Impeller for centrifugal pumps

• US 5,192,193 A
• Filed: 06/21/1991
• Issued: 03/09/1993
• Est. Priority Date: 06/21/1991
• Status: Expired due to Term

• Current Assignee: Flowserve Management Company (Flowserve Corporation)
• Original Assignee: Ingersoll-Dresser Pump Co. (Flowserve Corporation)
• Inventors: Cooper, Paul, Sloteman, Donald P.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): LARSON, JAMES
• Application Number:
  US07/719,025
• Time in Patent Office: 627 Days
• Field of Search: 416/179, 416/182, 416/183, 416/185, 416/186 R, 416/223 B, 416/243
• US Class Current: 416/186.00R
• CPC Class Codes: F04D 29/2277 for increasing NPSH or dealing with liquids near boiling-point
• CPC Class Codes: F04D 29/242 Geometry, shape

Abstract

A cavitation resistant impeller for liquid-conveying centrifugal pumps has a plurality of impeller vanes, each vane having, in combination, a leading inlet edge with a root portion extending upstream of its tip portion; a vane thickness that is greater upstream of the impeller throat than the vane thickness downstream of the impeller throat; and an elliptical nose on the leading inlet edge. The invention can be used in straight-vaned impellers or in Francis-type impellers.

Claims

1. In an impeller for liquid-conveying centrifugal pumps having a front shroud member, a rear hub member, a plurality of vanes therebetween having leading inlet edges disposed at the periphery of a circle, and an inlet throat opening between a suction side of one vane and a pressure side of an adjacent vane, means for inhibiting cavitation comprising:

(a) each vane including;

(i) a span between said shroud member and said hub member;

(ii) a leading inlet edge having a root portion extending upstream of a tip portion;

(iii) said leading inlet edge forming a concave surface beginning at a location between said tip portion and the mid-point of said span, said concave surface extending upstream to said root portion; and

(iv) a vane thickness upstream of said inlet throat opening greater than a vane thickness downstream of said throat opening.

2. The invention of claim 1 in which a line tangent to said concave surface intersects the surface of said hub member, at an angle not greater than 45 degrees.

3. The invention of claim 2 in which said leading inlet edge has an elliptical nose.

4. An impeller for liquid-conveying centrifugal pumps comprising:

(a) a front shroud member;

(b) a rear hub member spaced from said shroud member;

(c) a plurality of vanes therebetween having leading inlet edges disposed at the periphery of a circle, each pair of vanes forming an inlet throat opening between a suction side of one vane and a pressure side of an adjacent vane;

(d) each vane including;

(i) a span between said shroud member and said hub member;

(ii) a leading inlet edge having a root portion extending upstream of a tip portion;

(iii) said leading inlet edge forming a concave surface beginning at a location between said tip portion and the mid-point of said span, said concave surface extending upstream to said root portion;

(iv) a vane thickness upstream of said throat opening greater than a vane thickness downstream of said throat opening; and

(v) an elliptical nose on said leading inlet edge.

5. An impeller for liquid-conveying centrifugal pumps comprising:

(a) a front shroud member;

(b) a rear hub member spaced from said shroud member;

(c) a plurality of vanes therebetween having leading inlet edges disposed at the periphery of a circle, each pair of vanes forming an inlet throat opening between a suction side of one vane and a pressure side of an adjacent vane;

(d) each vane including;

(i) a span between said shroud member and said hub member;

(ii) a leading inlet edge having a root portion extending upstream of a tip portion;

(iii) said leading inlet edge forming a concave surface beginning at a location between said tip portion and the mid-point of said span, said concave surface extending upstream to said root portion; and

(iv) an elliptical nose on said leading inlet edge.