air purifier

Abstract

To efficiently irradiate the airflow with ultraviolet light.SOLUTION: An air purifier 10 includes: a light source 14 that emits ultraviolet light 40 in the direction of airflow; and a blunt object 16 that is mounted to the light source 14 and projects in the direction opposite to the airflow direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air purification device. [Background technology]

[0002] Air purifiers that purify air by irradiating it with ultraviolet light are known. For example, a technique has been proposed in which a swirling airflow is generated in a cyclone chamber and the swirling airflow is irradiated with ultraviolet light (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-122645 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned prior art requires a fan to generate a swirling airflow, which makes the device configuration complicated.

[0005] The present invention has been made in view of the above problems, and one of its exemplary purposes is to provide a technique for efficiently irradiating an airflow with ultraviolet light. [Means for solving the problem]

[0006] An air purifying device according to one aspect of the present invention includes a light source that irradiates ultraviolet light in the direction of air flow, and a blunt object that is attached to the light source and protrudes in the opposite direction to the air flow.

[0007] According to the present invention, ultraviolet light can be efficiently irradiated onto an airflow. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of an air purification device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a schematic configuration of the light source in FIG. [Figure 3] FIG. 2 is a diagram illustrating a schematic configuration of the bluff body of FIG. 1. [Figure 4] 10A and 10B are diagrams schematically illustrating the effects of the air purification device according to the embodiment. [Figure 5] FIG. 10 is a diagram schematically illustrating the configuration of an air purification device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. To facilitate understanding of the description, the dimensional ratios of the components in each drawing do not necessarily correspond to the actual dimensional ratios.

[0010] 1 is a diagram schematically illustrating the configuration of an air purifying device 10 according to an embodiment. The air purifying device 10 includes a housing 12, a light source 14, and a blunt object 16. The air purifying device 10 is configured to purify air by irradiating air flowing through an internal space 18 of the housing 12 with ultraviolet light 40 from the light source 14.

[0011] The housing 12 has an internal space 18 through which air flows. The housing 12 has an inner surface 20 exposed to the internal space 18. The inner surface 20 of the housing 12 is made of a metal material such as a galvanized iron plate, a galvalume steel plate (registered trademark), or a stainless steel plate. The inner surface 20 of the housing 12 may be made of a material that reflects ultraviolet light 40. Examples of materials that reflect ultraviolet light include metal materials such as aluminum (Al) and fluorine-based resin materials such as polytetrafluoroethylene (PTFE). The inner surface 20 of the housing 12 may be provided with a photocatalytic material that is activated by ultraviolet light 40. Examples of photocatalytic materials that can be used include titanium oxide.

[0012] The housing 12 includes an inlet 22, an inflow section 23, a main body section 24, an outlet section 25, and an outlet 26. Air flowing in from the inlet 22 as indicated by arrow F1 passes through the inlet 23, main body section 24, and outlet section 25 in that order, and flows out from the outlet 26 as indicated by arrow F2. The housing 12 is provided, for example, midway through a duct through which air flows. The inlet 22 is connected, for example, to an upstream duct, and the outlet 26 is connected, for example, to a downstream duct.

[0013] The main body portion 24 is configured so that its flow path cross-sectional area is larger than those of the inlet 22 and the outlet 26. The main body portion 24 extends, for example, linearly in a predetermined direction, and is configured so that its flow path cross-sectional area is constant. The inlet portion 23 connects the inlet 22 and the main body portion 24. The inlet portion 23 is configured so that its flow path cross-sectional area gradually increases from the inlet 22 toward the main body portion 24. The outlet portion 25 connects the main body portion 24 and the outlet 26. The outlet portion 25 is configured so that its flow path cross-sectional area gradually decreases from the main body portion 24 toward the outlet 26.

[0014] In the drawings, the direction in which main body 24 extends is designated as the z direction, and two directions perpendicular to the z direction are designated as the x and y directions. The air flows in internal space 18 in the +z direction. These directions are set for the sake of convenience in explanation and do not in any way limit the orientation of air purifier 10 when installed or used.

[0015] The light source 14 is disposed in the internal space 18 of the housing 12. The light source 14 is disposed inside the main body 24. The light source 14 is configured to irradiate ultraviolet light 40 in the air flow direction (e.g., the +z direction). The light source 14 is disposed, for example, near the inlet 23, and irradiates the ultraviolet light 40 from the upstream side to the downstream side of the main body 24.

[0016] The light source 14 includes at least one light-emitting unit 30. The light source 14 may include multiple light-emitting units 30. The multiple light-emitting units 30 are arranged at intervals in a first direction (e.g., the x direction). The first direction (e.g., the x direction) is a direction that intersects or is perpendicular to the direction in which the ultraviolet light 40 is irradiated (e.g., the +z direction). In the example shown in FIG. 1, the light source 14 includes three light-emitting units 30. The number of light-emitting units 30 included in the light source 14 is not particularly limited, and may be one, two, or four or more.

[0017] The light-emitting unit 30 includes a substrate 32 and a light-emitting element 34. The light-emitting element 34 is provided on a first surface 32a of the substrate 32. The light-emitting element 34 is an LED (Light Emitting Diode) configured to output ultraviolet light. The light-emitting element 34 is configured to output ultraviolet light having a wavelength of, for example, 200 nm or more and 320 nm or less, for example, a wavelength of 240 nm or more and 280 nm or less.

[0018] FIG. 2 is a diagram schematically illustrating the configuration of the light source 14 in FIG. 1. The substrate 32 extends in a second direction (e.g., y direction) perpendicular to a first direction (e.g., x direction). The substrate 32 has a strip shape. The light source 14 may include a plurality of substrates 32. The plurality of substrates 32 are arranged at intervals in the first direction (e.g., x direction). Gaps 38 between the plurality of substrates 32 serve as passages for air. The width w1 of the substrate 32 in the first direction may be the same as, greater than, or smaller than the width w2 of the gap 38 in the first direction.

[0019] The light-emitting unit 30 can include a plurality of light-emitting elements 34. The plurality of light-emitting elements 34 are arranged in a second direction (for example, the y direction) on the substrate 32. In the example shown in Fig. 1 , one light-emitting unit 30 includes five light-emitting elements 34, and the light source 14 includes 3 x 5 = 15 light-emitting elements 34. The number of light-emitting elements 34 included in the light-emitting unit 30 is not particularly limited, and may be 1 to 4, or may be 6 or more.

[0020] Returning to FIG. 1 , the blunt object 16 is disposed in the internal space 18 of the housing 12. The blunt object 16 is attached upstream of the light source 14. The blunt object 16 is provided, for example, on the second surface 32b of the substrate 32 opposite the first surface 32a. The blunt object 16 protrudes in the opposite direction to the air flow direction (for example, the -z direction). The blunt object 16 has a blunt shape that creates a large pressure drag against the air flow, and has a shape that is different (for example, symmetrical) from the streamlined shape that creates a small pressure drag. The blunt object 16 has, for example, a semi-cylindrical shape and has a cylindrical surface that protrudes in the opposite direction to the air flow direction (for example, the -z direction).

[0021] 3 is a diagram schematically illustrating the configuration of the bluff bodies 16 of FIG. 1. The multiple bluff bodies 16 are arranged at intervals in a first direction (e.g., the x direction). Each of the multiple bluff bodies 16 extends in a second direction. Each of the multiple bluff bodies 16 has, for example, a cylindrical surface extending in the second direction. The width w3 in the first direction of each of the multiple bluff bodies 16 is equal to the width w1 in the first direction of the substrate 32. The area ratio of the multiple bluff bodies 16 to the cross-sectional area of ​​the flow channel is, for example, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more, and, for example, 90% or less, 80% or less, 70% or less, or 60% or less.

[0022] The bluff body 16 may be a solid member or a hollow member. The bluff body 16 may function as a heat dissipation member that dissipates heat generated when the light source 14 is in operation. The bluff body 16 may be made of a material with high thermal conductivity, or may be made of a metal material such as aluminum or copper. The surface of the bluff body 16 may be provided with minute irregularities (e.g., dimples). By providing the surface of the bluff body 16 with minute irregularities, it is possible to increase the friction drag against the air flow.

[0023] Next, we will explain the operation of the air purifying device 10. Air flows in a predetermined direction (z direction) in the internal space 18 of the housing 12. Because the flow path cross-sectional area of ​​the main body 24 is larger than the flow path cross-sectional areas of the inlet 22 and the outlet 26, the flow velocity of the air in the main body 24 is smaller than the flow velocity of the air in the inlet 22 and the outlet 26.

[0024] The light source 14 purifies the air flowing through the internal space 18 by irradiating it with ultraviolet light 40. By reducing the air flow velocity in the main body 24, the duration of action of the ultraviolet light 40 on the air flowing through the internal space 18 can be extended. By irradiating the ultraviolet light 40 from the light source 14 in the air flow direction (z direction) inside the main body 24, which extends in the air flow direction (z direction), the duration of action of the ultraviolet light 40 on the air flowing through the internal space 18 can be extended. This allows the air flowing through the internal space 18 to be efficiently purified.

[0025] FIG. 4 is a diagram illustrating the effects of the air purifying device 10 according to the embodiment. In FIG. 4, the air flow near the light source 14 and the bluff body 16 is schematically illustrated by dashed lines. As shown in FIG. 4, the bluff body 16 protruding in the opposite direction to the air flow generates a pressure drag force on the air flow. As a result, turbulence occurs in the air flow downstream of the bluff body 16, generating a Kármán vortex 42 directly in front of the light source 14. The generation of the Kármán vortex 42 increases the retention time of the air directly in front of the light source 14 compared to when the Kármán vortex 42 is not generated. By irradiating the ultraviolet light 40 from the light source 14 toward the Kármán vortex 42 where the air is retained, the duration of the ultraviolet light 40 on the air can be increased, thereby improving the purification performance of the ultraviolet light.

[0026] According to this embodiment, by providing a blunt object 16 on the back side of the light source 14, it is possible to generate a Karman vortex 42 in front of the light source 14, thereby lengthening the duration of action of the ultraviolet light irradiated onto the air from the light source 14. This improves the purification performance.

[0027] According to this embodiment, by using the blunt object 16 as a heat dissipation member, it is possible to increase the pressure resistance against the air flow toward the heat dissipation member, thereby promoting heat exchange between the heat dissipation member and the air flow and improving the heat dissipation performance of the light source 14.

[0028] FIG. 5 is a diagram schematically illustrating the configuration of an air purifying device 10 according to a modified example. This modified example differs in that the blunt body 16 has a prismatic shape rather than a semi-cylindrical shape. The blunt body 16 has a prismatic surface that protrudes in the opposite direction to the air flow direction (for example, the -z direction). The blunt body 16 has, for example, a triangular prism shape, and has two side surfaces that are exposed in the opposite direction to the air flow direction. This modified example can also achieve the same effects as the above-described embodiment.

[0029] In the above-described embodiment and modifications, the air purifying device 10 does not have to include the housing 12. In this case, the air purifying device 10 can be installed and used in any location where there is air flow.

[0030] The present invention has been described above based on examples. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiments, and that various design changes and modifications are possible, and that such modifications are also within the scope of the present invention.

[0031] Several aspects of the present invention will now be described.

[0032] A first aspect of the present invention is an air purifying device including a light source that irradiates ultraviolet light in the direction of air flow, and a blunt object attached to the light source and protruding in the opposite direction to the air flow. According to the first aspect, by providing a blunt object protruding in the opposite direction to the air flow, turbulence is generated in the airflow downstream of the light source, thereby lengthening the residence time of the air downstream of the light source. By irradiating the ultraviolet light from the light source at the location where the airflow is turbulent, the duration of action of the ultraviolet light on the air can be lengthened, thereby improving purification performance.

[0033] A second aspect of the present invention is the air purifying device according to the first aspect, wherein the blunt object is a heat dissipation member. According to the second aspect, by using the blunt object as the heat dissipation member, heat can be efficiently dissipated during operation of the light source. Because the heat dissipation member is located upstream, it can be efficiently exposed to the airflow. Furthermore, because the heat dissipation member has a blunt shape, it is possible to increase the pressure resistance against the airflow, and heat exchange between the heat dissipation member and the airflow can be promoted. This improves the heat dissipation performance of the light source.

[0034] A third aspect of the present invention is the air purifying device according to the first or second aspect, wherein the bluff body has a cylindrical or prismatic surface that protrudes in the opposite direction to the flow direction. According to the third aspect, by using a cylindrical or prismatic surface as the bluff body, an excessive increase in pressure loss of the air flowing through the internal space can be suppressed.

[0035] A fourth aspect of the present invention is the air purifying device according to any one of the first to third aspects, wherein fine irregularities are formed on the surface of the bluff object. According to the fourth aspect, by forming fine irregularities on the surface of the bluff object, it is possible to increase the frictional drag against the airflow and effectively generate turbulence in the airflow downstream of the light source.

[0036] A fifth aspect of the present invention is the air purifying device according to any one of the first to fourth aspects, wherein the light source comprises a substrate extending in a predetermined direction perpendicular to the flow direction and a plurality of light-emitting elements arranged in the predetermined direction on a first surface of the substrate, and the blunt object is attached to a second surface of the substrate opposite the first surface and extends in the predetermined direction. According to the fifth aspect, by arranging the plurality of light-emitting elements in a predetermined direction, ultraviolet light can be irradiated over a wide area. Furthermore, by extending the blunt object in the predetermined direction, turbulence in the air can be generated downstream of each of the plurality of light-emitting elements, thereby lengthening the duration of action of the ultraviolet light irradiated from each of the plurality of light-emitting elements on the air.

[0037] A sixth aspect of the present invention is an air purifier according to any one of the first to fourth aspects, wherein the light source includes a plurality of light-emitting units spaced apart in a first direction perpendicular to the flow direction, each of the plurality of light-emitting units including a substrate extending in a second direction perpendicular to the first direction and a plurality of light-emitting elements arranged in the second direction on a first surface of the substrate, and the blunt object is attached to a second surface of the substrate opposite the first surface and extending in the second direction. According to the sixth aspect, ultraviolet light can be irradiated over a wide area using a plurality of light-emitting elements arranged in a two-dimensional array. Furthermore, by arranging a plurality of blunt objects side by side, airflow turbulence can be generated downstream of each of the plurality of light-emitting elements arranged in the two-dimensional array. This allows the ultraviolet light irradiated from each of the plurality of light-emitting elements to have a longer effect on the air. [Explanation of symbols]

[0038] 10...air purification device, 12...casing, 14...light source, 16...blunt object, 18...internal space, 30...light-emitting unit, 32...substrate, 34...light-emitting element

Claims

1. a light source that irradiates ultraviolet light in the direction of air flow; a bluff object attached to the light source and protruding in a direction opposite to the flow direction; the light source includes a substrate extending in a predetermined direction perpendicular to the flow direction, and a plurality of light-emitting elements arranged in the predetermined direction on a first surface of the substrate, the blunt object is attached to a second surface of the substrate opposite to the first surface, and has a cylindrical surface that protrudes in a direction opposite to the flow direction and extends in the predetermined direction. Air purifier.

2. The air purifying device according to claim 1 , wherein the blunt object is a heat dissipating member.

3. The air purifying device according to claim 1 or 2, wherein fine irregularities are formed on the surface of the blunt object.

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