JP2006043550A - Air cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air cleaner capable of collecting odor molecules in contaminated air ionized by the ionizing section, dust and bacteria with high probability in the dust-collecting section and decomposing the odor molecules, dust and bacteria in contaminated air to a low-concentration range. <P>SOLUTION: The cleaner has an ionizing section 12 imparting an electric charge to odor gas ingredients, a dust-collecting section 13 collecting the odor gas ingredients 15 ionized by the ionizing section 3 to purify, a first pair 6 of electrodes applying an electric field in the ventilating direction 10 to 11 and a second pair 8 of electrodes applying an electric field in a direction different from that of the electric field applied to the first pair 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air purifier that removes odorous gas components from the air and purifies the air.

  In recent years, air purifiers have a discharge electrode for ionizing odor molecules, dust, and bacteria contained in polluted air on the gas flow inlet side, and are filled with dielectric particles downstream of the gas ventilation path. Dielectric particle-filled filter that decomposes and disinfects by applying an alternating voltage to the dielectric particle layer, collecting odor molecules, dust, and bacteria by electrostatic force and generating partial discharge in the dielectric particle layer A number of structures have been proposed. Further, by providing a catalyst part in which a catalyst or an adsorbent is attached to the dielectric particles, it is possible to purify air with higher efficiency.

  A conventional dielectric particle packed layer filter device has a dielectric particle layer composed of a particle layer having a small particle size and a particle layer having a large particle size in the outer cylinder of the filter, and the two layers are laminated along the gas flow. Has been. Wire mesh electrodes are installed on both surfaces of these particle layers, and an AC high-voltage power supply is connected. In addition, a discharge electrode for charging dust and bacteria is installed in front of the dielectric particle layer, and the discharge electrode and the wire mesh electrode are grounded. Further, a fan is installed at the outlet of the filter in order to discharge the gas outside the apparatus.

  In the above configuration, when a gas containing dust and bacteria enters the filter, the dust and bacteria in the air are charged positively or negatively by the corona discharge of the discharge electrode and taken into the dielectric. In addition, the electric field strength in the dielectric particles concentrates in a small space between adjacent particles, so a strong electric field is obtained, and partial discharge due to local ionization of air occurs in the small space, Bacteria in the gas taken into the particle layer by high-concentration ions and ozone are collected and destroyed by the dielectric, and the cleaned gas is discharged from the outlet through the fan (for example, see Patent Document 1). ).

Japanese Patent Laid-Open No. 2-119554 (page 2, lines 35 to 62, FIG. 1)

  However, in the conventional method for collecting a dust collecting part in the dielectric particle packed bed filter device of Patent Document 1, an electric field is applied in the same direction as the gas flow direction for odor molecules, dust, and bacteria that do not pass near the partial discharge. Therefore, there is a problem that it cannot be collected with high probability.

  The present invention has been made in order to solve the above-mentioned problems, and it is highly probable that odor molecules, dust, and bacteria in polluted air ionized by the ionization unit provided on the gas inlet side are collected at the dust collection unit. An object of the present invention is to obtain an air cleaning device that can collect and decompose odor molecules, dust, and bacteria in polluted air to a low concentration range.

  An air cleaning device according to the present invention includes an ionization unit that imparts an electric charge to an odor gas component, a dust collection unit that collects and purifies the odor gas component ionized by the ionization unit, and a first electric field that applies an electric field in a ventilation direction. And a second electrode pair that applies an electric field in a direction different from the electric field direction applied to the first electrode pair.

  According to the air cleaning device of the present invention, it is possible to improve the collection rate of odor molecules, dust, bacteria, etc., and to decompose and remove malodorous components and harmful substances up to a low concentration range by adsorption and chemical reaction. it can.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram of an air cleaning apparatus according to Embodiment 1 for carrying out the present invention. The air purifier includes a prefilter 1 provided near the entrance of the ventilation path, an ionization unit 12 including an ultraviolet light irradiation unit 3 for irradiating ultraviolet light to ionize odor molecules, dust, and bacteria, and further ionizing. A dust collection unit 13 including a dielectric particle layer filter 5 that collects and decomposes odor molecules, dust, and bacteria, and a second electrode pair 8 for applying an electric field so as to sandwich the dielectric particle layer filter 5 therebetween. It is comprised by.

More specifically, the contaminated air containing odor molecules, dust, and bacteria taken into the apparatus from the arrow 10 is collected by the pre-filter 1 provided near the entrance of the air passage, and then the pre-filter 1 is collected. Odor molecules, dust, and bacteria that have passed through the filter 1 are subjected to ultraviolet light (wavelength region: wavelength included in λ = 200 to 260 nm) from the light source 3a when passing through the ionization unit 12 provided with the ultraviolet light irradiation unit 3. It is ionized by irradiation. The ultraviolet light irradiation unit 3 is provided with a mercury lamp composed of a quartz glass bulb, and the space of the ventilation path 2 is irradiated with ultraviolet light with a uniform intensity.
In the above description, a mercury lamp is used as the ultraviolet light source 3a. However, the present invention is not limited to this, and an LED, an LD, or the like included in the wavelength range may be used.
In the present embodiment, the light source unit provided in the photoionization unit is described as one that irradiates ultraviolet light, but is not limited to this, and may be, for example, a light source that emits soft X-rays. .

  Also, on the downstream side of the ventilation path 2, a first electrode pair 6 formed by a metal structure such as a metal net or a punching metal to which an AC voltage power source 7 is connected is installed. A dielectric particle layer filter 5 composed of a plurality of dielectric particle layers in which a dielectric is laminated along the gas flow in the ventilation path 2 is installed. The dielectric particle layer filter 5 is provided with a catalyst and an adsorbent on the surface of a layer formed by uniformly laminating dielectric particles having a particle diameter of several μm to several 100 μm on a substrate made of a dielectric material or a ceramic substrate. It is formed by attaching.

The dielectric is made of a material having a relatively high dielectric constant such as barium titanate or tantalum oxide, and the catalyst is an oxide such as iron, copper, zinc, cobalt, nickel, manganese, gold, platinum, silver, etc. These noble metals are used alone or in combination, and zeolite, silica, activated carbon or the like is used as the adsorbent. In addition, the optimal catalyst and adsorbent are selected from the above description according to the type of the target odor molecule. Both ends of the dielectric particle layer filter 5 are connected to a pair of metal mesh electrodes forming the first electrode pair 6, and the dielectric particle layer filter 5 is set at a range where dielectric breakdown does not occur between the metal mesh electrodes at both ends. An electric field of several kV / cm to several tens kV / cm, more preferably 4 kV / cm to 6 kV / cm is applied. At this time, the applied voltage may be either alternating current or pulse.
A DC power source 9 is connected to the second electrode pair 8 placed so as to sandwich the dielectric particle layer filter 5, and a voltage of several kV to several tens kV, more preferably 4 kV to 6 kV is provided between the electrodes. Is applied.

  FIG. 2 is an explanatory diagram for explaining the dielectric particle layer filter 5. In the figure, the surface of the dielectric particle layer filter 5 has a structure in which one or more dielectric particles 51 having a particle size of several μm to several hundred μm are stacked, and a wire mesh electrode pair forming the first electrode pair 6. When an alternating voltage or a high pulse voltage is applied, an electric field having a high electric field strength is formed by concentrating the electric field in a small space between adjacent particles in the dielectric particle layer. Partial discharge occurs using the medium. The odor molecules 14, dust, and bacteria that have passed through the ionization unit 12 and turned into positive ions or negative ions pass through the wire mesh electrode on the upstream side of the ventilation path, and then the dielectric particle layer filter 5 by the electrostatic force generated by the electric field. By the partial discharge that is attracted to the dielectric particle layer and generated between the dielectric particles 51, it is decomposed by reacting with oxidizing active species such as ozone generated in the local space. Further, the ultraviolet light irradiation unit of the ionization unit provided in the air cleaning device of the present invention not only contributes to ionization, but also decomposes ozone, which is one of harmful substances in the air, into oxygen molecules and oxygen molecules, for example. Has an effect.

  The dielectric particle layer filter 5 described in the present embodiment has a structure in which the dielectric particles 51 are stacked on the flat dielectric substrate along the gas flow. However, the present invention is not limited to this. A cubic structure of a honeycomb structure having a square or square hole, a dielectric structure having a corrugated structure, or a cubic structure made of a substrate such as ceramics may be used. Alternatively, a dielectric layer may be uniformly formed on the inner wall, and a catalyst and an adsorbent may be attached to the surface of the dielectric layer.

  FIG. 3 is an explanatory diagram for explaining a mechanism for adsorbing and decomposing odor molecules, dust, and bacteria in the air cleaning apparatus according to Embodiment 1 for carrying out the present invention. In the figure, the dust collecting portion 13 is secondly sandwiched with a dielectric particle layer filter 5 in order to form an electric field in a direction perpendicular to the direction of the electric field formed along the gas flow by the wire mesh electrode pair. The electrode pair 8 is provided. Odor molecules 14 that have passed through the pre-filter 1 and taken into the apparatus from the direction of the arrow 10 are formed inside and on the surface of the dielectric particle layer after being ionized by being irradiated with ultraviolet light 4 at the ionization unit 12. By passing through the vicinity of the discharge space, it is attracted by the action of electrostatic force.

  Further, the odor molecules 15 that have become positive or negative ions that do not pass through the vicinity of the discharge space are different from the air flow direction by the action of the vertical electric field formed by the second electrode pair 8; More preferably, by applying a suction force in the vertical direction, the trajectory of the ionized odor molecules 15 in the ventilation path can be changed, and the probability of being taken into the dielectric particle layer can be increased. By providing the second electrode pair 8, the probability of collecting the odor molecules 15 that have become positive or negative ions that do not pass through the vicinity of the discharge space can be improved as compared with the prior art, and the low concentration range can be achieved. Odor components and harmful substances can be removed by adsorption and chemical reaction.

  According to the air purifying apparatus according to the present embodiment configured as described above, ionized odor molecules, dust, and bacteria can be collected and decomposed with high efficiency. Can be removed by adsorption and chemical reaction.

Embodiment 2. FIG.
FIG. 4 is an explanatory diagram for explaining the dielectric particle layer filter 5 of the air cleaning apparatus according to Embodiment 2 for carrying out the present invention. In the first embodiment, the first electrode pair 6 is provided with an electrode pair by a metal structure such as a metal mesh electrode or a punching metal. However, in the present embodiment, as shown in FIG. The discharge electrode is a flat projection type electrode 61 formed of a metal such as stainless steel or copper, and has an electrode pair structure in which an electrode 62 formed of a metal wire or the like is installed on the counter electrode on the gas outlet side, Electrodes 63 and 64 formed of a metal wire or the like are arranged at the entrance of the dust collecting portion, and a DC voltage of several kV to several tens of kV is applied from the power source 93. A high electric field in a direction different from the electric field formed by the electrodes 61 and 62 is formed. It should be noted that the electrodes 63 and 64 are arranged at positions having a distance at which no discharge occurs between the electrodes 63 and 64, and the applied voltage value is set so that the potential difference becomes small.
Even with the structure as described above, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
FIG. 5 is an explanatory diagram for explaining details of a mechanism for adsorbing and decomposing odor molecules, dust, and bacteria in the air purifying apparatus according to Embodiment 3 for carrying out the present invention. It is explanatory drawing when the electric field of the orthogonal | vertical direction is made uniform with respect to the flow direction, and when changing periodically. The odor molecules 151 to 154 that have passed through the ionization unit 12 and turned into positive ions or negative ions, ionized dust, and bacteria pass through the wire mesh electrodes that form the first electrode pair 6 on the upstream side of the ventilation path, Adsorbed to the dielectric particle layer catalyst and adsorbent, dielectric.
Normally, when an electric field perpendicular to the gas flow direction of the ventilation path is uniformly applied, among the ionized odor molecules 151 to 154, for example, those having a small mass such as formaldehyde are present on the upstream side of the ventilation path. The catalyst and adsorbent provided in the dielectric particle layer and the dielectric are attracted to the dielectric, while those having a large mass such as toluene tend to be attracted behind the upstream of the ventilation path.

In addition, by controlling the voltage applied to the second electrode pair 8 provided so as to sandwich the dielectric particle layer filter 5, the position where the massed ionized odor molecules 151, 152 are sucked is controlled. Can do. Specifically, by applying a voltage waveform 16 as shown in FIG. 6, that is, a high voltage in a periodic pattern to the second electrode pair 8, ionized odor molecules 151 and 152 having a large mass in the direction of the ventilation path are generated. The position on the attracted dielectric particle layer can be changed.
FIG. 7 is an explanatory diagram showing how the adsorption positions of ionized odor molecules 151 and 152 having a large mass are changed by a voltage change. As shown in the figure, when a higher electric field is applied, ions having a large mass are ionized. The probability that the odor molecules 151 and 152 are sucked on the upstream side of the ventilation path can be increased.

  According to the air cleaning device of the present embodiment configured as described above, suction is performed on the dielectric particle layer provided along the gas flow at the upstream and downstream positions of the gas flow in the dielectric particle layer filter 5. The amount of adsorption of the ionized odor molecules 151 and 152 having a large mass can be reduced and the bias of deterioration of the catalyst and the adsorbent can be suppressed, thereby improving the life. be able to. In addition, oxidizing active species such as ozone generated in the dielectric particle layer can be consumed with high efficiency, so that the outflow of oxidizing active species to the outside of the apparatus can be reduced as compared with the prior art.

Embodiment 4 FIG.
FIG. 8 is an explanatory diagram for explaining a dielectric particle layer filter according to Embodiment 4 for carrying out the present invention. In the figure, adsorbent / catalyst adhering portions 521 and adsorbent / catalyst adhering portions 522 having different mixing ratios are attached to the particle surface of the dielectric particle layer formed in the dielectric particle layer filter 5. ing. The adsorbing portion 522 has a high adsorbent concentration ratio, and an adsorbent concentration gradient is given depending on upstream and downstream positions in the air flow direction of the ventilation path. For example, the upstream adhering portion 522 has a high adsorbent concentration ratio.

  In addition, the catalyst formed on the dielectric particle layer may use different materials in the upstream and downstream portions of the gas flow in the ventilation path. For example, the upstream catalyst may have a small mass of odor molecules such as formaldehyde. Uses oxides such as copper, zinc, cobalt, nickel, and manganese, and noble metals such as gold, platinum, and silver alone or in combination, and the downstream catalyst has a large odor such as toluene. By adopting a structure that selects and provides the most appropriate one for molecules, dust, etc., the decomposition efficiency of odor molecules is improved, and catalyst and adsorbent deterioration due to odor molecule residues that remain undecomposed even if adsorbed. Can be suppressed.

  According to the air cleaning device of the present embodiment configured as described above, the admixture of the adsorbent and catalyst attached to the dielectric particle layer filter 5 is changed in the direction of the air passage, and the upstream catalyst and adsorbent are changed. By increasing the adsorbent concentration in the adhering portion 522, odor molecules having a small mass such as formaldehyde that are easily adsorbed on the upstream side can be collected with a very high probability. By selecting and installing, malodorous components and harmful substances can be removed by adsorption and chemical reaction to a low concentration range.

Embodiment 5. FIG.
FIG. 9 is an explanatory diagram for explaining an ultraviolet light source according to Embodiment 5 for carrying out the present invention. Unlike the light source shown in FIGS. 1 and 2, a vertically long column-shaped light source is a ventilation path. It is installed inside. As shown in the figure, by installing the vertically long columnar light source 3b in the ventilation path, the intensity of the ultraviolet light 4 irradiated to the odor molecules 14 in the ventilation path of the ionization unit 12 increases, so that higher ionization is achieved. Efficiency can be obtained. Furthermore, since the ultraviolet light 4 irradiated from the ionization unit 12 is not spatially shielded, the ultraviolet light 4 is irradiated to the inside of the dust collection unit 13, so the catalyst formed on the dielectric particle layer inside the dust collection unit 13. If a photocatalyst is used for this, it becomes an excitation source for activating it. In the present embodiment, FIG. 9 shows an example of the arrangement method of the light source 3b, and the arrangement method of the light source is not limited to this as long as high ionization efficiency is obtained and the low-pressure loss is achieved. For example, you may arrange | position in parallel with the ventilation direction.

  The air purifier according to the present embodiment configured as described above can drastically improve the collection rate of small odor molecules with a low van der Waals force, and therefore, malodor components up to a low concentration range. Can be adsorbed and removed by chemical reaction.

Embodiment 6 FIG.
FIG. 10 is an explanatory diagram for explaining an ultraviolet light source according to Embodiment 6 for carrying out the present invention. In the present embodiment, the light source 3a is disposed at the position shown in FIGS. 1 and 2, but the dielectric particle layer of the dust collection unit 13 is installed in an inclined state. Since the amount of irradiation to the entrance and its surrounding catalyst increases, photoexcitation can be performed with extremely high efficiency, and the activity can be improved.

  The air purifier according to the present embodiment configured as described above can drastically improve the collection rate of small odor molecules with a low van der Waals force, and therefore, malodor components up to a low concentration range. Can be adsorbed and removed by chemical reaction.

Embodiment 7 FIG.
FIG. 11 is an explanatory diagram for explaining an ultraviolet light source according to Embodiment 6 for carrying out the present invention. In the present embodiment, the light source 3b is disposed at the position shown in FIG. 9, but the dielectric particle layer of the dust collecting portion 13 is installed with an inclination.
That is, by installing the vertically long columnar light source 3b in the ventilation path, the intensity of the ultraviolet light 4 irradiated to the odorous molecules 14 in the ventilation path of the ionization unit 12 increases, so that higher ionization efficiency can be obtained. it can. Furthermore, since the ultraviolet light 4 irradiated from the ionization unit 12 is not spatially shielded, the ultraviolet light 4 is irradiated to the inside of the dust collection unit 13, so the catalyst formed on the dielectric particle layer inside the dust collection unit 13. If a photocatalyst is used for this, it becomes an excitation source for activating it.

  In addition, since the dielectric particle layer of the dust collection unit 13 is installed to be inclined, the amount of irradiation to the entrance of the dust collection unit 13 and the catalyst in the vicinity thereof increases, so that it is photoexcited with extremely high efficiency, The activity can be improved.

  The air purifier according to the present embodiment configured as described above can drastically improve the collection rate of small odor molecules with a low van der Waals force, and therefore, malodor components up to a low concentration range. Can be adsorbed and removed by chemical reaction.

Embodiment 8 FIG.
FIG. 12 is a schematic diagram for explaining the structure of the ionization part of the air cleaning apparatus according to Embodiment 8 for carrying out the present invention. In the present embodiment, the inner wall of the ventilation path 2 of the ionization unit 12 of the air purifier shown in FIG. 1 is formed of the ultraviolet light reflecting material 17 having a high reflectance characteristic. In the figure, the inner wall of the ventilation path 2 of the ionization unit 12 irradiated with ultraviolet light is formed by the ultraviolet light reflecting material 17 having high reflectance characteristics with respect to the wavelength range of λ = 200 to 260 nm. Since the ultraviolet light 4 is repeatedly reflected in the ventilation path 2, the irradiation amount to the odor molecules can be increased, so that high ionization efficiency can be obtained. In the present embodiment, aluminum is processed and formed on the ultraviolet light reflecting material 17 to form the inner wall of the ventilation path 2. Further, in the production of the ventilation path 2, a metal or resin processed base material formed by vapor deposition or sputtering may be used. Furthermore, since the reflectivity of the aluminum deposition surface decreases with time due to oxidation by ultraviolet rays, coating the magnesium surface with magnesium fluoride or fluorocarbon as an anti-oxidation film suppresses the decrease in reflectivity due to oxidation of ultraviolet light. An effect is obtained.

  According to the air cleaning device described in the present embodiment configured as described above, the inner wall of the ventilation path 2 of the ionization unit irradiated with the ultraviolet light 4 has high reflectance characteristics with respect to the wavelength range of λ = 200 to 260 nm. Since the irradiated ultraviolet light 4 is repeatedly reflected in the ventilation path 2, the amount of irradiation to odor molecules increases and can be ionized with high efficiency.

It is the schematic of the air purifying apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the dielectric material particle layer filter of FIG. FIG. 3 is a detailed explanatory diagram of FIG. 2. It is explanatory drawing of the air purifying apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the adsorption | suction and decomposition | disassembly mechanism of the air purifying apparatus which concerns on Embodiment 3 of this invention. It is explanatory drawing of the voltage pattern applied to the 2nd electrode pair shown in FIG. It is explanatory drawing which showed the change of the adsorption position of the odor ion with a large mass by the voltage change of FIG. It is explanatory drawing of the dust collection part of the air purifying apparatus which concerns on Embodiment 4 of this invention. It is explanatory drawing of the ionization part of the air purifying apparatus which concerns on Embodiment 5 of this invention. It is explanatory drawing of the ionization part and dust collection part of the air purifying apparatus which concerns on Embodiment 6 of this invention. It is explanatory drawing of the ionization part and dust collection part which concern on the air purifying apparatus of Embodiment 7 of this invention. It is the schematic of the ionization part of the air purifying apparatus which concerns on Embodiment 8 of this invention.

Explanation of symbols

  2 ventilation path, 3 ultraviolet light irradiation unit, 5 dielectric particle layer filter, 6 first electrode pair, 8 second electrode pair, 12 ionization part, 13 dust collection part, 14 odor molecule, 15 ionized odor molecule, 17 Ultraviolet light reflecting material, 52, 521, 522 Catalyst and adsorbent adhering part.

Claims (6)

  An ionization unit that imparts an electric charge to the odor gas component; a dust collection unit that collects and purifies the odor gas component ionized by the ionization unit; a first electrode pair that applies an electric field in the ventilation direction; An air cleaning apparatus comprising: a second electrode pair that applies an electric field in a direction different from an electric field direction applied to the electrode pair.   The air cleaning device according to claim 1, wherein the second electrode pair applies an electric field in a direction perpendicular to the direction of the electric field applied by the first electrode pair.   The air cleaner according to claim 1 or 2, wherein the intensity of the electric field applied by the second electrode pair is periodically controlled.   The dust collecting unit is attached with a catalyst and an adsorbent, and the ratio of the adhering amount of the catalyst and the adsorbent differs depending on the position in the gas flow direction passing through the dust collecting unit. The air purifier according to any one of claims 1, 2, and 3, wherein the ratio of the adsorbent is increased.   The air cleaning device according to any one of claims 1, 2, 3, and 4, wherein the ionization unit includes a light source for irradiating ultraviolet light in a wavelength region of λ = 200 to 260 nm. The inner wall of the gas ventilation path provided in the ionization part is made of a material having a high reflectance with respect to the wavelength region of the ultraviolet light. An air purifier according to claim 1.

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