Ozone generator

Abstract

To provide a power supply member having high durability.SOLUTION: An ozone generator of an embodiment comprises: a metal electrode; a tubular dielectric electrode having a conductive film formed on its inner surface and arranged with a discharge gap between itself and a metal electrode, into which an ozone source gas is supplied; a power supply member having a reticular member in which a plurality of metal wires are woven on its outer surface and inserted into the dielectric electrode; and a thin metal film wound around the power supply member and electrically connecting the reticular member and the conductive film.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The embodiments relate to an ozone generator. [Background technology]

[0002] There is known an ozone generator that generates ozone. For example, the ozone generator applies a high voltage from an external power supply to a dielectric electrode facing a metal electrode, thereby generating a silent discharge in the discharge gap between the electrodes. In this way, the ozone generator generates ozone from a raw material gas containing oxygen and the like that is supplied to the discharge gap. Such an ozone generator has a power supply member that applies a high voltage to the dielectric electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2010 / 021022 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned ozone generator, there is a risk of damage when a high current flows through the power supply member, and therefore a power supply member with high durability is required. In the above-mentioned prior art document, a metal plate is interposed between the power supply member and the conductive film, but there are irregularities on the inner surface of the dielectric electrode, and the conductive film formed on the inner surface of the dielectric electrode does not adhere to the metal plate, resulting in a drawback of low durability.

[0005] An object of the present invention is to provide an ozone generator which can provide a power supply member with high durability. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an ozone generator according to an embodiment includes a metal electrode, a tubular dielectric electrode provided with a conductive film on its inner surface and arranged with a discharge gap between the metal electrode and the metal electrode to supply a raw material gas for ozone, a power supply member having a mesh member on its outer surface into which a plurality of metal wires are woven and inserted into the dielectric electrode, and a thin metal film wound around the power supply member and electrically connecting the mesh member and the conductive film. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing an overall configuration of an ozone generator according to an embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the vicinity of the dielectric electrode according to the embodiment. [Diagram 3] FIG. 3 is a side view of the power supply member according to the embodiment. [Figure 4] FIG. 4 is a perspective view of the elastic member according to the embodiment. [Diagram 5] 5 is a cross-sectional view of the power supply member taken along line IV-IV in FIG. 3 according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The following exemplary embodiments and modifications include similar components. Therefore, in the following, similar components are given common reference numerals, and duplicated descriptions are partially omitted. The parts included in the embodiments and modifications can be configured by replacing them with corresponding parts of other embodiments and modifications. Furthermore, the configurations and positions of the parts included in the embodiments and modifications are the same as those of other embodiments and modifications unless otherwise specified.

[0009] (Example of ozone generator configuration) Fig. 1 is a cross-sectional view showing the overall configuration of an ozone generator 10 according to an embodiment. As shown in Fig. 1, the ozone generator 10 includes an airtight container 11, a metal electrode 22, a dielectric electrode 30, and a power supply member 50. A high-voltage power supply 14 and a cooling water supply unit 17 may also be included in the configuration of the ozone generator 10.

[0010] The airtight container 11 is configured as a hollow tube having a central axis along the Y direction. The airtight container 11 is provided with a gas inlet 12, a gas outlet 13, a high-voltage power supply inlet 15, a cooling water inlet 18, and a cooling water outlet 19, and houses a pair of end plates 21a, 21b, a plurality of metal electrodes 22, a plurality of dielectric electrodes 30, a plurality of fuses 16, and a plurality of spacers 42 and is kept airtight.

[0011] The pair of end plates 21a, 21b includes a conductive material such as stainless steel. The end plates 21a, 21b are formed in a disk shape, and the outer peripheries of the end plates 21a, 21b are fixed to the airtight container 11. The end plate 21b is disposed so as to face the end plate 21a and be substantially parallel to the end plate 21a. These end plates 21a, 21b are connected to the ground potential via the airtight container 11. The end plates 21a, 21b are also provided with a plurality of circular holes 26a, 26b, which are disposed at substantially equal intervals on the end plates 21a, 21b.

[0012] The metal electrodes 22 are made of the same material as the end plates 21a, 21b, and are configured in a tubular shape containing a conductive material such as stainless steel. The multiple metal electrodes 22 are supported at both ends by circular holes 26a, 26b, and are arranged at approximately equal intervals in the X and Z directions with their longitudinal directions, i.e., central axis directions, parallel to the Y direction.

[0013] Both ends of the metal electrode 22 are connected to the end plates 21a, 21b by, for example, welding. As a result, both ends of the metal electrode 22 are held by the pair of end plates 21a, 21b without being blocked, and are electrically connected to the end plates 21a, 21b. Therefore, the metal electrode 22 is connected to the ground potential via the end plates 21a, 21b.

[0014] The cooling water inlet 18 is provided at the bottom of the airtight container 11 between the end plates 21a and 21b, and introduces cooling water supplied from an external cooling water supply unit 17 into the space between the end plates 21a and 21b of the airtight container 11. The cooling water supply unit 17 is, for example, a chiller or a pump. The cooling water outlet 19 is provided at the top of the airtight container 11 between the end plates 21a and 21b, and discharges the cooling water that has filled and flowed into the space between the end plates 21a and 21b of the airtight container 11 to the outside.

[0015] That is, the inner wall surface of the airtight container 11 and the end plates 21a, 21b form the water channel 46 for the cooling water. As described above, both ends of the metal electrode 22 are connected to the end plates 21a, 21b by welding or the like, so the water channel 46 is not formed inside the metal electrode 22 and the cooling water does not enter the metal electrode 22. Therefore, the area indicated by dotted hatching in FIG. 1 becomes the water channel 46 for the cooling water.

[0016] The gas inlet 12 and the gas outlet 13 are provided in the airtight container 11 outside the portion sandwiched between the end plates 21a and 21b. Oxygen and other gases serving as raw material gases for ozone (O3) are introduced into the airtight container 11 from the gas inlet 12. Unreacted raw material gas and ozone are discharged to the outside from the gas outlet 13. The gas inlet 12 and the gas outlet 13 are preferably provided at positions furthest from each other, for example, at diagonal corners of the airtight container 11.

[0017] As a result, the raw material gas and ozone flow and fill the outside of the region sandwiched between the end plates 21a and 21b inside the airtight container 11. The raw material gas and ozone also flow and fill the outside of the region that serves as the water passage 46 for the cooling water, that is, the internal space of the metal electrode 22, in the region sandwiched between the end plates 21a and 21b.

[0018] The dielectric electrode 30 has a tubular shape with one end closed. Each dielectric electrode 30 is disposed inside one of the metal electrodes 22 in a space filled with a source gas or the like so as to be coaxial with the metal electrode 22. As a result, the outer circumferential surface of the dielectric electrode 30 faces the inner circumferential surface of the metal electrode 22, and a discharge gap 44 to which the source gas is supplied is formed between the dielectric electrode 30 and the metal electrode 22.

[0019] A spacer 42 is disposed between the dielectric electrode 30 and the metal electrode 22. The spacer 42 maintains a discharge gap 44 between the dielectric electrode 30 and the metal electrode 22 at a predetermined distance. The spacer 42 may be a protrusion integrated with the metal electrode 22.

[0020] A power supply member 50 is inserted into the other open end of the tubular dielectric electrode 30 and is electrically connected to the dielectric electrode 30. The power supply member 50 contains a conductive material such as stainless steel and has conductivity and ozone resistance. The power supply member 50 is disposed near the opening of the dielectric electrode 30. A fuse 16 is electrically connected to the power supply member 50.

[0021] The fuse 16 is connected to the power supply member 50 so that its central axis substantially coincides with that of the dielectric electrode 30. One end of the fuse 16 is electrically connected to the high-voltage power supply 14 via the high-voltage insulator 14a and the lead wire 14b. In this manner, by being interposed between the high-voltage power supply 14 and the dielectric electrode 30, the fuse 16 cuts off an overcurrent that flows when the dielectric electrode 30 is damaged by insulation breakdown, and separates the damaged dielectric electrode 30 from the other dielectric electrodes 30, thereby enabling the ozone generator 10 to continue operating.

[0022] The high-voltage power supply 14 is connected to the power supply member 50 via the lead wire 14b and the fuse 16. The high-voltage power supply 14 applies a high-frequency, high-voltage AC voltage to the dielectric electrode 30 via the fuse 16 and the power supply member 50.

[0023] 2 is an enlarged cross-sectional view of the vicinity of the dielectric electrode 30 according to the embodiment. As shown in FIG. 2, the dielectric electrode 30 has a tubular member 34 and a conductive film 36.

[0024] The tubular member 34 is made of a dielectric material such as quartz glass, borosilicate glass, high silicate glass, aluminosilicate glass, ceramics, etc., and is electrically insulating. The tubular member 34 is configured in a tubular shape with one end closed and the other end open.

[0025] The conductive film 36 contains a conductive material such as stainless steel, nickel, carbon, or aluminum, and is conductively provided on the inner surface of the tubular member 34. By having the conductive film 36, the dielectric electrode 30 functions as a counter electrode to the metal electrode 22.

[0026] The conductive film 36 can be formed by sputtering, spraying, vapor deposition, electroless plating, electrolytic plating, paint application, etc. of a conductive material. As a result, the conductive film 36 is formed into a tubular shape having approximately the same shape as the inner surface of the tubular member 34.

[0027] Fig. 3 is a side view of a power supply member 50 according to an embodiment. As shown in Fig. 3, the power supply member 50 has an elastic member 54 and a mesh member 52. In addition, a metal thin film 58 is wound around the surface of the power supply member 50.

[0028] The elastic member 54 is configured in a tubular shape with a bulging central portion in the axial direction, and is configured to be elastically deformable. One end of the elastic member 54 is connected to the fuse 16. The mesh member 52 is configured by twisting a plurality of metal wires into a mesh shape, and covers the elastic member 54. The metal thin film 58 is wound further outside the mesh member 52, and covers the entire power supply member 50.

[0029] Hereinafter, the individual configurations of the elastic member 54, the mesh member 52, and the metal thin film 58 will be described in detail with reference to FIGS.

[0030] Fig. 4 is a perspective view of the elastic member 54 according to the embodiment. As shown in Fig. 4, an elastically deformable elastic portion 54b is formed in the center of the elastic member 54. The elastic portion 54b is formed in a tubular shape with a larger diameter at the center compared to both end portions. The elastic portion 54b is provided with a plurality of openings 54a extending in the axial direction of the elastic member 54. The elastic member 54 includes a conductive material such as stainless steel, and is conductive and ozone resistant.

[0031] When inserted into the dielectric electrode 30, the elastic portion 54b of the elastic member 54 elastically deforms in the radial direction of the dielectric electrode 30. At this time, by having a plurality of openings 54a, the elastic portion 54b can be elastically deformed more easily, and the mesh member 52 provided on the outer periphery is pressed against the conductive film 36. The elastic member 54 is disposed inside the dielectric electrode 30 so as to be coaxial with the dielectric electrode 30.

[0032] FIG. 5 is a cross-sectional view of the power supply member 50 according to the embodiment taken along line IV-IV in FIG.

[0033] 5, the mesh member 52 is configured in a tubular shape with both ends in the longitudinal direction being open, and is provided so as to cover the above-mentioned elastic member 54. In this way, the mesh member 52 covers almost the entire outer surface of the elastic member 54.

[0034] The mesh member 52 is formed by weaving a strand 56t, which is formed by twisting together a plurality of metal wires 56, into a mesh shape. The wire diameter of the metal wires 56 constituting the strand 56t is, for example, 80 μm or more.

[0035] More specifically, the mesh member 52 is woven by stockinette stitch or the like so that the warp and weft threads of the multiple stranded wires 56t are arranged at approximately equal intervals. As a result, the mesh member 52 has a mesh shape in which the stranded wires 56t of the multiple metal wires 56 are arranged approximately evenly in the circumferential and longitudinal directions of the elastic member 54, and multiple openings are arranged two-dimensionally at approximately equal intervals.

[0036] The mesh member 52 configured in this manner is pressed radially outward by the elastic force of the elastic member 54, thereby coming into contact with and electrically connecting to the conductive film 36 of the dielectric electrode 30 via the metal thin film 58. As a result, the mesh member 52 electrically connects the conductive film 36 and the elastic member 54, making it possible to apply a high voltage to the conductive film 36.

[0037] The thin metal film 58 includes a conductive material such as stainless steel, and has conductivity and ozone resistance. That is, the thin metal film 58 may be, for example, stainless steel foil. The thin metal film 58 covers the mesh member 52 and is wound around the outer periphery of the power supply member 50. In addition, both ends of the thin metal film 58 along the axial direction of the power supply member 50 are woven inside both end portions of the mesh member 52 that are open ends.

[0038] As a result, the power supply member 50 can increase the contact area by contacting the metal thin film 58 with the conductive film 36 of the dielectric electrode 30, and also has the function of reducing the resistance value between the power supply member 50 and the dielectric electrode 30.

[0039] From the viewpoint of functioning as a protective film, the thickness of the metal thin film 58 is preferably less than 10 μm, and more preferably 5 μm or less. If the thickness of the metal thin film 58 is 10 μm or more, the hardness of the metal thin film 58 becomes too high, and the metal thin film 58 is likely to wrinkle when wrapped around the power supply member 50. This may result in the conductive film 36 being damaged. If the thickness of the metal thin film 58 is less than 10 μm, and more preferably 5 μm or less, sufficient strength as a protective film is obtained, damage to the conductive film 36 is suppressed, and the metal thin film 58 has an appropriate hardness, which improves workability when wrapped around the power supply member 50.

[0040] The hardness of the thin metal film 58 is preferably less than 400 HV, and more preferably less than 395 HV, in Vickers hardness.

[0041] The number of times that the metal thin film 58 is wound may be one, or two or more. However, from the viewpoint of strength, it is preferable that the metal thin film 58 is wound multiple times. By winding the metal thin film 58 multiple times, it is possible to suppress the current bias to the other end of the dielectric electrode 30 connected to the power supply member 50 due to the resistance between the power supply member 50 and the dielectric electrode 30 becoming too low. On the other hand, even if the number of times of winding is increased to three, four, five, etc., the resistance value between the power supply member 50 and the dielectric electrode 30 does not decrease any more, so it is more preferable that the metal thin film 58 is wound, for example, twice.

[0042] Next, the operation of the ozone generator 10 will be described.

[0043] In the ozone generator 10, raw material gas is supplied from the gas inlet 12 while cooling water supplied from the cooling water inlet 18 flows through the water passage 46 between the end plates 21a, 21b to cool the metal electrode 22. In this state, the high-voltage power supply 14 supplies an AC voltage between the conductive film 36 and the metal electrode 22 via the fuse 16, the elastic member 54 and the mesh member 52 of the power supply member 50, and the thin metal film 58. As a result, a high voltage is applied to the discharge gap 44 between the conductive film 36 and the metal electrode 22, and ozone is generated from the oxygen in the raw material gas by silent discharge generated in the discharge gap 44. The generated ozone is discharged from the gas outlet 13.

[0044] (Overview) In an ozone generator, a power supply member is inserted into the dielectric electrode, which is provided, for example, in a tubular shape, in order to apply a high voltage to the dielectric electrode. In order to reduce the contact resistance between the dielectric electrode and the power supply member and to suppress the variation in the resistance value between them, for example, a power supply member is used in which a mesh member made of metal wires woven in a mesh pattern is used to cover the surface of the power supply member.

[0045] However, since the mesh member is made of, for example, a knitted material, there are overlapping parts between the metal wires, and these overlapping parts come into point contact with the conductive film of the dielectric electrode. Therefore, even when the mesh member is used, it may not be possible to obtain a sufficient contact area with the conductive film, and as a result, the contact resistance may increase and the contact part may become heated. If the contact part with the conductive film becomes heated, the conductive film may deteriorate and be damaged.

[0046] The ozone generator 10 of the embodiment includes a power supply member 50 having a mesh member 52 on its outer surface into which a plurality of metal wires 56 are woven and inserted into the dielectric electrode 30, and a thin metal film 58 wound around the power supply member 50 and electrically connecting the mesh member 52 and the conductive film 36 of the dielectric electrode 30.

[0047] In this way, the metal thin film 58 interposed between the mesh member 52 and the conductive film 36 increases the contact area between the mesh member 52 and the conductive film 36, thereby reducing the contact resistance therebetween. This makes it possible to suppress heat generation in the contact area between the mesh member 52 and the conductive film 36 and to suppress damage to the conductive film 36.

[0048] Furthermore, the metal thin film 58 can cover the mesh member 52 with appropriate conformability, and can also be made to conform to the inner wall surface of the dielectric electrode 30 when the power supply member 50 is inserted into the dielectric electrode 30. Use of the metal thin film 58 can also improve operability in attaching the metal thin film 58 to the power supply member 50, inserting the power supply member 50 into the dielectric electrode 30, and the like.

[0049] As a result, the life of the dielectric electrode 30 including the conductive film 36 can be extended, and the efficiency of ozone generation can be improved.

[0050] According to the ozone generator 10 of the embodiment, the mesh member 52 is provided in a tubular shape with both ends open, and the metal thin film 58 is folded around both ends of the mesh member 52. In this way, the metal thin film 58 can be easily attached to the power supply member 50. In addition, the metal thin film 58 has the advantage that it is highly versatile and can be used at low cost without having to prepare a metal plate or the like according to the shapes of the power supply member 50 and the dielectric electrode 30, for example.

[0051] According to the ozone generator 10 of the embodiment, the metal thin film 58 has a thickness of less than 10 μm, and preferably has a thickness of 5 μm or less. This allows the metal thin film 58 to have an appropriate hardness, and the power supply member 50 wrapped around the metal thin film 58 can be inserted without damaging the conductive film 36 of the dielectric electrode 30. In addition, it is possible to improve the conformability to the power supply member 50 and the dielectric electrode 30, and further improve the workability.

[0052] According to the ozone generator 10 of the embodiment, the metal thin film 58 is wound twice or more around the power supply member 50. This makes it possible to suppress the occurrence of bias in the current in the dielectric electrode 30 due to the metal thin film 58 being too thin, and to apply a high voltage to the dielectric electrode 30 more uniformly.

[0053] In the above-described embodiment and modified example, the metal thin film 58 includes a conductive material such as stainless steel. However, the metal thin film 58 may be configured to include a material other than stainless steel. In this case, the metal thin film 58 is preferably configured of a material having a Vickers hardness of, for example, less than 400 HV, more preferably less than 395 HV, and having ozone resistance, and may include a conductive material such as gold (Au). In this case, the metal thin film 58 may be, for example, a gold foil or the like.

[0054] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0055] 10 Ozone Generator 11 Airtight container 14 High voltage power supply 17 Cooling water supply section 22 Metal electrode 30 Dielectric Electrode 34 Tubular members 36 Conductive Film 44 Discharge Gap 50 Power supply components 52 Mesh members 54 Elastic member 56 Metal wire 58 Metallic Thin Film

Claims

1. A metal electrode; a tubular dielectric electrode having a conductive film on its inner surface, the tubular dielectric electrode being disposed between the metal electrode and a discharge gap through which an ozone source gas is supplied; a power supply member having an outer surface formed of a mesh member in which a plurality of metal wires are woven, the power supply member being inserted into the dielectric electrode; a thin metal film that is wrapped around the power supply member and electrically connects the mesh member and the conductive film, Ozone generator.

2. The power supply member is an elastic member capable of elastically deforming in a radial direction of the dielectric electrode; The mesh member is covering the surface of the elastic member; 2. The ozone generator of claim 1.

3. The mesh member is The device is provided in a tubular shape with both ends open, The metal thin film is The mesh member is folded into both ends.

3. The ozone generator of claim 2.

4. The metal thin film is having a thickness of less than 10 μm; 2. The ozone generator of claim 1.

5. The metal thin film is having a thickness of 5 μm or less; 2. The ozone generator of claim 1.

6. The metal thin film is The wire is wound around the power supply member at least twice.

6. The ozone generator of claim 5.

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