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CN-116348681-B - Impeller seat for pump

CN116348681BCN 116348681 BCN116348681 BCN 116348681BCN-116348681-B

Abstract

The invention relates to an impeller seat (5) for a pump, the impeller seat (5) having an inlet wall, wherein the impeller seat (5) has an inlet radius measured from a central axis (a) extending axially to a circular intersection (11) between the inlet wall and an upper surface (12) of the impeller seat (5), the impeller seat (5) comprising a guide pin (13) connected to the inlet wall and extending radially inwards from the inlet wall, the guide pin (13) having an end radius measured from the central axis (a) extending axially to a radially innermost part of the guide pin (13), wherein an imaginary 15% circle (23) is offset radially inwards from the circular intersection (11) by fifteen percent of the difference between the inlet radius (R) and the end radius (R), the impeller seat (5) comprising a feed slot (14) arranged in the upper surface (12) of the impeller seat (5) and extending from the inlet wall (10) to the periphery of the impeller seat (5). The impeller seat (5) is characterized in that the groove inlet upstream edge line (34) is the radius of the impeller seat (5) intersecting the upstream edge (35) of the feed groove (14) at said circular intersection (11) seen in the direction of rotation of the pump (1), wherein the groove inlet upstream edge angle (λ) between the radius of the impeller seat (5) intersecting the upstream edge of the guide pin (13) at 15% circle (23) and the groove inlet upstream edge line (34) seen in the direction of rotation of the pump (1) is equal to or smaller than 20 degrees and equal to or larger than 0 degrees. The invention also relates to a pump comprising such a impeller seat.

Inventors

  • 5. Bradwade

Assignees

  • 赛莱默欧洲有限公司

Dates

Publication Date
20260505
Application Date
20211025
Priority Date
20201026

Claims (15)

  1. 1. An impeller seat (5) for a pump (1), the pump being configured for pumping a liquid containing solid matter, the impeller seat (5) having an axial inlet (9) defined by an inlet wall (10) and an upper surface (12) downstream of the axial inlet (9), wherein the impeller seat (5) has an inlet radius (R) measured from a central axis (a) extending axially to a circular intersection (11) between the inlet wall (10) and the upper surface (12) of the impeller seat (5), the impeller seat (5) comprising a guide pin (13) connected to and extending radially inwards from the inlet wall (10), the guide pin (13) having an end radius (R) measured from a central axis (a) extending axially to a radially innermost portion of the guide pin (13), wherein an imaginary 15% circle (23) is offset radially inwards from the circular intersection (11) by fifteen percent of the difference between the inlet radius (R) and the end radius (R), the impeller seat (5) comprising a groove (14), the impeller seat (5) comprising a groove (12) arranged in the impeller seat (5) extending from the radially innermost portion of the inlet wall (10) to the periphery of the impeller seat (5), Characterized in that the slot inlet upstream edge line (34) is a radius of the impeller seat (5) intersecting the upstream edge (35) of the feed slot (14) at said circular intersection (11), seen in the direction of rotation of the pump (1), wherein the radius of the impeller seat (5) intersecting the upstream edge of the guide pin (13) at 15% circle (23) seen in the direction of rotation of the pump and the slot inlet upstream edge line (34) between a slot inlet upstream edge angle (λ) equal to or smaller than 20 degrees and equal to or larger than 0 degrees, wherein the slot inlet upstream edge line (34) at the circular intersection (11) is located upstream of the radius of the impeller seat (5) intersecting the upstream edge of the guide pin (13) at 15% circle (23) seen in the direction of rotation of the pump, or coincides with the radius of the impeller seat intersecting the upstream edge of the guide pin at 15% circle seen in the direction of rotation of the pump.
  2. 2. Impeller seat (5) according to claim 1, wherein the slot inlet downstream edge line (36) is the radius of the impeller seat (5) intersecting the downstream edge (33) of the feed slot (14) at said circular intersection (11) seen in the direction of rotation of the pump (1), wherein the slot inlet downstream edge angle (τ) between the radius of the impeller seat (5) intersecting the upstream edge of the guide pin (13) at 15% circle (23) and the slot inlet downstream edge line (36) seen in the direction of rotation of the pump (1) is equal to or larger than 15 degrees and equal to or smaller than 30 degrees.
  3. 3. Impeller seat (5) according to claim 1 or 2, wherein the most upstream point of the upstream edge (35) of the feed slot (14) seen in the direction of rotation of the pump (1) is located at the slot inlet upstream edge line (34).
  4. 4. Impeller seat (5) according to claim 1 or 2, wherein the feed slot (14) is swept from the inlet wall (10) to the periphery of the impeller seat (5) in the direction of rotation of the pump (1).
  5. 5. Impeller seat (5) according to claim 1 or 2, wherein an imaginary 40% circle (25) is offset radially inwards from the circular intersection (11) by forty percent of the difference between the inlet radius (R) and the end radius (R), wherein the guide pin (13) comprises a leading edge (26) configured to scrape off contaminants from the impeller of the pump (1), wherein the guide pin (13) comprises a pre-leading edge (31) located upstream of the leading edge (26) of the guide pin (13), at least between the inlet wall (10) and the 40% circle (25) seen in the rotational direction and in the axial direction of the pump (1).
  6. 6. Impeller seat (5) according to claim 5, wherein the downstream edge (33) of the feed slot (14) is connected to the leading edge (26) of the guide pin (13) as seen in the direction of rotation of the pump (1).
  7. 7. Impeller seat (5) according to claim 5, wherein the axial distance between the pre-leading edge (31) and the leading edge (26) of the guide pin (13) is greater than 1mm and equal to or less than 4mm.
  8. 8. Impeller seat (5) according to claim 1 or 2, wherein an imaginary 85% circle (24) is offset radially inwards from the circular intersection by eighty-five percent of the difference between the inlet radius (R) and the tip radius (R), and wherein the leading edge line (29) is a projected straight line extending between the intersection between the 15% circle (23) and the leading edge (26) of the guide pin (13) and the intersection between the 85% circle (24) and the leading edge (26), and wherein the leading edge angle (β) between the radius of the impeller seat (5) intersecting the leading edge (26) at the 15% circle (23) and the leading edge line (29) is equal to or greater than 10 degrees and equal to or less than 30 degrees.
  9. 9. Impeller seat (5) according to claim 1 or 2, wherein at least a portion of the upper surface of the guide pin (13) is a planar surface, said at least a portion being defined by a 15% circle (23), an 85% circle (24), a leading edge (26) and a trailing edge (27).
  10. 10. Impeller seat (5) according to claim 9, wherein said at least a portion of the upper surface of the guide pin (13) is inclined with respect to a horizontal plane, wherein the distal end of the guide pin (13) is located upstream of the proximal end of the guide pin (13) as seen in the axial direction.
  11. 11. Pump (1) for pumping a liquid containing solid matter, the pump (1) comprising an open impeller (7) having a cover plate (15), a centrally located hub (16) and at least two blades (17) connected to the cover plate (15) and the hub (16) in a helical sweep, wherein each blade (17) of the impeller (7) comprises a leading edge adjacent to the hub (16), a trailing edge at the periphery of the impeller (7) and a lower edge (20), wherein the lower edge (20) extends from the leading edge to the trailing edge and separates a suction side (21) of the blade (17) from a pressure side (22) of the blade (17), characterized in that the pump (1) further comprises an impeller seat (5) according to any one of claims 1-10, wherein the leading edge of the blade (17) is configured to cooperate with a guide pin (13) of the impeller seat (5) during operation of the pump (1), and wherein the lower edge (20) of the blade (17) is positioned opposite to the upper surface (12) of the impeller seat (5).
  12. 12. Pump (1) according to claim 11, wherein the impeller (7) is movable back and forth in the axial direction relative to the impeller seat (5) during operation of the pump (1).
  13. 13. Pump (1) according to claim 11 or 12, wherein between 15% circle (23) and 85% circle (24), the scraping angle (δ) between the projected tangent of the leading edge (26) of the guide pin (13) and the projected tangent of the intersection between the leading edge of the blade (17) and the pressure side (22) of the blade (17) is greater than 90 degrees and equal to or less than 120 degrees, and wherein the leading edge of the blade (17) is swept helically from the hub (16) to the lower edge (20) of the blade (17).
  14. 14. Pump (1) according to claim 11 or 12, wherein the radially innermost portion of the guide pin (13) is located radially outside the hub (16) of the impeller (7).
  15. 15. Pump (1) according to claim 11 or 12, wherein the clearance between the leading edge of the vane (17) of the impeller (7) and the upper surface of the guide pin (13) is equal to or greater than 0.05mm and equal to or less than 1mm.

Description

Impeller seat for pump Technical Field The present invention relates generally to the field of pumps configured to pump liquids containing solid matter. Furthermore, the present invention relates to the field of submersible pumps, such as sewage pumps/pumps, in particular configured to pump liquids such as sewage/waste water, which may comprise polymers, sanitary products, fabrics, rags, disposable gloves, masks, etc. The invention relates in particular to an impeller seat suitable for use in said pumps and applications, and to a pump comprising such an impeller seat and an open impeller. The impeller seat of the pump is also termed the suction cover and the inlet insert. According to a first aspect, the invention relates to an impeller seat having an axial inlet defined by an inlet wall and an upper surface downstream of the axial inlet, wherein the impeller seat has an inlet radius (R) measured from a central axis (a) extending axially to a circular intersection between the inlet wall and the upper surface of the impeller seat. The impeller seat comprises a guide pin connected to and extending radially inwardly from said inlet wall, the guide pin having a tip radius (R) measured from a central axis (a) extending axially to a radially innermost portion of the guide pin, wherein an imaginary 15% circle is offset radially inwardly from said circular intersection by fifteen percent of the difference between said inlet radius (R) and said tip radius (R), the impeller seat comprising a feed slot arranged in an upper surface of the impeller seat and extending from the inlet wall to a periphery of the impeller seat. According to a second aspect, the invention relates to a pump comprising an open impeller having a cover plate, a centrally located hub and at least two helically swept blades connected to the cover plate and the hub, wherein each blade of the impeller comprises a leading edge adjacent the hub and a trailing edge at the periphery of the impeller and a lower edge, wherein the lower edge extends from the leading edge to the trailing edge separating the suction side of the blade from the pressure side of the blade. Background In sewage/wastewater treatment plants, septic tanks, water wells, pump stations, etc., solid substances/pollutants such as socks, sanitary napkins, papers, disposable diapers, disposable gloves, masks, wipes, etc., can occur, impeding the pump immersed in the basin/tank, so-called hard clogging of the pump. This means that solid matter enters the pump inlet and prevents rotation of the impeller. Thus, the pump is caught by some solid matter squeezed between the impeller and the pump casing/volute. When the impeller and impeller seat are located at a fixed distance from each other, the contaminants are sometimes too large to simply pass through the pump. The large pieces of solid matter may in the worst case cause the impeller to get stuck, severely damaging the pump, such as the bearings and the drive unit. Such unintentional shutdown is costly because of the expensive, tedious and unscheduled maintenance work required. European patent EP 1357294 discloses a pump comprising an impeller arranged to rotate in a volute of the pump, said impeller being suspended by a drive shaft, the pump comprising an impeller seat with a guide pin and a feed slot. The impeller is positioned at a fixed distance in the axial direction relative to the impeller seat. The guide pin is connected to the inlet wall of the impeller seat and extends straight towards the centre of the impeller and the centre of the impeller seat. European patent EP 1899609 discloses a pump which partly solves the problem of a fixed distance between the impeller seat and the impeller. The pump comprises an impeller arranged to rotate in a volute of the pump, said impeller being suspended by a drive shaft, the pump comprising an impeller seat with a guide pin and a feed slot. During operation of the pump, the impeller is movable in an axial direction relative to the impeller seat in order to allow larger pieces of solid matter to pass through, which may otherwise clog the pump or squeeze into the impeller. The guide pin is connected to the inlet wall of the impeller seat and extends straight towards the centre of the impeller and the centre of the impeller seat. The impeller is moved by the solid matter as it enters the gap between the leading edge of the blade and the guide pin and/or the gap between the lower edge of the blade and the upper surface of the impeller seat. Such pumps and applications are also protected by suitable monitoring and control units that monitor the operation of the pump and control the operation of the pump on the basis thereof. For example, when the rotational speed of the impeller decreases and/or the power consumption increases, the guide pin and/or the volute of the impeller become partially blocked and the monitoring and control unit enters a cleaning procedure comprising the step of counter-rotatin