FILTERING AND SEPARATING DEVICE FOR LIQUID MIXTURES UNDER PRESSURE BY MEANS OF MEMBRANES

Abstract

A device for filtering and separating pressurized liquid mixtures by means of a membrane includes a substantially pressure-tight container in which the membranes are accommodated in a pressure-tight manner. The container has at least one intake for the mixture, as well as at least one outlet for the permeate separated from the mixture by means of the membranes, and at least one outlet for the retentate, also referred to as a concentrate. The pressure-tight container is made of plastic.

Claims

1.-22. (canceled)

23. A device for filtering and separating a pressurized liquid mixture by means of membranes, the device comprising a pressure-tight container in which the membranes are received in a pressure-tight manner, and at least one intake for the mixture, as well as at least one outlet for a permeate separated from the mixture by means of the membranes, and at least one outlet for a retentate, wherein the pressure-tight container is made of a plastic.

24. The device according to claim 23, wherein the plastic is composed of epoxy resin.

25. The device according to claim 23, wherein the plastic is composed of aramid [poly(1,4-phelene terephthalamide)].

26. The device according to claim 23, wherein the plastic is composed of Kevlar.

27. The device according to claim 23, wherein the plastic is reinforced by fibers.

28. The device according to claim 27, wherein the reinforcement fibers are composed of glass fibers.

29. The device according to claim 27, wherein the reinforcement fibers are composed of carbon fibers.

30. The device according to claim 23, wherein the plastic is composed of polyvinyl chloride (PVC).

31. The device according to claim 23, wherein the container forms a tube-shaped element with a substantially circular cross section.

32. The device according to claim 23, wherein the intake for the mixture that is to be separated is formed on a first end element that can be received in the container at a first open end.

33. The device according to claim 32, wherein the outlet for the permeate generated by or in the membrane elements is formed on a second end element that can be received in the container at a second open end.

34. The device according to claim 23, wherein the outlet for the retentate conducted through membrane elements and exiting the device is formed on a second end element that can be received in the container at a second open end.

35. The device according to claim 33, wherein a first pressure element and a second pressure element are each placed on top of the first and second end elements at the respective open ends, such that they bear on the first and second end element, respectively.

36. The device according to claim 33, wherein multiple modules comprised of membrane elements that can be inserted and received in an interior of the container can each be releasably secured at both open ends of the container with a sealing ring, which releasably engages in a respective circumferential groove formed on a circumference of the interior of the container.

37. The device according to claim 36, wherein a disk-shaped adjustment flange is located between a sealing ring at the first open end of the container and a first pressure element.

38. The device according to claim 37, wherein the adjustment flange has numerous axial threaded holes parallel to an axis of the container.

39. The device according to claim 33, wherein the first and second substantially plate-shaped end elements each has a groove encompassing its radial circumferences for receiving a sealing element.

40. The device according to claim 23, wherein the membranes are configured in the container in the form of a coiled membrane unit.

41. The device according to claim 23, wherein the membranes are configured in the container in the form of a flat membrane unit, wherein the flat membranes are stacked on top of one another to form a stack.

42. The device according to claim 23, wherein the membranes form a pillow membrane.

43. The device according to claim 40, wherein a tensioning bolt passes axially through the membrane unit.

44. The device according to claim 43, wherein the permeate exiting the membranes is conveyed to the permeate outlet through the tensioning bolt.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention shall now be described in greater detail in reference to the following schematic drawings and based on exemplary embodiments.

[0031] Therein:

[0032] FIG. 1 shows a sectional view of a device in which the membranes are arranged in the form of a coiled membrane unit,

[0033] FIG. 2 shows a top view of the first open end of the container, with a sealing ring in place, as well as an adjusting flange,

[0034] FIG. 3 shows a top view of the other, second open end of the container, with a sealing ring placed therein,

[0035] FIG. 4 shows a section of an actual coil membrane unit, as it can be placed in a container,

[0036] FIG. 5 shows a view from above (end surface) of the coil membrane unit from FIG. 4, and

[0037] FIG. 6 shows a perspective illustration of the first, or second, end element.

DETAILED DESCRIPTION OF THE INVENTION

[0038] Reference is first made to FIG. 1, which shows a sectional view of the device 10. It should first be noted that devices 10 of this type are known per se in the prior art, i.e. in terms of their fundamental construction, such that there is no need to go into specific details with regard to the description of the device 10. These devices 10 are used for filtering and separating liquid mixtures, wherein these liquid mixtures can be liquid or gaseous mixtures. The separation of the mixture 11 is obtained inside the device 10 by means of membranes 12, wherein these membranes 12 are polymer membranes known per se in the prior art, which are configured, e.g. for nanofiltration, ultrafiltration, or reverse osmosis.

[0039] The membranes 12 are received in a container 13, configured as a coiled membrane unit 34, as illustrated, e.g., in FIGS. 4 and 5. The device 10 can also be configured such that a flat membrane unit 35 can be accommodated therein. The flat membranes 35 are stacked on top of one another, such that the liquid mixture 11 that is to be separated normally passes over the stacked membranes 12 in a meandering pathway, and exits the device 10 at the end of the stack as a retentate 18, also referred to as a concentrate.

[0040] When a coiled membrane unit 34 is used in the container 13, the mixture 11 that is to be separated is conveyed in parallel, axially through the entire coil of the membrane, without internal deflection over the entire coiled membrane, wherein all of the retentate 18 also exits the coiled membrane unit 34 axially here, and is conducted out of the device 10.

[0041] The container 13 in which the coiled membrane unit 34, or the flat membrane unit 35 is inserted axially at a first open end 13 in the course of assembly is pressure-tight, such that, e.g. it can withstand internal pressures in the interior 25 of the container 13 of more than 120 bar, by means of which the pressurized liquid mixture 11 is introduced via an intake. These high operating pressures continuously act on the interior 25 of the container 13 during an intended operation of the device 10, wherein the liquid mixtures 11 introduced therein are conducted by means of this pressure over the membrane element 12. The retentate 18 is removed from the container 13 via an outlet 21.

[0042] The container forms a tube-shaped element, and has a substantially circular cross section, wherein the circular cross section provides the container 13 with a good radial stability.

[0043] Although in theory all of the known membrane structures are suitable for use in the device 10 according to the invention, so-called pillow membranes are used for the membrane elements 12, i.e. pillow membranes are used for both the embodiment of the coiled membrane unit and the embodiment of the flat membrane unit, i.e. for the individual pillow membranes used therein. The pillow membranes characteristically have a discharge opening, through which the permeate generated and collected in the pillow is discharged, which is the case with both the membrane in the form of a coiled membrane unit as well as for the pillow membranes in a flat membrane unit.

[0044] In the embodiment of the device 10 according to FIG. 1, the permeate 16 is collected in the middle, and conveyed to an outlet 15, the permeate outlet, wherein the permeate 18 is then discharged from the device 10 for further use.

[0045] Specific to the device 10 illustrated herein is that the intake for the mixture 11 that is to be separated is formed on a first end element 19 at the top of the container, that can be received therein at a first open end 130, wherein the outlet 14 for the permeate generated by or in the membrane elements 12 is formed on a second end element 20 that can be received in the container 13 at a second opening 131. The outlet 22 for the membrane element 12, and thus for the retentate 18 exiting the device 13 is likewise formed on a second end element 20 that can be received in the container 13 at a second open end 131.

[0046] The actual sealing pressure of the two end elements in the axial direction, parallel to an imaginary axis 132 passing through the container 13, which also forms the axis for the membrane unit 34, 35, or the tensioning bolt 37 passing axially through the container 13, is formed by first and second pressure elements 23, 24, wherein the two pressure elements 23, 24 are placed on top of the first and second end elements 19, 20 at the respective open ends 130, 131, such that they bear on the first and second end elements 19, 20, respectively.

[0047] The module comprising the coiled membrane unit 34 or flat membrane unit 35 composed of membrane elements is secured in the interior 25 of the container by means of a respective sealing ring 26, 27, after this module is inserted into the interior 25 through one of the open ends 130, 131 of the container 13, including the respective end and pressure elements, which can be releasably secured in the interior 25 in a respective circumferential groove 28, 29 formed in the interior 25 of the container 13. In a simple manner, the module comprised of pressure elements, end elements, and the membrane units, regardless of which type of membrane units are used, is releasably secured in the interior 25 of the container 13 by the sealing rings 26, 27.

[0048] A disk-shaped adjustment flange 30 is located between the sealing ring 26 at the first open end according to the illustration in FIG. 1 of the container 13, and the first pressure element 23. The adjustment flange 30 has numerous axial threaded holes 31 parallel to the axis 132 of the container 13, in which corresponding adjustment screws engage. As a result, the pressure elements 23, 24 and thus the first and second end elements 19, 20 can be slightly displaced axially by turning the adjustment screws, such that the axial force applied to the second end element 20 and the second pressure element 24 through the axial displacement of the screws is ensured by a central axial tube in the coiled membrane unit 34, or by an analogous central, axial tube element if a flat membrane unit 35 is used.

[0049] The adjustment element 31 bears on the first circumferential groove 28 in the interior of the container 13. This is the upper or lower groove 28, 29 in FIGS. 2 and 3, respectively, which show the first open end 130 in FIG. 2, and the second open end 131 in FIG. 3.

[0050] The end elements 19, 20, cf. the perspective illustration in FIG. 6, which are substantially plate-shaped, each have a groove 32 that encompasses their respective radial circumference, wherein this groove 32 accommodates a respective sealing element 33, cf. FIG. 1. The sealing elements 33 have a sealing lip cross section, although the sealing elements can also have other cross sections. The tensioning bolt 27 passing axially through the center of coiled membrane unit 34, or the flat membrane unit 35, analogously, can have axial grooves, not shown herein, through which the permeate 16 collected in the middle is conducted out of the device 10. In the illustrations of the coiled membrane unit 34 in FIGS. 4 and 5, the grooves themselves are formed in the central tensioning tube in the coiled membrane unit 34, such that the tensioning bolt 37 in this embodiment of the device 10 can have a smooth surface, without any circumferential grooves. The flow of the permeate 16 is indicated symbolically by the arrow in FIG. 1.

LIST OF REFERENCE SYMBOLS

[0051] 10 device [0052] 11 liquid mixture [0053] 12 membrane/membrane element [0054] 13 container [0055] 130 first open end [0056] 131 second open end [0057] 132 container axis [0058] 14 intake [0059] 15 outlet [0060] 16 permeate [0061] 18 retentate (concentrate) [0062] 19 first end element [0063] 20 second end element [0064] 21 outlet (retentate outlet) [0065] 23 first pressure element [0066] 24 second pressure element [0067] 25 interior (container) [0068] 26 sealing ring [0069] 27 sealing ring [0070] 28 inner circumferential groove (first) [0071] 29 inner circumferential groove (second) [0072] 30 adjustment flange [0073] 31 threaded hole [0074] 32 groove [0075] 33 sealing element [0076] 34 coiled membrane unit [0077] 35 flat membrane unit [0078] 36 membrane stack [0079] 37 tensioning bolt