SLUDGE SEPARATOR

Abstract

A sludge separator, in particular for a vehicle washing system, has a sedimentation tank with a side wall and a base. The tank is divided into a lower sedimentation region, an intermediate region, and an upper fluid exchange region. The sludge separator has an inlet for supplying a fluid carrying solid particles into the tank, the inlet including an end section having an inlet opening. The inlet opening is arranged in the upper fluid exchange region and opens into the tank in a horizontal plane in a peripheral region of the tank. The sludge separator also has an outlet for discharging fluid out of the tank, the outlet having an outlet opening arranged in the upper fluid exchange region. The end section is orientated such that supplied fluid flows into the tank tangentially, and the outlet opening is arranged in a central region of the tank in a horizontal plane.

Claims

1-21. (canceled)

22. A sludge separator having a sedimentation tank that has a side wall and a base, wherein the sedimentation tank is divided in the vertical direction into a lower sedimentation region, an intermediate region and an upper fluid exchange region, an inlet for supplying a fluid carrying solid particles into the sedimentation tank, which inlet has an end section having an inlet opening, wherein the inlet opening is arranged in the upper fluid exchange region in the vertical direction and opens into the sedimentation tank in a horizontal plane in a peripheral region of the sedimentation tank, and an outlet for discharging fluid out of the sedimentation tank, which outlet has an outlet opening which is arranged in the upper fluid exchange region in the vertical direction, wherein the end section is orientated such that the supplied fluid flows into the sedimentation tank tangentially, wherein the outlet opening is arranged in a central region of the sedimentation tank in a horizontal plane and wherein several fins are arranged in the end section of the inlet.

23. The sludge separator according to claim 22, wherein the end section of the inlet is straight.

24. The sludge separator according to claim 22, wherein the end section of the inlet is orientated substantially tangentially in relation to the sedimentation tank.

25. The sludge separator according to claim 22, wherein the end section of the inlet is orientated substantially horizontally.

26. The sludge separator according to claim 22, wherein the fins are orientated parallel to each other.

27. The sludge separator according to claim 22, wherein the fins are each arranged in the end section in the flow direction of the fluid to be supplied.

28. The sludge separator according to claim 22, wherein the fins have even flow guiding surfaces, normals of which are each orientated orthogonally to the axial direction of the end section.

29. The sludge separator according to claim 22, wherein the fins divide the end section into several separate flow channels in a cross-section.

30. The sludge separator according to claim 22, wherein the fins are vertically orientated.

31. The sludge separator according to claim 22, wherein the extension of the fins in the axial direction of the end section is larger than in a cross-sectional direction of the end section.

32. The sludge separator according to claim 22, wherein the sludge separator only has the inlet opening.

33. The sludge separator according to claim 22, wherein the ratio of the smallest cross-sectional area of the inlet to the smallest cross-sectional area of the outlet is in a range of 2 to 10, in particular in a range of 4 to 8.

34. The sludge separator according to claim 22, wherein the outlet opening is orientated upwards.

35. The sludge separator according to claim 22, wherein the outlet opening is orientated downwards.

36. The sludge separator according to claim 22, wherein the outlet has an overflow opening which is arranged above the outlet opening.

37. The sludge separator according to claim 36, wherein the outlet has a vertically orientated first outlet pipe piece which has the outlet opening formed on one side and which merges on the other side into a horizontally orientated second outlet pipe piece, which in turn opens into a third outlet pipe piece which has a larger cross-section, and Wherein the third outlet pipe piece has a dam having an overflow edge and the overflow opening above the opening of the second outlet pipe piece.

38. The sludge separator according to claim 22, wherein the upper fluid exchange region occupies at most the upper 0% to 30%, in particular the upper 0% to 10%, of the height of the sedimentation tank in the vertical direction.

39. The sludge separator according to claim 22, wherein the inlet opening is arranged at approximately the same height as the outlet opening.

40. The sludge separator according to claim 22, wherein the outlet comprises a suction hose which is connected with the outlet opening in a gas-tight manner and wherein the suction hose opens on the outflow side into a discharge opening which is arranged underneath the outlet opening and above a base of the sedimentation tank.

41. A vehicle washing system having a sludge separator according to claim 22.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In the following, an exemplary embodiment of the sludge separator according to the invention is described with reference to the drawings:

[0049] The invention is now described using exemplary embodiments with reference to the drawings.

[0050] FIG. 1 shows an exemplary embodiment of the sludge separator according to the invention in a perspective view,

[0051] FIG. 2 shows a vertical cross-section of the exemplary embodiment of the sludge separator according to the invention,

[0052] FIG. 3 shows the exemplary embodiment of the sludge separator according to the invention in a view from above,

[0053] FIG. 4 shows the inlet of the exemplary embodiment of the sludge separator according to the invention in a first perspective view,

[0054] FIG. 5 shows the inlet of the exemplary embodiment of the sludge separator according to the invention in a second perspective view,

[0055] FIG. 6 shows the outlet of the exemplary embodiment of the sludge separator according to the invention of a first perspective view,

[0056] FIG. 7 shows the outlet of the exemplary embodiment of the sludge separator according to the invention of a second perspective view, and

[0057] FIG. 8 shows a vertical cross-section of a further exemplary embodiment of the sludge separator according to the invention.

DETAILED DESCRIPTION

[0058] The basic structure of the sludge separator 1 according to the invention is described in the following in relation to the FIGS. 1 to 3. The sludge separator 1 is part of a water circulation system of a gantry car wash. The fluid carrying solid particles supplied to the sludge separator 1 is therefore also referred to as dirty water in the following.

[0059] The sludge separator 1 comprises a cylindrical side wall 2, which is closed at the bottom by a circular disc-shaped base 3, so that a sedimentation tank 4 is formed in the interior of the sludge separator 1. At the top of the cylindrical side wall 4, the sludge separator 1 is closed by a cone lid 18.

[0060] In the vertical direction, the sedimentation tank 4 is separated into a lower sedimentation region A, an intermediate region B and an upper fluid exchange region C. The upper fluid exchange region C occupies, for example, the upper 0% to 30%, in particular the upper 0% to 10%, of the height of the sedimentation tank 4 in the vertical direction. The sedimentation region A occupies, for example, the lower 0% to 50%, in particular the lower 0% to 30%, of the height of the sedimentation tank 4 in the vertical direction.

[0061] In the upper fluid exchange region C, an inlet 5 and an outlet 7 are provided. To this end, a first opening 6 for the inlet 5 and a second opening 8 for the outlet 7 is arranged in the side wall 2. The inlet 5 has an inlet opening 9 via which dirty water containing solid particles can be supplied to the sedimentation tank 4. The outlet 7 has an outlet opening 11 via which fluid can be discharged from the sedimentation tank 4. Further details of the inlet 5 and of the outlet 7 are explained later.

[0062] As shown in FIG. 2, the inlet opening 9 is located at approximately the height of the outlet opening 11. In a state of equilibrium for supplied dirty water and discharged fluid, the inlet opening 9 is therefore arranged at the height of the level of fluid in the sedimentation tank 4. Both the inlet opening 9 and also the outlet opening 11 are, however, arranged in the upper part of the sludge separator 1, i.e. in the upper fluid exchange region C.

[0063] As shown in FIG. 3, a peripheral region D and a central region E are formed in a horizontal plane in which the inlet 9 and the outlet opening 11 are arranged. Starting from the central point Z of the horizontal cross-section of the sedimentation tank 4, the peripheral region D reaches from outside 0% to 30%, in particular from 0% to 10%, of the radius R in the direction of the central point Z and the central region E reaches from the central point Z to 40%, in particular 30%, of the radius R in the direction of the edge of the side wall 2 of the sedimentation tank 4. The radius R of the sedimentation tank 4 is 1 m in this case.

[0064] In the following, details of the inlet 5 are explained with reference to FIGS. 4 and 5.

[0065] The inlet 5 has a first inlet pipe piece 5-1. This first inlet pipe piece 5-1 is inserted with an opening into the first opening 6 of the side wall 2. It is orientated horizontally. On the other end of the first inlet pipe piece 5-1, a second inlet pipe piece 5-2 is connected, which is orientated vertically. A third inlet pipe piece 5-3 is connected to this second inlet pipe piece, which is also referred to as the end section 5-3 of the inlet 5. This end section 5-3 is orientated such that the dirty water supplied via the inlet 5 flows into the sedimentation tank 4 tangentially. It is furthermore orientated horizontally. The inlet pipe pieces 5-1 to 5-3 have a diameter of 150 mm. The inlet opening 9 is located in the outer peripheral region D of the sedimentation tank 4. Here, the normal of the surface formed by the inlet opening 9 is orientated tangentially to the side wall 2 of the sedimentation tank 4 and horizontally.

[0066] The sludge separator 1 only has one inlet opening 9 for supplying dirty water into the sludge separator 4.

[0067] Several fins 10 which are orientated parallel to each other are arranged in the end section 5-3. The end section 5-3 is cylinder-shaped, so that an axial direction of the end section 5-3 is defined. This axial direction is orientated horizontally and tangentially to the cylindrical side wall 2. The fins 10 are orientated vertically. They divide the end section 5-3 into several separate flow channels in a cross-section perpendicular to the axial direction of the end section 5-3. The fins10 have even flow guiding surfaces, the normals of which are each orientated orthogonally to the axial direction of the end section 5-3. The normals of the flow guiding surfaces of the fins 10 are therefore orientated horizontally. The end section 5-3 opens into the inlet opening 9. Here, the inlet opening 9 is separated into the openings that are formed by the flow channels, which are formed by the fins 10. The total area of the inlet opening 9 has the radius Rz. The normal of the surface of the inlet opening 9 is orientated horizontally and tangentially in relation to the cylindrical side wall 2.

[0068] The fins 10 are configured as thin, even plates, which are inserted vertically into the third inlet pipe piece 5-3, wherein their extension in the axial direction of the third inlet pipe piece 5-3 is larger than in the cross-sectional direction of the inlet pipe piece 5-3. The fins 10 ensure that the supplied dirty water, which tends to cause an autorotation by means of the angled arrangement of the three inlet pipe pieces 5-1 to 5-3, is guided in the end section 5-3 such that this autorotation is lost and the dirty water enters the sedimentation tank 4 at the inlet opening 9 in a tangential and horizontal manner, whereby a somewhat vertical speed component of the incoming dirty water is minimised.

[0069] With reference to FIGS. 6 and 7, details of the outlet 7 are described in the following:

[0070] The outlet 7 has a first outlet pipe piece 7-1 on one end of which the outlet opening 11 if formed. The first outlet pipe piece 7-1 is orientated vertically. The normal of the surface formed by the outlet opening 11 is orientated vertically. In the exemplary embodiment described here, the normal of the surface of the outlet opening 11 points downwards. Alternatively, the normal of the surface of the outlet opening 11 can, however, also point upwards. On the other end, the first outlet pipe piece 7-1 merges into a longer, second outlet pipe piece which is orientated horizontally. The second outlet pipe piece 7-2 merges, in turn, into a third outlet pipe piece 7-3 which has a larger cross-section. The end of the third outlet pipe piece 7-3 that is downstream is inserted into the second opening 8 of the side wall 2.

[0071] The interior diameter of the third outlet pipe piece 7-3 is 140 mm, the interior diameter of the outlet opening 11, of the first outlet pipe piece 7-1 and of the second outlet pipe piece 7-2 is respectively 25 mm, and the overflow edge 13 is 72 mm above the lower opening of the second outlet pipe piece 7-2 into the third outlet pipe piece 7-3.

[0072] The outlet 7 is inserted into the sludge separator 1 such that the outlet opening 11 is located in the central region E of the sedimentation tank 4. Fluid is therefore discharged from the sedimentation tank 4 from the centre via the outlet 7.

[0073] The outlet 7 has a smaller cross-section than the inlet 5, so that the dirty water 5 can be supplied at a higher volume rate via the inlet 5 than fluid is discharged from the sedimentation tank 4 via the outlet 7. In the exemplary embodiment of the sludge separator 1 described, the ratio of the smallest cross-section of the inlet 5 to the smallest cross-section of the outlet 7 is six.

[0074] During the operation of the sludge separator 1, dirty water is in particular intermittently supplied to the sedimentation tank 4, so that the level of fluid in the sedimentation tank 4 increases from a minimum height to a maximum height. As soon as the level of fluid exceeds the highest point of the outlet 7, fluid is simultaneously discharged out of the sedimentation tank 4 via the outlet 7. So that the level of fluid in the sedimentation tank 4 does not rise above a threshold height, an overflow opening 14 which is arranged above the outlet opening 11 is provided for the outlet 7. The overflow opening 14 is delimited by a dam 12 at the bottom, which forms an overflow edge 13. The dam 12 is located at the opening of the second outlet pipe piece 7-2 into the third outlet pipe piece 7-3, as is shown in FIGS. 6 and 7.

[0075] The upper fluid exchange region C (see FIG. 2) can be defined such that it reaches upwards to the overflow edge 13.

[0076] In order to adjust a minimum level of fluid, if no dirty water is supplied via the inlet 5, a suction hose 15 can be provided in a further exemplary embodiment that is shown in FIG. 8. This suction hose 15 is connected in a gas-tight manner with the outlet opening 11. The suction hose 15 can, for example, be closed at the opening of the second outlet pipe piece 7-2 into the third outlet pipe piece 7-3 at the opening of the second outlet pipe piece 7-2 (see FIG. 7).

[0077] On the outlet side, the suction hose 15 is then guided downwards outside the side wall 2, for example into a collecting tank. The suction hose 15 has an outlet opening 16 outside the side wall 2, which is arranged under the outlet opening 11. By means of the suction hose 15, the level of fluid in the sedimentation tank 4 can be determined by the syphon effect, via the height of the outlet opening 11, independently of the highest point of the outlet 7, if no more dirty water is supplied via the inlet 5. This level of fluid is then located at the height of the outlet opening 11, provided that the level of fluid in a collecting tank into which the outlet opening 16 opens, lies below the height of the outlet opening 11. If dirty water, for example from a gantry car wash, is then supplied to the sedimentation tank 4 again via the inlet 5, the level of fluid rises. This rising slows down if the level of fluid has exceeded the highest point of the outlet 7, since fluid is then discharged out of the sedimentation tank 4 via the outlet 7. The volume flow of the outlet 7 is, however, smaller than the volume flow of the dirty water supplied via the inlet 5, due to the smaller cross-sections. The rising of the level of fluid is therefore slowed down. Should the level of fluid exceed the height of the overflow edge 13, fluid drains off via the overflow opening 14. If the inflow of the dirty water via the inlet 5 ends, then the level of fluid sinks to the highest point of the outlet 7 or, if the suction hose 15 is used, to the outlet opening 11.

[0078] Flow simulations have been carried out for sludge separator 1, in order to identify which flows occur in the sedimentation tank 4. In the simulation it was assumed that fluid, more precisely a non-compressible two-phase fluid formed of air and water, is supplied via the inlet 5 at an ambient pressure of 1.013 bar and is discharged via the outlet 7. An adjustable mesh on the free water surface served as a basis for the simulation. The non-stationary simulation was carried out with time increments of 0.025 s over a simulation time of 180 s. Here, water flowed in at a rate of 200 l/min. A volume flow of up to 12.8l/min was set via the outlet 7, which is discharged from the sedimentation tank 4. The inlet opening was located at a height of 1.67 m. There were sedimented particles up to a height of 0.835 m above the base of the sedimentation tank 4.

[0079] The flow behaviour in the sedimentation tank 4, which was observed in the simulation, can be summarised as follows:

[0080] By means of the inflow of the fluid, the level of fluid increases. A rotational flow occurs during in-flow. A negative pressure area in the centre of the sedimentation tank 4 is thereby created, from which the fluid flowing out is discharged from the sedimentation tank 4 via the outlet opening 11. At the beginning of the inflow process, there is a minor vertical flow direction downwards next to the tangential flow direction in the sedimentation tank 4, which, however, reduces again as soon as the rotational flow has stabilised. If a volume of fluid has circled the sedimentation tank 4 peripherally, then there is a slight flow downwards when this volume of fluid meets with supplied fluid again.

[0081] If horizontal cross-sections of the sedimentation tank 4 are observed, there is substantially no vertical flow downwards or upwards from the central height of the sedimentation tank 4. Therefore, no sediment is transported upwards. Only 125 mm below the inlet opening 9, there is a vertical flow component when the fluid flows in, which decreases with increasing inflow duration. If a cross-section at the height of the inlet opening 9 is observed, it can be seen that a vertical flow component initially forms around the outer peripheral region, which, however, becomes lower as soon as a horizontally circulating inflow vortex has formed. In the centre at the outlet opening 11, a low-flow region forms that has substantially no vertical flow. A vertical flow occurs only by means of the fluid that enters the first outlet pipe piece 7-1 in the outlet 7 via the outlet opening 11.

LIST OF REFERENCE NUMERALS

[0082] 1 Sludge separator [0083] 2 Cylindrical side wall [0084] 3 Base [0085] 4 Sedimentation tank [0086] 5 Inlet [0087] 5-1 First inlet pipe piece [0088] 5-2 Second inlet pipe piece [0089] 5-3 Third inlet pipe piece; end section [0090] 6 First opening of the side wall [0091] 7 Outlet [0092] 7-1 First outlet pipe piece [0093] 7-2 Second outlet pipe piece [0094] 7-3 Third outlet pipe piece [0095] 8 Second opening of the side wall [0096] 9 Inlet opening [0097] 10 Fins [0098] 11 Outlet opening [0099] 12 Dam [0100] 13 Overflow edge [0101] 14 Overflow opening [0102] 15 Suction hose [0103] 16 Discharge opening [0104] 17 Sediment [0105] 18 Cone lid [0106] A Lower sediment region [0107] B Intermediate region [0108] C Upper fluid exchange region [0109] R Radius of the sedimentation tank [0110] Z Centre [0111] Rz Radius of the inlet opening