Apparatus and method for ionizing a gaseous medium

Abstract

A device for ionizing a gaseous medium, having a gas inlet channel (101) with a gas supply, a distribution channel (104) with at least one gas outlet and at least one ionization unit (304), wherein the at least one ionization unit (304) is embodied as a connection channel from the gas inlet channel (101) to the distribution channel (104) and an associated counter electrode (106) provided with an electrode (102). Here, the electrode (102) is arranged for ionizing a gas flowing from the gas inlet channel (101) via the ionization unit (304) to the distribution channel (104), wherein the gas flows around the electrode (102) and the at least one gas outlet is embodied as one or more nozzles (107) or a plurality of openings (107).

Description

Technical Field

[0001] This invention relates to an apparatus and a method for ionizing gaseous media and their applications. Background Technology

[0002] In industrial processes involving the production of various products, the undesirable adhesion of surface static charge and often accompanying dust particles to the workpiece is a common problem. To remove, or even avoid, these charges from the outset, systems with and without air assistance are known. For the latter, the concepts of various ionizers are primarily known in the prior art.

[0003] DE 10 2005 056 595 A1 discloses an ionizer with a hollow shell, which primarily houses a high-voltage unit and a control unit. Along the longitudinal direction of the shell, multiple electrode units in the form of needle-shaped electrodes and an air outlet for blowing airflow around the needle-shaped electrodes are arranged in rows. In the longitudinal direction, a portion of the hollow shell is made of plastic, and the air passage is designed such that a portion of the inner wall of the plastic shell serves as the wall of the passage. The air passage is connected to the air outlet.

[0004] KR 10 0 2008 035 228A describes a rod-shaped ionizer. This ionizer has a rod, a discharge electrode, a ground electrode, a high-voltage generating unit, a controller, and nozzles. The nozzles are arranged parallel to the rod to spray air at a predetermined pressure and a defined spray angle toward the object to be discharged. The nozzles can be charged via the discharge electrode. Therefore, a stable ion balance is achieved by using the nozzles and electrodes in such a way that each nozzle has an individual controller and the air ionized by the electrode is blown out of the nozzle.

[0005] WO 2006 / 0167 38A1 describes a device for eliminating static electricity. For this purpose, a pulsed AC high voltage formed in the form of a rectangular pulse voltage waveform is used. The disclosed static eliminator includes a discharge electrode for generating corona discharge, a grounding electrode, a high-voltage unit for generating the AC pulse high voltage, and a controller that controls the frequency and duty cycle of the AC pulse high voltage. The electrode is integrated into a nozzle, which blows ions out of the nozzle using compressed air. The frequency range of the applied high voltage is limited to between 1 Hz and 10 kHz. The set duty cycle range is 40% to 60%. The aforementioned static eliminator allows for adjustment of the discharge effect by freely controlling the frequency and duty cycle of the applied voltage.

[0006] DE 103 20 805A1 discloses an apparatus for processing a cylindrical substrate having at least one conductive core (e.g., wire, cable, or similar material), the apparatus having a processing space having an inlet and an outlet for the substrate to move, in particular continuously, relative to the apparatus, wherein a plasma can be ignited by applying a voltage to at least one electrode fixedly arranged on the apparatus and a counter electrode in the processing space, and wherein the applied voltage is an alternating current voltage, characterized in that the at least one conductive core itself forms the counter electrode, thereby forming a dielectric barrier between the electrode and the at least one conductive core, the dielectric barrier being formed by the substrate itself, and the ignitable plasma being an atmospheric pressure cryogenic plasma.

[0007] DE 10 2014 117 746 A1 describes a compressed air treatment chamber for improving the flow characteristics of compressed air or compressed gas mixture during a painting process, comprising: a shell forming a hollow space, at least one air inlet and at least one air outlet, at least one electrode disposed within the hollow space, and at least one high-voltage source for supplying high voltage to the electrode, wherein the air inlet and air outlet are arranged such that compressed air or compressed gas mixture can preferably flow through the hollow space in a longitudinal direction, wherein at least one insulating layer is disposed on the inner surface of the shell within the hollow space, and an electromagnetic field, preferably a non-uniform or partially non-uniform electromagnetic field, can be generated between the electrode and the mating electrode within the hollow space, having an active region through which the compressed air to be treated flows.

[0008] Furthermore, DE 10 2012 004 270 A1 discloses an apparatus for treating airflow, particularly for treating exhaust gas from an internal combustion engine. This apparatus has at least one radial space through which the airflow can flow radially, extending generally radially from a central region to an external collection space. The radial space is defined by a first and second wall portion that are approximately disc-shaped, and a plurality of electrodes pointing towards the radial space extend from the first wall portion. Here, the first and second disc-shaped walls preferably extend generally parallel to each other. The first disc-shaped wall portion is preferably formed of an electrically insulating material and has conductive electrodes fixed therein, these electrodes being electrically connected to each other by electrical conductors extending within or on the electrically insulating material. Around the central region, two or more parallel radial spaces may be provided sequentially in an axial direction.

[0009] US 6,744,617 B2 discloses a discharge electrode strip within a housing. In this housing, an air unit and a discharge electrode assembly are arranged in its lower region, and a high-voltage unit and a control unit are arranged in its upper region. Here, the housing is composed of separable left and right housing components, which are arranged detachably on top of each other.

[0010] US2009 / 0135538 ​​A1 describes an ionizer having a piezoelectric transformer formed of ferroelectric elements, which generates a high voltage in the secondary section when an alternating voltage is applied to the primary section of the transformer. By appropriately arranging grounding electrodes on the upper and lower surfaces of the secondary section of the piezoelectric transformer, dielectric barrier discharge is performed around the grounding electrodes through a dielectric film used for insulation. This generates positive and negative ions in an airflow, which is then blown from an air nozzle toward the object to be neutralized.

[0011] JP 2001085190 A describes an ionizer that generates a stable corona discharge. For this purpose, the ionizer uses a piezoelectric transformer to amplify the control signal. Here, the control signal to be amplified corresponds to the inherent oscillation frequency of the piezoelectric transformer.

[0012] EP 1 241 755 A2 discloses an ion generating apparatus. In this ion generating apparatus, an electric field for generating ions is generated and maintained between an electrode needle and a counter electrode plate. This generates surface discharge paths A and B, where surface discharge path A extends through an air discharge port and has the shortest distance between the electrode needle and the counter electrode plate, while surface discharge path B does not extend through the air discharge port. The distance between surface discharge paths A and B is modified by structural measures.

[0013] Existing systems suffer from configurational drawbacks in generating ion balance and spatially uniformly supplying ions (to the components to be discharged). Specifically, systems with ion balance (suitable for reducing electrostatic voltage relative to ground potential to significantly below + / - 50V) are too bulky. Such systems typically have individual electrode units, each correspondingly combined with a blower nozzle. This results in inconsistent and uncompact geometries. Furthermore, the relatively large distances between these electrode / blower units lead to non-uniform ion distribution in space, often resulting in streaked discharges on the components. In contrast, smaller systems without air assistance to blow ions fail to achieve the desired ion balance due to the physically induced imbalance between positive and negative corona discharges, coupled with the inevitable partial recombination of charge carriers, making it difficult to control ion balance and resulting in residual charges significantly higher than the aforementioned + / - 50V. Summary of the Invention

[0014] Therefore, the purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and to propose a suitable configuration scheme.

[0015] This objective is achieved through the features of the main claim and the features of the independent dependent claims. The preferred embodiments are the subject of each dependent claim.

[0016] According to the present invention, an apparatus for ionizing a gaseous medium has an inlet channel with a gas supply device, a distribution channel with at least one gas outlet, and at least one ionization unit. Here, the at least one ionization unit is provided with electrodes and is implemented as a connecting channel from the inlet channel to the distribution channel. The electrodes are configured to ionize the gas flowing from the inlet channel through the ionization unit to the distribution channel. The apparatus is characterized in that the gas flows around the electrodes and the at least one gas outlet is implemented as one or more nozzles or multiple openings.

[0017] For the purposes of this paper, ionization units are used to generate ions within a gaseous medium. Specifically, and not limited to this, ionization units generate ions through high electric field densities. Other forms of ionization units may include ultraviolet light sources, thermionic sources, or even radiation sources. Ionization units based on the principles of field ionization and field emission naturally require at least two electrodes to create the necessary strong electric field. Here, typically at least one electrode has a filamentary geometry (e.g., needle-like) to combine the electric field lines and the associated inhomogeneities in the electric field intensity, thereby locally generating the desired high field strength. Here, the accompanying counter electrodes are mostly designed to be planar. For example (but not limited to this), the counter electrodes may be arranged cylindrically around the needle-shaped electrode, and, in the case of close proximity, the use of electrically insulating materials prevents direct current in the form of breakdown or spark gaps that can be generated by the formed charge carriers.

[0018] For the purposes of this article, nozzles and openings are not required to have a circular cross-section. To be precise, nozzles and openings can be designed, for example, as slots, holes, or milled grooves of any geometry, but are not limited to these.

[0019] The solution to this objective includes a method for partially ionizing a gaseous medium using the apparatus of the present invention, wherein the method comprises the following steps:

[0020] A high voltage is applied between the electrode and the counter electrode.

[0021] The gaseous medium is introduced into the intake channel at a working pressure higher than the ambient pressure.

[0022] A gaseous medium is introduced into the ionization unit via a gas inlet, guided past the electrodes, and then exited from the ionization unit into the distribution channel via a gas outlet.

[0023] The gaseous medium is blown out of the distribution channel through at least one opening or nozzle.

[0024] In this invention, the operating pressure is the pressure required to make the gaseous medium flow from the inlet channel through the ionization unit until it is blown out. This is achieved through a pressure gradient, wherein the inlet channel is subjected to a pressure higher than that of the distribution channel, and the pressure conditions within the distribution channel are higher than the ambient pressure.

[0025] For the purposes of this paper, at least partial ionization of a gaseous medium means that not all existing gas particles exist in the form of atoms or neutral molecules.

[0026] Complete ionization of the gaseous medium is not the focus of this paper, as this would lead to potentially destructive currents between the ionization unit and the corresponding counter electrode due to increased conductivity. Of course, complete ionization is impossible under normal atmospheric conditions (pressure approximately 10¹³ hPa, relative humidity approximately 40%, ambient temperature approximately 20°C) due to recombination factors. This can only be achieved in plasma.

[0027] In this respect, partial ionization is an unchangeable situation.

[0028] In embodiments of the present invention, the gaseous medium is air, purified air, nitrogen, argon, carbon dioxide, oxygen, or a mixture thereof.

[0029] Therefore, industrially and commercially available gases or pre-prepared gas mixtures are preferably used. This allows for advantageous prediction of the desired degree of ionization. Furthermore, in embodiments of the invention, an additional bypass is arranged to guide the gaseous medium partially past the ionization unit. This allows the ionized medium to be mixed with the non-ionized portion of the gaseous medium after flowing around the electrodes, thereby enhancing the blowing effect. This allows for advantageous customization of the desired discharge and cleaning effects.

[0030] In embodiments of the invention, the opening or nozzle is defined as being arranged on the surface of the dispensing channel. Here, this arrangement is preferably defined by parameter settings of at least one one-dimensional curve in three-dimensional space, with the center point of the opening or nozzle positioned on this one-dimensional curve.

[0031] A preferred direction can be defined based on the pressure gradient from the inlet of the distribution channel to the gas outlet. The parameter setting of the center point of the opening or nozzle along this defined preferred direction is non-zero. This allows for the advantageous selection of the opening or nozzle position calculated in a flow-optimized manner. These parameters or parameter settings can be more easily implemented in production equipment, enabling automation of the production process. This allows for both highly personalized and cost-effective production. In its simplest case, the one-dimensional curve is, for example, a straight line or a circular arc.

[0032] In embodiments of the invention, the electrical insulation material of the ionization unit is made of plastic, glass, ceramic, or synthetic resin. This is advantageous because it allows for the influence of the inevitable erosion process caused by impacting ions. Since corona discharge also inevitably produces ozone (which can alter materials through its oxidizing effect), it is advantageous to select materials resistant to this oxidation. If economic benefits are a priority, highly abrasion-resistant materials can be used, which have a much lower initial purchase cost. On the other hand, for devices designed for continuous, maintenance-free operation, suitable ceramics are preferred. Generally, there are many possible choices of electrical insulation materials, which is advantageous in production because various geometries can be used.

[0033] In embodiments of the invention, the intake channel extends within the supply plane, and the distribution channel extends within the distribution plane. These two planes are generally parallel to each other. This allows for the consideration of intake channels of arbitrary shapes and distribution channels of similar shapes, wherein intake and distribution channels of such shapes extend parallel to each other. For example (but not limited to this), in the simplest case, two identical pipe sections are used. Here, the length of the pipe section used is many times greater than its diameter, and the two pipe sections extend substantially parallel in arrangement and orientation. In another, non-limiting example, the intake and distribution channels are designed as annular. This design allows the supply and distribution planes (using a more abstract definition of a plane) to be concentric. Here, a plane can be understood as the side surface of a concentric cylinder. This is advantageous because it allows the device to be adapted to the geometry of the object to be cleaned or discharged. This achieves favorable flow around the object and optimizes the surface effect of the cleaning medium.

[0034] In embodiments of the invention, the high voltage is implemented as an alternating high voltage. Here, the peak value of the voltage is between 1 kV and 50 kV. Preferably, it is between 1.5 kV and 40 kV, and particularly preferably between 2 kV and 35 kV. This is advantageous because it enhances the good trade-off between configuration and degree of ionization.

[0035] In embodiments of the invention, the high voltage required to form the necessary electric field is achieved by high-voltage sources integrated into the device, which are powered by an externally supplied low voltage. This is advantageous for the compactness of the device.

[0036] If the distribution channel is at least partially surrounded by a parallel-extending grounding conductor, it is beneficial to achieve a good ion balance and thereby minimize residual charge on the object to be discharged. For example, such an electrical conductor can be designed as a metal foil mesh or a metal sheet, but is not limited to this.

[0037] In embodiments of the present invention, measures for controlling and / or regulating the high voltage of the ionization unit are implemented within the device. This also includes, but is not limited to, monitoring devices for monitoring the high voltage and the degree of ionization of the gaseous medium.

[0038] In embodiments of the invention, the operating pressure of the gaseous medium is set between 50 mbar / 50 hPa and 20 bar / 2 MPa. This is advantageous because the desired flow conditions can be achieved within this pressure range. In gaseous media at pressures below 50 mbar / 50 hPa, statistical impaction processes increasingly become a transport phenomenon. As the pressure decreases, these processes become increasingly unsuitable for forming continuous flow and the resulting ion transport. At pressures above 20 bar or 2 MPa, gas particles, especially the generated ions, have significantly shortened mean free paths, leading to increased recombination. Furthermore, commercially available methods can be used to manage the favorable pressure range, which offers economic advantages in terms of construction and supply.

[0039] Another aspect of the invention relates to the use of a device according to the invention to at least partially ionize a gaseous medium. A cascaded device consisting of an inlet channel and multiple distribution channels (each distribution channel having at least one ionization unit) is also conceivable. This helps to achieve optimal discharge performance for even the most complex and large objects while maintaining the optimized configuration of a single ionizer according to the invention.

[0040] To achieve the present invention, the above embodiments and the features of the claims may be combined as appropriate. Attached Figure Description

[0041] The subject matter of the invention is further described below with the aid of non-limiting drawings and embodiments. Detailed Implementation

[0042] exist Figure 1A partial cross-sectional view of a linear channel layout with connecting ionization units is schematically shown. The cross-section is chosen such that one axis forming the plane corresponds to the longitudinal axis of the needle electrode 102 within the ionization unit, and the second axis corresponds to the longitudinal axis of the channel layout. Possible flow directions of a gaseous medium (e.g., air) through the ionization unit are also illustrated. Air flows along the inlet channel 101. Here, a portion of the airflow enters the ionization unit. This portion of the airflow forms a fluid 103 around the needle electrode 102. For clarity, the circuit between the needle electrode 102 and the counter electrode 106 is not shown. However, the ionization unit has a housing 105 made of electrically insulating material. If a voltage is connected according to the invention, the flowing air, after partial ionization, leaves the ionization unit through provided openings and enters the distribution channel 104. Nozzle openings 107 are provided in the distribution channel 104 through which the partially ionized air escapes from the device.

[0043] exist Figure 2 Two partial views of the ionization unit are schematically shown. These two partial views show cross-sectional views with and without a bypass. The cross-sectional plane is formed by a cylindrical axis extending along the needle electrode 106 and a radial axis extending along a hypothetical intake passage. The partial view on the left shows the ionization unit without a bypass, showing only the intake port 202 and the associated exhaust port 203. The partial view on the right shows the ionization unit with the intake port 202, the associated exhaust port 203, and the bypass 201.

[0044] exist Figure 3 The diagram schematically illustrates a longitudinal section of the device according to the invention. The cross-sectional plane is formed by the longitudinal direction of the device and the longitudinal direction of the ionization unit. Inside the device, a separate area is shown below the air intake passage. A high-voltage power supply 301 is arranged in this area, which is electrically connected to the needle electrode and the counter electrode of the ionization unit 304. The high-voltage unit is powered by a low-voltage interface 302. In the diagram, the low-voltage interface is arranged below the inlet 303 of the air intake passage. Thus, the gaseous medium flows along the air intake passage through the inlet 303, and then (according to the diagram)... Figure 2 One similar scheme involves guiding the ions through the ionization unit 304 and at least partially ionizing them. Immediately afterwards, a mass flow of air carries the ions from the ionization unit into the distribution channel 104. From there, the air-ion mixture flows out from the nozzle opening 107.

[0045] Similar to Figure 3 ,exist Figure 4 The image exemplifies and schematically illustrates a cascaded longitudinal section of the device of the present invention, consisting of two linear arrangements. Here, the orientation of the cross-sectional plane is as follows... Figure 3As shown, the distribution channel has an airtight separation section 401 to prevent unnecessary disruption to the airflow and ion balance within each section. It can also be seen that each of the two sections is supplied with air through the same intake channel; however, each section has its own high-voltage power supply 301 and its own ionization unit 304.

[0046] exist Figure 5 The device of the present invention is schematically shown in the figure. Figure 3 The image shows an external view of the linear layout. This external view is an isometric view with the nozzle opening 107 facing upwards. Furthermore, for better positioning, the air intake 303 and power supply interface 302 are both shown on the side furthest from the observer.

[0047] exist Figure 6 The diagram schematically illustrates an external view of a circular geometric implementation. The internal structure is shown here in conjunction with... Figure 3 and Figure 4 The internal structures are similar. Both the intake passage 101 and the distribution passage 104 have the same annular bottom surface. Here, these two bottom surfaces are arranged in a way that overlaps in their top view, so that the radially symmetrical passages are stacked vertically. Here, the nozzle opening 107 is arranged on the bottom plane of the distribution passage. The inlet 303 of the intake passage faces downward.

[0048] exist Figure 7 The diagram schematically illustrates the external shape of a circular geometric implementation. The internal structure is related to... Figure 3 and Figure 4 The internal structure is similar. The nozzle openings 107 are arranged continuously along a circumferential path curve on the concentric inner surface of the distribution channel. The intake port 303 of the intake channel is similar. Figure 6 Downwards.

[0049] In one embodiment, the intake passage 101 and the distribution passage 104 are similar to Figure 3 The described device is arranged as follows. Here, the maximum length reaches 300mm. The width of the device reaches 20mm, and the maximum height reaches 35mm. The casing is made of plastic and... Figure 5The device shown is similarly arranged. Here, the nozzle opening 107 is formed as 28 circular holes along the central longitudinal axis of the housing, each hole having a diameter of 1 mm and a distance of 10 mm between them. The inlet 303 of the air intake passage is implemented as a pluggable compressed air interface. During operation, the applied compressed air working pressure is between 0.2 bar (200 hPa) and 6.0 bar (0.6 MPa). A low pressure is supplied to and controlled by an electrical plug-in connector (302) for the high-pressure unit 301 arranged inside the device. Thus, a voltage up to 3 kV is achieved on the ionization unit 304. The high voltage is generated here by a piezoelectric transformer with a frequency of 70 kHz. Under this voltage and the set working pressure, a fluid of at least partially ionized air is formed, spreading out in a fan shape through the nozzle opening 107, which has a good ion balance between +35V and -35V.

[0050] Appendix Label Table

[0051] 101 Intake Channel

[0052] 102 Needle Electrode

[0053] 103 Fluid

[0054] 104 Allocation Channel

[0055] 105. A housing made of electrically insulating material.

[0056] 106 pairs of distribution electrodes

[0057] 107 Nozzle opening

[0058] 201 Bypass

[0059] 202 Air Inlet

[0060] 203 Discharge Outlet

[0061] 301 High Voltage Power Supply

[0062] 302 Power supply and electronic control interface

[0063] 303 Inlet of the intake channel

[0064] 304 Ionization Unit

[0065] 401 Airtight Separation Section

Claims

1. A device for ionizing a gaseous medium, comprising a gas inlet channel (101) with a gas supply, a distribution channel (104) with at least one gas outlet and at least one ionization unit (304), wherein the at least one ionization unit (304) is embodied as a connection channel from the gas inlet channel (101) to the distribution channel (104) and an associated counter electrode (106) provided with an electrode (102), and the electrode (102) is arranged for ionizing the gas flowing from the gas inlet channel (101) via the ionization unit (304) to the distribution channel (104), characterized in that, The gas flows around the electrode (102) and the at least one gas outlet is implemented as one or more nozzles (107) or multiple openings; the counter electrode (106) is arranged cylindrically around the electrode (102); the device applies alternating high voltage between the electrode (102) and the counter electrode (106).

2. The apparatus according to claim 1, characterized in that, The opening or nozzle (107) is arranged along a line on the surface of the distribution channel (104), wherein the parameter setting of the line is non-zero in the longitudinal direction of the distribution channel (104).

3. The apparatus according to claim 1 or 2, characterized in that, An insulating layer made of plastic, glass, ceramic or synthetic resin is arranged between the electrode (102) of the ionization unit (304) and the surrounding matching electrode (106).

4. The apparatus according to claim 1 or 2, characterized in that, The intake channel extends in the air supply plane, the distribution channel (104) extends in the distribution plane, and the two planes are generally parallel to each other.

5. The apparatus according to claim 1 or 2, characterized in that, The distribution channel (104) is at least partially surrounded by a grounding conductor, and the grounding conductor extends parallel to the distribution channel (104).

6. The apparatus according to claim 1 or 2, characterized in that, At least the distribution channel (104) is designed to cascade at least two devices for ionizing gaseous media.

7. A method for partially ionizing a gaseous medium using the apparatus of any one of claims 1 to 6, comprising the following steps: A high voltage is applied between the electrode (102) and the counter electrode (106). The gaseous medium is introduced into the intake passage (101) at a working pressure higher than the ambient pressure. The gaseous medium is introduced into the ionization unit (304) via the gas inlet, guided past the electrode (102), and led out from the ionization unit (304) into the distribution channel (104) via the gas outlet. The gaseous medium is blown out of the distribution channel (104) through at least one opening or nozzle (107).

8. The method according to claim 7, characterized in that, The high voltage is implemented as alternating high voltage.

9. The method according to claim 7 or 8, characterized in that, The peak value of the high voltage is in the range of 1 kV to 50 kV.

10. The method according to claim 9, characterized in that, The peak value of the high voltage ranges from 1.5 kV to 40 kV.

11. The method according to claim 10, characterized in that, The peak value of the high voltage is in the range of 2 kV to 35 kV.

12. The method according to claim 7 or 8, characterized in that, The operating pressure is between 50 hPa and 2 MPa.

13. The method according to claim 7 or 8, characterized in that, The gaseous medium is selected from air, purified air, nitrogen, argon, carbon dioxide, and oxygen, or mixtures thereof.

14. An application of using the apparatus of any one of claims 1 to 6 to at least partially ionize a gaseous medium.

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