Electrode arrangement for an air ionization device and air ionization device

Abstract

Electrode arrangement (10) for an air ionization device (12) comprising, • at least one cathode (14) with a free cathode end (16), wherein the cathode end (16) has a cathode tip (18) with a cathode radius (20) and a cathode end section (22) adjacent to the cathode tip (18), and • at least one anode (24) with a free anode end (26), wherein the anode end (26) has an anode tip (28) with an anode radius (30) and an anode end section (32) adjacent to the anode tip (28), wherein the cathode radius (20) is larger than the anode radius (30), and air ionization device (12) with such an electrode arrangement (10).

Description

[0001] The invention relates to an electrode arrangement for an air ionization device and an air ionization device.

[0002] Air ionization devices are used to generate positively and negatively charged ions from air molecules, typically oxygen, nitrogen, and water molecules. These ions then interact with airborne particles, pathogens, pollutants, and odors, leading to their neutralization or aggregation and ultimately facilitating their removal from the air. Ionization technology can therefore be used to purify and disinfect the air. Currently, bipolar ionization systems are often used for air purification. These systems consist of two electrodes that release positive and negative ions. These include carbon brushes made of carbon fibers or opposing plates or electrode materials, which may be separated by a dielectric medium.In addition, a variety of electrode shapes are used for dust separation using electrostatic precipitators. For most applications and current electrode shapes, a nonspecific ionization characteristic is typical and tolerable, or at least tolerated. For example, the generation of ozone is sometimes presented as an advantage.

[0003] Especially for the use of ionization technology for the targeted deactivation of viruses, bacteria and fungal spores as well as for odor reduction, it is essential to know the composition of the ion spectrum and to produce it specifically.

[0004] It is also essential to master the balance of positive and negative charge carriers.

[0005] Establishing a balance between negative and positive charge carriers to maintain an overall charge balance presents a technical challenge. In the past, attempts have been made to improve existing systems in this regard, for example, by adding a third electrode. Such an arrangement is shown in DE 101 57 524 B4. Alternating the generation of positive and negative charge carriers and the targeted removal of a polarity using a variety of devices are also common.

[0006] Further prior art documents cited are DE 28 54 716 A1 and DE 11 2006 001 667 T5.

[0007] However, experiments show that the results achieved with ionization technology for air purification and disinfection are unsatisfactory. It can be observed that ozone and other undesirable byproducts such as NO x can arise.

[0008] To avoid such effects, the voltage applied to the electrodes is reduced in practice. However, this has the disadvantage that the area around the electrode tip in which the desired ionization can occur is significantly reduced, thus reducing the number of ionized molecules and the efficiency of the air ionization device. A further disadvantage is that even the slightest contamination can adversely affect the properties of the electrode tip, and thus the ionization behavior.

[0009] The invention is therefore based on the object of providing an electrode arrangement and electrode shapes for an air ionization device with which a sufficient balance of negative and positive charge carriers can be established, with which the formation of undesirable by-products, such as ozone or NO x , reduced or even avoided, and which is also easy to produce.

[0010] The invention is further based on the object of providing a corresponding air ionization device.

[0011] The objects are achieved according to the invention by an electrode arrangement having the features of patent claim 1 and by an air ionization device having the features of patent claim 13.

[0012] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0013] An electrode arrangement according to the invention for an air ionization device comprises at least one cathode with a free cathode end, wherein the cathode end has a cathode tip with a cathode radius and a cathode end section adjacent to the cathode tip, and at least one anode, each with a free anode end, wherein the anode end has an anode tip with an anode radius and an anode end section adjacent to the anode tip. A cathode is preferably understood here and below to be a negatively charged electrode. An anode is preferably understood here and below to be a positively charged electrode. According to the invention, the cathode radius is larger than the anode radius.

[0014] This arrangement is based on the consideration that the formation of ozone, NO xand other undesirable byproducts of ionization can be attributed to the fact that the force acting on the molecules and electrons is too large and, with previous concepts, too unspecific or undefined. The forces acting on charged particles can be described by Coulomb's law according to the following formula: F=kCq1∗q2r2

[0015] Here, k describes cthe Coulomb constant, q1 and q2 are two spherically symmetrically distributed charge quantities, and r is the distance between their centers. Here, it is assumed that q1 describes the charge of an electrode tip, i.e., the cathode tip or the anode tip, q2 the charge of an electron of a molecule, and r the distance between the electrode tip and the electron. According to this model, the distance r can be increased, for example, by increasing the radius of the electrode tip, i.e., the cathode radius or the anode radius. With a larger cathode radius, for example, the force acting on the molecules and electrons can be reduced, thus reducing the risk of ozone and NO formation. x and other undesirable by-products during ionization.

[0016] Furthermore, the electrode arrangement described here is based on the consideration that the ionization of the air at the at least one cathode that can be achieved with it is based on two different mechanisms. It can be assumed that, on the one hand, electrons are added to the molecules directly at the cathode tip, and on the other hand, the high voltage at the at least one cathode creates a certain work function, which can result in a cloud of free electrons around the cathode tip. These free electrons can combine with molecules in the air to form negative ions. At the at least one anode, on the other hand, a corresponding work function and a corresponding cloud of free electrons cannot be assumed. At the at least one anode, ionization can therefore only take place by electrons being removed from the molecules to be ionized in the region of the anode tip.This consideration explains the imbalance of positive and negative ions frequently observed in bipolar ionization devices. In accordance with the above remarks on Coulomb's law, the inventive arrangement, in which the cathode radius is larger than the anode radius, can create a sufficient balance of negative and positive charge carriers in the ionized air. Here and in the following, equilibrium is preferably defined as an optimal ratio between positive and negative ions, which has an optimal deactivating effect on the germs, yet does not yet lead to a static charge in the room. Thus, an optimal balance can mean a slight preponderance of positive or negative charge carriers.

[0017] The cathode radius can be constant or variable. With a constant cathode radius, the cathode tip can have a spherical, preferably spherically convex, surface. This allows the charge q1 of the cathode tip to be calculated particularly easily, for example, using the following formula: q1=CCluster∗UKathode where C Kugel the capacity of a sphere and U Kathode describes the voltage applied to the cathode tip. For C Kugel the following expression can be used: CSphere=4∗π∗ε0∗r where r is the radius of the assumed sphere, preferably the constant cathode radius, and ε0 is the electric field constant.

[0018] With a variable cathode radius, the cathode tip can have a parabolic and / or elliptical contour. Such contours can be particularly advantageous from a manufacturing perspective.

[0019] The anode radius can be constant or variable. With a constant anode radius, the anode tip can have a spherical, preferably a spherically convex, surface. According to the explanations regarding the constant cathode radius, the charge of the anode tip can be calculated particularly easily. With a variable anode radius, the anode tip can have a parabolic and / or elliptical contour. The individual anode tips of the at least two can have differently shaped anode radii.

[0020] In a simple embodiment of the invention, the cathode end section can be cylindrical. Alternatively, the cathode end section can be conical, which can be advantageous because the cathode radius is advantageously very small. The cathode end section is preferably conical if the cathode radius is constant. Furthermore, to increase rigidity, it can be advantageous for the cathode end section to be conical, tapering conically toward the cathode tip.

[0021] Accordingly, the anode end section can be cylindrical or conical. If the anode end section is conical, it is preferably designed such that it tapers conically toward the cathode tip.

[0022] The cathode tip preferably has a tangent-continuous transition to the cathode end section. The anode tip can have a tangent-continuous transition to the anode end section.

[0023] In a preferred embodiment of the invention, the at least one cathode is arranged, preferably centrally, between the at least two anodes. By providing at least two anodes to the at least one cathode, a sufficient balance of negative and positive charge carriers in the ionized air can be easily established, thereby preventing the formation of undesirable by-products, such as ozone or NO. x , reduced or even avoided. Preferably, the above-described at least one anode is formed by the at least two anodes. The at least one cathode can be formed by exactly one cathode and / or the at least two anodes can be formed by exactly two anodes.

[0024] If the at least one cathode is arranged centrally between the at least two anodes, the at least one cathode is preferably at the same distance from each of the at least two anodes. Preferably, each of the at least two anodes has the same electrical potential. For this purpose, the same anode voltage can be applied to each of the at least two anodes. It is also conceivable for the at least one cathode to be arranged decentrally between the at least two anodes, so that each of the at least two anodes is at a different distance from the at least one cathode. Such an arrangement is preferably selected when the at least two anodes have different electrical potentials or different anode voltages.

[0025] In a further development of the invention, the cathode end and a cathode shaft adjacent to the cathode end and / or the anode end and an anode shaft adjacent to the anode end are made of different materials. This allows the cathode end or the anode end to be made of a material particularly suitable for ionization, and at the same time the cathode or the anode can be manufactured cost-effectively. The cathode shaft or the anode shaft can be made, for example, of a preferably coated, highly elastic steel. A corresponding coating can be made of tungsten carbide. This can, in particular, increase the service life of the cathode or anode. The cathode end, in particular the cathode tip, can be coated with tungsten carbide. The same applies to the anode end, in particular the anode tip. The cathode end and / or the anode end is preferably designed to be replaceable.For this purpose, the cathode end can be non-destructively detached from the cathode shaft and / or the anode end can be non-destructively detached from the anode shaft.

[0026] In one embodiment of the invention, the electrode arrangement has at least three anodes and exactly one cathode, wherein the at least three anodes are arranged in a ring around the exactly one cathode. As a result, a higher and / or spatially better distributed ionization power can be achieved with the electrode arrangement. The cathode voltage of the at least one cathode and the at least three anodes are preferably matched to the number of the at least one cathode and the at least three anodes. Preferably, the previously described at least two anodes are formed by the at least three anodes. The at least three anodes can be formed by exactly five anodes. Preferably, the at least one cathode is arranged centrally between the at least three anodes.

[0027] In one embodiment of the invention, the electrode arrangement comprises at least one electrode carrier with a carrier profile configured as a laminar profile and / or airfoil profile, wherein the at least one cathode and the at least one anode are arranged on the carrier profile. This allows for particularly effective ionization of the air. Preferably, the carrier profile is designed to be surrounded by an air flow. For this purpose, the carrier profile is preferably arranged in a flow channel of the air ionization device.

[0028] A laminar profile is preferably understood here and below to mean a carrier profile which is designed to generate a laminar flow in the air flow and / or not to disturb or change an existing laminar flow, i.e. to keep the effects on the flow as low as possible. If the carrier profile is designed as a laminar profile, the at least one cathode and the at least one anode are preferably arranged in a region in which a laminar flow is present when the laminar profile is used as intended. The carrier profile typically has an inflow side which is intended to be flowed against by the air flow. Preferably, the at least one cathode and the at least one anode are preferably arranged on an outflow side of the airfoil profile which is arranged opposite the inflow side in an intended inflow direction.One of the at least one anode and one of the at least one cathode can be arranged successively, preferably in a row, on the support profile.

[0029] The electrode arrangement can have a plurality of electrode supports, each with a longitudinal support axis. The electrode supports are preferably arranged relative to one another such that the longitudinal support axes are parallel to one another, and such that, in a transverse support direction perpendicular to the longitudinal support axes, one of the at least one cathode of a first of the electrode supports is followed by one of the at least one anode of an immediately adjacent second of the electrode supports. This preferably results in a checkerboard pattern of the at least one cathode and the at least one anode of the support profiles, aligned with the longitudinal support axes. The electrode supports can be arranged with the longitudinal support axis transverse to an intended flow direction of the support profiles.For generating a planar electric field, the electrode arrangement is preferably designed such that a distance between the electrodes immediately following one another along the transverse direction of the carrier is equal to the distance between the electrodes immediately following one another along the longitudinal axis of the carrier.

[0030] An air ionization device according to the invention comprises the electrode arrangement described above. A cathode voltage can be applied to the at least one cathode, and an anode voltage can be applied to the at least one anode. The anode voltages can be configured such that the different anodes have different or identical electrical potentials.

[0031] The cathode voltage and / or the anode voltage can be varied, preferably in real time, depending on at least one ambient condition of the air ionization device. For this purpose, the air ionization device preferably has a correspondingly designed control unit. The at least one ambient condition can include at least one of the following variables: air humidity, temperature, air velocity, air pressure, particle number, particle size, CO2 content, NO x -content, ion concentration.

[0032] The cathode voltage and / or the anode voltage can be modulated using at least one of the following modulation types: pulse modulation, amplitude modulation, frequency modulation. The cathode voltage and / or the anode voltage can thus be adapted, for example, to the at least one ambient condition, the distance between the at least one anode and the at least one cathode, and / or the anode radius or the cathode radius. A combination of the aforementioned modulation types is conceivable.

[0033] An embodiment of the invention is explained with reference to the following figures. It shows: Fig. 1 a schematic representation of an electrode arrangement of a first embodiment of an air ionization device, Fig. 2a is a schematic representation of a first embodiment of an alternative electrode of an air ionization device, Fig. 2b is a schematic representation of a second embodiment of an alternative electrode of an air ionization device, Fig. 3 a schematic representation of an electrode arrangement of a second embodiment of an air ionization device, Fig. 4 a schematic representation of an embodiment of an air ionization device.

[0034] The Fig. Figures 1 to 4 show various embodiments. For the sake of clarity, not all reference numerals are used in every figure. The same reference numerals are used for identical and functionally equivalent parts.

[0035] Fig. 1 shows a schematic representation of an electrode arrangement 10 of a first embodiment of an air ionization device 12. The electrode arrangement 10 comprises a cathode 14 with a free cathode end 16, wherein the cathode end 16 has a cathode tip 18 with a cathode radius 20 and a cathode end section 22 adjacent to the cathode tip 18. The electrode arrangement 10 further comprises two anodes 24, each with a free anode end 26, wherein the anode end 26 has an anode tip 28 with an anode radius 30 and an anode end section 32 adjacent to the anode tip 28. The cathode radius 20 is larger than the anode radius 30. Opposite the cathode tip 18, a cathode shaft 23 borders the cathode end 16. Likewise, opposite the anode tip 28, an anode shaft 33 adjoins the respective anode end 26.

[0036] With such an arrangement, a sufficient balance of negative and positive charge carriers in the ionized air flowing past can be easily established, thereby preventing the formation of undesirable by-products such as ozone or NO x , reduced or even avoided.

[0037] In Fig. In the embodiment shown in Figure 1, the cathode radius 20 is constant. The cathode tip 18 has a spherically convex surface. This allows the charge of the cathode tip 18 to be easily calculated.

[0038] With a variable cathode radius, the cathode tip can have a parabolic and / or elliptical contour. Such contours can be particularly advantageous from a manufacturing perspective.

[0039] The anode radius 30 is in the embodiment of the Fig. 1 is variably designed. The anode tip 28 has a parabolic and / or elliptical contour. The two anodes 24 are identically designed, so that the two anode tips 28 have the same anode radius 30. However, it is also conceivable for the anode tips 28 to have different radii. This is particularly advantageous at different potentials.

[0040] In the embodiment of the Fig. 1, the cathode end section 22 and the anode end sections 32 are each conical. The cathode end section 22 is conical in such a way that it tapers conically towards the cathode tip 18. The anode end section 32 is conical in such a way that it tapers conically towards the anode tip 28. Such an arrangement can be advantageous, among other things, for increasing the rigidity of the cathode end 16 or the anode end 26. The cathode tip 18 also has a continuous tangent transition 34 to the cathode end section 22. The two anode tips 28 also each have a continuous tangent transition to the anode end section 32.

[0041] The Fig. 2a and 2b show alternative embodiments of electrodes 36, wherein each of the two electrodes 36 can in principle be used as cathode 14 or anode 24. Therefore, instead of the terms cathode end 16 / anode end 26, cathode tip 18 / anode tip 28, cathode radius 20 / anode radius 30, cathode end section 22 / anode end section 32, and cathode shaft 23 / anode shaft 33, the terms electrode end 38, electrode tip 40, electrode radius 42, electrode end section 44, and electrode shaft 46 are used to designate the respective corresponding features.

[0042] At the Fig. In the electrode 36 shown in Figure 2b, the electrode end 38 and an electrode shaft 46 adjacent to the electrode end 38 are made of different materials. The electrode shaft 46 can be made, for example, of a preferably coated, highly elastic steel. A corresponding coating can be formed from tungsten carbide. This can, in particular, increase the service life of the electrode. The electrode end 38, in particular the electrode tip 40, can also be coated with tungsten carbide. Preferably, the electrode end 38 is designed to be non-destructively detachable from the electrode shaft 46 and thus replaceable.

[0043] Both in Fig. 2a and 2b have a variable electrode radius 42. The electrode tip 40 in Fig. 2a a parabolic contour, which in Fig. 2b, the electrode tip 40 has an elliptical contour. Fig. 2b, the entire electrode end 38 is formed with an elliptical contour. Fig. 2a, however, shows the cylindrical electrode end section 44 of the electrode 36 shown there. In addition, Fig. 2a the transition from the electrode tip 40 to the electrode end section 44 has a kink 48 and thus no tangent-continuous transition.

[0044] Fig. Figure 1 shows that in the electrode arrangement 10 shown there, the cathode 14 is arranged centrally between the two anodes 24. The cathode 14 has the same distance 50 from each of the two anodes 24. Preferably, the same anode voltage can be applied to each of the two anodes 24.

[0045] Fig. Figure 3 shows an embodiment of the electrode arrangement 10 with three electrode supports 52. Each of the electrode supports 52 has a support profile 54, which is designed as an airfoil profile 56 and preferably as a laminar profile 58. On each of the support profiles 54, a plurality of cathodes 14 and a plurality of anodes 24 are arranged alternately in a row 60. The cathodes 14 are all arranged centrally between the anodes 24. Each of the support profiles 54 is provided to be surrounded by an air flow. For this purpose, the support profiles 54 can be arranged in a Fig. 4 indicated flow channel 62 of the air ionization device 12.

[0046] Each of the support profiles 54 has an inflow side 64, which is intended to receive the airflow. The cathodes 14 and the anodes 24 are arranged on an outflow side 66 of the airfoil profiles 56, opposite the inflow side 64. In the case of the airfoil profiles 56, a laminar or at least slightly to undisturbed laminar flow is preferably present in the region of the outflow side 66 when used as intended.

[0047] Each of the electrode supports 52 also has a support longitudinal axis 67, wherein the electrode supports 52 are arranged relative to one another such that the support longitudinal axes 67 are arranged parallel to one another. In the embodiment of the Fig. 3, the electrode supports 52 are also arranged relative to one another such that the cathodes 14 of a first electrode support 68 are followed in a transverse direction 69 perpendicular to the support longitudinal axes 67 by the anodes 24 of an immediately adjacent second electrode support 72 and an immediately adjacent third electrode support 74. This results in a checkerboard pattern of the cathodes 14 and the anodes 24 aligned with the support longitudinal axes 67. The electrode supports 52 are arranged with the support longitudinal axis 67 transverse to an intended flow direction 70 of the support profiles 54. The electrode arrangement 10 is designed such that a distance 71 between the cathodes 14 and anodes 24 directly following one another along the transverse direction 69 is equal to the distance 50 between the cathodes 14 and anodes 24 directly following one another along the support longitudinal axis 67.

[0048] Fig. Figure 4 shows a schematic representation of an embodiment of the air ionization device 12, which comprises the electrode arrangement 10. The electrode arrangement 10 has five anodes 24 and the cathode 14, wherein the five anodes 24 are arranged in a ring around exactly one cathode 14. The cathode 14 is arranged centrally between the five anodes 24. A cathode voltage can be applied to the cathode 14 and an anode voltage can be applied to each of the five anodes 24. The electrode arrangement 10 comprises the electrode carrier 52, on which the cathode 14 and the anodes 24 are arranged in the flow channel 62. The flow channel 62 has a direction indicated by the arrow in Fig.4. The cathode 14 and the anodes 24 are arranged on the downstream side 66 of the electrode carrier 52 and point with the cathode tip 18 and the anode tips 28 in the flow direction 73. A further embodiment can consist in the arrangement of further annular electrode carriers, each of which can accommodate cathodes and anodes.

[0049] The cathode voltage and / or the anode voltage can be varied, preferably in real time, depending on at least one environmental condition of the air ionization device 10. For this purpose, the air ionization device 10 preferably has a correspondingly designed control unit.

[0050] The cathode voltage and / or the anode voltage can be modulated using at least one of the following modulation types: pulse modulation, amplitude modulation, frequency modulation. The cathode voltage and / or the anode voltage can thus be adapted, for example, to the at least one ambient condition, the distance 50 between the anodes 24 and the cathode 14, and / or the anode radius 30 or the cathode radius 20. List of reference symbols 10 Electrode arrangement 12 Air ionization device 14 Cathode 16 Cathode end 18 Cathode tip 20 cathode radius 22 Cathode end section 23 Cathode shaft 24 Anode 26 Anode end 28 Anode tip 30 anode radius 32 Anode end section 33 Anode shaft 34 tangent-continuous transition 36 Electrode 38 Electrode end 40 Electrode tip 42 Electrode radius 44 Electrode end section 46 Electrode shaft 48 bend 50 distance 52 electrode carriers 54 support profile 56 Wing profile 58 Laminar profile 60 row 62 flow channel 64 Inflow side 66 Downstream side 67 Beam longitudinal axis 68 first electrode carrier 69 Beam transverse direction 70 Flow direction 71 Distance along the beam transverse direction 72 second electrode carrier 73 Flow direction 74 third electrode carrier

Claims

[1] Electrode arrangement (10) for an air ionization device (12) comprising, • at least one cathode (14) with a free cathode end (16), wherein the cathode end (16) has a cathode tip (18) with a cathode radius (20) and a cathode end section (22) adjacent to the cathode tip (18), and • at least one anode (24) with a free anode end (26), wherein the anode end (26) has an anode tip (28) with an anode radius (30) and an anode end section (32) adjacent to the anode tip (28), characterized by that the cathode radius (20) is larger than the anode radius (30), such that the anode tip (28) is more pointed than the cathode tip (18). [2] Electrode arrangement according to claim 1, characterized by that the cathode radius (20) is constant or variable. [3] Electrode arrangement according to one of the preceding claims, characterized bythat the anode radius (30) is constant or variable. [4] Electrode arrangement according to one of the preceding claims, characterized by that the cathode end section (22) is cylindrical or conical. [5] Electrode arrangement according to one of the preceding claims, characterized by that the anode end section (32) is cylindrical or conical. [6] Electrode arrangement according to one of the preceding claims, characterized by that the cathode tip (18) has a tangent-continuous transition (34) to the cathode end section (22). [7] Electrode arrangement according to one of the preceding claims, characterized by that the anode tip (28) has a tangent-continuous transition (34) to the anode end section (32). [8] Electrode arrangement according to one of the preceding claims, characterized bythat the electrode arrangement (10) has at least two anodes (24), and the at least one cathode (14) is arranged, preferably centrally, between the at least two anodes (24). [9] Electrode arrangement according to one of the preceding claims, characterized by that the cathode end (16) and a cathode shaft (23) adjacent to the cathode end (16) and / or the anode end (26) and an anode shaft (33) adjacent to the anode end (26) are made of different materials. [10] Electrode arrangement according to one of the preceding claims, characterized by that the electrode arrangement (10) has at least three anodes (24) and exactly one cathode (14), wherein the at least three anodes (24) are arranged in a ring around the exactly one cathode (14). [11] Electrode arrangement according to one of the preceding claims, characterized bythat the electrode arrangement (10) has at least one electrode carrier (52) with a carrier profile (54) which is designed as a laminar profile (58) and / or airfoil profile (56), wherein the at least one cathode (14) and the at least one anode (24) are arranged on the carrier profile (54). [12] Electrode arrangement according to claim 11, characterized by that the electrode arrangement (10) has a plurality of support profiles (54), each with a support longitudinal axis, wherein the support profiles (54) are arranged such that the support longitudinal axes are arranged parallel to one another, and that in a support transverse direction perpendicular to the support longitudinal axes, one of the at least one cathode (14) of a first of the support profiles (54) is followed by one of the at least one anode (24) of an immediately adjacent second of the support profiles (54). [13] Air ionization device (12) with an electrode arrangement (10) according to one of the preceding claims, wherein a cathode voltage can be applied to the at least one cathode (14) and an anode voltage can be applied to the at least one anode (24). [14] Air ionization device according to claim 13, characterized by that the cathode voltage and / or the anode voltage can be changed, preferably in real time, depending on at least one ambient condition of the air ionization device (12). [15] Air ionization device according to one of claims 13 to 14, characterized by that the cathode voltage and / or the anode voltage can be modulated by means of at least one of the following modulation types: pulse modulation, amplitude modulation, frequency modulation.

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