Fluid sterilization device

Abstract

This invention provides a fluid sterilization device that suppresses the adhesion of scale and debris within the flow path pipe, has excellent flow straightening effects, high irradiation and utilization efficiency of ultraviolet light, and offers superior sterilization effects. [Solution] The system includes a fluid inlet, a flow channel pipe with a circular cross-section, a flow straightening section 30 having at least one spiral flow path that closes the inlet end of the flow channel pipe, is provided perpendicular to the central axis of the flow channel pipe, and comprises a water passage hole communicating with the inlet and a spiral water passage groove 32 communicating with the water passage hole, a light-shielding member 40 provided on the flow straightening section and having a water passage opening 41 that exposes at least the outlet end of the spiral water passage groove 32, and a light source module provided at the other end of the flow channel pipe perpendicular to the central axis of the flow channel pipe and opposite the flow straightening section 30, which irradiates ultraviolet light toward the fluid flow path.

Description

Technical Field

[0001] The present invention relates to a fluid sterilization device for sterilizing fluids such as water with ultraviolet light.

Background Art

[0002] There is known a fluid sterilization device that sterilizes a liquid by flowing a liquid to be sterilized through a pipe and irradiating ultraviolet light in the axial direction of the pipe toward the liquid flowing through the pipe. For example, Patent Document 1 discloses a sterilization device that can improve the sterilization ability by rectifying a fluid so as to have a flow in a first direction by providing a rectifying plate at an inlet and irradiating ultraviolet rays in the same direction to increase the action time of the ultraviolet rays.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a sterilization device, scale or the like may be deposited on the wall surface of the flow path pipe. For example, when using a fluid such as hard water, calcium or the like in the fluid is deposited and adheres to the wall surface of the flow path pipe, resulting in a problem that the sterilization performance deteriorates due to a decrease in the rectification effect and a decrease in the reflectance of ultraviolet light (UV light) of the flow path pipe.

[0005] In addition, when the fluid flows in with a non-uniform flow velocity distribution in which the rectification effect depends on the inflow velocity and inflow angle of the fluid, there is a problem that the rectification effect deteriorates. Furthermore, depending on the positional relationship between the joint part of the housing and the rectifying plate, there is a risk that UV light may leak to the outside.

[0006] Therefore, there is a need for a fluid sterilization device that suppresses the adhesion of scale and other particles to the walls of the flow channel, has an excellent flow straightening effect, and has high ultraviolet light irradiation efficiency. Furthermore, there is a need for a superior fluid sterilization device that solves problems such as reduced utilization efficiency of ultraviolet light due to leakage of ultraviolet light from the straightening plate, deterioration of surrounding components due to leaked ultraviolet light, and a tendency for debris to accumulate.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide a fluid sterilization device that suppresses the adhesion of scale, debris, etc. in the flow channel, has an excellent flow straightening effect, has high irradiation efficiency and utilization efficiency of ultraviolet light, and has an excellent sterilization effect. [Means for solving the problem]

[0008] The fluid sterilization device of the present invention is The fluid inlet and A flow channel pipe with a circular cross-section, A flow straightening section that blocks the inlet end of the flow channel pipe, is provided perpendicular to the central axis of the flow channel pipe, and has at least one spiral flow channel consisting of a water passage hole communicating with the inlet and a spiral water passage groove communicating with the water passage hole, A light-shielding member provided on the flow straightening section and having a water-conducting opening that exposes at least the outlet end of the spiral water-conducting groove, The other end of the flow channel is provided with a light source module that is perpendicular to the central axis of the flow channel and opposite to the rectifying section, and that irradiates ultraviolet light toward the fluid flow channel. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing a cross-section passing through the central axis of the fluid sterilization device of the first embodiment. [Figure 2A] This is a cross-sectional view showing a cross-section of the inlet including the central axis, and schematically illustrates the flow of the incoming fluid. [Figure 2B] This is a schematic cross-sectional view showing the flow of water that exits through the central water outlet of the light-shielding member. [Figure 3]This is an assembly diagram showing the rectifier and light-shielding member of the first embodiment. [Figure 4A] This is a perspective view showing the assembled rectifier and light-shielding components. [Figure 4B] This figure is similar to Figure 4A, but it is a three-dimensional view showing a cross-section including the central axis. [Figure 5A] This is a plan view showing the top surface of the flow straightening section. [Figure 5B] This is a plan view of the flow straightening section and light-shielding member as seen from the fluid outlet side. [Figure 6A] This is a schematic plan view showing the fluid flow in the rectifying section. [Figure 6B] This is a schematic plan view illustrating the fluid flow from the light-shielding member. [Figure 7] This is a schematic plan view showing the swirling flow from the spiral water channel and the flow from the water outlet of the light-shielding member. [Figure 8] This diagram schematically shows the fluid flow in the flow path within the flow channel of a fluid sterilization device. [Figure 9A] This is a three-dimensional view showing the flow straightening section and light-shielding member in a fluid sterilization device according to the second embodiment. [Figure 9B] This diagram shows the arrangement relationship between the water passage hole formation area and the light-shielding member when it is connected to the flow straightening section. [Figure 10] This is a schematic three-dimensional diagram showing the inlet of a comparative example fluid disinfection device (CMP). [Figure 11] This figure summarizes the results of the fluid analysis of the fluid sterilization apparatus for the first and second embodiments (EMB1, EMB2) and the comparative example (CMP). [Figure 12A] This is a schematic perspective view showing the light-shielding member of Modification 1 of the first embodiment. [Figure 12B] This is a schematic diagram of the light-shielding member of Modification Example 1 as viewed from the light source module side (top view). [Figure 13] This is a schematic plan view of the rectifier section of Modification Example 2 as seen from the light source module side (top view). [Figure 14] This is a schematic plan view of the rectifier section of Modification Example 3 as seen from the light source module side (top view). [Figure 15] It is a perspective view schematically showing the light-shielding member of Modification 4. [Figure 16] It is a perspective view schematically showing the light-shielding member of Modification 5.

Mode for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described, but these may be appropriately modified and combined. Also, in the following description and the accompanying drawings, substantially the same or equivalent parts will be described with the same reference numerals.

[0011] [First Embodiment] FIG. 1 is a cross-sectional view showing a cross-section passing through the central axis CZ of the fluid sterilization device 10 of the first embodiment. Note that FIG. 1 shows a rectangular coordinate system. Also, FIG. 2A is a view showing a cross-section including the central axis CZ of the inflow part 13, and is a cross-sectional view schematically showing the flow of the inflowing fluid A1. FIG. 2B is a cross-sectional view schematically showing the flow FLc flowing out through the central water passage 45 of the light-shielding member 40 among the flows of the fluid A1 shown in FIG. 2A.

[0012] The fluid sterilization device 10 includes a main body part 11, a light source part 12, an inflow part 13, and an outflow part 14. The fluid sterilization device 10 is generally arranged with the direction of the central axis CZ (z direction) upward, that is, in a vertical direction with the light source part 12 on the upper side (vertically placed).

[0013] The fluid sterilization device 10 is installed, for example, in a water storage tank such as an ice maker, a water supply pipe, a water heater, a water server, a circulation device (cooling water of a chiller), and a drink server. Note that sterilization in the circulation device is performed to prevent an increase in the viscosity of the circulating water and a resulting power loss due to the growth of bacteria in the circulating water.

[0014] The inflow part 13 is provided on one end side of the main body part 11 in the axial direction. The outflow part 14 is provided as a flow path through which the fluid flows out in the axial direction (z direction) via the light source part 12 with the central axis aligned with the central axis CZ of the main body part 11.

[0015] The inlet 13 is provided with an inlet 24 for the fluid to be disinfected, and the outlet 14 is provided with a fluid outlet 26. The inlet 13 and outlet 14 have threaded grooves (not shown) around their circumference so that they can be connected to a pipe (not shown) within the device in which the fluid disinfection device 10 is installed. Alternatively, they can be fixed within the device using quick fasteners (Koyo Co., Ltd.).

[0016] The inlet section 13 has an inlet 24 that is cylindrical and coaxial with the central axis CZ, and the outlet section 14 has an outlet 26 that is cylindrical and coaxial with the central axis CZ.

[0017] The light source unit 12 is attached to the main body unit 11 at the other end of the fluid sterilization device 10 in the direction of the central axis CZ (hereinafter also simply referred to as the axial direction) (in this embodiment, the outlet unit 14 side), with its central axis aligned with the central axis CZ of the main body unit 11.

[0018] The main body 11 includes an inner flow path tube 21, which is an inner tube arranged coaxially with the central axis CZ, and an outer tube 22 (housing). Both the flow path tube 21 and the outer tube 22 are straight tubes with a circular cross-section perpendicular to the central axis CZ.

[0019] The flow channel pipe 21 has a circular opening at the end on the light source unit 12 side. The outer pipe 22 has an open end on the light source unit 12 side and is formed as a closed inner wall at the end on the inlet unit 13 side.

[0020] The flow channel tube 21 is inserted into the outer tube 22 through the opening on the light source unit 12 side of the outer tube 22 and is housed inside the outer tube 22. The water-stopping O-rings 28a and 28b are fitted into grooves formed at the inlet and outlet ends of the flow channel tube 21 in the axial direction, preventing the fluid A1 from entering between the outer tube 22 and the flow channel tube 21.

[0021] At the circular inlet end of the outer pipe 22, which is on the side of the inlet 13, a flow straightening section 30 is provided perpendicular to the central axis CZ and closes the inlet end. The flow straightening section 30 is provided with a plurality of water passage holes 31 that communicate with the inlet 24 and a plurality of spiral water passage grooves 32 that communicate with the plurality of water passage holes 31. A spiral flow path 33 is formed by the water passage holes 31 and the spiral water passage grooves 32 that communicate with the water passage holes 31.

[0022] Furthermore, a light-shielding member 40 is provided in contact with the rectifier section 30. The light-shielding member 40 has a disc shape and is provided perpendicular to the central axis CZ. The light-shielding member 40 is sandwiched between the rectifier section 30 and the end of the flow channel pipe 21, and is provided in close contact with the rectifier section 30 and the end of the flow channel pipe 21.

[0023] The light-shielding member 40 is provided with multiple water passages 41 (outer circumference water passages) that allow fluid flowing out from the multiple spiral water passage grooves 32 of the flow straightening section 30 to pass through. The water passages 41 are defined between the wing portions 42 that protrude outward from the outer circumference of the light-shielding member 40 and are water passage openings provided on the outer circumference of the light-shielding member 40. The light-shielding member 40 reflects or absorbs ultraviolet light from the light source 12. Here, the light-shielding member 40 overlaps with the water passage holes 31 of the flow straightening section 30. Specifically, the light-shielding member 40 overlaps with the water passage holes 31 of the flow straightening section 30, and the water passages 41 of the light-shielding member 40 overlap with the spiral water passage grooves 32.

[0024] In this embodiment, the light-shielding member 40 is fitted and fixed between the flow straightening section 30 and the end of the flow channel pipe 21. However, the fixing method is not limited to this. It is sufficient that the multiple spiral water passage grooves 32 of the flow straightening section 30 and the multiple water passage ports 41 of the light-shielding member 40 are aligned and fixed.

[0025] The materials used for each component of the fluid sterilization device 10 are as follows, but are not limited to these. The outer tube 22 is made of a material that does not absorb fluid, such as a resin material like PP (polypropylene) or PPS (polyphenylene sulfide), or a metal material like SUS (stainless steel).

[0026] The flow channel tube 21 is made of a resin material that is reflective and durable against deep ultraviolet light, such as PTFE (polytetrafluoroethylene).

[0027] Furthermore, the light-shielding member 40 is made of a material that reflects ultraviolet rays, such as fluororesins such as PTFE, PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PCTFE (polychlorotrifluoroethylene), ETFE (ethylene-tetrafluoroethylene copolymer), ECTFE (ethylene-chlorotrifluoroethylene copolymer), PVF (polyvinylidene fluoride (polyvinylidene fluoride)), or metal materials such as SUS. Alternatively, the light-shielding member 40 can also be made of a material that absorbs ultraviolet rays, such as PP, PPS, chromium, black alumina, or carbon black.

[0028] The light source unit 12 has a light source module 50. The light source module 50 has its central axis coaxial with the central axis CZ and is provided at the other end of the flow channel pipe 21. The light source module 50 has at least one LED element 55 (light-emitting element) mounted inside.

[0029] As shown in Figure 1, the light source module 50 is held at its rear by a cylindrical outlet member 17 that surrounds the light source module 50 and is fixed to the outer tube 22. The outlet member 17 has a threaded portion on its inner surface, and by rotating, it fastens with a threaded portion on the outer tube 22 (threaded portion).

[0030] Furthermore, the outlet member 17 has an outlet 26 that communicates with the flow path 25 inside the flow path pipe 21 and is fixed to the outlet housing 18. The space between the outlet member 17 and the outer pipe 22 is sealed with a watertight O-ring 28c.

[0031] The UV light emitted from the LED element 55 of the light source module 50 is irradiated toward the inlet 13 via a light-transmitting plate 53 made of quartz glass or the like. In other words, the light emitted from the LED element 55 irradiates the fluid A1 that flows toward the light source module 50 through the flow channel 25 in the flow channel pipe 21, which is a sterilization chamber.

[0032] The LED element 55 emits deep ultraviolet light (UV-C) with a wavelength of around 265 nm, which has a high germicidal effect. Depending on the application, a light-emitting element that emits light at a different wavelength can also be used. The explanation below describes the case using the LED element 55, but a laser element (LD: Laser Diode) or the like may also be used as the light-emitting element.

[0033] The flow FL of fluid A1 is described below. As shown in Figure 2A, fluid A1 that flows in from the inlet 24 passes through the flow straightening section 30, then through the water inlets 41 and 45 of the light-shielding member 40, and flows out from the light-shielding member 40. As shown in Figure 2B, of the flow FL, fluid A1 flows out from the light-shielding member 40 through the central water inlet 45 (flow FLc).

[0034] In other words, the fluid A1 flowing out from the rectifier section 30 passes through the water inlets 41 and central water inlet 45 of the light-shielding member 40, forming a swirling flow within the flow tube 21 towards the light source module 50, and proceeds in the direction of the central axis CZ. Here, the fluid A1 that has passed through the water inlets 31 collides with the light-shielding member 40, causing the light-shielding member 40 to function as a resistance to the fluid A1 and induce the formation of a swirling flow.

[0035] As shown in Figure 1, the disinfected fluid A1 inside the flow channel 21 flows out through the gaps (flow channels) provided around and behind the light source module 50, and exits through the outlet 26 which is in communication with the flow channel 25 of the flow channel 21 (disinfected fluid A2).

[0036] (1) Rectifier and light-shielding member Figure 3 is an assembly diagram of the rectifier section 30 and light-shielding member 40 of this embodiment. Figure 4A is a perspective view showing the assembled rectifier section 30 and light-shielding member 40. Figure 4B is similar to Figure 4A, but is a three-dimensional view showing a cross-section including the central axis CZ.

[0037] Furthermore, Figure 5A is a plan view of the upper surface of the flow straightening section 30, that is, the flow straightening section 30 as viewed from the outlet side of the fluid A1, and Figure 5B is a plan view of the flow straightening section 30 and the light-shielding member 40 as viewed from the outlet side of the fluid A1. Figures 6A and 6B correspond to Figures 5A and 5B, respectively, and are schematic plan views showing the flow FL1 of the flow straightening section 30 and the flow FL2 of the light-shielding member 40 of the fluid A1.

[0038] In Figures 5A to 6B, hatching is applied to the water passage holes 31 of the flow straightening section 30 and the water passage openings 41 of the light-shielding member 40 for clarity and ease of understanding. The flow straightening section 30 and the light-shielding member 40 will be described in detail below with reference to these figures.

[0039] As shown in Figures 3, 4B, and 5A, the flow straightening section 30 has three water passage holes 31 that communicate with the inlet 24. The flow straightening section 30 also has three spiral water passage grooves 32 that communicate with the three water passage holes 31. A spiral flow channel 33 is formed by the water passage holes 31 and the spiral water passage grooves 32 that communicate with the water passage holes 31.

[0040] Furthermore, a cylindrical central recess 35 is provided in the center of the flow straightening section 30, communicating with the three water passage holes 31 and coaxial with respect to the central axis CZ. In addition, a circular central water passage 45 is provided in the center of the light-shielding member 40, coaxial with the central recess 35 of the flow straightening section 30 (i.e., centered on the central axis CZ). Preferably, the central water passage 45 has a diameter less than or equal to the diameter of the central recess 35 of the flow straightening section 30.

[0041] The three water passage holes 31 and the three helical water passage grooves 32 of the flow straightening section 30 are arranged to be rotationally symmetric with respect to the central axis CZ. That is, they are positioned at rotationally symmetrical positions of 120° (=360° / 3) with respect to the central axis CZ.

[0042] More specifically, the spiral water passage groove 32 is a spiral groove in which the curvature decreases (the radius of curvature increases) from the water passage hole 31 towards the outlet end as it approaches the outer circumference, and the groove depth decreases as it reaches the flat surface portion 30F of the flow straightening section 30. In other words, the three spiral water passage grooves 32 are formed as recesses in the flat surface.

[0043] Furthermore, it is preferable that the end (outlet end) of the spiral water channel 32 has an outlet end inclined portion 32S that has a greater inclination than the inclination of the bottom surface 32B of the spiral water channel 32 and reaches the flat surface portion 30F. As shown in Figure 6A, the swirling flow (flow FL1) flows smoothly out of the spiral water channel 32 without being disturbed by the outlet end inclined portion 32S. In this case, the bottom surface 32B of the spiral water channel 32 may be parallel to the flat surface portion 30F and may not have an inclination.

[0044] Furthermore, it is preferable that the spiral water channel 32 has a rectangular cross-section perpendicular to the flow direction, or an inverted trapezoidal shape that widens toward the flat surface portion 30F of the flow straightening section 30.

[0045] As shown in Figure 5A, each of the spiral water channels 32 is positioned so as not to overlap with other spiral water channels 32 within an angular range of approximately 120° with respect to the central axis CZ when viewed from above (i.e., when viewed from the flow channel pipe 21 side in the direction perpendicular to the straightening section 30).

[0046] The light-shielding member 40 has three water outlets 41 (openings) that correspond to the three spiral water passage grooves 32 and communicate with the three spiral water passage grooves 32. The water outlets 41 have the shape of a part of a ring centered on the central axis CZ. That is, the water outlets 41 are formed as strip-shaped openings along the circumference of a circle centered on the central axis CZ.

[0047] As shown in Figures 4A and 5B, at least the portion of the spiral water channel 32 including the outlet end is exposed from the water inlet 41. It is preferable that the width of the strip-shaped opening, the water inlet 41, is greater than the width of the spiral water channel 32. Furthermore, it is preferable that the side surface (inlet end) of the wing portion 42 of the light-shielding member 40 facing the outlet end inclined portion 32S of the spiral water channel 32 is formed as an inclined portion 40S in which the thickness of the member decreases toward the outlet end inclined portion 32S.

[0048] Figure 7 schematically shows the flow path after combining the flow straightening section 30 and the light-shielding member 40. As shown in Figures 6B and 7, the swirling flow (flow FL1) from the spiral water channel 32 flows smoothly from the outlet end inclined section 32S of the spiral water channel 32 to the inclined section 40S of the light-shielding member 40 without being disturbed (flow FL2). If the thickness of the light-shielding member 40 is thin, the inclined section 40S may not be provided, and a groove with a flat bottom surface may be formed. Furthermore, it is preferable that the outlet end inclined section 32S of the spiral water channel 32 and the inclined section 40S of the light-shielding member 40 are positioned as a continuous inclined surface. This suppresses disturbance of the swirling flow.

[0049] Although the description has focused on the case where the flow straightening section 30 has three water passage holes 31 and three spiral water passage grooves 32, it is also possible to have n water passage holes 31 and n spiral water passage grooves 32 (i.e., n spiral flow channels 33) (where n is an integer of 2 or more). Furthermore, it is preferable that the light-shielding member 40 is provided with n water passage openings 41 corresponding to the n spiral water passage grooves 32.

[0050] In this case, it is preferable that the n helical flow channels 33 have the same shape and size and are arranged in a rotationally symmetric manner with respect to the center of the flow straightening section 30 (i.e., the central axis CZ).

[0051] Furthermore, the water passage 41 of the light-shielding member 40 is sized to expose at least the end portion, which is the outflow portion of the spiral water passage groove 32, when viewed from above, and is provided at a position aligned with the spiral water passage groove 32. Preferably, it is formed so as to expose the entire groove width of the end portion of the spiral water passage groove 32, or the outflow end inclined portion 32S.

[0052] Figure 8 schematically shows the fluid flow FL in the flow path 25 within the flow path pipe 21 of the fluid sterilization device 10. In the fluid sterilization device 10, the fluid A1 flowing out from the flow straightening section 30 and the light-shielding member 40 forms a swirling flow and travels through the flow path pipe 21 toward the light source module 50 in the direction of the central axis CZ (flow FL).

[0053] In a swirling flow, the fluid spreads outward, causing it to flow towards the inner wall surface of the flow channel 21. As a result, the flow velocity near the inner wall surface increases, which suppresses and prevents the adhesion of scale, debris, etc., to the flow channel 21. In addition, the swirling flow increases the time the fluid is present in the flow channel 21, extending the sterilization time of the fluid by the light source module 50.

[0054] Furthermore, since the UV light from the light source module 50 is reflected by the light-shielding member 40, leakage light on the inlet side 13 can be suppressed. UV light passing through the water inlet 41 of the light-shielding member 40 is absorbed by the surface of the rectifier 30 and the inner wall of the outer pipe 22, thus preventing leakage light.

[0055] Furthermore, since the ultraviolet light reflected by the light-shielding member 40 is irradiated onto the fluid, the irradiation efficiency can be increased. In addition, since the reflected ultraviolet light is also reflected by the flow channel tube 21, the irradiation efficiency and utilization efficiency can be further increased.

[0056] Therefore, it is possible to provide a fluid sterilization device in which the adhesion of scale, debris, etc. to the flow channel pipe 21 is suppressed and prevented. Furthermore, leakage light on the inlet side 13 is suppressed, and the irradiation efficiency and utilization efficiency of UV light to the fluid are high, thus providing a fluid sterilization device with excellent sterilization performance.

[0057] [Second Embodiment] Figure 9A is a three-dimensional view showing the flow straightening section 30 and light-shielding member 70 of the inlet section 13 in the fluid sterilization device of the second embodiment. The light-shielding member 70 is provided in place of the light-shielding member 40 of the first embodiment described above. The flow straightening section 30 has the same configuration as in the first embodiment.

[0058] The light-shielding member 70 is a porous member having a disc shape and multiple water passage holes 71. The light-shielding member 70 is provided in close contact with the surface of the flow straightening section 30. The light-shielding member 70 also functions as a porous flow straightening member. The light-shielding member 70 is made of a material that reflects UV light from the light source module 50.

[0059] Multiple water passage holes 71 are arranged at uniform intervals within the water passage hole forming region 71R. The water passage hole forming region 71R has a circular shape centered on the central axis CZ. That is, the circle representing the water passage hole forming region 71R (shown by a dashed line) is the outer edge of the multiple water passage holes 71.

[0060] Furthermore, Figure 9B shows the arrangement relationship between the light-shielding member 70 and the water passage hole formation region 71R when the light-shielding member 70 is connected to the flow straightening section 30. The light-shielding member 80 is coaxial with the central axis CZ and, in a top view, is positioned to encompass the plurality of spiral water passage grooves 32 of the flow straightening section 30.

[0061] The flow FL of the fluid A1 that flows in from the inlet 24 is described as follows: the fluid A1 flows out of the flow straightening section 30 via the water passage holes 31 and the spiral water passage groove 32 of the flow straightening section 30. In addition, a portion of the fluid A1 that flows in from the inlet 24 flows out of the flow straightening section 30 via the central recess 35 of the flow straightening section 30.

[0062] The fluid A1 that flows out from the rectifier section 30 travels through multiple water passage holes 71 in the light-shielding member 70 and through the flow channel pipe 21 toward the light source module 50 in the direction of the central axis CZ.

[0063] (2) Evaluation of the fluid sterilization apparatus of the first and second embodiments (2.1) Evaluation of the rectifier and light-shielding members Fluid analysis (simulation) was performed to investigate how the fluid flow inside the flow channel pipe 21 changes due to the flow straightening section 30 and light-shielding member 40 of the first embodiment and the flow straightening section 30 and light-shielding member 80 of the second embodiment. Fluid analysis software (Fluent) was used for this simulation.

[0064] Figure 10 is a schematic three-dimensional view of the inlet 200 of the comparative example fluid sterilization device (CMP). In the comparative example fluid sterilization device (CMP), a porous light-shielding member 210 identical to the light-shielding member 80 of the second embodiment is provided, but the flow straightening section of the first and second embodiments is not provided.

[0065] In other words, the space between the inlet 24 and the light-shielding member 210 is a hollow section 213 having approximately the same inner diameter as the inner diameter of the flow channel pipe 21, and the porous light-shielding member 210 functions as a flow straightening plate.

[0066] Figure 11 shows the simulation results for [i] a fluid sterilization device (EMB1) equipped with a swirling flow straightening section 30 and an inlet section 13 having a light-shielding member 40 according to the first embodiment, and [ii] a fluid sterilization device (EMB2) equipped with a flow straightening section 30 and an inlet section 13 having a porous light-shielding member 80 according to the second embodiment, when the flow velocity distribution of the inflow fluid is changed, in comparison with [iii] a comparative fluid sterilization device (CMP).

[0067] Specifically, the following cases are shown for the flow velocity distribution in the cross-section of the inlet 24: [A] uniform within the plane (1.9 m / s), [B] high speed in the center (13.8 m / s), and [C] deflected in one direction with a flow velocity of 0.5 to 2.3 m / s within the plane.

[0068] For each case, the upper panel shows the velocity distribution along the length of the flow channel 21, and the lower panel shows the velocity distribution in a cross-section perpendicular to the central axis CZ at the center of the flow channel 21 along its length. The maximum velocity Vmax shown in the figure represents the maximum value at the center of the flow channel 21 along its length (indicated by a dashed line). For clarity, the velocity distributions are also indicated with the signs "F" (fast), "M" (medium), and "S" (slow).

[0069] The dimensions of the flow channel 21 used in the simulation were as follows: inner diameter D0 = 30 mm, length L0 = 90 mm.

[0070] Specifically, simulations were performed for the flow velocity, flow direction and velocity (vector), and average flow velocity in the flow channel pipe 21 in each of the cases [i], [ii], and [iii], with a flow rate of 8 L / min.

[0071] (2.2) Simulation results First, in the comparative example fluid sterilization device (CMP) of [iii], the rectification effect is large when the fluid flows in with a uniform velocity distribution in the plane ([A]), but depending on the velocity distribution of the incoming fluid (for example, in the case of [B]), a sufficient rectification effect cannot be obtained.

[0072] In the case of the swirling flow straightening section 30 (EMB1) [i], the maximum flow velocity Vmax is high at 2 m / s ([A], [B], [C]), but the effect of the fluid velocity distribution can be suppressed to 1-2%.

[0073] Furthermore, it can be seen that the flow velocity near the inner wall surface of the flow channel 21 is greater than in the center, which suppresses and prevents the adhesion of scale, debris, etc. to the flow channel 21. It can also be seen that the flow velocity is high throughout the entire area near the inner wall surface of the flow channel 21.

[0074] [ii] When a porous light-shielding member 80 (flow straightening plate) is used in addition to the swirling flow straightening section 30 (EMB2), the flow velocity becomes faster than when the fluid is not swirled, but the influence of the flow velocity distribution of the incoming fluid can be suppressed.

[0075] Furthermore, it can be seen that the flow velocity near the inner wall surface of the flow channel 21 is greater than that in the center, which suppresses and prevents the adhesion of scale, debris, etc. to the flow channel 21.

[0076] Therefore, according to the first and second embodiments, it is possible to provide a fluid sterilization device that suppresses and prevents the adhesion of scale, debris, etc., to the flow channel 21 and has an excellent flow straightening effect. Furthermore, it is possible to provide a fluid sterilization device with high UV light irradiation efficiency and utilization efficiency and excellent sterilization effect.

[0077] [Differentiation] Modified examples of the rectifier 30 of the first and second embodiments described above will be explained below.

[0078] (1) Variation 1 Figure 12A is a schematic perspective view showing a light-shielding member 100 according to Modification 1 of the first embodiment. The light-shielding member 100 includes a light-shielding plate 101 and a conical portion 105 that is erected perpendicularly to the light-shielding plate 101 and is coaxial with the central axis CZ (i.e., coaxial with the rectifier portion 30).

[0079] The conical portion 105 has a frustoconical cavity 106 (recess) at its bottom that is coaxial with the central axis CZ and whose cross-section decreases in the axial direction (z-direction) from the light-shielding plate 101. The cavity 106 is formed by penetrating the light-shielding plate 101. In other words, the cavity 106 is formed in communication with the central recess 35 of the rectifier portion 30.

[0080] The light-shielding plate 101 is provided with three first water inlets 102 that correspond to the three spiral water channels 32 of the flow straightening section 30.

[0081] Multiple second water inlets 107 are provided in the conical section 105. In the case shown in Figure 12A, two second water inlets 107 are provided for each of the first water inlets 102 of the light shielding plate 101. In other words, a total of six second water inlets 107 are provided in the conical section 105.

[0082] The number and arrangement of the second water inlets 107 are not limited to those shown in Figure 12A, but it is preferable that they be provided in positions that are rotationally symmetric with respect to the central axis CZ.

[0083] Figure 12B is a schematic diagram of the light-shielding member 100 as viewed from the light source module 50 side (top view). Each of the multiple second water inlets 107 is formed as an inclined water inlet whose opening direction is offset from the radial direction RD1 with respect to the central axis CZ.

[0084] More specifically, the second water inlet 107 is formed as an opening with an axis SD that is rotated counterclockwise by an angle θr with respect to the radial direction RD1 in a plane perpendicular to the central axis of the conical portion 105.

[0085] Therefore, the fluid that flows into the cavity 106 via the central recess 35 of the flow straightening section 30 passes through the second water inlet 107 and flows out as a swirling flow SF. The second water inlet 107 generates a swirling flow SF with the same swirling direction as the flow FL1 (Figure 6A) of the flow straightening section 30. In other words, the light-shielding member 100 also functions as a flow straightening section.

[0086] Furthermore, it is preferable that the conical portion 105 is formed of a material that is reflective to UV light. Since the surface of the conical portion 105 reflects UV light, a light-shielding member 100 with high efficiency in irradiating and utilizing UV light into the fluid can be realized.

[0087] As described above, the light-shielding member 100 of Modified Example 1 provides a fluid sterilization device in which the adhesion of scale, debris, etc. to the flow channel pipe 21 is suppressed and prevented. Furthermore, leakage light on the inlet side 13 is suppressed, providing a fluid sterilization device with high efficiency in irradiating and utilizing UV light to the fluid.

[0088] (2) Modification example 2 Figure 13 is a schematic plan view of the rectifier section 110 of the modified example 2, as seen from the light source module 50 side (top view).

[0089] The flow straightening section 110 has a plurality of water passage holes, for example, three water passage holes 111, that communicate with the inlet 24. The three water passage holes 111 are formed in positions that are rotationally symmetric with respect to the central axis CZ.

[0090] Furthermore, the flow straightening section 110 has three helical water passage grooves 112 that communicate with the three water passage holes 111. The three helical water passage grooves 112 are formed to be rotationally symmetric with respect to the central axis CZ. The flow straightening section 110 also has a central recess 115 centered on the central axis CZ.

[0091] In the modified example 2, the spiral water passage groove 112 of the rectifying section 110 is formed as a spiral groove that spirals from the water passage hole 111 and communicates with the central recess 115 when viewed from above.

[0092] The fluid that flows from the water passage hole 111 through the spiral water passage groove 112 into the central recess 115 flows out from the flow straightening section 110 as a swirling flow.

[0093] (3) Modification example 3 Figure 14 is a schematic plan view of the rectifier section 120 of the modified example 3 as seen from the light source module 50 side (top view).

[0094] The flow straightening section 120 has one water passage hole 121 that communicates with the inlet 24. The flow straightening section 120 also has one spiral water passage groove 122 that communicates with the water passage hole 121. Furthermore, the flow straightening section 120 has a substantially circular central recess 125 centered on the central axis CZ.

[0095] In the modified example 3, the spiral water passage groove 122 of the rectifying section 120 is formed as a spiral groove that, when viewed from above, spirals along a circumference centered on the central axis CZ from the water passage hole 121, with its outlet end communicating with the central recess 125.

[0096] The fluid that flows from the water passage hole 121 through the spiral water passage groove 122 into the central recess 125 becomes a swirling flow and flows out from the flow straightening section 120.

[0097] (4) Modification 4 Figure 15 is a schematic perspective view of the light-shielding member 130 of Modification 4. The light-shielding member 130 of Modification 4 differs from the light-shielding member 40 of the first embodiment in that it does not have a central water passage 45. In the case of not having a central water passage as in Modification 4, the water passage hole 31 does not necessarily have to be provided, and the inlet-side end of the spiral water passage groove 32 may communicate with the inlet 24, forming a spiral flow path 33.

[0098] The light-shielding member 130 does not have a central water inlet, and the fluid flowing out from the spiral water channel 32 of the flow straightening section 30 flows through the water inlet 41 and then from the light-shielding member 130 into the flow channel pipe 21, thus creating a strong swirling flow. Therefore, the effect of suppressing the adhesion of scale, debris, etc. to the flow channel pipe 21 is higher.

[0099] (5) Variation 5 Figure 16 is a schematic perspective view of the light-shielding member 140 of Modification 5. The light-shielding member 140 of Modification 5 differs from the light-shielding member 40 of the first embodiment in that it does not have a water passage 41 on its outer circumference.

[0100] In other words, the light-shielding member 140 has a disc shape and a circular central water inlet 145 coaxial with the central axis CZ. The fluid flowing in from the flow straightening section (for example, the flow straightening section of Modified Example 2 or Modified Example 3) flows into the flow channel pipe 21 through the central water inlet 145, so a straightened flow with a large flow velocity accompanied by swirling flow is obtained.

[0101] The embodiments and modifications described above can be combined and applied as appropriate. As described in detail above, this disclosure provides a fluid sterilization device that suppresses the adhesion of scale, debris, etc., in the flow channel, has an excellent flow straightening effect, high ultraviolet light irradiation efficiency and utilization efficiency, and has excellent sterilization effect. [Explanation of Symbols]

[0102] 10: Fluid sterilization device 12: Light source part 13:Inflow part 14: Outlet 21: Flow channel 22:Outer tube 24:Inlet 25: Flow path 26: Outlet 30,110,120: Rectifier 30F:Flat surface area 31,71,111,121: Water passage holes 32,112,122: Spiral water groove 32B: Bottom 32S:Outflow end slope 33: Spiral flow path 35,115,125: Central recess 40, 70, 80, 100, 130, 140: Light-shielding material 40S: Inclined section 41: Water outlet 42: Wing part 45,145: Central water outlet 50: Light source module 101: Light-blocking plate 102: First water inlet 105: Cone 106: Cavity 107: Second water outlet CZ: Center axis

Claims

1. The fluid inlet and A flow channel pipe with a circular cross-section, A flow straightening section that blocks the inlet end of the flow channel pipe, is provided perpendicular to the central axis of the flow channel pipe, and has at least one spiral flow channel consisting of a water passage hole communicating with the inlet and a spiral water passage groove communicating with the water passage hole, A light-shielding member provided on the flow straightening section and having a water-conducting opening that exposes at least the outlet end of the spiral water-conducting groove, A fluid sterilization device comprising: a light source module provided at the other end of the flow channel pipe, perpendicular to the central axis of the flow channel pipe and opposite to the flow straightening section, which irradiates ultraviolet light toward the fluid flow path.

2. The fluid sterilization device according to claim 1, wherein the flow straightening section has a plurality of helical flow channels arranged rotationally symmetrically with respect to the central axis of the flow channel pipe.

3. The fluid sterilization device according to claim 2, wherein each of the spiral water channels of the plurality of spiral channels has an increasing radius of curvature toward the outlet end, and the outlet end approaches the outer circumference.

4. The fluid sterilization device according to claim 1, wherein the flow straightening section is provided in the center of the flow straightening section and has a central recess that communicates with the water passage hole.

5. The fluid sterilization device according to claim 2, wherein the flow straightening section communicates with the water passage holes of the plurality of helical flow channels and has a cylindrical central recess that is coaxial with respect to the central axis.

6. The fluid sterilization device according to claim 1, wherein the water passage opening of the light-shielding member is a band-shaped opening along the circumference of a circle centered on the central axis.

7. The light-shielding member has a plurality of water-conducting openings, The fluid sterilization device according to claim 2, wherein each of the plurality of water passage openings corresponds to each of the spiral water passage grooves of the plurality of spiral flow paths and is a band-shaped opening along the circumference of a circle centered on the central axis.

8. The fluid sterilization device according to any one of claims 1 to 7, wherein the outlet end of the spiral water channel is provided with an outlet end inclined portion having a greater inclination than the bottom surface of the spiral water channel.

9. The fluid sterilization device according to claim 6 or 7, wherein the inlet end of the strip-shaped opening of the light-shielding member facing the outlet end of the spiral water channel has an inclined portion that becomes thinner toward the outlet end of the spiral water channel.

10. The fluid sterilization device according to claim 4 or 5, wherein the light-shielding member has a circular central water outlet coaxial with the central recess of the rectifying portion.

11. The fluid sterilization device according to claim 1, wherein the light-shielding member has a disc shape and is a porous flow straightening member having a plurality of water passage holes.

12. The fluid sterilization device according to claim 1, wherein the rectifier and light-shielding member are formed of a material that reflects light irradiated from the light source module.

13. The light-shielding member is erected on the light-shielding member and has a conical portion coaxial with the central axis, The fluid sterilization device according to claim 4 or 5, wherein the conical portion has a frustoconical cavity at its bottom that communicates with the central recess, and an inclined water outlet provided at an angle in the same direction as the rotational direction of the spiral water channel in a plane perpendicular to the central axis.

14. The flow straightening section is provided in the center of the flow straightening section and has a central recess that communicates with the water passage hole, The fluid sterilization device according to claim 2, wherein each of the plurality of spiral water passage grooves spirals out of the water passage hole and communicates with the central recess.

15. The flow straightening section has one water passage hole that communicates with the inlet of the flow channel pipe, and a central recess provided in the center of the flow straightening section. The fluid sterilization device according to claim 1, wherein the spiral water channel has an outlet end that communicates with the central recess.

16. The fluid sterilization device according to claim 14 or 15, wherein the light-shielding member has a disc shape and a circular central water outlet coaxial with the central axis.

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