JPH1027577A - Irradiation device and water treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the mercury vapor pressure evenly and adequately in the whole body in an arc tube, and obtain an even discharge in the whole body in the arc tube, without receiving the influence to the ambient temperature of the arc tube, even when the tube axial direction of the arc tube is of a long size. SOLUTION: To an arc tube 2 provided with a long size in the tube axial direction, the mercury (a) of the sealing amount 0.4mg/cm<2> or more which is larger than a normal amount is sealed. An exciting coil 10 to excite the arc tube 2 is provided. Mercury reservoirs 4 to reserve the mercury (a) are provided at almost the same intervals along the tube axial direction of the arc tube 2. A circulation to cool the excessive mercury vapor and to return it to the mercury reservoirs 4, as well as to evaporate the mercury (a) in the mercury reservoirs 4 by the discharge heat, is carried out constantly, and the mercury vapor pressure is maintained evenly and adequately in the whole body in the arc tube 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an irradiation apparatus using an electrodeless discharge lamp and a water treatment apparatus.

[0002]

2. Description of the Related Art Conventionally, as a water treatment apparatus which performs ultraviolet sterilization in sewage treatment or the like, a structure described in, for example, Japanese Patent Publication No. 7-3781 or Japanese Patent Application Laid-Open No. 2-37660 is known. Have been.

[0003] In the configuration described in Japanese Patent Publication No. 7-3781, an electrode-type ultraviolet lamp is used, and ultraviolet light radiated from the ultraviolet lamp is irradiated on water to be treated to sterilize bacteria contained in the water. , To purify.

The electrode type ultraviolet lamp has almost the same electrode structure as a fluorescent lamp or the like. Therefore, the life of the lamp is determined by the consumption of the electron-emitting substance applied to the electrode, and the lamp life is short. There are problems that must be done frequently.

In the configuration described in Japanese Patent Application Laid-Open No. 2-37660, mercury and a rare gas are sealed in a glass arc tube using an electrodeless discharge lamp, and several tens of kHz are applied by an excitation coil outside the arc tube. By applying high frequency, ultraviolet rays are emitted from mercury by discharge generated in the arc tube, the emitted ultraviolet rays are irradiated on the water inside the arc tube, and bacteria contained in the water are sterilized and purified. I have.

This electrodeless discharge lamp has the advantage that the lamp life is not determined by the consumption of the electron-emitting substance applied to the electrodes as in the electrode type ultraviolet lamp, and the lamp life is longer than that of the ultraviolet lamp. .

[0007]

However, since the arc tube of the lamp used in the conventional water treatment apparatus is arranged close to or directly in contact with the water to be treated, the mercury in the arc tube is affected by the water temperature. The vapor pressure tends to change, and uniform discharge cannot be obtained in the entire arc tube. In particular, when the arc tube is 30 cm or longer in the tube axis direction, mercury vapor exists only near the coldest part of a part of the long arc tube, and uniform discharge cannot be obtained in the entire arc tube. UV irradiation cannot be stabilized.

The present invention has been made in view of such a point, and even if the arc tube is long in the tube axis direction, the mercury vapor pressure is not affected by the ambient temperature of the arc tube and is entirely within the arc tube. It is an object of the present invention to provide an irradiation device and a water treatment device capable of maintaining uniform and appropriate discharge and obtaining uniform discharge in the entire arc tube.

[0009]

According to the present invention, there is provided an irradiation apparatus, comprising: an arc tube provided to be long in the tube axis direction; and mercury sealed in the arc tube at an amount of 0.4 mg / cm ² or more. When;
A rare gas sealed in the arc tube; an excitation coil for exciting the arc tube; and a plurality of mercury holding portions provided in the arc tube at substantially equal intervals along the tube axis direction to hold mercury. Is what it is. And 0.4mg / c to the arc tube
compared to m ² or more usually with a large amount of mercury is sealed, since a plurality of mercury holding portion for holding the mercury is provided at substantially equal intervals along the tube axis direction of the bulb, hold the mercury holding portion The mercury vaporized by the discharge heat and the excess mercury vapor is cooled and circulated back to the mercury storage section, and the mercury vapor pressure is uniform throughout the arc tube without being affected by the ambient temperature of the arc tube. Properly maintained, a uniform discharge can be obtained throughout the arc tube.

According to a second aspect of the present invention, in the irradiation apparatus according to the first aspect, the mercury holding portion is provided in a concave portion inside the protruding portion protruding from the outer surface of the arc tube. Thereby, the protruding portion becomes the coldest portion of the arc tube, and the retention of mercury in the mercury retaining portion is stabilized.

According to a third aspect of the present invention, in the irradiation apparatus of the second aspect, the excitation coil is provided outside the arc tube in engagement with the projection. Thereby, the excitation coil is positioned with respect to the arc tube.

According to a fourth aspect of the present invention, there is provided the irradiation apparatus according to any one of the first to third aspects, further comprising a metal piece provided in the mercury holding section. As a result, the mercury vapor is cooled by the metal pieces, and the holding of the mercury in the mercury holding section is stabilized. The metal pieces include, for example, aluminum (Al).

According to a fifth aspect of the present invention, there is provided the irradiation apparatus according to any one of the first to fourth aspects, further comprising an amalgam capable of releasing a mercury vapor of 0.4 mg / cm ² or more instead of mercury. Is what it is. This allows
Since the vapor pressure is lower than that of ordinary mercury, it is possible to cope even when the ambient temperature is relatively high.

According to a sixth aspect of the present invention, there is provided a water treatment apparatus comprising: a flow passage through which water flows; and an irradiation device according to any one of the first to fifth aspects, which is arranged so as to irradiate the water in the flow passage with light. Is what it is. Thereby, sterilization and purification of water are surely and stable.

According to a seventh aspect of the present invention, in the water treatment apparatus of the sixth aspect, the luminous tube of the irradiation device is submerged in the flow passage. Thereby, the light emitted from the arc tube is effectively irradiated on the water.

The water treatment apparatus according to claim 8 is the water treatment apparatus according to claim 6 or 7, wherein a plurality of irradiation devices are arranged in the flow passage. This makes it possible to improve the sterilization and purification effects or to increase the water treatment speed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a first embodiment. FIG. 1 is a sectional view of an electrodeless discharge lamp, FIG. 2 is a sectional view of an electrodeless discharge lamp, and FIG. FIG. 4 is a cross-sectional view of a water treatment apparatus, in which a portion is enlarged.

1 to 3, reference numeral 1 denotes an electrodeless discharge lamp, which has an arc tube 2. The arc tube 2 is made of quartz glass or translucent ceramic, and is long in the tube axis direction and has an outer tube portion 2a and an inner tube portion 2b.
, And a cylindrical discharge space 3 is formed therein. The outer diameter D of the arc tube 2 is about 80 m
m, the inner diameter d are formed to be about 30 mm, and the length L is formed to be about 1500 mm. In addition, the arc tube 2 is used with the tube axis direction oriented substantially vertically.

On the outer surface of the arc tube 2, a plurality of mercury holding portions 4 for holding mercury a at substantially equal intervals along the tube axis direction are integrally formed. Each mercury holding part 4 has a communicating part 5 projecting outward from the tube wall of the arc tube 2 and a projecting part 7 composed of a hanging part 6 bent downward from the tip of the communicating part 5. The discharge space 3 is provided inside the hanging portion 6 of the projection 7.
Are formed in the concave portion 8 communicating with the second member. A metal piece 9 made of, for example, aluminum (Al) is arranged at the bottom of the recess 8. In addition, the interval between the adjacent mercury storage units 4 is, for example, 200 mm, and desirably ranges from 150 to 600 mm.

The upper and lower ends of the inner tube portion 2b of the arc tube 2 project vertically from the arc tube 2, and the lower end is closed and the upper end is open.

The discharge space 3 of the arc tube 2 is filled with mercury a and a rare gas. Mercury a is retained in the concave portions 8 of the mercury retaining portions 4 respectively, and the total amount thereof is 25 g, which is larger than 0.1 g in a normal case.
A mercury vapor pressure of 4 mg / cm ² or more is obtained. In addition, as for the upper limit of the amount of enclosed mercury a, there is no problem if the volume of the recess 8 is large because the excess mercury a is only retained in the recess 8.

As the rare gas, argon (Ar) is 3 to
It is sealed in the range of 600 Pa, for example, 40 Pa
It is said.

In the discharge space 3, iodine (I),
For example, at least one of a halogen group of V11b in the periodic table, such as fluorine (F), chlorine (Cl), or bromine (Br), may be sealed. In addition, these fluorine, chlorine, bromine and iodine are contained in an amount of 5 × 10 ⁻⁴ to 4 × 10 ⁻² mg per 1 cc of the unit internal volume of the discharge space 3 of the arc tube 2.
It is set to be. That is, since there is no electrode, barium (Ba), calcium (Ca), or strontium (Sr) -based oxide, which is an electron-emitting substance, does not exist in the discharge space 3, so that a halogen group can be arbitrarily enclosed.

An excitation coil is provided inside the inner tube portion 2b of the arc tube 2.
10 is located inside the discharge space 3. The excitation coil 10 is spirally wound at an interval of, for example, 20 mm, and both ends are led out from the upper end opening of the inner tube portion 2b.

A photocatalytic film or a Teflon resin film is formed on the surface of the arc tube 2. The photocatalyst film is formed by applying a photocatalytic substance such as TiO ₂ (titanium oxide, titania), and the fluororesin film is formed by applying a polytetrafluoroethylene (C ₂ F ₄ ) or the like. Have been.

In FIG. 4, reference numeral 11 denotes a water treatment device.
The water treatment apparatus 11 includes a treatment tank 12 for performing a sterilization treatment of water W.
An inlet 13 through which water W to be treated flows in is formed at the upper part of the treatment tank 12, and an outlet 14 through which water W after treatment is discharged is formed at the lower part of the treatment tank 12. Outflow from 13
Flow paths 15 through which water flows are formed in the processing tanks 12 up to 14. The detection data from the water level sensor 16 that detects the water level in the processing tank 12 is input to the inflow port 13, and the inflow amount of the water W is adjusted so that the water level in the processing tank 12 maintains a constant height. A regulating valve 17 is provided.

The electrodeless discharge lamp 1 is disposed in the processing tank 12. The inner tube portion 2b protruding below the arc tube 2 is a processing tank 12
An inner tube portion 2b supported by a pedestal 18 installed at the bottom of the processing vessel 12 and protruding above the arc tube 2 has a lid 19 for closing the upper portion of the processing tank 12.
The discharge space 3 of the arc tube 2 is submerged.

A cap 20 is attached to the upper end of the inner tube 2b, and high-frequency generators (not shown) are connected to both ends of the excitation coil 10 derived from the cap 20.

A photocatalytic film or a Teflon resin film is formed on the inner surface of the processing tank 12. The photocatalyst film is formed by applying a photocatalytic substance such as TiO ₂ (titanium oxide, titania), and the fluororesin film is formed by applying a polytetrafluoroethylene (C ₂ F ₄ ) or the like. Have been.

Then, 1 MHz to 1
When high-frequency power of 00 MHz is supplied to the excitation coil 10,
High-frequency energy is generated in the excitation coil 10, and this high-frequency energy causes an arc or the like to be discharged in the discharge space 3 of the arc tube 2, and a wavelength region 2 having a strong sterilizing action and purifying action.
It emits light containing ultraviolet rays of 20 to 300 nm, especially 254 nm.

Water to be treated is introduced into the treatment tank 12 through an inlet 13. By irradiating the water W with ultraviolet rays radiated from the arc tube 2, the DN of bacteria contained in the water W is increased.
Destroy, kill, sterilize and purify A. At this time,
Since the entire discharge space 3 of the arc tube 2 is submerged, light radiated in all directions from the peripheral surface of the arc tube 2 is effectively applied to the water W. Sterilized and purified water W
Is discharged from the outlet 14 of the processing tank 12.

When a photocatalytic film is formed on the outer surface of the arc tube 2 and the inner surface of the processing tank 12, when ultraviolet rays are received, organic components are decomposed. That is, when light in a wavelength range having energy larger than the band gap (forbidden band) of a semiconductor is irradiated, electrons and holes (holes) of electrons are generated in the semiconductor, and an electron transfer reaction occurs. For example, TiO ₂ is a semiconductor having a band gap of about 3.0 eV, and when irradiated with so-called ultraviolet light having a wavelength larger than 410 nm having energy larger than this band gap, electrons and electron holes are generated in TiO ₂ , The movement of the holes causes an electron transfer reaction on the surface. In this electron transfer reaction, the holes have the power to pull out electrons corresponding to the energy of the band gap, that is, the oxidizing power, and the oxidizing power of the holes changes the substance attached or contacted to the surface of TiO _2. Let me. As described above, since TiO ₂ generates a strong oxidizing power when it receives ultraviolet rays, a substance adhered to the surface of the TiO ₂ of the arc tube 2 or the processing tank 12, for example, an organic substance such as acetaldehyde or methyl mercaptan,
In addition, it promotes oxidation and decomposition of substances such as hydrogen sulfide and ammonia. Therefore, the outer surface of the arc tube 2 and the surface of the processing tank 12 are hardly contaminated, the translucency can be maintained, and the cleaning can be facilitated.

Further, active oxygen or ozone (O ₃ ) such as a single atom (O) or excited oxygen (O ^* ) is generated from oxygen (O ₂ ) contained in water by the photocatalytic film, and active oxygen or oxygen (O ₃ ) is generated. Bacteria or algae are decomposed and sterilized by ozone, and purified.

When a fluororesin film is formed on the outer surface of the arc tube 2 and the inner surface of the processing tank 12, dirt is less likely to adhere, light transmittance can be maintained, and cleaning can be facilitated. .

The discharge space 3 of the arc tube 2 has a capacity of 0.4 mg.
/ Cm ² or more, and a plurality of mercury holding parts 4 for holding the mercury a are provided at substantially equal intervals along the tube axis direction of the arc tube 2. The mercury a retained in the section 4 evaporates with the discharge heat, and excess mercury vapor is cooled and circulated back to the mercury retaining section 4 to obtain an appropriate mercury vapor pressure. Therefore, the mercury vapor pressure is maintained uniformly and appropriately throughout the arc tube 2 without being affected by the water temperature of the water W, a uniform discharge is obtained throughout the arc tube 2, and ultraviolet irradiation can be stabilized. .

Further, since the mercury holding part 4 is provided in the concave part 8 inside the projecting part 7 projecting to the outer surface of the arc tube 2, the projecting part 7 becomes the coldest part of the arc tube 2 and the mercury holding part 4 The retention of mercury a can be stabilized.

Further, since the metal piece 9 is provided in the mercury holding section 4, the mercury vapor can be cooled by the metal piece 9 and the holding of mercury a in the mercury holding section 4 can be stabilized.

Then, as in the water treatment apparatus 11 shown in FIG. 4, the arc tube 2 is brought into direct contact with the water W, and at a water temperature of 14.degree.
When the lamp was turned on with an input power of 0 W, it was confirmed that uniform discharge occurred in the entire arc tube 2. In addition, it was confirmed that the sterilizing ability had the same processing ability as that of a conventional 1 kW low-pressure mercury lamp. Furthermore, the water temperature in winter is 5 ℃
, And even when the water temperature in summer is 27 ° C,
Similar results were confirmed. That is, compared to the conventional case,
Thus, a water treatment apparatus 11 having a high efficiency of about% was obtained.

In place of mercury a, 0.4 mg / cm
Amalgam which can release ^two or more mercury vapors may be used. In this case, since the vapor pressure is lower than that of ordinary mercury a, it is possible to cope with a case where the ambient temperature is relatively high.

FIG. 5 is a sectional view of an electrodeless discharge lamp 1 according to a second embodiment.

The excitation coil 10 is formed in a spiral shape around the outer periphery of the arc tube 2.
The excitation coil 10 can be positioned with respect to the arc tube 2 by engaging with the protruding portion 7 protruding therefrom.

Next, FIG. 6 is a sectional view of a water treatment apparatus 11 according to a third embodiment.

Inside the outer tube 21 made of ceramics, the arc tubes 2 of the plurality of electrodeless discharge lamps 1 are arranged in parallel along the axial direction of the outer tube 21. The arc tube 2 is formed in a double tube structure having an outer tube portion 2a and an inner tube portion 2b. Outer tube
An excitation coil 10 is spirally wound around the outer periphery of 21. A flow passage 15 through which water W to be treated flows is formed between the outer tube 21 and the arc tube 2 and inside the inner tube portion 2b of the arc tube 2.

In the arc tube 2, mercury holding portions 4 (not shown) are formed at substantially equal intervals along the tube axis direction. The mercury holding section 4 is provided with a concave portion on the lower surface side of the arc tube 2 so that the holding of the mercury a is stabilized.

When high-frequency power is supplied to the excitation coil 10, a discharge such as an arc occurs in the discharge space 3 of each arc tube 2 due to the high-frequency energy generated in the excitation coil 10.
Ultraviolet rays are emitted between the outer tube 21 and the arc tube 2 and the inner tube portion of the arc tube 2.
The water W flowing inside 2b is irradiated to be sterilized and purified.
At this time, since the plurality of arc tubes 2 are submerged, light radiated in all directions from the peripheral surface of the arc tube 2 is effectively applied to the water W. In addition, since the plurality of arc tubes 2 are submerged, it is possible to improve sterilization and purification effects or to increase the speed of water treatment. Furthermore, by arranging a plurality of arc tubes 2 in close proximity, the degree of activity is increased, and the sterilizing and purifying effects are improved.

In this case as well, the arc tube 2 and the outer tube
Even if a photocatalyst film or a Teflon resin film is formed at a location in contact with the water W, the same operation and effect as described above can be obtained.

An excitation coil 10 may be provided in the discharge space 3 inside the arc tube 2, and in this case, the arc tube 2 can be excited efficiently.

Further, such a water treatment apparatus can be applied to bath water treatment, sewage treatment and the like. Further, the same operation and effect can be obtained by applying the sterilizer to the treatment of not only water but also other liquids.

[0050]

According to the irradiation apparatus of the present invention, a large amount of mercury of 0.4 mg / cm ² or more is sealed in the luminous tube as compared with a normal case, and a plurality of mercury holding sections for holding the mercury are provided. Since the mercury held in the mercury storage unit is evaporated at the same time along the tube axis direction of the arc tube, the mercury stored in the mercury storage unit is evaporated by the discharge heat, and excess mercury vapor is cooled and circulated back to the mercury storage unit. The mercury vapor pressure is maintained uniformly and appropriately throughout the arc tube without being affected by the ambient temperature of the tube, and uniform discharge is obtained throughout the arc tube.

According to the irradiation device of the second aspect, in addition to the effect of the irradiation device of the first aspect, since the mercury holding portion is provided in the recess inside the projection projecting to the outer surface of the arc tube, the projection is provided. The part becomes the coldest part of the arc tube, and the holding of mercury in the mercury holding part can be stabilized.

According to the irradiation device of the third aspect, in addition to the effect of the irradiation device of the second aspect, the excitation coil is provided outside the arc tube by engaging with the protruding portion. The excitation coil can be positioned.

According to the irradiation apparatus of the fourth aspect, in addition to the effects of the irradiation apparatus of any one of the first to third aspects,
Since the metal piece is provided in the mercury holding section, the mercury vapor is cooled by the metal piece, and the holding of mercury in the mercury holding section can be stabilized.

According to the irradiation apparatus of the fifth aspect, in addition to the effects of the irradiation apparatus of any one of the first to fourth aspects,
Since amalgam capable of releasing mercury vapor of 0.4 mg / cm ² or more was used in place of mercury, the vapor pressure is suppressed more than that of ordinary mercury, so that it is possible to cope with a case where the ambient temperature is relatively high.

According to the water treatment apparatus of the present invention, since the water in the flow passage is irradiated with light by the irradiation apparatus of any one of claims 1 to 5, the sterilization and purification of the water can be surely and stabilized. it can.

According to the water treatment apparatus of the seventh aspect, in addition to the effect of the water treatment apparatus of the sixth aspect, since the luminous tube of the irradiation device is submerged in the flow passage, the light radiated from the luminous tube is reduced. Irradiates water effectively.

According to the water treatment device of the eighth aspect, in addition to the effect of the water treatment device of the sixth or seventh aspect, since a plurality of irradiation devices are arranged in the flow passage, the sterilization and purification effects can be improved. Alternatively, it can cope with an increase in the water treatment speed.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electrodeless discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the electrodeless discharge lamp of the embodiment.

FIG. 3 is an enlarged cross-sectional view of a mercury holding section of the electrodeless discharge lamp of the embodiment.

FIG. 4 is a cross-sectional view of the water treatment apparatus according to the embodiment.

FIG. 5 is a sectional view of an electrodeless discharge lamp showing a second embodiment of the present invention.

FIG. 6 is a sectional view of a water treatment apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 Arc tube 4 Mercury holding part 7 Projection part 8 Depression 9 Metal piece 10 Excitation coil 15 Flow path a Mercury

Claims (8)

[Claims] 1. An arc tube which is long in the direction of a tube axis;
Mercury sealed in the arc tube at an amount of 0.4 mg / cm ² or more; a rare gas sealed in the arc tube; an excitation coil for exciting the arc tube; And a plurality of mercury holding sections provided at intervals and holding mercury. 2. The irradiation apparatus according to claim 1, wherein the mercury holding part is provided in a concave part inside the protruding part protruding from the outer surface of the arc tube. 3. The irradiation device according to claim 2, wherein the excitation coil is provided outside the arc tube in engagement with the projection. 4. The irradiation apparatus according to claim 1, further comprising a metal piece provided in the mercury holding section. 5. The irradiation apparatus according to claim 1, further comprising an amalgam capable of releasing mercury vapor of 0.4 mg / cm ² or more instead of mercury. 6. A water comprising: a flow passage through which water flows; and the irradiation device according to any one of claims 1 to 5, which is arranged to irradiate light to the water in the flow passage. Processing equipment. 7. The water treatment apparatus according to claim 6, wherein the luminous tube of the irradiation device is disposed under water in the flow passage. 8. The water treatment apparatus according to claim 6, wherein a plurality of irradiation devices are arranged in the flow passage.