JPH10235154A - Deodorizing filter for deodorizing apparatus or air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorizing filter capable of efficiently cleaning air containing a malodor, having long life, simple in maintenance and high in the degree of freedom of arrangement. SOLUTION: A deodorizing apparatus or air cleaner utilizing photocatalytic reaction is constituted so that a paper like material formed from an adsorbent of a malodorous component containing activated carbon, a photocatalyst and a fire retardant by a papermaking process is used as a deodorizing filter and the contact efficiency of a malodorous component with the photocatalyst is enhanced by adsorbing the malodorous component by the adsorbent containing activated carbon and the adsorbed malodorous component is efficiently and successively decomposed and removed to efficiently clean malodor-containing air. As compared with a case using an adsorbent simply, this filter is not saturated and the life thereof is extended and the maintenance thereof becomes easy. This filter can be arranged in the vicinity of an electric precipitator generating a spark by enhancing flame retardancy by a flame retarder and the degree of freedom of the arrangement thereof is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing apparatus using a photocatalyst or a deodorizing filter for an air purifier for mainly removing tobacco odor.

[0002]

2. Description of the Related Art Conventionally, various air purifiers for purifying air in a room or in a passenger compartment have been proposed. For example, an electric collector for collecting dust and dirt by corona discharge has been proposed. There is a dust-type air purifier, which can collect dust and dirt, but cannot remove odors.For example, deodorization is performed using a deodorizer that adsorbs odorous components using an adsorbent such as activated carbon. I was

[0003]

In the system in which the malodorous component is adsorbed on activated carbon or the like, the malodorous component is only held by physical adsorption or chemical adsorption. It becomes impossible to deodorize. In order to obtain a good deodorizing effect, replacement must be performed in a relatively short cycle (for example, about three months), and there is a problem that maintenance is troublesome. This is the same even when using what is called impregnated carbon having a high adsorption capacity for polar substances, except that the exchange cycle becomes slightly longer.

It is also conceivable to use an ozone deodorizer for oxidizing and decomposing malodorous components by the oxidative decomposition power of ozone. However, when ozone is used, a saturation phenomenon unlike the adsorption method does not occur. An ozone concentration of 0.1 ppm or more is not preferable because of its harmfulness, and is not very effective as an air cleaning method.

On the other hand, there is a device using a photocatalyst as a deodorizing device. Since this deodorizing apparatus deodorizes using a catalytic action, it is almost maintenance-free if deodorizing is limited. However, the photocatalyst excellent in deodorizing ability is usually in a powder form.
The particle diameter is 1 μm or less, and the specific surface area is as large as 300 g / m ² . Since the surface of the photocatalyst powder is deodorized by an oxidative decomposition reaction, it is desirable that the powder be used so as not to lose its surface activity as much as possible. However, since it is difficult to use the powder as it is in an air purifier, if the powder is fixed to a carrier such as a plate with a binder, the surface of the photocatalyst powder is covered with the binder, and the photocatalytic property is lost. As disclosed in Japanese Unexamined Patent Publication No. 3-157125, even when sintering to ceramic or the like, the specific surface area is reduced and the photocatalytic property is reduced.

Therefore, if the photocatalyst powder is formed into a paper-like material, the photocatalyst powder can be fixed while securing the surface area of the photocatalyst powder, without impairing the photocatalytic property. The electric dust collection method used
Since a small spark may be generated due to the use of corona discharge applied with a high voltage to electrically attract dust, the deodorizing filter is particularly arranged adjacent to the electric dust collecting portion. In such cases, flame retardancy is required. Therefore, pulp, plastic fiber, or the like obtained by simply incorporating a photocatalyst is easily burnt and cannot be used as it is.

On the other hand, there is a tobacco odor as a malodorous component to be removed. Typical examples of tobacco odor components include ammonia, acetaldehyde, acetic acid and the like, but those which adsorb acetaldehyde well and deodorize and remove it are generally highly effective. However, although the photocatalyst is excellent in the adsorption and deodorization effects of ammonia and acetic acid, the rapid effect of acetaldehyde cannot be remarkably expected. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and its main purpose is to easily and efficiently purify air containing a bad smell, to have a long life and to maintain the air. An object of the present invention is to provide a deodorizing device or a deodorizing filter for an air purifier that is simple and easy to arrange.

[0008]

According to the present invention, there is provided a deodorizing filter for use in a deodorizing apparatus or an air purifier having a light source for exciting a photocatalyst, comprising an adsorbent for a malodorous component containing activated carbon. A deodorizing device or a deodorizing filter for an air purifier comprising a paper-like material into which a mixture of a photocatalyst excited by the light source to decompose malodorous components by a photocatalytic reaction and a flame retardant is provided. Is achieved by

[0009] By incorporating a flame retardant, such as aluminum hydroxide, into a paper material together with a photocatalyst and an adsorbent into a paper-like material, the filter becomes inflammable. Adsorbent containing activated carbon effective for acetaldehyde and photocatalyst that maintains high activity can be placed near, improve the degree of freedom of placement, and obtain a long-life deodorizing filter effective for tobacco odor, for example Can be.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the configuration of a deodorizing device in an air purifier to which the present invention is applied. The casing 1 is provided with an intake port 2 for inhaling air containing a malodorous component from a room or the like where air is to be purified.
Communicates with an exhaust port 4 through a ventilation passage 3 defined inside the casing 1. The intake port 2 is provided with a pre-filter 5 for preventing dust and the like from entering the inside. A deodorizing section 7 and a blower fan 8 are provided in this order at a stage subsequent to the pre-filter 5 in the ventilation path 3. It should be noted that a known electric precipitator is provided in front of the intake port 2 (not shown).

The deodorizing section 7 is provided at the center with a pair of cylindrical ultraviolet lamps extending in the left-right direction, that is, in the front-rear direction with respect to the plane of the drawing. It is composed of a pair of deodorizing filters 11 described below, which are formed by mixing a mixed powder of an adsorbent powder and a flame retardant powder, and an ultraviolet light reflecting plate 12 covering the upper surface, the lower surface, and both side surfaces between the filters 11. .

The wavelength of the ultraviolet lamp of the excitation light source 10 is 20
It has the ability to excite the photocatalyst at 0 nm to 400 nm, and it is preferable to use black light or chemical light in consideration of the influence on the human body such as generation of ozone.

The photocatalyst of the deodorizing filter 11 is Ti
It is preferable to use a metal oxide such as O ₂ (for example, TiO ₂ in which amorphous and crystal are mixed). This photocatalyst is powdered, adsorbent powder to be described later, and a flame retardant powder such as aluminum hydroxide are applied to the fiber, pressed and dried, and the formed paper is further corrugated to form a filter. To form a deodorizing filter 11. FIG. 2 is an enlarged view of the state of the fiber into which each powder is formed.

Here, when the photocatalyst powder gives energy, electrons are excited and holes are generated. These holes come into contact with malodorous component molecules on the surface of the photocatalyst powder to cause an oxidative decomposition reaction. For example, the above-mentioned titanium oxide can cause an oxidative decomposition reaction by applying energy effectively and easily with ultraviolet rays. The titanium oxide has a crystal structure of an anatase type and preferably has a specific surface area as large as possible.

On the other hand, in order to carry out the reaction by the photocatalyst efficiently, it is important to bring malodorous component molecules into contact with the photocatalyst as much as possible. Therefore, in this configuration, first, the malodor component molecules are adsorbed by the adsorbent, and the malodor component molecules captured by the adsorbent are oxidized and decomposed by titanium oxide. This adsorbent depends on the type and concentration of the odor to be deodorized, but since the odor that is generally generated contains several types of complex components, the odor is classified as acidic, neutral, or basic. When it does, it is desired to be effective for all of them. Such adsorbents may be impregnated with charcoal or, for example, Japanese Patent Application Laid-Open No.
It is preferable to use silica gel, zeolite, sepiolite, mizcanite, activated carbon, and the like as described in JP-A No. 6-No. In particular, for the tobacco odor, it is preferable to use activated carbon that has not been subjected to an impregnation treatment. The activated carbon may be mixed as an activated carbon fiber other than the powdered one. In this case, since it is a fibrous material, it can also contribute to improvement in paper strength (filter strength).

On the other hand, a flame retardant such as aluminum hydroxide is also incorporated in order to make the deodorizing filter less flammable, that is, as a flame retardant, so that the degree of freedom in arrangement with respect to the preceding electric precipitating part is increased. Here, for example, when an organic flame retardant is used, the effect cannot be exhibited due to the decomposability of the photocatalyst,
Since aluminum hydroxide is a powdery inorganic substance, it can be easily mixed into paper together with the photocatalyst and the adsorbent.

The fiber serving as the base of the paper is not a commonly used pulp but inorganic fibers, such as glass fiber, so that the paper itself does not decompose or collapse due to the oxidative decomposition power of the photocatalyst. Ceramic fiber, metal fiber,
Activated carbon fibers and sepiolite fibers having an adsorption function are suitable. However, in general, when fibers other than pulp fibers are used, the strength of the paper becomes weak. Therefore, if the minimum strength required for post-processing cannot be obtained, a valve may be used. When paper is formed using these fibers, it is considered that the strength is not sufficiently obtained.
By adding 5% to 10% of 0% heat-fused fiber (for example, polyethylene, polypropylene, polyester, etc.) and a liquid emulsion binder (for example, acrylic, urethane, etc.), the strength is improved, and such a problem is caused. Disappears.

As a method for introducing and supporting the photocatalyst powder between the fibers of the paper-like body or at the point of entanglement, it is preferable to use a wet papermaking method as in the case of making ordinary paper. Actually, the fiber as the base of the paper and the mixed powder of the photocatalyst powder, the adsorbent powder and the flame retardant powder are mixed in a paper machine, and the heat-bonded fibers and the emulsion binder for improving the strength of the paper are further mixed. Grab the input. Here, the liquid emulsion binder covers the surfaces of the photocatalyst and the adsorbent, and impairs the catalytic property and the adsorptivity. Therefore, it is better to reduce the amount of use as much as possible.
In addition, most of the photocatalyst powder, adsorbent powder and emulsion binder fall off from the mesh during papermaking as they are, and cannot be sufficiently supported, resulting in poor yield. A fixing agent is preferably used. This fixing agent prevents the powders from aggregating and falling off the mesh. Then, it presses and is dried at the temperature more than the fusion temperature of a heat fusion fiber, and a paper-like object is obtained. When this paper is used by incorporating it into a deodorizing device, by forming it into a filter by corrugation molding, the pressure loss is reduced and it is easy to use.

[0020]

EXAMPLES Titanium oxide (ST-0) was used as the photocatalyst powder.
1: Ishihara Sangyo Co., Ltd.), a titanium oxide-based adsorbent (ST-01: Ishihara Sangyo Co., Ltd.) as adsorbent powder, activated carbon not subjected to impregnation treatment, and a paper-like material into which aluminum hydroxide was added as a flame retardant. Performance of the deodorizing filter and titanium oxide (ST-01: manufactured by Ishihara Sangyo Co., Ltd.) as a comparative example,
FIG. 3 shows the measurement of the deodorizing performance of a deodorizing filter made of a paper-like body into which a titanium oxide-based adsorbent (ST-01: manufactured by Ishihara Sangyo Co., Ltd.) is incorporated as the adsorbent powder and the flame retardant is not incorporated. This was performed using an apparatus. Table 1 shows parts by weight of the components contained in these paper-like bodies.

[0021]

[Table 1]

The measuring device is an air purifier having the configuration shown in FIG. 1 (without an electric dust collecting unit) in an acrylic box of 1 m ³ .
, A cigarette smoke evacuator and a fan for internal stirring. The deodorizing performance was measured by placing the above deodorizing filter in an air purifier and performing the following operation in accordance with the Japan Electrical Manufacturers'Association's"Voluntary Standard for Air Purifier Deodorizing Performance Test". (1) While the tobacco is being burned by the tobacco smoke absorber, the operation of the air purifier is stopped. (2) The smoker burns five mild sevens with a smoke absorber, and when the fastest burning tobacco reaches the filter, stops operation of the smoke absorber and burns the rest naturally. (3) Three minutes after the burning of the tobacco that has been burned to the end, the ammonia concentration and the acetaldehyde concentration are simultaneously measured with a detector tube, and then the acetic acid concentration is measured. (4) Stop the stirring fan and operate the air purifier. (5) After a predetermined time, each concentration is measured in the same manner as in (3). (6) The sensory value is also measured at a predetermined time. At this time, a sampling port is provided in advance so that the inside air can be sampled without opening and closing the box, and the inside air is sampled from this through a pump. Evaluate the degree.

FIGS. 4 (a), 4 (b), 4 (a), 4 (b), and 4 (b) show how tobacco odor is removed (concentration change, sensory value) in Examples and Comparative Examples.
This is shown in (c) and FIG.

As shown in FIGS. 4 (a) and 4 (c), in the deodorizing filter of this embodiment, both ammonia and acetic acid are removed by 50% within one hour. Further, it can be seen that acetaldehyde does not rapidly decrease because it has less adsorptivity than ammonia and acetic acid, but clearly decreases after 24 hours.

On the other hand, in the comparative example, ammonia and acetic acid were removed at the initial stage, but acetaldehyde hardly decreased even after 24 hours. This shows that when activated carbon not impregnated with a high deodorizing effect is mixed with tobacco odor, tobacco odor can be removed more quickly than non-impregnated carbon that cannot be expected to have immediate effect.

In addition, the sensory value shows a difference larger than the change in concentration, and the odor intensity is barely 3 in the comparative example. However, in this example, the odor intensity is 3 after 1 to 4 hours, and the odor intensity is 3 after 24 hours. The odor intensity could be reduced to 2 or less.

As to the malodor other than the tobacco odor, as is clear from the description of Japanese Patent Application No. 8-303636 by the applicant of the present invention, both of the Examples and Comparative Examples are acidic, neutral and basic. It is possible to deodorize odors efficiently.

Here, the larger the total part of the photocatalyst and the adsorbent, the better the deodorizing ability. However, if the total part exceeds 50 when it is incorporated into paper, it becomes difficult to hold the powder, As the total amount of the agent and the agent increases, the strength of the paper becomes weaker, which causes a problem that it becomes difficult to form a filter by corrugation molding. Conversely, if the total amount of the photocatalyst and the adsorbent is small, sufficient deodorizing ability cannot be obtained. For example, if the total amount of the photocatalyst and the adsorbent is about 10, paper strength can be secured enough to withstand filter molding, but the deodorizing ability is not sufficient.

Therefore, it is preferable to increase the total amount of the photocatalyst and the adsorbent so as to maximize the deodorizing ability, and to obtain paper strength by reinforcing with a binder or the like. However, if the amount of the binder is too large, the photocatalytic property and the adsorptivity are impaired.
The content is preferably about 10 to 10% by weight. The total part 45 of the photocatalyst and the adsorbent was determined from these points. In addition, when the amount of activated carbon in the total part 45 is large, the acetaldehyde adsorptivity is also improved. However, a remarkable effect is not recognized in 20 parts or more. Further, if the number of activated carbons is 22.5, that is, the ratio to the amount of the photocatalyst exceeds 1: 1, it becomes difficult for the ultraviolet light of the excitation light to reach the photocatalyst powder, and the photocatalytic property is impaired.

In the process of removing the tobacco odor to be mainly removed according to this embodiment, first, activated carbon is efficiently adsorbed by acetaldehyde, and the adsorbed acetaldehyde is efficiently decomposed by a photocatalyst adjacent thereto. Also, for other bad smells, for example, the basic substance is ST
-01 and quickly adsorbed on fiber. The odor molecules adsorbed on ST-01 are oxidatively decomposed by the photocatalytic property of ST-01 itself, and are released as odorless molecules. The odor molecules adsorbed on the fibrous material are diffused into ST-01 and oxidatively decomposed as the odor molecules adsorbed on ST-01 are decomposed.

Similarly, the acidic substance is caused by the adsorption action to cause ST.
After being quickly adsorbed on -31, it is oxidatively decomposed in ST-01. Since ST-31 also has photocatalytic properties, it may be oxidatively decomposed while being adsorbed to some extent by the adsorbent itself.

On the other hand, the flame retardancy was measured according to UL-94V. Actually, the specimen to be burned is 12.5m wide.
m, the length was cut to 130 mm, the flame was brought close by a Bunsen burner, and the combustion state was observed. Table 2 shows the results.

[0033]

[Table 2]

When aluminum hydroxide is mixed as a flame retardant, the flame retardancy is improved according to the mixing ratio as shown in Table 2. No. In No. 5, the flame retardancy ratio should be small and it should be easy to burn. However, No. 5 was mixed with activated carbon.
1 to No. 4 and the tendency is different.
It conforms to L standard 94V-0.

It should be noted that aluminum hydroxide can be introduced into a papermaking process without any problem, and is not decomposed due to photocatalytic properties unlike organic flame retardants.

[0036]

As is apparent from the above description, according to the present invention, in a deodorizer or an air purifier utilizing a photocatalytic reaction, an adsorbent for a malodorous component containing activated carbon,
A photocatalyst for decomposing malodorous components by a photocatalytic reaction,
By using a paper-like material made by mixing a flame retardant and a paper material as a deodorizing filter, the adsorbent containing activated carbon first adsorbs the malodorous component, thereby improving the contact efficiency of the malodorous component with the photocatalyst, and Since the adsorbed malodor components are sequentially decomposed and removed efficiently, the air containing the malodor can be easily and efficiently cleaned. In addition, since it does not saturate as in the case of simply using an adsorbent, its life is extended and its maintenance is facilitated. In addition, by incorporating a flame retardant such as aluminum hydroxide to improve the flame retardancy, it can be disposed near an electric dust collector where sparks are generated, and the degree of freedom of the arrangement is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a deodorizing device according to a first embodiment to which the present invention is applied.

FIG. 2 is an enlarged view showing a state of fibers of a paper-like material in which a photocatalyst powder and an adsorbent powder are formed into fibers.

FIG. 3 is a diagram showing a configuration of a measuring apparatus for measuring the deodorizing performance of a paper-like body into which a photocatalyst powder and an adsorbent powder have been incorporated.

FIG. 4 is a graph showing the removal rate of ammonia (a), the removal rate of acetaldehyde (b), and the removal rate of acetic acid (c) by the deodorizing filter of the present invention containing activated carbon as an adsorbent and the deodorizing filter containing no activated carbon. .

FIGS. 5 (a) and (b) are graphs showing changes in sensory values between the deodorizing filter of the present invention containing activated carbon as an adsorbent and the deodorizing filter not containing activated carbon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Intake port 3 Ventilation path 4 Exhaust port 5 Pre-filter 7 Deodorizing part 8 Ventilation fan 10 Excitation light source 11 Deodorizing filter 12 Reflector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 39/14 B01D 39/14 BM 53/38 B01J 20/20 B 53/81 21/06 A B01J 20/20 35/02 J 21/06 B01D 53/34 116B 35/02 116Z 53/36 J

Claims (7)

[Claims] 1. A deodorizing filter used in a deodorizing device or an air purifier having a light source for exciting a photocatalyst, comprising: an adsorbent for one or more types of malodorous components containing powdered or fibrous activated carbon; A deodorizing filter comprising a paper-like material obtained by mixing and mixing a powdery photocatalyst, which is excited by the light source to decompose malodorous components by a photocatalytic reaction, and a powdery flame retardant. 2. The ratio of the weight of activated carbon contained in the adsorbent to the total weight of the adsorbent and the photocatalyst is 1: 1.
The deodorizing filter according to claim 1, wherein: 3. The activated carbon according to claim 1, wherein the activated carbon is an activated carbon that has not been subjected to an impregnation treatment.
The deodorizing filter according to 1. 4. The paper-like material according to claim 1, wherein said deodorizing powder is formed into said paper-like material by using a liquid binder and / or a fibrous binder so as to secure a required strength. The deodorizing filter according to any one of the above. 5. The method according to claim 1, wherein the liquid binder is 5% by weight to 10% by weight.
The deodorizing filter according to claim 4, which is contained in a range of weight%. 6. The method according to claim 4, wherein the fibrous binder is contained in a range of 10% by weight or less.
The deodorizing filter according to 1. 7. The deodorizing filter according to claim 1, wherein the flame retardant comprises aluminum hydroxide, and the aluminum hydroxide has a flame retardant ratio of 1 or more.