JP2004292256A - Ozonizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and inexpensively produce an ozonizer with high efficiency. <P>SOLUTION: The ozonizer is composed of the three layers of: a high voltage-side electrode 4; a dielectric layer 2 of quartz glass (or synthetic quartz glass, or SiO<SB>2</SB>, or mica) with a thickness of several hundreds μm to several mm; and a grounded electrode 1. As the high voltage-side electrode 4 and the grounded electrode 1, a printed electrode of gold, silver, copper or platinum is used. The high voltage-side electrode 4 is provided with many opening parts 5 with a diameter of several hundreds μm to several mm at the lengthwise and crosswise pitch of several hundreds μm. At the time when high frequency high voltage is applied to the space between both the electrodes, dielectric barrier discharge is generated at the opening parts 5, and ultraviolet rays are generated, so that oxygen as a gaseous starting material is ionized and changed into ozone. An MgO film 3 is formed on the surface of the high voltage-side electrode 4 and the surface of the dielectric substance 2 on the side of the opening parts 5 for increasing the efficiency of generating ozone and preventing the wear of the electrodes. By the constitution, the adhesion between the dielectric substance and the electrode is made satisfactory, the efficiency of generating ozone improves, and the production can be made easy and inexpensive. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ozone generator, and more particularly, to an ozone generator using dielectric barrier discharge.
[0002]
[Prior art]
The ozone generator is used for removing NOx generated during the treatment of industrial waste, an air washer, a deodorizer, and plant activation. There are many ozone generation methods. A method using thermal plasma, a method using an electrolytic method, a method using a discharge method, and the like are selected according to the required amount of generated ozone. Above all, an ozone generator used for sterilization, deodorization, decolorization, pulp bleaching, sterilization of medical equipment, and the like of water and sewage and industrial wastewater is generally a device using silent discharge.
[0003]
In recent years, flat-plate-type ozone generators using creeping discharge have been developed because such ozone generators are large in volume and low in electric efficiency. Recently, an ozone generator has been developed that efficiently generates high-concentration ozone at a level that allows water to absorb ozone efficiently. Ceramics are used as a dielectric material of the ozone generator, and a material obtained by laminating a metal (aluminum or the like) film on ceramics or the like is used as a material for electrodes on the high voltage side and the ground side. The discharge device for generating ozone is provided with a cooling device such as a heat sink or a Peltier element.
[0004]
[Problems to be solved by the invention]
However, the conventional ozone generating apparatus has a problem that the structure of the apparatus is very complicated, and it takes time and effort to manufacture.
[0005]
An object of the present invention is to solve the above-mentioned conventional problems and to realize a highly efficient ozone generator which can be easily and inexpensively manufactured.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, an ozone generator is provided with a high-pressure side electrode formed of a transfer-type printed electrode made of any one of gold, silver, copper, and platinum having a large number of discharge openings. A ground electrode formed of the continuous printed electrodes, and a dielectric layer formed of any of synthetic quartz glass, quartz glass, SiO ₂ , and mica sandwiched between the high-voltage side electrode and the ground electrode. Configuration. With this configuration, it is possible to easily and inexpensively manufacture an ozone generator that generates ozone with high efficiency. In addition, by applying an MgO film or an aluminum nitride film to the surface of the electrode on the discharge surface side and the surface of the dielectric on the opening side in these discharge devices, it is possible to prevent wear of the electrodes and extend the life of the discharge device.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
[0008]
(First Embodiment)
In the first embodiment according to the present invention, a high-voltage electrode formed by a printing electrode having a large number of discharge openings, a ground electrode formed by a continuous printing electrode, and a high-voltage electrode and a ground electrode are sandwiched. An ozone generator having a three-layer structure including a dielectric layer provided.
[0009]
FIG. 1 is a conceptual diagram of an ozone generator according to a first embodiment of the present invention. In FIG. 1, a high-pressure side electrode 4 and a ground electrode 1 are formed by thermally sintering a transfer sheet made of any one of gold, silver, copper, and platinum and a resin, thereby skipping the resin and forming a thin film of the metal. Is a printed electrode in which is adhered to a dielectric. The dielectric 2 is a synthetic quartz glass. The dielectric may be quartz glass, SiO ₂ , or mica. The MgO film 3 is a protective film that covers the surface of the high-voltage side electrode 4 and the dielectric surface facing the discharge opening described later. The ground electrode 1 is an electrode for applying a high frequency high voltage. The discharge opening 5 is a site where a discharge occurs. The discharge area of the discharge device was 100 mm × 100 mm.
[0010]
The ozone generator comprises three layers: an upper high-voltage electrode 3, a dielectric layer 2 made of synthetic quartz glass having a thickness of 150 μm, and a lower ground electrode 1. The uppermost high voltage side electrode 3 and the lowermost ground electrode 2 are solid transfer sheet type printing electrodes having a thickness of 25 μm selected from gold, silver, copper, and platinum. By using these materials, an electrode can be easily manufactured at low cost. The upper layer high voltage side electrode 4 is provided with a large number of openings 5 of several hundred μm to several mm at a vertical and horizontal pitch of several hundred μm.
[0011]
The operation of the ozone generator according to the first embodiment of the present invention configured as described above will be described. A high frequency high voltage of 5 kV at a frequency of 10 KHz is applied between the high voltage side electrode 4 and the ground electrode 1 of the ozone generator shown in FIG. A dielectric barrier discharge is generated in the discharge opening 5, and accordingly, ultraviolet light is generated. Oxygen in the atmosphere is ionized by the action of the ultraviolet rays, and ozone is generated. Ozone can be efficiently generated in the discharge opening 5 having a diameter of several hundred μm to several mm in the uppermost layer in the ozone generator. An MgO film 3 is formed on the surface of the high-voltage side electrode 4 and the surface of the dielectric 2 facing the opening in order to increase the efficiency of ozone generation. It operates without the MgO film 3.
[0012]
In order to confirm the ozone generation efficiency, a comparison was made between atmospheric discharge between the specifications of the present invention in which the dimensions of the ozone generator having the structure shown in FIG. Was. In a conventional discharge device, the dielectric is alumina ceramic and the electrode is an aluminum thick-film printed electrode. In order to confirm the electrode abrasion prevention effect of the deposited MgO film and the efficiency of ozone generation, the MgO film was deposited on the surface of the high-pressure side electrode and the dielectric surface facing the discharge opening, and the MgO film was not deposited. We also decided to compare the discharge in the atmosphere.
[0013]
FIG. 2 shows the results of a comparison of the ozone generation efficiency between the discharge device made of the conventional material and the discharge device studied in the present invention shown in FIG. From FIG. 2, it was confirmed that the discharge device using the synthetic quartz glass as the dielectric material and the printed electrode as the electrode did not compare so much with the ozone generation efficiency of the conventional discharge device when the same power was applied.
[0014]
FIG. 3 shows the ratio of the life at an ozone generation and maintenance rate of 80%, and the ozone generation amount for the case where the MgO film is deposited on the surface of the high voltage application side electrode and the case where the MgO film is not deposited on the dielectric surface facing the opening. Is shown. Those with the MgO film had better life and ozone generation efficiency than those without the MgO film, confirming the superiority of the MgO film.
[0015]
By using the printed electrode, an electrode having good adhesion to the dielectric can be easily manufactured at low cost. Good adhesion between the dielectric and the electrode leads to uniform formation of the dielectric layer and the metal layer, and a uniform electric field can be formed. Thereby, the surface can be uniformly discharged, and the ozone generation efficiency is improved. It has a sandwich-type three-layer structure in which a dielectric is sandwiched between two electrodes, and can be easily manufactured at low cost. In addition, energy loss can be reduced by using gold, silver, copper, and platinum printed electrodes having good conductivity as the electrode material.
[0016]
As described above, in the first embodiment according to the present invention, the ozone generator is connected to a high-pressure side electrode formed of a printed electrode made of any of gold, silver, copper, and platinum having a large number of discharge openings. A ground electrode formed by the printed electrode described above, and a dielectric layer formed of any of synthetic quartz glass, quartz glass, SiO _{2 ,} and mica sandwiched between the high-voltage side electrode and the ground electrode. Because of the layer structure, a highly efficient ozone generator can be easily and inexpensively manufactured. Further, by providing the MgO film or the aluminum nitride film on the surface of the electrode on the high voltage application side and on the surface of the dielectric facing the discharge opening, it is possible to obtain a long life and an improvement in ozone generation efficiency by preventing abrasion of the electrode. ]
Next, the relationship between the dielectric thickness related to the ozone generation efficiency and the discharge opening diameter on the high voltage application side was examined. When an applied voltage was applied to the discharge device of the present invention, the distribution of an electric field depending on the ozone generation efficiency was determined. FIG. 4 is a view showing the distribution of electrostatic potentials generated when a voltage of 4 kV is applied to a discharge device having an opening diameter of 100 μm and a dielectric thickness of 100 μm. FIG. 5 shows a diagram summarizing the relationship between the discharge opening diameter and the electric field near the discharge opening. FIG. 6 is a diagram summarizing the relationship between the thickness of the dielectric and the electric field near the discharge opening.
[0018]
The electrostatic potential distribution applied to the discharge device became strongest near the discharge opening and reached 10 ⁸ m / V near the opening. The electric field increased with the decrease in the aperture diameter, and the electric field also increased with the decrease in the thickness of the dielectric. Since the intensity of the electric field is reflected in the ozone generation amount, it can be seen that the ozone generation efficiency depends on the thickness and the opening diameter of the dielectric. It can be seen that when the dielectric size is larger than the opening size, the electric field loss increases, and the ozone generation efficiency decreases. As shown in FIG. 6, when the discharge opening diameter is 100 μm, the electric field sharply increases from a dielectric thickness of 100 μm or less. That is, when the thickness of the dielectric is smaller than the diameter of the opening, the electric field increases more remarkably. Therefore, considering the high efficiency of ozone generation, if the thickness of the dielectric is T (m) and the diameter of the opening is D (m), it is considered preferable to satisfy at least T ≦ D in terms of the discharge device structure. Can be
[0019]
(Second embodiment)
A second embodiment according to the present invention includes a first high voltage side electrode formed by a printing electrode having a large number of discharge openings, a ground electrode formed by a continuous printing electrode, and a first high voltage side electrode. A first dielectric layer formed of quartz glass sandwiched between the first electrode and a ground electrode, a second high-voltage electrode formed of a printed electrode having a large number of discharge openings, and a second high-voltage electrode. This is an ozone generator having a five-layer structure including a ground electrode and a second dielectric layer formed of quartz glass sandwiched between the ground electrodes. The dielectric may be any of quartz glass, SiO ₂ , and mica, and the printed electrode may be any of gold, silver, copper, and platinum.
[0020]
FIG. 7 is a conceptual diagram of an ozone generator according to the second embodiment of the present invention. In FIG. 7, the ground electrode 1 is an electrode formed of any one of gold, silver, copper, and platinum printed electrodes. The dielectric 2 is any of synthetic quartz glass, quartz glass, SiO ₂ , and mica. The MgO film 3 is a protective film. The high voltage side electrode 4 is a printed electrode of any of gold, silver, copper, and platinum, and is an electrode to which a high frequency high voltage is applied. The opening 5 is a site where a discharge occurs.
[0021]
The ground electrode 1 of the central layer is sandwiched between dielectrics 2 having a thickness of several tens μm to several mm. The outermost layer surface is the high-voltage side electrode 4 in which a large number of discharge openings 5 having a diameter of several tens of μm to several mm are opened at a pitch of several hundred μm in length and width. The high voltage side electrode 4, the dielectric 2, the ground electrode 1, the dielectric 2, and the high voltage side electrode 4 are composed of five layers.
[0022]
FIG. 8 is a conceptual diagram illustrating another example of the ozone generator according to the second embodiment of the present invention. In FIG. 8, an ozonizer 6 is an ozone generating element having a five-layer structure. The source gas 7 is a compressed gas containing oxygen. The ozone gas 8 is generated ozone. In this ozone generator, ozonizers 6 having discharge surfaces on both sides are arranged in parallel at intervals of about several mm.
[0023]
The operation of the ozone generator according to the second embodiment of the present invention configured as described above will be described. A high frequency high voltage current of several kHz at several kHz is applied between the high voltage side electrode 4 and the ground electrode 1 of the ozone generator shown in FIG. A dielectric barrier discharge is generated in the opening 5, and accordingly, ultraviolet light is generated. Oxygen in the atmosphere is changed to ozone by the action of the ultraviolet light. Since the electrodes on both surfaces of the outermost layer having the discharge opening 5 are used, ozone can be generated with a large surface area. An MgO film 3 is formed on the surface of the high-voltage side electrode 4 and the surface of the dielectric 2 facing the opening side to increase the efficiency of ozone generation. It operates without the MgO film 3.
[0024]
A source gas 7, which is a compressed gas containing oxygen, is blown between electrodes of an ozone generator in which a plurality of ozonizers 6, which are flat discharge elements having a five-layer structure shown in FIG. 8, are arranged in parallel. By increasing the number of the ozonizers 6, the discharge area can be easily enlarged. In this manner, the ozone gas 8 can be generated with high efficiency, and at the same time, the cooling can be efficiently performed. Therefore, a large-scale cooling device is not required, and the ozone generator can be made compact. Further, the manufacturing operation is facilitated and the manufacturing can be performed at low cost.
[0025]
As described above, in the second embodiment according to the present invention, the ozone generating device is formed by the first high-voltage side electrode formed by the printing electrode having a large number of discharge openings, and the continuous printing electrode. A ground electrode, a first dielectric layer formed of quartz glass sandwiched between the first high-voltage side electrode and the ground electrode, and a second high-voltage side formed by a printed electrode having a number of discharge openings Since it has a five-layer structure including the electrode and the second dielectric layer formed of quartz glass sandwiched between the second high-voltage side electrode and the ground electrode, a highly efficient ozone generator can be easily and easily provided. It can be manufactured at low cost.
[0026]
【The invention's effect】
As is apparent from the above description, in the present invention, the ozone generator, gold, silver, copper having a large number of openings, a high-pressure side electrode formed of any one of platinum printed electrodes, a continuous printed electrode And a dielectric layer formed of any one of quartz glass, synthetic quartz glass, SiO ₂ , and mica sandwiched between the high-voltage side electrode and the ground electrode. An efficient ozone generator can be easily and inexpensively manufactured. Further, by providing the MgO film or the aluminum nitride film on the electrode surface which is the discharge surface and the dielectric surface facing the opening side, the ozone generation efficiency is improved and the life can be extended.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of an ozone generator according to a first embodiment of the present invention;
FIG. 2 is a comparison table of ozone generation efficiency between the ozone generation device according to the first embodiment of the present invention and a conventional discharge device,
FIG. 3 is a table comparing the difference in the performance of a discharge device depending on the presence or absence of an MgO film,
FIG. 4 is an electrostatic distribution diagram when a voltage is applied to the discharge device,
FIG. 5 is a graph showing a relationship between a diameter of a discharge opening and an electric field,
FIG. 6 is a graph showing a relationship between a dielectric thickness and an electric field,
FIG. 7 is a conceptual diagram of an ozone generator according to a second embodiment of the present invention;
FIG. 8 is a conceptual diagram of another example of the ozone generator according to the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ground electrode 2 Dielectric 3 MgO film 4 High voltage side electrode 5 Discharge opening 6 Ozonizer 7 Source gas 8 Ozone gas

Claims (7)

In an ozone generating device comprising a dielectric sandwiched between a high voltage side electrode and a ground electrode, the high voltage side electrode and the ground electrode are printed electrodes selected from gold, silver, copper, or platinum. Wherein the dielectric layer is selected from any one of synthetic quartz glass, quartz glass, SiO ₂ , and mica. The ozone generator according to claim 1, wherein the printed electrode is formed by thermal sintering. 2. The ozone generator according to claim 1, wherein the high-voltage side electrode is formed by a printed electrode having a large number of discharge openings. 3. The ozone generator according to claim 1, wherein an MgO film or an aluminum nitride film is provided on a surface of the high-voltage side electrode and a surface of the dielectric facing the discharge opening side. The relationship between the dielectric thickness and the electrode opening diameter is set to D ≦ T, where D (m) is the thickness of the dielectric and T (m) is the electrode opening diameter. 4. The ozone generator according to any one of 4. The ozone generator according to claim 1, wherein the ground electrode is arranged in a central layer, the ground electrode is sandwiched between dielectrics, and the dielectric is covered with the high-voltage side electrode. The ground electrode is disposed in a central layer, the ground electrode is sandwiched between dielectrics, and a plurality of ozone generators having a structure in which the dielectric is covered with the high-voltage side electrode are arranged in parallel at a few mm intervals. The ozone generator according to claim 6.

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