JP2003033426A - Catalytic filter and air purifying unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air purifying unit equipped with a highly air-purifying ability even under a high-humidity condition. SOLUTION: An air-purifying unit A is equipped with a purifying unit body 1, a high-voltage application means 2, and an air-flow generating means 3. In the purifying unit body 1 a catalytic filter 10 bearing a mixture of titanium dioxide 11 and oxidizing catalyst 12 is arranged between electrodes for discharge 4, 5. The high-voltage application means 2 applies high voltage between the electrodes for discharge 4, 5. The air-flow generating means 3 generates an air flow to pass the surface of the catalytic filter 10.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalyst filter and an air purifier.

[0002]

2. Description of the Related Art In an air purifying apparatus for purifying air (decomposing odors and harmful gases), a room temperature oxidation heat catalyst, an ozone deodorizing catalyst, or a catalyst activated by discharge plasma has been conventionally used.

[0003]

However, these catalysts generally have the property of significantly deteriorating their performance in the presence of water vapor. This is because moisture is captured by the catalyst before the target gas and the active site is blocked. In general, a large amount of water vapor exists in a space that requires air cleaning, and therefore measures are required.

A first object of the present invention is to provide a catalyst filter which can obtain a high air purifying ability even under high humidity.

A second object of the present invention is to provide an air purifying device which can obtain a high air purifying ability even under high humidity.

[0006]

[Means for Solving the Problems] [Claims 1 to 3] Titanium dioxide is activated under discharge, and is approximately dissociated from water molecules by the following reaction: oxygen (O) and ozone O ₃
To generate. It should be noted that OH ⁻ ions are supplied in a large amount by ionizing water adsorbed on titanium dioxide or an oxidation catalyst by a high electric field. 2OH ⁻ + h ⁺ → 2H ₂ O + (O) (O) + O ₂ → O ₃ h ⁺ is a hole (O) dissociation oxygen Note that since dissociation oxygen (O) is supplied to the oxidation catalyst, titanium dioxide The carrying position is preferably upstream of the carrying position of the oxidation catalyst with respect to the air flow passing through the inside or the surface of the catalyst filter.

The oxidation catalyst oxidizes the target gas X under discharge as follows. X + (O) → XO XO is carbon dioxide and other oxidation products

[0008] In dry air, dissociated oxygen (O) is supplied from oxygen molecules in the air by electric discharge, but its generation amount tends to decrease with an increase in humidity. However, since titanium dioxide activated under discharge generates and supplies dissociated oxygen (O) from water molecules, the target gas X can be effectively oxidized even under high humidity.

[Claim 4] (When titanium dioxide is added) Titanium dioxide is added to a metallic soap solution which is a catalyst precursor, and a carrier is put in the titanium-added metallic soap solution. A metallic soap solution containing titanium is attached to. Then, the carrier to which the titanium-added metallic soap solution is attached is pulled up and fired. As a result, the metal becomes an oxidation catalyst that is oxidized and activated by discharge, and the organic components in the metal soap solution are removed.
Titanium dioxide and an oxidation catalyst are supported on the surface of the carrier.

When titanium is added to the metallic soap solution which is a catalyst precursor (when titanium is added), titanium is combined with the organic matter in the metallic soap solution to form organized titanium. A carrier is put in the titanium-added metal soap solution, and the titanium-added metal soap solution is attached to the carrier. Then, pull up the carrier to which the titanium-added metal soap solution is attached,
Bake. As a result, the organic components in the metal soap solution are removed, and the oxidation catalyst and titanium dioxide are supported on the carrier surface.

The soap solution is preferably octylic acid or naphthenic acid dissolved in an organic solvent. Oxidation catalyst is a substance that is activated by electric discharge, and for iron, manganese, or aluminum oxide, or iron, manganese,
A composite oxide in which silver, cobalt, copper, aluminum, or nickel is combined is suitable. The carrier is preferably an inorganic fiber body such as glass fiber, ceramic fiber, or metal fiber, and the shape is preferably woven cloth, knitted cloth, non-woven cloth, felt shape, or cotton shape.

[Claim 5] A solution to which titanium is added and a metal soap solution containing a metal serving as an oxidation catalyst are separately prepared. A solution containing titanium is attached to a first predetermined position of the carrier, and a metal soap solution is attached to a second predetermined position of the carrier. The carrier to which this solution and the metal soap solution are attached is fired to support the oxidation catalyst and titanium dioxide on the carrier.

In the catalyst filter of the fifth aspect, the oxidation catalyst and the titanium dioxide can be separately carried on different positions of the carrier. In addition, the supporting position of titanium dioxide,
Dissociated oxygen (O) to be supplied to the oxidation catalyst can be efficiently generated by setting the upstream side of the position where the oxidation catalyst is supported with respect to the air flow passing through the inside or the surface of the catalyst filter.

[Claim 6] An air purifying device comprises the catalyst filter according to any one of claims 1 to 5 as a single body, foldable or a plurality of laminated layers, and an air flow generated by an air flow generating means. Pass through the inside or the surface of the catalyst filter. Therefore, the air purification device
Even under high humidity, odorous components such as formaldehyde, toluene, acetaldehyde, and harmful components causing sick house can be efficiently decomposed.

[Claim 7] In the air purifying apparatus, a catalyst filter having titanium dioxide supported on a carrier is arranged between electrodes for discharging by applying a high voltage having a pulsating flow, an alternating current, or a pulsed waveform. The ozone generating unit, an air flow generating unit that generates an air flow so as to pass through the inside or the surface of the catalyst filter, and an ozone deodorizing catalyst that is located downstream of the ozone generating unit and combines ozone and a target gas. And a gas removing unit arranged.

Titanium dioxide supported on the catalyst filter of the ozone generating section is activated by electric discharge between the electrodes, and approximately dissociates oxygen (O) and ozone O ₃ from water molecules by the following reaction. It should be noted that OH ⁻ ions are supplied in a large amount by ionizing water adsorbed on titanium dioxide or an oxidation catalyst by a high electric field. 2OH ⁻ + h ⁺ → 2H ₂ O + (O) (O) + O ₂ → O ₃ h ⁺ is a hole (O) is dissociated oxygen

When the ozone generating section is dissociated oxygen (O) or ozone O
Efficiently produces ₃ even under high humidity and supplies it to the gas removal section located downstream of the ozone generation section. The ozone deodorizing catalyst combines ozone and a target gas to remove them.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the present invention (corresponding to claims 1, 2, 4, and 6) will be described with reference to FIG. As shown in FIG. 1, the air purifier A includes a purifier main body 1, a high voltage applying unit 2, and an air flow generating unit 3.

The purifying apparatus main body 1 comprises a catalyst filter 10 having a carrier carrying a mixture of titanium dioxide 11 and an oxidation catalyst 12, disposed between the discharge electrodes 4 and 5. In this embodiment, the carrier is glass fiber having a diameter of several μm and a thickness of 1 μm.
It is a glass woven fabric processed into a mm non-woven fabric. Further, the carrier may be an inorganic fiber body such as ceramic fiber or metal fiber other than glass fiber, and the shape is not only flat, but also woven fabric, knitted fabric, non-woven fabric, felt-like or cotton-like. May be

In this embodiment, the oxidation catalyst 12 is a manganese-cobalt type discharge activation catalyst which is activated by discharge. The oxidation catalyst 12 may be an oxide of iron, manganese, or aluminum, or a composite oxide of iron, manganese, and silver, cobalt, copper, aluminum, or nickel. .

The catalyst filter 10 is manufactured as follows. (1) Titanium is added to a metal soap solution which is a catalyst precursor, and titanium is combined with an organic component in the metal soap solution to form a titanium-added metal soap solution.

In this embodiment, the soap solution is octylic acid dissolved in toluene. The soap solution may be a solution of naphthenic acid dissolved in toluene, or a solution of octylic acid and naphthenic acid dissolved in toluene.

(2) A carrier is put into the titanium-added metal soap solution, and the titanium-added metal soap solution is adhered to the carrier,
Pull up.

(3) The carrier to which the titanium-added metallic soap solution adheres is fired at a temperature lower than the melting point of the glass fiber. As a result, the organic components in the metal soap solution are removed, and the titanium dioxide 11 and the oxidation catalyst 12 are supported on the carrier surface.

The air flow generating means 3 is a blower for generating an air flow that passes through the inside of the catalyst filter 10.

The discharge electrodes 4, 5 are in the shape of a mesh having a rectangular shape, and are arranged so as to sandwich the catalyst filter 10 from both sides. A high AC voltage is applied between the discharge electrodes 4 and 5 by the high voltage applying means 2. The high voltage applying means 2 may be configured to apply a high voltage having a pulsating flow or a pulse waveform between the discharge electrodes 4 and 5.

Here, the effect of increasing the amount of ozone produced by supporting titanium dioxide TiO ₂ will be described. Each glass woven fabric to be described later is mounted in the reactor 6 shown in FIG. 2 as follows, and the raw material air 31 is flowed from below the reactor 6 so as to pass through the glass woven fabric, and an alternating current is applied between the electrodes. Was applied to measure the relationship between the humidity (RH) and the ozone concentration (ppm) of the outflow air 32, the results shown in FIG. 3 were obtained. Curve 13 ... Glass woven fabric supporting titanium dioxide Curve 14 ... Glass woven fabric only

As shown in FIG. 2, in the reactor 6, a glass woven cloth is sandwiched between a glass cylinder 62 whose central portion is a cylindrical ground electrode 61, and a spiral discharge electrode 63 and a cylindrical ground electrode 61.
And are arranged.

The glass woven fabric supporting titanium dioxide TiO ₂ was attached to the woven fabric as shown by the curve 13 in FIG.
It was confirmed that the higher the humidity, the higher the ozone concentration of the outflow air 32. This is because the higher the humidity, the more marked the reactions (α) and (β) described later. However, as shown in the curve 14 of FIG. 3, it was found that the higher the humidity, the lower the ozone concentration of the outflow air 32 of the glass woven fabric alone.

Titanium dioxide Ti supported on glass woven cloth
O ₂ is activated under discharge, and approximately dissociates oxygen (O) and ozone O ₃ from water molecules by the following reaction.
It should be noted that OH ⁻ ions are supplied in a large amount by ionizing water adsorbed on titanium dioxide or an oxidation catalyst by a high electric field. 2OH ⁻ + h ⁺ → 2H ₂ O + (O) ………… (α) (O) + O ₂ → O ₃ ………… (β) h ⁺ is a hole (O) is dissociated oxygen

The oxidation catalyst can oxidize the target gas X under discharge as follows. X + (O) → XO XO is carbon dioxide and other oxidation products

Next, the following TiO ₂ -added product a,
The relationship between humidity (RH) and acetaldehyde removal rate (%) for Comparative Products b and c will be described with reference to FIG.・ TiO ₂ added product a is titanium dioxide 11 and oxidation catalyst 1
Catalyst filter 10 in which a mixture of 2 is supported on a glass woven cloth
Is the same as. -Comparative product b is a glass woven fabric carrying only the oxidation catalyst. -Comparative product c is a glass woven fabric carrying only titanium dioxide.

TiO ₂ additive product a and comparative products b and c are shown in FIG.
Installed in the same reactor 6 as above, so that air mixed with 100 ppm of acetaldehyde was flown from below the reactor 6 so as to pass through the catalyst filter 10, high voltage of alternating current was applied between the electrodes, and humidity ( The relationship between RH) and the acetaldehyde removal rate (%) was measured, and the results shown in FIG. 4 were obtained.

Curve ◯: Same as the catalyst filter 10 in which a mixture of titanium dioxide 11 and oxidation catalyst 12 (Mn-Co type) is supported on a glass woven cloth Curve Δ: oxidation catalyst (Mn-on a glass woven cloth) Co)) supported Curve × …… Glass woven fabric supported with titanium dioxide

The comparative product b (curve Δ) has a sharp decrease in acetaldehyde removal rate with increasing humidity, whereas the TiO ₂ -added product a (curve ○) has a high acetaldehyde removal ratio in the actual use range. It turned out to be maintainable. Since the comparative product c (curve x) has no oxidation catalyst, the generated dissociated oxygen (O) is not used and only a low acetaldehyde removal rate is obtained.

From the above experimental results, the air purifier A has the following advantages. Dissociated oxygen (O) in dry air
Is supplied by discharge from oxygen molecules in the air,
It has the property that the amount generated decreases with an increase in humidity. However, in the air purifier A, the titanium dioxide 11 activated under discharge generates dissociated oxygen (O) from water molecules and supplies it to the oxidation catalyst 12, so that a high gas removal rate can be obtained even under high humidity. It is possible to effectively oxidize the target gas X such as, formaldehyde, toluene and acetaldehyde.

Next, a second embodiment of the present invention (claim 1,
(Corresponding to 2, 3, 5, and 6) will be described based on FIG.
The air purifier B differs from the air purifier A in the following points.

The purifying apparatus main body 1 is provided with a catalyst filter 10 having titanium dioxide 11 and an oxidation catalyst 12 supported on a carrier from the upstream side between the discharge electrodes 4 and 5. In the present example, the carrier is a glass woven fabric obtained by processing glass fibers having a diameter of several μm into a non-woven fabric having a thickness of 1 mm. Further, the carrier may be an inorganic fiber body such as a ceramic fiber or a metal fiber, in addition to the glass fiber, as in the air purifying apparatus A, and the shape may be a woven cloth, a knitted cloth, a non-woven cloth, other than the flat plate shape. It may have a felt shape, a cotton shape, or the like.

Also in this embodiment, the oxidation catalyst 12 is a manganese-cobalt type discharge activation catalyst which is activated by discharge. The oxidation catalyst 12 may be an oxide of iron, manganese, or aluminum, or a composite oxide of iron, manganese, and silver, cobalt, copper, aluminum, or nickel. .

The catalyst filter 10 is manufactured as follows. (1) Titanium is added to a solution such as a soap solution to combine with an organic component in the solution to form an organic titanium solution.
A metal soap solution containing a metal serving as an oxidation catalyst is prepared in the soap solution.

In this embodiment, the soap solution is octylic acid dissolved in toluene. The soap solution may be a solution of naphthenic acid dissolved in toluene, or a solution of octylic acid and naphthenic acid dissolved in toluene.

(2) Half of the carrier (first predetermined position) is put into a solution containing titanium, and the solution is attached, pulled up, and then dried. Put the other half of the carrier (second predetermined position) in the metal soap solution, attach the metal soap solution, and pull up,
dry.

(3) The carrier to which this solution and the metallic soap solution adhere is fired at a temperature lower than the melting point of the glass fiber. This removes the organic content of the solution and the metallic soap solution,
Titanium dioxide 11 and oxidation catalyst 12 are supported on the surface of the carrier.

Next, the operation and advantages of the air purifying device B will be described. Titanium dioxide 11 of catalyst filter 10
Is activated under discharge and approximately generates dissociated oxygen (O) and ozone O ₃ from water molecules by the following reaction. It should be noted that OH ⁻ ions are supplied in a large amount by ionizing water adsorbed on titanium dioxide or an oxidation catalyst by a high electric field. 2OH ⁻ + h ⁺ → 2H ₂ O + (O) (O) + O ₂ → O ₃ h ⁺ is a hole (O) is dissociated oxygen. In the present embodiment, the supporting position of titanium dioxide 11 is
Since it is on the upstream side of the oxidation catalyst 12 with respect to the air flow passing through the surface of the catalyst filter 10, the generated dissociated oxygen (O) is efficiently supplied to the oxidation catalyst 12 located on the downstream side.

The oxidation catalyst 12 oxidizes the target gas X under discharge as follows. X + (O) → XO XO is carbon dioxide and other oxidation products

In dry air, dissociated oxygen (O) is supplied from oxygen molecules in the air by electric discharge, but its generation amount decreases with an increase in humidity. However, in the air purification device B, titanium dioxide 11 activated under discharge
However, since dissociated oxygen (O) is generated from water molecules and supplied to the oxidation catalyst 12 located on the downstream side, a higher gas removal rate can be obtained even under high humidity, and the target gas X such as formaldehyde, toluene, acetaldehyde, etc. Can be more effectively oxidized and decomposed.

Next, a third embodiment of the present invention (corresponding to claim 7) will be described with reference to FIG. The air purification apparatus C of this embodiment includes a high voltage applying means 2, an air flow generating means 3,
An ozone generator 7 and a gas remover 8 are provided.

The high voltage applying means 2 is a high voltage circuit for applying an alternating high voltage between the discharge electrodes 4 and 5. In addition,
The high voltage applying means 2 may be a high voltage circuit that generates a high voltage having a pulsating flow or a pulse waveform.

The air flow generating means 3 is an air purifying device A, B.
Similarly to the above, it is a blower for generating an air flow that passes through the inside of the catalyst filter 10.

The ozone generating section 7 comprises a catalyst filter 70 having titanium dioxide 71 supported on a carrier, disposed between the discharge electrodes 4 and 5. In the present example, the carrier is a glass woven fabric obtained by processing glass fibers having a diameter of several μm into a non-woven fabric having a thickness of 1 mm. Further, the carrier, in addition to glass fiber,
It may be an inorganic fiber body such as a ceramic fiber or a metal fiber, and the shape may be a woven cloth, a knitted cloth, a non-woven cloth, a felt shape, a cotton shape or the like other than the flat plate shape.

The gas removing section 8 is located on the downstream side of the ozone generating section 7 and has an ozone deodorizing catalyst 81 for coupling the ozone O ₃ and the target gas X.

Next, the operation and advantages of the air purifying device C will be described. The titanium dioxide 71 carried on the catalyst filter 70 of the ozone generating section 7 is activated by the discharge performed between the discharge electrodes 4 and 5, and is approximately dissociated oxygen (O) or ozone O ₃ from water molecules by the following reaction. To generate. It should be noted that OH ⁻ ions are supplied in a large amount by ionizing water adsorbed on titanium dioxide or an oxidation catalyst by a high electric field.

2OH ⁻ + h ⁺ → 2H ₂ O + (O) (O) + O ₂ → O ₃ h ⁺ is a hole (O) is dissociated oxygen.

The ozone generating section 7 efficiently generates dissociated oxygen (O) and ozone O ₃ even under high humidity, and the ozone generating section 7
The gas is supplied to the gas removing unit 8 located on the downstream side. The ozone deodorizing catalyst 81 combines ozone and a target gas to remove them.

In the air purifying apparatus C, the titanium dioxide 71 activated under discharge generates dissociated oxygen (O) from water molecules and supplies it to the ozone deodorizing catalyst 81 of the gas removing section 8, so that even under high humidity. A high gas removal rate is obtained, and target gases such as formaldehyde, toluene and acetaldehyde can be effectively oxidized and decomposed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an air purification device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a reactor.

FIG. 3 is a graph showing the relationship between humidity and the concentration of generated ozone.

FIG. 4 is a graph showing the relationship between humidity and acetaldehyde removal rate.

FIG. 5 is an explanatory diagram of an air purification device according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of an air purifying apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

1 Purification device body 2 High voltage applying means 3 Air flow generation means 4, 5 Discharge electrode (electrode) 7 Ozone generator 8 Gas removal section 10 Catalyst filter 11,71 Titanium dioxide 12 Oxidation catalyst 81 Ozone deodorizing catalyst A, B, C Air purification device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Mazuma Matsui             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor ▲ Tokushima Kazuo Shima             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor Tetsuhiko Kobayashi             1-83-1 Midorigaoka, Ikeda, Osaka Prefecture             AIST Kansai Center             -In (72) Inventor Atsushi Ueda             1-83-1 Midorigaoka, Ikeda, Osaka Prefecture             AIST Kansai Center             -In (72) Inventor Yusuke Yamada             1-83-1 Midorigaoka, Ikeda, Osaka Prefecture             AIST Kansai Center             -In F term (reference) 4C080 AA07 BB02 CC02 JJ05 JJ06                       KK02 MM08 NN01 NN02

Claims (7)

[Claims] 1. A catalyst filter arranged between electrodes for discharging by applying a high voltage having a pulsating current, an alternating current, or a pulsed waveform, and a carrier for an oxidation catalyst and titanium dioxide which are activated by the discharge. A catalyst filter, characterized in that the catalyst filter is supported on. 2. The catalyst filter according to claim 1, wherein all of the titanium dioxide and the oxidation catalyst are mixedly supported so that they are always located at positions close to each other. 3. The supporting position of the titanium dioxide is set with respect to the air flow passing through the inside or the surface of the catalyst filter,
The catalyst filter according to claim 1, wherein the catalyst filter is located upstream of a position where the oxidation catalyst is supported. 4. A catalyst filter arranged between electrodes for discharging by applying a high voltage having a pulsating current, an alternating current, or a pulsed waveform, wherein titanium is added to a metallic soap solution which is a catalyst precursor. Alternatively, titanium dioxide is added, the carrier is put into the titanium-added metal soap solution and pulled up, and the carrier on which the titanium-added metal soap solution is adhered is burned to generate an oxidation catalyst and titanium dioxide that are activated by electric discharge. A catalyst filter carried on the carrier. 5. A catalytic filter arranged between electrodes for discharging by applying a high voltage having a pulsating current, an alternating current, or a pulsed waveform, which comprises a solution containing only titanium as a metal, and an oxidizing and oxidizing method. A metal soap solution containing only a metal serving as a catalyst as a metal is separately prepared, the solution containing titanium is attached to a first predetermined position of a carrier, and the metal soap solution is attached to a second predetermined position of the carrier. And baking the carrier to which this solution and the metallic soap solution have adhered,
A catalytic filter comprising metal oxide and titanium dioxide supported on the carrier. 6. An air flow generating means, wherein the catalyst filter according to claim 1, claim 2, claim 3, claim 4, or claim 5 is used alone, is folded, or is laminated. An air purifying device characterized in that the air flow generated by the above-mentioned method passes through the inside or the surface of the catalyst filter. 7. An ozone generator in which a catalyst filter having titanium dioxide supported on a carrier is arranged between electrodes for discharging by applying a high voltage having a pulsating current, an alternating current, or a pulsed waveform, and the catalyst filter. An air flow generating means for generating an air flow so as to pass through the inside or the surface of the gas removing unit, and a gas removing unit located on the downstream side of the ozone generating unit and provided with an ozone deodorizing catalyst for combining ozone and a target gas. Air purification device equipped.