Centrifugal pump with rotor thrust balancing seal

Abstract

A centrifugal pump or compressor with a labyrinth seal that produces an axial thrust balance when the impeller shifts in the axial direction due to fluid pressure forces acting on the impeller, and a process for reducing the axial thrust imbalance by regulating the fluid leakage from a front pressure cavity of the pump. The impeller includes a front face that forms part of a front pressure cavity in which fluid pressure acts that produces a thrust imbalance on the impeller. A labyrinth seal with a plurality of teeth is formed between the housing and the front face of the impeller near the impeller inlet. The teeth form gaps with lands formed on the impeller face, where the lands are slanted and stepped such that axial displacement of the impeller changes the gap space to regulate the fluid pressure acting in the front cavity. A self regulating fluid pressure is developed within the front cavity to produce a balancing force against the impeller.