Multiple-stage centrifugal pump including a controlled leakage hydraulic balancing drum

Abstract

A multiple-stage centrifugal pump comprises a balancing drum coupled to the pump shaft, being axially locked, and turning in a pump body cavity with a minimum clearance; a rotary ring element mounted on the balancing drum and rotating therewith, but being able of axially moving with respect to the rotary shaft, and a fixed ring element mounted on the bottom of the body, a face of the rotary ring element having an annular surface and forming with the fixed ring element a radial breakage path therethrough the fluid flows, the outer diameter of the drum and rotary ring element forming an annular surface providing an axial pushing force, the outer diameter of the rotary ring element, forming a narrowed portion, being less than the diameter of the balancing drum, a pressure difference operating on these surfaces providing a contactless leakage between the rotary ring and fixed ring elements, the axial position of the rotary ring element depending on a combined action of two pushing forces, thereby providing a very stable operation of the pump, the rotary ring element participating in applying the balancing force of the pump rotor thereby limiting the leakage flow loss.

Dependencies are inferred from the claim text.