Device and a method for emptying a sewer well, a sewer well and a receiver of a sewer pumping station

Abstract

A device for emptying a sewer well that comprises a lower relatively heavy fraction and an upper relatively light fraction, the device comprising a lower suction nozzle with a lower suction opening for removing the lower fraction, said lower suction nozzle being connected to a pump, characterized in that at a position remote from the lower suction nozzle the device comprises an upper suction nozzle for removing the upper fraction.

Claims

1. A sewer pumping station device for emptying a sewer well that comprises a lower relatively heavy fraction and an upper relatively light fraction, the device comprising a lower suction nozzle with a lower suction opening for removing the lower fraction, said lower suction nozzle being connected to a pump via a lower discharge conduit of a lower discharge piping connected to the lower suction opening, wherein at a position remote from the lower suction nozzle the device comprises an upper suction nozzle for removing the upper fraction said upper suction nozzle being connected to an upper discharge conduit, wherein either the upper suction nozzle is connected by means of the upper discharge conduit to the lower discharge conduit of the lower discharge piping connected to the lower suction opening for simultaneously removing the lower fraction and the upper fraction by means of the pump, or or the upper discharge conduit comprises a discharge opening at the lower suction opening of the lower suction nozzle for simultaneously removing the lower fraction and the upper fraction through the lower discharge piping by means of the pump, and wherein the diameter of the upper discharge conduit is smaller than that of the lower discharge conduit, such that during said simultaneously removing an amount of the upper fraction will be smaller than an amount of the lower fraction because of pressure difference that occurs.

2. The sewer pumping station device as claimed in claim 1, wherein the pump is positioned downstream of the lower suction nozzle.

3. The sewer pumping station device as claimed in claim 1, wherein the pump is positioned in the lower suction nozzle.

4. The sewer pumping station device as claimed in claim 1, wherein an operable control valve is provided in the upper discharge conduit for selectively opening or closing the upper discharge conduit.

5. The sewer pumping station device as claimed in claim 1, wherein the upper suction nozzle comprises at least one supply opening.

6. The sewer pumping station device as claimed in claim 5, wherein the at least one supply opening of the upper suction nozzle has a width of maximum 15 cm.

7. The sewer pumping station device as claimed in claim 5, wherein the at least one supply opening of the upper suction nozzle is adapted for passage of PET bottles and objects of similar dimensions to the upper discharge conduit.

8. The sewer pumping station device as claimed in claim 1, wherein the pump is connected to a pressure sewer.

9. The sewer pumping station device as claimed in claim 1, wherein the upper suction nozzle is positioned at a fixed height above the lower suction nozzle.

10. The sewer pumping station device as claimed in claim 1, wherein the upper suction nozzle is positioned at a variable height above the lower suction nozzle.

11. A sewer well comprising a sewer pumping station device according to claim 1.

12. A receiving cellar of a sewage pumping station, comprising a sewer pumping station device according to claim 1.

13. A method for emptying a sewer well of a sewer pumping station with the sewer pumping station device according to claim 1, wherein the sewer well comprises a lower relatively heavy fraction and an upper relatively light fraction, the method comprising the step of sucking at least a part of the lower fraction by means of the pump through the lower suction nozzle with the lower suction opening near a bottom of the sewer well, wherein the method further comprises the step of sucking at least a part of the upper fraction by means of the pump through an upper suction nozzle located at a position remote from the lower suction nozzle, wherein the lower suction nozzle is connected with the lower discharge piping to the pump for removing the lower fraction through the lower discharge piping to the pump, the method further comprising the step of removing the upper fraction to the lower discharge piping by means of the upper discharge conduit from the upper suction nozzle for the simultaneous removal of the lower fraction and the upper fraction by means of the pump, and wherein due to the diameter of the upper discharge conduit being smaller than that of the lower discharge conduit, during said simultaneously removing, an amount of simultaneously removed upper fraction is smaller than an amount of simultaneously removed lower fraction because of pressure difference that occurs.

14. The method as claimed in claim 13, further comprising the step of supplying the lower and upper fractions removed from the sewer well to a pressure sewer by means of the pump.

15. The method according to claim 13, further comprising the step of transporting the lower and upper fractions removed from the sewer well by means of the pump to a sewage treatment plant.

16. The method according to claim 13, further comprising the steps of suctioning the lower fraction from the sewer well in a vertically upward direction by means of the lower suction nozzle, deflecting the lower fraction by means of a bend and supplying the upper fraction at the bend.

17. The method according to claim 13, comprising supplying flushing water at an upstream position to the upper discharge conduit for concurrent removal of the upper fraction and flushing water at a downstream position through the upper discharge conduit.

18. The method according to claim 13, comprising supplying flushing water to the upper discharge conduit for flushing flushing water therethrough.

Description

(1) The invention will be explained in more detail below with reference to a drawing. The drawing hereby shows in:

(2) FIG. 1 a schematic side view of a device according to the prior art,

(3) FIG. 2 a schematic side view of a device according to the invention,

(4) FIG. 3 a schematic perspective view of a device according to the invention,

(5) FIG. 4 a schematic side view of an alternative embodiment of a device according to the invention.

(6) In the figures, the same parts are designated by the same reference numerals. However, the parts necessary for a practical implementation of the invention are not all shown because of the simplicity of the representation.

(7) FIG. 1 schematically shows a device 1 for removing the contents of a sewer well 2 according to the prior art. This known and 5 generally used device 1 comprises one or more, in this case two, suction nozzles 3. The supply openings or suction apertures 4 of the suction nozzles are directed towards the bottom 5 of the sewer well 2. The contents of the sewer well 2 consist of a lower relatively heavy fraction 6 and an upper relatively light fraction 7. The lower fraction 6 consists largely of water and the upper relatively light fraction 7 consists largely of fats and oils. In FIG. 1, a wall 8 of the sewer well 2 is schematically indicated by dotted lines 8. The suction nozzles of the device 1 are passed through the wall 8 by means of discharge pipes 9 in order to be able to discharge the lower fraction from the sewer well 2. In the embodiment shown, the suction nozzles 3 form part of a bend 10 which is coupled to the discharge pipes, such that the discharge pipes can be guided horizontally through the wall 8 in a simple manner.

(8) FIG. 2 schematically shows a device 11 according to the invention in a sewer well 12. In the embodiment shown, the device 11 basically comprises the system known from the prior art, with two suction nozzles 13 in the embodiment shown. The suction nozzles 13 have supply openings or suction openings 14 directed towards the bottom 15 of the sewer well 12. The content of the sewer well 12 consists of a lower relatively heavy fraction 16 and an upper relatively light fraction 17. The lower fraction 16, just as in the sewer well 2 shown in FIG. 1, here also exists largely of water and the upper relatively light fraction 17 consists largely of fats and oils. In FIG. 2, a wall 18 of the sewer well 12 is schematically indicated by dotted lines 18. The suction nozzles 13 of the device 11 are passed through the wall 18 by means of lower discharge conduits 19 in order to enable the contents of the sewer well 12 to be discharged. In the embodiment shown, the suction 35 nozzles 13 form part of a bend 20 which is coupled to the lower discharge conduits 19, such that the lower discharge conduits 19 can be guided through the wall 18 in a simple manner with a slight incline. Actually, the lower suction nozzles 13 and the bend 20 actually form part of the lower discharge piping 29. In this description, the term lower discharge piping 29 relates to any part of the conduits from the suction openings 14 and further including the bend 20 and the lower discharge conduits 19.

(9) In addition to the suction nozzles 13 and the lower discharge conduits 19, an upper discharge conduit 21 is provided which is coupled with a first end 22 to the elbow 20 and which is coupled with an upper suction nozzle 24 at another end. a position where it can discharge the upper fraction 17 when the sewer pit 12 is sufficiently filled. A suction effect is applied to the lower suction nozzle 13 and the upper suction nozzle 24 by means of a pump. The lower fraction 16 is discharged via the lower suction nozzle 13 and the light fraction 17 is discharged via the upper suction nozzle 24. The amount of upper fraction 17 that is discharged together with the lower fraction 16 can be controlled by, for example, suitably selecting the diameter of the upper discharge conduit 21 relative to the diameter of the lower discharge conduits 19. If it is chosen to be smaller than that of the lower discharge conduit 19, the amount of the upper fraction 17 will be significantly smaller than the amount of the lower fraction 16 because of the pressure difference that occurs.

(10) Also, an adjustable valve 26 can be provided in the upper discharge conduit 21, whereby the passage through the upper discharge conduit 21 can be opened or closed to permit or disallow the discharge of light fraction 17, respectively. This allows the concentration of oils and fats in the discharge stream through the lower discharge conduit or discharge conduits 19 to be accurately controlled.

(11) In FIG. 2, a rinse water supply line 28 is clearly shown for supplying rinse water to the upper discharge conduit for joint removal of the upper fraction and rinse water through the upper discharge conduit. This reduces the chance of clogging.

(12) The valve 26 is preferably hydraulically operable to prevent electrical disturbances in the aqueous environment of the sewer well 2.

(13) FIG. 3 shows a schematic perspective view of the device 11 according to the invention. Here too, two suction nozzles 13 are shown, each of which is coupled to a lower discharge conduit 19. Both discharge conduits 19 are parallel and lead through a wall 18 of the sewer well 12. A pump (not shown) is located in a dry installation room on the other side of the wall 18. The actuation of the control valve or shut-off valve 26 is located adjacent to the upper discharge conduit 21 and is hydraulically actuated via a hydraulic conduit. The hydraulic conduit also leads through wall 18 to the dry installation room, where all electronics for controlling the pumps and the control valve 26 are located.

(14) FIG. 4 shows an alternative embodiment of a device 30 according to the present invention. In this embodiment all parts for removal of lower and upper fraction are situated inside the sewer well 31. In the embodiment shown, the device 30 comprises two lower suction nozzles 32, 33. Each suction nozzle 32, 33 is provided with a pump 34, 35 shortly downstream from the lower suction opening 36, 37 of each nozzle 32, 33. The pumps yield a suction force for sucking in lower fraction from the sewer well 31. The upper suction nozzle 38 for removing upper fraction 39 is connected to an upper discharge conduit 40 that splits into two sub-conduits 41, 42, each sub-conduit ending in an outlet opening 43, 44 close to the lower suction opening 36, 37 of each lower suction nozzle, respectively. As a result, the pump action sucks in lower fraction 45 and concurrently induces a suction force in the upper discharge conduit 40 resulting in removal of upper fraction 39 through the upper suction nozzle 38 towards and into each pump 34, 35.

(15) As a supporting feature, a flushing conduit 46, 47 is provided for adding flushing water into the upper discharge conduit 40, adding in an increased water flow towards the outlet openings of the sub-conduits. A flushing conduit 46, 47, optionally the same flushing conduit 46, 47 as mentioned previously, may be connected to the lower discharge piping 48, 49, preferably at a position downstream of the pump 34, 35, for adding in removal of lower 45, 35 and optionally upper 39, fraction.

(16) Valves 50, 51, 52 may be provided in any of the upper discharge conduit 40 and the sub-conduits 41, 42, respectively, for closing or opening these conduits. Also, the flushing conduits may be provided with valves 53, 54 for closing or opening the flushing conduits at will.

(17) The invention also extends to any combination of features described above independently of each other.

(18) The invention is not limited to the embodiments described above and shown in the figures. The invention is limited only by the appended claims.