CENTRIFUGAL PUMP IMPELLOR WITH NOVEL BALANCING HOLES THAT IMPROVE PUMP EFFICIENCY

摘要

A centrifugal pump impellor includes balancing holes that reduce axial thrust while minimizing the loss of pump efficiency. In one general aspect, the balancing holes penetrate the rear shroud between the blades, and are angled in both axial and rotational directions so as to direct the leakage fluid approximately parallel to the primary process fluid, so that it causes minimal interference with the primary fluid flow. In a second general aspect, the balancing holes extend from the rear cavity within the impellor blades and through the leading edges of the blades, thereby entering the primary flow in locations where the process fluid is almost static relative to the blades. This minimizes the impact on the flow of the process fluid past the blades, and thereby minimizes the loss of pump efficiency caused by the balance holes. In embodiments, each blade leading edge includes a plurality of balancing hole outlets.