JP5674749B2 - Air purification device - Google Patents

Description

The present invention relates to an air purification device that purifies air by the function of a photocatalyst.

Photocatalysts such as titanium oxide exhibit a function of decomposing organic substances when irradiated with light. Many various products using this function of the photocatalyst have been proposed. Among these products, devices and filters that purify air by decomposing odor (organic matter) components in the air with a photocatalyst have been actively developed. As such a thing, what improves a deodorizing rate by combining a photocatalyst with an adsorbent (refer patent document 1), or what improves the decomposition rate of ethylene by combining a photocatalyst and a zeolite (patent document) 2) has been proposed.

JP-A-1-189322 JP 7-16473 A

However, since the conventional air purification apparatus has a structure that allows air to pass through the base material to which the photocatalyst is attached, many catalysts cannot be attached to the base material, and the purification performance is insufficient. Moreover, since the function of the photocatalyst is expressed using a light source such as black light, improvement is desired from the viewpoint of running cost.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an air purification device that has excellent purification performance and can reduce running costs.

An air purification apparatus according to the present invention that meets the above-described object has a box having an air intake port and an air discharge port on a side plate, and a light intake window in which a top plate is formed of a transparent plate , and the air In an air purification apparatus comprising a plate material that purifies air from an intake port and discharges it from the air discharge port,
The plate material is dispersed and adhered to a porous substrate containing hydrophobic zeolite (adsorbent) at 70% by mass or more and cement as a binder at 5% to 30% by mass, and one surface of the substrate is sprayed. And titanium dioxide that functions as a photocatalyst,
In the box, the bottom plate and the side plate are in a rectangular parallelepiped shape made of a metal member made of iron, aluminum, copper, titanium, or an alloy thereof, and are inclined in a range of 10 degrees to 50 degrees, and the box the drain hole is provided in the lower edge portion, Rutotomoni is disposed said plate member along the air flow path formed in a zig-zag pattern on the box making the body by a partition plate disposed perpendicularly to the bottom plate, The plate material is arranged in a wave shape when viewed from the direction of air flow so that one surface on which the titanium dioxide is adhered is opposed to the light intake window, and the upper and lower sides of the plate material arranged in the wave shape are fixed on the upper side. The organic matter fixed by the member and the lower fixing member and adsorbed on the other surface side of the substrate is released from the one surface side and decomposed by the titanium dioxide.

According to the air purification apparatus of the present invention, since the plate material has the adsorbent and the photocatalyst, it can be decomposed by the photocatalyst while adsorbing organic substances contained in the air such as exhaust gas. In particular, the plate material is arranged along the air flow path, that is, the air to be purified is structured to flow along this plate material, so use a plate material with a sufficient amount of photocatalyst attached. Can improve the purification performance. Moreover, since sunlight can be taken in and the function of a photocatalyst can be expressed, running cost can be suppressed. Note that “one surface side of the plate material faces the light intake window” means that when one side of the plate material is viewed from the outside of the light intake window, the one surface side of the plate material is visible. The plate is not limited to a state in which one surface of the plate faces in parallel with the light intake window.

In the air purification apparatus according to the present invention, it is preferable that the plate material is disposed in a wave shape or a zigzag shape in the air flow direction. By doing in this way, both the irradiation area of the light to a board | plate material and the contact area with the distribute | circulating air can be increased, and purification performance can further be improved. Here, “the plate material is disposed in a wave shape or a zigzag shape” is not limited to a plurality of plates arranged in a wave shape or a zigzag shape, and other one wave plate or the like is left as it is. It also includes being disposed.

In the air purification apparatus according to the present invention, it is preferable that the box has a metal member exposed on the inner surface side and having a specific heat smaller than that of the adsorbent. The air purification apparatus according to the present invention is usually installed outdoors because it is operated by sunlight. For this reason, there is a high possibility that condensation will occur inside the box due to a difference in temperature between day and night, and this condensation may be adsorbed by the adsorbent, and the functions of the adsorbent and the photocatalyst may deteriorate. Thus, by arranging a metal member having a small specific heat in the box in this way, condensation can be preferentially generated on the surface of the metal member, and the occurrence of condensation on the plate material can be suppressed. In addition, by having a metal member with a small specific heat, when the temperature rises in the morning or when supplying high-temperature exhaust gas, the temperature inside the box rises quickly, and the resulting condensation evaporates in a relatively short time. Can be made.

In the air purification apparatus according to the present invention, it is also preferable that the metal member is a fixing member that fixes the plate member. By doing in this way, stability of a board | plate material can improve and the above-mentioned effect | action can fully be expressed.

In the air purification apparatus according to the present invention, the plate member has a substrate containing the adsorbent, and the photocatalyst adheres to the one surface side of the plate member by application or spraying to the one surface side of the substrate. ing. In this way, the adsorbent is sufficiently present on the other surface side of the substrate, while the photocatalyst does not adhere or decreases. Therefore, even when condensation occurs, moisture is preferentially adsorbed on the other surface side of the substrate, and the influence on the photocatalyst adhering to the one surface side can be suppressed.

In the air purification apparatus according to the present invention, since the adsorbent has hydrophobicity, adsorption of moisture to the adsorbent is suppressed, and purification performance can be improved.

In the air purifying apparatus according to the present invention, the box is inclined. By doing in this way, the taking-in efficiency of sunlight can be improved. Further, since the bottom plate of the box is also inclined, the dew condensation generated on the bottom plate can be efficiently and easily discharged outside the box.

The air purification apparatus according to the present invention has high purification performance and can reduce running costs.

1 is a schematic plan view of an air purification device according to an embodiment of the present invention. It is AA arrow line schematic sectional drawing of the air purification apparatus. It is a typical side view which shows the installation state of the air purification apparatus. It is a schematic diagram of the high-speed thermal spraying apparatus used for manufacture of the air purification apparatus.

Next, embodiments of the present invention will be described with reference to the accompanying drawings. As shown in FIG.1 and FIG.2, the air purification apparatus 10 which concerns on one embodiment of this invention is the box 11, the three partition plates 12a-12c arrange | positioned in the box 11, and adsorption | suction 16 plate members 13 having an agent and a photocatalyst are mainly provided.

The box 11 is a substantially rectangular parallelepiped, and includes a light intake window 14 serving as a top plate, four side plates 15 a to 15 d, and a bottom plate 16. Further, the box 11 has an air intake port 17 and an air exhaust port 18 provided in one side plate 15a.

The size of the box 11 is not particularly limited, and can be appropriately set according to the installation location, the amount of air (exhaust gas etc.) to be processed, and the like. For example, it can be 50 cm to 2 m in length, 1 m to 10 m in width, and 5 cm to 30 cm in height.

The light intake window 14 is a rectangular plate-shaped body made of a transparent material. The material of the light intake window 14 is not particularly limited as long as it is transparent and has predetermined strength and durability. Examples thereof include glass, synthetic resins such as acrylic resin, PET resin, and polyolefin resin. be able to.

The four side plates 15 a to 15 d are rectangular plate-like bodies, and are arranged so as to connect the respective edges of the light intake window 14 and the respective edges of the bottom plate 16. The material of the side plates 15a to 15d is not particularly limited, and may be transparent or opaque. Specific examples of the material for the side plates 15a to 15d include metal, ceramics, glass, synthetic resin, and wood. Metal is preferable, and metal having a specific heat smaller than that of the adsorbent included in the plate 13 is more preferable. By using such a metal member for the side plates 15a to 15d, condensation is preferentially generated on the surfaces of the side plates 15a to 15d at night and the like, and the occurrence of condensation on the plate material 13 can be suppressed. Further, by having the metal side plates 15a to 15d having a small specific heat, the temperature inside the box 11 rises rapidly when the temperature rises in the morning or when high temperature exhaust gas is supplied, and the resulting condensation is relatively short. Can be evaporated in time.

Examples of the metal member used for the side plates 15a to 15d include iron, aluminum, copper, titanium, or an alloy thereof (stainless steel, galvalume steel, etc.). Further, the metal member may be subjected to a surface treatment such as plating or resin coating in order to prevent corrosion.

At both ends of one side plate 15a, an air intake port 17 for taking in air (exhaust gas or the like) into the box 11 and an air discharge port 18 for discharging this air once taken out of the box 11 are provided. ing. The air intake 17 is connected to a duct 24 for exhaust gas from a factory. The air intake port 17 may be provided with a flow rate adjustment valve for adjusting the amount of air to be taken in. The air discharge port 18 is formed so that the bottom plate 16 side (the back side in FIG. 1) is open and air is discharged substantially downward.

The bottom plate 16 is a plate-like body that is disposed opposite to the light intake window 14 (top plate) and has the same shape (rectangle) as the light intake window 14. Examples of the material of the bottom plate 16 include metal, ceramics, glass, synthetic resin, and wood, but for the same reason as the side plates 15a to 15d, metal is preferable, and specific heat is higher than the adsorbent of the plate material 13. Smaller metals are more preferred. Examples of the metal member used for the bottom plate 16 include iron, aluminum, copper, titanium, and alloys thereof (stainless steel, galvalume steel, etc.). Further, the metal member may be subjected to a surface treatment such as plating or resin coating in order to prevent corrosion.

A plurality of drain grooves are formed at substantially equal intervals in a portion where the side plates 15d are laminated on the inner surface of the bottom plate 16 (lower end edge portion when being inclined as shown in FIG. 3). A drain hole is formed by the drain groove and the bottom surface of the side plate 15 d, and the dew condensation that occurs on the inner surface of the bottom plate 16 when it is disposed at an inclination can be discharged out of the system (outside the box 11).

One or more fine grooves may be formed on the entire inner surface of the bottom plate 16. This groove can function as a flow path for condensation. This groove may be formed integrally with the drain groove. Since the bottom plate 16 has the groove on the entire inner surface in this way, the dew condensation generated on the surface of the bottom plate 16 can be efficiently discharged outside the system (outside the box 11) through the groove. This groove can be formed, for example, the same as or inclined with respect to the inclination direction (width direction) of the box 11.

The three partition plates 12a to 12c are provided in parallel with each other at equal intervals along the longitudinal direction of the box 11 (in a direction perpendicular to the one side plate 15a). Further, the partition plates 12 a to 12 c are arranged perpendicular to the bottom plate 16. The length of the partition plates 12 a to 12 c is slightly shorter than the length of the bottom plate 14 in the longitudinal direction. The partition plates 12a and 12c are arranged so as to be connected to the side plate 15a and not to be connected to the side plate 15c at a position facing the side plate 15a. Moreover, the partition plate 12b is arrange | positioned so that it may not connect with the side plate 15a, but may connect with the side plate 15c in the position which opposes the side plate 15a. By arranging the partition plates 12a to 12c in this way, the air taken in from the air intake port 17 flows in a zigzag manner so as to reciprocate between the side plates 15a and 15c in the box 11, An air flow path is formed so as to be finally discharged from the air discharge port 18.

It does not specifically limit as thickness of partition plates 12a-12c, For example, it is about 3 mm or more and 3 cm or less. Further, the height of the partition plates 12a to 12c is such a height as to contact both the light intake window 14 and the bottom plate 16 of the box 11. That is, the height of the partition plates 12 a to 12 c is equal to the height of the side plates 15 a to 15 d of the box 11.

The material of the partition plates 12a to 12c is not particularly limited, and examples thereof include metals, ceramics, glass, synthetic resins, and wood. In addition, for the same reason as the side plates 15a to 15d, it can be made of metal. Moreover, it is good also as a partition plate which has an adsorbent and / or a photocatalyst. As the partition plate having the adsorbent and / or the photocatalyst, a plate material similar to the plate material 13 described in detail later can be used.

Each plate 13 has an adsorbent and a photocatalyst, and this photocatalyst is attached to at least one surface side. Each plate member 13 is disposed along the longitudinal direction of the box 11, that is, in parallel with the partition plates 12 a to 12 c. By being arranged in this way, the plate 13 is arranged along (in parallel with) the air flow path formed by the box 11 and the partition plates 12a to 12c. There are four plate members 13 between the side plate 15b and the partition plate 12a, between the partition plate 12a and the partition plate 12b, between the partition plate 12b and the partition plate 12c, and between the partition plate 12c and the side plate 15d. It is arranged one by one. Each of the four plate members 13 is arranged so as to form a mountain (ridge) by two pieces. By doing in this way, the several board | plate material 13 will be arrange | positioned by the zigzag shape by air flow direction view (longitudinal direction view in the box 11, sectional shape of FIG. 2). Moreover, it arrange | positions so that the one surface side to which the photocatalyst adheres may oppose the light intake window 14 (top plate) (one surface becomes the front side in FIG. 1, and the upper side in FIG. 2).

The length of the plate member 13 disposed between the side plate 15b and the partition plate 12a is the same as that of the partition plates 12a to 12c, and these are disposed so as to contact the side plate 15a and not contact the side plate 15c. The length of the plate member 13 disposed between the partition plate 12c and the side plate 15d is also the same as that of the partition plates 12a to 12c, and these are disposed so as to contact the side plate 15a and not to contact the side plate 15c. Moreover, the length of the board | plate material 13 arrange | positioned between the partition plate 12a and the partition plate 12b and between the partition plate 12b and the partition plate 12c is shorter than the partition plates 12a-12c, and these are side plate 15a and 15c. It is arranged not to touch.

The thickness of the plate 13 is not particularly limited, and can be, for example, 1 mm or more and 2 cm or less.

The plate member 13 is formed by adsorbing an adsorbent and a photocatalyst on at least one surface side of a substrate formed of glass, ceramics, metal, synthetic resin, etc., or at least one surface side of the substrate containing the adsorbent For example, the latter (having a substrate containing an adsorbent, and the photocatalyst is attached to one surface of the substrate) is preferable. In this way, the adsorbent is sufficiently present on the other surface side of the substrate, while the photocatalyst is not attached or reduced. Therefore, even when condensation occurs, moisture is preferentially adsorbed on the other surface side of the substrate, and the influence on the photocatalyst adhering to the one surface side can be suppressed.

As the adsorbent, known materials such as activated carbon, silica gel, and zeolite can be used. Among these, zeolite is preferable. As the zeolite, for example, one having a bulk specific gravity of 0.6 to 0.8 g / cm ³ , a specific surface area of 200 to 400 m ² / g, and a pore diameter of 5 to 10 mm can be used.

Moreover, as an adsorbent, what has hydrophobicity is preferable. By doing in this way, adsorption | suction of the water | moisture content to adsorption agent is suppressed, and purification performance can be improved. Hydrophobic adsorbents include hydrophobic zeolites with a high silica / alumina ratio (for example, HSZ series manufactured by Tosoh Corporation), and adsorbents such as zeolite that have been hydrophobized with a water repellent. Can be used. Examples of the water repellent include alkoxysilanes such as methyltrimethoxysilane and phenyltriethoxysilane, and silazanes such as hexamethyldisilazane. In addition, you may perform the hydrophobization process by this water repellent with respect to the board | substrate containing adsorption agent.

Examples of the substrate containing an adsorbent include a substrate made only of an adsorbent such as silica gel and zeolite, and a substrate containing an adsorbent such as silica gel and zeolite and other inorganic materials (cement, pearlite, etc.). . In addition, when a cement is included as another inorganic material, this cement functions as a binder of an adsorbent. Moreover, when pearlite is included, the porous property can be improved and the weight can be reduced. The content of the adsorbent such as zeolite in the substrate is preferably 50% by mass or more, and more preferably 70% by mass or more. The cement content in the substrate is preferably 5% by mass or more and 30% by mass or less. When the cement content is less than 5% by mass, the binder function may not be sufficiently exhibited. Conversely, if the cement content exceeds 30% by mass, the adsorptivity and the like may be reduced. The substrate may further contain other components such as waste paper.

The substrate is preferably porous. When such a porous substrate is used, the organic matter adsorbed on the other surface side to which the photocatalyst is not attached can be released from the one surface side to which the photocatalyst is attached, and this organic matter is decomposed. Can be done effectively.

The photocatalyst is not particularly limited as long as it is a compound having a photocatalytic function, and a known one can be used. Here, the photocatalytic function is a photo-semiconductor material, and when irradiated with light having energy larger than the band gap energy between the valence band and the conduction band, the electrons in the valence band are excited and conducted. It means a function of inducing a redox reaction by transitioning to a band to become excited electrons, generating electron-hole pairs between holes formed in the valence band and excited electrons. Examples of such a compound include titanium dioxide, tungsten oxide, tin oxide and the like, and titanium dioxide is preferable. Examples of titanium dioxide include those having a rutile crystal structure and those having an anatase crystal structure.

In addition, as the board | plate material 13, what disperse | distributed titanium dioxide as a photocatalyst by the thermal spraying etc. with respect to the porous substrate containing a zeolite as an adsorbent is preferable. Titanium dioxide adhered to porous zeolite in a dispersed state has improved photocatalytic activity because its local structure and electronic state change continuously.

The photocatalyst is preferably a photocatalyst having visible light responsiveness. By using a photocatalyst having visible light responsiveness in this way, sunlight can be utilized more effectively during the purification action.

The photocatalyst having visible light responsiveness refers to a photocatalyst that exhibits catalytic activity when irradiated with light in the visible light (360 nm to 830 nm) region in addition to light in the ultraviolet region. Examples of such a visible light responsive photocatalyst include (1) a titanium dioxide crystal lattice doped with one or more of nitrogen, carbon, and sulfur atoms, and (2) a photocatalyst carrying a sensitizer. Can be mentioned.

The visible light responsive photocatalyst (1) can be obtained by a known production method. For example, titanium oxide can be obtained in a sulfur dope by a sol-gel method using a titanium alkoxide mixed with a sulfur source such as thiourea as a raw material.

The sensitizer carried by the visible light responsive photocatalyst (2) means a sensitizer that generates excited electrons by visible light and supplies the excited electrons to a photocatalyst such as titanium dioxide. Examples of the sensitizer include metal hydroxides such as iron, copper, chromium, and nickel, oxyhydroxides, and oxides. Specifically, for example, CuO, Cu (OH) ₂ , FeO (OH), Fe (OH) ₃ , Ni (OH) ₂ , NiO (OH), Cr (OH) ₃ , Cr ₂ O (OH) ₄ , Cr ₂ O _{3 and the} like can be mentioned.

As a method for adsorbing the adsorbent or the photocatalyst to the substrate, a known method such as coating or spraying can be used. Among these, it is preferable to adhere by thermal spraying. By using the thermal spraying method, it is possible to suppress the use of binder components and the like, and the photocatalyst permeates into the substrate from the sprayed substrate surface, so that the exposure amount and adhesion amount of the photocatalyst can be increased, and the decomposition performance is improved. . An example of a specific procedure when the thermal spraying method is used will be described later.

The box 11 further includes a plurality of bar-shaped upper fixing members 19 and a plurality of bar-shaped lower fixing members 20. Each upper fixing member 19 and lower fixing member 20 are arranged between the side plate 15b and the partition plate 12a, between the partition plate 12a and the partition plate 12b, and between the partition plate 12b and the partition plate 12c in the width direction of the box 11. And four each between the partition plate 12c and the side plate 15d. In addition, four upper fixing members 19 and lower fixing members 20 are arranged at substantially equal intervals in the longitudinal direction of the box 11. Further, each upper fixing member 19 fixes the plate member 13 from above by a groove structure portion 22 provided in a direction perpendicular to the partition plates 12a to 12c and the plate member 13 in a plan view and below the upper fixing member 19. Is arranged. In addition, each lower fixing member 20 causes the plate member 13 from the lower side by a groove structure portion 23 provided in a direction perpendicular to the partition plates 12a to 12c and the plate member 13 in a plan view and on the upper side of the lower fixing member 20. It is arranged to be fixed.

The material of the upper fixing member 19 and the lower fixing member 20 is not particularly limited, and examples thereof include metal, ceramics, glass, synthetic resin, and wood. Metal is preferable, and the adsorbent that the plate member 13 has. A metal having a lower specific heat is more preferable. By using such a metal member for the upper fixing member 19 and the lower fixing member 20, condensation is preferentially generated on the surfaces of the upper fixing member 19 and the lower fixing member 20 at night and the like, and condensation on the plate 13 is performed. Can be suppressed. Further, by having the metal upper fixing member 19 and the lower fixing member 20 having a small specific heat, when the temperature rises in the morning, etc., or when high-temperature exhaust gas is supplied, the temperature rise inside the box 11 is accelerated, and occurs. Condensation can be evaporated in a relatively short time.

As shown in FIG. 3, the air purification apparatus 10 is arrange | positioned on the inclination stand 21 so that the box 11 may incline in use. At this time, the air intake port 17 is arranged on the upper side and the air discharge port 18 is arranged on the lower side so as to be inclined in the width direction of the box 11. The inclination angle θ may be set as appropriate according to the place (latitude) used, the season, etc., and may be, for example, 10 ° to 50 °.

According to the air purification device 10, since the plate member 13 has the adsorbent and the photocatalyst, it can be decomposed by the photocatalyst while adsorbing organic substances contained in the air such as exhaust gas taken in from the air intake port 17. In particular, the plate member 13 is arranged along an air flow path formed by the box 11 and the partition plates 12a to 12c, that is, the air to be purified flows along the plate member 13. Therefore, the plate material 13 to which a sufficient amount of the photocatalyst is attached can be used, and the purification performance can be improved. Moreover, since sunlight can be taken in and the function of a photocatalyst can be expressed, running cost can be suppressed. In addition, sunlight is taken in from the light taking-in window 14, and irradiates one surface side (upper surface side in FIG. 2) to which the photocatalyst adheres in each plate member 13.

The air taken into the box 11 is surrounded by the plate 13 and the bottom plate 16, and the space on the opposite side to the one surface side of the plate 13 also circulates. However, since air mixes in the region where the partition plates 12a to 12c and the plate material 13 do not exist in the air flow path (the left and right end portions of the box 11 in FIG. 1), the decomposition proceeds sufficiently. Further, the plate material 13 is arranged in a zigzag shape as viewed from the air flow direction (viewed in the left-right direction in FIG. 1, cross-sectional shape in FIG. 2). For this reason, both the irradiation area of the light to the plate 13 and the contact area with the circulating air can be increased, and the purification performance can be further enhanced.

Here, as an example of a method for forming the plate member 13, a specific procedure in the case of using a thermal spraying method having a slurry preparation process and a thermal spraying process will be described in detail.

1. Slurry preparation process In this process, particles containing a photocatalyst and a dispersion medium are supplied to a container (for example, a stirring tank) to prepare a slurry.

The particles containing a photocatalyst include particles (photocatalyst particles) usually made of a photocatalyst, and may contain other particles (binder particles and the like).

The content of photocatalyst particles (titanium dioxide particles and the like) in the slurry is usually 1% by mass to 30% by mass, preferably 3% by mass to 15% by mass, and more preferably 5% by mass to 10% by mass. . When the content of the photocatalyst particles is less than 1% by mass, the thickness of the film obtained by thermal spraying becomes too small, and there is a possibility that sufficient functions cannot be expressed. On the other hand, when this content exceeds 30% by mass, stress is generated inside the film obtained by thermal spraying due to the difference in thermal expansion coefficient between the film obtained by thermal spraying and the substrate, and cracks are likely to occur. Become.

The diameter (secondary particle diameter) of the photocatalyst particles is, for example, from 0.5 μm to 10 μm, and more preferably from 1 μm to 5 μm. When the diameter of the photocatalyst particles is less than 0.5 μm, the kinetic energy of the particles is lowered, and the film forming property may be lowered. On the contrary, when the diameter exceeds 10 μm, the dispersibility may be lowered. The primary particle diameter of the photocatalyst particles is preferably, for example, 10 nm or more and 50 nm or less. By using photocatalyst particles having a primary particle diameter in such a range, it is possible to exhibit sufficient film forming properties and the like while suppressing manufacturing costs. In addition, the diameter of the particle | grains in this specification says the value measured by a dynamic light scattering method.

When visible light responsiveness is developed by supporting a sensitizer on the photocatalyst, a water-soluble metal complex such as iron, copper, chromium, or nickel or a water-soluble metal salt may be contained in the slurry. These water-soluble metal complexes and water-soluble metal salts react with water when sprayed to become the above-mentioned hydroxide, oxyoxide or oxide, and are supported on the photocatalyst particles as a sensitizer.

Specific examples of the water-soluble metal complex include [Cu (NH ₃ ) ₄ ] ²⁺ , [Fe (CN) ₆ ] ⁴⁻ , [Fe (CN) ₆ ] ^{3−, and the} like. Specific examples of the salt include FeCl ₃ , Fe ₂ (SO ₄ ) ₃ , Fe (NO ₃ ) ₃ , CuSO ₄ , Cu (NO ₃ ) ₂ , CuCl ₂ , Ni (NO ₃ ) ₂ , NiCl ₂ , NiSO ₄ , Cr (NO ₃ ) _{3 and the} like.

The content of the water-soluble metal complex and the water-soluble metal salt in the slurry is 0.05 parts by mass or more and 0.5 parts by mass as the metal component amount with respect to 100 parts by mass of the metal component amount (for example, titanium component amount) in the photocatalyst particles. It can be as follows.

As the dispersion medium used in the slurry, water is usually used, but other organic solvents such as alcohols and mixtures of water and organic solvents can also be used.

The slurry can further contain a surfactant in order to enhance dispersibility. Examples of the surfactant include anionic surfactants such as polycarboxylic acid-based polymer surfactants and nonionic surfactants. As content of surfactant, 0.5 mass part or more and 3 mass parts or less are preferable with respect to 100 mass parts of particle | grains containing a photocatalyst.

The slurry can be prepared by supplying particles containing a photocatalyst and a dispersion medium to a container and stirring them. In addition, you may perform ultrasonic irradiation with stirring instead of stirring.

2. Thermal spraying process In this process, the slurry containing particles containing the photocatalyst prepared in the slurry adjustment process is sprayed onto the substrate surface. Although this thermal spraying can be performed by a known method, it is preferable to perform high-speed thermal spraying at a low temperature using a high-speed thermal spraying apparatus. By performing such spraying, for example, when anatase-type titanium dioxide particles are used as the photocatalyst particles, transformation to the rutile type during spraying is suppressed, and a sprayed coating with high catalytic activity can be obtained. Hereinafter, an example of the high-speed spraying apparatus will be described with reference to FIG.

A high-speed spraying device 30 shown in FIG. 4 mainly includes a spraying gun 31 and a slurry mixing unit 32 attached to the tip of the spraying gun 31. The slurry mixing unit 32 includes a cylindrical frame guide portion 33 (barrel) through which a thermal spray frame ejected from the tip of the thermal spray gun 31 passes, and the slurry (including a photocatalyst) in the thermal spray frame passing through the frame guide portion 33. And a slurry jet nozzle 34 for jetting the slurry into the thermal spray frame.

The slurry stored in the slurry tank 36 is supplied to the slurry mixing unit 32 by the pump 35 while ejecting the spray frame from the spray gun 31 using the high-speed spray device 30. The thermal spray frame is formed by mixing a high-pressure combustion support gas (for example, air + oxygen) and a fuel gas (for example, kerosene) in a combustion chamber in the thermal spray gun 31, and igniting the mixed gas. Further, a substrate is arranged at the spray destination of the thermal spray frame. By doing so, the slurry (particles including a photocatalyst, etc.) can collide with the substrate at a high speed on the flow of the thermal spray frame ejected from the tip of the frame guide portion 33, and a thermal spray coating is formed on the substrate. can do.

As the thermal spraying conditions, the flame temperature is preferably 700 ° C. or higher and 2,000 ° C. or lower, and more preferably 750 ° C. or higher and 1,500 ° C. or lower. Further, the frame ejection speed is preferably 800 m / sec or more and 2,000 m / sec or less. When the temperature of the thermal spray flame is less than 700 ° C., the flame temperature becomes too low, and it becomes difficult to stably form a coating on the substrate surface. On the other hand, when the temperature of the thermal spray flame exceeds 2000 ° C., the flame temperature becomes too high. For example, when anatase type titanium dioxide is used, the amount of titanium dioxide transformed from the anatase type to the rutile type increases, and titanium dioxide. May not be able to exhibit a sufficient photocatalytic function. The flame temperature is a temperature measured at a position 200 mm from the tip of the thermal spray gun 31 on the thermal spray frame center line. The temperature is measured using a thermocouple (for example, alumel / chromel up to 1,000 ° C, tungsten / tungsten rhenium above 1,000 ° C), and the tip of the thermocouple is inserted into the thermal spray frame. Let it be the value that was done.

The present invention is not limited to the above-described embodiment, and the configuration thereof can be changed without changing the gist of the present invention. For example, the number of partition plates and plate materials can be changed as appropriate. In addition to using a plurality of flat plates as the plate material, a single corrugated plate or the like can also be used. The photocatalyst may adhere to both surfaces of the plate material. Moreover, the light intake window may be formed on the side plate together with the top plate instead of the top plate.

Hereinafter, the content of the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to a following example.

The air purification apparatus having the shape shown in FIGS. 1 and 2 was produced, and was installed outdoors by being inclined as shown in FIG. The inclination angle θ was 30 °. Moreover, as a board | plate material, the following zeolite board was immersed in the process liquid (Water repellent: KBM-13 by Shin-Etsu Silicone Co., Ltd., methyltrimethoxysilane), and the board | substrate which used the hydrophobic process was used, and the one surface side of this board | substrate The one to which titanium dioxide was attached by high-speed flame spraying was used.
Zeolite board (composition)
・ Zeolite (manufactured by New Tohoku Chemical): 77% by mass
・ White cement (manufactured by Taiheiyo Cement): 15% by mass
・ Perlite (Mitsui Mining & Mining): 4% by mass
-Waste paper (newspaper): 4% by mass
Zeolite properties and particle size: 0.2 mm or less 80%, 0.1 mm or less 70%
Bulk specific gravity: 0.65 to 0.7 g / cm ³
・ Specific surface area 250-300 m ² / g
・ Pore diameter: 6.5 to 7 mm
-Water absorption: 60-80 mass%
Zeolite composition _· SiO 2: 72.1 _{wt%, Al} 2 O 3: 12.9 _{wt%, Fe} 2 O 3: 0.7 wt%, CaO: 2.6 _wt%, K 2 O: 2.1 mass %, Na ₂ O: 1.8% by mass, H ₂ O: 7.0% by mass, other: 0.8% by mass
As the air to be supplied, exhaust gas containing VOC generated in the painting process was used. The flow rate of this exhaust gas is adjusted by a flow control valve, and the VOC concentration (ppm) at the time of supply to the air purifier and the VOC at the time of discharge under two conditions of 6.5 m / s and 5.6 m / s. Concentration (ppm) was measured. For the measurement, a handy TVOC monitor FTVR-02 manufactured by Figaro Giken was used. The measurement results are shown in Table 1.

As shown in Table 1, it was confirmed that about 60 to 65% of VOC can be removed at both the flow rate of 6.5 m / s and 5.6 m / s.

The air purification apparatus according to the present invention can be suitably used as an air purification apparatus for factory exhaust gas, piggery, sewage treatment plants, etc. for the purpose of deodorization and deodorization.

10: Air purification device, 11: Box, 12a-12c: Partition plate, 13: Plate material, 14: Light intake window, 15a-15d: Side plate, 16: Bottom plate, 17: Air intake port, 18: Air exhaust Outlet, 19: upper fixing member, 20: lower fixing member, 21: inclined base, 22: groove structure, 23: groove structure, 24: duct, 30: high-speed spraying device, 31: spray gun, 32: slurry Mixing part, 33: Frame guide part, 34: Slurry jet nozzle, 35: Pump, 36: Slurry tank

Claims (2)

A box having an air intake port and an air discharge port on the side plate, and a top plate formed of a transparent plate material as a light intake window, and purifying the air from the air intake port to exhaust the air. In an air purification device comprising a plate material discharged from an outlet,
The plate functions as a porous substrate containing 70% by mass or more of hydrophobic zeolite and 5% by mass to 30% by mass of cement as a binder, and a photocatalyst dispersed and adhered to one surface of the substrate by thermal spraying. With titanium dioxide
In the box, the bottom plate and the side plate are in a rectangular parallelepiped shape made of a metal member made of iron, aluminum, copper, titanium, or an alloy thereof, and are inclined in a range of 10 degrees to 50 degrees, and the box the drain hole is provided in the lower edge portion, Rutotomoni is disposed said plate member along the air flow path formed in a zig-zag pattern on the box making the body by a partition plate disposed perpendicularly to the bottom plate, The plate material is arranged in a wave shape when viewed from the direction of air flow so that one surface on which the titanium dioxide is adhered is opposed to the light intake window, and the upper and lower sides of the plate material arranged in the wave shape are fixed on the upper side. An organic substance fixed by a member and a lower fixing member and adsorbed on the other surface side of the substrate is discharged from the one surface side and decomposed by the titanium dioxide. 2. The air purification apparatus according to claim 1 , wherein the photocatalyst exhibits catalytic activity by irradiation with light in the visible light region in addition to light in the ultraviolet light region.

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