Fluid sterilization device

Abstract

To provide a fluid sterilization device with excellent rectification effects, high ultraviolet irradiation efficiency, and superior sterilization performance.SOLUTION: A fluid sterilization device includes a flow passage pipe with a circular cross-section, and a flow straightening member 30 provided at one end of the flow passage pipe, perpendicular to the central axis of the flow passage pipe, having a circular plate-shaped straightening plate 31 and a conical portion 32 provided perpendicular to the straightening plate, and a light source module provided at the other end of the flow passage pipe, perpendicular to the central axis of the flow passage pipe and facing the flow straightening member, and irradiates ultraviolet light toward the fluid flow path. The straightening plate has a plurality of first openings 33-1, 33-2, 33-3 arranged in a band-like shape along a circumference centered on the center of the straightening plate. The conical portion has a frustum-shaped recess 35 at its base, which is coaxial with the central axis and penetrates the flow straightening plate, with its base connected to the inside of the multiple first openings. It also has multiple second openings 36-1, 36-2 provided in the wall portion 32B, which is the side wall of the conical portion within the recess.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fluid sterilization device that sterilizes fluids such as water using ultraviolet light. [Background technology]

[0002] BACKGROUND ART Fluid sterilization devices are known that sterilize a liquid by flowing the liquid to be sterilized in a pipe and irradiating the liquid flowing in the pipe with ultraviolet light in the axial direction of the pipe. For example, Patent Document 1 discloses a sterilization device that can rectify the fluid flow to a first direction by providing a straightening plate at the inlet, and can extend the duration of ultraviolet light action by irradiating ultraviolet light in the same direction, thereby improving sterilization ability.

[0003] Furthermore, Patent Document 2 discloses a fluid sterilization module that can prevent the formation of areas with high flow rates that result in insufficient ultraviolet irradiation due to differences in fluid flow rates. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-051290 [Patent Document 2] Japanese Patent Application Publication No. 2019-187657 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is a demand for a fluid sterilization device that has an excellent rectification effect and high ultraviolet light irradiation efficiency. In addition, there are problems such as a decrease in the utilization efficiency of ultraviolet light due to ultraviolet light leaking from the rectification plate, the leaked ultraviolet light inducing deterioration of surrounding components, and a tendency for dust clogging.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a fluid sterilization device that has an excellent flow rectification effect, high ultraviolet light irradiation efficiency, and excellent sterilization effect, and that prevents clogging with dust. [Means for solving the problem]

[0007] The fluid sterilization device of the present invention comprises: a flow pipe having a circular cross section; a straightening member provided at one end of the flow path pipe perpendicular to a central axis of the flow path pipe, the straightening member having a disk-shaped straightening plate and a conical portion provided perpendicular to the straightening plate; a light source module that is provided at the other end of the flow path pipe so as to face the rectifying member perpendicular to the central axis of the flow path pipe and that irradiates ultraviolet light toward the flow path of the fluid, the rectifying vane has a plurality of band-shaped first openings arranged along a circumference centered on the center of the rectifying vane, The conical portion is a bottom portion of the current plate is connected to an inner side of the plurality of first openings; a truncated cone-shaped recess at the bottom, the truncated cone-shaped recess being coaxial with the central axis and penetrating the straightening plate; The recess has a plurality of second openings provided in a wall portion that is a side wall of the conical portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view showing a cross section passing through the central axis of the fluid sterilization apparatus of the first embodiment. [Figure 2] FIG. 2 is a perspective view showing the flow guide member of the first embodiment. [Figure 3A] FIG. 4 is a schematic diagram of the flow regulating member as viewed from above. [Figure 3B] 3 is a schematic side view of the rectifying member when viewed from a side direction A shown in FIG. 2. FIG. [Figure 3C] 10 is a diagram showing a flow in which the fluid passing through the first opening 33 and the fluid passing through the second opening 36 join together. [Figure 4]FIG. 4 is a partially enlarged cross-sectional view showing an inlet portion and a flow straightening member. [Figure 5A] FIG. 10 is a perspective view showing a flow guide member according to a second embodiment. [Figure 5B] 5B is a schematic side view of the rectifying member when viewed from a side direction A shown in FIG. 5A. FIG. [Figure 6] FIG. 10 is a diagram showing the results of comparing the simulation results of the flow straightening member (EMB2) of the second embodiment with the simulation results when either the first opening or the second opening is omitted. [Figure 7] 10 is a diagram showing the results of comparing the structures of the recesses (hollow portions) of the flow rectifying member of the second embodiment (EMB2) and the flow rectifying member 30 of the first embodiment (EMB1) with a case where the recesses are cylindrical. [Figure 8] FIG. 4 is a partially enlarged cross-sectional view showing an inlet portion and a flow straightening member. [Figure 9] FIG. 10 is a perspective view showing a rectifying member according to a first modified example of the first embodiment. [Figure 10A] FIG. 10 is a perspective view showing a rectifying member according to a second modified example of the first embodiment. [Figure 10B] 10 is a schematic diagram of a straightening member of Modified Example 2 as viewed from above (top view). FIG. [Figure 11] 10 is a diagram showing the simulation results of the rectifying member having the second opening of the second modified example. FIG. [Figure 12] FIG. 4 is a partially enlarged cross-sectional view showing an inlet portion and a flow straightening member. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the following, preferred embodiments of the present invention will be described, but these may be modified and combined as appropriate. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

[0010] [First embodiment] Fig. 1 is a cross-sectional view showing a cross section passing through a central axis CZ of the fluid sterilization apparatus 10 of the first embodiment. Note that Fig. 1 shows a Cartesian coordinate system. The fluid sterilization device 10 includes a main body 11, a light source 12, an inlet 13, and an outlet 14. The fluid sterilization device 10 is generally placed with the direction of the central axis CZ (z direction) facing upward, i.e., aligned vertically with the light source 12 on the upper side (vertical placement).

[0011] The fluid sterilization device 10 is installed in, for example, a water storage tank of an ice maker or the like, a water supply pipe, a water heater, a water server, a circulation system (cooling water for a chiller), and a drink server. The sterilized water is usually provided for drinking. Note that sterilization in a circulation system is performed to prevent the viscosity of the circulating water from increasing due to the proliferation of bacteria in the circulating water, which leads to power loss.

[0012] The inlet portion 13 is provided on one end side of the main body portion 11 in the axial direction. The outlet portion 14 has a central axis aligned with the central axis CZ of the main body portion 11 and is provided as a flow path through which the fluid flows out in the axial direction (z direction) via the light source portion 12.

[0013] The inlet 13 is provided with an inlet 24 for the fluid to be sterilized, and the outlet 14 is provided with a fluid outlet 26. The inlet 13 and outlet 14 have threads (not shown) cut around their peripheries so that they can be connected to pipes (not shown) within the device in which the fluid sterilization device 10 is installed. Also, quick fasteners (Koyo Co., Ltd.) can be used to fix the device within the device in which it is installed.

[0014] The light source unit 12 is attached to the main body unit 11 at the other end (in this embodiment, on the outflow unit 14 side) of the fluid sterilization device 10 in the direction of the central axis CZ (hereinafter also simply referred to as the axial direction) with its central axis aligned with the central axis CZ of the main body unit 11.

[0015] The main body 11 includes a flow path pipe 21, which is an inner pipe arranged coaxially with the central axis CZ, and an outer pipe 22. Both the flow path pipe 21 and the outer pipe 22 are straight pipes with circular cross sections perpendicular to the central axis CZ. The flow path pipe 21 has circular openings at both ends in the axial direction. The outer pipe 22 is open only at one axial end and closed at the other end.

[0016] The flow path pipe 21 is inserted into the outer pipe 22 from the opening of the outer pipe 22 on the light source unit 12 side, and is housed inside the outer pipe 22. Watertight O-rings 28a, 28b are fitted into grooves formed at the other end and one end of the flow path pipe 21 in the axial direction, and prevent the fluid A1 from entering between the outer pipe 22 and the flow path pipe 21.

[0017] A flow straightening member 30 that closes the end of the flow path pipe 21 is provided on the inlet section 13 side of the flow path pipe 21. The flow straightening member 30 has a disk-shaped flow straightening plate 31 that is provided perpendicular to the central axis CZ, and a conical portion 32 whose central axis is provided perpendicular to the flow straightening plate 31.

[0018] The fluid A1 flowing in from the inlet portion 13 is rectified by the rectifying member 30 and flows parallel to the central axis CZ. Thereafter, the fluid A1 flows toward the light source unit 12 provided on the outlet portion 14 side.

[0019] Examples of materials for each component of the fluid sterilization apparatus 10 include, but are not limited to, the following: The flow path pipe 21 is made of a resin material that is resistant to deep ultraviolet light, such as polytetrafluoroethylene (PTFE). The outer pipe 22 is made of a metal material, such as stainless steel (e.g., SUS304). In each embodiment, the outer pipe 22 is made of a metal material. Alternatively, a resin that does not undergo hydrolysis, such as polypropylene (PP), may be used.

[0020] The light source unit 12 has a light source module 50. The light source module 50 has a central axis coaxial with the central axis CZ, and is provided at the other end of the flow path pipe 21. The light source module 50 has at least one LED element 55 (light-emitting element) mounted therein.

[0021] The light (UV) emitted from the LED elements 55 is irradiated toward the rectifying member 30 via a light-transmitting plate 53 made of quartz glass or the like. That is, the light emitted from the LED elements 55 is irradiated onto the fluid A1 flowing toward the light source module 50 through the flow path 25 in the flow path pipe 21, which is the sterilization chamber.

[0022] The LED element 55 emits deep ultraviolet light (UV-C) with a wavelength of around 265 nm, which has a high sterilization effect. Depending on the application, a light-emitting element that emits light with a wavelength different from the above wavelength can also be used. Note that although the case where the LED element 55 is used will be described, a laser element (LD: Laser Diode) or the like may also be used as the light-emitting element.

[0023] To explain the flow FL of the fluid A1, the fluid A1 passes through the rectifying member 30, advances in the axial direction within the flow path pipe 21 toward the light source module 50, passes around and behind the light source module 50, and flows out from the outlet 26. That is, the sterilized fluid A2 flows out from the outlet 26. The outlet 26 has a cylindrical shape coaxial with the central axis CZ, and is connected to the flow path 25 of the flow path pipe 21.

[0024] (1) Configuration of the flow control member Fig. 2 is a perspective view showing the airflow rectifying member 30 of this embodiment. Fig. 3A is a schematic diagram of the airflow rectifying member 30 as viewed from above (top view). Fig. 3B is a schematic diagram of the airflow rectifying member 30 as viewed from the side A shown in Fig. 2.

[0025] The flow straightening member 30 has a circular plate-shaped flow straightening plate 31 whose outer periphery is connected to the circular inlet end, which is one end of the flow path pipe 21 on the inlet 24 side. In other words, the flow straightening plate 31 is provided perpendicular to the central axis CZ of the flow path pipe 21.

[0026] The straightening plate 31 has a plurality of band-shaped first openings 33-1, 33-2, 33-3 along the circumference of a circle centered on the center C of the straightening plate 31 (hereinafter, when there is no need to distinguish between these first openings, they will be referred to as first openings 33).

[0027] More specifically, the plurality of first openings 33 are holes that penetrate the straightening plate 31 and have the shape of a portion of a ring along the circumference. The plurality of first openings 33 are separated in the circumferential direction by separation portions 34-1, 34-2, and 34-3 between the first openings 33 (hereinafter, when no particular distinction is made between these separation portions, they will be referred to as separation portions 34). The first openings preferably have an oval shape that is curved along an arc. This can suppress stagnation near the inlet 24 of the flow path pipe 21 and maintain the straightening effect.

[0028] In this embodiment, the first openings 33 have the same shape and size, but may have different shapes or sizes. Also, the present invention is not limited to a case where N (N=3) first openings 33 are provided.

[0029] Moreover, the rectifying member 30 is provided perpendicular to the rectifying plate 31 and has a conical portion 32 that is coaxial with the central axis CZ (i.e., coaxial with the rectifying plate 31). The conical portion 32 has a truncated conical recess 35 (hollow portion) at the bottom of the conical portion 32 that is coaxial with the central axis CZ and whose cross section decreases in the axial direction (z direction) from the rectifying plate 31. The recess 35 is formed to penetrate the rectifying plate 31.

[0030] 3B, the conical portion 32 is composed of a conical main body 32A, which is a cone, and a wall portion 32B that surrounds the recess 35. That is, the bottom surface of the conical main body 32A and the bottom surface 35B of the recess 35 (the upper bottom surface of the truncated cone) are flush with each other.

[0031] More specifically, the wall portion 32B is the bottom portion of the conical portion 32 and is a side wall surrounding the recess 35. The wall portion 32B of the conical portion 32 is provided with a plurality of second openings 36-1, 36-2, 36-3 (hereinafter, when there is no need to particularly distinguish between these second openings, they will be referred to as second openings 36).

[0032] Each of the second openings 36 is formed in the wall portion 32B as a band-shaped opening along the circumference in a plane parallel to the flow straightening plate 31. Each of the second openings 36 communicates with the inlet 24 via the recess 35, and also communicates with the flow path in the flow path pipe 21.

[0033] 3C, the fluid that flows in through the inlet 24 and passes through the recess 35 (hollow portion) and the second opening 36 and the fluid that flows in through the inlet 24 and passes through the first opening 33 join together and flow axially through the flow path pipe 21 (flow FL). This reduces the difference in flow velocity between the fluid in the outer periphery of the flow path that flows out through the straightening plate 31 and the fluid in the inner periphery of the flow path that flows out from the conical portion 32, making it possible to make the flow velocities uniform.

[0034] The plurality of first openings 33 are preferably provided at rotationally symmetric positions about the center (i.e., the central axis CZ) of the current vane 31. The plurality of second openings 36 are preferably provided at rotationally symmetric positions about the central axis (i.e., the central axis CZ) of the conical portion 32.

[0035] In this embodiment, the second openings 36 have the same shape and size, but they may have different shapes or sizes. Also, the embodiment will be described with respect to a case where M (M=3) second openings 36 are provided, but this is not limiting. Furthermore, it is preferable that the number (N) of first openings 33 and the number (M) of second openings 36 are the same (N=M), but they may be different.

[0036] (2) Positional relationship between the first opening, the second opening, and the separation unit 3A, the second openings 36-1, 36-2, and 36-3 are provided facing the corresponding separation portions 34-1, 34-2, and 34-3, respectively. Note that the second opening 36-1 preferably has a length (arc length) such that the corresponding separation portion 34-1 is included within the opening angle range θ2 of the second opening 36-1. The same applies to the other second openings 36-2 and 36-3 and separation portions 34-2 and 34-3.

[0037] In other words, when viewed vertically along the central axis CZ (top view), it is preferable that each of the second openings 36 is provided at a length and position such that the corresponding separation portion 34 is included within the opening angle range θ2 of the second opening 36-1.

[0038] 3A, the first opening 33 and the second opening 36 are disposed at angular positions offset from each other when viewed from above. That is, when the center C is the origin (polar coordinates), the first opening 33 and the second opening 36 are disposed at different angles from each other.

[0039] In this embodiment, the second opening 36-1 and the separation portion 34-1 between the first openings 33-1 and 33-2 are arranged so that the center C2 of the second opening 36-1 and the center C3 of the separation portion 34-1 between the first openings 33-1 and 33-2 are aligned on the same radius. Therefore, the angular position of the center C2 of the second opening 36-1 and the angular position of the center C1 of the first opening 33 are shifted from each other.

[0040] In other words, when N=M=3, the first opening 33 and the second opening 36 are arranged at an angle θ=360° / N / 2=60° relative to the center C.

[0041] 3A and 3B, the upper surface 36T of the second opening 36 is preferably formed to be flush with the bottom surface 35B (upper bottom surface) of the truncated cone-shaped recess 35. The second openings 36 are preferably formed to open all the way to the upper surface of the rectifying plate 31. By configuring the first opening 33 and the second opening 36 as described above, the power loss of the fluid passing through the flow straightening member 30 due to the flow straightening member 30 is suppressed. This makes it possible to increase the flow rate of the fluid flowing into the flow path pipe 21 with a smaller load.

[0042] (3) Positional relationship between the inlet and the recess (cavity) 4 is a partially enlarged cross-sectional view showing inflow section 13 and flow straightening member 30. Inflow section 13 has a cylindrical inflow port 24 that is coaxial with truncated cone-shaped recess 35 (hollow portion) of conical section 32. Outflow end 24A of inflow port 24 is circular and coaxial with recess 35, and has a diameter DP that is smaller than the diameter of inflow port 24.

[0043] It is preferable that the diameter DP of the outflow end 24A is the same as or smaller than the diameter of the bottom surface 35B of the recess 35. In this case, the fluid that flows in from the outflow end 24A directly hits the bottom surface 35B of the recess 35, passes through the second opening 36 of the conical portion 32, and flows out into the flow path pipe 21. The fluid that directly hits the bottom surface 35B of the recess 35 and turns around flows out into the flow path pipe 21 from the first opening 33 of the flow path plate 31, so that the flow straightening effect of the flow straightening member 30 is further enhanced.

[0044] Although the description has been given of the case where the inlet 24 has the outlet end 24A with a diameter smaller than the diameter of the inlet 24, the inlet 24 may be a cylindrical straight pipe.

[0045] [Second embodiment] Fig. 5A is a perspective view showing a rectifying member 40 of the second embodiment. Fig. 5B is a schematic side view of the rectifying member 30 when viewed from the side direction A shown in Fig. 5A.

[0046] The straightening member 40 of the second embodiment differs from the straightening member 30 of the first embodiment in that it has a protrusion 45 provided within the recess 35, but the other configurations are the same as those of the straightening member 30 of the first embodiment.

[0047] A conical convex portion 45 is provided inside the recess 35 (hollow portion) formed in the conical portion 32 of the flow straightening member 40, and is coaxial with the conical portion 32 and protrudes in the axial direction (-z direction) from the bottom surface of the recess 35. That is, a conical convex portion 45 is provided that protrudes toward the inlet 24 (see the circular dashed line in FIG. 5).

[0048] The fluid that flows into the recess 35 (hollow portion) from the inlet 24 has its flow path expanded laterally by the convex portion 45, and strikes the bottom surface 35B of the recess 35 at a gentle angle. Therefore, the fluid flows smoothly toward the second opening 36, and also smoothly merges with the fluid that has passed through the first opening 33.

[0049] Although the convex portion 45 has been described as having a conical shape, it may have a truncated conical shape. 1. Consideration of the first and second embodiments

[0050] (1) Examination and evaluation of the first and second openings A fluid analysis (simulation) was performed to examine how the flow of the fluid flowing inside the flow path pipe 21 changes due to the first opening 33 and the second opening 36. Fluid analysis software (Fluent) was used for the simulation.

[0051] 6 is a diagram showing the results of comparing the simulation results of the rectifying member 40 (EMB2) of the second embodiment with the simulation results when either the first opening 33 or the second opening 36 is omitted. That is, the simulation results are shown for (i) when only the first opening 33 is provided, (ii) when only the second opening 36 is provided, and (iii) when both the first opening 33 and the second opening 36 are provided (EMB2).

[0052] The sizes of the various parts of the flow regulating member 40 used in the simulation are as follows: Inner diameter D0 of the flow pipe 21 = 30 mm Length of flow pipe 21 L0 = 90 mm Height H1 of the cone body 32A = 12.7 mm Height of wall 32B H2 = 2mm Diameter D1 of the bottom of the cone section 32 = 17 mm Diameter D2 of the opening of the recess 35 = 16 mm Diameter D3 of the bottom surface 35B of the recess 35 = 11.4 mm Diameter D4 of the bottom of the protrusion 45 = 10 mm Height of protrusion 45 H4 = 2.9 mm The length (arc length) of the first opening 33 is L1 = 31.6 mm, and the width is W1 = 8.5 mm The length (arc length) of the second opening 36 is L2 = 4.2 mm, and the width is W2 = 2 mm. Specifically, in each of the cases (i), (ii), and (iii), a simulation was performed with a flow rate of 8 L / min for the flow velocity, flow direction, flow velocity (vector), and average flow velocity in the flow path pipe 21. Note that the flow velocity and vector are shown as results for a cross section including the central axis CZ, and the average flow velocity is shown as results for a cross section perpendicular to the central axis CZ at a position 35 mm away from the apex of the conical portion 32 of the flow straightening member 40.

[0053] For clarity of illustration, the flow speeds are indicated by symbols "F" (fast), "M" (medium), and "S" (slow).

[0054] The simulation results show that (i) when only the first opening 33 is provided, the fluid flows along the wall surface of the flow path pipe 21, so the flow is fast near the wall surface and slow in the center.

[0055] (ii) When only the second opening 36 is provided, it is found that the flow velocity distribution is unsteady and not constant.

[0056] (iii) When the first opening 33 and the second opening 36 are provided, it can be seen that the flow velocity distribution is made uniform by the merging of the fluids that have passed through the first opening 33 and the second opening 36. Furthermore, referring to the vector results, it can be seen that air stagnation is also suppressed. Therefore, it can be seen that (iii) when the first opening 33 and the second opening 36 are provided, an excellent flow straightening effect can be obtained by the merging of the fluids that have passed through the first opening 33 and the second opening 36.

[0057] (2) Internal structure of the recess (cavity) FIG. 7 is a diagram showing the results of comparing the structure of the recess 35 (hollow portion) of the rectifying member 40 (EMB2) of the second embodiment and the rectifying member 30 (EMB1) of the first embodiment with the case where the recess (hollow portion) has a cylindrical shape.

[0058] Specifically, simulations were performed with a flow rate of 8 L / min for (i) the case where the hollow portion is cylindrical, (ii) the case where the hollow portion is truncated cone shaped (EMB1, straightening member 30), and (iii) the case where a conical (inverted cone) protrusion 45 protruding toward the inlet 24 is provided inside the truncated cone shaped hollow portion (EMB2, straightening member 40).

[0059] The sizes of the parts of the flow straightening member 30 and the flow straightening member 40 used in the simulation are the same as those described above. For ease of viewing the figure, the flow velocities (S, M, F, etc.) at rotationally symmetric positions on the flow velocity distribution cross section are not shown.

[0060] (i) When the cavity is cylindrical, almost no flow division occurs, and the flow straightening effect is small. It is also found that fluid stagnation occurs on the inflow side of the first opening 33 (see vector diagram).

[0061] (ii) When the cavity is frustum-shaped (EMB1, flow straightening member 30), it is found that the flow is diverted and a flow straightening effect is obtained. It is also found that a small amount of fluid is retained near the bottom of recess 35 (cavity) (see vector diagram).

[0062] (iii) In the case where a conical protrusion 45 is provided inside the recess 35 (hollow portion) (EMB2, straightening member 40), the flow velocity distribution after straightening is not significantly affected by the protrusion 45, even compared to the case of (ii), and it is found that flow division occurs and a straightening effect is obtained. Furthermore, the fluid stagnation in the recess 35 (hollow portion) seen in the case of (ii) is not seen, and a better straightening effect is obtained.

[0063] Therefore, the difference in flow speed of the fluid in the flow path is small, so that the fluid is uniformly irradiated with ultraviolet light, resulting in a fluid sterilization device 10 with high ultraviolet light irradiation efficiency. In addition, the flow straightening member 30 has the strip-shaped first opening 33 and second opening 36, which prevents clogging with dust and the like.

[0064] As described above in detail, the first and second embodiments can provide a fluid sterilization apparatus 10 that has an excellent flow straightening effect and high ultraviolet light irradiation efficiency. In addition, a fluid sterilization apparatus that is suppressed from clogging with dust can be provided.

[0065] (3) Irradiation efficiency and utilization efficiency of irradiated light 8 is a partially enlarged cross-sectional view showing the inlet portion 13 and the rectifying member 30. In the above-described embodiment, the conical portion 32 of the rectifying member 30 is made of polytetrafluoroethylene (PTFE). PTFE has a high reflectivity for ultraviolet light, and diffuses and reflects the ultraviolet light from the light source module 50.

[0066] The ultraviolet light reflected from the cone portion 32 is irradiated onto the fluid, thereby realizing a fluid sterilization device with high irradiation efficiency. Furthermore, by using PTFE for the flow path pipe 21, the irradiation efficiency can be further improved.

[0067] It should be noted that PTFE is suitable for, but is not limited to, the material of the rectifying member 30. Fluorine resins such as, but not limited to, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and polyvinylidene fluoride (PVDF, polyvinylidene fluoride) can also be used.

[0068] Furthermore, it is preferable that the conical portion 32 has a thickness TC equal to or greater than a predetermined value at a position corresponding to the circumference of the outlet end 24A of the inlet 24. For example, if the conical portion 32 is made of polytetrafluoroethylene (PTFE), the ultraviolet light transmittance of PTFE is approximately 0.37% at a thickness of 5.4 mm, so by setting the thickness TC to 5.4 mm or greater, it is possible to suppress the leakage light to 0.37% or less. Note that this leakage light of 0.37% is a value calculated based on the tolerance values ​​recommended by the TLV.

[0069] Furthermore, it is preferable that the flow path pipe 21 is made of polytetrafluoroethylene (PTFE), which can further reflect the ultraviolet light reflected from the conical portion 32 and increase the utilization efficiency of the ultraviolet light.

[0070] 8, a light-shielding wall 38 may be provided on the outside of the outlet end 24A of the inlet 24 to block ultraviolet light leaking from the rectifying plate 31. The light-shielding wall 38 is made of, for example, polypropylene (PP). 2. Modification example

[0071] (1) Modification example 1 9 is a perspective view showing a straightening member 60 which is a first modified example of the first embodiment. The straightening member 60 of the first modified example has a straightening plate 31 provided with a plurality of first openings 33 (N=3) and a conical portion 62 provided with a plurality of second openings 66 (M=3).

[0072] The flow straightening member 60 of the first modified example differs from the flow straightening member 30 of the first embodiment in that each of the second openings 66 has a conical portion 62 formed in a wall portion 62B in the shape of a slit with a small opening height. The other configurations are the same as those of the flow straightening member 30 of the first embodiment, and each of the second openings 66 is provided facing each of the separation portions 34 of the corresponding first openings 33.

[0073] More specifically, in the conical portion 62, each of the second openings 66 is formed in the wall portion 62B at a height such that the lower surface 66B of the second openings 66 does not reach the upper surface of the straightening plate 31, and is formed with a step between it and the separation portion 34-1 of the first opening 33, which differs from the straightening member 30 of the first embodiment.

[0074] Preferably, the upper surface 66T of the second opening 66 is formed to be flush with the bottom surface 35B (upper bottom surface) of the recess 35. Preferably, the lower surface 66B of the second opening 66 is formed as a surface parallel to the upper surface 66T of the second opening 66, and is formed as a band-like opening with a constant width extending in the circumferential direction.

[0075] Furthermore, like the flow rectifying member 40 of the second embodiment, a protrusion 45 may be provided inside the recess 35 (hollow portion).

[0076] (2) Modification example 2 Fig. 10A is a perspective view showing a rectifying member 70 according to a second modified example of the first embodiment, and Fig. 10B is a schematic view of the rectifying member 70 as viewed from above (top view).

[0077] The flow straightening member 70 of the second modified example has a flow straightening plate 31 provided with a plurality of first openings 33 (N=3) and a conical portion 72 provided with a plurality of second openings 76 (M=6). As shown in Fig. 10B, each of the second openings 76-1 to 76-6 is formed so that the opening direction is shifted from the radial direction RD1 about the center C.

[0078] More specifically, the second opening 76-1 is formed as an opening whose axis is in a direction SD rotated by an angle θr clockwise with respect to the radial direction RD1 in a plane perpendicular to the central axis of the conical portion 72. The other second openings 76-2 to 76-6 are also formed as openings whose axes are in directions rotated by an angle θr with respect to their respective radial directions.

[0079] The second opening 76 is formed as at least one opening facing each of the first openings 33. In the present modified example 2, two second openings 76 are provided facing each of the first openings 33-1, 33-2, and 33-3.

[0080] According to the straightening member 70 of modified example 2, each of the second openings 76 is an opening whose axis is in the direction SD rotated by a certain angle θr relative to the radial direction, causing the fluid to swirl, thereby providing an excellent straightening effect.

[0081] The number, position, and size of the second openings 76 can be modified as needed. However, it is preferable that the second openings 76 are provided at rotationally symmetric positions with respect to the central axis of the conical portion 72.

[0082] Furthermore, like the flow rectifying member 40 of the second embodiment, a protrusion 45 may be provided inside the recess 35 (hollow portion).

[0083] (3) Simulation results for modified example 2 11 is a diagram showing the simulation results of the flow straightening member 70 having the second opening 76 of Modified Example 2. The simulation results are for the case where a conical protrusion 45 (see FIGS. 5A and 5B) is provided in the recess 35.

[0084] As shown in Figure 11, the flow velocity at the center along the axis is lower than that at the outer periphery, but because the fluid at the outer periphery is swirling, the axial flow velocity and average flow velocity are made uniform, and a rectifying effect is achieved.

[0085] (4) Modification example 3 12 is a partially enlarged cross-sectional view showing the inlet portion 13 and the flow straightening member 30. The outlet end of the inlet portion 13 is provided with a return portion 24B that is coaxial with the inlet 24 and has a diameter smaller than the diameter of the inlet 24.

[0086] The return portion 24B has a sidewall shape of a truncated cone whose cross-sectional area decreases toward the flow straightening member 30. By providing the return portion 24B, the flow path is narrowed and the flow rate of the fluid between it and the flow straightening member 30 increases, thereby suppressing stagnation and promoting the joining of the fluids flowing through the first opening 33 and the second opening 36, thereby improving the flow straightening effect.

[0087] As described above in detail, according to the present invention, it is possible to provide a fluid sterilization device that has an excellent rectification effect, little leakage of ultraviolet light, and high irradiation efficiency and utilization efficiency of ultraviolet light, and therefore has excellent sterilization performance. [Explanation of symbols]

[0088] 10: Fluid sterilization device 11: Main body 12: Light source part 13:Inflow part 14: Outlet 21: Flow path pipe 22:Outer tube 24:Inlet 24A: Outlet end of inlet 25: Flow path 26: Outlet 30, 40, 60, 70: Straightening material 31: Rectifier plate 32, 62, 72: Cone section 32A: Cone body 32B, 62B: Wall part 33: First opening 34: Separation part 35: Recess (hollow part) 35B: Bottom surface (upper bottom surface) 36, 66, 76: Second opening 36T:Top surface 38: Blackout wall 45: Convex 50: Light source module 55: LED element

Claims

1. a flow pipe having a circular cross section; a straightening member provided at one end of the flow path pipe perpendicular to a central axis of the flow path pipe, the straightening member having a disk-shaped straightening plate and a conical portion provided perpendicular to the straightening plate; a light source module that is provided at the other end of the flow path pipe so as to face the rectifying member perpendicular to the central axis of the flow path pipe and that irradiates ultraviolet light toward the flow path of the fluid, the rectifying vane has a plurality of band-shaped first openings arranged along a circumference centered on the center of the rectifying vane, The conical portion is a bottom portion of the current plate is coupled to an inner side of the plurality of first openings; a truncated cone-shaped recess at the bottom, the truncated cone-shaped recess being coaxial with the central axis and penetrating the straightening plate; The fluid sterilization device has a plurality of second openings provided in a wall portion that is a side wall of the conical portion of the recess.

2. the number of the plurality of second openings and the number of the plurality of first openings are the same; The fluid sterilization apparatus according to claim 1 , wherein each of the second openings faces a corresponding one of a plurality of separation sections that separate the first openings.

3. the number of the plurality of second openings and the number of the plurality of first openings are the same; a center in the circumferential direction of each of the plurality of second openings is aligned with a center in the circumferential direction of each of a plurality of separation portions that separate each of the plurality of first openings; The fluid sterilization device according to claim 1 .

4. The fluid sterilization apparatus according to claim 2 , wherein each of the plurality of first openings has the same shape and size, and each of the plurality of second openings has the same shape and size.

5. The fluid sterilization apparatus according to claim 2 , wherein the plurality of first openings and the plurality of second openings are provided at positions rotationally symmetrical with respect to the central axis.

6. The fluid sterilization apparatus according to claim 2 , wherein the upper surface of each of the plurality of second openings is flush with the upper bottom surface of the truncated cone-shaped recess.

7. The fluid sterilization apparatus according to claim 2 , wherein each of the plurality of second openings is provided with a length and position such that the corresponding separation portion is included within the opening angle range of the second opening when viewed from above.

8. a cylindrical inlet through which a fluid flows, the inlet being coaxial with the truncated cone-shaped recess, The fluid sterilization apparatus according to claim 1 , wherein the diameter of the inlet is the same as or smaller than the diameter of an upper bottom surface of the truncated cone-shaped recess.

9. The fluid sterilization apparatus according to claim 2 , wherein each of the second openings is formed at a height such that the lower surface of the second opening does not reach the upper surface of the rectifying plate.

10. The fluid sterilization apparatus according to claim 1 , wherein each of the plurality of second openings is formed as an opening having an angle with respect to the radial direction in a plane perpendicular to the central axis of the conical portion.

11. The fluid sterilization apparatus according to claim 10, wherein each of the second openings faces each of the first openings.

12. The fluid sterilization apparatus according to claim 10, wherein each of the plurality of second openings is provided at a rotationally symmetrical position with respect to the central axis of the conical portion.

13. The fluid sterilization device according to any one of claims 1 to 12, further comprising a conical or truncated conical protrusion that is coaxial with the cone portion and protrudes from an upper bottom surface of the truncated cone-shaped recess.

14. The fluid sterilization apparatus according to any one of claims 1 to 12, wherein the conical portion is made of polytetrafluoroethylene (PTFE).

15. The fluid sterilization apparatus according to claim 13, wherein the conical portion is made of polytetrafluoroethylene (PTFE).

16. The fluid sterilization apparatus according to claim 1, wherein the flow path pipe is made of polytetrafluoroethylene (PTFE).

17. The fluid sterilization apparatus according to claim 1 , further comprising a turnout portion having a sidewall shape of a truncated cone that is coaxial with the inlet and whose cross-sectional area decreases toward the flow straightening member.

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