JPH0312308A - Creeping discharge-type ozonizer - Google Patents

Abstract

PURPOSE:To form the creeping discharge-type ozonizer having a dielectric suitable for ozonization by forming the dielectric of the creeping discharge-type ozonizer with a dielectric woven fabric impregnated with an inorg. adhesive. CONSTITUTION:The creeping discharge-type ozonizer is provided with an induction electrode 1 coated with the dielectric 2, a discharge electrode 3 set on the surface of the dielectric 2 and an AC power source 4 for impressing an AC voltage between the electrodes 1 and 3 to generate a creeping discharge. The dielectric 2 is formed with the dielectric woven fabric 2a adhered to the surface of the induction electrode 1 with the inorg. adhesive 2b. An adhesive, which is cured after application at a low temp. of room temp. to about 300 deg.C and vitrified, is used as the inorg. adhesive. For example, water is vaporized from a paste obtained by adding water to an alkali metal silicate and the silicate is dehydration-condensed with silanol to obtain the adhesive, or the adhesive of the same system is preferably used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a creeping discharge type ozonizer (hereinafter simply referred to as an ozonizer) that generates ozone by creeping discharge. Regarding the ozonizer.

[Prior Art] Japanese Utility Model Application Publication No. 60-160661 discloses an ozonizer having a dielectric body made of a porcelain plate in which an induction electrode is embedded and a discharge electrode is disposed on the surface.

Japanese Unexamined Patent Publication No. 59-44782 discloses an ozonizer having a dielectric body made of porcelain in which an induction electrode is embedded and a discharge electrode is disposed on the inner peripheral surface.

In these ozonizers, a high AC voltage is applied between the two electrodes to generate creeping discharge on the surface of the dielectric material, and ozone is generated by this creeping discharge.

[Problems to be Solved by the Invention] The conventional ozonizer described above has the following problems in order to form a dielectric:
The fact that the ceramic molded product in which the induction electrode is embedded must be fired at a firing temperature of about several hundred degrees Celsius has been a major obstacle from an economic point of view. Additionally, cranks may occur in the dielectric due to the expansion and contraction of the induction electrode, which originally has a different coefficient of thermal expansion than the dielectric, during the firing process. Since the wall thickness of the capacitor is increased, there is also the problem that the capacitance decreases and the ozone generation ability decreases.

Furthermore, it is not easy to bake a dielectric made of porcelain into a complicated shape, and naturally the shape of the induction electrode and discharge electrode and the shape of the ozonizer have to be standardized due to the restrictions on the shape of the dielectric. There was also the problem that it was not possible to improve the ozone generation ability due to the reduction in area.

The present invention has been made in view of these problems, and an object to be solved is to provide a creeping discharge type ozonizer having a dielectric material suitable for ozone generation.

[Means for Solving the Problems] A creeping discharge type ozonizer of the present invention includes an induction electrode covered with a dielectric, a discharge electrode disposed on the surface of the dielectric, and an alternating current voltage applied between the two electrodes. In the creeping discharge type ozonizer, the dielectric body is composed of a dielectric woven fabric fixed to the surface of the induction electrode with an inorganic adhesive.

As the woven fabric, a glass fiber cloth woven with long glass fibers can be used. For example, a tape of glass fiber cloth is cut into a predetermined amount and then fixed or wrapped around the induction electrode. It is preferable that the thickness of the woven fabric fixed to the induction electrode be as constant as possible. In this way, it is easy to make the thickness of each part of the dielectric body uniform, and it is easy to keep the charge density on the surface constant.

The inorganic adhesive to be used is one that hardens at a low temperature from room temperature to about 300° C. after being applied to form a glass structure. For example, a paste made by adding water to an alkali metal silicate, which evaporates water and causes dehydration condensation between silanols, or a similar product is suitable, such as Sumitomo Chemical KK.
It is possible to use various types of aron ceramics such as Sumiceramu P1 made by Yasei Kagaku KK, or Tossguard 510 and PH91 made by Toshiba Silicone KK. Furthermore, a predetermined amount of powdered ceramic particles such as glass powder may be mixed with the inorganic adhesive.

In forming the dielectric, a woven cloth can be pasted on the surface of the induction electrode in advance and impregnated with an inorganic adhesive, or the woven cloth can be applied after applying the inorganic adhesive to the surface of the induction electrode. You can also do that.

Alternatively, a woven fabric impregnated with an inorganic adhesive may be attached to the surface of the induction electrode, or a woven fabric impregnated with an inorganic adhesive may be attached after the inorganic adhesive is applied to the surface of the induction electrode. It is preferable to apply the inorganic adhesive multiple times, and it is preferable to apply the inorganic adhesive after the previously applied inorganic adhesive layer has dried in order to achieve densification.

[Operation] When an AC voltage of a predetermined value or higher is applied between the induction electrode and the discharge electrode, a creeping discharge occurs in the air on and near the dielectric surface, and ozone is generated by this creeping discharge. Creeping discharge occurs in a pulsed manner every time the applied AC voltage exceeds a voltage value necessary for creeping discharge, and the discharge stops when the dielectric is charged.

The dielectric fabric improves the strength of the dielectric against stress caused by the difference in coefficient of thermal expansion between the dielectric and the induction electrode during discharge.

The dielectric inorganic adhesive cures at room temperature or low temperature to fill the voids inside the fabric and form an electrically insulating film that is stable against ozone and electrical discharge.

[Example] As shown in FIG. 1, the creeping discharge type ozonizer of this example includes an induction electrode 1 having a semi-cylindrical wall shape, a dielectric 2 fixed to the inner and outer surfaces of the induction electrode 1, and a dielectric 2. It consists of an electrode body consisting of a discharge electrode 3 disposed on the surface of the electrode body, and an AC power source section 4 that applies an AC voltage between the induction electrode 1 and the discharge electrode 3.

The induction electrode 1 is made of a semi-cylindrical aluminum plate with a thickness of about 1 mm and a diameter of about 10 cm.

As shown in a partial cross section in FIG. 2, the dielectric 2 is made of glass fiber cloth (woven cloth in the present invention) 2a bonded to the inner and outer surfaces of the induction electrode 1 with an inorganic adhesive 2b. It consists of. Of course, the inside of the glass fiber cloth 2a is impregnated with the inorganic adhesive 2b. The thickness of dielectric 2 is approximately Q, 13
mm, and the inorganic adhesive 2b is Aron Ceramic C (
Product name> is used.

The discharge electrode 3 is made of titanium and is formed into a mesh shape.

The AC power supply unit 4 is a circuit device that generates an AC high voltage of approximately 10 kV and approximately 1 kHz.

Next, manufacturing of the above electrode body will be explained. First, an inorganic adhesive 2b is applied to a thickness of about 50 μm on the surface of the induction electrode 1, and a glass fiber cloth 2a impregnated with the inorganic adhesive 2b is attached thereon. Next, after the inorganic adhesive 2b has dried to a certain extent, the inorganic adhesive 2b is applied to the surface of the glass fiber cloth 2a to a thickness of about 50 μm. Then, before the applied inorganic adhesive 2b dries, a discharge electrode 3 is attached, and then heated at about 150°C for about 60 minutes to make the inorganic adhesive 2b
harden.

To explain the operation of this ozonizer, first, two half-cylindrical wall-shaped electrode bodies are used to form a cylinder with openings at both ends, and a flow of dry air is caused to flow in the axial direction of this cylinder.

A creeping discharge is generated between the induction electrode 1 and the discharge electrode 3, and ozone is generated.

According to this embodiment, the glass fiber cloth 2a is bonded to the inorganic adhesive 2.
Induction electrode 1 and discharge electrode 3 at the stage before curing b
Since it serves as a spacer between the two, there is an advantage that the distance between the two can be easily made constant.

Naturally, the shape of the electrode body is not limited to that described above, and various other shapes are possible.

It is also possible to fix the dielectric 2 described above on the surface of the induction electrode 1 and then deform the induction electrode before the inorganic adhesive hardens.Furthermore, it is also possible to reapply the inorganic adhesive after this deformation. Good too.

[Effects of the Invention] The dielectric of the creeping discharge type ozonizer of the present invention is composed of a dielectric woven fabric impregnated with an inorganic adhesive, and has the following advantages.

(b) Even if the shape of the induction electrode is complex, it is easy to form a dielectric with a constant thickness on its surface, so it forms a small dielectric with a large surface area and uniform charge density. be able to.

(b) Unlike porcelain dielectrics, high-temperature heat treatment is not required, so even if the thickness of the dielectric is made thinner, cracks will not occur and the amount of charged charge will increase.

(c) Woven fabric is convenient for making the thickness of the dielectric constant, and also improves the strength of the dielectric, thereby increasing its durability and reliability. In addition, the required thickness (
Although it is not easy to form a dielectric material (with sufficient dielectric breakdown voltage), using woven fabric as a base material makes it easier.

(d) There is no need to use expensive high-melting point metals for the induction electrode, making it highly economical.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view of a dielectric 2. As shown in FIG. 1... Induction electrode 2... Dielectric 3... Discharge electrode

Claims (1)

[Claims] (1) A creeping surface comprising an induction electrode covered with a dielectric, a discharge electrode disposed on the surface of the dielectric, and an AC power supply unit that applies an AC voltage between the two electrodes to generate a creeping discharge. The discharge type ozonizer is a creeping discharge type ozonizer, wherein the dielectric is made of a dielectric woven fabric fixed to the surface of the induction electrode with an inorganic adhesive.