Impeller assembly for centrifugal pumps

Abstract

An impeller assembly for centrifugal pumps that enables self-priming in a relatively short time period includes an impeller and at least one winglet (e.g., six winglets with a trapezium cross-sectional shape). The impeller includes an impeller body with an eye opening therein. The eye opening is configured for the passage of a fluid (e.g., water) therethrough when the impeller assembly is in use. The impeller body also includes at least one vane, with a leading end, disposed about the eye opening. The at least one winglet is positioned to protrude into the eye opening of the impeller body and may, for example, be coupled to the leading end of the vane.

Description

[0001] 1. Field of the Invention[0002] The present invention relates, in general, to pump assemblies and, in particular, to impeller assemblies for centrifugal pumps.[0003] 2. Description of the Related Art[0004] Centrifugal pumps are widely used in chemical, food, irrigation and other industries to pump a variety of liquids (e.g., water) and liquid-solid mixtures. Centrifugal pumps are a type of kinetic energy pump that imparts energy to a liquid through centrifugal force produced by a rotating impeller. The energy is used to increase the pressure of the liquid and move the liquid from one point to another.[0005] FIG. 1 is a simplified cross-sectional depiction of a conventional centrifugal pump 10 that includes a stationary casing 12 and an impeller 14 with curved vanes 16 (also referred to as "blades" and shown as lines for simplicity) and an axially-disposed eye opening 18. Rotation of impeller 14, and thus curved vanes 16, (e.g., by a motor [not shown] operatively coupled to im...

AI Technical Summary

Benefits of technology

[0011] The provision of winglet(s) in the eye opening of impeller assemblies according to one exemplary embodiment of the present invention has been demonstrated to significantly reduce the time period required for a self-priming process when such impeller assemblies are used in centrifugal pumps. It is postulated, without being limiting, that this reduction is due to two effects. First, when in motion during use of the impeller assembly, the winglet(s) provide an air-foil-like dynamic with the eye opening that creates a vacuum-differential (also referred to as "lift") effect. The vacuum differential ("lift") effect enhances the evacuation of gas (e.g., air) from the centrifugal pump during a self-priming process. Second, moving winglet(s) serve to divide any gas bubbles (e.g., air bubbles) with which they come into contact into smaller gas bubbles. The smaller gas bubbles are more readily entrained in liquid passing through the centrifugal pump and, therefore, quickly evacuated from the centrifugal pump.

[0012] Furthermore, the inclusion of winglets in an impeller assembly according to one exemplary embodiment of the present invention results in simple and easily manufactured impeller assembly.

Problems solved by technology

A drawback of centrifugal pumps is that they must be "primed" prior to use.

Although self-priming centrifugal pumps (i.e., a centrifugal pump that is configured to automatically remove [evacuate] air from the suction inlet and that may handle liquids, gases and liquid-gas mixtures) are known, the time period required to complete a self-priming process in such self-priming centrifugal pumps may be undesirably long.

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