JP2007130042A - Air cleaner using photocatalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an efficient decomposition of air with an even air stream passing through a photocatalyst filter unit by acquiring the optimum velocity attributed to substances to be decomposed securing an effective area of a filter with a photocatalyst carrier without increase in size of the apparatus relating to a cleaner which takes in a large amount of air using a photocatalyst to be discharged outside a chamber immediately being lowered down below an exhaust reference value. <P>SOLUTION: In an air cleaner with a photocatalyst filter unit 10 which is disposed with a plurality of long and provided with photocatalyst carrier filters in parallel with each other so as to hold the ultraviolet ray sources 12 therein, the photocatalyst filter unit 10 is provided inclined to the air flow 7 flowing in and the long and thin ultraviolet ray sources 12 are made orthogonal to the air flow 9 along its length orthogonal to the inclination of the photocatalyst filter unit 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air purification device that uses a photocatalyst to decompose harmful chemical substances and bad odors to detoxify or deodorize, and particularly relates to a purification device that can take in a large amount of air and immediately discharge it to the outside as a discharge standard value or less. .

  Conventionally, a photoreactive semiconductor such as titanium oxide (hereinafter referred to as a photocatalyst) is excited by applying an ultraviolet light source (black light, mercury lamp, etc.) to generate OH radicals, and the activated photocatalyst passes air to be purified. Air purification devices that decompose pollutants and detoxify, deodorize, or sterilize are known.

  In such an air purification apparatus, for example, a photocatalyst carrier in which a microporous film is formed by applying a photocatalyst to a ceramic porous substrate and firing a dried and solidified film is used.

  In such an air purification apparatus using a photocatalyst carrier, the speed at which air passes through the photocatalyst carrier is a major problem in the step of decomposing organic matter in the air. For example, the flow rate of a duct for air conditioning or the like is 5 m / second or more, but this flow rate is too fast to decompose organic matter in the air with a photocatalyst.

  Although the optimum flow rate varies depending on the substance to be decomposed, it is about 0.4 m / sec for organic solvents such as toluene, 0.7 to 0.8 m / sec for ammonia and the like, and 1.2 for purifying air discharged from supermarkets and the like. -1.3 m / sec.

In addition, when incorporated as a device, a straight tube fluorescent lamp-shaped black light or the like is used as an ultraviolet light source and a holding frame thereof is required. turn into. When the passing speed of the photocatalyst carrier filter is considered as an intermediate speed of ammonia (v = 0.7 m / sec), when the duct flow rate is 5 m / sec, 5 m / sec ÷ 0.7 m / sec × 2 = 14. 3
Therefore, a device cross-sectional area of about 15 times the duct cross-sectional area is required.

  In this problem, it is desired to suppress the device cross-sectional area to about 4 to 5 times the duct cross-sectional area. Therefore, how to secure the effective area of the photocatalyst carrier filter without increasing the size of the apparatus is an important issue.

  For example, as disclosed in Japanese Patent Application Laid-Open No. 2003-230806, a gas processing body formed in a cylindrical shape using a gas processing body filter, a closing unit that closes one end side opening of the cylindrical gas processing body, and a gas processing With the casing covering the body, the gas introduced from the closing means side of the gas processing body in the casing passes through the gas processing body filter on the side of the gas processing body and is discharged from the inside of the gas processing body. What secures an area is known.

  In this gas processing apparatus, the gas processing body filter is a deodorizing photocatalytic filter, and the photocatalytic filter is combined with a light source to form a photocatalytic cartridge having a fixed shape.

  Further, as shown in JP-A-10-258118, an upstream photocatalyst plate filter into which air is introduced, a downstream photocatalyst plate filter that is arranged downstream of the upstream photocatalyst plate filter and from which air flows out, An upstream photocatalyst comprising an upstream photocatalyst plate filter disposed in the depth direction between the upstream photocatalyst plate filter and the downstream photocatalyst plate filter, and a catalyst excitation lamp that irradiates ultraviolet rays toward the downstream photocatalyst plate filter. It is known that at least one of the plate filter and the downstream photocatalyst plate filter is disposed obliquely with respect to the air inflow direction to ensure an effective area. This photocatalyst filter unit secures an effective area of the photocatalyst carrier filter by reducing its cross-sectional area.

  In this photocatalyst filter unit, each surface of the upstream photocatalyst plate filter and the downstream photocatalyst plate filter is composed of a photoexcitation catalyst material that is excited by ultraviolet rays from a single catalyst excitation lamp. This photocatalytic filter unit is provided in a single stage. However, when the indoor air is passed through the purification device several times for purification, the one that has not been decomposed in one pass gradually decomposes. Therefore, the photocatalytic filter unit may be one stage.

  As a next problem, there is a problem of maintenance of the photocatalyst carrier filter.

  When the organic matter in the air is decomposed with the photocatalyst, the decomposed organic matter turns into a salt, which adheres to the surface of the photocatalyst-supporting filter, and the decomposition performance decreases with time. For example, when a gas containing ammonia is decomposed, nitrate is generated and adheres to the surface of the filter.

  In order to solve this, it is better to wash the salt adhering to the photocatalyst carrier filter, but in order to wash the water with the photocatalyst carrier filter attached, a structurally fluorescent light source is used. Is not appropriate. A method other than removing the photocatalyst carrier filter, washing it with water or hot water, and attaching it again is not conceivable. Depending on the concentration of the organic matter to be decomposed, generally high-concentration gas that must be treated requires maintenance once a month.

  When the photocatalyst carrier filters are provided in multiple stages, the upstream side photocatalyst carrier filter requires more maintenance.

  Furthermore, ultraviolet light sources such as black light also have a lifetime and require periodic replacement.

  Therefore, a photocatalyst filter unit (cartridge) in which the photocatalyst carrier filter and the ultraviolet light source are integrated is desirably set in a range that can be held by a human hand (weight is within 20 kg / piece).

Even the one disclosed in Japanese Patent Application Laid-Open No. 2003-230806 described above is provided with an opening for maintenance of the opening / closing door in the casing so that the photocatalyst cartridge can be removed and taken out of the apparatus.
JP 2003-230806 A JP-A-10-258118

  In order to take in a large amount of high-concentration gas and immediately discharge it to the room below the discharge standard value, a photocatalyst filter unit consisting of a photocatalyst carrier filter and an ultraviolet light source is provided in multiple stages, and the air to be treated is passed through it in series. It is necessary to decompose organic matter. Depending on the concentration of gas in the air to be treated, it is necessary to pass at least two stages of photocatalytic filter units in series with a high concentration gas.

  Even in the above-mentioned Japanese Patent Application Laid-Open No. 2003-230806, it is possible to provide a cylindrical gas processing body in a multi-stage by further providing a cylindrical gas processing body, but the inside of the cylindrical gas processing body becomes smaller. As a result, the effective area of the photocatalyst carrier filter cannot be secured. Or, when the equivalents are connected in series, the device becomes longer correspondingly.

  Further, when the one disclosed in Japanese Patent Laid-Open No. 10-258118 is multistaged, the apparatus becomes correspondingly large.

  Next, when the photocatalyst carrier filter is simply tilted with respect to the air flow, the flow velocity at the center of the filter increases, the flow velocity at the end decreases, and the pressure loss tends to increase. If the filter is slanted, it is only the resistance against the air flow, and it is thought that it tends to concentrate on the flowable part. If there are a high-speed part and a low-speed part, it will be difficult to obtain an optimal flow rate depending on the substance to be decomposed.

  Even the above-mentioned Japanese Patent Application Laid-Open No. 10-258118 is thought to flow in a concentrated manner in a portion that is easy to flow, but there is no description of how to deal with it.

  Therefore, the present invention secures an effective area of the photocatalyst carrier filter without increasing the size of the device and can obtain an optimum flow rate by the substance to be decomposed, facilitates maintenance of the photocatalyst carrier filter and the ultraviolet light source, and does not increase the cross section of the device. An object of the present invention is to provide an air purification apparatus using a photocatalyst, in which photocatalyst filter units are provided in multiple stages, and an air flow passing through the photocatalyst filter unit is uniform and can be efficiently decomposed.

  An air purification apparatus using a photocatalyst according to the first aspect of the present invention comprises a photocatalyst filter unit 10 in which a plurality of elongated ultraviolet light sources 12 are arranged in parallel and a photocatalyst carrier filter 13 is provided in parallel so as to sandwich the ultraviolet light sources 12. In the apparatus for purifying air, the photocatalytic filter unit 10 is inclined with respect to the inflowing air flow 7.

  The air purifying apparatus using the photocatalyst according to the invention of claim 2 is one in which the longitudinal direction of the elongated ultraviolet light source 12 is orthogonal to the air flow 9 as the direction orthogonal to the inclination direction of the photocatalytic filter unit 10.

  In the air purification apparatus using the photocatalyst according to the invention of claim 3, two inclined photocatalyst filter units 10 are arranged in the shape of "F", and the total amount of the air flow 9 passing through one photocatalyst filter unit 10 is The other photocatalytic filter unit 10 passes in series.

  According to the first aspect of the present invention, a device for purifying air by a photocatalytic filter unit 10 in which a plurality of elongated ultraviolet light sources 12 are arranged in parallel and a photocatalyst carrier filter 13 is provided in parallel so as to sandwich the ultraviolet light sources 12 is interposed. Therefore, the photocatalyst filter unit 10 is provided to be inclined with respect to the inflowing air flow 7, and the effective area of the photocatalyst carrier filter 13 can be increased with respect to the cross-sectional area of the device accommodating the photocatalyst filter unit 10. Optimum flow rates can be obtained with materials that decompose without enlarging the apparatus.

  Further, since the photocatalyst filter unit 10 is provided with the plurality of elongated ultraviolet light sources 12 arranged in parallel and the photocatalyst carrier filter 13 provided in parallel so as to sandwich the ultraviolet light source 12, the photocatalyst carrier filter 13 and the ultraviolet light source 12 are provided. Maintenance can be made easy.

  According to the invention of claim 2, the longitudinal direction of the elongated ultraviolet light source 12 is orthogonal to the air flow 9 as a direction orthogonal to the inclination direction of the photocatalytic filter unit 10, and passes through the photocatalyst carrier filter 13 by the ultraviolet light source 12. Since the air flow 9 is rectified, the air flow passing through the photocatalytic filter unit 10 becomes uniform and can be efficiently decomposed.

  According to the third aspect of the present invention, two inclined photocatalytic filter units 10 are arranged in the shape of a letter “F”, and the total amount of the air flow 9 passing through one photocatalytic filter unit 10 is the other photocatalytic filter unit. Since 10 passes in series, the photocatalytic filter units 10 can be provided in multiple stages without increasing the cross section of the apparatus.

  FIG. 1 is a side view of an air purification apparatus 1 according to an embodiment of the present invention, which takes in a large amount of high-concentration gas, passes a two-stage photocatalytic filter unit 10 in series, and immediately sets it to an emission standard value or less. It is suitable for discharging outside.

  The air purification apparatus 1 is provided with a box-shaped sealed casing 2 having openings at both ends, and reducers 3 and 4 at both ends of the casing 2, and the inflowing air flow 7 enters from the reducer 3 in the horizontal direction. It is discharged in the horizontal direction as an air flow 8 that is exhausted from the reducer 4 through the interior.

  A large number of photocatalytic filter units 10 are installed in the housing 2, and the photocatalytic filter units 10 are inserted and held in the photocatalytic unit frame 5. In the embodiment, seven rows of photocatalyst unit frames 5 are arranged in the vertical direction, and three rows of photocatalyst unit frames 5 are arranged in the front-rear direction of FIG. 1, and two photocatalyst filter units 10 are arranged in each photocatalyst unit frame 5, for a total of 42 photocatalysts. A filter unit 10 is installed.

  The photocatalyst unit frame 5 has a box shape with openings at both ends, and its bottom plate 5a has a pair of inclined surfaces with a central portion raised in the shape of a "f", and the pair of inclined surfaces of the bottom plate 5a have openings through which air flows. 5b is provided. The photocatalyst unit frame 5 is provided with guide bodies 5c above both sides of the opening at both ends, the lower surface of the guide body 5c is parallel to the inclination of the bottom plate 5a, and the interval in which the photocatalytic filter unit 10 is placed between the guide body 5c and the bottom plate 5a. Keep it open. In the embodiment, the inclination angle of the bottom plate 5a is 15 degrees from the horizontal.

  A maintenance space in which the photocatalytic filter unit 10 can be taken out is provided on the upstream side and the downstream side where the photocatalyst unit frame 5 is installed in the housing 2, and a door is provided in the housing 2 corresponding to the space.

  The photocatalyst filter unit 10 is provided with a photocatalyst unit frame 11 that is a substantially square frame, and a plurality of ultraviolet light sources 12 are arranged in parallel at equal intervals in the photocatalyst unit frame 11. The photocatalyst unit frame 11 has a width of about 75 cm, a depth of about 60 cm, and a thickness of about 8.5 cm.

  As the ultraviolet light source 12, eight 20 W black lights (or including a fluorescent lamp for insect traps) in the shape of a long straight tube fluorescent lamp are arranged in parallel at equal intervals, and the interval is about the tube diameter of the ultraviolet light source 12.

  A plate-like photocatalyst carrier filter 13 is provided in parallel so as to sandwich the plurality of ultraviolet light sources 12 vertically. The photocatalyst carrier filter 13 is a ceramic porous substrate having a photocatalyst such as titanium oxide supported on the surface thereof, and four photocatalyst carrier filters 13 are arranged without gaps on one side.

  A prefilter 14 is placed on the photocatalyst carrier filter 13 on one side, and the prefilter 14 is on the side of the inflowing air stream 7.

  A handle 15 is provided on one side surface of the photocatalyst unit frame 11 parallel to the ultraviolet light source 12, and the photocatalyst filter unit 10 is put in and out of the photocatalyst unit frame 5 with the handle 15 during maintenance. The weight of the photocatalytic filter unit 10 is about 18 kg, and is in a range that can be held by a person.

  The photocatalyst filter unit 10 is held by the photocatalyst unit frame 5, and the photocatalyst filter unit 10 is provided so as to be inclined with respect to the inflowing air flow 7. In the Example, it arrange | positioned so that one end might become high and the other end might become low toward the downstream from the upstream of the air flow 7 which flows in. In addition, the inclination angle of the photocatalytic filter unit 10 is 15 degrees, but in order to secure an effective area of the photocatalyst carrier filter 13, the inclination is preferably 45 degrees or less (preferably 35 degrees or less).

  The longitudinal direction of the elongated ultraviolet light source 12 was orthogonal to the air flow 9 as a direction orthogonal to the inclination direction of the photocatalytic filter unit 10. In the embodiment, a plurality of horizontal ultraviolet light sources 12 are arranged with an inclination of 15 degrees in the vertical direction.

  The air flow 9 passing through the photocatalytic filter unit 10 is rectified through a narrow ultraviolet light source 12 orthogonal to the air flow 9. In other words, in the embodiment, the inflowing air flow 7 in the horizontal direction passes between the ultraviolet light sources 12 and is changed to a vertical flow, thereby forming an S-shaped flow path.

  If the ultraviolet light source 12 is arranged parallel to the air flow 9, the flow passes through a shortcut regardless of the ultraviolet light source 12, and its direction is hardly changed.

  The higher one of the two photocatalyst filter units 10 inclined in opposite directions is combined and arranged in the photocatalyst unit frame 5 in a “f” shape. The air flow 9 that has passed through one photocatalytic filter unit 10 passes through the opening 5b of the bottom plate 5a, and the entire amount passes through the other photocatalytic filter unit 10 in series.

  FIG. 6 shows a configuration corresponding to a low-concentration gas in the case where the inflowing air flow 7 passes through the one-stage photocatalytic filter unit 10. Each photocatalyst filter unit 10 is held by a plurality of photocatalyst unit frames 25 in the vertical direction, and the photocatalyst filter unit 10 is inclined with respect to the inflowing air flow 7.

  FIG. 7 shows a configuration when the inflowing air flow 7 passes through the three-stage photocatalytic filter unit 10 in an apparatus corresponding to a particularly high concentration gas. In this case, the two-stage photocatalyst filter unit 10 by the photocatalyst unit frame 5 shown in FIG. 2 and the one-stage photocatalyst filter unit 10 shown in FIG. 6 are passed in series.

  A flow rate holding plate 6 is provided horizontally from above the handle 15 of the photocatalyst filter unit 10 in the two-stage photocatalyst unit frame 5 to above the handle 15 of the photocatalyst filter unit 10 in the one-stage photocatalyst unit frame 25, In addition, the air flow 8 to be discharged is held upward and can be removed during maintenance. The flow rate holding plate 6 is preferably provided when the photocatalyst filter unit 10 has three or more stages. If the flow rate holding plate 6 is not provided, a vertical flow rate flow rate is separated.

  In the above embodiment, the example in which the inflowing air flow 7 is in the horizontal direction is shown, but the inflowing airflow 7 may be in the vertical direction.

  Further, the example in which the inflowing air flow 7 passes through the photocatalytic filter unit 10 in three stages in series has been shown, but the photocatalytic filter unit 10 may pass through four or more stages in series.

It is a side view which shows one Example of the air purification apparatus using a photocatalyst. It is the elements on larger scale which show the principal part which notched the part. It is a perspective view of a photocatalyst unit frame. It is a top view of a photocatalyst filter unit. FIG. 5 is a side view of FIG. 4. It is a figure which shows another Example of FIG. It is a figure which shows another Example of FIG.

Explanation of symbols

7 Incoming air flow 9 Air flow
10 Photocatalytic filter unit
12 UV light source
13 Photocatalyst carrier filter

Claims (3)

  In an apparatus for purifying air with a photocatalyst filter unit in which a plurality of elongated ultraviolet light sources are arranged in parallel and a photocatalyst carrier filter is provided in parallel so as to sandwich the ultraviolet light source, the photocatalyst filter unit is adapted to the inflowing air flow. An air purification device using a photocatalyst provided to be inclined.   The air purification apparatus using a photocatalyst according to claim 1, wherein the longitudinal direction of the elongated ultraviolet light source is orthogonal to the air flow as a direction orthogonal to the inclination direction of the photocatalytic filter unit.   The photocatalyst according to claim 2, wherein two inclined photocatalyst filter units are arranged in the shape of a "f", and the total amount of airflow that has passed through one photocatalyst filter unit passes through the other photocatalyst filter unit in series. Air purification device used.

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