JP2011110492A - Ultraviolet irradiation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress early devitrification, blackening, etc., in the case of a high input electric power by restricting the distance between an ultraviolet lamp affected by its temperature and a treatment unit. <P>SOLUTION: A pair of discharge electrodes 15a and 15b are oppositely arranged in the axial direction in a luminescent tube 14 made of an ultraviolet-transmitting quartz glass and having an air-tight discharge space 13. An ultraviolet lamp 100 is constituted by filling the discharge space 13 with a lamp filler comprising a rare gas, mercury, a halogen, or a luminescent metal in an amount sufficient to keep the space 13 in a state of an arc discharge, and the lamp filler is allowed to emit ultraviolet light when the lamp is on. The ultraviolet lamp 100 is inserted into the inner tube 21 of an ultraviolet-transmitting double structure treatment unit 200 in which a coolant 24 which cools the ultraviolet lamp 100 is circulated between the inner tube 21 and an outer tube 22. The distance D [mm] between the ultraviolet lamp 100 and the inner tube 21 of the treatment unit 200 and the input electric power P [W/cm] of the ultraviolet lamp 100 satisfy D≤-0.2P+35, and an ultraviolet reflective film 25 is formed on the inner surface of the outer tube 22. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation device used for photochemical treatment, photodisinfection, photowashing, and the like with ultraviolet rays irradiated from an ultraviolet lamp.

  In the conventional ultraviolet irradiation device, the surface of the ultraviolet irradiation lamp that irradiates ultraviolet rays becomes high temperature. Therefore, a cooling mechanism for preventing breakage is necessary, and generally a cooling method by air cooling is used. The air cooling method includes a direct method in which a gas is directly applied to a lamp for cooling, and an indirect method in which the gas around the transmission container is cooled by cooling the transmission container installed in the outer peripheral direction of the lamp with a liquid, thereby cooling the lamp. In particular, the latter method is used when the temperature rise of the irradiated object is suppressed or when there is a liquid that is the irradiated object in the lamp outer peripheral direction. (For example, Patent Document 1)

JP 2008-226806 A

  Although the technique of the above-mentioned patent document 1 can improve the processing capability for the irradiated object by increasing the lamp input power, the indirect method of cooling the lamp by cooling the gas around the lamp, Since the cooling capacity is limited, the input power is limited to 120 W / cm or less. In general, when the lamp surface temperature is kept on at 850 ° C. or higher, there is a problem that defects such as devitrification and blackening occur at an early stage.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ultraviolet irradiation device capable of extending the life even when it is turned on with high input power by limiting the distance between the ultraviolet lamp having an influence on the lamp temperature and the processing unit. .

  In order to solve the above-described problems, an ultraviolet irradiation device according to the present invention includes an arc tube provided with a discharge space having an airtight property made of an ultraviolet light transmissive material, and an arc tube in the axial direction of the arc tube. An ultraviolet lamp comprising: a pair of discharge electrodes arranged; and an enclosure composed of a rare gas, mercury, halogen, and a luminescent metal in an amount sufficient to maintain an arc discharge in the discharge space. A treatment unit that houses the ultraviolet lamp, cools the ultraviolet lamp between an inner tube and an outer tube, and transmits water from the ultraviolet lamp to perform water treatment of the liquid to be treated. The distance D [mm] between the lamp and the inner tube of the processing unit and the input power P [W / cm] of the ultraviolet lamp satisfy the relationship of D ≦ −0.2P + 35 (120 ≦ P ≦ 170). With Characterized in that the formation of the UV-reflecting film on the inner surface of the outer tube of the processing unit.

  According to the present invention, the life of the lamp can be extended even in a high input power state of 120 W / cm or more.

It is a system structure figure for explaining one embodiment about the ultraviolet irradiation device of this invention. It is a block diagram for demonstrating the ultraviolet lamp used in FIG. It is the I-I 'sectional view taken on the line of FIG. It is explanatory drawing for demonstrating the relationship of the distance of an ultraviolet lamp and a processing unit. It is explanatory drawing for demonstrating the relationship between input electric power, a ultraviolet lamp, and the distance between process units. It is sectional drawing of the principal part corresponded in FIG. 3 for demonstrating other embodiment regarding the ultraviolet irradiation device of this invention. It is sectional drawing of the principal part corresponded in FIG. 3 for demonstrating another other embodiment regarding the ultraviolet irradiation device of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  1 to 3 are diagrams for explaining an embodiment of the ultraviolet irradiation apparatus according to the present invention. FIG. 1 is a basic system structure diagram. FIG. 2 is a configuration diagram for explaining an ultraviolet lamp used in FIG. 3 is a cross-sectional view taken along the line II ′ of FIG.

  The ultraviolet irradiation device includes an ultraviolet lamp 100 and a processing unit 200. The ultraviolet lamp 100 and the processing unit 200 are positioned at predetermined intervals by spacers 12a and 12b attached to the sockets 11a and 11b of the ultraviolet lamp 100.

  As shown in FIG. 2, the ultraviolet lamp 100 is made of quartz glass having ultraviolet transparency, and electrodes 15 a and 15 b made of, for example, tungsten are disposed inside both ends in the longitudinal direction of the arc tube 14 that forms the discharge space 13. The The arc tube 14 is constituted by a single tube having an outer diameter φ of 27.5 mm, a wall thickness m of 1.5 mm, and a light emission length L of about 100 mm, for example.

  The electrodes 15a and 15b are welded to one end of the molybdenum foils 17a and 17b via the inner leads 16a and 16b, respectively. One end of an outer lead (not shown) is welded to the other end of the molybdenum foils 17a and 17b. The portions of the molybdenum foils 17a and 17b heat and seal the arc tube 14 from the inner leads 16a and 16b of the arc tube 14 to one end of the outer lead.

  The molybdenum foils 17a and 17b may be any material that has a thermal expansion coefficient close to that of quartz glass forming the arc tube 14, but molybdenum is used as a material suitable for this condition. The outer leads connected at one end to the molybdenum foils 17a and 17b, respectively, are insulated and sealed with power supply lead wires 19a and 19b electrically connected inside, for example, ceramic sockets 18a and 18b. Connected to the power circuit.

  In the arc tube 14, a sufficient amount of argon gas, which is a rare gas for maintaining arc discharge, is 1.3 kPa, and iron, tin, indium, bismuth, which are metals for emitting mercury and ultraviolet light, At least one of thallium and manganese and a halogen are enclosed.

  The processing unit 200 is made of a transparent material that is transparent to ultraviolet rays, such as cylindrical quartz glass. The processing unit 200 includes an inner tube 21 and an outer tube 22 provided outside thereof, and has a double tube structure. The ultraviolet lamp 100 is included in the inner tube 21.

  As shown in FIG. 3, the inner tube 21 of the processing unit 200 has an inner diameter d1 of 32 mm and an outer diameter d2 of 36 mm, and the outer tube 22 has an inner diameter d3 of 66 mm and an outer diameter d4 of 70 mm, for example.

  The processing unit 200 circulates a processing liquid 24 such as water to be subjected to photochemical processing from the outside through connection pipes 23a and 23b provided at outer peripheral ends. As shown in FIG. 1, the treatment liquid 24 enters water having a low temperature of 60 ° C. or less from the connection pipe 23 a, cools the ultraviolet lamp 100 from the connection pipe 23 b, and discharges the warmed water. If necessary, the warmed water may be cooled and input again from the connection pipe 23a. Therefore, the treatment liquid 24 also serves as cooling water for the ultraviolet lamp 100.

  On the inner surface of the outer tube 22, an ultraviolet reflecting film 25 is deposited and formed. The ultraviolet reflecting film 25 is composed of at least one kind of metal oxide such as tantalum oxide and hafnium and zirconium oxide. The ultraviolet reflection film 25 is adjusted in its component so that the ultraviolet ray of the light emitted from the ultraviolet lamp 100 is reflected and the infrared ray is transmitted.

  When the lamp length is 100 cm, 16 kW (160 W / cm) of lamp power is supplied, and when ultraviolet rays are emitted from the ultraviolet lamp 100, the photochemical treatment of the treatment liquid 24 that passes through the treatment unit 200 is performed.

  The ultraviolet reflection film 25 deposited on the inner surface of the outer tube 22 reflects the light emitted from the ultraviolet lamp 100 to a wavelength component of 400 nm or less and irradiates the treated water again to promote the photoreaction.

  At this time, the treatment liquid 24 is circulated through the treatment unit 200 and used as cooling water so that the temperature of the arc tube 14 of the ultraviolet lamp 100 does not exceed 850 ° C. It is known that when the surface temperature of the arc tube 14 reaches 850 ° C. or more, a blackening phenomenon occurs due to the reaction between the sealed gas and quartz glass which is the material of the arc tube 14.

  Here, the relationship between the distance D between the arc tube 14 of the ultraviolet lamp 100 configured as described above and the inner tube 21 of the processing unit 200 configured as described above is D [mm] and the lamp input power P [W / cm]. This will be described with reference to FIG.

  In FIG. 4, when the five types of input power of 80, 120, 140, 160, and 170 W / cm are supplied to the ultraviolet lamp 100, the favorable arc tube 14 and the inner tube 21 of the processing unit 200 at 850 ° C. or lower. The distance D is shown. In FIG. 4, considering the adverse effect of contact between the ultraviolet lamp 100 and the processing unit 200, data is an example in which 1 mm is the minimum value.

  At 80 W / cm, the surface temperature of the arc tube 14 does not exceed 850 ° C. in any of up to 15 mm shown in FIG. 4, which is favorable in terms of lamp life. However, in this case, there is a problem that the desired illuminance cannot be obtained because the input power is small.

  In addition, the distance is about 11 mm or less at 120 W / cm, the distance is about 6.5 mm or less at 140 W / cm, the distance is about 3 mm or less at 160 W / cm, and the distance is about 1.3 mm or less at 170 W / cm. When set, the lamp can be made to have a long life since the blackening phenomenon due to the reaction between the enclosed material and the arc tube 14 can be prevented while obtaining good illuminance at 850 ° C. or lower.

  FIG. 5 shows a characteristic in which the input power [W / cm] at this time and the distance between the good arc tube 14 and the inner tube 21 are plotted in D [mm] and connected by a straight line. As can be seen from FIG. 5, an approximate expression D = −0.2P + 35 is obtained from the relationship of the distance D to the input at which the lamp surface temperature is 850 ° C. From this, it was possible to control the lamp temperature to 850 ° C. or lower under the condition of D ≦ −0.2P + 35. However, the input power P (W / cm) is assumed to be 120 ≦ P ≦ 170.

  In this embodiment, when the input power is 120 to 170 W / cm, the distance D [mm] between the arc tube 14 and the inner tube 21 is a condition that satisfies the approximate expression of D ≦ −0.2P + 35. While the desired illuminance can be obtained, the blackening phenomenon can be suppressed and the life can be extended.

  Furthermore, by forming an ultraviolet reflecting film 25 that transmits infrared rays and reflects ultraviolet rays on the inner surface of the outer tube 22 of the processing unit 200, infrared rays that cause the temperature of the processing liquid 24 to rise are allowed to pass and ultraviolet rays are reflected. Then, it is possible to irradiate the treatment liquid 24 again to promote the photoreaction, and it is possible to improve the treatment capacity.

  In this embodiment, it is possible to improve the processing capability by once passing the treatment liquid through the ultraviolet reflecting film and performing the treatment by the photoreaction, and then reflecting only the ultraviolet ray and using it again as the photoreaction treatment.

  FIG. 6 is a cross-sectional view corresponding to FIG. 3 for explaining a modification of the embodiment relating to the ultraviolet irradiation apparatus of the present invention, and the same components as those in the above embodiment are denoted by the same reference numerals. To do.

  In this modification, the ultraviolet reflecting film 25 is formed on the outer surface of the outer tube 22 of the processing unit 200.

  In this case, since the ultraviolet reflecting film 25 is not exposed to the treatment liquid 25, it is possible to suppress the function of the ultraviolet reflecting film 25 from being reduced and the life from being shortened. In addition, when the ultraviolet reflecting film 25 is formed on the outer surface of the outer tube 22, the work can be more efficiently performed and more reliably formed as compared with the case where it is formed on the inner surface of the outer tube 22.

  FIG. 7 is a cross-sectional view corresponding to FIG. 3 for explaining another embodiment relating to the ultraviolet irradiation apparatus of the present invention, and the same components as those in the above embodiment are denoted by the same reference numerals.

In this embodiment, a photocatalyst 26 that absorbs ultraviolet rays and activates a processing liquid that passes through the processing unit 200 is formed on the outer surface of the outer tube 22 of the processing unit 200. When the photocatalyst 26 is irradiated with ultraviolet rays, a strong oxidizing power is generated on the surface thereof, and harmful substances such as organic compounds and bacteria that come into contact with the photocatalyst 26 can be removed. As the photocatalyst 26, for example, titanium dioxide (Tio ₂ ) is used.

  In this embodiment, the treatment liquid can be activated once by passing it through the photocatalyst, and the treatment liquid can be activated again by reflecting the ultraviolet rays with the photocatalyst. For this reason, the oxidizing power of the surface of the photocatalyst is improved, the treatment liquid can be more activated, and the ability to remove harmful substances such as organic compounds and bacteria can be improved.

DESCRIPTION OF SYMBOLS 100 Ultraviolet lamp 13 Discharge space 14 Arc tube 15a, 15b Electrode 300 Processing unit 21 Inner tube 22 Outer tube 23a, 23b Connection tube 24 Treatment liquid 25 Ultraviolet reflective film 26 Photocatalyst

Claims (3)

An arc tube with a discharge space having a hermeticity made of an ultraviolet light transmissive material;
A pair of discharge electrodes disposed opposite the arc tube in the axial direction of the arc tube;
An ultraviolet lamp comprising an enclosure made of a rare gas, mercury, halogen, and luminescent metal in a sufficient amount to maintain an arc discharge in the discharge space;
A processing unit that houses the ultraviolet lamp, cools the ultraviolet lamp between an inner tube and an outer tube, and transmits a UV ray from the ultraviolet lamp to perform a photochemical treatment of a liquid to be treated;
The distance D [mm] between the ultraviolet lamp and the inner tube of the processing unit and the input power P [W / cm] of the ultraviolet lamp have a relationship of D ≦ −0.2P + 35 (120 ≦ P ≦ 170). An ultraviolet irradiation device characterized by satisfying and forming an ultraviolet reflective film on the inner surface of the outer tube of the processing unit.   The ultraviolet irradiation apparatus according to claim 1, wherein the ultraviolet reflection film is formed on an outer surface of an outer tube of the processing unit. An arc tube with a discharge space having a hermeticity made of an ultraviolet light transmissive material;
A pair of discharge electrodes disposed opposite the arc tube in the axial direction of the arc tube;
An ultraviolet lamp comprising an enclosure made of a rare gas, mercury, halogen, and luminescent metal in a sufficient amount to maintain an arc discharge in the discharge space;
A treatment unit configured to house the ultraviolet lamp, circulate a coolant for cooling the ultraviolet lamp between the inner tube and the outer tube, and transmit ultraviolet rays;
The distance D [mm] between the ultraviolet lamp and the inner tube of the processing unit and the input power P [W / cm] of the ultraviolet lamp have a relationship of D ≦ −0.2P + 35 (120 ≦ P ≦ 170). An ultraviolet irradiation device characterized by satisfying and forming a photocatalyst on the inner surface of the outer tube of the processing unit.

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