JP2013154145A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner that generates an OH radical with high efficiency.SOLUTION: An electrode 3a and an electrode 3b are formed by coating the surfaces of electrode substrates 11 with dielectrics 12. A reflective material 13 is supported inside the dielectric 12 and exposed to the surface of the dielectric 12. When high voltage is applied to the electrode 3a and the electrode 3b, electric discharge is performed between the electrode 3a and the electrode 3b to generate ozone from oxygen in treated gas. The electrode 3a and the electrode 3b are irradiated with ultraviolet rays from an ultraviolet light source, and ultraviolet rays having passed through an opening 8b on the side close to the ultraviolet light source are reflected to the electrode 3b side by the reflective material on the surface of the electrode 3a. Ultraviolet rays irradiated toward the electrode 3b and the electrode 3a repeat reflection between the electrodes under the action of the reflective material so as to be irradiated over a wide range of the electrode surface, and react with moisture contained in air to generate an OH radical with strong oxidizing power from ozone generated by electric discharge.

Description

  The present invention relates to an air purification apparatus that generates active species by applying a high voltage between electrodes and performs sterilization, deodorization, and decomposition of organic substances of a gas to be treated by the action of the active species.

  As a conventional air purification device, a dielectric is applied to the surfaces of a pair of electrode plates having a plurality of openings, and a high voltage is applied between the electrodes to treat the active species such as ozone generated by discharge. An air purification device that purifies gas is known (for example, see Patent Document 1 below).

  Hereinafter, the air purification apparatus will be described with reference to FIG.

  As shown in FIG. 6, a dielectric 102 is applied to the electrode plate 101, and a high voltage is applied between opposing electrodes using a high voltage power supply 103. Since the gas to be treated passes through the opening 105 along the flow path 104, the gas to be treated is sterilized, deodorized and decomposed by the action of ozone generated by discharge on the surface of the electrode plate 101. is there.

  As another air purifying device, an air purifying device that generates OH radicals that are more active than ozone by applying ultraviolet light to ozone generated by an arbitrary method is known (for example, see Patent Document 2 below).

  Hereinafter, the air purification apparatus will be described with reference to FIG.

  As shown in FIG. 7, the ozone-containing air generated by the ozone generator 201 is introduced into a reaction vessel 204 having an inlet 202 and an outlet 203. The reaction vessel 204 is provided with a diffusion plate 205, and ozone is uniformly diffused into the reaction vessel. In addition, the reaction vessel 204 includes an ultraviolet transmission window 206, and ultraviolet rays are irradiated from an ultraviolet light source 207 provided outside the reaction vessel 204. The ultraviolet light source 207 is turned on by a power source 208.

OH radicals are generated by reacting with moisture contained in the air by the following reaction from ozone irradiated with ultraviolet rays.
O ₃ + hν → O ₂ + O (1D)
O (1D) + H ₂ O → 2OH ·
Since OH radicals have a stronger oxidizing power than ozone and show a high effect on the decomposition of organic substances and the sterilization of microorganisms, they can be used for air purification. By releasing OH radicals from the reaction vessel 204 through the outlet 203 to the gas to be processed, it is possible to efficiently decompose organic substances and sterilize microorganisms in the gas to be processed.

Note that in the above reaction formula, O (1D) represents singlet oxygen, and the π ^* 2p orbital is occupied in a singlet state by electrons having opposite spin directions and is in an excited state.

JP 2007-7330 A Japanese Patent Laid-Open No. 2003-3152

  By combining such a conventional air purification device, it is possible to generate OH radicals from ozone by irradiating ultraviolet rays between the electrodes that generate ozone. In order to improve the efficiency of ozone generation, When these are brought close to each other, it has become difficult to irradiate the entire surface of the electrode with ultraviolet rays, and the production efficiency of OH radicals is reduced.

  That is, in order to improve the generation efficiency of ozone generated by discharge, the electrodes may be brought close to each other so that discharge is established at a low voltage. On the other hand, in order to improve the generation efficiency of OH radicals generated by ultraviolet irradiation of ozone, it is only necessary to irradiate the electrode surface having a high ozone concentration with ultraviolet light. However, if the electrodes are brought close to each other in order to improve the ozone generation efficiency, the electrodes become shadows, making it difficult to irradiate the entire surface of the discharged electrode with ultraviolet rays.

  Therefore, the present invention solves the above-described conventional problems, and an object of the present invention is to provide an air purification device capable of achieving both ozone generation efficiency and OH radical generation efficiency.

  In order to achieve this object, the present invention is an air purifying device characterized in that a light reflecting material is carried on the surface of the opposing electrode, thereby achieving the intended object. It is.

  The present invention is configured to carry a light reflecting material on the surface of the opposing electrode. According to the above configuration, even when the electrodes are brought close to each other in order to improve the ozone generation efficiency by discharge, the ultraviolet rays received by the electrode end faces are repeatedly reflected by the light reflecting material on the electrode surface, thereby irradiating the entire surface of the electrodes with ultraviolet rays. Thus, even when the electrodes are opposed to each other and close to each other, an effect of generating OH radicals with high efficiency can be obtained.

1 is a schematic perspective view showing an air purification device according to Embodiment 1 of the present invention. Schematic enlarged sectional view showing the electrode part Schematic enlarged sectional view showing an example of another structure of the electrode part The schematic perspective view which shows the electrode part of the air purification apparatus of Embodiment 2 of this invention. Schematic expanded sectional view which shows the electrode part of the air purification apparatus of Embodiment 2 of this invention. Schematic perspective view showing a conventional air purification device Schematic showing a conventional air purification device

  The air purification device according to claim 1 of the present invention includes at least a pair of electrodes and an ultraviolet light source in a main body having an inflow port and an outflow port through which the gas to be treated flows in and out, and introduces the gas to be treated between the electrodes. And an air purifying device that generates active oxygen species by applying a voltage between the electrodes and irradiating ultraviolet rays from the ultraviolet light source, and has a configuration in which a light reflecting material is supported at least on the opposing surfaces of the electrodes. Have.

  As a result, since the ultraviolet light irradiated on the surface of the electrode is reflected by the light reflecting material, the ultraviolet light can be irradiated over a wide range of the electrode surface, so that even when the electrodes are facing each other, the efficiency is high. It produces an effect of generating OH radicals.

  In addition, the electrode has a plurality of openings, the electrode is arranged in a direction substantially perpendicular to the flow of the gas to be processed, and the plurality of opening diameters of each of the electrodes are the same, and arranged on the upstream side The opening diameter of the electrode may be larger than the opening diameter of the electrode disposed on the downstream side.

  As a result, the ultraviolet light that has passed through the opening on the upstream side is reflected by the light reflecting material on the surface of the downstream electrode, so that the upstream electrode is irradiated and the electrodes are in close proximity to each other. Also has the effect of generating OH radicals with high efficiency.

  The electrode has a plurality of openings, the electrode is arranged in a direction substantially perpendicular to the flow of the gas to be processed, and the electrode arranged on the downstream side of the opening center of the electrode arranged on the upstream side. The opening may be arranged so that the projection position of the electrode is different from the opening center of the electrode arranged on the downstream side.

  As a result, the ultraviolet light that has passed through the opening on the upstream side is reflected by the light reflecting material on the surface of the opposing electrode, so that the surface of the opposing electrode is irradiated. It produces an effect of efficiently generating OH radicals.

  Moreover, you may make it the structure which used quartz sand as a reflecting material carried on the surface of an electrode. As a result, the ultraviolet light is reflected on the surface of the quartz sand, and the ultraviolet light can be irradiated over a wide range of the electrode surface, so that even when the electrodes are opposed and close to each other, OH radicals are generated with high efficiency. There is an effect.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the air purification device 1 includes an electrode 3 a, an electrode 3 b, and an ultraviolet light source 4 inside a main body 2. The gas to be processed sucked into the main body 2 from the inlet 5 is discharged by the blower 6 via the outlet 7. The electrode 3a and the electrode 3b have an opening 8a and an opening 8b, respectively, and are electrically connected to the high-voltage pulse power source 9.

  In the flow of the gas to be processed, the opening 8b located in the upstream portion has a larger opening diameter than the opening 8a located in the downstream portion, and the ultraviolet light source 4 is disposed upstream of the electrode 3b disposed on the upstream side. Yes.

  The ultraviolet light source 4 is electrically connected to the power source 10. The main part A of the electrode 3a and the electrode 3b is shown in FIG.

  As shown in FIG. 2, the electrode 3 a and the electrode 3 b have a dielectric 12 coated on the surface of the electrode substrate 11. A reflective material 13 is carried inside the dielectric 12 and is exposed on the surface of the dielectric 12.

  According to such a configuration, by applying a high voltage to the electrodes 3a and 3b, discharge is performed between the electrodes 3a and 3b, and ozone is generated from oxygen in the gas to be processed. Since the gas to be processed sucked into the main body 2 from the inlet 5 passes between the electrodes via the opening 8b and the opening 8a, it is purified by the action of ozone generated between the electrodes 3a and 3b. It is what is done.

  Furthermore, ultraviolet rays are irradiated from the ultraviolet light source 4 to the electrodes 3a and 3b, and as shown by the broken line arrows in FIG. 2, the ultraviolet rays that have passed through the opening 8b having a large opening area are reflected by the reflecting material on the surface of the electrode 3a. The light is reflected toward the electrode 3b.

  Thus, the ultraviolet rays irradiated toward the electrode 3b and the electrode 3a are repeatedly reflected by the action of the reflecting material 13, thereby being irradiated over a wide range of the surfaces of the electrode 3a and the electrode 3b.

On the surface of the electrode 3a or the electrode 3b, OH radicals are generated by reacting with moisture contained in the air by the following reaction from ozone irradiated with ultraviolet rays.
O ₃ + hν → O ₂ + O (1D)
O (1D) + H ₂ O → 2OH ·
Since OH radicals have a stronger oxidizing power than ozone and show a high effect on the decomposition of organic substances and the sterilization of microorganisms, they can be used for air purification.

Note that in the above reaction formula, O (1D) represents singlet oxygen, and the π ^* 2p orbital is occupied in a singlet state by electrons having opposite spin directions and is in an excited state.

  In the present embodiment, unlike the conventional air purification device, the surface of the electrode on which ozone is generated by discharge between the electrodes 3a and 3b is irradiated with ultraviolet rays, so that ozone diffuses into the gas to be treated. The high-concentration ozone before the irradiation can be irradiated with ultraviolet rays, and the utilization efficiency of ultraviolet rays is high.

  Moreover, since the ultraviolet rays can be irradiated over a wide range by the action of the reflecting material 13 between the electrodes 3a and 3b that are close to each other so as to generate ozone at a low discharge voltage, the use efficiency of the ultraviolet rays is high. is there.

  In addition, since OH radicals directly generated during discharge also exist between the electrode 3a and the electrode 3b, a high concentration of OH radicals is combined with the OH radicals generated by irradiating ozone with ultraviolet rays. The air purification performance can be improved.

  In addition, since ozone is generated by discharge from oxygen in the gas to be processed and OH radicals are generated from moisture and ozone in the gas to be processed by ultraviolet irradiation, a gas containing oxygen and water is applied as the gas to be processed. Is. When moisture is not contained in the gas to be treated, it is possible to supply moisture to the air to be treated by adding a humidifying means upstream of the electrode portion.

  The reflective material 13 carried on the surfaces of the electrodes 3a and 3b is preferably a material that reflects ultraviolet rays with high efficiency. By using quartz sand as a reflective material, the surface of the quartz sand and the quartz sand and the dielectric 12 are used. Ultraviolet rays are reflected at the interface.

  In the present embodiment, since the surfaces of the electrodes 3a and 3b are coated with the dielectric 12 in order to realize a stable discharge between the electrodes 3a and 3b, the electrodes 3a and 3b A reflective material that does not easily affect the discharge between the electrodes 3b is required. Since a material having high electrical conductivity such as a metal may form a local discharge, it is preferable to use a material having low electrical conductivity as a reflector.

  The dielectric 12 and its coating method are not particularly limited. Specifically, a method of forming an inorganic oxide film by a sol-gel method is preferable, and materials such as SiO2, Al2O3, MgO, ZrO2, TiO2, ZnO, Y2O3, and BaTiO2 can be used. From the viewpoint of relative permittivity, BaTiO2, Al2O3, and TiO2 are preferably used.

  Note that the condition of the high voltage applied between the electrode 3a and the electrode 3b is not particularly limited. Specifically, a high voltage that does not shift to spark discharge may be applied according to the area of the electrodes 3a and 3b facing each other and the distance between the electrodes. A voltage may be applied.

  The ultraviolet light source 4 is not particularly limited. Since ozone generated by discharge absorbs a wavelength of 200 nm to 300 nm and releases oxygen atoms in an excited state, any light source that can irradiate ultraviolet rays with high efficiency, such as a high-pressure mercury lamp that emits ultraviolet rays of 254 nm, may be used.

  The power source 10 for turning on the ultraviolet light source 4 is not particularly limited. Specifically, if a mercury lamp is used as the ultraviolet light source 4, the ultraviolet light is turned on if the power source includes a transformer for obtaining a voltage necessary for lighting from a commercial power source and an inverter for obtaining a high frequency power source. Can do.

  Although the ultraviolet light source 4 is disposed upstream of the electrode 3b disposed on the upstream side, the ultraviolet light source 4 may be disposed on the downstream side of the electrode 3a disposed on the downstream side. In that case, the same effect can be obtained if the opening diameter of the opening 8a of the electrode 3a arranged on the downstream side is made larger than the opening diameter of the opening 8b of the electrode 3b arranged on the upstream side.

  That is, the ultraviolet rays that have passed through the opening 8a having a large opening area are reflected to the electrode 3a side by the reflecting material on the surface of the electrode 3b.

  The arrangement position of the ultraviolet light source 4 is not particularly limited, but may be an arrangement in which ultraviolet rays are irradiated between the electrode 3a and the electrode 3b, and from the electrode side where the opening diameter of the opening is large. Irradiation enables efficient irradiation between the electrode 3a and the electrode 3b.

  Further, the opening diameters of the openings of the electrodes 3a and 3b are not particularly limited, but the flow resistance of the gas to be treated can be reduced by increasing the opening diameter, but the electrode area contributing to the discharge This reduces the ozone generation efficiency. Therefore, it is preferable to make the opening diameter as small as possible so as not to greatly affect the flow resistance of the gas to be processed.

  Further, the amount of air to be processed that passes between the electrodes 3a and 3b can be increased by making the upstream opening diameter larger than the downstream opening diameter.

  FIG. 3 shows main parts of the electrode 3a and the electrode 3b having different structures according to the first embodiment. The same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The opening 8a and the opening 8b are electrodes in which the projection position of the center of the opening 8b of the electrode 3b arranged on the upstream side to the electrode 3a arranged on the downstream side is arranged on the downstream side in the flow path of the gas to be processed. Since the opening is arranged so as to be different from the center of the opening 8a of 3a, the ultraviolet rays that have passed through the opening 8b are reflected on the electrode 3b by the reflecting material on the surface of the electrode 3a as indicated by the broken line arrow in FIG. It will be reflected to the side.

  As described above, the ultraviolet rays irradiated toward the electrode 3b and the electrode 3a are repeatedly reflected by the action of the reflecting material 13, thereby being irradiated over a wide range of the surfaces of the electrodes 3a and 3b.

  According to this configuration, compared to the electrode structure in which the opening diameters of the two electrodes shown in FIG. 2 are different, since the two electrodes have the same opening diameter, there is no need to make separate electrodes, and the manufacturing cost of the electrodes Can be reduced.

  However, in order to effectively utilize the ultraviolet rays applied to the electrode surface by the action of the reflecting material, the opening of the electrode on the side where the ultraviolet light source is not installed does not significantly affect the flow resistance of the gas to be processed. It is preferable to make the opening diameter as small as possible.

(Embodiment 2)
FIG. 4 shows a schematic perspective view around the electrode part of the air purifying apparatus in the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  Unlike Embodiment 1, the electrode has no opening, and the gas to be processed flows between the electrodes along the electrode surface.

  The electrode 14a, the electrode 14b, and the side wall 15 form a flow path for the gas to be processed, and an inlet 16 and an outlet 17 are provided. The electrodes 14a and 14b are connected to a high voltage pulse power source 18. An ultraviolet light source 19 and an ultraviolet light transmission window 20 are provided above the inflow port 16, and the ultraviolet light source 19 is connected to a power source 21.

  FIG. 5 is a schematic cross-sectional view around the electrode portion of the air purifying apparatus in the second embodiment. The gas to be treated is sucked from the inflow port 16 and blown out from the outflow port 17 by the action of a blower (not shown).

  The surface of the side where the electrode 14a and the electrode 14b face each other is coated with a dielectric 22, and a reflecting material 23 is carried by the dielectric 22. The ultraviolet light source 19 is provided with a reflecting plate 24, and irradiates the surface of the electrode 14b with ultraviolet light emitted from the ultraviolet light source 19.

  According to such a configuration, similarly to the first embodiment, discharge is performed between the electrode 14a and the electrode 14b, and ozone is generated from oxygen in the gas to be processed.

  Furthermore, OH radicals can be generated from ozone by irradiating the electrode surface with ultraviolet rays. If the electrode 14a and the electrode 14b are brought close to each other in order to discharge at a low voltage, it becomes difficult to irradiate the surfaces of the opposing electrode 14a and the electrode 14b with ultraviolet rays. The light is reflected toward the electrode 14a by the reflective material on the surface.

  Thus, the ultraviolet rays irradiated toward the electrode 14b and the electrode 14a are repeatedly reflected by the action of the reflecting material 23, so that the ultraviolet rays are irradiated over a wide range of the surfaces of the electrode 14a and the electrode 14b.

  In particular, unlike the first embodiment, in the present embodiment in which the electrode 14a and the electrode 14b do not have an opening through which the gas to be processed passes, the ultraviolet light receiving area on the surfaces of the electrode 14a and the electrode 14b is increased. In this case, it is necessary to enlarge the area of the ultraviolet transmissive window or install the ultraviolet light source 19 between the electrode 14a and the electrode 14b.

  However, enlarging the ultraviolet light transmitting window 20 leads to a reduction in the area of the electrode 14a, and lowers the ozone generation efficiency. Further, when the ultraviolet light source 19 is installed between the electrode 14a and the electrode 14b, it becomes resistance when the gas to be processed is circulated, and the processing amount of the gas to be processed is reduced. Moreover, since the electrode 14a and the electrode 14b are brought close to each other for the purpose of starting discharge at a low voltage, if the ultraviolet light source 19 is placed between the electrode 14a and the electrode 14b, the proximity of the electrode 14a and the electrode 14b is hindered. That is, in the second embodiment, since the reflecting material 23 is carried on the surfaces of the electrodes 14a and 14b, the above problem can be solved.

  The material of the ultraviolet transmitting window 20 is preferably quartz glass. Any material other than quartz glass can be used as the ultraviolet light transmitting window as long as it has a characteristic of transmitting ultraviolet light having a wavelength necessary for converting ozone into OH radicals without being attenuated as much as possible.

  The use of OH radicals generated from ozone by ultraviolet rays is the same as in the first embodiment.

  As described above, the air purification apparatus of the present invention generates OH radicals with high efficiency by achieving both ozone generation efficiency and OH radical generation efficiency, and air that purifies air by the action of OH radicals. It is useful as a purification device.

DESCRIPTION OF SYMBOLS 1 Air purification apparatus 2 Main body 3a Electrode 3b Electrode 4 Ultraviolet light source 5 Inlet 6 Blower 7 Outlet 8a Opening 8a Opening 9 High voltage pulse power supply 10 Power supply 11 Electrode base material 12 Dielectric 13 Reflective material 14a Electrode 14b Electrode 15 Side wall 16 Inlet 17 Outlet 18 High-pressure pulse power supply 19 Ultraviolet light source 20 Ultraviolet light transmission window 21 Power supply 22 Dielectric 23 Reflector 24 Reflector 101 Electrode plate 102 Dielectric 103 High voltage power supply 104 Distribution path 105 Opening 201 Ozone generator 202 Inlet 203 Outlet 204 Reaction vessel 205 Diffusion plate 206 Ultraviolet transmission window 207 Ultraviolet light source 208 Power supply

Claims (4)

In the main body having an inlet and an outlet through which the gas to be processed flows in and out,
Comprising at least a pair of electrodes and an ultraviolet light source,
An air purifying apparatus that introduces a gas to be treated between the electrodes, generates a reactive oxygen species by applying a voltage between the electrodes and irradiating ultraviolet rays from the ultraviolet light source, and at least the surfaces of the electrodes facing each other An air purification device characterized in that a light reflecting material is supported on the air purification device. The electrode has a plurality of openings, and the electrode is disposed in a direction substantially perpendicular to the flow of the gas to be processed.
The air purification apparatus according to claim 1, wherein the plurality of opening diameters of the electrodes are the same, and the opening diameter of the electrode arranged on the upstream side is larger than the opening diameter of the electrode arranged on the downstream side. The electrode has a plurality of openings, and the electrode is disposed in a direction substantially perpendicular to the flow of the gas to be processed.
The air according to claim 1, wherein the opening is arranged so that a projection position of the opening center of the electrode arranged on the upstream side onto the electrode arranged on the downstream side is different from the opening center of the electrode arranged on the downstream side. Purification equipment. The air purification device according to any one of claims 1 to 3, wherein the light reflecting material is quartz sand.

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