Modulated diffuser pump

Abstract

This invention relates to a fully modulatable centrifugal pump capable of handling a fluid containing solid contaminant particles and minimizing the temperature rise of the pumped fluid. The pump is of the type that includes an impeller to propel the fluid through a radial outlet to a diffuser which includes a plurality of diffuser passages. The improvement is comprised of the following cooperative combination which includes rotatably mounted valve elements passing, in part, through the diffuser and across the diffuser passages. Each of the valve elements have a port therethrough to variably selectively allow fluid passage therethrough upon rotation of the valve element. A driving arrangement is coupled to each of the valve elements to thereby affect a yieldable rotation of the valve elements in one direction to progressively reduce the opening of the valve element port to the diffuser passage. The aforementioned driving arrangement is also drivingly coupled to the valve elements to provide a direct mechanical coupling to the valve element to thereby affect a nonyieldable rotation of the valve element in an opposite direction to increase the opening of the valve port to the diffuser passage, to thereby ensure that contaminant particles that lodge between a portion of said valve port and the diffuser passage and interrupt movement of one or more valve element port closings do not prevent the remaining valve port elements from closing. During the opposite rotation of the valve elements there is a direct mechanical drive that ensures the opening of the valve port to thereby release the contaminant particle and allow passage of the particle from the valve element and the diffuser.