Low flow-high pressure centrifugal pump

Abstract

Low flow centrifugal pump that develops more than 25 percent greater pressure than equivalent standard type spiral impellers with circular casings.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]The present application claims the benefit of the earlier filing date of U.S. Provisional Application No. 61 / 550,640, filed on Oct. 24, 2011, the contents of which are incorporated herein by reference as if set forth in their entirety.BACKGROUND OF THE INVENTION[0002]There has been a market for very low flow centrifugal pumps used on low viscosity liquids such as water, chemicals or hydrocarbons, but these products have not been available.[0003]The centrifugal pump basically consists of a rotating impeller within a volute as shown in FIG. 1. The majority of the volutes are designed like a logarithmic spiral as shown in FIG. 1a. The shape of the impeller and volute depends on the combination of desired flow, pressure and speed. In the industry of centrifugal pumps, the combination of the three criteria in a specific equation known throughout the industry is called specific speed (Ns). The range of this dimensionless number is 500 to over 40...

AI Technical Summary

Benefits of technology

The present invention is about pumps with a specific speed of less than 500. The invention has a circular casing with a close clearance to the impeller. The invention also has a double suction impeller which reduces axial thrust. However, the invention uses a singular suction casing which is less expensive and easier to install than a double suction impeller casing. In summary, the technical effect of the invention is to provide a cost-effective and easy-to-install pump with increased developed pressure using a circular casing with a double suction impeller.

Problems solved by technology

There has been a market for very low flow centrifugal pumps used on low viscosity liquids such as water, chemicals or hydrocarbons, but these products have not been available.

This produces a lot of circular leakage; resulting in low hydraulic efficiency.

However, even with the low efficiency there is still a market for a low flow pump.

Below that, the ratio of width to impeller diameter, number of vanes and wrap around of the vanes makes it very difficult to make a casting.

The cost of the molds, cleaning techniques, and quality of the attachment cannot always justify the costs.

Because there is only one shroud, a high portion of the developed pressure of the vanes only is on back side of the impeller and results in high axial thrust.

This does results in negative features; mechanically it is difficult to maintain the flatness of the impeller, it also weakens the support of the vanes, hydraulically it reduces the efficiency of the pump.

When this clearance is not maintained the hydraulic performance and efficiency is reduced.

This whole process gas more difficult to produce when the Ns is 500 or less.

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