TW202133216A - Barrier discharge lamp, barrier discharge lamp unit and liquid treatment device which has a luminous tube containing silicon dioxide material - Google Patents

Abstract

The present invention provides a barrier discharge lamp, a barrier discharge lamp unit and a liquid treatment device, which can improve luminous efficiency. An embodiment of the barrier discharge lamp includes: a luminous tube having a cylindrical shape, the internal space of which encloses a gas; an internal electrode provided in the internal space; and an external electrode provided outside the luminous tube. The outer diameter of the luminous tube is 10 mm or more and 25 mm or less. The input density is 0.3 W/cm or more and 1.4 W/cm or less.

Description

Barrier discharge lamp, barrier discharge lamp unit and liquid treatment device

The embodiment of the present invention relates to a barrier discharge lamp, a barrier discharge lamp unit, and a liquid treatment device.

For example, as methods for removing impurities in water, filtration methods, activated carbon adsorption methods, ion exchange methods, distillation methods, and reverse osmosis membrane desalination methods are known. In addition, in recent years, impurity removal using ultraviolet rays has been carried out. For example, if water is irradiated with ultraviolet rays, hydroxyl radicals with strong oxidizing power are generated. Hydroxyl radicals decompose Total Organic Carbon (TOC) in water into carbon dioxide through organic acids, so that pure water with higher purity can be produced compared to filtration methods. As a light source for irradiating ultraviolet rays, a low-pressure mercury lamp can be used.

Here, the absorption coefficient of water reaches its minimum near 500 nm, and it increases as it shifts from 500 nm to the long-wavelength side or the short-wavelength side. The low-pressure mercury lamp irradiates ultraviolet rays with peak wavelengths of 254 nm and 185 nm, but the absorption coefficient of water with such wavelengths of ultraviolet rays is small. Therefore, in order to obtain pure water of sufficient purity, it is necessary to extend the irradiation time or increase the power applied to the low-pressure mercury lamp. However, if the irradiation time is prolonged, the production efficiency decreases. If the applied power is increased, the mercury vapor pressure in the low-pressure mercury lamp increases, and the luminous efficiency decreases.

Therefore, it has been proposed to use a barrier discharge lamp (xenon excimer lamp), which irradiates ultraviolet rays having a peak wavelength of 172 nm with a greater absorption coefficient of water. However, the luminous efficiency of the barrier discharge lamp has a large temperature-dependent characteristic, so when the barrier discharge lamp is used for liquid treatment, there is room for improvement in improving luminous efficiency. [Prior Art Literature]

[Patent Literature] [Patent Document 1] Japanese Patent Laid-Open No. 2014-182916

[The problem to be solved by the invention] The problem to be solved by the present invention is to provide a barrier discharge lamp, a barrier discharge lamp unit and a liquid treatment device that can improve the luminous efficiency. [Technical means to solve the problem]

The barrier discharge lamp of the embodiment includes: a luminous tube, which has a cylindrical shape and is filled with gas in an internal space; an internal electrode, which is provided in the internal space; and an external electrode, which is provided outside the luminous tube. The outer diameter of the luminous tube is 10 mm or more and 25 mm or less. The input density is 0.3 W/cm or more and 1.4 W/cm or less. [Effects of the invention]

According to the embodiments of the present invention, a barrier discharge lamp, a barrier discharge lamp unit, and a liquid treatment device that can improve luminous efficiency can be provided.

Hereinafter, embodiments will be exemplified with reference to the drawings on the one hand. In addition, in each drawing, the same components are denoted by the same reference numerals, and detailed descriptions are appropriately omitted.

(Barrier discharge lamp 1) FIG. 1(a) is a schematic diagram for illustrating the barrier discharge lamp 1 of this embodiment. Fig. 1(b) is a schematic enlarged view of the A part of the barrier discharge lamp 1 of Fig. 1(a). Fig. 2 is a schematic cross-sectional view in the direction of the line B-B of the barrier discharge lamp 1 of Fig. 1(a). As shown in Fig. 1(a), Fig. 1(b) and Fig. 2, in the barrier discharge lamp 1, a luminous tube 2, a conductive part 3, an internal electrode 4, an anchor 5, and a support ( holder) 6, external electrode 7, lead 8 and lead 9.

The arc tube 2 has a cylindrical shape and has a form in which the overall length (length in the tube axis direction) is longer than the tube diameter. The arc tube 2 can be a cylindrical tube, for example. The outer diameter of the arc tube 2 can be set to, for example, 10 mm or more and 25 mm or less.

Sealing portions 2a are provided at the ends of the arc tube 2 on both sides in the tube axis direction, respectively. By providing the sealing portion 2a, the internal space of the arc tube 2 can be hermetically sealed. The sealing part 2a can be formed using a pinch seal method or a shrink seal method, for example.

On the outer surface of the luminous tube 2, a protrusion 2b may be provided. The protrusion 2b may be provided in order to exhaust the internal space of the arc tube 2 when manufacturing the barrier discharge lamp 1 or to introduce a gas described later into the internal space of the arc tube 2. The protrusion 2b can be formed by burning a tube formed of synthetic quartz glass after exhaust gas and gas introduction.

A gas is enclosed in the internal space of the arc tube 2. In the barrier discharge lamp 1, a dielectric barrier discharge is performed between the internal electrode 4 and the external electrode 7, and high-energy electrons are imparted to the enclosed gas to generate excimer excitation molecules. When the excimer excites molecular reduction, light having a specific peak wavelength is generated according to the type of gas. Therefore, the gas enclosed in the internal space of the arc tube 2 can be appropriately changed according to the use of the barrier discharge lamp 1. The gas enclosed in the internal space of the arc tube 2 can be, for example, a rare gas such as krypton, xenon, argon, and neon, or a mixed gas obtained by mixing a plurality of rare gases. The gas may further contain halogen gas and the like if necessary.

The gas pressure (sealing pressure) at 25° C. in the internal space of the arc tube 2 can be set to, for example, about 1.3 kPa to 200 kPa. The gas pressure (sealing pressure) at 25°C in the internal space of the arc tube 2 can be obtained from the standard state of the gas (standard ambient temperature and pressure (Standard Ambient Temperature and Pressure, SATP): temperature 25°C, 1 bar) out.

For example, when decomposing impurities contained in a liquid such as water, it is preferable that the enclosed gas be xenon. The sealing pressure of xenon gas can be set to about 47 kPa, for example. If the enclosed gas is xenon, ultraviolet rays with a peak wavelength of 172 nm can be generated, so that the decomposition of impurities can be effectively performed.

The conductive part 3 is provided inside the sealing part 2a. One conductive part 3 may be provided for one sealing part 2a. The planar shape of the conductive portion 3 can be a quadrilateral. The conductive part 3 has a film shape. The conductive part 3 may be formed of, for example, molybdenum foil.

The internal electrode 4 may have a coil 4a and a leg 4b. The coil 4a and the leg 4b may be integrally formed. The coil 4a and the leg 4b can be formed by plastic working a wire. The wire diameter (diameter) of the wire rod can be set to about 0.2 mm to 1.0 mm, for example.

The coil 4a and the leg 4b may contain tungsten as a main component, for example. The content of tungsten can be set to 50 wt% or more, for example. At this time, if doped tungsten in which potassium or the like is added to tungsten is used, the dimensional stability of the coil 4a can be improved.

The coil 4a has a spiral shape and is provided in the internal space of the arc tube 2. The coil 4a extends along the tube axis of the arc tube 2 in the central area of the internal space of the arc tube 2. If the interval between adjacent wires in the tube axis direction of the arc tube 2 is set to the pitch size P of the coil 4a, the pitch size P of the coil 4a can be set to, for example, about 0.5 mm to 3.0 mm. Moreover, the outer diameter D of the coil 4a in the direction orthogonal to the tube axis direction of the arc tube 2 can be set to, for example, about 1 mm to 5 mm.

The pins 4b are respectively provided at the ends of both sides of the coil 4a. The pin 4b has a linear shape and extends from the end of the coil 4a along the tube axis of the arc tube 2. The ends of the pins 4b are electrically connected to the conductive portion 3 inside the sealing portion 2a. The vicinity of the end of the pin 4b can be laser-welded or resistance-welded with the conductive portion 3.

As shown in FIG. 2, the anchor 5 can be arranged in the inner space of the luminous tube 2. The material of the anchor 5 can be the same as the material of the internal electrode 4, for example. The anchor 5 can be formed by plastic working a wire. For example, one end side of the anchor 5 may be provided on the outer surface of the coil 4a. For example, one end side of the anchor 5 may be wound on the outer surface of the coil 4a. For example, one end side of the anchor 5 may be spiral. For example, the other end side of the anchor 5 may be in contact with the inner wall of the luminous tube 2. For example, the other end side of the anchor 5 may have a shape curved along the inner wall of the arc tube 2. In addition, the case where the anchor 5 is attached to the coil 4a is illustrated, but the diameter of a part of the coil 4a may be increased and the anchor 5 may be used.

One end of the anchor 5 is arranged on the outer surface of the coil 4a, and the other end of the anchor 5 is in contact with the inner wall of the luminous tube 2, so that the anchor 5 is used to support the inner space of the luminous tube 2 Coil 4a. Furthermore, the anchor 5 is electrically connected to the coil 4 a, so that the anchor 5 functions as the internal electrode 4. That is, the anchor 5 functions as a supporting member supporting the coil 4a and a part of the internal electrode 4.

If the anchor 5 functions as a part of the internal electrode 4, the distance between the internal electrode 4 (anchor 5) and the external electrode 7 becomes small, and therefore, it can be started even if the starting voltage is low. Moreover, the light emission can be maintained even if the maintaining voltage is low. That is, the instant lighting performance can be improved, and the lighting state can also be stabilized. In addition, if the distance between the internal electrode 4 (anchor 5) and the external electrode 7 becomes smaller, the stability immediately after the lamp is started is also improved. Therefore, uneven light emission immediately after the lamp is started can be suppressed, and thus the light immediately after the start of the lamp can be directly used.

The anchor 5 may be provided in plurality in consideration of, for example, the light-emitting characteristic or starting characteristic of the lamp, the supporting performance of the coil 4a, and the like. At this time, if the interval between adjacent anchors 5 in the tube axis direction of the arc tube 2 is set as the pitch size of the anchors 5, the pitch size of the anchors 5 can be set to, for example, about 10 mm to 40 mm.

The holder 6 has a cylindrical shape, one end side is provided inside the sealing portion 2a, and the other end side is exposed from the sealing portion 2a. One support 6 may be provided for one sealing portion 2a. The support 6 may be formed of, for example, an inorganic material such as resin or ceramic. The support 6 may include steatite, alumina, or the like, for example.

The external electrode 7 may be provided on the outside of the luminous tube 2. The external electrode 7 can be formed using metals such as stainless steel, aluminum, nickel, silver, gold, and platinum, for example. The external electrode 7 generates a dielectric barrier discharge between the external electrode 7 and the internal electrode 4. As described above, when a dielectric barrier discharge occurs, excimer excitation molecules are generated in the internal space of the arc tube 2, and when the excimer excitation molecules are reduced, light having a specific peak wavelength is generated according to the type of gas. For example, when xenon gas is enclosed, ultraviolet rays with a peak wavelength of 172 nm are generated.

When the barrier discharge lamp 1 is used, for example, to decompose impurities contained in a liquid such as water, it is preferable that the light generated in the internal space of the arc tube 2 is irradiated in all directions around the arc tube 2. Therefore, the external electrode 7 can transmit the light generated in the internal space of the arc tube 2. For example, the external electrode 7 may be provided with a hole, a slit, or the like penetrating in the thickness direction. At this time, the light shielding rate of the external electrode 7 is preferably set to 10% or less.

For example, as shown in (a) of FIG. 1, the external electrode 7 may be formed in a mesh shape. For example, it may be the external electrode 7 having a plain weave structure. The wire used for the plain weave structure can be, for example, a stainless steel wire or an aluminum wire with a wire diameter of about 0.1 mm. The mesh interval can be set to about 2.8 mm in length and about 3 mm in width, for example.

If the external electrode 7 is made into a mesh shape, it is easy to make the light-shielding rate 10% or less. Furthermore, if the external electrode 7 is made into a mesh shape, the outer surface of the arc tube 2 can be covered, so that the area facing the internal electrode 4 can be increased. Therefore, it is easy to stably generate a dielectric barrier discharge over a large area.

For example, the external electrode 7 can be provided by molding a mesh-shaped metal into a cylindrical shape, and inserting the arc tube 2 inside the cylindrical metal body.

The wire 8 can be provided on at least one support 6. One end of the wire 8 passes through the interior of the support 6 and is electrically connected to the conductive portion 3 inside the sealing portion 2a. The vicinity of one end of the wire 8 can be laser-welded or resistance-welded with the conductive part 3. Furthermore, the gap between the wire 8 and the support 6 is sealed by a sealing material. The other end of the wire 8 can be exposed from the support 6. At the other end of the wire 8, a crimp terminal or a connector can be connected.

One end of the wire 9 is electrically connected to the external electrode 7 via a nickel sleeve 9a. At the other end of the wire 9, a crimp terminal or a connector can be connected. The lead wire 8 and the lead wire 9 can be electrically connected to the lighting circuit 201 (refer FIG. 7) provided in the liquid processing apparatus 200, for example.

Here, as described above, if the gas enclosed in the internal space of the arc tube 2 is xenon, ultraviolet rays with a peak wavelength of 172 nm can be generated. Ultraviolet rays with a peak wavelength of 172 nm have a greater absorption coefficient of water than the ultraviolet rays with a peak wavelength of 254 nm and 185 nm irradiated from a low-pressure mercury lamp. Therefore, if the barrier discharge lamp 1 is used for the decomposition of impurities contained in liquids such as water, the impurities can be effectively removed.

In addition, since the luminous efficiency of the barrier discharge lamp 1 has a large temperature-dependent characteristic, if the temperature becomes higher, the luminous efficiency of the barrier discharge lamp 1 decreases. When the barrier discharge lamp 1 is used for liquid treatment, the barrier discharge lamp 1 cannot be directly installed in the liquid. Therefore, the barrier discharge lamp 1 is provided inside the protection tube 101 (refer to FIG. 7). In addition, since the space between the barrier discharge lamp 1 and the inner wall of the protection tube 101 is filled with gas, it is difficult for the heat generated by the barrier discharge lamp 1 to be dissipated into the liquid. If the heat dissipation of the self-barrier discharge lamp 1 is suppressed, the temperature of the barrier discharge lamp 1 may increase and the luminous efficiency may decrease.

Fig. 3 is a graph illustrating the relationship between input density and relative illuminance (ultraviolet illuminance). The relative illuminance is measured using an ultraviolet illuminance meter UIT-250 manufactured by Ushio Motor. VUV-S172 is used for the head, and the measuring distance is set to 3 mm. The input density is the ratio of the applied power to the luminous length. The luminous length can be set to the length of the external electrode 7 in the tube axis direction of the luminous tube 2.

As can be seen from Figure 3, if the input density is set to 0.3 W/cm or more and 1.4 W/cm or less, the relative illuminance can be made 90% or more. This means that even when the barrier discharge lamp 1 is lit in an environment where heat dissipation to the surroundings is suppressed, if the input density is set to 0.3 W/cm or more and 1.4 W/cm or less, the light emission can be improved. efficient.

Furthermore, as described above, the ultraviolet rays generated in the internal space of the arc tube 2 are irradiated to the outside via the arc tube 2. Therefore, the arc tube 2 is formed of a material having a high transmittance of ultraviolet rays. The material with high transmittance of ultraviolet rays can be, for example, a material containing SiO ₂ such as synthetic quartz glass. However, if ultraviolet rays with a peak wavelength of 172 nm are incident on _{a material containing SiO 2} , the chemical structure of the material may change with time. For example, when ultraviolet rays are incident on SiO ₂ , the bond between Si and O may be cut. Therefore, if the barrier discharge lamp 1 is turned on for a long period of time, the chemical structure of the material of the arc tube 2 will be defective, and the transmittance of ultraviolet rays may be drastically decreased, and the illuminance maintenance rate may decrease.

According to the findings obtained by the present inventors, if the _{amount of OH groups contained in the material containing SiO 2} is increased, even if the bond between Si and O is cut by the incidence of ultraviolet rays, defects in the chemical structure can be repaired.

Fig. 4 is a graph illustrating the relationship between the OH group content, the illuminance maintenance rate, and the lighting time. As seen from FIG. 4, if the OH group content is 100 ppm or more, even the barrier discharge lamp 1 that generates ultraviolet rays with a peak wavelength of 172 nm can maintain a high illuminance maintenance rate for a long time. This means that the life of the barrier discharge lamp 1 can be increased.

However, it has been found that if the content of OH groups is increased too much, the transmittance of ultraviolet rays decreases. Fig. 5 is a graph illustrating the relationship between the content of OH groups and the relative ultraviolet illuminance. As can be seen from Figure 5, if the content of OH groups exceeds 1500 ppm, the transmittance of ultraviolet rays decreases, and therefore the relative ultraviolet illuminance decreases.

Therefore, as understood from FIGS. 4 and 5, it is preferable that the arc tube 2 is _{formed of a material containing SiO 2} such as synthetic quartz glass, and the OH group content is 100 ppm or more and 1500 ppm or less. With this setting, even if ultraviolet rays with a peak wavelength of 172 nm are generated in the internal space of the arc tube 2, a high illuminance maintenance rate can be maintained for a long time. Furthermore, it is possible to suppress a decrease in the transmittance of ultraviolet rays.

6(a) to 6(d) are schematic diagrams for illustrating barrier discharge lamps of other embodiments. In addition, in order to avoid becoming complicated, the same structural elements as those of the barrier discharge lamp 1 described above are appropriately omitted.

As shown in FIG. 6(a), the internal electrode 14 may have a coil 14a and a leg 4b. The coil 14a has a spiral shape and is provided in the internal space of the arc tube 2. If the interval between adjacent wires in the tube axis direction of the arc tube 2 is the pitch dimension Pa of the coil 14a, the pitch dimension Pa of the coil 14a can be set to, for example, about 15 mm to 90 mm. The coil 14a extends along the tube axis of the arc tube 2 in the internal space of the arc tube 2. The coil 4 a illustrated in FIGS. 1 (a) and 1 (b) is supported by the anchor 5, but the outer end of the coil 14 a is in contact with the inner wall of the arc tube 2. In addition, a slight gap may be provided between the outer end of the coil 14a and the inner wall of the arc tube 2. At this time, the anchor 5 can also be omitted.

If it is set in this way, the distance between the coil 14a and the external electrode 7 can be reduced, and thus the starting voltage can be started even if the starting voltage is lower. Moreover, the light emission can be maintained even if the voltage is kept lower. That is, the instant lighting performance can be further improved, and the lighting state can also be stabilized.

As shown in (b) of FIG. 6, the external electrode 17 may have a spiral shape and be wound on the outer surface of the luminous tube 2. If set in this way, it is possible to suppress the situation in which ultraviolet rays generated in the internal space of the arc tube 2 are blocked by the external electrode 17 when irradiated to the outside.

As shown in (c) of FIG. 6, the external electrode 17 may have a spiral shape and be wound on the outer surface of the luminous tube 2. Moreover, the anchor 5 can be omitted. If set in this way, it is possible to suppress the situation in which ultraviolet rays generated in the internal space of the arc tube 2 are blocked by the external electrode 17 when irradiated to the outside. Moreover, the manufacturing cost can be reduced by omitting the anchor 5.

As shown in (d) of FIG. 6, the external electrode 7 may be made into a mesh shape, and the internal electrode 4 has a coil 4 a and a leg 4 b. In addition, the anchor 5 can be omitted. If set in this way, the manufacturing cost can be reduced.

(Barrier discharge lamp unit 100 and liquid treatment device 200) Next, the barrier discharge lamp unit 100 and the liquid treatment apparatus 200 will be exemplified. In addition, as an example, the case where the barrier discharge lamp 1 illustrated in FIG. 1(a) is provided will be described below. However, for example, the barrier discharge lamp 1 illustrated in FIGS. 6(a) to 6(d) may also be provided. Discharge lamp.

FIG. 7 is a schematic diagram for illustrating the barrier discharge lamp unit 100 and the liquid treatment device 200. As shown in FIG. 7, in the liquid treatment apparatus 200, a barrier discharge lamp unit 100, a lighting circuit 201, and a controller 202 may be provided. The barrier discharge lamp unit 100 may include a barrier discharge lamp 1, a protection tube 101, a cover 102 and a sealing member 103.

The protection tube 101 has a cylindrical shape, and has a form in which the overall length (length in the tube axis direction) is longer than the tube diameter. The protection tube 101 can be a cylindrical tube, for example. One end of the protection tube 101 is blocked, and the other end is open. A flange 101a is provided at the end of the protective tube 101 on the opening side. In the internal space of the protection tube 101, the barrier discharge lamp 1 can be accommodated.

As shown in FIG. 7, the protection tube 101 may be provided in the liquid 300 (for example, water) which is a processing target. At this time, it is set so that the barrier discharge lamp 1 housed in the protection tube 101 is located inside the liquid 300. The cover 102 and the sealing member 103 are preferably set so as to be located outside the liquid 300. The protection tube 101 may be provided in a liquid 300 that does not flow in a water tank or the like, or may be provided in a liquid 300 that flows in a flow path such as a tank or a pipe.

The ultraviolet rays irradiated from the barrier discharge lamp 1 are irradiated to the liquid 300 through the protective tube 101. Therefore, the protective tube 101 is formed of a material having a high transmittance of ultraviolet rays. The protection tube 101 is formed of, for example, a material _{containing SiO 2 such as synthetic quartz glass.} At this time, as in the case of the arc tube 2 described above, the protection tube 101 is preferably formed of _{a material containing SiO 2} such as synthetic quartz glass, and the OH group content is set to 100 ppm or more and 1500 ppm or less. With this setting, even if ultraviolet rays with a peak wavelength of 172 nm are irradiated from the barrier discharge lamp 1, a high illuminance maintenance rate can be maintained for a long time. This means that the life of the barrier discharge lamp unit 100 can be extended. Furthermore, it is possible to suppress a decrease in the transmittance of ultraviolet rays.

The cover 102 has a plate shape and blocks the opening of the protection tube 101. The cover 102 is provided with a hole penetrating in the thickness direction. The lead 8 and the lead 9 extend to the outside through the hole provided in the cover 102. The gap between the lead 8 and the hole, and the gap between the lead 9 and the hole are sealed by a sealing material.

The sealing member 103 is provided between the cover 102 and the flange 101 a of the protection tube 101. The sealing member 103 can be, for example, an O ring or the like. By attaching the cover 102 and the sealing member 103 to the flange 101a of the protection tube 101, the internal space of the protection tube 101 is sealed so as to be airtight.

Here, if oxygen exists in the internal space of the protective tube 101, it may cause the attenuation of the ultraviolet rays irradiated from the barrier discharge lamp 1. Therefore, it is preferable to seal nitrogen or inert gas in the internal space of the protective tube 101. At this time, if the enclosed gas is nitrogen, the manufacturing cost can be reduced.

The lighting circuit 201 may have a high frequency generating circuit, for example. The high frequency generating circuit can generate electric power with a frequency of about 100 kHz and a voltage of 2 kVp-p, for example. The wire 8 and the wire 9 can be electrically connected to the lighting circuit 201. In addition, the lighting circuit 201 has a switch for switching between application of power to the discharge lamp 1 and stopping of the application of power. Furthermore, one lighting circuit 201 may apply power to a plurality of barrier discharge lamps 1.

The controller 202 may have arithmetic elements such as a central processing unit (CPU), and memory elements such as a semiconductor memory. The controller 202 can be a computer, for example. In the memory element, a control program for controlling the lighting circuit 201 can be stored. The arithmetic element can control the application of electric power to the barrier discharge lamp 1, the stopping of the application of electric power, and the like based on the control program stored in the memory element. The controller 202 can be provided with an input unit for the operator to input data, a monitor that displays the operating status or abnormal display of the barrier discharge lamp 1, a power switch, and the like. Moreover, a plurality of lighting circuits 201 may be controlled by one controller 202.

It has been found here that if the gap size S (shortest distance) between the inner wall of the protective tube 101 and the outer end of the external electrode 7 is too long, the relative illuminance of the ultraviolet rays irradiated from the protective tube 101 decreases.

FIG. 8 is a graph for illustrating the relationship between the gap size S and the relative illuminance of ultraviolet rays. The relative illuminance in Fig. 8 is the relative illuminance of ultraviolet rays when the input density is 1 W/cm. In addition, the relative illuminance of ultraviolet rays when the gap size S is 2 mm is set to 100%. As can be seen from FIG. 8, if the gap size S is set to 10 mm or less, the relative illuminance can be made 90% or more. This means that the attenuation of ultraviolet rays inside the protective tube 101 can be suppressed, and the extraction efficiency of ultraviolet rays can be improved. If the extraction efficiency of ultraviolet rays is improved, the removal rate of impurities in the liquid can be increased, the irradiation time can be shortened, or the applied power can be reduced.

As mentioned above, although some embodiment of this invention was illustrated, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, changes, etc. can be made within a range that does not deviate from the gist of the invention. These embodiments or their modifications are included in the scope or spirit of the invention, and are also included in the invention described in the scope of the invention application and its equivalent scope. Furthermore, each of the above-mentioned embodiments can be implemented in combination with each other.

1: Barrier discharge lamp 2: luminous tube 2a: Sealing part 2b: protrusion 3: Conductive part 4: Internal electrode 4a, 14a: coil 4b: wire pin 5: Anchor 6: Support 7: External electrode 8, 9: Wire 9a: Nickel sleeve 14: Internal electrode 17: External electrode 100: Barrier discharge lamp unit 101: protection tube 101a: flange 102: cover 103: Sealing member 200: Liquid handling device 201: Lighting Circuit 202: Controller 300: Liquid D: Outer diameter P, Pa: pitch size S: gap size

FIG. 1(a) is a schematic diagram for illustrating the barrier discharge lamp of this embodiment. Fig. 1(b) is a schematic enlarged view of a part A of the barrier discharge lamp of Fig. 1(a). Fig. 2 is a schematic cross-sectional view in the direction of line B-B of the barrier discharge lamp of Fig. 1(a). Fig. 3 is a graph illustrating the relationship between input density and relative illuminance (ultraviolet illuminance). Fig. 4 is a graph illustrating the relationship between the OH group content, the illuminance maintenance rate, and the lighting time. Fig. 5 is a graph illustrating the relationship between the content of OH groups and the relative ultraviolet illuminance. 6(a) to 6(d) are schematic diagrams for illustrating barrier discharge lamps of other embodiments. Fig. 7 is a schematic diagram for illustrating a barrier discharge lamp unit and a liquid treatment device. FIG. 8 is a graph for illustrating the relationship between the gap size and the relative illuminance of ultraviolet rays.

1: Barrier discharge lamp

2: luminous tube

2a: Sealing part

2b: protrusion

3: Conductive part

4: Internal electrode

4a: coil

4b: wire pin

5: Anchor

6: Support

7: External electrode

8, 9: Wire

9a: Nickel sleeve

D: Outer diameter

P: Pitch size

Claims (6)

A barrier discharge lamp includes: The luminous tube has a cylindrical shape and is filled with gas in the internal space; Internal electrodes are provided in the internal space; and The external electrode is arranged on the outside of the luminous tube, The outer diameter of the luminous tube is 10 mm or more and 25 mm or less, The input density is 0.3 W/cm or more and 1.4 W/cm or less. The barrier discharge lamp according to claim 1, wherein the arc tube includes a _{material containing SiO 2} and the content of the OH group of the material is 100 ppm or more and 1500 ppm or less. The barrier discharge lamp according to claim 1 or 2, wherein: The external electrode has a mesh shape. The barrier discharge lamp according to claim 1 or 2, wherein: The internal electrode has a coil. A barrier discharge lamp unit includes: The barrier discharge lamp according to any one of claim 1 to claim 4; and A protection tube containing the barrier discharge lamp, Nitrogen gas is sealed in the internal space of the protective tube accommodating the barrier discharge lamp, The gap size between the inner wall of the protective tube and the outer end of the outer electrode provided on the barrier discharge lamp is 10 mm or less. A liquid processing device includes: The barrier discharge lamp unit as described in claim 5; and The lighting circuit is electrically connected to the barrier discharge lamp provided in the barrier discharge lamp unit.

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