JP2023043997A - Ultraviolet irradiation device, ozone generator, and method for lighting excimer lamp - Google Patents

Abstract

To provide an excimer lamp capable of effectively irradiating ultraviolet rays in an ozone generator or the like.SOLUTION: An ozone generator 100 includes an excimer lamp 10 and a control unit 110. The control unit 110 repeatedly turns on and off the excimer lamp 10 at a frequency f2 that is lower than the frequency f1 at which a voltage is applied to the excimer lamp 10 such that the discharge in the transient state continues.SELECTED DRAWING: Figure 1

Description

There is an application for exception to loss of novelty

The present invention relates to excimer lamps, and more particularly to lamp lighting control.

In an excimer lamp, an electrode (hereinafter referred to as an outer electrode) is arranged on the outer peripheral surface of a discharge vessel made of a dielectric such as quartz glass. On the other hand, an electrode (hereinafter referred to as an inner electrode) is arranged inside the discharge vessel along the lamp axis, and a rare gas such as xenon gas is enclosed in the discharge vessel. By applying a voltage between the inner electrode and the outer electrode, a dielectric barrier discharge or a capacitively coupled high-frequency discharge occurs in the discharge space in the discharge vessel, and ultraviolet rays are emitted as excimer light (see, for example, patent documents 1).

Japanese Patent No. 6423642

For example, when an excimer lamp is used as an ozone generator, the required amount of ozone generation varies depending on the usage environment, usage conditions, etc., and in some cases, stable generation of low-concentration ozone is required. In addition, in a compact ozone generator using a battery, there are limits on the size and power of the excimer lamp, and ozone generation with reduced power consumption is required.

Therefore, lighting control of an excimer lamp capable of effectively irradiating ultraviolet rays is required according to the usage environment of an ozone generator or the like.

An ultraviolet irradiation device that is one aspect of the present invention can be applied to an ozone generator, and includes an excimer lamp and a controller that controls lighting of the excimer lamp. Then, the control unit repeatedly turns on and off the excimer lamp so as to continue the discharge in the transient state. As such lighting control, it is possible to set the frequency f2 of periodically repeating turning on and off of the excimer lamp to be lower than the frequency f1 of the voltage applied to the excimer lamp. f2 can be set in the range of 1 to 60 Hz.

For example, the ozone generator can include an operation detection switch that detects an input operation by the user. The operation detection switch can be configured to detect an input operation with a period of frequency f3=f2×n (n is a natural number).

An ozonizer according to another aspect of the present invention includes an excimer lamp and a controller that controls lighting of the excimer lamp, and the controller controls lighting and extinguishing of the excimer lamp so as to continue discharge in a transient state. repeat. For example, it is possible to perform lighting control that repeats lighting and extinguishing so that the amount of ozone generated when repeating transient discharge is half or less of the amount of ozone generated when discharging in steady state.

The ozone generator can comprise a channel tube in which the excimer lamp is arranged. Lighting control can be performed so that the flow rate of the oxygen-containing fluid flowing through the channel tube is 1 m ³ /min or less.

For example, the ozone generator can include an operation detection switch that detects an input operation by the user. The operation detection switch can be configured to detect an input operation with a period of frequency f3=f2×n (n is a natural number).

According to another aspect of the present invention, there is provided a method of lighting an excimer lamp including an electrode at least partially exposed in at least a discharge vessel, the method comprising: , the excimer lamp is repeatedly turned on and off.

According to the present invention, it is possible to provide an excimer lamp capable of effectively irradiating ultraviolet rays in an ozone generator or the like.

It is a schematic sectional view seen from the side of the excimer lamp in the ozone generator of the present embodiment. It is a block diagram of an ozone generator.

Hereinafter, an ozone generator provided with an excimer lamp, which is an embodiment of the present invention, will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of the excimer lamp in the ozone generator of this embodiment, viewed from the side.

The ozone generator 100 includes an excimer lamp 10 and is controlled by a controller (not shown here). The excimer lamp 10 is arranged in a channel tube 90 through which a raw material gas containing oxygen flows. While the source gas flows around the excimer lamp 10 by an intake fan (not shown), the excimer lamp 10 irradiates the source gas with ultraviolet rays to generate ozone.

The ozone generator 100 is configured here as a low-concentration ozone generator, and configured as a battery-driven compact device. That is, the ozone generator 100 incorporating the excimer lamp 10 and the ultraviolet irradiation device having the controller capable of controlling the lighting of the excimer lamp 10 can be installed horizontally so that the flow pipe 90 extends in the horizontal direction. Moreover, it is also possible to install the flow pipe 90 directly above so as to extend in the vertical direction.

The excimer lamp 10 has a substantially cylindrical portion having a constant inner diameter along the lamp axis C in a cross section surrounding the discharge space region, and is sealed at both ends by diameter-reduced portions having a reduced inner diameter along the lamp axis C. The discharge vessel 20 comprises a sealed discharge vessel 20 and is constructed of a dielectric material, such as quartz glass, which is transparent to ultraviolet radiation. A cylindrical portion of the discharge vessel 20 has a small-diameter portion 21 integrally formed through a diameter-reduced portion at the front end thereof, and a sealing pipe 22 integrally formed through a diameter-reduced portion at the rear end thereof. ing. That is, the discharge vessel 20 has the small-diameter portion 21 and the reduced-diameter portion integrally formed on the front end side of the cylindrical portion, and the sealing tube 22 and the reduced-diameter portion integrally formed on the rear end side of the cylindrical portion. ing. A discharge space S in the discharge vessel 20 is filled with a rare gas such as xenon.

In the sealing tube 22, the inner electrode 40 is arranged to extend along the lamp axis C, and the electrode tip portion (hereinafter referred to as the tip portion) 40T is exposed to the discharge space S to form the cylindrical portion of the discharge vessel 20. and along the lamp radial direction. That is, only the tip portion 40T of the inner electrode 40 faces the cylindrical portion of the discharge vessel 20 along the radial direction of the lamp, and the other portion of the inner electrode 40 faces the contraction of the discharge vessel 20 along the radial direction of the lamp. It is configured to face the diameter portion and not face the cylindrical portion of the discharge vessel 20 . On the other hand, the rear end side of the inner electrode 40 is connected to a feeder line (hereinafter referred to as inner feeder line) 25 via a sealing foil (metal foil) 24 .

An outer electrode 50 is provided on the outer surface 20S of the discharge vessel 20 . The outer electrode 50 exposes the outer surface 20S of the discharge vessel 20 and is helically wound with a conductive wire so as not to block the ultraviolet rays emitted from the discharge in the discharge vessel, mainly for the formation of the discharge in the discharge vessel. The discharge electrode portion (hereinafter referred to as a spiral electrode portion) 51 that contributes to holding electrode portions (hereinafter referred to as annular portions) 52, 54, 56 wound around.

The spiral electrode portion 51 is wound along the lamp axis C from the front end side to the rear end side of the cylindrical portion of the discharge vessel 20 so as to be in close contact with the outer surface 20S, and is welded to the annular portions 52, 54, and 56. It is an electrode portion electrically connected to the outer surface of the discharge vessel 20 and movement along the lamp axis C is suppressed by winding, and the thin wire extends over the entire range of the discharge space S in the lamp axis direction. It is disposed on the outer surface 20S so as to generate a shaped discharge. The annular portions 52 and 56 are located at both ends of the spiral electrode portion 51 of the discharge vessel 20, and particularly the annular portion 56 is located so as to face the tip portion 40T of the inner electrode 40 in the lamp radial direction. An annular portion 54 is located near the center of the lamp therebetween. The annular portion 54 is positioned closer to the center of the lamp than the tip portion 40T of the inner electrode 40 .

The annular portions 52 , 54 , 56 are configured by welding the end portions of a cylindrically wound conductive plate. The contact suppresses formation of a gap with respect to the outer surface 20S of the discharge vessel 20 and movement along the lamp axis C, and holds the spiral electrode portion 51 so as to sandwich it along the lamp axis C. Further, an extension portion 54B is provided in the annular portion 54 located near the central portion of the lamp.

The extending portion 54B extends along the direction away from the outer surface of the discharge vessel (here, extends linearly along the radial direction of the lamp), and its distal end portion 54BT is connected to the outer feeder line 70 on the ground side at the connecting portion BT. Connected.

The shortest distance between the discharge vessel 20 and the outer power supply line 70, that is, the distance D from the outer surface 20S of the discharge vessel 20 to the connection part BT, is the raw material gas flowing along the periphery of the discharge vessel 20 and the processing power. It is possible to determine it in consideration of the flow condition of the fluid, etc., and the ultraviolet illuminance in the region where the outer power supply line 70 and the connection portion BT are located. For example, in the case of ultraviolet rays with a wavelength of 172 nm, the ultraviolet intensity ratio is attenuated to 50% or less when traveling about 3 mm, and is attenuated to 20% or less when about 6 mm. It is determined to be at least the distance at which the UV intensity ratio is attenuated to 50% (ultraviolet attenuation distance), preferably at least the distance at which the UV intensity ratio is attenuated to 20%.

When a high-frequency high voltage is applied between the inner electrode 40 and the outer electrode 50, a dielectric barrier discharge occurs, and here, the wavelength range of vacuum ultraviolet rays, that is, ultraviolet rays with a wavelength of 200 nm or less (for example, a wavelength of 172 nm) is generated. It is radiated out of the discharge vessel 20 as excimer light. Ozone is generated by the raw material gas containing oxygen flowing around the excimer lamp 10 in the flow pipe 90 , and the gas containing ozone is discharged to the outside of the ozone generator 100 . Thereby, sterilization, deodorization, etc. can be performed.

FIG. 2 is a schematic block diagram of the ozone generator 100. As shown in FIG. Here, only the configuration related to lighting control of the excimer lamp 10 is illustrated.

The control unit 110 controls the operation of the ozone generator 100 including lighting control of the excimer lamp 10 . The lamp ON/OFF circuit 120 is connected to the lamp power circuit 130 and controls the operation of the lamp power circuit 130 so that the excimer lamp 10 can be periodically turned on and off repeatedly. A battery 140 that supplies power to each circuit such as the control unit 110 is composed of a secondary battery such as a lithium battery, and can be charged via a USB terminal cable.

The ozone generator 100 is provided in the apparatus housing 100A, and includes an operation unit 150 operated to start the ozone generation operation, set the ozone generation time, and the like. A switch circuit (hereinafter referred to as an operation detection switch) 160 detects a user's input operation to the operation unit 150 and is composed of a touch sensor. An indicator 170 configured by an LED or the like and provided on the housing 100A can display ozone generation time, remaining battery power, and the like.

In the present embodiment, the excimer lamp 10 is extinguished (extinguished) before the unstable discharge state (transient state discharge) immediately after lighting (ignition) transitions to a stable discharge state (steady state discharge). , and immediately after that turn it on again. By repeatedly turning on and off in this manner (hereinafter referred to as periodical lighting), a lighting method is adopted in which transient discharge is continuously generated.

In the dielectric barrier discharge, when a voltage is applied at a predetermined frequency, the discharge continues in the portion where the converging thin-line microplasma discharge is generated, and the discharge continues in the portion where the thin-line microplasma discharge is not generated. There is a so-called memory effect that does not occur. Here, in order to reset the so-called memory effect (return to the state before the discharge occurred), a reset lighting operation is performed in which the lamp is extinguished before the steady-state discharge that causes the memory effect is generated, and the transient discharge is repeated.

Periodic lighting is performed based on a frequency f2 that is lower than the frequency f1 of the applied voltage when the excimer lamp 10 is lit by applying a high frequency high voltage. For example, when the frequency f1 of the applied voltage is set in the range of 1 kHz to 500 kHz, the frequency f2 is set in the range of 1 to 60 Hz. In particular, it may be set in the range of 20 Hz to 40 Hz.

When the excimer lamp 10 is lit by periodic lighting by configuring that only the tip portion 40T of the inner electrode 40 faces the outer electrode 50 (in particular, the annular portion 56) along the radial direction of the lamp, microplasma discharge occurs. In the discharge vessel 20 , a discharge is formed that is biased toward the tube wall, and a dense and uniform discharge does not occur throughout the discharge vessel 20 . Therefore, even if the discharge space area along the lamp axis C in the discharge vessel 20 is enlarged, the amount of ozone generated does not increase significantly, and low-concentration ozone (low amount of ozone) can be stably generated. can. Also, the foreign matter emitted from the inner electrode 40 does not accumulate in the area surrounding the discharge space area of the discharge vessel 20, but accumulates on the inner surface of the discharge vessel 20 on the rear end side of the tip portion 40T of the inner electrode 40. Therefore, blocking of ultraviolet rays by deposits is suppressed.

Also, by periodically lighting the excimer lamp 10, the microplasma discharge (discharge column) generated in the dielectric barrier discharge is generated at a different position for each blinking (reset). This is due to microplasma discharge occurring in a spatial region with low electrical resistance (temperature) at the moment of relighting.

Continuous generation of transient discharge while shifting to a relatively low-temperature spatial region prevents continuous irradiation of ultraviolet rays and generation of ozone in the same region, unlike steady-state discharge. Therefore, on the inner surface side of the discharge vessel 20, foreign matter emitted from the inner electrode 40 is prevented from continuously adhering or accumulating in the same area. suppressed from declining. In addition, on the outer surface side of the discharge vessel 20, the chemical reaction (oxidation) of foreign matter that adheres or accumulates on the connecting portion between the outer electrode and the power supply line is suppressed, so that the adhesion of foreign matter, deterioration of the electrode, and abnormal discharge are prevented. Suppressed. In addition, the uniform discharge within the discharge vessel 20 does not cause a temperature rise in the entire discharge vessel 20, and the temperature rise in the vicinity of the surface of the discharge vessel 20, which has a high ultraviolet intensity, is suppressed, thereby preventing thermal decomposition by ozone. Suppressed. Therefore, low-concentration ozone can be stably generated continuously, and the ozone generation time can be lengthened with respect to the battery capacity.

In addition, in order to intentionally generate snaking and flickering, which are regarded as abnormal discharge states in lighting and exposure, a converging thin-line microplasma discharge extends from the tip 40T of the internal electrode 40 and spreads to the inner surface of the discharge vessel 20. Along the way, irregular and complex periodic changes occur constantly. Due to such a discharge state, the same area of the discharge vessel 20 is not continuously irradiated with ultraviolet rays, and a visually dramatic transitional discharge is repeated. You can get used to interior design and so on.

Since the ultraviolet irradiance emitted from a transient discharge is lower than the ultraviolet irradiance emitted from a steady state discharge, if the transient discharge continues, the amount of ozone generated is less than the amount of ozone generated by the steady state discharge. less than half. In addition, in order to continue generating ozone at a low concentration, the operation of the intake fan 180 is controlled so that the flow rate of the raw material gas is 1 m ³ /min or less.

The operation detection switch 160 monitors (detects) input operations to the operation unit 150 at regular time intervals. A frequency f3 as a detection cycle (detection cycle) of the operation detection switch 160 is set to be n times (n is a natural number) the frequency f2. That is, monitoring is performed in accordance with the periodic lighting (reset timing) operation of the excimer lamp 10 . As a result, there is no effect on the lamp power supply circuit 130 during the transient discharge.

The excimer lamp 10 is not limited to the configuration of the discharge vessel in which a part of the inner electrode 40 is exposed to the discharge space S, and the shape of the discharge vessel, the arrangement configuration of the inner electrodes, and the like are arbitrary. For example, it can also be applied to a double-tube structure lamp. Further, it is possible to construct not only a battery-driven compact ultraviolet irradiation device or an ozone generator, but also an ultraviolet irradiation device or an ozone generator using a commercial power source.

REFERENCE SIGNS LIST 10 excimer lamp 20 discharge vessel 100 ozone generator 110 controller 120 lamp ON/OFF circuit

Claims (10)

an excimer lamp and
A control unit that controls lighting of the excimer lamp,
An ultraviolet irradiation device, wherein the control unit repeatedly turns on and off the excimer lamp so as to continue discharge in a transient state. 2. The ultraviolet irradiation device according to claim 1, wherein a frequency f2 at which the excimer lamp is periodically turned on and off is lower than a frequency f1 of the voltage applied to the excimer lamp. 3. An excimer lamp according to claim 2, wherein said frequency f2 is defined in the range of 1 to 60 Hz. further comprising an operation detection switch for detecting an input operation by the user,
4. The ultraviolet irradiation device according to any one of claims 2 and 3, wherein said operation detection switch detects an input operation with a period of frequency f3=f2*n (n is a natural number). An ozone generator comprising the ultraviolet irradiation device according to any one of claims 1 to 4. an excimer lamp and
A control unit that controls lighting of the excimer lamp,
The ozonizer according to claim 1, wherein the control unit repeatedly turns on and off the excimer lamp so as to continue discharge in a transient state. 7. The ozone generator according to claim 6, wherein the amount of ozone generated when repeating the transient state discharge is half or less of the amount of ozone generated when the discharge is in the steady state. further comprising a channel tube in which the excimer lamp is arranged;
8. The ozone generator according to claim 6 or 7, wherein the flow rate of the oxygen-containing fluid flowing through the flow pipe is 1 m ^<3> /min or less. further comprising an operation detection switch for detecting an input operation by the user,
9. The operation detection switch detects an input operation at a detection cycle of frequency f3=f2*n (f2 is the frequency of repeating turning on and off of the excimer lamp, n is a natural number). The ozone generator according to any one of the above. A method for lighting an excimer lamp having an electrode at least partially exposed in at least a discharge vessel, comprising:
A method of lighting an excimer lamp, characterized in that the excimer lamp is repeatedly turned on and off so as to continue discharge in a transient state.

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