JP2009234861A - Ozonizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ozonizer which is hard to be corroded and has high reliability. <P>SOLUTION: In an ozonizer which has discharge tubes each having such a constitution that one end is closed, a metal film is formed on the inner surface and a cylindrical high voltage electrode is provided, and a ground electrode tube arranged concentrically on the outside of the discharge tubes across a discharge gap, in a can-like body 1 constituted as an air-tight vessel, cools the outer peripheral side of the ground electrode tube by cooling water, applies a high voltage to the high voltage electrode, and generates ozone in a raw material gas containing oxygen made to flow in the discharge gap, the ozonizer is characterized in that the can-like body is partitioned into two spaces, the discharge tubes and the ground electrode tube are arranged in each of the two spaces, and an outlet pipe 12 for the ozonized gas is installed on the closed side of the discharge tubes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ozone generator, and more particularly to an ozone generator capable of avoiding corrosion and deterioration of internal components of a discharge tube.

  In general, an ozone generator generates ozone by flowing a raw material gas between electrodes arranged in an airtight container. The electrode is a metal electrode and a dielectric electrode, or a pair of dielectric electrodes constitutes a discharge electrode, and a spacer is inserted between them to form a minute discharge gap. Then, an ozone raw material gas is caused to flow in the discharge gap between the two electrodes, and a high voltage is applied between the two electrodes to generate a silent discharge in the discharge gap, and the silent discharge generates ozonized gas.

In the ozone generator described above, the inside of the ozone generator generates NOx in addition to ozone, which is a very corrosive environment. The inside of the ozone generator is 7 by the heat of silent discharge.
Since the temperature may be higher than 0 ° C., corrosion is likely to proceed from both temperature and corrosive gas.

  FIG. 4 is a cross-sectional view showing a schematic configuration of a conventional ozone generator. As shown in FIG. 4, the ozone generator has an airtight container 1, and in the internal space of the airtight container 1, a plurality of ground electrode tubes 2 having both ends opened are arranged in parallel to each other. A cooling water chamber 3 is formed on the outer periphery of the ground electrode tube 2.

  Inside the ground electrode tube 2, a discharge tube 4 having a metal film formed therein is inserted and mounted concentrically from both ends of the ground electrode tube 2. A spacer 5 is installed between the ground electrode tube 2 and the discharge tube 4, and a discharge gap 6 is formed between the ground electrode tube 2 and the discharge tube 4 by the spacer 5.

  A source gas containing oxygen is supplied from the source gas inlet pipe 11 into the hermetic vessel 1, flows in the discharge gap 6 formed between the discharge tube 4 and the ground electrode tube 2, and exits the ozonized gas 12. Spill from. On the other hand, cooling water is supplied to the cooling water chamber 3 from the cooling water inlet pipe 13, and the cooling water is discharged from the cooling water outlet pipe 14.

  Therefore, when a high voltage is applied between the discharge tube 4 and the ground electrode tube 2 from a high-frequency power source (not shown) via the high-voltage insulator 10, the fuse 7, and the lead wire 9, a silent discharge is formed in the discharge gap 6, and ozone Will occur.

The heat generated by the silent discharge is cooled by the cooling water supplied to the cooling water chamber 3, and the cooling water is discharged from the cooling water outlet pipe 14. As a result, an increase in gas temperature in the discharge gap is suppressed, and ozone with a high concentration and high yield is obtained.
Japanese Patent No. 3828970 (4th page, Fig. 1) JP 2007-169134

  However, the conventional ozone generator described above has problems of corrosion and deterioration. Further, when silent discharge is generated at a high power density, the ozonized gas may reach 70 ° C. Due to these corrosive gases and temperatures, the internal components of the ozone generator gradually deteriorate.

  In addition, since the current concentrates on the electron supply portion, deterioration due to electrochemical corrosion tends to occur in the portion of the metal film in contact with the electron supply, which becomes a factor inducing a decrease in ozone generation efficiency.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an ozone generator that does not easily corrode and does not deteriorate even if the internal components of the ozone generator have a high power density. To do.

To achieve the above object, the present invention provides:
In a can configured as an airtight container, one end is closed, a discharge tube provided with a cylindrical high voltage electrode having a metal film formed on the inner surface, and a concentric circle outside the discharge tube via a discharge gap. A ground electrode tube disposed in the source gas containing oxygen that cools the outer peripheral side of the ground electrode tube with cooling water, applies a high voltage to the high-voltage electrode, and circulates in the discharge gap. In the ozone generator that generates ozone in
The can body is divided into two spaces, the discharge tube and the ground electrode tube are disposed in each of the spaces, and an ozonized gas outlet pipe is installed on the closed side of the discharge tube. .

  According to the present invention, the ozonized gas does not come into contact with the components installed on the opening side of the discharge tube, thereby preventing corrosion of the components of the discharge tube disposed inside the ozone generator. This can suppress the life of the discharge tube.

  An embodiment of the present invention will be described below with reference to FIG. In the figure, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing the internal configuration of the first embodiment of the present invention. The can body 1 which is an airtight container is divided into two by a partition wall at the center in the longitudinal direction to form two spaces. In each space formed inside the can body 1, a large number of discharge tubes 4 are disposed at both ends of the ground electrode tube 2 made of stainless steel inside the ground electrode tube 2 provided along the inner wall of the can body 1. Inserted into the inner space of the can body 1 by the spacer 5 and placed concentrically.

  The overall shape of the discharge tube 4 is substantially straight, one end is closed, the other end is provided with a fuse 7 and a power supply 8, and a metal film is formed on the inner wall. This discharge tube 4 is positioned and arranged inside the can 1 so that the closed end faces the partition wall.

  A discharge gap 6 is formed between the ground electrode tube 2 and the discharge tube 4 by the spacer 5 disposed between the ground electrode tube 2 and the discharge tube 4 in the radial direction of the can 1. A fuse 7 and a power supply 8 are concentrically disposed in the discharge tube 4.

  The fuse 7 is supported by a fuse holder (not shown), and the power supply 8 is made of, for example, stainless steel and coated with a graphite-based conductive paint.

  A high voltage is applied between the discharge tube 4 and the ground electrode tube 2 in the ozone generator configured as described above from a high-frequency power source (not shown) through the high-voltage insulator 10, the fuse 7, the power supply 8 and the lead wire 9. Then, a silent discharge is formed in the discharge gap 6 and ozonized gas is generated.

Nitric acid is generated in the process in which the source gas generates ozonized gas inside the ozone generator. The reaction process is shown below.
e + N ₂ → e + N + N
N + O ₂ → NO + O
NO + O ₃ → NO ₂ + O ₂
NO ₂ + NO ₃ → N ₂ O ₅
N ₂ O ₅ + H ₂ O → HNO ₃
Here, e is an electron generated during discharge, N is nitrogen, and O is oxygen.

  When ozone raw material gas is supplied from the raw material gas inlet pipe 11 into the can 1 of the ozone generator, the ozone raw material gas is discharged into the discharge gap 6 formed between the discharge tube 4 and the ground electrode tube 2. The generated ozonized gas flows out of the can body 1 from the outlet pipe 12.

  The heat generated by the silent discharge is cooled by the cooling water supplied to the ground electrode tube 2, but by itself, the heat trapped inside the discharge tube 4 cannot be completely removed, and the inside of the can 1 is several tens of meters. A temperature rise of ℃ is produced.

  As described above, in the first embodiment, as a result of dividing the can body 1 into two spaces at the central position in the figure, the outlet pipe 12 is provided so that the ozonized gas always passes through the closed portion of the discharge tube 4. It has been.

  According to the above structure, in the gas flow path, the ozonized gas passes through the closed portion of the discharge tube 4 having the component parts and does not contact the open portion. Therefore, the fuse 7 and the power supply 8 that are the component parts of the discharge tube 4. , Deterioration of the metal film inside the discharge tube 4 can be prevented.

(Second embodiment)
FIG. 2 is a diagram showing a second embodiment of the present invention, in which the position of the feeder 8 is selected to prevent the deterioration of each component including the feeder. In the second embodiment, the power supply 8 is disposed at the end of the discharge tube 4 and a position (17L / 20) corresponding to 17/20 of the total length L of the discharge tube 4 from the end.

  By arranging the power supply 8 at such a position, even if a large current flows through the discharge tube 4, the current is distributed to two locations, and the electrochemical reaction is greatly reduced.

  Furthermore, the electrochemical deterioration is also suppressed by arranging the position of the power supply 8 at a position corresponding to 13 to 19/20 of the total length L of the discharge tube 4 from the end of the discharge tube 4.

  According to the second embodiment, the current value in the conventional ozone generator can be about 35%. As a result, it is possible to reduce deterioration due to electrochemical corrosion that easily occurs in the vicinity of the power supply 8.

(Third embodiment)
FIG. 3 is a diagram showing a third embodiment of the present invention, and shows an example in which the position of the feeder 8 is further limited. In this case, the power supply 8 is arranged at a position corresponding to ¼ L from both ends of the discharge tube 4 when the total length of the discharge tube 4 is L.

  When a large current is passed through the discharge tube 4, electrochemical corrosion may occur in the vicinity of the power supply 8, but the manner in which an electrochemical reaction occurs changes by appropriately selecting the position of the power supply 8.

  That is, since the current is distributed to two places by arranging the power supply 8 at a position corresponding to the above-mentioned 1/4 L from both ends of the discharge tube 4, the current value of the portion of the power supply 8 is the current in the conventional ozone generator. It can be about 25% of the value. As a result, it is possible to reduce deterioration due to electrochemical corrosion that easily occurs in the vicinity of the power supply 8.

The figure which shows the 1st Example of this invention. The figure which shows the 2nd Example of this invention. The figure which shows the 3rd Example of this invention. Sectional drawing which shows schematic structure of the conventional ozone generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Ground electrode pipe 3 Cooling water chamber 4 Discharge pipe 5 Spacer 6 Discharge gap 7 Fuse 8 Electric supply 9 Lead wire 10 High pressure insulator 11 Raw material gas inlet piping 12 Ozonation gas outlet piping 13 Cooling water inlet piping 14 Cooling water outlet Piping

Claims (4)

In a can configured as an airtight container, one end is closed and a cylindrical high voltage electrode having a metal film formed on the inner surface is provided, and a concentric circle is formed outside the discharge tube via a discharge gap. A ground electrode tube disposed in the source gas containing oxygen that cools the outer peripheral side of the ground electrode tube with cooling water, applies a high voltage to the high-voltage electrode, and circulates in the discharge gap. In the ozone generator that generates ozone in
The can body is divided into two spaces, the discharge tube and the ground electrode tube are disposed in each of the spaces, and an ozonized gas outlet pipe is installed on the closed side of the discharge tube. Ozone generator.   The ozone generator according to claim 1, wherein an electric supply portion is installed at two locations of the discharge tube.   The site of supplying electrons to the discharge tube is installed at two positions corresponding to 13/20 to 19/20 of the total length of the discharge tube from one end of the discharge tube. The ozone generator described.   The ozone generator according to any one of claims 1 to 3, wherein the electric supply of the discharge tube is made of stainless steel and coated with a graphite-based conductive paint.

Images