JP4959437B2 - Ozone generator. - Google Patents

Description

  The present invention relates to a technology of an ozone generator that generates ozone gas by applying a high voltage between two opposing electrodes and passing oxygen or air through a discharge space that occurs between the two electrodes formed.

Ozone is applied in many fields such as sterilization, deodorization, and decolorization due to its strong oxidizing power, but in order to generate ozone, as shown in the silent discharge ozone generator of FIG. Are provided so as to face the plate electrodes a and b in parallel. One electrode a covers a dielectric d such as a ceramic, and the dielectric d and the other electrode b form a discharge space e. There is known an ozone generator that applies high voltage from a high-frequency, high-voltage AC power source c, discharges in a discharge space e, and generates ozone by passing air or oxygen gas f through the discharge space e.
This ozone generator is capable of silent discharge because of its large discharge area and has been used for ozone generation for a long time, but because of the high frequency and high voltage applied between both electrodes, the amount of power consumption becomes a problem, In addition, since most of the electric power is converted into heat and the ozone generated by the heat is decomposed, there is a problem that the efficiency is low, and furthermore, a power supply device for generating a high voltage and a discharge unit that receives it. Since a water cooling device or the like for cooling the generated heat is required, there is a problem that the overall equipment becomes relatively large.
Therefore, a structure for increasing discharge efficiency is required because of the need for downsizing and low power consumption, and a technique for providing a large number of protruding electrodes as disclosed in Patent Document 1 and shown in the silent discharge ozone generator of FIG. Is provided. However, although it consumes less power than both plate electrodes, it still consumes more power, and there is a demand for the development of an ozone generator that can save further power consumption.

Japanese Patent Laid-Open No. 08-59213

  An object of the present invention has been made in view of the above-described problems. In an ozone generator having a large number of protruding electrodes, an ozone generator that can be reduced in size and weight, has lower power consumption, and has good ozone generation efficiency. Is to provide.

By the way, Patent Document 1 discloses a technique that uses a so-called multi-point electrode having a large number of protrusions, thereby reducing power consumption compared to both flat-plate electrodes. When the density of protrusions becomes extremely dense, the power consumption decreases.However, when the denseness becomes finer and approaches the flat plate, the power consumption increases and the optimum density of the protrusion density exists. It was. And the optimum density was found to vary depending on the metal of the electrode.
In the research process, many conventional protruding electrodes were usually made of copper, brass or the like having good electrical conductivity, but the tip of the protruding electrode for generating ozone has a sharp needle tip shape. In this needle tip shape, the tip end is severely worn by the discharge, and if the tip shape and the height of the projection change due to the wear, the expected discharge cannot be obtained, and the variation between the projections also increases. There is a problem that the efficiency of discharge is reduced, especially the wear of the tip at the beginning of use is severe, the ozone generation capacity fluctuates greatly during this period, it becomes difficult to control the amount of ozone generated, the degree of tip wear As a result, it was found that the ozone generation efficiency also decreased.

For this reason, when a discharge device using a needle-like protruding electrode made of stainless steel (SUS) other than copper or brass was continuously operated, the amount of ozone generation decreased sharply from the start of discharge until 5 days and was unstable. However, after that, it became clear that the amount of ozone generated was stable, and the amount of ozone generated was maintained at a high level. When the state of the tip of the protruding electrode in a stable state is enlarged, the corner of the tip starts to wear out and becomes stable in an R shape or a flat shape. It has been found that ozone generation efficiency is good and stable performance is maintained.
Furthermore, in order to increase the ozone generation concentration, it is necessary to reduce the gap at the base of the projection, which is a part other than the discharge space, as much as possible, and to efficiently pass the raw material air and oxygen gas to the discharge space. However, when the temperature of the apparatus becomes high due to discharge, the ozone gas generated at the corner is thermally decomposed, so the vicinity of the discharge space must be cooled. Therefore, since the projection shape also serves as a cooling fin of the electrode, paying attention to the gap at the base of the projection, leaving only the minimum gap, the projection is a prism, pyramid, cone shape and the surface area It has been found that if the void at the base of the protrusion is reduced by increasing or decreasing the ratio, the ratio of the passing amount of air or oxygen gas in the discharge space can be increased while maintaining the cooling effect.

The present invention has been made on the basis of the above-mentioned knowledge in order to solve the above-mentioned problems, and the ozone generator of the invention of claim 1 has a large number of surfaces covered with a dielectric material on a surface facing a smooth flat electrode. A discharge space is formed by a projection electrode having a plurality of projections, and the projection electrodes are made of stainless steel. The shortest distance between the tip of each projection of the projection electrode and the flat electrode is made equal, and the density of the projections is 5.8. ˜33.7 / cm ² , high voltage is applied to the flat electrode and the protruding electrode, and oxygen or air is passed through the discharge space to generate ozone.
According to a second aspect of the present invention, in the ozone generator according to the first aspect, the base of the flat electrode and the base of the multi-projection electrode facing each other are flat.
According to a third aspect of the present invention, in the ozone generator according to the first aspect, the base of the multi-projection electrode has a columnar shape, and the flat electrodes facing each other have a cylindrical shape surrounding the columnar projection electrode. .
According to a fourth aspect of the present invention, in the ozone generator of any one of the first to third aspects, as the projections of the multi-projection electrode become closer to the base of the substrate, the cross-sectional area is increased, and the tip of the projection is 0.1 to 0.7 mm ² It has the flat part of this.
According to a fifth aspect of the present invention, in the ozone generator according to any one of the first to fourth aspects, the protruding electrode has a weight shape having a cross-sectional area that is larger as it is closer to the base of the base, and the interval between the bases of adjacent protruding electrodes is 1. It is characterized by being 0.0 mm or less.

According to the first to third aspects of the present invention, since the protruding electrodes are made of stainless steel in the ozone generator, the wear due to discharge can be reduced, and the density of the protrusions of the large number of protruding electrodes is 5.8 to 33.7 / With the multi-point shape of cm ² , the number of discharges can be increased, the discharge start voltage can be lowered, the ozone generation efficiency can be increased, the power consumption can be reduced, and the power circuit can be downsized. .
According to the invention of claim 4, in addition to the effect of claim 1, the shape change due to the wear of the protrusion is reduced, and the ozone generation amount can be stabilized from the beginning of operation, and the ozone generation amount can be stabilized for a long time. Thus, the control of the power supply is facilitated.
According to the invention of claim 5, in addition to the effects of claims 1 to 4, since the surface area of the electrode is widened, the heat dissipation effect to dissipate heat generated by the discharge is great, and the adjacent electrodes It is cooled by the flow of raw material air etc. passing between and the generated ozone gas. As a result, it is possible to increase the ozone generation efficiency by suppressing the decomposition of ozone by heat, and the generation efficiency (ozone generation amount per unit power consumption) is good. The size can be reduced.

A preferred embodiment of the ozone generator of the present invention will be described with reference to the drawings. First, the shape of a single protrusion of a multi-projection electrode will be described.
The tip of each electrode of the protruding electrode, which is the discharge electrode, can make use of the characteristics of the protrusion if it is sharp, but actually the tip starts to wear out due to the influence of the discharge from the beginning of the discharge and becomes rounded, but eventually, It has been found that the progress of wear becomes very slow when the size of the R shape or the planar shape progresses to a certain extent, but the discharge is unstable during the progress of wear at the initial stage of discharge, and as an ozone generator It is difficult to control, and the height is uneven, so the number of discharges and discharge efficiency may be reduced.
In the embodiment of the present invention, the tip is given a certain R shape or chamfering shape in advance so as to ensure stable discharge and high level discharge efficiency from the beginning. In addition, if the area of the flat portion at the tip is made too large, it becomes close to a flat plate electrode, and therefore it is necessary to planarize it so as not to lose the characteristics of the “projection” electrode.
Also, if the cross-sectional area at the tip and the cross-sectional area up to the base are the same as in the case of a cylinder or a prism, the wear will continue to the base, so the cross-sectional area of the protrusion must increase as it approaches the base. It is preferable that the top of the cone, polygonal pyramid, or polygonal column is a polygonal pyramid, and these shapes may be selected as appropriate.

As an example of the shape of the protruding electrode that satisfies the above conditions, a quadrangular pyramid embodiment 1 shown in FIG. 3 will be described.
As shown in FIG. 3 (a), a quadrangular pyramid-shaped protrusion that becomes thicker toward the bottom (base) is set to have a diagonal angle α = 20 ° to 90 ° at the tip. In Example 1, in FIG. As shown in the figure, the flat portion 11 near the tip is made thicker as it goes downward, so that it stops at a position where there is wear due to discharge and does not proceed easily. The area of the flat portion 11 at the tip is 0.5 mm ² and 0.1 to 0.7 mm ² (see Examples 2 to 3 [Graph 2] described later).
In other words, the tip of the protrusion is worn out because the electric charge is concentrated and discharged at one sharp point on the tip of the protrusion, and the sharp point is worn away, but as a result, the entire shape eventually becomes an R shape, and if it progresses further Theoretically, it is considered to be a flat surface, but the closer to the flat surface, the more difficult it is to discharge, and as a result, wear does not easily progress.
In the first embodiment, the tip angle α = 30 °. However, if the tip angle is too large, it is difficult to discharge from the beginning. Therefore, there is a limit naturally, and the tip angle α = 20 ° to 90 ° is effectively used. it can.

As described above, in Example 1 of the present invention, based on the above-described knowledge, a stable discharge-shaped projecting electrode is provided in advance, so that stable discharge can be performed over a long period of time, and other projecting electrodes can be used. The discharge efficiency is maintained at the same level with the same height. Furthermore, copper or brass is preferable as the material from the viewpoint of electrical conduction. However, wear due to discharge is large, and in this embodiment, stainless steel (SUS) is used in order to reduce wear and lengthen the use period. .
The standard of stainless steel used in this experiment is SUS304. If the standard is stainless steel (SUS), the standard is austenite such as SUS303, SUS304, SUS305, SUS309, SUS310, SUS316, and ferrite such as SUS409, SUS410, and SUS430. It can be used.

Further, a large number of protruding electrodes in which the protruding electrodes are assembled will be described. The tip of Example 1 has an unprocessed shape, that is, the shape of FIG. 3A with a sharp tip angle α = 30 °. Reference Example 1 is shown in FIG. 4 in which 1465 protruding electrodes made of stainless steel are provided on a stainless steel substrate 2 having a width of 60 mm and a length of 220 mm as shown in FIG. The example is an example, not a reference example.), And an electrode having a brass base with a similar shape provided with a protrusion is referred to as a reference example 2, and the ozone generator of FIG. 5 (however, FIG. 5 shows an electrode having a flat tip portion). (Example 1), not a reference example), and the initial change in the amount of ozone generated was examined by continuous operation, and [Graph 1] in FIG.
As can be seen from [Graph 1], when the stainless steel (SUS) needle-like projection electrode discharge device of Reference Example 1 is continuously operated, the amount of ozone generated decreases sharply from the start of discharge until the 5th, and is unstable. After that, the amount of ozone generated was stable. When the state of the tip portion of the projection in a stable state is enlarged, the corner of the tip portion begins to wear and becomes an R shape, and the flat area is a flat portion of 0.1 to 0.7 mm ² . . On the other hand, the brass of Reference Example 2 is thought to be due to the intense wear and tear caused by the discharge, but it can be seen that the amount of ozone generated is drastically changed and the control is extremely difficult. In Reference Example 2, the change in the amount of ozone generation is drastic because the heights of the protrusions are not uniform.
Therefore, it can be seen that if the material of the protruding electrode is stainless steel, stable performance can be obtained for a long time.

FIG. 7 [Graph 2] shows an appropriate value for the area of the flat portion.
The protrusion electrode 1 in Example 1 has the shape shown in FIG. 3B, the area of the flat portion 11 is 0.5 mm ² , and the opposing angle α is 30 ° from the base of the base 2 of each protrusion (FIG. 4). The height is 5 mm, and as shown in FIG. 4, 1465 stainless steel protrusions are aligned vertically and horizontally on the stainless steel substrate 2, and the protrusion density is 11.1 / cm ^2. It is in the state.
As shown in FIG. 5, the dense protruding electrodes 1 are fixed to the upper frame 51 on the upper side of the ozone generator, and the surface covered with the opposing ceramic dielectric 4 is the flat electrode 3 on the lower lower side. A discharge space e is fixed to the frame 52, the dielectric 4 (flat electrode 3) and the protruding electrode 1 are in parallel and the distance between the protrusion tips is 1.5 mm. Air (or oxygen gas) is formed in the discharge space e. ). Further, a lead wire 21 is connected from the base 2 of the protruding electrode 1 and a lead wire 31 is connected from the flat electrode (base) 3, and a high voltage is applied to both electrodes by a high frequency high voltage AC power source as in the conventional device. Yes.
Here, if the dielectric 4 is too thick, the distance between the protruding electrode 1 and the flat electrode 3 increases, and a large amount of power is required for discharge, resulting in an increase in power consumption. The ceramic dielectric 4 is desirably as thin as possible. However, since there is a limit in terms of strength, a thickness of 2 mm is used in the embodiment. If the dielectric is made of ceramic, a thickness of 1.5 to 2 mm can be used.
The gap distance between the ceramic dielectric 4 covering the flat electrode 3 and the protrusion tip of the protrusion electrode 1 is 1.5 mm. Smaller gap distances are easier to discharge and consume less power. In order to facilitate discharge, an interval distance of 0 mm is possible, but the amount of ozone generated is small. In addition, the amount of ozone generated increases as the distance increases, but at the same time, the power consumption increases significantly. If the distance is 2.5 mm or more, the power consumption becomes too large and is not practical. From these facts, the interval distance can be set to 0 to 2.5 mm, but the interval in this embodiment is set to 1.5 mm in consideration of the balance between the amount of ozone generation and the power consumption. The distance between the electrodes is 1.5 mm + 2 mm = 3.5 mm.

The side surfaces of the adjacent protrusions do not contribute to the discharge, but form a cooling space g in which the protrusion electrode 1 is cooled by touching air or the like. Similarly, the discharge state was examined at 0.1 mm ² in Example ² and 0.7 mm ² in Example 3, but it was the same as Example 1 except for the size of the flat portion 11 at the tip. In this experiment, the supply air to the ozone supply device is 5 liters / min, and this value is used unless otherwise noted in the subsequent experiments.
From this [Graph 2], it can be seen that in Examples 1, 2 and 3 that maintain a stable state, the amount of ozone generation is large when the area of the flat part at the tip of the protrusion of Example 2 is 0.1 mm ^2. However, when the wear is enlarged and inspected, it is more than in Example 1 and Example 3, and conversely, if the flat surface of the tip of the protrusion becomes large, it becomes difficult to discharge, and Comparative Example 1 is also made of stainless steel. If it is 0.0 mm ² , the amount of ozone generated is small and the efficiency is low. Therefore, the area of the flat portion 11 at the tip of the protrusion in the protrusion electrode 1 is preferably 0.1 to 0.7 mm ² , and if the area is increased beyond this, the performance becomes inferior to the flat plate electrode, so that the wear is taken into consideration. More preferably around ² .

[Protrusion density]
The amount of ozone produced is roughly proportional to the power consumption if the energy loss of heat dissipation is ignored, so the amount of ozone produced can be compared by the power consumption. For example, as can be seen in [Graph 2], discharge can be started at a low voltage, and more ozone can be generated at a low voltage over the whole. Active species can be generated efficiently by reducing the amount of charge in the discharge and generating a large amount of discharge. Therefore, if the number of protrusions is increased and the number of microdischarges is increased, the amount of ozone generated can be increased.
However, if there are too many protrusions, it will approach the “plane” accordingly, and the number of micro discharges will decrease, and the effect of the “protrusion” electrode will be impaired, and the protrusion density is limited. Conversely, if the number of protrusions is small, this will not change from the flat surface.

As a result of the study by the present inventors, it has been found that there is an optimum value or an optimum range for the density of the number of projections that are densely discharged in the discharge electrode, and the density varies depending on the material of the electrode. .
As the material of the protruding electrode that obtains stable discharge performance for a long period of time, stainless steel is optimal as the electrode wear is small, and the protruding shape is optimally conical, polygonal pyramid, or polygonal pyramid with a flat part at the tip It is. Here, with respect to the optimum protrusion density, the relationship between the input energy density and the amount of ozone generation was examined by changing the size proportionally in the shape of Example 1 and changing the density. Graph 3].
In this [Graph 3], Example 1, Examples 4 to 6, Comparative Example 2 and Comparative Example 3 are all quadrangular pyramid shapes, tip inclination angle α = 30 °, tip flat area 0.5 mm ^2. The base electrode was manufactured by cutting on a stainless base 2 having a width of 60 mm and a length of 220 mm, and only the protrusion density was changed as follows.
Example 1 ··· 1465: protrusion density 11.1 / cm ²
Example 4... 765: protrusion density 5.8 / cm ²
Example 5 ··· 3075: protrusion density 23.3 / cm ²
Example 6 • 4448: protrusion density of 33.7 / cm ²
Comparative Example 2 ... 396: Protrusion density: 3.0 / cm ²
Comparative Example 3 8092: Protrusion density 61.3 / cm ²
As can be seen from this [Graph 3], the amount of ozone generated at 17 J / L is 0.3 g / h in the electrode of Comparative Example 2 with a small protrusion density of 3.0 / cm ² , and the protrusion density of Example 1 is 11 g / h. is about 1/3 as compared with .1 present / cm ² 0.9 g / h, to the contrary, 61.3 present / cm ozone generation amount at ² 0.5 g / h in Comparative example 3 the projection density is large Thus, it is almost half of the projection density of 11.1 pieces / cm ² in Example 1 compared to 0.9 g / h.
Therefore, from [Graph 3], the protrusion density is preferably 5.8 / cm ^{2 in} Example 4 to 33.7 / cm ^{2 in} Example 6, more preferably 23.3 in Example 5 to Example. 6 of 33.7 pieces / cm ² .
Note that the range of the protrusion density varies depending on the material of the protrusion. For example, in brass with good electrical conductivity, 1000 pieces: protrusion density 7.6 pieces / cm ^{2 to} 2000 pieces: protrusion density 15.2 pieces / cm ² . there were.

[Cooling action]
As shown in FIG. 5, the protruding electrode 1 of the embodiment discharges from a large number of protruding tip portions, so that it is heated when used for a long time, and the temperature of the discharge space rises. In the ozone generator, when the temperature around the electrode rises, the ozone generation efficiency tends to decrease, and this is shown in [Graph 4] in FIG.
From this graph 4, the temperature rises from 13 ° C. to 14 ° C. and 20 ° C., and when it reaches 50 ° C., the ozone generation efficiency decreases to about 1/4 to 1/6, which is caused by ozone generated by high heat. Is considered to be decomposed.
In addition, as described above, adjacent side faces of the quadrangular pyramids that are the protruding electrodes of Example 1 do not contribute to the discharge, but form a cooling space g that cools the protruding electrodes 1 by touching air or the like. This will be described with reference to [Graph 5] in FIG. 10. Comparative Example 4 of the projection electrode having the projection density of 11.1 / mm ² and the projection height of 5 mm in Example 1 and the flat electrode is shown in FIG. When the temperature when air was fed at 40 liters / min was measured, the temperature in Example 1 was maintained at about 70 ° C., but in Comparative Example 4 of the flat plate, the temperature rose to 120 ° C. Since the multi-protrusion shape of Example 1 has a cooling effect, it is particularly effective in an ozone generator.
In order to increase the air flow area, the shape that enhances the cooling effect is larger than the shape having no gap at the base of adjacent protrusions in FIG. 11 (a), as in Example 7 in FIG. 11 (b). If a gap of 0.5 mm is provided at the base, the cooling effect is further enhanced.
However, if the cooling space g is too large, the cooling space does not contribute to the discharge, and the source gas such as air and oxygen that passes through the space does not contribute to ozone generation. It is necessary to balance the generation amount.

Therefore, as in Example 8 of FIG. 12, the cross-sectional area (volume) is increased by making the shape of the gray portion rather than the cross-sectional shape (shaded portion in the drawing) of FIG. Reduces the cooling space, prevents the flow of useless air that is not involved in discharge or cooling, conversely increases the air contact area on the side surface of the protrusion, and further, with a 0.5mm width at the base of the pair of protrusions A groove 12 having a depth of about 4.0 mm from the tip may be provided to increase the area itself contributing to cooling. In this case, the groove width is preferably 0.3 mm to 1.0 mm or less, and the depth is preferably about 3 to 5 mm from the tip of the protrusion. More preferably, as in Examples 7 and 8, the groove width is 0.5 mm. A depth of about 4 mm is good.
In Example 1, the electrode shape having a width of 0.5 mm and a depth of 4 mm from the tip of the protrusion as in Example 8 can be used in the summer without using a separate water-cooled cooling device. The amount of ozone generated did not decrease even when operated continuously for 30 days at a maximum room temperature of 45 ° C. and a maximum humidity of 95%.
If the groove width exceeds 1.0 mm, the proportion of air that contributes to ozone generation decreases and the concentration of ozone decreases, and if the groove width is 0.3 mm or less, it becomes difficult for air to pass through and the cooling effect decreases. Since ozonolysis occurs, a separate cooling device is required.

Next, in each of the above-described embodiments, the tip angle α = 20 ° to 90 ° with a quadrangular pyramidal projection that becomes thicker as it goes downward as shown in FIG. However, if a substantially flat portion is formed, it may be hemispherical as in the ninth embodiment shown in FIGS. 13A and 13B. In this case, the hemispherical tip 11a of the protruding electrode 1a is used. Thus, assuming the virtual plane h, the area of the quadrangular (polygonal) plane formed on the extension of each side of the quadrangular pyramid may be 0.1 to 0.7 mm ² .
Moreover, although the base part of the electrode which each Example opposes is flat form, it is good also as a cylindrical shape like Example 10 shown in FIG. 14, and protrusion density is 5.8-33.7 pieces in the center cylinder 2b. / Cm ² protruding electrode 1b, a cylinder is formed so as to form a discharge space e around the central protruding electrode 1b, a flat electrode (base) 3b having a flat surface is provided on the inner wall of the cylinder, and The dielectric 4b may be provided so as to cover the inner wall.
Further, conversely, the inner wall on the cylindrical side may be a protruding electrode, the central column (2b) side may be a flat electrode with a flat surface, and the center column 2b as an electrode may be covered with a dielectric.
In any case, equalizing the shortest distance between the tip of each protrusion of the protrusion electrode and the flat electrode increases the actual discharge area.

As described above, in this example, since the protruding electrodes are made of stainless steel in the ozone generator, wear due to discharge can be reduced, and the density of the protrusions of the multiple protruding electrodes is 5.8 to 33.7 / cm 3. ² and the multi-point shape increases the number of discharges, lowers the discharge start voltage, increases ozone generation efficiency, reduces power consumption, reduces the power circuit size, and changes in shape due to wear of protrusions. The amount of ozone can be reduced and the amount of ozone generated can be stabilized from the beginning of operation. Furthermore, the ozone generation amount can be stabilized for a long period of time, and the supply power can be easily controlled. In addition, since the surface area of the electrode is increased, the heat dissipation effect of radiating the heat generated along with the discharge is great, and cooling is performed by the flow of the generated ozone gas and the raw material air passing between adjacent electrodes. As a result, it is possible to increase ozone generation efficiency by suppressing the decomposition of ozone by heat, and by improving the generation efficiency (ozone generation amount per unit power consumption), power consumption can be reduced by that much, At the same time, the power supply can be downsized.
Needless to say, the present invention is not limited to the above-described embodiments as long as the features of the present invention are not impaired. For example, although the shape of the protrusion is a quadrangular pyramid in the embodiment, the upper portion of the cone, polygonal pyramid, or polygonal column is not limited to the polygonal pyramid, and the cross-sectional area increases from the tip of the protrusion toward the base of the base. Any shape is acceptable.

It is a principle figure explaining the action | operation of the conventional silent discharge type ozone generator. It is a principle figure explaining the action | operation of the silent discharge type ozone generator of a prior art. FIGS. 3A and 3B are diagrams for explaining a tip shape of a protruding electrode in Example 1 (Examples 1 to 8) of the present invention, FIG. 3A is a protruding part before processing, and FIG. It is the perspective view which showed the state of the flat part. FIG. 4 (a) is a plan view, FIG. 4 (b) is a side view from the front, and FIG. 4 (c) is from the side. FIG. It is sectional drawing of the whole ozone generator of the Example of this invention. It is a figure of [graph 1] of the state of the initial attenuation of the ozone generation amount in the reference examples 1 and 2. It is a figure of [a graph 2] of the amount of ozone generation of the example of the present invention and the comparative example by the difference in the size of the flat part of electrode shape. It is a figure of [graph 3] of the input energy density of the Example and comparative example of this invention, and ozone generation amount. It is a figure of [graph 4] of the electrode ambient temperature and the production | generation efficiency of ozone in the Example of this invention. It is a figure of [graph 5] of the cooling effect of the electrode shape of Example 1 and Comparative Example 4. 11A and 11B are diagrams illustrating a cooling structure according to an embodiment of the present invention. FIG. 11A illustrates a cooling effect at the base of adjacent protrusions, and FIG. 11B illustrates a cooling effect by providing a gap at the root. FIG. It is sectional drawing of another Example which raises the cooling effect of the Example of this invention. FIG. 13 (a) is a perspective view of another embodiment of the tip of the protruding electrode of the present invention, and FIG. 13 (b) is a side view thereof. It is a perspective view of another Example of this invention.

Explanation of symbols

e ... discharge space, g ... cooling space, h ... virtual plane 1, 1a, 1b ... projecting electrode, 11, 11a ... flat part, 12 ... groove 2 ... projection Electrode base, 2b ... Center cylinder (projection electrode base), 21 ... Lead wire,
3, 3b ... Flat electrode (base), 31 ... Lead wire,
4, 4b ... Dielectric
51..Upper frame, 52 ... Lower frame,

Claims (5)

A discharge space is formed by a flat electrode having a smooth surface covered with a dielectric and a protruding electrode having a large number of protrusions on the surface facing the surface,
The protruding electrode is made of stainless steel,
The shortest distance between the tip of each projection of the projection electrode and the flat electrode is made equal, and the density of the projections is set to 5.8 to 33.7 / cm ^{2. A} high voltage is applied to the flat electrode and the projection electrode,
An ozone generator that generates ozone by passing oxygen or air through the discharge space.   2. The ozone generator according to claim 1, wherein the base of the flat electrode and the base of the multiple protruding electrodes facing each other have a flat plate shape.   2. The ozone generator according to claim 1, wherein the base of the multiple protruding electrodes has a cylindrical shape, and the opposed flat electrodes have a cylindrical shape surrounding the cylindrical protruding electrodes. 4. The projection of the multi-projection electrode has a cross-sectional area that increases as it approaches the base of the base, and the tip of the projection has a flat portion of 0.1 to 0.7 mm < ² >. Ozone generator.   5. The protruding electrode according to claim 1, wherein the protruding electrode has a spindle shape with an area increasing as it approaches the base of the base, and the interval between the adjacent protruding electrodes is 1.0 mm or less. Ozone generator.

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