Double exhaust centrifugal pump

Abstract

The invention relates to a centrifugal pump. The pump ( 10 ) comprises an impeller ( 20 ) and a casing ( 50 ) surrounding the impeller, the impeller having a main passage ( 24 ) that divides into a first passage ( 241 ) and a second passage ( 242 ) with a common feed inlet ( 22 ) parallel to the axis of rotation (A) of the pump, the common feed inlet ( 22 ) being the inlet of the main passage ( 24 ), the first passage ( 241 ) having a first outlet ( 243 ) that is radially oriented, opening out at a first diameter relative to the axis of rotation (A) and suitable for supplying fluid at a first pressure, and the second passage ( 242 ) having a second outlet ( 244 ) that is oriented radially and situated behind the first outlet ( 243 ), opening out at a second diameter that is greater than the first diameter, the second outlet ( 244 ) being suitable for supplying the fluid at a second pressure that is higher than the first pressure, the impeller ( 20 ) co-operating with the casing ( 50 ) to form an axial balancing system having a chamber ( 90 ) formed between the rear face ( 27 ) of the impeller and the portion ( 57 ) of the casing that faces the rear face ( 27 ), the inlet to the chamber ( 90 ) being situated at the level of the second outlet ( 244 ).

1 . A pump, characterized in that it comprises an impeller and a casing surrounding the impeller, said impeller having a main passage that divides into a first passage and a second passage with a common feed inlet parallel to the axis of rotation of said pump, said common feed inlet being the inlet of said main passage, the first passage having a first outlet that is radially oriented, opening out at a first diameter relative to the axis of rotation and suitable for supplying fluid at a first pressure, and the second passage having a second outlet that is oriented radially and situated behind said first outlet, opening out at a second diameter that is greater than said first diameter, said second outlet being suitable for supplying the fluid at a second pressure that is higher than said first pressure, said impeller co-operating with said casing to form an axial balancing system having a chamber formed between the rear face of said impeller and the portion of said casing that faces said rear face, the inlet to said chamber being situated at the level of the second outlet. 
     
     
         2 . The pump according to  claim 1 , characterized in that said first passage and said second passage are separated by a shroud having at least a portion that extends between said first outlet and said second outlet. 
     
     
         3 . The pump according to  claim 2 , characterized in that said shroud is extended upstream into said main passage towards said common feed inlet. 
     
     
         4 . The pump according to  claim 2 , characterized in that the external portion of said shroud that extends between said first outlet and said second outlet is provided with a dynamic sealing gasket at its interface with an intermediate wall of said casing. 
     
     
         5 . The pump according to  claim 1 , characterized in that the interface between the front wall of said main passage and said casing is provided with a dynamic sealing gasket. 
     
     
         6 . The pump according to  claim 1 , characterized in that it further includes an inducer and a flow-straightening nozzle upstream from said common feed inlet. 
     
     
         7 . The pump according to  claim 3 , characterized in that:
 the external portion of said shroud that extends between said first outlet and said second outlet is provided with a dynamic sealing gasket at its interface with an intermediate wall of said casing;   the interface between the front wall of said main passage and said casing is provided with a dynamic sealing gasket; and   it further includes an inducer and a flow-straightening nozzle upstream from said common feed inlet.