JPH0714341Y2 - Ozone generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a discharge body for generating ozone.

[Prior art]

Ozone is obtained by discharging in dry air, has a strong oxidizing action, and is used for deodorization, sterilization, bleaching and the like.

As a discharge body for generating such ozone, one using ceramics as disclosed in JP-A-59-44782 and 59-44797 is considered.

This is a ceramic plate obtained by firing and integrating two unfired ceramic plates 11a and 11b as shown in FIGS.
11 is a linear discharge electrode on the surface of 11 and a planar induction electrode inside.
13 are formed respectively, and the discharge electrode 12
Is equipped with an electrode lead-out part 12a on the back surface through the end, and the induction electrode 1
3 has an electrode lead-out portion 13a on the back surface through a through hole. When a high voltage is applied to the electrode extraction parts 12a and 13a, a creeping discharge is generated from the discharge electrode 12 and ozone is generated.

Further, in such an ozone generating discharge body, since the discharge electrode 12 on the surface is easily oxidized and consumed during discharge, for example, as shown in JP-A-57-196703, glass is used in the discharge region. It is coated or applied by the applicant in Japanese Patent Application No. 63-7
As already proposed as No. 2702, it was considered to coat the discharge electrode 12 with ceramics.

[Problems of conventional technology]

However, in the case where the discharge region is covered with glass, the glass layer is also eroded by the discharge and the ozone generation efficiency is lowered, so that the applied voltage must be frequently adjusted in order to keep the ozone generation amount constant. There was a problem.

Further, in the case where the discharge electrode 12 was coated with ceramics, the discharge electrode 12 was not consumed, but it was difficult to remove the deposits on the surface of the ceramic coating layer. That is, in these discharge bodies, the discharge area was wiped periodically with gauze soaked with benzine to remove the deposits, but since the surface of the ceramic coating layer is a rough surface, the deposits are There is a problem that it is difficult to remove and the ozone generation efficiency is reduced by this deposit.

[Means for Solving the Problems]

In view of the above, the present invention relates to an ozone generating discharge body,
A discharge electrode formed on the surface of a ceramic body is covered with a first coating layer made of ceramics, and the first coating layer is further covered with a second coating layer made of glass.

〔Example〕

Hereinafter, an ozone generating discharge body according to an embodiment of the present invention will be described with reference to the drawings.

As shown in the exploded perspective view of FIG. 1 and the sectional view of FIG. 2, the ozone generating discharge body of the present invention has a linear discharge electrode 2 on the surface of a ceramic plate 1 and a planar induction inside. Electrode 3
And a first coating layer 4 made of ceramics is formed so as to cover the discharge electrode 2.
A second coating layer made of glass is formed so as to cover the coating layer 4. The discharge electrode 2 has an electrode lead-out portion 2a on the back surface through the end of the ceramic plate 1, while the internal electrode 3 has an electrode lead-out portion 3a on the back surface of the ceramic plate 1 through a through hole. These electrode extraction parts 2a, 3a
When an AC voltage is applied between the discharge electrode 2 and the induction electrode 3 through the discharge, a discharge is generated between both electrodes. At this time, since the first coating layer 4 made of ceramics is formed on the discharge electrode 2, it is not consumed by the discharge, and the second coating layer 5 made of glass covers the first coating layer 4. Since the surface is formed, the surface is smooth and the deposits are easily removed, and a constant ozone generation efficiency can be maintained for a long period of time.

In order to manufacture such an ozone generating discharge body, first, two unfired ceramic plates 1a and 1b are prepared, and one ceramic plate is prepared.
A linear discharge electrode 2 is formed on 1a, and a planar induction electrode 3 is formed on the other ceramic plate 1b by applying a paste such as tungsten or molybdenum. Next, these unsintered ceramic plates 1a and 1b are laminated, a first coating layer 4 made of ceramics is formed so as to cover the discharge electrode 2, the whole is fired and integrated, and then a second coating layer made of glass. 5 may be formed.

The ceramic plate 1 is made of alumina, zirconia,
Ceramics with a dielectric constant of about 5 to 10 such as forsterite is used. The first coating layer 4 is formed by printing, spraying, or spraying PVD on the same kind of ceramic as the ceramic plate 1 or an insulating ceramic having a similar coefficient of thermal expansion.
It is formed by means of a (physical vapor deposition) method, a CVD (chemical vapor deposition) method, etc. The first coating layer 4 not only completely covers the discharge electrode 2 but is wider than the induction electrode 3. It is formed in the range. Further, the second coating layer 5 is
It is formed by screen-printing glass such as borosilicate glass in a range covering the first coating layer 4 and then firing it.

Further, if the thickness t ₁ of the first coating layer 4 is smaller than 15 μm, pinholes are generated and the electrodes are oxidized at an early stage. Therefore, the thickness t ₁ of the first coating layer 4 is set to 15 μm or more. Was excellent. On the other hand, the film thickness t ₂ of the second coating layer 5 was 5 μm or more in order to smooth the surface, which was excellent. Furthermore, these first coating layer 4 and second coating layer 5
The film is the sum t ₁ + t ₂ thick, 1/2 and larger than the distance T between the electrodes, less likely to discharge, since the ozone generation efficiency becomes extremely poor, the sum t ₁ of thickness It was excellent that + t ₂ was 1/2 or less of the distance T between the electrodes.

Next, another embodiment of the present invention will be described.

The ozone generating discharge body shown in FIGS. 3 (a) and 3 (b) has a comb-shaped discharge electrode 2 on the surface of a ceramic plate 1 and an induction electrode 3 inside, and the discharge electrode 2 is made of ceramics. It is covered with the first coating layer 4 and further covered with the second coating layer 5 made of glass.

Further, the ozone generating discharge body shown in FIGS. 4 (a) and 4 (b) is provided with a ring-shaped discharge electrode 2 on the surface of a disk-shaped ceramic plate 1 and an induction electrode 3 inside, and each electrode is taken out. Parts 2a, 3a are formed on the surface of the discharge electrode 2 side,
The discharge electrode 2 is covered with a first coating layer 4 made of ceramics, and a second coating layer 5 made of glass is formed on the first coating layer 4.

Furthermore, in the ozone generating discharge body shown in FIGS. 5 (a) and 5 (b), the discharge electrode 2 and the induction electrode 3 are formed in a comb shape, and both are formed on the same surface of the ceramic plate 1. It is covered with a first coating layer 4 made entirely of ceramics, and the first coating layer 4 is covered with a second coating layer 5 made of glass.

As described above, the shapes of the ceramic plate 1 and the electrodes can be freely changed, but any of them can prevent the discharge electrode 2 from being consumed by the first coating layer 4 made of ceramics, and the second coating made of glass. Since the surface can be made smooth by the coating layer 5, it is possible to easily remove the deposit.

Here, the ozone-generating discharge device of the present invention shown in FIGS. 1 and 2 was actually manufactured and tested. The ceramic body 1 was made of alumina ceramics having an Al ₂ O ₃ content of 92% and the balance being MgO, SiO ₂ , CaO, etc., and the distance T between both electrodes was 0.5 mm. The discharge electrode 2 and the induction electrode 3 are both made of tungsten and have a thickness of 10 μm. The first coating layer 4 is made of alumina ceramics having the same composition as that of the ceramic plate 1, and the thickness t ₁ is 17 μm, and the second coating layer 5 is formed. Was made of borosilicate glass and had a thickness T ₂ of 6 μm.

Further, as comparative examples, those having exactly the same shape and material, in which only the alumina ceramic coating layer was formed, and those in which only the glass coating layer was formed were prepared.

A high-frequency voltage adjusted so that the initial value of the ozone generation amount was 0.11 ppm was applied to the ozone generating discharge bodies of the examples of the present invention and the comparative example, and the temperature was set to 6 ° C. and the humidity of 40%. The amount of ozone generated after being used for a month was examined, and subsequently, the amount of ozone generated after manually wiping the discharge region with gauze soaked with benzine was examined. The results are shown in Table 1.

From Table 1, in Comparative Examples 2-1 to 2-3 in which only the coating layer made of glass was formed, the ozone generation amount after 3 months was reduced by 35 to 43% from the initial value, and it was considerably wiped. Although it recovered, it was still 18 to 22% lower than the initial value. Further, when the surface after wiping is observed, it is considered that a part of the glass layer is melted due to the electric discharge, and thus the ozone generation efficiency is lowered.

Furthermore, in Comparative Examples 3-1 to 3-3 in which only the coating layer made of ceramics was formed, the ozone generation amount after 3 months was reduced by about 22 to 25% from the initial value, Even though it did not recover much, it was 12 to 15% less than the initial value. Further, although not shown in Table 1, the discharge body was taken out after this, ultrasonic cleaning was carried out, and the ozone generation amount was measured again. As a result, it was restored to the same level as the initial value. That is, in Comparative Examples 3-1 to 3-3, it is considered that the adhered matter could not be removed completely by wiping the surface with gauze, and the ozone generation efficiency decreased due to the remaining adhered matter.

On the other hand, in Examples 1-1 to 1-3 of the present invention, the ozone generation amount after 3 months was about 20 to 23% less than the initial value, and after wiping, it was the initial value. On the other hand, it was recovered to a value decreased by 0 to 4%, and excellent results were shown.

(Effect of the Invention) As described above, according to the present invention, in the ozone-generating discharge body, the discharge electrode formed on the surface of the ceramic body is covered with the first coating layer made of ceramics, and the first coating layer is further formed. By covering the electrode with the second coating layer made of glass, the electrode is prevented from being consumed by the discharge and the surface becomes a smooth surface, so that the adhered matter can be easily removed only by wiping, so that the ozone is kept constant over a long period of time. It is possible to provide an ozone-generating discharge body having features such that generation efficiency can be maintained and long-term use is possible.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a discharge body for ozone generation according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 3 (a), 4 (a), and 5 (a) are perspective views showing another embodiment of the present invention, and FIG. 3 (b) is a line BB in FIG. 3 (a). FIG. 4B is a sectional view taken along line CC in FIG. 4A, and FIG. 5B is a sectional view taken along line DD in FIG. FIG. 6 is an exploded perspective view showing a conventional discharge body for ozone generation,
FIG. 7 is a sectional view taken along the line EE in FIG. 1: Ceramic plate, 2: Discharge electrode 3: Induction electrode, 4: First coating layer 5: Second coating layer

Claims (1)

[Scope of utility model registration request] 1. A discharge body for ozone generation having a discharge electrode on the surface of a ceramic body, wherein the discharge electrode is covered with a first coating layer made of ceramics, and the first coating layer is made of a second coating made of glass. A discharge body for ozone generation characterized by being covered with a layer.