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Title:
A PUMP FOR PUMPING A LIQUID OR SLURRY
Document Type and Number:
WIPO Patent Application WO/2017/108045
Kind Code:
A1
Abstract:
The invention relates to a pump 100 for pumping slurry, such as manure, said pump in the orientation intended for use, comprising: -an outer housing 2 comprising an upper end 4 and a lower end 6 and one or more side walls 8,8',8'' extending between the upper end 4 and said lower end 6 of said outer housing, wherein said lower end 6 of said outer housing comprising a bottom part 10, wherein said bottom part comprising an inlet opening 12 for slurry; -an inner housing 14 comprising an upper end 16 and a lower end 18; said inner housing being contained within the outer housing 2 and said inner housing extending from an opening 20 in the side wall of the outer housing to a position 22 below said opening in the side wall; said inner housing and outer housing thereby defining a flow space 23 for slurry; -a motor 24, said motor being confined within the inner housing 14; said motor comprising a driveshaft 26 arranged at a lower end 18 of said inner housing; -an impeller 28, said impeller being connected to and being configured to be driven by said driveshaft 26 of said motor 24; wherein said upper end 4 of said outer housing 2 comprises an outlet opening 30 for slurry; wherein the lower end 18 of the inner housing 14 is positioned above said bottom part 10 of the outer housing; thereby defining an impeller space 32 between the lower end 18 of said inner housing and said bottom part 10 of said outer housing; wherein said impeller 28 being arranged in said impeller space; characterized in that said bottom part 10, at an inner perimeter 34 thereof, defining a smoothly curved transition wall 36, connecting the bottom 38 of the bottom part 10 to the side wall(s) 8,8',8'', 8''' of the outer housing.

Inventors:
PEDERSEN FREDDY (DK)
Application Number:
PCT/DK2016/050416
Publication Date:
June 29, 2017
Filing Date:
December 07, 2016
Export Citation:
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Assignee:
F P PRODUCTION GRINDSTED APS (DK)
International Classes:
F04D7/04; F04D13/04; F04D13/08
Foreign References:
DE1259710B1968-01-25
US3398694A1968-08-27
Attorney, Agent or Firm:
OTELLO LAW FIRM (DK)
Download PDF:
Claims:
Claims

1. A pump 100 for pumping slurry, such as manure, said pump in the orientation intended for use, comprising:

-an outer housing 2 comprising an upper end 4 and a lower end 6 and one or more side walls 8, 8', 8" extending between the upper end 4 and said lower end 6 of said outer housing, wherein said lower end 6 of said outer housing comprising a bottom part 10, wherein said bottom part comprising an inlet opening 12 for slurry;

-an inner housing 14 comprising an upper end 16 and a lower end 18;

-a motor 24, said motor being confined within the inner housing 14; said motor comprising a driveshaft 26 arranged at a lower end 18 of said inner housing;

-an impeller 28, said impeller being connected to and being configured to be driven by said driveshaft 26 of said motor 24;

wherein said upper end 4 of said outer housing 2 comprises an outlet opening 30 for slurry; wherein the lower end 18 of the inner housing 14 is positioned above said bottom part 10 of the outer housing; thereby defining an impeller space 32 between the lower end 18 of said inner housing and said bottom part 10 of said outer housing;

wherein said impeller 28 being arranged in said impeller space;

wherein said bottom part 10, at an inner perimeter 34 thereof, defining a smoothly curved transition wall 36, connecting the bottom 38 of the bottom part 10 to the side wall(s) 8, 8', 8", 8 " ' of the outer housing;

characterized in that said inner housing being contained within the outer housing 2 and said inner housing extending from an opening 20 in the side wall of the outer housing to a position 22 below said opening in the side wall; said inner housing and outer housing thereby defining a flow space 23 for slurry.

2. A pump 100 according to claim 1, wherein said motor 24 being a hydraulic motor or an electric motor.

3. A pump 100 according to claim 2, wherein said motor 24 is a hydraulic motor having an operational hydraulic pressure of 50 - 600 bar, such as 100 - 550 bar, for example 150 - 500 bar, such as 200 - 450 bar, e.g. 250 - 400 bar or 300 - 350 bar. 4. A pump 100 according to any of the preceding claims, wherein the outlet opening 30 for slurry comprises a flange 40, thus allowing connection of an outlet hose to said outlet opening.

5. A pump 100 according to any of the preceding claims, wherein the inlet opening 12 for slurry comprises a flange 42, thus allowing connection of an inlet hose to said inlet opening.

6. A pump 100 according to any of the preceding claims, wherein the inner housing 2 and/or the outer housing 14 is made from steel.

7. A pump 100 according to any of the preceding claims, wherein at least part of the inner housing 14 and/or the outer housing 2 independently is having the shape of an oblique cone or an oblique pyramid.

8. A pump 100 according to claim 7, wherein the outer housing 2 is being tapered in an upward direction and/or wherein the inner housing 14 is being tapered in an upward direction.

9. A pump 100 according to claim 7 or 8, wherein the outer housing 2 and the inner housing 14 are being obliquely arranged in opposite directions.

10. A pump 100 according to any of the preceding claims, wherein said pump comprising a sealing or a gasket 44, sealing off an upper end of said driveshaft 26 from a lower end of said driveshaft, thereby preventing passage of liquid or slurry from the flow space 23 between the inner and outer housing into the interior 46 of the inner housing.

11. A pump 100 according to any of the preceding claims, wherein said outer housing 2 comprises an upper element 48 and a lower element 50, said upper element and lower element being connected to each other, such as by welding.

12. A pump 100 according to any of the preceding claims, wherein said impeller 28 comprising a disk 52, said disk comprising an upper side 54 and a lower side 56, said lower side comprising a number of radially extending impeller ribs 58.

13. A pump 100 according to claim 12, wherein said number of impeller ribs 58 being 2 - 15, such as 3 - 14, for example 4 - 13, such as 5 - 12, e.g. 6 - 11, such as 7 - 10 or 8 - 9. 14. A pump 100 according to claim 12 or 13, wherein each said impeller ribs 58 are being plate- shaped and having a leading surface 60 and a trailing surface 62.

15. A pump 100 according to claim 12 or 13, wherein each said impeller ribs 58 comprising a closed, hollow or solid element having a leading surface 60 and a trailing surface 62, wherein at least the trailing surface are being convexly shaped.

16. A pump 100 according to any of the claims 12 - 15, wherein each said impeller rib 58 being curved in a radial direction.

17. A pump 100 according to any of the preceding claims further comprising one or more baffles 64, said one or more baffles being arranged in the flow space 23 between said inner housing 2 and said outer housing 14.

18. A pump 100 according to any of the claims 1 - 17, wherein the number of baffles 64 is 1 - 20, such as 2 - 19, for example 3 - 18, such as 4 - 17, e.g. 5 - 16, such as 6 - 15, for example 7 - 14, such as 8 - 13, such as 9 - 12 or 10 - 11.

19. A pump 100 according to claim 17 or 18, wherein the baffles 64 are oriented, in relation to the intended rotational direction of the impeller 28 during use, in such a way that they are inclined upwardly.

20. A pump 100 according to any of the preceding claims, wherein said inlet opening 12 for slurry is arranged at the bottom 38 of said bottom part 10 of said outer housing.

21. A pump 100 according to claim 20, wherein the bottom 38 of said bottom part 10 of said outer housing 2 comprising a removable plate 66, wherein said removable plate comprising said inlet opening 12 for slurry.

22. A pump 100 according to any of the claims 1 - 21 furthermore comprising one or more cables or hoses 68 for providing power to said motor 24.

23. A pump 100 according to any of the claims 1 - 22 comprising at the upper end 16 of the inner housing 14 a top seal 70, sealing off the interior 46 of the inner housing.

24. A pump 100 according to any of the claims 1 - 23, wherein said bottom part 10 of said outer housing is having a circular cross-section.

25. A pump 100 according to any of the preceding claims, wherein the pump in its interior is having a design, a geometry and dimensions comprising a 360° flow space for liquid or slurry at a lower part of the interior of said pump, or at the impeller space 32, thus allowing liquid or slurry being pumped to perform a 360° flow at a lower part of said pump, or at the impeller space 32.

26. A pump 100 according to any of the preceding claims, wherein the impeller 28 comprises a number of flow directional elements, wherein said flow directional elements, in relation to the intended rotational direction of the impeller during use, being upwardly inclined in a rearward direction.

27. A pump 100 according to claim 26 and any of the claims 12 - 16, wherein each rib comprises a flow directional element.

28. A pump 100 according to claim 26 or 27, wherein said flow directional elements are being arranged at an outer circumference of said impeller.

29. Use of a pump 100 according to any of the claims 1 - 28 for pumping liquid or slurry.

30. Use according to claim 29, wherein the liquid or slurry is being animal manure or slurry, such as sewer slurry.

31. A method for pumping liquid or slurry, such as manure, said method comprising the steps: i) providing a pump 100 according to any of the claims 1 - 28;

ii) activating the motor 24 of the pump in such a way that said impeller 28 rotates;

iii) allowing liquid or slurry to approach and enter the inlet opening 12 of the outer housing 2; iv) allowing liquid or slurry to be pumped from the inlet opening 12 of the outer housing 2 to the outlet opening 30 of the outer housing 2.

Description:
A pump for pumping a liquid or slurry

Field of the invention

The present invention relates to the field of handling of slurries, such as manure. More specifically, the present invention relates in a first aspect to a pump for pumping liquid or slurries.

In a second aspect the present invention relates to a use of a pump according to the first aspect of the present invention for pumping liquid or slurry.

In a third aspect the present invention relates to a method for pumping liquid or slurry, such as manure.

Background of the invention

Within the field of agriculture and holding of livestock it is common practice to collect manure from animals in large holding tanks with the view to spread the manure as fertilizer on crop fields at a later time.

This operation requires transfer of the manure from the holding tank to a mobile spreader comprising a spreader for spreading manure.

In the process of transferring the manure from the holding tank to the mobile tank, a pump is submerged into the slurry in the holding tank. The pump is connected to a hose which extends to an inlet of the mobile tank.

Various designs of pumps for this purpose are known.

WO 2012/069055 Al discloses a pump for pumping slurries, such as manure. The pump comprises a housing which in its interior comprises a pump wheel. The pump wheel is mounted on a driveshaft and is configured to be displaced in an axial direction in its bearing. This axial displacement allows the pump wheel to rotate in both directions and hence allows the pump to pump slurries in two opposite direction without the risk of clogging of the pump. The motor driving the pump wheel is arranges outside the pump housing itself. In a pumping configuration in which slurry is pumped upwards, the slurry will enter the room between blades of the rotary wheel, whereafter the slurry will exit through the exit opening which is arranged opposite to the pump motor. Accordingly, in the design of the pump disclosed in

WO 2012/069055 Althe slurry being pumped will not be allowed to be swirled around on the interior walls of the pump housing and exit the pump housing once a particular height of the pump housing is reached. In other words, in case the slurry reached a height immediately below the motor, that slurry will not be directly lead, via the interior walls of the housing, to the exit opening. The slurry will only be allowed to exit the exit opening once the slurry has reached a height of the pump housing corresponding to a height immediately below the motor and once that slurry is located immediately below the exit opening.

Accordingly, in the pump disclosed in WO 2012/069055 Al, the power of the pump motor is not the limiting factor for the efficiency. Rather the design of the flow channel within the pump housing is being the limiting factor for the efficiency.

The same problem applies in respect of other prior art slurry pumps.

Accordingly, there exists a need for improving the design of a pump for pumping slurry avoiding the disadvantages of the prior art.

It is an objective of the present invention to provide a solution to the above stated problem in order to reduce or even eliminate the disadvantages encountered by the prior art pumps.

Brief description of the invention

This objective is attained with the present invention in its first, second and third aspect.

Accordingly, in a first aspect the present invention relates to a pump for pumping slurry, such as manure, said pump in the orientation intended for use, comprising:

-an outer housing comprising an upper end and a lower end and one or more side walls extending between the upper end and said lower end of said outer housing, wherein said lower end of said outer housing comprising a bottom part, wherein said bottom part comprising an inlet opening for slurry;

-an inner housing comprising an upper end and a lower end;

-a motor, said motor being confined within the inner housing; said motor comprising a driveshaft arranged at a lower end of said inner housing;

-an impeller, said impeller being connected to and being configured to be driven by said driveshaft of said motor;

wherein said upper end of said outer housing comprises an outlet opening for slurry;

wherein the lower end of the inner housing is positioned above said bottom part of the outer housing; thereby defining an impeller space between the lower end of said inner housing and said bottom part of said outer housing;

wherein said impeller being arranged in said impeller space;

wherein said bottom part, at an inner perimeter thereof, defining a smoothly curved transition wall, connecting the bottom of the bottom part to the side wall(s) of the outer housing;

characterized in that said inner housing being contained within the outer housing and said inner housing extending from an opening in the side wall of the outer housing to a position below said opening in the side wall; said inner housing and outer housing thereby defining a flow space for slurry.

In a second aspect the present invention relates to a use of a pump according the first aspect for pumping liquid or slurry.

In a third aspect the present invention relates to a method for pumping liquid or slurry, such as manure, said method comprising the steps:

i) providing a pump according to the first aspect of the present invention;

ii) activating the motor of the pump in such a way that said impeller rotates;

iii) allowing liquid or slurry to approach and enter the inlet opening of the outer housing; iv) allowing liquid or slurry to be pumped from the inlet opening of the outer housing to the outlet opening of the outer housing.

The present invention in its various aspects provides for improved pumping efficiency. This improved pumping efficiency is brought about by the special design of the flow channel for slurry or liquid between the inlet opening and the outlet opening of the pump of the present invention.

Brief description of the figures

Fig. 1 is a perspective view showing the outer housing accommodating an inner housing of an embodiment of the pump of the present invention.

Fig. 2 is an explosive view showing the individual elements making up an embodiment of the pump of the present invention.

Fig. 3 is a cross-sectional view showing an embodiment of the pump of the present invention.

Fig. 4 is another cross-sectional view showing an embodiment of the pump of fig. 3.

Fig. 5 is a perspective view showing an impeller assembly of an embodiment of the pump of the present invention.

Fig 6 is a perspective view showing a motor assembly of an embodiment of the pump of the present invention.

Fig. 7 is a perspective view showing a sealing of cables of a power supply to the motor of the pump of the present invention.

Fig. 8 is a perspective view showing an impeller assembly of an embodiment of the pump of the present invention. Detailed description of the invention

The present invention relates in a first aspect the present invention relates to a pump for pumping slurry, such as manure, said pump in the orientation intended for use, comprising:

-an outer housing comprising an upper end and a lower end and one or more side walls extending between the upper end and said lower end of said outer housing, wherein said lower end of said outer housing comprising a bottom part, wherein said bottom part comprising an inlet opening for slurry;

-an inner housing comprising an upper end and a lower end;

-a motor, said motor being confined within the inner housing; said motor comprising a driveshaft arranged at a lower end of said inner housing;

-an impeller, said impeller being connected to and being configured to be driven by said driveshaft of said motor;

wherein said upper end of said outer housing comprises an outlet opening for slurry;

wherein the lower end of the inner housing is positioned above said bottom part of the outer housing; thereby defining an impeller space between the lower end of said inner housing and said bottom part of said outer housing;

wherein said impeller being arranged in said impeller space;

wherein said bottom part, at an inner perimeter thereof, defining a smoothly curved transition wall, connecting the bottom of the bottom part to the side wall(s) of the outer housing;

characterized in that said inner housing being contained within the outer housing and said inner housing extending from an opening in the side wall of the outer housing to a position below said opening in the side wall; said inner housing and outer housing thereby defining a flow space for slurry.

The special design involving the inner housing being arranged within the outer housing and accommodating a motor driving an impeller provides for a significant suction power and hence a significant capacity of a pump for pumping liquids or slurries.

In one embodiment of the pump of the first aspect of the present invention the motor being a hydraulic motor or an electric motor.

In one embodiment of the pump of the first aspect of the present invention the motor being is a hydraulic motor having an operational hydraulic pressure of 50 - 600 bar, such as 100 - 550 bar, for example 150 - 500 bar, such as 200 - 450 bar, e.g. 250 - 400 bar or 300 - 350 bar.

Hydraulic motors are preferred because any clogging of the impeller in a hydraulic pump does not amount to any detrimental stress of the hydraulic motor driving the pump. Furthermore, hydraulic outputs are often available in vehicles intended for use with the pump of the first aspect. In one embodiment of the pump of the first aspect of the present invention the outlet opening 30 for slurry comprises a flange 40, thus allowing connection of an outlet hose to said outlet opening.

This embodiment allows liquid or slurry exiting the pump to be directed via an outlet hose to a desired location.

In one embodiment of the pump of the first aspect of the present invention the the inlet opening for slurry comprises a flange, thus allowing connection of an inlet hose to said inlet opening.

In this embodiment the pump may be used in a situation in which the pump is not submerged into the liquid or slurry to be pumped.

In one embodiment of the pump of the first aspect of the present invention the inner housing and/or the outer housing is made from steel.

Steel has proven a suitable material for the manufacture of the invention the inner housing and the outer housing.

In one embodiment of the pump of the first aspect of the present invention at least part of the inner housing and/or the outer housing independently is having the shape of an oblique cone or an oblique pyramid.

In one embodiment of the pump of the first aspect of the present invention the outer housing is being tapered in an upward direction and/or wherein the inner housing is being tapered in an upward direction.

In one embodiment of the pump of the first aspect of the present invention the outer housing and the inner housing are being obliquely arranged in opposite directions.

These designs of the outer housing and/or the inner housing of the pump provides for a flow space between the inner and outer housing of the pump which has proven very efficient in terms of capacity of the pump.

In one embodiment of the pump of the first aspect of the present invention the pump comprising a sealing or a gasket, sealing off an upper end of said driveshaft 26 from a lower end of said driveshaft, thereby preventing passage of liquid or slurry from the flow space between the inner and outer housing into the interior of the inner housing.

In one embodiment of the pump of the first aspect of the present invention outer housing comprises an upper element and a lower element, said upper element and lower element being connected to each other, such as by welding.

This design allows the inner element to be arranged within the outer element. In one embodiment of the pump of the first aspect of the present invention impeller comprising a disk, said disk comprising an upper side and a lower side, said lower side comprising a number of radially extending impeller ribs.

In one embodiment of the pump of this aspect, the number of impeller ribs 58 being 2 - 15, such as 3 - 14, for example 4 - 13, such as 5 - 12, e.g. 6 - 11, such as 7 - 10 or 8 - 9.

In one embodiment of the pump of the first aspect of the present invention impeller ribs are being plate-shaped and having a leading surface and a trailing surface.

In one embodiment of the pump of the first aspect of the present invention each said impeller ribs comprising a closed, hollow or solid element having a leading surface and a trailing surface, wherein at least the trailing surface are being convexly shaped.

In one embodiment of the pump of the first aspect of the present invention each said impeller rib being curved in a radial direction.

These designs of the impeller have proven to be efficient in terms of pumping capacity.

In one embodiment of the pump of the first aspect of the present invention the pump comprising one or more baffles, said one or more baffles being arranged in the flow space between said inner housing and said outer housing.

In one embodiment of the pump of the first aspect of the present invention the number of baffles is 1 - 20, such as 2 - 19, for example 3 - 18, such as 4 - 17, e.g. 5 - 16, such as 6 - 15, for example 7 - 14, such as 8 - 13, such as 9 - 12 or 10 - 11.

In one embodiment of the pump of the first aspect of the present invention the baffles are oriented, in relation to the intended rotational direction of the impeller during use, in such a way that they are inclined upwardly.

Inclusion of baffles, optionally in the above described design, improves aligning the flow of liquid or slurry within the interior of the pump into a direction towards the upper outlet opening. Furthermore, the baffles may provide increased physical strength and integrity.

In one embodiment of the pump of the first aspect of the present invention the inlet opening for slurry is arranged at the bottom of said bottom part of said outer housing.

In one embodiment of the pump of the first aspect of the present invention the bottom of said bottom part of said outer housing comprising a removable plate, wherein said removable plate comprising said inlet opening for slurry.

Providing the bottom of said bottom part of said outer housing with a removable plate allows for better inspection and/or repair and/or replacement of the impeller.

In one embodiment of the pump of the first aspect of the present invention the pump furthermore comprising one or more cables or hoses for providing power to said motor.

Cables or hoses allows for providing power to that pump. In one embodiment of the pump of the first aspect of the present invention the upper end of the inner housing comprises a top seal, sealing off the interior of the inner housing.

A top seal prevents liquid or slurry to enter the interior of the inner housing, thereby protecting the motor being accommodated in that housing.

In one embodiment of the pump of the first aspect of the present invention the bottom part of said outer housing is having a circular cross-section.

A circular cross-section of the bottom part of the outer housing may be preferred as the impeller itself performs a circular motion. Hence, in this way the bottom part of the outer housing may be adapted to the geometry of the impeller or the impellers circular motion. In one embodiment of the pump of the first aspect of the present invention the the pump in its interior is having a design, a geometry and dimensions comprising a 360° flow space for liquid or slurry at a lower part of the interior of said pump, or at the impeller space, thus allowing liquid or slurry being pumped to perform a 360° flow at a lower part of said pump, or at the impeller space.

This design allows liquid or slurry to be pumped to be swirled around within the pump before the movement of liquid or slurry is being converted to a more linear and upright directed motion. Accordingly, this design enhances efficiency of the pump.

In one embodiment of the pump of the first aspect of the present invention the the impeller comprises a number of flow directional elements, wherein said flow directional elements, in relation to the intended rotational direction of the impeller during use, being upwardly inclined in a rearward direction.

In one embodiment of the pump of the first aspect of the present invention each rib comprises a flow directional element.

In one embodiment of the pump of the first aspect of the present invention the flow

directional elements are being arranged at an outer circumference of said impeller.

These designs of the impeller improve efficiency in terms of capacity of the pump.

In a second aspect the present invention relates to a use of a pump according the first aspect for pumping liquid or slurry.

In one embodiment of the use of the second aspect of the present invention the use is for pumping liquid or slurry.

In one embodiment of the use of the second aspect of the present invention the liquid or slurry is being animal manure or slurry, such as sewer slurry.

In a third aspect the present invention relates to a method for pumping liquid or slurry, such as manure, said method comprising the steps:

) providing a pump according to the first aspect of the present invention; ii) activating the motor of the pump in such a way that said impeller rotates; iii) allowing liquid or slurry to approach and enter the inlet opening of the outer housing; iv) allowing liquid or slurry to be pumped from the inlet opening of the outer housing to the outlet opening of the outer housing.

Referring now in details to the drawings for the purpose of illustrating preferred embodiments of the present invention, Fig. 1 illustrates the design of the housing of a pump 100 of one embodiment of the present invention.

Fig. 1 shows the outer housing 2 having an upper end 4 and a lower end 6. The outer housing 2 comprises a number of side walls 8, 8', 8", 8" ' collectively forming an oblique pyramid making up the housing 2.

The outer housing comprises in its interior a flow space 23 for slurry. The outer housing 2 has been made by welding a bottom part 10 or lower element 50 together with an upper element 48.

An inner element 14 having an upper end 16 and a lower end 18 (not seen in fig. 1) is arranged in an opening 20 in the side wall 8, 8', 8", 8"'. The interior 46 of the inner housing 14 is intended for accommodating a motor, whereas the interior of the outer housing comprises a flow space in which slurry, such as manure, may flow from an inlet opening 12 to an outlet opening 30 by means of power provided by the motor arranged in the interior 46 of the inner housing. This principle is further illustrated in fig. 2 which is an explosive view of one embodiment of the pump 10ο according to the first aspect of the present invention.

Fig. 2 shows the outer housing 2. The housing comprises an upper element 48 and a lower element 50. The upper element 48 and a lower element 50 will preferably be welded together.

The side wall 8 of the outer housing comprises an opening 20. In the opening 20 is accommodated an inner housing 14. The interior of the inner housing in turn accommodates the motor 24. The mother at a lower end thereof comprises a driveshaft 26 which is connected to an impeller 28. The impeller comprises a disk 52 which at its lower side comprises a number of radially extending ribs.

In use the motor 24 drives the driveshaft 26 which turns the impeller 28. The ribs 58 of the impeller ensures that liquid or slurry being located in the vicinity of the impeller will be swirled around in a rotational movement, thus following a flow path defined by the inner wall of the outer hosing. Baffles 64 may assist in directing this rotational movement to an upward directed movement of liquid or slurry, hence ultimately resulting to a movement of slurry from the inlet opening 12 located at a position immediately below the lower end of the outer housing 2 through the interior of the outer housing, and finally expelling the liquid or slurry through the outlet opening 30 at an upper end 4 of the outer housing.

Furthermore, the baffles may additionally serve the purpose of providing improved structural integrity of the pump, in that the baffles may provide a physical contact between the inner and the outer housing. Such contact may for example minimize formation of vibrations in the pump.

Fig 3 and 4 are both cross-sectional views of an embodiment of the pump according to the first aspect of the present invention.

In fig. 4 the cross-sectional plane is a vertical symmetry plane cutting through the middle part of the inner housing 14, whereas in fig. 3 the cross-sectional plane is a vertical plane arranged perpendicular to the cross-sectional plane of fig. 4.

Fig. 3 and 4 shows the arrangement of the motor 24 within the interior 46 of the inner housing 14. The motor comprises a drive shaft 26 which is connected to the impeller 28. The impeller is arranged in an impeller space defined between the lower end 18 of the inner housing and the bottom part 10 of the outer housing.

The impeller comprises an impeller disk 52 having an upper side 54 and a lower side 56. On the lower side 56 of the impeller is arranged a number of radially extending impeller ribs 58. The impeller ribs 58 each comprises a leading surface 60 and a trailing surface 62.

Baffles 64 aid in guiding the rotational flow of liquid or slurry, brought about by the impeller, into an upward directional movement of liquid or slurry.

The bottom part 10 or the lower element 50 of the outer housing comprises at an inner perimeter 34 thereof a smoothly curved transition wall 36. The transition wall 36 will by virtue of its smoothly curved nature improve efficiency in directing the initially circulating liquid or slurry to an upwardly moving liquid or slurry.

Fig. 5 is a perspective view showing an impeller assembly of an embodiment of the pump of the present invention. Fig. 5 shows the lower element 50 or the bottom part 10 of the outer housing. On top of the lower element 50 or the bottom part 10 of the outer housing is arranged an impeller 28. The impeller comprises a number of radially extending impeller ribs arranged at a lower side 56 of the disk 52 of the impeller.

Also seen in fig. 5 is the smoothly curved transition wall arranged at the inner perimeter 34 of the lower element of the outer housing 2.

Fig. 6 is a perspective view showing a motor assembly of an embodiment of the pump of the present invention. As seen, the motor assembly is arranged on top of the impeller 28.

Fig. 7 is a perspective view showing a sealing of cables of a power supply to the motor of the pump of the present invention. Fig. 7 illustrates the outer housing 2 comprising the inner housing 14. In the inner housing is arranged an impeller 28 (not seen in fig. 7). The upper end 16 of the inner housing, defining the opening into the interior 46 of the inner housing 14, is closed with a top seal 70 sealing off the interior of the inner housing.

Two connecting pieces 72 for providing hydraulic pressurized liquid to the hydraulic motor arranged in the interior 46 of the inner housing 14 are present at the outer side of the seal 70. In the manufacture of the pump, the upper element 48 and the lower element 50 of the outer housing 2 and the inner housing 14 are being made separately. Subsequently the upper element 48 the outer housing 2 and the inner housing 14 are being welded to each other so that the inner housing 14 fits into the opening 20 in the side wall of the outer housing. Also, the lower element 50 of the outer housing 2 is being welded to the upper element 48 of the outer housing 2. 'Thereafter the motor is mounted in the interior 46 of the inner housing 14. Next the impeller assembly is mounted onto the driveshaft 26 of the motor 24.

Fig. 8 is a perspective view showing alternative embodiment of an impeller assembly of the pump of the present invention. Fig. 8 shows the lower element 50 or the bottom part 10 of the outer housing. On top of the lower element 50 or the bottom part 10 of the outer housing is arranged an impeller 28. The impeller comprises a number of radially extending impeller ribs 58 arranged at a lower side 56 of the disk 52 of the impeller.

The impeller 28 furthermore comprises a number of flow directional elements 63. The flow directional elements 63 are, in relation to the intended rotational direction of the impeller during use, being upwardly inclined in a rearward direction.

Fig. 8 shows that each flow directional element 63 is being arranged at an outer circumference of said impeller and are being arranged on a rib 58.

List of reference numerals

2 Outer housing of pump

4 Upper end of outer housing

6 Lower end of outer housing

8,8',8", 8" ' Side wall of outer housing

10 Bottom part of outer housing

12 Inlet opening for slurry

14 Inner housing of pump

16 Upper end of inner housing

18 Lower end of inner housing

20 Opening in side wall of outer housing

22 Position below opening in side wall of outer housing

23 Flow space for slurry

24 Motor

26 Driveshaft of motor

28 Impeller

30 Outlet opening for slurry

32 Impeller space

34 Inner perimeter of bottom part of outer housing

36 Smoothly curved transition wall of bottom part

38 Bottom of bottom part

40 Flange at outlet opening

42 Flange at inlet opening

44 Sealing or gasket

46 Interior of inner housing

48 Upper element of outer housing

50 Lower element of outer housing 52 Disk of impeller

54 Upper side of disk of impeller

56 Lower side of disk of impeller

58 Radially extending impeller rib of impeller 60 Leading surface impeller rib

62 Trailing surface of impeller rib

63 Flow directional element

64 Baffle

66 Removable plate at bottom part of outer housing 68 Cable or hose for motor

70 Top seal sealing off interior of inner housing

72 Connecting piece for a hydraulic hose

100 Pump