Impeller for a centrifugal slurry pump

Abstract

A improved impeller for use in a centrifugal slurry pump is provided, comprising: a top shroud; a bottom shroud; and a middle portion therebetween, said middle portion having at least one substantially vertical wall defining a slurry flow channel, wherein the top shroud, bottom shroud and middle portion are configured as one piece to together define a first unitary body; at least one vane nose positioned at a leading edge of the at least one substantially vertical wall; and, optionally, a retaining ring mounted over the top shroud to secure the vane nose within the body.

We claim: 
     
         1 . An impeller for use in a centrifugal slurry pump comprising:
 a top shroud; a bottom shroud; and a middle portion therebetween, said middle portion having at least one substantially vertical wall defining a slurry flow channel, wherein the top shroud, bottom shroud and middle portion are configured as one piece to together define a first unitary body; and   at least one vane nose positioned at a leading edge of the at least one substantially vertical wall   
     
     
         2 . The impeller as claimed in  claim 1 , further comprising:
 a retaining ring mounted over the top shroud to secure the vane nose within the body.   
     
     
         3 . The impeller of  claim 1 , wherein the vane nose comprises a first material and the first unitary body comprises a second material different from the first material. 
     
     
         4 . The impeller of  claim 2 , wherein the vane nose is formed of sintered tungsten carbide. 
     
     
         5 . The impeller of  claim 2 , wherein the first unitary body is formed of chromium white iron. 
     
     
         6 . The impeller of  claim 2 , wherein the vane nose comprises a curved nose body, and upper and lower ends. 
     
     
         7 . The impeller of  claim 6 , wherein the upper end defines an upwardly extending tab for engaging a slot of the retaining ring. 
     
     
         8 . The impeller of  claim 6 , wherein an elongate side tab projects from the nose body beyond each of the upper and lower ends for insertion into a recess formed within the at least one substantially vertical wall of the middle portion. 
     
     
         9 . The impeller of  claim 8 , wherein the vane nose is inserted into the recess in an orientation that is inclined at an angle less than 90 degrees relative to the bottom shroud. 
     
     
         10 . The impeller of  claim 2 , wherein the top shroud defines a recess configured to receive at least one protrusion of the retaining ring. 
     
     
         11 . The impeller of  claim 10 , wherein the retaining ring and top shroud comprise at least one corresponding aperture for receiving a fastener therethrough to attach the retaining ring to the top shroud. 
     
     
         12 . The impeller of  claim 11 , wherein the bottom shroud comprises a disc having a hub operatively connectable to a drive shaft for causing rotation of the impeller about a central axis. 
     
     
         13 . The impeller of  claim 2 , wherein the first unitary body, the at least one vane nose and the retaining ring are each manufactured individually. 
     
     
         14 . The impeller of  claim 2 , wherein the at least one vane nose and the retaining ring are configured as one piece to together define a secondary unitary body. 
     
     
         15 . The impeller of  claim 14 , wherein the first unitary body comprises a first material and the second unitary body comprises a second material different from the first material. 
     
     
         16 . The impeller as claimed in  claim 15 , wherein the second unitary body further comprises a hub cover.