METHOD AND APPARATUS FOR REDUCING PARTICLES IN A SCREW PUMP LUBRICANT

• US 20100278671A1
• Filed: 04/30/2009
• Published: 11/04/2010
• Est. Priority Date: 04/30/2009
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Drexel, Michael V., Ghasripoor, Farshad, Kothnur, Vasanth
• Application Number:
  US12/433,441
• Publication Number:
  US 20100278671A1
• Time in Patent Office: Days
• US Class Current: 418/1
• CPC Class Codes: F04C 13/005 Removing contaminants, deposits or scale from the pump; Cleaning
• CPC Class Codes: F04C 13/008 Pumps for submersible use, i.e. down-hole pumping
• CPC Class Codes: F04C 15/0088 Lubrication of machines or engines in general F01M
• CPC Class Codes: F04C 2/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C3/00
• CPC Class Codes: Y10T 29/49242 Screw or gear type, e.g., Moineau type

Abstract

A screw pump system has a plurality of rotors disposed inside a pump casing. Each rotor comprises a shaft and a set of threads disposed on the shaft configured to mesh with at least one other set of threads. A plurality of bearings are coupled to each end of each of the rotors. A plurality of gears are coupled to an end of each of the rotors. The gears are configured to reduce a size of particulates in a lubrication fluid by flowing the particulates through the rotating gears. The gears may serve as timing gears for the rotors as well as perform pumping of the lubrication fluid.

Claims

1. A pump system, comprising:

a plurality of rotors disposed inside a pump casing, wherein each rotor comprises a shaft and a set of threads disposed on the shaft configured to mesh with at least one other set of threads;

a plurality of bearings coupled to each end of each of the rotors; and

a plurality of gears coupled to an end of each of the rotors, wherein the plurality of gears are configured to reduce a size of particulates in a lubrication fluid by flowing the particulates through the rotating gears.

2. The system of claim 1, wherein the plurality of bearings are configured to be lubricated by the lubrication fluid.

3. The system of claim 1, wherein the lubrication fluid comprises a process fluid to be pumped by the pump system.

4. The system of claim 1, wherein the plurality of rotors are configured to pump a process fluid comprising a multiphase fluid including gas and liquid mediums.

5. The system of claim 1, wherein the pump casing comprises a plurality of chambers, wherein a barrier between a rotor chamber and a gear chamber is not sealed and is configured to enable the lubrication fluid to flow between the chambers.

6. The system of claim 5, wherein the pressure in each of the chambers is managed to control the flow of the lubrication fluid between the chambers.

7. The system of claim 1, wherein the gears comprise cemented tungsten carbide.

8. The system of claim 1, wherein the gears are configured to circulate the lubrication fluid through a plurality of chambers within the pump system.

9. The system of claim 1, comprising a gear housing, wherein the size of particulates may also be reduced by a grinding of the particulates between the plurality of gears and the gear housing.

10. A method for lubricating a pump system, comprising:

rotating a plurality of rotors disposed inside a pump casing to pump a process fluid, wherein each rotor comprises a shaft and a set of threads disposed on the shaft configured to mesh with at least one other set of threads;

directing a portion of the pumped process fluid into a chamber containing a plurality of bearings coupled to the plurality of rotors; and

crushing particulates within the process fluid inside the chamber to reduce a size of the particulates and enable the process fluid to lubricate the plurality of bearings.

11. The method of claim 10, wherein directing a portion of the pumped process fluid into a chamber comprises separating a portion of particulates from the pumped process fluid prior to directing the process fluid into the chamber.

12. The method of claim 10, wherein crushing particulates within the process fluid comprises flowing the process fluid through a plurality of gears coupled an end of each of the plurality of rotors.

13. The method of claim 12, wherein the gears comprise tungsten carbide.

14. The method of claim 10, wherein rotating a plurality of rotors disposed inside a pump casing to pump a process fluid comprises pumping a multi-phase fluid including gas and liquid mediums.

15. The method of claim 10, wherein rotating a plurality of rotors disposed inside a pump casing to pump a process fluid comprises pumping the process fluid through a rotor chamber, wherein a barrier between the rotor chamber and a gear chamber is not sealed and is configured to enable the process fluid to flow between the chambers.

16. The method of claim 10, comprising turning gears coupled to an end of each of the plurality of rotors to circulate the process fluid through a plurality of chambers within the pump system.

17. A method of manufacture, comprising:

disposing a plurality of rotors inside a pump casing, wherein each rotor comprises a shaft and a set of threads disposed on the shaft configured to mesh with at least one other set of threads to pump a process fluid;

coupling a plurality of bearings to each end of each of the rotors; and

coupling a plurality of gears to an end of each of the rotors, wherein the plurality of gears are configured to reduce a size of particulates in the process fluid by flowing the particulates through the rotating gears.

18. The method of claim 17, wherein coupling a plurality of gears to an end of each of the rotors comprises coupling cemented tungsten carbide gears to an end of each of the rotors.

19. The method of claim 17, wherein disposing a plurality of rotors inside a pump casing comprises disposing the plurality of rotors in a rotor chamber of the pump casing, wherein a barrier between the rotor chamber and a gear chamber is not sealed and is configured to enable the process fluid to flow between the chambers.

20. The method of claim 17, comprising coupling the pump casing to a separator configured to separate a portion of the particulates from the process fluid.

21. The method of claim 20, wherein the process fluid is configured to lubricate the plurality of bearings.

22. The method of claim 17, wherein the gears are configured to circulate the process fluid through a plurality of chambers within the pump system.