Rotary Parts For A Slurry Pump

Abstract

A rotary part being an impeller or expeller for a pump which can be rotated in a forward direction about a rotation axis X-X. The rotary part comprises a shroud having an outer peripheral edge portion and opposed first, and second faces, a plurality of expelling vanes projecting from one or more of the second faces of the shroud, each expelling vane having an inner side and an outer side which is at or near the outer peripheral edge portion of the shroud, the expelling vanes extending in a direction between the rotation axis X-X towards the outer peripheral edge portion of the shroud, each expelling vane further including a leading side facing in the forward direction and having an inner edge and an outer edge, a trailing side facing in a rearward direction and an up per side spaced from the outer face of the shroud. The leading side includes a forwardly inclined section which is inclined forwardly from a radial line Y-Y extending from the rotation axis X-X and which passes through the inner edge of the leading side.

1 - 20 . (canceled) 
     
     
         21 . An impeller for a pump which can be rotated in a forward direction about a rotation axis X-X; the impeller comprising:
 two shrouds, one being a front shroud, the other being a back shroud, pumping vanes extending between the shrouds, the front and back shrouds each having an outer peripheral edge portion and opposed inner and outer faces,   a plurality of expelling vanes extending along the outer face of at least one of the front shroud and back shroud each expelling vane having an inner side and an outer side which is at or near the outer peripheral edge portion of the at least one of the front and back shroud, the expelling vanes extending in a direction between the rotation axis X-X towards the outer peripheral edge portion of the at least one of the front and back shroud,   each expelling vane further having:
 a leading side facing in the forward direction and having an inner edge that is the innermost edge of the expelling vane and an outer edge that is an outermost edge of the expelling vane, 
 a trailing side facing in a rearward direction, and 
 an upper side spaced from the outer face of the at least one of the front and back shroud, 
 characterised in that the leading side includes a forwardly inclined section which is inclined forwardly from a radial line Y-Y extending from the rotation axis X-X and which passes through the inner edge of the leading side, 
 the forwardly inclined section extending from the inner edge towards the shroud outer peripheral edge portion of the at least one of the front and back shroud, 
 and the forwardly inclined section having a profile which is linear. 
   
     
     
         22 . The impeller according to  claim 21 , characterised in that the forwardly inclined section extends from the inner edge and terminates at the outer edge of the leading side. 
     
     
         23 . The impeller according to  claim 21 , characterised in that the forwardly inclined section is inclined at an angle of up to 30° from the radial line Y-Y. 
     
     
         24 . The impeller according to  claim 21 , characterised in that the forwardly inclined section is inclined at an angle of from 4° to 15° from the radial line Y-Y. 
     
     
         25 . The impeller according to  claim 21 , characterised in that the forwardly inclined section is inclined at an angle of from 4° to 8° from the radial line Y-Y. 
     
     
         26 . The impeller according to  claim 21 , characterised in that the forwardly inclined section is inclined at an angle of 4° from the radial line Y-Y. 
     
     
         27 . The impeller according to  claim 21 , characterised in that the upper side has a main surface, the distance between the shroud outer face and the main surface being 0.1 to 0.3 D, where D is the diameter of the shroud. 
     
     
         28 . The impeller according to  claim 21 , characterised in that the pumping vanes are backwardly sloped.