JP2023164522A - Excimer lamp, ultraviolet irradiation device and ozone generator - Google Patents

Abstract

To prevent generation and outflow of high concentrations of ozone by localized ultraviolet irradiation and localized generation of ozone to prevent generation of unwanted ozone.SOLUTION: An excimer lamp 10 capable of radiating ultraviolet to produce ozone includes: a cylindrical discharge container (20) filled with discharge gas; and a pair of electrodes (30) and (40) extending in an axial direction along an outer peripheral surface of the discharge container and positioned opposite each other across a central part of the discharge container. By applying a high-frequency voltage to the pair of electrodes (30) and (40), an electrical discharge is generated in a space region near the axis between the pair of electrodes (30) and (40), and a dielectric barrier discharge is generated in a space region along the entire radial direction of the container covered by each electrode. An ultraviolet irradiance emitted from the space region between the pair of electrodes (30) and (40) to outside the discharge container is relatively low, and an ultraviolet irradiance emitted from the space region covered by each electrode to outside the discharge container is relatively high.SELECTED DRAWING: Figure 3

Description

The present invention relates to a discharge lamp such as an excimer lamp, and particularly to a lamp configuration that can generate low concentration ozone safely for humans.

In an excimer lamp, a pair of electrodes is placed on the outer surface of the discharge vessel, and a rare gas is sealed inside the discharge vessel. A dielectric barrier discharge is generated by applying a voltage between the electrodes, and the discharge is discharged from the discharge vessel to the outside of the lamp. emits ultraviolet light towards the target. Ozone produced by ultraviolet irradiation has sterilizing ability (oxidizing power), so excimer lamps can be used as light sources for deodorizing devices, sterilizing/sterilizing devices, and the like.

For example, by placing two excimer lamps in a container, the first excimer lamp irradiates ultraviolet rays to generate ozone, and the second excimer lamp irradiates ultraviolet rays of different wavelengths to generate active oxygen. (See Patent Document 1).

Japanese Patent Application Publication No. 2002-316041

When performing sterilization, deodorization, etc., it is sufficient to generate ozone within a range that is effective for the target object. Therefore, depending on the size and configuration of the object, it is desirable to downsize the excimer lamp. However, conventional excimer lamps generate ozone at a higher concentration (large amount) than necessary, so a complicated lamp blinking control circuit is required to generate ozone at a lower concentration (small amount). Therefore, when a continuous lighting state or an overpower lighting state occurs due to a device failure, there is a risk that high concentration ozone may flow out. Furthermore, in order to prevent the leakage of highly concentrated ozone, safety measures such as the use of an ozone sensor are required, which increases the size of the device and consumes a large amount of power.

Therefore, there is a need for a discharge lamp such as an excimer lamp that can irradiate ultraviolet rays without producing excess ozone.

An excimer lamp that is an embodiment of the present invention is an excimer lamp that can emit ultraviolet rays that generate ozone, and includes a cylindrical discharge vessel filled with discharge gas and an axis extending along the outer circumferential surface of the discharge vessel. A pair of electrodes are arranged opposite each other across the center of the discharge vessel, and when a high frequency voltage is applied to the pair of electrodes, a discharge is generated in a spatial region near the axis between the pair of electrodes. occurs, and a dielectric barrier discharge occurs in which discharge occurs in the entire spatial region in the radial direction of the vessel covered by each electrode, and the relative intensity of ultraviolet rays emitted from the spatial region between the pair of electrodes toward the outside of the discharge vessel However, the intensity of ultraviolet rays emitted from the spatial region covered by each electrode to the outside of the discharge vessel becomes relatively high.

An excimer lamp that is another aspect of the present invention is an excimer lamp that can emit ultraviolet rays that generate ozone, and includes a cylindrical discharge vessel filled with discharge gas, and a cylindrical discharge vessel filled with a discharge gas. A pair of electrodes extend in the axial direction and are arranged opposite to each other across the center of the discharge vessel, and when a high frequency voltage is applied to the pair of electrodes, a voltage is generated between the pair of electrodes within the discharge vessel. A dielectric barrier discharge that straddles the discharge vessel occurs, and the discharge is biased toward both ends of the discharge vessel in the axial direction of the discharge vessel, and is directed from the space between a pair of electrodes to the outside of the discharge vessel. The intensity of ultraviolet rays emitted from the discharge vessel is relatively low, and the intensity of ultraviolet rays emitted from the spatial region covered by each electrode to the outside of the discharge vessel is relatively high.

For example, each of the pair of electrodes is a cylindrical electrode that makes surface contact with the outer peripheral surface of the discharge vessel. For example, a pair of electrodes are arranged along the outer peripheral surface of the discharge vessel near both ends of the discharge vessel.

An excimer lamp which is another aspect of the present invention is an excimer lamp capable of emitting ultraviolet rays that generate ozone, and includes a cylindrical discharge vessel filled with discharge gas, and a cylindrical discharge vessel filled with a discharge gas, each extending in the axial direction of the outer peripheral surface of the discharge vessel. A pair of electrodes extend along the discharge vessel and are arranged opposite to each other across the center of the discharge vessel, and when a high frequency voltage is applied to the pair of electrodes, the A dielectric barrier that causes discharge to occur in a spatial area that is relatively narrow in the radial direction, and where a pair of electrodes in the discharge vessel make contact with the outer peripheral surface of the discharge vessel, and that causes discharge to occur in a spatial area that is relatively thick in the radial direction. A discharge occurs, and in a dielectric barrier discharge, the discharge is biased toward both ends within the discharge vessel with respect to the axial direction of the discharge vessel, and the discharge occurs across a pair of electrodes. Ultraviolet radiation emitted from a locally generated discharge within the discharge vessel is blocked by at least one electrode. Here, the term "locally generated discharge" refers to a discharge that is biased toward both ends with respect to the electrode axis.

In the present invention, since ultraviolet rays caused by biased discharge are blocked by the electrodes, generation of excess ozone can be suppressed. For example, at least one electrode is disposed at a position facing a spatial region where strong discharge occurs unevenly in the axial or radial direction of the discharge vessel.

For example, the axial length of the discharge vessel is 10 mm to 30 mm, and the outer diameter of the discharge vessel is 3 mm to 10 mm. For example, the wall thickness of the discharge vessel is within the range of 0.2 mm to 4 mm.

An ultraviolet irradiation device according to another aspect of the present invention includes the excimer lamp described above. An ozone generator according to another aspect of the present invention includes the excimer lamp described above.

For example, an excimer lamp that is one embodiment of the present invention is an excimer lamp that can emit ultraviolet rays that generate ozone, and includes a cylindrical discharge vessel filled with discharge gas, and a central part of the discharge vessel sandwiched between the excimer lamps. A pair of electrodes arranged opposite to each other along the axial direction, the pair of electrodes arranged along the outer peripheral surface of the discharge vessel near both ends of the discharge vessel, and the axial length of the discharge vessel is 10 mm. ~30mm, the outer diameter of the discharge vessel is 3mm~10mm, each pair of electrodes is composed of a cylindrical electrode that makes surface contact with the outer peripheral surface of the discharge vessel, and a high frequency voltage is applied to the pair of electrodes. This is a dielectric barrier discharge in which a discharge occurs in the discharge vessel from near one end of the discharge vessel to near the other end of the discharge vessel. A dielectric barrier discharge occurs in which the discharge is biased toward both ends. For example, the wall thickness of the discharge vessel is within the range of 0.2 mm to 4 mm. An ultraviolet irradiation device according to another aspect of the present invention includes the excimer lamp described above. An ozone generator according to another aspect of the present invention includes the excimer lamp described above.

A discharge lamp according to another aspect of the present invention includes a cylindrical discharge vessel filled with discharge gas, and a pair of electrodes each extending in the axial direction along the outer peripheral surface of the discharge vessel. For example, the outer diameter of the discharge vessel is in the range of 3 mm to 10 mm, the axial length of the discharge vessel is in the range of 10 mm to 30 mm, and the discharge gas is set in the range of 0.1 kPa to 30 kPa. It is possible to consist of a noble gas. In the discharge lamp of the present invention, ultraviolet rays emitted from a locally generated discharge within the discharge vessel are blocked by at least one electrode. Here, the term "locally generated discharge" refers to a discharge that is biased toward both ends with respect to the electrode axis.

For example, a discharge lamp that is one embodiment of the present invention includes a cylindrical discharge vessel filled with discharge gas, and a pair of electrodes that extend in the axial direction along the outer peripheral surface of the discharge vessel. For example, the outer diameter of the discharge vessel is in the range of 3 mm to 10 mm, the axial length of the discharge vessel is in the range of 10 mm to 30 mm, and the discharge gas is set in the range of 0.1 kPa to 30 kPa. It is possible to consist of a noble gas.

In the discharge lamp of the present invention, ultraviolet rays emitted from a locally generated discharge within the discharge vessel are blocked by at least one electrode. Here, the term "locally generated discharge" refers to a discharge that is biased toward both ends with respect to the electrode axis.

In the present invention, since ultraviolet rays caused by biased discharge are blocked by the electrodes, generation of excess ozone can be suppressed. For example, at least one electrode is disposed at a position facing a spatial region where strong discharge occurs unevenly in the axial or radial direction of the discharge vessel.

For example, a pair of electrodes are arranged opposite to each other along the axial direction of the discharge vessel, and are each composed of a cylindrical electrode that makes surface contact with the discharge vessel, and the length of the cylindrical electrode in the axial direction is set in a range of 2 mm to 15 mm. Is possible.

In a discharge lamp according to another aspect of the present invention, ultraviolet rays are emitted toward the outside of the discharge vessel from a strong discharge that occurs unevenly in the axial or radial direction of the discharge vessel in the discharge vessel filled with discharge gas. Producing ozone locally by at least partially blocking it.

In an ozone generation method according to another aspect of the present invention, a pair of electrodes each extending in the axial direction is arranged along the outer peripheral surface of a cylindrical discharge vessel filled with discharge gas, so that ozone is generated locally. First, by applying a high frequency voltage between the pair of electrodes, at least one of the electrodes blocks ultraviolet rays emitted from the discharge generated within the discharge vessel.

According to the present invention, by locally irradiating ultraviolet rays to locally generate ozone so as not to generate unnecessary ozone, it is possible to prevent high concentration ozone from being generated and flowing out. .

1 is a schematic side view of a discharge lamp that is an embodiment of the present invention. FIG. 3 is a schematic front view of the discharge lamp seen from the end side. 3 is a schematic cross-sectional view of the discharge lamp along line A-A' in FIG. 2; FIG.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic side view of a discharge lamp according to an embodiment of the present invention. FIG. 2 is a schematic front view of the discharge lamp seen from the end side.

The discharge lamp 10 has a discharge space S formed therein and includes a cylindrical discharge vessel 20 formed of quartz glass or the like. A pair of electrodes 30 and 40 having mutually different polarities are arranged on both ends 20T1 and 20T2 of the discharge vessel 20. The discharge lamp 10 is configured here as a small excimer lamp, the axial length W of the discharge vessel is in the range of 10 mm to 30 mm, the outer diameter D of the discharge vessel 20 is in the range of 3 mm to 10 mm, and a pair of The axial distance between the electrodes 30 and 40 (inter-electrode distance L) can be set in the range of 2 mm to 15 mm.

For example, the axial length W of the discharge vessel may be set to 20 mm, the outer diameter D of the discharge vessel 20 may be set to 5.2 mm, and the distance L between the electrodes may be set to 10 mm. However, the axial length W of the discharge vessel 20 represents the distance between the outer ends of the pair of electrodes 30 and 40. Further, the pair of electrodes 30 and 40 have the same shape, and for example, the axial length M of each electrode can be set in a range of 3 mm to less than 10 mm (for example, 5 mm).

The discharge space S of the discharge vessel 20 is filled with xenon gas of 1 Torr to 225 Torr (0.1 kPa to 30 kPa, more preferably 7 kPa to 20 kPa). A pair of conductive wires (not shown) connected to a DC power source (not shown) are connected to the pair of electrodes 30 and 40, and high frequency (1kHz to 500kHz, More preferably, the range is 1 kHz to 100 kHz, for example, a high voltage (5 kV to 10 kV) of 60 kHz is applied. The discharge vessel 20 and the electrodes 30, 40 are each held by a holding member (not shown).

As shown in FIG. 2, the pair of electrodes 30 and 40 are configured as cylindrical electrodes that are in close contact with each other in the entire circumferential direction along the outer peripheral surface 20S of the discharge vessel 20, and are provided with a gap that allows light to pass through. It is composed of an electrode member with a curved surface that is not curved. The pair of electrodes 30 and 40 are arranged opposite to each other along the axial direction X of the discharge vessel, and have electrodes arranged with mutually different polarities with respect to the axial direction X. Note that although the thick portion of the discharge vessel 20 is omitted in FIG. 2, the wall thickness can be set in the range of 0.2 mm to 4 mm (for example, 1.5 mm).

When a high frequency voltage is applied to the pair of electrodes 30 and 40, a dielectric barrier discharge occurs within the discharge vessel 20, and ultraviolet rays are emitted toward the outside of the discharge vessel 20. In this embodiment, the pair of electrodes 30 and 40 are disposed opposite to each other along the axial direction X with the central portion of the discharge vessel 20 interposed therebetween, so that local discharge occurs within the discharge vessel 20. This will be explained below.

FIG. 3 is a schematic cross-sectional view of the discharge lamp along line A-A' in FIG.

As shown in FIG. 3, near the center of the discharge vessel 20, a weak discharge CC occurs in a narrow region (only near the central axis of the discharge vessel). On the other hand, in the spatial region covered by the pair of electrodes 30 and 40, a strong discharge CC occurs in a thick region (the entire radial direction of the discharge vessel). In the discharge vessel 20, the discharge state is different between the spatial region near the electrodes 30 and 40 and the spatial region near the center, and the discharge is biased toward both ends of the discharge vessel 20, resulting in localized discharge. A discharge occurs within the discharge vessel 20.

Near the center of the discharge vessel 20 that is not covered by the pair of electrodes 30 and 40, a weak discharge occurs in a narrow region, and the illuminance of the emitted ultraviolet rays is low. On the other hand, on both end sides of the discharge vessel 20, strong discharge CC occurs in the thick region, and the illuminance of the emitted ultraviolet rays is high. As a result, a portion of the ultraviolet rays emitted from the strong discharge CC is blocked by the pair of electrodes 30 and 40, thereby forming a light shielding portion that blocks ultraviolet rays emitted from the discharge. The outer peripheral surface of the discharge vessel may be covered with a non-conductive member other than the electrode as a light shielding part that blocks ultraviolet rays.

As a result, ultraviolet rays are locally radiated to the outside of the discharge vessel 20 from near the center of the discharge vessel 20 . As a result, ozone is generated only near the center, unnecessary ozone is not generated, and ozone is generated locally.

As described above, according to the present embodiment, for the discharge lamp 10 equipped with the cylindrical discharge vessel 20, a pair of electrodes 30 and 40 having mutually different polarities are provided on the outer circumferential surface of both ends 20T1 and 20T2 of the discharge vessel 20. By applying a voltage, a local discharge occurs within the discharge vessel 20, and ozone is locally generated. As a result, even if the discharge lamp continues to be lit at maximum power, the maximum concentration of ozone that can be generated is limited, so that it is possible to prevent high concentration ozone from being generated and flowing out. Therefore, a safe and highly reliable discharge lamp can be provided.

10 discharge lamp 20 discharge vessel 30 electrode 40 electrode

Claims (9)

An excimer lamp capable of emitting ultraviolet rays that generates ozone,
a cylindrical discharge container filled with discharge gas;
a pair of electrodes each extending in the axial direction along the outer peripheral surface of the discharge vessel and disposed opposite to each other with a center portion of the discharge vessel in between,
A dielectric material in which, when a high frequency voltage is applied to the pair of electrodes, a discharge occurs in a spatial region near an axis between the pair of electrodes, and a discharge occurs in a spatial region of the entire radial direction of the container covered by each electrode. Barrier discharge occurs,
The intensity of ultraviolet rays emitted from the spatial region between the pair of electrodes toward the outside of the discharge vessel is relatively low, and the intensity of ultraviolet rays radiated from the spatial region covered by each electrode toward the outside of the discharge vessel is relatively low. An excimer lamp that is characterized by its high height. An excimer lamp capable of emitting ultraviolet rays that generates ozone,
a cylindrical discharge container filled with discharge gas;
a pair of electrodes each extending in the axial direction along the outer peripheral surface of the discharge vessel and disposed opposite to each other with a center portion of the discharge vessel in between,
By applying a high frequency voltage to the pair of electrodes, a dielectric barrier discharge straddles between the pair of electrodes within the discharge vessel, and a discharge within the discharge vessel with respect to the axial direction of the discharge vessel. A dielectric barrier discharge occurs in which the discharge is biased towards both ends of the
The intensity of ultraviolet rays emitted from the spatial region between the pair of electrodes toward the outside of the discharge vessel is relatively low, and the intensity of ultraviolet rays radiated from the spatial region covered by each electrode toward the outside of the discharge vessel is relatively low. An excimer lamp that is characterized by its high height. 3. The excimer lamp according to claim 2, wherein each of the pair of electrodes is a cylindrical electrode that makes surface contact with the outer peripheral surface of the discharge vessel. The excimer lamp according to claim 2, wherein the pair of electrodes are arranged along the outer peripheral surface of the discharge vessel near both ends of the discharge vessel. An excimer lamp capable of emitting ultraviolet rays that generates ozone,
a cylindrical discharge container filled with discharge gas;
a pair of electrodes each extending along the axial direction of the outer circumferential surface of the discharge vessel and facing each other with a center portion of the discharge vessel in between;
By applying a high frequency voltage to the pair of electrodes, a discharge occurs in a relatively narrow spatial region in the radial direction at the center of the discharge vessel, and the A dielectric barrier discharge occurs in a relatively wide spatial region in the radial direction at a portion where the pair of electrodes contacts the outer circumferential surface of the discharge vessel,
An excimer lamp characterized in that, in the dielectric barrier discharge, the discharge is biased toward both ends within the discharge vessel with respect to the axial direction of the discharge vessel, and the discharge occurs across the pair of electrodes. The axial length of the discharge vessel is 10 mm to 30 mm,
The excimer lamp according to claim 5, wherein the discharge vessel has an outer diameter of 3 mm to 10 mm. The excimer lamp according to claim 5, wherein the wall thickness of the discharge vessel is within a range of 0.2 mm to 4 mm. An ultraviolet irradiation device comprising the excimer lamp according to any one of claims 1 to 7. An ozone generator comprising the excimer lamp according to any one of claims 1 to 7.

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