Low inlet vorticity impeller having enhanced hydrodynamic wear characteristics

An impeller for a centrifugal pump comprising:

• a vane (1) extending in a Z-direction between a front side shroud (15) which is annular in shape and defines a suction inlet orifice (14), and a rear side shroud (16);
• the vane (1) comprising a radially inward leading edge (6), a radially outward trailing edge (7), a convex side (4), and a concave side (5), the vane (1) further being connected to the front side shroud (15) and to the rear side shroud (16), the impeller further comprising a front side blending (2) and a rear side blending (3);
• the front side blending (2) being provided proximate a central region of the impeller and adjacent to the front side shroud (15) between a surface of the vane (1) and a surface of the front side shroud (15);
• the front side blending (2) extending from a first point (s1) on the convex side (4) of the vane (1), circumferentially along the vane's perimeter, and peripherally around the leading edge (6) of the vane (1), to a second point (s6) on the concave side (5) of the vane (1) along the vane's perimeter;
• the rear side blending (3) being provided proximate the central region of the impeller and adjacent to the rear side shroud (16) between a surface of the vane (1) and a surface of the rear side shroud (16);
• the rear side blending (3) extending from a first point (p1) on the convex side (4) of the vane (1), circumferentially along the vane's perimeter, and peripherally around the leading edge (6) of the vane (1), to a second point (p4) on the concave side (5) of the vane (1) along the vane's perimeter;
• each of the front side blending (2) and rear side blending (3) being provided proximate to and extending from the leading edge (6) of the vane (1);
• wherein each of the front side blending (2) and rear side blending (3) are configured with a geometry which geometrically differs from a uniform radius fillet (8), the geometry of each of the front side blending (2) and the rear side blending (3) discouraging the formation of horseshoe vortices proximate the leading edge (6) of the vane (1) during operation;
• wherein by virtue of discouraging the formation of horseshoe vortices proximate the leading edge (6) of the vane (1) during operation, each of the front side blending (2) and the rear side blending (3) are adapted to resist wear to the vane (1) caused by abrasion during operation, thereby extending the life of the impeller;
• wherein a width of the rear side blending (3) increases from a first width (w1) near the first point (p1) of the rear side blending (3), to a larger third width (w3) near the second point (p4) of the rear side blending (3), as the rear side blending (3) progresses circumferentially along the vane's perimeter and peripherally around the leading edge (6) from the first point (p1) of the rear side blending (3) to the second point (p4) of the rear side blending (3);
• and wherein the rear side blending (3) further comprises a transitional second width (w2) between the first width (w1) and the third width (w3) at a point along the vane's perimeter which is circumferentially disposed between the first point (p1) of the rear side blending (3) and the second point (p4) of the rear side blending (3);
• wherein the leading edge (6) is encompassed between the first point (p1) of the rear side blending (3) and the second point (p4) of the rear side blending (3) when viewed along said Z-direction in a plane which is perpendicular to said Z-direction;
• wherein the transitional second width (w2) of the rear side blending (3) is larger than the first width (w1) and smaller than the third width (w3).

An impeller for a centrifugal pump comprising:

• a vane (1) extending in a Z-direction between a front side shroud (15) which is annular in shape and defines a suction inlet orifice (14), and a rear side shroud (16);
• the vane (1) comprising a radially inward leading edge (6), a radially outward trailing edge (7), a convex side (4), and a concave side (5), the vane (1) further being connected to the front side shroud (15) and to the rear side shroud (16), the impeller further comprising at least one of a front side blending (2) and a rear side blending (3);
• the front side blending (2) being provided proximate a central region of the impeller and adjacent to the front side shroud (15) between a surface of the vane (1) and a surface of the front side shroud (15);
• the front side blending (2) extending from a first point (s1) on the convex side (4) of the vane (1), circumferentially along the vane's perimeter, and peripherally around the leading edge (6) of the vane (1), to a second point (s6) on the concave side (5) of the vane (1) along the vane's perimeter;
• the rear side blending (3) being provided proximate the central region of the impeller and adjacent to the rear side shroud (16) between a surface of the vane (1) and a surface of the rear side shroud (16);
• the rear side blending (3) extending from a first point (p1) on the convex side (4) of the vane (1), circumferentially along the vane's perimeter, and peripherally around the leading edge (6) of the vane (1), to a second point (p4) on the concave side (5) of the vane (1) along the vane's perimeter;
• each of the front side blending (2) and rear side blending (3) being provided proximate to and extending from the leading edge (6) of the vane (1);
• the geometry of each of the front side blending (2) and the rear side blending (3) being adapted to optimize flow patterns adjacent the vane and between the respective front and rear side shrouds in a manner which discourages the formation of horseshoe vortices proximate the leading edge (6) of the vane (1) during operation;
• wherein by virtue of discouraging the formation of horseshoe vortices proximate the leading edge (6) of the vane (1) during operation, each of the front side blending (2) and the rear side blending (3) are adapted to resist wear to the vane (1) caused by abrasion during operation, thereby extending the life of the impeller;
• wherein the front side blending (2) transitions to a front side uniform radius fillet (10) at the first point (s1) and at the second point (s6) on the front side blending (2) where portions of the front side blending (2) terminate, the front side uniform radius fillet (10) being provided between a surface of the vane and a surface of the front side shroud (15);
• and wherein the rear side blending (3) transitions to a rear side uniform radius fillet (9) at the first point (p1) and at the second point (p4) on the rear side blending (3) where portions of the rear side blending (3) terminate;
• the rear side uniform radius fillet (9) being provided between a surface of the vane and a surface of the rear side shroud (16);
• wherein the rear side blending transitions to the rear side uniform radius fillet (9) at an angle (B1), at the second point (p4) of the rear side blending;
• the angle (B1) being measured about an axis defining the Z-direction, between the leading edge of the vane and the second point (p4) of the rear side blending;
• and wherein the front side blending transitions to the front side uniform radius fillet (10) at an angle (B2), at the second point (s6) of the front side blending;
• the angle (B2) being measured about the axis defining the Z-direction, between the leading edge of the vane and the second point (s6) of the front side blending, and wherein the angle (B2) is greater than the angle (B1).