Fluid sterilizer

Abstract

To provide a fluid sterilizer capable of improving sterilization effect at low cost.SOLUTION: A fluid sterilizer (1) includes a light source unit (30) that emits ultraviolet light and a flow path space (70) which is a space that allows a fluid to flow through and into which the ultraviolet light from the light source unit (30) is incident. The light source unit (30) includes a mounting substrate (32) that has a recess (321) at a position facing the flow path space (70), and a plurality of semiconductor light-emitting elements (31) that are mounted on a bottom surface (322) of the recess (321) and emits the ultraviolet light. The bottom surface (322) of the recess (321) is concavely shaped such that optical axes (311) of the plurality of semiconductor light-emitting elements (31) intersect with each other in the direction in which the ultraviolet light proceeds.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fluid sterilization device. [Background technology]

[0002] Sterilization devices that sterilize bacteria and viruses in running water by irradiating them with ultraviolet light are known. Mercury lamps are widely used as the light source. Mercury lamps have the problem that they are highly toxic and have a large environmental impact because they use mercury. In addition, the use of mercury lamps also creates the problem of the sterilization device becoming larger. Therefore, efforts are being made to replace mercury lamps with ultraviolet LEDs.

[0003] Patent Document 1 discloses a water sterilization device using LEDs that emit ultraviolet light, in which ultraviolet LEDs are arranged at equal intervals around a water inlet provided at one end of a flow tube through which water flows and around a water outlet provided at the other end of the flow tube, and ultraviolet light is emitted from each ultraviolet LED in the axial direction of the flow tube. In this configuration, the ultraviolet intensity near the center is higher than the ultraviolet intensity near the outer edge in the radial direction of the flow tube, so that the sterilization effect near the center where the flow speed is faster is enhanced, and the sterilization effect of the device as a whole is improved. Patent Document 1 also discloses that the intensity distribution of ultraviolet light in the flow tube is adjusted using a lens or a concave mirror as a mechanism for adjusting the directionality of the emitted light from the ultraviolet LED. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-74114 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration disclosed in Patent Document 1, the optical axes of the multiple ultraviolet LEDs are all arranged parallel to the axial direction of the flow tube, which is not sufficient to increase the ultraviolet intensity near the center of the flow tube, and there is room for improvement in terms of improving the sterilization effect. Furthermore, if a mechanism for adjusting the directivity of the emitted light is used to increase the ultraviolet intensity near the center in the radial direction of the flow tube, the configuration becomes complicated and the cost becomes high.

[0006] The present invention has been made in view of the above background, and aims to provide a fluid sterilizing device which has a simple configuration, is low cost, and has an improved sterilizing effect. [Means for solving the problem]

[0007] One aspect of the present invention is A fluid sterilization device having a light source unit that emits ultraviolet light and a flow path space in which a fluid flows and into which the ultraviolet light from the light source unit is incident, the light source unit includes a plurality of semiconductor light-emitting elements that emit ultraviolet light, a mounting substrate having a recess at a position facing the flow path space, and a plurality of semiconductor light-emitting elements that emit ultraviolet light and are mounted on a bottom surface of the recess, The bottom surface of the recess in the fluid sterilization device is concave so that the optical axes of the semiconductor light emitting elements intersect with each other in the traveling direction of the ultraviolet light. Effect of the Invention

[0008] In the above-mentioned fluid sterilization device, the bottom surface of the recess formed on the mounting substrate is concave, and multiple semiconductor light-emitting elements that emit ultraviolet light are mounted on the bottom surface, so that the optical axes of the multiple semiconductor light-emitting elements intersect with each other in the direction of travel of the ultraviolet light. This allows the ultraviolet light emitted from the multiple semiconductor light-emitting elements to be concentrated in the flow path space to increase the ultraviolet intensity, thereby improving the sterilization effect of the fluid flowing through the flow path space. In addition, since there is no need to use a mechanism for adjusting the directivity of the ultraviolet light emitted from the multiple semiconductor light-emitting elements, the configuration is simpler than when such a mechanism is used, and costs can be reduced.

[0009] Furthermore, by concentrating the ultraviolet light within the flow path space, the amount of ultraviolet light irradiated onto the wall surface forming the flow path space is reduced. As a result, damage to the wall surface forming the flow path space caused by ultraviolet light can be reduced, and the life of the fluid sterilization device can be extended. In addition, the amount of ultraviolet light absorbed by the wall surface forming the flow path space is also reduced, and the sterilization effect can be improved. In addition, it is now easier to use materials for the wall surface forming the flow path space that are more susceptible to deterioration by ultraviolet light or have a low reflectance of ultraviolet light than in the past, expanding the range of material selection.

[0010] As described above, according to the above aspect, it is possible to provide a fluid sterilizing device that has a simple configuration, is low cost, and has an improved sterilizing effect. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view of the fluid sterilization device in the first embodiment, taken along a plane including the axis of the flow path pipe. [Diagram 2] FIG. 2 is an exploded view of the fluid sterilization device according to the first embodiment. [Diagram 3] 4 is a first cross-sectional view of the light source unit taken along a plane including the axis of the flow path pipe in the first embodiment. FIG. [Figure 4] 4 is a cross-sectional view of the light source unit in a plane including the axis of the flow path pipe and at a position 90 degrees different from the cross section of FIG. 3 in the first embodiment. [Diagram 5] FIG. 2 is a top view of a mounting board on which a light emitting element is arranged in the first embodiment. [Figure 6] FIG. 11 is a cross-sectional view of a light source unit taken along a plane including an axis of a flow path pipe in a second embodiment. [Figure 7] 7 is a cross-sectional view of a light source unit in a plane including an axis of a flow path pipe and at a position 90 degrees different from the cross section of FIG. 6 in a second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a light source unit taken along a plane including an axis of a flow path pipe in a third embodiment. [Figure 9] FIG. 11 is a cross-sectional view of the fluid sterilization device in embodiment 4, taken along a plane including the axis of the flow path pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] It is preferable that the optical axes of the plurality of semiconductor light-emitting elements intersect with each other within the flow path space. In this case, the ultraviolet light emitted from the plurality of semiconductor light-emitting elements can be further concentrated within the flow path space to increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space.

[0013] It is preferable that the semiconductor light-emitting element is mounted on the bottom surface of the recess so that the optical axis of the semiconductor light-emitting element is perpendicular to the portion of the bottom surface of the recess where the semiconductor light-emitting element is mounted, and the optical axes of the plurality of semiconductor light-emitting elements are inclined at different angles to the flow direction of the fluid in the flow path space. In this case, the ultraviolet light emitted from the plurality of semiconductor light-emitting elements can be further concentrated in the flow path space to increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space.

[0014] The bottom surface of the recess is preferably formed as a curved surface, which makes it easier to form the recess and reduces manufacturing costs.

[0015] It is preferable that at least a part of the curved surface has a cross-sectional shape along a parabola in a plane parallel to the flow direction in the flow path space. In this case, the ultraviolet light emitted from the plurality of semiconductor light-emitting elements can be further concentrated in the flow path space to increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space.

[0016] The bottom surface of the recess is formed by connecting a plurality of inclined surfaces. In this case, the inclination angle of the optical axis is stable when mounting the semiconductor light emitting element on the bottom surface of the recess, making it easy to mount the semiconductor light emitting element and preventing misalignment of the optical axis.

[0017] It is preferable that the light source unit has a light-transmitting plate that covers the ultraviolet light emission sides of the semiconductor light-emitting elements and is arranged to be in contact with the flow path space, and the ultraviolet light emitted from the semiconductor light-emitting elements passes through the light-transmitting plate and enters the flow path space. In this case, the light source unit comes into contact with the fluid flowing through the flow path space via the light-transmitting plate, so that heat dissipation from the light source unit via the fluid is promoted, and the heat dissipation performance of the light source unit can be improved.

[0018] The space between the recess of the mounting substrate and the light-transmitting plate is preferably filled with a sealing member having a thermal conductivity higher than that of air, in which case the sealing member promotes heat dissipation from the semiconductor light-emitting element, thereby further improving the heat dissipation of the light source unit.

[0019] The sealing member is preferably a liquid containing a fluoride compound, which can improve the heat dissipation of the light source unit and can improve the efficiency of extracting ultraviolet light from the semiconductor light emitting element because the refractive index of the liquid is higher than that of air and is close to that of the material constituting the light emitting surface of the semiconductor light emitting element.

[0020] The flow path space is formed as an internal space of a cylindrical member, the cylindrical member includes a transparent tube that transmits ultraviolet light and a reflector provided on the outer peripheral surface of the transparent tube, the transparent tube is preferably made of at least one of quartz, sapphire, ultraviolet light transmitting glass, and fluororesin, and the reflector is preferably made of at least one of PTFE unbaked film and aluminum thin film. In this case, the inner wall of the cylindrical member can be made a smooth surface by the transparent tube, and the reflector can reflect the ultraviolet light that transmits the transparent tube into the flow path space, improving the utilization rate of the ultraviolet light.

[0021] The flow path space is formed as an internal space of a cylindrical member, and the cylindrical member can be made of a SUS tube or a Cu tube. In this case, the reflectance of the cylindrical member is relatively low for ultraviolet light, but since the ultraviolet light emitted from the light source is concentrated within the flow path space, even if the cylindrical member is made of a material with a relatively low reflectance, the decrease in the utilization rate of the ultraviolet light is relatively small, and the cylindrical member can be easily manufactured, thereby reducing costs.

[0022] (Embodiment 1) 1. Overview of the configuration of the fluid sterilization device 1 FIG. 1 is a cross-sectional view showing the configuration of the fluid sterilization device 1 in the first embodiment, and is a cross-section taken along a plane including the axis of the fluid sterilization device 1. FIG. 2 is an exploded view of the fluid sterilization device 1 in the first embodiment. FIG. 3 is a cross-sectional view showing the configuration of the light source unit 30 in the first embodiment. As shown in FIGS. 1 and 2, the fluid sterilization device 1 in the first embodiment has a housing 10, a flow path pipe 20, a light source unit 30, a spacer 40, and a plate 50. As shown in FIGS. 2 and 3, the light source unit 30 has a semiconductor light emitting element 31, a mounting board 32, a seal unit 33, a light source case 34, and a light-transmitting plate 35.

[0023] The fluid sterilization device 1 of the first embodiment is a device that sterilizes a fluid by flowing the fluid inside the flow path pipe 20 and the spacer 40 and irradiating the fluid with ultraviolet light emitted from the light source unit 30. The internal space of the flow path pipe 20 and the spacer 40 is the flow path space 70 (a space through which the fluid flows during sterilization and an area irradiated with ultraviolet light). The fluid to be sterilized can be any liquid, such as water, oil, or alcohol. A liquid may be mixed with a solid as long as it has fluidity, and in this specification, a mixture of a liquid and a solid that has fluidity is also included in the fluid. In this embodiment 1, water is used as the fluid to be sterilized. Note that the fluid sterilization device 1 of the first embodiment is approximately cylindrical, but may have any shape as long as it can flow the fluid, for example, may be cylindrical, such as a square tube.

[0024] 2. Details of each component of the fluid sterilization device 1 Next, each component of the fluid sterilization device 1 will be described in detail.

[0025] 2-1. Chassis 10 1 and 2, the housing 10 is cylindrical, with an inlet 11 provided at one end face in the axial direction, and an outlet 12 provided near the other end face on the side of the cylinder constituting the housing 10. The material of the housing 10 is, for example, black PP (polypropylene). Inside the housing 10, a plate 50, a flow path pipe 20, and a spacer 40 are coaxially arranged in this order from the inlet 11 side.

[0026] The other end face of the housing 10 is open. A screw thread 13 is provided on the inner peripheral surface of the tube near the other end face. A light source unit 30 is fitted into the other end face of the housing 10 and screwed in, and the other end face of the housing 10 is sealed by the light source unit 30.

[0027] O-rings 60 are provided between the housing 10 and the plate 50, between the plate 50 and the flow path pipe 20, and between the flow path pipe 20 and the spacer 40 to prevent water from leaking between the various components. Water flowing in from the inlet 11 is irradiated with ultraviolet light emitted from the light source unit 30 as it passes through the plate 50, the flow path pipe 20, and the spacer 40 in sequence, and is then discharged from the outlet 12. The positions of the inlet 11 and the outlet 12 may be arbitrary, and the positions of the two may be interchanged.

[0028] 2-2. Flow path pipe 20 The flow path pipe 20 is made of a cylindrical member, and the internal space of the cylindrical member becomes the flow path space. In the present embodiment 1, as shown in FIG. 1, the flow path pipe 20 is cylindrical, and has a transparent tube 21 and a reflector 22 provided in contact with the outer circumferential surface of the transparent tube 21. The outer circumferential surface of the reflector 22 is in contact with the inner circumferential surface of the housing 10. The reflector 22 has a high reflectance of ultraviolet light, and can reflect the ultraviolet light on the side surface of the flow path pipe 20 to efficiently irradiate the ultraviolet light to the water flowing through the flow path pipe 20. The extension direction of the central axis 20a of the flow path pipe 20 is the axial direction Y, the directions perpendicular to the axial direction Y are the radial directions X1 and X2, and the first radial direction X1 and the second radial direction X2 are perpendicular to each other.

[0029] The transparent tube 21 is a cylindrical tube made of quartz, and water to be sterilized flows inside the tube. The material of the transparent tube 21 is not limited to quartz, and any material that transmits ultraviolet light and has low absorptivity may be used. For example, sapphire, ultraviolet light transmitting glass, fluororesin, etc. may be used. In particular, a material with a small refractive index difference with water is preferable, and in this respect, the quartz of the first embodiment is suitable. For example, a material with a refractive index of 1.3 to 1.5 is preferable. In addition, since the ultraviolet light emitted from the light source unit 30 is concentrated in the flow path, the amount of irradiation to the transparent tube 21 is reduced compared to the conventional method, the transparent tube 21 may be made of a material that is relatively easily deteriorated by ultraviolet light, such as acrylic resin.

[0030] The transparent tube 21 may have any thickness within a range having strength to withstand water pressure and ultraviolet light transmittance, for example, 0.4 to 3 mm. A material and thickness having an ultraviolet light transmittance of 80% or more in the case of perpendicular incidence is preferable.

[0031] It is preferable that the inner peripheral surface of the transparent tube 21 is as flat as possible, and for example, it is preferable that the RMS (root mean square height) is 1 μm or less. Bacteria are less likely to adhere to the unevenness of the inner peripheral surface, and the inner peripheral surface is less likely to become dirty, which can suppress a decrease in sterilization efficiency and prevent the generation of air bubbles. In addition, a water-repellent coating such as a fluororesin may be formed on the inner peripheral surface of the transparent tube 21 to make the inner peripheral surface of the transparent tube 21 water-repellent and prevent dirt from adhering to the inner peripheral surface of the transparent tube 21.

[0032] The reflector 22 is provided in contact with the outer circumferential surface of the transparent tube 21. The reflector 22 reflects the ultraviolet light that passes through the transparent tube 21 and heads toward the outside.

[0033] The reflector 22 is formed by wrapping an unsintered PTFE (polytetrafluoroethylene) film around the outer circumferential surface of the transparent tube 21 one or more times. In other words, the reflector 22 is a laminate (laminate) of the unsintered PTFE film on the transparent tube 21. The unsintered PTFE film is a film in the form of a sheet or tape, which is formed by rolling PTFE fine powder in an unsintered state. The PTFE fine powder is a white powder formed by agglomerating fine particles of PTFE.

[0034] For example, powder for paste extrusion molding (II-1 or II-2) specified in JIS K 6896:1995 can be used as the PTFE fine powder. II-1 satisfies the following properties: apparent density (g / ml) 0.50±0.15, moisture (%) 0.04 or less, high-temperature volatile matter (%) 0.1 or less, melting point (°C) 327±10, specific gravity 2.13 to 2.20, tensile strength (MPa) 17.6 or more, elongation (%) 200 or more. The measurement method for these properties is in accordance with JIS K 6896:1995. II-2 has the same properties as II-1 except that the specific gravity is 2.18 to 2.28.

[0035] The PTFE unsintered film may be an unsintered film manufactured using powder for paste extrusion molding specified in JIS K 6896:1995 and containing no additives. In particular, a PTFE unsintered tape specified in JIS K 6885:2005 may be used. The PTFE unsintered tape specified in JIS K 6885:2005 satisfies the following qualities: Apparent density (g / cm 3 ) is 1.0 or more, tensile strength (MPa) is 7.0 or more, elongation (%) is 20 or more, volatile loss (%) is 0.5 or less, and non-flammable. The measurement methods for these qualities are in accordance with JIS K 6885:2005.

[0036] The PTFE unsintered film has self-adhesiveness because it is unsintered. Therefore, when the PTFE unsintered film is wound around the transparent tube 21, there is no gap between the transparent tube 21 and the PTFE unsintered film, and no gap between the PTFE unsintered films. Therefore, the PTFE unsintered film can be adhered and fixed to the transparent tube 21 without using adhesives or the like, and the reflector 22 can be easily formed.

[0037] Incidentally, an air layer may remain partially in the gap between the transparent tube 21 and the PTFE unsintered film, or between the PTFE unsintered films. Even if an air layer remains, reflection occurs due to the difference in refractive index at the interface with the air layer, and ultraviolet light that has passed through the air layer is reflected by the PTFE unsintered film, so that it does not have a significant effect on the ultraviolet light reflectance of the reflector 22. Therefore, when forming the reflector 22 by winding the PTFE unsintered film around the transparent tube 21, it is not necessary to wind it tightly so as not to leave an air layer, and the reflector 22 can be formed easily.

[0038] The reflector 22 has a high reflectance to ultraviolet light. This is due to the following reasons. First, PTFE itself is a material with a high reflectance to ultraviolet light. Second, due to the self-adhesiveness of the PTFE unsintered film, no gaps are generated between the transparent tube 21 and the PTFE unsintered film, and between the PTFE unsintered films. Third, since the PTFE fine powder becomes fibrous when shear stress is applied, the particles of the PTFE unsintered film are fibrous, resulting in a high particle density.

[0039] The thickness of the reflector 22 is preferably 0.02 mm or more, and the number of turns of the PTFE unsintered film may be set to achieve such a thickness. The reflectance can be equal to or higher than that of barium sulfate, which is a common material used as a reflector. In particular, the thickness of the reflector 22 is preferably 0.2 mm or more. The reflectance can be equal to or higher than that of the flow passage tube 20 made of a PTFE bulk having a thickness of 8 mm. There is no particular upper limit to the thickness of the reflector 22, but since the ultraviolet light reflectance saturates as the thickness increases, it is preferable to set the thickness to 2 mm or less. The thickness of the reflector 22 may be thinner than that of the transparent tube 21. The thickness and width of the PTFE unsintered film may be arbitrary, but may be values ​​standardized in JIS K 6885:2005.

[0040] O-rings 60 are disposed on both ends of the flow path pipe 20. This makes it possible to prevent water from entering between the outer circumferential surface of the transparent tube 21 and the inner circumferential surface of the housing 10, more specifically, between the outer circumferential surface of the transparent tube 21 and the inner circumferential surface of the reflector 22, and between the outer circumferential surface of the reflector 22 and the inner circumferential surface of the housing 10.

[0041] In addition to the above, aluminum may be used as the reflector 22. For example, the reflector 22 can be formed by wrapping a thin aluminum film around the outer circumferential surface of the transparent tube 21, or by forming a thin aluminum film on the outer circumferential surface of the transparent tube 21 by vapor deposition or sputtering. In this case, it is desirable that the thickness of the aluminum film is 1 mm or more.

[0042] 2-3.Light source section 30 As shown in Figs. 1 and 2, the light source unit 30 is cylindrical, and a screw thread 36 is provided on the side of the cylinder (the side of a light source case 34 described below) as shown in Figs. 3 and 4. As shown in Fig. 1, this screw thread 36 corresponds to the screw thread 13 of the housing 10. The light source unit 30 is screwed into the open end face of the housing 10, whereby the screw thread 36 and the screw thread 13 fit together and are screwed in place. The light source unit 30 is also disposed at one axial end of the flow path pipe 20 via a spacer 40.

[0043] The light source unit 30 emits ultraviolet light, and the ultraviolet light enters the spacer 40 and the inside of the flow path pipe 20 from one end of the spacer 40. This allows the fluid flowing through the spacer 40 and the flow path pipe 20 to be sterilized by being irradiated with ultraviolet light. The detailed configuration of the light source unit 30 will be described later.

[0044] 2-4.Spacer 40 1 and 2, the spacer 40 is disposed between the flow path tube 20 and the light source unit 30. The spacer 40 is a cylindrical tube made of PTFE, and is disposed coaxially with the flow path tube 20. The spacer 40 is provided to efficiently reflect ultraviolet light radiated from the light source unit 30 that has a large angle with respect to the axial direction Y of the flow path tube 20, thereby increasing the efficiency of irradiation of the ultraviolet light to the fluid flowing through the flow path tube 20.

[0045] 2-5. Plate 50 As shown in Figs. 1 and 2, the plate 50 is disposed between the inlet 11 of the housing 10 and the flow path pipe 20. The plate 50 is disk-shaped and disposed coaxially with the flow path pipe 20. The material of the plate 50 is PTFE. By using PTFE with high ultraviolet light reflectance, ultraviolet light reaching the end face of the flow path pipe 20 on the inlet 11 side is reflected back into the flow path pipe 20, thereby increasing the efficiency of irradiation of the ultraviolet light to the fluid flowing through the flow path pipe 20. The plate 50 is provided with a plurality of through holes. The fluid flowing in from the inlet 11 is dispersed by passing through the plurality of through holes of the plate 50, and then flows into the flow path pipe 20.

[0046] 3. Details of each component of the light source unit 30 Next, the configuration of the light source unit 30 will be described in detail with reference to the drawings. As shown in Fig. 3 and Fig. 4, the light source unit 30 is substantially cylindrical, and includes a semiconductor light emitting element 31, a mounting substrate 32, a sealing portion 33, a light source case 34, and a light-transmitting plate 35.

[0047] 3-1. Semiconductor light emitting device 31 As shown in FIG. 3 and FIG. 4, the semiconductor light emitting element 31 is mounted on a bottom surface 322 of a recess 321 of a mounting substrate 32 described later. The semiconductor light emitting element 31 is a bare chip that emits ultraviolet light. The wavelength of the ultraviolet light can be determined according to the fluid that flows through the flow path space 70. In this embodiment, water is used as the fluid, and therefore the wavelength of the ultraviolet light is preferably 250 to 285 nm, which is a wavelength that has high sterilization efficiency for water. The configuration of the semiconductor light emitting element 31 is not limited, and may be either a face-up type or a flip-chip type. A plurality of semiconductor light emitting elements 31 are provided, but the number of the semiconductor light emitting elements 31 is not limited as long as it is two or more, and in this embodiment 1, five semiconductor light emitting elements 31a, 31b, 31c, 31d, and 31e are included as shown in FIG. 5.

[0048] 3-2. Mounting board 32 The mounting substrate 32 is a substrate on which the semiconductor light emitting element 31 is mounted. As shown in FIG. 3, the mounting substrate 32 has a recess 321 on the side facing the flow path pipe 20. The bottom surface 322 of the recess 321 is concave. In the first embodiment, the bottom surface 322 is a gently curved surface and has a mortar shape. The bottom surface 322 has a shape along a parabola in a cross section parallel to the axial direction Y. The center position C0 of the bottom surface 322 is the deepest position in the recess 321 of the bottom surface 322, is located on the central axis 20a of the flow path pipe 20, and the tangent line at the center position C0 is perpendicular to the axial direction Y of the flow path pipe 20. The bottom surface 322 is inclined so as to approach the flow path pipe 20 as it moves outward in the radial direction X from the center position C0 of the bottom surface 322.

[0049] 5, on the bottom surface 322 of the recess 321, the first semiconductor light emitting element 31a is mounted at a central position C0 of the bottom surface 322, and the second semiconductor light emitting element 31b, the third semiconductor light emitting element 31c, the fourth semiconductor light emitting element 31d, and the fifth semiconductor light emitting element 31e are mounted along an imaginary circle C1 centered on the central position C0 of the bottom surface 322. The semiconductor light emitting elements 31b to 31e are arranged at equal intervals on the imaginary circle C1.

[0050] 3 and 4, the side wall 323 of the recess 321 stands in the axial direction Y, and is formed in an annular shape as shown in Fig. 5. This makes the inner space of the recess 321 approximately cylindrical. The upper surface of the side wall 323 is flat, and a light-transmitting plate 35 (described later) is attached thereto.

[0051] A circuit-forming member (not shown) electrically connected to the semiconductor light-emitting element 31 is mounted on the mounting board 32. The circuit-forming member is a drive circuit for causing the semiconductor light-emitting element 31 to emit light, a connector header for connecting the drive circuit to a power cable, etc. Other electronic components (not shown) provided on the mounting board 32 include a thermistor for measuring the temperature of the mounting board 32, and a connector header for connecting the thermistor to a power cable.

[0052] In the first embodiment, no heat sink is provided on the back surface of the mounting substrate 32. Therefore, electronic components and circuits may be mounted on the back surface of the mounting substrate 32. For example, only the semiconductor light emitting element 31 may be mounted on the front surface of the mounting substrate 32, and electronic components other than the semiconductor light emitting element 31 may be mounted on the back surface. By mounting on both sides, the area of ​​the mounting substrate 32 can be reduced, and the light source unit 30 can be made more compact.

[0053] The material of the mounting board 32 is not limited, but aluminum is used in this embodiment. Conventionally, a heat sink was connected to the back surface of the mounting board 32, and therefore the mounting board 32 was made of a material with high thermal conductivity, such as aluminum. On the other hand, in the first embodiment, the mounting board 32 is not a main heat dissipation path, as described later, and therefore the mounting board 32 may have low thermal conductivity. Therefore, the first embodiment has a wider range of material choices for the mounting board 32 than the conventional embodiment. For example, a glass epoxy board such as FR-4 or CEM3, or a flexible board made of polyimide, may be used. Also, the mounting board 32 may be subjected to various processes, such as drilling holes.

[0054] 3-3. Optical axis 311 of semiconductor light emitting element 31 The optical axis 311 of the semiconductor light emitting element 31 is an axis in the stacking direction of the semiconductor layers for emitting ultraviolet light in the ultraviolet light emitted by the semiconductor light emitting element 31, that is, an axis in a direction perpendicular to the main surface of the element substrate on which the semiconductor layers are stacked. The optical axis 311 is, for example, an axis located at the center of the irradiation range of the ultraviolet light of the semiconductor light emitting element 31 exhibiting a predetermined light distribution characteristic. The optical axis 311 may be a virtual line extending from the semiconductor light emitting element 31 in the direction in which the luminous intensity of the ultraviolet light is maximized in the irradiation range of the ultraviolet light, but is not limited to this depending on the configuration of the semiconductor light emitting element 31. As shown in FIG. 3 and FIG. 4, in the present embodiment 1, the optical axis 311 of the semiconductor light emitting element 31 is perpendicular to the portion of the bottom surface 322 on which the semiconductor light emitting element 31 is mounted.

[0055] In the first embodiment, the optical axis 311a of the first semiconductor light emitting element 31a is tangent to the central position C0 of the bottom surface 322 on which the first semiconductor light emitting element 31a is mounted, and is perpendicular to the axial direction Y of the flow path pipe 20. Therefore, the optical axis 311a is parallel to the axial direction Y of the flow path pipe 20 and coincides with the central axis 20a of the flow path pipe 20.

[0056] 3, the bottom surface 322 is curved so as to approach the flow path pipe 20 as it moves outward in the radial direction X from the central position C0 as described above, and the second semiconductor light emitting element 31b is mounted on the bottom surface 322 at a portion on an imaginary circle C1 that is a position shifted outward in the radial direction X from the central position C0. The optical axis 311b of the second semiconductor light emitting element 31b is perpendicular to the portion on the imaginary circle C1 of the bottom surface 322. Therefore, the optical axis 311b of the second semiconductor light emitting element 31b is inclined with respect to the axial direction Y.

[0057] 3 and 4, the other three semiconductor light emitting elements 31c, 31d, and 31e are also mounted on the bottom surface 322 at positions on an imaginary circle C1 that is shifted outward in the radial direction X from the central position C0, and are perpendicular to the positions on the imaginary circle C1 where the semiconductor light emitting elements 31c, 31d, and 31e are mounted. Therefore, the optical axes 311c, 311d, and 311e are also inclined with respect to the axial direction Y.

[0058] As a result, the optical axes 311a-311e intersect with each other in a region closer to the flow path tube 20 than the mounting substrate 32. In this embodiment 1, an intersection F of the optical axes 311a-311e is located inside the flow path tube 20. Furthermore, in this embodiment 1, as shown in FIG. 1, the intersection F is located at the center of the axial direction Y of the flow path tube 20. Alternatively, the intersection F may be located outside the flow path tube 20 in a region closer to the flow path tube 20 than the mounting substrate 32. The inclination angle of the optical axes 311a-311e with respect to the axial direction Y is determined according to the position of the intersection F, which is set appropriately.

[0059] In the first embodiment, the optical axes 311a-311e intersect with each other at one intersection point F. Alternatively, for example, three of the optical axes 311a-311e (311a, 311b, 311d) may intersect with each other at a first intersection point F, and the remaining optical axes 311a, 311c, 311e may intersect with each other at a second intersection point different from the first intersection point F. In this case, one or both of the first intersection point and the second intersection point may be located inside the flow path pipe 20, or may be located outside the flow path pipe 20.

[0060] 3-4.Transparent plate 35 The light-transmitting plate 35 has a light-transmitting property that transmits ultraviolet light, and covers the ultraviolet light emitting side of the multiple semiconductor light-emitting elements 31 as shown in Fig. 3 and Fig. 4. In the present embodiment 1, the light-transmitting plate 35 is flat, and is joined to the upper surface of the side wall portion 323 of the mounting substrate 32 by resin or solder. This seals the recess 321. The light-transmitting plate 35 is configured to be in contact with the flow path space 70.

[0061] The light-transmitting plate 35 functions as a window that transmits the ultraviolet light emitted from the semiconductor light-emitting elements 31. The ultraviolet light emitted from the multiple semiconductor light-emitting elements 31 passes through the light-transmitting plate 35 and enters the flow path space 70. As a result, the fluid flowing through the flow path space 70 is sterilized by the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31. The light-transmitting plate 35 and the semiconductor light-emitting elements 31 are spaced apart by a predetermined distance, and in the first embodiment, the inner space of the recess 321 between them is filled with air.

[0062] It is not necessary for the entire upper surface of the light-transmitting plate 35 to be in contact with the flow path space 70, but it is preferable that the entire upper surface be in contact with the flow path space 70. Also, the side surface of the light-transmitting plate 35 may be in contact with the flow path space 70.

[0063] The light-transmitting plate 35 is not limited to a flat plate shape, and may be a convex lens type. If the light-transmitting plate 35 is a convex lens type, the directivity of the ultraviolet light emitted from the semiconductor light-emitting element 31 is increased and the directivity angle is narrowed, so that the ultraviolet light can be more efficiently irradiated onto the fluid flowing through the flow path space 70. In particular, when there is a large difference between the refractive index of the material of the light-transmitting plate 35 and the refractive index of the fluid flowing through the flow path space 70, it is preferable to use a convex lens type.

[0064] The material of the light-transmitting plate 35 may be any material that transmits the ultraviolet light emitted from the semiconductor light-emitting element 31, but a material with a thermal conductivity of 0.25 W / m·K or more is preferable. This is to improve heat dissipation efficiency. For example, sapphire, quartz, borosilicate glass, fluororesin, etc. can be used. In terms of improving heat dissipation efficiency, a material with high thermal conductivity is preferable, and sapphire is used in the first embodiment. The light-transmitting plate 35 may be formed of a material with a thermal conductivity higher than that of the mounting substrate 32. Heat can be conducted more efficiently from the semiconductor light-emitting element 31 to the light-transmitting plate 35 through the inner space of the recess 321, improving heat dissipation efficiency.

[0065] The thickness of the light-transmitting plate 35 is preferably 0.1 mm or more. Since the spread of heat is increased and the heat dissipation area is widened, heat can be dissipated more efficiently to the fluid flowing through the flow path space 70 via the light-transmitting plate 35. However, if the light-transmitting plate 35 is too thick, the thermal resistance increases, so it is preferable to set the area and thickness of the light-transmitting plate 35 so as to obtain appropriate heat dissipation characteristics.

[0066] 3-5. Light source case 34 2, 3, and 4, the light source case 34 is cylindrical and holds the mounting board 32 therein. The material of the light source case 34 is not limited, and in the present embodiment 1, it is PP, but it may be SUS or the like instead. An opening 34b is provided on the upper surface (the surface on the spacer 40 side) of the light source case 34 to transmit the ultraviolet light from the semiconductor light emitting element 31. Inside the light source case 34, the mounting board 32 is arranged so that the opening 34b and the light-transmitting plate 35 overlap in the axial direction Y, and in the present embodiment 1, the light-transmitting plate 35 is arranged so that the upper surface of the light-transmitting plate 35 is flush with the bottom surface of the opening 34b.

[0067] Furthermore, a plurality of protrusions 34a are provided on the outer upper surface of the light source case 34. The protrusions 34a are in contact with the spacer 40. The protrusions 34a create gaps 34c between the upper surface of the light source case 34 and the spacer 40, allowing the fluid flowing through the flow path space 70 to flow from the inside of the spacer 40 through the gaps 34c to the exhaust port 12. The inside of the spacer 40 and the gaps 34c also form part of the flow path space 70.

[0068] A screw thread 36 is provided on the outer peripheral surface of the light source case 34. The screw thread 36 corresponds to the screw thread 13 provided on the inner peripheral surface of the housing 10. The light source unit 30 fitted into the housing 10 is screwed in by engaging the screw thread 36 with the screw thread 13 of the housing 10. Note that the light source unit 30 may be fixed to the housing 10 by a method other than screwing.

[0069] 3-6.Sealing part 33 The sealing portion 33 is a caulking material formed to fill the gap between the mounting board 32 and the light source case 34. The sealing portion 33 is a waterproof polymeric material such as urethane resin, silicone resin, or epoxy resin. The sealing portion 33 covers the side surface of the light source case 34 and the circuit forming members such as the drive circuit of the mounting board 32, preventing the electronic components mounted on the mounting board 32 from coming into contact with water. The upper surface of the light-transmitting plate 35 is not covered by the sealing portion 33 and is in contact with the flow path space 70.

[0070] The seal portion 33 may be mixed with thermally conductive particles or thermally conductive fibers. By imparting high thermal conductivity to the seal portion 33, the heat from the semiconductor light emitting element 31 is easily dispersed through the seal portion 33, and heat dissipation can be improved. In particular, it is preferable that the light source case 34 is also made of a material with high thermal conductivity, such as metal, and both the seal portion 33 and the light source case 34 are made of a material with high thermal conductivity. Since the light source case 34 is in contact with the flow path space 70, the light source case 34 is in direct contact with the fluid flowing through the flow path space 70, and heat can be dissipated from the seal portion 33 to the fluid flowing through the flow path space 70 via the light source case 34. Therefore, heat dissipation can be further improved. The seal portion 33 may be in contact with the flow path space 70, and heat may be dissipated from the seal portion 33 to the fluid flowing through the flow path space 70.

[0071] 4. Heat dissipation paths Next, the heat dissipation path of the heat generated from the semiconductor light emitting element 31 will be described. When the fluid flowing through the flow path space 70 is introduced from the inlet 11 to flow through the flow path pipe 20 and the spacer 40, and the fluid is irradiated with ultraviolet light from the light source unit 30 to sterilize, heat is generated from the semiconductor light emitting element 31 of the light source unit 30. The heat generated from the semiconductor light emitting element 31 is conducted to the mounting board 32, and is conducted from the mounting board 32 and the inner space of the recess 321 to the light-transmitting plate 35. Here, the light-transmitting plate 35 is disposed so as to be in contact with the flow path space 70, and is in direct contact with the fluid flowing between the spacer 40 and the light source case 34. Therefore, the heat is efficiently conducted from the light-transmitting plate 35 to the fluid. In this way, in the first embodiment, the heat generated from the semiconductor light emitting element 31 can be efficiently dissipated to the fluid.

[0072] The seal portion 33 contacts both the mounting board 32 and the light source case 34, and the light source case 34 contacts the flow path space 70. Therefore, a heat dissipation path is also formed through which heat is conducted in the order of the mounting board 32, the seal portion 33, the light source case 34, and the fluid flowing through the flow path space 70. Heat dissipation through this heat dissipation path becomes effective when the seal portion 33 is made of a material containing thermally conductive particles to enhance thermal conductivity.

[0073] Furthermore, when the seal portion 33 is in contact with the flow path space 70, a heat dissipation path is also formed through which heat is conducted in the order of the mounting substrate 32, the seal portion 33, and the fluid flowing through the flow path space 70. Heat dissipation through this heat dissipation path is also effective when the thermal conductivity of the seal portion 33 is increased.

[0074] 5. Effects As described above, in the fluid sterilization device 1 of the first embodiment, the bottom surface 322 of the recess 321 formed in the mounting substrate 32 is concave, and multiple semiconductor light-emitting elements 31 emitting ultraviolet light are mounted on the bottom surface 322, so that the optical axes 311 of the multiple semiconductor light-emitting elements 31 intersect with each other in the traveling direction of the ultraviolet light. This makes it possible to concentrate the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31 within the flow path space 70 to increase the ultraviolet intensity, thereby improving the sterilization effect of the fluid flowing through the flow path space 70. In addition, since there is no need to use a mechanism for adjusting the directivity of the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31, the configuration is simpler than when such a mechanism is used, and costs can also be reduced.

[0075] Furthermore, in the first embodiment, the optical axes 311 of the multiple semiconductor light-emitting elements 31 intersect with each other within the flow path space 70. This allows the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31 to be further concentrated within the flow path space 70 to increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space 70.

[0076] Furthermore, in the first embodiment, the semiconductor light-emitting element 31 is mounted on the bottom surface 322 of the recess 321 such that the optical axis 311 of the semiconductor light-emitting element 31 is perpendicular to the portions C0 and C1 on the bottom surface 322 of the recess 321 where the semiconductor light-emitting element 31 is mounted, and the optical axes 311 of the multiple semiconductor light-emitting elements 31 are inclined at different angles relative to the flow direction of the fluid in the flow path space 70 (i.e., the axial direction Y). This makes it possible to further concentrate the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31 in the flow path space 70 to increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space 70.

[0077] In the first embodiment, the bottom surface 322 of the recess 321 is formed as a curved surface, which makes it easier to form the recess 321 and reduces the manufacturing cost.

[0078] In the first embodiment, at least a part of the curved surface forming the bottom surface 322 has a cross-sectional shape along a parabola in a plane parallel to the axial direction Y, which is the flow direction in the flow path space 70. This makes it possible to further concentrate the ultraviolet light emitted from the multiple semiconductor light-emitting elements 31 in the flow path space 70 and increase the ultraviolet intensity, thereby further improving the sterilization effect of the fluid flowing through the flow path space 70.

[0079] In addition, in the first embodiment, the light source unit 30 has a light-transmitting plate 35 that covers the ultraviolet light emission sides of the semiconductor light-emitting elements 31 and is arranged to be in contact with the flow path space 70. The ultraviolet light emitted from the semiconductor light-emitting elements 31 passes through the light-transmitting plate 35 and enters the flow path space 70. As a result, the light source unit 30 comes into contact with the fluid flowing through the flow path space 70 via the light-transmitting plate 35, and thus heat dissipation from the light source unit 30 via the fluid is promoted, and the heat dissipation of the light source unit 30 can be improved.

[0080] In the first embodiment, the flow path space 70 is formed as an internal space of the flow path tube 20, which is a cylindrical member, and the flow path tube 20, which is a cylindrical member, includes a transparent tube 21 that transmits ultraviolet light and a reflector 22 provided on the outer circumferential surface of the transparent tube 21, the transparent tube 21 being made of at least one of quartz, sapphire, ultraviolet light transmitting glass, and fluororesin, and the reflector 22 being made of at least one of a PTFE unbaked film and an aluminum thin film. This allows the inner wall of the flow path tube 20, which is a cylindrical member, to have a smooth surface due to the transparent tube 21, and the reflector 22 reflects ultraviolet light transmitted through the transparent tube 21 to the flow path space 70, improving the utilization rate of the ultraviolet light.

[0081] As described above, according to the above embodiment, it is possible to provide a fluid sterilization device 1 that has an improved sterilization effect at low cost.

[0082] (Embodiment 2) In the first embodiment, as shown in Figures 3 and 4, the bottom surface 322 of the recess 321 is formed by a curved surface, but instead, in the second embodiment, as shown in Figures 6 and 7, the bottom surface 322 of the recess 321 is formed by connecting a plurality of inclined surfaces 322a, 322b, 322c, 322d, and 322e. The first semiconductor light emitting element 31a is mounted on the inclined surface 322a, the second semiconductor light emitting element 31b is mounted on the inclined surface 322b, the third semiconductor light emitting element 31c is mounted on the inclined surface 322c, the fourth semiconductor light emitting element 31d is mounted on the inclined surface 322d, and the fifth semiconductor light emitting element 31e is mounted on the inclined surface 322e.

[0083] The optical axis 311a of the first semiconductor light emitting element 31a is perpendicular to the inclined surface 322a, the optical axis 311b of the second semiconductor light emitting element 31b is perpendicular to the inclined surface 322b, the optical axis 311c of the third semiconductor light emitting element 31c is perpendicular to the inclined surface 322c, the optical axis 311d of the fourth semiconductor light emitting element 31d is perpendicular to the inclined surface 322d, and the optical axis 311e of the fifth semiconductor light emitting element 31e is perpendicular to the inclined surface 322e. In the second embodiment, the same reference numerals are used for configurations equivalent to those in the first embodiment, and description thereof will be omitted.

[0084] In the second embodiment, the inclination angle of the optical axis 311 is stable when mounting the semiconductor light emitting element 31 on the bottom surface 322 of the recess 321, which facilitates mounting the semiconductor light emitting element 31 and prevents misalignment of the optical axis 311. Also, in the second embodiment, the same effects as those in the first embodiment are achieved, except for the effect that the bottom surface 322 of the recess 321 in the first embodiment is a curved surface.

[0085] In this embodiment 2, one semiconductor light-emitting element 31 is provided on each of the inclined surfaces 322a-322e constituting the bottom surface 322 of the recess 321, but this is not limited to this, and the inclined surfaces 322a-322e constituting the bottom surface 322 of the recess 321 may include those on which no semiconductor light-emitting element 31 is provided, or the inclined surfaces 322a-322e may include those on which a plurality of semiconductor light-emitting elements 31 are provided.

[0086] (Embodiment 3) In the first embodiment, the space between the recess 321 of the mounting substrate 32 and the light-transmitting plate 35 (the inner space of the recess 321) is filled with air. Instead, in the third embodiment, as shown in FIG. 8, the inner space of the recess 321 is filled with a sealing member 90. The material of the sealing member 90 is a material having a thermal conductivity higher than that of air, and may be a liquid such as oil or resin, or a solid such as hardened resin or glass. The thermal conductivity of the sealing member 90 is preferably 0.1 W / m·K or more. In the third embodiment, a fluorine-based inert liquid is used as the sealing member 90. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0087] According to the third embodiment, the sealing member 90 promotes heat dissipation from the semiconductor light emitting element 31, thereby further improving the heat dissipation performance of the light source unit 30. In addition, by using a fluorine-based inert liquid as the sealing member 90, the chemical stability of the semiconductor light emitting element 31 can be improved.

[0088] Furthermore, the emission surface of the semiconductor light-emitting element 31 for ultraviolet light is formed by a transparent electrode or a transparent substrate covering the light-emitting layer provided in the semiconductor light-emitting element 31, and the refractive index of the ultraviolet light in the transparent electrode or the transparent substrate is about 1.7. The refractive index of the fluorine-based inert liquid constituting the sealing member 90 is about 1.3. Therefore, the refractive index of the sealing member 90 is closer to the refractive index of the material constituting the emission surface of the semiconductor light-emitting element 31 than that of air, which has a refractive index of about 1.0. Therefore, by providing the sealing member 90, the reflection of the ultraviolet light on the emission surface of the semiconductor light-emitting element 31 is reduced, and the efficiency of extracting the ultraviolet light from the semiconductor light-emitting element 31 can be improved.

[0089] (Embodiment 4) In the first embodiment, the flow path pipe 20 is composed of a transparent tube 21 and a reflector 22, but instead, it can be composed of a metal tube. In the fourth embodiment shown in Fig. 9, the flow path space 70 is formed as an internal space of the flow path pipe 20, which is a cylindrical member, and the flow path pipe 20 is composed of a SUS tube or a Cu tube. Note that the flow path pipe 20 can also be a metal tube whose inner wall is plated with a material having a relatively low reflectance of ultraviolet light. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0090] In embodiment 4, the flow path tube 20, which is a cylindrical member forming the flow path space 70, has a relatively low reflectance of ultraviolet light. However, since the ultraviolet light emitted from the light source unit 30 is concentrated within the flow path space 70, even if the flow path tube 20 is made of a material with a relatively low reflectance, the decrease in the utilization rate of ultraviolet light is relatively small, and the flow path tube 20 can be easily manufactured, thereby reducing costs.

[0091] Although the first to fourth embodiments have been described with respect to sterilization of liquids, any fluid can be sterilized, and it is also possible to sterilize gases, mixtures of gases and liquids, and mixtures of gases and powdered solids.

[0092] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist of the present invention. [Explanation of symbols]

[0093] 1:Fluid sterilizer 10: Housing 20: Flow pipe 30: Light source section 31, 31a to 31e: semiconductor light emitting element 311, 311a~311e: Optical axis 32: Mounting board 321: Recess 322: Bottom 33: Seal part 34: Light source case 35: Translucent plate 40: Spacer 50: Plate

Claims

1. A fluid sterilization device having a light source unit that emits ultraviolet light and a flow path space in which a fluid flows and into which the ultraviolet light from the light source unit is incident, the light source unit includes a mounting substrate having a recess at a position facing the flow path space, and a plurality of semiconductor light emitting elements that are mounted on a bottom surface of the recess and emit ultraviolet light, A fluid sterilization device, wherein a bottom surface of the recess is concave such that optical axes of the plurality of semiconductor light emitting elements intersect with each other in a traveling direction of the ultraviolet light.

2. The fluid sterilization device according to claim 1 , wherein optical axes of the semiconductor light emitting elements intersect with each other within the flow path space.

3. the semiconductor light emitting element is mounted on a bottom surface of the recess such that an optical axis of the semiconductor light emitting element is perpendicular to a portion of the bottom surface of the recess where the semiconductor light emitting element is mounted; The fluid sterilization device according to claim 1 or 2, wherein the optical axes of the plurality of semiconductor light-emitting elements are inclined at different angles relative to a flow direction of the fluid in the flow path space.

4. The fluid sterilization device according to claim 1 or 2, wherein a bottom surface of the recess is formed by a curved surface.

5. The fluid sterilization device according to claim 4 , wherein at least a part of the curved surface has a cross-sectional shape along a parabola in a plane parallel to a flow direction in the flow path space.

6. The fluid sterilization device according to claim 1 or 2, wherein a bottom surface of the recess is formed by connecting a plurality of inclined surfaces.

7. 3. The fluid sterilization device according to claim 1 or 2, wherein the light source unit has a light-transmitting plate that covers the ultraviolet light emission sides of the semiconductor light-emitting elements and is arranged to be in contact with the flow path space, and the ultraviolet light emitted from the semiconductor light-emitting elements passes through the light-transmitting plate and enters the flow path space.

8. The fluid sterilization device according to claim 7 , wherein a space between the recess of the mounting substrate and the light-transmitting plate is filled with a sealing member having a thermal conductivity higher than that of air.

9. The fluid sterilization device according to claim 8 , wherein the sealing member is a fluorine-based inert liquid.

10. The flow path space is formed as an internal space of a cylindrical member, the cylindrical member includes a transparent tube that transmits ultraviolet light and a reflector provided on an outer circumferential surface of the transparent tube, the transparent tube is made of at least one of quartz, sapphire, ultraviolet light transmitting glass, and fluororesin; 3. The fluid sterilization device according to claim 1, wherein the reflector is formed of at least one of an unsintered PTFE film and an aluminum thin film.

11. The flow path space is formed as an internal space of a cylindrical member, The fluid sterilization device according to claim 1 or 2, wherein the cylindrical member is made of a SUS tube or a Cu tube.

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