Multistage centrifugal pump for conveying a fluid

Abstract

A multistage centrifugal pump for conveying a fluid includes a pump housing with an inlet and an outlet, first and second stage impellers for conveying the fluid from the inlet to the outlet, and a shaft for rotating each impeller about an axial direction. Each impeller is a double suction impeller, having a first suction side, a second suction side for receiving the fluid and a discharge side for discharging the fluid. The discharge side of the first stage impeller includes two separate exits, a first exit for discharging the fluid into a first crossover line, and a second exit for discharging the fluid into a second crossover line. The first crossover line is in fluid communication with the first suction side of the second stage impeller, and the second crossover line is in fluid communication with the second suction side of the second stage impeller.

What is claimed: 
     
         1 . A multistage centrifugal pump for conveying a fluid, comprising:
 a pump housing with an inlet and an outlet for the fluid;   a first stage impeller and a second stage impeller configured to convey the fluid from the inlet to the outlet; and   a shaft configured to rotate each impeller about an axial direction, each impeller being a double suction impeller, having a first suction side, a second suction side to receive the fluid and a discharge side to discharge the fluid, the discharge side of the first stage impeller comprising two separate exits, the two separate exits being a first exit to discharge the fluid into a first crossover line and a second exit to discharge the fluid into a second crossover line, the first crossover line in fluid communication with the first suction side of the second stage impeller, and the second crossover line in fluid communication with the second suction side of the second stage impeller.   
     
     
         2 . The multistage centrifugal pump in accordance with  claim 1 , wherein the first crossover line and the second crossover line are arranged within the pump housing. 
     
     
         3 . The multistage centrifugal pump in accordance with  claim 1 , further comprising a first volute configured to guide a first stream of the fluid from the discharge side of the first stage impeller into the first crossover line, and a second volute configured to guide a second stream of the fluid into the second crossover line. 
     
     
         4 . The multistage centrifugal pump in accordance with  claim 1 , wherein the first exit and the second exit are displaced by 180° with respect to each other, when viewed in a circumferential direction of the first stage impeller. 
     
     
         5 . The multistage centrifugal pump in accordance with  claim 1 , wherein the first suction side of the first stage impeller is in fluid communication with the inlet by a first suction line, the second suction side of the first stage impeller is in fluid communication with the inlet by a second suction line, and the first suction line and the second suction line are arranged within the pump housing. 
     
     
         6 . The multistage centrifugal pump in accordance with  claim 1 , wherein the first stage impeller and the second stage impeller are the only two impellers. 
     
     
         7 . The multistage centrifugal pump in accordance with  claim 1 , wherein the multistage centrifugal pump is a between-bearing pump. 
     
     
         8 . The multistage centrifugal pump in accordance with  claim 2 , further comprising a first volute configured to guide a first stream of the fluid from the discharge side of the first stage impeller into the first crossover line, and a second volute configured to guide a second stream of the fluid into the second crossover line. 
     
     
         9 . The multistage centrifugal pump in accordance with  claim 2 , wherein the first exit and the second exit are displaced by 180° with respect to each other, when viewed in a circumferential direction of the first stage impeller. 
     
     
         10 . The multistage centrifugal pump in accordance with  claim 3 , wherein the first exit and the second exit are displaced by 180° with respect to each other, when viewed in a circumferential direction of the first stage impeller. 
     
     
         11 . The multistage centrifugal pump in accordance with  claim 2 , wherein the first suction side of the first stage impeller is in fluid communication with the inlet by a first suction line, the second suction side of the first stage impeller is in fluid communication with the inlet by a second suction line, and the first suction line and the second suction line are arranged within the pump housing. 
     
     
         12 . The multistage centrifugal pump in accordance with  claim 3 , wherein the first suction side of the first stage impeller is in fluid communication with the inlet by a first suction line, the second suction side of the first stage impeller is in fluid communication with the inlet by a second suction line, and the first suction line and the second suction line are arranged within the pump housing. 
     
     
         13 . The multistage centrifugal pump in accordance with  claim 4 , wherein the first suction side of the first stage impeller is in fluid communication with the inlet by a first suction line, the second suction side of the first stage impeller is in fluid communication with the inlet by a second suction line, and the first suction line and the second suction line are arranged within the pump housing. 
     
     
         14 . The multistage centrifugal pump in accordance with  claim 2 , wherein the first stage impeller and the second stage impeller are the only two impellers. 
     
     
         15 . The multistage centrifugal pump in accordance with  claim 3 , wherein the first stage impeller and the second stage impeller are the only two impellers. 
     
     
         16 . The multistage centrifugal pump in accordance with  claim 4 , wherein the first stage impeller and the second stage impeller are the only two impellers. 
     
     
         17 . The multistage centrifugal pump in accordance with  claim 5 , wherein the first stage impeller and the second stage impeller are the only two impellers. 
     
     
         18 . The multistage centrifugal pump in accordance with  claim 2 , wherein the multistage centrifugal pump is a between-bearing pump. 
     
     
         19 . The multistage centrifugal pump in accordance with  claim 3 , wherein the multistage centrifugal pump is a between-bearing pump. 
     
     
         20 . The multistage centrifugal pump in accordance with  claim 4 , wherein the multistage centrifugal pump is a between-bearing pump.