Air purification device

Abstract

The present invention relates to a cleaning device (1) for cleaning air, which has a filter medium (2) and upstream of the filter medium (2) an electrode arrangement (4) with an electrode (5) and a counter electrode (6) of an ionizer device (3), between which an electrical voltage is applied during operation for corona discharge. An improved and long-lasting cleaning effect as well as a simplified implementation are achieved by connecting the counter electrode (6) to the filter medium (2) via an electrical conductor (15), wherein a Zener diode (14) is arranged in the conductor (15). The invention also relates to an air conditioning system (100) and a vehicle (200) with such a cleaning device (1).

Description

[0001] The present invention relates to a purification device for purifying air, particularly for a vehicle. The invention also relates to an air conditioning system and a vehicle with such a purification device.

[0002] Air purification is desirable in numerous applications. For this purpose, purification devices containing a filter medium are typically used. To clean the air, the air flows through the filter medium, which filters out particles such as dust, thus purifying the air.

[0003] It is known to equip the cleaning device with an ionizer device.

[0004] Such a cleaning device is known, for example, from EP 3 488 933 A1. The cleaning device comprises an ionizer device with an electrode and a counter electrode upstream of a filter medium. The filter medium is arranged between two further electrodes arranged downstream of the ionizer device. During operation, opposite-polar electrical voltages are present between the electrode and counter electrode of the ionizer device and the electrodes between which the filter medium is arranged.

[0005] The present invention is concerned with the object of providing improved or at least different embodiments for a cleaning device of the type mentioned at the outset as well as for an air conditioning system and a vehicle with such a cleaning device, which are characterized in particular by a long-lasting cleaning effect of air.

[0006] This object is achieved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0007] The present invention is therefore based on the fundamental idea of ​​generating an electrostatic charge in the filter medium in a cleaning device comprising a filter medium and an ionizer device arranged upstream of the filter medium by electrically connecting the filter medium to a counter electrode of the ionizer device. According to the invention, it was recognized that the electrical connection of the filter medium to the counter electrode leads to an electrostatic buildup of charge carriers in the filter medium, hereinafter also referred to as filter charge carriers. These charge carriers, in synergistic interaction with charge carriers in the air generated by the ionizer device, hereinafter also referred to as air charge carriers, which include, in particular, ionized particles in the air, lead to improved and long-lasting filtering of particles from the air.The electrostatic buildup in the filter medium is not required permanently, so the electrical connection between the filter medium and the counter electrode is used only for the electrostatic buildup of filter charge carriers, also referred to below as reactivation. As a result, simplified operation of the cleaning device results in a long-lasting, improved cleaning effect. The electrical connection between the filter medium and the counter electrode is established and separated automatically using a Zener diode, which is arranged between the filter medium and the counter electrode and blocks the electrical connection when the counter electrode and filter medium are at the same electrical potential.The trigger for reactivation is therefore a voltage difference between the counter electrode and the filter medium that is greater than the intrinsic and thus adjustable and definable breakdown voltage of the Zener diode. This makes reactivation easier and permissible, with the Zener diode simultaneously preventing a higher voltage from being present between the electrode and the filter medium than between the electrode and the counter electrode. This ensures reliable operation and increased operational safety, while at the same time preventing or at least reducing voltage breakdowns between the electrode and the filter medium, and thus damage to the filter medium. Overall, this results in a long-lasting, improved cleaning effect while simplifying and ensuring safe operation.

[0008] According to the inventive concept, the cleaning device has the filter medium for filtering particles from the air. A flow path for the air leads through the filter medium. The cleaning device also has an ionizer device. The ionizer device comprises an electrode arrangement through which the flow path leads upstream of the filter medium. The electrode arrangement has an electrode with at least one emitter and a counter electrode, between which an electrical voltage is applied during operation for the corona discharge in the air. The filter medium has at least one electrically conductive section and at least one dielectric section. The respective at least one electrically conductive section is also referred to below as the conductive section and the respective at least one dielectric section is also referred to below as the static section.The filter medium thus has at least one conducting section and at least one static section. The at least one conducting section and the at least one static section follow one another along the flow path. An electrical conductor electrically connects at least one of the at least one conducting sections and the counter electrode. The Zener diode is arranged in the conductor in such a way that it blocks the electrical connection between the at least one conducting section and the counter electrode when the at least one conducting section and the counter electrode are at the same electrical potential.

[0009] If the Z-diode blocks the electrical connection between the counter electrode and the at least one conducting section, the cleaning device is operated in an operating mode, which is also referred to below as the control operating mode.

[0010] If the Z-diode releases the electrical connection between the counter electrode and the at least one conducting section, i.e. if the counter electrode and the at least one conducting section are electrically connected, the cleaning device is operated in a different operating mode, which is also referred to below as reactivation mode.

[0011] The change from the control operating mode to the reactivation mode is determined, as explained above, by the breakdown voltage of the Z-diode, also known as the Z-voltage, as well as the electrical potential between the counter electrode and the at least one conducting section.

[0012] The switch between the control mode and the reactivation mode is automatic and thus automated by the Zener diode. This eliminates the need for separate switching between the operating modes, such as active control.

[0013] The filter medium is preferably electrostatically charged in advance, especially before initial operation in the cleaning device. In reactivation mode, this charge is at least partially restored, which may decrease during operation of the cleaning device, especially in regular operating mode. In reactivation mode, the previously existing electrostatic charge is thus at least partially reactivated.

[0014] During operation of the ionizer device, the respective emitter serves to emit electrons. In reactivation mode, electrons can pass from the emitter through the air to the filter medium, thus leading to reactivation.

[0015] Preferably, the respective emitter is designed as a mandrel or needle.

[0016] In principle, the filter medium can be designed in any way as long as it cleans the air by absorbing particles, preferably also odors, and has at least one guide section and at least one static section.

[0017] For example, at least one of the at least one static sections may consist of fibers or comprise fibers.

[0018] For example, at least one of the at least one guide sections may be activated carbon or comprise activated carbon.

[0019] Preferably, the respective static section and the respective conducting section are formed as a single layer in the filter medium. This means that the respective conducting section is an electrically conductive layer, and the respective static section is a dielectric layer in the filter medium. This results in improved flow and cleaning efficiency.

[0020] The cleaning device is used to clean air and can be used in any application.

[0021] The cleaning device can be used, for example, in an air conditioning system, in particular in a so-called “HVAC system”, where the English abbreviation “HVAC” stands for “Heating, Ventilating and Air Conditioning”.

[0022] The air conditioning system preferably has at least one heat exchanger through which air flows during operation, so that during operation of the heat exchanger heat is transferred from the air to the heat exchanger, or vice versa.

[0023] The cleaning device is used in particular in a vehicle. Within the vehicle, the cleaning device is primarily used to clean the air supplied to the interior of the vehicle. The cleaning device can be part of such an air conditioning system.

[0024] For corona discharge, a voltage in the kilovolt range is advantageously applied between the electrode and the counter electrode. For example, the voltage is between 5 kV and 11 kV, especially 8 kV.

[0025] The cleaning device preferably has a voltage source for applying the electrical voltage between the electrode and the counter electrode. The electrode and counter electrode are each electrically connected to one pole of the voltage source.

[0026] In preferred embodiments, the electrical connection of the counter electrode to the at least one conducting section is made by means of the voltage source. This leads to improved operational reliability and simple implementation. During operation of the ionizer device, the electrode is connected to a first pole, in particular to a negative pole, of the voltage source, and the counter electrode is connected to a second pole, in particular to a counter pole and thus a counter potential, of the voltage source. The conductor connects the counter electrode and the at least one conducting section to the second pole and to one another. The Zener diode is arranged between the second pole and the at least one conducting section in the conductor.

[0027] The "poles" in this sense are those that arise due to a potential difference, which is advantageously provided by the voltage source. Accordingly, the opposite pole can also be the grounded pole.

[0028] The order of the at least one guide section and the at least one static section along the flow path can be arbitrary.

[0029] Preferred embodiments are those in which the respective at least one conducting section is arranged downstream of one of the at least one static sections. This means that at least one static section is arranged along the flow path between each of the at least one conducting section and the electrode arrangement. This leads to improved reactivation in reactivation mode and increased operational reliability, in particular due to an at least reduced risk of voltage breakdown between the electrode and the filter medium. In this way, damage to the filter medium is prevented or at least reduced. As a result, the longevity of the filter medium and consequently the cleaning effect is improved.

[0030] Preferred embodiments are those in which a negative corona discharge occurs during operation of the ionizer device. A negative corona discharge preferably occurs both in the standard operating mode and in the reactivation mode. Accordingly, the electrode, in particular the at least one emitter, is negatively polarized, and the counter electrode forms the counter potential.

[0031] Preferably, the duration of the control operating mode is considerably longer than the duration of the reactivation mode. The Zener diode is designed accordingly, particularly with regard to the breakdown voltage. This prevents, in particular, excessive electrostatic charging of the filter medium and thus, in particular, the repulsion of airborne charge carriers by the filter medium. This means that the cleaning effect is improved.

[0032] Advantageously, the duration of each reactivation mode is between 1 minute and 10 minutes. This means that the operating time in each reactivation mode is between 1 minute and 10 minutes. For example, the operating time of each reactivation mode is between 2 and 5 minutes, in particular 5 minutes.

[0033] For example, the Zener diode can be designed such that an operating time in the control mode is at least ten times an operating time in the reactivation mode.

[0034] Preferably, the at least one emitter and the filter medium are spaced apart from one another, wherein a distance between at least one of the at least one emitters and the filter medium along the flow path is between 0 mm and 30 mm, in particular 7 mm. Preferably, the distance between the foremost static section facing the at least one emitter and at least one emitter along the flow path is between 0 mm and 30 mm, in particular 7 mm. Thus, effective and rapid reactivation is achieved with sufficiently high operational reliability in reactivation mode. Consequently, an improved cleaning effect is achieved with sufficiently high operational reliability.

[0035] The emitters can protrude towards the counter electrode or towards the filter medium.

[0036] The electrode may comprise rods spaced apart from one another transversely to the flow path, from each of which at least one emitter protrudes, preferably towards the counter electrode.

[0037] The distance between the bars is advantageously between 20 mm and 60 mm, for example 30 mm.

[0038] In particular, at least two emitters protrude from the respective rod, spaced transversely to the flow path and transversely to the spacing of the rods, toward the filter medium and / or toward the counter electrode. The distance between the emitters of a rod is advantageously between 10 mm and 30 mm, for example, 20 mm.

[0039] The electrode, in particular the emitter, for example the respective rod, advantageously has a high electrical conductivity and is preferably made of stainless steel.

[0040] In principle, the counter electrode can be designed in any way. The counter electrode preferably has high electrical conductivity and is made of stainless steel, for example.

[0041] The counter electrode is advantageously permeable to air. The flow path therefore leads through the counter electrode. This leads to improved generation of air charge carriers.

[0042] In preferred embodiments, the counter electrode has an electrically conductive grid, in particular, an electrically conductive grid through which the flow path passes. This results in reduced flow resistance in the cleaning device. This allows, in particular, the cleaning device to be operated more effectively and designed more compactly.

[0043] The grid preferably has a mesh size between 1 mm and 6 mm, for example 3 mm.

[0044] It is understood that in addition to the cleaning device, the air conditioning system and the vehicle with the cleaning device also belong to the scope of this invention.

[0045] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0046] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0047] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0048] They show, schematically Fig. 1 a highly simplified, circuit diagram-like representation of a cleaning device in a vehicle air conditioning system, Fig. 2 a simplified sectional view of the cleaning device, Fig. 3 an isometric exploded view of the cleaning device with a circuit diagram representation of electrical connections, Fig. 4 a detailed view of a filter medium of the cleaning device.

[0049] A cleaning device 1, as shown for example in the Fig. 1 to 4, serves to clean air. For this purpose, a flow path P of the air leads through the cleaning device 1. The cleaning device 1 can, as Fig. 1, can be used in an air conditioning system 100 and / or in a vehicle 200. The vehicle 200 can include the air conditioning system 100. After passing through the cleaning device 1, the air flows into an interior 201 of the vehicle 200. The interior 201 is therefore arranged downstream of the cleaning device 1. The air conditioning system 100 has at least one heat exchanger 101 for heat transfer with the air. The flow path P leads through the heat exchanger 101. In Fig. 1, a single heat exchanger 101 of the air conditioning system 100 is visible, which is arranged purely as an example downstream of the cleaning device 1. Of course, the air conditioning system 100 can also have more heat exchangers 101. At least one of the at least one heat exchanger 101 is in a Fig. 1, through which a fluid, for example a refrigerant or a coolant, circulates fluidically separated from the air during operation of the air conditioning system 100.

[0050] The cleaning device 1 has, in particular the Fig. 2 and Fig. 3, has a filter medium 2 for filtering particles from the air. The flow path P of the air leads through the filter medium 2. During operation, the air flows through the filter medium 2, whereby the filter medium filters particles, for example dust and fine dust, from the air. The filter medium 2 preferably also filters odors from the air. The filter medium 2 is designed accordingly. In its new state, the filter medium 2 is preferably electrostatically charged, i.e. it has charge carriers (not shown), which are also referred to below as filter charge carriers. The cleaning device 1 also has an ionizer device 3 for corona discharge in the air and, associated therewith, for charging and ionizing molecules and particles in the air. By means of the ionizer device 3, charge carriers are generated in the air, which are also referred to below as air charge carriers.The ionizer device 3 has an arrangement 4 of electrodes 5, 6 for the corona discharge, which is also referred to below as the electrode arrangement 4. The electrode arrangement 4 thus has electrodes 5, 6 with different polarity during operation, which are also referred to below as electrode 5 and counter electrode 6 for easier differentiation. An electrical voltage of, for example, a few kV is therefore applied between the electrode 5 and counter electrode 6 during corona discharge operation. The flow path P leads through the electrode arrangement 4 upstream of the filter medium 2. The electrode 5 has emitters 7, which emit electrodes during operation of the ionizer device 3. In the exemplary embodiments shown, the emitters 7 are each designed as a mandrel 8. The respective emitter 7 protrudes, for example, in the direction of the filter medium 2 or in the direction of the counter electrode 6.In the illustrated embodiments, electrode 5 and counter electrode 6 are each made of stainless steel, for example. Fig. 4 shows a detailed view of the filter medium 2. It can be seen that the filter medium 2 has at least one electrically conductive section 9, hereinafter also referred to as conductive section 9, and at least one dielectric section 10, hereinafter also referred to as static section 10, which follow one another along the flow path P. In Fig. 4, purely by way of example and for the sake of simplicity, it is assumed that the filter medium 2 has a static section 10 and a guide section 9. In the exemplary embodiments shown, the static section 10 and the guide section 9 are each formed as a layer 11. In the exemplary embodiments shown, the respective at least one guide section 9 is arranged downstream of one of the at least one static sections 10. In the exemplary embodiments shown, this means that the static section 10 is arranged upstream of the guide section 9.

[0051] How Fig. 4, the filter medium 2 in the illustrated embodiments is a folded filter medium 2 in which the layers 11 are folded. The static section 10, for example, comprises fibers 12, thus in the illustrated embodiments a layer 11 made of fibers 12. The conducting section 9, for example, comprises activated carbon 13, thus in the illustrated embodiments a layer 11 made of activated carbon 13.

[0052] As will be explained below, the cleaning device 1 makes it possible to establish and block an electrical connection between the counter electrode 6 and the conducting section 9. This is done by means of a Fig. 3, which is arranged in an electrical conductor 15. The conductive section 9 and the counter electrode 6 are electrically connected to one another by means of the conductor 15. The Zener diode 14 is arranged in the conductor 15 in such a way that the Zener diode 14 blocks the electrical connection between the conductive section 9 and the counter electrode when the at least one conductive section and the counter electrode are at the same electrical potential. In contrast, the Zener diode 14 opens the electrical connection when the voltage between the counter electrode 6 and the conductive section 9 exceeds the breakdown voltage of the Zener diode 14, also known as the Zener voltage. If the Zener diode 14 breaks the electrical connection between the conductive section 9 and the counter electrode 6, the cleaning device 1 is operated in a first operating mode, which is also referred to below as the control operating mode.If the Zener diode 14 releases the electrical connection between the conductive section 9 and the counter electrode 6, i.e. if the conductive section 9 and the counter electrode 6 are electrically connected to one another, the cleaning device 1 is operated in a second operating mode, which is also referred to below as the reactivation mode. In the reactivation mode, a transfer of charge carriers, in particular electrons emitted from the at least one emitter 7, to the filter medium 2 occurs. This leads to a rebuilding of the electrostatic charge of the filter medium 2, which decreases during the operation of the cleaning device 1. At the same time, in the reactivation mode, the potentials of the counter electrode 6 and the filter medium 2 and consequently of the conductive section 9 are equalized. Once the potentials are equalized, the Zener diode 14 blocks the electrical connection. The cleaning device 1 thus automatically switches to the normal operating mode.If the potential difference between counter electrode 6 and conductive section 9 exceeds the Z-voltage, the Z-diode 14 releases the electrical connection, so that the cleaning device 1 automatically switches to reactivation mode. This results in an automated, automatic switch between the standard operating mode and the reactivation mode. The cleaning device 1 is therefore automatically operated successively, in particular alternately, in standard operating mode and in reactivation mode. The operating time of the respective reactivation mode is advantageously less than 10 minutes, for example between 1 minute and 10 minutes. The operating time of the respective standard operating mode is also advantageously considerably longer than the operating time of the respective reactivation mode. For example, the operating time of the standard operating mode is at least ten times the operating time of the reactivation mode.The Zener diode 14 is designed accordingly, in particular selected with a suitable breakdown voltage.

[0053] How Fig. 3, the cleaning device 1 in the illustrated embodiments comprises a voltage source 16, by means of which the voltage between electrode 5 and counter electrode 6 is generated. To provide the voltage, the voltage source 16 comprises a first pole 17 and a second pole 18. The first pole 17 in the illustrated embodiments is a negative pole 19 of the voltage source 16. The second pole 18 is a counter pole 20, i.e. in particular also a grounded pole 21, of the voltage source 16, as in Fig. 3. Thus, during operation of the ionizer device 3, both in the control mode and in the reactivation mode, a negative corona discharge occurs in the air. Fig. 3, in the exemplary embodiments shown, the electrical connection of the counter electrode 6 to the conductive section 9 is made by means of the voltage source 16. For this purpose, the conductor 15 electrically connects the second pole 18 to the conductive section 9 and thus also the conductive section 9 to the counter electrode 6. The Z-diode 14 is arranged between the second pole 18 and the conductive section 9 in the conductor 15. In the normal operating mode, the electrical connection of the conductive section 9 to the second pole 18 is broken, so that the electrical connection of the conductive section 9 to the counter electrode 6 is also broken. In the reactivation mode, the Z-diode 14 releases the electrical connection of the conductive section 9 to the second pole 18, so that the electrical connection between the conductive section 9 and the counter electrode 6 is also released.

[0054] In the view of the Fig. 3 shows that the electrode 5, in the exemplary embodiments shown, has rods 22 spaced apart from one another transversely to the flow path, from which emitters 7 each protrude towards the counter electrode 6. In the exemplary embodiments shown, the electrode 5 has, purely by way of example, five such rods 22, each with six emitters 7. The rods 22, including the emitters 7, are identical in the exemplary embodiments shown, purely by way of example. The spacing between the successive rods 22 can be between 20 mm and 60 mm, for example 30 mm. The spacing between the emitters 7 following one another along the respective rod 22 can be between 10 mm and 30 mm, for example 20 mm.

[0055] As in particular Fig. 2, the emitters 7 and the filter medium 2 are spaced apart from one another. A distance of at least one of the at least one emitter 7, preferably the respective emitter 7, from the filter medium 2, preferably from the static section 10, along the flow path P is preferably between 0 mm and 30 mm, for example 7 mm.

[0056] In particular Fig. 3 that the counter electrode 6 in the embodiments shown is designed as a grid 23 through which the flow path P leads. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 488 933 A1

[0004]

Claims

[1] Cleaning device (1) for cleaning air, in particular for a vehicle (200), - with a filter medium (2) for filtering particles from the air, through which a flow path (P) of the air leads, - with an ionizer device (3) which has an electrode arrangement (4) through which the flow path (P) leads upstream of the filter medium (2), - wherein the electrode arrangement (4) comprises an electrode (5) with at least one emitter (7) and a counter electrode (6), between which an electrical voltage is applied during operation for corona discharge in the air, - wherein the filter medium (2) has at least one electrically conductive guide section (9) and at least one dielectric static section (10), which follow one another along the flow path (P), - with an electrical conductor (15) which electrically connects at least one of the at least one conducting sections (9) and the counter electrode (6) to one another, - with a Z-diode (14) arranged in the conductor (15) in such a way that the Z-diode (14) blocks the electrical connection between the at least one conducting section (9) and the counter electrode (6) when the at least one conducting section (9) and the counter electrode (6) are at the same electrical potential. [2] Cleaning device according to claim 1, characterized by , - that the cleaning device (1) has a voltage source (16) for applying the electrical voltage between the electrode (5) and the counter electrode (6), - that during operation of the ionizer device (3), the electrode (5) is connected to a first pole (17), in particular to a negative pole (19), of the voltage source (16) and the counter electrode (6) is connected to a second pole (18), in particular to a positive pole (20) of the voltage source (16), - that the conductor (15) connects the counter electrode (6) and the at least one conducting section (9) to the second pole (18) and to each other, - that the Zener diode (14) is arranged between the second pole (18) and the at least one conducting section (9) in the conductor (15). [3] Cleaning device according to claim 1 or 2, characterized by that the respective at least one guide section (9) is arranged downstream of one of the at least one static sections (10). [4] Cleaning device according to one of claims 1 to 3, characterized bythat in the control mode and in the reactivation mode the electrode (5) is negatively polarized and the counter electrode (6) forms the counter potential. [5] Cleaning device according to one of claims 1 to 4, characterized by that the at least one emitter (7) and the filter medium (2) are spaced apart from one another, wherein a distance of at least one of the at least one emitter (7) to the filter medium (2) along the flow path (P) is between 0 mm and 30 mm, in particular 7 mm. [6] Cleaning device according to one of claims 1 to 5, characterized by that the electrode (5) has rods (22) spaced apart from one another transversely to the flow path (p), from each of which at least one emitter (7) protrudes. [7] Cleaning device according to one of claims 1 to 6, characterized by that the counter electrode (6) has or is an electrically conductive grid (23) through which the flow path (P) leads. [8] Cleaning device according to one of claims 1 to 7, characterized by that the respective static section (10) and the respective guide section (9) are formed as a layer (11) in the filter medium (2). [9] Air conditioning system (100), in particular for a vehicle (200), through which a flow path (P) of air leads, - with at least one heat exchanger (101) for heat transfer with the air, - with a cleaning device (1) according to one of the preceding claims arranged in the flow path (P). [10] Vehicle (200) with a cleaning device (1) according to one of claims 1 to 8, in particular with an air conditioning system (100) according to claim 9.

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