Plasma generator and particulate removal device

Abstract

The present invention provides a plasma generator capable of increasing the plasma generation area. [Solution] The plasma generator 4 comprises a dielectric layer 8, a first electrode 10 and a second electrode 12 arranged on the first main surface 18 of the dielectric layer 8, a third electrode 14 arranged on the second main surface 20 of the dielectric layer 8 so as to face the first electrode 10 and the second electrode 12 via the dielectric layer 8, and a diode 16 electrically connected between the first electrode 10 and the second electrode 12. An AC voltage from the power supply 6 is applied between the first electrode 10 and the third electrode 14, and between the second electrode 12 and the third electrode 14, and a potential difference is generated between the first electrode 10 and the second electrode 12 by the diode 16, thereby generating plasma P on the first main surface 18 of the dielectric layer 8 by dielectric barrier discharge.

Description

Technical Field

[0001] The present invention relates to a plasma generation device and a particulate removal device provided with the same.

Background Art

[0002] Carbon fine particles are one of the main components of air pollutants such as PM2.5 and PM0.1, and also contribute to global warming by absorbing sunlight. A plasma generation device for removing such carbon fine particles by plasma has been proposed (see, for example, Patent Document 1).

[0003] A conventional plasma generation device includes a dielectric layer, a first electrode plate disposed on one main surface of the dielectric layer, and a second electrode plate disposed on the other main surface of the dielectric layer. By applying an alternating voltage supplied from an external power source between the first electrode plate and the second electrode plate, plasma is generated on one main surface of the dielectric layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described conventional plasma generation device, there is a problem that the plasma generation region on one main surface of the dielectric layer is narrow, and it is difficult to efficiently remove carbon fine particles.

[0006] The present invention aims to solve the above-described problems, and an object thereof is to provide a plasma generation device capable of increasing the plasma generation region and a particulate removal device provided with the same.

Means for Solving the Problems

[0007] To achieve the above objective, a plasma generator according to one aspect of the present invention comprises a dielectric layer having a first main surface and a second main surface opposite to the first main surface, a first electrode and a second electrode disposed on the first main surface of the dielectric layer, a third electrode disposed on the second main surface of the dielectric layer so as to face the first electrode and the second electrode via the dielectric layer, and a circuit element electrically connected between the first electrode and the second electrode, wherein an AC voltage from a power source is applied between the first electrode and the third electrode and between the second electrode and the third electrode, respectively, and a potential difference or voltage phase difference is generated between the first electrode and the second electrode by the circuit element, thereby generating plasma by dielectric barrier discharge on the first main surface of the dielectric layer. [Effects of the Invention]

[0008] According to one aspect of the present invention, the plasma generation area can be increased. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of the particulate matter removal device according to Embodiment 1. [Figure 2] This is a plan view showing a plasma generator according to Embodiment 1. [Figure 3] This figure shows the equivalent circuit of the particulate matter removal device according to Embodiment 1. [Figure 4] This is a schematic diagram showing the configuration of the particulate matter removal device according to Embodiment 2. [Figure 5] This figure shows the equivalent circuit of the particulate matter removal device according to Embodiment 2. [Figure 6] This graph shows the changes in voltage amplification factor and voltage phase difference in response to a change in composite capacitance in the particulate removal device according to Embodiment 2. [Figure 7] This is a schematic diagram showing the configuration of the particulate matter removal device according to Embodiment 3. [Figure 8]This figure shows the equivalent circuit of the particulate matter removal device according to Embodiment 3. [Figure 9] This is a schematic diagram showing the configuration of the particulate matter removal device according to Comparative Example 1. [Figure 10] This is a schematic diagram showing the configuration of the particulate matter removal device according to Comparative Example 2. [Figure 11] This graph shows the experimental results of Experiment 1 in Comparative Example 1. [Figure 12] This graph shows the experimental results of Experiment 1 in Comparative Example 2. [Figure 13] This graph shows the experimental results of Experiment 1 in Example 1 (where the second electrode side is the cathode). [Figure 14] This graph shows the experimental results of Experiment 1 in Example 1 (where the second electrode side is the anode). [Figure 15] This graph shows the experimental results of Experiment 1 in Example 2 (Le=1.07H, Ce=50pF). [Figure 16] This graph shows the experimental results of Experiment 1 in Example 2 (Le=1.07H, Ce=100pF). [Figure 17] This graph shows the experimental results of Experiment 1 in Example 2 (Le=1.07H, Ce=150pF). [Figure 18] This graph shows the experimental results of Experiment 1 in Example 2 (Le=1.07H, Ce=200pF). [Figure 19] This graph shows the experimental results of Experiment 2. [Figure 20] This is a photograph showing the experimental results of Experiment 3 in Comparative Example 1. [Figure 21] This is a photograph showing the experimental results of Experiment 3 in Comparative Example 2. [Figure 22] This is a photograph showing the experimental results of Experiment 3 in Example 1. [Figure 23] This is a photograph showing the experimental results of Experiment 3 in Example 2 (Le=1.07H, Ce=50pF). [Figure 24] This is a photograph showing the experimental results of Experiment 3 in Example 2 (Le=1.07H, Ce=100pF). [Figure 25] This is a photograph showing the experimental results of Experiment 3 in Example 2 (Le=1.07H, Ce=150pF). [Figure 26] This is a photograph showing the experimental results of Experiment 3 in Example 2 (Le=1.07H, Ce=200pF). [Figure 27] These are photographs showing the first electrode, the second electrode, and the dielectric layer before carbon black was applied, as used in Experiments 4-1 and 4-2. [Figure 28] These are photographs and graphs showing the experimental results of Experiment 4-1 in Comparative Example 1. [Figure 29] These are photographs and graphs showing the experimental results of Experiment 4-1 in Comparative Example 2. [Figure 30] These are photographs and graphs showing the experimental results of Experiment 4-1 in Example 2. [Figure 31] These are photographs and graphs showing the experimental results of Experiment 4-2 in Comparative Example 1. [Figure 32] These are photographs and graphs showing the experimental results of Experiment 4-2 in Comparative Example 2. [Figure 33] These are photographs and graphs showing the experimental results of Experiment 4-2 in Example 1. [Figure 34] These are photographs and graphs showing the experimental results of Experiment 4-2 in Example 2. [Figure 35] This graph shows the experimental results of Experiment 5 in Example 3. [Figure 36] This graph shows the experimental results of Experiment 6. [Figure 37] This is a schematic diagram showing the configuration of a particulate matter removal device according to a modified example. [Figure 38] This figure shows the equivalent circuit of a particulate removal device according to a modified example. [Figure 39] This graph shows the changes in voltage amplification factor and voltage phase difference in response to changes in composite capacitance in a modified particulate removal device. [Modes for carrying out the invention]

[0010] (Technology 1) A plasma generator comprising: a dielectric layer having a first main surface and a second main surface opposite to the first main surface; a first electrode and a second electrode disposed on the first main surface of the dielectric layer; a third electrode disposed on the second main surface of the dielectric layer so as to face the first electrode and the second electrode via the dielectric layer; and a circuit element electrically connected between the first electrode and the second electrode, wherein an AC voltage from a power source is applied between the first electrode and the third electrode and between the second electrode and the third electrode, respectively, and the circuit element generates a potential difference or voltage phase difference between the first electrode and the second electrode, thereby generating plasma on the first main surface of the dielectric layer by dielectric barrier discharge.

[0011] According to Technology 1, a circuit element is electrically connected between the first electrode and the second electrode. As a result, when an AC voltage from a power source is applied between the first electrode and the third electrode, and between the second electrode and the third electrode, the circuit element generates a potential difference or voltage phase difference between the first electrode and the second electrode. Therefore, a large potential difference can be generated between the first electrode and the second electrode, and plasma due to creepage dielectric barrier discharge can be generated not only at the outer edges of the first and second electrodes, but also in the region between the first and second electrodes. Consequently, the plasma generation region on the first main surface of the dielectric layer can be increased.

[0012] (Technology 2) The plasma generator according to Technology 1, wherein the circuit element is a diode for generating a potential difference between the first electrode and the second electrode, the cathode of the diode is electrically connected to one of the first electrode and the second electrode, the anode of the diode is electrically connected to the other of the first electrode and the second electrode, and the third electrode is grounded.

[0013] According to Technology 2, a potential difference can be generated between the first electrode and the second electrode by electrically connecting a diode between them.

[0014] (Technology 3) The plasma generator according to Art 1, wherein the circuit element is an inductor, and the plasma generator further comprises a capacitor electrically connected between the second electrode and the third electrode, the inductor and the capacitor constitute an LC series resonant circuit for generating a voltage phase difference between the first electrode and the second electrode, and the third electrode is grounded.

[0015] According to Technology 3, an inductor is electrically connected between the first electrode and the second electrode, and a capacitor is electrically connected between the second electrode and the third electrode. By configuring an LC series resonant circuit with these inductors and capacitors, a voltage phase difference can be generated between the first electrode and the second electrode.

[0016] (Technology 4) The plasma generator according to Art 1, wherein the circuit element is a capacitor, and the plasma generator further comprises an inductor electrically connected between the second electrode and the third electrode, the inductor and the capacitor constitute an LC series resonant circuit for generating a voltage phase difference between the first electrode and the second electrode, and the third electrode is grounded.

[0017] According to Technology 4, a capacitor is electrically connected between the first electrode and the second electrode, and an inductor is electrically connected between the second electrode and the third electrode. By configuring an LC series resonant circuit with these inductors and capacitors, a voltage phase difference can be generated between the first electrode and the second electrode.

[0018] (Technology 5) A plasma generator according to any one of the technologies 1 to 4, wherein the first electrode has a plurality of first electrode pieces formed in a comb-like shape, and the second electrode has a plurality of second electrode pieces formed in a comb-like shape, and the plurality of first electrode pieces and the plurality of second electrode pieces are arranged alternately on the first main surface of the dielectric layer.

[0019] According to Technology 5, the plasma generation region on the first main surface of the dielectric layer can be increased more effectively.

[0020] (Technology 6) A particulate removal device for removing organic particulate matter from air using plasma, comprising a plasma generator according to any one of the technologies 1 to 5, and a power supply for supplying an AC voltage to the plasma generator.

[0021] According to Technology 6, by using the plasma generator described above, the plasma generation area on the first main surface of the dielectric layer can be increased. As a result, organic fine particles can be efficiently removed.

[0022] Embodiments of the present invention will be described in detail below with reference to the drawings. The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0023] (Embodiment 1) [1-1. Configuration of the particulate removal device] First, the configuration of the particulate removal device 2 according to Embodiment 1 will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram showing the configuration of the particulate removal device 2 according to Embodiment 1. Figure 2 is a plan view showing the plasma generator 4 according to Embodiment 1. Figure 3 is a diagram showing the equivalent circuit 34 of the particulate removal device 2 according to Embodiment 1.

[0024] As shown in Figure 1, the particulate removal device 2 is a device for removing carbon particles (an example of organic particles) from the air using plasma P. The particulate removal device 2 is equipped with a plasma generator 4 and a power supply 6.

[0025] The plasma generator 4 is a device for generating plasma P by surface dielectric barrier discharge (SDBD). As shown in Figures 1 and 2, the plasma generator 4 comprises a dielectric layer 8, a first electrode 10, a second electrode 12, a third electrode 14, and a diode 16 (an example of a circuit element).

[0026] In Figure 1, the dielectric layer 8, the first electrode 10, the second electrode 12, and the third electrode 14 are shown as a cross-sectional view of a key part of the plasma generator 4, obtained by cutting a portion of it along line II in Figure 2.

[0027] The dielectric layer 8 is a flat dielectric plate having a first main surface 18 and a second main surface 20. The second main surface 20 is the main surface opposite to the first main surface 18. The dimensions of the dielectric layer 8 are, for example, 50 mm in length x 100 mm in width x 1 mm in thickness. The dielectric layer 8 is formed from, for example, acrylic resin, silicone rubber, silicone resin, alumina ceramics, sapphire (high-purity alumina ceramics), polyimide, polytetrafluoroethylene (PTFE) resin, polyethylene terephthalate (PET) resin, Pyrex® glass, quartz glass, polyetheretherketone (PEEK) resin, or various oils and fats.

[0028] The first electrode 10 is a thin plate-shaped main electrode and is positioned on the first main surface 18 of the dielectric layer 8. The first electrode 10 is formed of, for example, (a) a metallic material such as aluminum, titanium, nickel, gold, silver, or SUS, (b) a conductive oxide such as indium tin oxide (ITO), or (c) conductive rubber.

[0029] As shown in Figure 2, the first electrode 10 has a plurality of first electrode pieces 22 and a first connecting piece 24. The plurality of first electrode pieces 22 are formed in a comb-like shape in plan view and are arranged substantially parallel to each other. The first connecting piece 24 is formed in an elongated shape and connects the base ends of the plurality of first electrode pieces 22 to each other. The overall dimensions of the first electrode 10 are, for example, 34 mm in length and 72.5 mm in width. The length of each of the plurality of first electrode pieces 22 in the short direction is, for example, 2.5 mm.

[0030] The second electrode 12 is a thin plate-shaped auxiliary electrode and is positioned on the first main surface 18 of the dielectric layer 8. The second electrode 12 is positioned away from the first electrode 10 (i.e., so as not to be in direct contact with the first electrode 10). The second electrode 12 is formed of, for example, (a) a metallic material such as aluminum, titanium, nickel, gold, silver, or SUS, (b) a conductive oxide such as indium tin oxide (ITO), or (c) conductive rubber.

[0031] As shown in Figure 2, the second electrode 12 has a plurality of second electrode pieces 26 and a second connecting piece 28. The plurality of second electrode pieces 26 are formed in a comb-like shape in plan view and are arranged substantially parallel to each other. The second connecting piece 28 is formed in an elongated shape and connects the base ends of the plurality of second electrode pieces 26 to each other. The plurality of first electrode pieces 22 and the plurality of second electrode pieces 26 are arranged alternately on the first main surface 18 of the dielectric layer 8. The length of each of the plurality of second electrode pieces 26 in the short direction is, for example, 1 mm. The length of the second connecting piece 28 in the short direction is, for example, 2.5 mm.

[0032] Furthermore, the distance between adjacent first electrode pieces 22 and second electrode pieces 26 is, for example, 3.5 mm. The distance between each tip of multiple second electrode pieces 26 and the first connecting piece 24 is, for example, 5 mm. Furthermore, the distance between each tip of multiple first electrode pieces 22 and the second connecting piece 28 is, for example, 5 mm.

[0033] The third electrode 14 is a thin plate-shaped ground electrode and is grounded to earth. The third electrode 14 is positioned on the second main surface 20 of the dielectric layer 8 so as to face the first electrode 10 and the second electrode 12 via the dielectric layer 8. The third electrode 14 is formed of, for example, (a) a metallic material such as aluminum, titanium, nickel, gold, silver, or SUS, (b) a conductive oxide such as indium tin oxide (ITO), or (c) conductive rubber. In this embodiment, the third electrode 14 is grounded to earth (0V), but it is not limited to this and may be electrically connected to a ground that is a reference potential other than 0V.

[0034] Diode 16 is a circuit element for generating a potential difference between the first electrode 10 and the second electrode 12, and is electrically connected between the first electrode 10 and the second electrode 12. The cathode 30 of diode 16 is electrically connected to the second electrode 12, and the anode 32 of diode 16 is electrically connected to the first electrode 10. For the sake of explanation, the diode 16 is not shown in Figure 2.

[0035] Note that the connection direction of the diode 16 may be reversed from the above. That is, the cathode 30 of the diode 16 may be electrically connected to the first electrode 10, and the anode 32 of the diode 16 may be electrically connected to the second electrode 12.

[0036] Power supply 6 is an AC power supply for supplying AC voltage and is electrically connected between the first electrode 10 and the third electrode 14. As a result, power supply 6 applies AC voltage between the first electrode 10 and the third electrode 14, and between the anode 32 of the diode 16 and the third electrode 14 (i.e., between the second electrode 12 and the third electrode 14). Power supply 6 supplies, for example, a positive / negative pulsed or sinusoidal high-frequency high voltage as AC voltage.

[0037] The equivalent circuit 34 of the particulate matter removal device 2 described above is as shown in Figure 3. In the equivalent circuit 34 shown in Figure 3, the first electrode 10 and the third electrode 14 constitute the main capacitor 36, and the second electrode 12 and the third electrode 14 constitute the subcapacitor 38. The main capacitor 36 and the subcapacitor 38 are connected in parallel to each other. The third electrode 14 of the main capacitor 36 and the third electrode 14 of the subcapacitor 38 are both grounded to earth.

[0038] Furthermore, diode 16 is connected in series with subcapacitor 38. The cathode 30 of diode 16 is electrically connected to the second electrode 12 of subcapacitor 38. The anode 32 of diode 16 is electrically connected to the first electrode 10 of main capacitor 36. In other words, diode 16 is electrically connected between the first electrode 10 of main capacitor 36 and the second electrode 12 of subcapacitor 38.

[0039] Furthermore, the power supply 6 is connected between the first electrode 10 and the third electrode 14 of the main capacitor 36. As a result, the power supply 6 applies an AC voltage between the first electrode 10 and the third electrode 14 of the main capacitor 36, and between the anode 32 of the diode 16 and the third electrode 14 of the subcapacitor 38 (i.e., between the second electrode 12 and the third electrode 14 of the subcapacitor 38).

[0040] [1-2. Operation of the particulate removal device] Next, the operation of the particulate removal device 2 according to Embodiment 1 will be described with reference to Figures 1 and 3.

[0041] As shown in Figure 3, ±V from power supply 6 p The AC voltage is applied between the first electrode 10 and the third electrode 14 of the main capacitor 36, and between the second electrode 12 and the third electrode 14 of the sub-capacitor 38, respectively. Here, V p This represents the single-sided amplitude of the AC voltage.

[0042] +V is applied to the first electrode 10 of the main capacitor 36. p When an AC voltage is applied, the third electrode 14 of the main capacitor 36 is grounded, causing positive charges to move to the first electrode 10 and negative charges to move to the third electrode 14. The resulting potential difference creates an electric field around the outer edge of the first electrode 10 that is strong enough to cause partial dielectric breakdown of the air. As a result, as shown in Figure 1, on the first main surface 18 of the dielectric layer 8, a plasma P is generated by creepage dielectric barrier discharge around the outer edge of the first electrode 10 due to current flowing along the first main surface 18 of the dielectric layer 8.

[0043] Additionally, +V is supplied to the second electrode 12 of the subcapacitor 38. p When an AC voltage is applied, the diode 16 is forward-biased, and current flows through it. At this time, since the third electrode 14 of the subcapacitor 38 is grounded, positive charge moves to the second electrode 12 and negative charge moves to the third electrode 14. Due to the potential difference created in this way, an electric field is formed around the outer edge of the second electrode 12 that is strong enough to cause partial dielectric breakdown of the air. As a result, as shown in Figure 1, on the first main surface 18 of the dielectric layer 8, a plasma P is generated by creepage dielectric barrier discharge as current flows along the first main surface 18 of the dielectric layer 8 around the outer edge of the second electrode 12.

[0044] Meanwhile, -V is applied to the first electrode 10 of the main capacitor 36. p When an AC voltage is applied, the charge distribution in the main capacitor 36 is such that +V is applied to the first electrode 10 of the main capacitor 36. pThis is the opposite of the case when an AC voltage is applied. Therefore, in this case as well, plasma P is generated at the outer edge of the first electrode 10 on the first main surface 18 of the dielectric layer 8 due to creepage dielectric barrier discharge.

[0045] Furthermore, -V is applied to the second electrode 12 of the subcapacitor 38. p When an AC voltage is applied, the diode 16 is reverse-biased, and no current flows through the diode 16. Therefore, the charge distribution in the subcapacitor 38 is +V on the second electrode 12 of the subcapacitor 38. p The charge distribution remains almost the same as when an AC voltage is applied. As a result, the potential of the first electrode 10 of the main capacitor 36 and the potential of the second electrode 12 of the subcapacitor 38 are opposite in sign, and a large potential difference is generated between the first electrode 10 of the main capacitor 36 and the second electrode 12 of the subcapacitor 38. Consequently, as shown in Figure 1, on the first main surface 18 of the dielectric layer 8, a current flows along the first main surface 18 of the dielectric layer 8 between the first electrode 10 and the second electrode 12 (for example, between adjacent first electrode pieces 22 and second electrode pieces 26), generating plasma P due to creepage dielectric barrier discharge.

[0046] [1-3. Effects] In this embodiment, as described above, a diode 16 is electrically connected between the first electrode 10 and the second electrode 12. As a result, when an AC voltage from the power supply 6 is applied between the first electrode 10 and the third electrode 14, and between the second electrode 12 and the third electrode 14, a large potential difference is generated between the first electrode 10 and the second electrode 12.

[0047] As a result, plasma P is generated by creepage dielectric barrier discharge not only at the outer edges of the first electrode 10 and the second electrode 12, but also between the first electrode 10 and the second electrode 12, on the first main surface 18 of the dielectric layer 8. Therefore, the plasma P generation area on the first main surface 18 of the dielectric layer 8 can be increased, and carbon fine particles can be removed efficiently.

[0048] (Embodiment 2) [2-1. Configuration of the particulate removal device] Referring to FIGS. 4 to 6, the configuration of the particulate removal device 2A according to Embodiment 2 will be described. FIG. 4 is a schematic diagram showing the configuration of the particulate removal device 2A according to Embodiment 2. FIG. 5 is a diagram showing the equivalent circuit 34A of the particulate removal device 2A according to Embodiment 2. FIG. 6 is a graph showing changes in the voltage amplification factor and the voltage phase difference with respect to changes in the synthetic capacitance in the particulate removal device 2A according to Embodiment 2. In the present embodiment, the same components as those in the above Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

[0049] As shown in FIG. 4, in the particulate removal device 2A according to Embodiment 2, the configuration of the plasma generation device 4A is different from that in the above Embodiment 1. Specifically, the plasma generation device 4A includes an inductor 40 (an example of a circuit element) instead of the diode 16 described in the above Embodiment 1. The inductor 40 is electrically connected between the first electrode 10 and the second electrode 12.

[0050] The plasma generation device 4A further includes a capacitor 42. The capacitor 42 is electrically connected between the second electrode 12 and the third electrode 14 (ground). That is, the capacitor 42 is connected in series with the inductor 40. The inductor 40 and the capacitor 42 constitute an LC series resonance circuit for generating a voltage phase difference between the first electrode 10 and the second electrode 12.

[0051] The equivalent circuit 34A of the particulate removal device 2A described above is as shown in FIG. 5. In the equivalent circuit 34A shown in FIG. 5, the inductor 40 is electrically connected between the first electrode 10 of the main capacitor 36 and the second electrode 12 of the sub-capacitor 38. Also, the capacitor 42 is connected in parallel with the sub-capacitor 38.

[0052] Here, let the voltage of the first electrode 10 be V and the voltage of the second electrode 12 be V sThe inductance of inductor 40 is L e The capacitance (electrostatic capacitance) of the subcapacitor 38 is C s The capacitance of the main capacitor 36 is C m The capacitance of capacitor 42 is C e capacitance C s and C e The combined capacitance is C(=C s +C e When the parasitic resistance is R and the angular frequency is ω, the voltage amplification factor |V| is the value obtained by dividing the magnitude of the voltage Vs at the second electrode 12 by the magnitude of the voltage V at the first electrode 10. s / V| is expressed by the following equation (1).

[0053]

number

[0054] Furthermore, the voltage phase difference Δφ between the first electrode 10 and the second electrode 12 is expressed by the following equation (2).

[0055]

number

[0056] Note that the inductance L e = 1.07H, capacitance C m Assuming a capacitance of 83pF and resistance R=96.5Ω, the voltage amplification factor |V| is calculated as a result of the change in the combined capacitance C(pF). s When the changes in / V|(dB) and the voltage phase difference Δφ(°) are calculated, the graph shown in Figure 6 is obtained. In Figure 6, the black circles plot the voltage amplification factor |V s The graph of / V| is shown, and the white circles plot the graph of the voltage phase difference Δφ.

[0057] As shown in Figure 6, at a combined capacitance C = 250 pF, the voltage amplification factor |V s The resonance point where / V| takes its extreme value occurs, and the voltage phase difference Δφ reverses by 180° at this resonance point.

[0058] As can be seen from the graph in Figure 6, capacitance C e If set to be smaller than the resonant capacitance, the discharge will become more active, resulting in a combined capacitance C(=C s +C e ) approaches the resonant capacitance. If the discharge becomes too active and the combined capacitance C exceeds the resonant capacitance, it is thought that negative feedback will act, causing the discharge to become less active as it moves away from the resonance point. In other words, the combined capacitance C has the property of being fixed near the resonant capacitance.

[0059] On the other hand, capacitance C e If the resonant capacitance is set to be greater than the resonant capacitance, the combined capacitance C is thought to be fixed near the resonant capacitance, but the discharge is inactive while it is fixed.

[0060] [2-2. Operation of the particulate removal device] Next, the operation of the particulate removal device 2A according to Embodiment 2 will be described with reference to Figures 4 and 5.

[0061] As shown in Figure 5, ±V from power supply 6 p The alternating voltage is applied between the first electrode 10 and the third electrode 14 of the main capacitor 36, and between the second electrode 12 and the third electrode 14 of the sub-capacitor 38.

[0062] Furthermore, due to the LC series resonance between the inductor 40 and the capacitor 42, a voltage is applied to the second electrode 12 of the subcapacitor 38 with a different phase than that applied to the first electrode 10 of the main capacitor 36. As a result, a large voltage phase difference is generated between the first electrode 10 of the main capacitor 36 and the second electrode 12 of the subcapacitor 38. Consequently, as in the first embodiment described above, as shown in Figure 4, plasma P is generated between the first electrode 10 and the second electrode 12 on the first main surface 18 of the dielectric layer 8 due to creepage dielectric barrier discharge.

[0063] [2-3. Effects] Therefore, the same effects as in Embodiment 1 can be obtained in this embodiment as well.

[0064] In this embodiment, the plasma generator 4A is equipped with a capacitor 42, but it is not limited to this, and the capacitance C of the sub-capacitor 38 may also be included. s If the coefficient is sufficiently large, the capacitor 42 may be omitted. In this case, the inductor 40 and the subcapacitor 38 will form an LC series resonant circuit.

[0065] (Embodiment 3) The configuration of the particulate removal device 2B according to Embodiment 3 will be described with reference to Figures 7 and 8. Figure 7 is a schematic diagram showing the configuration of the particulate removal device 2B according to Embodiment 3. Figure 8 is a diagram showing the equivalent circuit 34B of the particulate removal device 2B according to Embodiment 3. In this embodiment, the same reference numerals are used for components that are the same as those in Embodiment 1, and their descriptions are omitted.

[0066] As shown in Figure 7, the particulate removal device 2B according to Embodiment 3 has a different configuration of the plasma generator 4B compared to Embodiment 1. Specifically, the plasma generator 4B includes a resistor 44 (an example of a circuit element) instead of the diode 16 described in Embodiment 1. The resistor 44 is electrically connected between the first electrode 10 and the second electrode 12.

[0067] The equivalent circuit 34B of the particulate removal device 2B described above is as shown in Figure 8. In the equivalent circuit 34B shown in Figure 8, resistor 44 is connected in series with subcapacitor 38. Resistor 44 is electrically connected between the first electrode 10 of the main capacitor 36 and the second electrode 12 of the subcapacitor 38.

[0068] In this embodiment, by electrically connecting a resistor 44 between the first electrode 10 and the second electrode 12, a voltage phase difference can be generated between the first electrode 10 and the second electrode 12, similar to Embodiment 2. As a result, similar to Embodiment 2, as shown in Figure 7, plasma P is generated between the first electrode 10 and the second electrode 12 on the first main surface 18 of the dielectric layer 8 due to creepage dielectric barrier discharge.

[0069] Therefore, in this embodiment as well, similar to Embodiment 2 described above, the plasma P generation region on the first main surface 18 of the dielectric layer 8 can be increased.

[0070] Here, the voltage across the first electrode 10 is V m The voltage of the second electrode 12 is set to V s The capacitance of the subcapacitor 38 is C s When the resistance value of resistor 44 is R and the angular frequency is ω, the voltage V across the second electrode 12 is... s The magnitude of the voltage V of the first electrode 10 m The complex notation of the voltage amplification factor, which is the value obtained by dividing by the magnitude of the voltage, is given by the following equation (3).

[0071]

number

[0072] Here, the resistance value R of the resistor 44 required to generate a sufficiently large voltage phase difference between the first electrode 10 and the second electrode 12 is considered to be given by the following equation (4).

[0073]

number

[0074] The angular frequency ω when the AC voltage from power supply 6 is 10kHz is set to 62800 rad / s, and the capacitance C of subcapacitor 38 is set to 32800 rad / s. sConsidering that the capacitance increases from 45pF when there is no discharge to about 150pF when discharged, the resistance R that satisfies equation (4) above will be between 100kΩ and 350kΩ.

[0075] (experiment) To confirm the effects described above by the particulate removal device 2 (2A, 2B) according to the present invention, Experiments 1 to 4 described below were performed for Comparative Example 1, Comparative Example 2, Example 1, and Example 2 shown below.

[0076] As Comparative Example 1, the particulate removal device 100 shown in Figure 9 was used. Figure 9 is a schematic diagram showing the configuration of the particulate removal device 100 according to Comparative Example 1. In the plasma generator 102 of this particulate removal device 100, the second electrode 12 was electrically suspended.

[0077] As Comparative Example 2, the particulate removal device 200 shown in Figure 10 was used. Figure 10 is a schematic diagram showing the configuration of the particulate removal device 200 according to Comparative Example 2. In the plasma generator 202 of this particulate removal device 200, the first electrode 10 and the second electrode 12 are short-circuited, and the same AC voltage from the power supply 6 is applied to each of the first electrode 10 and the second electrode 12.

[0078] As Example 1, the particulate removal apparatus 2 according to Embodiment 1, as shown in Figures 1 to 3, was used. As described in Embodiment 1 above, in the plasma generator 4 of this particulate removal apparatus 2, a diode 16 was electrically connected between the first electrode 10 and the second electrode 12.

[0079] As Example 2, a particulate removal device 2A according to Embodiment 2, as shown in Figures 4 and 5, was used. In the plasma generator 4A of this particulate removal device 2A, an inductor 40 was electrically connected between the first electrode 10 and the second electrode 12, and a capacitor 42 was electrically connected in parallel with the subcapacitor 38.

[0080] [Experiment 1 (Voltage and Current Waveform Measurement)] In Experiment 1, Comparative Example 1, Comparative Example 2, Example 1, and Example 2 were tested using a power supply with a frequency of 9.8kHz and 7kV.pp When positive and negative pulsed AC voltages were supplied to the plasma generator, the voltage waveforms of the first and second electrodes, as well as the current waveform flowing through the entire plasma generator, were measured.

[0081] In Experiment 1, as Example 1, the voltage waveforms of the first and second electrodes, as well as the current waveform flowing through the entire plasma generator, were measured for two cases: when the cathode of the diode was on the second electrode side, and when the anode of the diode was on the second electrode side.

[0082] Furthermore, in Experiment 1, as Example 2, the capacitance C of the capacitor constituting the LC series resonant circuit was used. e The voltage waveforms of the first and second electrodes, as well as the current waveform flowing through the entire plasma generator, were measured for capacitance values ​​of 50pF, 100pF, 150pF, and 200pF. e However, in either case, the inductance L of the inductor constituting the LC series resonant circuit e The time was 1.07 hours.

[0083] The experimental results of Experiment 1 are shown in the graphs in Figures 11 to 18. In Figures 11 to 18, the solid line graph shows the voltage waveform indicating the time change of the voltage V (kV) at the first electrode, and the dashed line graph shows the voltage V at the second electrode. s The graph shows the time variation of the voltage (kV). The dashed line graph shows the time variation of the current i (A) flowing through the entire plasma generator. Voltage V is the potential of the first electrode relative to the reference point, with earth (0V) as the reference point. Voltage Vs is the potential of the second electrode relative to the reference point, with earth as the reference point.

[0084] In the experimental results of Comparative Example 1, as shown in Figure 11, the voltage V of the second electrode s Although it shifted slightly in the positive direction from 0V, there was almost no change observed.

[0085] In the experimental results of Comparative Example 2, as shown in Figure 12, the voltage V of the second electrodes The voltage V at the first electrode is always the same voltage value (V s Since (=V), the potential difference between the first electrode and the second electrode was always 0V.

[0086] In the experimental results of Example 1 (where the cathode of the diode is on the second electrode side), as shown in Figure 13, the potential difference between the first electrode and the second electrode was larger than that of Comparative Examples 1 and 2. In particular, the potential difference between the first electrode and the second electrode was largest when the voltage V of the first electrode took its negative maximum value (-3.5kV).

[0087] In the experimental results of Example 1 (where the anode of the diode is on the second electrode side), as shown in Figure 14, the potential difference between the first electrode and the second electrode was larger than that of Comparative Examples 1 and 2. In particular, the potential difference between the first electrode and the second electrode was largest when the voltage V of the first electrode reached its positive maximum value (+3.5kV).

[0088] Example 2 (L e =1.07H, C e The experimental results for Example 2 (L = 50 pF) were as shown in the graph in Figure 15. e =1.07H, C e The experimental results for Example 2 (L = 100pF) are shown in Figure 16. e =1.07H, C e The experimental results for Example 2 (L = 150 pF) are shown in Figure 17. e =1.07H, C e The experimental results for (=200pF) are shown in Figure 18.

[0089] In Example 2, as shown in Figures 15 to 18, C e When =50pF, the voltage across the second electrode V s The amplitude was largest. Also, the potential phase difference between the first electrode and the second electrode was C e =50pF, 100pF is around 90°, C eAt 150pF and 200pF, the phase difference was approximately 180°. This indicates that the voltage phase difference between the first electrode and the second electrode was larger compared to Comparative Examples 1 and 2.

[0090] [Experiment 2 (Inference of plasma expansion due to power consumption)] In Experiment 2, the voltage V applied to the first electrode was determined for Comparative Example 1, Comparative Example 2, Example 1, and Example 2. pp We measured the change in power consumption of the plasma generator when the peak-to-peak voltage was increased. It was inferred that higher power consumption indicated more plasma generation.

[0091] In Experiment 2, as Example 1, the voltage V applied to the first electrode was determined when the cathode of the diode was on the second electrode side and when the anode of the diode was on the second electrode side. pp We measured the change in power consumption in the plasma generator when the value was increased.

[0092] Furthermore, in Experiment 2, as Example 2, the capacitance C of the capacitor constituting the LC series resonant circuit was used. e When the capacitance is set to 50pF, 100pF, 150pF, and 200pF, the voltage applied to the first electrode is V pp The change in power consumption in the plasma generator was measured when capacitance C was increased. e However, in either case, the inductance L of the inductor constituting the LC series resonant circuit e The time was 1.07 hours.

[0093] The experimental results for Experiment 2 are shown in Figure 19. In Figure 19, the horizontal axis represents the voltage V applied to the first electrode. pp The vertical axis represents power consumption (W) in the plasma generator, with the vertical axis representing the power consumption (W) in the plasma generator.

[0094] As shown in Figure 19, Example 2 had the highest power consumption (i.e., the most plasma was generated), C e The power consumption increased in the order of 50pF, 100pF, 150pF, and 200pF.

[0095] Furthermore, in Example 1, V pp At 7.5kV, the creepage dielectric barrier discharge between the first and second electrodes became more active, and the power consumption increased rapidly (i.e., the plasma expanded).

[0096] [Experiment 3 (Observation of Luminescence)] In Experiment 3, for Comparative Example 1, Comparative Example 2, Example 1, and Example 2, when a positive and negative pulsed AC voltage of 7.5 kVpp was supplied from the power supply to the plasma generator, the emission of light due to the plasma on the first main surface of the dielectric layer was captured and observed using a camera.

[0097] In Experiment 3, as Example 2, the capacitance C of the capacitor constituting the LC series resonant circuit was used. e The emission of plasma on the first main surface of the dielectric layer was observed when capacitance C was set to 50pF, 100pF, 150pF, and 200pF. e However, in either case, the inductance L of the inductor constituting the LC series resonant circuit e The time was 1.07 hours.

[0098] The results of Experiment 3 were as shown in the photographs in Figures 20 to 26.

[0099] In Comparative Example 1, as shown in Figure 20, plasma emission (the white area) was observed only at the outer edge of the first electrode.

[0100] In Comparative Example 2, as shown in Figure 21, plasma emission was observed only at the outer edges of the first electrode and the second electrode.

[0101] In Example 1, as shown in Figure 22, plasma emission was observed not only at the outer edges of the first electrode and the second electrode, but also in the region between the first electrode and the second electrode.

[0102] In Example 2, as shown in Figures 23 to 26, plasma emission was observed not only at the outer edges of the first electrode and the second electrode, but also in the region between the first and second electrodes, similar to Example 1.

[0103] [Experiment 4 (PM Decomposition Test)] [Experiment 4-1 (0-2 minutes: 7kV)] pp )] In Experiment 4-1, Comparative Example 1, Comparative Example 2, and Example 2 were supplied with 7kV from the power supply. pp A sinusoidal AC voltage with a frequency of approximately 28 kHz was supplied to the plasma generator and discharged for 2 minutes, causing the carbon black (particulate matter: PM) attached to the surfaces of the first electrode, the second electrode, and the dielectric layer to be decomposed by the plasma.

[0104] In Experiment 4-1, the first electrode, the second electrode, and the dielectric layer were of the shape and dimensions shown in Figure 27. A quartz glass layer approximately 1 mm thick was used as the dielectric layer.

[0105] The experimental results of Experiment 4-1 are shown in Figures 28 to 30. In Figures 28 to 30, (a) is a photograph showing the first electrode, second electrode, and dielectric layer at the beginning of the discharge, and (b) is a photograph showing the first electrode, second electrode, and dielectric layer after 2 minutes of discharge. In addition, in Figures 28 to 30, (c) is a graph showing the results of image analysis of each of the photographs in (a) and (b).

[0106] In (c), the horizontal axis shows the vertical position (mm) of each photograph in (a) and (b), with the double dashed lines on the left and right indicating the position of the second electrode, and the double dashed line in the center indicating the position of the first electrode. In addition, the vertical axis in (c) shows the increase in "darkness" due to carbon black, ΔD, relative to the photograph in Figure 27 before carbon black was applied. ΔD is an average value in the longitudinal direction of the first and second electrodes, and is assumed to be proportional to the concentration of carbon black applied to the surfaces of the first electrode, the second electrode, and the dielectric layer. In (c), the dashed line graph shows ΔD at the beginning of discharge, and the solid line graph shows ΔD after 2 minutes of discharge.

[0107] In Comparative Example 1, as shown in Figures 28(a) to (c), the amount of carbon black after 2 minutes of discharge was slightly reduced compared to the initial stage of discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 28(a) and (b) using image analysis. av The figure was 26%. In Comparative Example 1, the power consumption P = 17.6W.

[0108] In Comparative Example 2, as shown in Figures 29(a) to (c), the amount of carbon black after 2 minutes of discharge was almost the same as at the beginning of the discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 29(a) and (b) using image analysis. av The figure was 0.28%. In Comparative Example 2, the power consumption P = 3W.

[0109] In Example 2, as shown in Figures 30(a) to (c), the amount of carbon black after 2 minutes of discharge was significantly reduced compared to the initial stage of discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 30(a) and (b) using image analysis. av The ratio was 34%, and for each R of Comparative Example 1 and Comparative Example 2 av It exceeded [the previous value]. In Example 2, the power consumption P = 9.5W.

[0110] [Experiment 4-2 (0-1 minute: 5.56kV] pp , 1-2 minutes: 6kVpp )] In Experiment 4-2, Comparative Example 1, Comparative Example 2, Example 1, and Example 2 were supplied with 5.56kV from the power supply. pp The applied voltage waveform is a sinusoidal AC with a frequency of approximately 28 kHz, which is supplied to the plasma generator and discharged for 1 minute, after which 6kV pp A positive and negative pulsed AC voltage was supplied to the plasma generator and discharged for another minute, causing the carbon black attached to the surfaces of the first electrode, the second electrode, and the dielectric layer to be decomposed by the plasma.

[0111] In Experiment 4-2, as in Experiment 4-1, the first electrode, second electrode, and dielectric layer were of the shape and dimensions shown in Figure 27. A quartz glass layer approximately 1 mm thick was used as the dielectric layer.

[0112] The experimental results of Experiment 4-2 are shown in Figures 31 to 34. In Figures 31 to 34, (a) is a photograph showing the first electrode, second electrode, and dielectric layer at the beginning of the discharge, and (b) is a photograph showing the first electrode, second electrode, and dielectric layer after 2 minutes of discharge. In addition, in Figures 31 to 34, (c) is a graph showing the results of image analysis of each of the photographs in (a) and (b).

[0113] In Comparative Example 1, as shown in Figures 31(a) to (c), the amount of carbon black after 2 minutes of discharge was almost the same as at the beginning of the discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 31(a) and (b) using image analysis. av The figure was -0.2%. In Comparative Example 1, the power consumption P = 6W during the first 1-2 minutes after the start of discharge.

[0114] In Comparative Example 2, as shown in Figures 32(a) to (c), the amount of carbon black after 2 minutes of discharge was almost the same as at the beginning of the discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 32(a) and (b) using image analysis. av The figure was 0.9%. In Comparative Example 2, the power consumption P = 3.7W during the first 1-2 minutes after the start of discharge.

[0115] In Example 1, as shown in Figures 33(a) to (c), the amount of carbon black after 2 minutes of discharge was significantly reduced compared to the initial stage of discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 33(a) and (b) using image analysis. av The ratio was 5.8%, and the ratios of each R in Comparative Example 1 and Comparative Example 2 were 5.8%. av It exceeded [the previous value]. In Example 1, the power consumption P = 6W during the first 1-2 minutes after the start of discharge.

[0116] In Example 2, as shown in Figures 34(a) to (c), the amount of carbon black after 2 minutes of discharge was significantly reduced compared to the initial stage of discharge. The reduction rate of carbon black R was calculated by comparing the images in Figures 34(a) and (b) using image analysis. av The ratio was 3.7%, and the ratios of each R in Comparative Example 1 and Comparative Example 2 were 3.7%. av This exceeded the previous result. In Example 2, the power consumption P was 6W during the first 1-2 minutes after the start of discharge.

[0117] [summary] From the results of each of the experiments 1 to 4 described above, it was confirmed that Examples 1 and 2 can increase the plasma generation area compared to Comparative Examples 1 and 2.

[0118] (Other experiments) [Experiment 5 (Voltage and Current Waveform Measurement)] In Experiment 5, for Example 3, the power supply was set to 9.8kHz, 7kV. pp When positive and negative pulsed AC voltages were supplied to the plasma generator, the voltage waveforms of the first and second electrodes, as well as the current waveform flowing through the entire plasma generator, were measured.

[0119] As Example 3, the particulate removal device 2B according to Embodiment 3, shown in Figure 7, was used. As described in Embodiment 3 above, in the plasma generator 4B of this particulate removal device 2B, a resistor 44 was electrically connected between the first electrode 10 and the second electrode 12. The resistance value of the resistor 44 was 200 kΩ.

[0120] The experimental results of Experiment 5 are shown in the graph in Figure 35. In Figure 35, the solid line graph shows the voltage waveform indicating the time change of the voltage V (kV) at the first electrode, and the dashed line graph shows the voltage V at the second electrode. s This is a voltage waveform showing the time variation of (kV). The dashed line graph shows the current waveform showing the time variation of the current i(A) flowing through the entire plasma generator. Note that voltage V is the potential of the first electrode relative to the reference point, with earth being the reference point. s This is the potential of the second electrode relative to the reference point, with the earth being the reference point.

[0121] In Example 3, as shown in Figure 35, it was confirmed that a voltage phase difference occurred between the first electrode and the second electrode.

[0122] [Experiment 6 (Inference of plasma expansion due to power consumption)] In Experiment 6, the voltage V applied to the first electrode was determined for Comparative Example 1, Comparative Example 2, Example 2, Example 3, Example 4, and Example 5. pp We measured the change in power consumption of the plasma generator when the power was increased. It was inferred that higher power consumption indicated more plasma was being generated.

[0123] In Experiment 6, as Example 4, a 1.07H inductor was added to the particulate removal device 2B according to Embodiment 3, as shown in Figures 7 and 8. This inductor was connected in parallel to the subcapacitor 38.

[0124] Furthermore, in Experiment 6, Example 5 used the same configuration as Example 4 but with the resistor omitted.

[0125] The experimental results of Experiment 6 are shown in Figure 36. In Figure 36, the horizontal axis represents the voltage V applied to the first electrode. pp The vertical axis represents power consumption (W) in the plasma generator, with the vertical axis representing the power consumption (W) in the plasma generator.

[0126] (modified version) In the above embodiment 2, the plasma generator 4A is equipped with an inductor 40 as a circuit element, but it may be configured as follows, for example. Figure 37 is a schematic diagram showing the configuration of the modified particulate removal device 2C. Figure 38 is a diagram showing the equivalent circuit 34C of the modified particulate removal device 2C. Figure 39 is a graph showing the changes in voltage amplification factor and voltage phase difference with respect to a change in combined capacitance in the modified particulate removal device 2C. In this modified example, the same reference numerals are used for components that are the same as in the above embodiment 2, and their descriptions are omitted.

[0127] As shown in Figure 37, in the modified particulate removal device 2C, the connection points of the inductor 40 and capacitor 42 of the plasma generator 4C differ from those of the embodiment 2 described above. Specifically, the capacitor 42 (an example of a circuit element) is electrically connected between the first electrode 10 and the second electrode 12. The inductor 40 is electrically connected between the second electrode 12 and the third electrode 14 (ground). In other words, the inductor 40 and the capacitor 42 constitute an LC series resonant circuit for generating a voltage phase difference between the first electrode 10 and the second electrode 12.

[0128] The equivalent circuit 34C of the particulate removal device 2C described above is as shown in Figure 38. In the equivalent circuit 34C shown in Figure 38, the capacitor 42 is electrically connected between the first electrode 10 of the main capacitor 36 and the second electrode 12 of the sub-capacitor 38. In addition, the inductor 40 is connected in parallel with the sub-capacitor 38.

[0129] Here, the voltage of power supply 6 is expressed in complex notation.

number

number

[0130]

Equation

[0131] Here, the condition for the amplitude of the voltage of the second electrode 12 to become theoretically infinitely large is given by the following formula (6).

[0132]

Equation

[0133] Also, when the left side of the above formula (6) is positive, the voltage phase difference between the voltage of the power supply 6 and the voltage of the second electrode becomes 0°, and when the left side of the above formula (6) is negative, the voltage phase difference between the voltage of the power supply 6 and the voltage of the second electrode becomes 180°.

[0134] Note that the inductance L e = 1.07H, and the capacitance C m = 83 pF. When calculating the respective changes in the voltage amplification factor (dB) and the voltage phase difference (°) with respect to the change in the combined capacitance C (pF), it becomes like the graph shown in FIG. 39. In FIG. 39, the black circle plots show the graph of the voltage amplification factor, and the white circle plots show the graph of the voltage phase difference. The voltage amplification factor in FIG. 39 means the following formula (7).

[0135]

Equation

[0136] (Other modification examples, etc.) Although the plasma generating apparatus according to Embodiments 1 to 3 and their variations has been described above, the present invention is not limited to these Embodiments 1 to 3 and their variations. For example, each of the above embodiments and variations may be combined.

[0137] In the embodiments 1 to 3 and their variations described above, the first electrode 10 has a plurality of first electrode pieces 22, and the second electrode 12 has a plurality of second electrode pieces 26, but the invention is not limited thereto. For example, the first electrode 10 may have one or more first electrode pieces 22, and the second electrode 12 may have one or more second electrode pieces 26.

[0138] Furthermore, in the embodiments 1 to 3 and their variations described above, the particulate removal device 2 (2A, 2B, 2C) removes carbon particles as organic particulate matter using plasma P, but it is not limited to this, and may also remove (exterminate / decompose) viruses, bacteria, pests, etc. [Industrial applicability]

[0139] The plasma generator according to the present invention can be applied, for example, as a particulate removal device for removing organic particulate matter such as carbon nanoparticles from the air. [Explanation of Symbols]

[0140] 2,2A,2B,2C,100,200 Particulate removal device 4,4A,4B,4C,102,202 Plasma Generator 6 Power supply 8. Dielectric layer 10 First electrode 12 Second electrode 14. Third electrode 16 diodes 18. First main surface 20 Second main surface 22 First electrode piece 24 First connecting piece 26 Second electrode piece 28. Second connecting piece 30 Cathode 32 anodes Equivalent circuits for 34, 34A, 34B, and 34C 36 Main Capacitor 38 Subcapacitors 40 Inductors 42 Capacitors 44 resistors P Plasma

Claims

1. A dielectric layer having a first main surface and a second main surface opposite to the first main surface, A first electrode and a second electrode are arranged on the first main surface of the dielectric layer, A third electrode is disposed on the second main surface of the dielectric layer so as to face the first electrode and the second electrode via the dielectric layer, The device comprises a circuit element electrically connected between the first electrode and the second electrode, An AC voltage from the power supply is applied between the first electrode and the third electrode, and between the second electrode and the third electrode, respectively, and a potential difference or voltage phase difference is generated between the first electrode and the second electrode by the circuit element, thereby generating plasma by dielectric barrier discharge on the first main surface of the dielectric layer. Plasma generator.

2. The circuit element is a diode for generating a potential difference between the first electrode and the second electrode. The cathode of the diode is electrically connected to one of the first electrode and the second electrode. The anode of the diode is electrically connected to the other of the first electrode and the second electrode. The third electrode is grounded. The plasma generator according to claim 1.

3. The aforementioned circuit element is an inductor, The plasma generator further includes a capacitor electrically connected between the second electrode and the third electrode. The inductor and the capacitor constitute an LC series resonant circuit for generating a voltage phase difference between the first electrode and the second electrode. The third electrode is grounded. The plasma generator according to claim 1.

4. The aforementioned circuit element is a capacitor, The plasma generator further includes an inductor electrically connected between the second electrode and the third electrode, The inductor and the capacitor constitute an LC series resonant circuit for generating a voltage phase difference between the first electrode and the second electrode. The third electrode is grounded. The plasma generator according to claim 1.

5. The first electrode has a plurality of first electrode pieces formed in a comb-like shape, The second electrode has a plurality of second electrode pieces formed in a comb-like shape, The plurality of first electrode pieces and the plurality of second electrode pieces are arranged alternately on the first main surface of the dielectric layer. A plasma generator according to any one of claims 1 to 4.

6. A particulate removal device for removing organic particulate matter from the air using plasma, A plasma generator according to claim 1, The plasma generator comprises a power supply for supplying an AC voltage. Particulate removal device.

Images