JP6736027B2 - Excimer lamp for liquid processing - Google Patents

Description

TECHNICAL FIELD The present invention relates to an excimer lamp for liquid treatment, and particularly to an excimer lamp for liquid treatment used for decomposing organic substances in water.

Japanese Patent Laid-Open No. 2007-160241 (Patent Document 1) is known as a water treatment device using an ultraviolet irradiation device used for decomposing organic matter (TOC) in water.
The structure is shown in FIG. 8, and the ultraviolet irradiation device 20 is adapted to generate ultraviolet rays by the mercury-argon plasma 21 and radiate the ultraviolet rays through the quartz tube 22. In this device, plasma 21 is generated by supplying electricity from the power stabilizer to the filament 23. The inner wall of the wastewater treatment tank 24 is formed by a transparent quartz jacket 25 having excellent ultraviolet ray transparency. There is some space between the quartz tube 22 and the quartz jacket 25. Then, the sewage 26 is made to flow in from below the treatment tank 24, rises in the flow path having a donut-shaped cross section, is decomposed by the ultraviolet rays emitted from the quartz tube 22 during this time, and the treated water 27 is made to flow out from above. ..
In this device, the light emission of mercury is used to irradiate ultraviolet rays having wavelengths of 185 nm and 254 nm.

However, in water, there are substances that are difficult to decompose even with light having a wavelength of 185 nm, which is the light emission of mercury, and the substance of Patent Document 1 has a problem that these substances cannot be decomposed.
In order to decompose these substances, it is necessary to irradiate vacuum ultraviolet rays having a shorter wavelength, for example, 172 nm which is the emission of Xe excimer and 147 nm which is the emission of Kr excimer.
However, when the ultraviolet light source in Patent Document 1 is replaced with an excimer lamp having an external electrode structure, for example, if an ultraviolet ray of 172 nm is used, the ultraviolet ray of 172 nm is absorbed by the surrounding air, so that the excimer lamp This results in a complicated structure in which the surrounding must be replaced with an inert gas such as nitrogen gas.

A liquid processing technique having a structure different from that of Patent Document 1 having such a problem has been proposed. In Japanese Patent Publication No. 2005-536843 (Patent Document 2), the liquid to be processed is stored in the internal space of the excimer lamp. A technique of processing by passing through is disclosed.
The cross-sectional structure is shown in FIG. 9, and this excimer lamp 30 has a discharge vessel 31 composed of an outer tube 32 and an inner tube 33, and an outer electrode 34 is arranged outside the outer tube 32, By disposing the transparent inner electrode 35 inside the tube 33, a discharge space is formed between the outer tube 32 and the inner tube 33, and a phosphor film 36 is formed outside the inner tube 33. .. Then, the liquid to be treated is caused to flow into the inner tube 33 and is treated by the ultraviolet rays radiated inside through the inner tube 33 of the discharge vessel 31.

However, if the electrode 35 is formed in the inner tube 33, the liquid to be treated comes into direct contact with the electrode 35, and the substance forming the electrode may elute into the liquid to be treated. This is a particular problem when processing beverages or pure water.
Further, the electrode itself is eroded and worn by the liquid to be treated, and it is difficult to maintain the performance for a long period of time.
Further, the work itself of providing the electrode 35 inside the thin inner tube 33 is extremely complicated and difficult.
Furthermore, when the phosphor 36 is applied on the outer surface of the inner tube 33, the phosphor also emits light, but absorbs ultraviolet rays. The irradiation does not effectively irradiate vacuum ultraviolet rays having a short wavelength such as 172 nm.

JP, 2007-160241, A Japanese Patent Publication No. 2005-536843

In view of the problems of the above-mentioned conventional techniques, the problem to be solved by the present invention is that excimer lamps for liquid treatment, such as decomposition treatment of organic substances in a liquid using ultraviolet rays, are simple in electrode mounting work, It is an object of the present invention to provide an excimer lamp which has a long life and can efficiently irradiate a liquid to be treated with ultraviolet rays, and is particularly suitable for decomposing organic substances in the liquid.

In order to solve the above-mentioned problems, the present invention comprises an outer tube made of a dielectric material, an inner tube that is disposed inside the outer tube, and has a UV transparent inner tube through which the liquid to be treated flows, the outer tube and the outer tube In a liquid processing excimer lamp having a discharge vessel in which a discharge space filled with a discharge gas is formed between the inner tube and the inner tube, a high-voltage side electrode and a low-voltage side electrode are arranged to face each other outside the outer tube. It is characterized by
Further, the outer pipe and the inner pipe are attached by welding at both ends of the outer pipe, and the inner pipe is expanded at both attachment ends from the outer diameter of the central portion in the longitudinal direction. It is characterized by
Further, the outer tube is made of a material that transmits ultraviolet rays, and the outer electrode is made of a material that reflects ultraviolet rays.
An ultraviolet reflecting film is provided inside the outer tube.
Further, a phosphor film is provided inside the outer tube.
Further, a phosphor film is provided inside the ultraviolet reflection film.
In addition, a plurality of the inner tubes are provided.
Further, the outer tube and/or the inner tube is characterized by a flat rectangular tube shape.

According to the excimer lamp for liquid treatment according to the present invention, the high-voltage side electrode and the low-voltage side electrode are arranged opposite to each other outside the outer tube of the discharge vessel having the double-tube structure, so that the inside of the inner tube flows. Stable operation for a long time without exposing the electrode to the treatment liquid, eluting the electrode constituents into the liquid to be treated and without eroding the electrode itself Is secured.
Further, since the pair of electrodes is arranged outside the outer tube, the work of mounting the electrodes is simple.
Also, considering that the short distance ultraviolet rays reach in the liquid (range), the inner tube has to have a small diameter by nature, and heating is required during welding work with the outer tube by the burner. Due to this, the inner diameter may be further reduced and the pipe may be blocked. However, in the present invention, the inner pipe and the outer pipe are welded to each other, and the both ends of the inner pipe are wider than the central portion. There is no concern that the inner tube will be blocked due to the diameter.

Sectional drawing (A) and XX sectional view (B) of the 1st Example of this invention. Sectional drawing of a 2nd Example. Sectional drawing of a 3rd Example. Sectional drawing of a 4th Example. Sectional drawing of the 5th-7th Example. Sectional drawing (A) and XX sectional view (B) of an 8th Example. Sectional drawing of a 9th Example. Conventional UV water treatment equipment. Conventional excimer lamp for water treatment.

FIG. 1 shows an excimer lamp 1 for liquid treatment of the present invention. The excimer lamp 1 for liquid treatment is composed of an outer tube 3 made of a dielectric material and ultraviolet rays arranged concentrically inside the outer tube 3. It comprises a discharge vessel 2 consisting of a transparent inner tube 4.
The inner pipe 4 is arranged so as to penetrate the outer pipe 3, and is welded to the inner pipe 4 at both ends of the outer pipe 3. As a result, a sealed discharge space S is formed between the outer tube 3 and the inner tube 4, and the discharge space S is filled with a discharge gas such as xenon gas.
The outer tube 3 is made of a dielectric material, for example, glass is used, but it is not always necessary that the outer tube 3 is transparent to ultraviolet rays. Then, as shown in FIG. 1B, a high voltage side electrode 5 and a low voltage side electrode 6 are provided on the outside (outer surface) of the outer tube 3 so as to face each other. As the pair of high-voltage side electrode 5 and low-voltage side electrode 6, a conductive material printed, a plate-shaped metal plate, or the like is used.
In the above description, when an ultraviolet ray transmissive material such as synthetic quartz glass is used as the outer tube 3, a material that reflects ultraviolet rays, such as a metal plate such as an aluminum plate, is used as the high voltage side electrode 5 and the low voltage side electrode 6. Thus, it can function as an electrode and can also function as an ultraviolet ray reflecting member that reflects the ultraviolet rays that have passed through the outer tube 3 and returns them to the discharge space S.

On the other hand, the inner tube 4 is made of a material that transmits ultraviolet rays, particularly a material that transmits a vacuum ultraviolet ray region. For example, synthetic quartz glass, sapphire, or the like.
Ultraviolet rays generated in the discharge space S due to the discharge between the high-voltage side electrode 5 and the low-voltage side electrode 7 pass through the inner tube 4 and are radiated therein.

A liquid to be treated such as water flows inside the inner tube 4, and ultraviolet rays from the discharge space S are irradiated from the entire peripheral surface of the inner tube 4 to decompose organic substances in the liquid.
According to this configuration, since there is no inclusion such as an electrode inside the inner tube 4, that is, in the liquid flow path, foreign matter does not enter the liquid to be treated.
Further, since vacuum ultraviolet rays having a short wavelength have a short reach (range) in liquid (water), it is desirable that the inner tube 4 has a small diameter, for example, an inner diameter of about 2 mm. Thus, the complicated work of providing the inner electrode on the inner side (inner surface) of the thin inner tube 4 is eliminated, and the work of mounting the electrode on the outer side of the outer tube 3 is sufficient, and the workability is extremely improved.

In the embodiment shown in FIG. 1, an ultraviolet reflection film 7 is formed inside the outer tube 3 on the discharge space S side. In this case, the outer tube 3 does not need to be transparent to ultraviolet light, and, for example, fused silica glass can be used.
Then, the ultraviolet rays generated in the discharge space S are reflected by the ultraviolet reflection film 7 and can be efficiently emitted into the inner tube 4.
Further, in the first embodiment, a getter 10 for adsorbing the impure gas in the discharge space S is arranged in the inner tube 4.

As the liquid to be treated, water such as pure water, wastewater generated in the manufacturing process of papermaking and synthetic fibers, liquid containing flavors added to food and drink such as flavors, coffee jelly, milk, cooling used for cooling the equipment Examples include factory circulating water such as water, and wastewater containing radioactive substances containing formic acid and ascorbic acid.

FIG. 2 shows another second embodiment, in which the phosphor 8 is applied to the inside of the outer tube 3 on the discharge space S side.
The vacuum ultraviolet rays generated by the excimer discharge in the discharge space 2 can be converted into ultraviolet rays having main wavelengths near other wavelengths, for example, 230 nm, 220 nm, and 190 nm by the phosphor 8, and the liquid to be treated can be irradiated with the ultraviolet rays. These wavelengths are appropriately selected according to the substance contained in the liquid to be treated, and depending on the case, both the vacuum ultraviolet rays of 172 nm by excimer discharge and the ultraviolet rays of 220 nm by the phosphor 8, for example, are irradiated. You can also

FIG. 3 shows still another third embodiment, in which an ultraviolet reflecting film 7 is formed inside the outer tube 3, and a phosphor 8 is laminated inside the ultraviolet reflecting film 7. In this example, the ultraviolet rays which are converted by the phosphor 8 and are about to be emitted to the outside are reflected by the ultraviolet reflection film 7 and returned to the discharge space S to be radiated into the inner tube 4.
In the second embodiment shown in FIG. 2 and the third embodiment shown in FIG. 3, the outer tube 3 does not need to be UV transparent, and fused silica glass can be used here.

In the above embodiments, the high voltage side electrode 5 and the low voltage side electrode 6 are configured as a pair of electrodes, but as shown in FIG. 4, they may be configured as two pairs of electrodes or more pairs of electrodes. Good. In the fourth embodiment shown in FIG. 4, two high-voltage side electrodes 5 and 5 and two low-voltage side electrodes 6 and 6 which are spaced apart from each other on the outer circumference of the outer tube 3 are arranged to face each other. By doing so, the position of the discharge can be controlled so that the inner tube 4 is efficiently surrounded by the discharge.

The outer tube 3 and the inner tube 4 are not limited to the cylindrical shape, and other shapes can be adopted, for example, a flat rectangular tube shape, and such an embodiment is shown in FIG. 3 and/or the inner tube 4 is shown as a flat square tube.
In the fifth embodiment shown in FIG. 5A, the outer tube 3 has a cylindrical shape, and the inner tube 4 has a flat rectangular tube shape.
In the sixth embodiment shown in FIG. 5B, the outer tube 3 has a flat rectangular tube shape, and the inner tube 4 has a cylindrical shape.
In the seventh embodiment shown in FIG. 5(C), both the outer tube 3 and the inner tube 4 have a flat rectangular tube shape.

FIGS. 6A and 6B show yet another eighth embodiment, and in this example, a plurality of inner tubes 4 are provided.
That is, a plurality of inner pipes 4, 4 in this example, two inner pipes 4, 4 are provided so as to penetrate one outer pipe 3. Of course, the number of the inner pipes 4 is not limited to two, and it may be three, four or more.
With such an arrangement, a large amount of liquid to be processed can be processed.

A further ninth embodiment is shown in FIG. 7, in which the inner pipe 4 passing through the outer pipe 3 is elongated at both ends thereof, that is, at both mounting ends 4a, 4a of the outer pipe 3. The diameter is larger than the outer diameter of the central portion in the direction.
The vacuum ultraviolet rays that are irradiated onto the inner tube 4 and enter the inside thereof are absorbed by a liquid to be treated such as water flowing inside, so that the reaching distance thereof is short. Therefore, in order to irradiate the liquid to be treated with sufficient ultraviolet rays, the inner tube 4 cannot be made too large in diameter, and its inner diameter is, for example, about 2 mm.
Therefore, if the ends of the outer tube 3 and the inner tube 4 are heated and melted in the process of molding the discharge vessel, the inner diameter of the inner tube 4 may be reduced, and the tubes may be blocked.
In this embodiment, since both mounting end portions 4a, 4a of the inner pipe 4 are expanded, even if the inner pipe 4 is slightly contracted during welding, it will not be blocked.
Further, even in the welding work, it is difficult to handle the inner pipe 4 having a small diameter, but the workability is improved by enlarging the welding attachment portions 4a and 4a.

As described above, according to the excimer lamp for liquid treatment of the present invention, the high-voltage side electrode and the low-voltage side electrode are arranged to face each other outside the outer tube of the discharge vessel having the double-tube structure. Therefore, the electrode is not exposed to the liquid to be processed flowing in the inner pipe, the electrode constituent substance is not eluted into the liquid to be processed, and the electrode itself is not eroded, Stable operation for a long time is secured.
Since the electrode is provided outside the outer tube, the mounting work is greatly simplified and the electrode area is large compared with the conventional technique in which the electrode is provided inside the thin inner tube. It is possible to have high input.
In addition, there is no fear that the inner pipe will be shrunk and closed by expanding the diameter at both attachment ends of the inner pipe, which is the welded portion of the inner pipe and the outer pipe, from the central portion.

1 Excimer Lamp for Liquid Treatment 2 Discharge Vessel 3 Outer Tube 4 Inner Tube 4a (Expansion) Mounting End 5 High Voltage Side Electrode 6 Low Voltage Side Electrode 7 Ultraviolet Reflecting Film 8 Phosphor 10 Getter S Discharge Space

Claims (8)

An outer tube made of a dielectric material, and an inner tube that is disposed inside the outer tube and that is transparent to ultraviolet rays and through which the liquid to be treated flows.
In the excimer lamp for liquid processing, which has a discharge vessel in which a discharge space filled with a discharge gas is formed between the outer tube and the inner tube,
An excimer lamp for liquid treatment, wherein a high-voltage side electrode and a low-voltage side electrode are arranged opposite to each other outside the outer tube. The outer pipe and the inner pipe are attached by welding at both ends of the outer pipe, and the inner pipe is expanded at both attachment ends from the outer diameter of the central portion in the longitudinal direction. The excimer lamp for liquid treatment according to claim 1, which is characterized in that. The excimer lamp for liquid treatment according to claim 1 or 2, wherein the outer tube is made of an ultraviolet-transparent material, and the high-voltage side electrode and the low-voltage side electrode are made of a material that reflects ultraviolet rays.
The excimer lamp for liquid treatment according to claim 1, wherein an ultraviolet reflecting film is provided inside the outer tube. The excimer lamp for liquid treatment according to claim 1, wherein a phosphor film is provided inside the outer tube. The excimer lamp for liquid treatment according to claim 4, wherein a phosphor film is provided inside the ultraviolet reflection film. The excimer lamp for liquid treatment according to claim 1, wherein a plurality of the inner tubes are provided. The excimer lamp for liquid treatment according to any one of claims 1 to 7, wherein the outer tube and/or the inner tube has a flat rectangular tube shape.

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