Radial impeller and casing for centrifugal pump

An impeller for a centrifugal pump comprising:

• (a) a hub extending along an impeller axis, the impeller axis defining an axial direction along the hub;
• (b) at least two vanes having a helical vane sweep and extending from the hub in a radial direction away from the impeller axis to a radial vane edge at the farthest extent of the vane from the hub,
• each vane extending along the hub in the direction of the impeller axis from a first location to a second location, the direction along the impeller axis from the first location to the second location defining an axial inlet direction;
• each vane extending around the hub in a first circumferential direction to sweep an arc from a first location along the impeller axis to a second location along the impeller axis;
• each vane defining:
• a high pressure surface facing at least partially along the axial inlet direction, the high pressure surface extending from a high pressure surface leading edge at the first location in the axial inlet direction in the first circumferential direction to a high pressure surface trailing edge at the second location, the high pressure surface leading edge and the high pressure surface trailing edge extending outwardly from the hub away from the impeller axis,
• a low pressure surface facing at least partially along the impeller axis in a second axial direction that is opposite the axial inlet direction, the low pressure surface separated from the high pressure surface in the first circumferential direction, the separation between the high pressure surface and the low pressure surface in the first circumferential direction increasing with distance from the impeller axis to a first location closely adjacent to the radial vane edge;
• and
• (c) a full circular shroud of a diameter equal to that of the impeller that is oriented and integral to the axial rear of the impeller,
• wherein the shroud comprises a front side;
• wherein the ratio of the depth of the shroud to the impeller vane axial height is about 0.337:1,
• wherein the impeller vane axial height is the distance between a first plane defined by the first location to a second plane defined by the second location, the first and second planes each perpendicular to the impeller axis;
• wherein each vane extends along the hub to a lower vane body, the lower vane body extending along the front side of the shroud about a central axis that lies in a plane that is perpendicular to the impeller axis;
• and
• wherein the lower vane body of each vane includes a lower leading surface and a lower trailing surface, the lower leading surface meeting the high pressure surface at a lower leading edge and the lower trailing surface meeting the low pressure surface at a lower trailing edge.