JP2000300960A - Gas treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make decomposable efficiently a toxic gas of a high concentration with a small sized apparatus. SOLUTION: A plurality of ultraviolet lamps 38 are arranged inside a gas passage 22 wherein its section is made spiral, and a photocatalyst is supported on its wall face, and a blower 14 is connected to one end of the gas passage 22. When the photocatalyst is irradiated with ultraviolet rays of an ultraviolet lamp 38, the photocatalyst shows a photocatalyst activity. When the blower 14 is operated, an air containing a formalin gas in a room flows into the gas passage 22, and comes in contact with the photocatalyst. The formalin gas is decomposed into carbonic acid gas and water, made harmless, and exhausted into the room. Since the gas passage 22 is allowed to have a spiral section, a pressure loss is less in comparison with that of a filter or a honeycomb. Further, the air does not stagnate in the gas passage 22, the air containing the formalin gas allowed to flow in, is uniformly brought into contact with over the whole wall face of the gas passage 22, and the formalin gas can be efficiently decomposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas processing apparatus for decomposing harmful gases such as formalin gas in air.

[0002]

2. Description of the Related Art Conventionally, in a clean room or the like, an indoor fumigation process is usually performed using formalin gas on a regular basis.

[0003] In the fumigation treatment, a predetermined concentration of fumigation gas is filled, and after a certain period of time, the gas is discharged outside the room.

Gas is discharged using a dedicated exhaust system instead of a normal air conditioner, and finally the concentration of the gas in the exhaust is reduced using a device such as a scrubber to discharge the gas to the atmosphere. ing.

[0005] These exhaust facilities are used only for exhaust gas treatment after fumigation treatment, but they are expensive as equipment investment for fumigation treatment which is usually performed only several times / year. It is.

As a device capable of decomposing harmful gases, there is an air purifier used in a normal room.

[0007] In an air purifier using a photocatalyst such as titanium dioxide, a paper or metal honeycomb supporting a photocatalyst in order to efficiently contact the air to be treated or the odor or harmful substances of the air with the photocatalyst. In addition, a breathable nonwoven fabric or paper carrying a photocatalyst is used.

[0008]

The purpose of this type of air purifier is to decompose and remove relatively low-concentration components in the air. For example, such as a fumigation gas in a clean room, a high-purity gas of 1000 ppm or more is used. It is not suitable for treating gas with a high concentration.

In order to treat a gas having a high concentration, it is necessary to increase the area of the photocatalyst, that is, the area of the above-mentioned filter and honeycomb, but there are the following problems. (1) When a filter or honeycomb having a large planar area is used, it is difficult to uniformly transmit the gas to be processed through the filter or the honeycomb surface, and the apparatus becomes large and the processing efficiency is poor. (2) If filters are used repeatedly, the pressure loss increases, and an excessively large facility such as a transmitter is required.

The present invention has been made in view of the above circumstances, and has as its object to provide a small-sized gas processing apparatus capable of efficiently decomposing harmful gases having a high concentration.

[0011]

According to a first aspect of the present invention, there is provided a gas processing apparatus, comprising: a gas passage having a spiral cross section and carrying a photocatalyst on a wall surface; a light source for irradiating the photocatalyst with light; And a blower that allows the gas to be treated to flow in from one end of the gas passage in the spiral direction and discharges the gas from the other end.

Next, the operation of the gas processing apparatus according to the first aspect will be described.

The gas processing apparatus according to the first aspect is used, for example, by being arranged in a clean room filled with fumigation gas (a harmful gas such as formalin gas).

In the gas treatment apparatus, air containing fumigation gas in the room flows in from one end in the spiral direction of the gas passage and is discharged from the other end. The harmful gas comes into contact with the photocatalyst carried on the wall of the gas passage. Decomposed and rendered harmless.

The photocatalyst has photocatalytic activity when irradiated with light from a light source.

Further, since the gas passage has a spiral shape in cross section and the gas flows from one end to the other end in the spiral direction, the pressure loss is smaller than that of a filter or a honeycomb, and the gas is retained in the gas passage. In addition, the introduced gas can be brought into uniform contact with the entire wall surface of the gas passage, whereby the harmful gas can be efficiently decomposed.

According to a second aspect of the present invention, in the gas processing apparatus according to the first aspect, a mesh supporting a photocatalyst is disposed in the gas passage.

Next, the operation of the gas processing apparatus according to the second aspect will be described.

Since the photocatalyst in the mesh decomposes the harmful gas in the gas, the processing efficiency of the harmful gas is improved.

According to a third aspect of the present invention, in the gas processing apparatus according to the second aspect, a plurality of the meshes are provided in the gas passage and are close to the light source in a transmission path of light emitted from the light source. The mesh arranged at the position is characterized in that the mesh is coarser than the mesh arranged at a position far from the light source in the light transmission path.

Next, the operation of the gas processing apparatus according to the third aspect will be described.

When a plurality of meshes are arranged at an interval in a direction away from the light source, the mesh arranged at a position far from the light source in the light transmission path is the shadow of the mesh closer to the light source in the light transmission path. Therefore, the light irradiation amount (required light energy) is reduced.

Therefore, the mesh can be efficiently illuminated on the mesh far from the light source and the wall surface on the back side of the mesh by coarsening the mesh near the light source and making the mesh far from the light source fine. .

According to a fourth aspect of the present invention, in the gas processing apparatus according to any one of the first to third aspects, the wall surface of the gas passage is formed with countless irregularities. And

Next, the operation of the gas processing apparatus according to claim 4 will be described.

In the gas processing apparatus according to the fourth aspect, since the wall surface of the gas passage is formed with innumerable irregularities, the area of the wall surface,
That is, the processing area of the harmful gas increases. Thereby, gas processing can be performed more efficiently.

According to a fifth aspect of the present invention, in the gas processing apparatus according to any one of the first to fourth aspects, at least one of the wall surface and the mesh is formed of a light transmitting material. It is characterized by having.

Next, the operation of the gas processing apparatus according to claim 5 will be described.

When the photocatalyst is a thin film that transmits light, if the wall or mesh is formed of a material that transmits light, no shadow of light is generated in the gas passage, and the light from the light source is uneven on the wall or mesh. Irradiation without treatment improves processing efficiency.

Further, when the wall surface is made of a material that does not transmit light, a large number of light sources are required so as not to cause shadows of light. Can be reduced.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the gas processing apparatus of the present invention will be described with reference to FIGS.

FIG. 2A shows a gas processing apparatus 1 according to this embodiment.
FIG. 2B is a front view of the gas processing apparatus 10.

The gas processing apparatus 10 includes a box-shaped frame 12, a blower 14, a photocatalytic reaction unit 16, and a controller 18.

The control device 18 controls the blower 14, an ultraviolet lamp 38 described later, and the like.

As shown in FIG. 1, the photocatalytic reaction unit 1
Reference numeral 6 denotes a gas passage 22 which is disposed inside the box 20 and has a spiral cross section.

The gas passage 22 of the present embodiment is a photocatalyst panel (in accordance with the present invention) in which a long plate material having a photocatalyst (not shown) supported on its surface is spirally wound a plurality of times at regular intervals. It is formed by closing both end portions in the axial direction of the (wall surface) 24 with side plates 26.

For example, in the case of metal, the photocatalyst panel 24 is obtained by forming a photocatalyst film on a surface of a plate material such as titanium, aluminum, stainless steel or the like by a spray pyrolysis method, a roller coating method, a dip coating method, or the like. be able to. Further, as the material of the plate material constituting the photocatalyst panel 24, ceramics, a polymer material (synthetic resin), or the like can be used in addition to metal.

The photocatalyst panel 24 of this embodiment has an anodic oxide film on a surface of a plate made of a titanium-containing metal material.
Further, the outermost layer has a titanium oxide thin film having photocatalytic activity.

Hereinafter, a method for forming a photocatalytic film on the surface of a plate made of a titanium-containing metal material will be described in detail.

The photocatalyst panel 24 is formed by stacking a layer having photocatalytic activity on the surface of a plate made of a titanium-containing metal material.

The plate made of a titanium-containing metal material used in the present embodiment includes pure titanium and an alloy containing titanium. By anodizing the titanium-containing metal material, an anodized film containing titanium oxide is formed on the substrate, and the titanium oxide has photocatalytic activity.

The metal material containing titanium is substantially 100%
Pure titanium made of titanium or an alloy containing titanium may be used. From the viewpoint of the photocatalytic performance of the obtained metal material, the titanium content in the entire alloy used for the substrate is 90% or more. It is preferred that

Here, “substantially” has a meaning that includes the presence of impurities and mixtures that do not impair the photocatalytic effect.

The metal constituting the alloy together with titanium is not particularly limited as long as it has good compatibility with titanium.
Depending on the purpose, for example, Ti-5Al-2.5Sn alloy, Ti-6Al-4V alloy, Ti-15Mo-5Zr
General-purpose titanium alloys such as -3Al alloy can also be used.

From the viewpoint of the photocatalytic effect, it is preferable to use an element selected from the group consisting of Group 5 to Group 11 elements and Group 14 elements which has the function of improving the photocatalytic activity when used in combination with titanium oxide. . Among them, a remarkable element for improving the photocatalytic activity, for example, platinum, gold, palladium, ruthenium, nickel, cobalt, chromium, molybdenum, and silicon are more preferable, and any one of palladium, ruthenium, nickel, and chromium is more economical. Most preferably, it is selected. Further, from the viewpoint of further developing photocatalytic activity by forming an oxide, metals such as iron, tungsten, and zinc are also preferable.

The preferable addition amount of these concomitant elements is in the range of 0.005 to 2.0% by weight of each element with respect to the whole metal material. If the addition amount is less than 0.005% by weight, it is difficult to obtain a favorable effect of improving the photocatalytic activity.

When such anodizing treatment is performed, the surface
The closer the part, the more titanium oxide [TiO _TwoIs high.
The ratio of titanium [Ti] increases inside the substrate,
Acid having photocatalytic activity on the surface part involved in photocatalytic reaction
If there is a lot of titanium oxide and it shows efficient photocatalytic activity
In both cases, the anodic oxide film is integrated with the base metal material
As a result, a photocatalytic active layer with excellent strength and durability can be formed.
It is formed.

In the present embodiment, titanium oxide is used as a substance exhibiting a photocatalytic function.
No. 0, particularly, titanium oxide,
Iron oxide, tungsten oxide, zinc oxide, strontium titanate and the like are widely known.

As the metal material having photocatalytic activity of this embodiment, a titanium-containing metal material which is a raw material of titanium oxide having particularly excellent photocatalytic effect is used. Metallic materials can also be suitably applied.

The plate made of the titanium-containing metal material is previously processed into a desired shape suitable for the intended use form, and then anodized.

Before performing the anodic oxidation treatment, a pretreatment such as a heat treatment may be performed.

The product formed into a desired shape is subjected to surface cleaning and then subjected to an oxidizing treatment. The photocatalytic activity enables uniform and dense treatment, and enables easy processing even in a complicated shape. Anodizing treatment in an electrolyte solution is preferred from the viewpoint of excellent strength of the layer having a.

By performing the oxidation treatment, the surface portion of the titanium-containing metal material is oxidized to form an anodic oxide layer containing titanium oxide.

A plate made of a titanium-containing metal material formed into a desired shape and subjected to a pretreatment is, for example, 1% by weight.
Anodizing treatment is performed in a phosphoric acid aqueous solution at a voltage of 10 to 250 V to oxidize a metal material, particularly titanium contained therein, and form a titanium oxide film (anodic oxidation film) having a thickness of several hundred angstroms to several thousand angstroms on the surface. Film).

According to this anodic oxidation treatment, fine and uniform surface oxidation can be performed, so that a metal material having a complicated shape can be easily processed into a material having a uniform and excellent photocatalytic function. .

In order to fix the anodic oxide film formed on the surface of the metal material substrate, to improve the strength and adhesion, and to improve the photocatalytic properties, after forming this anodic oxide film, the air oxidation treatment is continued. It is effective to do

This is to perform a heat treatment in the atmosphere. The processing is preferably performed at a temperature of 200 to 600 ° C. for 10 to 300 minutes, more preferably at a temperature of 230 to 300 ° C. and a processing time of 30 to 150 minutes.

On the surface of the heat-treated anodic oxide film,
To obtain more effective photocatalytic activity, a thin film containing titanium oxide powder is coated.

As a method of forming the titanium oxide powder-containing thin film, there is a method of coating the surface of the anodic oxide film by directly dispersing a titanium oxide powder having photocatalytic activity or the like in an appropriate dispersion medium.

The thickness of the titanium oxide powder-containing thin film is preferably from 200 Å to 2 μm.

If it is less than 200 angstroms, it is difficult to obtain a sufficient photocatalytic activity, and if it exceeds 2 microns, the light transmittance (transparency) of the powder-containing thin film decreases.

The titanium oxide powder used here may be modified with an element having a function of improving the photocatalytic function. These elements coexist with titanium oxide and can be a reduction reaction site in a photocatalytic reaction, and typically include elements belonging to Groups 5 to 11 and 14 of the periodic table. Platinum, gold,
It is preferable to be selected from the group consisting of palladium, silver, copper, ruthenium, nickel, cobalt, chromium, and molybdenum. Of these, platinum, gold, palladium, ruthenium, nickel, chromium,
Silver is more preferred, and palladium, ruthenium, nickel and chromium are particularly preferred in terms of ease of processing and price.

As the titanium oxide to be coated, commercially available titanium oxide powder can be used. For example, high-temperature sintering of titanium, electric oxidation, chemical vapor deposition, vacuum vapor deposition, co-precipitation, metal halogenation, inorganic metal Neutralization and hydrolysis of salts,
It can also be prepared by a conventional method such as hydrolysis of metal alkoxide and sol-gel method.

The modification of titanium oxide with the above-mentioned elements can be performed by a known method such as an impregnation method, a precipitation method, an ion exchange method, a photoelectric deposition method, a kneading method and the like.

In the present embodiment, the method of forming the titanium oxide powder-containing thin film on the surface of the anodic oxide film is at least one of a spray coating method, a dip coating method, a spin coating method and a sputtering method. Is adopted.

A titanium oxide powder-containing thin film is formed on part or all of the surface of the anodic oxide film formed on the plate material by these methods.

The titanium oxide powder-containing thin film formed by such a method has a photocatalytic activity.
Although the structure is porous when viewed microscopically, there are many cases where there is a problem in strength and adhesion, but in the present embodiment, since an anodized film excellent in density, strength and adhesion is formed under this thin film. Excellent overall strength and adhesion can be obtained.

Further, in order to improve the strength and adhesion of the titanium oxide powder-containing thin film, it is preferable to perform a heat treatment even after the formation of the titanium oxide powder-containing thin film.

This heat treatment can be selected depending on the strength and photocatalytic performance required for the site to which the material having photocatalytic activity is applied. As in the case of the above-mentioned atmospheric oxidation treatment, the heat treatment is performed at 200 to 600 ° C. 10-30 in the temperature range of
It is preferably performed in the range of 0 minutes, more preferably, the temperature is in the range of 230 to 300 ° C, and the processing time is 30 to
The range is 150 minutes.

The heating time is less than 10 minutes or the temperature is 200
When the temperature is lower than ° C, the film strength and adhesion are insufficiently improved, and when the temperature exceeds 600 ° C, the color tone of the underlying anodic oxide film turns gray.

Further, even if the heat treatment is carried out for more than 150 to 300 minutes, the effect is not improved, which is not preferable from an economic viewpoint.

The heat treatment is performed, for example, in an electric furnace for about 30 minutes.
It is preferable to carry out for up to 150 minutes and then gradually cool to room temperature.

Rapid cooling is not preferable because cracks occur due to the difference in the coefficient of thermal expansion between the film and the substrate, and the adhesion decreases.

By setting the thickness of the thin film to about several microns, the thin film has transparency and photocatalytic activity.

Therefore, high photocatalytic performance can be achieved by the two-layer structure of the thin film and the anodic oxide film.

After forming the titanium oxide powder-containing thin film,
In the case where the heat treatment is performed in the atmosphere as described above, the heat treatment after forming the anodic oxide film can be omitted. That is, two types of anodized film and titanium oxide powder-containing thin film
By performing heat treatment after the formation of the layer, a metal material having photocatalytic activity having similar characteristics can be obtained.

As shown in FIGS. 1 and 3, a plurality of holes 28 are spirally arranged in the side plate 26, and a rubber packing 30 is press-fitted into these holes 28.

A groove 32 is formed in the rubber packing 30, and an edge portion of the photocatalyst panel 24 is inserted and supported in the groove 32.

Further, a plurality of lamp insertion holes 34 are formed in the side plate 26 along the spiral direction, and a rod-shaped ultraviolet lamp (for example, black light, Germicidal lamp, etc.) 38
Is inserted.

Since the ultraviolet lamp 38 can also be expected to decompose gas by the ultraviolet light itself, a lamp capable of irradiating ultraviolet light of 250 nm or less is used.

Further, the photocatalyst surface of the photocatalyst panel 24 is irradiated.
UV intensity is 30μW / cm ^TwoTo be more than
An ultraviolet lamp 38 is provided.

As shown in FIG. 3, a rubber sheet 39 is adhered to the inner surface of the side plate 26,
In addition, a sealant for closing a gap between the rubber packing 36 and the side plate 26 is provided on the outer peripheral surface. Further, a sealing agent 37 for closing a gap between the ultraviolet lamp 38 and the rubber packing 36 is also provided on the outer peripheral surface.

As shown in FIGS. 1 and 4, a cylindrical pipe 42 is provided at the axis of the photocatalyst panel 24.

As shown in FIG. 1 and FIG.
Has one end connected to the suction side of the blower 14 and the other end closed.

As shown in FIG. 2, an exhaust duct 44 is connected to the exhaust side of the blower 14.

As shown in FIG. 1, a slit-shaped suction port 46 is formed on the outer peripheral surface of the pipe 42 along the axial direction.

The pipe 42 is, as shown in FIG.
It is inserted into the hole 50 of the side plate 26 via a rubber packing (not shown).

An intake duct 54 is connected to the outer peripheral side of the photocatalyst panel 24 via a filter 52 for removing dust and the like in the air flowing in. (Operation) Next, the operation of the gas processing apparatus 10 of the present embodiment will be described.

The gas treatment apparatus 10 is disposed in, for example, a clean room fumigated with formalin gas, and can be used to decompose and detoxify formalin gas in the room.

First, the gas processing apparatus 10 is placed in a clean room, the ultraviolet lamp 38 is turned on, and the blower 14 is operated. The ultraviolet lamp 38 is preferably turned on at least 30 times before the blower 14 is operated. When the ultraviolet lamp 38 is turned on, ultraviolet light emitted from the ultraviolet lamp 38 is irradiated on the photocatalyst panel 24, and the photocatalyst carried on the panel surface exhibits photocatalytic activity.

When the blower 14 operates, the intake duct 54
Air containing more formalin gas in the room is sucked, and dust is removed by the filter 52, and then flows into the gas passage 22.

The air containing formalin gas flows through the gas passage 22 from the outer side to the inner side, and contacts the photocatalyst of the photocatalyst panel 24 during this time, and the formalin gas (HCHO)
Is decomposed into carbon dioxide (CO ₂ ) and water (H ₂ O) to make it harmless, and is discharged indoors through the suction port 46 and the blower 14.

By circulating the air in the clean room with the gas processing device 10, the formalin gas in the clean room can be decomposed and made harmless.

In the gas processing apparatus 10 of the present embodiment, the gas passage 22 has a spiral shape in cross section, and the gas flows from one end to the other end in the spiral direction. Therefore, pressure loss is smaller than that of a filter or a honeycomb, and The gas that has flowed in can be brought into uniform contact with the entire wall surface of the gas passage 22 without stagnation of the gas in the gas passage 22, so that the formalin gas can be decomposed efficiently. (Other Embodiments) As shown in FIGS. 5A and 5B, in this embodiment, a photocatalyst mesh 40 is provided between the ultraviolet lamps 38 in the gas passage 22.
A to 40D are provided.

The photocatalyst meshes 40A to 40D are elongated in the axial direction of the photocatalyst panel 24 (the front and rear directions in FIG. 5A), and the surface of the mesh made of the same material as the photocatalyst panel 24 has a photocatalyst ( (Not shown).

The photocatalyst meshes 40A and 40D near the photocatalyst panel 24 are connected to the photocatalyst mesh 40 near the center of the passage.
B, coarser than 40C. The photocatalyst meshes 40 </ b> A to 40 </ b> D are curved so as to be parallel to the photocatalyst panel 24.

In this embodiment, when the ultraviolet lamp 38 is turned on, the ultraviolet light emitted from the ultraviolet lamp 38 is applied to the wall surface of the photocatalyst panel 24 and the photocatalyst meshes 40A to 40A.
Irradiated to D, the photocatalysts supported on these surfaces exhibit photocatalytic activity.

The ultraviolet rays (arrow L) reflected by the photocatalyst panel 24 are reflected on the photocatalyst meshes 40A, 40A near the wall.
D, and the ultraviolet light transmitted through the eyes of the photocatalyst meshes 40A and 40D is applied to the photocatalyst meshes 40B and 40C disposed between the photocatalyst meshes 40A and 40D.
Is irradiated. Here, the photocatalyst meshes 40A and 40D close to the ultraviolet lamp 38 in the passage of the reflected ultraviolet light are coarse and the photocatalyst mesh 40 disposed behind the photocatalyst mesh 40A, 40D is roughened.
Since the eyes of B and 40C are made finer, the entirety of the plurality of photocatalyst meshes 40A to 40D can be efficiently irradiated with ultraviolet rays.

By increasing the mesh size near the ultraviolet lamp 38, it is possible to prevent the required light energy from reaching the photocatalyst panel 24.

The formalin gas in the air comes into contact with the photocatalyst panel 24 and the photocatalyst of the photocatalyst meshes 40A to 40D and is decomposed and made harmless.
Is discharged into the room through

In this embodiment, the photocatalyst mesh 40A
Since the photocatalyst area was increased by providing ~ 40D, formalin gas could be decomposed more efficiently.

In this embodiment, the photocatalyst meshes 40A to 40D are parallel to the wall of the spiral gas passage 22.
To increase the photocatalyst area, but not limited to this,
As shown in FIG. 6, planar photocatalyst meshes 58 </ b> A to 58 </ b> C oriented in the radial direction of the photocatalytic reaction unit 16 may be arranged between the ultraviolet lamps 38 in the gas passage 22. In this case, the meshes of the photocatalyst meshes 58A and 58C near the ultraviolet lamp 38 are coarse and the meshes of the photocatalyst mesh 58B far from the ultraviolet lamp 38 are finely set so that the entire photocatalyst meshes 58A to 58C are irradiated with ultraviolet rays.

As shown in FIGS. 7A and 7B,
The photocatalyst meshes 60 </ b> A to 60 </ b> C rolled into a cylindrical shape are placed between the ultraviolet lamps 38 in the gas passage 22.
They may be arranged in an arc along the wall surface. In this case, the meshes of the photocatalyst meshes 60A and 60C near the ultraviolet lamp 38 are coarse and the photocatalyst mesh 60 far from the ultraviolet lamp 60 is coarse.
The eyes of B are set finely, and the photocatalyst meshes 60A to 60C
It is preferable that the entire surface be irradiated with ultraviolet rays.

Further, as shown in FIG. 8, cylindrically rounded photocatalyst meshes 62A to 62D are arranged between the ultraviolet lamps 38 in the gas passage 22 in an arc shape while being alternately shifted left and right. Is also good.

In each of the above embodiments, the photocatalyst meshes 40A to 40D and the photocatalyst mesh 58 are provided in the gas passage 22 in order to increase the photocatalyst area within a predetermined volume.
A to 58C, the photocatalyst meshes 60A to 60C, and the photocatalyst meshes 62A to 62D are arranged. As shown in FIG. 9, the countless projections 64 (and / or dimples such as golf ball dimples) are formed on the surface of the photocatalyst panel 24, as shown in FIG. A concave portion may be formed (if a plate material is pressed, the opposite surface of the convex portion 64 becomes the concave portion 66).
Thereby, the surface area of the photocatalyst panel 24, that is, the photocatalyst area can be increased.

In each of the above embodiments, the photocatalyst panel 24, the photocatalyst meshes 40A to 40D, the photocatalyst meshes 58A to 58C, the photocatalyst meshes 60A to 60C, and the photocatalyst meshes 62A to 62D are made of titanium material and are opaque. However, the material is not limited to this, and may be a transparent material such as glass or synthetic resin.

When the photocatalyst panel 24 is formed of a transparent material that transmits ultraviolet light, and when the photocatalyst is a thin film that transmits light, a shadow of light (that is, a portion that is not irradiated with ultraviolet light) is formed inside the gas passage 22. The ultraviolet light emitted from the ultraviolet lamp 38 is uniformly applied to the wall surface and the photocatalyst mesh, thereby improving the processing efficiency.

When the photocatalyst panel 24 is made of a material that does not transmit light, a large number of ultraviolet lamps 38 are required to prevent the shadow of light. However, when the photocatalyst panel 24 is transparent, almost no shadow is generated. Therefore, the number and the wattage of the ultraviolet lamps 38 can be reduced, and the apparatus cost and the operating cost can be reduced.

When the photocatalyst panel 24 is transparent, the ultraviolet lamp 38 can be disposed outside the photocatalyst panel 24 without being disposed in the gas passage 22. By doing so, it is possible to reduce the air resistance of the gas passage 22 and increase the amount of blown air. In this case, it is preferable that the inner surface of the box 20 be a mirror surface, silver color, white color, or the like that easily reflects ultraviolet rays.

When the photocatalyst is supported on a transparent material such as glass or synthetic resin, for example, the photocatalyst meshes 40A to 40D may be made of a plate material.

When the photocatalyst panel 24 is made of metal or the like,
The panel surface may be finished to a mirror surface that easily reflects light, and a transparent photocatalyst may be supported here. By doing so, light is reflected in various directions, and the shadow of light can be reduced,
This also improves processing efficiency.

In the above embodiment, the gas processing device 1
0 was used for the decomposition of formalin gas that was subjected to fumigation treatment in a clean room. However, the present invention is not limited to this, and is applicable to all decomposition of gases that can be decomposed by a photocatalyst. Of course, it is good. (Test Example) In order to confirm the effect of the present invention, as shown in FIG. 10, formalin gas was supplied to the photocatalytic reaction unit 16 and the blower 14 having the structure described in the above embodiment by about 890 p.
Gas generating tank 68 filled with air containing pm and duct 70
Were connected to form a closed-loop formalin gas decomposition test apparatus, and the decomposition rate of formalin gas was measured. The arrow in FIG. 10 indicates the direction in which air flows.

[0113] In this test apparatus, the air blowing amount of the blower 14 is 10 m ³ / min, the volume of the gas generating tank 1 m ³
It is.

The photocatalyst of the photocatalytic reaction unit 16 uses TiO ₂ , and the area of the photocatalyst is 5 m ² ×
2 (front and back), open cylindrical mesh (pitch of mesh wire: 2 mm; diameter: 30 mm x length: 450 mm) 5
0 and a fine cylindrical mesh (pitch of mesh wire: 0.5 mm; diameter: 30 mm x length: 450 mm) 5
0 are located in the passage. The width of the passage is 70
cm, thickness 7 cm, total extension 7 m. In addition, 27 ultraviolet lamps of 20 W were used.

The ultraviolet lamp was turned on three minutes before the operation of the blower 14 to decompose impurities on the photocatalyst surface in advance, and then the blower 14 was operated to start decomposing formalin gas.

The concentration of formalin gas in the apparatus was measured at regular intervals, and the results shown in the graph of FIG. 11 were obtained. The concentration of formalin gas was measured using a detector tube.

As a result of the test, about 12
After a minute, the concentration of formalin gas in the apparatus reached 0 ppm (measurement limit), which proved that a high-concentration formalin gas could be decomposed in a short time even with a small size.

[0118]

As described above, the gas processing apparatus of the present invention has an excellent effect that, despite its small size, high-concentration harmful gases can be efficiently decomposed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a photocatalytic reaction unit of a gas processing apparatus according to one embodiment of the present invention.

FIG. 2A is a side view of a gas processing apparatus according to an embodiment of the present invention, and FIG. 2B is a front view of the gas processing apparatus.

FIG. 3 is a sectional view of a side plate portion of the photocatalytic reaction unit.

FIG. 4 is a sectional view of a photocatalytic reaction unit.

FIG. 5A is a cross-sectional view of a part of a photocatalytic reaction unit of a gas processing apparatus according to another embodiment, and FIG. 5B is a perspective view of a mesh provided inside the photocatalytic reaction unit. .

FIG. 6 is a cross-sectional view of a part of a photocatalytic reaction unit of a gas processing apparatus according to still another embodiment.

FIG. 7A is a cross-sectional view of a part of a photocatalytic reaction unit of a gas processing apparatus according to still another embodiment, and FIG.
FIG. 3 is a perspective view of a mesh provided inside the photocatalytic reaction unit.

FIG. 8 is a cross-sectional view of a part of a photocatalytic reaction unit of a gas processing apparatus according to still another embodiment.

FIG. 9 is a perspective view of a photocatalytic panel of a gas processing apparatus according to still another embodiment.

FIG. 10 is a schematic configuration diagram of a formalin gas decomposition test apparatus.

FIG. 11 is a graph showing the relationship between the concentration of formalin gas and the operation time of the test apparatus.

[Explanation of symbols]

 Reference Signs List 10 gas treatment device 14 blower (blower) 22 gas passage 24 photocatalyst panel (wall surface, photocatalyst) 38 ultraviolet lamp (light source) 40A mesh 40B mesh 40C mesh 40D mesh 58A mesh 58B mesh 58C mesh 60A mesh 60B mesh 60C mesh 62A mesh 62A mesh 62C mesh 62D mesh 64 Convex part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Nakamura 4-1-1-13, Honcho, Chuo-ku, Osaka-shi, Osaka Inside the Osaka head office of Takenaka Corporation (72) Inventor Yasuhiro Nishimura 4 Honcho, Chuo-ku, Osaka-shi, Osaka No. 1-113, Takenaka Corporation Osaka Main Store (72) Inventor Yohei Sasaki 8-21-1, Ginza, Chuo-ku, Tokyo Inside Tokyo Main Store Takenaka Corporation (72) Inventor Koji Miyoshi Central Tokyo 8-21-1, Ginza-ku, Tokyo Takenaka Corporation Tokyo Main Branch (72) Inventor Yoshimasa Ito 1-8-2 Marunouchi, Chiyoda-ku, Tokyo Kobe Steel, Ltd.Tokyo Head Office (72) Inventor Hiroyuki Takahara 100-1 Miyamae, Fujisawa-shi, Kanagawa F-term in Shinko Actec Co., Ltd. (Reference) 4C080 AA07 AA10 BB02 CC02 CC12 JJ03 KK08 MM02 QQ11 QQ17 QQ20 4D048 AA17 AA19 AB0 1 AB03 BA07X BA13X BA41X BB05 BB07 CC21 CC23 CC36 CC38 CC45 CC63 EA01 4G069 AA03 BA04A BA04B BA18 BA48A CA07 CA10 CA11 CA17 EA06 EA12 EB03 EE08

Claims (5)

[Claims] 1. A gas passage having a spiral cross section and carrying a photocatalyst on a wall surface; a light source for irradiating light to the photocatalyst on the wall surface; A gas blower for inflowing a gas to be processed and discharging the gas from the other end. 2. The gas processing apparatus according to claim 1, wherein a mesh supporting a photocatalyst is disposed in the gas passage. 3. A plurality of meshes are provided in the gas passage, and a mesh disposed at a position close to the light source in a transmission path of light emitted from the light source is far from the light source in a transmission path of the light. The gas processing apparatus according to claim 2, wherein the mesh is coarser than the mesh arranged at the position. 4. The gas processing apparatus according to claim 1, wherein a number of irregularities are formed on a wall surface of the gas passage. 5. The gas processing apparatus according to claim 1, wherein at least one of the wall surface and the mesh is formed of a material that transmits light.