JP2000072410A - Ozone generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce highly concentrated ozone with a large capacity, to prolong the service life and to improve the stability by providing a dielectric layer covering a pair of electrodes on one surface of a dielectric plate. SOLUTION: A gaseous raw material 14 is introduced into a gas space 1a and a high voltage is impressed between a pair of electrodes. Though a high electric field is generated on the surface of the dielectric layer 4 and creeping discharge 18 is generated between linear members 2a and 3a constituting a pair of the electrodes at this time, the spattering deterioration of the electrodes due to the creeping discharge 18 does not occur to perform stable operation because the electrodes are covered with the dielectric layer 4. Further, the insulation of the electrodes is facilitated by covering the electrodes with the dielectric layer 4. The highly concentrated ozone can be generated by setting the width W of the linear members 2a and 3a to <=200 μm. Further, the generation of an electric field on the rear surface of an dielectric plate is suppressed and abnormal discharge is prevented by setting the thickness T of the dielectric plate 1 to be larger than a space (d) between the linear members 2a, 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generator for generating ozone from gases such as oxygen and air by surface discharge.

[0002]

2. Description of the Related Art Conventionally, sterilization, deodorization, decolorization of water and sewage,
Ozone is used to deodorize and decolorize industrial wastewater, decolorize pulp, and sterilize medical equipment. As an ozone generator for generating such ozone, a surface discharge ozone having a plurality of electrodes provided on a dielectric surface and generating ozone from an ozone source gas by generating a silent discharge between the plurality of electrodes. Generators are known.

[0003]

A conventional ozone generator generates ozone by generating a silent discharge between a plurality of electrodes as described above. In particular, a large-sized ozone generating apparatus having a small gap between the electrodes has been desired for generating high-concentration ozone, but it is difficult to uniformly reduce the gap between the electrodes using a large-area electrode.

[0004] In the creeping discharge ozone generator, the electrodes on the dielectric surface are sputtered and deteriorated by the discharge.

[0005] The present invention has been made in view of such a point, and an object of the present invention is to provide an ozone generator having a high concentration, a large capacity, a long life, and a high stability.

[0006]

SUMMARY OF THE INVENTION The present invention provides a dielectric plate,
An ozone generator comprising: a pair of electrodes provided on one surface of a dielectric plate; and a dielectric layer provided on one surface of the dielectric plate so as to cover the pair of electrodes.

According to the present invention, since the pair of electrodes are both covered with the dielectric layer, the pair of electrodes does not deteriorate by sputtering.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of the ozone generator according to the present invention.

1 and 2, an ozone generator includes a rectangular dielectric plate 1 made of glass and a conductive material such as a silver paste provided on the surface (one surface) of the dielectric plate 1 by screen printing or the like. It comprises one pair of electrodes 2 and the other electrode 3 and a dielectric layer 4 provided on the surface of the dielectric plate 1 so as to cover the pair of electrodes 2 and 3. The pair of electrodes 2 and 3 are respectively composed of a plurality of linear members 2a and 3a.

On the back (other side) side of the dielectric plate 1,
A metal heat sink (cooling plate) 6 having a cooling pipe 5 a through which cooling water 5 passes is provided in close contact with the dielectric plate 1.
Further, a wire 7 provided on the dielectric plate 1 is connected to the pair of electrodes 2 and 3 using the same material and the same method as the electrodes 2 and 3. Part of the wiring 7 protrudes outward from the dielectric plate 7 to form a wiring extraction portion 8 not covered by the dielectric layer 4. The other end of the lead wire 10, one end of which is connected to an AC power supply 9,
1 connected.

A packing 12 is disposed on the outer surface of the electrodes 2 and 3 on the surface of the dielectric plate 1, and a gas guide plate 13 is mounted on the packing 12 so that the dielectric plate 1 and the gas guide 1 are disposed.
3, a gas space 1a is formed. Further, a raw material gas 14 is supplied to the gas guide 13 from the outside in the gas space 1a.
A gas inlet 15 for introducing the gas into the inside and a gas outlet 17 for extracting ozone 16 from the gas space 1a are provided.

As shown in FIG. 1 and FIG.
When a high voltage is applied from the AC power supply 9 to the surface of the dielectric layer 4, a surface discharge 18 can be generated on the surface of the dielectric layer 4, and the surface discharge 18 generates ozone from the ozone raw material gas.

A linear member 2 forming a pair of electrodes 2 and 3
a, 3a are usually arranged at an interval d of 50 to 100 μm, and each of the linear members 2a, 3a has a width W. In this case, a high voltage is applied from the AC power supply 9 to the pair of electrodes 2,
3, a high electric field is generated on the surface of the dielectric layer 4, and a creeping discharge 18 is generated between the linear members 2a and 3a (FIG. 2).

Next, the operation of the present embodiment having the above configuration will be described.

First, a source gas 14 is introduced into a gas space 1a from a gas inlet 15, and a high voltage is applied between a pair of electrodes 2 and 3 by an AC power supply 9. In this case, a high electric field is generated on the surface of the dielectric layer 4 and a creeping discharge 18 is generated between the linear members 2a and 3a. However, since the pair of electrodes 2 and 3 is covered with the dielectric layer 4, Stable operation is possible without sputter deterioration of the pair of electrodes 2 and 3 due to the creeping discharge 18.

In the creeping discharge 18, the electrons e generated by the discharge dissociate the oxygen molecules O2 and generate atomic oxygen O as shown in the equation (1). Then, (2) atoms of oxygen O combines with other oxygen molecules O ₂ as type, ozone O ₃ is produced. _{e + O 2 → e + O} + O (1) O + O 2 + O 2 → O 3 + O 2 * (2) (2) equation _O ^{2 *} is more other _{O 2} molecules energy surplus when O + _{O 2} is bonded to _{O 3} I got it.

In the creeping discharge 18, (3) and (4)
As shown in the equation, a reverse reaction from ozone O ₃ to oxygen molecule O ₂ also occurs. e + O ₃ → e + O + O ₂ (3) O + O ₃ → O ₂ + O ₂ (4) The ozone 16 thus generated in the gas space 1 a flows out of the gas outlet 17.

In order to generate high-concentration ozone, it is desirable that the energy of the electron e is high. The energy of the electron e can be controlled by the electrode structure and the electrode dimensions. The width W of the linear members 2a, 3a of the pair of electrodes 2, 3 is 200 μm.
By setting as follows, high-concentration ozone can be generated. In particular, it is desirable that the electrode width W be 100 μm or less.

Further, since the creeping discharge 18 is generated by the AC power supply 9, an electric field is generated on the back surface of the dielectric plate 1, and an abnormal discharge may occur between the dielectric plate 1 and the heat sink 6. To insulate this, the thickness T of the dielectric plate 1
Is larger than the distance d between the linear members 2a and 3a of the pair of electrodes 2 and 3, thereby suppressing generation of an electric field on the back surface of the dielectric plate.
This abnormal discharge can be prevented.

The surface discharge 18 is generated on the surface of the dielectric layer 4 as described above. In order to efficiently remove the heat generated by the surface discharge 18, the dielectric plate 1 must be cooled. This is the most efficient cooling method. In this embodiment, as shown in FIGS. 1 and 2, by cooling the heat sink 6 on the back surface of the dielectric plate 1 with the cooling water 5, the dielectric plate 1 can be reliably cooled by the heat sink 6. it can. In this case, since the dielectric plate 1 is installed on the heat sink 6, even if the dielectric plate 1 is damaged, the cooling water 5 flows through the cooling pipe 5a in the heat sink 6, and is a cooling medium. There is no fear of leakage of the cooling water 5 and the like, and high reliability can be obtained. Therefore, the cooling efficiency by the cooling water 5 can be increased, and the gas temperature in the creeping discharge 18 can be suppressed low. Therefore, by preventing the thermal decomposition of ozone, high-concentration ozone can be generated.

When one side of the dielectric plate 1 is 60 cm, the linear members 2a and 3a of the electrodes 2 and 3 are 1000
About this book is provided. Further, by providing the wiring 7 connected to the electrodes 2 and 3 from the same material and the same method as the electrodes 2 and 3 on the dielectric plate 1, stable voltage supply using the wiring 7 becomes possible. In addition, by covering the pair of electrodes 2 and 3 with the dielectric layer 4, the electrodes 2 and 3 can be easily insulated. Further, a part of the wiring 7 protrudes in the outer peripheral direction of the dielectric plate 1 to form a wiring extraction part 8 not covered with the dielectric layer 4, and the lead 10 connected to the AC power supply 9 is connected to the wiring extraction part 8. By connecting with the spring-type crimping device 11, the voltage can be easily supplied to the pair of electrodes 2 and 3, and the reliability is easily improved.

Next, a modification of the present invention will be described with reference to FIG. In the modification shown in FIG. 3, the linear members 2a and 3a of the pair of electrodes 2 and 3 are not arranged at equal intervals, but are arranged at an interval d and an interval i larger than this.
And is substantially the same as the embodiment shown in FIG. In FIG. 3, the same portions as those of the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 3, the abnormal discharge can be prevented by making the thickness T of the dielectric plate 1 larger than the smaller distance d.

Referring to FIG. 4, another modification of the present invention will be described. In FIG. 4, one electrode 2 made of a conductive material such as silver paste by screen printing or the like is provided on the surface of a dielectric plate 1 made of glass, and an intermediate dielectric layer 20 is provided on one electrode 2 on the electrode 2. The other electrode 3 arranged in a layer is provided. Further, a dielectric layer 4 is coated on the other electrode 3. The rest is substantially the same as the ozone generator shown in FIG. In FIG. 4, the same portions as those of the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 4, one electrode 2 and a linear member 2a
When a high voltage is applied from the AC power supply 9 to the surface of the dielectric layer 4 and a linear member 3a of the other electrode 3, a high electric field is generated on the surface of the dielectric layer 4 to cause a creeping discharge. One electrode 2 and the other electrode 3
Are covered with the dielectric layer 4, there is no spatter deterioration due to the discharge of the one electrode 2 and the other electrode 3, and a long life and high reliability can be obtained.

In FIG. 4, by using one of the electrodes 2 on the dielectric plate 1 side as a ground potential or a low potential, wiring defects can be prevented.

[0027]

As described above, according to the present invention,
By forming a large-area electrode uniformly by a high-precision manufacturing method such as screen printing, a large-capacity creeping discharge can be performed. This enables high-concentration and high-efficiency ozone generation. Furthermore, by covering with a dielectric layer, it is possible to prevent a decrease in electrode life due to sputter deterioration, and to provide a highly reliable ozone generator.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a surface discharge ozone generator according to the present invention.

FIG. 2 illustrates a structure of an electrode.

FIG. 3 is a diagram showing a modified example of the ozone generator according to the present invention.

FIG. 4 is a diagram showing another modified example of the ozone generator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric plate 2, 3 Electrode 2a, 3a Linear member 4 Dielectric layer 6 Heat sink 9 AC power supply 13 Gas guide 18 Surface discharge

Continued on the front page (72) Inventor Shinji Kobayashi 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Hamakawasaki Plant (72) Inventor Ichiro Yamanashi 1-Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Plant (72) Inventor Yuji Okita 2-24-24 Harumi-cho, Fuchu-shi, Tokyo Toshiba FA System Engineering Co., Ltd. F-term (reference) 4G042 CA01 CC02 CC07 CC12 CC16

Claims (6)

[Claims] 1. A dielectric plate, comprising: a pair of electrodes provided on one surface of a dielectric plate; and a dielectric layer provided on one surface of the dielectric plate to cover the pair of electrodes. Ozone generator. 2. The apparatus according to claim 1, further comprising: a guide plate disposed on one surface of the dielectric plate at a predetermined distance from the one surface; and a cooling plate fixed to the other surface of the dielectric plate. The ozone generator according to claim 1. 3. A pair of electrodes each comprising a linear member, wherein the linear members of one electrode and the linear members of the other electrode are alternately arranged at a constant interval. Ozone generator. 4. The ozone generator according to claim 3, wherein the thickness of the dielectric plate is larger than the distance between the linear members. 5. The ozone generator according to claim 3, wherein each of the linear member of one electrode and the linear member of the other electrode has a width of 200 μm or less. 6. The dielectric plate according to claim 1, wherein one electrode and the other electrode are provided in a layer shape, and an intermediate dielectric layer is interposed between the one electrode and the other electrode. The ozone generator according to the above.