JP2018167167A - Water treatment apparatus - Google Patents

Abstract

To provide a water treatment apparatus capable of decomposing hydrogen peroxide contained in water i.e., a treatment object without using a catalyst.SOLUTION: The water treatment apparatus comprises a first pipe for water to pass therethrough, a second pipe disposed to surround the first pipe, a third pipe disposed to surround the second pipe, discharge gas filled in a space disposed between the second pipe and the third pipe, a first electrode attached to the outer wall of the third pipe, a second electrode attached either to the inner wall of the second pipe or to the outer wall of the first pipe, and a phosphor layer disposed at least either on the inner wall of the third pipe or on the outer wall of the second pipe. The discharge gas is constituted of a material that emits first light when a prescribed voltage is applied between the first electrode and the second electrode. The phosphor layer is constituted of a material that emits second light having a longer wave length relative to the first light and having a main emission wavelength of 189 nm or more and 250 nm or less when the first light is made incident thereon. The first pipe is constituted to include a material that blocks light of a wavelength of shorter than 189 nm.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a water treatment apparatus, and more particularly to an apparatus that performs treatment by irradiating water with ultraviolet light.

  In a cleaning process in a manufacturing process of a semiconductor device, a large amount of pure water (ultra pure water) for rinsing it is used together with a high concentration chemical solution and detergent. In recent years, with the miniaturization, high density, and high integration of circuit patterns in semiconductor devices, demands for the quality of pure water are increasing. Pure water used in the washing process and the like is required to have a very low level of total organic carbon (TOC), which is one of the water quality management items. This is because if the pure water contains a large amount of organic matter, the organic matter may be carbonized in the subsequent heat treatment step, resulting in poor insulation.

  In recent years, various methods for decomposing and removing a small amount of organic substances contained in pure water have been studied against the background of increasing demand for the quality of pure water. A representative example of such a method is a method for decomposing and removing organic substances using an ultraviolet light oxidation treatment apparatus.

  In the ultraviolet light oxidation treatment device, the treatment is performed by irradiating water (ultraviolet light) from a low-pressure mercury lamp to water treated by a reverse osmosis membrane separation device or the like. Water is excited by the irradiation energy of ultraviolet light, and generates radicals, specifically, hydrogen radicals (.H) and hydroxy radicals (.OH) as shown in the following formula (1). Repeat the reaction to return.

Further, hydrogen peroxide is generated in the treatment by the ultraviolet light oxidation treatment apparatus. Specifically, when water is excited by ultraviolet light, hydrogen peroxide (H ₂ O ₂ ) is generated as shown in the following formula (2).

  When water contains hydrogen peroxide, it is not preferable to use the water in a semiconductor device manufacturing process, for example, because hydrogen peroxide may affect the semiconductor device manufacturing process. For this reason, pure water is required to have a very low concentration of hydrogen peroxide as well as TOC.

  In order to solve such problems caused by hydrogen peroxide, the treated water discharged by the ultraviolet light oxidation treatment device is removed by a hydrogen peroxide removal member such as a resin or an adsorbent. It has been proposed to supply the ion exchange apparatus after the treatment (for example, see Patent Document 1 below).

  Specifically, in a water treatment system, an anion exchange tower filled with an anion exchange resin (hydrogen peroxide removal resin) or a carbon-based adsorbent (peroxidation) between an ultraviolet light oxidation treatment device and an ion exchange device. It has been proposed to provide an adsorption tower packed with an adsorbent for hydrogen removal.

JP 2011-176733 A

  However, when hydrogen peroxide is removed by the above method, there is a problem that the apparatus becomes extremely large. Moreover, since the used catalyst is disposed of, there is a problem that the load on the environment is large. An object of this invention is to provide the water treatment apparatus which can decompose | disassemble the hydrogen peroxide contained in the water which is a process target, without using a catalyst in view of said subject.

The water treatment apparatus according to the present invention is
A first pipe for water flow,
A second tube made of a dielectric material provided to surround the first tube;
A third tube made of a dielectric provided to surround the second tube;
A discharge gas filled in a space sandwiched between the second tube and the third tube;
A first electrode provided on the outer wall of the third tube;
A second electrode provided on the inner wall of the second tube or the outer wall of the first tube;
At least a phosphor layer provided on the inner wall of the third tube or the outer wall of the second tube,
The discharge gas is made of a material that emits first light when a predetermined voltage is applied between the first electrode and the second electrode,
The phosphor layer is made of a material that emits second light having a longer wavelength than the first light and a main emission wavelength of 189 nm to 250 nm when the first light is incident thereon,
The first tube includes a material that blocks light having a wavelength of less than 189 nm.

  The above water treatment apparatus uses the principle of an excimer lamp. When a voltage is applied between the first electrode and the second electrode, discharge is performed on the discharge gas filled in the space sandwiched between the second tube and the third tube, each made of a dielectric. And excimer emission occurs. The light from this excimer emission corresponds to the first light.

  A phosphor layer is provided at least on the inner wall of the third tube or the outer wall of the second tube. When the first light is incident on the phosphor layer, the first light excites fluorescence. Thereby, the second light having a longer wavelength than the first light is emitted from the phosphor layer. The phosphor layer is made of a material that emits second light having a longer wavelength than the first light and a main emission wavelength of 189 nm to 250 nm when the first light is incident. That is, the second light has a main emission wavelength of 189 nm to 250 nm. More preferably, the second light has a main emission wavelength of 189 nm or more and 210 nm or less.

  The first light and the second light are incident on the outer wall of the second tube, and then pass through the wall portion of the second tube and are incident on the outer wall of the first tube. Here, the first tube includes a material that blocks light of less than 189 nm. For this reason, the first light is blocked at the wall of the first tube, while the second light is transmitted to the inside of the first tube.

  Water (hereinafter referred to as “liquid to be treated”) to be treated is passed through the inside of the first pipe. More specifically, water containing hydrogen peroxide is used as the liquid to be treated. For example, as the liquid to be treated, water that has undergone a step of removing TOC is used.

  In other words, the liquid to be treated containing hydrogen peroxide is irradiated with light of 189 nm or more. Since the main light emission wavelength of the second light is 189 nm or more and 250 nm or less, the light in the vicinity of the peak wavelength of the second light is irradiated to the liquid to be processed that flows inside the first tube.

  FIG. 1 is a drawing schematically showing an absorption spectrum of hydrogen peroxide. In FIG. 1, the horizontal axis indicates the wavelength of light, and the vertical axis indicates the absorption coefficient. FIG. 1 shows that light having a wavelength band of 250 nm or less is absorbed by hydrogen peroxide. In addition, according to FIG. 1, the high absorptance is shown about the light of a wavelength band 210 nm or less. When light is absorbed by hydrogen peroxide, a reaction represented by the following formula (3) occurs. That is, hydrogen peroxide is decomposed into water and oxygen.

  FIG. 2 is a drawing schematically showing the transmission spectrum of water. According to FIG. 2, it is shown that the wavelength (absorption edge on the short wavelength side) at which the transmittance of water greatly decreases exists at 189 nm. That is, even when light having a wavelength of 189 nm or more is irradiated to water, water absorbs little or no light. That is, the reaction of the above formula (2) does not occur.

  That is, according to the water treatment apparatus, the liquid to be treated containing the hydrogen peroxide is irradiated with light having a wavelength band that is not easily absorbed by water and is easily absorbed by hydrogen peroxide. Therefore, although decomposition of hydrogen peroxide proceeds, decomposition of water does not proceed. As a result, the amount of hydrogen peroxide contained in the liquid to be treated can be reduced. According to this configuration, the amount of hydrogen peroxide contained in the liquid to be treated can be reduced by irradiating light, so that there is no need to use a catalyst as in the conventional case.

  In the present specification, “blocking light” may mean that 75% or more of incident light is not transmitted. The first tube is configured not to transmit 75% or more of light having an incident wavelength of less than 189 nm, and is preferably configured not to transmit 85% or more of light.

  The discharge gas may be made of a material that does not contain fluorine. For example, Xe, Ar, Kr, ArCl, ArBr, or the like can be used as the discharge gas.

  When ArF is used as a discharge gas, it is known that excimer emission with a main emission wavelength of 193 nm occurs. However, there is a problem that the luminous efficiency is low and fluorine has a high environmental load. According to the above configuration, it is possible to irradiate the liquid to be processed with light having a wavelength band suitable for decomposition of hydrogen peroxide while using a material having a low environmental load as a discharge gas.

The discharge gas is made of a material containing Xe,
The main emission wavelength of the first light may be 172 nm.

  Excimer light emission using Xe can generate light with high light emission efficiency. The main emission wavelength of this excimer light is 172 nm. As shown in FIG. 2, light having a wavelength of 172 nm exhibits a high absorption rate with respect to water. Therefore, if the excimer light having a wavelength of 172 nm is directly applied to the liquid to be processed, the reaction based on the above formulas (1) and (2) proceeds, and hydrogen peroxide is generated. According to FIG. 1, since the light of 172 nm is also absorbed by hydrogen peroxide, the reaction based on the above equation (3) also proceeds. However, water is decomposed at a faster rate than the rate at which hydrogen peroxide is decomposed, and hydrogen peroxide contained in the liquid to be treated cannot be substantially reduced.

  However, according to the above configuration, excimer light having a main emission wavelength of 172 nm is irradiated on the phosphor layer, so that light having a longer emission wavelength than that of the main emission wavelength of 189 nm to 250 nm (second Light). Furthermore, the first tube through which the liquid to be treated is passed is configured to include a material that blocks light of less than 189 nm. As a result, the liquid to be treated is irradiated with light (second light) having a main emission wavelength of 189 nm or more and 250 nm or less, but is not irradiated with excimer light (first light) having a main emission wavelength of 172 nm. Therefore, water contained in the liquid to be treated is hardly decomposed and hydrogen peroxide is decomposed, so that the amount of hydrogen peroxide contained in the liquid to be treated can be reduced.

The water treatment device
A reflective layer provided on the inner wall of the third tube and capable of reflecting the first light and the second light;
The phosphor layer may be formed on the upper surface of the reflective layer.

  According to this configuration, the excimer light (first light) generated in the discharge space and the fluorescence (second light) generated by the first light being incident on the phosphor layer are converted into the second tube side. Can be guided with high efficiency. When the first light is incident on the phosphor layer, it is converted into the second light in the phosphor layer, but a part of the first light passes through the phosphor layer and reaches the inner wall of the third tube. As described above, by providing the reflective layer on the inner wall of the third tube, the first light can be reflected by the reflective layer and incident again into the phosphor layer. As a result, the intensity of the second light is increased.

  The second light generated in the phosphor layer includes light traveling toward the second tube and light traveling toward the inner wall of the third tube. As described above, by providing the reflective layer on the inner wall of the third tube, the traveling direction of the second light reaching the inner wall of the third tube can be changed to the second tube side. As a result, the intensity of the second light irradiated to the liquid to be processed is increased.

  After the material constituting the reflective layer is fired on the inner wall of the third tube, the material constituting the phosphor layer is fired to provide the reflective layer and the phosphor layer on the inner wall of the third tube. it can.

  The first tube may be made of quartz glass having a lower OH group content than the second tube and the third tube.

  Quartz glass is a material having a wide wavelength range of light with high transmittance. When the content of OH groups mixed in quartz glass is lowered, the absorption edge can be shifted to the long wavelength side. That is, by making the content of the OH group of the material constituting the first tube less than that of the second tube or the third tube, the first tube has a function of blocking light of short wavelengths. Is possible. The first tube may be configured to have a smaller OH group content than the second tube or the third tube to the extent that the ability to block light of less than 189 nm is developed.

  The first tube may include a light blocking layer that blocks the first light on an outer wall of the first tube.

  The light blocking layer may be made of the same material as the phosphor layer. By setting it as this structure, the 1st light which injected into the outer wall of the 1st pipe | tube is converted into a 2nd light, and this to-be-processed liquid is irradiated with this 2nd light.

  The first electrode may be made of a metal material capable of reflecting the first light and the second light.

  By adopting such a configuration, even if there is light transmitted through the outer wall of the third tube among the first light or the second light, it can be reflected by the first electrode and returned to the second tube side. it can. Thereby, the intensity | strength of the 2nd light irradiated to a to-be-processed liquid is raised.

  ADVANTAGE OF THE INVENTION According to this invention, the water treatment apparatus which can decompose | disassemble the hydrogen peroxide contained in the water which is a process target is achieved, without using a catalyst.

It is drawing which shows typically the absorption spectrum of hydrogen peroxide. It is drawing which shows the transmission spectrum of water typically. It is a typical top view of a water treatment apparatus. It is typical sectional drawing of a water treatment apparatus. It is drawing which shows the spectrum of Xe excimer light typically. It is a graph which shows the relationship between elapsed time and the hydrogen peroxide containing density | concentration in a to-be-processed liquid when flowing a to-be-processed liquid with respect to a water treatment apparatus. It is typical sectional drawing of another embodiment of a water treatment apparatus. It is typical sectional drawing of another embodiment of a water treatment apparatus. It is typical sectional drawing of another embodiment of a water treatment apparatus. It is typical sectional drawing of another embodiment of a water treatment apparatus. It is typical sectional drawing of another embodiment of a water treatment apparatus.

  An embodiment of a water treatment apparatus according to the present invention will be described with reference to the drawings. In addition, each following drawing shows one Embodiment of a water treatment apparatus, and is not the meaning which limits this invention to the structure shown in figure. Moreover, in each figure, the dimension ratio of drawing and an actual dimension ratio do not necessarily correspond.

  FIG. 3 is a schematic plan view of the water treatment apparatus of the present embodiment. 4 is a cross-sectional view taken along line A1-A1 of FIG. FIG. 3 corresponds to a plan view when the water treatment device 1 is viewed in the Y-axis direction. FIG. 4 corresponds to a plan view when the water treatment apparatus 1 is viewed in the X-axis direction. The X-axis direction corresponds to the direction in which the liquid 2 to be processed flows.

  The water treatment device 1 includes a first pipe 11 for water passage, a second pipe 12 provided so as to surround the first pipe 11, and a third pipe 13 provided so as to surround the second pipe 12. Prepare. In the present embodiment, the first tube 11, the second tube 12, and the third tube 13 are all made of quartz glass.

  The discharge space 10 between the second tube 12 and the third tube 13 is filled with a predetermined discharge gas. In the present embodiment, description will be made assuming that the discharge space 10 is filled with Xe gas.

  A first electrode 21 is formed on the outer wall of the third tube 13. A second electrode 22 is formed on the outer wall of the first tube 11. In the present embodiment, both the first electrode 21 and the second electrode 22 have a mesh shape. 3 and 4, there is a space between the first tube 11 and the second tube 12 as much as the discharge space 10 provided between the second tube 12 and the third tube 13. This is shown schematically as if it were. That is, the space between the first tube 11 and the second tube 12 may actually be sufficiently narrow.

When a voltage is applied between the first electrode 21 and the second electrode 22, a voltage is applied in the discharge space 10, and discharge plasma is generated. This plasma excites Xe atoms in the discharge space 10 to generate excimer excited molecules Xe ₂ ^* . Excimer emission occurs when the excited molecule Xe ₂ ^* returns to the ground state. FIG. 5 schematically shows the spectrum of Xe excimer light. As shown in FIG. 5, Xe excimer light shows a spectrum having a peak at 172 nm. In the present embodiment, Xe excimer light corresponds to “first light”.

  In the present embodiment, the water treatment device 1 includes a reflective layer 31 and a phosphor layer 33 on the inner wall of the third tube 13. The phosphor layer 33 is formed on the upper surface of the reflective layer 31.

The phosphor layer 33 is made of a material that emits fluorescence having a wavelength longer than that when Xe excimer light having a main wavelength of 172 nm is incident, and a main emission wavelength of 189 nm to 250 nm. As an example, the phosphor layer 33 can use, for example, YPO ₄ : Pr. The fluorescence generated by the phosphor layer 33 corresponds to “second light”.

The reflective layer 31 is made of a material that can reflect excimer light (first light) and fluorescence (second light). For the reflective layer 31, for example, a granular material made of SiO ₂ can be used. After the material constituting the reflective layer 31 is fired on the inner wall of the third tube 13, the material constituting the phosphor layer 33 is fired, whereby the reflective layer 31 and the phosphor layer are fired on the inner wall of the third tube 13. 33 can be provided.

  The 1st pipe | tube 11 for water flow is comprised including the material which interrupts | blocks the light below 189 nm. The first tube 11 is preferably configured to block light of less than 189 nm by 75% or more, and more preferably configured to block 85% or more.

  When the 1st pipe | tube 11 is comprised with quartz glass, an absorption edge can be adjusted by adjusting content of OH group. If the content of OH groups contained in quartz glass is reduced, the absorption edge can be shifted to the longer wavelength side. Therefore, when all of the 1st pipe | tube 11, the 2nd pipe | tube 12, and the 3rd pipe | tube 13 are comprised with quartz glass, the quantity of the OH group contained in the 1st pipe | tube 11 is used for the 2nd pipe | tube 12 and the 3rd pipe | tube. By reducing the amount of OH groups contained in 13, the first tube 11 can block light of less than 189 nm.

  In addition, as another method for adjusting the absorption end of the first tube 11, it can be realized by adjusting the doping amount of heavy metal ions such as Ti, Fe, Cr, and V, for example. By increasing the heavy metal doping amount, the absorption edge can be shifted to the long wavelength side.

  The liquid 2 to be treated that passes through the first pipe 11 is water to be treated, and more specifically, water containing hydrogen peroxide.

  According to the above configuration, a part of the excimer light (first light) generated in the discharge space 10 is converted into fluorescence (second light) having a longer wavelength than the excimer light by the phosphor layer 33. The first light and the second light pass through the second tube 12 and enter the first tube 11. Since the first tube 11 is configured to block light of less than 189 nm as described above, second light is mainly incident on the inside of the first tube 11. That is, the second light having a main emission wavelength of 189 nm or more and 250 nm or less is irradiated to the liquid to be treated 2 that passes through the inside of the first tube 11.

  As shown in FIG. 1, since light having a wavelength of 189 nm or more and 250 nm or less is absorbed by hydrogen peroxide, the reaction of the above formula (3) occurs and hydrogen peroxide is decomposed. On the other hand, light in the above wavelength range is hardly absorbed by water as shown in FIG. 2, so that the reaction of the above formula (2) does not occur at all. As a result, the amount of hydrogen peroxide contained in the liquid to be treated 2 can be reduced.

  FIG. 6 is a graph showing the relationship between the elapsed time and the concentration of hydrogen peroxide in the liquid to be treated 2 when the liquid 2 to be treated is flowed through the water treatment apparatus 1 of the present embodiment. It is. The water treatment apparatus 1 employed the following conditions.

First tube 11: inner diameter 17 mm, outer diameter 19 mm, length in the X-axis direction 500 mm
Second pipe 12: inner diameter 20 mm, outer diameter 22 mm, length in the X-axis direction 480 mm
Third tube 13: inner diameter 37 mm, outer diameter 40 mm, length in the X-axis direction 480 mm
Discharge space 10: radial width 7.5 mm
Discharge gas: Gas pressure 39.9 kPa (300 Torr)
Lighting power: 150W
Liquid to be treated 2: Flow rate 10L / min

  Further, the concentration of hydrogen peroxide contained in the liquid to be treated 2 was measured by using a flow injection analysis method (FIA method). The flow injection analysis method is defined, for example, in Japanese Industrial Standard JIS K 0126.

  According to FIG. 6, it can confirm that the density | concentration of the hydrogen peroxide contained in the to-be-processed liquid 2 is falling with progress of processing time.

  In addition, the dimension and conditions of the water treatment apparatus 1 used by the Example shown in FIG. 6 are an example to the last. For example, even when the concentration of hydrogen peroxide in the liquid to be treated 2 is measured under the following dimensions and conditions, a result showing the same tendency is obtained.

First tube 11: inner diameter 14 to 26 mm, outer diameter 16 to 30 mm, length in the X-axis direction 450 to 1500 mm
Second pipe 12: inner diameter 17-35 mm, outer diameter 19-40 mm, length in the X-axis direction 430-1500 mm
Third tube 13: inner diameter 34 to 70 mm, outer diameter 37 to 75 mm, length in the X-axis direction 430 to 1500 mm
Discharge space 10: radial width 7.5 to 15 mm
Discharge gas: Gas pressure 39.9 to 53.2 kPa (300 to 400 Torr)
Lighting power: 100-900W
Liquid to be treated 2: Flow rate 5 to 40 L / min

[Another embodiment]
Hereinafter, another embodiment will be described. The following different embodiments can be combined with each other.

  <1> As shown in FIG. 7, the first electrode 21 provided on the outer wall of the third tube 13 may be formed so as to cover the outer wall of the third tube 13. In the present embodiment, since it is not necessary to radiate the first light and the second light to the outside of the third tube 13, the first electrode 21 is not necessarily configured in a mesh shape as shown in FIG. Also good.

  In this case, the first electrode 21 is preferably made of a metal material having a high reflectance with respect to the first light and the second light. As an example, the first electrode 21 can be made of highly reflective aluminum (for example, a bright aluminum alloy).

  Moreover, you may provide the reflection layer which consists of material with a high reflectance with respect to 1st light and 2nd light in the outer side of the 1st electrode 21. FIG. In this case, the first electrode 21 does not necessarily need to be a material having a high reflectance with respect to the first light and the second light. In addition, you may provide a reflection layer in the outer side of the mesh-shaped 1st electrode 21 as shown in FIG. As the reflective layer, for example, granular materials such as alumina and steatite can be used.

  <2> As shown in FIG. 8, the water treatment apparatus 1 may have a configuration in which the phosphor layer 34 is provided on the outer wall of the second pipe 12. The phosphor layer 34 can be made of the same material as the phosphor layer 33. With this configuration, excimer light (first light) generated in the discharge space 10 can be converted into second light with high efficiency.

  <3> As shown in FIG. 9, the water treatment apparatus 1 may be configured not to include the reflective layer 31 on the inner wall of the third pipe 13. In this case, it is preferable to increase the thickness of the phosphor layer 33. As an example, in the water treatment apparatus 1 shown in FIG. 4, the reflective layer 31 has a thickness of 10 to 1000 μm, and the phosphor layer 33 has a thickness of 10 to 1000 μm. In the water treatment apparatus 1 shown in FIG. 9, the thickness of the phosphor layer 33 is 50 to 2000 μm.

  By increasing the thickness of the phosphor layer 33, it is possible to enhance the function of returning the light incident on the phosphor layer 33 to the second tube 12 side.

  <4> As shown in FIG. 10, the second electrode 22 may be provided on the inner wall of the second tube 12.

  <5> As shown in FIG. 11, the water treatment device 1 may include a light blocking layer 36 on the outer wall of the first pipe 11. The light blocking layer 36 is made of a material that blocks light of less than 189 nm. Also in this configuration, since the first light is not substantially incident on the first tube 11, the second light is mainly applied to the liquid 2 to be processed. For example, the light blocking layer 36 can be formed of a dielectric multilayer film.

  As another example, the light blocking layer 36 can be made of the same material as the phosphor layer 33. According to such a configuration, the first light remaining without being converted into the second light is converted into the second light by the light blocking layer 36 when entering the outer wall of the first tube 11. As a result, the first tube 11 can be provided with a function that does not substantially transmit the first light.

  <6> The first tube 11, the second tube 12, and the third tube 13 have been described as being made of quartz glass, but may be made of other materials. The 2nd pipe | tube 12 and the 3rd pipe | tube 13 are comprised with a dielectric material, and should just be the structure which can implement | achieve excimer light emission by a dielectric barrier discharge between the 2nd pipe | tube 12 and the 3rd pipe | tube 13. FIG.

  <7> The gas filled in the discharge space 10 is not limited to xenon (Xe) gas. Any material that can generate excimer light having a main emission wavelength of less than 189 nm may be used. For example, in the case of Ar excimer, the main emission wavelength is 126 nm. In the case of Kr excimer, the main emission wavelength is 146 nm. In the case of ArBr excimer, the main emission wavelength is 165 nm. In the case of ArCl excimer, the main emission wavelength is 175 nm.

  <8> The phosphor layer 33 may be configured by mixing a plurality of types of fluorescent substances. As an example, when the first light is incident, the phosphor layer 33 may generate third light having a main emission wavelength of about 250 nm to 270 nm in addition to the second light described above. According to this configuration, the third light is also transmitted to the liquid 2 to be processed through the first tube 11. Since DNA and RNA have an absorption spectrum peak in the vicinity of 260 nm, the treatment liquid 2 can be sterilized as the amount of hydrogen peroxide contained in the treatment liquid 2 decreases.

1: Water treatment device 2: Liquid to be treated 10: Discharge space 11: First tube 12: Second tube 13: Third tube 21: First electrode 22: Second electrode 31: Reflective layer 33: Phosphor layer 34: Phosphor layer 36: light blocking layer

Claims (8)

A first pipe for water flow,
A second tube made of a dielectric material provided to surround the first tube;
A third tube made of a dielectric provided to surround the second tube;
A discharge gas filled in a space sandwiched between the second tube and the third tube;
A first electrode provided on the outer wall of the third tube;
A second electrode provided on the inner wall of the second tube or the outer wall of the first tube;
At least a phosphor layer provided on the inner wall of the third tube or the outer wall of the second tube,
The discharge gas is made of a material that emits first light when a predetermined voltage is applied between the first electrode and the second electrode,
The phosphor layer is made of a material that emits second light having a longer wavelength than the first light and a main emission wavelength of 189 nm to 250 nm when the first light is incident thereon,
The said 1st pipe | tube is comprised including the material which interrupts | blocks the light whose wavelength is less than 189 nm, The water treatment apparatus characterized by the above-mentioned.   The water treatment apparatus according to claim 1, wherein the discharge gas is made of a material that does not contain fluorine. The discharge gas is made of a material containing Xe,
The water treatment apparatus according to claim 1 or 2, wherein a main emission wavelength of the first light is 172 nm. A reflective layer provided on the inner wall of the third tube and capable of reflecting the first light and the second light;
The water treatment apparatus according to claim 1, wherein the phosphor layer is formed on an upper surface of the reflection layer.   5. The water according to claim 1, wherein the first tube is made of quartz glass having a lower OH group content than the second tube and the third tube. Processing equipment.   The water treatment apparatus according to claim 1, wherein the first pipe includes a light blocking layer that blocks the first light on an outer wall of the first pipe.   The water treatment apparatus according to claim 6, wherein the light blocking layer is made of the same material as the phosphor layer. The water treatment apparatus according to any one of claims 1 to 7, wherein the first electrode is made of a metal material capable of reflecting the first light and the second light.

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