FILTER DEVICE

Description

[0001] The invention relates to a filter device according to the preamble of patent claim 1.

[0002] It is known that some suspensions, and in particular contaminated water, can be at least partially purified using a filter device comprising a porous filter. Typically, such a filter comprises a porous membrane through which a liquid to be filtered, in particular a suspension, is passed. Solid particles that do not pass through the pores of the membrane, known as retentate, remain on the membrane, while permeate passes through the membrane. Depending on the desired degree of purity of the filtrate, the permeate can be further purified of suspended substances using additional filters with smaller pore diameters.

[0003] To clean the membrane of the retentate, it is usually backwashed. In this process, a flushing fluid or previously purified solution flows through the membrane in the opposite direction, ideally releasing some of the retentate from the membrane.

[0004] A disadvantage of filter systems with porous filters is that conventional backwashing often produces inadequate results, and some filters can only be backwashed with additional effort. This frequently leads to so-called membrane fouling, a decrease in performance caused by increasing membrane resistance over time due to an increasingly thick retentate layer on the membrane. Membrane fouling is essentially caused by an increased particle concentration in the liquid being treated and the composition of dissolved constituents.

[0005] US 2002 / 0168758 A1 shows a bioreactor with a three-part arrangement for purifying blood or plasma, wherein cells are developed in an outer arrangement, blood or plasma flows in a middle arrangement and a fluid is arranged in an inner arrangement.

[0006] US 2013 / 0333178 A1 describes a bioreactor and a method for using the bioreactor. The bioreactor comprises three chambers and three channels connected to the chambers. A first chamber contains a substance to be purified, a second chamber contains a purifier, and a third chamber contains a liquid.

[0007] US 6,372,495 B1 shows a bioreactor for cultivating cells using a 3D matrix material.

[0008] US 5,968,358 A shows a method for washing a hollow fiber membrane used for blood dialysis.

[0009] US 5,738,792 A shows a method for filtering matter from a liquid solution through a membrane by means of a rotor within a concentric housing.

[0010] DE 2 243 723 A1 shows a reverse osmosis device with a tubular membrane and fluidized bed arrangement.

[0011] EP 0 748 250 A1 shows a membrane filter arrangement in which the fluid to be filtered is recirculated on the retentate side of a membrane filter and in which the filtered fluid is recirculated on the permeate side of the membrane filter in such a way that the two streams are passed simultaneously along the membrane filter.

[0012] US 4,787,982 A shows an assembly comprising a flexible tubular semipermeable membrane which is used in devices for osmosis, dialysis and electrodialysis.

[0013] US 2008 / 0000824 A1 shows a cross-flow filter for filtering a starting material.

[0014] The object of the invention is therefore to provide a filter device of the type mentioned at the outset, with which the disadvantages mentioned can be avoided and with which membrane fouling of at least one membrane of the double membrane arrangement is reduced.

[0015] According to the invention, this is achieved by the features of patent claim 1.

[0016] This results in the advantage that membrane fouling of at least one membrane of the at least one double membrane arrangement is reduced. Because the intermediate space comprises a flushing channel for flushing the intermediate space, the intermediate space can be easily and thoroughly flushed with a flushing fluid, whereby retentate is removed from at least one membrane. In order to flush essentially the entire intermediate space, it is provided that the flushing channel extends from at least one third connection for introducing a flushing fluid into the intermediate space to at least one fourth connection for discharging the flushing fluid from the intermediate space, and that the at least one third connection and the at least one fourth connection open into the intermediate space.Due to the improved removal of retentate and the resulting greatly reduced membrane fouling, the maintenance requirements of the filter device are also significantly reduced and a constant flow rate of the fluid to be filtered through the double membrane arrangement is enabled.

[0017] The invention further relates to a method for operating a filter device according to claim 11.

[0018] The invention therefore further has the object of specifying a method of the type mentioned at the outset, with which the disadvantages mentioned can be avoided and with which membrane fouling of at least one membrane of the double membrane arrangement is reduced.

[0019] According to the invention, this is achieved by the features of patent claim 11.

[0020] The advantages of the process correspond to the advantages of the filter mentioned above.

[0021] The subclaims relate to further advantageous embodiments of the invention.

[0022] Express reference is hereby made to the wording of the patent claims, whereby the patent claims are incorporated into the description at this point by reference and are deemed to be reproduced verbatim.

[0023] If at least one adsorption filter is arranged between the second membrane and the at least one second connection, the advantage is that, in addition to particles, trace substances such as pharmaceuticals, X-ray contrast media, personal care products, cleaning agents, plasticizers, biocides, microplastics, complexing agents, pesticides, flame retardants, veterinary pharmaceuticals and the metabolites of one or more of the aforementioned compounds can be filtered from a fluid, in particular from a liquid such as wastewater, by means of the filter device.

[0024] The combination of at least one double membrane arrangement with at least one adsorption filter in the filter device makes it possible to filter solid particles and trace substances from fluids, especially liquids, using a single filter device. This eliminates the need for individual, consecutively arranged filter modules and the need for piping systems connecting these individual filter modules, thus reducing space requirements and simplifying the control technology.

[0025] The invention will be described in more detail with reference to the accompanying drawings, in which only a preferred embodiment is shown by way of example. In the drawings: Fig. 1 a preferred embodiment of a filter device as a schematic sketch in an axonometric view; Fig. 2 the preferred embodiment of the filter device in a section in an axonometric view; Fig. 3the preferred embodiment of the filter device in a longitudinal section; Fig. 4 a schematic view of a dead-end filtration process in the preferred embodiment of the filter device in the longitudinal section; Fig. 5 a schematic view of a cross-flow filtration process in the preferred embodiment of the filter device in the longitudinal section; Fig. 6 a schematic view of a first tangential rinsing process of at least a first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 7 a schematic view of a second tangential rinsing process of the at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 8 a schematic view of a third tangential rinsing process of the at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 9a schematic view of a first tangential rinsing process of at least one intermediate space in the preferred embodiment of the filter device in the longitudinal section; Fig. 10 a schematic view of a second tangential rinsing process of the at least one intermediate space in the preferred embodiment of the filter device in the longitudinal section; Fig. 11 a schematic view of a tangential flushing process of at least one intermediate space simultaneously with a flushing of at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 12 a schematic view of a first vertical rinsing process of at least one intermediate space and simultaneously of at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 13a schematic view of a second vertical rinsing process of at least one intermediate space and simultaneously of at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 14 a schematic view of a third vertical rinsing process of at least one intermediate space and simultaneously at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 15 a schematic view of a fourth vertical rinsing process of at least one intermediate space and simultaneously at least one first membrane in the preferred embodiment of the filter device in the longitudinal section; Fig. 16 a schematic view of a first rinsing process via an adsorbent arranged between double membrane arrangements in the preferred embodiment of the filter device in the longitudinal section; Fig. 17a schematic view of a second rinsing process via an adsorbent arranged between double membrane arrangements in the preferred embodiment of the filter device in the longitudinal section and Fig. 18 a schematic view of a rinsing process of an adsorption filter.

[0026] The Fig. 1 to 18show at least parts of a preferred embodiment of a filter device 1 for filtering a fluid to be filtered with at least one double membrane arrangement 2, wherein the filter device 1 has at least one first connection 3 for introducing the fluid to be filtered into the at least one double membrane arrangement 2 and at least one second connection 4 for discharging a filtrate of the fluid to be filtered from the filter device 1, wherein the at least one double membrane arrangement 2 - seen in the flow direction of the fluid to be filtered - has a first membrane 5 and subsequently a second membrane 6, wherein an intermediate space 7 is formed between the first membrane 5 and the second membrane 6, wherein the intermediate space 7 comprises a flushing channel for flushing the intermediate space 7,that the flushing channel extends from at least one third connection 8 for introducing a flushing fluid into the intermediate space 7 to at least one fourth connection 9 for discharging the flushing fluid from the intermediate space 7, and that the at least one third connection 8 and the at least one fourth connection 9 open into the intermediate space 7.

[0027] Furthermore, a method for operating a filter device 1 is provided, wherein in a filtration process, a fluid to be filtered is passed through at least one first connection 3 through at least one double membrane arrangement 2 of the filter device 1, wherein the fluid to be filtered is then passed first through a first membrane 5 and subsequently through a second membrane 6 of the at least one double membrane arrangement 2, wherein an intermediate space 7 is formed between the first membrane 5 and the second membrane 6, wherein a filtrate of the fluid to be filtered is subsequently discharged from the filter device 1 via at least one second connection 4, wherein in a rinsing process, a rinsing fluid is introduced through at least one third connection 8 into a rinsing channel enclosed by the intermediate space 7, wherein the rinsing channel extends from the at least one third connection 8 to at least one fourth connection 9,wherein the flushing fluid is conducted through the flushing channel to the at least one fourth connection 9 and the intermediate space 7 is flushed, and the flushing fluid is discharged from the intermediate space 7 by means of the at least one fourth connection 9.

[0028] The filter device 1 serves to filter a fluid, in particular a liquid to be filtered. The filter device 1 has at least one double membrane arrangement 2. The filter device further has at least one first connection 3 for introducing the fluid to be filtered through the at least one double membrane arrangement 2 and at least one second connection 4 for discharging a filtrate of the fluid to be filtered from the filter device 1. The at least one double membrane arrangement 2 has - viewed in the flow direction of the fluid to be filtered - a first membrane 5 followed by a second membrane 6. After being introduced into the double membrane arrangement 2, the fluid to be filtered is then passed through a first membrane 5 and subsequently through a second membrane 6 of the at least one double membrane arrangement 2.As it flows through the first membrane 5, solid particles in particular are retained on the first membrane 5. These solid particles in particular have a diameter larger than the pore diameter of the first membrane 5. The retained solid particles, so-called retentate, remain on the first membrane 5, while permeate penetrates the first membrane 5 and enters a space 7 formed between the first membrane 5 and the second membrane 6. This permeate then flows to the second membrane 6, with further retentate being retained on the second membrane 6 and further permeate permeating the second membrane 6. This further permeate may already be the desired filtrate and be discharged from the filter device 1, but the further permeate can also be further filtered.This is particularly useful if, in addition to solid particles, trace substances are also to be removed from the fluid to be filtered.

[0029] The fluid to be filtered may preferably be a liquid.

[0030] The fluid to be filtered can also be a gas.

[0031] During a flushing process, a flushing fluid is introduced through at least one third port 8 into a flushing channel enclosed by the intermediate space 7, the flushing channel extending from the at least one third port 8 to at least one fourth port 9. The flushing fluid is conducted through the flushing channel to the at least one fourth port 9, thereby flushing substantially the entire intermediate space 7. The flushing fluid contaminated with retentate, in particular the further retentate from the second membrane 6, is then drained from the intermediate space 7 by means of the at least one fourth port 9.

[0032] This results in the advantage that membrane fouling of at least one membrane 5, 6 of the at least one double membrane arrangement 2 is reduced. Because the intermediate space 7 comprises a flushing channel for flushing the intermediate space 7, the intermediate space 7 can be easily and thoroughly flushed with a flushing fluid, whereby retentate is removed from at least one membrane 5, 6. In order to flush essentially the entire intermediate space 7, it is provided that the flushing channel extends from at least one third connection 8 for introducing a flushing fluid into the intermediate space 7 to at least one fourth connection 9 for discharging the flushing fluid from the intermediate space 7, and that the at least one third connection 8 and the at least one fourth connection 9 open into the intermediate space 7.Due to the improved removal of retentate and the resulting greatly reduced membrane fouling, the maintenance requirement of the filter device 1 is also significantly reduced and a constant flow rate of the fluid to be filtered through the double membrane arrangement 2 is enabled.

[0033] In times of increasing environmental awareness, the filtration of trace substances such as pharmaceuticals, X-ray contrast media, personal care products, cleaning agents, plasticizers, biocides, microplastics, complexing agents, pesticides, flame retardants, veterinary pharmaceuticals, and metabolites of the aforementioned compounds is becoming increasingly important in wastewater treatment. It is known that, in addition to the direct environmental damage caused by these substances, they can enter groundwater, where they can contaminate potential drinking water for humans and animals. Furthermore, contaminated water can be absorbed by plants. Frequent ingestion, even of small amounts, of water contaminated with these substances can trigger agglomeration effects of pollutants by plants and / or animals, resulting in various illnesses in humans and animals.Adsorption filters are typically used to filter trace substances. These adsorption filters are usually separate filter modules through which the fluid to be filtered is passed.

[0034] In order to filter particles and trace substances from fluids, in particular from liquids such as wastewater, at least one separate module with one or more porous filters and subsequently at least one separate module with one or more adsorption filters are usually used, which requires increased space and complex installation of the individual modules with additional lines.

[0035] Particularly preferably, at least one adsorption filter 10 can be arranged between the second membrane 6 and the at least one second connection 4. This provides the advantage that, in addition to particles, trace substances such as pharmaceuticals, X-ray contrast media, personal care products, cleaning agents, plasticizers, biocides, microplastics, complexing agents, pesticides, flame retardants, veterinary pharmaceuticals, and metabolites of one or more of the aforementioned compounds can be filtered from a fluid, in particular from a liquid such as wastewater, by means of the filter device 1.

[0036] The combination of at least one double membrane arrangement 2 with at least one adsorption filter 10 in the filter device 1 makes it possible to filter solid particles and trace substances from fluids, in particular liquids, using a single filter device 1. This eliminates the need for individual, consecutively arranged filter modules and the need for piping systems connecting these individual filter modules, thus reducing space requirements and simplifying control technology.

[0037] Preferably, the adsorption filter 10 may comprise activated carbon and / or zeolites. Activated carbon has strong adsorbing properties and a large internal surface area, allowing trace substances to be adsorbed particularly well. Zeolites are crystalline aluminosilicates that have a loose, three-dimensionally cross-linked structure and are used in particular as molecular sieves.

[0038] It may be intended that the zeolites are naturally occurring zeolites and / or synthetically produced zeolites.

[0039] It can be provided that the adsorption filter 10 comprises substances that have a physisorptive and / or chemisorptive effect.

[0040] It can preferably be provided that the filter device 1 comprises a housing 15, wherein the at least one double membrane arrangement 2 is arranged substantially in the housing 15.

[0041] Preferably, it can be provided that the filter device 1 has a plurality of double membrane arrangements 6, preferably four, in particular five, preferably seven, double membrane arrangements 6.

[0042] It can be particularly preferably provided that the adsorption filter 10 is formed by a space of the housing 15 surrounding the at least one double membrane arrangement 2 with adsorbent arranged in the space.

[0043] In this case, it can preferably be provided that the adsorbent essentially directly surrounds or envelops the at least one double membrane arrangement 2, in particular the second membrane 6 of the at least one double membrane arrangement 2.

[0044] In the figures described below, the flow direction of the rinsing fluid and / or the flow direction of the fluid to be filtered is illustrated by arrows.

[0045] Preferably, it can be provided that the adsorption filter 10 substantially fills the space of the housing 15 surrounding the at least one double membrane arrangement 2, which is shown by way of example in the Fig. 1 and 2 is shown.

[0046] Preferably, the at least one second connection 4 may include a police filter 11. The police filter 11 may be arranged, for example, screwed, in the second connection 4.

[0047] It can also be provided that the police filter 11 is arranged substantially immediately before the second connection 4.

[0048] Preferably, the backup filter 11 performs both a final cleaning function and a backup function. If one or more of the upstream filters fail, for example, due to damage, the backup filter 11 can at least partially filter the fluid to be filtered.

[0049] Preferably, it can be provided that the police filter 11 comprises activated carbon, in particular an activated carbon adsorber.

[0050] Furthermore, it can preferably be provided that a pore size of the first membrane 5 is larger than a pore size of the second membrane 6. It is advantageous here that retentate with larger particles is first retained at the first membrane 5 and then the further retentate with smaller particles is retained at the second membrane 6.

[0051] For this purpose, it can preferably be provided that a pore size of the first membrane 5 is at least 0.1 µm, in particular at least 1.5 µm, preferably at least 3 µm.

[0052] Preferably, it can be provided that a pore size of the first membrane 5 is a maximum of 4 µm, in particular a maximum of 5 µm, preferably a maximum of 6 µm.

[0053] It can further be provided that a pore size of the second membrane 6 is at least 0.01 µm, in particular at least 0.025 µm, preferably at least 0.05 µm.

[0054] Furthermore, it can be provided that a pore size of the second membrane 6 is a maximum of 0.06 µm, in particular a maximum of 0.08 µm, preferably a maximum of 0.1 µm.

[0055] Due to the different pore sizes of the first membrane 5 and the second membrane 6, particles of different sizes can be selectively filtered at the respective membranes 5, 6. This prevents a thick layer of retentate, also known as a filter cake, with different particle sizes from rapidly forming, as occurs, for example, when using a single membrane with a small pore size, and thus promotes membrane fouling.

[0056] Preferably, the first membrane 5 and / or the second membrane 6 may comprise at least one thermoplastic, in particular at least one polysulfone and / or at least one polyestersulfone and / or at least one polyvinylidene fluoride and / or at least one polypropylene and / or at least one polyamide. Advantageously, the first membrane 5 and / or the second membrane 6 are easy to manufacture and chemically resistant to some solvents and / or acids and / or alkalis.

[0057] Particularly preferably, it can be provided that the first membrane 5 and / or the second membrane 6 comprise at least one ceramic material, in particular Al 2 O 3 and / or TiO 2 and / or ZrO 2 . It is advantageous here that the first membrane 5 and / or the second membrane 6 are particularly robust, particularly mechanically, and easy to clean.

[0058] Preferably, it can be provided that a thickness of the first membrane 5 and / or the second membrane 6 is at least 8 µm, preferably at least 100 µm, in particular at least 150 µm.

[0059] Particularly preferably, it can be provided that the thickness of the first membrane 5 and / or the second membrane 6 is a maximum of 200 µm, in particular a maximum of 300 µm, preferably a maximum of 400 µm.

[0060] It has been shown that particularly good filtration can be achieved with the previously mentioned thicknesses of the first membrane 5 and / or the second membrane 6.

[0061] Particularly preferably, it can be provided that the first membrane 5 and the second membrane 6 are tubular, wherein the first membrane 5 is arranged substantially within the space spanned by the second membrane 6, whereby the intermediate space 7 can be formed particularly easily.

[0062] Particularly preferably, it can be provided that the first membrane 5 is arranged coaxially to the second membrane 6.

[0063] The advantage here is that this arrangement of the membranes 5, 6 is particularly space-saving and, despite the small space requirement of the membranes 5, 6, a large surface area of ​​the membranes 5, 6 is achieved.

[0064] It can also preferably be provided that the first membrane 5 and second membrane 6 are formed substantially hollow cylindrical.

[0065] For this purpose, it can preferably be provided that the first membrane 5 has a smaller diameter than the second membrane 6, which is exemplified in Fig. 2 is illustrated.

[0066] Alternatively, the first membrane 5 and / or the second membrane 6 can be plate-shaped. This allows for a particularly simple structure.

[0067] Preferably, it can be provided that a width of the intermediate space 7 is at least 0.5 mm, preferably at least 1.5 mm, in particular at least 3 mm.

[0068] It can also preferably be provided that a width of the intermediate space 7 is a maximum of 6 mm, in particular a maximum of 5 mm, preferably a maximum of 4 mm.

[0069] It has been shown that with the above-mentioned widths of the intermediate space 7, the intermediate space 7 can be particularly well rinsed with a rinsing fluid.

[0070] Particularly preferably, it can be provided that the filter device 1 has an inflow space 14, wherein the at least one first connection 3 opens into the inflow space 14, wherein the first membrane 5 extends away from the inflow space 14, which is shown for example in the Fig. 1 and 3 to 18 is shown.

[0071] Preferably, it can be provided that in a further flushing process, the flushing fluid first flows through the at least one first connection 3 into the inflow space 14 of the filter device 1, wherein the first membrane 5 is tubular and opens into the inflow space 14, wherein the flushing fluid then flows into an interior space 12 of the first membrane 5 and flushes through the interior space 12, wherein the interior space 12 extends from the at least one first connection 3 to at least one fifth connection 13, wherein the flushing fluid is discharged from the at least one fifth connection 13 out of the filter device 1, which is shown by way of example in the Fig.6 to 8 In these cases, in the Fig. 6 to 8 In the so-called tangential rinsing processes shown as examples, the retentate is removed in particular from the inner wall of the first membrane 5.

[0072] Tangential here means that the rinsing fluid or the fluid to be filtered flows through the intermediate space 7 and / or the interior space 12 of the first membrane 5 without essentially penetrating through the first membrane 5 or through the second membrane 6.

[0073] Preferably, it can be provided that a plurality of first membranes 5 of a plurality of double membrane arrangements 2 open into the inflow space 14, which results in the advantage that the fluid to be filtered or the rinsing fluid can be distributed evenly between the plurality of first membranes 5 of the plurality of double membrane arrangements 2.

[0074] It can preferably be provided that the interior space 12 of the first membrane 5 comprises a fluid channel, wherein the fluid channel extends from the at least one first connection 3 to the at least one fifth connection 13.

[0075] It can also be provided that at least one adsorption filter 10 is arranged in the interior space 12 of the first membrane 5.

[0076] It can further be provided that the adsorption filter 10 essentially fills the volume of the interior space 12 of the first membrane 5.

[0077] It can also be provided that at least one adsorption filter 10 is arranged in the intermediate space 7.

[0078] It can further be provided that the adsorption filter 10 essentially fills the volume of the intermediate space 7.

[0079] Furthermore, it can be particularly preferably provided that a flushing chamber 16 is arranged adjacent to the inflow chamber 14, wherein the first membrane 5 penetrates the flushing chamber 16 and the intermediate space 7 opens into the flushing chamber 16, which is exemplified in the Fig. 3 to 18 is shown.

[0080] Preferably, it can be provided that several intermediate spaces 7 of several double membrane arrangements 2 open into the rinsing chamber 16, whereby rinsing fluid can be easily introduced into the several intermediate spaces 7.

[0081] Particularly preferably, the rinsing process can be performed during an interruption of the filtration process and / or after the filtration process. Depending on the amount of fluid to be filtered and the degree of contamination of the fluid to be filtered with solid particles and / or trace substances, and the associated thickness of the retentate layer on the first membrane 5 and / or on the second membrane 6, this layer can be removed by a rinsing process, thereby preventing membrane fouling.

[0082] Particularly preferably, it can be provided that the filter device 1 is constructed essentially symmetrically, which is exemplified in Fig. 3 is shown. Fig. 3shows a filter device 1 with a housing 15, a plurality of double membrane assemblies 2, comprising a plurality of first membranes 5 and a plurality of second membranes 6, as well as four first and fifth connections 3, 13, wherein two of the first and fifth connections 3, 13 open into an inflow chamber 14 and the other two of the first and fifth connections 3, 13 open into a further inflow chamber 14, a plurality of intermediate spaces 7 formed by the first membranes 5 and by the second membranes 6, which open into a rinsing chamber 16 and into a further rinsing chamber 16, four third and fourth connections 8, 9, wherein two third and fourth connections 8, 9 open into the rinsing chamber 16 and two third and fourth connections 8, 9 open into a further rinsing chamber 16, two opposite second connections 4, each with two police filters 11 and adsorbent arranged between the double membrane assemblies 2,which forms an adsorption filter 10.,

[0083] This creates a space-saving multi-barrier device with which both solid particles and trace substances can be filtered from fluids, especially from wastewater.

[0084] It can preferably be provided that the first connection 3 can be exchanged with the fifth connection 13 and the third connection 8 with the fourth connection 9. Due to the symmetry of the Fig. 1 and Fig. 3 The basic function of the filter device 1 shown as an example remains the same when changing the connection.

[0085] Preferably, it can be provided that the first connection 3 and / or the second connection 4 and / or the third connection 8 and / or the fourth connection 9 and / or the fifth connection 13 are present twice in the filter device 1. Redundancy during one or more flushing processes is advantageous here.

[0086] For the sake of clarity, the connections 3, 4, 8, 9 and 13 are designated with a corresponding reference symbol depending on their use, wherein as a rule the first connection 3 designates an inflow to preferably an interior space 12 of at least one first membrane 5, in particular to an inflow space 14, the second connection 4 designates an inflow or outflow into the housing 15 or out of the housing 15, the third connection 8 designates an inflow to at least one intermediate space 7, in particular to a rinsing space 16, the fourth connection 9 designates an outflow from at least one intermediate space 7, in particular from a rinsing space 16, and the fifth connection 13 designates an outflow from preferably an interior space 12 of at least one first membrane 5, in particular from an inflow space 14, unless stated otherwise.

[0087] Due to the preferred symmetry of the filter device 1, the exchange of the aforementioned connections for introducing or discharging fluids into or from the filter device 1 is possible, thereby enabling different types of filtration and rinsing processes, as shown by way of example in the following filtration and rinsing processes.

[0088] The "X" when connecting to the Fig. 4 to 18 means that this port is blocked for this filtration or rinsing process.

[0089] It can preferably be provided that the filter device 1 essentially has six areas, - viewed from the outside inwards - two inflow spaces 14, each with at least one connection for introducing or discharging a fluid to be filtered or a rinsing fluid into or from the inflow space 14 or the filter device 1, for example at least one first connection 3 and at least one fifth connection 13, each adjacent to the inflow spaces 14, a rinsing space 16, each with at least one third connection 8 and / or a fourth connection 9, and a central part with at least one second connection 4.

[0090] For this purpose, it can preferably be provided that the filter device 1 is rotationally symmetrical about an imaginary axis through the second connection 4. This results in the advantage that, depending on the installation situation, the filter device 1 can be operated essentially the same from a left side and a right side.

[0091] Fig. 4shows, by way of example, a schematic view of a dead-end filtration process, in which the fluid to be filtered is introduced into an inflow chamber 14 of the filter device 1 through two diagonally opposite first connections 3 and is then passed into the first membranes 5 of a plurality of double membrane arrangements 2, wherein retentate is retained at the first membranes 5 and permeate penetrates the first membranes 5, wherein the permeate reaches the intermediate spaces 7 formed by the first membranes 5 with the second membranes 6, wherein further retentate is retained at the second membranes 6 and further permeate penetrates the second membranes 6, wherein the further permeate reaches the adsorption filter 10 arranged essentially directly on the double membrane arrangements 2, wherein the adsorption filter 10 removes trace substances, if present,from the further permeate and the filtrate reaches the second connection 4 and is discharged from the filter device 1. It can preferably be provided that the second connection 4 has a police filter 11.

[0092] Fig. 5shows, by way of example, a schematic view of a cross-flow filtration process in which the fluid to be filtered is introduced into an inflow chamber 14 through a first connection 3 and is then passed into the first membranes 5 of a plurality of double membrane arrangements 2, wherein retentate is retained at the first membranes 5 and permeate penetrates the first membranes 5, wherein the permeate reaches the spaces 7 formed by the first membranes 5 and the second membranes 6, wherein further retentate is retained at the second membranes 6 and further permeate penetrates the second membranes 6, wherein the further permeate reaches the adsorption filter 10 arranged essentially directly on the double membrane arrangements 2, wherein the adsorption filter 10 can filter trace substances, if present, from the further permeate and the filtrate reaches the second connection 4,from which the filtrate is discharged from the filter device 1, while fluid contaminated with retentate, in particular from the inner wall of the first membrane 5, is discharged from the filter device 1 through the fifth connection 13. For this purpose, the retentate can, in particular, have a large pore diameter. Here, too, it can preferably be provided that the second connection 4 has a police filter 11, or that a police filter 11 is arranged directly at the second connection 4.

[0093] The Figs. 9 and 10show, by way of example, tangential flushing processes of several intermediate spaces 7 of several double membrane arrangements 2. Here, the flushing fluid is preferably introduced into the flushing chamber 16 through at least one third connection 8, wherein the flushing fluid is subsequently directed into the flushing channels of the individual intermediate spaces 7 and removes retentate, in particular from the inner wall of the second membranes 6. The mixture of retentate and flushing fluid is discharged from the filter device 1 by means of at least one fourth connection 9.

[0094] Fig: 11shows, by way of example, a schematic view of a tangential flushing process of at least one intermediate space 7 simultaneously with a flushing of at least one first membrane 5. In this case, the flushing fluid is preferably introduced into the filter device 1 simultaneously through a first connection 3 and a third connection 8, in particular one located opposite it. Flushing fluid introduced from the third connection 8 flushes, as described above, in particular tangentially, the at least one intermediate space 7, and flushing fluid introduced from the first connection 3 flushes, as described above, in particular tangentially, the interior space 12 of the first membrane 5. It can also preferably be provided that retentate, which is also located on a side of the first membrane 5 facing the intermediate space 7, is removed during the flushing process.This retentate can be formed, for example, by turbulence of the fluid to be filtered immediately after the pores or by growth effects on particles that are retained by the first membrane 5.

[0095] In this case, it can be provided that the at least one intermediate space 7 and the interior space 12 of the at least one first membrane 5 are flushed simultaneously.

[0096] Alternatively, it can be provided that the at least one intermediate space 7 and the interior space 12 of the at least one first membrane 5 are rinsed one after the other.

[0097] It can also be provided that an intermediate space 7 of a double membrane arrangement 2 and the interior space 12 of a first membrane 5 of another double membrane arrangement 2 are flushed simultaneously or sequentially. For example, this can be selectively adjusted by means of the flushing fluid pressure at the first port 3 and at the third port 8.

[0098] It can preferably be provided that flushing fluid contaminated with solid particles or trace substances is guided into at least one inflow chamber 14 or into at least one flushing chamber 16 before being discharged through the fourth connection 9 or through the fifth connection 13 from the filter device 1.

[0099] The Fig. 12 to 15show, by way of example, schematic views of vertical rinsing processes of at least one intermediate space 7 and, at the same time, a first membrane 5 of at least one double membrane arrangement 2, in particular one adjacent to the at least one intermediate space 7. In this case, in particular the rinsing fluid is introduced through a third connection 8 into in particular a rinsing chamber 16 and then into the at least one intermediate space 7 of the double membrane arrangement 2, wherein the rinsing fluid passes through the first membrane 5 into the interior space 12 of the first membrane 5 and in the process retentate is removed from the first membrane 5 and the mixture of retentate and rinsing fluid flows through the interior space 12 to the fifth connection 13 and is removed from the filter device 1 by means of the fifth connection 13. In this case, in particular retentate can be removed from a side of the second membrane 6 facing the intermediate space 7 and retentate can be removed from a side of the first membrane 5 facing away from the intermediate space 7.

[0100] It is advantageous, in particular in the case of different tangential and subsequent vertical rinsing processes, that retentate on, for example, the first membrane 5, which could not be removed or could not be completely removed by a tangential rinsing process through the interior 12 of the first membrane 5, can be detached, in particular with a subsequent vertical rinsing process in which rinsing fluid presses onto the retentate layer or the filter cake from a direction opposite to the flow direction.

[0101] In the Fig. 16 to 18 Flushing processes via an adsorbent arranged between several double membrane arrangements 2 are shown as examples.

[0102] Fig. 16shows, by way of example, how flushing fluid is passed through a second connection 4 into the housing 15 of the filter device 1, the flushing fluid in the housing 15 flushes through the adsorbent arranged around the at least one double membrane arrangement 2, which forms the adsorption filter 10, and penetrates through the second membrane 6, against the flow direction of the fluid to be filtered, into an intermediate space 7 of at least one double membrane arrangement 2. In this case, the flushing fluid can, on the one hand, remove residues from the adsorbent and, on the other hand, the further retentate, which is retained on a side of the second membrane 6 facing the intermediate space 7, from the second membrane 6 and is passed through the flushing channel of the intermediate space 7 and subsequently through at least a fourth

[0103] Connection 9 can be discharged from the filter device 1. The rinsing fluid contaminated with the additional retentate can, for example, be discharged simultaneously from the filter device 1 from two diagonally opposite fourth connections 9. The second connection 4 can have a police filter 11.

[0104] Fig. 17shows, by way of example, how flushing fluid is passed through a second connection 4 into the housing 15 of the filter device 1, the flushing fluid flushes through the adsorption agent arranged in the housing 15 around the at least one double membrane arrangement 2, which forms the adsorption filter 10, and penetrates through the second membrane 6, against the flow direction of the fluid to be filtered, into an intermediate space 7 of at least one double membrane arrangement 2 and subsequently into the interior space 12 of at least one first membrane 5. The flushing fluid, which is contaminated in particular with retentate, is preferably discharged from the filter device 1 through a first connection 3 and through a fifth connection 13, wherein the connections 3, 13 are arranged in particular diagonally opposite one another. In this way, residues or retentate can be removed from the adsorption filter 10, from the second membrane 6 and from the first membrane 5.

[0105] Fig. 18shows an example of a flushing process for the adsorption filter 10. In this case, flushing fluid is preferably passed through a second connection 4 into the housing 15 of the filter device 1, wherein the flushing fluid flushes through adsorbent arranged in the housing 15 around the at least one double membrane arrangement 2, which forms the adsorption filter 10. In this case, it can be provided that the flushing fluid contaminated with residues is drained out of the filter device 1 through a further second connection 4. It can also be provided that the flushing fluid, in particular contaminated adsorbent, is flushed out of the housing 15 via the further second connection 4. For example, adsorbent heavily contaminated with residues, in particular activated carbon, must be replaced with uncontaminated adsorbent in order to ensure the functionality of the filter device 1.

[0106] In the context of the present disclosure, features are typically introduced with an indefinite article, "ein, eine, eines, einer." Unless the context indicates otherwise, this indefinite article is not to be understood as a numerical indication, so the disclosure is not limited to a single occurrence of the respective feature.

[0107] Furthermore, an "or" is to be interpreted as inclusive and not exclusive. Therefore, for two generic terms, "A" and "B," "A or B" does not exclude the possibility of "A and B," unless it is clear from the context or the description that only one of the two generic terms, "A" and "B," is intended.

Claims

1. Filter device (1) for filtering a fluid to be filtered, having at least one double-membrane arrangement (2), Filter device (1) having at least one first connection (3) for introducing the fluid to be filtered into the at least one double-membrane arrangement (2) and at least one second connection (4) for discharging a filtrate of the fluid to be filtered out of the filter device (1), the at least one double-membrane arrangement (2) - viewed in the flow direction of the fluid to be filtered - having a first membrane (5) and, downstream, a second membrane (6), an interspace (7) being embodied between the first membrane (5) and the second membrane (6), the interspace (7) comprising a flushing channel for flushing the interspace (7) the flushing channel extending from at least one third connection (8) for introducing a flushing fluid into the interspace (7) to at least one fourth connection (9) for discharging the flushing fluid from the interspace (7), the at least one third connection (8) and the at least one fourth connection (9) opening into the interspace (7), characterized in that that at least one adsorption filter (10) is arranged between the second membrane (6) and the at least one second connection (4).

2. Filter device (1) according to claim 1, characterized in that the adsorption filter (10) comprises activated carbon and / or zeolites.

3. Filter device (1) according to claim 1 or 2, characterized in that the at least one second connection (4) has a control filter (11).

4. Filter device (1) according to one of claims 1 to 3, characterized in that a pore size of the first membrane (5) is larger than a pore size of the second membrane (6).

5. Filter device (1) according to one of the claims 1 to 4, characterized in that the first membrane (5) and the second membrane (6) are embodied in a tubular form, the first membrane (5) being arranged essentially within the space spanned by the second membrane (6).

6. Filter device (1) according to one of the claims 1 to 5, characterized in that the first membrane (5) is arranged coaxially with the second membrane (6).

7. Filter device (1) according to one of the claims 1 to 6, characterized in that a width of the interspace (7) is at least 0.5 mm, preferably at least 1.5 mm, in particular at least 3 mm.

8. Filter device (1) according to one of the claims 1 to 7, characterized in that a width of the interspace (7) is at most 6 mm, in particular at most 5 mm, preferably at most 4 mm.

9. Filter device (1) according to one of the claims 1 to 8, characterized in that the filter device (1) has an inflow space (14), wherein the at least one first connection (3) opens into the inflow space (14), wherein the first membrane (5) extends away from the inflow space (14).

10. Filter device (1) according to one of claims 1 to 9, characterized in that a flushing space (16) is arranged adjacent to the inflow space (14), the first membrane (5) penetrating the flushing space (16) and the interspace (7) opening into the flushing space (16).

11. Method for operating a filter device (1), wherein in a filtering process - a fluid to be filtered is passed through at least one first connection (3) through at least one double-membrane arrangement (2) of the filter device (1), - wherein the fluid to be filtered is then passed first through a first membrane (5) and then through a second membrane (6) of the at least one double-membrane arrangement (2), an interspace (7) being embodied between the first membrane (5) and the second membrane (6), - wherein subsequently a filtrate of the fluid to be filtered is discharged from the filter device (1) via at least one second connection (4), wherein at least one adsorption filter (10) is arranged between the second membrane (6) and the at least one second connection (4), wherein, in a flushing process, - a flushing fluid is introduced through at least one third connection (8) into a flushing channel surrounded by the interspace (7), - wherein the flushing channel extends from the at least one third connection (8) to at least one fourth connection (9), - wherein the flushing fluid is conducted through the flushing channel to the at least one fourth connection (9) and the interspace (7) is flushed, - and the flushing fluid is discharged from the interspace (7) by means of the at least one fourth connection (9).

12. Method according to claim 11, characterized in that the flushing process is carried out during an interruption of the filtration process and / or after the filtration process.

13. Method according to claim 11 or 12, characterized in that in a further flushing process, the flushing fluid first flows through the at least one first connection (3) into an inflow space (14) of the filter device (1), the first membrane (5) being embodied in a tubular manner and opening into the inflow space (14), the flushing fluid then flowing into an interior space (12) of the first membrane (5) and flushing the interior space (12), the interior space (12) extending from the at least one first connection (3) to at least one fifth connection (13), the flushing fluid being diverted out of the Filter device (1) from the at least one fifth connection (13).