JP2005160914A - Air purifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air purifier, which exerts a deodorizing/bactericidal effect with ultraviolet light and oxidation/reduction action with a photocatalyst to suitably decompose/sterilize contaminants in air by effective use of ultraviolet light or the like of a wide wavelength range emitted from an ultraviolet light source. <P>SOLUTION: An air purifier 1 comprises an ultraviolet light discharge tube 2 to emit ultraviolet light of 185 nm and 254 nm wavelength, and ultraviolet light of 360 nm wavelength to excite a photocatalyst, and a photocatalyst bearing member 3 to bear the photocatalyst provided with a space on a position where the light to excite the photocatalyst reaches. The ultraviolet light of 185 nm wavelength emitted from the ultraviolet light discharge tube 2 converts oxygen molecules to ozone to exert the deodorizing/bactericidal effect, the ultraviolet light of 254 nm wavelength exerts the deodorizing/bactericidal effect with itself, and the ultraviolet light of 360 nm wavelength excites the photocatalyst for oxidation/reduction action so that contaminants or the like in the air can be decomposed/sterilized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air purifying apparatus that suitably decomposes and sterilizes pollutants in the air by using a deodorizing / sterilizing action by ultraviolet rays and an oxidizing / reducing action by a photocatalyst such as titanium oxide using ultraviolet rays irradiated from an ultraviolet light source. Is.

Conventionally, as an air purification device that performs deodorization and sterilization using a photocatalyst in which holes and electrons excited by light exhibit oxidation / reduction action, a sterilization sheet in which a photocatalyst such as fibrous titanium oxide is fixed to a polyester film Body and an ultraviolet light source such as a light-emitting diode or a cold cathode discharge tube that irradiates the sterilization sheet body with light such as ultraviolet rays to excite the photocatalyst, and irradiates the sterilization sheet body exposed to the outside from the inside. What to do is devised. Then, the photocatalytic action of titanium oxide or the like is activated by irradiating light to the sterilizing sheet body, thereby exhibiting deodorizing / sterilizing / decomposing effects against odorous components, bacteria, and contaminants in the air.
JP-A-8-266609

  However, in the above-described conventional air purification device, the photocatalyst fixed on the surface of the sterilization sheet body is irradiated with light and exhibits a photocatalytic action, but new air does not contact the photocatalyst one after another. , Deodorizing, sterilizing and decomposing can only be performed on very small amounts of air present on the surface of the photocatalyst. Therefore, if this air purification device is left alone in the space, it will exhibit a wide range of deodorizing, sterilizing and decomposing effects. I couldn't. In addition, ultraviolet light sources such as cold cathode discharge tubes that form appropriate phosphor layers on the inner surface are often irradiated with ultraviolet rays in a wide wavelength range of 185 nm to 360 nm. Although all of its strong photoelectric effect and photochemical reaction can exert excellent deodorizing, sterilizing, and decomposing actions, UV light in a wide wavelength range of 185 nm to 360 nm is not actually used, and the wavelength that excites the photocatalyst Only ultraviolet rays were used.

  Therefore, in the present invention, in order to solve the above-described problems, light in a wide wavelength range irradiated from an ultraviolet light source is effectively used, deodorizing / sterilizing action by ultraviolet light itself, and oxidation / oxidation by a photocatalyst such as titanium oxide. An object of the present invention is to provide an air purifying apparatus that suitably decomposes and sterilizes pollutants in the air by a reducing action.

In order to achieve the above object, an air purification device of the present invention comprises an ultraviolet light source that irradiates light from ultraviolet light that excites a photocatalyst such as ultraviolet light having a wavelength of 185 nm and 254 nm and titanium oxide (TiO ₂ ) to visible light, And a photocatalyst carrying member that carries a photocatalyst arranged at intervals at a position where light having a wavelength that excites the photocatalyst from the ultraviolet light source arrives. Changes the oxygen molecules to ozone and exerts deodorizing and sterilizing action, and the ultraviolet light having the wavelength of 254 nm exhibits the deodorizing and sterilizing action by itself, and the light from the ultraviolet light that excites the photocatalyst to visible light is a photocatalyst. Decomposes and disinfects odorous components, bacteria, and pollutants in the air by exciting the photocatalyst of the support member and exerting oxidation and reduction action And it features.

  In addition, the photocatalyst carrying member is made to adhere a linear body or non-woven fabric carrying a photocatalyst to a glass substrate that blocks ultraviolet rays having wavelengths of 185 nm and 254 nm and transmits light from ultraviolet rays to visible light that excites the photocatalyst. It is characterized by.

According to the air purification apparatus of the present invention, an ultraviolet light source for irradiating ultraviolet light having a wavelength of 185 nm and 254 nm and ultraviolet light that excites a photocatalyst such as titanium oxide (TiO ₂ ) to visible light, and a photocatalyst from the ultraviolet light source. A photocatalyst carrying member that carries a photocatalyst disposed at a position where light having a wavelength for exciting the light reaches, and the ultraviolet ray with the wavelength of 185 nm irradiated from the ultraviolet light source converts oxygen molecules into ozone. The UV light having the wavelength of 254 nm exhibits its deodorizing and bactericidal action by itself, and the light from the ultraviolet light to the visible light that excites the photocatalyst acts on the photocatalyst of the photocatalyst carrying member. Exciting and exhibiting oxidation / reduction action excites ultraviolet rays and photocatalysts with wavelengths of 185 nm and 254 nm irradiated from an ultraviolet light source. By using light from ultraviolet rays to visible light effectively, ozone deodorizing and sterilizing action, ultraviolet light itself deodorizing and sterilizing actions, and photocatalysts such as titanium oxide, etc., are used to remove pollutants in the air. It can be suitably decomposed and sterilized.

  In addition, the photocatalyst carrying member adheres a linear body or non-woven fabric carrying a photocatalyst to a glass substrate that blocks ultraviolet rays having a wavelength of 185 nm and 254 nm and transmits light from ultraviolet rays to visible light that excites the photocatalyst. As a result, the surface area of the photocatalyst can be remarkably increased and air can be circulated suitably, and the linear body and nonwoven fabric carrying the photocatalyst are not deteriorated by ultraviolet rays of 185 nm and 254 nm. By the oxidation / reduction action, pollutants in the air can be suitably decomposed and sterilized over a long period of time.

  FIG. 1 shows an air purifying apparatus 1 according to the present invention. In this embodiment, a flat type ultraviolet discharge tube 2 and a photocatalyst carrying member 3 are arranged with an interval. By allowing air to pass between the ultraviolet discharge tube 2 and the photocatalyst carrying member 3 and on the surface of the photocatalyst carrying member 3 (by an appropriate air blowing means not shown), the pollutants in the air are suitably decomposed and sterilized. It is.

The ultraviolet discharge tube 2 itself emits ultraviolet rays having a wavelength of 185 nm and 254 nm. When excited by the ultraviolet rays having a wavelength of 185 nm and 254 nm, the inner surface is coated with a phosphor 4 that emits ultraviolet rays having a wavelength of 360 nm. 5 and a front glass 6 made of ultraviolet transmissive glass such as quartz glass is used as a discharge space, and the periphery is sealed, and an ultraviolet radiation gas made of a mixed gas of argon and mercury or xenon is sealed inside. The discharge electrode is not particularly shown, but may be formed opposite to the glass surface or may be an electrodeless type. Moreover, as the phosphor 4, (CaZn) ₃ (PO ₄ ) ₂ : Tl, Ca ₃ (PO ₄ ) ₂ : Tl, SrB ₄ O ₇ : Eu, (Ba, Sr, Mg) ₃ Si ₂ O ₇ : Pb BaSi ₂ O ₅ : Pb, YPO ₄ : Ce, Ce (Mg, Ba) Al ₁₁ O ₁₉ , LaPO ₄ : Ce, YAl ₃ (BO ₃ ) ₄ : Gd, YFa: Gd, Pr, etc. Consists of including.

  The photocatalyst-supporting member 3 is coated with a photocatalyst activated by ultraviolet light having a wavelength of 360 nm on one surface of a glass substrate 7 made of soft glass that blocks ultraviolet light having a wavelength of 360 nm while blocking ultraviolet light having a wavelength of 185 nm and 254 nm. The long and narrow linear bodies 8 such as fibers and wires are densely arranged almost vertically and planted by flocking or the like. The linear body 8 is formed on the surface of the glass substrate 7 not facing the ultraviolet discharge tube 2 so as not to be deteriorated by ultraviolet rays having wavelengths of 185 nm and 254 nm.

The photocatalyst is made of titanium oxide (TiO ₂ ) or the like in which holes and electrons excited by light exert an oxidation / reduction action, and is supported on the linear body 8 by an impregnation supporting method or a CVD method (chemical vapor deposition method). is there. In the impregnation support method, for example, the linear body 8 (or the photocatalyst support member 3 provided with the linear body 8) is immersed in a methanol solution of titanium isopropoxide to impregnate the components, and then in a 0.1N HCl aqueous solution. For 3 hours and then dried at 120 ° C. for 1 hour. This operation is repeated 1-3 times, and further, the photocatalyst is supported on the linear body 8 by baking at 550 ° C. for 15 hours. In the CVD method, steam containing titanium tetrachloride obtained by bubbling oxygen or dry air in titanium tetrachloride is introduced into an electric furnace maintained at 100 to 400 ° C. on which the linear body 8 is placed. The photocatalyst is supported on the linear body 8 with The photocatalyst supported on the surface of the linear body 8 exerts a strong oxidizing action by being excited by irradiation with ultraviolet light having a wavelength of about 360 nm or near ultraviolet light having a wavelength of about 400 nm. It oxidizes and decomposes pollutants. As the photocatalyst, metal oxides such as ZnO, SrTiO ₃ , BaTiO ₃ , and Fe ₂ O ₃ can be used in addition to the above titanium oxide, and among these, anatase type titanium oxide is most preferably used. can do.

In the air purification apparatus 1 of the present embodiment having such a configuration, first, the ultraviolet discharge tube 2 is discharged, so that ultraviolet rays having wavelengths of 185 nm and 254 nm are irradiated, and a part of the ultraviolet light passes through the front glass 6. Among them, the ultraviolet light having a wavelength of 185 nm transmitted through the front glass 6 acts on oxygen molecules to generate ozone, and this ozone deodorizes the air passing between the ultraviolet discharge tube 2 and the photocatalyst support member 3.・ Exhibits bactericidal action to oxidize and decompose odorous components, bacteria, and pollutants in the air. Further, the ultraviolet light having a wavelength of 254 nm transmitted through the front glass 6 exerts a deodorizing and sterilizing action by itself, so that the odor component, bacteria, Oxidative decomposition of pollutants.
Further, the remaining ultraviolet rays having a wavelength of 185 nm and 254 nm irradiated by the ultraviolet discharge tube 2 generate ultraviolet rays having a wavelength of 360 nm by exciting the phosphor 4 applied to the inner surface of the rear glass 5, and the wavelength of 360 nm. The ultraviolet rays pass through the front glass 6 and further pass through the glass substrate 7 of the photocatalyst carrying member 3 to activate the photocatalyst deposited on the linear body 8. The activated photocatalyst exhibits a deodorizing and sterilizing action on the air passing through the gaps between the linear bodies 8 of the photocatalyst carrying member 3 to oxidize and decompose odor components, bacteria, and pollutants in the air.

  In this way, the ultraviolet discharge tube 2 and the photocatalyst are supported so that the air purifying apparatus 1 that exerts a deodorizing and sterilizing action on the air to oxidize and decompose odorous components, bacteria, and pollutants further functions continuously. The air is taken in by a fan member or the like from one side of the apparatus so that new air is always circulated between the members 3 and the surface of the photocatalyst supporting member 3, and the air is deodorized and sterilized. Is sent from the other side.

  Moreover, as another Example of the air purification apparatus of this invention, as shown in FIG. 2, it is set as the structure which used the nonwoven fabric instead of the linear body mentioned above. That is, one surface of a flat-type ultraviolet discharge tube 2 and a glass substrate 9 made of soft glass that transmits ultraviolet light having a wavelength of 360 nm while blocking ultraviolet rays of 185 nm and 254 nm (surface not facing the ultraviolet discharge tube 2). In addition, an air purification device 12 having a structure in which a photocatalyst carrying member 11 provided with a non-woven fabric 10 coated with a photocatalyst activated by an ultraviolet ray having a wavelength of 360 nm is provided at an interval, and the ultraviolet discharge tube 2 and the photocatalyst carrying are provided. By allowing air to pass between the member 11 and the surface of the photocatalyst carrying member 11, contaminants in the air are suitably decomposed and sterilized.

As an example of this nonwoven fabric 10, fibers formed from a core part made of high melting point polypropylene and a sheath part made of low melting point polyethylene surrounding the core part are randomly stacked and heat-treated to obtain a low melting point fiber. By melting only polyethylene, the fibers are bonded to form a nonwoven fabric. Then, the nonwoven fabric 10, the impregnation method or the CVD method as described above is supported photocatalyst such as titanium oxide (TiO _2), which shall be fixed to one surface of the glass substrate 9 and the photocatalyst carrying member 11 It is.

In the above-described embodiment, the photocatalyst excited by irradiation with ultraviolet light having a wavelength of about 360 nm or near ultraviolet light having a wavelength of about 400 nm has been described, but the present invention is not limited to this and is currently known. The photocatalyst excited by light from 300 to 520 nm wavelength to visible light or a photocatalyst excited by longer wavelength light that will be discovered in the future may be used. The phosphor 4 is also described as emitting phosphors having a wavelength of 360 nm when excited by ultraviolet rays of 185 nm and 254 nm, but is not limited thereto, and has a wavelength of 300 to 520 nm (or more). It may emit light from ultraviolet rays to visible light.
In addition, the material used for the photocatalyst carrying member is not limited to the above-mentioned linear body or nonwoven fabric, and has a large surface area with air permeability that can carry a photocatalyst such as a porous material and can circulate air. If there is anything.

It is explanatory drawing which shows the air purification apparatus of this invention. It is explanatory drawing which shows the other Example of the air purification apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air purification apparatus 2 Ultraviolet discharge tube 3 Photocatalyst carrying member 4 Phosphor 5 Back glass 6 Front glass 7 Glass substrate 8 Linear body 9 Glass substrate 10 Nonwoven fabric 11 Photocatalyst carrying member 12 Air purification apparatus

Claims (2)

An ultraviolet light source that irradiates light from ultraviolet light that excites a photocatalyst such as ultraviolet light having a wavelength of 185 nm and 254 nm and titanium oxide (TiO ₂ ) to visible light, and a position where light having a wavelength that excites the photocatalyst from the ultraviolet light source reaches. And a photocatalyst carrying member that carries photocatalysts arranged at intervals, and the ultraviolet light with the wavelength of 185 nm irradiated from the ultraviolet light source changes oxygen molecules into ozone to exert a deodorizing and sterilizing action. In addition, the ultraviolet light having a wavelength of 254 nm exhibits a deodorizing and sterilizing action by itself, and light from the ultraviolet light to the visible light that excites the photocatalyst excites the photocatalyst of the photocatalyst carrying member to exhibit an oxidizing / reducing action. An air purification device that decomposes and sterilizes odorous components, bacteria, and pollutants in the air.   The photocatalyst-carrying member is formed by adhering a linear or non-woven fabric carrying a photocatalyst to a glass substrate that blocks ultraviolet rays having wavelengths of 185 nm and 254 nm and transmits light from ultraviolet rays to visible light that excites the photocatalyst. The air purifier according to claim 1.

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