JPH08141559A - Ultraviolet radiation apparatus - Google Patents

Abstract

PURPOSE: To provide a long life ultraviolet radiation apparatus which is simple in structure and has high ultraviolet conversion efficiency and power efficiency. CONSTITUTION: Ultraviolet ray with a single wavelength is radiated by generating silent discharge or corona discharge between electrodes 1, 1 of metal rods 3 with glass lining 2 applied which are arranged in a quartz glass tube 4 transmitting ultraviolet rays in which a rare gas or a mixed gas of a rare gas and a halogen gas is sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet irradiation device suitable for decomposing organic substances (TOC) in ultrapure water devices, wastewater treatment and recovery devices, nuclear power plant primary cooling water, etc. using ultraviolet rays. Regarding

[0002]

2. Description of the Related Art When a discharge is performed between electrodes in a gas-tight sealed container,
Generally, a combination of bonding a metal material to an insulating glass material is used.The conventional bonding method is to apply a conductive paint on the glass material, plate the metal, deposit the metal, or deposit the metal. There are known methods of thermal spraying, applying a conductive double-sided tape, winding a metal foil, or winding a wire mesh. However, in all of these methods, the adhesion between the glass material and the metal material is insufficient, and a gap may occur between them. If there is such a gap, useless discharge occurs, so that power efficiency decreases.

Further, since the bonding strength between glass and metal is low, it may be damaged by impact, and when it is placed in a hot and humid environment, or when cooling water is passed through the metal material, Metal material may peel off. As a result, an inhomogeneous discharge phenomenon may be observed, and in some cases, the light emission may be completely stopped. Therefore, the life of the conventional discharge device is generally short.

In the case where an ultraviolet ray having a specific wavelength is taken out by causing an electric discharge between electrodes in a hermetically sealed container in which a specific gas is sealed and a liquid to be treated is irradiated with this ultraviolet ray to cause a chemical change. However, when the electrode for extracting the ultraviolet rays is exposed to the liquid to be treated, problems such as corrosion, deterioration, and electric leakage may occur. If the purity of the liquid to be treated is required, such a problem may occur. Not preferable.

Therefore, as shown in FIG. 3, metal plating 22 (or metal vapor deposition or metal spraying) is applied to the inner quartz glass tube 21, and a wire net 24 is wound around the outer quartz glass tube 23. In order to isolate the water from the water to be treated 26 in the water tank 25, a quartz glass tube 27 is further arranged on the outer side of the water, and a rare gas is enclosed in a closed space 31 formed by the quartz glass tubes 21 and 23. 28 applies a constant voltage between the metal plating 22 and the wire net 24,
It is known to have a structure capable of discharging. However, when the quartz glass tube 27 for protecting the wire mesh is installed in this way, ultraviolet rays are absorbed in the quartz glass tube 27 and the closed space 29, so that the ultraviolet conversion efficiency decreases. In particular,
Ultraviolet rays do not penetrate unless the inside of the closed space 29 is set to a high vacuum or N ₂ gas is filled.

[0006] In addition, unnecessary discharge may occur in a slight gap between the wire netting 24 and the quartz glass tube 23, and a gas for preventing such discharge is enclosed in the closed space 29 by opening the valve 30. There is a need to. As a result, the device becomes very complex and expensive.

The present invention has been made in view of the above problems of the prior art, and its purpose is to irradiate ultraviolet rays having a simple structure, high ultraviolet ray conversion efficiency and power efficiency, and long life. To provide a device.

[0008]

In order to achieve the above-mentioned object, the present invention encloses a rare gas or a mixed gas of a rare gas and a halogen gas in a closed container which transmits ultraviolet rays, and arranges the sealed container in the closed container. In a device for irradiating a single wavelength of ultraviolet light by causing a silent discharge or a corona discharge phenomenon between at least one pair of electrodes, an ultraviolet irradiation device characterized by using a glass lining metal material for the above-mentioned electrodes is provided. As an invention, in the first invention, the electrode is a tubular structure having a metal material on the inner surface side and a glass lining on the outer surface side, wherein a refrigerant flow path penetrating the metal material on the inner surface side is formed. A second aspect of the present invention is an ultraviolet irradiation device.

As a closed container material which transmits ultraviolet rays,
For example, quartz glass can be used. He, Ne, Ar, Kr, Xe or the like can be used as the rare gas, and F ₂ , Cl ₂ , Br ₂ , HCl, SF ₆ or the like can be used as the halogen gas mixed with the rare gas. be able to.

[0010]

[Operation] When at least one pair of electrodes is placed in a hermetically sealed container containing a rare gas or a mixed gas of a rare gas and a halogen gas and a voltage is applied between the paired electrodes, silent discharge or corona discharge occurs. . The energy excites the enclosed gas to form a dimer (so-called "excimer"), and when the excimer decomposes, a single wavelength of ultraviolet light is generated. The ultraviolet rays pass through the ultraviolet transmitting material and are irradiated to the outside.

When water surrounds the ultraviolet transmitting material, organic substances in the water are decomposed.

If this electrode is made of a glass lining metal material, the glass lining has a good adhesiveness and does not easily peel off, so that it has a long life. In addition, since there is no unnecessary gap with the metal material, there is no useless discharge phenomenon and the power efficiency is high. Furthermore, since a protective container is not required, the efficiency of converting ultraviolet rays is high.

By passing the refrigerant into the electrode, the electrode temperature is kept below a certain level, and the discharge phenomenon proceeds smoothly.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a vertical sectional view of an ultraviolet irradiation device of the present invention. In FIG. 1, reference numeral 1 denotes an electrode composed of a metal rod 3 provided with a glass lining 2, and a pair of electrodes 1 and 1 are inserted into a quartz glass tube 4 and an end portion of the quartz glass tube 4 is sealed. . The quartz glass tube 4 is filled with, for example, Xe gas through a conduit 5. The pipe line 6 is for discharging the enclosed gas. A constant voltage is applied between the electrodes 1 and 1 by the power supply 7, and a discharge phenomenon occurs. In this case, since the Xe gas is sealed, the ultraviolet ray having a single wavelength of 172 nm passes through the quartz glass tube 4 and is irradiated into the water tank 8. Due to the ultraviolet rays, organic substances existing in the raw water flowing into the water tank 8 from the pipe 9 are decomposed and converted into carbon dioxide gas, and the water thus purified is discharged from the pipe 10. Although FIG. 1 shows an example in which one unit of the ultraviolet irradiation device is arranged in the water tank, a plurality of ultraviolet irradiation devices can be arranged in the water tank when the amount of raw water is large. It is also possible to arrange a plurality of pairs of electrodes in the quartz glass tube. By doing this, it is possible to increase the ultraviolet irradiation amount,
A large amount of organic substances contained in raw water can be decomposed.

FIG. 2 shows a glass tube lining 12 provided on a metal tube 11 instead of the electrode 1 made of a metal rod in the ultraviolet irradiation apparatus shown in FIG.
The difference is that an electrode 14 having a coolant flow path 13 for passing water is used. In this case, the electrode 14 and the quartz glass tube 15 penetrate the water tank 8.

Next, an ultraviolet irradiation experiment was conducted using the ultraviolet irradiation device having the structure shown in FIG. 2, which will be described below.

SUS304 outer diameter 10 mm, thickness 1 mm,
Refrigerant flow path 13 in two metal tubes 11 of 1500 mm in length
And a metal tube 11 having a glass lining 12 having a thickness of 1 mm on the outer surface, an outer diameter of 30 mm, a thickness of 2 mm and a length of 1
Inserted in a synthetic quartz glass tube 15 of 000 mm, SUS3
Both ends of the quartz glass tube 15 were closed by a plate 16 made of 04 having a diameter of 40 mm and a thickness of 5 mm and sealed with an epoxy resin 17. In this case, the glass tube lined metal tube 11
The interval was 5 mm. The ultraviolet irradiation device having such a configuration was inserted into the water tank 8 made of SUS304 having the structure as shown in FIG. 2, the valve 18 was opened, and the quartz glass tube 15 was filled with Xe gas. In addition, the water tank 8 is about 200p from the pipe line 9.
Raw water containing organic matter in pb concentration was passed through. And
When a voltage of 5 kV and 20 kHz was applied between the electrodes 14 and 14 by the power supply 7 while the cooling water was being introduced into the passage 13, ultraviolet rays having a single wavelength of 172 nm were generated and the conduit 1
When the organic matter concentration in the water taken out from 0 was examined, it was about 1
It was 0 ppb. In this state, raw water, cooling water, and Xe gas were continuously supplied for 1000 hours, but no abnormality was found in the equipment.

For comparison, in the above experiment,
One of the two glass tubes 11 made of glass lining was made of synthetic quartz glass having an outer diameter of 10 mm, a thickness of 2 mm, and a length of 1,500 mm, and aluminum vapor deposition was performed on the inner surface of the quartz glass tube. The ultraviolet irradiation experiment was performed under the same conditions as above except that the one used was used. As a result, after 500 hours, the aluminum vapor deposition film was partly peeled off, the discharge phenomenon became non-uniform, and abnormal light emission was observed.

[0019]

According to the present invention, it is possible to provide an ultraviolet irradiation device having a simple structure, high ultraviolet conversion efficiency and high power efficiency, and a long life.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an ultraviolet irradiation device of the present invention.

FIG. 2 is a vertical cross-sectional view of another embodiment of the ultraviolet irradiation device of the present invention.

FIG. 3 is a vertical cross-sectional view of a conventional ultraviolet irradiation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrode 2 ... Glass lining 3 ... Metal rod 4 ... Quartz glass tube 11 ... Metal tube 12 ... Glass lining 13 ... Refrigerant distribution path 14 ... Electrode 15 ... Quartz glass tube

Claims (2)

[Claims] 1. A rare gas or a mixed gas of a rare gas and a halogen gas is sealed in a hermetic container that transmits ultraviolet rays, and a silent discharge or a corona discharge phenomenon occurs between at least one pair of electrodes arranged in the hermetic container. An apparatus for irradiating a single-wavelength ultraviolet ray by raising the ultraviolet ray irradiation apparatus, wherein a glass lining metal material is used for the electrode. 2. The electrode has a tubular structure in which the inner surface side is made of a metal material and the outer surface side is made of a glass lining, and a coolant flow path that penetrates the inner surface side metal material is formed. UV irradiation device.