CN110947020A

CN110947020A - Optical processing apparatus and optical processing method

Info

Publication number: CN110947020A
Application number: CN201811124879.5A
Authority: CN
Inventors: 今村笃史; 后藤一浩; 藤次英树
Original assignee: Ushio Denki KK
Current assignee: Ushio Denki KK
Priority date: 2018-09-26
Filing date: 2018-09-26
Publication date: 2020-04-03

Abstract

An optical processing device and an optical processing method, which realize an optical processing device more excellent in sterilization and deodorization capability than the conventional one, comprising: a housing; a gas inlet for introducing a gas to be treated containing oxygen into the casing; an excimer lamp which is disposed in a tube body made of quartz glass in which a discharge gas containing Xe is sealed and which emits first light having a main emission wavelength of 172nm and second light having an intensity in at least a part of a wavelength range of 250nm to 560 nm; an exhaust port for discharging a treated gas containing ozone generated by irradiating the treated gas introduced into the cabinet with first light emitted from the excimer lamp; and a photocatalyst disposed at a position where the second light emitted from the excimer lamp can enter, the photocatalyst containing a material that can be excited by the second light.

Description

Optical processing apparatus and optical processing method

Technical Field

The present invention relates to a light processing apparatus, and more particularly, to an apparatus including an excimer lamp. The present invention also relates to a light processing method using the device including the excimer lamp.

Background

In recent years, techniques for performing deodorization and sterilization using light have been developed. For example, patent document 1 below discloses a process using a mercury lamp that generates light having wavelengths of 185nm and 365 nm. This document describes the following main contents: the odor is deodorized by a decomposition treatment using ozone generated by light having a wavelength of 185nm and a decomposition treatment using a photocatalytic action of light having a wavelength of 365 nm.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001-009241

Patent document 2: japanese laid-open patent publication No. 7-78591

Disclosure of Invention

Problems to be solved by the invention

The technique of patent document 1 is a technique using a mercury lamp. Mercury lamps use mercury as a discharge medium, and are not preferable because they place a large burden on the environment. The present applicant has developed an excimer lamp which is a lamp capable of generating ultraviolet light without using mercury (see patent document 2).

The present inventors have studied to perform sterilization and deodorization using light having a wavelength shorter than 185nm (for example, 172nm) in order to more efficiently generate ozone because of the low ability of generating ozone with light of 185nm disclosed in patent document 1. For example, according to an excimer lamp using xenon (Xe) gas as described in patent document 2, light having a main emission wavelength of 172nm can be generated. Therefore, the present inventors considered that ozone can be efficiently generated by irradiating a gas to be treated containing oxygen (for example, air) with light emitted from the excimer lamp.

However, according to the active studies of the present inventors, it was confirmed that the phenomenon of the decrease in the illuminance of light having a wavelength of 172nm with the lapse of time was observed when such an excimer lamp was caused to emit light continuously. This phenomenon means that the ozone generating ability is reduced with the passage of time, and means that the sterilizing and deodorizing ability is reduced.

In view of the above problems, an object of the present invention is to provide an optical processing apparatus and an optical processing method which are superior in sterilizing and deodorizing ability to conventional techniques.

Means for solving the problems

The optical processing apparatus of the present invention is characterized by comprising:

a housing;

a gas inlet for introducing a gas to be treated containing oxygen into the casing;

an excimer lamp which is disposed in the housing, comprises a tube body made of quartz glass in which discharge gas containing Xe is sealed, and emits first light having a main emission wavelength of 172nm and second light having an intensity in at least a part of a wavelength range of 250nm to 560 nm;

an exhaust port for discharging a treated gas containing ozone generated by irradiating the gas to be treated introduced into the housing with the first light emitted from the excimer lamp; and

and a photocatalyst disposed at a position where the second light emitted from the excimer lamp can enter, the photocatalyst containing a material that can be excited by the second light.

As described above, when the excimer lamp was continuously caused to emit light, a phenomenon was observed in which the illuminance of light having a wavelength of 172nm was reduced with the lapse of time. The present inventors studied the cause as follows. By irradiating light having a wavelength of 172nm onto quartz glass constituting a tube body of an excimer lamp, the bonding of a part of the quartz glass is cut, and a defect is formed at the cut portion. Further, since a part of the light having a wavelength of 172nm is absorbed by the defect, the illuminance of the light having a wavelength of 172nm irradiated from the excimer lamp is lowered.

In contrast, according to the light processing device of the present invention, the first light having the main emission wavelength of 172nm and the second light having the intensity in at least a part of the wavelength range of 250nm to 560nm on the longer wavelength side than the first light are emitted. This second light is located on the long wavelength side compared to the first light, and is not easily absorbed by defects formed on the quartz glass. Therefore, the intensity of the second light emitted from the excimer lamp does not decrease with time or the rate of decrease is extremely slow compared to the first light.

The light processing device further includes a photocatalyst made of a material that can be excited by the second light emitted from the excimer lamp. Therefore, even if the concentration of ozone contained in the treated gas decreases due to a decrease in the intensity of the first light with the lapse of time, the photocatalytic effect can be exhibited by irradiating the photocatalyst with the second light. That is, the decrease in the ozone treatment ability can be compensated by the photocatalytic action. Therefore, a light processing device superior in sterilizing and deodorizing ability to the conventional device is realized.

The discharge gas and the oxygen gas may be sealed in the tube, and the second light may exhibit an intensity in at least a part of a wavelength range of 500nm to 550 nm.

It is common that quartz glass contains various impurities depending on raw materials or manufacturing methods. As a specific example, the quartz glass may contain OH groups. In this case, the quartz glass is irradiated with light having a wavelength of 172nm, and when the bonds in the quartz glass are broken, OH groups are released into the tube. Next, the OH group reacts with Xe gas enclosed in a tube made of quartz glass to form XeO. When XeO is discharged, light is generated that exhibits an intensity in at least a part of the wavelength range of 500nm to 550nm inclusive.

In this case, the photocatalyst is configured to include a material that can be excited by light having an intensity in at least a part of a wavelength range of 500nm to 550nm, whereby the photocatalytic effect of the second light derived from XeO can be achieved. In this case, even if the illuminance of the first light decreases with the lapse of time, the illuminance of the second light increases, and the sterilization and deodorization ability by the photocatalytic action exerted by the irradiation of the photocatalyst with the second light increases. Further, the formed XeO becomes oxygen to be left in the tube after the discharge is stopped.

As a material of such a photocatalyst that can be excited by the second light, for example, titanium dioxide (TiO2) carrying an activator made of a metal salt such as iron chloride (FeCl3), tungsten oxide (WO3) kneaded with palladium or a copper compound, and the like can be used.

The tube may include an oxygen-deficient defect in a part thereof, and the second light may exhibit an intensity in at least a part of a wavelength range of 250nm to 450 nm.

When the material constituting the silica glass is irradiated with the first light having the principal emission wavelength of 172nm, the bonding may be cut off, and an Oxygen deficient defect (ODC) may be formed in a part thereof. The oxygen-deficient defect is excited upon absorption of the first light and emits light (luminescence) exhibiting an intensity in at least a part of a wavelength range of 250nm to 450nm inclusive.

Therefore, by making the photocatalyst a structure containing a material that can be excited by light indicating intensity in at least a part of a wavelength range of 250nm to 450nm, a photocatalytic effect by the second light derived from the luminescence emitted from the oxygen deficient defect is achieved. In this case, even if the illuminance of the first light decreases with the lapse of time, the illuminance of the second light increases, and the sterilization and deodorization ability based on the photocatalytic action exerted by the irradiation of the photocatalyst with the second light also increases.

As a material of such a photocatalyst that can be excited by the second light, for example, titanium dioxide (TiO2) that is an activator made of a metal salt such as iron chloride (FeCl3) supported thereon, tungsten oxide (WO3) kneaded with palladium or a copper compound, and the like can be used.

The intensity of the second light may be 0.5% or more of the intensity of the first light.

The invention relates to a light treatment method using an ozone generating device,

the ozone generation device is provided with:

a housing;

an excimer lamp which is disposed in the housing, includes a tube body in which a discharge gas containing Xe is sealed, and emits first light having a main emission wavelength of 172nm and second light having an intensity in at least a part of a wavelength range of 250nm to 560 nm;

an exhaust port for discharging a treated gas containing ozone generated by irradiating the gas to be treated introduced into the housing with the first light emitted from the excimer lamp;

the light processing method is characterized in that:

the ozone generating device discharges the treated gas containing ozone into a target space to perform ozone treatment, and the photocatalyst disposed in the target space is irradiated with the second light emitted from the excimer lamp to perform photocatalytic treatment.

According to the above method, even if the concentration of ozone contained in the treated gas is decreased, the photocatalyst effect can be exhibited by irradiating the photocatalyst with the second light. That is, the decrease in the ozone treatment capability for the target space can be supplemented by the photocatalytic action. Therefore, a light treatment method having superior sterilization and deodorization performance compared to the conventional one is realized.

In the above-mentioned method, it may be,

the ozone generating device is provided in a first space in the object space,

disposing the photocatalyst in a second space adjacent to the first space in the object space,

a boundary between the first space and the second space is shielded, and a window through which the second light passes is provided in the boundary.

Since ozone is a material toxic to the human body, it is preferable that a space (first space) from which the gas to be treated containing ozone is discharged is unmanned. On the other hand, since the second space is shielded from the first space, the gas to be treated containing ozone does not flow into the second space, and therefore, it does not matter if there is any person. Further, since a window through which the second light can pass is formed at a boundary portion between the first space and the second space, the second light enters the second space through the window. As a result, the second light is incident on the photocatalyst provided in the second space, whereby the sterilization and deodorization function in the second space can be realized.

Effects of the invention

According to the present invention, a light processing apparatus and a light processing method having a superior sterilizing and deodorizing ability as compared with the conventional one are realized.

Drawings

Fig. 1 is a diagram schematically showing a configuration of an embodiment of an optical processing apparatus according to the present invention.

FIG. 2 is a diagram schematically showing a spectrum of Xe excimer light.

Fig. 3 is a graph comparing spectra of light emitted from the tube body at the initial lighting stage and after a predetermined time has elapsed after the start of lighting.

Fig. 4 is a schematic view for explaining an embodiment of the light processing method of the present invention.

Fig. 5 is a graph comparing spectra of light emitted from a tube in the absence XeO and in the presence XeO.

Fig. 6 is a diagram schematically showing the configuration of another embodiment of the optical processing apparatus of the present invention.

Detailed Description

An embodiment of an optical processing apparatus and an optical processing method according to the present invention will be described with reference to the drawings. In each drawing, the dimensional ratio of the drawing does not necessarily coincide with the actual dimensional ratio.

[ Structure ]

Fig. 1 is a diagram schematically showing a configuration of an optical processing apparatus according to an embodiment. As shown in fig. 1, the light treatment device 1 of the present embodiment includes an ozone generation device 10 and a photocatalyst 20.

(ozone generator 10)

The ozone generator 10 includes the arc tube 2. The arc tube 2 includes a tube body 21 made of quartz glass. The ozone generating device 10 includes an external electrode 3 disposed outside the pipe 21 and an internal electrode 4 disposed inside the pipe 21.

The ozone generator 10 includes a housing 5 for housing a tube 21 and electrodes (3, 4). The ozone generator 10 includes an air inlet 6 and an air outlet 8. The gas inlet 6 introduces a gas to be treated G1 containing at least oxygen into the interior of the casing 5. The gas G1 to be treated is irradiated with light emitted from the arc tube 2, whereby a treated gas G2 containing ozone is generated. The exhaust port 8 discharges the processed gas G2 to the outside of the cabinet 5. In the present embodiment, a fan 61 is provided in the intake port 6. For example, the flow rate of the gas to be treated G1 sucked through the intake port 6 can be adjusted by controlling the rotation speed of the fan 61. In the present embodiment, the target gas G1 is, for example, air.

The ozone generating device 10 includes a power supply 7 for applying a voltage (e.g., ac high-voltage power) between the external electrode 3 and the internal electrode 4.

Arc tube 2 includes first sealing portion 22 and second sealing portion 23 at both ends to seal the interior of tube 21. The tube 21 is filled with a discharge gas. The discharge gas contains xenon (Xe). A more detailed example of the discharge gas is a gas in which Xe and Ne are mixed at a predetermined ratio (for example, 3: 7).

Light-emitting tube 2 includes metal foil 24 embedded in first sealing portion 22 and external lead 25 partially embedded in first sealing portion 22. The metal foil 24 is connected to the internal electrode 4 and the external lead 25. Thereby, the internal electrodes 4, the metal foil 24, and the external leads 25 are electrically connected to each other.

In the present embodiment, the external electrode 3 is formed in a cylindrical shape, and the tube 21 is inserted into the external electrode 3. The external electrode 3 includes an optical path portion 31 through which light emitted from the inside of the tube 21 passes or passes. In the present embodiment, the optical path portion 31 is formed of a through hole.

For example, the external electrode 3 may be formed so that a plurality of through holes are formed in the plate-like member, a plurality of rod-like members may be arranged in a lattice shape or a mesh shape, or a rod-like member may be arranged in a spiral shape. The optical path portion 31 may be formed of a translucent member.

In the present embodiment, the internal electrode 4 is formed in a rod shape and is disposed inside the tube 21. Since the end portions of inner electrode 4 are embedded in the sealing portions (22, 23) of light-emitting tube 2, inner electrode 4 is fixed to light-emitting tube 2.

In the present embodiment, the housing 5 is configured to allow or transmit light L2 exhibiting intensity in at least a part of a wavelength range of 250nm to 560 nm. For example, the housing 5 may be made of a material that transmits the light L2, or may have a window portion that transmits the light L2. The light L2 corresponds to second light described later.

(photocatalyst 20)

In the present embodiment, the photocatalyst 20 is composed of a material that is excited and ionized when light exhibiting intensity in at least a part of a wavelength range of 250nm to 560nm is incident, and exhibits a photocatalytic effect. The photocatalyst 20 is made of, for example, a material carrying titanium dioxide (TiO2) containing an activator made of a metal salt such as ferric chloride (FeCl 3).

[ Effect ]

The operation of the optical processing apparatus 1 will be described below.

A voltage is applied between the outer electrode 3 and the inner electrode 4 by a power supply 7. As described above, the pipe body 21 is made of quartz glass, which is a dielectric. Discharge plasma is generated in the tubular body 21 made of a dielectric material, and the discharge gas sealed in the tubular body 21 is excited by the discharge plasma. Specifically, Xe atoms are excited and an excited molecule Xe is generated²*. In the excited molecule Xe²Upon returning to the ground state, excimer emission L1 is generated. Fig. 2 schematically shows a spectrum of Xe excimer light. As shown in FIG. 2, the spectrum of Xe excimer light having a peak at 172nm is shown. In the present embodiment, the Xe excimer light L1 corresponds to "first light".

When the process gas G1 is introduced into the cabinet 5 through the inlet 6, the process gas G1 is irradiated with the first light L1 emitted from the inside of the pipe 21 and passing through the optical path 31. The first light L1 having a main emission wavelength of 172nm cuts off the bonding of oxygen molecules contained in the gas to be treated G1, and generates ozone. Namely, the treated gas G1 is converted into a treated gas G2 containing ozone. The processed gas G2 is discharged from the exhaust port 8. Thus, the treated gas G2 containing ozone is discharged into the space, and is sterilized and deodorized by ozone.

However, a part of the first light L1 having the main emission wavelength of 172nm is irradiated to the tube 21. At this time, the bonds contained in the silica glass constituting the tube body 21 are cut off, and defects are generated in the silica glass. Specifically, an oxygen deficiency defect (ODC) is formed in the pipe body 21. Next, the oxygen-deficient defect is excited upon absorption of the first light L1, and emits second light (luminescence) showing intensity in at least a part of a wavelength range of 250nm to 450 nm.

When the excimer light emission state continues, the number of the oxygen deficiency defects increases. Accordingly, the absorption amount of the first light L1 increases, and thus the intensity of the first light decreases. In contrast, the intensity of the second light generated by exciting the oxygen deficient defect by the first light increases with the passage of time.

Fig. 3 is a graph comparing the spectrum of light emitted from the tube 21 in the initial stage of lighting and after a predetermined time has elapsed after the start of lighting. From FIG. 3, it was confirmed that the light intensity at a wavelength of about 172nm decreases with the passage of time, and the light intensity in a range of from 250nm to 450nm increases. Light having a wavelength in the range of 250nm to 450nm corresponds to luminescence (second light L2) originating from the oxygen deficient defect.

The light of this wavelength band (second light L2) does not have energy for bonding oxygen in the gas G1. Therefore, the second light L2 is not absorbed by the process gas G1, but is emitted to the outside through the cabinet 5. The second light L2 is irradiated to the photocatalyst 20 disposed outside the housing 5. When the second light L2 is incident, the constituent material of the photocatalyst 20 is excited to perform a photocatalytic action. That is, the sterilization and deodorization treatment of the surroundings is performed by the photocatalytic action of the photocatalyst 20.

That is, according to the light treatment device 1 of the present embodiment, even if the amount of ozone contained in the treated gas G2 is reduced, the photocatalytic action by the photocatalyst 20 is improved, and the sterilization and deodorization ability can be supplemented by the photocatalytic action.

Fig. 4 is a schematic view for explaining an embodiment of the light processing method of the present invention. In fig. 4, the ozone generating device 10 is disposed in the first space 71, and the photocatalyst 20 is disposed in the second space 72. The first space 71 and the second space 72 are adjacent to each other and shielded from each other by a boundary portion 73. However, a light-transmitting window 74 is provided at least in a part of the boundary portion 73. The light-transmitting window 74 is made of a material that can transmit the second light L2.

With this configuration, the first space 71 of the target space is sterilized and deodorized by the ozone-containing treated gas G2 discharged from the ozone generating device 10. Further, the second space 72 in the target space is irradiated with the second light L2 emitted from the arc tube 2 included in the ozone generating apparatus 10 toward the photocatalyst 20, thereby performing the sterilization and deodorization process by the photocatalytic action of the photocatalyst 20.

[ other embodiments ]

Other embodiments will be described below.

(1) The quartz glass constituting the tube body 21 may contain OH groups. In this case, when the tube 21 is irradiated with the first light L1 having a wavelength of 172nm, the bonds in the quartz glass are broken, and OH groups are released into the discharge space. Next, XeO is generated by the reaction of the OH radicals with the gas enclosed in the tube 21. When XeO is discharged, light (green light) exhibiting an intensity in at least a part of the wavelength range of 500nm to 560nm is generated.

Fig. 5 is a graph comparing the spectra of light emitted from the tube 21 in the case where XeO is present in the tube 21 and in the case where XeO is not present. According to fig. 5, when XeO is present in the tube 21, it is confirmed that the intensity of light in the wavelength range of 500nm to 560nm is improved. In addition, it was confirmed from fig. 5 that the intensity of light in the wavelength range of 500nm to 550nm was significantly improved.

Therefore, the photocatalyst 20 is configured to contain a material that is excited when light having a wavelength range of 500nm to 560nm is incident and exhibits a photocatalytic effect, and to realize a photocatalytic function by the second light derived from XeO.

The photocatalyst 20 may be formed of a material that can exhibit a photocatalytic effect on both the second light (wavelength of 250nm to 450 nm) originating from the oxygen deficiency defect and the second light (wavelength of 500nm to 560 nm) originating from XeO.

(2) A slight amount of oxygen may be introduced into the pipe body 21. As a result, as described in the above-described other embodiment (1), XeO is contained in the tube 21, and thus the second light having a wavelength band of 500nm to 560nm is generated.

(3) In the above-described embodiment, the structure in which the arc tube 2 is the tube body 21 having the single-layer structure has been described in the ozone generating device 10, but this is merely an example. For example, as shown in fig. 6, the arc tube 2 may have a double-layer tube 26, and the double-layer tube 26 may have a double-layer structure including an outer tube 26a serving as a dielectric and an inner tube 26b serving as a dielectric. Fig. 6 is a diagram schematically showing the structure of ozone generating apparatus 10 in another embodiment.

In the ozone generating apparatus 10 shown in fig. 6, the arc tube 2 includes a double-layer tube 26 having an outer tube 26a as a dielectric and an inner tube 26b as a dielectric, and an annular sealing end 27 for hermetically sealing the outer tube 26a and the inner tube 26 b. The discharge gas is sealed between the outer tube 26a and the inner tube 26 b.

The internal electrode 4 is formed in a cylindrical shape. Further, since the internal electrode 4 is disposed inside the double-layer tube 26 (the internal tube 26b), the double-layer tube 26 (the external tube 26a and the internal tube 26b) is disposed between the external electrode 3 and the internal electrode. The inner electrode 4 is fixed to the arc tube 2 so as to be in contact with the double-layer tube body 26 (inner tube 26 b). In this configuration, the gas G1 to be treated may be circulated inside the inner tube 26b, and the first light L1 emitted from the arc tube 2 may be irradiated to generate the treated gas G2 containing ozone.

(4) In the ozone generating apparatus 10 of the above embodiment, the air inlet 6 is configured to include the fan 61. However, for example, the fan 61 may be provided on the side of the exhaust port 8, or may be provided on both the intake port 6 and the exhaust port 8.

(5) The photocatalyst 20 may be provided also on the inner surface side of the casing 5 in the ozone generating device 10. Thus, the gas G1 to be treated is subjected to photocatalytic action, and a treated gas G2 containing high-purity ozone is generated.

Description of the reference symbols

1: optical processing device

3: external electrode

4: internal electrode

5: casing (CN)

6: air inlet

7: power supply

8: exhaust port

10: ozone generator

20: photocatalyst and process for producing the same

21: pipe body

22: a first sealing part

23: second sealing part

24: metal foil

25: external lead wire

26: double-layer pipe body

26 a: outer tube

26 b: inner pipe

27: sealing the end

31: light path part

61: fan with cooling device

71: the first space

72: second space

73: boundary portion

74: light-transmitting window

G1: gas to be treated

G2: treated gas

Claims

1. An optical processing apparatus, comprising:

a housing;

2. The light processing device of claim 1,

oxygen gas is sealed in the tube together with the discharge gas,

the second light exhibits an intensity in at least a part of a wavelength range of 500nm or more and 550nm or less.

3. A light processing device according to claim 1 or 2,

the tube body includes an oxygen deficient defect in a portion thereof,

the second light exhibits an intensity in at least a part of a wavelength range of 250nm or more and 450nm or less.

4. A light processing device according to claim 1 or 2,

the intensity of the second light is 0.5% or more of the intensity of the first light.

5. A light treatment method using an ozone generator, characterized in that,

the ozone generating device is provided with:

a housing;

an excimer lamp which is disposed in the housing, includes a tube body in which a discharge gas containing Xe is sealed, and emits first light having a main emission wavelength of 172nm and second light having an intensity in at least a part of a wavelength range of 250nm to 560 nm; and

an exhaust port for discharging a treated gas containing ozone generated by irradiating the treated gas introduced into the housing with the first light emitted from the excimer lamp,

6. The light processing method of claim 5,

the ozone generating device is provided in a first space in the object space,