JP2000167355A - Purifying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purifying apparatus which has an improved purifying capability, and can be easily maintained by placing a photocatalytic filter unit in a cylinder through which a fluid to be treated flows in the axial direction and by causing a part of the unit to cross the direction of flow of the fluid. SOLUTION: This purifying apparatus 1 has a photocatalyst filter unit 4 placed in a cylinder 3 stood and installed on a base 2. The unit 4 comprises a photocatalytic filter 13 in the form of bands twisted and attached radially and spirally around an axial member and an excitation light emitting tube 14 inserted into the inside of the axial member. Contaminated air flowing from an inlet port 5 into the cylinder 3 by driving a fan 15 is brought into contact with the photocatalytic filter 13, and various compounds in the contaminated air is oxidatively decomposed by a photocatalyst activated by ultraviolet rays from the excitation light emitting tube 14. Thus cleaned air is exhausted out of the cylinder 3. The photocatalytically functional layer homogeneously receives a large amount of ultraviolet rays, and surely carries out a photocatalytic function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification apparatus for decomposing and purifying organic compounds and inorganic gases in a gas or liquid (hereinafter referred to as a fluid) by a photocatalytic function.

[0002]

2. Description of the Related Art As petrochemical products increase, complex pollution of harmful organic compounds inside and outside a living environment has become a problem. As a means for solving this, a purifying apparatus utilizing oxidative decomposition by a photocatalytic semiconductor is used.

For example, there is an apparatus in which a filter carrying a photocatalyst semiconductor on the surface of a substrate is placed in a fluid in which the harmful organic substance floats so that the harmful organic substance comes into contact with the photocatalyst semiconductor. However, in the conventional device, the filter carrying the photocatalyst extends along the flow direction of the fluid, so the contact efficiency between the harmful organic substance and the photocatalytic functional layer is low, and the photocatalytic semiconductor is sufficiently activated by the electromagnetic wave of the excitation wavelength. There is a problem that can not be done.

For this reason, various proposals have been made regarding the shape and arrangement of a filter having a photocatalytic function layer. For example, Japanese Patent Laying-Open No. 7-108138 discloses a device in which a photocatalyst is supported on a blade-shaped reaction plate made of a thin plate, and the reaction plate is arranged in a blind shape in an air passage.
Japanese Patent Application Laid-Open No. HEI 8-121827 discloses a device in which a photoexcited catalytic nonwoven fabric bent in a mountain shape is installed before and after an ultraviolet lamp installed in a purified air passage. JP 9
No. 187,491 discloses an apparatus having a member in which a substrate having a photocatalyst layer on both surfaces is radially provided around a light source in an air passage. Japanese Patent Application Laid-Open No. 9-248426 discloses a movable body in which a photocatalytic function layer is provided on the surface of a convex portion that carries or stirs a fluid, and an ultraviolet radiation member is housed inside.

[0005]

It is said that the oxidation-reduction decomposition using a photocatalyst produces decomposition performance when a substance to be treated comes into contact with an active radical species such as O ₂ ⁻ and OH ⁻ . Therefore, in the above-described conventional apparatus, when the amount of the substance to be treated is large, it takes time to surely contact the photocatalyst filter and the substance to be treated, or the chance that the photocatalyst filter contacts the substance to be treated is small. There was a problem. Further, in order to realize the photocatalytic function, the photocatalytic filter needs to receive an excitation wavelength suitable for the photocatalytic semiconductor metal, but the conventional apparatus has not been configured to efficiently receive light. In particular, in the conventional purifying device, it is difficult to remove the intermediate products adhered and deposited on the surface of the photocatalytic filter, and maintenance and inspection are troublesome.

Accordingly, a first object of the present invention is to provide a purification apparatus capable of creating more opportunities for contact with a substance to be treated. A second object of the present invention is to provide a purification device capable of reliably receiving an excitation wavelength in a photocatalytic semiconductor metal and effectively using scattered light. A third object of the present invention is to provide a purification device having a structure capable of easily removing deposits including intermediate products.

[0007]

According to the present invention, there is provided a photocatalyst having a cylinder through which a fluid to be processed flows along an axial direction, and a photocatalyst filter unit housed inside the cylinder. The filter unit has a shaft member and a plurality of photocatalyst filters having three-dimensionally permeable contacts disposed around the shaft member, and at least a part of the photocatalyst filter crosses the flow direction of the fluid to be treated. Tactics were adopted. In the present invention, it is preferable that the photocatalytic filter unit has an excitation wavelength luminous body inside the shaft member. In the present invention, it is preferable that the photocatalyst filter unit is detachably housed inside the cylinder, and the cylinder preferably has means for opening and closing at least a part thereof. In the present invention, the cylinder is preferably formed of a material capable of reflecting excitation wave light and has a photocatalytic function layer on the inner surface. In the present invention, the cylinder preferably has a translucent decorative window. In the present invention, the photocatalytic filter preferably has a substrate made of a metal material and a photocatalytic functional layer. In order to achieve the above object, the present invention has a photocatalyst filter unit through which a fluid to be treated flows from one end to the other end, wherein the photocatalyst filter unit has a transparent contact surrounding the excitation wavelength luminous body. The transparent contact photocatalyst filter may include a porous member including a metal nonwoven fabric and a photocatalyst functional layer carried thereon. In this configuration, the excitation wavelength light emitting device has an arc tube that extends in a direction intersecting with the direction in which the fluid to be processed flows and is bent at least at one end, and the porous members are disposed on both sides of the excitation wavelength light emitting device. Is preferably performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a purification device according to one embodiment of the present invention, and FIG. 2 is a view taken along line AA of FIG. In both figures, reference numeral 1 denotes a purifying device, which includes a cylindrical cylinder 3 erected on a base 2 and a photocatalytic filter unit 4 housed therein. The cylinder 3 has, at a lower end thereof, an inlet 5 through which a fluid to be treated (for example, contaminated air) flows, and a filter 6 and a photocatalyst above the contaminated air for removing foreign substances (dust) in the contaminated air. It has a socket part 7 for receiving one end of the filter unit 4. An outlet 8 through which purified air flows out is formed at the upper end of the cylinder 3, and a lid 1, which is openably and closably attached via a hinge 9, to an upper end surface of the cylinder 3.
0 is sealed. A socket 1 for receiving the other end of the photocatalytic filter unit 4 is provided on the inner surface of the lid 10.
1 is attached. Reference numeral 12 denotes a translucent decorative window, which is formed, for example, by cutting out a part of the cylinder 3 and attaching a transparent sheet (plastic plate) thereto.

The photocatalyst filter unit 4 includes a plurality of strip-shaped photocatalyst filters 13 having transmission contact properties, which are radially and spirally twisted around a shaft member (not shown) formed in a frame shape. , An excitation light emitting tube 14 inserted inside the shaft member. Excitation arc tube 14
Are socket portions 7 and 1 at both ends.
1 and a fan 15 is mounted on one end side. Both ends of the excitation light emitting tube 14 may be inserted and fixed in the socket portion, or may be rotatably supported with respect to the socket portion. As the excitation light emitting tube 14, a lamp that emits ultraviolet light such as a black light or a fluorescent light can be used.

The cylinder 3 reflects ultraviolet light emitted from the excitation luminous tube 14 and guides the ultraviolet light to the photocatalytic filter 13. For example, when the ultraviolet light is near ultraviolet light, an excitation wavelength such as an aluminum alloy or stainless steel is used. It is desirable to form with a material having a function that can reflect light. Furthermore, if a photocatalytic function layer is formed on the inner peripheral surface of the cylinder 3, air can be more efficiently purified.

According to the purification device 1, the contaminated air flowing into the cylinder 3 from the inflow port 5 by driving the fan 15 removes coarse foreign substances by the filter 6 and comes into contact with the photocatalyst filter 13 so as to emit light by excitation. The various compounds in the contaminated air are oxidized and decomposed by the photocatalyst activated by the ultraviolet light from the tube 14, and then the clean air is discharged out of the cylinder 3. Since each photocatalyst filter 13 is arranged obliquely with respect to the excitation light emitting tube 14, the photocatalyst functional layer can receive a large amount of ultraviolet light evenly, and the photocatalytic function can be reliably achieved. . If the oxidative decomposition by the photocatalyst is continuously performed, in the case of a nitrogen compound, a sulfur compound or a chlorine compound, an intermediate product adheres to the surface of the photocatalytic functional layer, and the decomposition efficiency is reduced. In this case, after opening the lid 10 as shown by the dashed line in FIG. 2, the photocatalytic filter unit 4 is pulled up to the position shown by the broken line in FIG. 2, and the photocatalytic filter unit 4 is washed with water (for example, weakly acidic water). Then, it may be set in the cylinder 3.

FIG. 3 is a perspective view of a purifying apparatus according to another embodiment of the present invention, and FIG. 4 is a view taken along the line BB of FIG. 3, in which the same functional parts as in FIGS. Indicated by In this purification device 1, the photocatalyst filter unit 4 is formed by arranging a plurality of disk-shaped photocatalyst filters 40 in the axial direction and arranging a plurality of strip-shaped photocatalyst filters 41 in a radial manner. The cylinder 3 has a structure in which the semi-cylindrical bodies 3a and 3b are connected by a hinge 30, and a dividing surface 31 is formed in the axial direction. According to the purification device 1, similarly to the device of FIG. 1, the contaminated air flowing into the cylinder 3 from the inflow port 5 is filtered by the filter 6, comes into contact with the photocatalyst filters 40 and 41, and The various compounds in the contaminated air are oxidized and decomposed by the photocatalyst activated by the ultraviolet light, and the clean air is discharged from the outlet 8. When the photocatalyst filter unit 4 is to be cleaned, the cylinder 3 is opened to the position shown by the broken line in FIG.

In the present invention, the photocatalyst filter 1 described above is used.
3 has a structure in which a photocatalytic function layer is formed on the surface of a base, and as shown in FIG. 5, a base is formed by forming a porous layer 23 composed of fine particles 22 on a substrate 20 having many holes 21. Thus, it is preferable that the porous laminate has a permeable contact performance and a large surface area (hereinafter, referred to as a multi-surface area porous laminate). The fine particles constituting the porous layer for providing the photocatalytic filter with a large surface area are ceramic,
The material is not limited, such as glass, metal, and plastic, but is preferably the same as the material of the substrate. The substrate may be a net such as a wire net, expanded metal, punched metal, or the like. In this case, the positional relationship between the substrate and the fine particles is important, and the fine particles are in effective contact with the periphery of the hole 21 through which the gas or liquid containing the substance to be processed passes, and at a position where the excitation wavelength is received. Must be arranged. In FIG. 5, a represents the amount of permeation per unit time when a gas or liquid containing the substance to be processed permeates the multi-surface area porous laminate {planar projected area (A)}.
Plane projected area (b) of the region where the inner photocatalytic semiconductor metal is formed in the multi-surface area porous laminate and the planar projected area (A)
If the ratio (surface area ratio) of the surface area (c) of the side surface of the multi-surface area porous laminate and the above-mentioned plane projected area (A) (side surface surface ratio) is C / A, the excitation wavelength It is preferable to satisfy the conditions that the amount of transmission (a) and the surface area ratio (b / A) are as large as possible and that the side surface area ratio (C / A) is as small as possible, assuming that is generated from above and below the drawing.

Further, in order to satisfy the condition for functionalizing the photocatalyst, it is necessary that the photocatalytic semiconductor metal receives the excitation wavelength, and it is desirable that a large number of plate-shaped photocatalytic filters receive light uniformly on both sides. Therefore, in the present invention, the plate-shaped photocatalytic filter is inclined with respect to the excitation wavelength source, so that more light can be received on the film forming surface.

In the present invention, it is desirable to form a porous layer made of fine particles on the surface of a substrate having a plurality of holes as follows. This porous layer has, for example, an average particle size of 1
A slurry (solid content: 60 to 80% by weight) obtained by mixing a metal powder of 0 to 400 μm in a solvent such as water is applied to the surface of a substrate, dried, and then sintered. As the metal material for forming the substrate or the fine powder, SUS304, S
Austenitic stainless steel such as US310 and SUS316, Ti or its alloy (Ti-Mn-based, Ti-Cr
System), Cu or an alloy thereof, Al or an alloy thereof (Al-Si-Mg system), Fe or an alloy thereof. However, in the case of an Fe-based material, it is preferable to form an oxidation-resistant film (iron oxide) on the surface. If the particle size of the metal powder is too small, the price increases (the pulverization time increases), and if it is too large, fine pores cannot be obtained.
It is preferable to use one having an average particle size of 10 to 400 μm. The sintering temperature may be determined according to the material of the metal powder, but if it is too low, a sufficient sintering density is not obtained, and the strength is reduced. On the contrary, coarse pores are formed, so SUS, Ti,
In the case of Cu, the range is preferably 800 to 1000 ° C, and in the case of Al, the range is preferably 300 to 400 ° C.

[0016] The porous layer thus obtained is
It preferably has a pore diameter of 1000 μm. If the pore diameter is too large, it will not be possible to prevent fine foreign substances even when used for air purification, and it will not be possible to obtain clean air.
It is necessary to be 1000 μm or less. When the thickness of the porous layer is small, the strength is insufficient, and when the thickness is large, the permeation resistance increases. Therefore, the thickness of the porous layer is preferably 10 to 100 μm.

The metal particles forming the porous layer are often regular particles (spherical or granular powder particles) or irregular particles (particles having sharp corners such as angular powder particles). Shape. When a melting means such as baking is employed for fixing to the substrate, the material is preferably the same as that of the substrate because of good compatibility. However, even if the materials are different, they can be fixed without using an appropriate binder in an appropriate amount. When the substrate and the particles for increasing the surface area are made of different kinds of materials, it is necessary to match the coefficient of linear expansion or to maintain elasticity corresponding to the linear expansion of one of the materials. It is. As the binder, inorganic glass, frit (glaze), metal powder, ordinary thermoplastic resin, or the like can be used. In order to laminate the metal particles, there are means such as repeating the spraying and dipping several times, and also repeating the transfer (printing) using a screen. In the case of laminating the particles coarsely as the substrate side is densely separated from the substrate at the time of lamination, the degree of dispersion (density) of the particles in the spray liquid or dipping liquid is adjusted or the roughness of the screen used for printing is adjusted. Select It is also possible to select the particle size of the particles to be laminated. Furthermore, it is also possible to select a laminated structure in a cross section. That is, several screens that can be accurately positioned are used, and the structure is such that the base side is the base in the cross-sectional configuration of the laminate and the apex is provided at a position away from the base. Also according to this structure, the metal particles are consequently coarsely laminated as the substrate side is densely separated from the substrate.

FIG. 6 is a perspective view of a purification apparatus according to another embodiment of the present invention, and FIG. 7 is a sectional view taken along the line BB of FIG.
4 are denoted by the same reference numerals. The purifying device 1 has a rectangular parallelepiped shape, and has a structure in which a photocatalytic filter unit 4 is detachably mounted around an excitation wavelength generating device 140. The excitation wavelength generator 140 includes a U-shaped cold cathode tube 141 and a glass cover 142 surrounding the cold cathode tube 141.
Having. The photocatalyst filter unit 4 includes a U-shaped transmission contact photocatalyst filter 13. The photocatalyst filter 13 includes a cover 16 and a cover 17 made of a metal plate.
And a photocatalytic functional layer (not shown) formed on a side facing the metal nonwoven fabric mat 18 and the excitation wavelength light emitting device 140. Examples of the metal material forming the covers 16, 17 and the metal nonwoven fabric mat 18 include A
1, Ti or Cu or an alloy thereof, stainless steel, or the like can be used. On the inner peripheral side of the metal nonwoven fabric mat 18, a metal mesh body made of, for example, a wire mesh or a punching metal (a plurality of cuts are made in a thin metal plate, and the cuts are pulled substantially in a perpendicular direction to form a net). (Not shown), and a photocatalytic functional layer (not shown) is provided thereon.
Is carried. The metal nonwoven fabric mat 18 has, for example, a wire diameter of 10 to 100 μm and a length of several mm to several tens.
It is formed by laminating aluminum rectangular fibers of mm or aluminum long fibers having a length of several tens of cm or more in a U-shape, and then press-bonding as necessary. According to the purification device 1, the contaminated air that has flowed into the photocatalyst filter unit 4 from under the photocatalyst filter unit 4 comes into contact with the photocatalyst filter 13, and is activated in the contaminated air by the photocatalyst activated by ultraviolet rays from the cold cathode tube 141. Are oxidatively decomposed, and clean air is discharged from above the unit 4. When the photocatalyst filter unit 4 is to be washed, the photocatalyst filter unit 4 may be pulled out upward as shown by a broken line in FIG.

In the present invention, the photocatalytic functional layer is formed by mixing a sol liquid mixed with a photocatalytic semiconductor such as TiO ₂ .
It can be formed by attaching it to the surface of the substrate by spraying or dipping, drying it, and baking it at a temperature of 50 ° C to less than 500 ° C. If amorphous titanium peroxide or titanium oxide is mixed in the sol in a titanium weight ratio (dry amount) of 1: 1 or 1: 5 in addition to the photocatalyst semiconductor, the photocatalyst semiconductor is produced at a relatively low temperature. The particles can be firmly supported.

Further, P is used for complementing functions such as fungicide sterilization.
t, Ag, Rh, RuO ₂ , Nb, Cu, Sn, NiO
Of zeolite, silica (silicon dioxide), alumina, zinc oxide, magnesium oxide, rutile type titanium oxide, zirconium phosphate, etc. One or more kinds of inorganic materials, various types of activated carbon, porous phenol resins and melamine resins can be mixed.

The photocatalyst layer may be formed after the surface of the substrate is sprayed with a protective material such as an aqueous solution of titanium peroxide to perform a base treatment for forming a protective film. In any case, if a film is formed in advance with an aqueous solution of titanium peroxide (oxysanthainic titanium titanium acid), T
The adhesion and spreadability of the iO ₂ sol liquid are improved, so that the iO ₂ sol is easily wetted, and the photo functional layer can be uniformly and widely formed on the surface of the substrate. This aqueous solution of titanium peroxide has excellent spreadability even when the substrate is made of a metal such as stainless steel, and is effective in applying the TiO ₂ sol solution widely and uniformly. The aqueous solution of titanium peroxide also functions as a binder, but does not include a ceramic-based composition, and has good compatibility with metals, so the photocatalytic functional layer formed on the surface of the base may be bent or vibrated even if the base is bent. Less peeling.

As the photocatalytic semiconductor, TiO is used.₂Besides Zn
O, SrTiO₃, CdS, CdO, CaP, InP,
In₂O₃, CaAs, BaTiO₃, K₂NbO₃,
Fe ₂O₃, Ta₂O₅, WO₃, SnO₂, Bi₂O
₃, NiO, Cu₂O, SiC, SiO₂, MoS₂,
MoS₃, InPb, RuO₂, CeO₂and so on.
Among them, titanium oxide TiO₂(Anatase type)
Characteristics are stable, harmless to human body, photocatalyst
As the best.

The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the cross section of the container (cylinder) for storing the photocatalyst filter is not limited to a circular or rectangular shape, but may be another shape such as an elliptical shape or a polygonal shape. You may. In addition, the present invention is not limited to the purification of indoor air, but may be applied to purification of air, purification of sewage (domestic wastewater, factory wastewater, sewage, etc.).

[0024]

According to the purification apparatus of the present invention, there are many opportunities for the organic compound floating in the fluid to come into contact with the photocatalytic functional layer, and high purification performance can be obtained. In addition, the purification device of the present invention,
Since the photocatalyst filter unit is detachably housed in the case, maintenance and inspection are easy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a purification device according to one embodiment of the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a perspective view showing a purification device according to another embodiment of the present invention.

FIG. 4 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 5 is a schematic view showing a cross section of a substrate constituting the plate-shaped photocatalytic filter of the present invention.

FIG. 6 is an exploded perspective view showing a purification device according to another embodiment of the present invention.

FIG. 7 is a sectional view in the B direction of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Purification device, 3 cylinders, 4 photocatalyst filter units, 10 lids, 13 photocatalyst filters, 14
Excitation arc tube

Continued on the front page F-term (reference) 4D048 AA17 AA21 AB01 AB03 BA02X BA06X BA07X BA13X BA14X BA15X BA16X BA17X BA19X BA20X BA21X BA22X BA24X BA26X BA27X BA32X BA35X BA36X BA38X BA41X BA42X BA44CCBA07 BB01 CC EA04 4D050 AA12 AB11 BC04 BC06 BC09 BD02 4D064 AA19 BK03

Claims (8)

[Claims] 1. A cylinder through which a fluid to be treated flows along an axial direction, and a photocatalyst filter unit housed inside the cylinder, wherein the photocatalyst filter unit is three-dimensionally arranged around a shaft member and the periphery thereof. And a photocatalyst filter having a plurality of transmissive contacts, and at least a part of the photocatalyst filter crosses the flow direction of the fluid to be treated. 2. The purifying apparatus according to claim 1, wherein said photocatalytic filter unit has an excitation wavelength luminous body inside a shaft member. 3. The purifying apparatus according to claim 1, wherein the photocatalytic filter unit is removably housed inside the cylinder, and the cylinder has means for opening and closing at least a part of the cylinder. . 4. The cylinder according to claim 1, wherein the cylinder is formed of a material capable of reflecting excitation wave light, and has a photocatalytic functional layer including a photocatalytic semiconductor metal on an inner surface thereof.
A purification device according to any one of claims 1 to 3. 5. The purification device according to claim 4, wherein the cylinder has a translucent cosmetic window. 6. The purification device according to claim 1, wherein the photocatalytic filter has a substrate made of a metal material and a photocatalytic functional layer. 7. A photocatalytic filter unit through which a fluid to be treated flows from one end side to the other end side and an excitation wavelength light emitting device, wherein the photocatalytic filter unit is a transmissive contact photocatalyst surrounding the excitation wavelength light emitting device. A purifying apparatus comprising a filter, wherein the transmissive contact photocatalytic filter has a porous member including a metal non-woven fabric and a photocatalytic functional layer carried thereon. 8. The excitation wavelength light emitting device extends in a direction intersecting the direction in which the fluid to be processed flows and has a turn at least at one end, and the porous members are arranged on both sides of the excitation wavelength light emitting device. Purification device characterized by the above-mentioned.