AIR PURIFICATION DEVICE FOR CLEANING AIR AND METHOD FOR OPERATING AN AIR PURIFICATION DEVICE

Description

[0001] The invention relates to an air purification device for purifying air, comprising a housing on which an air inlet and an air outlet are formed, which are fluidically connected to one another via a flow path running in the housing. An air conveying device for conveying the air along the flow path and an air filter for filtering foreign particles from the air are arranged in the flow path. The air filter has at least one filter body of a motor vehicle particulate filter made of a ceramic material with a lipophilic surface. The invention further relates to a method for operating an air purification device.

[0002] For example, DE 10 2018 008 259 A1 is known from the prior art. This document describes filter systems for suspended matter with particle sizes from 400 pm to less than or equal to 500 µm and their use. Furthermore, WO 2021 / 009085 A1 discloses an air filter with a membrane layer made of silicon carbide. CN 105 561 685 B describes the use of a honeycomb body as an air filter in an interior air filter device.

[0003] It is an object of the invention to propose an air purification device for purifying air which has advantages over known air purification devices, in particular a particularly high filter performance with low pressure loss.

[0004] This is achieved according to the invention with an air cleaning device for cleaning air having the features of claim 1. It is provided that a heating device is fluidically located between the air inlet and the air filter.

[0005] Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0006] The air purification device is used to purify the air, i.e. to at least partially remove foreign particles contained in the air. The air to be purified is sucked in by the air purification device as raw air from an external environment of the air purification device, cleaned or filtered, and then expelled back into the external environment as clean air. It goes without saying that the external environment of the air purification device can be any volume of air. In this respect, the external environment can be understood, for example, as the interior of a building, in particular a residential building, or the like. The foreign particles that are to be filtered out of the air with the aid of the air purification device are, in particular, microorganisms. In the context of this description, microorganisms are understood to mean, in particular, bacteria, viruses and / or fungi.

[0007] The air purification device has the housing on which the air inlet and the air outlet are formed. The air inlet is, for example, in the form of an air inlet opening or at least has one. The air inlet opening is designed in a wall of the housing, in particular on an outer wall of the housing. Analogously, the air outlet is in the form of an air outlet opening or at least has one. The air outlet opening is also made, in particular, in the wall or outer wall of the housing. The air is sucked in as raw air through the air inlet and expelled as clean air through the air outlet. The air inlet and the air outlet are fluidically connected to one another via the flow path, wherein the flow path runs at least partially, preferably entirely, within the housing. In particular, the air flows continuously within the housing from the air inlet to the air outlet.

[0008] The air conveying device and the air filter are located in or along the flow path. The fluid conveying device serves to convey air from the air inlet to the air outlet and accordingly along the flow path. The air conveying device is, for example, a fan, blower, or the like. The fluid conveying device can also include an ion wind generator. This serves to convey the air along the flow path and / or (additionally) purify the air.

[0009] An ion wind generator is an air conveying device by means of which the air flow along the flow path can be generated or is generated at least temporarily. The ion wind generator generally has two electrodes arranged at a distance from one another, by means of which an electric field is generated. For this purpose, a first electric potential is applied to a first of the electrodes, and a second electric potential, different from the first electric potential, is applied to a second electrode.

[0010] In addition to moving air, the ion wind generator purifies the air, as the ions it generates effectively bind foreign particles. Specifically, the ions cause the foreign particles to cluster, aggregating them. Due to their greater weight, the aggregated foreign particles can be separated from the air particularly effectively. Additionally or alternatively, the ion wind generator generates ozone during operation. This cleans and / or disinfects the air, killing or at least inactivating bacteria and / or viruses.

[0011] Furthermore, the air filter is arranged in the flow path. This serves to filter out foreign particles from the air. The air filter could be designed as a HEPA filter and accordingly have a filter element arranged in the flow path and through which air flows, at least temporarily. The filter element consists, for example, of at least fibers, in particular glass fibers, which filter out and store foreign particles from the air through deep filtration. In this design, the air filter can also be referred to as a HEPA filter.

[0012] However, such a filter element becomes clogged over time due to the foreign particles aggregating within it, requiring periodic replacement. This is costly, and if microorganisms are present as foreign particles in the filter element, they can escape during the filter element replacement, causing the microorganisms to spread. Furthermore, such a filter element is typically not reusable, requiring significant resource consumption and generating a large amount of waste that may even require separate disposal due to the microorganism load.

[0013] For this reason, the air filter is instead provided with the filter body of the motor vehicle particulate filter. This means that the filter body of the air filter is configured identically to the filter body of a motor vehicle particulate filter, or that the filter body is used either in the motor vehicle particulate filter or in the air purification device. In other words, the filter body is structurally identical to the filter body of the motor vehicle particulate filter. The filter body consists of the ceramic material, for example, at least partially or entirely of one of the following materials: silicon carbide, cordierite, and aluminum titanate.

[0014] The filter body or the ceramic material has a surface that is at least temporarily exposed to, overflowed by, and / or through by the air flowing along the flow path. This surface is therefore also referred to as the air-conducting surface. The filter body is designed such that its surface, particularly the air-conducting surface, is lipophilic. This has the advantage that moisture is extracted from the foreign particles upon contact with the filter body. This leads to the inactivation of microorganisms, which generally require moisture or a humid environment.

[0015] The filter body can, in principle, be designed in any desired way. Particularly preferably, the filter body is a wall-flow filter body, in which the air flowing along the flow path flows through the filter body and thus through the ceramic material. For this purpose, the ceramic material is porous. Overall, the described air purification device achieves particularly good filtration performance with low pressure loss due to the use of the filter body of the motor vehicle particulate filter. In addition, the lipophilic surface of the filter body or the ceramic material serves to quickly deactivate any microorganisms that may be contained in the foreign particles. The use of the described filter body also enables its regeneration, thus eliminating the need to change the air filter or the filter element.Instead, an almost continuous operation of the air purification device with the filter body is implemented.

[0016] A further development of the invention provides that the filter body has a plurality of flow channels arranged in parallel in terms of flow technology, each of which completely penetrates the filter body, wherein each of the flow channels is closed by means of a closure. The filter body has, on the one hand, an inlet side and, on the other hand, an outlet side. For example, the filter body is cylindrical, in particular circular-cylindrical, and the inlet side corresponds to a first end face of the filter body and the outlet side to a second end face of the filter body, wherein the two end faces are arranged at a distance from one another, in particular are spaced parallel from one another. Preferably, the two end faces are connected to one another via a lateral surface of the filter body.

[0017] The filter body is penetrated by a plurality of flow channels, each of which fluidically connects the inlet side to the outlet side. This means that each of the flow channels runs from the inlet side to the outlet side. In particular, each of the flow channels thus extends through the first end face and the second end face of the filter body. The flow path extends through the filter body from its inlet side to its outlet side, namely through the flow channels. Preferably, the flow channels are not only arranged fluidically parallel to one another, but also have longitudinal center axes running parallel to one another. Particularly preferably, the flow channels run straight throughout, so that their longitudinal center axes are also straight throughout.

[0018] To create a wall-flow filter body, each of the flow channels is closed by a closure. This means that the air flowing into a first of the flow channels can only flow as far as the closure closing this flow channel. To continue flowing towards the outlet side, the air must first flow through the porous ceramic material to reach a second flow channel. Through this second flow channel, it can then flow further towards the outlet side. By flowing the air through the ceramic material, particularly effective air cleaning is achieved.

[0019] The closure is understood to mean, in particular, a plug that is inserted into the respective flow channel either on the inlet side or on the outlet side. The closure is designed in such a way that it fluidically closes the respective flow channel from the inlet side and towards the outlet side. This forces the air flowing into one of the flow channels to flow through the ceramic material in order to reach another of the flow channels.

[0020] A further development of the invention provides that the flow channels comprise first flow channels and second flow channels, wherein the closures are arranged in the first flow channels at a first axial position relative to a longitudinal center axis of the filter body and in the second flow channels at a second axial position different from the first axial position. In other words, the flow channels can be divided into the first flow channels and the second flow channels. Preferably, the flow channels consist exclusively of the first flow channels and the second flow channels.

[0021] Preferably, the first flow channels and the second flow channels are arranged alternately in one or more directions, so that two of the first flow channels each accommodate one of the second flow channels between them, and conversely, two of the second flow channels each accommodate one of the first flow channels between them. The first flow channels and the second flow channels differ with regard to the axial position at which the closure is arranged.

[0022] In the first flow channels, the closures are located at the first axial position and in the second flow channels at the second axial position. The two axial positions are spaced apart from one another. In other words, the first axial position and the second axial position are at different distances from the inlet side and the outlet side, respectively. For example, the first axial position is closer to the inlet side than the second axial position. Particularly preferably, the first axial position is located in the half of the filter body facing the inlet side, and the second axial position is located on the half of the filter body facing the outlet side.

[0023] For example, the first axial position is at a distance from the inlet side that corresponds to at most 30%, at most 20%, or at most 10% of the total axial extension of the filter body. Conversely, the second axial position is preferably at a distance from the outlet side that corresponds to at most 30%, at most 20%, or at most 10% of the total extension of the filter body. This achieves particularly effective air purification.

[0024] A further development of the invention provides that an air inlet grille is arranged in the air inlet, and / or that the air conveying device is arranged fluidically between the air filter and the air outlet, and / or that a pre-filter is present fluidically between the air inlet and the air filter. In a first variant of the air cleaning device, the air inlet grille is arranged in the air inlet. The air inlet grille is understood to be the arrangement of several struts which partially close the air inlet and filter out coarse contaminants from the air before they enter the air cleaning device or the housing through the air inlet.

[0025] For example, the air intake grille consists of several struts extending from a housing wall that radially defines the air intake to a hub that connects the struts. The hub, for example, has a projection that extends outward from the air intake to give the air intake or air cleaning device the appearance of an aircraft engine.

[0026] In a second variant of the air purification system, the air conveying device is arranged fluidically between the air filter and the air outlet. This means that it is located downstream of the air filter with respect to the main air flow direction, so that it draws the air through the air filter and blows it toward the air outlet. This reliably prevents contamination of the air conveying device by foreign particles.

[0027] In a third variant of the air purification device, the pre-filter and the heating device are arranged between the air inlet and the air filter. In other words, the pre-filter and the heating device are located upstream of the air filter or the filter body. If both the pre-filter and the heating device are implemented, the pre-filter is arranged upstream of the heating device. Accordingly, the heating device is fluidically located between the pre-filter and the air filter.

[0028] The pre-filter serves to filter out coarse foreign particles from the air before they reach the air filter and / or the heating device. The pre-filter has, for example, a honeycomb structure. Additionally or alternatively, it is color-coded to contrast with the housing of the air cleaning device. Particularly preferably, the pre-filter is designed like a motor vehicle radiator inlet, thus further enhancing the engine-like appearance of the air cleaning device.

[0029] The heating device serves to heat the air supplied to the air filter. The heating device is preferably provided and configured to heat the air to a temperature sufficient to burn off or at least passivate foreign particles present in the air filter or the filter body and accordingly regenerate the filter body.

[0030] Of course, it is possible to combine one or more of the described variants of the air purification device. Thus, the air purification device can comprise the air inlet grille in the air inlet, the air conveying device arranged between the air filter and the air outlet, as well as the pre-filter and / or the heating device, preferably both the pre-filter and the heating device. This enables particularly effective and sustainable air purification.

[0031] A further development of the invention provides that a bypass channel is configured in the housing, which is arranged fluidically parallel to the air filter and fluidically in series with the air conveying device. In other words, the bypass channel is arranged such that air conveyed by the air conveying device can be guided around the air filter through the bypass channel. If the bypass channel is closed, the air conveyed by the air conveying device flows (completely) through the air filter. If the bypass channel is partially or completely open, the air flows at least partially through the bypass channel and only partially through the air filter. This allows the air to be guided around the air filter, for example during regeneration of the air filter with the aid of the heating device.

[0032] A further development of the invention provides that the air outlet is formed by a motor vehicle tailpipe. The motor vehicle tailpipe extends out of the housing. It is preferably contrasting in color and / or material with the housing. The motor vehicle tailpipe therefore has a different color and / or is made of a different material than the housing. The motor vehicle tailpipe is preferably cut at an angle, whereby, when the air cleaning device is arranged as intended, it is longer at the top than at the bottom. Such a design of the air outlet serves to enable a user to associate the air cleaning device with a motor vehicle, so that positive aspects of the air cleaning device are also transferred to the motor vehicle.

[0033] A further development of the invention provides that the housing has a maintenance opening for removing the air filter, which is at least temporarily closed by a cover. Despite the long service life of the filter body, it may become necessary to replace it or to regenerate it externally. To enable this, the housing has the maintenance opening. This is arranged and dimensioned such that the filter body can be removed from the housing through it or that it allows the filter body to be replaced. To prevent untreated air from escaping from the housing, the maintenance opening is closed by means of the cover. In particular, the cover is always arranged to close the maintenance opening as long as the air cleaning device is in operation and air is being conveyed along the flow path by means of the air conveying device. The described design of the air cleaning device enables simple maintenance.

[0034] A further development of the invention provides that the cover is at least temporarily locked by means of a latch. The latch prevents unintentional and / or unauthorized opening of the maintenance opening. For example, the cover is locked as long as the air cleaning device is in operation, i.e., air is being conveyed along the flow path by means of the air conveying device. Additionally or alternatively, the cover can be locked to prevent removal of a filter body laden with foreign particles. Only after the filter body has been regenerated using the heating device is the cover released by the latch to open the maintenance opening. However, this preferably only occurs when a temperature of the filter body falls below or is lower than a threshold value.

[0035] The invention further relates to a method for operating an air purification device for purifying air, in particular an air purification device according to the embodiments within the scope of this description, wherein the air purification device has a housing on which an air inlet and an air outlet are formed, which are fluidically connected to one another via a flow path running in the housing, wherein an air conveying device for conveying the air along the flow path and an air filter for filtering foreign particles from the air are arranged in the flow path. It is provided that the air filter has at least one filter body of a motor vehicle particulate filter made of a ceramic material with a lipophilic surface.Furthermore, it is provided that a regeneration of the filter body is carried out at least temporarily by operating a heating device arranged in the flow path upstream of the filter body to heat the air supplied to the filter body.

[0036] The advantages of such an approach or such a design of the air purification device have already been pointed out. Both the air purification device and the method for its operation can be further developed according to the explanations in this description, so reference is made to these in this regard.

[0037] The invention provides for at least temporary regeneration of the filter body by operating a heating device arranged upstream of the filter body in the flow path to heat the air supplied to the filter body. During operation of the air purification device, foreign particles formed from the air collect in the filter body and accumulate there. To prevent clogging of the filter body and to continue to achieve high filtration performance with low pressure loss, the filter body is regenerated from time to time.

[0038] Regeneration involves heating the air supplied to the filter body using the heating device. In particular, the air is heated during regeneration to such an extent that the foreign particles present in the filter body are oxidized or burned. This requires a comparatively high temperature.

[0039] If the air purification device is solely used to filter microorganisms from the air, it is sufficient to heat the air to a lower temperature, for example to at least 50 °C, at least 60 °C or at least 70 °C. Preferably, however, the air is heated to at least 100 °C, at least 125 °C or at least 150 °C. The heating of the air supplied to the filter body is carried out over a specific period of time, for example over at least 3 minutes, at least 5 minutes or at least 20 minutes. Additionally or alternatively, it is provided that the air is heated until a pressure difference across the filter body falls below a threshold value.

[0040] Additionally or alternatively, during regeneration, the filter body may be removed from the housing and heated in an external device, particularly to a temperature at which the foreign particles present in the filter body oxidize or burn. The external device could be, for example, an oven or similar device. Regeneration of the filter body enables the continuous provision of high-quality air.

[0041] A further development of the invention provides that, at least when the temperature of the filter body deviates from the ambient temperature, the air temperature downstream of the filter body is adjusted to a target temperature by at least partially opening a bypass channel arranged fluidically parallel to the air filter. The bypass channel allows the air to be directed around the filter body. Since the filter body and the air flowing through it have a high temperature during regeneration, which is higher than the ambient temperature, it is necessary to cool the air downstream of the filter body to bring it to an acceptable level before it exits the air cleaning device.

[0042] For this purpose, the bypass channel is at least partially opened so that a portion of the air conveyed by the air filter device flows through the bypass channel and only a portion of the air flows through the filter body. The air flowing through the filter body and the air flowing through the bypass channel are recombined downstream of the filter body, cooling the air that has flowed through the filter body. The air is then expelled from the air cleaning device through the air outlet. The described procedure enables reliable regeneration of the filter body without compromising user comfort.

[0043] A further development of the invention provides that the regeneration of the filter body is carried out when a pressure difference across the filter body, measured by at least one pressure sensor, exceeds a threshold value. The pressure difference indicates how many foreign particles are absorbed in the filter body. The higher the pressure difference, the greater the quantity of foreign particles. If the pressure difference exceeds the threshold value, it is concluded that regeneration of the filter body is necessary. Regeneration of the filter body is initiated accordingly. This ensures long-term, reliable operation of the air purification device.

[0044] A further development of the invention provides that a cover closing a maintenance opening is locked after a certain operating time following commissioning or the last regeneration, and / or that the cover is kept locked until regeneration of the filter body has taken place. The described procedure serves to prevent the removal of a filter body laden with foreign particles from the housing. Accordingly, the cover is locked at the latest after a certain operating time of the air cleaning device has elapsed. Additionally or alternatively, it is provided to lock the cover as soon as the pressure difference across the filter body exceeds or is greater than a (further) threshold value. Additionally or alternatively, the cover is only unlocked again once regeneration of the filter body has taken place.This ensures that the filter body removed from the housing is microbiologically safe.

[0045] The features and feature combinations described in the description, in particular the features and feature combinations described in the following description of the figures and / or shown in the figures, can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments are also to be considered encompassed by the invention that are not explicitly shown or explained in the description and / or the figures, but which emerge from or can be derived from the explained embodiments.

[0046] The invention will be explained in more detail below with reference to the exemplary embodiments shown in the drawing, without limiting the invention. The only Figure 1 shows a schematic sectional view of an air purification device.

[0047] The Figure 1 shows a schematic sectional view of an air purification device 1 used to purify air. The air purification device 1 has a housing 2 on which an air inlet 3 and an air outlet 4 are formed. During operation of the air purification device 1, air from an external environment 5 is sucked into the air purification device 1 as raw air through the air inlet 3 and expelled back into the external environment 5 as clean air through the air outlet 4. This is indicated by arrows 6 and 7.

[0048] The air inlet 3 and the air outlet 4 are fluidically connected to one another via a flow path running through the housing 2. An air filter 8 and an air conveying device 9 are located along the flow path, the latter being only indicated very schematically. The air filter 8 is arranged upstream of the air conveying device 9 with respect to a main flow direction of the air flowing through the air cleaning device 1. It has a filter body 10 made of a ceramic material with a lipophilic surface. The filter body 10 is designed as the filter body of a motor vehicle particulate filter or is constructed analogously to such a filter. In this respect, the filter body contains several flow channels 11 and 12 arranged in parallel in terms of flow technology, which are only indicated here.

[0049] Preferably, the entire filter body 10 is interspersed with such flow channels 11 and 12, wherein each of the flow channels 11 and 12 extends completely through the filter body 10 in the main flow direction of the air. In particular, there are several flow channels 11 and several flow channels 12, wherein the flow channels 11 can also be referred to as first flow channels 11 and the flow channels 12 can also be referred to as second flow channels 12. The flow channels 11 and 12 are each closed by means of a closure, which can be designed as a plug. The closures of the flow channels 11 and 12 are arranged at different axial positions, namely such that the filter body 10 is designed as a wall-flow filter body 10.

[0050] It can be seen that the air inlet 3 contains an air inlet grille 13, which is composed of several struts 14 arranged in a star shape and which meet at a central hub 15 or are fastened to one another via the hub. Furthermore, it can be seen that, in terms of flow, a pre-filter 16 and a heating device 17 are arranged between the air inlet 3 and the air filter 8. In the exemplary embodiment shown here, the heating device 17 is in the form of a heating coil which largely overlaps an end face of the filter body 10, in particular by at least 50%, at least 60%, or at least 70%.

[0051] Furthermore, a bypass channel 18 is formed in the housing 2, which on the one hand opens into an annular chamber 19 formed in the housing 2 and at least partially, but preferably continuously, surrounds the air inlet 3 in the circumferential direction. The annular chamber 19 opens into the external environment 5 via an outlet opening 20. With the aid of a valve element 21 arranged in the annular chamber 19, a flow cross-section of the outlet opening 20 can be adjusted. In a first setting, the outlet opening 20 is preferably completely closed and in a second position at least partially open. In the first setting, the bypass channel 18 is thus fluidically closed and in the second setting at least partially open. The flow resulting in the second setting is indicated by the arrows 22.The bypass channel 18 is arranged such that it is fluidically in series with the air conveying device 9, but fluidically parallel to the filter body 10. Air flowing through the bypass channel 18 is thus guided around the air filter 8.

[0052] Furthermore, the air purification device 1 has a maintenance opening 23 formed in the housing 2, which is at least temporarily closed by a cover 24. The maintenance opening 23 enables the removal or replacement of the air filter 8. The cover 24 is at least temporarily locked by a latch 25. Preferably, the valve element 21 is adjustable or displaceable by means of a first magnetic actuator 26, and the latch 25 is adjustable or displaceable by means of a second magnetic actuator 27.

[0053] Finally, the air cleaning device 1 has a pressure sensor 28, by means of which the differential pressure across the air filter 8 can be measured. The pressure sensor 28 is preferably arranged downstream of the air filter 8, centrally in the flow path, in order to implement a reliable and accurate pressure measurement. Furthermore, it should be noted that the air outlet 4 is formed by a motor vehicle tailpipe 29 or is visually similar to one.

[0054] The described air purification device 1 enables reliable air purification or reliable filtering of foreign particles from the air. Since these foreign particles may contain microorganisms, provision is made for regenerating the air filter 8 from time to time. For this purpose, the air supplied to the air filter 8 is heated by means of the heating device 17, namely to a temperature that at least inactivates the microorganisms. The warm air flows through the air filter 8 according to the arrows 30. Downstream of the air filter 8, it is combined with air that has been guided around the air filter 8 through the bypass duct 18 in order to adjust the air flowing out of the air outlet 4 into the outside environment 5 to a comfortable temperature.

[0055] Of course, the described air filter device 1 is not limited to the embodiment shown here. Rather, the air cleaning device 1 can be integrated into a ventilation system, for example, a ventilation system of a building or residential building. In any case, the particularly good filtering performance of the filter body 10 of the motor vehicle particulate filter can be utilized to achieve particularly thorough air cleaning.

[0056] The filter body 10 is preferably designed such that it has a filter efficiency of at least 95% for particles up to a diameter of 5 nm. Typical viruses that are to be filtered out of the air by means of the air purification device 1 have a diameter of 60 to 140 nm. For such particles, the air filter 8 has a filter efficiency or a separation rate of at least 90%, at least 92%, or at least 94%. LIST OF REFERENCE SYMBOLS:

[0057] 1Air cleaning device 2Housing 3Air inlet 4Air outlet 5External environment 6Arrow 7Arrow 8Air filter 9Air conveying device 10Filter body 11Flow channel 12Flow channel 13Air inlet grille 14Strut 15Hub 16Pre-filter 17Heater 18Bypass channel 19Annular chamber 20Orifice opening 21Valve element 22Arrow 23Maintenance opening 24Cover 25Latch 261st solenoid actuator 272nd solenoid actuator 28Pressure sensor 29Vehicle tailpipe 30Arrow

Claims

1. Air purifying device (1) for purifying air, comprising a housing (2), on which an air inlet (3) and an air outlet (4) are formed, which are fluidically interconnected via a flow path extending in the housing (2), wherein an air conveying device (9) for conveying the air along the flow path and an air filter (8) for filtering foreign particles out of the air are arranged in the flow path, wherein the air filter (8) comprises at least one filter body (10) of a motor vehicle particle filter made of a ceramic material having a lipophilic surface, characterized in that a heating device (17) is provided fluidly between the air inlet (3) and the air filter (8).

2. Air purifying device according to claim 1, characterized in that the filter body (10) has multiple flow channels (11, 12) fluidically arranged in parallel, which respectively pass completely through the filter body (10), wherein each of the flow channels (11, 12) is closed by means of a closure.

3. Air purifying device according to claim 2, characterized in that the flow channels (11, 12) comprise first flow channels (11) and second flow channels (12), wherein the closures in the first flow channels (11) are arranged at a first axial position with respect to a longitudinal center axis of the filter body (10) and in the second flow channels (12) are arranged at a second axial position different from the first axial position.

4. Air purifying device according to any one of the preceding claims, characterized in that an air inlet grille (13) is arranged in the air inlet (3), and / or that the air conveying device (9) is fluidly arranged between the air filter (8) and the air outlet (4), and / or that a pre-filter (16) is fluidly arranged between the air inlet (3) and the air filter (8).

5. Air purifying device according to any one of the preceding claims, characterized in that a bypass channel (18) is formed in the housing (2), which channel is arranged fluidically in parallel to the air filter (8) and fluidically in series with the air conveying device (9).

6. Air purifying device according to any one of the preceding claims, characterized in that the housing (2) has a maintenance opening (23) for removing the air filter (8), which is at least temporarily closed by means of a lid (24).

7. Method for operating an air purifying device (1) for purifying air, in particular an air purifying device (1) according to one or more of the preceding claims, wherein the air purifying device (1) has a housing (2) on which an air inlet (3) and an air outlet (4) are formed, which are fluidly interconnected via a flow path extending in the housing (2), wherein an air conveying device (9) for conveying the air along the flow path and an air filter (8) for filtering foreign particles out of the air are arranged in the flow path, wherein the air filter comprises at least one filter body (10) of a motor vehicle particle filter made of a ceramic material having a lipophilic surface, characterized in that a regeneration of the filter body (10) is carried out at least temporarily by operating a heating device (17) arranged in the flow path upstream of the filter body (10), to heat the air supplied to the filter body (10).

8. Method according to claim 7, characterized in that, at least at a temperature of the filter body (10) that deviates from an ambient temperature, a temperature of the air present downstream of the filter body (10) is set to a target temperature, by at least partially opening a bypass channel (18) fluidically arranged in parallel to the air filter (8).

9. Method according to claim 7 or 8, characterized in that the regeneration of the filter body (10) is carried out when a pressure difference across the filter body (10) measured by at least one pressure sensor (28) exceeds a threshold value.