DE102021212079A1 - Filter element and fluid filter with a filter element - Google Patents

Abstract

The invention relates to a filter element (1) for a fluid, in particular air, to flow through from a dirty side (50) to a clean side (52) along a direction of flow (A), the filter element (1) having:- a frame element (2) , which encircles the direction of flow (A) along a direction of rotation (U) and is in particular closed in the form of a ring;-- a filter medium (3) which is set up for filtering the fluid flowing through the filter element (1);wherein the filter medium (3) is inside the Frame element is arranged, wherein at least one UV light source (4) is provided in or on the frame element (2), which irradiates the filter medium with UV light.

Description

field of invention

The invention relates to a filter element and a fluid filter with a filter element.

State of the art

Fluid filters or their filter elements which can filter liquids or gases are known from the prior art. For example, filters for gases, e.g. air filters, can capture particles as small as viruses and bacteria (so e.g. <1000nm = 1um). However, even after being absorbed or trapped in a filter medium of the filter element, such bacteria or virus may live on the filter surface for several hours or even days, or may be dangerous to living beings' health. In addition, such bacteria, viruses, etc. can pose a risk in the use, handling or maintenance of such fluid filters or such filter elements, since the microbes and/or biologically harmful organisms /e.g. viruses) can be released.

To sterilize air is out of the U.S. 6,855,295 B2 known to provide an air purification device with a UV light source.

Disclosure of Invention

The invention is based on the finding that there is little room or space, for example in motor vehicles in the ventilation system for the occupants, to arrange complex UV light sources and that it is difficult, given the limited lifetime of UV light sources, to replace a UV -Light source to accomplish inexpensively. The solution known from the prior art requires a great deal of space, has complicated air routing and is not suitable for all applications.

There may therefore be a need to provide a filter element that takes up as little space as possible, can be changed easily and with little effort, and in which colonization of a filter medium of the filter element with harmful organisms, such as viruses and/or bacteria, is permanently and reliably avoided or at least greatly reduced is, at the same time that agent or agents that contribute or contribute to the reduction of such harmful organisms or pollutants is or are easy and inexpensive to replace.

Advantages of the Invention

This need can be met by the subject matter of the present invention according to the independent claims. Advantageous embodiments of the present invention are described in the dependent claims.

According to a first aspect of the invention, a filter element is proposed for flow of a fluid, in particular air, from a dirty side to a clean side along a direction of flow.

The filter element has a frame element which encircles the direction of flow along a direction of circulation. The frame element can, for example, be closed in the form of a ring, with various shapes being possible, e.g. round, oval, triangular, rectangular, trapezoidal or generally polygonal (also with rounded corners). The filter element also has a filter medium which is set up for filtering the fluid flowing through the filter element. For example, dirt, particles, bacteria, viruses, etc. can be separated from the fluid flowing through the filter medium on or in the filter medium. It is possible, for example, that e.g. particles in the range of less than 10um (microns) or even less than 1um or less than 0.5um, e.g. even particles, bacteria, viruses, etc. with a size of only 0.3um or only 0.2um can be reliably deposited. The filter media is positioned within the frame member. At least one UV light source is provided in or on the frame element, which irradiates the filter medium with UV light.

This has the advantageous effect that the filter element or the filter medium is reliably protected against permanent colonization with biologically active microorganisms such as bacteria and/or viruses and/or fungal spores, etc., particularly in a humid environment and/or in an environment contaminated with microorganisms because the UV light reliably inactivates such microorganisms. A further advantageous effect is that the at least one UV light source can be simultaneously removed when changing the filter element from a fluid filter in which the filter element is installed or from a ventilation system in which the filter element is installed. This ensures that the UV light source can be easily replaced in the course of removing the (old) filter element and installing a new filter element, so that functional sterilization or disinfection of the air or the filter medium can always be achieved. Alternatively, at least when changing the filter element, it can be checked whether the UV Light source is still sufficiently functional and / or is unpolluted, so can fulfill their function. Finally, this has the advantageous effect that the overall system of fluid filtering and biological inactivation of harmful organisms is particularly small and compact.

The UV light source can be designed as an LED, for example. As a result, a particularly small and cost-effective UV light source can advantageously be implemented, which also consumes little power.

Provision can be made, for example, for the at least one UV light source to draw its energy from an energy source integrated into the filter element, e.g. a battery. Such a (possibly rechargeable) battery can be replaced when changing the filter element, for example. Alternatively or additionally, it can be provided that the UV light source of the filter element is supplied with power from an energy source that is separate from the filter element. This can be a (possibly rechargeable) battery, for example, which can be assigned to a fluid filter in which the filter element is mounted, or an on-board network of a motor vehicle or a room air filter for buildings, etc. In the case of an energy supply of the UV light source with an energy source separate from the filter element, it can be provided that a connection for the energy supply is provided on the filter element. Provision can be made, for example, for the connection to be designed to send signals which indicate the presence of the at least one UV light source and/or which indicate the performance or the aging status of the at least one UV light source. In this way, when a corresponding signal is received, a receiver, e.g. a control unit of a room air filter or a motor vehicle, can detect whether the correct filter element is used, whether the at least one UV light source is present and/or whether the at least one UV light source is sufficiently functional. If, for example, a sent signal indicates an error (e.g. there is no signal at all because the wrong filter element has been installed or an error signal is sent/received or the sent/received signal exceeds or falls below a target value), e.g. an error can be detected and, for example, a user can be warned by an optical, haptic, acoustic or similar signal.

Within the scope of the application, a radial direction extends perpendicularly to the direction of flow, which can also be referred to as an axial direction, particularly in the case of a linear flow through the filter element.

The arrangement of the filter element within the frame element can only be given as an example when viewed from the radial direction, in other words: the filter medium is surrounded by the frame element in this example and does not protrude further along the direction of flow.

A further development provides that the filter element is set up to be installed in a fluid filter as an interchangeable part. Alternatively or additionally, the filter element can be exchangeably arranged or mounted in a fluid control system, e.g. a room air filter and/or an air conditioning system of a motor vehicle.

This has the advantageous effect that the filter element can be replaced without destroying the fluid filter or the system in which the filter element is installed or mounted. Such a change can take place, for example, by pushing or inserting a new filter element into a receptacle provided on the fluid filter or in a receptacle provided in the system, after the filter element previously placed there has been removed.

The fact that the at least one UV light source is provided on the clean side of the filter medium has the advantageous effect that the filtered air is not contaminated by biologically active microorganisms (e.g. bacteria, viruses, spores, etc.) settled on the clean side of the filter medium or on the frame element becomes.

It goes without saying that in another embodiment the at least one UV light source can be provided on the dirty side. This prevents biologically active microorganisms from being separated in the filter medium at all.

Finally, it can be provided that at least one UV light source is provided on or in the frame element both on the dirty side and on the clean side.

In a development of the invention, it is provided that the frame element protrudes beyond a plane of the filter medium at that point at which the UV light source is arranged, viewed along the direction of flow.

This has the advantageous effect that the area of the filter medium illuminated by the UV light source is enlarged. This advantageously reduces the probability that individual areas of the filter medium will not be irradiated by UV light as a result of shadows being cast. Furthermore, in the case of a (e.g. leporello-like) folded filter medium, an inactivation of microorganisms that are located in the folds can also be effected easily and reliably in this way.

A plane of the filter medium is to be understood as meaning a plane that can be placed on the side of the filter medium facing the UV light source. If the UV light source is located, for example, on the dirty side, the frame element thus protrudes upstream beyond the plane of the filter medium that is located on the dirty side. If the UV light source is located, for example, on the clean side, the frame element thus protrudes downstream beyond the plane of the filter medium that is on the clean side.

For example, the at least one UV light source is spaced at least 5 mm, preferably at least 10 mm and very particularly preferably at least 15 mm from the respective plane of the filter medium, viewed along the direction of flow. For example, a height of the frame element above the plane can be approximately 10 mm to 50 mm, for example 50 mm or 45 mm or 35 mm or 30 mm or 25 mm 15 mm or 10 mm. Of course, other heights are also possible.

In a further development it is provided that the frame element has at least two points at which at least one UV light source is arranged, the two points viewed along the direction of rotation being at least 30°, preferably at least 60°, particularly preferably at least 90°. are offset to each other. This has the advantageous effect that the risk of shadow formation is reduced. As a result, the illumination can advantageously be made more uniform. In other words, the filter medium can be more effectively cleaned of biologically active microorganisms. Furthermore advantageously, the light intensity of the individual UV light sources can thereby be reduced and the same light intensity can nevertheless be achieved on the filter medium and on the frame element, which is sufficient to biologically inactivate the microorganisms. As a result, the service life of the UV light sources can advantageously be increased. Furthermore, less expensive UV light sources can be used. Finally, smaller UV light sources can be used in this way.

It can be provided, for example, that more than two UV light sources are provided. For example, three, four, five, six or even more UV light sources can be provided on or in the frame element. For example, in the case of a rectangular or polygonal frame shape in which each corner is formed by two frame element sides, at least two UV light sources can be provided in each frame side. Provision can also be made, for example, for at least one UV light source or at least two or at least three or at least four or at least five, e.g. six, seven or eight UV light sources to be arranged per 10 cm of the frame element viewed in the circumferential direction. Provision can preferably be made for the UV light sources to be arranged at equal distances from one another, viewed along the circumferential direction, at least along one of the side surfaces or frame sides of the frame element. Provision can be made for two adjacent UV light sources to be at different distances from the plane of the filter medium, viewed along the direction of flow, with the distance differing by at least 30%, for example. A particularly good illumination of the filter medium can be brought about as a result.

In a further development it is provided that the at least one UV light source is arranged on or in the frame element such that the entire side of the filter medium facing the UV light source is irradiated by the at least one UV light source. This has the advantageous effect that there are no shaded areas on the side of the filter medium facing the UV light source on which biologically active microorganisms (e.g. fungi, spores, bacteria, viruses, protozoa, amoebas, etc.) can permanently settle. In this way it is ensured that the fluid to be filtered or the filtered fluid does not (additionally) absorb any load from biologically active microorganisms.

It goes without saying that if a plurality of UV light sources are provided, it is not absolutely necessary for each individual UV light source to be able to irradiate the entire side of the filter medium facing it. In this case it is sufficient that the majority of the UV light sources irradiate the side of the filter medium facing them in their entirety. However, it can also be provided that with a plurality of UV light sources, individual or all UV light sources irradiate the entire side of the filter medium facing them.

In a further development it is provided that the at least one UV light source is attached to the frame element so that it can be detached in a non-destructive manner. Such a fastening can be effected, for example, by a clip connection, a screw connection, a bayonet connection, a plug connection or the like. This has the advantageous effect that the at least one UV light source can be replaced easily and inexpensively. If the filter element is changed, for example, and at the same time the at least one UV light source is still functional, this UV light source does not need to be replaced, which is environmentally friendly and sustainable and saves costs. Also in the opposite case, that at least one UV light source is no longer functional, this UV light source can simply be changed rare without having to replace the filter element.

In a development, it is provided that the filter element has a reflector element that reflects UV radiation, the reflector element being arranged on the frame element, with the at least one UV light source being arranged between the reflector element and the filter medium when viewed along the direction of flow .

This advantageously brings about improved illumination of the surface or plane of the filter medium and of the frame element with UV radiation. This in turn increases the effectiveness of the inactivation of biologically active microorganisms that have settled on and/or in and/or on the filter medium and/or frame element. Furthermore, better illumination can also be achieved, e.g. in pockets and/or folds of the filter medium. In other words: even in the depths of the filter medium, biologically active substances can be effectively inactivated.

The reflector element can be designed, for example, as a grid or a net. This advantageously enables a very uniform illumination of the plane of the filter medium and the frame element. A configuration as a lattice or mesh also advantageously increases the flow resistance to the fluid only slightly or not at all. A deflection of the flow (e.g. around a reflector element designed as a larger closed area) is also not necessary, which has a positive effect on the flow properties. In addition, this advantageously protects the at least one UV light source from being touched and thus from possible damage.

The reflector element is preferably designed in such a way that it reflects at least 75% of UV radiation, preferably at least 90% and particularly preferably at least 95%.

In a further development it is provided that the filter medium has UV light-conducting fibers, the fibers in particular having different lengths and/or light exit points within the filter medium. This advantageously enables UV radiation to be coupled into shaded areas of the filter medium and/or into a volume of the filter medium. This enables an improvement in the inactivation of biologically active microorganisms which, for example, have not settled or settled on the surface which is visible from the outside or which can be directly illuminated. For example, a section of a fiber that conducts UV light, e.g. a glass fiber, running on the (visible) surface can couple in UV light. This coupled UV light is then passed on within the fiber and coupled out again at at least one light exit point (e.g. an end point of the fiber and/or at various points along the fiber). Biologically active microorganisms are then inactivated or killed off in the vicinity of the at least one light exit point of the fiber.

It goes without saying that fibers other than glass fibers are also conceivable.

It is also understood that the filter medium can predominantly (i.e. more than 50%) consist of materials that are different from the UV light-conducting fibers, e.g. cellulose, polymer fibers (e.g. produced using the meltblown process), etc. In this way, the fibers that conduct UV light can perform a different function than the material or materials of the filter medium that are primarily intended for filtering the fluid.

A further development provides that the filter element also has an after-treatment filter medium, with the after-treatment filter medium being arranged downstream of the filter medium, with the after-treatment filter medium being set up to neutralize ozone. This has the advantageous effect that living beings, e.g. animals and/or people, who come into contact with the filtered fluid, e.g. with air, do not come into contact with ozone or only to a small extent. For example, ozone can form when UV radiation hits air.

The post-treatment filter medium can include, for example, one of the materials from the group consisting of activated carbon, metal oxides, MnO, CuO, or combinations of these materials.

In a further development it is provided that the UV light source is set up to be operated with a first intensity different from zero and with a second intensity different from zero, the second intensity being at least 1.5 times greater than the first Intensity, in particular at least twice as great.

This has the advantageous effect that the filter element can be operated in different operating states. For example, the first intensity can be used in normal operation. This can be, for example, an operation in which people and/or animals are exposed to the filtered fluid, for example while driving a motor vehicle in which the filter element is operated. The use of the (lower) first intensity also conserves the at least one UV light source and thus increases their service life. Operation with the first intensity takes into account, for example, the fact that when the filter medium is operated with a flow, hardly any biologically active organisms can settle on or in the filter medium and then possibly multiply there. In addition, account is taken of the fact that when the UV light sources are in operation, substances that are undesirable for humans and/or animals, such as ozone, can possibly form.

In a further operating mode, e.g. a particularly thorough inactivation of microorganisms can take place by using the second intensity. For example, deeper layers of the filter medium can also be reached. Such an operation can take place, for example, at longer time intervals and can be provided, for example, when no fluid is flowing through the filter element or no people and/or animals are exposed to the filtered fluid.

In a further development it is provided that the UV light source is set up to receive a wirelessly transmitted start signal and only to start emitting UV light after the start signal has been received. In this way, inactivation of microorganisms or disinfection of the filter element can be triggered remotely by a user, e.g. when the user does not need the filter element himself (e.g. when he is not in the room in which the filtered fluid flows out). This can be done, for example, with a (mobile) device such as a laptop, PC, smartphone, tablet or remote control. Advantageously, the user does not necessarily have to be in the immediate vicinity of the filter element or of a control device that activates the filter element. The signal can only be sent or received, for example, by means of WLAN, Bluetooth, NFC or the like.

According to a second aspect of the invention, a fluid filter is proposed.

The fluid filter has a housing and a filter element arranged in the housing so that it can be changed, as described above.

In a vehicle or in a (mobile) room air filter, for example, the pipe system upstream and downstream of the filter element can be viewed as the housing.

This advantageously provides a fluid filter which is inexpensive and easy to maintain by replacing the filter element and which ensures that contamination of the fluid filter with biologically active microorganisms is reduced or does not exist at all. In this way, permanent and reliable operation of the fluid filter is advantageous for users.

The filter element can, for example, be used independently or in fluid filters, e.g. as a HEPA filter (HEPA = "High Efficient Particulate Air (filter)"), vehicle interior filters, room air filters for (mobile) stationary filters, as filters for or in air conditioning systems, as water filters, Etc.

character list

Further features and advantages of the present invention will become apparent to those skilled in the art from the following description of exemplary embodiments, which, however, are not to be construed as limiting the invention, with reference to the accompanying drawings.

• 1: einen schematischen Querschnitt durch einen Fluidfilter mit einem Filterelement;
• 2a: eine schematische perspektivische Aufsicht auf ein Filterelement;
• 2b: einen schematischen Querschnitt durch das Filterelement aus 2a;
• 3: eine schematische perspektivische Aufsicht auf ein weiteres Filterelement;
• 4a: eine schematische perspektivische Aufsicht auf ein weiteres Filterelement;
• 4b: einen schematischen Querschnitt durch das Filterelement aus 4a.

Show it

• 1 : a schematic cross section through a fluid filter with a filter element;
• 2a : a schematic perspective view of a filter element;
• 2 B : a schematic cross-section through the filter element 2a ;
• 3 : a schematic perspective view of a further filter element;
• 4a : a schematic perspective view of a further filter element;
• 4b : a schematic cross-section through the filter element 4a .

1 shows a schematic cross section through a fluid filter 100 with a filter element 1. The fluid filter 100 has a housing 70 and the filter element 1 arranged in the housing 70 so that it can be changed. The housing 70 can be tubular, for example. It can, for example, be a fluid-guiding system in a motor vehicle. The filter element 1 can be inserted or pushed into a recess in the housing or receptacle 72 for the filter element 1 of the housing 70 . In this embodiment, the filter element 1 is set up, for example, to be installed in the fluid filter 100 as an interchangeable part.

The filter element 1 for a fluid to flow through from a dirty side 50 to a clean side 52 in a flow direction A has: a frame element 2, which encircles the flow direction A along a circumferential direction U, and a filter medium 3, which is set up for filtering the filter element 1 flowing fluid. The filter medium 3 can, for example, particles, dirt, dust, moisture (if the fluid is a gas), remove bacteria, viruses, etc. from the fluid as the fluid passes through the filter medium 3 coming from the dirt side 50 . The filter medium 3 can be a filter medium 3 with a depth filter effect and/or a filter medium 3 with a surface filter effect. The filter element 1, in particular the filter medium 3, can be set up to filter out particles, bacteria, viruses, etc. from the fluid that are larger than 20 μm (microns) or that are larger than 10 μm or that are larger than 1 μm or which exceed a size of 100nm (nanometers). In other words: it is possible, for example, to filter out viruses, bacteria, etc., which have a size of, for example, only 100 nm or 200 nm or 300 nm or 0.5 μm etc. from the fluid.

The filter medium 3 is arranged within the frame element 2 . The fluid flows through it lying within the frame element 2 (or framed by the frame element). The frame element 2 can, for example, be closed in the form of a ring when viewed along the circumferential direction U. As a result, the filter medium 3 can be held particularly reliably in or by the frame element 2 and the risk of a leakage path of the fluid on the way from the dirty side 50 to the clean side 52 past the filter element 1 is minimized.

At least one UV light source 4 is provided in or on the frame element 2 and irradiates the filter medium 3 with UV light. In the filter element 1 shown, the frame element 2 has at least two points at which at least one UV light source 4 is arranged, the two points being offset from one another by at least 60°, preferably at least 90°, viewed along the circumferential direction U. In the cross section of 1 two UV light sources 4 can be seen on opposite sides, so that the offset is 180° along the circumferential direction U. The UV light source advantageously causes the filter medium 3 to be disinfected, as well as the fluid that flows past the at least one UV light source 4 . In other words: biologically active microorganisms such as fungi, spores, bacteria, viruses, protozoa or multicellular organisms such as amoebas, etc. can be killed or biologically inactivated by the UV light irradiation, so that fluid which flows through the filter element 1 does not or only can still be contaminated to a very small extent with such (still biologically active) microorganisms. As a result, the filter element 1 and the fluid filter 100 become considerably more hygienic.

In this embodiment, the two visible UV light sources 4 are arranged on the clean side 52 of the filter medium 3 when a normal operating condition is considered. In principle, embodiments are also conceivable in which the at least one UV light source is arranged on the dirty side 50 or in which at least one UV light source 4 is provided both on the dirty side 50 and on the clean side 52 .

The fluid can be, for example, a liquid (e.g. water) or a gas, e.g. air.

The frame element 2 protrudes beyond a plane E of the filter medium 3 at that point at which the UV light source 4 is arranged, viewed along the direction of flow A.

The at least one UV light source 4 is arranged on or in the frame element 2 such that the entire side of the filter medium 3 facing the UV light source 4 is irradiated by the at least one UV light source 4 . By using multiple UV light sources in the filter element 1 in 1 the illumination of that side of the filter medium which faces the UV light source 4 (or here: the UV light sources 4) is further improved. This minimizes the risk of shadowed areas appearing on this side.

The at least one UV light source 4 is fastened to the frame element 2 in a non-destructively detachable manner, for example. This can be realized, for example, by a clip connection, a screw connection, a bayonet connection, a plug connection or the like. It goes without saying that a non-destructively detachable connection of the at least one UV light source 4 to the frame element 2 is also possible, e.g. by gluing the UV light source 4 on or in the frame element 2 or by injecting the UV light source 4 on or in the Frame element 2.

The filter element 1 also has a reflector element 5 that reflects UV radiation. The reflector element 5 is arranged on the frame element 2 , the at least one UV light source 4 being arranged between the reflector element 5 and the filter medium 3 viewed along the flow direction A. This reflector element 5 is designed here as a grating 6 merely by way of example. It can also be designed as a net or as a reflection plate without openings. The use of a grating 6 or a net has the advantage that the fluid can pass through the reflector element 5 evenly and without significant deflection, as a result of which fewer or no turbulences are caused and the flow resistance is only slightly increased.

In 1 the UV rays emanating from the UV light sources 4 are shown. It is recognizable as some of these rays impinge directly on the surface of the filter medium 3. Other rays run in a direction pointing away from the surface or plane E of the filter medium 3. These rays are not lost through the reflector element 5, but are reflected back in the direction of the filter medium 3, where they contribute to the inactivation of biological microorganisms . At the same time, it is prevented that (too much) UV radiation from the filter element 1 escapes into the environment and possibly causes damage there (eg eyes of a viewer or material aging). In this way, it is also advantageously possible to reach deeper areas of the filter medium 3, for example folds and/or pockets, which lie below the plane E and would be shaded by direct light radiation.

In the embodiment shown, it is provided—just by way of example—that the filter medium 3 has UV light-conducting fibers 7 (but at least a single UV-conducting fiber 7). Here, for example, these fibers 7 have different lengths and/or light exit points 8 within the filter medium 3 . As a result, the UV light or UV radiation emitted by the at least one UV light source 4 can also reach locations within the filter medium 3 to which the UV radiation would not otherwise reach. As a result, the disinfecting effect of the UV light source 4 with regard to the filter medium 3 is improved.

The filter element 1 shown by way of example also has an after-treatment filter medium 9 , with the after-treatment filter medium 9 here being arranged downstream of the filter medium 3 , for example. The post-treatment filter medium 9 is designed to neutralize ozone. Ozone can be created, for example, by the action of UV radiation on the fluid flowing through the filter element 1. For example, the post-treatment filter media 9 may contain activated carbon. Alternatively or additionally, it can also contain one or more metal oxides, e.g. MnO and/or CuO or other metal oxides. For example, it can bind ozone. Alternatively or additionally, it can be designed to convert the ozone into substances that are harmless to health, e.g. by means of a catalytic reaction.

The at least one UV light source 4 or here: at least one of the plurality of UV light sources 4, in particular all UV light sources, can be set up to be operated with a non-zero first intensity and with a non-zero second intensity . In this case, the second intensity can be at least 1.5 times greater than the first intensity. In a preferred embodiment, the second intensity is at least twice the first intensity. This advantageously enables different operating modes, e.g. permanent disinfection (first intensity, e.g. during normal operation) and e.g. boost disinfection (second intensity, in which e.g. the UV radiation kills or biologically inactivates microorganisms that have settled deeper in the filter medium).

In this embodiment, the UV light source 4 is set up, merely by way of example, to receive a wirelessly transmitted start signal 82 and to start emitting UV light only after the start signal 82 has been received. The start signal 82 can be sent by means of a transmitter 80, for example. The transmitter 80 can be a smartphone, a tablet, a PC, a separate remote control, etc., for example. For example, WLAN, Bluetooth, NFC, infrared waves, etc. can be used to transmit the start signal 82 . It goes without saying that the signal can be received by the UV light source 4 as such or by a receiver 84 coupled to the at least one UV light source 4 .

For reasons of clarity, an energy source for the at least one UV light source 4 and/or the at least one (signal) receiver 84 is shown in 1 and also in the 2a until 4b not shown. It is also not shown that the at least one UV light source 4 or the filter element 1 can be set up to send a signal which, for example, indicates a status of the at least one UV light source 4 . In this way, a (further) receiver can be used, for example, to determine or monitor whether, for example, the correct filter element 1 is installed in the fluid filter 100 . Alternatively or additionally, it can be determined and/or monitored whether the at least one UV light source 4 is still sufficiently functional, e.g. can emit a sufficiently high intensity, etc. Such a signal to be sent can be, for example, a single value, e.g. a voltage value, which is compared in the (further) receiver or an evaluation circuit with a threshold value. If the threshold value is exceeded or not reached, an error flag can be set and/or the user can be informed of a necessary action, for example replacing the filter element 1 and/or the at least one UV light source 4 . In an alternative or additional embodiment, the signal can also already be in the form of a status signal which, for example, directly indicates an error or a situation that does not correspond to a target situation.

2a shows a schematic perspective view of a filter element 1 and 2 B shows a schematic cross section through the filter element 1 2a . The filter element 1 is, for example mountable in a fluid filter 100. Dirty side 50 and clean side 52 are provided here for guidance, assuming the filter element is properly assembled in a fluid filter 100. The filter element 1 is thus in the 2a and 2 B flows through from bottom to top with a fluid, such as a liquid or a gas, such as air.

The filter element 1 shown has a rectangular frame element 2 with four frame sides 10 . The frame element 2 is closed in the form of a ring here. The filter medium 3 is attached inside the frame element 2 , ie it is arranged inside the frame element 2 . It is fastened in a fluid-tight manner, for example, to the surfaces of the four frame sides 10 that face radially inward, so that no leakage path from the dirty side 50 to the clean side 52 is possible. Two of the frame sides 10 that face each other (in 2a and 2 B : the left side of the frame 10 and the right side of the frame 10) protrude beyond the plane E, viewed along the flow direction A. These two frame sides 10 each have a plurality of UV light sources 4 (here: eight UV light sources 4 each). The UV radiation emanating from the UV light sources 4 is indicated schematically (for reasons of clarity only for some UV light sources 4).

The UV light sources 4 can (as also in the other figures) only be embodied as LEDs by way of example, although other embodiments are also possible.

The UV light sources 4 are each arranged on or in the frame side 10 pointing radially inwards. They can be attached there, e.g. by a detachable connection. Provision can also be made for individual or all UV light sources 4 to be cast into the respective frame side 10 of the frame element 2, e.g. in an injection molding process.

The UV light sources 4 can, for example, be arranged at the same distance from one another in the respective side 10 of the frame. Within a frame side 10, they can be at a distance of less than 15 cm from one another, for example, preferably less than 10 cm. For example, they can be 5mm or 10mm or 15mm or 2cm or 5cm apart. Assuming, for example, that a filter element has a lateral extension of e.g. 25 cm, at least two UV light sources 4 can be arranged on a frame side 10 at a distance of 15 cm. If the distance is only 15mm, for example, then 16 UV light sources 4 can be arranged on the frame side 10.

In this exemplary embodiment, the UV light sources 4 are all arranged approximately at the same height above the plane E in or on the frame element 2, viewed along the direction of flow A. For example, the distance from the plane A, which passes e.g. through the upper side of the filter medium 3 can be placed between 5mm and 10cm, preferably between 1cm and 5cm. It can also be provided that the UV light sources 4 are not all arranged at the same height, for example UV light sources 4 that are adjacent to one another can be spaced apart from one another viewed along the direction of flow A, e.g. by at least 0.25 cm or by at least 0.5 cm or by at least 1 cm or by at least 2 cm, e.g. by 0.25 cm or by 0.5 cm or by 1 cm or by 2 cm or by 5 cm. This enables a closer arrangement of UV light sources 4 along the circumferential direction U and/or a more uniform illumination of the surface of the filter medium 3.

In the embodiment shown here, the radiation direction of the UV light sources 4 is aligned perpendicularly to a fold of the filter medium 3 folded like a fan. In another embodiment, it can be provided that the folds of the filter medium 3 run parallel to the radiation direction of the UV light sources 4 in order to increase the disinfection effect in the lower-lying areas (i.e. areas that lie below level E).

In yet another embodiment it can be provided that two frame sides 10 adjoining one another have the UV light sources 4, the radiation directions of which are thus approximately orthogonal to one another.

3 shows a schematic perspective view of another filter element 1. In contrast to the filter element 1 from FIGS 2a and 2 B protrude at the in 3 Filter element 1 shown all four frame sides 10 beyond the plane E, viewed along the flow direction A. A plurality of UV light sources 4 are arranged in or on each of the (here: four) frame sides 10 . In this way, particularly uniform illumination is achieved over the entire filter medium 3, which also extends into the lower-lying areas of the filter medium 3, ie, for example, into pockets or folds that lie below the plane E. Rays from some UV light sources 4 are indicated schematically, which indicate the illumination of the filter medium 3 .

4a shows a schematic perspective view of another filter element 1. 4b shows a schematic cross section through the filter element 1 4a .

The filter element 1 from the 4a and 4b shows in contrast to the one from 3 a reflector element 5. This is designed here by way of example as a grating 6 and reflects at least 75%, preferably at least 90%, of UV radiation. In this way, a significantly larger proportion of the UV radiation emitted by the UV light sources 4 reaches the filter medium 3. In this way, lower-lying areas of the filter medium 3 can also be exposed to the UV radiation in a simple manner. Finally, the reflector element 5 also ensures that the majority of the emitted UV rays do not leave the filter element 1, which protects the material located outside of the filter element 1 and also protects eg a fitter from unintentional exposure to UV radiation.

It can also be provided in an alternative embodiment that the filter element 1 from 4a and 4b has only a single UV light source 4 or that it has a plurality of UV light sources, but that these are not arranged on or in or on all four frame sides 10 .

4b shows schematically indicated UV rays, which emanate from some UV light sources 4 (for reasons of clarity, as in Figs 2a and 3 UV rays emanating from all UV light sources 4 are not shown). This indicates the illumination of the filter medium 3, also taking into account the rays reflected on the reflector element 5.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 6855295 B2 [0003]

Claims (13)

Filter element for a fluid, in particular air, to flow through from a dirty side (50) to a clean side (52) along a direction of flow (A), the filter element (1) having: - a frame element (2) which encircles the direction of flow (A) along a direction of circulation (U) and is in particular closed in the form of a ring; -- a filter medium (3) which is set up for filtering the fluid flowing through the filter element (1); wherein the filter medium (3) is arranged within the frame element (2), at least one UV light source (4) which irradiates the filter medium (3) with UV light being provided in or on the frame element (2). filter element after claim 1 , wherein the filter element (1) is adapted to be mounted as an interchangeable part in a fluid filter (100). Filter element according to one of the preceding claims, wherein the at least one UV light source (4) is provided on the clean side (52) of the filter medium (3). Filter element according to one of the preceding claims, wherein the frame element (2) projects beyond a plane (E) of the filter medium (3) at that point at which the UV light source (4) is arranged, viewed along the direction of flow (A). Filter element according to one of the preceding claims, wherein the frame element (2) has at least two points at which at least one UV light source (4) is arranged, the two points being offset from one another by at least 60°, preferably at least 90°, viewed along the direction of rotation (U). Filter element according to one of the preceding claims, wherein the at least one UV light source (4) is arranged on or in the frame element (2) in such a way that the entire side of the filter medium (3) facing the UV light source (4) is affected by the at least one UV -Light source (4) is irradiated. Filter element according to one of the preceding claims, wherein the at least one UV light source (4) is non-destructively releasably attached to the frame element (2), in particular by a clip connection, a screw connection, a bayonet connection, a plug connection. Filter element according to one of the preceding claims, wherein the filter element (1) has a reflector element (5) that reflects UV radiation, in particular a grid (6) or a mesh, wherein the reflector element (5) is arranged on the frame element (2), wherein the at least one UV light source (4) viewed along the direction of flow (A) is arranged between the reflector element (5) and the filter medium (3). Filter element according to one of the preceding claims, wherein the filter medium (3) has UV light-conducting fibers (7), the fibers (7) in particular having different lengths and/or light exit points (8) within the filter medium (3). Filter element according to one of the preceding claims, wherein the filter element (1) further comprises an after-treatment filter medium (9), the after-treatment filter medium (9) being arranged downstream of the filter medium (3), wherein the aftertreatment filter media (9) is adapted to neutralize ozone. Filter element according to one of the preceding claims, wherein the UV light source (4) is set up to be operated with a first intensity that is different from zero and with a second intensity that is different from zero, wherein the second intensity is at least 1.5 times as great as the first intensity, in particular at least twice as great. Filter element according to one of the preceding claims, wherein the UV light source (4) is set up to receive a wirelessly transmitted start signal (82) and to start emitting UV light only after receipt of the start signal (82). . Fluid filter comprising: -- a housing (70) and - A filter element (1) according to one of the preceding claims which is exchangeably arranged in the housing (70).

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