US 4,541,782 A · Pump system

Abstract

A submersible pump system comprises a lowermost electrically driven pump unit (4,55) providing an inlet to the system for liquid to be pumped and one or more like pumps (5,55) positioned above it and connected in series. Electric power is supplied to the units by way of conductors within a central pipe (14) concentric with an outer cofferdam pipe (12), dielectric oil being circulated through the conductor pipe and between it and the cofferdam pipe and thus through the pump unit motors which have hollow drive shafts (21) around the conductor pipe. The pump stack may be located within a well casing (52), by sealing rings (62) expanded by the dielectric oil pressure, or surrounded by an outer load-bearing pipe (10). The liquid pumped flows externally of the pump stack and the system can be constructed in separate lengths which can be readily assembled on installation.

Claims17

Dependent claims

A submersible pump system comprising a pump stack including a plurality of pump units, spaced vertically apart, each pump unit having an electric motor, impeller means driven by said electric motor, and an inlet and an outlet for liquid being pumped, the outlet of a lower pump unit communicating with the inlet of a next adjacent upper pump unit whereby said pump units operate in series, pipe means extending between said pump units, tubular electrical conductor means having an internal surface and an external surface, said tubular electrical conductor means being located within said pipe means and being connected to the electric motors of said pump units for supplying power to said motors, means including said internal surface and said external surface of said tubular electrical conductor means defining supply and return paths for dielectric liquid providing insulation for said electrical conductor means, and means for circulating said dielectric liquid along said supply and return paths.

A pump system comprising:

a pipe stack received within a well casing;
a pump unit at the lower end of said pipe stack, said pump unit having impeller means, an electric motor driving said impeller means, inlet means and outlet means for fluid being pumped by said impeller means, and sealing means responsive to fluid pressure to effect a seal between said pump unit and said well casing at a position above said inlet means and below said outlet means;
conductor means extending along said pipe stack for supplying power to said electric motor;
a pipe surrounding said conductor means;
means defining a fluid circuit having a supply path and a fluid return path along said pipe stack to said pump unit,
means for circulating dielectric fluid on said circuit along said supply path to said pump unit and therefrom along said return path, said conductor means being tubular and having one of said supply and return paths along its outer surface and the other of said supply and return paths along its inner surface, whereby said dielectric fluid provides insulation for said conductor means;
and
means communicating said sealing means with said fluid circuit whereby said seal is effected in response to fluid pressure in said circuit.

5 more elements

Dependencies are inferred from the claim text.

Pump system

Life of this patent

Pump system

Life of this patent

Abstract

Claims17