Impeller seat with a guide pin for a pump

Patent metadata

Field	Value
Publication number	US-12025153-B2
Application number	US-202118033910-A
Country	US
Kind code	B2
Filing date	Oct 25, 2021
Priority date	Oct 26, 2020
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

An impeller seat for a pump, the impeller seat comprising an inlet wall, an inlet radius, and a guide pin connected to and extending radially inwards from the inlet wall. The guide pin includes a tip radius. A 40%-circle is offset radially inwards from a circular intersection forty percent of the difference between the inlet radius and the tip radius. The guide pin comprises a leading edge configured for scraping off pollutants from an impeller of the pump, and, at least between the inlet wall and the 40%-circle, comprises a pre-leading edge located upstream the leading edge of the guide pin, seen in the direction of rotation of the pump and seen in an axial direction.

First claim

The invention claimed is:

1. An impeller seat for a pump configured for pumping liquid comprising solid matter, said impeller seat comprising:
an axial inlet defined by an inlet wall and an upper surface located downstream of the axial inlet;
an inlet radius (R) measured from an axially extending centre axis (A) to a circular intersection between the inlet wall and the upper surface of the impeller seat; and
a guide pin connected to and extending radially inwards from said inlet wall, the guide pin having a tip radius (r) measured from the axially extending centre axis (A) to the radially innermost part of the guide pin, wherein an imaginary 40%-circle is offset radially inwards from said circular intersection forty percent of a difference between said inlet radius (R) and said tip radius (r);
wherein the guide pin comprises:
a leading edge configured for scraping off pollutants from an impeller of the pump, and
at least between the inlet wall and the 40%-circle, a pre-leading edge located upstream the leading edge of the guide pin, seen in the direction of rotation of the pump and seen in an axial direction, such that the guide pin displays a stepwise configuration.

2. The impeller seat according to claim 1 , further comprising:
an imaginary 85%-circle offset radially inwards from said circular intersection eighty-five percent of the difference between said inlet radius (R) and said tip radius (r); and wherein:
the pre-leading edge is located upstream the leading edge of the guide pin at least between the inlet wall and the 85%-circle.

3. The impeller seat according to claim 1 , further comprising:
an imaginary 15%-circle offset radially inwards from said circular intersection fifteen percent of the difference between said inlet radius (R) and said tip radius (r); and
wherein:
the leading edge of the guide pin is principally straight at least between the 15%-circle and the 40%-circle.

4. The impeller seat according to claim 1 , further comprising:
an imaginary 85%-circle offset radially inwards from said circular intersection eighty-five percent of the difference between said inlet radius (R) and said tip radius (r); and
an imaginary 15%-circle offset radially inwards from said circular intersection fifteen percent of the difference between said inlet radius (R) and said tip radius (r); and
wherein:
at least one portion of an upper surface of the guide pin is a plane surface, said at least one portion being defined by the 15%-circle, the 85%-circle, the leading edge of the guide pin and a trailing edge of the guide pin.

5. The impeller seat according to claim 4 , wherein:
the at least one portion of the upper surface of the guide pin is tilted in relation to a horizontal plane; and
a distal end of the guide pin is located upstream the proximal end of the guide pin, seen in an axial direction.

6. The impeller seat according to claim 1 , wherein:
the axial distance between the pre-leading edge and the leading edge of the guide pin is in a range of more than 1 mm and equal to or less than 4 mm.

7. The impeller seat according to claim 1 , further comprising:
an imaginary 85%-circle offset radially inwards from said circular intersection eighty-five percent of the difference between said inlet radius (R) and said tip radius (r);
an imaginary 15%-circle offset radially inwards from said circular intersection fifteen percent of the difference between said inlet radius (R) and said tip radius (r); and
a leading edge line defined by a projected straight line extending between an intersection between the 15%-circle and the leading edge of the guide pin and an intersection between the 85%-circle and the leading edge; and
a leading edge angle (β) between a first radius of the impeller seat intersecting the leading edge of the guide pin at the 15%-circle
wherein:
the leading edge line is in a range of equal to or more than 10 degrees and equal to or less than 30 degrees.

8. The impeller seat according to claim 1 , wherein:
the pre-leading edge and the leading edge of the guide pin are connected via an intermediate surface; and
a drop angle (η) between an upper surface of the guide pin and the intermediate surface at the leading edge of the guide pin and taken perpendicular to the leading edge of the guide pin is in a range of equal to or more than 90 degrees and equal to or less than 120 degrees.

9. The impeller seat according to claim 1 , wherein:
the leading edge of the guide pin, at least between the inlet wall and the imaginary 40%-circle, is located downstream the pre-leading edge, seen in the direction of rotation of the pump, at least twenty percent of the distance between the pre-leading edge and a trailing edge of the guide pin taken perpendicular to said leading edge of the guide pin.

10. The impeller seat according to claim 1 , further comprising:
a feeding groove arranged in the upper surface of the impeller seat and extending from the inlet wall to a periphery of the impeller seat.

11. The impeller seat according to claim 10 , further comprising:
a downstream edge of the feeding groove, seen in the direction of rotation of the pump, connected to the leading edge of the guide pin at an inlet of the feeding groove.

12. A Pump for pumping liquid comprising solid matter, the pump comprising:
an open impeller having a cover plate, a centrally located hub, and at least two spirally swept blades connected to the cover plate and to the hub, each blade having a leading edge adjacent the hub, and a trailing edge at a periphery of the impeller, and a lower edge extending from the leading edge to the trailing edge and separating a suction side of the blade from a pressure side of the blade; and
the impeller seat of claim 1 , wherein the leading edge of each blade is configured to cooperate with the guide pin of the impeller seat during operation of the pump and the lower edge of each blade is located opposite the upper surface of the impeller seat.

13. The pump according to claim 12 , wherein the impeller is displaceable back and forth in an axial direction in relation to the impeller seat during operation of the pump.

14. The pump according to claim 12 , wherein the impeller seat further comprises:
an imaginary 85%-circle offset radially inwards from said circular intersection eighty-five percent of the difference between said inlet radius (R) and said tip radius (r), and
an imaginary 15%-circle offset radially inwards from said circular intersection fifteen percent of the difference between said inlet radius (R) and said tip radius (r), and
wherein a scraping off angle (δ) between a projected tangent to the leading edge of the guide pin and a projected tangent to an intersection between the leading edge of the blade and the pressure side of the blade, between the 15%-circle and the 85%-circle, is more than 90 degrees and equal to or less than 120 degrees, and wherein the leading edge of the blade is spirally swept from the hub to the lower edge of the blade.

15. The pump according to claim 12 , wherein a radially innermost part of the guide pin is located radially outside the hub of the impeller.

16. The pump according to claim 12 , wherein a gap between the leading edge of the blade of the impeller and the upper surface of the guide pin is in a range of equal to or more than 0.05 mm and equal to or less than 1 mm.

Assignees

• Xylem Europe Gmbh

Inventors

• Bredwad Viktor

Classifications

• F04D7/045 Primary

  with means for comminuting, mixing stirring or otherwise treating · CPC title

• F05D2240/121

  related to the leading edge of a stator vane · CPC title

• F04D29/4273 Primary

  suction eyes · CPC title

• F05D2260/607

  Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles · CPC title

• F05D2250/51

  Inlet · CPC title