Filter system with ionization device
Patent Information
- Application Number
- DE102023126909
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-10-04
- Publication Date
- 2025-04-10
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
The invention relates to a filter system, in particular for use in vehicles, and to a vehicle module comprising a corresponding filter system. Furthermore, a vehicle comprising a corresponding vehicle module is disclosed.Modern filtration technology today knows numerous powerful alternatives and further developments to the well-known methods for separating undesired components from fluid streams, which are mostly based on a substantially mechanical separation, mostly on a merely partially permeable filter element, which can consist for example of a porous material.One of these further developments, which is used in particular for gas cleaning, is the so-called electrostatic separation, the devices used also being referred to as electrostatic precipitators. In these electrostatic precipitators, the particles to be removed are ionized by an electrode in a first step and are subsequently deposited on an oppositely charged precipitation electrode. Corresponding electrostatic precipitators are used in particular in industrial plants.However, other requirements are placed on the performance characteristics of interior air filters, in particular for use in vehicles, wherein, for example, reliable separation of pollen and / or particulate matter and / or odors and / or exhaust gases is also desired.In order to meet these requirements for indoor air filters, the concept of electrostatic separation, which in many cases is strictly not filtration, has been combined with mechanical separation methods to obtain efficient filter elements. The combination of classic filter materials with an ionization device makes it possible in many cases to already significantly increase the separation performance of filters, wherein the corresponding filter elements are referred to as electrostatic separators with filter functionality for the purposes of clear identification within the scope of the present invention. However, in the case of corresponding filter elements, it is observed that the separation performance can decrease over the service life of the filter element, which is frequently attributed to an electrostatic charge in the filter material that is reduced over time.To solve this problem, it has been proposed to design electrostatic separators with filter functionality such that a polarization of the filter material can be caused in the filter insert by the application of a voltage to two polarization elements via the build-up of an electric field. In combination with an ionization device, this polarization of the filter material can enable efficient separation, which can advantageously be preserved for the most part over the entire service life of the filter element. Background information on the basic technology is disclosed, for example, in WO 2007 / 135232 A1 or EP 3 448 540 B1.Particularly advantageous configurations of these electrostatic separators with filter functionality can be obtained if the polarization elements are at least partially integrated into the filter medium installed in the filter insert. For this purpose, individual layers of a multilayer filter medium can be designed as electrically conductive layers. Such an electrically conductive conductor layer of the filter medium can, for example, together with a second polarization element arranged on the vehicle side or together with a second electrically conductive conductor layer, cause the polarization of a dielectric filter material. Due to the at least partial integration of the polarization elements into the filter medium and thus the filter insert, efficient filter inserts are obtained which in particular have an advantageous weight and make it possible to reduce or even completely eliminate the requirements imposed on the devices required on the vehicle side if no vehicle-side polarization elements have to be provided in order to realize the polarization of the dielectric layer.The basically advantageous configuration of the filter media or of the filter inserts with integrated electrically conductive conductor layers is, however, also associated with challenges, in particular in industrial production.The integration of conductor layers functioning as polarization element into multilayer filter media is not trivial from a manufacturing standpoint. For this reason, solutions are proposed in the prior art, such as in particular the occurrence of manufacturing errors, which can result from undesired contacting of the conductor layers, for example, can be avoided, as is disclosed in DE 102023121052 A1, for example.In the course of developing a powerful filter system, the inventors have recognized that, in particular, the use of activated carbon layers in the multilayer filter medium can make the processing of the starting materials considerably more difficult, in particular in a continuous process. The integration of corresponding activated carbon layers into the multilayer filter medium leads, in particular when using many industrially customary separation methods, for example in many pinch cuts, to an undesirable reduction in the breakdown voltage which can be achieved with the multilayer filter medium. Without wishing to be bound by this theory, the inventors assume that the mechanical stress occurring in the separation process can lead to the formation of activated carbon dust, which can enter the dielectric layer in the cut region and increase its electrical conductivity locally in an undesired manner.This finding of the disadvantageous effect of activated carbon layers in multilayer polarization filter media on their processing is particularly disadvantageous with regard to the industry requirements, in particular in the field of the vehicle industry. For many applications, especially in the vehicle sector, filter systems are expected to have advantageous absorption properties with respect to pollutants, which in many cases makes it necessary to use activated carbon in the filter system. Accordingly, there are regularly requirements which necessitate the use of such so-called combimedias, in the filter media composite of which an activated carbon layer is provided.In the course of the increasing requirements for the performance of modern filter systems and the quality of the interior air filtering desired by the vehicle manufacturers, the development is directed towards providing in the future significantly larger amounts of activated carbon and thus significantly larger weights per unit area in order to optimize the desired performance properties in the range of immediate breakthrough and the total absorption capacity for pollutants. The instant breakthrough indicates how large the percentage proportion of a specific gas is, which passes through the filter system despite the activated carbon used.In order to contact the entire fluid to be filtered with the activated carbon, it is also necessary to design the activated carbon layer over the entire surface in a multi-layer filter medium, so that no bypassing of the activated carbon is possible. At the same time, limits are set in the production of the packing density for the activated carbon particles, since the pressure loss and the flow resistance which arise must not become too great.Even in conventional combi filters which provide an activated carbon layer in the multi-layer filter medium, the increasing requirements for the quantity of activated carbon to be used in light of the requirements for the flow properties result in the required installation space increasing, although the required installation space is likewise a frequently limited resource, in particular in the area of the vehicle industry.The use of electrostatic precipitators with filter functionality can reduce the installation space required. The desired large inflow surface of the multilayer filter medium used, in combination with the desired high adsorption effect by activated carbon, however, also leads in these systems, which are advantageous per se, to an increase in the installation space required. In addition, the thickness of the multilayer filter media also increases, which has an effect on the field strength of the electric field which serves for the polarization of the dielectric layer.In addition, the inventors have found that the difficulties described above in the production of multilayer filter media into which at least one conductor layer is integrated are additionally made more difficult by the required high activated carbon contents in such a way that many of the solutions proposed in the prior art for process control are also not suitable, or are not sufficiently suitable, in order to solve the production-related problems.The primary object of the present invention was to eliminate or at least alleviate the disadvantages of the prior art.In particular, it was an object of the present invention to specify a particularly efficient filter system with which excellent results can be achieved both in particle filtration and in pollutant adsorption.It was an object of the present invention that the filter system to be specified should be comparable with respect to performance in pollutant adsorption to classic combi filter systems in which an activated carbon layer is integrated into the multilayer filter medium. In this respect, it was a desirable requirement that the filter system to be specified should also be adaptable to requirements which increase in the future for higher adsorption capacities and even further increase in activated carbon contents.In this respect, it was an object of the present invention that the advantageous adsorption performance should not be associated with a reduced durability of the multilayer filter medium used, wherein it was particularly desirable that filter media having an advantageous breakdown voltage and an advantageous polarization effect can be used.In addition, it was an object of the present invention that the filter media used in the filter system to be specified should be particularly easy to produce and should be time-efficient and cost-effective. In this case, it was a desirable requirement that the multilayer filter media to be used should be producible as far as possible on classical installations and using established processing methods without a disadvantageous reduction in the breakdown voltage occurring, in particular in the case of multilayer filter media in which two conductor layers are integrated as polarization elements.It was a further object of the present invention that the filter system to be specified should have an advantageous ratio between filter performance and pollutant adsorption on the one hand and the required installation space on the other hand.In addition, it was an object of the present invention that the filter system to be specified should have to be maintained in a particularly time- and cost-effective manner.In addition, it was an object of the present invention to provide a vehicle module which comprises a corresponding filter system.It was a secondary object of the present invention to additionally specify a vehicle having a corresponding vehicle module.The present inventors have now found that the above-described objects can be advantageously achieved by combining an electrostatic precipitator with filter functionality with a separate activated carbon stage as defined in the claims.By this procedure, it is possible to provide the required adsorption capacity by a separate activated carbon filter stage, whereby the need to provide a separate activated carbon layer in the multi-layer filter medium of the electrostatic precipitator with filter functionality is advantageously eliminated. This allows the production method to be simplified and the handling properties of the multilayer filter media, in particular their breakdown voltage, to be significantly improved. In addition, the inventors have found that the separation of the activated carbon filter stage can achieve a significant improvement in the overall installation space required, since the flow-relevant properties of the activated carbon stage can be adjusted separately from the inflow surface of the multilayer filter medium.The above objects are achieved, accordingly, by the subject matter of the invention as defined in the claims. Preferred embodiments according to the invention are evident from the dependent claims and the following explanations.Such embodiments, which are referred to below as preferred, are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments referred to below as particularly preferred are thus very particularly preferred. Also preferred are embodiments in which a feature of one embodiment designated as preferred to any extent is combined with one or more further features of other embodiments designated as preferred to any extent. Features of preferred vehicle modules and vehicles result from the features of preferred filter systems.The invention relates in particular to a filter system comprising:i) a fluid guidance system for guiding a fluid to be filtered,ii) an ionization device for ionizing constituents of the fluid to be filtered,iii) a filter cartridge comprising:a) a multilayer filter medium comprising as first polarization element an electrically conductive first conductor layer and a filter layer, wherein the filter layer comprises at least one dielectric layer, andb) an electrical contacting system for connecting the filter insert to a voltage source, preferably a high-voltage source, wherein the electrical contacting system is configured such that a voltage can be applied to the first conductor layer,iv) a second polarization element, andv) an activated carbon stage separate from the multilayer filter medium, comprising an activated carbon volume, wherein the activated carbon volume comprises activated carbon in a mass fraction of 50% or more, based on the mass of the activated carbon volume,wherein the filter system is configured such that a voltage difference can be applied between the first conductor layer and the second polarization element for polarizing the dielectric layer.The filter system according to the invention serves for the filtration of fluids and is thus designed in particular for the filtering of air. In this respect, the filter system according to the invention is suitable in particular for use in vehicles. A filter system according to the invention is thus particularly relevant, wherein the filter system is an air filter system, preferably an interior air filter system, particularly preferably an interior air filter system for vehicles, in particular for land vehicles. Thus, additionally or alternatively, a filter system according to the invention is also particularly relevant, wherein the fluid to be filtered is an air mixture, preferably the air mixture guided from the outside into the interior of a vehicle through a vehicle ventilation system. Thus, additionally or alternatively, a filter system according to the invention is also particularly relevant, wherein the fluid guidance system is part of a vehicle ventilation system, preferably a blower.The filter system according to the invention comprises at least five components. The first component forms a fluid guidance system which is provided to guide the fluid to be filtered through the filter system and in particular to guide it to the further components of the filter system, so that these further components can act on the fluid to be filtered as intended. It can be seen as an advantage of the method according to the invention that it is not restricted further with regard to the selection of the fluid guidance system than typically used fluid guidance systems, for example in the area of vehicle ventilation. By way of example, a filter system according to the invention is provided, wherein the fluid guidance system comprises one or more fluid guidance lines, preferably pipes and / or shafts.The filter system according to the invention comprises an ionization device. In accordance with the expert's understanding, this ionization device is a component of an electrostatic separator with a filter function, wherein the first and / or second polarization element, in particular formed as layers of the multi-layer filter medium, can interact with the ionization device and can function in particular as a precipitation electrode. In other words, this is a filter system according to the invention, wherein the ionization device, the filter insert and the second polarization element form an electrostatic separator with filter functionality.In the filter system according to the invention, the ionization device is provided with the task of ionizing, for example, dirt particles in the fluid to be filtered and thus of promoting the separation of the dirt particles on the polarized filter layers of the multi-layer filter medium. Suitable ionization devices are known to the person skilled in the art and are disclosed, for example, in WO 2023 / 012166 A1. Relevant for essentially all embodiments are electrical ionization devices which are also known from other fields of technology and can bring about ionization in particular by corona discharge. From the standpoint of safety engineering and with regard to their handling and performance, such electric ionization devices are far superior to other methods of ionization, in particular using ionizing radiation. A filter system according to the invention is preferred, wherein the ionization device is an electric ionization device, wherein the ionization device is preferably configured to cause the ionization of components of the fluid to be filtered at least partially, preferably substantially completely, by means of corona discharge. In addition or alternatively, a filter system according to the invention is preferred, wherein the ionization device does not comprise a radiation source for ionizing radiation.The skilled person understands that the sought interaction between the ionization device and the multi-layer filter medium in the filter insert means that the filter insert with the multi-layer filter medium functioning as a precipitation electrode should be placed downstream of the ionization device in the flow direction. A filter system according to the invention is preferred accordingly, wherein the ionization device is arranged in the filter system such that the fluid to be filtered guided in the fluid guide system flows through it upstream of the filter insert, preferably directly upstream of the filter insert.The filter insert to be used according to the invention comprises a multilayer filter medium which comprises at least one electrically conductive first conductor layer. This first conductor layer is provided to cooperate as a polarization element during the polarization of the filter layer provided in the multilayer filter medium.In embodiments which are particularly simple in terms of construction, the second polarization element can be embodied, for example, as a metallic plate or grating. A filter system according to the invention is preferred accordingly with regard to the structural complexity, wherein the second polarization element is a metal plate or a metal grid.In one embodiment, the second polarization element can be formed by an element separate from the filter insert, which element can be arranged, for example, on the vehicle side. The advantage of this embodiment can be seen in the fact that the second polarization element is displaced out of the filter insert. This not only allows the weight of the filter inserts to be used according to the invention to be reduced, but also simplifies their construction, as a result of which the design as an exchangeable filter insert is facilitated. In addition, the amount of waste which arises during the replacement of a filter insert is reduced. A filter system according to the invention is preferred, wherein the second polarization element is not part of the filter insert or an element separate from the filter insert.Even if it may be advantageous for certain applications to introduce the second polarization element outside the filter insert according to the invention, the inventors find it particularly advantageous for practice to integrate the second polarization element into the filter insert. Although it would theoretically be conceivable in this case to provide the second polarization element as an element separate from the multilayer filter medium, for example again as a metallic plate, this is less preferred with regard to the total weight. In this respect, the inventors find it particularly advantageous for substantially all embodiments if the second polarization element for the polarization is likewise integrated into the multilayer filter medium, such that the multilayer filter medium comprises, in addition to a first conductor layer, also a second conductor layer and the filter layer can be arranged between this first conductor layer and the second conductor layer. A corresponding configuration of the multilayer filter medium is associated only with a slight increase in weight and leads to an advantageous polarization effect on the filter layer arranged directly between the conductor layers. In addition, it is hereby possible, without high additional costs and the need for installation space, to integrate all the parts necessary for the polarization effect into the replaceable filter insert, whereby all the components required for the proper functioning of the polarization are advantageously replaced when replacing the filter insert, so that simple maintenance of the overall system is advantageously possible.A filter system according to the invention is accordingly preferred, wherein the multilayer filter medium additionally comprises an electrically conductive second conductor layer, wherein the filter layer is arranged between the first conductor layer and the second conductor layer and wherein the second polarization element is formed by the second conductor layer.In this case, the electrical contacting of the second conductor layer can expediently likewise take place via the electrical contacting system, so that the need for further contacting systems for electrically connecting the second conductor layer is advantageously dispensed with. In this case, this is a filter system according to the invention, wherein the electrical contact-making system is configured such that a voltage difference can be applied between the first conductor layer and the second conductor layer.The further components of the filter system according to the invention, which can be assigned to the electrostatic separator with filter functionality alongside the ionization device, are the filter insert, which comprises the first conductor layer functioning as first polarization elements and at least one dielectric layer to be polarized, and the second polarization element, which interacts with the first conductor layer for the polarization of the dielectric layer. The filter system is designed such that a voltage difference can be applied between the first conductor layer functioning as the first polarization element and the second polarization element, resulting in an electric field that can polarize the dielectric layer. In addition to the first conductor layer, the multilayer filter medium also comprises at least one dielectric layer and optionally further layers. Further information regarding the layers of the multilayer filter medium and regarding the electrical contacting system is disclosed below.It can be seen as an advantage of the filter system according to the invention that the multi-layer filter media to be used in the filter insert can be processed in the usual manner and with conventional devices, in particular by means of pleated and laminated structures, wherein the process engineering difficulties associated with the processing of multi-layer filter media containing activated carbon can be avoided in an advantageous manner. For most applications, a filter system according to the invention is preferred, wherein the filter insert comprises the multi-layer filter medium as pleated filter medium. A filter system according to the invention is preferred, wherein at least one of the sides of the pleated multilayer filter medium, preferably at least two sides, particularly preferably at least the longitudinal sides, very particularly preferably all sides, are laminated with a lamination material, wherein the lamination material is preferably selected from the group consisting of foams, in particular of plastics, in particular thermosetting plastics, and textile planar structures, in particular nonwovens and felts, preferably textile planar structures.As a further element, the filter system according to the invention comprises an activated carbon stage which is separated from the multilayer filter medium according to the invention. In accordance with the expert's understanding, this means that the activated carbon stage is not part of the multilayer filter medium, so that the activated carbon stage is in particular not directly connected to the further layers of the multilayer filter medium, in particular is not materially bonded.As expressed by the name, the activated carbon level comprises activated carbon. Activated carbon is well known to the skilled person in the field of filtration technology and is commercially available from numerous suppliers in various configurations.The activated carbon stage serves the purpose in the filter system according to the invention to realize the high adsorption effect for pollutants desired by vehicle manufacturers without activated carbon having to be integrated into the multilayer filter medium for this purpose. This advantageously results in a clearly increased flexibility in the dimensioning of the activated carbon content and the design of the activated carbon filter stage, which can now be effected separately from the dimensions of the multi-layer filter medium and the flow properties required for the multi-layer filter medium.According to the invention, the activated carbon stage comprises an activated carbon volume. The expression "activated carbon volume" expresses that it is a structure with a certain volume, which is however relatively flexible with regard to the design configuration. According to the inventors' judgment, the activated carbon volume will in many cases be an activated carbon layer, wherein the thickness of this layer, in particular the thickness along the flow direction in the filter system, can be adapted by the person skilled in the art to the respective application requirements. The expression "activated carbon volume" thus takes into account the fact that, starting from an activated carbon layer, a further increase in the average thickness from a certain point can lead to the expression "layer" no longer correctly describing the geometric shape of the activated carbon volume. Preference is given to a filter system according to the invention, wherein the activated carbon volume is an activated carbon layer, wherein the activated carbon layer preferably has a weight per unit area in the range from 50 to 1000 g / m 2, particularly preferably in the range from 100 to 600 g / m 2. Additionally or alternatively, a filter system according to the invention is also preferred, wherein the activated carbon volume comprises activated carbon in an amount in the range from 20 to 2000 g, preferably in the range from 100 to 1000 g, particularly preferably in the range from 120 to 600 g.At least in principle, it is possible for the activated carbon volume to comprise further components in addition to activated carbon. Here, particular importance is attached to materials which can function as carrier material or carrier structure for the activated carbon in the activated carbon volume, in particular textile planar structures or honeycomb structures. In this case, a filter system according to the invention is preferred, in particular with a view to a robust design of the activated carbon stage, wherein the activated carbon volume comprises a three-dimensional carrier structure with cavities, wherein the activated carbon is arranged in the cavities of the three-dimensional carrier structure, wherein the three-dimensional carrier structure is preferably a textile planar structure or a honeycomb body, preferably a textile planar structure, in particular a nonwoven.However, even the above definition about the mass fraction of activated carbon in the activated carbon volume expresses that the activated carbon volume consists at least to a large extent of activated carbon in accordance with the expert understanding. According to the inventors' judgment, it is particularly preferred with a view to an advantageous adsorption effect for pollutants to provide the highest possible proportion of activated carbon in the activated carbon stage or the activated carbon volume, in particular also from the viewpoint of a construction optimized in terms of installation space. A filter system according to the invention is namely preferred, wherein the activated carbon stage consists of 80% or more, preferably 90% or more, particularly preferably 95% or more, in particular preferably 98% or more, of the activated carbon volume, based on the mass of the activated carbon stage. In addition or alternatively, a filter system according to the invention is preferred, wherein the activated carbon volume comprises activated carbon in a mass fraction of 70% or more, preferably 80% or more, particularly preferably 90% or more, based on the mass of the activated carbon volume.In the experiments of the inventors, the use of particulate activated carbon and activated carbon with a high specific surface area has proven particularly preferred, since advantageous adsorption properties can be obtained with this. Preference is accordingly given to a filter system according to the invention, wherein the activated carbon is particulate activated carbon, wherein the activated carbon preferably has an average diameter d50in the range from 0.1 to 4 mm, preferably in the range from 0.2 to 2 mm. Additionally or alternatively, a filter system according to the invention is preferred, wherein the activated carbon has a specific BET surface area according to DIN ISO 9277:2014-01 of 500 m 2 / g or more, preferably of 1000 m 2 / g or more, particularly preferably of 2000 m 2 / g or more.In particular when particulate activated carbon is used, it is preferred, both in the production of volumes of activated carbon with support structures and in those without support structures, to fix the activated carbon in the volume of activated carbon by means of a binder. A filter system according to the invention is preferred, wherein the activated carbon is fixed in the activated carbon volume by a binder.Even if it would be at least theoretically conceivable to provide the activated carbon stage at any desired point in the filter system, the inventors would find it particularly advantageous if the activated carbon stage is arranged such that filter functionality flows through it only after the electrostatic separator. This advantageously makes it possible to trap ozone which is formed in the ionization device before it is conducted, for example, into the interior of a vehicle. This positioning is superior in double respects to an arrangement between the ionization device and the filter insert, which could at least theoretically fulfil the same functionality with respect to ozone. Such an interposed activated carbon stage would contaminate the activated carbon stage successively with particles which could not be removed from the filter cartridge beforehand. In addition, the additional distance between the ionization device and the associated precipitation electrode in the filter insert would reduce the degree of ionization of the disadvantageous particles arriving at the filter insert, which can result in efficiency losses. A filter system according to the invention is preferred accordingly, wherein the activated carbon stage is arranged in the filter system such that the fluid to be filtered guided in the fluid guide system flows through it downstream of the filter insert, preferably directly downstream of the filter insert.As explained above, due to the advantageous fact that the activated carbon stage can be designed essentially without consideration of the structural requirements of the multi-layer filter medium and the required flow properties of the multi-layer filter medium, it is possible to reduce the installation space required for the activated carbon stage compared to the installation space by which the filter insert would theoretically have to be increased if the activated carbon is integrated as an activated carbon layer. The inventors have found it advantageous to make use of this possibility and in this case in particular to make the activated carbon stage smaller than the filter insert. A filter system according to the invention is accordingly preferred, wherein the required installation space of the activated carbon stage is smaller than the required installation space of the filter insert, preferably by 10% or more, particularly preferably by 20% or more, very particularly preferably by 30% or more, in particular preferably by 40% or more.To optimize maintainability and increase the service life of the overall filter system, the inventors propose that preferably at least the filter insert should be designed as an exchangeable filter insert, wherein it is favorable to additionally or alternatively also configure the ionization device to be exchangeable. In this respect, the ionization device and the filter insert can also be combined in a common component which can be exchanged in its entirety. A filter system according to the invention is preferred, wherein the ionization device is arranged in the filter system so as to be replaceable reversibly and non-destructively, preferably independently of the filter insert and / or the activated carbon stage, preferably independently of the activated carbon stage, and / or wherein the filter insert is arranged in the filter system so as to be replaceable reversibly and non-destructively, preferably independently of the ionization device and / or the activated carbon stage, preferably independently of the activated carbon stage. In addition or alternatively, a filter system according to the invention is preferred, wherein the ionization device and the filter insert are connected to one another and / or contact one another in the filter system, wherein the ionization device and the filter insert contact one another electrically in the filter system preferably via a frame structure and / or are connected via it.Against the background of the above embodiment for exchangeability of the ionization device and the filter insert, the inventors propose that the activated carbon stage can also be advantageously designed as an exchangeable component, so that it can easily be exchanged, in particular after reaching the total adsorption capacity, without the other parts of the filter system also occurring as waste. A filter system according to the invention is preferred, wherein the activated carbon stage is arranged in the filter system in a reversibly and non-destructively replaceable manner, preferably independently of the ionization device and / or the filter insert, particularly preferably independently of the ionization device and the filter insert.However, a filter system according to the invention is also conceivable, wherein the filter insert and the activated carbon stage are integrated into a common filter component or are connected to one another, so that the fluid to be filtered flows through the multi-layer filter medium of the filter insert and the activated carbon volume one after the other.Starting from an advantageous embodiment with an exchangeable activated carbon stage, the inventors propose that the filter system can be provided with a detection mechanism, by means of which the correct fit of the activated carbon stage in the filter system according to the invention can be verified, wherein in the case that the detection mechanism indicates that the activated carbon stage is not installed or is not installed correctly, the startup of the filter system, in particular of the ionization device, or even of the entire vehicle, can be prevented. This advantageously ensures that the ionization device, in the operation of which ozone can be generated, is not switched on if the sufficient removal of the generated ozone is not ensured by the activated carbon stage, so that in particular vehicle occupants are protected from undesired ozone generation. A corresponding detection mechanism can be designed without any restrictions by the skilled person, for example as a mechanical mechanism in which the activated carbon stage used must act on an activation element, by means of a weakly energized measurement circuit which is only closed by a correctly inserted activated carbon stage and / or using optical sensors which can detect the correct seating of the activated carbon stage, for example on the basis of a detection mark. A filter system according to the invention is preferably accordingly preferred, wherein the filter system comprises a detection mechanism, wherein the detection mechanism is configured to detect the presence and / or the correct arrangement of the activated carbon stage in the filter system, wherein the filter system is preferably configured to prevent activation of the ionization device if the detection mechanism does not detect the presence and the correct arrangement of the activated carbon stage in the filter system.The inventors have succeeded in identifying preferred configurations for the multilayer filter medium to be used according to the invention and for the individual layers thereof, in particular the conductor layers. In the light of the above explanations, the skilled person understands that it is preferred for substantially all embodiments to utilize the advantages of the separate activated carbon stage in that the multi-layer filter medium is designed to be largely free of activated carbon. For substantially all embodiments, a filter system according to the invention is correspondingly particularly preferred, wherein the mass proportion of activated carbon in the multi-layer filter medium and / or in the filter insert is 5% or less, preferably 1% or less, particularly preferably 0.5% or less, very particularly preferably 0.1% or less, in particular preferably substantially 0%, based on the mass of the multi-layer filter medium or of the filter insert. In particular, if small amounts of activated carbon are used in the conductor layers in order to ensure the electrical conductivity, it is advantageous then to make at least the remaining filter layer as free as possible of activated carbon. For many embodiments, a filter system according to the invention is accordingly additionally or alternatively preferred, wherein the mass fraction of activated carbon in the filter layer is 5% or less, preferably 1% or less, particularly preferably 0.5% or less, very particularly preferably 0.1% or less, particularly preferably substantially 0%, based on the mass of the filter layer.Furthermore, a filter system according to the invention is preferred first, wherein the first conductor layer comprises a first textile fabric, preferably a first textile fabric coated or impregnated at least in sections with an electrically conductive first material, and / or wherein the second conductor layer comprises a second textile fabric, preferably second textile fabric coated or impregnated at least in sections with an electrically conductive second material.The term "textile fabric" is clear to the skilled person and denotes two-dimensional textile products which can be woven, knitted, needled or knitted, for example. In accordance with the expert's understanding, non-textile fibrous fabrics, for example paper and cardboard, in which the fibers are held together, for example, primarily by binding agents, do not belong to the textile fabrics. Even if a wide range of textile fabrics were in principle possible for the textile fabrics of the conductor layers, the inventors have been able to achieve the best performance characteristics, in particular with so-called "nonwovens" and in this case in particular with spunbonded nonwovens. A corresponding textile fabric made of a non-conductive material can be advantageously achieved by equipping the textile fabric with a conductive material, wherein, according to the inventors' judgment, in principle a multiplicity of possible methods are suitable. A filter system according to the invention is thus preferred, wherein the first textile fabric and / or the second textile fabric, preferably the first textile fabric and the second textile fabric, is a nonwoven, preferably a spunbonded nonwoven.The distinction between an electrically conductive material as distinct from an electrically insulating material is without any constraint for those skilled in the art and based on their skilled and clear technical understanding of these terms. In this respect, a material in the context of the present invention is particularly considered to be an electrically conductive material when its specific electrical resistance at 20° C. is 10 6 Ω*m or less, preferably 10 5 Ω*m or less, particularly preferably 10 4 Ω*m or less. Conversely, a material in the context of the present invention is particularly applicable as an electrically insulating material when its specific electrical resistance at 20° C. is 10 7 Ω*m or more, preferably 10 9 Ω*m or more, particularly preferably 10 11 Ω*m or more. Accordingly, metals and alloys, however, are also carbon blacks, such as, in particular, conductive carbon black, and plastics made conductive by additives, are electrically conductive materials, whereas typical unmodified plastics such as PET or PE likewise belong to the electrically insulating materials, such as, for example, most glasses and ceramics. The electrical resistivity of materials is a value well known to the skilled person, which can be found in reference tables relevant for most materials. The measurement of the specific electrical resistance in other components takes place in accordance with the usual practice either according to DIN EN ISO 3915 from 1999, which is used in particular for particularly conductive materials, or according to IEC 60093 from 1993, which is used in the case of high specific electrical resistances. The question as to which of the two standards is to be used is directed to the specifications of the two regulations and the properties of the respective material investigated.The skilled person understands that the electrical conductivity of conductor layers, for example of the first conductor layer, can in many cases, for example when using composite materials, result from the presence of conductive material paths which run in an otherwise largely insulating material. Thus, for example, a dielectric fleece whose fibers are provided with a thin layer of conductive carbon black can be an electrically conductive layer, although the macroscopic specific resistance of the composite material is relatively high as a result of the dielectric carrier material.Furthermore, a filter system according to the invention is additionally or alternatively preferred, wherein the first textile fabric and / or the second textile fabric, preferably the first textile fabric and the second textile fabric, consist of a plastic, based on the mass of the textile fabric, to a mass fraction of 80% or more, preferably 90% or more, particularly preferably 95% or more, very particularly preferably substantially 100%, wherein the plastic is preferably selected from the group consisting of polyacrylonitriles, polyolefins, polyesters, fluoropolymers and mixtures of these plastics, particularly preferably polyacrylonitriles, polypropylene, polyethylene terephthalate, polyvinylidene fluoride and mixtures of these plastics, particularly preferably polyethylene terephthalate and polyvinylidene fluoride.In addition or alternatively, a filter system according to the invention is also preferred, wherein the first conductor layer and / or the second conductor layer, preferably the first conductor layer and the second conductor layer, can be produced or produced by finishing the respective textile planar structure, in particular the nonwoven, with the respective electrically conductive material by a method selected from the group consisting of impregnation, dip coating, in particular with a pad system, spray coating, application coating, in particular by means of a dispersion in the kiss-coat method, and pressure coating.Additionally or alternatively, a filter system according to the invention is preferred, wherein the electrically conductive first material and / or the electrically conductive second material, preferably the electrically conductive first material and the electrically conductive second material, are selected from the group consisting of metals, conductive plastics and carbon, preferably carbon, in particular carbon black or graphene, wherein the electrically conductive material is particularly preferably identical for the first conductor layer and the second conductor layer.Additionally or alternatively, a filter system according to the invention is preferred, wherein the first conductor layer and / or the second conductor layer, preferably the first conductor layer and the second conductor layer, are electrically conductive as a result of the coating of the respective textile fabric at least over 80% or more of the surface area, preferably over 90% or more, particularly preferably over 95% or more, very particularly preferably over 98% or more, in particular preferably substantially over the full surface area.Even if the conductor layers can contribute to the filtration performance of the filter media, in particular if they are designed as textile fabrics, the inventors find it advantageous if the conductor layers are designed with sufficient open pores, so that they primarily restrict the passage of air through the filter medium as little as possible. With regard to the weight of the conductor layers, at least when textile fabrics are used, there is in this respect a conflict of goals between the influence on the total weight of the filter medium and an advantageous stabilizing effect of the conductor layers on the filter medium and thus an improvement in the mechanical properties. In this respect, the inventors have succeeded in identifying suitable weights per unit area for the textile fabrics, with which this conflict of goals can be solved in an advantageous manner. Against this background, a filter system according to the invention is preferred, wherein the first conductor layer and / or the second conductor layer, preferably the first conductor layer and the second conductor layer, have an air passage at 200 Pa in the range from 500 to 30000 L / (m 2 s), preferably in the range from 2000 to 20000 L / (m 2 s). Additionally or alternatively, a filter system according to the invention is also preferred, wherein the first textile fabric and / or the second textile fabric, preferably the first textile fabric and the second textile fabric, have a basis weight in the range from 5 to 200 g / m 2, preferably in the range from 10 to 150 g / m 2, particularly preferably in the range from 15 to 50 g / m 2.With regard to the general structure of the multilayer filter medium, a filter system according to the invention is preferred, wherein the filter layer comprises one or more further layers, preferably further layers arranged between the first conductor layer and the second conductor layer, wherein the filter layer preferably comprises two or more dielectric layers, particularly preferably three or more dielectric layers.In addition or alternatively, a filter system according to the invention is also preferred, wherein at least one of the dielectric layers, preferably all of the dielectric layers, consists of a dielectric plastic material to a mass fraction of 80% or more, preferably 90% or more, particularly preferably 95% or more, very particularly preferably substantially 100%, based on the mass of the dielectric layer. Particularly preferred here is a filter system according to the invention, wherein the dielectric plastic material is selected from the group consisting of polyolefins, in particular polytetrafluoroethylene, polytetrafluoroethylenepropylene, polypropylene, and polyethylene, polyesters, in particular polyethylene terephthalate, polycarbonates, polyamides, polyvinylidene fluoride, polyacrylonitrile, and polylactides. Particularly preferred is additionally or alternatively a filter system according to the invention, wherein the dielectric plastic material has a specific electrical resistance at 20° C. of 10 7 Ω*m or more, preferably at 10 9 Ω*m or more, particularly preferably at 10 11 Ω*m or more.A filter system according to the invention is preferred for the predominant number of embodiments, wherein at least one of the dielectric layers is a particle filter layer which comprises a third textile planar structure.Particularly preferred is a filter system according to the invention, wherein the third textile fabric is a nonwoven fabric, wherein the third textile fabric is preferably selected from the group consisting of needle-punched nonwovens, electrospun nonwovens and meltblown nonwovens. Particularly preferred additionally or alternatively is a filter system according to the invention, wherein the particle filter layer has a weight per unit area in the range from 10 to 200 g / m 2, preferably in the range from 15 to 150 g / m 2, particularly preferably in the range from 20 to 110 g / m 2.With regard to the mechanical stability, a filter system according to the invention is preferred, wherein at least one of the dielectric layers is a protective layer which comprises a fourth textile planar structure. a multilayer filter medium according to the invention is particularly preferred, wherein the fourth textile planar structure is a nonwoven, preferably a spunbonded nonwoven.In addition or alternatively, a filter system according to the invention is preferred, wherein the protective layer has an air passage at 200 Pa in the range from 500 to 30000 L / (m 2 s), preferably in the range from 2000 to 20000 L / (m 2 s). Additionally or alternatively, a filter system according to the invention is also preferred, wherein the protective layer has a weight per unit area in the range from 15 to 400 g / m 2, preferably in the range from 50 to 200 g / m 2. In turn, a filter system according to the invention is preferred additionally or alternatively, wherein the protective layer comprises one or more active ingredients selected from the group consisting of antiallergic active ingredients and biocidal active ingredients.Particularly preferred is additionally or alternatively also a filter system according to the invention, wherein the protective layer has a Cucumbery flexural rigidity, determined according to ASTM D6125-97, in the range from 0.4 to 40 mN, preferably in the range from 0.5 to 20 mN, particularly preferably in the range from 0.6 to 10 mN.Regardless of whether only one conductor layer is integrated into the filter insert as part of the polarization system, or whether both polarization elements are integrated into the filter insert, in particular in the form of two conductor layers, a structure is required which distributes the voltage necessary for the polarization, which is applied to the filter insert from the outside, to the polarization element or elements in the filter insert. Within the scope of the present invention, the corresponding structure is referred to as an electrical contacting system, which is configured to connect the parts of the polarization system provided in the filter insert according to the invention, i.e. in particular the first conductor layer and optionally the second conductor layer, in an electrically conductive manner to an external voltage source, which can be part of a vehicle module, for example. A filter system according to the invention is preferred, wherein the voltage source is a high-voltage source. In addition or alternatively, with regard to the positioning, a filter system according to the invention is preferred, wherein the electrical contacting system is connected to the lamination of the pleated filter medium, preferably in a materially bonded manner.The electrical contacting system to be provided according to the invention can be designed by the person skilled in the art according to the respective application requirements and the design requirements of the filter system, in particular of the vehicle filter module. Regardless of the specific configuration of the electrical contacting system, the latter will usually comprise a first contacting element, which is provided to produce an electrically conductive contacting with the first conductor layer of the multilayer filter medium. For substantially all embodiments, a filter insert according to the invention is preferred, wherein the electrical contacting system comprises a first contact point and a second contact point for contacting the voltage source.Even if very simple embodiments of the electrical contacting system are theoretically conceivable, which for example rely on the use of cables, the inventors have designed a particularly advantageous electrical contacting system with a view to a time- and cost-effective production, which electrical contacting system can be combined particularly efficiently with the conductor layer or layers, in particular by adhesion by means of an electrically conductive plastic material. According to the inventors' judgment, it is especially advantageous if classical electrical wiring is not used or if it is used only to a small extent, but rather the contacting system is designed as largely as possible from components which consist of an electrically conductive plastic. A filter system according to the invention is accordingly preferred, wherein the electrically conductive components of the electrical contacting system are formed at least partially, preferably predominantly, particularly preferably substantially completely, by an electrically conductive plastic. Particularly preferred here is a filter system according to the invention, wherein the electrically conductive plastic of the electrical contacting system has a specific electrical resistance at 20° C. of 10 6 Ω*m or less, preferably 10 5 Ω*m or less, particularly preferably 10 4 Ω*m or less.According to the inventors' judgment, these electrically conductive components, which preferably consist of an electrically conductive plastic, should be arranged on a preferably thin substrate, which functions as a carrier and advantageously makes it possible to assemble the electrically conductive components of the electrical contacting system before attachment to the filter insert to be used according to the invention and to apply them during the production process in only a single step, for example to the lateral lamination of the filter insert. Accordingly, a filter system according to the invention is preferred, wherein the electrically conductive components of the electrical contacting system are conductive components arranged on a substrate and / or in a substrate. In addition or alternatively, a filter system according to the invention is preferred, wherein the substrate is selected from the group consisting of electrically insulating films, preferably plastic films, wherein the average thickness of the substrate is preferably in the range from 20 to 500 μm, particularly preferably in the range from 80 to 150 μm.The use of a thin substrate, in particular a film, in combination with conductive components formed from plastic advantageously allows the electrical contacting system not only to be designed in a particularly space-saving and low-weight manner, but results in an electrical contacting system with high flexibility, in which the substrate and the conductive components lying thereon can be adapted particularly easily to the structural requirements of the filter insert to be used according to the invention.The experiments of the inventors have shown in particular that a corresponding electrical contact-making system can be advantageously printed on the substrate, wherein other additive manufacturing methods could also be considered at least theoretically. A filter system according to the invention is thus preferred, wherein the electrical contacting system can be produced by printing on the substrate with an electrically conductive material, preferably an electrically conductive plastic, wherein the printing is preferably a screen printing method.In particular, additive manufacturing methods advantageously make it possible to obtain an electrical contacting system which is provided with the electrically conductive components on only one side and consequently has an underside, the properties of which are largely influenced by that of the substrate, which can advantageously be embodied as an electrically insulating substrate. With regard to the attachment, a filter system according to the invention is thus preferred, wherein the electrical contacting system comprises the electrically conductive components of the electrical contacting system at least partially, preferably predominantly, particularly preferably substantially completely, preferably at least the contact points and the contacting elements, on the same side of the substrate.In a particularly preferred embodiment, the substrate is designed as a comparatively thin film, in the central region of which essential elements of the electrical contacting system are arranged, for example the contact points for the external voltage source or also a possible voltage divider. The inventors propose that lateral wing-like or tab-like projections can be formed, on which the contacting elements are applied, which are provided for contacting the conductor layers. When such a contacting system is applied to the lateral lamination of a filter insert according to the invention, the wing-like tabs can be folded over particularly easily, so that they each contact the conductor layer and can subsequently be glued, for example, with an electrically conductive adhesive, in such a way that a cohesive connection is produced by the plastic material without this connection being made more difficult by excessively strong mechanical stresses. A filter system according to the invention is preferred accordingly, wherein the first contacting element and / or the second contacting element, preferably the first contacting element and the second contacting element, are arranged on laterally protruding projections of the substrate, wherein the laterally protruding projections preferably have a deformation region and a contact region, wherein the contact region transversely to the longitudinal direction of the filter insert is preferably wider than the deformation region. Particularly preferred is a filter system according to the invention, wherein the laterally protruding projections are L-shaped. Particularly preferred in this case is additionally or alternatively a filter insert according to the invention, wherein the laterally protruding projections are embodied in the deformation region to be reversibly and non-destructively deformable, in particular bendable.The filter inserts to be used according to the invention are intended to be combined with the ionization device in the filter system according to the invention. The voltage required for ionization will generally be significantly higher than the polarization voltage necessary for polarization or that can be applied to the maximum extent, which is limited by the voltage at which undesired breakdown occurs, in particular when the two polarization elements are integrated into the multilayer filter medium. One conceivable solution would be to provide different voltage sources for the ionization device and the filter insert. However, the inventors have recognized that such a provision of separate high-voltage sources is in many cases not possible or is associated with a high outlay on apparatus, and therefore a corresponding configuration is less preferred. For this purpose, it is proposed to design the electrical contact-making system as a voltage divider, by means of which a voltage taken over by the ionization device can be matched to the requirements of the filter insert. A filter system according to the invention is thus preferred, wherein the electrical contacting system is a voltage divider. For this purpose, the electrical contacting system can have contact points which are provided for being contacted directly or indirectly via the ionization device with an electrical potential difference which is designed for the ionization device. Between these contact points, a resistance path is provided, which preferably has a meandering contour. The voltage that is dropped across the first contacting element or, if applicable, the second contacting element can be advantageously adjusted by positioning the contacting element along this resistance path, so that, for example, only a reduced voltage is present between the two contacted conductor layers compared to the ionization device. Against this background, a filter system according to the invention is preferred, wherein in the electrical contacting system the first contact point is electrically conductively connected to the second contact point via a resistance path, wherein the first contacting element is electrically conductively connected to the resistance path between the first contact point and the second contact point, and wherein the second contacting element is electrically conductively connected to the second contact point. In addition or alternatively, a filter system according to the invention is also preferred, wherein the resistance path is formed in meandering fashion. Additionally or alternatively, a filter system according to the invention is preferred, wherein the first contacting element and / or the second contacting element, preferably the first contacting element and the second contacting element, are connected to the resistor path such that the contact area between the resistor path and the contacting element is larger than the cross section of the resistor path orthogonal to the longitudinal direction of the resistor path. In addition or alternatively, a filter system according to the invention is preferred, wherein the second contact element is not electrically conductively connected to the resistor path between the first contact point and the second contact point.In particularly preferred embodiments, in addition to the electrically conductive components of the contacting system, machine-readable information, for example in the form of a QR code, can also be provided on the substrate. In particular, if the electrical contacting system is applied to the lateral lining of the filter insert, this is particularly easy to read from the outside. This makes it possible to provide the customer or the workshop operation with important information about the handling and / or the installation of corresponding filter inserts. In addition, it is possible to rely on the machine-readable information marking already during the production of the filter inserts, for example if the information stored therein comprises instructions about the control of the devices and / or the selection of materials. A filter system according to the invention is preferred, wherein the electrical contacting system comprises a machine-readable information marking, preferably a matrix code or a QR code, wherein the machine-readable information marking comprises information and / or operating instructions about the application position of the electrical contacting system in the filter insert and / or the method parameters for connecting the contact elements to the corresponding conductor layers by means of the corresponding adhesive.The invention also relates to a vehicle module comprising:I) a filter system according to the invention, andII) a supply unit, wherein the supply unit is configured to supply the filter system, in particular the ionization device, the second polarization element and the filter insert with electrical energy.The term "vehicle module" in this case denotes, in accordance with the expert's understanding, the combination of the filter system according to the invention with those components of the vehicle which are required for operating the filter system according to the invention, in particular the supply unit for the provision of the required voltage.Finally, a vehicle comprising a vehicle module according to the invention is also disclosed.The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the attached figures. In the figures, the following are shown: FIG. 1 shows a schematic illustration of a vehicle module according to the invention with a filter system according to the invention in a preferred embodiment. FIG. 2 shows a perspective illustration of a filter insert to be used according to the invention in a preferred embodiment.FIG. 1 shows a schematic illustration of a vehicle module 36 according to the invention in a greatly simplified illustration. In FIG. 1, the further components of the filter system 10 according to the invention are arranged in the fluid guidance system 12 which is abstracted by dotted lines, wherein the flow direction of the fluid to be filtered, which can be in particular ambient air entering a vehicle from the outside, is indicated by the broad arrows.The fluid to be filtered initially passes through the ionization device 14 of the filter system 10 according to the invention, which receives the electrical energy required for operation via the supply unit 38 of the vehicle module 36. The ionization device 14 ionizes constituents of the air, in particular dust particles, by means of a corona discharge, whereupon the ionized constituents are guided further in the direction of the filter insert 16 by the fluid flow. In the filter insert 16, the ionized constituents of the air strike the multilayer filter medium 18.In the example shown in FIG. 1, the fluid to be filtered initially flows through the first conductor layer 22, which functions as a first polarization element 20, and together with the second conductor layer 34, which forms the second polarization element, serves to polarize the filter layer 24 arranged between the first conductor layer 22 and the second conductor layer 34.In the example shown in FIG. 1, the filter layer 24 is designed as a particle filter layer. Both the first conductor layer 22 and the second conductor layer 34 and the filter layer 24 are formed as textile surfaces in the example shown, namely nonwoven fabrics, wherein the electrical conductivity of the first conductor layer 22 and of the second conductor layer 34 is realized in each case as a coating containing conductive carbon black. The voltage required for the polarization is in turn provided by the supply unit 38 assigned to the vehicle module 36, wherein the first conductor layer 22 and the second conductor layer 34 are contacted by the electrical contacting system 26.Particles, in particular ionized constituents of the air, are separated in the filter insert 16. In the example of FIG. 1, the activated carbon stage 30 is arranged downstream of the filter insert 16 in the flow direction, which stage comprises the activated carbon volume 32, which in the example shown is embodied as an activated carbon layer, the average thickness of which is 3 mm and which has a weight per unit area of approximately 300 g / m 2. In the example shown in FIG. 1, the activated carbon volume 32 comprises particulate activated carbon having an average diameter of approximately 0.45 mm. The particulate activated carbon is shaped with binder into one, two or more layers, which are surrounded on both sides by a covering fleece.Both the ionization device 14 and the filter insert 16 and the activated carbon stage 30 are designed in the embodiment shown as reversibly and non-destructively replaceable components, wherein the filter system 10 also comprises a detection mechanism (not shown) with which the correct seating of the activated carbon stage 30 can be detected, wherein otherwise an activation of the ionization device 14 is prevented in order to prevent an undesired exposure of the vehicle occupants to the ozone generated in the ionization device 14.FIG. 2 shows a perspective illustration of a filter insert 16 to be used according to the invention, which filter insert has a pleated multilayer filter medium 18, which is fixed by a lamination 40 on both sides with a felt material. On the side wall formed by the lateral lamination 40, the electrical contacting system 26 is provided, which is designed as a voltage divider made of an electrically conductive plastic on an insulating substrate and comprises two contact points, via which the voltage provided by the supply unit 38 can be taken off indirectly via the ionization device 14, wherein the voltage dropped on the multi-layer filter medium 18 can be adjusted via the voltage divider.Reference numerals denote reference numerals10 Filter system 12 Fluid guidance system 14 Ionization device 16 Filter insert 18 Multilayer filter medium 20 First polarization element 22 First conductor layer 24 Filter layer 26 Electrical contacting system 28 Second polarization element 30 Activated carbon stage 32 Activated carbon volume 34 Second conductor layer 36 Vehicle module 38 Supply unit 40 LaminationReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 2007 / 135232 A1
[0006] EP 3 448 540 B1
[0006] DE 102023121052 A1
[0009] WO 2023 / 012166 A1
[0034]
Claims
A filter system (10) comprising: i) a fluid guidance system (12) for guiding a fluid to be filtered, ii) an ionization device (14) for ionizing components of the fluid to be filtered, iii) a filter insert (16) comprising: a) a multi-layer filter medium (18) comprising as first polarization element (20) an electrically conductive first conductor layer (22) and a filter layer (24), wherein the filter layer comprises at least one dielectric layer, and b) an electrical contacting system (26) for connecting the filter insert to a voltage source, wherein the electrical contacting system (26) is configured such that a voltage can be applied to the first conductor layer (22), iv) a second polarization element (28), and v) an activated carbon stage (30) separate from the multi-layer filter medium (18), comprising an activated carbon volume (32), wherein the activated carbon volume (32) comprises activated carbon in a mass proportion of 50% or more, based on the mass of the activated carbon volume (32), wherein the filter system (10) is configured such that a voltage difference can be applied between the first conductor layer (22) and the second polarization element (28) for polarizing the dielectric layer.The filter system (10) of claim 1, wherein the multilayer filter medium (18) additionally comprises an electrically conductive second conductor layer (34), wherein the filter layer (24) is arranged between the first conductor layer (22) and the second conductor layer (24), and wherein the second polarization element (28) is formed by the second conductor layer (34).The filter system (10) of claim 1, wherein the second polarizing element (28) is a metal plate or a metal mesh.Filter system (10) according to one of Claims 1 to 3, wherein the ionization device (14) is arranged in the filter system (14) in such a way that the fluid to be filtered guided in the fluid guide system (12) flows through it upstream of the filter insert (16).Filter system (10) according to one of Claims 1 to 4, wherein the activated carbon stage (30) is arranged in the filter system (10) in such a way that the fluid to be filtered guided in the fluid guide system (12) flows through it downstream of the filter insert (16).Filter system (10) according to one of claims 1 to 5, wherein the ionization device (14) is arranged in the filter system (10) so as to be replaceable reversibly and non-destructively, and / or wherein the filter insert (16) is arranged in the filter system (10) so as to be replaceable reversibly and non-destructively, and / or wherein the activated carbon stage (30) is arranged in the filter system (10) so as to be replaceable reversibly and non-destructively.Filter system (10) according to one of Claims 1 to 6, wherein the required installation space of the activated carbon stage (30) is smaller than the required installation space of the filter insert (18).The filter system (10) of any of claims 1 to 7, wherein the activated carbon volume (30) comprises a three-dimensional support structure having cavities, the activated carbon being disposed in the cavities of the three-dimensional support structure.The filter system (10) according to any one of claims 1 to 8, wherein the activated carbon is particulate activated carbon, wherein the activated carbon preferably has an average diameter d50 in the range of 0.1 to 4 mm.Vehicle module (36) comprising: I) a filter system (10) according to any one of claims 1 to 9, and II) a supply unit (38), wherein the supply unit is configured to supply the filter system with electrical energy.