Centrifugal pump with an open-faced impeller

摘要

A centrifugal pump with an open-faced impeller for conveying a working liquid, the pump comprising at least one open-faced impeller provided with blades placed inside a casing defining a suction pipe facing the bottoms of the blades in the vicinity of a central shaft that drives the impeller and forming a part of a rotary assembly, and a delivery pipe fitted with a fixed diffuser disposed facing the peripheral ends of the blades. An active axial balancing system for the rotary assembly, which balancing system is integrated in the impeller and comprises a balancing chamber interposed between the rear face of the body of the impeller and an outer rear portion of the casing. The balancing chamber communicating with the delivery pipe via a first nozzle whose axial clearance is kept invariable in operation and which is defined by the peripheral end of the impeller itself acting as a balancing turntable, and a nozzle piece secured to the outer rear portion of the casing and interposed between the diffuser and said peripheral end of the impeller. The balancing chamber communicating directly or indirectly with the suction pipe of the pump via a second nozzle.