Method for Operating a Wastewater-Lifting System

Abstract

A wastewater-lifting system and a method for operating a wastewater-lifting system guides wastewater loaded with bulky materials into a bulky material collection tank having at least one separating screen. During intake of wastewater, the bulky materials are retained in the bulky material collection tank and pre-cleaned wastewater passes into a liquid collection tank via a connection line and one or both of a pump and a bypass line connected to the connection line. During the wastewater intake a pivoting flap in the connection line closes flow to the pump except for a flushing cross section, and opens the bypass line. During a pumping operation, the pivoting flap opens the connection line from the pump and closes the bypass line.

Claims

1-14. (canceled)

15. A method for operating a wastewater-lifting system in which wastewater laden with bulky materials is guided through a bulky material-collecting tank having at least one separating screen arranged in its interior, comprising the steps of: during intake of wastewater, retaining the bulky materials the bulky material-collecting tank and feeding pre-cleaned wastewater from which the bulky materials have been removed via a connecting line to a liquid-collecting tank via one or both of a pump and a bypass line connected to the connecting line between the bulky material-collecting tank and the pump, wherein the connecting line contains a pivoting flap which, during the intake of wastewater, closes a portion the connecting line between the bypass line and the pump except for a flushing cross section configured to allow flushing flow around the pivoting flap toward the pump, and opens the bypass line to permit the pre-cleaned wastewater to flow to the liquid-collecting tank, and during a pumping process, closes the bypass line and opens the portion of the connecting line between the pump and the bypass line to permit the pump to pass pre-cleaned wastewater from the liquid-collecting tank through the connecting line to the bulky material-collecting tank.

16. The method as claimed in claim 15, wherein a flow rate of the wastewater laden with bulky materials flow and a flow rate of pre-cleaned wastewater generated by pump flow during the pumping process are substantially equal.

17. The method as claimed in claim 16, wherein a difference the between flow rate of the wastewater laden with bulky materials flow and the flow rate of pre-cleaned wastewater generated by pump flow during the pumping process is less than 40%.

18. The method as claimed in claim 16, wherein a difference the between flow rate of the wastewater laden with bulky materials flow and the flow rate of pre-cleaned wastewater generated by pump flow during the pumping process is less than 20%.

19. The method as claimed in claim 15, wherein the pivoting flap is connected to a flange of the bypass line. a flange of the connecting line, or to a flange of a flap connector arranged in the connecting line via a foot-side joint.

20. The method as claimed in claims 17, wherein during the intake of wastewater the pivoting flap is inclined in the connecting line at an angle which is not perpendicular to a direction of flow through the connecting line toward the pump.

21. The method as claimed in claim 18, wherein the angle is 10° to 30° relative to a plane perpendicular to the direction of flow through the connecting line to the pump.

22. The method as claimed in claim 19, wherein at least one stop limits the angle to not be perpendicular to the direction of flow through the connecting line to the pump.

23. The method as claimed in claim 15, wherein when the pivoting flap is closed toward the pump except for allowing the flushing flow around the pivoting flap during the intake of wastewater, the flushing cross section is at least in part formed by a bulged portion of the connecting line adjacent to the pivoting flap.

24. The method as claimed in claim 19, wherein the pivoting flap is arranged in an interior of the flap connector.

25. The method as claimed in claim 15, wherein the flap connector is arranged in a 3-way connector in the connecting line, and the bypass line is connected to the 3-way connector via a branch.

26. A wastewater-lifting system, comprising: a bulky material-collecting tank to receive wastewater laden with bulky materials and having at least one separating screen arranged in its interior configured to retain bulky material and allow flow of pre-cleaned wastewater separated from the bulky material out of the bulky material-collecting tank; pump connected on one side to the bulky material-collecting tank via a connecting line and on an opposite side to a liquid-collecting tank; a bypass line arranged between the connecting line and the liquid-collecting tank, the bypass line connecting to the connecting line between the bulky material-collecting tank and the pump; and a pivoting flap in the connecting line, wherein the wastewater-lifting system is configured such that during intake of wastewater, the wastewater pre-cleaned from the bulky material-collecting tank passes into the liquid-collecting tank via one or both of the pump and the bypass line, and the pivoting flap closes the connecting line at a location between the bypass line and the pump in a direction of the pump except for a flushing cross section configured to allow flushing flow around the pivoting flap toward the pump and opens the bypass line, and during a pumping process, the pre-cleaned wastewater being withdrawn from the liquid-collecting tank by the pump, opens the connecting line in a direction from the pump to the bulky material-collecting tank and closes the bypass line.

27. The wastewater-lifting system as claimed in claim 26, wherein the pivoting flap is connected to a flange of the bypass line. a flange of the connecting line, or to a flange of a flap connector arranged in the connecting line via a foot-side joint.

28. The wastewater-lifting system as claimed in claim 26, wherein the pivoting flap is arranged in an interior of the flap connector.

29. The wastewater-lifting system as claimed in claim 26, wherein when the pivoting flap is closed toward the pump except for allowing the flushing flow around the pivoting flap during the intake of wastewater, the flushing cross section is at least in part formed by a bulged portion of the connecting line adjacent to the pivoting flap.

30. The wastewater-lifting system as claimed in claim 26, wherein the flap connector is arranged in a 3-way connector in the connecting line, and the bypass line is connected to the 3-way connector via a branch.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows a wastewater-lifting system according to an embodiment of the invention and the operation thereof in an overview.

[0027] FIG. 2 shows a detail of the system as per FIG. 1 in the region of the flap connector during an intake of wastewater.

[0028] FIG. 3 shows the system as per FIG. 2 during the pumping process.

[0029] FIG. 4 shows the flap connector as per FIGS. 1-3 in section in a detail illustration.

DETAILED DESCRIPTION

[0030] The figures illustrate a wastewater-lifting system. This first of all has an inflow 1 for wastewater, which, via an inflow distributor 2 and a feed line 3, transfers the wastewater in each case into two bulky material-collecting tanks 4 in the exemplary embodiment. In the context of the exemplary embodiment, the wastewater-lifting system is of symmetrical configuration and has two bulky material-collecting tanks 4 and additionally also two discharge lines or connecting lines 5, via which the wastewater pre-cleaned with the aid of the bulky material-collecting tanks 4 passes into in each case one associated pump 6.

[0031] The bulky material-collecting tank 4 or the two bulky material-collecting tanks 4 in each case ensure that the wastewater flowing in altogether via the inflow 1 and the inflow distributor 2 and laden with solids is freed of the bulky materials or solids, which remain in the associated bulky material-collecting tank 4. The wastewater pre-cleaned in this manner then passes into the pump 6 via the discharge line 5 or connecting line, or directly into a liquid-collecting tank 8 via a bypass 7. The pre-cleaned wastewater flowing through the respective pump 6 passes, via a feed line 9, likewise into the liquid-collecting tank 8. The intake of the wastewater corresponds to this.

[0032] During a pumping or lifting process, the pre-cleaned wastewater is then sucked in from the liquid-collecting tank 8 via the feed line 9, in each case by the pump 6, and forced through the discharge line or connecting line 5 into the bulky material-collecting tank 4. Here, the pre-cleaned wastewater entrains the solids retained in the bulky material-collecting tank 4 and transfers the wastewater via a pressure line 11 to a further system, or generally for further treatment. In this way, during the subsequent pumping process, the bulky materials are released from the bulky material-collecting tank 4 and flushed practically without resistance into the pressure line 11.

[0033] From FIG. 1, it can be seen that both the pump 6 and the respective bulky material-collecting tank 4, in conjunction with the discharge line or connecting line 5, the feed line 9 and finally the bypass line 7, are altogether arranged outside the liquid-collecting tank 8 and are thus easily accessible. This applies in particular to the bulky material-collecting tank 4, which, according to the exemplary embodiment, has a closable opening (not illustrated in more detail in FIG. 1). Via said closable opening, the separating screen (not explicitly illustrated) that is situated in the interior of the bulky material-collecting tank 4 can be removed and reinserted. In this way, for the separating screen, maintenance tasks can be carried out or else an exchange can be realized.

[0034] What is then also essential to the invention is a pivoting flap 12, which can be seen in particular in FIGS. 2 and 3. According to the exemplary embodiment, the pivoting flap 12 is provided in the connecting line 5. In fact, the pivoting flap 12 can be found in the interior of a flap connector 13. The flap connector 13, including the pivoting flap 12 situated therein, works in the manner of a 3-way valve, as will be explained in more detail below. Moreover, the flap connector 13 is inserted as a 3-way connector into the connecting line 5. The flap connector 13 is coupled to the bypass line 7 via a branch.

[0035] During the intake of wastewater (illustrated in FIG. 2), the pivoting flap 12 in the connecting line 5 or in the flap connector 13 inserted into the connecting line 5 closes the connecting line 5 except for a flushing cross section 14. Said flushing cross section 14 is established as an annular space or annular cross section in that the pivoting flap 12, in the closed state illustrated in FIG. 2, is spaced apart from the inner wall of the flap connector 13. In fact, the connecting line 5 or the flap connector 13 provided in the connecting line 5 has in the region of the pivoting flap 12, in the state closed during the intake of wastewater, a bulged portion 15 which specifies the flushing cross section 14. That is to say, between the inner wall of the bulged portion 15 and the outer edge of the pivoting flap 12, in the state closed according to the illustration in FIG. 2 and during the intake of wastewater, there is established an arched annular space which altogether specifies and defines the flushing cross section 14.

[0036] Consequently, it is possible via the flushing cross section 14 for a specific fraction of the wastewater pre-cleaned with the aid of the bulky material-collecting tank 4 to flow through the pump 6, via the feed line 9 and finally into the liquid-collecting tank 8 during the intake of water according to the illustration in FIG. 2. In this way, both the pump 6 and the feed line 9 and the pivoting flap or shut-off flap 12 are flushed around or flushed free, with the result that, in this case, any residues are removed and the reliable functioning of the shut-off flap 12 is ensured even over long time scales.

[0037] During the pumping process according to the illustration in FIG. 3, however, the pre-cleaned wastewater sucked in from the liquid-collecting tank 8 via the feed line 9 with the aid of the pump 6 ensures that the pivoting flap 12 is transferred into the position as per FIG. 3. In this way, the pumping process ensures that the connecting line 5 or the flap connector 13 connected into the connecting line 5 is opened and, by contrast, the bypass line 7, with the aid of the pivoting flap 12, is closed. This is necessary in order that the pre-cleaned wastewater is not returned to the liquid-collecting tank 8 via the bypass line 7, but flows completely through the bulky material-collecting tank 4, during the pumping process. As a consequence of this, the pre-cleaned wastewater can detach the solids retained in the bulky material-collecting tank 4 from the separating screen and flush the wastewater out into the pressure line 11.

[0038] The pivoting flap 12 is connected via a foot-side joint 16 to a flange of the flap connector 13 in the exemplary embodiment. Consequently, the flap connector 13 with the pivoting flap 12 arranged in an articulated manner therein can, as a finished installation module, be installed into the connecting line 5 and connected to the bypass line 7 as illustrated. Moreover, the flap connector 13 in question can, according to requirement, be easily removed and for example cleaned.

[0039] The pivoting flap 12 is, without restriction, one which may have a metallic core and an outer plastic casing, as can be seen in FIG. 4. Moreover, in this context, the foot-side joint 16 ensures that the shut-off flap 12 can assume the positions illustrated in the comparison of FIGS. 2 and 3 without difficulty and without wear.

[0040] In fact, the shut-off flap or pivoting flap 12 is inclined in the connecting line 5 during the intake of wastewater illustrated in FIG. 2. Here, an angle α observed in this context of the inclination in relation to a horizontal H indicated in FIG. 2 can take values from approximately 10° to 30°. It can also be seen here that the pivoting flap 12 is limited in terms of its inclination with the aid of at least one stop. The stop may be an inner wall-side support ring for the pivoting flap 12 that is provided in the flap connector 13, as FIG. 4 in particular makes clear. Said support ring is realized in the region of or adjacent to the bulged portion 15. It can also be seen that the support ring, in conjunction with a lug-like projection on the bottom side of the pivoting flap 12, altogether specifies the flushing cross section 14 which is established. It goes without saying that other stops are also conceivable, provided that the flushing cross section 14 required during the intake of wastewater and necessary according to the invention remains as before.

[0041] Finally, within the context of the invention, the configuration is such that a wastewater flow associated with the wastewater intake and a pump flow associated with the pumping process are substantially equal in size. That is to say, the volume of inflowing wastewater during the intake of wastewater and the volume of the pumped pre-cleaned wastewater during the pumping process largely correspond. In the present case, this means that differences of less than 20% are observed between the two discussed and comparable volumes within a specified equal period of time, as has been described already in the introduction. This can be achieved and set without difficulty through the corresponding selection of the geometry of the connecting line 5, of the bypass line 7, of the pump 6 and also of the flap connector 13 and of the pivoting flap 12 as well as through selection of the pump 6 with corresponding throughflow cross section. As a consequence of this, according to the invention, in the interior of the liquid-collecting tank 8, there are observed practically no pressure peaks as in the prior art, and so the mechanical stability of said liquid-collecting tank is permanently increased.

[0042] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.