JP2002255514A - Ozone generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ozone generator whose ozone generation efficiency is high, preventing an uneven discharge due to a biased flow of a source gas in a discharge gap. SOLUTION: A ozone generation tube is composed of a cylindrical earth electrode which forms a dielectric layer 52 on the inner wall of the circumstance, and a hollow cylindrical high voltage electrode 6 which is concentrically arranged through a discharge gap 56 inside of the dielectric layer 52 of the earth electrode, and a chassis housing the ozone generation tube and having two side panels to airtightly keep a cylindrical body section whose both ends are open and an open mouth is provided, a water jacket which forms a cooling water flow passage for cooling the earth electrode is provide between this chassis and the earth electrode, and an electric source which supplies an electric power to the ozone generation tube is provided, and in the ozone generator which generates ozone by discharging source gas by passing the gas containing oxygen introduced into the chassis through the discharge gap 56, partition members are installed in the discharge gap to make the discharge gap 56 into a helical passage 30 of the source gas (for example, the helical passage is formed by a wire 31a).

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 used for water and sewage treatment, pulp bleaching, and the like, and more particularly, to a configuration of a discharge portion of the ozone generating tube.

[0002]

2. Description of the Related Art An ozone generator has a sterilizing and
It is widely used in water treatment facilities and the like utilizing the decolorizing and deodorizing power, and many proposals have been made regarding the device configuration and operation method (for example, Japanese Patent Application Laid-Open No. 9-3158).
03, JP-A-11-130409, etc.).

FIG. 5 shows the structure of a so-called single-sided cooling type ozone generator described in the above-mentioned Japanese Patent Application Laid-Open No. H11-130409, wherein FIG.
FIG. 2 is an enlarged partial cross-sectional view showing a part of the ozone generating tube. FIG. 6 shows a cross-sectional structure of an ozone generating tube of a so-called double-sided cooling type ozone generating device described in Japanese Patent Application Laid-Open No. 9-315803.

[0004] The two types of ozone generators have the same basic structure except that the cooling of the ozone generation tube is performed on one side or on both sides. This will be described below with reference to FIG.

[0005] The housing of the ozone generator comprises a cylindrical body 1 made of stainless steel having both ends opened, and side plates 21 and 22 made of two stainless steels fastened to both open ends. And is constituted by. Since the two side plates 21 and 22 and the body 1 are required to be air-tightly connected, flat ends (in FIG. 5, simply packings) 81 and 82 are provided on both ends of the opening, respectively. They are connected using fastening means.

At least one pair of support plates 41 and 42 made of stainless steel for holding a large number of ozone generating tubes are fitted on the inner surface side of the body 1 at appropriate intervals. The side plate 21 and the side plate 2 are provided on the tube wall of the body 1.
A gas inlet 11 for supplying a source gas is provided at a position intermediate between the first side support plate 41 and the side plate 22 and the second side plate 2 on the opposite side.
A gas outlet 12 for taking out the generated gas containing ozone is provided at a position intermediate with the support plate 42 on the second side.

Further, a cooling water inlet 13 for flowing cooling water is provided at an intermediate position between the two support plates 41 and 42,
A cooling water outlet 14 for discharging the cooling water is provided substantially opposite to the cooling water outlet 14. Normally, a cooling water inlet 13 is provided at a lower portion, and a cooling water outlet 14 is provided at an upper portion. Also, the side plate 2 of the body 1
A voltage introduction terminal 72 is mounted at a position close to 1.

The ozone generating tube supported by the supporting plates 41 and 42 has a cylindrical grounding electrode 5 made of stainless steel on the grounding side with both ends open, and a substantially constant gap length inside the grounding electrode 5. And a high-voltage electrode 6 disposed with a discharge gap 56 between them.

As shown in FIG. 5B, the ground electrode 5
A metal tube 51 made of stainless steel and a lining on the inner surface thereof (a glass tube is inserted inside the metal tube 51, and the glass is softened by induction heating while applying an internal pressure to form a glass layer on the inner surface of the metal tube 51. And a glass dielectric layer 52 formed by the above-described technique.

Near both ends of the lower portion of the outer surface of the high voltage electrode 6,
A protrusion 61 for holding the discharge gap 56 is formed by welding. The ozone generating tube is supported by the support plates 41 and 42 by being fitted into through holes formed in the support plates 41 and 42, and the contact portion thereof is provided by an O-ring (not shown) so that cooling water does not leak. Sealed.

One of the high-frequency voltages supplied from the high-frequency power supply 73 to the ozone generating tube is supplied from the voltage introducing terminal 72 mounted on the body 1 to the high-voltage electrode 6 of each ozone generating tube via the lead wire 71. Is done. The other of the high-frequency voltage of the high-frequency power supply 73 is connected to the ground potential point, is also connected to the body 1, and is connected to the ground electrode 5 via a lead wire (not shown).

The cooling water for cooling the ground electrode 5 of the ozone generating tube is cooled by a heat exchanger 93 and pressurized by a pump 92. Usually, the cooling water is converted into pure water by an ion exchanger (not shown) and the cooling pipe 91 is cooled. The cooling water inlet 13 is supplied to the water jacket 3 to cool the ground electrode 5, and the cooling water outlet 1
4 returns to the heat exchanger 93 through the cooling pipe 91. Industrial water is often used as the secondary cooling water.

The conventional ozone generator is configured as described above. The source gas containing oxygen supplied from the gas inlet 11 flows into the discharge gap 56 from the opening of the ground electrode 5 on the side plate 21 side, and the gas outlet Flowed out of 12.
An exhaust valve (not shown) is mounted downstream of the gas outlet 12, and by adjusting the valve opening of the exhaust valve, the pressure of the source gas containing oxygen in the ozone generator is reduced to, for example, 0.17 MPa. Has been adjusted. When a high-frequency voltage is applied from the high-frequency power supply 73 between the ground electrode 5 and the high-voltage electrode 6 of the ozone generating tube through which the source gas containing oxygen having such a pressure value flows, silent discharge occurs. Some of the source gas containing oxygen is ozonized.

The number of ozone generating tubes housed in the body 1 differs depending on the required amount of generated ozone, and if the number of ozone generating tubes is larger than one, it may be several hundred. In some cases, a glass tube is used instead of lining the glass dielectric layer as described above.

Next, the outline of the ozone generator of the double-sided cooling system will be described with reference to FIG. FIG. 6 shows the cross-sectional structure of the ozone generating tube. In FIG. 6, the same members as those shown in FIG. As shown in FIG. 6, at the end of the high voltage electrode 6,
The cooling water inlet and outlet pipes 13a and 13b are welded.

In order to supply cooling water from the outside to the high-voltage electrode 6, for example, the cooling water is introduced into a gas space between the side plate 22 on the ozone outlet side and the support plate 42 defining the water jacket 3 in FIG. Arrange two cooling water distributors for discharge,
Each cooling water distributor and the pipe 13 of the high voltage electrode 6
a and 13b are connected by an insulating tube (for details of the entire ozone generator, refer to Japanese Patent Application Laid-Open No. 9-3158).
No. 03).

[0017]

The above-mentioned conventional ozone generator has the following problems.

When comparing a plurality of high-voltage electrodes manufactured with the same specifications, it was found that the ozone concentration may be different despite the same discharge conditions.

FIG. 4 shows the relationship between the discharge power and the relative value of ozone concentration in a conventional ozone generator. The ground electrode was common, and five high-voltage electrodes were replaced to measure each ozone concentration. One of the five high-voltage electrodes showed a relatively low ozone concentration. When the surface of the high-voltage electrode is visually observed after ozone is generated, the surface of the high-voltage electrode having a relatively low ozone concentration has unevenness in discharge traces (a surface in which the stainless steel surface is oxidized and turns brown). was there.

The reason why the discharge trace becomes uneven is considered as follows. The dimensions of the high voltage electrode are about 7 cm in diameter and about 1 m in length. For manufacturing reasons, the electrodes are bowed in an arcuate manner, which results in partially different discharge gap lengths. When the source gas moves inside the discharge gap, it flows easily in a wide place and hardly flows in a narrow place, so that the source gas drifts in the discharge gap. For these reasons, it is considered that a high-voltage electrode having a large bend tends to have a non-uniform discharge and a low ozone concentration.

As a solution to the above-mentioned problem, it is sufficient to use only a high-voltage electrode having a small bend. However, in this case, the yield is reduced and a problem arises in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to prevent non-uniform discharge caused by drift of a raw material gas in a discharge gap, and to improve ozone generation efficiency. To provide an ozone generator with high performance.

[0023]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical tube-shaped ground electrode having both ends opened and a dielectric layer formed on an inner peripheral surface, and a dielectric layer of the ground electrode. At least one pair of ozone generating tubes each including a hollow cylindrical high-voltage electrode concentrically provided with a discharge gap inside, and a cylindrical body having both ends opened and a tube for hermetically closing the openings.
A housing having two side plates and incorporating the ozone generating tube;
A water jacket provided between the housing and the ground electrode to form a cooling water flow path for cooling the ground electrode, and a power supply for supplying power to the ozone generating tube, and introduced into the housing. In an ozone generator for flowing a source gas containing oxygen into the discharge gap and generating ozone by discharging the source gas, a partition member for forming the discharge gap as a spiral flow path of the source gas is formed in the discharge gap. (The invention of claim 1).

[0024] According to the above, the raw material gas can be spirally and substantially uniformly circulated in the discharge gap by the partition member. As a result, the drift of the source gas is eliminated, and a uniform discharge is generated on the entire surface of the electrode, so that the ozone generation efficiency can be improved.

Further, as an embodiment of the above invention, the following inventions 2 and 3 are preferable. That is, in the ozone generator according to claim 1, the spiral flow path is a flow path formed by spirally winding a wire as a partition member around an outer periphery of a high-voltage electrode. invention).

Further, in the ozone generating apparatus according to the second aspect, the wire has a rectangular or circular cross section, and the material thereof is stainless steel (the invention of the third aspect). According to the invention of claims 2 and 3,
The desired ozone generator can be obtained with a simple structure.

According to the invention, the projection 6 for holding the discharge gap 56 shown in FIGS.
1 is unnecessary because the partition member can also serve the function.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the drawings, the same components as those of the conventional device are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1 is a partially enlarged plan view of a high-voltage electrode of an ozone generator according to the present invention. In this embodiment, a stainless steel flat wire 31 is connected to the high voltage electrode 6.
An example of spirally winding around the outer periphery of the head is shown.

FIG. 2 is a partially enlarged sectional view of an ozone generating tube of the ozone generating apparatus according to the present invention. In the embodiment shown in FIG. 2, a rod-shaped wire 31a made of stainless steel and having a circular cross section is used.
Is spirally wound around the outer periphery of the high voltage electrode 6.

In the embodiment of FIGS. 1 and 2, as shown in FIG. 2, the discharge gap 56 surrounded by the glass dielectric layer 52 and the high-voltage electrode 6 is formed by the wire 31 or 3.
1a forms a structure partitioned into a spiral continuous space, and a spiral flow path 30 is formed. This spiral channel 3
Reference numeral 0 denotes a case where a stainless steel wire 31 or 31a having a thickness or an outer diameter of, for example, 0.3 mm is helically wound at a pitch of, for example, 5 cm and fixed to the outer periphery of the high voltage electrode 6, and then inserted into the ground electrode 5. Formed.

FIG. 3 shows the ozone generation characteristics showing the effect of the present invention. The gas pressure is 0.17 MPa, the cooling water temperature is 10 ° C.
The results of measuring the relationship between the discharge power and the ozone concentration under the conditions described above are shown. Similar to FIG. 4, the ozone concentration increases as the discharge power increases, but the ozone concentration at a discharge power of 1000 watt was normalized to 100. A total of five high voltage electrodes were used in the experiment, which are the same as the high voltage electrodes used in the conventional ozone generation characteristics of FIG. A wire was wound around the surface of the high-voltage electrode, and the same measurement was performed. As a result, almost the same ozone generation characteristics were obtained for all five wires. As a result of visually observing the surface of the high-voltage electrode, the discharge trace was uniform for all the electrodes.

The effect based on the above embodiment can be obtained irrespective of whether or not the high-voltage electrode 6 is cooled, that is, whether single-sided cooling or double-sided cooling is performed. Further, the same effect can be obtained even with an ozone generator of a type in which a glass tube is inserted inside a ground electrode.

[0034]

As described above, according to the present invention, a cylindrical tubular ground electrode having both ends open and a dielectric layer formed on the inner peripheral surface, and a discharge gap inside the dielectric layer of the ground electrode are provided. At least one pair of ozone generating tubes comprising a hollow cylindrical high-voltage electrode concentrically installed, a cylindrical body having both ends opened, and two side plates for hermetically closing the openings. A housing containing the generation tube, a water jacket provided between the housing and the ground electrode to form a cooling water flow path for cooling the ground electrode, and a power supply for supplying power to the ozone generation tube. In the ozone generator, a source gas containing oxygen introduced into the housing is passed through the discharge gap, and ozone is generated by discharging the source gas.
By disposing a partition member for forming the discharge gap as a spiral flow path of the raw material gas in the discharge gap, particularly, the spiral flow path has a wire as a partition member on the outer periphery of a high-voltage electrode. By using a flow path formed by helically winding, it is possible to provide a simple structure and prevent non-uniform discharge due to the non-uniform flow of the raw material gas in the discharge gap, and thus achieve high ozone generation efficiency. A generator can be provided.

[Brief description of the drawings]

FIG. 1 is a partially enlarged plan view of a high-voltage electrode according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of an ozone generating tube according to another embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between discharge power and an ozone concentration relative value according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between discharge power and an ozone concentration relative value related to a conventional ozone generator.

FIG. 5 is a diagram showing an example of the configuration of a conventional ozone generator (single-sided cooling system).

FIG. 6 shows a different conventional ozone generator (double-sided cooling system).
Partial enlarged cross-sectional view of an ozone generating tube related to an example of the configuration of

[Explanation of symbols]

1: trunk, 3: water jacket, 5: ground electrode, 6: high voltage electrode, 30: spiral flow path, 31, 31a: wire, 5
2: dielectric layer, 56: discharge gap.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takaya Nishikawa 1-1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term in Fuji Electric Co., Ltd. 4G042 CA01 CC03 CC11 CC13 CC16 CC20 CC21 CE04

Claims (3)

[Claims] 1. A cylindrical tube-shaped ground electrode having both ends open and a dielectric layer formed on an inner peripheral surface, and a hollow cylindrical high voltage concentrically installed through a discharge gap inside the dielectric layer of the ground electrode. A housing having at least one set of ozone generating tubes including electrodes, a cylindrical body having both ends opened, and two side plates for hermetically closing the openings, and housing the ozone generating tube; A water jacket provided between the housing and the ground electrode to form a cooling water flow path for cooling the ground electrode, and a power supply for supplying power to the ozone generating tube, and oxygen introduced into the housing. In the ozone generator which flows the raw material gas containing into the discharge gap and generates ozone by discharging the raw material gas, a partition member for making the discharge gap a spiral flow path of the raw material gas is formed in the discharge gap. O which is characterized by Down generator. 2. The ozone generator according to claim 1, wherein the spiral flow path is a flow path formed by spirally winding a wire as a partition member around an outer periphery of a high voltage electrode. A characteristic ozone generator. 3. The ozone generator according to claim 2, wherein the wire has a rectangular or circular cross section, and the material thereof is stainless steel.