DRAINAGE PUMP ASSEMBLY

Abstract

A drainage pump assembly includes a drainage pump and an outlet conduit connected to the drainage pump. The drainage pump includes a pump chamber and is configured to pump liquid having solid matter. The outlet conduit includes a sedimentation trap having an inlet opening, an outlet opening and a belly located between the inlet opening and the outlet opening. A first conduit extends between the pump chamber of the drainage pump and the belly of the sedimentation trap. The first conduit includes a non-return valve. The outlet opening of the sedimentation trap is configured to be connected to a second conduit.

Claims

1.-14. (canceled)

15. A drainage pump assembly comprising a drainage pump and an outlet conduit connected to said drainage pump, the drainage pump comprising a pump chamber and being configured to pump liquid comprising solid matter, wherein the outlet conduit comprises: a sedimentation trap having an inlet opening, an outlet opening and a belly located between said inlet opening and said outlet opening, wherein the belly is closed to an outside of the sedimentation trap except via said inlet opening and said outlet opening, and a first conduit extending between the pump chamber of the drainage pump and the belly of the sedimentation trap, wherein said first conduit comprises a non-return valve, and wherein the outlet opening of the sedimentation trap is configured to be connected to a second conduit.

16. The drainage pump assembly according to claim 15, wherein the outlet conduit comprises the second conduit connected to the outlet opening of the sedimentation trap.

17. The drainage pump assembly according to claim 15, wherein the belly of the sedimentation trap has a belly volume V [dm.sup.3] that is equal to a factor X [dm] times a cross sectional area A [dm.sup.2] of the outlet opening of the sedimentation trap, wherein the factor X is equal to or greater than 2.

18. The drainage pump assembly according to claim 15, wherein the belly of the sedimentation trap has a belly volume V [dm.sup.3] that is equal to a factor X [dm] times a cross sectional area A [dm.sup.2] of the outlet opening of the sedimentation trap, wherein the factor X is equal to or less than 12.

19. The drainage pump assembly according to claim 15, wherein a center axis of the inlet opening of the sedimentation trap has a negative slope.

20. The drainage pump assembly according to claim 15, wherein a center axis of the outlet opening of the sedimentation trap has a positive slope.

21. The drainage pump assembly according to claim 15, wherein an inlet pipe fitting is connected to the inlet opening of the sedimentation trap.

22. The drainage pump assembly according to claim 21, wherein the inlet pipe fitting comprises an inlet opening, wherein a center axis of the inlet opening of the inlet pipe fitting extends in a vertical direction.

23. The drainage pump assembly according to claim 15, wherein an outlet pipe fitting is connected to the outlet opening of the sedimentation trap.

24. The drainage pump assembly according to claim 23, wherein the outlet pipe fitting comprises an outlet opening, wherein a center axis of the outlet opening of the outlet pipe fitting extends in a vertical direction.

25. The drainage pump assembly according to claim 15, wherein the non-return valve is connected to the inlet opening of the sedimentation trap.

26. The drainage pump assembly according to claim 25, wherein the non-return valve is constituted by a flap valve.

27. The drainage pump assembly according to claim 25, wherein a valve member of the non-return valve is biased towards an open position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A more complete understanding of the abovementioned and other features and advantages of the present invention will be apparent from the following detailed description of preferred embodiments in conjunction with the appended drawings, wherein:

[0016] FIG. 1 is a schematic illustration of an inventive drainage pump assembly located in a mine,

[0017] FIG. 2 is a schematic perspective view from above of a sedimentation trap according to a first embodiment,

[0018] FIG. 3 is a schematic perspective cross sectional view of the sedimentation trap according to FIG. 2,

[0019] FIG. 4 is a schematic perspective view of a non-return valve used in the sedimentation trap according to FIG. 2,

[0020] FIG. 5 is a schematic perspective view from above of a sedimentation trap according to a second embodiment,

[0021] FIG. 6 is a schematic cross sectional view of the sedimentation trap according to FIG. 5,

[0022] FIG. 7 is a schematic perspective view from above of a sedimentation trap according to a third embodiment, and

[0023] FIG. 8 is a schematic perspective cross sectional view of the sedimentation trap according to FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0024] The present invention relates specifically to the field of drainage pump assemblies especially configured for pumping liquid comprising solid matter, such as sand and stone material.

[0025] Reference is initially made to FIG. 1, disclosing a preferred embodiment of a drainage pump assembly, generally designated 1. The drainage pump assembly 1 comprises a drainage pump 2 and an outlet conduit, generally designated 3.

[0026] The disclosed drainage pump 2 comprises an inlet 4, a pump housing 5 and a pump outlet 6. Thereto, the drainage pump 2 comprises in a conventional way a hydraulic unit having a pump chamber (not disclosed), and comprises a drive unit (not disclosed). The drive unit and the pump chamber are arranged in the pump housing 5. The drive unit comprises an electrical motor arranged in the liquid tight pump housing 5, and a drive shaft extending from the electrical motor. An impeller (not disclosed) is arranged in the pump chamber and is driven in rotation by the drive shaft during operation of the drainage pump 2, wherein liquid is sucked into said inlet 4 and pumped out of said outlet 6 when the drainage pump 2 is active. The pump housing 5 and the impeller, and other essential components, are preferably made of metal. The electrical motor is powered via an electrical cable extending from a power supply, and the drainage pump 2 comprises a liquid tight lead-through receiving the electrical cable. According to an alternative embodiment, the drive unit comprises an internal combustion engine and a suitable gear box arrangement, wherein the drive shaft is driven in rotation by the internal combustion engine via said gear box arrangement. Drainage pump arrangements comprising internal combustion engines are conventionally used in dry installations, i.e. the entire pump is then located above the liquid surface and an inlet pipe extend from the pump inlet into the liquid.

[0027] The drainage pump 2 may also comprise a control unit, such as an Intelligent Drive or Variable Frequency Drive (VFD), located inside the liquid tight pump housing 4. The control unit is configured to control the operational speed of the drainage pump 2. The components of the drainage pump 2 are usually cold down by means of the liquid surrounding the drainage pump 2. The drainage pump 2 is designed and configured to be able to operate in a submerged configuration/position, i.e. during operation be located entirely under the liquid surface. However, it shall be realized that the submersible drainage pump 2 during operation must not be entirely located under the liquid surface but may continuously or occasionally be partly located above the liquid surface.

[0028] The drainage pump 2 is in the disclosed application located in a first/lower basin 7 and is intended to transport/pump liquid comprising solid matter from said first/lower basin 7 to a second/higher basin 8. Thereto, it shall be realized that it is conceivable that another drainage pump is located in the second basin 8 and intended to transport the liquid from the second basin 8 to a third basin, etc. The basins may be natural recesses/cavities/pits or prepared recesses/cavities/pits.

[0029] Reference is now also made to FIGS. 2-4 in order to disclose the essential features of the invention, wherein FIGS. 2-4 disclose a first embodiment of a sedimentation trap. The outlet conduit 3 comprises a sedimentation trap, generally designated 9, and a first conduit 10. The sedimentation trap 9 has an inlet opening 11, an outlet opening 12 and a belly 13 located between said inlet opening 11 and said outlet opening 12. The first conduit 10 extends between the pump chamber of the drainage pump 2 and the belly 13 of the sedimentation trap 9. Thereto, said first conduit 10 comprises a non-return valve, generally designated 14.

[0030] The belly 13 establishes a direct, i.e. unbroken, fluid communication path extending from the inlet opening 11 to the outlet opening 12. Thus, since the sedimentation trap 9 is part of the outlet conduit 3, the sedimentation trap 9 is configured in such a way that when the drainage pump 2 is active and liquid is conveyed through the outlet conduit 3, no liquid is stagnant in the sedimentation trap 9 or in the first conduit 10. All liquid entering the inlet opening 11 of the sedimentation trap 9 when the drainage pump 2 is active will pass directly through the belly 13 and leave the sedimentation trap 9 via the outlet opening 12 in one straight/rapid sequence, i.e. both the inflow to the sedimentation trap 9 and also the discharge from the sedimentation trap 9 is driven/operated by the drainage pump 2. Of course some turbulence may arise in the belly 13 of the sedimentation trap 9, i.e. the liquid flow is not necessarily laminar. The belly 13 of the sedimentation trap 9 is closed to the outside of the sedimentation trap 9 except via the inlet opening 11 and the outlet opening 12, i.e. delimited from the atmosphere/surroundings. Thus the closed belly 13 is configured to automatically convey liquid from the inlet opening 11 to the outlet opening 12.

[0031] The belly 13 is a structural formation arranged in such a way that liquid will become stagnant in the belly 13 and solid matter will settle in the belly 13 when the drainage pump 2 is not pumping liquid and the non-return valve 14 is closed. Thus, the belly 13 bulges in relation to the inlet opening 11 and the outlet opening 12. The belly 13 may also be denominated a sump, an interior cavity, a sink, a reservoir, i.e. a structural formation that is used to temporarily store/accumulate solid matter. The outlet opening 12 of the sedimentation trap 9 is configured to be connected to a second conduit 15, wherein the second conduit 15 is configured to transport the pumped liquid to said second basin 8. The non-return valve 14 is preferably arranged at the inlet opening 11 of the sedimentation trap 9. Another feasible location of the non-return valve is at the outlet opening 6 of the drainage pump 2.

[0032] In the disclosed embodiment, the non-return valve 14 is constituted by a flap valve and is connected to the inlet opening 11 of the sedimentation trap 9, wherein a valve disc 16 of the flap valve is located in or facing the belly 13 and a valve seat 17 of the flap valve is facing the belly 13. The valve seat 17 comprises a rim 17′ arranged to engage the valve disc 16 when the non-return valve is closed. The valve disc 16 and the valve seat 17 are preferably made of metal. The valve disc 16 is connected to the valve seat 17 via a hinge member 18. The hinge member 18 is preferably made of rubber, preferably vulcanized to the valve disc 16 and valve seat 17, respectively. It is also feasible to use an adhesive to attach the hinge member 18 to the valve disc 16 and valve seat 17, respectively. The valve disc 16 (or valve member) is preferably biased towards an open position. When the pump is deactivated the liquid in the outlet conduit will force the non-return valve 14 to close.

[0033] Preferably a centre axis of the inlet opening 11 of the sedimentation trap 9 has a negative slope. Said centre axis extends perpendicular to the cross section area of the inlet opening 11. The term negative slope is defined in view of the flow direction of the pumped liquid when the drainage pump 2 is active. Preferably a centre axis of the outlet opening 12 of the sedimentation trap 9 has a positive slope. Said centre axis extends perpendicular to the cross section area of the outlet opening 12. The term positive slope is defined in view of the flow direction of the pumped liquid when the drainage pump 2 is active. The diameter of the cross section area of the outlet opening 12 is preferably in the range 75-125 millimeters, however both smaller and larger diameters are conceivable.

[0034] According to the disclosed embodiment, an inlet pipe fitting 19 is connected to the inlet opening 11 of the sedimentation trap 9. The inlet pipe fitting 19 comprises an inlet opening 20, wherein a centre axis of the inlet opening 20 of the inlet pipe fitting 19 preferably extends in the vertical direction. Thereto, an outlet pipe fitting 21 is connected to the outlet opening 12 of the sedimentation trap 9. The outlet pipe fitting 21 comprises an outlet opening 22, wherein a centre axis of the outlet opening 22 of the outlet pipe fitting 21 extends in the vertical direction. The term vertical is defined having the sedimentation trap 9 standing in an operational position on a horizontal surface. According to an alternative embodiment, the centre axis of the inlet opening 20 of the inlet pipe fitting 19 is essentially parallel to the centre axis of the inlet opening 11 of the sedimentation trap 9. According to an alternative embodiment, the centre axis of the outlet opening 22 of the outlet pipe fitting 21 is essentially parallel to the centre axis of the outlet opening 12 of the sedimentation trap 9. Thus, the sedimentation trap 9 according to the first embodiment is generally U-shaped.

[0035] The belly 13 of the sedimentation trap 9 has a belly volume V [decimeter.sup.3] that is equal to a factor X [decimeter] times the cross sectional area A [decimeter.sup.2] of the outlet opening 12 of the sedimentation trap 9, wherein the factor X is equal to or greater than 2, and wherein the factor X is equal to or less than 12. Preferably, the factor X is equal to or greater than 5, and equal to or less than 9. The belly volume V has to be large enough to be able to receive the solid matter sliding backwards into the sedimentation trap 9 when the non-return valve 14 is closed and small enough not to generate a huge pressure drop of the pumped liquid when the drainage pump 2 is active and the pumped liquid enters the sedimentation trap 9. The belly volume V is equal to a maximum liquid volume that the sedimentation trap 9 is configured to hold/keep when a detached sedimentation trap 9 is standing in an operational position on a horizontal surface. Thus, provided that the detached sedimentation trap 9 is standing in an operational orientation on a horizontal surface, the belly volume V is delimited by the housing of the sedimentation trap 9 and a horizontal plane that is tangent to the lowest portion of the inlet opening 11 and the outlet opening 12 of the sedimentation trap 9.

[0036] During operation of the drainage pump 2, i.e. when the drainage pump 2 is active and transport liquid, the sedimentation trap 9 is configured in such a way that the pumped liquid shall fluidize the solid matter that has settled in the belly during the drainage pump 2 deactivation time or the time the non-return valve 14 as been closed. Thus, the pumped liquid flow shall be directed towards the location of the belly where the solid matter is intended to settle.

[0037] It shall be pointed out that the drainage pump 2 must not be completely deactivated for the non-return valve 14 to close the outlet conduit 3. The drainage pump 2 can be operated by means of a of the control unit. The control unit may be built-in into the drainage pump 2, i.e. preferably located into the pump top, or the drainage pump 2 may be operatively connected to an external control unit. In an operational mode wherein the operational speed of the drainage pump 2 is below the operational speed required to transport liquid through the outlet conduit 3, the non-return valve 3 will close due to the flow resistance from the liquid that is present in the outlet conduit 3.

[0038] Reference is now made to FIGS. 5 and 6, disclosing a second embodiment of the sedimentation trap 9, and only differences in view of the first embodiment will be discussed. The corresponding elements/components have been given the same reference number throughout the specification.

[0039] In the second embodiment of the sedimentation trap 9, the sedimentation trap 9 is arranged/designed as a maze. In the disclosed embodiment, a centre axis of the inlet opening 11 and a centre axis of the outlet opening 12 are essentially parallel and preferably aligned with each other. The sedimentation trap 9 comprises at least two lobes/windings 23 providing a generally helical shaped flow path from the inlet opening 11 to the outlet opening 12, wherein the helical shaped flow path comprises at least one full turn. In the disclosed embodiment the sedimentation trap 9 comprises three lobes 23. The advantage of having a helical shaped flow path is that the orientation of the sedimentation trap 9 does not have negative effect on the function of the sedimentation trap 9. The belly 13 will be arranged in at least one of the lobes 23.

[0040] Reference is now made to FIGS. 7 and 8, disclosing a third embodiment of the sedimentation trap 9, and only differences in view of the first embodiment will be discussed. The corresponding elements/components have been given the same reference number throughout the specification.

[0041] In the third embodiment of the sedimentation trap 9, the sedimentation trap 9 is arranged/designed as a cyclone. In the disclosed embodiment the sedimentation trap 9 comprises an inlet pipe 24 extending from the inlet opening 11 to the belly 13. The inlet pipe 24 is arranged above the belly 13, and the inlet pipe 24 is configured to create a swirling liquid flow in the belly 13. Thereto, a centre axis of the outlet opening 12 is arranged essentially vertical, and the outlet opening 12 is arranged at the top of the sedimentation trap 9. Thus, the disclosed embodiment provides a generally cyclone shaped liquid flow, entering the belly 13 in a tangential direction and leaving the belly 13 in an axial direction at the top of the sedimentation trap 9.

FEASIBLE MODIFICATIONS OF THE INVENTION

[0042] The invention is not limited only to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein, thus the present invention is defined by the wording of the appended claims and thus, the equipment may be modified in all kinds of ways within the scope of the appended claims.

[0043] It shall also be pointed out that all information about/concerning terms such as above, under, upper, lower, etc., shall be interpreted/read having the equipment oriented according to the figures, having the drawings oriented such that the references can be properly read. Thus, such terms only indicates mutual relations in the shown embodiments, which relations may be changed if the inventive equipment is provided with another structure/design.

[0044] It shall also be pointed out that even thus it is not explicitly stated that features from a specific embodiment may be combined with features from another embodiment, the combination shall be considered obvious, if the combination is possible.

[0045] Throughout this specification and the claims which follows, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or steps or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.