JPH1024216A - Photocatalyst utilizing device having fluid transport means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for an expensive UV lamp and to surely dissipate the impurities and bacteria depositing in the air and water and on the blade and passage wall by forming a photocatalyst bed on the surface of a fluid transport means surrounded by the passage wall in contact with a fluid and furnishing a means for supplying light to the photocatalyst bed. SOLUTION: A photocatalyst bed is formed on the surface of an air fan 10, when the device is applied to the indoor unit of an air conditioner consisting of a suction grille 11, dustproof filter 16, heat exchanger 15, air fan 10, wind direction plate 12 and outer frame 13. The wind direction plate 12 and a part (window 14) of the outer frame 13 are formed from a light-transmissive material for the indoor illumination or to receive sunlight. The air 100 sucked into the room is passed through the grille 11, filter 16 and heat exchanger 15, freed from dust, cooled and then agitated by the fan 10. In this case, since the impurities such as bacteria are collided with the fan surface, the impurities are decomposed by the photocatalyst activated by the indoor-illuminating light received from the light-transmissive wind direction plate 12 and window 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocatalyst utilizing apparatus incorporating a means for transporting a gas or liquid containing a small amount of impurities or various germs, and more particularly to the use of a photocatalyst to eliminate impurities, deodorize, and remove bacteria. The present invention relates to various photocatalyst utilization devices having a built-in fluid transport means.

[0002]

2. Description of the Related Art Heretofore, photocatalysts such as titanium oxide have been able to redox various substances only by light.
A photocatalyst utilizing device for deodorization and elimination of odor components and various bacteria by extinction has been studied. The prior art will be described by taking the deodorization of air as an example and using a known example in JP-A-3-157125. The basic structure of a deodorizer using a photocatalyst is such that a titanium oxide photocatalyst is disposed around an ultraviolet lamp provided in the center of a gas flow path, so that the catalyst can be effectively irradiated with ultraviolet rays from the ultraviolet lamp. Air containing an odor component is sent between the catalyst and the ultraviolet lamp with a fan, and the wavelength is 40
The odor component is completely decomposed into carbon dioxide and water on the photocatalyst surface activated by ultraviolet light of about 0 nm, disappears, and is deodorized. Thus, the basic structure of a conventional photocatalyst utilization device is
It is a photocatalyst, a light source, a blower fan, and four elements of each partition so that light does not leak outside.

[0003]

However, the photocatalyst utilizing apparatus based on the prior art has a drawback that the apparatus cost and the operating cost are high, which has been a great obstacle to practical use and commercialization. This is because the decomposition process speed of the photocatalyst is slow, the apparatus becomes large, and titanium oxide as a photocatalyst requires an expensive ultraviolet lamp for generating an ultraviolet ray having a wavelength of 400 nm or less, so that the apparatus cost increases. Furthermore, the operation cost is high because the power consumption of the lamp is large. Therefore, a suction fan of an air conditioner such as an air conditioner indoor unit or a dehumidifier, a suction fan of an air purifier such as a dust remover or a deodorizer, a suction fan of a fan or a ventilation fan, a suction fan of a vacuum cleaner, and the like; A photocatalyst-based device that removes trace impurities and bacteria in the air and water for gas carriers such as cooling fans for equipment that has heating elements such as motors and computers in washing machines, and liquid carriers such as water pumps. Was not economically viable.

[0004] For this reason, at present, the processing speed is slow, and it is practically used only as a sufficient use for room lights and sunlight. For example, it is economically advantageous to apply a photocatalyst to the surface for the purpose of eliminating and removing a small amount of impurities and bacteria that slowly adhere or grow on the surface of the toilet or the wall of the toilet.

The present invention solves the above-mentioned known problems and provides various photocatalyst utilization devices incorporating the above-mentioned fluid transport means having a function of eliminating impurities, deodorizing, and sterilizing using a photocatalyst. Things.

[0006]

The inventor of the present invention has found that the main cause of the above-mentioned problem is that the prior art has adhered only to an increase in irradiation light intensity and catalytic reactivity as a means for improving the processing speed of a photocatalyst. The problem was solved by changing the viewpoint. That is, in the prior art, an ultraviolet lamp is indispensable, and the processing speed is increased by increasing the amount of the photocatalyst and the amount of irradiation, so that the apparatus and the operating cost are inevitably increased. is there.

The inventor of the present invention has studied the operation principle of the photocatalyst in various ways. As a result, the main cause of the slow processing speed is attributed to the surface solid reaction of the photocatalyst, and the speed at which the substances to be removed such as odor components reach the catalyst surface is low. Discovered to be slow. That is, for example, the performance of removing the odor component by the photocatalyst is as follows: (1)
Speed and amount of light reaching the catalyst surface, (2) speed and amount of activation of the catalyst by light irradiation, (3) speed and amount of odor components reaching the activated catalyst surface, (4) catalyst The rate and amount of the odor components completely decomposed in contact with are greatly affected by the four factors.

Conventionally, attention has been paid only to light and catalyst (1)
(2) In order to promote (4), measures to increase the light source and the amount of catalyst were being studied. Therefore, a light blocking wall is required to prevent the light of the light source from leaking outside. In the present invention, in order to improve the processing speed, attention should be paid to the behavior of the substance to be removed such as the odor component rather than the increase in the light intensity. Was found. The reason is that even if the light intensity or the amount of catalyst is increased, the processing speed and amount are not increased in proportion to it, so the amount of light and catalyst is not insufficient, and it can be effectively used even in the sun or indoor weak light. Thought it could work. Furthermore, considering the fact that stirring greatly affects the removal in water, etc., it is concluded that the obstacle to improving the processing speed lies in the slow speed at which the odor components reach the catalyst in (3). did.

[0009] From the hydrodynamic considerations, the inventors have found that:
By arranging the photocatalyst in a place where the flow field is turbulent and the velocity boundary layer is thin and the mass transfer velocity is high, the arrival speed of the substances to be removed (odor components, etc.) to the catalyst and the products after the reaction (carbon dioxide or water) Etc.), and
(2) Since the influence of the amount of light is small, the invention uses a structure that uses indoor lighting or sunlight outside the device as a light source, that is, arranges a light transmitting wall that receives light completely opposite to a conventional light blocking wall. did.

The basic realizing means is that (1) a photocatalytic layer is formed on the surface of a fluid transporting means such as a fan or a pump or a casing thereof where the disturbance is large and the velocity boundary layer is extremely thin; (2) Makes the flow path wall near the photocatalyst layer a light-transmitting material and introduces and irradiates external light to the photocatalyst.

Hereinafter, specific means of the present invention will be described.

1. By forming a photocatalyst layer on the surface in contact with the fluid of the fluid transport means, and having a means for supplying light to the catalyst layer, the velocity boundary layer is thinned and the substance to be removed is quickly moved to the catalyst surface, Increase the decomposition processing speed.

2. A photocatalyst layer is also formed on the thin flow path wall surface of the velocity boundary layer covering the fluid transport means, and a means for supplying light to the catalyst layer is provided, thereby increasing the catalytic reaction surface and increasing the amount of decomposition treatment. .

3. As a means for supplying light, a part of the flow path wall and the guide plate are made of a light transmissive material and have a structure that can supply light outside the device to the photocatalyst. As a result, an ultraviolet lamp is not required.

4. By using a transparent wall or a material that selectively transmits ultraviolet light as the external light introducing means, the outside of the apparatus, illumination or a light source of sunlight can be effectively used, so that an ultraviolet lamp is not required.

5. By making the opposing wall of the flow path wall into which light inflows a mirror surface or the like for reflecting light so that the reflected light is incident on the photocatalyst layer on the surface of the fluid transport means, the reflected light can be reused for the photocatalyst. Can improve the efficiency of use.

6. By forming a transparent photocatalyst layer on the surface of the fluid transport means or the surface of the light transmitting wall or mirror wall of the flow path and having a means for supplying light to the catalyst layer, the catalyst can be irradiated without disturbing the light irradiation amount. Since the reaction surface can be enlarged, the amount and speed of decomposition treatment can be increased.

[7] A photocatalyst layer is formed on the surface of the blades and casing of a gas carrier such as a suction fan of an air conditioner such as an air conditioner indoor unit or a dehumidifier, and a suction fan of an air purifier such as a dust remover or a deodorizer. By making a part transparent, airborne bacteria can be eliminated by indoor lighting.

8. A photocatalytic layer is formed on the surface of the hood and the hood of a gas carrier such as a ventilation fan and a suction blower fan such as an air conditioner for windows, and by making part of the hood transparent, both indoor lighting and sunlight can be used. In addition, it is possible to sterilize indoor air and eliminate oil and the like adhering to the surfaces of the blades and the hood.

9. A photocatalytic layer is formed on the surfaces of the blades and casing of a gas carrier such as a suction fan such as a vacuum cleaner, and a part of the casing is made transparent. It can eliminate impurities and bacteria attached to the surface.

10. A photocatalyst layer is formed on the surface of the blades and casing of a gas carrier such as a cooling fan of equipment that has a heating element such as a motor of a washing machine or a computer, and a part of the casing is made transparent to utilize indoor lighting. As a result, impurities and bacteria adhering to the indoor air and the surface of the fan or casing can be eliminated.

11. By forming a photocatalytic layer on the surfaces of the blades and casing of a liquid transporter such as a water pump and making a part of the casing transparent, it is possible to eliminate impurities and bacteria adhered to the transported water and the blades and casing.

By the above means, (1) a photocatalyst layer is formed on the surface of a fluid transporting means such as a fan or a pump, or a casing thereof, in which turbulence is large and the velocity boundary layer is extremely thin;
(2) Use of various photocatalysts capable of high-speed processing by eliminating the need for expensive ultraviolet lamps by introducing external light into the photocatalyst and irradiating the photocatalyst with a light-transmitting material for the flow path wall near the photocatalyst layer. Equipment can be provided.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. FIG. 1 shows an embodiment of an air conditioner according to the present invention using a photocatalyst in an indoor unit of an air conditioner.
The basic configuration of the apparatus is as follows: suction grill 11, dust filter 1
6, heat exchanger 15, blower fan 10, wind direction plate 12, and
It is composed of an outer frame 13.

The features of the present invention are that a photocatalyst layer is formed on the surface of the blower fan 10 in which the air is extremely turbulent and the speed boundary layer is thin, and that the wind direction plate 12 is used to take in indoor lighting and outside sunlight. That is, a part (window 14) of the outer frame 13 is made of a light transmissive material. Thereby, the sucked indoor air 100 is dust-removed and cooled by the suction grill 11, the dust-proof filter 16, and the heat exchanger 15, and then stirred at high speed by the blower fan 10, so that particles, odor components, bacteria, etc. in the air are removed. Impurities frequently hit the fan surface. The photocatalyst on the surface of the fan, which rotates at high speed, activates by taking in the room illumination light from the light-permeable wind direction plate 12 and the window 14, and immediately decomposes the impinging impurities, thereby producing decomposition products such as carbon dioxide and water. Is quickly discharged into the room together with the cooling air 110 from the wind direction plate 12 on the strong turbulence, and new impurities are promptly supplied to the photocatalyst by collision. As a result, the decomposition processing speed of the photocatalyst operated by indoor lighting or the like is dramatically increased,
Cold air with little odor and bacteria can be supplied indoors without using an ultraviolet lamp or the like.

If the surface of the guide 18 on the fan side is mirror-finished, room light can be effectively supplied to the fan surface by reflection. A dew tray 17 for storing water condensed by cooling is installed below the heat exchanger 15, and when used for a long time, water in the dish is contaminated with impurities and propagated bacteria. In order to increase the processing capacity, a photocatalyst layer may be formed on the outer frame 13 around the fan, the guide 18 and the surface of the exposure tray 17 on the fan side where light reaches. Further, if a thin-film photocatalyst having a light transmittance on the order of microns is used, the photocatalyst can be arranged also on the wind direction plate 12 for lighting, the window 14 and the mirrored guide 18, so that the throughput can be increased. In addition, dew tray 1
7 is made of a light-transmitting material and the thin film catalyst is formed not only on the fan (outside) side but also on the water (inside) side, so that water impurities and bacteria in the dish can be photolyzed. Inside pollution can be prevented.

The above is the embodiment of the indoor unit of the air conditioner. However, if the heat exchanger 15 is a moisture removal layer such as silica gel as a moisture adsorbent, if it is a simple filter, the heat exchanger 15 is an air duster and a moisture supply layer. The present invention is also applicable to various air conditioners such as humidifiers.

FIG. 2 shows an embodiment using a photocatalyst of a vacuum cleaner. The photocatalyst is formed on the surface of the suction fan blade 20. After the dust 115 in the air 100 sucked from the suction port 21 is removed by the filter 27, impurities and bacteria in the air collide with the photocatalyst on the surface of the blade rotating at high speed to be decomposed, and are processed through the exhaust filter 26. Air 1
20 is discharged. The supply of light to the photocatalyst uses room light through a light-transmissive window 24 around the blade 20.
If a photocatalyst is formed on the flow path wall of the outer frame 23 and the surface of the motor 25 through which light reaches and high-speed air flows, the amount of decomposition treatment can be further increased. Further, when a light-transmitting thin-film catalyst is also formed on the blade (inner) side of the window 24, the amount of decomposition treatment can be increased.

FIG. 3 shows an embodiment in which a photocatalyst is used for a ventilation fan. The photocatalyst layer is formed on the inner surfaces of the blades 30 and the outer frame 33 of the suction fan. The sucked air 100 is agitated and transported by the blades 30 rotating at a high speed through the suction guide 31 and discharged from the discharge guide 32 to the outside. Impurities such as oil contained in the indoor air 100 are distributed to the blades 30 and the outer frame 33.
Much adheres to the inner surface. Light is supplied to the blades and the photocatalyst inside the outer frame using both light such as indoor lighting and sunlight outdoors. Therefore, the suction guide 31 and the discharge guide 3
2 uses a lattice structure or a light transmissive material that easily transmits light. As a result, the impurities attached to the blades and the inner surface of the outer frame are quickly decomposed by the photocatalyst in the room and the sun. Needless to say, impurities and bacteria in the air can be similarly eliminated. Suction guide 31, discharge guide 32, and motor 3
When a photocatalyst is also formed on the surface of the casing of No. 5, the amount of decomposition treatment increases, and impurities and bacteria on those surfaces can be eliminated and removed. FIG. 3 shows an embodiment of a ventilation fan, but the present invention can be similarly applied to a window air conditioner in which a heat exchanger is installed in a flow path as an apparatus that uses both indoor light and sunlight.

FIG. 4 shows an embodiment in which a photocatalyst is used in a computer in which a heating element 400 such as an electric integrated circuit is built in a computer or the like. The photocatalyst layer is composed of the cooling fan blades 40 and the outer frame 4.
3 on the inner surface. The room air 100 flows in from the intake guide 41, cools the heating element 400, and the warmed air is rapidly stirred and transported by the blades 40 and discharged from the discharge guide 42 into the room. The impurities and bacteria in the air mixed from the room and the heating element adhere to the outer frame 43, the blades 40 and the like, and contaminate the room air. By arranging the light-transmitting window 44 on a part or the whole of the outer frame 43, the blades and the photocatalyst on the inner surface of the outer frame are activated by the light flowing from the room. Not only impurities and bacteria attached to the surface but also impurities and bacteria in high-speed air frequently collide with the catalyst surface, so that both impurities and bacteria are quickly decomposed. Further intake guide 41
If the discharge guide 42 is made of a light-transmitting material or a photocatalyst layer is formed on its surface, the decomposition treatment capacity can be increased.
In the case of a light-transmitting window or guide, forming a light-transmitting thin-film photocatalytic layer is effective without obstructing lighting. As another similar embodiment having a cooling fan, there is a cooling fan of a stirring motor of a washing machine or a cooling fan of various measuring devices,
The present invention can be applied if a photocatalyst is formed on the blades of those fans and a part or all of the casing around the fan is made of a light-transmitting material or structure.

FIG. 5 shows an embodiment in which a photocatalyst is used for a water pump. A photocatalyst layer was formed on the surface of the water supply blade 50, and a part or the whole of the casing 53 around the photocatalyst layer was made of a light transmitting material. The photocatalyst layer on the surface of the water supply blade 50 rotated at a high speed is activated by external sunlight or the like, thereby eliminating impurities and bacteria mixed in the fan surface and water. As in the previous embodiment, if a light-transmitting thin-film photocatalyst layer is formed on the inner surface of the casing 53, the decomposition treatment capacity can be increased. 2
00 indicates a water inflow direction, and 210 indicates a drainage direction.
Reference numerals 51 and 52 denote pipes.

In the above embodiment, the thin photocatalyst layer is formed on the surfaces of the blades and the casing, but the whole may be made of a photocatalyst. However, considering that the catalytic reaction occurs on the surface to which light reaches, it is more economical to form the layer only on the surface from the viewpoint of reducing the amount of catalyst used. Light-transmitting materials include transparent glass and plastic, but it is effective to use quartz glass or the like that selectively transmits ultraviolet light.

The photocatalyst used in the present invention includes Sn
O ₂ , ZnS, ZnO, WO ₃ , TiO ₂ , SrTiO ₃
Substances that are selectively active in light in the ultraviolet region, such as
There are substances such as C, CdS, Fe ₂ O ₃ , GaP, and CdSe that are active in light up to the visible region.

[0034]

The present invention is based on a completely different idea from the conventional photocatalyst utilization method (improving the processing speed focusing on light and catalyst), and focusing on the behavior of the substance to be removed from the viewpoint of fluid dynamics. It is formed on the surface of the fan, pump and casing, and makes part or all of the surrounding casing etc. light-transmissive, so that the use of illumination and sunlight outside the device eliminates the need for expensive ultraviolet lamps. With an inexpensive device, impurities and bacteria attached to the air, water, blades and flow path walls can be economically eliminated with a photocatalyst.

[Brief description of the drawings]

FIG. 1 is an air conditioner utilizing a photocatalyst according to the present invention.

FIG. 2 is a photocatalyst-based vacuum cleaner according to the present invention.

FIG. 3 is a ventilation fan utilizing a photocatalyst according to the present invention.

FIG. 4 is a computer using a photocatalyst according to the present invention.

FIG. 5 is a photocatalyst-based water pump according to the present invention.

[Explanation of symbols]

10: blower fan, 20, 30, 40: blade, 50: water blow blade.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriko Watanabe 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yoshinori Furukawa 7-1 Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Hitachi Research Laboratory, Hitachi, Ltd.

Claims (5)

[Claims] 1. A photocatalyst utilization apparatus characterized in that a photocatalyst layer is formed on a surface of a fluid transporting means surrounded by a flow path wall which is in contact with a fluid, and new means for supplying light to the catalyst layer is provided. . 2. The photocatalyst utilization apparatus according to claim 1, further comprising means for forming a photocatalyst layer on the surface of the flow channel wall and supplying light to the catalyst layer. 3. A structure according to claim 1, wherein a part of the flow path wall is made of a light-transmitting material as a means for supplying light, so that light from outside the flow path wall can be supplied. A photocatalyst utilization device characterized by the above-mentioned. 4. The method according to claim 1, wherein an opposing wall of the flow channel wall, into which light flows, is a mirror surface for reflecting light, and the reflected light is incident on the photocatalytic layer on the surface of the fluid transport means. Photocatalyst utilization device. 5. The method according to claim 1, wherein a transparent photocatalyst layer is formed on the surface of the fluid transporting means or on the surface of the light transmitting wall or the mirror wall of the flow path, and means for supplying light to the catalyst layer is provided. A photocatalyst utilization device characterized by the above-mentioned.