Fluid sterilization device

Abstract

To provide a fluid sterilization device which can be reduced in its size and can cope with ultraviolet ray deterioration of a housing.SOLUTION: A housing main body 12 and an outer cover 14 form a housing. A straight pipe 18 and a light source unit 19 are inserted into the housing in an axial direction. A derivation channel 35 is formed in the housing, and is communicated with a notch 181 which is formed on the light source unit 19 side of the straight pipe 18. A shield ring 20 has ultraviolet ray resistance greater than that of the housing. A taper part 201 of the shield ring 20 defines the derivation channel 35 and protects the housing from ultraviolet ray which leaks from the notch 181 to an external part of the straight pipe 18.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] The present invention relates to a fluid sterilization device that sterilizes a fluid by irradiating the fluid with ultraviolet light. [Background technology]

[0002] It is known that a fluid to be sterilized flowing from one end to the other end of a flow pipe is sterilized by irradiating the fluid with ultraviolet light from the other end of the flow pipe. In this case, an outlet is provided at the other end of the flow pipe to discharge the fluid to be sterilized from the flow pipe (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-202205 A [Patent Document 2] Patent Publication No. 2022-68062 Summary of the Invention [Problem to be solved by the invention]

[0004] If the fluid sterilization device is constructed such that components such as the flow path pipe and the light source are inserted and stored as storage parts from the opening side of the housing and then fastened from the opening side, the assembly structure can be simplified, the arrangement space can be saved, and the device can be made smaller. In this case, typically, the flow path pipe is made of a material with excellent ultraviolet resistance such as PTFE (polytetrafluoroethylene tetrafluoroethylene resin), while the housing is generally made of a rigid and inexpensive resin.

[0005] When the outlet is provided at the other end of the flow path tube, i.e., the end on the light source side, the intensity of ultraviolet light near the outlet is high, and there is a problem that the housing is easily deteriorated by being exposed to ultraviolet light that leaks out of the flow path tube from the outlet.

[0006] The fluid sterilization devices in Patent Documents 1 and 2 do not have a structure in which the flow path pipe is stored in a housing together with other components such as a light source to streamline assembly, and do not raise the problem of the housing deteriorating due to ultraviolet light leaking out from the outlet of the flow path pipe.

[0007] An object of the present invention is to provide a fluid sterilizing device that can effectively prevent deterioration of the housing caused by ultraviolet light leaking out from the outlet of the flow path pipe. [Means for solving the problem]

[0008] The present invention relates to A fluid sterilization device for sterilizing a liquid, comprising: A housing having one end side and the other end side coaxially on a straight axis; the housing includes a first cylindrical portion at the one end and a second cylindrical portion at the other end having an inner diameter larger than that of the first cylindrical portion, a flow path pipe that is axially inserted into the first cylindrical portion of the housing so that a fluid to be sterilized flows in one direction from the one end side to the other end side, and has a notch that extends a predetermined length in the axial direction from an opening on the other end side toward the one end side; an opening closing member provided in the second cylindrical portion of the housing, the opening closing member having an ultraviolet light transmitting portion and closing the opening of the flow path pipe; a light source that irradiates ultraviolet light into the flow passage pipe from the other end side in the axial direction through the ultraviolet light transmitting portion of the opening closing member; a shielding member provided within the second cylindrical portion of the housing, having a higher ultraviolet resistance than the housing, disposed on the outer circumferential side of the flow path pipe, defining an upstream end of an outlet flow path for the fluid to be sterilized from the notch, and shielding an inner circumferential side of the housing from ultraviolet light emitted from the notch of the flow path pipe; It is equipped with: Effect of the Invention

[0009] According to the present invention, a shielding member having higher UV resistance than the housing is provided in the irradiation range of the UV light leaking out from the notch at the other end of the flow path pipe, and shields the housing from the leaking UV light. This makes it possible to reduce the size of the fluid sterilization device while protecting the housing from UV light. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a longitudinal cross-sectional view of a fluid sterilization device. [Diagram 2] FIG. 2 is an exploded perspective view showing the storage components stored in the cylindrical portion of the housing body disassembled in the axial direction of the fluid sterilization device. [Diagram 3] 2 is an exploded perspective view of the light source device and the outer ret disassembled in the axial direction and viewed from one axial end side. FIG. [Figure 4] 4 is an exploded perspective view of the light source device and the outer ret disassembled in the axial direction and viewed from the other axial end side. FIG. [Figure 5A] 2 is an enlarged view of an area including an expanded diameter portion and an outer cover in the axial direction in FIG. 1. [Figure 5B] FIG. 5B is an enlarged view of the upper half of FIG. 5A with respect to the central axis Rx. [Figure 6] FIG. 13 is a perspective view of a modified reflector. [Figure 7] This is a diagram showing a simulation analysis of the UV irradiance distribution in a fluid sterilization device with the upper limit of the irradiance distribution set to 40 mw / cm2. [Figure 8] This is a diagram showing a simulation analysis of the UV irradiance distribution in a fluid sterilization device with the upper limit of the irradiance distribution set to 10 mw / cm2. [Figure 9] This is a diagram showing a simulation analysis of the UV irradiance distribution in a fluid sterilization device with the upper limit of the irradiance distribution set to 5mw / cm2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described. It goes without saying that the present invention is not limited to the embodiment. Note that the same reference numerals will be used throughout the drawings to designate components common to a plurality of embodiments.

[0012] (composition) 1 is a longitudinal sectional view of a fluid sterilization device 10. Rx indicates the central axis of the fluid sterilization device 10. The fluid sterilization device 10 has a cylindrical housing body 12 and a cap-shaped outer cover 14. The housing body 12 and the outer cover 14 form the housing of the fluid sterilization device 10, and are screwed together at their respective male threaded portions 121 and female threaded portions 141 with their central axes aligned with the central axis Rx of the fluid sterilization device 10. The screwing of the male threaded portion 121 and the female threaded portion 141 tightens the components housed within the housing in the axial direction, simplifying the assembly structure of the components housed.

[0013] The housing body 12 has a cylindrical portion 122, an inlet 123, an expanded diameter portion 124, and a stopper portion 125. The inlet 123 protrudes a predetermined length from one axial end side of the cylindrical portion 122 toward the one end side along the central axis Rx. The stopper portion 125 is formed as an inner surface of one axial end side of the cylindrical portion 122, and an inlet passage of the inlet 123 opens at the center. The stopper portion 125 has a role of preventing the components housed in the cylindrical portion 122 from moving toward the one end side in the axial direction. The expanded diameter portion 124 protrudes radially from the cylindrical portion 122 at one end side and opens at the other end side.

[0014] The outer cover 14 has an opening 142 at the center of the cover part. The outer cover 14 prevents the stored components from coming off the housing body 12 by the cover part that defines the circular opening 142 at the center, and has the role of pressing the stored components toward the stopper part 125 after the outer cover 14 is screwed to the housing body 12.

[0015] 2 is an exploded perspective view showing the components housed in the cylindrical portion 122 of the housing body 12, disassembled in the axial direction of the fluid sterilization device 10. The components housed include a shield 15, a straightening plate 16, and a straight pipe 18, and their central axes are aligned with the central axis Rx of the housing, and they are arranged in that order in the axial direction from one end to the other end, and inserted into the housing body 12 from the opening side at the other end.

[0016] The shield 15, together with the rectifying plate 16 and the straight pipe 18, is made of a material having ultraviolet resistance. One end of the shield 15 is abutted against the inner surface of the stopper portion 125 to shield the inner surface of the stopper portion 125 from UV (ultraviolet rays) and protect the stopper portion 125 from UV. The shield 15 also has a tapered portion 151 on the inner periphery side. The tapered portion 151 has a diameter equal to the inner diameter of the inlet 123 and the straight pipe 18 on the small diameter side and the large diameter side, respectively, and communicates with the inlet 123 and the sterilization chamber 182, respectively. By having the tapered portion 151, UV reflected by the tapered portion 151 is reflected toward the rectifying plate 16, thereby improving the utilization efficiency of UV.

[0017] The straightening plate 16 has a plurality of straightening holes 162 in the peripheral portion surrounding the central portion 161. The central portion 161 functions as a dam for the fluid to be sterilized (e.g., water) that flows into the straightening plate 16 from the pressure pump (not shown) via the inlet 123 and the shield 15. That is, the fluid to be sterilized is decelerated when it hits the central portion 161, and then flows into the straight pipe 18 from the straightening holes 162. This makes the flow rate of the fluid to be sterilized uniform between the inside and outside in the radial direction in the sterilization chamber 182. In addition, by having the inlet (the smallest diameter portion of the tapered portion 151) of the shield 15 and the central portion 161 of the straightening plate 16 on the central axis Rx, UV emitted from the straight pipe 18 toward the straightening plate is prevented from leaking out of the fluid sterilization device 10. Here, the area of ​​the central portion 161 is equal to or larger than the area of ​​the inlet of the shield 15.

[0018] The straight pipe 18 defines a sterilization chamber 182 on the inner periphery. A plurality of notches 181 are formed in the peripheral wall of the straight pipe 18 on the other axial end side at equal angular intervals in the circumferential direction, and extend a predetermined length from the opening at the other end of the straight pipe 18 toward the one end side. An O-ring 183 fits into an annular groove on the outer periphery of the straight pipe 18 to prevent leakage of the fluid to be sterilized at the outer periphery.

[0019] 3 and 4 are exploded perspective views of the light source device 19 and the housing sealing member 32, respectively, as viewed from one axial end side and the other axial end side when disassembled in the axial direction. Fig. 5A is an enlarged view of a range including the expanded diameter portion 124 and the outer cover 14 in the axial direction in Fig. 1, and Fig. 5B is an enlarged view of the upper half with respect to the central axis Rx in Fig. 5A.

[0020] 3 to 5B, the light source device 19 and the housing sealing member 32 are arranged on one end side and the other end side, respectively, and are housed in the expanded diameter portion 124 with their central axes aligned with the central axis Rx. The light source device 19 is disassembled into the shielding ring 20, the O-ring 191, the quartz glass 22, the reflector 24, the UV-LED 26, the substrate 28, and the heat dissipation cover 30 in that order from one end side to the other end side in the axial direction.

[0021] In the light source device 19, the side from which UV is emitted and the opposite side are appropriately referred to as the front side and back side, respectively. The front side and back side of the light source device 19 face one end side and the other end side, respectively, in the axial direction of the fluid sterilization device 10. An O-ring 191 is fitted between the periphery of the quartz glass 22 and an annular step on the front side of the reflector 24 to provide a seal. The quartz glass 22 and the O-ring 191 form an opening sealing member that seals the opening on the other end side of the straight tube 18 serving as a flow path tube.

[0022] The reflector 24, together with the shielding ring 20, is made of a material resistant to ultraviolet light. The reflector 24 has a reflecting surface 241, a protruding surface 242, a peripheral surface 243, and a recess 244. The reflecting surface 241 is formed in a taper that gradually increases in diameter from the back surface side toward the front surface side on the inner peripheral side of the reflector 24. The protruding surface 242 protrudes radially outward from the peripheral edge of the reflecting surface 241. The peripheral surface 243 is formed in the shape of a cylindrical side surface, and extends from the radial outer end of the protruding surface 242 toward the other end in the axial direction. The recess 244 is formed to open to the peripheral portion of the back surface of the reflector 24.

[0023] The reflector 24 has, on the back surface side (FIG. 4), a circumferential end face 247, and an annular step portion 248 formed along the inner periphery of the circumferential end face 247 and recessed toward the back.

[0024] A plurality of UV-LEDs 26 (two in the illustrated example) and a plurality of electric components 27 are mounted on the center and periphery of the front surface side of the substrate 28, respectively. The UV-LEDs 26 are exposed within a tapered reflecting surface 241 from the rear surface side of the reflector 24, and the electric components 27 are housed in a recess 244 on the rear surface of the reflector 24. A pair of opposing recesses 281 and a pair of recesses 282 are formed on the periphery of the circular substrate 28.

[0025] The UV emitted by the UV-LED 26 belongs to the deep ultraviolet light that is highly effective for sterilizing fluids, and has a wavelength range of, for example, 100 to 400 nm. In particular, within the ultraviolet wavelength range, UVC light with a wavelength of 100 to 280 nm is more preferable because it has a particularly high sterilizing effect.

[0026] The heat dissipation cover 30 is made of metal and has a cylindrical portion 301 on the back side. A harness (not shown) for wiring to the electric components 27 of the board 28 is inserted into the cylindrical portion 301. A pair of protrusions 302 are formed on the front side of the heat dissipation cover 30 and fit into a pair of recesses 282 of the board 28. An O-ring 192 (FIG. 5A) is fitted between the inner periphery of the heat dissipation cover 30 and the outer periphery of an annular step portion on the other axial end side of the peripheral surface 243.

[0027] The housing sealing member 32 has, on its inner surface, spacers 320 as a plurality of ridges formed at equal angular intervals in the circumferential direction, and convex portions 321 formed on the ridge top surfaces of the spacers 320 spaced 180° apart in the circumferential direction. The arc-shaped protruding edge 324 fits onto the outside of the circumferential surface 243 of the reflector 24.

[0028] The harness hole 322 passes through the housing sealing member 32 in the axial direction. A cylindrical portion 301 with an O-ring 193 fitted around its periphery is fitted into the harness hole 322. The protrusion 321 is formed to allow for component commonality with other types of fluid sterilization devices, and can be omitted in this fluid sterilization device 10. This is because the circumferential positioning of the heat dissipation cover 30 and the housing sealing member 32 is achieved by the engagement of the cylindrical portion 301 with the harness hole 322.

[0029] The housing sealing member 32 has, on the back surface side, a sealing portion 325 and an outlet 326 that protrudes from the sealing portion 325 to the other end side in the axial direction along the central axis Rx. The outlet 326 passes through the inner periphery side of the opening 142 of the outer cover 14 and reaches the outside of the outer cover 14 at its protruding end.

[0030] 5A and 5B, the shield ring 20 has an annular end surface at one end in the axial direction fitted to the inner circumference of the enlarged diameter portion 124 using an O-ring 196. The shield ring 20 has a cylindrical side portion 202 and a tapered portion 201 on the inner circumference of one end side and the other end side in the axial direction, respectively. In the axial direction, the position P1 of the end of one end side of the shield ring 20, the position P2 of the small diameter end of the tapered portion 201, the position P3 of the large diameter end of the tapered portion 201, the end position (position of one end in the axial direction) Q1 of the notch 181, and the start position (position of the other end in the axial direction) of the notch 181, i.e., the other end position Q2 of the straight pipe 18, are arranged in the illustrated example as P1, Q1, P2, P3 (=Q2) in that order from one end side to the other end side in the axial direction. However, it is preferable that P1 and Q1 are at the same axial position (P1=Q1). This is because the entirety of notch 181 is exposed to tapered portion 201, increasing the effective area of ​​notch 181, and a space with a triangular cross section is formed between one end of tapered portion 201 and the outer peripheral surface of straight tube 18, preventing the fluid to be sterilized from remaining in the triangular space.

[0031] In Fig. 5A and Fig. 5B, Fn indicates the flow of the fluid to be sterilized in the fluid sterilization device 10. The outlet flow path 35 is formed in the space between the light source device 19 in the fluid sterilization device 10 and the tapered portion 201 of the shield ring 20, the expanded diameter portion 124, or the inner surface of the sealing portion 325 of the housing sealing member 32, as a passage for leading the fluid to be sterilized, which is led outward in the radial direction from the notch 181 of the straight tube 18, to the outside of the fluid sterilization device 10. The outlet flow path 35 has a first flow path portion 351, a second flow path portion 352, a third flow path portion 353, a fourth flow path portion 354, and a fifth flow path portion 355 in this order in the flow direction of the fluid to be sterilized. The first flow path portion 351, the second flow path portion 352, and the third flow path portion 353 all have an annular shape when viewed in the axial direction. The fourth flow path portion 354 and the fifth flow path portion 355 have a circular shape when viewed in the axial direction.

[0032] The first flow path section 351 is formed in a space between the tapered section 201 and the protruding surface 242 in the axial direction, and serves as the most upstream portion of the outlet flow path 35 to guide the fluid to be sterilized to the downstream side immediately after it is led out from the notch 181. The second flow path section 352 is formed as a passing section between the corner section of the boundary between the protruding surface 242 and the circumferential surface 243 and the tapered section 201. The third flow path section 353 is formed in an annular shape between the expanded diameter section 124 and the circumferential surface 243. The fourth flow path section 354 is formed as a gap in the axial direction between the rear surface of the light source device 19 and the inner surface of the housing sealing member 32.

[0033] (material) The following are examples of materials for each component constituting the fluid sterilization device 10. (a) Housing (housing body 12 and outer cover 14): Engineering plastic such as PC (polycarbonate) or POM (polyacetal) (b) Shield 15, straightening plate 16, straight pipe 18, shielding ring 20 and reflector 24: PTFE (polytetrafluoroethylene tetrafluoroethylene resin), PFA (perfluoroalkoxyalkane), PVF (polyvinyl fluoride), PVDF (polyvinylidene fluoride) or other fluid to be sterilized and fluororesin (c) Heat dissipation cover 30: Metal

[0034] The above material (b) is selected as a material having higher ultraviolet resistance and UV reflectance than the above material (a). The above material (a) is selected as a material having higher corrosion resistance against the fluid to be sterilized than metal. The reason for selecting the above material (b) for the shield 15 and the shield ring 20 is that the shield 15 and the shield ring 20 are made of a material that is lightly processed PTFE, and therefore can be manufactured by a simple process.

[0035] (action) The fluid to be sterilized is pressure-fed to fluid sterilization device 10 from a pressure pump (not shown) and introduced into sterilization chamber 182 of straight pipe 18 through inlet 123 of housing main body 12, tapered section 151 of shield 15 and straightening holes 162 of straightening plate 16. The reason why straightening plate 16 has central section 161 with no through-holes is to straighten the fluid to be sterilized along with the straightening holes 162 of straightening plate 16, and to make the flow rate in sterilization chamber 182 uniform across the radial direction of sterilization chamber 182.

[0036] The UV-LEDs 26 emit UV light in the axial direction of the light source device 19 toward the quartz glass 22. Of the ultraviolet light emitted from the UV-LEDs 26, the ultraviolet light that spreads in the radial direction and is irradiated onto the reflecting surface 241 is reflected by the reflecting surface 241 toward the central axis Rx. The ultraviolet light passes through the quartz glass 22 and is irradiated onto the fluid to be sterilized in the sterilization chamber 182. As a result, the fluid to be sterilized is sterilized.

[0037] When the fluid to be sterilized collides with the surface of quartz glass 22, its direction changes from the axial direction of straight tube 18 to the radially outward direction, and it exits straight tube 18 through notch 181. Because the total cross-sectional flow area of ​​multiple notches 181 is smaller than the cross-sectional flow area of ​​sterilization chamber 182, the flow rate of the fluid to be sterilized increases at notch 181. The flow rate of the fluid to be sterilized is further increased by tapered portion 201.

[0038] In Fig. 1, the fluid sterilization device 10 is placed horizontally (with its longitudinal direction aligned horizontally), but it can also be used in a vertical position (with its longitudinal direction aligned vertically) with the inlet 123 and the outlet 326 at the bottom and top, respectively. In this case, when the equipment, such as a water server, equipped with the fluid sterilization device 10, stops operating, the pump also stops operating, and air remains in the upper part of the straight pipe 18. It is preferable that this remaining air be quickly discharged outside the next time the pump starts operating. This is because air weakens the intensity of UV light.

[0039] As described above, the flow velocity of the fluid to be sterilized increases at the notch 181, so in the fluid sterilization device 10, any air remaining in the upper part of the straight pipe 18, i.e., at the height of the notch 181, does not remain there for long, but is quickly and smoothly discharged out of the straight pipe 18 by the high-speed fluid to be sterilized.

[0040] On the other hand, UV emitted from quartz glass 22 to sterilization chamber 182 that spreads widely outward in the radial direction is emitted to the outside of straight tube 18 through notch 181. Hereinafter, UV that enters notch 181 from the inner periphery side of straight tube 18 is also referred to as "leaking UV".

[0041] As described above, the axial positional relationships are defined as described above for position P1 on one end side of the shielding ring 20, position P2 on the boundary between the cylindrical side surface portion 202 and the tapered portion 201, position P3 on the open end of the shielding ring 20, position Q1 on the end of the notch 181, and position Q2 on the other end of the straight tube 18, so that the leaking UV is blocked by the fluid sterilization device 10 and prevented from being irradiated to the inner surface of the housing main body 12. That is, the entire amount of the leaking UV is irradiated to the tapered portion 201 of the shielding ring 20 and reflected radially inward, or is reflected to the cylindrical side surface portion 202 via a portion of the one end side of the notch 181 and immediately returns to the straight tube 18, and the remainder is irradiated to the tapered portion 201 of the shielding ring 20 and reflected.

[0042] On the other hand, the fluid to be sterilized passes through first flow path portion 351, and then passes through second flow path portion 352 sandwiched between tapered portion 201 and a corner portion of reflector 24. The leaking UV that is irradiated onto tapered portion 201 is reflected by tapered portion 201 and then splits into three destinations: (a) notch 181 in the peripheral wall at the other axial end of straight tube 18, (b) a portion of the peripheral wall at the other axial end of straight tube 18 where notch 181 is not formed, and (c) protruding surface 242. The leaking UV that is reflected to destination (a) passes through notch 181 and returns into straight tube 18, and contributes to the re-sterilization of the fluid to be sterilized in sterilization chamber 182. Of the leaking UV, the reflected UV at (b) and (c) is reflected again at the reflected destination and is repeatedly reflected between the tapered portion 201 and the reflector 24 until its intensity is sufficiently weakened, thereby contributing to sterilization of the fluid to be sterilized in the first flow path portion 351 and the second flow path portion 352.

[0043] The taper angle or contour shape of the tapered section 201 is set so that the leaking UV does not escape to the third flow path section 353 downstream of the second flow path section 352 due to repeated alternating reflections between the tapered section 201 and the reflector 24, but remains in the first flow path section 351 and the second flow path section 352, or finally returns to the sterilization chamber 182 via the notch 181.

[0044] After passing through second flow path section 352, the fluid to be sterilized flows in the axial direction through annular third flow path section 353 between circumferential surface 243 of reflector 24 and the inner circumferential surface of enlarged diameter section 124, and then hits the inner surface of sealing section 325 and changes its traveling direction radially inward. Then, the fluid flows around to fourth flow path section 354 on the rear side of light source device 19, and collects at an opening on one end side of outlet 326, which serves as the radial center, along the inner surface of sealing section 325. Fourth flow path section 354 is formed as a gap sandwiched between the rear side of light source device 19 and sealing section 325 of housing sealing member 32 in the axial direction.

[0045] The fluid to be sterilized comes into contact with the back surface of the heat dissipation cover 30 of the light source device 19 in the fourth flow path section 354, and cools the heat dissipation cover 30. Since the heat generated by the UV-LEDs 26 is conducted to the substrate 28 and then to the metallic heat dissipation cover 30, the cooling of the heat dissipation cover 30 by the fluid to be sterilized in the fourth flow path section 354 contributes to the cooling of the UV-LEDs 26. Here, the notch 181 and the tapered section 201 increase the flow rate of the fluid to be sterilized, thereby improving the cooling performance of the heat dissipation cover 30.

[0046] The substrate 28 is also called a metal substrate, and the mounting area for components that require heat dissipation is made of metal, so that the substrate 28 has a structure that increases the thermal conductivity to the back side.

[0047] The fluid to be sterilized then flows out of the fluid sterilization device 10 via the fifth flow path portion 355.

[0048] (Reflector Modification) 6 is a perspective view of a modified reflector 24b. Reflector 24b differs from reflector 24 (FIGS. 3 and 4) in that protruding surface 242 is not perpendicular to the central axis but is tapered to match the shape of tapered portion 201, and that a plurality of grooves 245 are formed in tapered protruding surface 242 at equal angular intervals in the circumferential direction.

[0049] As a result, it is possible to prevent the gap between the protruding surface 242 of the reflector 24b and the tapered portion 201 from being locally narrower than that between the protruding surface 242 of the reflector 24. In addition, the groove 245 ensures that the flow cross-sectional area of ​​the first flow path portion 351 is sufficiently large.

[0050] (Analysis of illuminance distribution) 7 to 9 are diagrams obtained by simulating the illuminance distribution of UV light in the fluid sterilization device 10. In the analysis of the illuminance distribution in Figs. 7 to 9, the emission intensity (brightness) of the UV light emitted from the UV-LEDs 26 is set to be the same. However, the upper limit of the illuminance distribution analysis is set to 40 mw / cm2. 2 , 10mw / cm 2 and 5mw / cm2 It is configured in this way. Therefore, in each illuminance distribution diagram, the positions with illuminance above the upper limit are uniformly assigned to the uppermost region. The simulation was performed using ASAP of Breault Research Organization.

[0051] Also, in the description of FIGS. 1 and 2, it was explained that the straight tube 18 side of the central portion 161 of the rectifying plate 16 serves as a UV reflection surface. However, in the illuminance distributions of FIGS. 7 to 9, it is calculated that UV is not reflected at the central portion 161.

[0052] In the illuminance distributions of FIGS. 7 to 9, the upper limit illuminance Lu is divided into four equal parts, and it shows which stage of the four-stage illuminance level each position belongs to. That is, when the illuminance is L, the first illuminance stage is 0 ≦ L < Lu / 4, the second illuminance stage is Lu / 4 ≦ L < Lu / 2, the third illuminance stage is Lu / 2 ≦ L < 3·Lu / 4, and the fourth illuminance stage is 3·Lu / 4 ≦ L.

[0053] From FIG. 7, it can be seen that the vicinity of the emission of the UV-LED 26 has a strong illuminance of 30 mw / cm 2 or more, and there is an illuminance region of 10 mw / cm 2 to 20 mw on the outer peripheral side of the notch 181. From FIG. 8, it can be seen that the radially inner part of the tapered portion 201 and the shield 15 are in an illuminance region of 2.5 mw / cm 2 to 5.0 mw. From FIG. 9, it can be seen that the maximum diameter side of the tapered portion 201 is in an illuminance region of 1.25 mw / cm 2 to 2.5 mw.

[0054] That is, from the simulation results of the illuminance distributions of FIGS. 7 to 9, by providing the tapered portion 201, it is possible to prevent ultraviolet light from leaking into the region of the housing (the housing main body 12 and the outer cover 14), and suppress deterioration due to ultraviolet rays.

[0055] (Supplementary explanation) In the fluid sterilization device 10, water is used as the fluid to be sterilized. However, in the present invention, the fluid to be sterilized may be a liquid other than water.

[0056] The fluid sterilization device 10 includes two UV-LEDs 26 as light sources that emit UV light. The fluid sterilization device of the present invention may include one light source that emits UV light, or three or more light sources.

[0057] In the fluid sterilization device 10, quartz glass 22 is used as the ultraviolet ray transmitting portion. The ultraviolet ray transmitting portion of the present invention can be made of any material other than quartz glass 22, so long as it transmits ultraviolet rays and is resistant to corrosion by the fluid to be sterilized.

[0058] The cylindrical portion 122 and the expanded diameter portion 124 of the fluid sterilization device 10 correspond to the first and second cylindrical portions of the present invention, respectively, and house the straight tube 18 as a flow path tube and the light source device 19, respectively. The shielding ring 20 is fitted onto the end of the straight tube 18 on the notch 181 side in the expanded diameter portion 124. The tapered portion 201 of the shielding ring 20 forms an outlet passage in the expanded diameter portion 124 for the fluid to be sterilized that is led out from the notch 181 as an outlet of the straight tube 18, and also protects the expanded diameter portion 124 by receiving ultraviolet light that leaks out of the straight tube 18 from the notch 181.

[0059] Examples of fluids to be sterilized by the fluid sterilization device 10 include water stored in the water tank of an ice maker, water in a water supply pipe or a water heater, drinking water in a water server, cooling water in a circulation device (chiller), and drinking liquid in a drink server. [Explanation of symbols]

[0060] 10 Fluid sterilization device, 18 Straight pipe (flow path pipe), 19 Light source device, 20 Shielding ring (shielding member), 22 Quartz glass (ultraviolet light transmitting portion), 24, 24b Reflector, 26 UV-LED (light source), 28 Substrate, 30 Heat dissipation cover, 32 Housing sealing member, 35 Outlet flow path, 24 Expanded diameter portion, 122 Cylindrical portion (first cylindrical portion), 124 Expanded diameter portion (second cylindrical portion), 11 4···outer cover, 125···stopper portion, 142···opening, 181···notch, 201···tapered portion, 202···cylindrical side portion, 241···reflecting surface, 242···projecting surface, 243···circumferential surface, 245···groove, 325···closing portion, 326···outlet, 351···first flow path portion, 352···second flow path portion, 353···third flow path portion, 354···fourth flow path portion, 355···fifth flow path portion.

Claims

1. A fluid sterilization device for sterilizing a liquid, comprising: A housing having one end side and the other end side coaxially on a straight axis; the housing includes a first cylindrical portion at the one end and a second cylindrical portion at the other end having an inner diameter larger than that of the first cylindrical portion, a flow path pipe that is axially inserted into the first cylindrical portion of the housing so that a fluid to be sterilized flows in one direction from the one end side to the other end side, and has a notch that extends a predetermined length in the axial direction from an opening on the other end side toward the one end side; an opening closing member provided in the second cylindrical portion of the housing, the opening closing member having an ultraviolet light transmitting portion and closing the opening of the flow path pipe; a light source that irradiates ultraviolet light into the flow passage pipe from the other end side in the axial direction through the ultraviolet light transmitting portion of the opening closing member; a shielding member provided within the second cylindrical portion of the housing, having a higher ultraviolet resistance than the housing, disposed on the outer circumferential side of the flow path pipe, defining an upstream end of an outlet flow path for the fluid to be sterilized from the notch, and shielding an inner circumferential side of the housing from ultraviolet light emitted from the notch of the flow path pipe; A fluid sterilization device comprising:

2. 2. The fluid sterilization device of claim 1, A fluid sterilization device, wherein the blocking member has a tapered portion on an inner periphery thereof that expands from the one end side to the other end side in the axial direction of the flow path pipe.

3. 3. The fluid sterilization device of claim 2, A fluid sterilization device, wherein the shielding member has a higher reflectance to ultraviolet rays than the housing.

4. 4. The fluid sterilization device of claim 3, The fluid sterilization device further comprises a reflector that is disposed between the light source and the opening sealing member in the axial direction, has a reflective surface on its inner circumferential side that reflects the ultraviolet light from the light source, and has an outer circumferential side that forms the outlet flow path in an annular gap between the shielding member and the housing.

5. 5. The fluid sterilization device according to claim 4, the reflector has a protruding surface that protrudes radially outward from the flow path pipe and faces the tapered portion in the axial direction, and has a higher ultraviolet resistance than the housing; A fluid sterilization device, characterized in that the tapered portion of the shielding member reflects the ultraviolet light toward the notched hole and the protruding surface of the reflector.

6. 5. The fluid sterilization device according to claim 4, A fluid sterilizing device, wherein the reflector has a groove extending along the flow of the fluid to be sterilized in a portion that defines the outlet flow path.

7. 5. The fluid sterilization device according to claim 4, the opening closing member, the reflector, and the light source constitute a light source device, Further, a housing sealing member having a sealing portion that is formed as a gap in the axial direction between the light source device and the housing, and an outlet that protrudes from the center of the sealing portion to the outside of the housing and guides the fluid to be sterilized in the gap to the outside of the housing, the housing has a stopper portion at the one end side in the axial direction that prevents a movement of a component housed in the housing toward the one end side, and a fastening portion that fastens the component housed in the housing toward the stopper portion via the closing portion of the housing closing member, The flow path pipe and the light source device are accommodated in the housing as the accommodation parts, A fluid sterilization device, characterized in that the flow path pipe, the light source device, and the housing sealing member are aligned with their central axes and arranged in a row in the axial direction in order from the one end side.

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