Fluid sterilization device

Abstract

In a fluid sterilization device 1, fluid in an irradiation flow path part (10) is sterilized through irradiation with UV light. The irradiation flow path part (10) includes: an outer tube (12) formed from a rigid body; and a resin inner tube (14) disposed inside the outer tube (12). When a primary-side housing and a secondary-side housing in the irradiation flow path part (10) are defined as a first housing (21) and a second housing (22), respectively, the inner tube (14) is water-tightly fixed only to the second housing (22) via an elastic member (50).

Description

Fluid sterilization device

[0001] The present invention relates to a fluid sterilization device. This application claims priority based on Japanese Patent Application No. 2024-195584 filed in Japan on November 8, 2024, and incorporates its content herein by reference.

[0002] Technologies for sterilizing fluids using the sterilizing power of UV light are known. Patent Document 1 describes a fluid sterilization device that irradiates a fluid flowing through an irradiation channel with UV light to sterilize the fluid.

[0003] Japanese Patent No. 6458779

[0004] When irradiating a fluid in an irradiation channel with UV light to sterilize the fluid, in order to enhance the sterilization efficiency, a resin with a high reflectivity may be used for the material of the member constituting the inner surface of the irradiation channel. In Patent Document 1, polytetrafluoroethylene is used as the resin with a high reflectivity.

[0005] By the way, in cases such as performing hot water sterilization, the fluid in the irradiation channel may reach a high temperature. Therefore, when the material of the member constituting the inner surface of the irradiation channel is resin, creep deformation may occur in the member.

[0006] Therefore, an object of the present invention is to provide a fluid sterilization device in which deformation such as creep deformation is unlikely to occur in the member constituting the inner surface of the irradiation channel.

[0007] The fluid sterilization device of the present invention includes two opposing housings and a cylindrical irradiation channel portion located between the two housings. The fluid in the irradiation channel portion is sterilized by being irradiated with UV light. The irradiation channel portion includes an outer tube formed of a rigid body and an inner tube made of resin disposed inside the outer tube. When the housing on the primary side in the irradiation channel portion is defined as the first housing and the housing on the secondary side is defined as the second housing, the inner tube is watertightly fixed only to the second housing via an elastic member.

[0008] According to the present invention, it is possible to provide a fluid sterilization device in which deformation such as creep deformation is unlikely to occur in the member constituting the inner surface of the irradiation channel.

[0009] Figure 1 is a perspective view showing an example of the external appearance of a fluid sterilization apparatus according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the irradiation channel section according to an embodiment of the present invention. Figure 3 is a cross-sectional view of the irradiation channel section according to an embodiment of the present invention, showing an enlarged view of the fixed portion.

[0010] (Fluid Sterilization Device) Embodiments for carrying out the invention will be described with reference to the drawings. Figure 1 is a perspective view showing an example of the external appearance of the fluid sterilization device 1 according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the irradiation channel section 10, etc. The fluid sterilization device 1 is a device for sterilizing fluids. The fluid sterilization device 1 sterilizes fluids by irradiating them with UV light.

[0011] As shown in Figure 1, the fluid sterilization device 1 comprises two housings and an irradiation channel section 10. One of the two housings is called the first housing 21, and the other is called the second housing 22. The first housing 21 and the second housing 22 are located opposite each other. The irradiation channel section 10 is located between the first housing 21 and the second housing 22.

[0012] The fluid sterilization device 1 further includes a UV light source. The UV light source is not shown. The UV light source irradiates the fluid with UV light. The UV light source is located inside, for example, at least one of the first housing 21 and the second housing 22.

[0013] (Irradiation channel section) The irradiation channel section 10 is the part inside which the fluid is sterilized. The shape of the irradiation channel section 10 is cylindrical. As shown in Figure 2, the irradiation channel section 10 comprises an outer tube 12 and an inner tube 14.

[0014] (Outer tube) The outer tube 12 is a component that defines the outer shape of the irradiation flow path section 10. The outer tube 12 has a round tube shape. The outer tube 12 is made of a rigid body. Examples of rigid bodies include metal, ceramic, and carbon resin.

[0015] By forming the outer tube 12 from a rigid body, the pressure resistance of the irradiation channel section 10 can be improved. Furthermore, when the rigid body shields the UV light, leakage of UV light to the outside of the irradiation channel section 10 can be suppressed.

[0016] (Inner tube) The inner tube 14 is a tube located inside the outer tube 12. The shape of the inner tube 14 is round. The inner tube 14 is made of resin. There is a gap 40 between the outer tube 12 and the inner tube 14.

[0017] If the resin forming the inner tube 14 transmits UV light, the fluid in the gap 40 between the outer tube 12 and the inner tube 14 can be sterilized. To more efficiently sterilize the fluid in the gap 40 with UV light transmitted through the inner tube 14, the thickness of the inner tube 14 may be adjusted. In order to ensure UV light transmission while maintaining strength, the thickness of the inner tube 14 is preferably 1 mm to 10 mm, and more preferably 3 mm to 5 mm.

[0018] An example of a resin used to form the inner tube 14 is fluororesin.

[0019] Fluorine materials are generally resistant to contamination. By forming the inner tube 14 from a fluorine material, the adhesion of contaminants to the inner tube 14 can be suppressed.

[0020] Fluorine materials are generally resistant to corrosion. By forming the inner tube 14 from a fluorine material, the inner tube 14 can be easily cleaned using various chemicals without having to worry about corrosion of the inner tube 14.

[0021] An example of a fluoropolymer is PTFE (Polytetrafluoroethylene).

[0022] PTFE is a material that reflects UV light with high reflectivity. By forming the inner tube 14 with PTFE, the sterilization efficiency of the fluid inside the inner tube 14 can be increased.

[0023] In Figure 1, arrow 100 indicates the vertical direction. Arrow 200 indicates the direction in which the irradiation channel section 10 extends. The direction of arrow 200 is called the irradiation channel direction 200. The irradiation channel direction 200 is approximately parallel to the vertical direction 100. In other words, the fluid sterilization device 1 is installed so that the irradiation channel direction 200 is approximately parallel to the vertical direction 100.

[0024] (Housing) In Figure 1, arrow 101 indicates a downward vertical direction. Arrow 102 indicates an upward vertical direction. The first housing 21 is a housing located vertically below the irradiation flow path section 10. The second housing 22 is a housing located vertically above the irradiation flow path section 10.

[0025] The first housing 21 closes the lower end of the irradiation channel section 10. The second housing 22 closes the upper end of the irradiation channel section 10. As shown in Figure 1, the first housing 21 is provided with a fluid inlet 31. The second housing 22 is provided with a fluid outlet 32. Arrows 301, 302, and 303 in Figure 1 indicate the direction of fluid flow. The fluid flows into the fluid sterilization device 1 from the inlet 31 as indicated by arrow 301. In this embodiment, the fluid flows in from the inlet 31 in a direction that intersects (perpendicular to) the fluid flow direction in the flow channel irradiation section 10. The fluid flows vertically upward 102 through the irradiation channel section 10 as indicated by arrow 303. The fluid sterilized in the irradiation channel section 10 flows out of the fluid sterilization device 1 from the outlet 32 ​​as indicated by arrow 302. In this embodiment, the fluid flows out from the outlet 32 ​​in a direction that intersects (perpendicular to) the fluid flow direction in the flow channel irradiation section 10.

[0026] The orientation and number of inlets and outlets are not limited to the example shown in Figure 1. The orientation and number of inlets and outlets can be changed.

[0027] (Elastic Member) The fixing of the inner tube 14 to the housing will now be explained. The inner tube 14 is fixed to the second housing 22 only in a watertight manner via the elastic member 50. The framed area 201 in Figure 2 shows the part in which the inner tube 14 is fixed to the second housing 22. The part indicated by the framed area 201 is called the fixing part 201. In the fixing part 201, it is sufficient that the inner tube 14 is fixed to the second housing 22 in a watertight manner at least at one location. The fixing part 201 may be provided with parts for purposes other than fixing the inner tube 14 to the second housing 22. Also, it is sufficient that the inner tube 14 is fixed to the second housing 22 in a watertight manner, and members other than the elastic member 50 may be placed between the inner tube 14 and the second housing 22.

[0028] In the fixing portion 201, the inner tube 14 is in contact with the second housing 22 via the elastic member 50. Figure 2 shows the case where the elastic member 50 is a rubber O-ring. As shown in Figure 2, the O-ring 50 is attached to the outer circumference of the upper end of the inner tube 14. The inner tube 14 is fixed to the second housing 22 in a watertight manner by being tightened to the second housing 22 via the elastic member 50.

[0029] When the elastic member 50 is an O-ring, it becomes easier to control the degree of tightening of the second housing 22 to the inner tube 14 compared to when the elastic member 50 is a flat packing. However, the elastic member 50 is not limited to being an O-ring.

[0030] The inner tube 14 and the second housing 22 are fixed in a watertight manner, so that even if fluid enters the gap 40, it is possible to prevent unsterilized fluid from flowing to the secondary side of the fluid sterilization device 1. This is because the end 42 of the gap 40 on the second housing 22 side is sealed in a watertight manner with the elastic member 50 to the interior 26 of the second housing 22.

[0031] Refer to Figure 3 for a more detailed explanation. Figure 3 is a cross-sectional view of the irradiation channel section 10 and the like, showing an enlarged view of the fixed section 201. Arrows A1 and A2 in Figure 3 indicate the fluid intrusion paths. Intrusion path A1 is the intrusion path that travels through the gap 40 from the primary side of the fluid sterilization device 1. Intrusion path A2 is the intrusion path from the inside 26 of the second housing 22. In the fluid sterilization device 1 of this embodiment, the inner pipe 14 and the second housing 22 are fixed in a watertight manner by the elastic member 50, so both intrusion paths A1 and A2 end at the elastic member 50.

[0032] The fluid that flows into the void 40 from the entry path A1 is unsterilized fluid. In the fluid sterilization device 1 of this embodiment, the entry path A1 ends at the elastic member 50. Therefore, it is possible to suppress the flow of unsterilized fluid to the secondary side of the fluid sterilization device 1.

[0033] On the other hand, the inner tube 14 and the first housing 21 are not fixed in a watertight manner, as shown in Figure 2. This is because there is no elastic member 50 between the inner tube 14 and the first housing 21. In other words, no fixing portion 201 is formed between the inner tube 14 and the first housing 21, unlike the fixing portion 201 between the inner tube 14 and the second housing 22.

[0034] Therefore, the end 44 of the void 40 on the first housing 21 side is connected to the interior 24 of the first housing 21, and consequently to the interior 60 of the irradiation flow path section 10. The fluid in the void 40 can be discharged from the end 44.

[0035] Furthermore, since the inner tube 14 and the first housing 21 are not fixed in a watertight manner, and the gap 40 is connected to the interior 24 of the first housing 21 or the interior 60 of the irradiation channel section 10, the difference between the water pressure in the gap 40 and the water pressure inside the irradiation channel section 10 can be reduced. In other words, the difference between the water pressure between the inner tube 14 and the outer tube 12 and the water pressure inside the inner tube 14 can be reduced. This means that large pressures are suppressed from being applied to the inner tube 14 from either the inside or outside of the inner tube 14.

[0036] The plastic deformation that occurs when stress is continuously applied to an object is called creep deformation. In the fluid sterilization device 1 of this embodiment, creep deformation in the inner pipe 14 can be suppressed because the pressure applied to the inner pipe 14 can be reduced.

[0037] (Thick-walled section) The inner tube 14 has a thick-walled section 16 that is thicker than the rest of the inner tube 14. The length D14 shown in Figure 2 indicates the thickness of the inner tube 14 excluding the fixing section 201. The length D16 indicates the thickness of the inner tube 14 at the fixing section 201. Length D16 is longer than length D14. The thick-walled section 16 is formed on the upper end side of the inner tube 14, and the O-ring 50 is attached to this thick-walled section 16.

[0038] By making the length D16 longer than the length D14, deformation of the inner tube 14 can be suppressed even when the inner tube 14 is tightened to the second housing 22 in order to fix the inner tube 14 to the second housing 22.

[0039] The length D16 / length D14 can be between 1.0 and 3.0.

[0040] (Housing recess) As shown in Figure 3, a recess 80 is formed in the second housing 22 at a position corresponding to the fixing portion 201. The recess 80 is formed on the inner surface 72 of the second housing 22 at a position facing the outer surface 74 of the inner tube 14. The elastic member 50 is placed inside the recess 80.

[0041] It is preferable that the size of the recess 80 is such that most of the elastic member 50 can enter the recess 80. By forming the recess 80, even when the elastic member 50 is disposed between the second housing 22 and the inner tube 14, it is possible to suppress the occurrence of excessive play between the second housing 22 and the irradiation flow path portion 10.

[0042] (Installation direction of the fluid sterilization device) The fluid sterilization device 1 of the present embodiment is installed such that the irradiation flow path direction 200 is substantially parallel to the vertical direction 100. At the time of installation, the first housing 21 is positioned below the vertical direction 100, and the second housing 22 is positioned above the vertical direction 100. And the inner tube 14 and the first housing 21 are not fixed in a watertight manner.

[0043] Therefore, in the fluid sterilization device 1 of the present embodiment, even when fluid intrudes into the gap 40 between the outer tube 12 and the inner tube 14, the fluid is easily discharged from the end portion 44 on the first housing 21 side of the gap 40. That is, it is possible to suppress the fluid from remaining in the gap 40.

[0044] (Fixing of the outer tube to the housing) The outer tube 12 can be fixed to the first housing 21 and the second housing 22 in the same form as the inner tube 14. Specifically, as shown in FIG. 2, the outer tube 12 is fixed to the first housing 21 via an elastic member 52. A recess 82 having a shape corresponding to the shape of the elastic member 52 is formed in the first housing 21. The fixing of the outer tube 12 to the second housing 22 can be performed in the same manner as the fixing of the outer tube 12 to the first housing 21. The outer tube 12 is fixed to the second housing 22 via an elastic member 54. A recess 84 having a shape corresponding to the shape of the elastic member 54 is formed in the second housing 22.

[0045] As described above, the embodiments of the present invention have been described. The present invention is not limited to the above-described embodiments, and various modifications, variations, and combinations are possible.

[0046] For example, as a modification of the fluid sterilization device 1, a modification example of changing the position of the elastic member 50 used when fixing the inner pipe 14 to the second housing 22 can be considered. In the embodiment described above, the elastic member 50 was located between the outer surface 74 of the inner pipe 14 and the inner surface 72 side of the second housing 22. The elastic member 50 may be disposed between the end portion on the second housing 22 side in the irradiation flow path direction 200 of the inner pipe 14 (the portion indicated by the arrow 501 in FIG. 2) and the second housing 22 (the portion indicated by the arrow 502 in FIG. 2). Also by this, it is possible to suppress the fluid in the gap 40 from flowing out to the secondary side of the fluid sterilization device 1.

[0047] <1>A fluid sterilization device comprising: two opposed housings; and a cylindrical irradiation flow path portion located between the two housings, wherein the fluid in the irradiation flow path portion is sterilized by being irradiated with UV light, the irradiation flow path portion includes an outer pipe formed of a rigid body and a resin inner pipe disposed inside the outer pipe, and when the housing on the primary side in the irradiation flow path portion is defined as the first housing and the housing on the secondary side is defined as the second housing, the inner pipe is fixed in a watertight manner only to the second housing via an elastic member.

[0048] According to such a configuration, even when fluid intrudes between the outer pipe and the inner pipe, it is possible to suppress the fluid from flowing to the secondary side in a non-sterilized state.

[0049] <2>The fluid sterilization device according to <1>, wherein there is a gap between the outer pipe and the inner pipe that communicates with the inside of the irradiation flow path portion.

[0050] According to such a configuration, the difference between the pressure inside the inner pipe and the pressure between the inner pipe and the outer pipe can be reduced. Therefore, it is possible to suppress the occurrence of creep deformation in the inner pipe.

[0051] <3>The fluid sterilization device according to <1> or <2>, wherein a thick portion having a greater thickness than other portions of the inner pipe is formed in the inner pipe, and the inner pipe is fixed to the second housing at the thick portion.

[0052] (Effect) According to such a configuration, it is possible to suppress the deformation of the inner pipe due to tightening for fixing.

[0053] <4> The fluid sterilization apparatus according to any one of <1> to <3>, wherein the first housing is located on the lower side in the vertical direction and the second housing is located on the upper side in the vertical direction.

[0054] With this configuration, even if fluid enters the space between the outer and inner tubes, the fluid can be easily discharged.

[0055] <5> The fluid sterilization apparatus according to any one of <1> to <4>, wherein the elastic member is an O-ring.

[0056] When the elastic component is an O-ring, the tightening control of the housing becomes easier compared to when the elastic component is a flat packing.

[0057] <6> The fluid sterilization apparatus according to any one of <1> to <5>, wherein the inner tube is formed of a UV-transmitting material.

[0058] This configuration makes it easy to sterilize the fluid between the outer and inner tubes.

[0059] (Contribution to the United Nations-led Sustainable Development Goals (SDGs)) This disclosure includes matters that contribute to achieving Sustainable Development Goal 6, "Clean Water and Sanitation," and Goal 9, "Industry, Innovation and Infrastructure."

[0060] 1 Fluid sterilization device 10 Irradiation channel section 12 Outer tube 14 Inner tube 16 Thick-walled section 21 First housing 22 Second housing 24 Interior 26 Interior 31 Inlet 32 ​​Outlet 40 Gap 50 Elastic member 60 Interior 72 Inner surface 74 Outer surface 80 Recess 100 Vertical direction 101 Arrow 102 Upward vertical direction 201 Fixing section

Claims

1. A fluid sterilization device comprising two housings positioned opposite each other, and a cylindrical irradiation channel located between the two housings, wherein the fluid in the irradiation channel is sterilized by irradiation with UV light, and the irradiation channel comprises a rigid outer tube and a resin inner tube positioned inside the outer tube, and when the housing on the primary side of the irradiation channel is designated as the first housing and the housing on the secondary side is designated as the second housing, the inner tube is watertightly fixed to the second housing only via an elastic member.

2. The fluid sterilization apparatus according to claim 1, wherein there is a gap between the outer tube and the inner tube that communicates with the inside of the irradiation channel section.

3. The fluid sterilization apparatus according to claim 1 or 2, wherein the inner tube has a thicker walled portion than the rest of the inner tube, and the inner tube is fixed to the second housing at the thicker walled portion.

4. The fluid sterilization apparatus according to claim 1 or 2, wherein the first housing is positioned on the lower side in the vertical direction and the second housing is positioned on the upper side in the vertical direction.

5. The fluid sterilization apparatus according to claim 1 or 2, wherein the elastic member is an O-ring.

6. The fluid sterilization apparatus according to claim 1 or 2, wherein the inner tube is formed of a UV-transmitting material.

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