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) 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;   (b) at least one vane nose positioned at a leading edge of the at least one substantially vertical wall;   (c) a retaining ring mounted over the top shroud to secure the vane nose within the body; and   (d) an outer wear ring mounted on a periphery of the top shroud.   
     
     
         2 . 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. 
     
     
         3 . The impeller of  claim 1 , wherein the vane nose is formed of sintered tungsten carbide. 
     
     
         4 . The impeller of  claim 1 , wherein the first unitary body is formed of chromium white iron. 
     
     
         5 . The impeller of  claim 1 , wherein the vane nose comprises a curved nose body, and upper and lower ends. 
     
     
         6 . The impeller of  claim 5 , wherein the upper end defines an upwardly extending tab for engaging a slot of the retaining ring. 
     
     
         7 . The impeller of  claim 5 , 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. 
     
     
         8 . The impeller of  claim 7 , 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. 
     
     
         9 . The impeller of  claim 1 , wherein the top shroud defines a recess configured to receive at least one protrusion of the retaining ring. 
     
     
         10 . The impeller of  claim 9 , 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. 
     
     
         11 . The impeller of  claim 10 , 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. 
     
     
         12 . The impeller of  claim 1 , wherein the first unitary body, the at least one vane nose and the retaining ring are each manufactured individually. 
     
     
         13 . The impeller of  claim 1 , wherein the at least one vane nose and the retaining ring are configured as one piece to together define a secondary unitary body. 
     
     
         14 . The impeller of  claim 13 , wherein the first unitary body comprises a first material and the second unitary body comprises a second material different from the first material. 
     
     
         15 . The impeller as claimed in  claim 14 , wherein the second unitary body further comprises a hub cover. 
     
     
         16 . The impeller of  claim 1  wherein either or both the retaining ring and the outer wear ring comprise a hard or wear-resistant material. 
     
     
         17 . The impeller of  claim 16  wherein either or both the retaining ring and the outer wear ring comprise a plurality of carbide segments affixed to the top shroud. 
     
     
         18 . The impeller of  claim 17  wherein both the retaining ring and the outer wear ring comprise a plurality of carbide segments, each separated by a gap, wherein the gaps are connected by a groove formed in the top shroud to mimic the function of an expeller vane. 
     
     
         19 . The impeller of  claim 1  wherein the retaining ring and the outer wear ring abut each and completely cover the top shroud. 
     
     
         20 . The impeller of  claim 19  wherein the retaining ring and the outer wear ring are comprised in a unitary element. 
     
     
         21 . The impeller of  claim 20  wherein the unitary retaining ring and outer wear ring comprises a single carbide tile. 
     
     
         22 . The impeller of  claim 21  wherein the unitary retaining ring and outer wear ring comprise expeller vanes or groove which mimic the function of expeller vanes.