Fluid sterilization device

Abstract

The housing main body (12) and the outer cover (14) constitute a housing. The straight tube (18) and the light source device (19) are inserted into the housing in the axial direction. The lead-out flow path (35) is formed in the housing and communicates with a cutout (181) formed on the light source device (19) side of the straight tube (18). The shield ring (20) has higher ultraviolet resistance than the housing. The tapered section (201) of the shield ring (20) defines the lead-out flow path (35), and the protective housing is affected by ultraviolet rays that leak out of the straight tube (18) from the cutout (181).

Description

Technical Field

[0001] The present invention relates to a fluid sterilizing device for sterilizing the fluid by irradiating the fluid with ultraviolet rays. Background Art

[0002] A technology is known to sterilize a fluid to be sterilized flowing from one end to the other end of a flow tube by irradiating ultraviolet rays from the other end. In this case, a guide port is provided at the other end of the flow tube to guide the fluid to be sterilized out of the flow tube (for example, Patent Document 1 and Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-202205

[0006] Patent Document 2: Japanese Patent Application Publication No. 2022-68062 Summary of the invention

[0007] Problems to be solved by the invention

[0008] When the components such as the flow tube and the light source are inserted into the opening side of the housing as storage accessories and fastened from the opening side to form an assembled structure in the fluid sterilization device, the assembly structure can be simplified, the configuration space can be saved, and miniaturization can be achieved. In this case, generally speaking, the flow tube is made of a material with excellent ultraviolet resistance such as PTFE (polytetrafluoroethylene tetrafluoroethylene resin), and the housing is made of a rigid and inexpensive resin.

[0009] When the outlet is provided at the other end of the flow tube, that is, the end on the light source side, the ultraviolet intensity near the outlet is high, and there is a problem that the housing receives ultraviolet rays leaking from the outlet to the outside of the flow tube and is easily degraded.

[0010] The fluid sterilization devices of Patent Documents 1 and 2 do not have a structure for rationalizing assembly by housing the flow tube together with other accessories such as a light source, and do not mention the problem of degradation of the shell due to ultraviolet rays leaking to the outside from the outlet of the flow tube.

[0011] An object of the present invention is to provide a fluid sterilizing device capable of effectively preventing a housing from being deteriorated due to the influence of ultraviolet rays leaking out from a lead-out port of a flow path tube.

[0012] Means for solving problems

[0013] The present invention relates to a fluid sterilization device for sterilizing liquid, the fluid sterilization device comprising:

[0014] A housing having one end side and another end side coaxially with an axis formed as a straight line, the housing including a first cylindrical portion at the one end side and a second cylindrical portion having an inner diameter larger than that of the first cylindrical portion and at the other end side;

[0015] a flow tube inserted into the first cylindrical portion of the housing in the axial direction so that the sterilized fluid flows in one direction from the one end side to the other end side, the flow tube having a cutout extending in the axial direction from the opening of the other end side to the one end side by a predetermined length;

[0016] an opening sealing member, which is disposed in the second cylindrical portion of the housing, has an ultraviolet light transmitting portion and seals the opening of the flow tube;

[0017] a light source for irradiating ultraviolet rays into the flow tube from the other end side in the axial direction through the ultraviolet light transmitting portion of the opening closing member; and

[0018] A shielding component is arranged in the second cylinder portion of the shell, the shielding component has higher ultraviolet resistance than the shell, and is arranged on the outer peripheral side of the flow tube to divide the upstream end of the outlet flow path for the sterilized fluid to be discharged from the incision, and shields the outgoing light of ultraviolet rays from the incision of the flow tube relative to the inner peripheral side of the shell.

[0019] According to the present invention, a shielding member having higher ultraviolet resistance than the housing is provided within the irradiation range of ultraviolet rays leaking from the cutout at the other end of the flow path tube to the outside, shielding the housing from the leaked ultraviolet rays. Thus, the housing can be protected from the influence of ultraviolet rays and the fluid sterilizing device can be miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a longitudinal sectional view of the fluid sterilization device.

[0021] Figure 2 This is an exploded perspective view showing the storage attachment stored in the cylindrical portion of the housing body exploded along the axial direction of the fluid sterilizing device.

[0022] Figure 3 This is an exploded perspective view when the light source device and the outlet are exploded along the axial direction and viewed from one axial end side.

[0023] Figure 4 This is an exploded perspective view when the light source device and the outlet are exploded along the axial direction and viewed from the other end side in the axial direction.

[0024] Figure 5A is Figure 1 An enlarged view of the range including the enlarged diameter portion and the outer cover in the axial direction.

[0025] Figure 5B is Figure 5A An enlarged view of the upper half relative to the central axis Rx.

[0026] Figure 6 It is a perspective view of a reflector according to a modified example.

[0027] Figure 7 The upper limit of the illumination distribution is set to 40mw / cm 2 A diagram showing the UV illumination distribution in a fluid sterilization device analyzed through simulation.

[0028] Figure 8 The upper limit of the illuminance distribution is set to 10mw / cm 2 A diagram showing the UV illumination distribution in a fluid sterilization device analyzed through simulation.

[0029] Fig. 9 The upper limit of the illumination distribution is set to 5mw / cm 2 A diagram showing the UV illumination distribution in a fluid sterilization device analyzed through simulation. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described. Of course, the present invention is not limited to the embodiments. It should be noted that the same reference numerals are used throughout the drawings for components common to a plurality of embodiments.

[0031] (structure)

[0032] Figure 1 1 is a longitudinal sectional view of the fluid sterilization device 10. Rx represents the central axis of the fluid sterilization device 10. The fluid sterilization device 10 has a cylindrical shell body 12 and a cover 14 in the shape of a lid. The shell body 12 and the cover 14 constitute the shell of the fluid sterilization device 10, and the central axis is aligned with the central axis Rx of the fluid sterilization device 10 and is screwed together using the respective external threaded portion 121 and the internal threaded portion 141. The screwing of the external threaded portion 121 and the internal threaded portion 141 simplifies the assembly structure of the storage accessories by tightening the storage accessories in the shell in the axial direction.

[0033] The housing body 12 has a cylindrical portion 122, an inlet 123, an expanded diameter portion 124, and a stopper 125. The inlet 123 protrudes from one axial end side of the cylindrical portion 122 to one end side along the central axis Rx by a predetermined length. The stopper 125 is formed as an inner surface of one axial end side of the cylindrical portion 122, and the inlet passage of the inlet 123 opens at the center. The stopper 125 has a function of preventing the storage accessory in the cylindrical portion 122 from moving to one axial end side. The expanded diameter portion 124 protrudes radially from the cylindrical portion 122 at one end side and opens at the other end side.

[0034] The outer cover 14 has an opening 142 at the center of the cover. The outer cover 14 has the following functions: by defining the cover with a circular opening 142 in the center, the storage accessory is prevented from being separated from the housing body 12, and after the outer cover 14 and the housing body 12 are screwed together, the storage accessory is pushed toward the stopper 125.

[0035] Figure 2 This is an exploded stereogram showing the storage accessories stored in the cylindrical portion 122 of the housing body 12 decomposed along the axial direction of the fluid sterilization device 10. The storage accessories include a shielding body 15, a rectifying plate 16, and a straight pipe 18, and their central axes are aligned with the central axis Rx of the housing, and arranged in this order from one end to the other end in the axial direction, and the shielding body 15, the rectifying plate 16, and the straight pipe 18 are inserted into the interior of the housing body 12 from the opening side of the other end side of the housing body 12.

[0036] The shielding body 15 is made of a material having UV resistance together with the rectifying plate 16 and the straight pipe 18. One end side of the shielding body 15 abuts against the inner surface of the stopper 125, shielding UV (ultraviolet rays) from the inner surface of the stopper 125, and protecting the stopper 125 from UV. The shielding body 15 also has a tapered portion 151 on the inner circumference. 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 is connected to the inlet 123 and the sterilization chamber 182, respectively. By having the tapered portion 151, the UV reflected by the tapered portion 151 is reflected in the direction of the rectifying plate 16, thereby improving the utilization efficiency of UV.

[0037] The rectifying plate 16 has a plurality of rectifying holes 162 in the peripheral portion surrounding the central portion 161. The central portion 161 has a function of intercepting the sterilized fluid (e.g., water) that flows from the pressure pump (not shown) to the rectifying plate 16 via the inlet 123 and the shielding body 15. That is, the sterilized fluid is decelerated after hitting the central portion 161, and then flows into the straight pipe 18 from the rectifying holes 162. As a result, the flow velocity of the sterilized fluid is uniformed at the radial inner and outer sides in the sterilization chamber 182. In addition, by having the inlet of the shielding body 15 (the smallest diameter portion of the tapered portion 151) and the central portion 161 of the rectifying plate 16 on the central axis Rx, UV emitted from the straight pipe 18 toward the rectifying plate direction is prevented from leaking from the fluid sterilization device 10. The area of ​​the central portion 161 is larger than the area of ​​the inlet of the shielding body 15.

[0038] The inner circumference of the straight tube 18 is divided into a sterilization chamber 182. A plurality of cutouts 181 are formed at equal angles in the circumferential direction on the circumferential wall of the straight tube 18 at the other axial end, and extend a predetermined length from the opening at the other end of the straight tube 18 to one end. An O-ring 183 is embedded in an annular groove on the outer circumference of the straight tube 18 to prevent leakage of the sterilized fluid from the outer circumference.

[0039] Figure 3 and Figure 4 It is an exploded perspective view in which the light source device 19 and the housing closing member 32 are exploded in the axial direction and viewed from one end side and the other end side in the axial direction. Figure 5A is Figure 1 An enlarged view of the range including the enlarged diameter portion 124 and the outer cover 14 in the axial direction, Figure 5B is Figure 5A An enlarged view of the upper half relative to the central axis Rx.

[0040] exist Figure 3 to Figure 5B In the embodiment, the light source device 19 and the housing sealing member 32 are arranged at one end side and the other end side of the enlarged diameter portion 124, respectively, and are housed in the enlarged diameter portion 124 in such a manner that their central axes are aligned with the central axis Rx. The light source device 19 is decomposed 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 order from one end side to the other end side in the axial direction.

[0041] In the light source device 19, the side from which UV is emitted and the opposite side thereof are appropriately referred to as the surface side and the back side, respectively. The surface side and the back side of the light source device 19 are respectively oriented toward one end side and the other end side in the axial direction of the fluid sterilizing device 10. The O-ring 191 is fitted between the periphery of the quartz glass 22 and the annular step portion on the surface side of the reflector 24 to implement sealing. The quartz glass 22 and the O-ring 191 constitute an opening sealing member that seals the other end side opening of the straight tube 18 as a flow path tube.

[0042] The reflector 24 is made of a material having ultraviolet resistance together with the shielding ring 20. 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 on the inner peripheral side of the reflector 24 in a tapered shape with a diameter gradually increasing from the back side toward the front side. 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 radially outer end of the protruding surface 242 to the other end in the axial direction. The recess 244 is formed in a manner of opening at the peripheral portion of the back side of the reflector 24.

[0043] The reflector 24 is on the back side ( Figure 4 ) has a circumferential end surface 247 and an annular step portion 248 formed along the inner circumference of the circumferential end surface 247 and recessed inward.

[0044] A plurality of (two in the example shown) UV-LEDs 26 and a plurality of electrical accessories 27 are mounted on the center and the periphery of the surface side of the substrate 28. The UV-LEDs 26 are exposed from the back side of the reflector 24 into the conical reflecting surface 241, and the electrical accessories 27 are housed in the recess 244 on the back side of the reflector 24. A pair of recesses 281 and a pair of recesses 282 are formed on the periphery of the circular substrate 28.

[0045] The UV emitted by the UV-LED 26 is deep ultraviolet light with a high sterilization effect on fluids, and the wavelength range is, for example, 100 to 400 nm. In particular, UVC with a wavelength of 100 to 280 nm in the ultraviolet wavelength range is more preferred because it has a particularly high sterilization effect.

[0046] The heat sink 30 is made of metal and has a cylinder 301 on the back side. A wire harness (not shown) is inserted through the cylinder 301, and the wire harness is used for wiring the electrical accessories 27 of the substrate 28. A pair of protrusions 302 are formed on the surface side of the heat sink 30 and fit into a pair of recesses 282 of the substrate 28. O-ring 192 ( Figure 5A ) is embedded between the inner periphery of the heat dissipation cover 30 and the outer periphery of the annular step portion on the other axial end side of the peripheral surface 243.

[0047] The housing closing member 32 has a plurality of spacers 320 and convex portions 321 on the inner surface side. The spacers 320 are formed at equal angles in the circumferential direction. The convex portions 321 are formed on the convex top surfaces of the spacers 320 that are 180° apart in the circumferential direction. The arc-shaped protruding edge 324 is fitted with the outer side of the circumferential surface 243 of the reflector 24.

[0048] The harness hole 322 axially penetrates the housing closing component 32. The barrel 301 is inserted into the harness hole 322, and an O-ring 193 is inserted around the barrel 301. The convex portion 321 is formed to be shared with the accessories of other types of fluid sterilization devices, and the convex portion 321 can be omitted in the fluid sterilization device 10. This is because the heat dissipation cover 30 and the housing closing component 32 can be positioned in the circumferential direction by fitting the barrel 301 and the harness hole 322.

[0049] The housing closing member 32 has a closing portion 325 on the rear side and an outlet 326 protruding from the closing portion 325 to the other end side in the axial direction along the central axis Rx. The outlet 326 passes through the inner peripheral side of the opening 142 of the cover 14 and reaches the outside of the cover 14 at the protruding end.

[0050] exist Figure 5A and Figure 5BIn the embodiment, the annular end surface of the shield ring 20 at one axial end side is fitted into the inner circumference of the expanded diameter portion 124 using an O-ring 196. The shield ring 20 has a cylindrical side surface portion 202 and a tapered portion 201 on the inner circumference of the one axial end side and the other axial end side, respectively. The position P1 of the end portion at one end side of the shield ring 20, the position P2 of the end portion at the small diameter side of the tapered portion 201, the position P3 of the end portion at the large diameter side of the tapered portion 201, the position Q1 of the terminal end of the cutout 181 (the position of one axial end), and the position Q1 of the starting end of the cutout 181 (the position of the other axial end), that is, the position Q2 of the other end of the straight pipe 18, are arranged in the axial direction in the example shown in the figure, in order from the one end side to the other end side, P1, Q1, P2, P3 (= Q2). However, it is preferable that P1 and Q1 are located at the same position in the axial direction (P1=Q1). This is because the entirety of the cutout 181 is exposed in the tapered portion 201, the effective area of ​​the cutout 181 is increased, and a space with a triangular cross-section is formed between one end of the tapered portion 201 and the outer peripheral surface of the straight tube 18, which can prevent the sterilized fluid from being retained in the triangular space.

[0051] exist Figure 5A and Figure 5B In FIG. 1 , Fn represents the flow of the sterilized fluid in the fluid sterilization device 10. The lead-out flow path 35 is a passage for leading the sterilized fluid led out of the cutout 181 of the straight tube 18 to the outside of the fluid sterilization device 10 in the radial direction, and is formed in the space between the light source device 19 in the fluid sterilization device 10 and the inner surface of the tapered portion 201 of the shielding ring 20, the enlarged diameter portion 124, or the closing portion 325 of the housing closing member 32. The lead-out 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 the flow direction of the sterilized fluid. 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.

[0052] The first flow path portion 351 is formed in the space sandwiched between the tapered portion 201 and the extended surface 242 in the axial direction, and serves as the most upstream portion of the lead-out flow path 35 to guide the sterilized fluid just led out from the incision 181 to the downstream side. The second flow path portion 352 is formed as a passing portion between the corner of the boundary between the extended surface 242 and the peripheral surface 243 and the tapered portion 201. The third flow path portion 353 is formed in an annular shape between the enlarged diameter portion 124 and the peripheral surface 243. The fourth flow path portion 354 is formed as an axial gap between the back surface of the light source device 19 and the inner surface of the housing closing component 32.

[0053] (Material)

[0054] The following is an example of the materials of the components constituting the fluid sterilizing device 10 .

[0055] (a) Shell (shell body 12 and outer cover 14): engineering plastics such as PC (polycarbonate) and POM (polyacetal);

[0056] (b) Shield 15, rectifying plate 16, straight pipe 18, shield ring 20 and reflector 24: PTFE (polytetrafluoroethylene tetrafluoroethylene resin), PFA (perfluoroalkoxyalkane) or PVF (polyvinyl fluoride), PVDF (polyvinylidene fluoride) and other sterilized fluids and fluororesins;

[0057] (c) Heat dissipation cover 30: metal.

[0058] The material of (b) is selected to have higher UV resistance and UV reflectivity than the material of (a). It should be noted that the material of (a) is selected to have higher corrosion resistance to the sterilized fluid than metal. The reason for selecting the material of (b) for the shielding body 15 and the shielding ring 20 is that the shielding body 15 and the shielding ring 20 are composed of parts that have been lightly processed on PTFE, so a material that can be manufactured by simple processing can be used.

[0059] (effect)

[0060] The sterilized fluid is pressure-fed to the fluid sterilizing device 10 from a pressure-feeding pump (not shown), and is introduced into the sterilization chamber 182 of the straight pipe 18 via the inlet 123 of the housing body 12, the tapered portion 151 of the shield 15, and the rectifying hole 162 of the rectifying plate 16. The reason why the rectifying plate 16 has a central portion 161 without a through hole is that the sterilized fluid can be rectified along with the rectifying hole 162 of the rectifying plate 16, and the flow velocity in the sterilization chamber 182 can be uniformed at the radial position of the sterilization chamber 182.

[0061] The UV-LED 26 emits UV toward the quartz glass 22 along the axial direction of the light source device 19. The ultraviolet rays emitted from the UV-LED 26 are radially spread and irradiated to the reflecting surface 241, and are reflected by the reflecting surface 241 toward the central axis Rx. The ultraviolet rays are irradiated to the sterilized fluid in the sterilization chamber 182 through the quartz glass 22. Thus, the sterilized fluid is sterilized.

[0062] The sterilized fluid collides with the surface of the quartz glass 22, changes from the axial direction of the straight tube 18 to the radially outer side, and flows out of the straight tube 18 from the cutout 181. The total flow cross-sectional area of ​​the plurality of cutouts 181 is smaller than the flow cross-sectional area of ​​the sterilization chamber 182, so the flow velocity of the sterilized fluid increases at the cutout 181. Moreover, the flow velocity of the sterilized fluid is further increased by the tapered portion 201.

[0063] exist Figure 1 In the embodiment, the fluid sterilizing device 10 is placed horizontally (a placement method in which the length direction is consistent with the horizontal direction), but it can also be used in a vertical placement method in which the inlet 123 and the outlet 326 are respectively facing downward and upward (a placement method in which the length direction is consistent with the vertical direction). In this case, as the drinking machine or other equipment equipped with the fluid sterilizing device 10 stops, the operation of the pressure pump also stops, and air remains in the upper part of the straight pipe 18. Preferably, the remaining air is quickly discharged to the outside when the pressure pump starts to work next time. This is because air will weaken the intensity of UV.

[0064] As described above, the flow rate of the sterilized fluid increases at the incision 181. Therefore, in the fluid sterilization device 10, the air remaining in the upper part of the straight tube 18, that is, the height of the incision 181, will not remain for a long time, but will be quickly and smoothly discharged from the outside of the straight tube 18 by forming a high-speed sterilized fluid.

[0065] On the other hand, UV emitted from quartz glass 22 into sterilization chamber 182 that is widely spread radially outward is emitted from slit 181 to the outside of straight tube 18. Hereinafter, UV that enters slit 181 from the inner circumference of straight tube 18 is also referred to as "leakage UV".

[0066] As described above, the positional relationship in the axial direction between the position P1 of one end side of the shield ring 20, the position P2 of the boundary between the cylindrical side surface portion 202 and the tapered portion 201, the position P3 of the opening end of the shield ring 20, the position Q1 of the terminal end of the cutout 181, and the starting position of the cutout 181, i.e., the position Q2 of the other end of the straight tube 18, is set in the above manner, and as a result, the leaked UV is blocked by the fluid sterilizing device 10, and the leaked UV is prevented from irradiating the inner surface of the housing body 12. That is, the leaked UV is all irradiated onto the tapered portion 201 of the shield ring 20 and reflected radially inward, or is reflected onto the cylindrical side surface portion 202 via a portion of one end side of the cutout 181 and immediately returns to the straight tube 18, and the remaining portion is irradiated onto the tapered portion 201 of the shield ring 20 and then reflected.

[0067] On the other hand, after passing through the first flow path portion 351, the sterilized fluid passes through the second flow path portion 352 sandwiched between the tapered portion 201 and the corner portion of the reflector 24. Among the leaked UV, the leaked UV irradiated to the tapered portion 201 is reflected by the tapered portion 201, and the reflection target is divided into the following three parts: (a) the cutout 181 on the peripheral wall of the other axial end of the straight tube 18; (b) the part of the peripheral wall of the other axial end of the straight tube 18 where the cutout 181 is not formed; and (c) the protruding surface 242. Among the leaked UV, the UV whose reflection target is (a) returns to the straight tube 18 through the cutout 181, which helps to re-sterilize the sterilized fluid in the sterilization chamber 182. The UV with reflection targets (b) and (c) among the leaked UV is reflected again by the reflection target, and then repeatedly re-reflected between the conical portion 201 and the reflector 24 until the intensity is sufficiently weakened, which helps to sterilize the sterilized fluid in the first flow path portion 351 and the second flow path portion 352.

[0068] The conical portion 201 is set to a conical angle value or contour shape so that the leaked UV will not leak out of the third flow path portion 353 on the downstream side of the second flow path portion 352 due to the alternating and repeated reflection of the conical portion 201 and the reflector 24, but will remain in the first flow path portion 351 and the second flow path portion 352 or eventually return to the sterilization chamber 182 through the incision 181.

[0069] After passing through the second flow path portion 352, the sterilized fluid flows axially in the annular third flow path portion 353 between the circumferential surface 243 of the reflector 24 and the inner circumferential surface of the enlarged diameter portion 124, and then abuts against the inner surface of the closing portion 325, and the direction of travel changes radially inward. Then, the sterilized fluid goes around to the fourth flow path portion 354 on the back side of the light source device 19, and converges along the inner surface of the closing portion 325 to the opening on one end side of the outlet 326 constituting the radial center portion. The fourth flow path portion 354 is formed as a gap sandwiched between the back side of the light source device 19 and the closing portion 325 of the housing closing component 32 in the axial direction.

[0070] The sterilized fluid contacts the back side of the heat sink 30 of the light source device 19 in the fourth flow path 354, cooling the heat sink 30. The heat generated by the UV-LED 26 is conducted to the substrate 28, and then to the metal heat sink 30. Therefore, the cooling of the heat sink 30 by the sterilized fluid in the fourth flow path 354 contributes to the cooling of the UV-LED 26. The flow rate of the sterilized fluid is increased by the cutout 181 and the tapered portion 201, thereby improving the cooling performance of the heat sink 30.

[0071] It should be noted that the substrate 28 is also called a metal substrate, and the mounting area of ​​the components that require heat dissipation is made of metal, and has a structure in which the thermal conductivity increases toward the back side.

[0072] The sterilized fluid then flows out of the fluid sterilization device 10 through the fifth flow path 355 .

[0073] (Modification of reflector)

[0074] Figure 6 24b is a perspective view showing a modified example of the reflector 24b. Figure 3 as well as Figure 4 ) is that the protruding surface 242 is not perpendicular to the central axis, but is formed in a conical shape matching the shape of the conical portion 201, and a plurality of grooves 245 are formed on the conical protruding surface 242 at equal angles in the circumferential direction.

[0075] As a result, the extending surface 242 of the reflector 24 b can prevent the distance between the extending surface 242 of the reflector 24 and the tapered portion 201 from being locally narrowed. In addition, the groove 245 can ensure a sufficient flow cross-sectional area of ​​the first flow path portion 351 .

[0076] (Analysis of Illuminance Distribution)

[0077] Figure 7 to Figure 9 2 is a diagram showing the UV illumination distribution in the fluid sterilization device 10 analyzed by simulation. Figure 7 to Figure 9 In the analysis of the illuminance distribution, the emission intensity (brightness) of UV emitted from UV-LED 26 is set to be the same. The upper limit of the illuminance distribution analysis is 40mw / cm 2 、10mw / cm 2 and 5mw / cm 2 Therefore, in each illuminance distribution diagram, the position of illuminance above the upper limit is always in the uppermost stage area. In addition, the simulation was performed using ASAP of Breault Research Organization.

[0078] In addition, Figure 1 and Figure 2 In the description, the straight tube 18 side of the central portion 161 of the rectifying plate 16 is a UV reflecting surface, but in Figure 7 to Figure 9 In the illumination distribution, the calculation is performed under the condition that no UV reflection occurs in the central portion 161.

[0079] exist Figure 7 to Figure 9 In the illumination distribution, the upper limit illumination Lu is divided into four equal parts to indicate which stage of the four stages of illumination each position belongs to. That is, if the illumination is set to L, the first illumination stage is 0≤L<Lu / 4, the second illumination stage is Lu / 4≤L<Lu / 2, the third illumination stage is Lu / 2≤L<3·Lu / 4, and the fourth illumination stage is 3·Lu / 4≤L.

[0080] from Figure 7 It can be seen that the emission area near the UV-LED 26 is 30mw / cm 2 The above strong illumination exists at 10 to 20 mw / cm on the outer peripheral side of the cutout 181. 2 Illumination area. Figure 8 It can be seen that the radial inner part of the tapered portion 201 and the shield 15 are 2.5 to 5.0 mw / cm 2 The illumination area from Fig. 9 It can be seen that the maximum diameter side of the tapered portion 201 is 1.25 to 2.5 mw / cm 2 illumination area.

[0081] That is, according to Figure 7 to Figure 9 From the simulation results of the illumination distribution, it can be seen that by providing the tapered portion 201, it is possible to prevent ultraviolet light from leaking to the area of ​​the housing (housing body 12 and cover 14), thereby suppressing degradation caused by ultraviolet light.

[0082] (Replenish)

[0083] 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.

[0084] The fluid sterilizing device 10 includes two UV-LEDs 26 as a light source for emitting UV. In the fluid sterilizing device of the present invention, the light source for emitting UV may be one or three or more.

[0085] In the fluid sterilizing device 10, quartz glass 22 is used as the ultraviolet light transmitting portion. The ultraviolet light transmitting portion of the present invention may be made of a material other than quartz glass 22 as long as it is permeable to ultraviolet light and has corrosion resistance to the sterilized fluid.

[0086] The cylindrical portion 122 and the enlarged diameter portion 124 of the fluid sterilizing device 10 correspond to the first cylindrical portion and the second cylindrical portion of the present invention, respectively, and respectively accommodate the straight tube 18 as a flow path tube and the light source device 19. The shielding ring 20 is externally inserted at the end of the cutout 181 side of the straight tube 18 at the enlarged diameter portion 124. The tapered portion 201 of the shielding ring 20 forms a lead-out passage at the enlarged diameter portion 124 for the sterilized fluid led out of the cutout 181 as the lead-out port of the straight tube 18 to the outside, and receives ultraviolet rays leaking out of the cutout 181 to the outside of the straight tube 18, thereby protecting the enlarged diameter portion 124.

[0087] Examples of the fluid to be sterilized as the sterilization object of the fluid sterilization device 10 include water stored in the water tank of an ice maker, water supplied in a water pipe or a water heater, drinking water in a water dispenser, cooling water in a circulation device (cooler), and beverage liquid in a beverage machine.

[0088] Explanation of symbols

[0089] 10 ... fluid sterilizing 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 ... enlarged diameter portion, 122 ... cylindrical portion (first cylindrical portion), 124 ... enlarged diameter portion (second cylinder), 114...outer cover, 125...stop portion, 142...opening, 181...cutout, 201...conical portion, 202...cylindrical side portion, 241...reflecting surface, 242...extending surface, 243...circumferential surface, 245...groove, 325...sealed portion, 326...export port, 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, which sterilizes liquid. The fluid sterilization device is characterized by comprising: A housing having one end side and another end side coaxially with an axis formed as a straight line, the housing including a first cylindrical portion at the one end side and a second cylindrical portion having an inner diameter larger than that of the first cylindrical portion and at the other end side; a flow tube inserted into the first cylindrical portion of the housing along the axial direction so that the sterilized fluid flows in one direction from the one end side to the other end side, the flow tube having a cutout extending from the opening of the other end side to the one end side along the axial direction by a predetermined length; an opening sealing member, which is disposed in the second cylindrical portion of the housing, has an ultraviolet light transmitting portion and seals the opening of the flow tube; a light source for irradiating ultraviolet rays into the flow tube from the other end side in the axial direction through the ultraviolet light transmitting portion of the opening closing member; as well as A shielding component is arranged in the second cylinder portion of the shell, the shielding component has higher ultraviolet resistance than the shell, and is arranged on the outer peripheral side of the flow tube to divide the upstream end of the outlet flow path for the sterilized fluid to be discharged from the incision, and shields the outgoing light of ultraviolet rays from the incision of the flow tube relative to the inner peripheral side of the shell.

2. The fluid sterilization device according to claim 1, characterized in that: The shield member has a tapered portion on an inner peripheral side that expands from the one end side toward the other end side in the axial direction of the flow tube.

3. The fluid sterilization device according to claim 2, characterized in that: The shielding member has a higher reflectivity with respect to ultraviolet rays than the housing.

4. The fluid sterilization device according to claim 3, characterized in that: A reflector is also provided, which is arranged between the light source and the opening closing component in the axial direction. The reflector has a reflecting surface on the inner side for reflecting the ultraviolet rays from the light source, and forms the outlet flow path in the annular gap between the shielding component and the shell on the outer side.

5. The fluid sterilization device according to claim 4, characterized in that: The reflector has a protruding surface, which protrudes radially to the outside of the flow tube and is arranged opposite to the tapered portion in the axial direction, and the reflector has higher ultraviolet resistance than the housing. The tapered portion of the shielding member reflects the ultraviolet rays toward the cutout and the protruding surface of the reflector.

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

7. The fluid sterilization device according to claim 4, characterized in that: The opening closing member, the reflector and the light source constitute a light source device. The fluid sterilization device further comprises a housing sealing member, the housing sealing member comprising: a sealing portion, which forms the axial gap between the sealing portion and the light source device; and an outlet, which protrudes from the center of the sealing portion toward the outside of the housing to guide the sterilized fluid in the gap to the outside of the housing. The housing comprises: a stopper portion, which prevents the storage accessory in the housing from moving toward the one end side at the one end side in the axial direction; and a fastening portion, which fastens the storage accessory to the stopper portion via the closing portion of the housing closing member. The flow tube and the light source device are housed in the housing as the housing fitting, and the flow tube, the light source device, and the housing closing member are sequentially arranged in a row from the one end side in the axial direction with their central axes aligned.

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