Air filter device for air conditioning system

Abstract

The invention relates to an air filter device for an air-conditioning system, in particular for sorting particles, preferably dirt particles, from air, comprising: an air path through which air can flow in a flow direction; an ion generator arranged in the air path for generating ions in the air path; and a grid structure made of an electrically conductive material arranged in the air path upstream of the ionizer with respect to the flow direction and constituting a first electrode. A filter element is arranged in the air path downstream of the ionizer with respect to the flow direction, the filter element having a layer forming a second electrode. Furthermore, the air filter device comprises a high voltage source having an electrical counter terminal and an electrical terminal for generating a high voltage between the counter terminal and the terminal. The terminal is electrically connected with the ion generator. The reverse terminal is electrically connected with the first and second electrodes. In the region of the ionizer, a third electrode is arranged electrically separate from the ionizer, and the third electrode is electrically connected to the first and second electrodes.

Description

Technical Field

[0001] The invention relates to an air filter device for air conditioning facilities. Background Art

[0002] Modern air conditioning systems for air conditioning the vehicle interior of a motor vehicle typically include filter elements which serve to remove pollutants, harmful gases, dust particles and unpleasant odors from the air conducted into the vehicle interior.

[0003] What is proved to be problematic here is precisely the high dust load in the surrounding environment of the motor vehicle and then the surrounding environment of the air conditioning device, which just needs to realize filtering dust from the air to be introduced into the vehicle interior space and puts forward a particularly high requirement. For this reason, it is known that a filter element with a fiber filter layer is used to clean dust particles. Since the structure space for the use of air conditioning devices in modern motor vehicles is typically limited, the structure space provided to such filter elements in the air conditioning devices is relatively small. However, in order to still ensure that a large amount of air can be transported to the vehicle interior space by means of air conditioning devices, the filter element must have a lower flow resistance so that the pressure loss generated in the air is also kept lower. For this reason, traditional filter elements are usually equipped with an open-pore filter fiber layer for particle separation, so that the mechanical dust separation efficiency of the filter element realized thus appears relatively low.

[0004] To solve this problem, it is known to improve the separation of dust particles by electrostatic charging. However, the electrostatic reserve generated during the production process causes the filter element to fail relatively quickly in actual operation as the filter element ages and is thus increasingly loaded with dust. Summary of the invention

[0005] Therefore, the task of the present invention is to point out a new path in the development of air filter devices. In particular, an improved embodiment should be provided for such air filter devices, so that the air filter devices utilize the above-mentioned working principle of electrostatic charging and achieve improved particle separation throughout the life cycle of the filter element.

[0006] This object is achieved by the subject matter of the independent patent claims. Preferred embodiments are the subject matter of the dependent patent claims.

[0007] The basic idea of ​​the invention is therefore that the air filter device is equipped with an ionizer having a plurality of so-called ejection electrodes (the relevant technicians also refer to the ejection electrodes as "corona ejection electrodes"), which are used to generate ions in the air path, and a matching electrode is arranged upstream of the ionizer, which is arranged electrically separated from the ejection electrodes in the air path. In this way, an electric field is generated in the air path, by which particles present in the air can be ionized.

[0008] According to the invention, it is now provided that the electrostatically chargeable filter element arranged downstream of the ionizer is electrically connected to the counter-electrode arranged upstream of the ionizer. As a result, in addition to the counter-electrode arranged upstream of the ionizer, further counter-electrodes are produced downstream of the ionizer. An electric field is now produced between the ejection electrode and these counter-electrodes, which leads to improved charging of the particles and to a polarization effect in the filter element.

[0009] Furthermore, according to the invention, counter electrodes are arranged between the ejection electrodes of the ionizer, which are arranged electrically separated from the ejection electrodes in the air path. The field line course of the corona discharge field generated in this way has a particularly favorable effect on the collection of charged particles into the electrostatically charged filter element, which leads to a further enhancement of the polarization effect in the material of the filter element. As a result, the polarization of the filter element is maintained or reestablished for a long period of time, and thus the efficiency of particle separation is improved during long-term operation of the air filter device, even when a large number of particles are already present in the filter element.

[0010] As a result, an air filter device is provided by means of the measures described above, in which an efficient separation of particles from air conducted through the air path is ensured over the entire service life of the air filter device or of a filter element used in the air filter device.

[0011] Specifically, the air filter device according to the present invention comprises an air path through which air can flow in a flow direction. An ionizer for generating ions is arranged in the air path of the air filter device, the ionizer having an ionizer electrode, which may include a plurality of ejection electrodes. In the air path, a grid structure made of a conductive material is arranged upstream of the ionizer with respect to the flow direction, the grid structure constituting a first electrode. The first electrode constitutes a mating electrode relative to the ejection electrode of the ionizer and charges particles upstream of the ejection electrode.

[0012] In the air path, downstream of the ionizer in terms of the flow direction, a filter element is arranged, which has a layer forming the second electrode. The layer is made of or includes an electrically conductive material. The filter element can preferably be configured as a pleated bellows, ie, has a bellows-like geometry.

[0013] The air filter device also includes a high-voltage source with an electrical counter-terminal and an electrical terminal for generating a high voltage, in particular between -5 kV and -15 kV, between the counter-terminal and the terminal. According to the invention, a third electrode is arranged in the region of the ionizer, electrically separated from the ionizer, and the third electrode is electrically connected to the first and second electrodes.

[0014] The ionizer of the air filter device can for example generate a direct current corona discharge, an alternating current corona discharge or a pulsed corona discharge. For this reason, in principle, a negative and positive potential can be applied on the ionizer or on the ionizer electrode or the spray electrode.

[0015] However, preferably, in order to generate the corona discharge, a DC voltage with negative polarity is applied; this is because compared with a corona discharge with positive polarity, a corona discharge with negative polarity ensures that the corona flow from the electrons has a higher stability and a higher value. Therefore, it is preferred to configure the electrical terminal of the high-voltage source as a negative terminal and the electrical counter terminal as a positive terminal of the high-voltage source. Alternatively to this, it is also possible to configure the electrical terminal of the high-voltage source as a positive terminal of the high-voltage source and to configure the electrical counter terminal as a negative terminal of the high-voltage source.

[0016] According to an advantageous development of the air filter device according to the invention, the ionizer comprises an ionizer electrode for generating ions in the air path. The ionizer electrode can in turn have a plurality of so-called spray electrodes.

[0017] According to a further advantageous development, the ionizer electrode can include at least two electrode strips arranged at a distance from each other, from which at least one electrode tip, preferably designed in the form of a needle, protrudes toward the first electrode for generating ions. Preferably, the electrode tips each extend counter to the flow direction.

[0018] In this way, a very strong electric field can be generated in the region of the relevant electrode tip, which greatly facilitates the generation of a large number of ions by the ionizer.Each electrode tip can form a respective ejection electrode of the ionizer.

[0019] The distance between the grid structure forming the first electrode and the electrode strips of the ionizer measured in the flow direction is preferably between 20 mm and 50 mm, preferably approximately 25 mm.

[0020] Particularly expediently, at least two electrode strips extend in the air path, in particular in a straight line, in a direction of extension transversely, preferably orthogonally, to the flow direction. In this way, the entire cross section of the air path is covered by the ionizer to generate ions.

[0021] According to another advantageous improvement, the ionizer electrode can include at least two, preferably a plurality of electrode strips arranged spaced apart from each other, which preferably extend parallel to each other. In this improvement, the third electrode includes at least two electrode elements arranged spaced apart from each other, wherein the electrode elements of the third electrode are respectively arranged between two adjacent electrode strips of the ionizer. This further improves the field line orientation of the corona field.

[0022] Particularly preferably, at least three electrode strips and at least two electrode elements can alternate in a transverse direction extending perpendicularly to the flow direction, preferably also perpendicularly to the extension direction.

[0023] Particularly preferably, at least one electrode element can be designed as an electrode plate.

[0024] It is particularly preferred that the electrode plates are arranged in a plane extending in the flow direction, thereby preventing the electrode plates from causing a strong pressure drop in the air that strikes the electrode plates or flows past them.

[0025] In a further preferred embodiment, the ionizer and the third electrode are arranged in a plane which extends transversely, in particular orthogonally, to the flow direction.

[0026] In another preferred embodiment, at least two, preferably a plurality, particularly preferably all adjacent electrode strips are arranged at a spacing, measured orthogonally to the extension direction, of between 20 mm and 60 mm, preferably between 25 mm and 35 mm. This prevents the electrode strips from causing a strong pressure drop in the air flowing past.

[0027] According to an advantageous development, at least two, preferably a plurality, particularly preferably all adjacent electrode tips can be arranged at a distance from one another measured in the extension direction of between 1 mm and 30 mm, preferably between 5 mm and 9 mm. This prevents the electrode strips from causing a strong pressure drop in the air that strikes the electrode plate or flows past it.

[0028] Particularly preferably, the electrode tips are arranged in a grid-like manner in the air path. This measure leads to an improved field line profile of the corona field in the air path.

[0029] In a further preferred embodiment, at least one electrode tip tapers in particular conically toward the first electrode, ie, thus particularly preferably counter to the flow direction. This preferably applies to a plurality, particularly preferably all, of the electrode tips.

[0030] In another preferred embodiment, the filter element comprises a layer made of an electrically insulating material, in particular a dielectric material, through which air can flow for separating particles from the air, and the layer made of the electrically insulating material is arranged in the air path upstream or downstream of the layer forming the second electrode. This layer made of an electrically insulating material or a dielectric material can be electrostatically charged. This can improve the efficiency of being able to accumulate charged particles on the filter element. In addition, the electrically insulating material or the dielectric material also prevents spark discharges from the ionizer to the conductive layer of the filter element.

[0031] The layer can be designed in particular as a carrier layer for forming a layer of the second electrode. This ensures that the corona field passes through the carrier layer and thus also guides the ionized particles to be sorted through the second layer. It is therefore particularly suitable that the two layers of the filter element are arranged one after the other in the flow direction.

[0032] It is particularly expedient if the layer of the filter element forming the second electrode is formed from activated carbon or at least comprises such activated carbon. The activated carbon effectively prevents ozone from penetrating the filter element.

[0033] According to another advantageous refinement, the grid structure comprises at least two, preferably a plurality of, first grid bars arranged spaced apart from each other, which extend transversely, preferably orthogonally, to the flow direction in the air path. In this refinement, the grid structure further comprises at least two, preferably a plurality of, second grid bars arranged spaced apart from each other, which extend transversely, preferably orthogonally, to both the first grid bars and the flow direction in the air path.

[0034] Particularly preferably, the first, second and third electrodes can be electrically connected to one another. In this way, a particularly ionization-favorable course of the field lines of the electric field is produced.

[0035] The effectiveness of the polarization effect applied by the electric field to the filter element depends on the strength of the electric field generated. The higher the strength of the electric field, the greater the polarization effect generated. Therefore, the corona discharge electrode should be as close as possible to the inlet surface of the filter element. Therefore, in another preferred embodiment, the distance between the ionizer, in particular the electrode strips of the ionizer and the filter element is at most 30 mm, preferably at most 7 mm.

[0036] Particularly preferably, the material of the grid structure or the material of the (first and / or second) grid bars can be steel, in particular stainless steel or include steel. Alternatively or additionally, in this variant, the material of the ionizer or the material of the ionizer electrodes can be steel, in particular stainless steel or include steel, in particular stainless steel.

[0037] Further important features and advantages of the invention emerge from the dependent claims, the drawings and the associated description of the figures in conjunction with the drawings.

[0038] It is understood that the features mentioned above and yet to be explained below can be used not only in the respectively stated combination but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0040] In which respectively schematically:

[0041] Figure 1 A perspective view showing an example of an air filter device according to the present invention;

[0042] Figure 2 Show Figure 1 A side view of an air filter assembly; DETAILED DESCRIPTION

[0043] Figure 1 and Figure 2 A perspective view showing an example of an air filter device 1 according to the invention, Figure 2 Shown in side view. Figure 1 and Figure 2 The air filter device 1 comprises an air path 2 through which air L can flow along a flow direction S. In addition, the air filter device 1 further comprises an ion generator 3 for generating ions arranged in the air path 2. In addition, the air filter device 1 further comprises a grid structure 4 made of a conductive material, which is arranged upstream of the ion generator 3 in the air path 2 with respect to the flow direction S and constitutes a first electrode 5a.

[0044] like Figure 1 and Figure 2It can be seen that the grid structure 4 has a plurality of first grid bars 11a arranged at a distance from each other, which extend in the air path 2 orthogonally to the flow direction S. In addition, the grid structure 4 also includes a plurality of second grid bars 11b arranged at a distance from each other, which extend in the air path 2 orthogonally both to the first grid bars 11a and to the flow direction S. Steel, in particular stainless steel, is a possible material for the grid structure 4 or the first and second grid bars 11a, 11b. The first and second grid bars 11a, 11b can be spread out in a plane extending perpendicularly to the flow direction S.

[0045] Furthermore, the air filter device 1 comprises a filter element 6 which is arranged downstream of the ionizer 3 in the air path 2 with respect to the flow direction S. The filter element 6 in turn comprises a layer 7 which forms a second electrode of the air filter device 1. In the present example, this layer 7 is made of an electrically conductive material, for example.

[0046] In the example of the figures, the filter element 6 further comprises a layer 9 made of an electrically insulating material through which the air L can flow, which serves to separate particles from the air L. The layer 9 is arranged in the air path 2, for example, upstream of the layer 7 forming the second electrode 5b. The layer 7 of the filter element 6 forming the second electrode 5b is activated carbon 10. The two layers 7, 9 of the filter element 6 can be stacked one after the other in the flow direction S.

[0047] In addition, the air filter device 1 also includes a high voltage source 8 with an electrical terminal 8a and an electrical counter-terminal 8b, which is used to generate a high voltage between the terminal 8a and the counter-terminal 8b. Suitably, a voltage between 5 kV and 15 kV can be provided between the terminal 8a and the counter-terminal 8b. As shown in the figure, the terminal 8a is preferably configured as a negative terminal, and the counter-terminal 8b is configured as a positive terminal. However, an inverted configuration can also be imagined, in which the terminal 8a is configured as a positive terminal, and the counter-terminal 8b is configured as a negative terminal (not shown).

[0048] according to Figure 1 , the terminal 8a is electrically connected to the ionizer 3, and the counter-terminal 8b is electrically connected to the first and second electrodes 5a, 5b. In addition, a third electrode 5c is arranged in the region of the ionizer 3, electrically separated from the ionizer, and the third electrode is electrically connected to the first and second electrodes 5a, 5b. The counter-terminal 8b is therefore also electrically connected to the third electrode 5c.

[0049] The ionizer 3 has an ionizer electrode 14 configured as an ejection electrode 17 for generating ions in the air path 2. The ionizer electrode 14 comprises a plurality of electrode strips 12 arranged at a distance from each other, wherein a plurality of electrode tips 13, each configured in a needle shape, protrude from each electrode strip 12 toward the first electrode 5a, from which the ions can be generated. The electrode tips 13 constitute the ejection electrode 17. The electrode tips 13 extend away from the respective electrode strips 12, respectively, counter to the flow direction S toward the grid structure 4.

[0050] like Figure 1 and Figure 2 As shown in the figure, the electrode tip 13 can be arranged in the air path 2 in a grid shape, and can also taper conically toward the first electrode 5a. The material of the ionizer 3 or the ionizer electrode 14 and its electrode strips 12 can be steel, such as stainless steel. The individual electrode strips 12 extend in a straight line in the air path 2 along a common extension direction E extending orthogonally to the relative flow direction S. The distance between the electrode strips 12 of the ionizer 3 and the filter element 6 is at most 30 mm, preferably at most 7 mm.

[0051] In the exemplary embodiment, all adjacent electrode strips 12 are arranged at a spacing A1 measured orthogonally to the extension direction E, which is between 20 mm and 60 mm, preferably between 25 mm and 35 mm. In addition, in the exemplary embodiment, all adjacent electrode tips 13 are arranged at a spacing measured along the extension direction E, which is between 1 mm and 30 mm, preferably between 5 mm and 9 mm.

[0052] according to Figure 1 and Figure 2 , the third electrode 5c includes a plurality of electrode elements 15 arranged spaced apart from each other. Each electrode element 15 can be configured as an electrode plate 16. Each electrode plate 16 is arranged in a plane E1 extending along the flow direction S. Here, the electrode elements 15 of the third electrode 5c are arranged spaced apart from two adjacent electrode strips 12 of the ion generator 3. Therefore, the electrode strips 12 and the electrode elements 15 alternate along the transverse direction Q, which in this example extends perpendicularly to the flow direction S and also perpendicularly to the extension direction E of the electrode strips 12.

Claims

1. An air filter device (1) for an air conditioning system, the air filter device being used in particular for separating particles, preferably dirt particles, from air (L), the air filter device comprising: - an air path (2) through which air (L) can flow in the flow direction (S), - an ion generator (3) arranged in the air path (2) for generating ions in the air path (2), - a grid structure (4) made of an electrically conductive material, arranged upstream of the ionizer (3) in the air path (2) with respect to the flow direction (S) and constituting a first electrode (5a), - a filter element (6) arranged downstream of the ionizer (3) in the air path (2) with respect to the flow direction (S), the filter element having a layer (7) forming the second electrode (5b), the layer comprising or consisting of an electrically conductive material, - a high-voltage source (8) having an electrical terminal (8a) and an electrical counter-terminal (8b), the high-voltage source being used to generate a high voltage, in particular between 5 kV and 15 kV, between the terminal (8a) and the counter-terminal (8b), - in, The terminal (8a) is electrically connected to the ion generator (3), and the counter terminal (8b) is electrically connected to the first and second electrodes (5a, 5b), - in, A third electrode (5c) is arranged in the region of the ionizer (3) so as to be electrically separated from the ionizer and is electrically connected to the first and second electrodes (5a, 5b).

2. The air filter device according to claim 1, It is characterized in that - the electrical terminal (8a) is configured as a negative terminal of the high voltage source (8) and the electrical counter terminal is configured as a positive terminal of the high voltage source, or - the electrical terminal (8a) is configured as a positive terminal of the high voltage source (8), and the electrical counter terminal is configured as a negative terminal of the high voltage source.

3. The air filter device according to claim 1 or 2, It is characterized in that The ionizer (3) has an ionizer electrode (14) for generating ions in the air path (2), the ionizer electrode preferably comprising a plurality of ejection electrodes (17).

4. The air filter device according to any one of claims 1 to 3, It is characterized in that The ionizer electrode (14) comprises at least two electrode strips (12) arranged at a distance from one another, from each of which at least one electrode tip (13), preferably designed in the form of a needle, projects toward the first electrode (5a) for generating ions.

5. The air filter device according to claim 4, It is characterized in that The at least two electrode strips (12) extend in the air path (2), in particular in a straight line, along an extension direction (E) transversely, preferably orthogonally, to the flow direction (S).

6. An air filter device according to any one of the preceding claims, It is characterized in that The third electrode (5c) comprises at least two electrode elements (15) arranged spaced apart from each other, wherein the electrode elements (15) of the third electrode (5c) are respectively arranged between two adjacent electrode strips (12) of the ionizer (3) and spaced apart from the two adjacent electrode strips.

7. The air filter device according to claim 6, It is characterized in that At least three electrode strips (12) and at least two electrode elements (15, 15) are arranged alternately in a transverse direction (Q) extending perpendicularly to the flow direction (S), preferably also perpendicularly to the extension direction (E).

8. The air filter device according to claim 6 or 7, It is characterized in that At least one electrode element (15) is designed as an electrode plate (16).

9. The air filter device according to claim 8, It is characterized in that At least one electrode plate (16) is arranged in a plane (E1) extending along the flow direction (S).

10. The air filter device according to any one of claims 4 to 9, It is characterized in that At least two, preferably a plurality, particularly preferably all adjacent electrode strips (12) are arranged at a spacing (A1) measured orthogonally to the extension direction (E) of between 20 mm and 60 mm, preferably between 25 mm and 35 mm.

11. The air filter device according to any one of claims 4 to 10, It is characterized in that At least two, preferably a plurality, particularly preferably all adjacent electrode tips (13) are arranged at a distance from one another measured in the extension direction (E) of between 1 mm and 30 mm, preferably between 5 mm and 9 mm.

12. The air filter device according to any one of claims 4 to 11, It is characterized in that The electrode tips (13) are arranged in a grid-like manner in the air path (2).

13. An air filter device according to any one of claims 3 to 12, It is characterized in that At least one, preferably a plurality, particularly preferably all of the electrode tips (13) tapers, in particular conically, toward the first electrode (5a).

14. An air filter device according to any one of the preceding claims, It is characterized in that The filter element (6) comprises a layer (9) of electrically insulating material through which air can flow for separating particles from the air (L), the layer of electrically insulating material being arranged in the air path (2) upstream or downstream of the layer (7) forming the second electrode (5b).

15. The air filter device according to claim 14, It is characterized in that The layer (7) of the filter element (6) forming the second electrode (5b) is formed from activated carbon (10) or at least comprises activated carbon (10).

16. The air filter device according to claim 14 or 15, It is characterized in that The two layers (7, 9) of the filter element (6) are stacked one behind the other in the flow direction (S).

17. An air filter device according to any one of the preceding claims, It is characterized in that - the grid structure (4) comprises at least two, preferably a plurality of, first grid bars (11a) arranged spaced apart from one another, and extending in the air path (2) transversely, preferably orthogonally, to the flow direction (S), The grid structure (4) comprises at least two, preferably a plurality of, second grid bars (11b) arranged at a distance from one another, which extend in the air path (2) transversely, preferably orthogonally, both to the first grid bars (11a) and to the flow direction (S).

18. An air filter device according to any one of the preceding claims, It is characterized in that The distance between the ionizer (3), in particular the electrode strips (12) of the ionizer (3), and the filter element (6) is at most 30 mm, preferably at most 7 mm.

19. An air filter device according to any one of the preceding claims, It is characterized in that The first electrode, the second electrode and the third electrode (5a, 5b, 5c) are electrically connected to each other.

20. An air filter device according to any one of the preceding claims, It is characterized in that - the material of the grid structure (4) or the material of the (first and / or second) grid bars (11a, 11b) is steel, in particular stainless steel, or comprises steel; or / and The material of the ionizer (3) or the material of the ionizer electrode (14) is steel, in particular stainless steel, or comprises steel, in particular stainless steel.

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