Screw type pump or motor

摘要

A pump assembly comprising a stator and a rotor having vanes of opposite handed thread arrangements is described. A radial gap is located between the stator vanes and the rotor vanes such that rotation of the rotor causes the stator and rotor to co-operate to provide a system for moving fluid longitudinally between them. The operation of the pump results in a fluid seal being is formed across the radial gap. The described apparatus can also be operated as a motor assembly when a fluid is directed to move longitudinally between the stator and rotor. The presence of the fluid seal results in no deterioration of the pump or motor efficiency, even when the radial gap is significantly greater than normal working clearance values. Furthermore, the presence of the radial gap makes the pump/motor assembly ideal for deployment with high viscosity and/or multiphase fluids.

主权项

1. A pump assembly for use with a high viscosity or multiphase hydrocarbon fluid comprising:
a stator having an internal surface of constant diameter and one or more stator vanes extending from the internal surface to a constant stator vane radial height along a length of the stator; and a rotor having an external surface of constant diameter and one or more rotor vanes extending from the external surface to a constant rotor vane radial height along a length of the rotor, wherein the one or more stator vanes have an opposite handed thread with respect to a thread of the one or more rotor vanes and the stator and rotor co-operating to provide, on rotation of the rotor, a system for moving the high viscosity or multiphase hydrocarbon fluid longitudinally between them, wherein a radial gap, having a constant value in the range of 1.28 mm to 10 mm, is located between the constant stator vane radial height and the constant rotor vane radial height along a length of the pump assembly, and wherein a ratio of the constant rotor vane radial height to the constant stator vane radial height has a constant value in the range of 1.1 to 20 along the length of the pump assembly.