Ultraviolet irradiation device

Abstract

To provide an ultraviolet irradiation device that can stably emit high-strength ultraviolet rays in a relatively small configuration, and can be used as a light source device for an ultraviolet sterilizer.SOLUTION: An ultraviolet irradiation device 100 includes a tubular housing 20 having an opening 20a at its end, a light emitting element 10 that is housed within the housing 20 and can emit ultraviolet rays UV, a window 24 placed between the light emitting element 10 and the opening 10a of the housing, a mounting substrate 14 on which the light emitting element is mounted, and a heat transfer member 18 disposed on the circumference of the light emitting element between the mounting substrate and the window. Some of the heat generated by the light emitting element 10 is transmitted to the window 24 via the substrate 14 and the heat transfer member 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet irradiation device, and more particularly to an ultraviolet irradiation device that is suitably used for an ultraviolet sterilization device. [Background technology]

[0002] A technique for sterilizing fluids by irradiating them with ultraviolet light is known. This method has the advantage of not affecting water quality and not generating harmful substances because it does not use chemicals.

[0003] An ultraviolet sterilization device is configured to be attached to, for example, a pipe, and sterilizes bacteria and the like contained in the fluid flowing through the pipe by irradiating the inside of the pipe with ultraviolet light. Patent Document 1 discloses a device that is built into a fitting connected to the pipe and sterilizes the fluid flowing through the pipe by irradiating it with ultraviolet light. A small ultraviolet sterilization device configured in this way is highly convenient because it can be easily connected to an existing flow pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 090687 Summary of the Invention [Problem to be solved by the invention]

[0005] To improve the sterilization power of an ultraviolet sterilizer, it is preferable to irradiate with stronger ultraviolet light. However, in a small sterilizer such as the one described above, if a light-emitting element that irradiates strong ultraviolet light is used, the entire device is likely to become hot, increasing the possibility of damage to the light-emitting element, etc.

[0006] For this reason, there has been a demand for an ultraviolet irradiation device that can be suitably used in an ultraviolet sterilization device that can operate stably while improving sterilization capability.

[0007] The present invention has been made to solve the above-mentioned problems, and its main object is to provide an ultraviolet irradiation device to be used in an ultraviolet sterilization device that can irradiate high-intensity ultraviolet rays to improve sterilization ability while preventing damage to elements, even in a relatively small device configuration. [Means for solving the problem]

[0008] An ultraviolet irradiation device according to an embodiment of the present invention comprises a cylindrical housing having an opening at its tip, a light-emitting element housed in the housing and capable of emitting ultraviolet light, a window disposed between the light-emitting element and the opening of the housing, a mounting substrate on which the light-emitting element is disposed, and a heat transfer member disposed between the mounting substrate and the window and around the light-emitting element, and is configured so that a portion of the heat generated by the light-emitting element can be conducted to the window via the mounting substrate and the heat transfer member.

[0009] In one embodiment, the thermal conductivity of the heat transfer member is higher than the thermal conductivity of the housing.

[0010] In one embodiment, the thermal conductivity of the mounting substrate is higher than the thermal conductivity of the housing.

[0011] In one embodiment, the light-emitting element is covered with a sealing resin, and the sealing resin is in contact with the window.

[0012] In one embodiment, the heat transfer member is in contact with both the mounting substrate and the window.

[0013] In one embodiment, the ultraviolet irradiation device further includes an insert nut arranged on the back side of the mounting substrate, and an internal thread is provided on the inner circumferential surface of the housing, so that the mounting substrate, the heat transfer member, and the window can be pressed and fixed to the tip of the housing by screwing the external thread of the insert nut into the internal thread of the housing.

[0014] In one embodiment, the ultraviolet irradiation device further includes an annular seal disposed between the window and the leading end of the housing.

[0015] In one embodiment, the mounting substrate and the heat transfer member are integrally formed.

[0016] In one embodiment, an external thread is provided on the outer peripheral surface of the housing, and the ultraviolet irradiation device is configured to be attachable by threading it into an internal thread provided on an opening of a pipe through which a fluid flows. [Effects of the Invention]

[0017] According to the ultraviolet irradiation device of the embodiment of the present invention, an ultraviolet sterilization device with good sterilization power can be operated stably. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing a configuration of an ultraviolet irradiation device according to an embodiment of the present invention. [Figure 2] 5A and 5B are diagrams for explaining heat dissipation paths in the ultraviolet irradiation device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the embodiments described below.

[0020] FIG. 1 shows an ultraviolet irradiation device 100 according to an embodiment of the present invention. The ultraviolet irradiation device 100 has a cylindrical metal housing 20 having an opening 20a at its tip. The housing 20 is preferably corrosion-resistant and is formed of, for example, stainless steel. An external thread 20s is provided on the outer circumferential surface of the housing 20. In the following, a housing 20 provided with such an external thread will be described as a screw housing 20.

[0021] The outer thread 20s of the screw housing 20 is threadedly engaged with an inner thread provided in an attachment portion (opening) provided in the pipe, for example. This allows the ultraviolet irradiation device 100 to be screwed and fixed to the pipe with high sealing performance. The ultraviolet irradiation device 100 is attached from the outside and can be used as a light source device for sterilizing a fluid (here, water W) in the pipe.

[0022] The ultraviolet irradiation device 100 has a light emitting element 10 capable of emitting ultraviolet light UV housed inside a screw housing 20, a submount 12 on which the light emitting element 10 is mounted, and a mounting substrate 14 on which the submount 12 is mounted. The submount 12 and the mounting substrate 14 are arranged on the rear side of the light emitting surface of the light emitting element 10.

[0023] The light emitting element 10 can emit deep ultraviolet light having a wavelength of, for example, 100 to 380 nm, which is considered effective for sterilization. In this embodiment, an LED is used as the light emitting element 10, and the light emitting surface side of the LED is covered with a dome-shaped sealing resin 10a with good ultraviolet transmittance. The number of light emitting elements 10 (LEDs) is not limited to one, and two or more may be provided.

[0024] The substrate of the light-emitting element 10 may be, for example, a sapphire substrate, and the submount 12 on which it is mounted may be, for example, a ceramic substrate such as an alumina substrate or an AlN substrate. The mounting substrate 14 on which the submount 12 is mounted may be, for example, an aluminum plate. The mounting substrate 14 is preferably made of a material with relatively good thermal conductivity, and preferably has a thermal conductivity at least higher than that of the screw housing 20.

[0025] The ultraviolet light UV emitted from the light-emitting element 10 is irradiated onto the water W outside through an opening 20a of the screw housing 20 via a window 24 provided in the front (i.e., the front side of the light-emitting surface of the light-emitting element 10). In this embodiment, the window 24 is disposed between the light-emitting element 10 and the opening 20a of the screw housing 20 (i.e., in the storage space inside the screw housing 20) so as to close the opening 20a of the screw housing 20.

[0026] The window 24 is preferably made of a material with good ultraviolet transmittance, such as sapphire, AlN crystal, quartz, calcium fluoride, magnesium fluoride, fluororesin with good diffuse transmittance, etc. Sapphire glass is preferably used because it is relatively inexpensive, generally has high corrosion resistance to various fluids, and is very hard.

[0027] Furthermore, in this embodiment, since the sealing resin 10a is interposed between the light-emitting element 10 and the window 24, the refractive index difference at the window boundary surface for the ultraviolet light UV can be reduced compared to when the sealing resin 10a is not interposed. This makes it difficult for the ultraviolet light UV emitted from the light-emitting element 10 to be refracted or reflected on the window surface, allowing the ultraviolet light UV to be efficiently irradiated onto the water W. Furthermore, the sealing resin 10a is preferably transparent to ultraviolet light.

[0028] In the ultraviolet irradiation device 100 of this embodiment, the window 24 is fixed to the tip of the screw housing 20 via an annular sealant (packing) 22. In this embodiment, the diameter of the opening 20a at the tip of the screw housing 20 is formed smaller than the diameter of the storage section, and the window 24 is pressed and fixed around the opening 20a against the rear surface of the tip of the screw housing 20 with the annular sealant 22 sandwiched therebetween.

[0029] In this embodiment, an insert nut 26 is used that is disposed on the back side of the mounting board 14 in order to secure the window 24 at the tip of the screw housing 20 with high sealing performance. An internal thread is provided on the inner peripheral surface of the screw housing 20 near the entrance to the accommodation section, and the external thread of the insert nut 26 can be screwed in from the outside.

[0030] In this configuration, a sealant 22 is placed at the inner tip of the screw housing 20, and after the window 24, the submount 12 on which the light emitting element 10 is mounted, the heat transfer member 18 (described later), and the mounting substrate 14 are accommodated in that order, an insert nut 26 is screwed in from the outside, thereby pressing and fixing these components with high sealing performance inside the screw housing 20. This makes it possible to prevent external water W from entering the inside of the screw housing 20, thereby preventing damage to the internal elements, etc.

[0031] It is preferable to use an elastic material for the sealant 22 so that the window 24 is not easily broken even by the pressing force caused by screwing in the insert nut 26. In this embodiment, since ultraviolet light UV is emitted from the light emitting element 10, it is particularly preferable to use fluororubber (FKM) or fluororesin (PTFE) for the sealant 22, which have good resistance to ultraviolet light UV.

[0032] Wiring 28 connected to light-emitting element 10 is drawn from the back surface of submount 12 to the outside through through-holes provided in mounting substrate 14 and insert nut 26. In this configuration, light-emitting element 10 can be controlled via wiring 28, and ultraviolet light UV can be irradiated at any timing and with a desired intensity. Insert nut 26 may have an annular shape with a thread on the outside, and wiring 28 may be drawn from its central opening.

[0033] In this embodiment, a resin cylindrical member 16 that is resistant to ultraviolet light (UV) is provided around the light emitting element 10. The cylindrical member 16 is provided to prevent the surrounding components from being affected by ultraviolet light (UV) irradiation in the lateral direction. However, when a light emitting element 10 with high directivity is used, the cylindrical member 16 does not necessarily have to be provided.

[0034] Furthermore, in the ultraviolet irradiation device 100 of this embodiment, a heat transfer member 18 (here, an aluminum block) with good thermal conductivity is arranged around the light emitting element 10. The heat transfer member 18 is typically arranged so as to be in contact with the mounting substrate 14 and the window 24, and is used to efficiently conduct heat from the light emitting element 10 to the outside. Thermally conductive grease or thermally conductive paste may be applied to the connection surface between the mounting substrate 14 and the heat transfer member 18. Alternatively, a plate-shaped metal with good thermal conductivity may be sandwiched between the mounting substrate 14 and the heat transfer member 18. Note that when sandwiching the plate-shaped metal, if an air layer is formed between the members, the heat transfer efficiency decreases, so it is desirable to sandwich the members as closely as possible.

[0035] The heat transfer member 18 is formed from, for example, aluminum, which has excellent heat dissipation properties, workability, and availability, but other metal materials such as copper, silver, brass, nickel, titanium, etc. Furthermore, the material is not limited to metal materials, and semiconductor materials such as Si single crystal, SiC single crystal, GaN single crystal, and AlN single crystal, as well as ceramic materials such as alumina and AlN, may also be used.

[0036] The thermal conductivity of the heat transfer member 18 is preferably higher than the thermal conductivity (for example, 15 to 25 W / mK) of the stainless steel screw housing 20. The thermal conductivity of the heat transfer member 18 is, for example, 50 W / mK or higher, preferably 100 W / mK or higher, and more preferably 200 W / mK or higher (aluminum, copper, silver, SiC single crystal, etc.).

[0037] By providing the heat transfer member 18 in this way, the heat generated by the light emitting element 10 is more easily conducted to the surroundings. This reduces the possibility that the element itself will become too hot and be damaged, and enables stable irradiation of ultraviolet light UV with higher intensity. Therefore, when the ultraviolet irradiation device 100 is used as a light source for sterilization, the sterilization power can be improved.

[0038] The heat transfer member 18 may be configured as a single annular block having a central opening inside which the light emitting element 10 is placed, or may be configured as a plurality of blocks arranged to surround the periphery of the light emitting element 10. The heat transfer member 18 may be provided in any manner as long as it can efficiently transfer heat from the light emitting element 10 to the outside.

[0039] Fig. 2 shows the heat dissipation paths from the light emitting element 10. As shown in Fig. 2, in the ultraviolet irradiation device 100 attached from the outside to the opening of the pipe 30, heat is generated from the light emitting element 10 as ultraviolet rays are irradiated, and the heat is dissipated to the outside through various paths.

[0040] The first heat dissipation path H1 is considered to be a path in which heat is transferred to the screw housing 20 via the submount 12, the mounting substrate 14, and the insert nut 26. The heat transferred to the screw housing 20 is released into the water W in contact with the screw housing 20 or into the piping 30.

[0041] However, the first heat dissipation path H1 may not be sufficient in heat dissipation because the thermal conductivity of the screw housing 20, which is typically made of a metal that requires corrosion resistance (e.g., stainless steel), is not very high. Also, to improve sealing, a flexible sheet or sealant may be inserted in the threaded portion between the piping 30 and the screw housing 20, which may reduce solid conduction to the piping 30.

[0042] The second heat dissipation path H2 may be a path in which heat is dissipated from the light-emitting element 10 to the water W via the window 24. Here, the heat generated in the light-emitting element 10 is dissipated to the external water W via the sealing resin 10a in contact with the light-emitting element 10 and the window 24 in contact with the sealing resin 10a.

[0043] In the ultraviolet irradiation device 100 of this embodiment, a possible third heat dissipation path H3 is a path in which heat is dissipated from the submount 12 and the mounting substrate 14 via the heat transfer member 18 to the window 24 and external water W. By using the heat transfer member 18 in this way to also dissipate heat transferred to the mounting substrate 14 (a material with a relatively high thermal conductivity) to the water W, it is possible to improve the heat dissipation from the mounting substrate 14 to the outside compared to the case where only the first heat dissipation path H1 is used.

[0044] When the heat transfer member 18 and the mounting substrate 14 are made of the same material (for example, aluminum), the heat transfer member 18 and the mounting substrate 14 may be integrally formed.

[0045] Although the embodiments of the present invention have been described above, various modifications are possible. For example, in the above embodiment, the sealing resin 10a is dome-shaped, but it may have other shapes, and may fill the entire space formed between the window 24 and the light-emitting element 10. Furthermore, the sealing resin 10a is not limited to a solid resin, and a liquid resin may also be used. [Industrial Applicability]

[0046] An ultraviolet irradiation device according to an embodiment of the present invention is suitably used, for example, as a light source device for an ultraviolet sterilization device that sterilizes bacteria and the like contained in a fluid flowing through a pipe. [Explanation of symbols]

[0047] 10 Light-emitting element 10a Sealing resin 12 Submount 14 Mounting board 16 Cylinder member 18 Heat transfer material 20 Housing (screw housing) 22 Sealing material 24 Windows 26 Insert nut 28 Wiring 100 Ultraviolet irradiation device UV ultraviolet light

Claims

1. a cylindrical housing having an opening at its tip; a light-emitting element accommodated in the housing and capable of emitting ultraviolet light; a window disposed between the light-emitting element and the opening of the housing; a mounting substrate on which the light-emitting element is disposed; a heat transfer member disposed between the mounting substrate and the window and disposed around the light emitting element; Equipped with The ultraviolet irradiation device is configured so that a portion of the heat generated by the light emitting element can be conducted to the window via the mounting substrate and the heat transfer member.

2. The ultraviolet irradiation device according to claim 1 , wherein the thermal conductivity of the heat transfer member is higher than the thermal conductivity of the housing.

3. The ultraviolet irradiation device according to claim 1 , wherein the thermal conductivity of the mounting substrate is higher than the thermal conductivity of the housing.

4. 3. The ultraviolet irradiation device according to claim 1, wherein the light emitting element is covered with a sealing resin, the sealing resin being in contact with the window.

5. The ultraviolet irradiation device according to claim 1 , wherein the heat transfer member is in contact with both the mounting substrate and the window.

6. Further, an insert nut is provided on the back surface side of the mounting board, 3. The ultraviolet irradiation device according to claim 1, wherein an internal thread is provided on an inner peripheral surface of the housing, and the mounting board, the heat transfer member, and the window can be pressed and fixed to a tip end portion of the housing by screwing an external thread of the insert nut into the internal thread of the housing.

7. The ultraviolet irradiation device according to claim 6 , further comprising an annular seal disposed between the window and the leading end of the housing.

8. The ultraviolet irradiation device according to claim 1 , wherein the mounting substrate and the heat transfer member are integrally formed.

9. 3. The ultraviolet irradiation device according to claim 1, wherein an external thread is provided on the outer peripheral surface of the housing, and the external thread is configured to be capable of being threadedly engaged with an internal thread provided on an opening of a pipe through which a fluid flows.

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