

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