Abstract
A membrane module and a membrane separating method for processing liquids, that includes: the liquid stream of a liquid to be processed is supplied, via an inlet, to a separating membrane designed as a flat membrane, such that a purified permeate passes the separating membrane; and the separating membrane is irradiated by UV light at least on the side of the separating membrane facing the inlet, the irradiation by UV light occurring by means of a mat and/or a fabric and/or a grating and/or a net, which consists, in full or in part, of optical waveguide fibers which out-couple light laterally, forming an irradiation element.
Claims
1. A membrane separation process for treating liquid comprising: feeding a liquid stream of the liquid to be treated to a separation membrane designed as a planar membrane via an inflow so that a purified permeate passes through the separation membrane, wherein the separation membrane is irradiated with UV light at least on a side of the separation membrane facing the inflow, wherein the irradiation with the UV light is effected by means of a noncrimp fabric and/or a woven fabric and/or a lattice and/or a mesh that completely or partially consists of an irradiation element formed optical fibers which laterally couple out light.
2. The membrane separation process as claimed in claim 1, wherein the separation membrane and the irradiation element are part of a membrane module, wherein a first partial stream passes through the separation membrane as purified permeate and leaves the membrane module, and a second partial stream is guided past the separation membrane and leaves the membrane module as unpurified retentate comprising an addition portion of the components retained by the separation membrane.
3. The membrane separation process as claimed in claim 2, wherein the UV light irradiation is effected by means of the irradiation element which is integrated into the membrane module and especially performs a function of a feed spacer.
4. The membrane separation process as claimed in claim 1, wherein the liquid stream is fed to the separation membrane designed as the planar membrane and dead-end filtration is carried out for the liquid be treated.
5. The membrane separation process as claimed in claim 1, wherein a part of the irradiation element that couples out UV light is positioned in an immediate vicinity of the separation membrane or rests thereon.
6. The membrane separation process as claimed in claim 1, wherein the irradiation element of the membrane has a conduit into a pressure tube of a membrane module and optionally a conduit into an interior of the membrane module.
7. The membrane separation process as claimed in claim 1, wherein the irradiation of the membrane via the irradiation element is effected in an intermittent, pulsed or continuous manner.
8. The membrane separation process as claimed in claim 1, wherein the irradiation is effected with constant irradiance or the irradiation is effected with varying irradiance.
9. The membrane separation process as claimed in claim 1, wherein the membrane separation process is a membrane separation process for treating drinking water, municipal wastewater, pre-treated municipal wastewater, industrial waters and/or saline waters.
10. The membrane separation process as claimed in claim 1, wherein the membrane separation process is a membrane separation process, a microfiltration process, an ultrafiltration process, a nanofiltration process, a forward osmosis process, a reverse osmosis process, a membrane distillation process, or an electrode ionization process.
11. A membrane module comprising a separation membrane, wherein the separation membrane has an irradiation element at least on a side across which liquid to be treated is supplied thereto, wherein part of the irradiation element is formed as a woven fabric and/or noncrimp fabric and/or lattice and/or mesh composed of UV-light-radiating optical fibers or as a woven fabric, noncrimp fabric, lattice or mesh composed of UV-light-radiating optical fibers and non-UV-light-radiating plastic fibers.
12. The membrane module as claimed in claim 11, wherein the membrane module comprises a coupling device for connection of a light source.
13. The membrane module as claimed in claim 11, wherein the irradiation element comprises a light guiding element for low-loss transmission of UV light through a conduit into the membrane module.
14. The membrane module as claimed in claim 11, wherein the irradiation element is designed in such a way that reflection is effected for lateral out-coupling of the light radiation.
15. The membrane module as claimed in claim 11, wherein the membrane module is designed as a spiral-wound module.
16. The membrane module as claimed in claim 11, wherein the irradiation element is designed as part of a feed spacer or as a feed spacer.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0082] FIG. 1 shows a schematic depiction of a membrane module with its material flows according to the prior art.
[0083] FIG. 2 shows the in-principle structure of a spiral-wound module according to the prior art.
[0084] FIG. 3 shows feed spacers in diamond and square form according to the prior art.
[0085] FIG. 4 shows the arrangement of a spiral-wound module in a pressure tube.
[0086] FIG. 5 shows a membrane module according to FIG. 1 containing a corresponding biofilm.
[0087] FIG. 6 shows schematic depictions of an irradiation element according to a first exemplary embodiment of the present invention.
[0088] FIG. 7 shows a schematic depiction of a membrane module according to a first exemplary embodiment of the present invention.
[0089] FIG. 8 shows an in-principle depiction of a membrane module according to the prior art having a planar membrane, with performance of dead-end filtration for liquid treatment.
[0090] FIG. 9 shows a membrane module according to an exemplary embodiment of the present invention in an in-principle depiction of a single optical fiber in a tube or capillary membrane.
[0091] FIG. 10 shows a membrane module according to an exemplary embodiment of the present invention in an in-principle depiction of a capillary membrane in a capillary module.
[0092] FIG. 11 shows schematic depictions of a section through a light out-coupling element according to an exemplary embodiment of the present invention as woven fabric and noncrimp fabric.
DETAILED DESCRIPTION
[0093] In the various figures, the same parts are always provided with the same reference signs.
[0094] FIGS. 1 to 5 have already been described above.
[0095] FIG. 6 (a-j) schematically depicts an irradiation element 26 in a preferred embodiment of the invention as a mesh fabric. The irradiation element 26 consists of a UV light source 26d, light in-coupling element 26c, light guiding element 26b and light out-coupling element 26a. When the invention is used in membrane modules 1, the light guiding element 26b is guided into the interior of the membrane module 1 via a conduit 27. FIGS. 6a-6j show various embodiments of the irradiation element 26. An irradiation element 26 can be realized according to one embodiment of the present invention. It is also conceivable to realize the irradiation element 26 according to a combination of the embodiments shown here.
[0096] FIG. 6(a) shows an irradiation element 26. The light out-coupling element 26a consists of non-UV-light-radiating linear elements (e.g., polypropylene fibers) 26e which run largely parallel to the flow direction in the feed-concentrate channel (x) and UV-light-radiating linear elements 26f (e.g., multimodal or monomodal glass fibers) which run at an angle (here, 90°) to said flow direction. Each linear element 26f is coupled to a linear light guiding element 26b, which in turn leads into the light in-coupling element 26c.
[0097] In an alternative embodiment (FIG. 6(g)), the UV-light-radiating linear elements 26f are connected to a single linear light guiding element 26b. It is likewise guided into the interior of the membrane module 1 through a conduit 27.
[0098] In a further alternative embodiment (FIG. 6(i)), the conduit 27 is directly integrated to the light in-coupling element 26c, and so no light guiding element 26b is used between conduit 27 and light in-coupling element 26c.
[0099] In a further alternative embodiment (FIG. 6(j)), UV-light-radiating linear elements 26f are designed in such a way that both ends of the element are connected either to the same light guiding element 26b or to different ones (as shown).
[0100] FIG. 6b shows an irradiation element 26. The light out-coupling element 26a consists of UV-light-radiating linear elements 26f which run largely parallel to the flow direction in the feed-concentrate channel (x) and non-UV-light-radiating linear elements 26e which run at an angle (here, 90°) to said flow direction.
[0101] FIG. 6c shows an irradiation element 26. The light out-coupling element 26a consists of non-UV-light-radiating linear elements 26e which run largely parallel to the flow direction in the feed-concentrate channel (x) and any desired sequence of UV-light-radiating linear elements 26f and non-UV-light-radiating linear elements 26e which run at an angle (here, 90°) to said flow direction.
[0102] FIG. 6d shows an irradiation element 26. The light out-coupling element consists of a combination of non-UV-light-radiating linear elements 26e and UV-light-radiating linear elements 26f. By way of example, an arrangement of non-UV-light-radiating linear elements 26e and UV-light-radiating linear elements 26f is chosen here analogously to the embodiment in FIG. 6a. As an alternative to the embodiments from FIGS. 6a-6c, an irradiation element can have one or more light sources, comprising a common light source 26d or multiple light sources 26d and separate light in-coupling elements 26c, light guiding elements and conduits 27 into the interior of the membrane module.
[0103] FIG. 6e shows an irradiation element 26. The design of the light out-coupling element 26a is largely analogous to the embodiment in FIG. 6(c). However, in contrast to the embodiment in FIG. 6c, individual UV-light-radiating regions 26f are not realized over the entire length of the irradiation element 26, but only partially over a limited length of the irradiation element 26.
[0104] FIG. 6f shows an irradiation element 26. The light out-coupling element 26a is formed with irregularly running linear UV-light-radiating linear elements 26f which are introduced in a lattice, mesh, noncrimp fabric and/or woven fabric composed of non-UV-light-radiating linear elements 26e.
[0105] In a preferred embodiment (FIG. 6(m)), the non-UV-light-radiating linear elements 26e are predominantly fixed to one another at intersecting sites 26g (e.g., by thermal processes such as heat setting or calendering and/or by means of adhesives (e.g., epoxy resins, polyurethane systems)) in order to achieve an increased mesh strength of the lattice, mesh, noncrimp fabric or woven fabric. UV-light-radiating linear elements 26f are only fixed at isolated sites 26h, mostly in the outer region of the light out-coupling element 26a, either to non-UV-light-radiating linear elements 26e or UV-light-radiating linear elements 26f (e.g., by thermal processes such as heat setting or calendering and/or by means of adhesives (e.g., epoxy resins, polyurethane systems)).
[0106] FIG. 6(h) shows an irradiation element 26. The light out-coupling element 26a is substantially composed of non-UV-light-radiating linear elements 26e which have one or more punctual light out-coupling sites 26a.
[0107] FIG. 6(k) shows an irradiation element 26. The light out-coupling element 26a is composed of linear elements 26e and 26f which are arranged at an angle (here, approximately +45° and −45° in relation to the flow direction of the inflow (x). The linear elements are arranged in such a way that they intersect and form a diamond shape.
[0108] FIG. 6(l) shows an irradiation element 26. The light out-coupling element 26a is composed of linear elements. The UV-light-radiating linear elements 26e
[0109] What is realized in FIG. 7 by way of example is the basic structure of the irradiation element 26 in a structure of a spiral-wound module 1 according to an exemplary embodiment of the present invention, analogous to that described in FIG. 3. In contrast to the prior art, what is used instead of a conventional feed spacer 4 in the form of a customary woven fabric mat formed from individual polymer strands is a feed spacer 4, designed as irradiation element 26, in the structure of the spiral-wound module 1. The feed spacer 4 designed as irradiation element 26 is, too, advantageously designed as a woven fabric (mat) having corresponding spacer elements, which in this case are composed of non-UV-light-radiating linear elements 26e and UV-light-radiating linear elements 26f.
[0110] The spiral-wound module 1 is formed or constructed from multiple membrane envelopes 5, which are wrapped around a permeate collecting tube 12 with separation by irradiation elements 26 and are enclosed by an outer shell element 20.
[0111] The conduit 27a of the light guiding elements 26b is effected in different ways depending on the embodiment of the irradiation element (see FIG. 6 (a-j)).
[0112] In the preferred embodiment, the conduit is effected through the shell element 20 and the pressure tube 21 (as depicted in FIG. 7).
[0113] In an alternative embodiment, the conduit is effected through the shell element 20 and the front plate 25 or the rear plate (not shown in FIG. 7) of a pressure tube. This embodiment is preferably used when the light guiding and light out-coupling elements of the irradiation element run at an angle (here, 90°) to the flow direction x (see, for example, FIG. 6(a)).
[0114] In a further embodiment, the conduit 27a is solely effected either through the pressure tube 21 or the front plate 25 or the rear plate (not shown) of a pressure tube. This third embodiment is preferably used when the light guiding and light out-coupling elements of the irradiation element run in the flow direction x (see, for example, FIG. 6(b)).
[0115] A combination of these two embodiments is possible, too. In this case, parts of the light guiding elements 26b are guided outside the pressure tube according to one of the embodiments.
[0116] FIG. 8 shows a membrane module 1 according to the prior art having a planar membrane 3, with performance of dead-end filtration for liquid treatment.
[0117] FIG. 9 shows a schematic depiction of a membrane module according to an exemplary embodiment of the present invention. What is proposed is a separation membrane 3 which is provided on its inflow side with an irradiation element L, preferably also in the form of a woven fabric mat 5 composed of optical fibers 4 or bundles produced therefrom—or such a woven fabric mat 5 is arranged on this side of the separation membrane 10. As already described in the embodiment relating to the spiral-wound module 1, UV light is supplied via individual optical fibers 4 which are connected to a corresponding UV light source 7 via a coupling module 6. Owing to the arrangement according to the invention of a fiber-optic woven fabric mat 5 on the inflow side on the separation membrane 3, the buildup of a corresponding filter cake K is greatly reduced or considerably delayed, meaning that cleaning and maintenance work or membrane exchange need not be done until considerably later.
[0118] FIG. 10 shows a membrane module according to an exemplary embodiment of the present invention in an in-principle depiction with a capillary membrane in capillary module 29. The light source 26d is connected to the light guiding element 26 via the light in-coupling element 26c, so that UV light can be coupled from the light source 26d into the light guiding element 26b. The light guiding element 26b guides the UV light into the capillary module 29 through the conduit 27 and into the capillary membrane 28 via light out-coupling elements 26a.
[0119] FIG. 11 (a-d) depicts a schematic section through a light out-coupling element in exemplary embodiments as a noncrimp fabric (FIG. 11 (a, b)) and woven fabric (FIG. 11 (c-e)).
[0120] FIG. 11a shows a schematic section through a light out-coupling element designed as a noncrimp fabric. Resting on a non-UV-light-radiating linear element 26e is a UV-light-radiating linear element 26f.
[0121] FIG. 11b shows a schematic section through a light out-coupling element designed as a noncrimp fabric. Resting on a UV-light-radiating linear element 26a is a UV-light-radiating linear element 26a.
[0122] FIG. 11c shows a schematic section through a light out-coupling element designed as a woven fabric. A UV-light-radiating linear element 26f is placed above or below a non-UV-light-radiating linear element 26e.
[0123] FIG. 11d shows a schematic section through a light out-coupling element designed as a woven fabric. A non-UV-light-radiating linear element 26e is placed above or below a UV-light-radiating linear element 26f.
[0124] FIG. 11e shows a schematic section through a light out-coupling element designed as a woven fabric. A UV-light-radiating linear element 26a is placed above or below a UV-light-radiating linear element 26f.
LIST OF REFERENCE SIGNS
[0125] 1 Membrane module (spiral-wound module) [0126] 2 Front side of the membrane module [0127] 3 Outflow side of the membrane module [0128] 4 Feed spacer [0129] 4a, 4b, 4c, 4d, 4e Linear elements of the feed spacer [0130] 5 Membrane (membrane envelope) [0131] 6 Front side of the membrane envelope [0132] 7 Upper side of the membrane envelope [0133] 8 Outflow side of the membrane envelope [0134] 9 Lower membrane layer of the membrane envelope [0135] 10 Permeate spacer [0136] 11 Upper membrane layer of the membrane envelope [0137] 12 Permeate collecting tube [0138] 13 Concentrate outflow [0139] 14 Permeate outflow [0140] 15 Anti-spacing device [0141] 17 Inflow [0142] 18 Permeate [0143] 19 Concentrate [0144] 20 Shell element [0145] 21 Pressure tube [0146] 22 Permeate port adapter [0147] 23 Interconnector [0148] 24 Pressure tube connector for the feed stream [0149] 25 Front plate of the pressure tube [0150] 26 Irradiation element [0151] 26a Light out-coupling element [0152] 26b Light guiding element [0153] 26c Light in-coupling element [0154] 26d UV light source [0155] 26e Non-UV-light-radiating linear elements [0156] 26f UV-light-radiating linear elements [0157] 26g Fixation of the non-UV-light-radiating linear elements 26e to one another [0158] 26h Fixation of the UV-light-radiating linear elements 26f to non-UV-light-radiating linear elements 26e or UV-light-radiating linear elements 26f [0159] 27 Conduit of the light guiding elements into a membrane module [0160] 27a Conduit of the light guiding elements through the pressure tube of a spiral-wound module [0161] 27b Conduit of the light guiding elements through the pressure tube of a capillary module [0162] 28 Capillary membrane [0163] 29 Capillary module (inside-out operation) [0164] K Filter cake (dead-end filtration)
