Filter for filtering fluids

Abstract

The invention relates to a filter (01) for filtering fluids, comprising a housing (02) and a filter insert (03) accommodated in the housing (02), wherein the filter insert (03) comprises at least one first layer (04) and a second layer (04) of textile fabric, in particular nonwoven material, wherein the textile fabric forms intermediate spaces, wherein the layers (04) are arranged one on top of another. The filter comprises layers (04), each having at least one recess (05), wherein the recesses (05) are several times larger than the intermediate spaces, and wherein the recess (05) of the first layer (04) is arranged offset with respect to the recess (05) of the second layer (04). Alternatively, the filter (01) comprises at least one end cap (06), wherein the end cap (06) is arranged on an edge of the layers (04) and the edges are adhesively bonded to the end cap (06).

Description

[0001] Scw / Thm / mau / fle

[0002] February 4, 2026

[0003] Filters for filtering fluids

[0004] The invention relates to a filter for filtering fluids.

[0005] It is a well-known problem that fluids used for a wide variety of purposes become contaminated due to process-related factors or by byproducts and / or waste materials in particulate form. To ensure that the fluids can continue to perform their function or be safely disposed of and / or reused, it is often necessary to remove the contaminating particles. Filters are used for this purpose; the fluids are passed through these filters, which retain the particles.

[0006] One typical application for these filters is in engines, especially internal combustion engines, which use lubricating oil to improve the smooth operation of various machine parts. However, abrasion introduces minute particles into the lubricating oil, which are then removed by oil filters. Engines are also used on heavy-duty ships. In these situations, conditions such as rough seas can occur, making filter changes impossible or unsafe. A permanent engine failure in such a situation would be disastrous.

[0007] From DE 10 2008 046 952 Al, a filter for an internal combustion engine is known that can serve the aforementioned purpose. The filter is characterized by a mixture of elastic fibers and flexible strips that explicitly allow particles up to a certain size to pass through, as these particles have a beneficial effect in lubricating oil for internal combustion engines.

[0008] A disadvantage of filters known in the prior art is their specific application area. Most filters are limited to use in a few areas and / or with a limited number of fluids. The filter described above is also an example of filters with very narrow application ranges, as it is explicitly intended for use with fuels and lubricants. The problem of limited applicability is further exacerbated by the fact that replacement is necessary when the filter becomes saturated.

[0009] State-of-the-art filters usually completely block the flow of fluid, which can lead to devastating consequences, particularly the destruction of, for example, a machine in which the filter is installed. However, replacing the filter and / or shutting down the machine is often not immediately possible due to various reasons. In the previously described example of heavy-lift vessels, heavy seas can be such a reason preventing filter changes. Furthermore, the specialized nature of these filters has the disadvantage of being more expensive to manufacture and more difficult to store.

[0010] There is therefore a great need for a universally applicable, and thus cost-effective and readily available, filter that can reliably and safely filter the widest possible range of fluids over the long term. This filter should also be suitable for applications where immediate filter replacement upon saturation of the filter element is not possible. The present invention aims to provide such a filter in order to overcome the aforementioned difficulties.

[0011] This task is solved in a surprisingly simple but effective way by a filter according to the teaching of claim 1 and claim 8.

[0012] According to the invention, a filter for filtering fluids is proposed, wherein the filter comprises a housing and a filter element received in the housing, the filter element comprising at least a first layer and at least a second layer of a textile fabric, in particular nonwoven fabric, wherein the textile fabric forms spaces between the layers and wherein the layers are arranged one on top of the other. The invention is characterized in that each layer comprises at least one recess, wherein the recesses of the layers are several times larger than the spaces between them, and that the recess of the first layer is arranged offset from the recess of the second layer.

[0013] The basic idea of ​​the invention is that the recesses in the filter layers create a bypass, so that when the filter becomes saturated, the fluid to be filtered can continue to flow through the filter via the opening bypass, thus preventing a significant slowdown or complete cessation of the fluid flow. Therefore, the fluid can continue to flow through the filter as intended, reducing the risk of failure and / or damage to the device in which the filter is used, or to other devices connected to it. Even if the filter cannot be changed promptly due to its application, its functionality is maintained.Although the larger size of the recesses, compared to the spaces between them, results in a reduced filtering effect when the bypass is activated, this reduced filtering effect is usually harmless in the short term and / or significantly less harmful in the long term than a strong slowing down or complete cessation of the fluid flow.

[0014] The filter should be suitable for filtering fluids of all kinds. For this purpose, it comprises a housing into which the fluid can be introduced and from which it can be discharged. The housing preferably includes an inlet opening and an outlet opening. The filter element is housed within the casing and arranged such that the fluid to be filtered passes through the filter element as it travels through the casing. The casing is particularly preferably cylindrical or rectangular, with the inlet opening preferably located on a first end face of the cylinder or rectangular prism and the outlet opening located on a second end face opposite the first.

[0015] Any fluid is conceivable within the scope of the invention. Particularly preferred fluids are fuel, especially gasoline, kerosene, diesel or biodiesel; machine oil, especially engine oil, gear oil, hydraulic oil or turbine oil; coolant; acid; solvent; a fuel additive; a foodstuff, especially cooking oil; a beverage, especially juice or nectar; and / or vinegar; and / or exhaust gas. In particular, the filter according to the invention is suitable for removing bacteria from biodiesel. The filter removes at least 98% of the bacteria from the biodiesel in a single pass.

[0016] The filter element's function is to retain particles above a predetermined size. This function is performed by the textile fabric, which is arranged in layers. The textile fabric comprises at least a first layer and a second layer, which are arranged one on top of the other. The textile fabrics are designed to have a very large surface area relative to their height. They are arranged so that their surfaces are in contact with each other. Preferably, the first and second layers of the textile fabric are formed from the same fabric, by winding the fabric cylindrically or rectangularly and enclosing a space in the center. Each complete winding forms one layer. It is also preferably conceivable that the textile fabric is folded to form the first and second layers.The side surfaces of the folds each form the layers. Even more preferably, the layers are formed by individual sections of textile fabrics arranged in stacks. Most preferably, the filter element is arranged in the housing such that the fluid, on its way through the filter, enters on one side surface of the first layer and exits on an opposite side surface of the second and / or a final layer. This arrangement allows the fluid to flow through all layers, resulting in a particularly reliable filtering effect. A nonwoven fabric is especially preferred. Nonwovens are simple and inexpensive to produce. Preferably, the filter element comprises between 40 and 60 layers.The most preferred filter insert includes at least three, four, five, six, seven, eight, nine, ten, eleven, twelve, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100 layers, wherein the individual layers have a recess, the recess being several times larger than the spaces between the layers, and the recesses in each layer being offset from the recesses in the adjacent layer(s). This results, on the one hand, in a better filtration effect of the filter, and on the other hand, it increases the pressure required to trigger the bypass function.The triggering mechanism of the bypass function is described elsewhere. The textile fabric forms spaces between its fibers. Particles from the fluid are retained in these spaces, thus achieving the filter's filtration effect. The size of the spaces determines the minimum size of the particles to be filtered. Filtration of particles down to 0.5 pm is particularly preferred. The required size of the spaces for this filtering effect is known to those skilled in the art. The textile fabric preferably comprises elastic fibers and flexible, but inelastic, fibers. This allows for the retention of larger particles and the passage of smaller particles. The elastic fibers are preferably made of polypropylene and / or polyester. The flexible fibers are preferably made of cellulose.The size of the gaps is determined by the average spacing of the fibers. The average diameter of the gaps is preferably between 10 µm and 200 pm. Particularly preferably, the diameter of the gaps is at least 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 110 pm, 120 pm, 130 pm, 140 pm, 150 pm, 160 pm, 170 pm, 180 pm or 190 pm and / or at most 190 pm, 180 pm, 170 pm, 160 pm, 150 pm, 140 pm, 130 pm, 120 pm, 110 pm, 100 pm, 90 pm, 80 pm, 70 pm, 60 pm, 50 pm, 40 pm, 30 pm or.

[0017] 20 pm.

[0018] The first and second layers each have a recess that is several times larger than the spaces between the layers. The recesses are staggered relative to each other. When the filter becomes saturated, the recesses create a bypass by forcing the individual layers apart due to a pressure drop or rise in the fluid. This allows the fluid to flow from the recess in the first layer, between the layers, to the recess in the second layer. The filter is therefore not blocked. However, due to the larger recess size, the filtration efficiency is reduced, preferably to about 15 m / s. The bypass function is particularly preferably activated when the relative pressure is above 3 bar and / or below -0.4 bar. The relative pressure values ​​are referenced to a standard pressure of 1 bar absolute pressure and correspond to an absolute pressure of 4 bar or 0.6 bar, respectively.Under normal circumstances, the first and second layers are positioned so that the fluid cannot flow between them. Therefore, the normal filtering effect is maintained safely and reliably. The trigger pressure can be adjusted by the distance between the cutouts, the size, and / or the number of layers.

[0019] Preferably, the filter element has a length of 25 mm to 3,000 mm. Adjusting the length ensures the filter remains universally applicable. More preferably, the filter is manufactured in different lengths with regular increments. Particularly preferably, the filter includes a sensor capable of measuring the saturation, pH value, and / or water content of the fluid before and / or after filtration. The sensor provides information about the filter's condition and can indicate a necessary replacement at an early stage. This is particularly advantageous because the bypass function prevents the fluid from slowing down, which, in prior art filters, can be an indicator of saturation. Even more preferably, the housing includes an RFID chip. Specific data can be stored on the RFID chip, identifying the filter, providing copy protection, and / or containing information on the filter's use.

[0020] The term "textile fabric" refers to a textile product in which fibers are woven together in a structured or unstructured manner or laid flat on top of each other.

[0021] The term "layer" refers to an area of ​​a textile fabric that is in contact with at least one side surface of another layer of a textile fabric. The term "cutout" refers to a continuous separation of a section in a textile fabric, preferably produced by stippling. It is also conceivable that the cutout is elongated, for example, straight or curved.

[0022] The term "bypass" refers to a circumvention of the flow path intended for the fluid during normal operation.

[0023] The term "mean diameter of the spaces" refers to the arithmetic mean of the diameter across a large proportion, preferably all, of the spaces. It is known to those skilled in the art that in a textile fabric, the fibers touch each other at some points and run closer together, but at other points they are further apart. Here, what is meant is the mean diameter of the spaces along the entire length.

[0024] The term "length" refers to the extent of the filter element in the intended flow direction of the fluid.

[0025] The term "particle" refers to small particles of physical, chemical, and / or biological origin that are suspended in a fluid. In particular, bacteria and viruses are considered particles within the meaning of this disclosure.

[0026] The built-in bypass in the filter opens up further application areas for the filter, making it universally applicable. This reduces costs and ensures continued reliable function, even in the event of filter oversaturation.

[0027] Advantageous embodiments of the invention, which can be implemented individually or in combination, are described in the dependent claims. It is conceivable that the first layer and the second layer comprise at least two recesses, wherein the recesses are arranged in a regular pattern and wherein the pattern of the first layer is offset from the pattern of the second layer. Particularly in the case of large filter elements, the use of at least two recesses allows for a reduction in the pressure required to trigger the bypass. This enables the reliable production of even large filter elements. It is conceivable that the number of recesses in a cylindrically wound filter element increases from the inside out, layer by layer.

[0028] In a further development of the invention, it is conceivable that the recesses are at least five times larger than the spaces between them. This enables a good and reliable bypass system. The filter can therefore be used safely in a wide variety of applications. Particularly preferred are the recesses being at least ten, fifteen, and / or twenty times larger than the spaces between them.

[0029] Furthermore, it is conceivable that the filter includes at least one end cap, with the end cap positioned at an edge of the layers and the edges bonded to the end cap. This bonding prevents lateral flow of the fluid to be filtered, even if it is a low-viscosity and / or light fluid. The filter can therefore be used for a wide variety of fluids. The number of end caps depends on the arrangement of the layers and / or the design of the filter. For a filter element wound into a cylinder, it is particularly preferred if an end cap is positioned at both ends of the cylinder and bonded to it. For rectangular layers, it is preferred if an end cap is positioned on each side of the rectangle. It is also conceivable that the filter includes at least two end caps that together enclose the layers at their edges.The term "edge" refers to the boundary area of ​​the side surface and / or the tip of a fold of the side surface.

[0030] In a further development of the invention, it is conceivable that the edges are bonded to the end cap using a two-component structural epoxy resin adhesive. Two-component adhesives form reliable and strong bonds. Structural epoxy resin adhesives are characterized by their durability and resistance to most fluids, especially those mentioned elsewhere. They are also suitable for use in high-temperature environments. Preferably, the components are epoxy and amine. A further preferred mixing ratio by volume and / or weight is two to one, epoxy to amine. Even more preferably, the adhesive includes a corrosion inhibitor and / or glass beads to ensure optimal adhesive thickness. Most preferably, the adhesive is solvent-free and / or PVC-free.

[0031] In a further development, it is conceivable that the end cap is made of a material consisting entirely of linear polyphenylene sulfide. Linear polyphenylene sulfide is characterized by its chemical resistance to most fluids, especially those mentioned elsewhere. Furthermore, polyphenylene sulfide has good flow properties and can therefore be processed quickly and cost-effectively. In addition, it is highly durable and therefore resilient. Moreover, it can be used safely and reliably up to a temperature of 130°C. The filter can therefore be used in a wide variety of applications. Furthermore, the housing is also preferably made of polyphenylene sulfide.

[0032] The material, especially the polyphenylene sulfide, is particularly preferred in a glass fiber reinforced form. In particular, a glass fiber content of 20% to 60% by weight and / or volume is preferred, even more than at least 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58% or 59% and / or at most 59%, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%. 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, or 21% are preferred. The fiberglass makes the material particularly resistant and therefore suitable for use in high-stress applications.

[0033] It is assumed that the definitions and / or explanations of the above-mentioned terms apply to all aspects described below in this description, unless otherwise stated.

[0034] According to the invention, a filter for filtering fluids is further proposed, wherein the filter comprises a housing and a filter element received in the housing, the filter element comprising at least a first layer and a second layer of textile fabric, in particular nonwoven fabric, wherein the textile fabric forms spaces between the layers and wherein the layers are arranged one on top of the other. The filter is characterized in that the filter comprises at least one end cap, wherein the end cap is arranged at an edge of the layers and the edges are bonded to the end cap.

[0035] The basic idea of ​​the invention is that the at least one end cap creates an inescapable barrier for most fluids, including low-viscosity and / or light fluids. The fluid therefore cannot flow past layers of textile fabric. The filter can thus be used for a wide variety of fluids.

[0036] The filter should be suitable for filtering all types of fluids. For this purpose, it comprises a housing into which the fluid can be introduced and from which it can be discharged. The housing preferably includes an inlet opening and an outlet opening. The filter element is housed within the casing and arranged such that the fluid to be filtered passes through the filter element as it travels through the casing. This passage is ensured by the bonding at the end cap. The casing is preferably cylindrical or rectangular, with the inlet opening preferably located on a first end face of the cylinder or rectangular prism and the outlet opening on a second end face opposite the first. Furthermore, the end caps are preferably positioned at the inlet and outlet openings in such a way that they form a seal against the surrounding environment.

[0037] Any fluid is conceivable within the scope of the invention. Particularly preferred fluids are fuel, especially gasoline, kerosene, diesel or biodiesel; machine oil, especially engine oil, gear oil, hydraulic oil or turbine oil; coolant; acid; solvent; a fuel additive; a foodstuff, especially cooking oil; a beverage, especially juice or nectar; and / or vinegar; and / or exhaust gas. In particular, the filter according to the invention is suitable for removing bacteria from biodiesel. The filter removes at least 98% of the bacteria from the biodiesel in a single pass.

[0038] The filter element's function is to retain particles above a predetermined size. This function is performed by the textile fabric, which is arranged in layers. The textile fabric comprises at least a first layer and a second layer, arranged one on top of the other. The textile fabrics are designed to have a large surface area relative to their height. They are arranged so that their surfaces are in contact with each other. Preferably, the first and second layers of the textile fabric are formed from the same fabric, which is wound cylindrically or rectangularly, enclosing a space in the center. Each complete winding forms one layer. It is also preferably possible for the textile fabric to be folded to form the first layer, the second layer, and / or further layers.The side surfaces of the folds each form the layers. Even more preferably, the layers are formed by individual sections of textile fabrics arranged in stacks. Most preferably, the filter element is arranged in the housing such that the fluid, on its way through the filter, enters on one side surface of the first layer and exits on an opposite side surface of the second and / or a final layer. This arrangement allows the fluid to flow through all layers, resulting in a particularly reliable filtering effect. A nonwoven fabric is especially preferred. Nonwovens are simple and inexpensive to produce. Preferably, the filter element comprises between 40 and 60 layers.Preferably, the filter element comprises at least three, four, five, six, seven, eight, nine, ten, eleven, twelve, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100 layers, wherein the individual layers are bonded to at least one end cap along at least one edge. This results in improved filtration of the filter, as the fluid flows reliably through all layers.

[0039] The textile fabric forms spaces between its fibers. These spaces retain particles from the fluid, thus achieving the filter's filtration effect. The size of these spaces determines the minimum particle size that can be filtered. Filtration of particles down to 0.5 pm is particularly preferred. The required size of the spaces for this filtering effect is known to those skilled in the art. The textile fabric preferably comprises elastic fibers and flexible, but inelastic, fibers. This allows for the retention of larger particles and the passage of smaller particles. The elastic fibers are preferably made of polypropylene and / or polyester. The flexible fibers are preferably made of cellulose. The size of the spaces is determined by the average spacing of the fibers.The average diameter of the gaps is preferably between 10 pm and 200 pm. Particularly preferably, the diameter of the gaps is at least 20 pm, 30 pm, 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 110 pm, 120 pm, 130 pm, 140 pm, 150 pm, 160 pm, 170 pm, 180 pm or 190 pm and / or at most 190 pm, 180 pm, 170 pm, 160 pm, 150 pm, 140 pm, 130 pm, 120 pm, 110 pm, 100 pm, 90 pm, 80 pm, 70 pm, 60 pm, 50 pm, 40 pm, 30 pm or 20 pm.

[0040] The layers are bonded at their edges to at least one end cap. The bonding and the end cap serve to effectively and completely prevent fluid from flowing past the layers, thus preventing the fluid from passing through them. The adhesive and the material used for the bonding should be as durable and resistant as possible. Possible embodiments are disclosed in the dependent claims. The number of end caps depends on the arrangement of the layers or the design of the filter. For a filter element wound into a cylinder, it is particularly preferred if an end cap is arranged on both ends of the cylinder and bonded to it. For rectangular layers, it is preferred if an end cap is arranged on each side of the rectangle. It is also conceivable that the filter comprises at least two end caps which together enclose the layers at their edges.Preferably, the filter element has a length of 25 mm to 3,000 mm. Adjusting the length ensures the filter remains universally applicable. More preferably, the filter is manufactured in different lengths at regular intervals. Particularly preferably, the filter includes a sensor capable of measuring the saturation, pH value, and / or water content of the fluid before and / or after filtration. The sensor provides information about the filter's condition and can indicate when a replacement is necessary. Even more preferably, the housing includes an RFID chip. Specific data can be stored on the RFID chip, identifying the filter, providing copy protection, and / or containing information on the filter's use.

[0041] Bonding the layers to the end cap in the filter opens up further areas of application, and in particular enables the filtering of a wide variety of fluids, making it universally applicable. This reduces costs and simplifies inventory management.

[0042] In a further development of the invention, it is conceivable that the edges are bonded to the end cap using a two-component structural epoxy resin adhesive. Two-component adhesives form reliable and strong bonds. Structural epoxy resin adhesives are characterized by their durability and resistance to most fluids, especially those mentioned elsewhere. They are also suitable for use in high-temperature environments. Preferably, the components are epoxy and amine. A further preferred mixing ratio by volume and / or weight is two to one, epoxy to amine. Even more preferably, the adhesive includes a corrosion inhibitor and / or glass beads to ensure optimal adhesive thickness. Most preferably, the adhesive is solvent-free and / or PVC-free.In a further development, it is conceivable that the end cap is made of a material consisting entirely of linear polyphenylene sulfide. Linear polyphenylene sulfide is characterized by its chemical resistance to most fluids, especially those mentioned elsewhere. Furthermore, polyphenylene sulfide has good flow properties and can therefore be processed quickly and cost-effectively. It is also highly strong and therefore durable. Moreover, it can be used safely and reliably up to a temperature of 130°C. The filter can therefore be used in a wide variety of applications. Furthermore, the housing is also preferably made of polyphenylene sulfide.

[0043] In a preferred embodiment, the material, in particular the polyphenylene sulfide, is glass fiber reinforced. In particular, a glass fiber content of 20% to 60% by weight and / or volume is preferred, even more than at least 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58% or 59% and / or at most 59%, 58%, 57%, 56%, 55%, 54%, 53%, 52%, 51%, 50%, 49%, 48%. 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, 30%, 29%, 28%, 27%, 26%, 25%, 24%, 23%, 22%, or 21%. The fiberglass makes the material particularly resistant and therefore suitable for use in high-stress applications.

[0044] It is conceivable that the first and second layers each have a recess that is several times larger than the spaces between the layers. The recesses are arranged offset from one another. When the filter becomes saturated, the recesses create a bypass by forcing and / or pulling the individual layers apart due to a pressure drop or rise in the fluid. This allows the fluid to flow from the recess in the first layer, between the layers, to the recess in the second layer. The filter is therefore not blocked. However, due to the larger recess, the filtration efficiency is reduced, preferably to about 15 pm. The bypass function is particularly preferably activated when the relative pressure is above 3 bar and / or below -0.4 bar. The relative pressure values ​​are referenced to a standard pressure of 1 bar absolute pressure and correspond to an absolute pressure of 4 bar or 0.6 bar, respectively.Under normal circumstances, the first and second layers are positioned so that the fluid cannot flow between them. Therefore, the normal filtering effect is maintained safely and reliably. The trigger pressure can be adjusted by the distance between the cutouts, the size, and / or the number of layers.

[0045] It is conceivable that the first and second layers each comprise at least two recesses, the recesses being arranged in a regular pattern, with the pattern of the first layer offset from the pattern of the second layer. Particularly in large filter elements, the use of at least two recesses allows for a reduction in the pressure required to trigger the bypass. This enables the reliable production of even large filter elements. It is also conceivable that the number of recesses in a cylindrically wound filter element increases from the inside out, layer by layer.

[0046] In a further development of the invention, it is conceivable that the recesses are at least five times larger than the spaces between them. This enables a good and reliable bypass system. The filter can therefore be used safely in a wide variety of applications. Particularly preferred are the recesses being at least ten, fifteen, and / or twenty times larger than the spaces between them. Further details, features, and advantages of the invention will become apparent from the following description of the preferred embodiments in conjunction with the dependent claims. The respective features can be implemented individually or in combination with one another. The invention is not limited to the embodiments shown. The embodiments are shown schematically in the figures.

[0047] Specifically, we show:

[0048] Fig. 1 shows a perspective view of an embodiment of a filter according to the invention; and

[0049] Fig. 2 shows a perspective view of another embodiment of a filter according to the invention.

[0050] Fig. 1 shows a perspective view of an embodiment of a filter 01 according to the invention. The filter 01 comprises a housing 02 in which a filter element 03 is inserted. The filter element 03 comprises several layers 04 of textile fabric, of which only one layer 04 is shown by way of example in Fig. 1. The filter element 03 is formed by rolling a long textile fabric cylindrically in the manner of a kitchen roll, so that the fabric overlaps itself and thus forms the layers 04. The layer 04, as well as the adjacent layers 04 not shown in Fig. 1, has a plurality of recesses 05 arranged in a regular pattern. The recesses 05 are largely offset from one another. During operation of the filter 01, a fluid is introduced into the free space 07 in the middle of the cylindrically rolled filter insert 03, whereby the fluid flows through the layers 04.The layers 04 have gaps that retain particles contained in the fluid. Once the filter element 03 is saturated, the layers 04 are forced apart, and the fluid can flow between them from one recess 05 in one layer 04 to the next in the next layer 04. At particularly high saturation and the associated high pressure, the individual layers 04 can tear between at least two recesses 05, thus further facilitating the flow of the fluid. The filter element 03 is bonded to each end of the cylinder with an end cap 06, which prevents the fluid to be filtered from flowing past it laterally. The filter 01 also includes a sensor 08, which is arranged between the end caps 06. The sensor 08 can measure the saturation, pH value, and / or water content of the fluid before and / or after filtration.This allows conclusions to be drawn about the condition of filter 01 and / or filter element 03, which can indicate a necessary replacement at an early stage. An RFID chip 09 is located in the end cap 06, which contains information about filter 01, in particular a type and / or serial number or operating instructions.

[0051] Fig. 2 shows a perspective view of another embodiment of a filter 01 according to the invention, which has essentially the same features as the embodiment in Fig. 1. These features will therefore not be discussed in detail. In Fig. 2, it can be seen that the recess 05 is elongated (not shown in detail). In this way, it is possible for a fluid to be introduced into the free space 07 in the middle of the cylindrically rolled filter element 03 during operation of the filter 01. The fluid then flows through the layers 04, with an elongated recess 05 being formed on the layers 04. As soon as the filter element 03 is saturated, the layers 04 are forced apart, and the fluid can flow between them through the recess 05. Reference numeral list 01 Filter

[0052] 02 Housing

[0053] 03 Filter insert

[0054] 04 Location

[0055] 05 Exclusion

[0056] 06 End cap

[0057] 07 Free space

[0058] 08 Sensor

[0059] 09 RFID chip

Claims

Patent claims 1. Filter (01) for filtering fluids comprising a housing (02) and a filter element (03) received in the housing (02), wherein the filter element (03) comprises at least a first layer (04) and a second layer (04) of textile fabric, in particular nonwoven fabric, wherein the textile surface structure forms spaces, wherein the layers (04) are arranged on top of each other, characterized by that the layers (04) each comprise at least one recess (05), wherein the recesses (05) are several times larger than the spaces between them, and that the recess (05) of the first layer (04) is arranged offset from the recess (05) of the second layer (04).

2. Filter (01) according to claim 1, characterized by that the first layer (04) and the second layer (04) comprise at least two recesses (05), wherein the recesses (05) are arranged in a regular pattern and wherein the pattern of the first layer (04) is offset from the pattern of the second layer (04).

3. Filter (01) according to one of claims 1 or 2, characterized by that the recesses (05) are at least 5 times larger than the spaces between them.

4. Filter (01) according to one of the preceding claims, characterized by that the filter (01) comprises at least one end cap (06), wherein the end cap (06) is arranged on an edge of the layers (04) and the edges are bonded to the end cap (06).

5. Filter (01) according to claim 4, characterized by that the edges are bonded to the end cap (06) using a two-component structure epoxy resin adhesive.

6. Filter (01) according to one of claims 4 or 5, characterized by that the end cap (06) is made of a material comprising linear polyphenylene sulfide.

7. Filter (01) according to claim 6, characterized by that the material is glass fiber reinforced and in particular has a proportion of 20% to 60% glass fiber.

8. Filter (01) for filtering fluids comprising a housing (02) and a filter element (03) received in the housing (02), wherein the filter element (03) comprises at least a first layer (04) and a second layer (04) of textile fabric, in particular nonwoven fabric, wherein the textile surface structure forms spaces and wherein the layers (04) are arranged on top of each other, characterized by that the filter (01) comprises at least one end cap (06), wherein the end cap (06) is arranged on an edge of the layers (04) and the edges are bonded to the end cap (06).

9. Filter (01) according to claim 8, characterized by that the edges are bonded to the end cap (06) using a two-component structure epoxy resin adhesive.

10. Filter (01) according to one of claims 8 or 9, characterized by that the end cap (06) is made of a material comprising linear polyphenylene sulfide.

11. Filter (01) according to claim 10, characterized by that the material is glass fiber reinforced and in particular has a proportion of 20% to 60% glass fiber.

12. Filter (01) according to one of claims 8 to 11, characterized by that the layers (04) each comprise at least one recess (05), wherein the recesses (05) are several times larger than the spaces between them, and that the recess (05) of the first layer (04) is arranged offset from the recess (05) of the second layer (04).

13. Filter (01) according to claim 12, characterized by that the first layer (04) and the second layer (04) comprise at least two recesses (05), wherein the recesses (05) are arranged in a regular pattern and wherein the pattern of the first layer (04) is offset from the pattern of the second layer (04).

14. Filter (01) according to one of claims 12 or 13, characterized in that that the cutouts (05) are at least 5 times larger than the spaces between them.

Images