CN114203521A

CN114203521A - Excimer lamp, ultraviolet irradiation device, and ozone generation device

Info

Publication number: CN114203521A
Application number: CN202110271044.8A
Authority: CN
Inventors: 小林刚; 福田刚士; 两角洋二
Original assignee: Orc Manufacturing Co Ltd
Current assignee: Orc Manufacturing Co Ltd
Priority date: 2020-09-17
Filing date: 2021-03-11
Publication date: 2022-03-18
Anticipated expiration: 2041-03-11
Also published as: CN114203521B; KR20220037327A; TW202213438A; JP7462524B2; KR102821089B1; JP2022049928A; TWI845818B

Abstract

The present invention provides an excimer lamp, an ultraviolet irradiation device and an ozone generating device, the excimer lamp effectively irradiates an object to be irradiated with ultraviolet rays. In an excimer lamp (10) having a discharge vessel (10T) in which an inner electrode (40) is covered by an inner tube (30), the front end portion (31) of the inner tube (30) is brought into the small diameter portion (21). Inside, on the other hand, the inner electrode (40) is prevented from entering the small diameter portion, and the position of the front end portion (41) of the inner electrode (40) along the lamp axis (E) is located on the rear end side of the small diameter portion (21). (center side of discharge vessel).

Description

Excimer lamp, ultraviolet irradiation device, and ozone generation device

Technical Field

The present invention relates to an excimer lamp, an ultraviolet irradiation apparatus and an ozone generating apparatus having the excimer lamp, and more particularly to a structure of a tip portion of a discharge vessel of the excimer lamp.

Background

In an excimer lamp, a rare gas is sealed in a discharge vessel (light-emitting tube), and discharge is performed by applying a voltage between an outer electrode provided on the outer surface of the light-emitting tube and an inner electrode provided in the light-emitting tube, thereby emitting excimer light. The excimer light can be irradiated with ultraviolet rays, and can be used as a light source for ozone generation by ultraviolet irradiation or the like.

In order to reduce the starting voltage of an excimer lamp, the following arrangement structure of electrodes is known: the tip of the internal electrode is extended into a tip formed at one end of the discharge vessel, and the external electrode is extended to the outer surface of the tip (see patent document 1). Such an electrode arrangement structure can be adopted also in an excimer lamp having a double tube structure (see patent document 2).

Patent document 1: japanese patent laid-open No. 2014-154274

Patent document 2: japanese patent laid-open publication No. 2016-

On the one hand, a high voltage is applied to the inner electrode of the excimer lamp, and on the other hand, the end portion is the remaining part of the exhaust path in the discharge vessel during the manufacturing process of the excimer lamp, and has a smaller inner diameter than the discharge vessel (outer tube). Therefore, dielectric breakdown is likely to occur between the inner electrode extending to the tip of the tip pipe and the outer electrode extending to the outer surface of the tip portion. In addition, when a conductor having the same potential (ground) as the outer electrode is brought into contact with the end header, insulation breakdown is likely to occur similarly.

Disclosure of Invention

Therefore, a structure of the discharge vessel that suppresses the occurrence of dielectric breakdown is desired.

The excimer lamp of the present invention has: a discharge vessel provided with a small diameter portion at a tip end thereof; an inner electrode disposed within the discharge vessel; and an inner tube that covers the inner electrode. The "front end" here corresponds to one end of the discharge vessel. The "small diameter portion" is a portion having a diameter smaller than a constant diameter portion (a portion having a constant inner diameter and a constant outer diameter) of the discharge vessel, and can be formed in various shapes along the axis (lamp axis) of the discharge vessel. The container may be configured to protrude from the container end toward the front end side (container outer side), or may be formed with a portion protruding toward the rear end side (container inner side).

The inner electrode may be configured to extend along the lamp axis, and may be configured as a foil-like electrode, for example. The distal end of the inner tube may be tapered, and the inner electrode may be embedded in the inner tube so as to concentrate an electric field.

In the present invention, the front end of the inner tube enters the small diameter portion, and the front end of the inner electrode along the lamp axis is located on the rear end side of the small diameter portion. The shape of the small diameter portion may be varied depending on the shape of the inner tube, the shape of the small diameter portion, and the like.

For example, when the distal end portion of the inner tube is tapered, at least a part of the side surface of the distal end portion may be configured to contact the inner surface of the small diameter portion. The contact portion of the small diameter portion, which contacts at least a part of the side surface of the distal end portion, may have a curved surface shape.

The small diameter portion may be provided with a cylindrical portion protruding toward the outside of the container and/or the inside of the container, and the inner pipe may be configured to contact the cylindrical portion.

For example, the distance between the front end of the inner tube and the front end of the inner electrode along the lamp axis may be larger than the distance between the inner electrode and the outer peripheral surface of the inner tube along the lamp radial direction.

Further, the distance interval between the tip of the inner tube and the tip of the inner electrode along the lamp axis may be longer than the distance interval between the tip of the inner tube and the tip of the small diameter portion along the lamp axis.

The ultraviolet irradiation device according to one aspect of the present invention may be configured as a device having any of the features of the excimer lamp described above, and the excimer lamp may be provided in the device case in a state where the outer electrode or the conductor having the same potential as the outer electrode is in contact with or close to the end of the small diameter portion or the discharge vessel.

The ozone generating device according to an aspect of the present invention may be configured as a device having any of the features of the excimer lamp described above, and the ozone generating device may include a support member having the same potential as the outer electrode, the support member supporting the excimer lamp with the small diameter portion thereof being disposed toward the intake fan at a distal end portion of the small diameter portion or an end portion of the discharge vessel.

According to the present invention, it is possible to suppress the occurrence of dielectric breakdown in an excimer lamp, an ozone generating apparatus having an excimer lamp, or the like.

Drawings

FIG. 1 is a view showing a schematic internal structure of an ozone generating apparatus having an excimer lamp according to embodiment 1.

Fig. 2 is an enlarged view showing the front end portion of the excimer lamp.

Fig. 3 is a diagram showing a modification of the discharge vessel of embodiment 1.

Fig. 4 is a diagram showing another modification of the discharge vessel of embodiment 1.

Fig. 5 is a schematic configuration diagram of an excimer lamp provided in the ultraviolet irradiation apparatus according to embodiment 2.

Description of the reference symbols

10: an excimer lamp; 10T: a discharge vessel; 20: an outer tube; 30: an inner tube; 40: an inner electrode; 50: an outer electrode; 100: an ozone generating device.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a view showing a schematic internal structure of an ozone generating apparatus according to embodiment 1. In addition, the excimer lamp and the housing are depicted in a cross-sectional view in fig. 1.

The ozone generating apparatus 100 has an ultraviolet irradiation device in which the excimer lamp 10 is housed in a housing 100K, and the excimer lamp 10 is disposed such that the lamp axis E thereof is along the vertical direction. A blower (not shown) is provided below the excimer lamp 10, and the gas sucked into the housing 100K flows in the vertical direction (lamp axis E) in the housing 100K and flows out from the opening 100P on the upper surface.

The excimer lamp 10 irradiates ultraviolet rays, for example, ultraviolet rays having a wavelength of 172 nm. Ozone is generated by irradiating the gas containing oxygen flowing around the excimer lamp 10 with ultraviolet rays, and the gas containing ozone is discharged from the opening 100P. Thereby, sterilization, disinfection, and the like are performed.

The excimer lamp 10 is supported by the

support members

70, 71, 72 in the housing 100K. The

support members

70, 71, and 72 are attached to the wall 75 disposed in the housing 100K, respectively, and the support members 71 and 72 are sandwiched between the outer electrodes 50 to prevent the excimer lamp 10 from being displaced mainly in the radial direction. The support member 70 supports one end (hereinafter referred to as a tip end) of the excimer lamp 10 from below to prevent displacement of the excimer lamp 10 mainly in the axial direction.

The discharge vessel (arc tube) 10T of the excimer lamp 10 has an outer tube 20 made of a dielectric material such as quartz glass and having a substantially cylindrical cross section. An inner tube 30 having a substantially cylindrical cross section is provided in the outer tube 20, and a foil electrode (hereinafter referred to as an inner electrode) 40 extending along a lamp axis E, which is a tube axis, is embedded (coated) in the inner tube 30. A rare gas such as xenon gas or a mixed gas of a rare gas and a halogen gas is sealed as a discharge gas in the discharge space S in the discharge vessel 10T.

The inner tube 30 as a dielectric is disposed coaxially with the outer tube 20, and is heat-welded to the rear end side of the discharge vessel 10T to form a discharge space S. The inner electrode 40 is disposed inside the inner tube 30 with the lamp axis E as the center when viewed from the end of the inner tube 30. The inner electrode 40 is not exposed in the discharge space S formed between the inner tube 30 and the outer tube 20. Further, the inner tube may be heat-welded to the inner tube, instead of being embedded in the inner tube, to form the inner electrode.

An outer electrode 50 is provided on the outer surface 20S of the outer tube 20. Here, the outer electrode 50 is formed of a metal wire wound in a spiral shape, and a part thereof is electrically connected to a grounded power supply line (not shown) via the support members 70 and 71 and the wall portion 75.

A power supply unit, not shown, is provided in the casing 100K. The power supply unit converts a commercial ac voltage into a dc voltage, converts the dc voltage into a high-frequency voltage by a switching circuit, and supplies the high-frequency voltage to the step-up transformer. The step-up transformer steps up the high-frequency voltage, and applies the high-frequency high voltage between the inner electrode 40 and the outer electrode 50 through the power feed line 60. Alternatively, the commercial ac voltage may be converted into a dc voltage by an inverter and supplied to the step-up transformer.

The discharge vessel 10T is provided with projection-shaped portions (hereinafter referred to as small diameter portions) 21, 22 at both ends of a constant diameter portion 20M surrounding the discharge space S. The small diameter portion 22 is a portion of the rear end side of the inner tube 30 that protrudes toward the lamp rear end along the lamp axis E without being covered by the outer tube 20, and the power supply line 60 penetrates the inside of the small diameter portion 22.

The small diameter portion 21 is formed in the lamp manufacturing process, and protrudes from the discharge vessel 10T (vessel exterior) toward the lamp tip side along the lamp axis E. Here, the distal end side of the outer tube 20 is heated and deformed to be reduced in diameter, and is welded to a tip tube having a smaller diameter than the outer tube 20, thereby integrally molding a small diameter portion 21 having a smaller diameter than the constant diameter portion 20M. Further, the tip pipe used for lamp manufacturing may be provided at a position different from the small diameter portion.

In the present embodiment, the front end 31 of the inner tube 30 enters the small diameter portion 21, and the front end 31 of the inner tube 30 is supported in contact with the small diameter portion 21. On the one hand, the fitting state is formed, and on the other hand, the tip portion 41 of the inner electrode 40 does not enter the small diameter portion 21. This will be explained in detail below.

Fig. 2 is an enlarged view showing the vicinity of the small diameter portion of the discharge vessel 10T.

The front end 31 of the inner tube 30 tapers, here in the shape of a shell. On the other hand, on the distal end side of the outer tube 20, a reduced diameter portion 20T that is reduced in diameter from the constant diameter portion 20M toward the small diameter portion 21 is formed in a bowl-like curved surface shape, and the small diameter portion 21 is formed to protrude from the center portion of the reduced diameter portion 20T.

Here, the reduced diameter portion 20T of the outer tube 20 and the inner surface 21S of the small diameter portion 21 are continuous and smooth curved surface shapes, and a score is not given to a connecting portion between the reduced diameter portion 20T and the small diameter portion 21. Two curvature changing points Q11, Q12 appear in the cross-sectional shape of the inner surface of the discharge vessel 10T from the reduced diameter portion 20T to the small diameter portion 21.

When a curve along the cross-sectional shape of the inner surface of the discharge vessel 10T from the reduced diameter portion 20T to the small diameter portion 21 is approximated by a circle (a circle of curvature), the curvature changing portion (changing point) Q11 corresponds to a boundary position where the center of curvature of the circle of curvature shifts from the discharge space S to the lamp outside. That is, the discharge space S corresponds to a boundary position between the inner surface cross-sectional portion having a concave shape in the discharge space S and the inner surface cross-sectional portion having a concave shape outside the lamp.

On the other hand, the curvature changing portion Q12 corresponds to a boundary position where the center of curvature of the curvature circle shifts from the lamp outer side to the discharge space S again. That is, the position corresponds to a boundary position that shifts from the inner surface cross-sectional portion that is concave on the lamp outer side to the inner surface cross-sectional portion that is concave on the discharge space S side.

If the curvature changing portion Q11 is used to define the small diameter portion 21, the small diameter portion 21 indicates a portion of the axial range between the front end 21T of the discharge vessel 10T and the curvature changing portion Q11, and has a length K1 along the lamp axis E. The reduced diameter portion 20T is formed on the rear end side of the discharge vessel 10T with respect to the curvature changing portion Q11, and represents a portion reduced in diameter toward the small diameter portion 21.

The inner tube 30 arranged along the vertical direction is positioned by a part of a side surface (outer surface in the circumferential direction) 31S of the distal end portion 31 contacting the contact portion 23, and is supported by the discharge vessel 10T. Here, the contact portion 23 indicates a curved surface portion between the curvature changing portions Q11 and Q12 of the small diameter portion 21. The distance L1 along the lamp axis E between the tip end apex 31T of the inner tube 30 and the tip end apex 21T is shorter than the distance L2 along the lamp axis E between the inner tube tip end apex 31T of the inner tube 30 and the tip end 41 of the inner electrode 40.

The distance L2 is longer than the shortest distance T between the edge 40L of the lamp radial direction end of the foil-shaped inner electrode 40 and the outer peripheral surface 30S of the inner tube 30. That is, the insulation distance of the inner electrode 40 embedded in the inner tube 30 along the lamp axis E direction is longer than the insulation distance along the radial direction.

As described above, the excimer lamp 10 is supported by the support member 70, which is grounded, at the tip tube tip apex 21T of the small diameter portion 21. Here, the edge 40L of the foil-shaped inner electrode 40 has a blade shape that is sharpened from the center toward the edge in the width direction. When a high voltage is applied to the inner electrode 40 having such an electrode shape, electric field concentration occurs in the edge portion 40L (particularly, the distal end portion 41).

However, since the distance L2 (the thickness of the inner tube 30 in the lamp axial direction) and the distance L1 (the distance between the inner tube tip apex 31T and the cap tube tip apex 21T in the lamp axial direction) are secured as the insulation distances, it is possible to prevent the insulation breakdown from the support member 70. As a result, discharge is generated between the inner electrode 40 and the outer electrode 50, and ultraviolet rays are emitted from the entire discharge vessel 10T.

Thus, the front end 31 of the inner tube 30 reaches the internal space of the small diameter portion 21 of the discharge vessel to be fitted, while the front end 41 of the inner electrode 40 is positioned on the rear end (discharge vessel center) side of the small diameter portion 21 without reaching the internal space of the small diameter portion 21 along the lamp axis E. Therefore, the length of the inner electrode 40 along the lamp axis E and the length of the wound outer electrode 50 can be included in the vicinity of the reduced diameter portion 20T of the outer tube 20, and the light emission length can be increased without changing the overall length of the lamp.

Further, since the inner tube 30 is supported in contact with the small diameter portion 21, the inner tube 30 can be held stably and coaxially in the outer tube 20, and the inner surface of the small diameter portion as the contact portion 23 has a curved surface shape, so that the tip end portion 31 of the inner tube 30 can be contacted without being damaged. Further, since the distal end portion 31 of the inner tube 30 has a curved shape and is tapered, the contact can be achieved so as to stably maintain the coaxial shape even for dimensional errors caused by the respective thermoforming.

In the discharge vessel 10T, the portion from the reduced diameter portion 20T to the small diameter portion 21 along the lamp axis hardly contributes to discharge (emits ultraviolet rays). Therefore, the reduced diameter portion 20T of the discharge vessel 10T may be formed into a substantially flat shape instead of a bowl-like curved surface shape.

Fig. 3 is a diagram showing a modification of the discharge vessel of embodiment 1. A flat portion 20TM is formed as a substantially flat surface along a direction perpendicular to the lamp axis E (lamp radial direction). By reducing the length (projection height) K1' of the reduced diameter portion 21-1 along the lamp axis E, the compact excimer lamp 10-1 can be constituted along the lamp axis E, and by bringing the discharge region close to the reduced diameter portion 20T of the discharge vessel 10T, the light emission length can be increased over the entire lamp length.

The inner tube 30 may be supported (positioned) in contact with the small diameter portion 21-1 of the discharge vessel 10T in various configurations. For example, the following structure may be adopted: the inner diameter of the diameter portion 21-1 is increased relative to the outer diameter of the distal end portion 31 of the inner tube 30, and the inner tube distal end portion apex 31T is positioned close to the tip tube distal end portion apex 21T, so that the inner surface of the small diameter portion 21-1 is supported in contact with the inner tube distal end portion apex 31T side position or the bottom portion 21B of the curvature changing portion Q12.

Further, a cylindrical portion along the lamp axis E may be formed in the inner surface of the small diameter portion 21-1 at a boundary position where the center of curvature of the curvature circle shifts from the lamp outer side to the discharge space S side, that is, at an inner surface portion having the curvature changing portion Q12, and a length (protruding height) K1' along the lamp axis E of the small diameter portion 21-1 may be increased so as to be in a fitting state in which the cylindrical portion is in contact with the tip end portion 31. The distal end 31 of the inner tube 30 may be tapered, and the inner surface of the small diameter portion may be tapered to fit thereto without adopting a curved surface shape. In this case, the inner surface portion having the curvature changing portions Q11, Q12 may not be a curved surface shape. The inner tube 30 may have an axial range in which the tip end 31 and the small diameter portion 21-1 overlap each other in the radial direction.

Fig. 4 is a diagram showing another modification of the discharge vessel of embodiment 1. The small diameter portion 21-2 is formed to protrude from the tip of the reduced diameter portion 20T toward the lamp rear end (container inside) along the lamp axis E at one end side. The small diameter portion 21-2 has a cylindrical portion at least a part of which protrudes toward the discharge space, and the tip end 31 of the inner tube 30 is fitted to the cylindrical portion of the small diameter portion 21-2. In addition, the side surface of the tip end portion 31 may contact the inner surface of the small diameter portion 21-2, and the tip end portion apex 31T may contact the inner surface of the bottom portion 21B of the small diameter portion 21-2. The small diameter portion may protrude only inward without protruding outward from the lamp.

Next, an ultraviolet irradiation apparatus including the excimer lamp of embodiment 2 will be described with reference to fig. 5. In embodiment 2, the outer electrode is provided over the small diameter portion, and is electrically connected to the power supply portion for the outer electrode via the small diameter portion.

FIG. 5 is a schematic internal configuration diagram of an excimer lamp of the ultraviolet irradiation apparatus according to embodiment 2.

The ultraviolet irradiation apparatus 100 'has an excimer lamp 10'. Here, the excimer lamp 10' is disposed inside a translucent sleeve 11 provided in a lateral direction (horizontal direction) in a casing (not shown) of the ultraviolet irradiation apparatus, and a fluid to be irradiated with ultraviolet rays such as washing water flows on the outer peripheral side of the sleeve 11.

An outer electrode 50' made of a metal film such as an aluminum film is provided on the outer surface 20' S of the discharge vessel 10' T. The outer electrode 50' covers the entire outer surface at both ends of the discharge vessel 10' T, and on the other hand, only a part of the surface of the constant diameter portion 20' M between the both ends is covered so as not to interfere with ultraviolet irradiation. The outer electrode 50 'covering the small diameter portion 21' is connected to an outer electrode power supply line via a metal socket not shown. In addition, the thickness of the outer electrode 50' is exaggeratedly depicted in fig. 3.

As in embodiment 1, the range of the small diameter portion 21' and the like can be defined by using the curvature changing portion in the cross-sectional view. The inner surface of the outer tube 20 'connected from the constant diameter portion 20' M to the small diameter portion 21 'via the reduced diameter portion 20' T is a continuous and smooth curved surface shape, and curvature changing portions Q20, Q21, Q22, Q23 are present in the cross section thereof. The small diameter portion 21' has a cylindrical portion.

The curvature changing portion Q20 is a boundary portion between the constant diameter portion 20' M of the outer tube 20 and the reduced diameter portion 20T, and the curvature changing portion Q21 corresponds to a boundary portion between the reduced diameter portion 20T and a flat portion along the lamp radial direction. The curvature changing portion Q22 is a boundary portion between the flat portion and the small diameter portion 21' in the lamp radial direction, and the curvature changing portion Q23 corresponds to a boundary portion between the reduced diameter portion on the lamp rear end side of the small diameter portion 21 and the cylindrical portion. The curvature changing portion Q24 is a boundary portion between the cylindrical portion of the small diameter portion 21 'and the reduced diameter portion on the lamp tip side, and the bottom portion 21B is a bottom portion of a recess portion which is an inner surface of the small diameter portion 21'.

The small diameter portion 21' defined as above is a length along the lamp axis E from the curvature changing portion Q22 to the tip end portion apex 21T of the tip pipe (including no flat portion). The front end apex 31T of the inner tube 30 is fitted to the front end side (inside) of the lamp with respect to the curvature changing portion Q22 of the small diameter portion 21 in the lamp axial direction, and the end 41' of the inner electrode 40 is located on the rear end side (discharge vessel center side) with respect to the curvature changing portion Q22 of the small diameter portion 21. I.e., not into the small diameter portion 21'. This can prevent dielectric breakdown.

The fitting state of the inner tube 30 'and the small diameter portion 21' of the discharge vessel 10'T can be achieved by various configurations in which the tip portion 31' of the inner tube 30 'and the small diameter portion 21' contact each other, and a flat portion or a cylindrical portion may not be provided as in embodiment 1. Further, the inner surface of the outer tube 20' connected from the constant diameter portion 20' M to the small diameter portion 21 via the reduced diameter portion 20' T may not have a continuous and smooth curved surface shape.

For example, the constant diameter portion 20'M of the outer tube 20' and the flat portion may be connected without providing the curved surface between the curvature changing portions Q20 and Q21, the flat portion and the cylindrical portion may be connected without providing the curved surface between the curvature changing portions Q22 and Q23, or the flat bottom portion may be used instead of the curved surface between the curvature changing portion Q24 and the bottom portion 21B.

The arrangement of the excimer lamp is not limited to the embodiments 1 and 2, and various modifications can be made. In this case, although the outer electrode may be disposed in a state close to the conductor having the same potential as the outer electrode, the above-described structure can prevent dielectric breakdown. The excimer lamp shown in embodiment 1 may be incorporated into an ultraviolet irradiation device, or the excimer lamp shown in embodiment 2 may be incorporated into an ozone generation device.

Claims

1. An excimer lamp, characterized in that,

The excimer lamp has:

A discharge vessel, which is provided with a small diameter portion at the front end;

an inner electrode disposed within the discharge vessel; and

an inner tube, which wraps the inner electrode,

The front end portion of the inner tube enters the small diameter portion,

The front end position along the lamp axis of the inner electrode is located on the rear end side of the small diameter portion.

2. The excimer lamp according to claim 1, characterized in that,

The front end of the inner tube is tapered,

At least a part of the side surface of the front end portion is in contact with the inner surface of the small diameter portion.

3. The excimer lamp according to claim 2, characterized in that,

A contact portion of the small diameter portion that is in contact with at least a part of the side surface of the distal end portion has a curved surface shape.

4. The excimer lamp of claim 1, wherein

The small diameter portion has a cylindrical portion protruding toward the outside and/or inside of the container,

The inner tube is in contact with the cylindrical portion.

5. The excimer lamp of claim 1, wherein

The distance interval along the lamp axis between the front end portion of the inner tube and the inner electrode is larger than the distance interval along the lamp radial direction between the inner electrode and the outer peripheral surface of the inner tube.

6. The excimer lamp of claim 1, wherein

The distance interval along the lamp axis between the front end of the inner tube and the inner electrode is longer than the distance interval along the lamp axis between the front end of the inner tube and the front end of the small diameter portion.

7. The excimer lamp of claim 1, wherein

The front end of the inner tube is tapered,

The inner electrode has a foil shape, and is embedded in the inner tube so as to concentrate an electric field.

8. An ultraviolet irradiation device having the excimer lamp according to any one of claims 1 to 7, characterized in that,

The excimer lamp is installed in the device casing in a state in which an outer electrode or a conductor having the same potential as the outer electrode is in contact with the small diameter portion or an end portion of the discharge vessel or in a state close to it.

9. An ozone generator comprising the excimer lamp according to any one of claims 1 to 7, characterized in that:

This ozone generator includes a support member that has the same potential as the outer electrode, and the support member supports the excimer provided with the small diameter portion facing the intake fan at the front end portion of the small diameter portion or the end portion of the discharge vessel. Lights are supported.