Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2261—Rotors specially for centrifugal pumps with special measures
  • F04D29/2288—Rotors specially for centrifugal pumps with special measures for comminuting, mixing or separating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/181—Axial flow rotors
  • F04D29/183—Semi axial flow rotors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/24—Vanes
  • F04D29/242—Geometry, shape
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D7/00—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts
  • F04D7/02—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type
  • F04D7/04—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being viscous or non-homogenous
  • F04D7/045—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being viscous or non-homogenous with means for comminuting, mixing stirring or otherwise treating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2210/00—Working fluids
  • F05D2210/10—Kind or type
  • F05D2210/11—Kind or type liquid, i.e. incompressible
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S415/00—Rotary kinetic fluid motors or pumps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S416/00—Fluid reaction surfaces, i.e. impellers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S417/00—Pumps

Definitions

• the invention concerns a pump impeller and more precisely a pump impeller for centrifugal- or half axial pumps for pumping of fluids containing pollutants.
• Sewage water contains a lot of different types of pollutants, the amount and structure of which depend on the season and type of area from which the water emanates.
• plastic material, hygiene articles, textile etc are common, while industrial areas may produce wearing particles.
• the worst problems are rags and the like which stick to the leading edges of the vanes and become wound around the impeller hub. Such incidents cause frequent service intervals and a reduced efficiency.
• closed pump impellers are often used, i.e. such with two cover discs, an upper and a lower as well as intermediate vanes, because these types of impellers reduce the axial load on the pump in comparison to the open type impellers.
• closed impellers have a lesser lead-through, which means higher risk for clogging.
• closed impeller wheels they are generally designed with leading edges placed in the central inlet siich that they are rather straight as seen in the flow direction. It has been found that during use, and in particular when the liquid contains rather large quantities of abrasive pollution, there is considerable wear on the leading edges of the vanes. There is further a risk that pollutants such as rags, plastic bags and other elongated objects get stuck on the leading edges, thereby requiring cleaning of the pump.
• the aim of the present invention is to remedy the above mentioned problems and in particular in connection with closed impeller wheels.
• an impeller wheel of a centrifugal or half axial type to be used in a pump for pumping liquids wherein the impeller is arranged with one or several vanes, that the vanes are attached to cover discs on each side, forming a so called closed impeller wheel, characterized in that the leading edges of the vanes are swept backwards at the inlet opening in one of the cover discs of the impeller.
• leading edges co-operate with cutting means arranged in a central inlet opening of the pump.
• leading edges protrude somewhat out of the inlet opening, and that the cutting means constitute at least one narrowing section of the gap between the central inlet opening of the pump and the leading ledges of the impeller, whereby, when the leading edges sweep past these sections during operation, a ciitting action is obtained there between.
• the leading edge of the vanes co-operate with two narrowing parts of the inlet opening of the pump housing.
• the sweep angle ⁇ should be in the region 40 - 60° and the sweeping of the leading edges may generally follow the curvature of a logarithmic spiral. In all an impeller wheel with improved performance and wear resistance is obtained, leading to long operation cycles between maintenance and service.
• Fig. 1 is an axial cross- section through a pump according to the invention
• Fig. 2a is a perspective view from above of an impeller wheel comprising the present invention
• Fig. 2b is a view corresponding to Fig. 2a from below
• Fig. 3 is a view from below of the impeller wheel of Fig. 2, and
• Fig. 4 is a bottom plate to be mounted in a pump and co-operating with the impeller wheel according to Fig. 1.
• Fig. 1 shows an impeller wheel of the closed type mounted in a pump comprising a drive shaft 10 connected to an electrical motor (not shown) for driving the pump.
• a pump impeller 12 is mounted, comprising upper 14 and lower 16 cover discs, vanes 18 and back vanes 19.
• the above mentioned components are mounted in a pump housing 20, having a bottom wall 22, an inlet 24 and an outlet 26.
• the pump impeller 12 is mounted such in the pump housing that there is a gap 28 between the peripheral surface of the lower cover disc 16 and an inner side wall of the pump housing 20, a space 29 between the lower disc and the bottom wall as well as a gap 30 between a lower surface of the lower cover disc 16 and an upper surface of the bottom wall 22.
• the liquid is sucked in axially through the inlet 24 and leaves the pump through the outlet 26 according to flow arrows A, B and C.
• the vanes 18 are designed such that the leading edges 40 are swept strongly backwards at the inlet opening 42 of the impeller wheel, in relation to the direction of rotation R.
• the sweep angle could be increased from the hub and outwards.
• the sweep of the leading edges could be defined by a logarithmic spiral where the sweep angle ⁇ is ⁇ /2 - ⁇ , where ⁇ is the angle of the logarithmic spiral.
• the sweep angle should be in the region 40 - 60°.
• the leading edges are placed generally in a plane perpendicular to the axis of rotation 10 of the impeller.
• the advantage with this design is to make sure that pollutants slide towards the periphery instead of getting stuck on the edges. It has further been shown that the wear on the leading edges are reduced when they have this configuration instead of the conventional design. Further, the leading edges protrude somewhat out of the central opening of the impeller, Fig. 1.
• the edge parts 44 of the vanes protruding above the bottom surface of the lower cover disc 16 can be arranged to co-operate with the edge part 46 of the stationary inlet 24 of the housing arranged in a bottom plate 22.
• the circular inlet is thus arranged with two oppositely arranged straight parts 50 whereby the gap between the vanes and the edge part of the inlet becomes very small. Elongated pollution such as rags, plastic bags and the like that have been stuck on the leading edges of the vanes will be cut here.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Geometry (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (16)

Applications Claiming Priority (2)

Publications (1)

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ID=33516498

Family Applications (1)

Country Status (26)

Families Citing this family (9)

Citations (6)

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• 2004
  • 2004-11-19 SE SE0402840A patent/SE0402840L/xx not_active IP Right Cessation
• 2005
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  • 2005-11-03 BR BRPI0518009-0A patent/BRPI0518009A/pt not_active IP Right Cessation
  • 2005-11-03 AU AU2005305920A patent/AU2005305920B2/en not_active Expired - Fee Related
  • 2005-11-03 ZA ZA200704866A patent/ZA200704866B/xx unknown
  • 2005-11-03 JP JP2007541908A patent/JP4489119B2/ja not_active Expired - Fee Related
  • 2005-11-03 NZ NZ555389A patent/NZ555389A/en unknown
  • 2005-11-03 CA CA002585171A patent/CA2585171A1/en not_active Abandoned
  • 2005-11-03 US US11/719,842 patent/US20090208336A1/en not_active Abandoned
  • 2005-11-03 WO PCT/EP2005/055726 patent/WO2006053831A1/en active Application Filing
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  • 2005-11-03 MX MX2007005925A patent/MX2007005925A/es active IP Right Grant
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• 2007
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  • 2007-06-18 NO NO20073096A patent/NO20073096L/no not_active Application Discontinuation
  • 2007-11-13 HK HK07112392A patent/HK1106814A1/xx not_active IP Right Cessation

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