JP2003135582A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner capable of purging air of gaseous contaminates, e.g. aldehyde and volatile organic compounds or the like, by disposing a dielectric between discharge-inducing electrodes with the intervention of a catalyst. SOLUTION: The air cleaner has a discharge electrode 11 and a counter electrode 12, purges air of substances to be removed, and decomposes the substance by means of a discharge between the electrodes 11 and 12. The electrode portions 11a and 12a of the electrodes 11 and 12 made from conductor material are covered with respective dielectric layer portions 11b and 12b made from dielectric material and a dielectric member 14 with a catalyst layer 13 formed thereon is provided inside a space formed by the electrodes 11 and 12. An air passage 15 is formed in the vicinity of the catalyst layer 13 so that the air containing the substances to be removed passes through the air passage 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifying device, and more particularly to various odors and volatile organic compounds (volatile organic compounds) caused by exhaust gas generated in the living environment and in the interior of automobiles, which flows from indoor and outdoor air. VOCs) and air purification of gaseous pollutants contained in the air such as formaldehyde.

[0002]

2. Description of the Related Art Conventionally, an air purifying device of this type is disclosed in Japanese Patent Laid-Open No. 2000-15036. According to this publication, a trapping means for adsorbing odors in the air and pollutant gases such as volatile organic compounds such as aldehydes generated from building materials, walls, and furniture inside the purified air passage, and disposed below the trapping means. The heating means for heating the captured trapping means to desorb the adsorbed pollutant gas, and the decomposition means for disassembling the desorbed pollutant gas arranged above the trapping means are provided. Has been.

The decomposition means has a multi-layer structure of a porous catalyst body carrying a catalyst, and the lowermost layer thereof is a porous catalyst body and at the same time functions as an electric heating element. . Then, by carrying out two operation modes, an adsorption mode operation for purifying indoor polluted air and a regeneration mode operation for desorbing and decomposing adsorbed pollutant gas, removal of contaminants and regeneration processing of the trapping means are performed. Is.

[0004]

However, in the above publication, in the above publication, the heating means is operated to desorb the adsorbed trapping means, and the oxidative decomposition of the desorbed polluted gas is promoted by the decomposing means. Therefore, a large amount of power is consumed by operating the electric heating element.

Further, the inventors have studied an air purifying device of a desirable form when a catalyst is activated under the use of discharge. For example, as shown in FIG. 7A, the discharge electrode 100, the counter electrode 110, and both electrodes 10 thereof.
The catalyst layer 120 and the dielectric layer 110b are disposed between the layers 0 and 110. Moreover, the discharge electrode 100 and the catalyst layer 12
An air passage 130 is formed in the vicinity of the catalyst layer 120 at an extremely short distance from 0.

In the counter electrode 110, the electrode portion 110a made of a conductive material is used as a dielectric layer 110 made of a dielectric material.
b, and the dielectric layer 110b is covered by the catalyst layer 12
Partial contact with 0.

As a result, the discharge electrode 100 and the catalyst layer 12 are formed.
A high electric field is generated in a small space of the air passage 130 formed by 0 and 0, and electric discharge, that is, corona discharge is performed to purify air of gaseous pollutants.

However, according to the above-mentioned embodiment, FIG.
As shown in (b), if a portion of the catalyst layer 120 or the dielectric layer 110b is peeled off for some reason, the conductor of the electrode portion 110a is exposed at the peeled portion and a discharge is generated between the discharge electrode 100. We found a problem that the purification performance declined by concentrating on the peeled part.

Therefore, the object of the present invention was made in view of the above points, and by disposing a dielectric between both electrodes for discharging via a catalyst, for example, aldehyde and volatile organic compounds can be eliminated. An object of the present invention is to provide an air purification device capable of purifying gaseous pollutants.

[0010]

In order to achieve the above object, the technical means described in claims 1 to 3 is adopted. That is, according to the first aspect of the invention, the discharge electrode (11) and the counter electrode (12) facing the discharge electrode (11) are provided, and the discharge between the electrodes (11, 12) causes a discharge in the air. In an air purification apparatus that purifies and decomposes a substance to be removed, both electrodes (11, 12) cover electrode portions (11a, 12a) made of a conductive material with dielectric layer portions (11b, 12b) made of a dielectric material. And a dielectric member (14) carrying a catalyst (13) activated under discharge or having a catalyst layer formed therein is provided in the space formed by both electrodes (11, 12), and the catalyst ( It is characterized in that an air passage (15) is formed in the vicinity of 13), and the air containing the substance to be removed flows in the air passage (15).

According to the first aspect of the invention, a dielectric member (14) carrying a catalyst (13) or having a catalyst layer is provided on both electrodes (11, 12), and the dielectric member (14) is provided in the vicinity of the catalyst (13). By being configured to flow the air containing the substance to be removed in the air passage (15), for example, by applying a high voltage to the discharge electrode (11) to generate a discharge, a catalyst of a noble metal and a metal oxide is formed. Gaseous substances can be adsorbed, oxidized, and decomposed by generating active oxygen due to discharge energy.

Further, in general, an air purifying apparatus for adsorbing, desorbing and oxidizing these gaseous pollutants,
Although a large amount of heat energy such as heating is required, the energy consumption can be reduced and the power consumption can be reduced as compared with the conventional case because the energy consumption can be reduced by the corona discharge or the creeping discharge of the present invention.

By forming both electrodes (11, 12) so as to cover the electrode portions (11a, 12a) made of a conductive material with the dielectric layer portions (11b, 12b) made of a dielectric material, the dielectric layer portion ( 11b, 12b) and catalyst (13)
Even if some of them are rarely peeled off for some reason, they are uniformly discharged and are not concentrated in one place, so there is no fear of degrading the purification performance.

Further, since the operating mode is oxidation and decomposition while purifying by these corona discharge and creeping discharge, it is possible to cope with the control device having a simple structure without setting the regenerating operation mode, which is low cost. Can provide products.

According to the second aspect of the invention, the dielectric member (1
4) uses a dielectric material or the like made of either a conductor material or a dielectric material to form a flat plate shape, a net shape, a linear shape, a non-woven cloth shape, a wool shape, or a corrugated shape or a granular shape. , A plurality of discharges are performed toward the catalyst (13).

According to the second aspect of the invention, by specifically forming the shape of the dielectric member (14) to the above-mentioned shape, the inside of the air passage (15) can be fully discharged to generate a purification. The ability can be improved. In particular, by forming it into a wool shape, it is possible to have a large number of sites for discharging per unit area, so that the air purification device can be downsized.

In the invention described in claim 3, the catalyst (13)
Is an oxide of iron, manganese, or aluminum, a complex oxide of iron, manganese, and silver, cobalt, copper, aluminum, nickel, or titanium; It is characterized in that either titanium or a mixture of gold is used and is formed on either the supporting or the catalyst layer.

According to the third aspect of the invention, examples of the catalytic substance include oxides and complex oxides of the above-mentioned metals, titanium dioxide, and a mixture of gold.
By loading a mixture of gold ultrafine particles on the catalyst,
For example, aldehydes generate a large amount of CO upon discharge, but ultrafine particles of gold in particular show extremely high activity for CO oxidation, which results in purification and purification of formaldehyde and acetaldehyde among aldehydes. Suitable for oxidation.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. First, in FIG. 2, a housing 1 having a purified air passage 1a therein, and the inside of the housing 1 from the upstream side of the purified air passage 1a are a pre-filter 2, a dust collection filter 3, and a purification filter 10.
And the blower 4 are arranged in this order. Pre-filter 2
Is provided to capture relatively large dust and dust contained in the air taken in through the suction port (not shown), and usually a honeycomb material or a flat plate shape is used.

The dust collecting filter 3 is provided for trapping relatively large particulate substances such as house dust (dust, dust, etc.) in the air, soot substances in cigarette smoke, and ordinary filtration. Filters or electrostatic filters are used.

The purification filter 10 mainly removes odors, volatile organic compounds (VOCs), formaldehyde, and other gaseous pollutants contained in the air from the purified air that has passed through the pre-filter 2 and the dust collection filter 3. It is provided to do so.

As shown in FIG. 1A, the purification filter 10 includes a discharge electrode 11, a counter electrode 12 facing the discharge electrode 11, and a catalyst in a space formed by these two electrodes 11, 12. The layer 13 and the dielectric member 14 are arranged.

The discharge electrode 11 and the counter electrode 12 are formed so that the electrode portions 11a and 12a made of a conductive material are covered with the dielectric layer portions 11b and 12b made of a dielectric material, respectively. The counter electrode 12 side is connected to the ground side, and the discharge electrode 11 side is connected to a high voltage power source (not shown). This high-voltage power supply is an AC high-voltage generator that generates a positive-polarity or negative-polarity high-voltage substantially rectangular wave or alternately, and applies a high voltage of several kV to 20 kV to the discharge electrode 11 side.

The catalyst layer 13 is made of a mixture of manganese and titanium dioxide here, and is used as the dielectric layer portions 11b and 12b.
Although it is arranged so as to be in close contact with b, it is not limited to this, and preferably, an oxide of any one of iron (Fe), manganese (Mn), and aluminum (Al), and iron (Fe) and manganese (Mn). On the other hand, silver (Ag), cobalt (Co), copper (Cu), aluminum (Al), nickel (Ni),
A composite oxide of a combination of any of the titanium (Ti), may be used any of those obtained by mixing titanium dioxide (TiO ₂₎ or gold (Au) for all of them.

Further, in this embodiment, the dielectric member 14 is
It is formed into a wool-like (for example, cotton-like) shape such as a metal scrubber by using a hair wire such as a dielectric made of either a conductor material or a dielectric material. An air passage 15 is formed in the space between the catalyst layers 13 in which the dielectric member 14 is arranged, and the air containing the substance to be purified circulates in the air passage 15.

Therefore, since it is possible to have a large number of discharge sites per unit area by forming it in a wool shape, it is possible to uniformly generate corona discharge. In addition, the dielectric member 14 and the catalyst layer 13 are partially in contact with each other or provided at an extremely short distance. Although the dielectric member 14 is formed in a wool shape here, it may be formed in a flat plate shape, a grid shape, a linear shape, or a net shape, although not shown.

A blower outlet (not shown) is provided on the downstream side of the blower 4, and purified air is blown out into the room for indoor cleaning.

Next, the operation of this embodiment having the above configuration will be described. First, the operation switch (not shown)
Is operated, the blower 4 is rotated and a predetermined high voltage is applied to the electrode portion 11a of the discharge electrode 11. As shown in FIG. 1B, when a high voltage is applied to the electrode portion 11a, a potential gradient is generated between the electrode portion 11a of the counter electrode 12 via the dielectric layer portions 11b and 12b, the catalyst layer 13 and the dielectric member 14. Cause

Here, the potential gradient is small inside the dielectric layer portions 11b and 12b and the dielectric member 14 formed of conductors, for example, but the potential gradient is large in the air passage 15. Thereby, a corona discharge is generated by concentrating the electric field on the air passage 15.

Further, when corona discharge occurs in the air passage 15, active oxygen is generated, and a gaseous pollutant is chemically adsorbed with the active oxygen on the surface of the catalyst.
By decomposing the adsorbed substance by oxidation with active oxygen, removal and regeneration can be performed even with a small amount of heat energy.

That is, for example, in order to oxidize and decompose target gas molecules using a catalyst of a noble metal such as platinum,
A large amount of heat energy is required to heat the catalyst, but the corona discharge eliminates the need for heat energy.

Furthermore, for example, when a catalyst of a mixture of ultrafine particles of gold (Au) is used, aldehydes produce a large amount of CO upon discharge, and gold (Au) is specifically oxidized by CO (CO → Sub-freezing reaction is possible due to very high activity against CO ₂ ). Therefore, it is suitable for purification and oxidation of formaldehyde and acetaldehyde among aldehydes.

According to the first embodiment described above, fine particles such as dust and dirt in the air are trapped by the pre-filter 2 and the dust collecting filter 3, and the dust in the cigarette smoke is provided downstream of the dust collecting filter 3. A purifying filter 10 for removing gaseous substances such as acetaldehyde gas, ammonia gas, acetic acid gas, formaldehyde gas, and volatile organic compounds (VOC), which are odorous components, is provided with the purifying filter 10. It has an electrode 11 and a counter electrode, and both electrodes 11,
A catalyst layer 13 and a dielectric member 14 which are activated under discharge are provided in a space formed by 12, and an air passage 15 is formed in the vicinity of the catalyst layer 13, and a corona discharge is generated in the air passage 15. By doing so, it is possible to adsorb, oxidize and decompose the gaseous pollutants by generating active oxygen by the catalyst of the metal oxide and the discharge energy.

The electrodes 11 and 12 are made of a conductive material, and the electrode portions 11a and 12a are made of a dielectric material.
By forming so as to be covered with 1b and 12b, even if some of the dielectric layer portions 11b and 12b and the catalyst layer 13 are peeled off for some reason, the discharge is evenly distributed and concentrated in one place. There is no risk of degrading purification performance.

Further, in general, in order to oxidize the adsorbed gaseous substance, thermal energy such as heating is required, but since corona discharge can respond with low energy by active oxygen, power consumption is higher than that in the conventional case. Consumption can be reduced and power consumption can be reduced.

Further, since the operation mode in which oxidative decomposition is performed while performing adsorption by corona discharge, it is possible to provide a low-cost product that can be handled by a control device having a simple structure without setting a regeneration operation mode.

Further, by using a catalyst of a mixture of ultrafine particles of gold (Au), for example, aldehydes produce a large amount of CO upon discharge, but gold is particularly C-specific.
Due to its very high activity for O oxidation, it is suitable for purification and oxidation of formaldehyde and acetaldehyde among aldehydes.

(Second Embodiment) In the purification filter 10 of the first embodiment described above, the dielectric member 14 disposed between the discharge electrode 11 and the counter electrode 12 is formed in a wool shape and both catalyst layers 13 are formed. However, the present invention is not limited to this, and the catalyst is mixed with a dielectric material such as powder or a fibrous dielectric material to form a plurality of granular protrusions on the side surface of the air passage 15 as shown in FIG. You may form the dielectric member 14 which has the installation part 14a. Preferably, the protruding portion 14a is formed of a dielectric material and both electrodes 1
It should be exposed between 1 and 12.

As a result, the electric field is concentrated in the vicinity of the granular projecting portion 14a, so that discharge is likely to occur. Therefore, even if the space formed between the electrodes 11 and 12 becomes large, discharge easily occurs in the vicinity of the protruding portion 14a.

In the above embodiment, the dielectric member 14 having the granular projections 14a is formed. However, as shown in FIG. 4, the dielectric member 14 has a flat plate shape, a grid shape, a linear shape,
Both electrodes 11 are formed by forming one of the net-shaped base materials into a corrugated shape,
You may arrange | position between 12 pieces.

By forming the corrugated shape, the air passage 1
The ventilation resistance of the air flowing through 5 can be reduced.

(Third Embodiment) In the above embodiments, the dielectric member 14 is disposed between the electrodes 11 and 12 with the catalyst layer 13 interposed therebetween, but the dielectric member 14 may carry a catalyst.
As shown in FIG. 5, a dielectric member 14 carrying a catalyst is arranged between both electrodes 11 and 12.

As a result, similarly to the above-described embodiment, adsorption of a gaseous pollutant, oxidation and decomposition can be performed by generation of active oxygen by the catalyst and discharge energy.

(Other Embodiments) In the above embodiments, the dielectric member 14 carrying the catalyst active under discharge or having the catalyst layer 13 formed therein is provided in the space formed by the electrodes 11 and 12. Although the air passage 15 is formed in the vicinity of the catalyst, a plurality of both electrodes 11 and 12 are used and a plurality of dielectric members 14 are arranged between the electrodes 11 and 12 in order to further improve the removal amount. By doing so, a plurality of air passages 15 may be formed.

More specifically, as shown in FIG. 6, by stacking a plurality of discharge electrodes 11, a dielectric member 14 carrying a catalyst, a counter electrode 12 and a dielectric member 14 in this order, a plurality of air passages are formed. 15 is formed. This allows
It is possible to provide an air purification device having a large purification capacity.

Further, in the above embodiment, the dust collecting filter 3
By using an electrostatic filter or an electrostatic precipitator filter, and the discharge electrode and counter electrode of these filters,
It is preferable to share a high voltage power source (not shown) applied to the discharge electrode 11 and the counter electrode 12. This eliminates the need for a power source for the dust collecting filter 3 and reduces the cost.

Further, in the above embodiment, the discharge electrode 11
The purification in which the corona discharge is generated in the air passage 15 between the counter electrode 12 and the counter electrode 12 has been described, but the present invention is not limited to this.
It can also be applied to a creeping discharge that discharges along the surface of a dielectric or a boundary surface with a gas.

Further, in the above-mentioned embodiment, the odor in the living environment and the purification and regeneration of pollutant gases such as aldehydes generated from building materials, walls and furniture have been described, but the present invention is not limited to this. Of course, it can be applied to purification and regeneration of various odors and harmful components in exhaust gas invading from the outside air, and various odors.

[Brief description of drawings]

FIG. 1A is an overall configuration diagram showing an overall configuration of a purification filter 10 in the first embodiment of the present invention, and FIG. 1B is a characteristic diagram showing characteristics of a potential gradient for each configuration of the purification filter 10.

FIG. 2 is a schematic diagram showing an overall configuration of an air purification device according to a first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a shape form of a dielectric member 14 according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a shape form of a dielectric member 14 according to a second embodiment of the present invention.

FIG. 5 is a purification filter 1 according to a third embodiment of the present invention.
It is a whole block diagram which shows the whole 0 structure.

FIG. 6 is an overall configuration diagram showing an overall configuration of a purification filter 10 according to another embodiment.

FIG. 7A is an explanatory view showing a configuration of an air purification device using a discharge electrode, and FIG. 7B is an explanatory view showing a form in which a dielectric is peeled off.

[Explanation of symbols]

11 ... Discharge electrode 11a, 12a ... Electrode part 11b, 12b ... Dielectric layer portion 12 ... Counter electrode 13 ... Catalyst layer (catalyst) 14 ... Dielectric member 15 ... Air passage

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01D 53/36 H

Claims (3)

[Claims] 1. A discharge electrode (11) and the discharge electrode (1)
1) which has a counter electrode (12) facing the electrode (1) and which purifies and decomposes a substance to be removed in the air by discharge between the electrodes (11, 12). , 12) are electrode layers (11a, 12a) made of a conductor material and dielectric layer portions (11a, 12a) made of a dielectric material.
b, 12b), and a dielectric member (14) that is formed so as to be covered with a catalyst (13) that is activated under discharge and has a catalyst layer formed in the space formed by the electrodes (11, 12). Is provided, and an air passage (15) is formed in the vicinity of the catalyst (13) so that the air containing the substance to be removed flows in the air passage (15). Air purification device. 2. The dielectric member (14) is made of a dielectric material made of either a conductor material or a dielectric material, and is formed into a flat plate shape, a net shape, a linear shape, a non-woven cloth shape, a wool shape, or a corrugated shape thereof. The air purification apparatus according to claim 1, wherein the air purification apparatus is formed into any shape of granules and a plurality of discharges are performed toward the catalyst (13). 3. The catalyst (13) is a composite oxide obtained by combining iron, manganese, or aluminum oxide with iron, manganese, or silver, cobalt, copper, aluminum, nickel, or titanium. 3. A material and a mixture of titanium dioxide and gold mixed with all of them, which are formed on either the carrier or the catalyst layer. The air purification device described in 1.