Filter element for a filter module and filter module

Abstract

Filter element (1) for a filter module (15), with a tube filter (2) for filtering a fluid passing through the tube filter (2), characterized by that a fastening part (4) for fastening the pipe filter (2) to the filter module (15) is provided on at least one end region (3) of the pipe filter (2).

Description

[0001] The present invention relates to a filter element for a filter module, comprising a tube filter for filtering a fluid passing through the tube filter.

[0002] Furthermore, the present invention relates to a filter module with two opposite module heads, wherein the module heads preferably have mutually corresponding and / or aligned hole patterns with at least one hole each, and with at least one filter element which is connected and / or fastened at its end regions in associated holes of the module heads.

[0003] Filter elements and filter modules of this type are used in practice to treat highly particle-laden, abrasive, highly acidic, or highly alkaline media in an environmentally friendly manner. These applications typically occur in industrial environments, for example, for the filtration or treatment of industrial wastewater, such as grinding wastewater, industrial or pickling acids from metalworking processes, or for the filtration of industrial or hydroxine sludge. Filter elements and filter modules of the type mentioned above are also used for the filtration of food products, such as fruit juices. In particular, the principle of cross-flow filtration is used, which has proven particularly effective in the filtration of liquid fluids, meeting even the most stringent filtration requirements.

[0004] Filter modules or filter devices of the type mentioned above typically comprise a plurality of tubular filter elements anchored to opposite end faces or membrane heads of the filter module. The filter elements or tubular filters, i.e., their inner peripheral surface, together represent the total active filter area of ​​the filter module and thus the filter capacity. The filter modules, in turn, are operated in specially designed systems, which, by means of appropriate pumps, valves, and switching technology, provide the actual filtration system. The core component for implementing the filtration process is the filter module, which can be used individually or in groups within the system, or connected together in the form of a plurality of filter modules, depending on the specific requirements of the respective filtration application.

[0005] A state-of-the-art solution involves the use of tube filters made of extruded polypropylene (PP) or sintered polyethylene (PE). During production, PP tube filters are homogenized with a highly viscous oil, such as castor oil, at elevated temperatures and pressed through an extruder. During the subsequent cooling process, the polymer forms the polymer-rich phase and the oil the polymer-poor phase. In the next step, the oil is washed out of the membrane using a hot solvent bath. PE tube filters, in contrast, are typically manufactured using a sintering process.

[0006] One advantage of this type of tube filter is that only one material, either PP or PE, is used in the construction of the filter modules or filter elements. This facilitates the connection or front-end welding of the tube filters threaded into the module heads. This is largely due to the tube filters' sufficient wall thickness and the fact that favorable material pairings for welding are possible, since the module heads themselves are also made of PP or PE or a thermoplastic.

[0007] However, the disadvantage of the known method for producing sintered or extruded tube filters is the very complex process management, accompanied by corresponding challenges to ensure sufficient filtration quality as well as high energy and process-related manufacturing costs.

[0008] Furthermore, the tube filters known from the art are limited in their filtration properties, particularly with regard to the desired separation limits for the respective application. A "separation limit" preferably defines a material-dependent property of the tube filter, according to which all particles whose size or diameter exceeds the separation limit cannot pass through the tube filter material and are retained on the surface of the tube filter material.

[0009] For example, PE tube filters can achieve separation limits of about 1 µm and PP tube filters can achieve separation limits of about 0.2 µm, which is often insufficient for demanding filtration operations.

[0010] Against this backdrop, there is a high demand for high-performance filter elements that can be manufactured sustainably and reliably, or with reduced effort. At the same time, a broad and individually adjustable filtration spectrum must be covered, especially while maintaining the smallest and most precise separation limits possible. At the same time, an efficient, simple, reliable, and chemically stable connection of the filter elements to or into higher-level filter modules must be ensured.

[0011] Against this background, the object of the invention is to provide a filter element and a filter module which are characterized by individually adjustable and sophisticated filter properties, reliable operation and high chemical resistance and, ultimately, by a user-friendly and technically and economically sustainable implementation.

[0012] In particular, the aim is to create the possibility for reliable filtration of chemically problematic or aggressive liquids while meeting narrow or low separation limits. Furthermore, the filtration should be characterized by comparatively low filtration resistance and low energy consumption during filtration, as well as flexible adaptation to individual filtration requirements.

[0013] The above object is achieved by a filter element according to claim 1 and a filter module with the filter element according to the invention according to claim 9. Advantageous further developments are the subject of the subclaims.

[0014] In a filter element according to the invention, a fastening part for fastening the tube filter to the filter module is provided at at least one end region of the tube filter. The fastening part is preferably a separate element or component manufactured separately from the tube filter. While the tube filter is designed to implement filtration, the fastening part preferably has no filtering properties.

[0015] The solution according to the invention therefore provides a fastening part which ultimately implements the connection or anchoring of the filter element to the filter module decoupled from the tube filter. This makes it possible to adapt or adjust the properties of the tube filter as desired or independently of the fastening part. In particular, tube filters can be used whose direct anchoring or connection to the filter module is usually not possible or can only be implemented in a disadvantageous way, for example with the aid of casting resin or sealing materials. This problem is solved according to the invention by the fastening part connected to the tube filter, via which an indirect connection or anchoring of the tube filter to the filter module or to the module head takes place. The material properties of the fastening part and / or its shape can be specifically adapted to a corresponding section of the filter module, so that a more robust orchemically resistant joining area on the filter module is guaranteed.

[0016] In this respect, the solution according to the invention combines the advantages of flexibly adaptable and high-performance tube filters with a robust and chemically resistant connection or anchoring to the filter module via the fastening part additionally connected to the tube filter.

[0017] The fastening part preferably has a fastening section projecting axially from the tube filter, preferably wherein the fastening part has an inner receiving area for a joining tool and a peripheral joining area for connection to a preferably complementarily designed joining area of ​​the filter module.

[0018] The fastening section is thus preferably locally decoupled or spatially separated from the tube filter. The fastening section is preferably made of a meltable material, preferably a thermoplastic. As a result of heat applied to the inside and / or front of the fastening section by the heated joining tool entering the inner receiving area, the fastening section melts on the circumference and / or front and forms a solid material connection or weld with the joining area of ​​the filter module adjacent to the fastening section on the circumference, thereby achieving a reliable and chemically resistant connection.

[0019] The inner receiving area preferably forms an extension of the flow channel of the tube filter.

[0020] Particularly preferably, the fastening part has a peripheral portion that surrounds the end region of the tube filter at least in sections, preferably wherein the peripheral portion is axially adjacent to the fastening portion and / or is integrally bonded, in particular molded, to the end region of the tube filter. This enables a robust and gentle material connection between the fastening part and the end region, especially in the case of comparatively thin-walled tube filters.

[0021] The fastening part is preferably open at the end and / or at least partially permeable and / or sleeve-shaped and / or cap-shaped.

[0022] Preferably, the fastening part, in particular at least the fastening section, comprises or consists of a thermoplastic material, preferably polypropylene. This enables a reliable material connection or weldability of the filter element or the fastening part to a preferably also thermoplastic or similar plastic of the filter module.

[0023] According to a preferred embodiment, it is provided that the ratio of the inner diameter of the pipe filter to the outer diameter of the fastening part is at least 40%, preferably at least 50%, in particular at least 60%, particularly preferably at least 65%, further preferably at least 70%.

[0024] In other words, the mounting part protrudes only slightly radially from the tube filter. This optimizes the filter surface, which is crucial for filtration.

[0025] In a particularly preferred embodiment, it is also provided that the tube filter has a wall thickness of at most 0.8 mm, preferably at most 0.7 mm, in particular at most 0.55 mm, particularly preferably less than 0.55 mm. The comparatively thin-walled design of the tube filter is associated with reduced filtration resistance or increased filtration flow, and ultimately increased filtration efficiency.

[0026] The filter element preferably has a cutoff of at most 1000 nm, preferably at most 500 nm, more preferably at most 150 nm, especially at most 100 nm, and most preferably at most 50 nm. This enables efficient filtration even under demanding conditions, where the separation of even the smallest particles in the nanometer range, especially down to 1 nm, is desired.

[0027] For the end connection of the filter element to or in the filter module, a fastening part is preferably provided at both end regions of the tube filter, in particular with one fastening part having a different dimension than the other fastening part, in particular a reduced outer diameter. This simplifies the connection of the filter element to the module head of the filter module, since the filter element can be inserted or threaded into an associated hole in the module head with the fastening part with the reduced outer diameter first.

[0028] Furthermore, the tube filter preferably comprises a porous and / or fluid-permeable, preferably nonwoven, carrier layer and a membrane layer applied to the inside of the carrier layer, preferably with the carrier layer being coated and / or impregnated with the membrane layer on the inside. The selected membrane layer or carrier layer can be individually adjusted to the desired filter properties or separation limits. Furthermore, the preferred structure of the tube filter, consisting of a porous carrier layer and a membrane layer, enables high chemical resistance and durability. At the same time, a comparatively low filtration resistance and a comparatively high filtration flow rate, and ultimately a high filter efficiency, are achieved.

[0029] Particularly preferably, the carrier layer comprises at least one material web wound into a tubular sleeve, preferably wherein the carrier layer consists of at least two material webs that overlap one another and / or are wound into a tubular sleeve. The production of the tubular filter using wound material webs is flexible and simple, and can be implemented with reduced energy consumption. Furthermore, the desired filtration properties and the sleeve diameters can be specifically controlled by selecting the mandrel and / or the material web and / or the material feed speed and / or the winding or feed angle and / or the material of the material web, for example, based on polypropylene (PP) or polyethylene (PE).

[0030] The filter module according to the present invention has at least one filter element according to the invention.

[0031] This allows the advantages described above to be realized. In particular, it is possible for the filter element to be secured, particularly welded, in a corresponding hole in the module head via the fastening part. This results in a chemically extremely resistant connection or fastening of the filter element in the hole of the module head.

[0032] Accordingly, in a method for producing a filter element preferably according to the invention, a fastening part is attached to at least one end region of the tube filter, in particular wherein the fastening part is overmolded and / or integrally bonded to the end region of the tube filter at least in sections. In other words, the fastening part is molded directly onto the end region of the tube filter, preferably by injection molding, in particular by injection molding.

[0033] This enables an efficient, reliable, robust, and material-saving connection of the fastening part to the pipe filter. In particular, the connection of the fastening part to the pipe filter can be implemented cost-effectively, even in large quantities.

[0034] Finally, to produce a filter module according to the invention, after inserting a filter element into aligned, opposite holes in the membrane heads, the filter element is secured in the associated hole via the fastening part. This is achieved, in particular, by welding or melting a fastening section of the fastening part to an associated joining area of ​​the hole in which the fastening part is received.

[0035] Specifically, a welding head, particularly a wedge-shaped and / or tapered head, is heated and inserted into the inner receiving area of ​​the fastening section, particularly by contact-bonding. As a result of the heat emitted by the welding head and the internal pressure exerted by the welding head, the fastening section melts, resulting in a materially bonded, circumferential weld with the joining section of the hole of the respective module head, which is circumferentially adjacent to the fastening section.

[0036] This results in a mechanically robust and chemically resistant connection or welding of the fastening part within an assigned hole in the module head.

[0037] The above-mentioned aspects and features as well as further aspects and features resulting from the claims and the following description can be realized independently of one another and in various combinations.

[0038] Further advantages, features, properties, and aspects of the present invention will become apparent from the claims and the following description of a preferred embodiment with reference to the drawings. It shows: Fig. 1 a schematic side view of a filter element according to the invention; Fig. 2 a sectional view of the filter element according to the invention from Fig. 2; Fig. 2A a partial enlargement of the illustration from Fig. 2 in the area of ​​a fastening part of the filter element; Fig. 3 a schematic side view of a filter element according to the invention according to a preferred embodiment; Fig. 4 a schematic representation of the internal structure of a tube filter of the filter element according to the invention; Fig. 5 a perspective view of a filter module according to the invention; Fig. 6 a front view of a module head of the filter module; Fig. 7 a longitudinal section of the filter module Fig. 6; Fig. 7A a partial enlargement in the area of ​​a joining section of the fastening part of the filter element within a hole of the filter module during assembly by means of a joining tool; Fig. 8 shows a plant structure for producing a tube filter of the filter element according to the invention; and Fig. 9 a sectional view of the system structure from Fig. 8 for coating the inside of the tube filter with a polymer membrane layer.

[0039] In the figures, some of which are not to scale and are merely schematic, the same reference symbols are used for identical or similar parts, whereby corresponding or comparable properties and advantages can be achieved, even if a repeated description is omitted.

[0040] The Fig. 1 schematically shows a filter element 1 according to the invention. The filter element 1 is in particular the core or an essential part of a higher-level filter module 15, which is Fig. 5 ff.

[0041] The filter module 15 generally serves to filter fluids, in particular liquids, for example, for the treatment of grinding wastewater, for the treatment of pickling acids from metalworking processes, or for the filtration of industrial sludges, such as hydroxide sludge. Filter elements 1 according to the invention or filter modules 15 according to the invention equipped therewith can also be used for the filtration of food products or beverages, such as apple juice, and / or wastewater.

[0042] Accordingly, the filter element 1 comprises a tube filter 2 for filtering a fluid passing through the tube filter 2. Filtration occurs according to the principle of transverse filtration, whereby the fluid to be filtered enters the tube filter 2 and then passes through it radially or through its wall. Filtration then occurs through the material of the wall of the tube filter 2, whose porosity or limited permeability accordingly traps particles or solids above a certain size.

[0043] The connection of the filter element 1 or the tube filter 2 to or in the filter module 15 is preferably carried out via end regions 3 of the tube filter 2. An end region 3 is to be understood in particular as an end-side axial section of the tube filter 2, which comprises an associated axial end of the tube filter 2, as in Fig. 1 is shown.

[0044] The end region 3 occupies a comparatively small axial section relative to the total length of the tube filter 2, for example, less than 10%, in particular less than 5%, particularly preferably less than 1%. Therefore, the tube filter 2 is preferably not in contact with the filter module 15 over a large part of its axial extent. This enables a substantially barrier-free flow of the fluid to be filtered.

[0045] For connecting or fastening the pipe filter 2 to the filter module 15, a fastening part 4 is provided at the end area 3 of the pipe filter 2. In this respect, as can be seen from Fig. 1, the end area 3 is covered by the fastening part 4.

[0046] Particularly preferably, fastening parts 4 are provided on both sides or at both end regions 3, as can be seen from the embodiment according to Fig. 3 is evident.

[0047] The fastening part 4 ultimately ensures that the filter element 1 or the tube filter 2 is attached to the filter module 15 in a manner that is decoupled from the tube filter 2. In other words, the tube filter 2 is connected indirectly or contactlessly to the filter module 15 via the fastening part 4. This allows for a flexible design or, if necessary, adaptation of the tube filter 2 with regard to the desired filter properties.

[0048] As can be seen from the enlarged section according to Fig. 2A, the fastening part 4 has a fastening section 5 that protrudes axially from the pipe filter 2.

[0049] In particular, the fastening section 5 has an end opening 5A.

[0050] In addition, the fastening section 5 preferably has an inner receiving area 6. The receiving area 6 is preferably accessible via the opening 5A.

[0051] The inner receiving area 6 serves in particular to accommodate a joining tool 16 (cf. Fig. 7A). The inner receiving area 6 is preferably dimensioned in coordination with the joining tool 16 such that the joining tool 16 entering through the opening 5A preferably cannot come into contact with the pipe filter 2 or its front side and / or inner surface.

[0052] In the illustrated and preferred embodiment, the receiving area 6 has a preferably funnel-shaped receiving surface 6B that widens towards the opening 5A. The fastening section 5 can merge smoothly or seamlessly into the pipe filter 2 or its inner circumference.

[0053] The joining tool 16 can enter the fastening section 5 through the opening 5A and thereby strikes the receiving surface 6A. The frictional connection formed between the joining tool 16 and the receiving surface 6A preferably prevents the heatable or heated joining tool 16 from striking the front side of the pipe filter 2.

[0054] Particularly preferably, a particularly cylindrical transition surface 6B is provided between the receiving surface 6A and the end face of the tube filter 2. The transition surface 6B can transition smoothly and / or seamlessly into the adjacent tube filter 2 on the inside. In this respect, the receiving surface 6A is connected to the tube filter 2 on the inside via the transition surface 6B. This enables homogeneous and advantageous flow conditions within the fastening part 4.

[0055] In addition, the fastening section 5 has an outer or circumferential, in particular cylindrical, joining region 7. The circumferential joining region 7 serves in particular for at least partial connection to a preferably complementary joining region 17 of the filter module 15. The joining region 7 preferably has a cylindrical outer surface.

[0056] In the illustrated and preferred embodiment, the fastening part 4 has a circumferential section 8 that at least partially surrounds the end region 3 of the tube filter 2. In this respect, the fastening part 4 is preferably connected directly to the tube filter 2 or the end region 3 via the circumferential section 8, in particular by a material bond. In particular, the end region 3 is completely enclosed by the circumferential section 8. In contrast, the fastening section 5 protrudes axially relative to the end region 3, so that there is no circumferential overlap between the fastening section 5 and the end region 3 of the tube filter 2.

[0057] The peripheral portion 8 preferably directly adjoins the fastening portion 5 axially. In particular, the fastening part 4 is formed by the fastening portion 5 and the peripheral portion 8, in particular in one piece.

[0058] It can also be seen that the fastening part 5 is open at the end and / or at least partially permeable to flow, preferably via the opening 5A of the fastening section 5.

[0059] In general, the fastening part 4 is preferably sleeve-shaped and / or cap-shaped.

[0060] In general, the fastening section 5 is formed from a weldable plastic, for example a thermoplastic plastic, in particular polypropylene or polyethylene, or comprises such a material.

[0061] The ratio of an inner diameter d of the tube filter 2 to an outer diameter D of the fastening part 4 is at least 50%, preferably at least 60%, in particular at least 65%, particularly preferably at least 70%.

[0062] It is also preferred if the tube filter has a wall thickness s of at most 0.8 mm, preferably at most 0.7 mm, in particular at most 0.55 mm or less than 0.55 mm.

[0063] In order to implement efficient filtering, it is preferred if the filter element 1 or the tube filter 2 has a separation limit of at most 1000 Nm, preferably of at most 500 Nm, preferably of at most 250 Nm, in particular of at most 100 Nm, most preferably of at most 50 Nm.

[0064] As shown by Fig. As can be seen in Figure 3, the filter element 1 preferably has fastening elements 4 at both end regions 3. The fastening elements 4 can be of identical design.

[0065] Preferably, however, a fastening part 4 and a further fastening part 9 that differs from it are provided at the end regions 3. This deviation preferably concerns an external dimensioning and not the internal structure.

[0066] To identify or distinguish the further fastening part 9 from the fastening part 4, a marking may be provided, in this case in the form of a circumferential groove 9A. However, other markings are also possible, which can be applied in particular to the outside of the further fastening part 9.

[0067] In this case, the additional fastening part 9 differs from the fastening part 4 in its dimensions, particularly in its outer diameter. This allows for corresponding advantages with regard to the connection of the filter element 1 within the filter module 15, as will be explained and described below.

[0068] The internal structure of the tube filter 2 and its wall layer is described below using the schematic diagram in Fig. 4 explained.

[0069] The tube filter 2 preferably has a porous and / or fluid-permeable, preferably nonwoven, carrier layer 10. The carrier layer 10 is preferably formed in multiple layers, in particular two layers, at least in sections in the axial direction of the tube filter 2. In general, the carrier layer 10 can be made of different materials, preferably plastic materials, in order to specifically adjust the desired filtration properties.

[0070] A polymeric membrane layer 11 is preferably applied to the inside of the carrier layer 10. This membrane layer 11 is preferably formed on the inside and / or continuously on the inner circumference of the tube filter 2. As can be seen from the illustration according to Fig. 4, the membrane layer 11 penetrates the carrier layer 10. In other words, the carrier layer 10 is impregnated at least partially, preferably completely, on the inside by the membrane layer 11. This impregnation or impregnation preferably extends at least substantially over the entire length of the carrier layer 10. However, the impregnation or impregnation can also extend beyond the inner layer of the carrier layer 10 to the outer layer of the carrier layer 10.

[0071] In particular, the carrier layer 10 is wound into a tubular sleeve or has at least one material web 12 wound into a tubular sleeve.

[0072] In particular, the carrier layer 10 consists of at least one, preferably two overlapping material web or material webs 12 wound to form a tubular sleeve. For the production of the carrier layer 10 to form a wound tubular sleeve based on material web 12, the following will be explained in connection with Fig. 8 and Fig. 9 will be discussed in more detail. In this respect, the carrier layer 10 can be formed as a single layer, preferably as a multi-layer or double-layered layer.

[0073] In Fig. 5 shows the filter module 15 according to the invention, which comprises a plurality of filter elements 1 according to the invention.

[0074] The filter module 15 has two opposite module heads 13.

[0075] The module heads 13 have mutually corresponding hole patterns with a plurality of holes 14.

[0076] The hole patterns of the opposing module heads 13 are preferably identical to one another or aligned with one another, so that each filter element 1 is assigned holes 14 of the module heads 13 that are aligned opposite one another.

[0077] In the filter module 15 shown, the module heads 13 are connected to one another via a housing 18, preferably welded.

[0078] In addition, the filter module 15 has at least one, preferably two, permeate outlets 19. The permeate outlets 19 serve to discharge the filtered fluid from the housing 18.

[0079] Preferably, each module head 13 is assigned a permeate outlet 19.

[0080] It should be noted, however, that in a cartridge according to the invention, the housing 18 or the permeate outlets 19 can be omitted. The cartridge according to the invention is then formed by the opposing module heads 13 and the filter elements 1 extending between them and connected to the module heads 13. This assembly or cartridge can then be subsequently accommodated internally in a separate housing with permeate outlets.

[0081] The connection of the filter elements 1 into the associated holes of opposite module heads 13 is carried out in particular in such a way that a particularly rod-like threading tool 27 is inserted on one side into a hole 14 of one, here the left, module head 13 and is led out again on the opposite side at a further hole 14 of the opposite, here the right, module head 13 arranged in alignment therewith.

[0082] At the end of this rod-like tool, a connection area, preferably a threaded section, is provided. The filter element 1 is connected to this connection area via the fastening part 4, preferably by screwing. Subsequently, the threading tool 27 with the fastening part 4 or filter element 1 connected to it is guided back along a threading direction E, with the fastening part 4 initially entering through the hole 14 again through the module head 13 (here on the right), guided along within the housing 18, and entering via the threading tool 27 again into the aligned hole 14 in the opposite, here on the left, module head 13.

[0083] At this point, the additional fastening part 9 has also entered the opposite hole 14. The threading tool 27 can then be removed from the fastening part 4. The fastening parts 4, 9 are then aligned or can be aligned in a defined manner, particularly at the front with the module heads 13.

[0084] It is preferred that the fastening part 4 has a slightly reduced diameter compared to the further fastening part 9 and / or the holes 14. This simplifies the threading of the fastening part 4 into the aligned, opposite holes 14. However, the fastening part 4 can also have a substantially identical diameter to the hole 14(s).

[0085] In contrast, the additional fastening part 9 can have a slightly larger diameter than the fastening part 4 and, preferably, than the hole 14. In other words, the additional fastening part 9 has an oversize compared to the holes 14.

[0086] This facilitates the attachment of the filter element 1 to the module heads 13, provided that the additional fastening part 9 has entered the associated hole 14. In particular, due to the oversize, a frictional connection of the additional fastening element 9 in the associated hole 14 is established. If necessary, the additional fastening part 9 can be driven into the hole 14 or secured by force by applying force to the front side in the threading direction E, for example by means of a percussive action.

[0087] On this basis, for each pair of aligned, opposite holes 14, a corresponding, preferably initially positive and / or non-positive, connection of filter elements 1 is then made via the fastening parts 4 and 9, respectively.

[0088] In particular, the fastening parts 4 and 9 enable a chemically resistant connection, in particular a liquid connection, in the associated holes 14 of the module heads 13.

[0089] This will be explained below using Fig. 7 or the enlarged view according to Fig. 7A explained.

[0090] Shown are the filter elements 1, which may have previously been inserted into the hole patterns by force-fitting.

[0091] For the material-to-material connection, a joining tool 16, preferably a particularly wedge-shaped and / or pointed welding head 16A of the joining tool 16, can be inserted into the opening 5A of the fastening part 4 or the inner receiving section 6.

[0092] The heated welding head 16A thereby enters the inner receiving section 6 or the receiving surface 6A of the fastening section 5 in a force-fitting manner. The joining tool 16 or the welding head presses the fastening section 5 radially outward.

[0093] In the illustrated and preferred embodiment, the heated welding head 16A extends beyond the receiving surface 6A into the region of the transition surface 6B. The transition surface 6B, or its axial extent, is selected in particular such that the welding head 16A does not come into contact with the pipe filter 2 or its inner surface. In particular, the welding head 16A is tapered and / or tapered, so that there is also a radial spacing of the welding head 16A with respect to the transition surface 6B and / or the inner surface of the pipe filter 2.

[0094] The joining tool 16 preferably has a welding stop 16B, which, when the welding head 16A is fully inserted, abuts the front side of the fastening part 4 or its fastening section 5 or the peripherally adjacent module head 13. Due to the heating of the welding stop 16B, the front side of the fastening part 4 or the fastening section 5 is preferably also welded circumferentially to the adjacent joining area of ​​the module head 13 or the hole 14.

[0095] This enables a particularly reliable and robust welding of the fastening part 4 within the hole 14 of the module head 13.

[0096] As a result of the heat transfer and pressure effect of the joining tool 16 in the inner receiving section 6 or in the fastening section 5 and / or on the front side of the fastening section 5, a partial circumferential and / or front-side melting of the fastening part 4, in particular of the fastening section 5, occurs. Due to the circumferential and / or front-side melting, a material-to-material connection then occurs between the circumferential joining area 7 of the fastening part 4 and the complementarily formed joining area 17 of the hole 14. In addition, a weld is preferably also carried out at the front-side transition of the fastening section 5 to the adjacent module head 13.

[0097] This is done for each individual hole 14 with the fastening part 4 accommodated therein, or for each additional fastening part 9 on the opposite module head 13.

[0098] As a result, a chemically resistant composite or a robust connection of the filter element 1 to the opposite module heads 13 is implemented.

[0099] The following is based on Fig. 8 a system or a related method for producing the tube filter 2, which is preferably designed as a tube sleeve membrane, is explained.

[0100] To produce the pipe filter 2 in the form of a pipe sleeve, nonwoven material webs 12 or nonwoven webs are unwound from supply rolls (not shown) and fed in an overlapping arrangement to a stationary mandrel 20, in particular a hard metal mandrel. The feed takes place at an acute feed angle, i.e., less than 90°, for example 60°, relative to the axial axis of the mandrel 20. It should be noted that ultimately, a single-layer or any desired multi-layer feed of the material web 12 or webs can also be implemented to produce the pipe sleeve. The thickness and the respective air permeability of the material web 12 and / or the selected material of the material web 12 can also be adapted depending on the intended use or the filtration requirement.

[0101] As a result, a spiral or tubular sleeve consisting of the material webs 12 is produced, which is in particular continuously wound around the fixed mandrel 20.

[0102] The material webs 12 for winding the pipe sleeve are conveyed by an endless winding belt 21, which is driven by two rotating towers (not shown in detail). The winding belt 21 forms a loop around the material webs 12 guided on the mandrel 20 and, through its concentricity, pulls the winding material or material webs 12 from the supply rolls onto the mandrel 20, as well as pressing the stacked material webs 12 together to form the thus formed endless round sleeve as the pipe filter 2.

[0103] Before the attack or before the wrapping belt 21 is wrapped, the overlapping material webs 12 are preferably connected.

[0104] In the present case, this is done using an ultrasonic method or by means of sonotrodes 22. As a result, the material webs 12 are connected or welded to one another, so that a helical bonding or welding of the pipe sleeve or the pipe filter 2 takes place.

[0105] The internal application of the polymer membrane layer 11 to the pipe sleeve or carrier layer 10 is described below using Fig. 10 explained.

[0106] By varying the mandrel diameter and the feed angle, it is possible to produce corresponding pipe filters 2 as pipe sleeves with different diameters and thus to optimally adapt the product to the intended use.

[0107] Just below the sonotrodes 22 or the winding belt 21, a polymer casting solution for forming the membrane layer 11 is introduced through cavities in the mandrel 20 through outlets 23 into a surrounding cavity 24, also called the polymer space. The cavity 24 corresponds to the space between the mandrel 20 and the surrounding tubular sleeve or wound carrier layer 10 made of the material webs 12. As a result, the carrier layer 10 or the wound tubular sleeve is impregnated or coated on the inside with the polymer casting solution.

[0108] A round doctor blade 25, also called a bob, is provided at the lower end of the mandrel 20. The diameter of the round doctor blade 25 preferably defines a gap width or a doctor blade gap of the applied polymer film or membrane layer 11.

[0109] The axial length of the circular doctor blade 25 determines, in particular via the flow feed speed, the contact time of the polymer casting solution with the carrier layer 10 and is thus decisive or preferred for the anchoring of the membrane layer 11.

[0110] This is followed by an air gap 26, which, together with the flow rate, determines the contact time of the polymer casting solution on the carrier layer 10 with the ambient air. The pipe sleeve or the carrier layer 10 coated on the inside in this way is conveyed orthogonally or with the top side impacting into a water bath 27, thus initiating a precipitation process of the polymer casting solution.

[0111] The water bath 27 can be set to different temperatures to optimally adjust the membrane or filter properties.

[0112] In addition to the previously described so-called Non Solvent Induced Phase Separation (NPIS) process, it is also possible to produce the membranes using alternative processes, such as Vapor Induced Phase Separation (VIPS) or Temperature Induced Phase Separation (TIPS) processes, in order to open up a wider range of separation limits.

[0113] Once the desired carrier layer 10 or pipe sleeve with internally coated membrane layer 11 has been produced in the desired length, a so-called flying knife, which is not shown, automatically cuts it to a predetermined axial length.

[0114] PP or polypropylene is preferably used as the nonwoven carrier layer 10. However, PE or polyethylene is also possible for the carrier layer 10. This ensures the best possible chemical resistance.

[0115] High-performance plastics, such as PVDF or PEEK or similar, are preferably used as the membrane layer 11 or membrane polymer.

[0116] After the pipe filter 2 has been manufactured, it is provided with fastening parts 4, 9 made of PP or PE at both ends.

[0117] For this purpose, particular emphasis is placed on the injection molding process using a suitable injection molding tool and an injection molding machine.

[0118] The filter elements 1 modified in this way are, as previously explained, drawn into the opposite membrane heads 13 and then welded accordingly in or with the associated holes 14 of the module heads 13.

[0119] In this way, it is possible to insert filter elements 1 into a plastic housing of a filter module 15 or the module heads 13 without the use of adhesive or sealing materials, for example potting resins.

[0120] The pipe filter 2 or the pipe sleeve membrane can be manufactured in different diameters by varying the system parameters.

[0121] For example, diameters of the tube filter of 5.4 mm, 8.2 mm, 10.2 mm, and 12.5 mm are adjustable or possible as needed. The choice of diameter depends on the optimization of the respective filter application, particularly with regard to maximum filter efficiency and appropriate energy consumption.

[0122] Furthermore, the filter element 1 or the tube filter 2, as a tubular sleeve membrane, allows the application or coating of a variety of characterized or individually adaptable polymer films. This allows for variable adjustment of the separation limits, as well as the diameters. In particular, the separation limits are not fixed at, for example, 1 µm or 0.2 µm, but rather separation limits of up to 50 nm or less than 50 nm are possible, which offers numerous advantages in practical applications, such as significantly reduced cleaning effort for the membrane modules and a longer service life.

[0123] In addition, the present invention allows the use of tube filters 2 or tube sleeve membranes, which, despite comparatively narrow or low separation limits of up to 50 nm, possibly even less than 50 nm, allow comparatively high water flow rates and thus an efficient and energy-saving filtration process. This is due in particular to the special properties of the membrane polymer used, the casting solution, or associated additives, which are also due to the use of the carrier layer 10, in particular based on a nonwoven material. In contrast to the extruded PP tube membrane known from the prior art, the solution according to the invention thus allows a corresponding reduction in filtration resistance, which enables efficient filtration operation.

[0124] In addition, the injection-molded attachment parts 4, 9 onto the tube filters 2 allows the filter elements 1 to be manufactured without the disadvantageous use of casting resin using suitable welding technology, in particular using the joining tool 16. In this way, the advantages of tubular sleeve membrane technology based on the specially designed tube filter 2 can be utilized, while simultaneously enabling high chemical resistance due to the connection of the attachment parts 4, 9 and the associated joining process for connection to the higher-level filter module 15. List of reference symbols: 1 filter element 2 pipe filters 3 End area 4 Fastening part 5 Fastening section 5A opening 6 Recording area 6A recording surface 6B Transition surface 7 Joining area 8 Circumferential section 9 additional fastening part 9A groove 10 Carrier layer 11 Membrane layer 12 Material web 13 Module head 14 holes 15 filter module 16 Joining tool 16A welding head 16B Welding stop 17 Joining area 18 housings 19 Permeate outlet 20 thorn 21 winding straps 22 sonotrodes 23 Outlet 24 cavity 25 round doctor blades 26 Air gap 27 Threading tool d inner diameter D outer diameter E Threading direction s wall thickness

Claims

[1] Filter element (1) for a filter module (15), with a tube filter (2) for filtering a fluid passing through the tube filter (2), characterized by , that a fastening part (4) for fastening the pipe filter (2) to the filter module (15) is provided on at least one end region (3) of the pipe filter (2). [2] Filter element according to claim 1, characterized by that the fastening part (4) has a fastening section (5) projecting axially from the tube filter (2), preferably wherein the fastening section (5) has an inner receiving area (6) for a joining tool (16) and / or a peripheral joining area (7) for connection to a preferably complementarily designed joining area (17) of the filter module (15). [3] Filter element according to claim 1 or 2, characterized bythat the fastening part (4) has a circumferential section (8) which surrounds the end region (3) of the pipe filter (2) at least in sections, preferably wherein the circumferential section (8) is axially adjacent to the fastening section (5) and / or is materially connected, in particular injection-molded, to the end region (3) of the pipe filter (2). [4] Filter element according to one of the preceding claims, characterized by that the fastening part (4) is open at the end and / or at least partially permeable and / or sleeve-shaped and / or cap-shaped and / or that the fastening part (4), preferably at least the fastening section (5), comprises or consists of a thermoplastic material, preferably polypropylene (PP). [5] Filter element according to one of the preceding claims, characterized bythat the ratio of an inner diameter (d) of the tube filter (2) to an outer diameter (D) of the fastening part (4) is at least 50%, preferably at least 60%, in particular at least 65%, particularly preferably at least 70%, and / or that the tube filter (2) has a wall thickness (s) of at most 0.8 mm, preferably at most 0.7 mm, in particular at most 0.55 mm and / or that the filter element (1) has a separation limit of at most 1000 nm, preferably at most 500 nm, preferably at most 250 nm, in particular at most 100 nm, very particularly preferably at most 50 nm. [6] Filter element according to one of the preceding claims, characterized bythat a fastening part (4, 9) is provided at both end regions (3) of the tube filter (2), preferably wherein one fastening part (4) differs from another fastening part (9), particularly preferably wherein the another fastening part (9) has a reduced outer diameter compared to the fastening part (4). [7] Filter element according to one of the preceding claims, characterized by that the tube filter (2) has a porous and / or fluid-permeable, preferably nonwoven, carrier layer (10) and a membrane layer (11) applied to the inside of the carrier layer (10), preferably wherein the carrier layer (10) is coated and / or impregnated on the inside with the membrane layer (11). [8] Filter element according to one of the preceding claims, characterized bythat the carrier layer (10) has at least one material web (12) wound into a tubular sleeve, preferably wherein the carrier layer (10) consists of at least one material web (12) wound into a tubular sleeve (12), in particular of two material webs (12) overlapping one another and wound into a tubular sleeve. [9] Filter module (15) for filtering a fluid, with two opposite module heads (13), wherein the module heads (13) preferably have mutually corresponding and / or aligned hole patterns with at least one hole (14) each, and with at least one filter element (1) which is connected and / or fastened at its end regions (3) in associated holes (14) of the module heads (13), characterized by , that at least one filter element (1) is designed according to one of the preceding claims. [10] Filter module according to claim 9, characterized bythat the filter element (1) is fixed, in particular welded, in the hole (14) via the fixing part (4) on the circumference.

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