JP2022135946A - Sterilization purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sterilization purifier which enables purification of gas, and effective sterilization and inactivation of bacteria and viruses.

SOLUTION: A sterilization purifier 1 includes: a photocatalyst filter 5 having a sheet and a plurality of photocatalysts carried on the sheet; a light source 4 having a substrate 4a facing the photocatalyst filter 5, and a first light-emitting element 4a and a second light-emitting element 4c provided on a surface facing the photocatalyst filter 5 of the substrate; and a frame 2 which has a box shape and stores the light source 4 and the photocatalyst filter 5. The first light-emitting element emits ultraviolet light having a peak wavelength of 315 nm or more and 400 nm or less. The second light-emitting element contains a silicone resin as a sealing material, and emits ultraviolet light having a peak wavelength of 280 nm or less.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

An embodiment of the present invention relates to a sterilizing and purifying device.

Reflecting the growing awareness of health, there is an increasing demand for gas purification (for example, air purification) in so-called closed spaces such as trains, automobiles, refrigerators, and living spaces. For example, there is an increasing demand for removal of ammonia and ethylene generated from food, removal of VOCs (Volatile Organic Compounds) such as acetaldehyde contained in cigarette smoke, and deodorization.
Therefore, a photocatalyst device has been proposed that includes a light source having a plurality of light-emitting diodes and a photocatalyst filter carrying a photocatalyst.

Here, generally, a so-called ultraviolet-light-responsive photocatalyst is used for the photocatalyst filter. Therefore, a light emitting diode that emits ultraviolet light is used as the light source. Since ultraviolet light has a bactericidal effect, if a photocatalyst device equipped with a light-emitting diode that irradiates ultraviolet light is used, it is possible to purify the gas by the active oxygen species generated by the photocatalytic action, and also to purify the gas. Bacteria and viruses can be sterilized or inactivated to some extent by the active oxygen species and the ultraviolet light.

However, in recent years, there has been a demand for more effective sterilization and inactivation of bacteria and viruses. In this case, it is possible to provide a photocatalyst device for gas purification such as deodorization and a sterilization device for removing and inactivating bacteria and viruses. This will lead to an increase in the size of the equipment and an increase in the installation space.
Therefore, it has been desired to develop a technique capable of purifying gas and effectively removing and inactivating bacteria and viruses.

JP 2011-218073 A Utility Model Registration No. 3228240

The problem to be solved by the present invention is to provide a sterilization/purification device capable of purifying gas and effectively sterilizing or inactivating bacteria, viruses, and the like.

A sterilization purification device according to an embodiment comprises a photocatalyst filter having a sheet and a plurality of photocatalysts supported on the sheet; a substrate facing the photocatalyst filter; and a substrate facing the photocatalyst filter. A light source having a first light emitting element and a second light emitting element provided on a surface; and a box-shaped frame in which the light source and the photocatalytic filter are accommodated. The first light emitting element emits ultraviolet light having a peak wavelength of 315 nm or more and 400 nm or less. The second light emitting element contains a silicone resin as a sealing material, and emits ultraviolet light with a peak wavelength of 280 nm or less. The gas to be treated flows through the frame from the photocatalyst filter side toward the light source side facing the photocatalyst filter. The second light emitting element is provided closer to the center of the frame than the first light emitting element. The light source is provided downstream of the photocatalyst filter in the flow of the gas. The width dimension of the substrate is smaller than the width dimension of the photocatalytic filter.

According to the embodiment of the present invention, it is possible to provide a sterilization and purification device capable of purifying gas and effectively sterilizing and inactivating bacteria and viruses.

1 is a schematic exploded view for illustrating a sterilization/purification device according to an embodiment; FIG. FIG. 2 is a schematic cross-sectional view of the sterilization/purification device in FIG. 1 taken along line AA. (a) and (b) are schematic cross-sectional views for illustrating a sterilization/purification device according to another embodiment. (a) and (b) are schematic cross-sectional views for illustrating a sterilization/purification device according to a comparative example. It is a graph for illustrating the sterilization effect of airborne bacteria in a closed space. 4 is a graph for illustrating the effects of the arrangement of light sources and photocatalyst filters;

Hereinafter, embodiments will be illustrated with reference to the drawings. In addition, in each drawing, the same reference numerals are given to the same constituent elements, and detailed description thereof will be omitted as appropriate.
FIG. 1 is a schematic exploded view for illustrating the sterilization/purification device 1 according to the present embodiment.
FIG. 2 is a schematic cross-sectional view of the sterilization/purification device 1 in FIG. 1 taken along line AA.
As shown in FIGS. 1 and 2, the sterilization/purification device 1 has, for example, a frame 2, a lid 3, a light source 4, and a photocatalytic filter 5. FIG.

The frame 2 has a box shape. When viewed from the gas G inflow side, the outline of the frame 2 can be substantially rectangular as illustrated in FIG. In this case, the outline of the frame 2 can be, for example, substantially polygonal. However, considering the attachment and detachment of the light source 4 and the photocatalytic filter 5, which will be described later, and space efficiency, it is preferable that the outline of the frame 2 is substantially square.

One end 2a of the frame 2 is open. The end 2b of the frame 2 facing the end 2a is closed. One side surface 2c of the frame 2 is provided with a hole 2c1. A hole 2d1 is provided in a side surface 2d of the frame 2 that faces the side surface 2c.

The hole 2c1 of the side surface 2c and the hole 2d1 of the side surface 2d serve as inlets or outlets for the gas G to be processed. In this case, as shown in FIG. 2, for example, the hole 2c1 in the side surface 2c can be used as an inlet for the gas G, and the hole 2d1 in the side surface 2d can be used as an outlet for the gas G. The hole 2c1 of the side surface 2c may be used as an outlet for the gas G, and the hole 2d1 of the side surface 2d may be used as an inlet for the gas G. In other words, the flow direction of the gas G is not particularly limited.

The gas G can be, for example, a gas whose main component is air and which contains substances to be treated, bacteria, viruses, and the like. The substance to be treated may be any substance that can be purified by photocatalytic action. Substances to be treated can be, for example, VOCs such as ammonia, ethylene, and acetaldehyde.

In addition, at least one of the side surfaces 2c and 2d of the frame 2 may be provided with a filter, grid, or the like. If a filter is provided, it is possible to prevent dust from being sucked inside the frame 2 . Therefore, it is possible to suppress deterioration of the photocatalyst action due to adhesion of dust or the like to the photocatalyst or the light emitting element. If a grid is provided, it is possible to prevent fingers and foreign matter from entering the frame 2 .

A plurality of grooves 2e1 are provided on a side surface 2e of the frame 2 that intersects with the side surface 2c. A plurality of grooves 2f1 are provided on a side surface 2f of the frame 2 that faces the side surface 2e. The plurality of grooves 2e1 and the plurality of grooves 2f1 are opened inside the frame 2. As shown in FIG. The plurality of grooves 2e1 and the plurality of grooves 2f1 are arranged side by side between the side surface 2c and the side surface 2d of the frame 2. As shown in FIG. The plurality of grooves 2e1 and the plurality of grooves 2f1 extend between the ends 2a and 2b of the frame 2. As shown in FIG.

The groove 2e1 is provided substantially parallel to the opposing groove 2f1. A pair of grooves 2e1 and 2f1 facing each other are so-called slots. Each of the light source 4 and the photocatalyst filter 5 is inserted into a pair of grooves 2e1 and 2f1 (slots). The photocatalyst filter 5 inserted in the pair of grooves 2e1 and 2f1 is substantially parallel to the light source 4 inserted in the other pair of grooves 2e1 and 2f1. Therefore, the light emitted from the light source 4 can be efficiently incident on the photocatalyst filter 5 .

If a pair of grooves 2e1 and 2f1 into which the light source 4 and the photocatalyst filter 5 are inserted are provided, the light source 4 and the photocatalyst filter 5 can be inserted into and removed from the inside of the frame 2, respectively. Therefore, it is possible to improve maintainability.

The material of the frame 2 is not particularly limited. However, if the material of the frame 2 is a thermoplastic resin, the frame 2 can be formed using an injection molding method. Therefore, the manufacturing cost can be reduced.

For example, the material of the frame 2 can be ABS resin (acrylonitrile-butadiene-styrene copolymer synthetic resin). If the material of the frame 2 is ABS resin, the moldability can be improved and the cost can be reduced. In this case, if the material of the frame 2 is reinforced ABS resin, the strength of the frame 2 can be improved. The reinforced ABS resin is a mixture of ABS resin and glass fiber.

Also, the material of the frame 2 may be, for example, polypropylene resin or acrylic resin (polymethyl methacrylate resin). In this case, if the material of the frame 2 is an acrylic resin, resistance to ultraviolet light emitted from the light source 4 and resistance to VOCs contained in the gas G are improved. Also, if the polymerization degree of the acrylic resin is about 10,000 to 15,000, odor generation can be suppressed.

Also, the material of the frame 2 can be metal. If the frame 2 is made of metal, the rigidity of the sterilization/purification device 1 can be increased. Metals can be, for example, iron, stainless steel, aluminum alloys, and the like.

A lid 3 is provided at the end 2 a of the frame 2 . A lid 3 covers the opening provided at the end 2a. If the lid 3 is provided, it is possible to prevent the light source 4 and the photocatalyst filter 5 provided inside the frame 2 from detaching. In addition, it is possible to prevent dust and the like from entering the inside of the frame 2 . The lid 3 can be attached to the frame 2 using screws or the like. Alternatively, the lid 3 may be provided with a hook or the like, and the hook may be held by a concave portion or a convex portion provided on the frame 2 . If the lid 3 is detachably attached to the frame 2, it is possible to improve maintainability. The material of the lid 3 is not particularly limited. For example, the lid 3 material can be the same as the frame 2 material.

At least one light source 4 can be provided. A light source 4 is provided inside the frame 2 . The light source 4 faces the photocatalytic filter 5 . In the flow direction of the gas G, the light source 4 may be provided on the upstream side of the photocatalyst filter 5, may be provided on the downstream side, or may be provided on both sides.

The light source 4 has, for example, a substrate 4a, a light emitting element 4b (corresponding to an example of a first light emitting element), and a light emitting element 4c (corresponding to an example of a second light emitting element).
The substrate 4a has a plate shape. The substrate 4a is provided in the gas G flow path. Therefore, if the board|substrate 4a is provided, there exists a possibility that the distribution|circulation of the gas G may be obstructed. In this case, a plurality of holes penetrating in the thickness direction can be provided in the substrate 4a. However, if the size of the hole is small, the pressure loss becomes large, so the flow of the gas G is hindered. If the size of the hole is increased, the arrangement and number of the light emitting elements 4b and 4c and the wiring pattern are restricted.

Therefore, as shown in FIG. 1, the width dimension W1 of the substrate 4a is made smaller than the width dimension W2 of the photocatalyst filter 5. As shown in FIG. The width dimension is the dimension in the direction in which the pair of grooves 2e1 and 2f1 (slots) extend. By doing so, it is possible to ensure the appropriate circulation of the gas G, and to suppress the occurrence of restrictions on the arrangement and number of the light emitting elements 4b and 4c and the wiring patterns.
According to the knowledge obtained by the present inventors, if "W1 (mm)/W2 (mm)" is smaller than 0.5, it becomes easy to ensure proper circulation of the gas G.

The material and structure of the substrate 4a are not particularly limited. For example, the substrate 4a can be made of an inorganic material (ceramics) such as aluminum oxide or aluminum nitride, or an organic material such as paper phenol or glass epoxy. Also, the substrate 4a may be a metal core substrate or the like in which the surface of a metal plate is coated with an insulating material.

When the amount of heat generated by the light emitting elements 4b and 4c is large, it is preferable to form the substrate 4a using a material with high thermal conductivity from the viewpoint of heat dissipation. Examples of materials with high thermal conductivity include ceramics such as aluminum oxide and aluminum nitride, high thermal conductive resins, and metal core substrates. The high thermal conductive resin is, for example, a resin such as PET (polyethylene terephthalate) or nylon mixed with a filler made of aluminum oxide, carbon, or the like.
Further, the substrate 4a may have a single-layer structure or may have a multi-layer structure.

The light-emitting element 4b can be provided on the surface of the substrate 4a facing the photocatalytic filter 5 . When the photocatalyst filter 5 is provided on one side of the light source 4, the light emitting element 4b can be provided on one side of the substrate 4a. When the photocatalytic filters 5 are provided on both sides of the light source 4, the light emitting elements 4b can be provided on both sides of the substrate 4a.

The light emitting element 4b is electrically connected to, for example, a wiring pattern provided on the surface of the substrate 4a. The type of the light emitting element 4b is not particularly limited. The light-emitting element 4b can be, for example, a surface-mounted light-emitting element such as a PLCC (Plastic Leaded Chip Carrier) type. The light-emitting element 4b may be, for example, a bullet-shaped light-emitting element having a lead wire.

Also, the light emitting element 4b may be mounted by a COB (Chip On Board). When the light-emitting element 4b is mounted by COB, a chip-shaped light-emitting element, wiring that electrically connects the light-emitting element and the wiring pattern, a sealing portion that covers the chip-shaped light-emitting element and the wiring, and the like, can be provided on the substrate 4a.

At least one light emitting element 4b can be provided. However, if a plurality of light emitting elements 4b are provided, a wide area of the photocatalytic filter 5 can be irradiated with light. A plurality of light emitting elements 4b can be connected in series. Although there is no particular limitation on the arrangement of the plurality of light emitting elements 4b, it is preferable to provide them substantially evenly on the surface of the substrate 4a. If the plurality of light emitting elements 4b are provided substantially evenly on the surface of the substrate 4a, it becomes easy to evenly irradiate the surface of the photocatalytic filter 5 with light.

Here, the reaction speed of the photocatalyst 5b changes depending on the absorption wavelength range and light intensity (light amount) of the photocatalyst 5b. Therefore, the arrangement and number of the plurality of light emitting elements 4b are determined by the amount of light emitted by one light emitting element 4b, the area of the sheet 5a supporting the photocatalyst 5b, the light emitting surface of the light emitting element 4b and the sheet 5a. can be determined based on the distance between
For example, the arrangement and number of the plurality of light emitting elements 4b are set so that the light irradiation intensity is 1 mW/cm ² or more in 60% or more of the total area of the photocatalytic filter 5 (sheet 5a) closest to the light source 4. preferably.

The light emitting element 4b emits light having a predetermined wavelength toward the sheet 5a supporting the photocatalyst 5b. In this case, if the material or composition of the photocatalyst 5b changes, the absorption wavelength range of the photocatalyst 5b will change. Therefore, the light-emitting element 4b that emits light of an appropriate wavelength is selected according to the absorption wavelength range of the photocatalyst 5b.

For example, if the photocatalyst 5b is an ultraviolet-light-responsive photocatalyst containing titanium oxide or the like, the light-emitting element 4b may be a light-emitting diode or laser diode that emits ultraviolet light having a peak wavelength of, for example, 315 nm or more and 400 nm or less. can do.
In addition, if the photocatalyst 5b is a visible light responsive photocatalyst such as tungsten oxide, the light emitting element 4b has a peak wavelength of, for example, a light emitting diode, a laser diode, or an organic light emitting diode that emits visible light having a peak wavelength of 405 nm or more and 600 nm or less. It can be a diode or the like.
In this case, a plurality of light emitting elements 4b having the same peak wavelength can be provided, or a plurality of types of light emitting elements 4b having different peak wavelengths can be provided.

The light emitting element 4c can be provided on the surface of the substrate 4a on which the light emitting element 4b is provided.
As with the light-emitting element 4b described above, the light-emitting element 4c may be a surface-mounted light-emitting element such as a PLCC type, a bullet-type light-emitting element having lead wires, or a chip-shaped light-emitting element mounted by COB. may

At least one light emitting element 4c can be provided. However, if a plurality of light emitting elements 4c are provided, a wide area of the photocatalytic filter 5 can be irradiated with ultraviolet light.
The light emitting element 4c is electrically connected to, for example, a wiring pattern provided on the surface of the substrate 4a. In this case, for example, the light emitting elements 4c and 4b can be connected in series, or the light emitting elements 4c and 4b can be connected in parallel. Further, for example, the plurality of light emitting elements 4c and the plurality of light emitting elements 4b can be connected in series, or the plurality of light emitting elements 4c and the plurality of light emitting elements 4b can be connected in parallel.

Although there is no particular limitation on the arrangement of the plurality of light emitting elements 4c, it is preferable to provide them substantially evenly on the surface of the substrate 4a. If the plurality of light emitting elements 4c are provided substantially evenly on the surface of the substrate 4a, it becomes easy to evenly irradiate the surface of the photocatalytic filter 5 with light. For example, the light-emitting elements 4c and the light-emitting elements 4b can be provided alternately, or a row of a plurality of light-emitting elements 4c and a row of a plurality of light-emitting elements 4b can be arranged side by side in the width direction of the surface of the substrate 4a. In the case of the light source 4 illustrated in FIG. 1, one light emitting element 4c is provided substantially in the center of the substrate 4a, and two light emitting elements 4c are provided with the light emitting element 4c interposed therebetween.

The number of light emitting elements 4c can be the same as the number of light emitting elements 4b, or can be different.
For example, similar to the light-emitting element 4b described above, the photocatalyst filter 5 (sheet 5a) closest to the light source 4 is 60% or more of the total area, and the light irradiation intensity is 1 mW / cm ² or more. The arrangement and number of the elements 4c can be set.

Here, when the gas G flows inside the frame 2, bacteria and viruses contained in the gas G may adhere to the surface of the photocatalyst filter 5 (sheet 5a). Ultraviolet light has a bactericidal effect, so if ultraviolet light with a peak wavelength of 315 nm or more and 400 nm or less is irradiated from the light emitting element 4b, bacteria and viruses can be sterilized or inactivated to some extent. can be done.

However, in recent years, there is a demand for effective sterilization and inactivation of bacteria and viruses as well as gas purification in closed spaces. In this case, the shorter the peak wavelength of the ultraviolet light, the stronger the bactericidal action.
Therefore, the light emitting element 4c emits ultraviolet light having a shorter peak wavelength than the ultraviolet light emitted from the light emitting element 4b.

For example, the light emitting element 4c can be a light emitting diode or a laser diode that emits ultraviolet light with a peak wavelength of 280 nm or less. In this case, the shorter the peak wavelength, the stronger the bactericidal action, but the price of the light emitting element 4c increases. Therefore, the light-emitting element 4c is preferably a light-emitting diode or a laser diode that emits ultraviolet light with a peak wavelength of 270 nm or more and 280 nm or less.

If such a light-emitting element 4c is provided, it is possible to irradiate the surface of the photocatalyst filter 5 (sheet 5a) with ultraviolet light having a stronger bactericidal action than the ultraviolet light emitted from the light-emitting element 4b. Effective sterilization and inactivation of viruses and the like can be performed. In addition, it is possible to effectively eliminate and inactivate bacteria and viruses contained in the gas G flowing inside the frame 2 .
Details of the effect of the light emitting element 4c will be described later.

The photocatalyst filter 5 has, for example, a sheet 5a and a plurality of photocatalysts 5b.
The sheet 5a is, for example, woven with a plurality of linear bodies. That is, the sheet 5a is a woven fabric containing a plurality of linear bodies.
Here, generally, the sheet carrying the photocatalyst is formed using a plurality of glass fibers. Since the sheet formed from a plurality of glass fibers has low rigidity, a frame-shaped member is required to hold the periphery of the sheet. Further, in recent years, there is a demand for improved processing capability, and there is a tendency for the flow rate and flow velocity of the gas G that permeates the sheet to increase.

Therefore, in order to suppress the deformation of the central region of the seat, the frame-shaped member may be provided with crosspieces or the like. If a frame-like member or a crosspiece is provided, there will be a region where the light emitted from the light emitting elements 4b and 4c cannot enter and the gas G cannot flow, making it impossible to improve the processing capacity.

Therefore, the sheet 5a according to the present embodiment is formed from a plurality of linear bodies containing metal. Materials for the filamentous body include, for example, stainless steel, nickel, monel, phosphor bronze, titanium, copper, copper alloys, silver, and silver alloys.
The wire diameter (thickness) of the linear body can be, for example, 0.016 mm or more and 2.0 mm or less.

If the sheet 5a is formed using such a linear body, the rigidity of the sheet 5a can be increased, so that the flow rate and flow velocity of the gas G passing through the sheet 5a can be increased. In addition, there is no need to provide a frame-like member or crosspiece for reinforcement. Therefore, it is possible to improve the processing capacity of the sterilization/purification device 1 .

Here, if the filamentous body contains a metal, the infectivity of a virus or the like adhering to the surface of the filamentous body is maintained for a certain period of time. However, as described above, the ultraviolet light emitted from the light-emitting element 4c has a strong bactericidal action, so viruses and the like adhering to the surface of the linear body can be easily removed and inactivated.
In addition, if the material of the linear body is a metal that generates copper ions, such as copper or a copper alloy, the copper ions can be used to sterilize or inactivate viruses attached to the surface of the linear body. can.
If the material of the filaments is a metal that generates silver ions, such as silver or a silver alloy, the silver ions can also eliminate or inactivate viruses and the like adhering to the surface of the filaments.

When a plurality of filamentous bodies are woven, gaps are generated in areas defined by adjacent filamentous bodies. That is, the sheet 5a is provided with a plurality of gaps penetrating in the thickness direction. If a plurality of gaps penetrating in the thickness direction are provided, the plurality of gaps serve as gas G flow paths.

There is no particular limitation on the weaving method of the plurality of linear bodies. In this case, if the twill folding is used, a meandering gap is formed in the thickness direction of the sheet 5a. By twill folding, the rigidity of the sheet 5a can be improved and the pressure loss can be reduced. By flat folding, the rigidity of the sheet 5a can be improved and the pressure loss can be reduced.

Here, when the number of gaps between 1 inch (25.4 mm), that is, the number of meshes increases, gaps with small cross-sectional areas are provided. As the cross-sectional area of the gap becomes smaller, the pressure loss of the gas G flowing through the gap becomes larger. In this case, if the pressure loss exceeds 50 Pa, the flow rate of the gas G passing through the sheet 5a is reduced, and there is a possibility that desired processing capacity cannot be obtained. According to knowledge obtained by the present inventors, if the number of meshes is set to 500 or less, the pressure loss can be reduced to 50 Pa or less. Therefore, the number of meshes is preferably 500 or less.

A plurality of photocatalysts 5b are carried on the sheet 5a. The plurality of photocatalysts 5b are, for example, granules. The type of the photocatalyst 5b can be appropriately selected according to the use of the sterilization/purification device 1, substances contained in the gas G, and the like. For example, the photocatalyst 5b can be an ultraviolet-light-responsive photocatalyst, a visible-light-responsive photocatalyst, or the like. The ultraviolet light-responsive photocatalyst contains, for example, titanium oxide. Visible-light-responsive photocatalysts include, for example, tungsten oxide, nitrogen-doped titanium oxide, and titanium oxide implanted with different metal ions.

In this case, as described above, if the photocatalyst 5b is an ultraviolet-light-responsive photocatalyst, the light-emitting element 4b can be a light-emitting element that emits ultraviolet light. Since the wavelength of the ultraviolet light emitted from the light emitting element 4b is longer than the wavelength of the ultraviolet light emitted from the light emitting element 4c, the sterilization effect is weaker than that of the ultraviolet light emitted from the light emitting element 4b. However, if the ultraviolet light is emitted from the light emitting element 4b, the sterilization effect of the ultraviolet light emitted from the light emitting element 4c can be enhanced.

Therefore, it is preferable that the photocatalyst 5b is an ultraviolet-light-responsive photocatalyst such as titanium oxide, and the light-emitting element 4b is a light-emitting diode or laser diode that emits ultraviolet light.

At least one photocatalyst filter 5 can be provided. When a plurality of photocatalyst filters 5 are provided, the plurality of photocatalyst filters 5 can be arranged side by side between the side surface 2c and the side surface 2d of the frame 2. FIG. The photocatalytic filter 5 can be arranged side by side with the light source 4 . The photocatalytic filter 5 can be provided side by side with the light source 4 on the side of the substrate 4a on which the light emitting elements 4b and 4c are provided.

The number of photocatalyst filters 5 is not particularly limited. The number of photocatalyst filters 5 can be appropriately changed according to the flow rate of the gas G, the amount of substances contained in the gas G, the light intensity (light amount) of the light emitted from the light source 4, and the like. In this case, the number of photocatalyst filters 5 can be the same as the number of light sources 4 or can be greater than the number of light sources 4 .

Here, the light source 4 can be provided between the photocatalyst filters 5 by providing the light emitting elements 4b and 4c on both sides of the substrate 4a. The longer the distance between the light source 4 and the photocatalyst filter 5, or the greater the number of other photocatalyst filters 5 provided between the light source 4 and the photocatalyst filter 5, the slower the speed of the photocatalytic reaction. The bactericidal effect is reduced. If the light emitting elements 4b and 4c are provided on both sides of the substrate 4a, the light source 4 can be provided between the photocatalyst filters 5, so that the light source 4 and the photocatalyst filter 5 farthest from the light source 4 can be arranged. can shorten the distance between Also, the number of other photocatalyst filters 5 provided between the light source 4 and the photocatalyst filter 5 can be reduced. Therefore, the speed of the photocatalytic reaction can be increased, and the sterilization effect and the like can be improved.

The photocatalyst filter 5 can be formed, for example, as follows.
First, a sheet 5a is formed by weaving a plurality of linear bodies.
Next, an emulsion solution is produced.
For example, phosphoric acid or the like is added to pure water to generate an aqueous solution with a pH (hydrogen ion concentration) adjusted to 2-7.
Subsequently, a plurality of photocatalysts 5b are added to the aqueous solution.
An emulsion solution can be produced in the manner described above.

Next, the sheet 5a is immersed in the emulsion solution for about 10 minutes.
Next, the sheet 5a is pulled out from the emulsion solution and dried.
Drying can be heat drying.
The photocatalyst filter 5 can be formed in the manner described above.

FIGS. 3(a) and 3(b) are schematic cross-sectional views for illustrating a sterilization/purification device 1a according to another embodiment.
FIG. 3(b) is a schematic cross-sectional view of the sterilization/purification device 1a in FIG. 3(a) taken along line BB.
FIGS. 4A and 4B are schematic cross-sectional views for illustrating a sterilization/purification device 100 according to a comparative example.
4(b) is a schematic cross-sectional view of the sterilization/purification device 100 in FIG. 4(a) taken along line CC.

First, a sterilization/purification device 100 according to a comparative example will be described.
As shown in FIGS. 4(a) and 4(b), the sterilization/purification device 100 has a frame 2, a lid 3, a light source 4, a photocatalyst filter 5, a filter 6, and a fan .
The filter 6 is provided on the side surface 2d of the frame 2, for example.
The fan 7 is provided on the side surface 2c of the frame 2, for example.

The fan 7 exhausts the gas G inside the frame 2 , so that the gas G outside the frame 2 is introduced into the frame 2 via the filter 6 .
Therefore, as shown in FIG. 4B, a flow of gas G is formed inside the frame 2 from the filter 6 side toward the fan 7 side.

Here, silicone resin is used as a sealing material for the light emitting elements 4b and 4c. Although the silicone resin has high resistance to ultraviolet rays, part of the silicone resin may be decomposed when the light emitting elements 4b and 4c are irradiated with ultraviolet rays. In this case, the shorter the peak wavelength of the irradiated ultraviolet rays, the easier it is for the silicone resin to decompose. Therefore, the decomposition of the silicone resin used in the light emitting element 4c is more likely to occur.

Further, heat is generated when the light emitting elements 4b and 4c are irradiated with ultraviolet rays. When the generated heat heats the silicone resin, the decomposition of the silicone resin is more likely to occur.
When the silicone resin is decomposed, gas containing components of the silicone resin is emitted from the light emitting elements 4b and 4c. The gas emitted from the light emitting elements 4b and 4c is discharged to the outside of the frame 2 along with the flow of the gas G flowing inside the frame 2. As shown in FIG.

At this time, as shown in FIG. 4B, the light source 4 (light emitting elements 4b and 4c) is provided upstream of the flow of the gas G flowing inside the frame 2, and the photocatalyst filter 5 is provided downstream of the light source 4. is provided, the silicone resin component contained in the gas G easily adheres to the photocatalyst 5 b of the photocatalyst filter 5 . When the silicone resin component adheres to the photocatalyst 5b, it becomes difficult for ultraviolet rays to enter the photocatalyst 5b, and it becomes difficult for the gas G to be processed to come into contact with the photocatalyst 5b. Therefore, the functions of the sterilization/purification device 100 (purification of gas, sterilization and inactivation of bacteria, viruses, etc.) may deteriorate over time.

As shown in FIGS. 3(a) and 3(b), a sterilization/purification device 1a according to another embodiment has a frame 2, a lid 3, a light source 4, a photocatalyst filter 5, a filter 6, and a fan 7. FIG.
In the sterilization/purification device 1a, the filter 6 is provided on the side surface 2c of the frame 2, for example. The filter 6 faces the photocatalyst filter 5 and is provided on the side opposite to the light source 4 side. The filter 6 is provided to prevent dust from being sucked inside the frame 2 .

The fan 7 is provided on the side surface 2d of the frame 2, for example. The fan 7 is provided on the side of the light source 4 opposite to the photocatalyst filter 5 side. A fan 7 exhausts the gas G inside the frame 2 . The fan 7 forms a flow of the gas G from the side of the photocatalyst filter 5 toward the side of the light source 4 facing the photocatalyst filter 5 .

The fan 7 exhausts the gas G inside the frame 2 , so that the gas G outside the frame 2 is introduced into the frame 2 via the filter 6 .
Therefore, as shown in FIG. 3B, a flow of gas G is formed inside the frame 2 from the filter 6 side toward the fan 7 side.
That is, the gas G to be processed flows from the photocatalyst filter 5 side toward the light source 4 side facing the photocatalyst filter 5 .

As shown in FIG. 3B, in the sterilization purification device 1a, the photocatalytic filter 5 is provided upstream of the flow of the gas G flowing inside the frame 2, and the light source 4 ( Light emitting elements 4b, 4c) are provided. As shown in FIG. 2 , in the sterilization purification device 1 as well, the photocatalyst filter 5 is provided upstream of the flow of the gas G, and the light source 4 is provided downstream of the photocatalyst filter 5 .
Therefore, even if the gas containing the silicone resin component is released from the light emitting elements 4b and 4c, the flow of the gas G prevents the released gas from reaching the photocatalyst filter 5. FIG.
As a result, it is possible to suppress deterioration of the functions of the sterilization/purification device 1a (purification of gas, sterilization and inactivation of bacteria, viruses, etc.) over time.
Details regarding the effect of the arrangement of the light source 4 and the photocatalyst filter 5 will be described later.

Next, the effect of the light emitting element 4c will be further described.
FIG. 5 is a graph for illustrating the sterilization effect of airborne bacteria in a closed space.
D1 in FIG. 5 is the case where only the light emitting element 4b is provided.
D2 in FIG. 5 is the case where the light emitting element 4b and the light emitting element 4c are provided. That is, D2 is the case of the sterilization/purification device 1 .
Confirmation of the sterilization effect of airborne bacteria was performed inside the chamber. The volume of the closed space was 1 ^m3 . The gas contained in the closed space was air containing airborne bacteria.

The light-emitting element 4b was a light-emitting diode that emits ultraviolet light having a peak wavelength of 400 nm and a light intensity of 3500 mW (forward current of 350 mA).
The light-emitting element 4c was a light-emitting diode that emits ultraviolet light having a peak wavelength of 280 nm and a light intensity of 140 mW (forward current of 350 mA).
The photocatalyst 5b of the photocatalyst filter 5 contains particles of titanium oxide and has an average particle size of about 200 μm.
The sheet 5a of the photocatalyst filter 5 was woven with stainless steel filaments and had 200 meshes.

As can be seen from D1 in FIG. 5, when only the light-emitting element 4b was provided, the removal rate of airborne bacteria was about 45% after 30 minutes from the start of energization.
On the other hand, as can be seen from D2 in FIG. 5, when the light emitting element 4b and the light emitting element 4c are provided, the removal rate of airborne bacteria after 30 minutes from the start of energization can be 99% or more. did it.
Incidentally, when only the light emitting element 4b was provided, it took 131 minutes for the removal rate of airborne bacteria to reach 99%.
When the light-emitting element 4b and the light-emitting element 4c were provided, it took 26 minutes for the removal rate of airborne bacteria to reach 99%.

If the light-emitting element 4b is provided, the light emitted from the light-emitting element 4b is incident on the photocatalyst 5b carried on the sheet 5a of the catalyst filter 5, so that active oxygen species and the like can be generated. . If the active oxygen species and the like are generated, the substances contained in the gas G can be treated with the active oxygen species and the like. That is, purification of the gas G can also be performed at the same time.

Next, the effect of arrangement of the light source 4 and the photocatalyst filter 5 will be further described.
FIG. 6 is a graph for illustrating the effects of the arrangement of the light source 4 and the photocatalyst filter 5. In FIG.
FIG. 6 shows changes in deodorizing performance against acetaldehyde over time. The deodorizing performance maintenance rate on the vertical axis is "(deodorizing performance after a predetermined time has elapsed/initial deodorizing performance) x 100".
Note that E1 in FIG. 6 is the case of the sterilization/purification device 100 according to the comparative example described above. That is, this is the case where the light source 4 is provided on the upstream side of the flow of the gas G, and the photocatalyst filter 5 is provided on the downstream side of the light source 4 .
E2 in FIG. 6 is the case of the sterilization/purification devices 1 and 1a described above. That is, this is the case where the photocatalyst filter 5 is provided on the upstream side of the flow of the gas G, and the light source 4 is provided on the downstream side of the photocatalyst filter 5 .

When the light source 4 is provided on the upstream side of the flow of the gas G and the photocatalytic filter 5 is provided on the downstream side of the light source 4 as in the sterilization purification device 100 according to the comparative example, E1 in FIG. , the deodorizing performance retention rate was 19% after 1600 hours from the start of operation.
On the other hand, when the photocatalyst filter 5 is provided on the upstream side of the flow of the gas G and the light source 4 is provided on the downstream side of the photocatalyst filter 5 as in the case of the sterilization purification devices 1 and 1a, , E2 in FIG. 6, the deodorizing performance retention rate after 1600 hours from the start of operation was 84%.
That is, when the photocatalyst filter 5 was provided upstream of the flow of the gas G and the light source 4 was provided downstream of the photocatalyst filter 5, the deodorizing performance maintenance rate could be significantly improved.

As described above, the sterilization and purification device 1 according to the present embodiment can purify gas and effectively sterilize and inactivate bacteria and viruses.
Although some embodiments of the present invention have been illustrated above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof. Moreover, each of the above-described embodiments can be implemented in combination with each other.

1 sterilization purification device 1a sterilization purification device 2 frame 3 lid 4 light source 4a substrate 4b light emitting element 4c light emitting element 5 photocatalyst filter 5a sheet 5b photocatalyst 6 filter 7 fan G gas

Claims (4)

a photocatalyst filter comprising a sheet and a plurality of photocatalysts carried on the sheet;
a light source having a substrate facing the photocatalytic filter, and a first light emitting element and a second light emitting element provided on a surface of the substrate facing the photocatalytic filter;
a box-shaped frame housing the light source and the photocatalyst filter;
and
The first light emitting element emits ultraviolet light having a peak wavelength of 315 nm or more and 400 nm or less,
The second light emitting element contains a silicone resin as a sealing material and irradiates ultraviolet light with a peak wavelength of 280 nm or less,
The gas to be treated flows through the frame from the photocatalyst filter side toward the light source side facing the photocatalyst filter,
the second light emitting element is provided closer to the center of the frame than the first light emitting element;
The light source is provided on the downstream side of the gas flow of the photocatalytic filter,
The width dimension of the substrate is smaller than the width dimension of the photocatalyst filter. 2. The sterilizing and purifying device according to claim 1, further comprising a filter facing said photocatalyst filter and provided on a side opposite to said light source. 3. The sterilizing and purifying device according to claim 1, further comprising a fan that forms a flow of the gas from the side of the photocatalyst filter toward the side of the light source facing the photocatalyst filter. 4. The sterilizing and purifying device according to claim 3, wherein the fan is provided on the side of the light source opposite to the photocatalyst filter side.

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