Slurry Pump Impeller

Abstract

A pump impeller which includes: a back shroud having an inner main face with an outer peripheral edge and a central axis, the impeller in use being rotatable about the central axis in a direction of rotation, a plurality of pumping vanes extending from the inner main face of the back shroud, the pumping vanes being disposed in spaced apart relation, and each pumping vane including: opposed first and second side faces, a leading edge in the region of the central axis and a trailing edge in the region of the outer peripheral edge of the back shroud, and with a passageway between adjacent pumping vanes, wherein the first side face at the leading edge is in a plane which is at an acute angle with respect to a plane of the inner main face of the back shroud, and the first side face at the trailing edge is in a plane which is at an obtuse angle with respect to the plane of the inner main face of the back shroud.

1 . A pump impeller which includes:
 a front shroud and a back shroud each having an inner main face with an outer peripheral edge and a central axis, the inner main faces being generally at right angles to the central axis, the impeller in use being rotatable about the central axis in a direction of rotation,   a plurality of pumping vanes extending from the inner main face of the back shroud to the inner main face of the front shroud, the pumping vanes being disposed in spaced apart relation, and each pumping vane including:   opposed first and second side faces wherein the first side face is a pumping or pressure side face,   a leading edge in the region of the central axis,   a trailing edge in the region of the outer peripheral edge of the front and back shrouds, and   with a passageway between adjacent pumping vanes,   wherein the first side face at the leading edge is in a plane which is at an acute angle with respect to a plane of the inner main face of the back shroud, and the first side face at the trailing edge is in a plane which is at an obtuse angle with respect to the plane of the inner main face of the back shroud wherein the angle of the first side face progressively changes when moving from the leading edge to the trailing edge.   
     
     
         2 . A pump impeller according to  claim 1 , wherein the first side face at the leading edge is in a plane which is at an acute angle in a range of about 45° to less than about 90°. 
     
     
         3 . A pump impeller according to  claim 1  wherein the first side face at the trailing edge is in a plane which is at an obtuse angle in a range of greater than about 90° to about 135°. 
     
     
         4 . A pump impeller according to  claim 1 , wherein each pumping vane includes a leading edge section terminating at the leading edge, the leading edge section tapering inwardly towards the leading edge, and a trailing edge section terminating at the trailing edge, the trailing edge section tapering inwardly towards the trailing edge, each pumping vane including a main section between the leading and trailing edge sections which has a width or thickness which is generally constant from one side edge thereof to an opposed side edge thereof and along its length from the leading edge section to the trailing edge section. 
     
     
         5 - 6 . (canceled) 
     
     
         7 . A pump impeller according to  claim 1 , wherein the first side face is a leading face with respect to the direction of rotation. 
     
     
         8 . A pump impeller according to  claim 1 , wherein the first side face is a pumping or pressure side face. 
     
     
         9 . A pump impeller according to  claim 1 , wherein the first side face is configured such that the surface thereof, at any line between the leading and trailing edges which is at 90° from one side edge to the other, is flat or linear in the direction of that line. 
     
     
         10 . A pump impeller according to  claim 1 , wherein the pumping vanes are curved in a lengthwise direction between the leading and trailing edges. 
     
     
         11 . A pump impeller according to  claim 10  wherein the vanes are backwardly curved with respect to the direction of rotation of the impeller. 
     
     
         12 . A pump impeller which includes:
 a back shroud having an inner main face with an outer peripheral edge and a central axis, the impeller in use being rotatable about the central axis in a direction of rotation,   a plurality of pumping vanes extending from the inner main face of the back shroud, the pumping vanes being disposed in spaced apart relation, and each pumping vane including:   opposed first and second side faces wherein the first side face is a pumping or pressure side face,   opposed side edges one of which is located at the back shroud,   a leading edge in the region of the central axis,   a trailing edge in the region of the outer peripheral edge of the back shroud, and   with a passageway between adjacent pumping vanes,   wherein a line extending from one side edge to the other side edge of the pumping vane at the leading edge is at an acute angle with respect to a plane of the inner main face of the back shroud, and a line extending from one side edge to the other side edge of the pumping vane at the trailing edge is at an obtuse angle with respect to the plane of the inner main face of the back shroud, and wherein the angle of the line extending from one side edge to the other side edge progressively changes when moving from the leading edge to the trailing edge.   
     
     
         13 . A pump impeller according to  claim 12 , further including a front shroud having an inner main face, the pumping vanes extending between the inner main faces of the front and back shrouds and joined to said shrouds at the said opposed side edges. 
     
     
         14 . (canceled)