Fluid sterilization device

Abstract

The present invention comprises: an outer tube; a flow path tube that is held by the outer tube, defines a fluid flow path, and has a circular cross section perpendicular to the central axis; a light source module that has a disk-shaped translucent plate provided perpendicular to the axial direction of the flow path tube and a light source cover that accommodates the translucent plate, and that radiates ultraviolet light toward the fluid flow path via the translucent plate; a hollow part that holds the back surface part of the light source module and surrounds the light source module to provide a space in which a flow path is formed between the light source module and the hollow part; and an outflow port member having an outflow port that communicates with the hollow part. The light source cover has an annular front surface that covers the circumference of the translucent plate and is perpendicular to the axial direction, and a plurality of protrusions that are provided on the annular front surface and have a width that covers an annular part that is a part of the annular front surface from the inner circumferential part of the annular front surface to the outer circumferential part. The outflow port member and the outer tube are configured so as to press the light source module forward in the axial direction to bring the plurality of protrusions into contact with the end surface of the flow path tube.

Description

Fluid sterilization device

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

[0002] BACKGROUND ART Fluid sterilization devices are known that sterilize a liquid by flowing the liquid to be sterilized through a pipe and irradiating the liquid flowing through the pipe with ultraviolet light in the axial direction of the pipe.

[0003] For example, Patent Document 1 describes a fluid sterilization device that efficiently cools a light source using water to be sterilized, thereby suppressing a rise in temperature of the LED and suppressing a decrease in the output efficiency of the light source. In this device, multiple holes for passing water are provided around the light source, and the light source is cooled when a fluid passes around the light source.

[0004] Furthermore, Patent Document 2 describes a fluid sterilization device that can suppress temperature rise of a light source and increase ultraviolet irradiation efficiency. The device includes a first flow path pipe, a second flow path pipe for returning the fluid from the first flow path, and a plurality of communication holes arranged around the light source. The fluid flows through flow paths in a flange that supports the first and second flow path pipes.

[0005] JP 2018-008213 A JP 2018-140001 A

[0006] However, in fluid sterilizers such as those described in Patent Documents 1 and 2, the flow path is small, which makes it easy for air to accumulate in the light source, resulting in a decrease in sterilization efficiency. Furthermore, there is a problem that the pressure loss is large, which increases the pump output required to flow a large amount of water. Furthermore, in the fluid sterilizer described in Patent Document 2, the flow path is narrowed by a flange, which makes it easy for air and fluid to stagnate in the light source.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide a fluid sterilization device that prevents air and fluid from stagnating on the light source side.

[0008] The fluid sterilization device of the present invention comprises: an outer tube; a flow path tube held by the outer tube, defining a fluid flow path, and having a circular cross section perpendicular to the central axis; a light source module having a circular light-transmitting plate arranged perpendicular to the axial direction of the flow path tube and a light source cover accommodating the light-transmitting plate, and irradiating ultraviolet light toward the fluid flow path via the light-transmitting plate; and an outlet member holding a rear portion of the light source module and surrounding the light source module to provide a space for forming a flow path between the light source module and the light source module, the outlet member having an outlet communicating with the hollow portion, wherein the light source cover covers the periphery of the light-transmitting plate and has an annular front surface perpendicular to the axial direction and a plurality of protrusions arranged on the annular front surface with a width that covers a circular portion that is a part of the annular front surface from the inner peripheral portion to the outer peripheral portion of the annular front surface, and the outlet member and the outer tube are configured to press the light source module forward in the axial direction, causing the plurality of protrusions to abut against the end face of the flow path tube.

[0009] 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. FIG. 3 is a cross-sectional view showing an enlarged view of the light source unit and its surrounding area shown in FIG. 1. FIG. 4 is a cross-sectional view schematically showing the flow of fluid A1 in area W. FIG. 5 is a perspective view of the light source module. FIG. 6 is a side view of the light source module as seen from the lateral direction. FIG. 7 is a view showing a case where the light source cover has a plurality of protrusions that are detachable from the cover main body. FIG. 8 is a perspective view schematically showing a light source module of modified example 1 of this embodiment. FIG. 9 is a perspective view schematically showing a light source module of modified example 2 of this embodiment. FIG. 10 is a perspective view schematically showing a light source module of modified example 3 of this embodiment. FIG. 11 is a side view schematically showing a light source module of modified example 4 of this embodiment. FIG. 12 is a side view schematically showing a light source module of modified example 5 of this embodiment.

[0010] 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.

[0011] [First embodiment] Fig. 1 is a cross-sectional view showing a cross section passing through a central axis CZ of a fluid sterilization apparatus 10 according to a first embodiment. Fig. 1 also shows a Cartesian coordinate system.

[0012] 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 arranged vertically with the direction of the central axis CZ (z direction) facing upward, i.e., with the light source 12 at the top (vertical placement). The fluid sterilization device 10 is installed, for example, in a water storage tank of an ice maker or the like, a water supply pipe, a water heater, a water server, a circulation device (chiller cooling water), and a drink server. The sterilized water is usually used for drinking. Note that sterilization in a circulation device is performed to prevent the viscosity of the circulating water from increasing due to the proliferation of bacteria in the circulating water, resulting in power loss.

[0013] The inlet 13 is provided axially at one end of the main body 11. The outlet 14 has a central axis aligned with the central axis CZ of the main body 11 and is provided as a flow path through which the fluid flows out in the axial direction (z direction) via the light source 12.

[0014] The inlet 13 is provided with an inlet 15 for the fluid to be sterilized, and the outlet 14 is provided with a fluid outlet 26. The inlet 13 and the outlet 14 have threads (not shown) cut into their peripheries to connect to pipes (not shown) within the device in which the fluid sterilization device 10 is installed.

[0015] 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 simply referred to as the axial direction) with its central axis aligned with the central axis CZ of the main body unit 11.

[0016] 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. One axial end of the outer pipe 22 has an opening larger than the outer diameter of the flow path pipe 21, and the other end has an opening large enough that the flow path pipe 21 cannot pass through.

[0017] The flow path pipe 21 is inserted into the outer pipe 22 from the opening on the light source unit 12 side of the outer pipe 22, and is housed inside the outer pipe 22. Water-stopping O-rings 30a, 30b are fitted into triangular grooves formed on 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.

[0018] A circular plate-shaped rectifying plate 31 is provided on the inlet portion 13 side of the flow path pipe 21 to close the end of the flow path pipe 21. The rectifying plate 31 is provided perpendicular to the central axis CZ and has a plurality of rectifying holes 31a uniformly distributed within its surface. The fluid A1 flowing in from the inlet portion 13 is rectified by the rectifying plate 31 and flows parallel to the central axis CZ. The fluid A1 then flows toward the light source unit 12 provided on the outlet portion 14 side.

[0019] Examples of materials for the components of the fluid sterilization device 10 include, but are not limited to, the following: The flow path pipe 21 is made of a resin material such as polytetrafluoroethylene (PTFE). The outer pipe 22 is made of a metal material such as stainless steel (e.g., SUS304). The light source cover 52 is made of a resin material such as polypropylene (PP). In the following example, quartz glass is used as the light-transmitting plate 53.

[0020] (1) Light Source Section Fig. 2A is an enlarged cross-sectional view of the light source section 12 and its surrounding region W shown in Fig. 1. Fig. 2B is a cross-sectional view schematically showing the flow (arrows) of fluid A1 in region W shown in Fig. 1.

[0021] The light source section 12 has a light source module 50. The light source module 50 is provided at the other end of the flow path pipe 21 so that its central axis is coaxial with the central axis CZ.

[0022] The light source module 50 includes a light source base 51 , a light source cover 52 , quartz glass 53 (light-transmitting plate), a light source substrate 54 , at least one LED element 55 , and a reflector 56 .

[0023] 2A and 1 , the outlet member 17 has a light source holding portion 17B that holds the rear portion of the light source module 50 and fixes the light source module 50. The outlet member 17 also has a cylindrical housing portion 17A that surrounds the light source module 50. The housing portion 17A has a threaded portion on its inner surface, and is fastened to a threaded portion on the outer pipe 22 by rotation (screw fastening portion 32). A watertight O-ring 33 provided between the housing portion 17A and the outer pipe 22 seals the gap between the housing portion 17A and the outer pipe 22.

[0024] The light source cover 52 of the light source module 50 has an overall disk shape that is coaxial with the central axis CZ of the flow path pipe 21. As shown in Fig. 2A, the housing 17A has a hollow portion 17H that surrounds the entire light source module 50 and provides a space where a flow path is formed between the light source module 50 and the housing 17A.

[0025] More specifically, hollow portion 17H of housing portion 17A is coaxial with central axis CZ, and provides a space in which flow path 12C having an annular cross section (a cross section perpendicular to central axis CZ) is formed between hollow portion 17H and the cylindrical side surface of light source cover 52. Hollow portion 17H also provides a space in which flow path 12R communicating with flow path 12C is formed on the back surface of light source module 50. Hollow portion 17H communicates with outlet 26, and sterilized fluid A2 flows out from outlet 26.

[0026] Therefore, the fluid A1 flows through the flow path 12L on the front surface of the light source module 50, the flow path 12C on the side surface, and the flow path 12R on the rear surface of the light source module 50, and then flows out of the flow outlet 26 (see FIG. 2B). The flow outlet 26 has a cylindrical shape coaxial with the central axis CZ.

[0027] In the light source module 50, a waterproof O-ring 59 is provided between the light source base 51 and the quartz glass 53. Therefore, a sealed storage space is formed between the light source base 51 and the quartz glass 53 by fastening the light source base 51 and the light source cover 52 together using threaded portions 58 provided on the light source base 51 and the light source cover 52.

[0028] At least one LED element 55 (light-emitting element) mounted on a light source substrate 54 is provided within the accommodation space of the light source module 50. Light emitted from the LED element 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.

[0029] 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.

[0030] Fig. 3A is a perspective view of the light source module 50, and Fig. 3B is a side view of the light source module 50 when viewed from the side direction A shown in Fig. 3A. The light source module 50 has a disk-shaped quartz glass 53 coaxial with the central axis CZ of the flow path pipe 21, and a light source cover 52 that houses the quartz glass 53. The light source cover 52 has an annular front surface 52S that surrounds the periphery of the quartz glass 53.

[0031] The front surface 52S of the light source cover 52 is formed as a flat surface, and the front surface 52S of the light source cover 52 and the front surface 53S of the quartz glass 53 are configured to be flush with each other.

[0032] In this specification, the "front surface" and "forward surface" of the light source module or light source cover refer to the surface from which the irradiated light (ultraviolet light) is emitted from the light source module and the irradiation direction of the irradiated light (-z direction).

[0033] In addition, the term "annular" in this specification includes not only a case where the front surface has a flat annular shape, but also a case where the front surface has an annular shape when viewed from the axial direction, such as a case where the front surface has a side surface shape of a truncated cone, or a case where the front surface is composed of multiple coaxial annular flat or curved surfaces.

[0034] A plurality of protrusions 61 are provided on the front surface 52S of the light source cover 52 of the light source module 50. The protrusions 61 protrude from the front surface 52S and have a footprint (installation surface) having a width that covers a part of the annular portion of the front surface 52S from the inner periphery to the outer periphery of the annular front surface 52S.

[0035] Although the protrusion 61 is shown to have a shape that radially widens from the inner periphery toward the outer periphery, it may have a shape that decreases in width toward the outer periphery, or may have a constant width.

[0036] The plurality of protrusions 61 have the same shape and size. Preferably, the protrusions 61 have a smooth surface whose height gradually increases from the inner periphery toward the outer periphery, and a flat top surface 61S at the top that is parallel to the front surface 53S of the quartz glass 53.

[0037] Furthermore, a claw 61T is provided at the tip of the inner periphery of the protrusion 61, which presses the quartz glass 53 and prevents the quartz glass 53 from falling off. An inclined surface is provided so that the height increases from the tip of the protrusion 61 toward the top surface 61S.

[0038] The light source module 50 is fixed such that the top surfaces 61S of the protrusions 61 abut against the annular end surface 21E of the flow path pipe 21. Therefore, the space between the protrusions 61, which is between the end surface 21E of the flow path pipe 21 and the front surface 52S of the light source cover 52, is defined as the flow path 12L.

[0039] It is preferable that the protrusion 61 abuts against the end surface 21E of the flow path pipe 21 over the entire width. More specifically, as shown in Fig. 3A, the top surface 61S of the protrusion 61 is a band-like flat surface extending from one side surface 61J of the protrusion 61 to the other side surface 61K opposite to the side surface 61J, and is preferably formed as a flat surface along an arc centered at the center (i.e., center O) of the annular front surface 52S. Furthermore, as shown in Fig. 3B, it is preferable that the outer surface of the protrusion 61 in the outer circumferential direction be formed to be flush with the outer surface of the light source cover 52 in order to prevent retention.

[0040] 2B, the flow of fluid A1 will be described. Fluid A1 flowing through flow path 25 in flow path pipe 21 hits the front surface of light source module 50, i.e., front surface 53S of quartz glass 53 and front surface 52S of light source cover 52, and then flows laterally (in a direction parallel to front surfaces 53S and 52S) over front surface 53S of quartz glass 53 and front surface 52S of light source cover 52.

[0041] More specifically, the fluid A1 flows laterally through the space between the protrusions 61, that is, the space between the end face 21E of the flow path pipe 21 and the front face 52S of the light source cover 52, as flow path 12L, and then flows through the hollow portion 17H on the side and back of the light source module 50 as flow paths 12C and 12R, to the outlet 26.

[0042] It is preferable that the plurality of protrusions 61 are provided at rotationally symmetric positions about the center O of the quartz glass 53, that is, the center of the annular front surface 52S, in terms of ensuring a uniform flow of the fluid A1 and preventing stagnation.

[0043] In this embodiment, the front surface 53S of the quartz glass 53 and the front surface 52S of the light source cover 52 are flush with each other, which prevents air and fluid from stagnating. Furthermore, the flow velocity increases in the flow path between the protrusions 61, making it difficult for air and fluid to stagnate. Furthermore, the protrusions 61 reduce the proportion of obstructions to the fluid in the flow path, which is a cause of stagnation, and the inclined front surface of the protrusions 61 provides little resistance to the fluid, making it difficult for stagnation to occur.

[0044] Although the above description has been given of the case where the multiple protrusions 61 are integrally formed with the cover main body 52A, this is not limiting. As shown in Fig. 3C , the light source cover 52 may be composed of the cover main body 52A and multiple protrusions 61 that are detachable from the cover main body 52A. The light source cover 52 may be configured by selecting or combining the number, size (footprint), shape, etc. of the multiple protrusions 61 as appropriate depending on the flow rate and flow velocity of the fluid A1.

[0045] Furthermore, although the case where the front surface 52S of the light source cover 52 and the front surface 53S of the quartz glass 53 are flush with each other has been described, this is not limiting. The front surface 52S of the light source cover 52 may be a surface that is set back from the front surface 53S of the quartz glass 53 toward the rear of the light source module 50 (rear, in the +z direction). In other words, the front surface 53S of the quartz glass 53 may be configured to protrude forward more than the front surface 52S of the light source cover 52.

[0046] As a non-limiting example of the size of the light source module 50, the outer diameter of the quartz glass 53 is 20 mm, the inner diameter of the quartz glass 53 housing is 22 mm, and the outer diameter of the light source cover 52 is 36 mm. In this case, for example, by reducing the thickness of the periphery of the quartz glass 53 of the light source cover 52 by approximately 0 to 5 mm and ensuring that the front surface 52S of the light source cover 52 does not protrude (is slightly recessed) from the front surface 53S of the quartz glass 53 in the direction of the flow path pipe 21, it is possible to prevent the accumulation of air and fluid.

[0047] 1 and 2A again, the outlet member 17 has an outlet 26 (outlet) and is fixed to the outlet housing 18. In addition, the light source base 51 on the back of the light source module 50 is connected to and fixed to the outlet member 17.

[0048] The housing 17A of the outlet member 17 is screwed to the outer pipe 22 by threads formed on the inner wall of the housing 17A and the outer wall end of the outer pipe 22 (screw fastening portion 32). A watertight O-ring 33 seals water between the housing 17A and the outer pipe 22.

[0049] Therefore, by screwing the housing part 17A and the outer tube 22 together, the light source module 50 advances in the axial direction and is pressed by the housing part 17A, and the light source module 50 is sandwiched between the outlet member 17 and the flow path pipe 21, so that it is securely held. More specifically, by screwing the housing part 17A and the outer tube 22 together, the flat top surface 61S of the protrusion 61 of the light source module 50 abuts against the end surface 21E of the flow path pipe 21. Therefore, the light source module 50 is securely held, and the flow path 12L between the protrusions 61 is defined.

[0050] The end of the flow path pipe 21 on the inlet portion 13 side abuts against the inlet portion 13 and is held there, restricting movement of the flow path pipe 21 toward the inlet portion 13, so that the top of the protrusion 61 is reliably pressed against the end surface 21E of the flow path pipe 21. Alternatively, the flow path pipe 21 may be fixed to the outer pipe 22.

[0051] Therefore, with this configuration, the space between the end surface 21E of the flow path pipe 21 and the front surface 52S of the light source cover 52, and between the protrusions 61, functions as a flow path 12L (see FIG. 2B).

[0052] Furthermore, by ensuring the flow path 12L, water cooling of the light source module 50 can be effectively performed. Furthermore, since the outlet member 17 and the outer pipe 22 are fastened by screws, loosening and detachment of the watertight O-ring can be prevented. Furthermore, dimensional tolerances of the components can be accommodated, and the light source module 50 can be reliably held and fixed.

[0053] 4 is a perspective view schematically showing a light source module 70 according to Modification 1 of the present embodiment. For clarity of the drawing, the quartz glass 53 (light-transmitting plate) is shown hatched.

[0054] In the light source module 70 of the first modified example, an inclined surface is provided on the front surface 72S of the light source cover 72. More specifically, the front surface 72S has a flat, annular inner peripheral surface 72S1 that is parallel to the front surface 53S of the quartz glass 53, and an outer peripheral surface 72S2 that is inclined and recessed from the outer peripheral edge of the inner peripheral surface 72S1 toward the back surface of the light source module 70 (rearward).

[0055] Note that, similar to the front surface 52S of the light source cover 52 in the above-described embodiment, the inner peripheral surface 72S1 is flush with the front surface 53S of the quartz glass 53 or is a surface that is set back further rearward than the front surface 53S of the quartz glass 53. Furthermore, the inclined outer peripheral surface 72S2 is not limited to being inclined linearly, and may also be a curved inclined surface (i.e., a conical surface).

[0056] According to the light source module 70 of this modified example 1, the pressure loss when the fluid A1 flows laterally through the flow path 12L between the end face 21E of the flow path pipe 21 and the front face 72S of the light source cover 72 is reduced, and stagnation of air and fluid can be more effectively suppressed.

[0057] 5 is a perspective view schematically showing a light source module 80 according to a second modified example of the present embodiment. In the light source module 80 according to the second modified example, a step 83 is provided on a front surface 82S of a light source cover 82.

[0058] More specifically, the front surface 82S has a flat, annular inner surface 82S1 parallel to the front surface 53S of the quartz glass 53, a step 83 recessed rearward from the outer edge of the inner surface 82S1, and an annular outer surface 82S2 connected to the lower end of the step 83.

[0059] The inner surface 82S1 is either flush with the front surface 53S of the quartz glass 53 or is a surface that is set back from the front surface 53S of the quartz glass 53 toward the rear surface of the light source module 80, similar to the front surface 52S of the light source cover 52 in the above-mentioned embodiment.

[0060] Furthermore, the inner peripheral surface 82S1 and / or the outer peripheral surface 82S2 are not limited to being flat surfaces parallel to the front surface 53S of the quartz glass 53, but may be surfaces inclined backward. Furthermore, the inner peripheral surface 82S1 and / or the outer peripheral surface 82S2 may be curvedly inclined conical surfaces.

[0061] According to the light source module 80 of this modified example 2, the pressure loss when the fluid A1 flows through the flow path 12L between the end face 21E of the flow path pipe 21 and the front face 72S of the light source cover 72 is reduced, and the stagnation of air and fluid can be more effectively suppressed.

[0062] 6 is a perspective view schematically illustrating a light source module 90 according to a third modification of the present embodiment. In the light source module 90 according to the third modification, a protrusion 91 consisting of a pair of protrusion pieces is provided on a front surface 92S of a light source cover 92.

[0063] More specifically, a plurality of protrusions 91 are provided on the front surface 92S of the light source cover 92, and each of the protrusions 91 consists of a pair of protrusion pieces 91A and 91B spaced apart from each other by a slit 93 (gap) extending from the inner periphery to the outer periphery of the protrusion 91.

[0064] According to the light source module 90 of this modified example 3, the slit 93 serves as a flow path for the fluid A1, thereby increasing the flow path for the fluid A1 and suppressing stagnation near the outer surface of the protrusion 91, thereby more effectively suppressing stagnation of air and fluid.

[0065] 7 is a side view schematically illustrating a light source module 100 according to a fourth modification of the present embodiment. The light source module 100 according to the fourth modification has a quartz glass plate 103 (light-transmitting plate) having a convex front surface.

[0066] More specifically, the quartz glass 103 has a convex curved front surface 103S. The entire front surface 103S protrudes further toward the flow path pipe 21 than the front surface 52S of the light source cover 52.

[0067] According to the light source module 100 of the fourth modified example, the fluid A1 that strikes the front surface 103S of the quartz glass 103 flows smoothly along the front surface 103S, so that stagnation of air and fluid can be more effectively suppressed.

[0068] (5) Modification 5 Fig. 8 is a side view schematically illustrating a light source module 110 according to Modification 5 of the present embodiment. The light source module 110 according to Modification 5 has a convex quartz glass plate 113 (light-transmitting plate) having an inclined front surface.

[0069] More specifically, the quartz glass 113 has a convex front surface 113S. The quartz glass 113 has an inner peripheral surface 113T that is a flat surface parallel to the front surface 52S of the light source cover 52, and an outer peripheral surface 113U that is linearly inclined and recedes from the outer periphery of the inner peripheral surface 113T toward the back surface (rear) of the light source module 110.

[0070] According to the light source module 110 of this modified example 5, the fluid A1 that hits the inner surface 113T of the quartz glass 113 flows smoothly along the outer surface 113U, thereby more effectively suppressing the stagnation of air and fluid.

[0071] (6) Other Modifications The above-described embodiment and modifications 1 to 5 may be combined or modified as appropriate within the scope of the present invention. For example, the light-transmitting plate of modification 4 or 5 may be applied to any of the light source modules of modifications 1 to 3. In this case, the front surface of the light source cover may be set back from the outer peripheral edge of the convex-shaped light-transmitting plate toward the back surface of the light source module.

[0072] As described above in detail, according to the present invention, it is possible to provide a fluid sterilization device in which air and fluid are prevented from stagnating on the light source side.

[0073] DESCRIPTION OF SYMBOLS 10: Fluid sterilization device 11: Main body 12: Light source 12C, 12L, 12R: Flow path 13: Inlet 14: Outlet 15: Inlet port 17: Outlet member 17A: Housing 17B: Light source holder 17H: Hollow portion 18: Outlet housing 21: Flow path pipe 21E: End surface 22: Outer pipe 25: Flow path 26: Outlet 32: Screw fastening portion 50, 70, 80, 90, 100, 110: Light source module 51: Light source base 52: Light source cover 52A: Cover main body 52S: Front surface 53: Light-transmitting plate 53S: Front surface 55: LED element 58: Screw portion 61: Protrusion 61J, 61K: Side surface 61S: Top surface

Claims

1. A fluid sterilization device comprising: an outer tube; a flow path tube held by the outer tube, defining a fluid flow path and having a circular cross section perpendicular to its central axis; a light source module having a circular light-transmitting plate arranged perpendicular to the axial direction of the flow path tube and a light source cover accommodating the light-transmitting plate, and irradiating ultraviolet light toward the fluid flow path via the light-transmitting plate; and an outflow outlet member holding a rear portion of the light source module and having a hollow portion surrounding the light source module to provide a space for forming a flow path between the light source module and the light source module, and having an outflow outlet communicating with the hollow portion, wherein the light source cover covers the periphery of the light-transmitting plate and has an annular front surface perpendicular to the axial direction, and a plurality of protrusions arranged on the annular front surface with a width sufficient to cover a circular portion that is part of the annular front surface from the inner periphery to the outer periphery of the annular front surface, and the outflow outlet member and the outer tube are configured to press the light source module forward in the axial direction, causing the plurality of protrusions to abut against an end face of the flow path tube.

2. A fluid sterilization device as described in claim 1, wherein the front surface of the light-transmitting plate is a flat surface, and the annular front surface of the light source cover is a flat surface that is flush with the front surface of the light-transmitting plate, or a flat surface that is recessed further back than the front surface of the light-transmitting plate toward the rear of the light source module.

3. The fluid sterilization device according to claim 1, wherein the plurality of protrusions have the same shape and size.

4. The fluid sterilization device according to claim 1, wherein the plurality of protrusions are provided at positions rotationally symmetrical with respect to the center of the annular front surface.

5. A fluid sterilization device according to claim 1, wherein the protrusion has a flat top surface that abuts against the end surface of the flow path pipe.

6. A fluid sterilization device as described in any one of claims 1 to 5, wherein the top surface of the protrusion is strip-shaped extending from one side of the protrusion to the other side opposite the one side, and is a flat surface along an arc centered on the center of the annular front surface.

7. A fluid sterilization device according to claim 1, wherein the outlet member and the outer tube have screw fastening portions that screw together to press the light source module forward in the axial direction.

8. A fluid sterilization device as described in claim 1, wherein the front surface of the light-transmitting plate is a flat surface, and the annular front surface of the light source cover has a flat annular inner surface parallel to the front surface of the light-transmitting plate, and an outer surface inclined rearward from the outer peripheral edge of the inner surface.

9. A fluid sterilization device as described in claim 1, wherein the front surface of the light-transmitting plate is a flat surface, and the annular front surface of the light source cover has a flat annular inner surface parallel to the front surface of the light-transmitting plate, a step recessed from the outer peripheral edge of the inner surface toward the back surface of the light source module, and an annular outer peripheral surface connected to the lower end of the step.

10. A fluid sterilization device as described in claim 1, wherein said protrusion comprises a pair of protrusion pieces spaced apart from each other by a gap extending from the inner periphery to the outer periphery of said protrusion.

11. The fluid sterilization device according to claim 1, wherein the light-transmitting plate has a convex front surface.

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