JP2016036772A - Ultraviolet irradiation type water purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation type water purifier that can efficiently perform the water purification treatment of water to be treated, and can avoid occurrence of troubles such as electric leakage.SOLUTION: An ultraviolet irradiation type water purifier includes an ultraviolet lamp that emits ultraviolet rays having a wavelength range of at least 200-300 nm. The ultraviolet lamp includes a discharge vessel having a double-pipe structure that has an outer pipe and an inner pipe arranged coaxially with each other, and is formed with a discharge space, enclosing a gas for discharge, between the inner peripheral surface of the outer pipe and the outer peripheral surface of the inner pipe. An external electrode is installed on the outer peripheral surface of the outer pipe, and an inner electrode is installed on the inner peripheral surface of the inner pipe. A space formed inside the inner pipe is a water-to-be-treated flowing space through which water to be treated subjected to water purification treatment flows. The inner electrode is grounded.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ultraviolet irradiation type water purifier.

  Currently, for example, decomposition of various organic substances (TOC; total organic carbon) in a fluid to be treated such as water, inactivation of bacteria, viruses, fungi, mold spores, protozoa and similar microorganisms, or for sterilization In addition, a technique for irradiating a fluid to be processed with ultraviolet rays is known.

In particular, as described in Patent Document 1 and Patent Document 2, for example, it is useful to irradiate ultraviolet rays (UV-C) having a wavelength of 200 to 300 nm for sterilization of microorganisms related to drinking water. Hereinafter, decomposition treatment of various organic substances in drinking water, deactivation treatment of microorganisms, and sterilization treatment are collectively referred to as “purified water treatment”. In addition, a wavelength range of 200 to 300 nm suitable for water purification treatment is referred to as a “wavelength range for water purification”.
As an ultraviolet light source that emits ultraviolet light (UV-C) in the wavelength range for water purification, for example, Patent Document 1 proposes to use a rare gas fluorescent lamp having a double-tube structure. It has been proposed to use a dielectric barrier discharge lamp (excimer lamp) having a double tube structure. These lamps include a discharge vessel in which a discharge space in which a discharge gas is sealed is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube arranged on the same axis. An electrode is provided opposite to each of the inner peripheral surface of the surface and the inner tube.

In the lamp having the double tube structure as described above, in order to avoid an accident such as an electric shock, the electrode disposed in the outer tube is grounded, and the electrode disposed in the inner tube is opposed to the electrode disposed in the outer tube. In general, it is configured to have a high potential.
Patent Document 2 describes that the electrode disposed on the outer tube side is grounded and the water to be treated is in contact with the outer surface of the dielectric barrier discharge lamp.

JP 2001-15078 A Special table 2009-542437

Thus, when purifying water (drinking water) by irradiating ultraviolet rays in the wavelength region for water purification, the penetration depth of the ultraviolet rays in the wavelength region for water purification into water is said to be about several centimeters. . This is described in, for example, JP2013-536003A.
Therefore, when using a double-barrier dielectric barrier lamp or a rare gas rare gas fluorescent lamp as an ultraviolet lamp that emits ultraviolet light in the wavelength range for water purification, water to be purified (in the inner tube) It is preferable to distribute the water to be treated. In general, in the double tube structure lamp described above, the inner diameter of the inner tube is often several centimeters or less, and when the water to be treated flows inside the inner tube, the entire treated water is used for water purification. This is because it is considered that the water purification treatment can be effectively realized because the ultraviolet rays in the wavelength range penetrate.

However, in the double tube structure lamp, when the drinking water that is the treated water is circulated inside the inner tube, the electrode disposed on the outer peripheral surface of the outer tube is a ground electrode. Such a malfunction may occur.
That is, since the electrode located in the space in which the water to be treated is circulated, that is, the electrode disposed on the inner peripheral surface of the inner tube, is a high-voltage side electrode having a high potential with respect to the ground electrode, In contrast, there is a possibility of electric leakage to an undesired place on the ground side through drinking water having a low electrical resistance.
Moreover, when an electric current flows into drinking water, an ionic substance contained in the drinking water is electrically affected, and there is a concern that the taste of the drinking water purified by ultraviolet rays may be affected.

  The present invention has been made based on the circumstances as described above, and is capable of efficiently performing water purification treatment of water to be treated, and avoiding the occurrence of problems such as electric leakage. It aims at providing an irradiation type water purifier.

The ultraviolet irradiation type water purifier of the present invention comprises an ultraviolet lamp that emits ultraviolet rays having a wavelength range of at least 200 to 300 nm,
The ultraviolet lamp has an outer tube and an inner tube arranged coaxially with each other, and a discharge space in which a discharge gas is sealed is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube. A discharge vessel having a double tube structure, and an outer electrode is provided on the outer peripheral surface of the outer tube and an inner electrode is provided on the inner peripheral surface of the inner tube, and is formed inside the inner tube. The space is a treated water circulation space in which treated water to be purified is circulated, and the inner electrode is grounded.

  In the ultraviolet irradiation type water purifier of the present invention, the ultraviolet lamp can be constituted by a dielectric barrier discharge lamp or a rare gas fluorescent lamp.

Moreover, in the ultraviolet irradiation type water purifier of this invention, it is preferable that the said inner side electrode is comprised with the electroconductive material which has corrosion resistance with respect to the said to-be-processed water at least.
In such a configuration, the conductive material is preferably titanium oxide.

  Furthermore, in the ultraviolet irradiation type water purifier of the present invention, it is preferable that an agitating member that circulates the water to be treated while being agitated is provided inside the treated water circulation space.

Furthermore, in the ultraviolet irradiation type water purifier of the present invention, it comprises a housing made of an electrically insulating plastic resin having a lamp housing chamber in which the ultraviolet lamp is housed and arranged,
It is preferable that an inner surface of a wall defining the lamp housing chamber is provided with an ultraviolet light shielding member in a region irradiated with ultraviolet rays from the ultraviolet lamp disposed in the lamp housing chamber. .
In such a structure, it is preferable that the ultraviolet light shielding member is made of an ultraviolet reflective material that reflects ultraviolet light from the ultraviolet lamp.

  According to the ultraviolet irradiation type water purifier of the present invention, light including ultraviolet rays in a specific wavelength range from an ultraviolet lamp is distributed to the entire treated water that is circulated in the treated water circulation space formed inside the inner tube. Since it penetrates, water purification treatment can be performed effectively. And since the inner side electrode located in the to-be-processed water distribution space where the to-be-processed water distribute | circulates is earth | grounded, it is prevented that it leaks to an undesired location on the ground side through to-be-treated water. . In addition, since no current flows in the water to be treated, for example, in the purification of drinking water, the ionic substances contained in the drinking water are not affected electrically, and the taste of the drinking water is affected. Is also avoided.

It is sectional drawing along the lamp | ramp central axis which shows the structure in an example of the ultraviolet irradiation type water purifier of this invention roughly. It is the elements on larger scale which show a part of ultraviolet irradiation type water purifier shown in FIG. It is the sectional view on the AA line in FIG. It is sectional drawing along the lamp | ramp central axis which shows schematically the structure of the principal part in the other example of the ultraviolet irradiation type water purifier of this invention. It is the sectional view on the AA line in FIG. It is sectional drawing along the lamp | ramp central axis which shows the structure in an example of a noble gas fluorescent lamp roughly.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional view along the center axis of the lamp, schematically showing the configuration of an example of the ultraviolet irradiation type water purifier of the present invention. FIG. 2 is a partially enlarged view showing a part of the ultraviolet irradiation water purifier shown in FIG. 3 is a cross-sectional view taken along line AA in FIG.
This ultraviolet irradiation type water purifier includes a housing 10 having therein a lamp housing chamber L1 and a power supply arrangement chamber L2 that are partitioned from each other, and includes ultraviolet rays in a wavelength range of at least 200 to 300 nm (wavelength range for water purification). A straight tubular ultraviolet lamp that emits light is arranged in the lamp housing chamber L1, and a power supply device 15 for supplying power to the ultraviolet lamp is arranged in the power supply arrangement chamber L2.

The lamp housing chamber L1 in the housing 10 is configured such that each of both end portions of a hole forming a columnar space extending in one direction is closed by a pair of lamp support members 11 and 11 that support both ends of the ultraviolet lamp. ing.
The housing 10 is made of, for example, an electrically insulating plastic resin. As such an electrically insulating plastic resin, for example, an epoxy resin, a silicone resin, a phenol resin, a polyethylene resin, a polypropylene resin, a polystyrene resin, or the like can be used.

The ultraviolet lamp in this example is composed of a dielectric barrier discharge lamp (excimer lamp) 20 that emits ultraviolet rays having a central wavelength in a wavelength region of, for example, 200 to 300 nm.
The dielectric barrier discharge lamp 20 includes a double-tube structure discharge vessel 21 having an outer tube 22 and an inner tube 23 arranged coaxially with each other. The inner tube 23 is disposed inside the outer tube 22 with both end portions protruding axially outward from both ends of the outer tube 22. Both end portions of the outer tube 22 are hermetically sealed to the outer peripheral surface of the inner tube 23, so that a discharge space S 1 is formed between the inner peripheral surface of the outer tube 22 and the outer peripheral surface of the inner tube 23. Is formed.
As a material constituting the outer tube 22 and the inner tube 23, for example, a dielectric material such as quartz glass can be used.

  In the discharge space S1, a discharge gas (excimer emission gas) that generates excimer molecules that emit ultraviolet light in the wavelength range for water purification by dielectric barrier discharge is enclosed. For example, when a mixed gas of krypton gas and chlorine gas is used as the discharge gas, ultraviolet light having a center wavelength of 222 nm is emitted from the KrCl excimer. Further, when mercury and xenon gas are used as the discharge gas, ultraviolet light having a center wavelength of 254 nm is emitted from the HgXe excimer. Furthermore, when a mixed gas of xenon gas and bromine gas is used as the discharge gas, ultraviolet light having a center wavelength of 283 nm is emitted by the HgBr excimer.

  On the outer peripheral surface of the outer tube 22 in the discharge vessel 21, the outer electrode 25 is disposed in close contact with the outer peripheral surface of the outer tube 22. The outer electrode 25 is configured by, for example, a conductive wire made of aluminum being spirally wound around the outer peripheral surface of the outer tube 22. The outer electrode 25 is, for example, a mesh electrode in which conductive strands are arranged according to a pattern having a mesh or the like, or a light in which a film made of a conductive material is formed according to a pattern having a mesh or the like. You may be comprised by the transparent electrode etc. which permeate | transmit the ultraviolet-ray radiated | emitted from the transparent electrode or the dielectric barrier discharge lamp 20. FIG. Further, the outer electrode 25 does not necessarily have to be formed as a light-transmitting material that transmits ultraviolet rays emitted from the dielectric barrier discharge lamp 20, or formed according to a pattern having a gap, It may be a non-translucent strip electrode.

  Further, the inner electrode 26 is disposed in close contact with the inner peripheral surface of the inner tube 23 on the inner peripheral surface of the inner tube 23 in the discharge vessel 21. The inner electrode 26 is configured by, for example, a conductive strand wound spirally around the inner peripheral surface of the inner tube 23. The inner electrode 26 only needs to be configured so that ultraviolet rays generated in the discharge space can be taken out of the discharge vessel 21. Like the outer electrode 25, the inner electrode 26 includes a mesh electrode, a light transmissive electrode, a transparent electrode, and the like. May be.

In this dielectric barrier discharge lamp 20, protrusions 24 protruding radially outward are formed on the wall of the inner tube 23 that defines the discharge space 21, and getter chambers are formed at both ends of the discharge space S1. S2 is formed. In the getter chamber S2, for example, a getter member 28 that adsorbs an impurity gas such as oxygen gas, hydrogen gas, carbon monoxide gas, and water molecular gas is disposed. Thereby, the fall of the ultraviolet output with time resulting from the said impure gas can be suppressed small.
As the getter member 28, at least one member selected from a porous or powdery metal oxide, nitride, or carbide can be used. When no halogen gas is used as the discharge gas, titanium, tantalum, an alloy of aluminum and zirconium, barium, or the like can be used as the getter member 28.

The dielectric barrier discharge lamp 20 is disposed in the lamp housing chamber S1 in a state where the lamp center axis La is positioned on the center axis of the air hole constituting the lamp housing chamber S1 in the housing 10, for example. The both ends of the inner tube 23 in the discharge vessel 21 are held by the lamp support members 11 and 11. Each end of the inner tube 23 in the dielectric barrier discharge lamp 20 protrudes to the outside of the housing 10, and the water to be treated W in which the space formed inside the inner tube 23 is purified is circulated. The treated water distribution space R is defined as the treated water distribution space R.
The outer electrode 25 and the inner electrode 26 are connected to the power supply device 15 arranged in the power supply arrangement chamber L2 of the housing 10 via a wiring member (indicated by a two-dot chain line in FIG. 1). The outer electrode 25 is connected to the high-voltage side terminal HV in the power supply device 15 and functions as a high-voltage power supply electrode. The inner electrode 26 located in the treated water circulation space R is grounded, and is used as a ground electrode. Function. Since the outer electrode 25, the wiring member for connecting the outer electrode 25 and the power supply device 15, and the power supply device 15 are contained in the housing 10 made of an electrically insulating plastic resin material, the user of the ultraviolet irradiation water purifier is used. It is possible to avoid an accident such as electric shock.

  Thus, in the dielectric barrier discharge lamp 20 described above, the inner electrode 26 that is in contact with the water to be treated W has a conductive property that at least the surface in contact with the water to be treated W has corrosion resistance to the water to be treated W. It is composed of materials. By adopting such a configuration, it is possible to avoid the occurrence of problems such as disconnection due to corrosion of the inner electrode 26, and a part of the inner electrode 26 is dissolved in the drinking water which is the water W to be treated. It is also possible to avoid problems such as adversely affecting the quality of drinking water.

Specifically, the inner electrode 26 itself is coated with a conductive wire having corrosion resistance against the water to be treated W, or with a conductive material whose surface has corrosion resistance against the water to be treated W ( It is composed of a coated conductive wire.
For example, titanium oxide, stainless steel, nickel, or the like can be used as the conductive material having corrosion resistance to the water to be treated W. Of these, titanium oxide is preferably used. Titanium oxide functions as a photocatalyst when irradiated with ultraviolet rays having a wavelength of 380 nm or less. Therefore, it is also possible to use ultraviolet rays in a wavelength range (300 to 380 nm) that is not very effective for the purification of drinking water, for example, other than the purified water wavelength range (200 to 300 nm) emitted from the dielectric barrier discharge lamp 20. It is possible to efficiently perform the water purification treatment of the water to be treated W. When the inner electrode 26 is constituted by a transparent electrode having a titanium oxide film formed on the surface, for example, the ultraviolet rays generated in the discharge space S1 are shielded or reduced, but the titanium oxide film It becomes possible to perform the water purification treatment of the water W to be treated by the photocatalytic action.

Further, in the dielectric barrier discharge lamp 20 described above, an agitating member 30 that circulates the water to be treated W while being agitated is provided inside the inner tube 23 through which the water to be treated W is circulated. Specifically, the stirring member is composed of a plurality of plate-like fins provided at positions spaced apart from each other in the axial direction on the inner peripheral surface of the inner tube 23, and the water to be treated is bent by these fins. A flow path for W is formed.
Since the ultraviolet light from the dielectric barrier discharge lamp 20 is absorbed by the water to be treated W flowing through the water distribution space R to be treated, the intensity of the ultraviolet light advances toward the inner side in the radial direction (the lamp central axis direction). Attenuates as you go. That is, since the ultraviolet intensity irradiated to the water to be treated W is distributed (varied) in the radial direction, the water purifying effect on the water to be treated W is also non-uniform. However, since the stirring member 30 is provided inside the inner pipe 23, the water to be treated W is circulated along the bent flow passage and stirred in the water to be treated circulation space R. The water purification process of the to-be-processed water W can be performed substantially uniformly.

  The fins constituting the stirring member 30 can be made of, for example, synthetic quartz glass, titanium oxide, or a metal material whose surface is coated with titanium oxide.

  In the ultraviolet irradiation type water purifier, the dielectric barrier discharge lamp is provided from the dielectric barrier discharge lamp 20 through the outer tube 22 and the outer electrode 25 on the inner surface of the wall defining the lamp housing chamber L1 of the housing 10. An ultraviolet light shielding unit configured by an ultraviolet reflecting member 35 that reflects the ultraviolet ray in the water purification treatment wavelength band toward the dielectric barrier discharge lamp 20 in a region irradiated with the ultraviolet ray in the water purification treatment wavelength band emitted to the outside. A member is provided. By setting it as such a structure, it can prevent that the electrically insulating plastic resin which comprises the housing | casing 10 is photodegraded by irradiating the ultraviolet-ray of the wavelength range for water purification. As a result, the photo-decomposed electrically insulating plastic resin contaminates (attaches) the surface of the outer tube 22 of the dielectric barrier discharge lamp 20, so that the lamp itself becomes high temperature and the lamp life is shortened. You can avoid that. Moreover, the ultraviolet-ray of the wavelength range for water purification processes reflected by the ultraviolet-ray reflection member 35 can be made to contribute again to the water purification process of to-be-processed water, and a processing efficiency can be improved.

  The ultraviolet reflecting member 35 can be constituted by, for example, an aluminum mirror or a diffusion mirror made of a mixture of silica particles and alumina particles. Moreover, you may be comprised by giving the coating which consists of ultraviolet reflective materials, such as aluminum and stainless steel, for example to the area | region where the ultraviolet-ray of lamp | ramp storage chamber S1 is irradiated.

  Further, as the ultraviolet light shielding member, a material that does not transmit ultraviolet light in the wavelength region for water purification emitted from the dielectric barrier discharge lamp 20 and is stable (has resistance) to ultraviolet light in the wavelength region for water purification treatment. Can be configured. Examples of such a material include ceramics.

In the ultraviolet irradiation type water purifier, when a high frequency (for example, kHz order) high voltage is applied between the inner electrode 26 and the outer electrode 25 in the dielectric barrier discharge lamp 20, so-called dielectric is formed in the discharge space S1. A body barrier discharge occurs, and light containing ultraviolet light in the wavelength region for water purification is emitted from excimer molecules generated by the dielectric barrier discharge. On the other hand, to-be-treated water W (indicated by a solid arrow in FIG. 1 for convenience) is introduced into the to-be-treated water circulation space R formed inside the inner tube 23 in the dielectric barrier discharge lamp 20.
Light including ultraviolet light in the wavelength range for water purification from the dielectric barrier discharge lamp 20 (indicated by hatched arrows for convenience in FIGS. 2 and 3) passes through the inner tube 23 to the inside of the inner tube 23. Irradiated to the treated water circulated along the flow path bent in the treated water circulation space R, the treated water W is purified, and purified water (indicated by white arrows in FIG. 1). As discharged.

  Thus, according to the ultraviolet irradiation type water purifier having the above-described configuration, the water to be treated is distributed in the inner tube 23 by the light containing ultraviolet light in the wavelength region for water purification from the dielectric barrier discharge lamp 20. Since it permeates the entire treated water W distributed in R, water purification treatment can be performed effectively. In addition, since the inner electrode 26 located in the treated water circulation space R through which the treated water W is circulated is grounded, electric leakage is caused to an undesired location on the ground side via the treated water W. Is prevented. In addition, since no current flows through the water to be treated W, for example, in the water purification treatment of drinking water, the ionic matter contained in the drinking water is not affected electrically, and the drinking water taste is affected. This is also avoided.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, the ultraviolet lamp is not limited to a dielectric barrier discharge lamp (excimer lamp), and may be configured to use a rare gas fluorescent lamp that emits ultraviolet light in the wavelength region for water purification treatment.

FIG. 4 is a cross-sectional view along the center axis of the lamp, schematically showing the configuration of the main part in another example of the ultraviolet irradiation type water purifier of the present invention. 5 is a cross-sectional view taken along line AA in FIG.
In this ultraviolet irradiation type water purifier, a rare gas fluorescent lamp 40 is used as an ultraviolet lamp, and an ultraviolet light shielding member is not provided on the inner surface of the wall defining the lamp housing chamber L1 of the housing 10. Has the same structure as the ultraviolet irradiation water purifier shown in FIGS. The same components as those in the ultraviolet irradiation water purifier shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted.

  The rare gas fluorescent lamp 40, which is an ultraviolet lamp for irradiating the water to be treated with ultraviolet rays in the wavelength range for water purification, is obtained by the light emission of excimer molecules in the dielectric barrier discharge lamp 20 having the double tube structure as described above. The phosphor layer 46 that emits ultraviolet rays in the wavelength region for water purification treatment is excited by the ultraviolet rays.

As shown in FIG. 6, the rare gas fluorescent lamp 40 has an outer tube 22 and an inner tube 23 that are arranged coaxially with each other, and between the inner peripheral surface of the outer tube 22 and the outer peripheral surface of the inner tube 23. The discharge vessel 21 is provided with a discharge space S1 in which a discharge gas is sealed. Here, as the discharge gas, for example, a rare gas such as xenon gas, argon gas, or krypton gas can be used.
The outer electrode 25 is disposed in close contact with the outer peripheral surface of the outer tube 22 on the outer peripheral surface of the outer tube 22 in the discharge vessel 21, and the inner electrode 26 is disposed on the inner peripheral surface of the inner tube 23. It is arranged in close contact with the inner peripheral surface.

A low softening point glass layer 45 is provided on the outer peripheral surface of the wall of the inner tube 23 defining the discharge space S1, and a phosphor layer 46 is further provided on the outer peripheral surface of the low softening point glass layer 45. ing.
Further, an ultraviolet reflecting film 47, a low softening point glass layer 45, and a phosphor layer 46 are laminated in this order on the inner peripheral surface of the wall of the outer tube 22 that defines the discharge space S1.

  The low softening point glass layer 45 is made of hard glass such as borosilicate glass or aluminosilicate glass, for example.

As the phosphor constituting the phosphor layer 46, for example, praseodymium-activated lanthanum phosphate phosphor ((La _1-x , Pr _x ) PO ₄ [x = 0.02 to 0.04]) is used. It is done. For example, when xenon gas is used as the discharge gas, it is excited by vacuum ultraviolet rays having a central wavelength of 172 nm and emits light including ultraviolet rays in the wavelength region for water purification having a central wavelength of 230 nm.

The ultraviolet reflective film 47 is, for example, calcium pyrophosphate (Ca ₂ P ₂ O ₇ ), calcium phosphate (Ca ₃ (PO ₄ ) ₂ ), magnesium pyrophosphate (Mg ₂ P ₂ O ₇ ), and Ba—Na—Si—. Any one of O, SiO ₂ , and Al ₂ O ₃ is preferably included, and the total amount of these is preferably included in the ultraviolet reflection film 47 in a proportion exceeding 50%.

  Note that the ultraviolet reflecting film 47, the low softening point glass layer 45, and the phosphor layer 46 shown in FIGS. 4 to 6 are exaggerated for easy understanding. As an actual configuration example, the thickness of the outer tube 22 and the inner tube 23 is, for example, 0.5 to 2 mm, the thickness of the ultraviolet reflecting film 47 is 15 to 50 μm, and the thickness of the low softening point glass layer 45. The thickness is 1 to 30 μm, and the average thickness of the phosphor layer 46 is 10 to 20 μm.

The rare gas fluorescent lamp 40 is disposed in the lamp housing chamber S1 in a state where the lamp center axis La is positioned, for example, on the center axis of the hole constituting the lamp housing chamber S1 in the housing 10. The both ends of the inner tube 23 in the discharge vessel 21 are held by the lamp support members 11 and 11. Each end of the inner tube 23 in the rare gas fluorescent lamp 40 protrudes outside the housing 10, and the space to be treated in which the water formed in the space formed inside the inner tube 23 is circulated. The treated water distribution space R is used.
The outer electrode 25 and the inner electrode 26 are connected to the power supply device 15 arranged in the power supply arrangement chamber L2 of the housing 10 via a wiring member, and the outer electrode 25 functions as a high-voltage power supply electrode. The inner electrode 26 located in the treated water circulation space R is grounded and functions as a ground electrode.

  Further, in the rare gas fluorescent lamp 40 described above, an agitating member 30 that circulates the water to be treated W while being agitated is provided inside the inner tube 23 through which the water to be treated W is circulated. Specifically, the stirring member 30 includes a plurality of plate-like fins provided at positions spaced apart from each other in the axial direction on the inner peripheral surface of the inner tube 23, and the object to be processed is bent by these fins. A flow path for water W is formed.

  In the ultraviolet irradiation type water purifier, when a high frequency (for example, kHz order) high voltage is applied between the inner electrode 26 and the outer electrode 25 of the rare gas fluorescent lamp 40, a so-called dielectric is formed in the discharge space S1. Barrier discharge occurs. The phosphor is excited by irradiating the phosphor layer 46 with vacuum ultraviolet rays from the excimer molecules generated by the dielectric barrier discharge, and light including ultraviolet rays in the wavelength region for water purification (in FIGS. 4 and 5, for convenience, Is indicated by a hatched arrow) directly through the inner tube 23 or through a flow path that is reflected by the ultraviolet reflecting film 47 and bent in the treated water circulation space R. Irradiated to the treated water W. Thereby, the water purification process of the to-be-processed water W is performed, and it discharges | emits as purified water.

  Thus, even with the ultraviolet irradiation type water purifier having the above configuration, the same effect as that of the ultraviolet irradiation type water purifier including the dielectric barrier discharge lamp can be obtained.

DESCRIPTION OF SYMBOLS 10 Housing | casing 11 Lamp support member 15 Power supply device 20 Dielectric barrier discharge lamp 21 Discharge vessel 22 Outer tube 23 Inner tube 24 Projection part 25 Outer electrode 26 Inner electrode 28 Getter member 30 Stirring member 35 Ultraviolet reflecting member 40 Noble gas fluorescent lamp 45 Low softening point glass layer 46 Phosphor layer 47 Ultraviolet reflection film L1 Lamp housing chamber L2 Power supply placement chamber S1 Discharge space S2 Getter chamber R Untreated water distribution space

Claims (7)

Comprising an ultraviolet lamp that emits ultraviolet rays in a wavelength range of at least 200 to 300 nm;
The ultraviolet lamp has an outer tube and an inner tube arranged coaxially with each other, and a discharge space in which a discharge gas is sealed is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube. A discharge vessel having a double tube structure, and an outer electrode is provided on the outer peripheral surface of the outer tube and an inner electrode is provided on the inner peripheral surface of the inner tube, and is formed inside the inner tube. The ultraviolet irradiation type water purifier is characterized in that the space is a treated water circulation space through which treated water to be purified is circulated, and the inner electrode is grounded.   2. The ultraviolet irradiation type water purifier according to claim 1, wherein the ultraviolet lamp comprises a dielectric barrier discharge lamp or a rare gas fluorescent lamp.   The ultraviolet irradiation according to claim 1 or 2, wherein the inner electrode has at least a surface in contact with the water to be treated made of a conductive material having corrosion resistance against the water to be treated. Water purifier.   The ultraviolet irradiation water purifier according to claim 3, wherein the conductive material is titanium oxide.   The ultraviolet irradiation type according to any one of claims 1 to 4, wherein an agitating member that circulates the treated water while stirring is provided inside the treated water circulation space. Water purifier. It has a housing made of an electrically insulating plastic resin, having a lamp housing chamber in which the ultraviolet lamp is housed and disposed,
The ultraviolet light shielding member is provided on an inner surface of a wall defining the lamp housing chamber in a region irradiated with ultraviolet rays from the ultraviolet lamp disposed in the lamp housing chamber. The ultraviolet irradiation type water purifier as described in any one of Claim 1 thru | or 5.   The ultraviolet irradiation type water purifier according to claim 6, wherein the ultraviolet light shielding member includes an ultraviolet reflecting member that reflects ultraviolet rays from the ultraviolet lamp.

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