High efficiency double suction impeller

Abstract

A new double suction impeller, in particular for centrifugal pumps and hydraulic power recovery turbines, wherein the flow-path arrangement has inter-blade channels intersecting each other at the impeller's outer diameter so that the equivalent number of blades is doubled with respect to a conventional configuration obtained by the coupling of two single suction impellers.

1 . A double suction impeller, comprising:
 a hub associated to a tubular center bore, the hub comprising:   a plurality of blades integrally attached to the hub and to a left side shroud and to a right side shroud, the left side shroud and the right side shroud being provided with a center aperture adjacent to the tubular center bore, the outer edge of the left side shroud and the outer edge of the right side shroud defining the impeller exit, the impeller exit having a width and a median plane wherein each pair of adjacent blades of the plurality of blades define a plurality of inter-blade channels adapted to connect a plurality of input apertures, located within the center apertures of both the left side shroud and the right side shroud, to a plurality of output apertures located on the impeller exit, the inter-blade channels comprising left side inter-blade channels, having their respective input apertures located within the center aperture of the left side, and right side inter-blade channels, having their respective input apertures located within the center aperture of the right side shroud,   characterized in that the left side inter-blade channels and the right side inter-blade channels intersect the median plane of the impeller exit in a way to dispose the plurality of output apertures of the left side inter-blade channels to be aligned and alternated with the output apertures of the right side inter-blade channels, on the impeller exit.   
     
     
         2 . The double suction impeller according to  claim 1 , characterized in that the double suction impeller is made of a single piece. 
     
     
         3 . The double suction impeller according to one or more of claims from  2 , characterized in that the center bore is adapted to receive the impeller drive shaft, the impeller drive shaft being drivingly connected to said center bore by a key and a keyway. 
     
     
         4 . The double suction impeller according to  claim 3 , characterized in that the center aperture comprises an aperture edge and an aperture rim. 
     
     
         5 . The double suction impeller according to  claim 4 , characterized in that it further comprises: a suitable housing having axial inlets and a circumferential volute or diffuser outlet passage. 
     
     
         6 . A centrifugal pump comprising a double suction impeller according to  claim 5 . 
     
     
         7 . A hydraulic power recovery turbine comprising a double suction impeller according to  claim 5 .