High Flow and Low NPSHr Horizontal Pump

Abstract

A surface pumping system has a motor and a pump driven by the motor. The pump has a discharge on a first end of the pump, a suction end on a second end of the pump, and a plurality of stages between the suction end and the discharge. Each of the plurality of stages includes an impeller and a diffuser that encases the impeller. Each diffuser is an independent pressure vessel. In some embodiments, the diffuser and impeller in each stage are large and configured for use in low net positive suction head (NPSH) applications.

What is claimed is: 
     
         1 . A surface pumping system comprising:
 a motor; and   a pump driven by the motor, wherein the pump comprises:
 a discharge on a first end of the pump; 
 a suction end on a second end of the pump, wherein the discharge is between the suction end and the motor; 
 a plurality of stages between the suction end and the discharge, wherein each of the plurality of stages comprises:
 an impeller; and 
 a diffuser that encases the impeller, wherein each diffuser is an independent pressure vessel. 
 
   
     
     
         2 . The surface pumping system of  claim 1 , wherein the surface pumping system further comprises a shaft assembly and wherein the shaft assembly is driven by the motor and wherein impeller of the plurality of stages is connected to the shaft assembly. 
     
     
         3 . The surface pumping system of  claim 1 , wherein the diffuser of each stage does not include a separate housing around the diffuser. 
     
     
         4 . The surface pumping system of  claim 1 , wherein at least one of the plurality of stages is configured as a mixed flow stage. 
     
     
         5 . The surface pumping system of  claim 4 , wherein at least one of the plurality of stages is configured as a radial flow stage. 
     
     
         6 . The surface pumping system of  claim 1 , wherein the plurality of stages comprises a first stage, a second stage and a third stage. 
     
     
         7 . The surface pumping system of  claim 6 , wherein the first stage comprises a diffuser having an first outer diameter and wherein the second stage comprises a diffuser having a second outer diameter that is smaller than the first outer diameter. 
     
     
         8 . The surface pumping system of  claim 6 , wherein the first stage is configured as a mixed flow stage and the second stage is configured as a radial flow stage. 
     
     
         9 . A surface pumping system comprising:
 a motor; and   a pump driven by the motor, wherein the pump comprises:
 a discharge on a first end of the pump; 
 a suction end on a second end of the pump; 
 a plurality of stages between the suction end and the discharge, wherein each of the plurality of stages comprises:
 an impeller; and 
 a diffuser that encases the impeller, wherein each diffuser is an independent pressure vessel. 
 
   
     
     
         10 . The surface pumping system of  claim 9 , wherein the discharge is between the suction end and the motor. 
     
     
         11 . The surface pumping system of  claim 9 , wherein the pump further comprises a shaft seal module connected to the discharge of the pump. 
     
     
         12 . The surface pumping system of  claim 11 , wherein the surface pumping system further comprises a thrust chamber between the motor and the pump and wherein the shaft seal module is connected between the discharge of the pump and the thrust chamber. 
     
     
         13 . A surface pumping system comprising:
 a frame;   a motor mounted to the frame;   a thrust chamber mounted to the frame adjacent to the motor;   a pump mounted to the frame adjacent to the thrust chamber and wherein the pump comprises:
 a discharge on a first end of the pump; 
 a shaft seal module connected between the discharge and the thrust chamber; 
 a suction end on a second end of the pump, wherein the discharge is between the suction end and the motor; and 
 a plurality of stages between the suction end and the discharge, wherein each of the plurality of stages comprises:
 an impeller; and 
 a diffuser that encases the impeller, wherein each diffuser is an independent pressure vessel; and 
 
   a shaft, wherein the shaft extends from the motor to the impellers through the thrust chamber and the shaft seal module.   
     
     
         14 . The surface pumping system of  claim 13 , wherein the shaft comprises a plurality of interconnected shaft segments. 
     
     
         15 . The surface pumping system of  claim 14 , wherein the diffuser of each stage does not include a separate housing around the diffuser. 
     
     
         16 . The surface pumping system of  claim 13 , wherein at least one of the plurality of stages is configured as a mixed flow stage. 
     
     
         17 . The surface pumping system of  claim 16 , wherein at least one of the plurality of stages is configured as a radial flow stage. 
     
     
         18 . The surface pumping system of  claim 13 , wherein the plurality of stages comprises a first stage, a second stage and a third stage. 
     
     
         19 . The surface pumping system of  claim 18 , wherein the first stage comprises a diffuser having an first outer diameter and wherein the second stage comprises a diffuser having a second outer diameter that is smaller than the first outer diameter. 
     
     
         20 . The surface pumping system of  claim 19 , wherein the first stage is configured as a mixed flow stage and the second stage is configured as a radial flow stage.