JP5390630B2 - Filter and air purifier - Google Patents

Description

The present invention relates to a filter and an air cleaner. Specifically, for example, the present invention relates to a filter having a photocatalytic function capable of detoxifying pollutants, antibacterial, and sterilizing, and an air cleaner using such a filter.

  With the progress of an aging society, the proportion of elderly people with reduced immunity in the total population is increasing, and accordingly, from the viewpoint of prevention of nosocomial infections and food poisoning, etc. Strengthening hygiene management is an urgent issue. In response to this social background, various antibacterial processed products have been developed, and in recent years, the use of a photocatalytic function for antibacterial processing has attracted particular attention.

  Here, the “photocatalytic function” refers to a catalyst that is excited when irradiated with light energy larger than the band gap energy of its conduction band and valence band, and generates an electron-hole pair to cause oxidation and reduction reactions. This means the function of the substance (photosemiconductor substance).

Among photocatalysts, photocatalysts using titanium dioxide (TiO ₂ ) in particular are inexpensive, excellent in chemical stability, and have high catalytic activity. Due to their powerful organic substance decomposing activity, At the same time, it can decompose toxic substances such as endotoxin, which is an outer cell wall component of Gram-negative bacteria, and toxins produced by bacteria (for example, verotoxin produced by pathogenic E. coli), and the photocatalyst itself is harmless to the human body. Has the advantage of being.

  Therefore, research and application of photocatalysts using titanium dioxide have been performed, and titanium dioxide photocatalysts are widely used for antibacterial processing of food containers, building materials, and the like (see, for example, Patent Document 1 and Patent Document 2).

  Since titanium dioxide exhibits photocatalytic activity only under ultraviolet irradiation, it cannot exhibit sufficient catalytic activity under room light containing almost no ultraviolet component. Therefore, titanium dioxide doped with atoms such as nitrogen, carbon and sulfur in the crystal lattice has been proposed as a photocatalyst exhibiting photocatalytic activity under visible light irradiation. In particular, sulfur-doped titanium dioxide absorbs light in the visible light region. It is known that it has a high coefficient and high catalytic activity under visible light (for example, see Patent Document 3).

By the way, conventionally, a photocatalytic filter in which a photocatalyst is supported on a ceramic porous body is applied to an air conditioner, an air purifier, a water treatment device, and the like.
For example, Patent Document 4 discloses that a porous ceramic body carrying titanium oxide is irradiated with ultraviolet rays, and the malodor of gas is removed by the photocatalytic action of titanium oxide.

  In addition, in the conventional photocatalyst filter, the photocatalyst layer was formed in the surface of the porous ceramics filter by dipping (dipping) in the photocatalyst coating liquid (for example, refer patent document 4 and patent document 5).

JP 2007-51263 A JP 2006-346651 A JP 2004-143032 A Japanese Patent Laid-Open No. 3-157125 JP 2005-349309 A

  However, since the photocatalyst layer (dipping layer) formed by dipping is dense, cracks are likely to occur even when a small bending stress is applied to the filter (see FIG. 1B). In FIG. 1B, reference numeral 101 denotes a porous ceramic filter, reference numeral 102 denotes a dipping layer, and reference numeral 103 denotes a crack.

The present invention has been made in view of the above points, and an object of the present invention is to provide a filter capable of improving the strength of a photocatalyst layer and an air cleaner using such a filter.

  In order to achieve the above object, in the fibrous filter according to the present invention, a fibrous filter body composed of fibers having a diameter of 50 μm to 500 μm and having a porosity of 50% to 90%, and a surface of the fiber. And a titanium dioxide film formed by thermal spraying technology.

  In order to achieve the above object, in the air cleaner according to the present invention, a fibrous filter body having a diameter of 50 μm to 500 μm and a porosity of 50% to 90%, A fibrous filter having a titanium dioxide film formed on the surface by a thermal spraying technique, and a light source for irradiating the fibrous filter with light.

Further, in the air purifier according to the present invention, the diameter is made of aluminum fibers of 50 microns and 500 microns, a basis weight ^{500g / m 2 ~10000g / m 2} , a porosity of 50% to 90% fibrous A filter body, a fibrous filter having a titanium dioxide film on which 0.1% by mass to 10% by mass of an antibacterial metal is supported, and a light applied to the fibrous filter A light source for irradiating the light source.

  Here, since the titanium dioxide film was formed by thermal spraying technology, the titanium dioxide film was formed on the fiber surface so that the titanium dioxide particles pierced, and the upper layer was partially sintered by thermal spraying heat. In this state, the titanium dioxide film is formed, so that cracking is hardly generated and durability can be improved.

  That is, the titanium dioxide film on the surface of the fibrous filter body is in such a state that the titanium dioxide particles pierce the surface of the fibrous filter body, and the anchor effect provides high adhesion between the fibrous filter body and the titanium dioxide film. The titanium dioxide film that is realized and laminated on the upper layer realizes high adhesion by partially sintering the titanium dioxide particles.

Moreover, if the diameter of the fiber which comprises a fibrous filter main body is less than 50 micrometers, the intensity | strength of a fibrous filter main body is not enough, and the film-forming of the titanium dioxide film by a thermal spraying technique is difficult, and there exists a concern about the fall of a yield.
On the other hand, if the diameter of the fiber constituting the fibrous filter body exceeds 500 μm, the amount of fiber occupying in the fixed space is too large. And, since the fiber is excessively present in the fixed space, the existence region of the titanium dioxide film cannot be sufficiently secured, and the ratio of the titanium dioxide film in the fixed space becomes too small. It becomes difficult to fully exhibit the photocatalytic function.
Therefore, the diameter of the fiber constituting the fibrous filter body is set to 50 μm to 500 μm. In addition, it is desirable for the diameter of the fiber which comprises a fibrous filter main body to be 100 micrometers-200 micrometers.

Furthermore, when the porosity of the fibrous filter body is less than 50%, the air resistance becomes too large to make it difficult for air to pass through the fibrous filter body, and the harmful substance (degradable substance) and the titanium dioxide film come into contact with each other. It becomes difficult to do. This means that when the fibrous filter body is used for an air cleaner, it becomes difficult to sufficiently perform the function as an air cleaner.
On the other hand, when the porosity of the fibrous filter main body exceeds 90%, the amount of fibers occupying in the fixed space is too small. And considering that a titanium dioxide film is formed on the surface of the fiber, the amount of fibers is too small, so the amount of film formation of the titanium dioxide film in a certain space is not sufficient, and the photocatalytic function of the titanium dioxide film It is difficult to fully exhibit the above.
Therefore, the porosity of the fibrous filter body is set to 50% to 90%. The porosity of the fibrous filter body is preferably 60% to 80%.

  By the way, titanium dioxide has anatase type and rutile type crystal structures, and it is known that anatase type titanium dioxide exhibits a higher photocatalytic function than rutile type titanium dioxide. Yes. Therefore, a high photocatalytic function can be realized by forming a titanium dioxide film so that the anatase crystal structure is 70% by mass or more. However, since anatase-type titanium dioxide is generally more expensive than rutile-type titanium dioxide, it is preferable to use rutile-type titanium dioxide when importance is placed on cost.

  The crystal lattice of titanium dioxide is doped with sulfur, carbon, nitrogen, etc., or carries a sensitizer which is at least one compound selected from metal complexes or metal salts such as iron, copper, chromium, nickel. As a result, visible light responsive titanium dioxide can be realized, and such visible light responsive titanium dioxide can be employed.

  In addition, the antibacterial action is further enhanced by supporting an antibacterial metal (for example, Ag, Cu, Ni, Co, Zn, etc.) on the titanium dioxide film. In addition, when there are too few antibacterial metals, an antibacterial effect cannot be exhibited, and even if there are too many antibacterial metals, an antibacterial effect will decline on the contrary. Therefore, it is preferable that 0.1% by mass to 10% by mass of the antibacterial metal is supported on the titanium dioxide film.

By the way, if the basis weight of the fibrous filter body is less than 500 g / m ² , the amount of fibers per unit area is too small. And considering that the titanium dioxide film is formed on the surface of the fiber, the amount of fiber is too small, the amount of film formation of the titanium dioxide film per unit area is not sufficient, and the photocatalytic function of the titanium dioxide film is It will be difficult to fully demonstrate.
On the other hand, when the basis weight of the fibrous filter main body exceeds 10,000 g / m ² , the amount of fibers per unit area is too large. And, since the fiber exists in the unit area excessively, the existence area of the titanium dioxide film cannot be secured sufficiently, and the ratio of the titanium dioxide film per unit area becomes too small, and the photocatalyst of the titanium dioxide film It becomes difficult to perform the function sufficiently.
Therefore, the basis weight of the fibrous filter body has a ^{500g / m 2 ~10000g / m 2} . Incidentally, it is preferable basis weight of the fibrous filter body is a ^{500g / m 2 ~3000g / m 2} .

  The fibers constituting the fibrous filter body include metal fibers (for example, aluminum fibers, stainless steel fibers, nickel fibers), inorganic fibers (for example, glass fibers, carbon fibers, alumina fibers, ceramic fibers, rock fibers, slugs). Fiber), organic fiber (for example, plastic fiber) and the like.

  Moreover, as a light source which irradiates light to a fibrous filter, the black light which emits an ultraviolet-ray, an ultraviolet LED lamp, a visible light LED lamp, a fluorescent lamp, an incandescent lamp, a cold cathode tube (CCFL: Cold Cathode Fluorescent Lamp) etc. are mentioned. It is done.

  In the filter and the air cleaner to which the present invention is applied, the strength of the photocatalyst layer is increased by reducing the cracking of the titanium dioxide film and improving the durability.

It is a schematic diagram for demonstrating the structure of a photocatalyst layer. It is a mimetic diagram for explaining an example of an air cleaner to which the present invention is applied. It is a schematic diagram for demonstrating another example of the air cleaner to which this invention is applied. It is a schematic diagram for demonstrating another example of the air cleaner to which this invention is applied.

Hereinafter, modes for carrying out the invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings. The description will be given in the following order.
1. 1st Embodiment (about a fibrous filter (1))
2. Second Embodiment (Fibrous Filter (2))
3. Third Embodiment (Fibrous Filter (3))
4). 4th Embodiment (about an air cleaner (1))
5. 5th Embodiment (about an air cleaner (2))
6). Sixth embodiment (about air cleaner (3))
7). 7th Embodiment (about an air cleaner (4))
8). Eighth embodiment (about air cleaner (5))

<1. First Embodiment>
FIG. 1A is a schematic diagram for explaining an example of a fibrous filter to which the present invention is applied. The fibrous filter shown here is formed on the fibrous filter body 1 and the surface of the fibrous filter body 1. And a titanium dioxide film formed thereon.

The fibrous filter body 1 is composed of aluminum fibers having a diameter of 50 μm to 500 μm (hereinafter, the aluminum fibers constituting the fibrous filter body 1 are referred to as “aluminum fibers”), and the basis weight is 500 g. / M ^{2 to} 10000 g / m ² and the porosity is 50% to 90%.

  The titanium dioxide film is formed by causing the titanium dioxide particles 2 as photocatalyst particles to collide with the surface of the fibrous filter body using a thermal spraying technique. In addition, the film formation of a titanium dioxide film can use the spraying temperature variable type high-speed spraying apparatus described in Unexamined-Japanese-Patent No. 2005-68457, for example.

Here, since the titanium dioxide film of the present embodiment is formed by causing the titanium dioxide particles 2 to collide with the fibrous filter body 1 using a thermal spraying technique, the titanium dioxide film is formed on the surface of the aluminum fiber. A titanium dioxide film is formed in such a manner that the particles 2 pierce (see the titanium dioxide particles indicated by symbol g in FIG. 1 (a)), and high adhesion between the aluminum fibers and the titanium dioxide particles 2 due to the anchor effect. Can be realized.
In addition, the titanium dioxide particles 2 are partially sintered by the heat during thermal spraying (see the titanium dioxide particles indicated by the symbol h in FIG. 1 (a)), thereby high adhesion between the titanium dioxide particles 2. Can be realized.
Therefore, as compared with the photocatalyst layer formed by dipping, even when bending stress is applied to the fibrous filter body 1, cracks are hardly generated, and the strength of the photocatalyst layer (titanium dioxide film) can be improved.

In addition, the gap between the aluminum fibers is extremely short compared to the diameter of the hole in the conventional porous ceramic filter (corresponding to the gap between the aluminum fibers). For this reason, the distance between the harmful substance (substance to be decomposed) passing through the fibrous filter and the titanium dioxide film is short, the harmful substance easily comes into contact with the titanium dioxide film, and the distance between the harmful substance and the titanium dioxide film is short. Therefore, the concentration gradient of harmful substances increases and the mobility of harmful substances increases.
Therefore, compared with the case where a porous ceramic filter is used, the fibrous filter of the first embodiment can be expected to improve gas decomposition performance.

  Tables 1 and 2 show the results of the acetaldehyde decomposition test using the “filter having a photocatalyst layer formed by dipping on a porous ceramic filter” and the acetaldehyde decomposition test using the fibrous filter of the first embodiment. Results are shown.

  Specifically, Table 1 shows the decrease in acetaldehyde concentration over time, and a decomposition test of acetaldehyde using a “filter having a photocatalyst layer formed by dipping on a porous ceramic filter” (indicated by symbol i in Table 1). In FIG. 4, 80 ppm of acetaldehyde decreased in 4 hours, whereas in the decomposition test of acetaldehyde using the fibrous filter of the first embodiment (indicated by symbol j in Table 1), 90 ppm in 2 hours. Acetaldehyde is reduced.

  Carbon dioxide is generated by the decomposition of acetaldehyde. Table 2 shows the generation of carbon dioxide over time. "Filter with a photocatalyst layer formed by dipping on a porous ceramic filter" In the acetaldehyde decomposition test (denoted by symbol i in Table 2) using 130, 130 ppm of carbon dioxide was generated in 2 hours, whereas the decomposition of acetaldehyde using the fibrous filter of the first embodiment In the test (indicated by symbol j in Table 2), 150 ppm of carbon dioxide is generated in 2 hours.

  Table 3 shows the results of a decomposition test of formaldehyde (indicated by symbol m in Table 3) and a result of a decomposition test of acetaldehyde (indicated by symbol n in Table 3) using a “filter having a photocatalyst layer formed by dipping on a porous ceramic filter”. Show). Specifically, the relationship between time and concentration is shown.

  Table 4 shows the results of the decomposition test of formaldehyde (indicated by symbol m in Table 4) and the results of the decomposition test of acetaldehyde (indicated by symbol n in Table 4) using the fibrous filter of the first embodiment. Show. Specifically, the relationship between time and concentration is shown.

  From the results in Tables 1 to 4, the fibrous filter of the first embodiment clearly has improved gas decomposition performance compared to “a filter in which a photocatalyst layer is formed by dipping on a porous ceramic filter”. I understand that.

  Thus, the fibrous filter of 1st Embodiment is excellent in decomposition | disassembly performance (gas decomposition | disassembly) and durability compared with "the filter which formed the photocatalyst layer by dipping on the porous ceramics filter".

  In addition, since the fibrous filter of the first embodiment can be manufactured extremely thin, a fibrous filter of approximately 1 mm to 7 mm can be realized, and a “porous ceramic filter having a thickness of 10 mm or more” Compared with a “filter having a photocatalyst layer formed by dipping”, it is excellent also in space saving. Furthermore, since it is thin, it is excellent in workability.

  Here, in the present embodiment, the description is given by taking aluminum fiber as an example, but the material of the fibrous filter main body does not necessarily need to be an aluminum material, and is a metal such as copper, nickel, titanium, and stainless steel. It may be made of a material, and may be made of a non-metallic material such as glass as long as the fibrous filter body can be formed.

<2. Second Embodiment>
Another example of the fibrous filter to which the present invention is applied has a fibrous filter body 1 and a titanium dioxide film formed on the surface of the fibrous filter body 1 (see FIG. 1A). This point is the same as in the first embodiment described above. The titanium dioxide film of the present embodiment carries 1% by mass of Ag.

The fibrous filter body 1 is made of aluminum fibers having a diameter of 50 μm to 500 μm, has a basis weight of 500 g / m ^{2 to} 10,000 g / m ² , and has a porosity as in the first embodiment. Is 50% to 90%.

  The titanium dioxide film is formed by colliding the titanium dioxide particles 2 that are photocatalyst particles and the Ag particles that are antibacterial materials against the surface of the fibrous filter body using a thermal spraying technique. In addition, the point which can use the high-speed thermal spraying apparatus of the spraying temperature variable type described in Unexamined-Japanese-Patent No. 2005-68457 can be used for film-forming of a titanium dioxide membrane | film | coat like the above-mentioned 1st Embodiment. It is.

Here, in the present embodiment, the titanium dioxide particles 2 and the antibacterial metal (for example, Ag particles) are caused to collide with the surface of the fibrous filter body by using a thermal spraying technique, thereby simultaneously forming the titanium dioxide film. The case where Ag particles are carried is described as an example. However, it is sufficient if the Ag particles can be supported on the titanium dioxide film, and the Ag particles may be supported by any method.
For example, the particles such as Ag may be supported by colliding titanium dioxide particles, on which the particles such as Ag are initially attached to the surface thereof, with the surface of the fibrous filter body using a thermal spraying technique. Further, after forming the titanium dioxide film, Ag ions or the like may be supported by an ultraviolet light deposition method or the like.

  By the way, as a result of conducting an Escherichia coli bactericidal performance test using Escherichia coli as a test bacterium for examining the antibacterial effect of the fibrous filter of the present embodiment, 6 orders of E. coli (1 million minutes) were obtained in a short time of about 5 minutes. It was confirmed that it could be decreased rapidly until 1).

  Table 5-1 shows the results of the acetaldehyde decomposition test (indicated by symbol a in Table 5-1) using the “filter having a photocatalyst layer formed by dipping on a porous ceramic filter”, and the second embodiment. The result of the decomposition test of acetaldehyde using the fibrous filter (shown by symbol b in Table 5-1) is shown. Specifically, the relationship between time and concentration is shown.

  From the results of Table 5-1, the fibrous filter of the second embodiment can decompose acetaldehyde, which is a kind of VOC, into water and carbon dioxide to a low concentration (about one billionth). I understand that there is.

  Here, in this embodiment, the case where Ag is supported is described as an example, but the antibacterial metal supported by the titanium dioxide film is not necessarily Ag, and other antibacterial metals may be used. Also good.

<3. Third Embodiment>
Still another example of the fibrous filter to which the present invention is applied includes a fibrous filter body 1 and a titanium dioxide film formed on the surface of the fibrous filter body 1 (see FIG. 1A). This point is the same as in the first embodiment described above. Note that the titanium dioxide film of the present embodiment carries 12.5% by mass of zeolite (an example of an adsorbent).

The fibrous filter body 1 is made of aluminum fibers having a diameter of 50 μm to 500 μm, has a basis weight of 500 g / m ^{2 to} 10,000 g / m ² , and has a porosity as in the first embodiment. Is 50% to 90%.

  The titanium dioxide film is formed by colliding the titanium dioxide particles 2 that are photocatalyst particles and the zeolite that is the adsorbent with the surface of the fibrous filter body using a thermal spraying technique. In addition, the point which can use the high-speed thermal spraying apparatus of the spraying temperature variable type described in Unexamined-Japanese-Patent No. 2005-68457 can be used for film-forming of a titanium dioxide membrane | film | coat like the above-mentioned 1st Embodiment. It is.

  Here, in the present embodiment, the titanium dioxide particles 2 and the adsorbent (for example, zeolite) are collided with the surface of the fibrous filter body by using a thermal spraying technique, so that the zeolite is simultaneously formed with the titanium dioxide film. In the description, the case of carrying is taken as an example. However, it is sufficient if the zeolite can be supported on the titanium dioxide film, and the zeolite may be supported by any method.

  By the way, the result of the decomposition test of acetaldehyde using the fibrous filter of the present embodiment (indicated by symbol A in Table 5-2) and the result of the decomposition test of acetaldehyde using the fibrous filter not supporting zeolite. (Indicated by symbol B in Table 5-2) is shown in Table 5-2. Specifically, the relationship between time and concentration is shown.

  From the results shown in Table 5-2, it can be seen that by supporting zeolite, the decomposition rate of acetaldehyde is approximately three times as high.

  Here, in the present embodiment, the case where zeolite is supported is described as an example, but the adsorbent supported by the titanium dioxide film is not necessarily zeolite, and other materials such as apatite and activated carbon are used. It may be an adsorbent.

<4. Fourth Embodiment>
FIG. 2 is a schematic diagram for explaining an example of an air purifier to which the present invention is applied. The air purifier 10 shown here has a fan 11 disposed below the inside thereof, and an ultraviolet LED above the fan 11. A lamp 12 is disposed, and a fibrous filter 13 is disposed further above the ultraviolet LED lamp 12.

  The fan 11 is configured to be able to blow air upward, and when the fan 11 rotates, an air flow is formed such that air is drawn in from the lower side of the air cleaner 10 and exhausted from the upper side.

  The ultraviolet LED lamp 12 is configured to be able to irradiate light having a wavelength of 365 nm toward the fibrous filter 13, and the photocatalytic function of the fibrous filter 13 is exhibited by the light from the ultraviolet LED lamp 12. .

  The fibrous filter 13 uses the fibrous filter of the above-described second embodiment.

  In the air cleaner 10 configured as described above, air containing bacteria, viruses, VOC gas, and harmful gas is sucked from below by the intake action caused by the rotation of the fan 11. The sucked air passes through the fibrous filter 13 so that bacteria, viruses, VOC gas and harmful gas are decomposed and sterilized, and exhausted from above as clean air.

  Table 6 shows the result of the ammonia decomposition test using the “ionic air cleaner” (indicated by the symbol c in Table 6) and the result of the ammonia decomposition test using the air cleaner of the fourth embodiment. (Indicated by d in Table 6). Specifically, the relationship between time and concentration is shown.

  Table 7 shows the result of a decomposition test of acetaldehyde using an “ionic air cleaner” (indicated by symbol c in Table 7) and the result of a decomposition test of acetaldehyde using the air cleaner of the fourth embodiment. (Indicated by symbol d in Table 7). Specifically, the relationship between time and concentration is shown.

  From the results of Tables 6 and 7, it can be seen that the air cleaner of the fourth embodiment can decompose ammonia, which is an odor component, and acetaldehyde, which is a kind of VOC, to a low concentration.

<5. Fifth embodiment>
FIG. 3 is a schematic view for explaining another example of the air cleaner to which the present invention is applied. The air cleaner 10 shown here has a fan 11 disposed below the inside thereof, and above the fan 11. A visible light LED lamp 14 is disposed, and a fibrous filter 13 is disposed further above the visible light LED lamp 14.

  The fan 11 is configured to be able to blow air upward, and by rotating the fan 11, an air flow is formed such that air is sucked from below the air cleaner 10 and exhausted from above. This is the same as the fourth embodiment described above.

  The visible light LED lamp 14 is configured to be able to irradiate light having a wavelength of 415 nm toward the fibrous filter 13, and the photocatalytic function of the fibrous filter 13 is exhibited by the light from the visible light LED lamp 14. It becomes.

  The fibrous filter 13 uses the fibrous filter of the above-described second embodiment.

  In the air cleaner 10 configured as described above, air containing bacteria, viruses, VOC gas, and harmful gas is sucked from below by the intake action caused by the rotation of the fan 11. The sucked air passes through the fibrous filter 13 so that bacteria, viruses, VOC gas and harmful gas are decomposed and sterilized, and exhausted from above as clean air.

  Table 8 shows the result of the ammonia decomposition test using the “ionic air cleaner” (indicated by symbol e in Table 8) and the result of the ammonia decomposition test using the air cleaner of the fifth embodiment. (Indicated by symbol f in Table 8). Specifically, the relationship between time and concentration is shown.

  Table 9 shows the results of the acetaldehyde decomposition test using the “ionic air cleaner” (indicated by symbol e in Table 9) and the results of the acetaldehyde decomposition test using the air cleaner of the fifth embodiment. (Indicated by symbol f in Table 9). Specifically, the relationship between time and concentration is shown.

  From Tables 8 and 9, it can be seen that the air cleaner of the fifth embodiment can decompose ammonia, which is a odor component, and acetaldehyde, which is a kind of VOC, to a low concentration.

  Moreover, since visible light is used as a light source, it is gentle to human eyes and skin. Furthermore, since the visible light LED lamps are already distributed in large quantities and can be obtained at a very low cost, the air cleaner of the fifth embodiment can be realized at a low cost.

<6. Sixth Embodiment>
FIG. 4A is a schematic diagram for explaining still another example of an air cleaner to which the present invention is applied. The air cleaner shown here has a dust collection filter 15 disposed therein, and is a dust collector. A photocatalytic filter portion 16 is disposed adjacent to the filter 15, and the fan 11 is disposed on the opposite side of the photocatalytic filter portion 16 from the dust collection filter 15.

  The fan 11 is configured so as to form an air flow that is sucked from the dust collection filter 15 side by rotating.

  As shown in FIG. 4B, the photocatalytic filter portion 16 is configured by surrounding a black light 18 with a fibrous filter 13 and a reflecting plate 17. The fibrous filter 13 uses the fibrous filter of the second embodiment described above, and the black light 18 emits a UV sterilization line having a wavelength of 254 nm and a UV ozone ray having a wavelength of 185 nm. It is configured.

  In the air purifier configured as described above, the fan 11 rotates to supply air containing bacteria, viruses, VOC gas, and harmful gas to the photocatalytic filter unit 16. In the photocatalyst filter part 16, by passing through the fibrous filter 13, bacteria, viruses, VOC gas and harmful gas are decomposed and sterilized, and exhausted as clean air.

  Table 10 shows the results of the ammonia decomposition test using the “ion + deodorizing filter type air cleaner” (indicated by the symbol p in Table 10) and the ammonia decomposition test using the “activated carbon type air cleaner”. The results (indicated by symbol q in Table 10) and the results of the ammonia decomposition test using the air cleaner of the sixth embodiment (indicated by symbol r in Table 10) are shown. Specifically, the relationship between time and concentration is shown.

  Table 11 shows the results of the acetaldehyde decomposition test using “ion + deodorizing filter type air purifier” (indicated by “p” in Table 11) and the results of the acetaldehyde decomposition test using “activated carbon type air purifier”. (Shown by symbol q in Table 11) and the results of the acetaldehyde decomposition test using the air cleaner of the sixth embodiment (shown by symbol r in Table 11). Specifically, the relationship between time and concentration is shown.

  From Table 10 and Table 11, it can be seen that the air cleaner of the sixth embodiment can decompose ammonia, which is an odor component, and acetaldehyde, which is a kind of VOC, to a low concentration.

<7. Seventh Embodiment>
In still another example of the air cleaner to which the present invention is applied, a dust collection filter 15 is disposed in the interior thereof, and the photocatalytic filter section is adjacent to the dust collection filter 15 as in the sixth embodiment. 16 is disposed, and the fan 11 is disposed on the opposite side of the photocatalytic filter portion 16 from the dust collection filter 15 (see FIG. 4A).

  Further, the fan 11 is configured in such a way that an air flow such as intake from the dust collection filter 15 side is formed by rotation, which is the same as in the sixth embodiment.

  As shown in FIG. 4B, the photocatalytic filter portion 16 is configured by surrounding a black light 18 with a fibrous filter 13 and a reflecting plate 17. The fibrous filter 13 uses the fibrous filter of the second embodiment described above, and the black light 18 is configured to emit UV ultraviolet light having a wavelength of 365 nm.

  In the air purifier configured as described above, the fan 11 rotates to supply air containing bacteria, viruses, VOC gas, and harmful gas to the photocatalytic filter unit 16. In the photocatalyst filter part 16, by passing through the fibrous filter 13, bacteria, viruses, VOC gas and harmful gas are decomposed and sterilized, and exhausted as clean air.

  Table 12 shows the results of the acetaldehyde decomposition test using the air cleaner according to the sixth embodiment (indicated by symbol s in Table 12) and the acetaldehyde decomposition test using the air cleaner according to the seventh embodiment. (Indicated by t in Table 12). Specifically, the relationship between time and concentration is shown.

  Tables 13 and 14 show the results of a complete decomposition performance test of VOC (acetaldehyde / toluene) using the air cleaner of the seventh embodiment. In Table 13, the symbol u represents acetaldehyde, the symbol v in Table 13 represents carbon dioxide, the symbol u in Table 14 represents toluene, and the symbol v in Table 14 represents carbon dioxide.

  From Table 12, the air cleaner of the seventh embodiment decomposes ammonia, which is an odor component, and acetaldehyde, which is a kind of VOC, to a low concentration at a higher speed than the air cleaner of the sixth embodiment. It can be seen that it is possible. Moreover, it turns out that the decomposition | disassembly performance of VOC is very high from the air cleaner of 7th Embodiment from Table 13 and Table 14. FIG.

<8. Eighth Embodiment>
In still another example of the air cleaner to which the present invention is applied, a dust collection filter 15 is disposed in the interior thereof, and the photocatalytic filter section is adjacent to the dust collection filter 15 as in the sixth embodiment. 16 is disposed, and the fan 11 is disposed on the opposite side of the photocatalytic filter portion 16 from the dust collection filter 15 (see FIG. 4A).

  Further, the fan 11 is configured in such a way that an air flow such as intake from the dust collection filter 15 side is formed by rotation, which is the same as in the sixth embodiment.

  As shown in FIG. 4C, the photocatalyst filter unit 16 is configured by a cold cathode tube 19 surrounded by a fibrous filter 13. The fibrous filter 13 uses the fibrous filter of the second embodiment described above, and the cold cathode tube 19 is configured to emit a germicidal line having a wavelength of 365 nm.

  In the air purifier configured as described above, the fan 11 rotates to supply air containing bacteria, viruses, VOC gas, and harmful gas to the photocatalytic filter unit 16. In the photocatalyst filter part 16, by passing through the fibrous filter 13, bacteria, viruses, VOC gas and harmful gas are decomposed and sterilized, and exhausted as clean air.

  Table 15 shows a case where a commercially available air cleaner equipped with a photocatalyst is used (indicated by reference characters C and D in Table 15) and a case where the air cleaner according to the eighth embodiment is used (reference symbol E in Table 15). The result of the floating bacteria count after the air purifier is operated is shown. Specifically, after spraying Bacillus subtilis in a 1000 L container, the air purifier is operated, and the number of bacteria is measured by sucking the air in the container with a pump.

  As is apparent from Table 15, it can be seen that the air cleaner of the eighth embodiment has an extremely high decomposition and sterilization function of Bacillus subtilis.

DESCRIPTION OF SYMBOLS 1 Fibrous filter main body 2 Titanium dioxide particle 10 Air cleaner 11 Fan 12 LED lamp 13 Fibrous filter 14 Visible light LED lamp 15 Dust collection filter 16 Photocatalyst filter part 17 Reflector 18 Blacklight 19 Cold cathode tube

Claims (5)

A filter body composed of aluminum fibers having a diameter of 50 μm to 500 μm, a basis weight of 500 g / m ^{2 to} 10000 g / m ² , and a porosity of 50% to 90%;
By spraying the titanium dioxide particles, the titanium dioxide particles are stuck into the surface of the filter body in an anchor shape, and the titanium dioxide particles are formed into a film on the filter body in a state of being partially sintered by heat during spraying, and anatase A filter comprising: a titanium dioxide film having a type crystal structure of 70% by mass or more. The filter according to claim 1, wherein an antibacterial metal is supported on the titanium dioxide film. The filter according to claim 1 or 2, wherein an adsorbent is supported on the titanium dioxide film. By spraying titanium dioxide particles with a filter body composed of aluminum fibers having a diameter of 50 μm to 500 μm, a basis weight of 500 g / m ^{2 to} 10000 g / m ² , and a porosity of 50% to 90%, Titanium dioxide particles pierce the surface of the filter body in an anchor shape, and the titanium dioxide particles are formed into a film on the filter body in a state of being partially sintered by heat during spraying, and the anatase type crystal structure is 70% by mass or more. A filter having a titanium dioxide film;
An air cleaner comprising: a light source that emits light to the filter. The air cleaner according to claim 4, wherein the light source is any one of a black light that emits ultraviolet light, an ultraviolet LED lamp, a visible light LED lamp, a fluorescent lamp, an incandescent lamp, or a cold cathode tube.

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