Fluid sterilizer

Abstract

To provide a fluid sterilizer capable for forming a spiral flow.SOLUTION: A fluid sterilizer has: a flow channel pipe 100 in which an inflow port 101 is formed on a sidewall of a first end side, and an outflow port 102 is formed on a second end side; and a light source part 110 which emits ultraviolet light to the second end side. The light source part 110 has: a light-emitting element which emits ultraviolet light; a post part 120 which is provided so as to protrude from an end face of a first end of the flow channel pipe 100 toward a second end side; and a housing part 130 which is provided for a tip of the post part 120, and houses the light-emitting element, where the housing part 130 is formed so as to spread outward the radial direction of the post part 120 from the tip of the post part 120 over the whole circumference of the tip of the post part 120, a flow channel central axis of the inflow port 101 matches a direction parallel with a line crossing the central axis O of the flow channel pipe 100 which is a direction not crossing the central axis O of the flow channel pipe 100, and a position, shape and size of the inflow port 101 are constituted such that fluid flown from the inflow port 101 circulates around the post part 120.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fluid sterilization device.

Background Art

[0002] There is known a sterilization device that sterilizes and inactivates bacteria and viruses in running water by irradiating ultraviolet light. A mercury lamp is widely used as a light source. Since the mercury lamp uses mercury, it has a problem of strong toxicity and a large environmental load. In addition, there is also a problem that the sterilization device becomes large when using a mercury lamp. Therefore, the replacement of the mercury lamp with an ultraviolet LED is in progress.

[0003] As fluid sterilization devices using ultraviolet LEDs, there are Patent Documents 1 and 2. Patent Documents 1 and 2 disclose a configuration in which a columnar light source portion protruding from one end of a flow path tube toward the other end side is provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to efficiently sterilize a fluid and reduce the pressure loss, it is effective to form a spiral flow in the flow path tube. However, it has been difficult to generate a spiral flow in conventional fluid sterilization devices.

[0006] The present invention has been made in view of such a background, and aims to provide a fluid sterilization device capable of forming a spiral flow.

Means for Solving the Problems

[0007] One aspect of the present invention is a fluid sterilization device having a flow path tube that forms a flow path space for flowing a fluid, an inlet formed in a side wall on a first end side, and an outlet formed on a second end side, and a light source unit disposed at a position near the inlet in the flow path space and radiating ultraviolet light toward the second end side, wherein the light source unit has a light emitting element that emits ultraviolet light, a column portion provided so as to project from an end surface of the first end of the flow path tube toward the second end side, and a storage portion provided at a tip of the column portion and housing the light emitting element, wherein the storage portion is formed so as to extend from the tip of the column portion radially outward of the column portion over the entire circumference of the tip of the column portion, a flow path central axis of the inlet coincides with a direction parallel to a line intersecting a central axis of the flow path tube and not intersecting the central axis of the flow path tube, and in the fluid sterilization device, a position, a shape, and a size of the inlet are configured such that a fluid flowing in from the inlet circulates around the column portion.

Advantages of the Invention

[0008] In the fluid sterilization device of the above aspect, the fluid flowing in from the inlet flows so as to circulate around the column portion, and then passes through a ring-shaped region between the storage portion and an inner wall of the flow path tube. Therefore, a spiral flow can be efficiently formed in the flow path tube.

Brief Description of the Drawings

[0009]

Figure 1

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Modes for Carrying Out the Invention

[0010] The fluid sterilization device includes a flow path tube that forms a flow path space for flowing fluid, with an inlet formed in the side wall on the first end side and an outlet formed on the second end side, and a light source unit disposed at a position near the inlet in the flow path space and emitting ultraviolet light toward the second end side. The light source unit includes a light emitting element that emits ultraviolet light, a column portion provided to protrude from the end face of the first end of the flow path tube toward the second end side, and a storage portion provided at the tip of the column portion for housing the light emitting element. The storage portion is formed to extend radially outward from the tip of the column portion over the entire circumference of the tip of the column portion. The central axis of the flow path of the inlet is in a direction parallel to the line intersecting the central axis of the flow path tube and does not intersect the central axis of the flow path tube. The position, shape, and size of the inlet are configured such that the fluid flowing in from the inlet circulates around the column portion.

[0011] In the above-described fluid sterilization device, the cross-sectional area S1 perpendicular to the central axis direction of the flow path of the inlet with respect to the flow path region of the inlet may be configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S2 perpendicular to the central axis of the flow path tube with respect to the ring-shaped region formed between the storage portion and the inner wall surface of the flow path tube. When S1 and S2 are set in this way, the flow rate of the fluid flowing through the inlet per unit time and the flow rate of the fluid flowing through the ring-shaped region per unit time become approximately equal, and the pressure loss can be reduced.

[0012] In the above-described fluid sterilization device, the extension line of the central axis of the flow path of the inlet may be provided at a position where it does not interfere with the light source portion. Further, when viewed from the central axis direction of the flow path of the inlet, the ratio of the region where the flow path region of the inlet and the light source portion interfere with respect to the flow path region of the inlet may be configured to be 90% or more and 100% or less, and when viewed from the axial direction of the inlet, the flow path region of the inlet and the column portion may be configured not to interfere with each other. By doing so, the fluid flowing into the flow path tube smoothly flows into the region on the side surface of the column portion, and a flow path that rotates around the column portion is easily formed. Therefore, the pressure loss can be reduced. Further, a spiral flow can be easily formed.

[0013] In the above-described fluid sterilization device, the cross-sectional area S3 of one side cross-section among the cross-sections including the central axis of the flow path tube with respect to the region surrounded by the side surface of the column portion, the back surface of the storage portion, the extended surface of the back surface of the storage portion, the inner wall surface of the flow path tube, and the end surface of the first end may be configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S1 perpendicular to the axial direction of the inlet with respect to the flow path region of the inlet. By setting S1 and S3 in this way, the flow rate of the fluid flowing from the inlet into the flow path tube per unit time and the flow rate of the fluid circulating around the column portion per unit time become substantially equal. Therefore, the pressure loss can be reduced.

[0014] In the above-described fluid sterilization device, further, a second light source unit that is disposed at a position from the outlet in the flow path space and emits ultraviolet light toward the first end side is provided. The outlet is formed in the side wall on the second end side. The second light source unit includes a second light emitting element that emits ultraviolet light, a second column portion provided so as to protrude from the end surface of the second end of the flow path tube toward the first end side, and a second storage portion provided at the tip of the second column portion and housing the second light emitting element. The second storage portion is formed so as to spread radially outward from the tip of the second column portion over the entire circumference of the tip of the second column portion. The central axis of the flow path of the outlet coincides with a direction parallel to the line intersecting the central axis of the flow path tube and not intersecting the central axis of the flow path tube. The position, shape, and size of the outlet may be configured such that the fluid flowing out to the outlet circulates around the second column portion.

[0015] In the above-described fluid sterilization device, the cross-sectional area S4 perpendicular to the central axis direction of the flow path of the outlet with respect to the flow path region of the outlet may be configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S5 perpendicular to the central axis of the flow path tube with respect to the ring-shaped region formed between the second storage portion and the inner wall surface of the flow path tube.

[0016] In the above-described fluid sterilization device, the ratio of the region where the flow path region of the outlet and the second light source unit interfere with respect to the flow path region of the outlet, as viewed from the central axis direction of the flow path of the outlet, may be configured to be 90% or more and 100% or less.

[0017] Of the cross-sections including the central axis of the flow path tube of the region surrounded by the side surface of the second column portion, the back surface of the second storage portion, the extended surface of the back surface of the second storage portion, the inner wall surface of the flow path tube, and the end surface of the second end, the cross-sectional area S6 of one side cross-section may be configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S4 perpendicular to the central axis direction of the flow path of the outlet with respect to the flow path region of the outlet.

[0018] (Embodiment 1) 1. Outline of the configuration of the fluid sterilization device 1 FIG. 1 is a perspective view showing the configuration of the fluid sterilization apparatus 1 in Embodiment 1. As shown in FIG. 1, the fluid sterilization apparatus in Embodiment 1 has a flow path tube 100 and has two light source units 110 inside thereof. In FIG. 1, an X-axis is taken in the direction of the central axis O of the flow path tube 100, a Y-axis is taken in a direction perpendicular to the X-axis and parallel to the central axis L1 of the inlet, and a Z-axis is taken in a direction perpendicular to the X-axis and the Y-axis.

[0019] FIG. 2 is a cross-sectional view showing the configuration of the fluid sterilization apparatus in Embodiment 1, which is a cross-section (ZX plane) at II-II in FIG. 1. As shown in FIG. 2, inside the flow path tube 100, light source units 110 are respectively arranged at both ends of the flow path tube 100. Further, FIG. 3 is a cross-sectional view showing the configuration of the fluid sterilization apparatus in Embodiment 1, which is a view showing a part (on the side of the first end portion 100a) of the cross-section (XY plane) at III-III in FIG. 1. Further, FIG. 4 is a cross-sectional view showing the configuration of the fluid sterilization apparatus in Embodiment 1, where FIG. 4(a) is a cross-section (YZ plane) at IVa-IVa in FIG. 1, and FIG. 4(b) is a cross-section (YZ plane) at IVb-IVb in FIG. 1.

[0020] The fluid sterilization apparatus 1 in Embodiment 1 is an apparatus that flows a fluid from the inlet 101 of the flow path tube 100 into the flow path space inside the flow path tube 100, irradiates the fluid with ultraviolet light from the light source unit 110 to sterilize the fluid, and discharges the sterilized fluid from the outlet 102. The fluid to be sterilized may be a gas or a liquid, and may be a mixture of a gas and a liquid, a mixture of a gas and a powdery solid, etc., as long as it has fluidity. In the case of a liquid, for example, water, oil, alcohol, a solution using these as a solvent, etc.

[0021] 2. Details of each component of the fluid sterilization apparatus 1 Next, each component of the fluid sterilization apparatus 1 in Embodiment 1 will be described in detail.

[0022] 2-1. Configuration of the flow path tube 100 The flow path tube 100 is cylindrical and has a cylindrical space inside. This space is the flow path space through which the fluid to be sterilized flows. Light source units 110 are provided at both ends respectively. Here, one end of the flow path tube 100 is defined as the first end 100a, and the other end as the second end 100b. Among the two light source units 110, the one provided on the first end 100a side is the light source unit 110a, and the one provided on the second end 100b side is the light source unit 110b. Also, an inlet 101 is provided on the side wall of the first end 100a side of the flow path tube 100, and an outlet 102 is provided on the side wall of the second end 100b side. The inlet 101 and the outlet 102 are cylindrical and have a flow path region through which the fluid flows.

[0023] The material of the flow path tube 100 is SUS, titanium, PTFE (polytetrafluoroethylene), etc. It may also be a structure where the inner wall surface of a resin material resistant to ultraviolet light is covered with a material having a high reflectivity of ultraviolet light. The resin material resistant to ultraviolet light is, for example, vinyl chloride. Also, the material having a high reflectivity of ultraviolet light is aluminum, PTFE, etc. Further, it may be a structure where the outer wall surface of a material that transmits ultraviolet light is covered with a material having a high reflectivity of ultraviolet light. The material that transmits ultraviolet light is, for example, sapphire, ultraviolet-transmitting glass, fluororesin, acrylic resin, etc.

[0024] The inner wall surface of the flow path tube 100 preferably has an arithmetic mean roughness Ra of 0.2 nm to 10 μm. This reduces the resistance of the inner wall surface and makes it easier to maintain the flow. More preferably, it is 0.2 nm to 3 μm, and even more preferably, it is 0.2 nm to 1 μm.

[0025] As shown in Fig. 4(a), the inlet 101 is arranged such that the inflow direction of the fluid flowing in from the inlet 101 is offset with respect to the central axis O of the flow path tube 100. That is, the flow path central axis (hereinafter simply referred to as the central axis of the inlet 101) L1, which is the central axis of the flow path region of the inlet 101, coincides with a direction parallel to the line intersecting the central axis O of the flow path tube 100 and not intersecting the central axis O of the flow path tube 100. When viewed in cross-section as shown in Fig. 4(a), the central axis L1 of the inlet 101 is displaced by Y1 in the Y direction so as not to pass through the central axis O of the flow path tube 100. By offsetting the position of the inlet 101 in this way, a spiral flow can be formed in the flow path space within the flow path tube 100, and the tangential direction of the spiral flow is the direction of the central axis L1 of the inlet 101. Also, as shown in Fig. 2, the angle formed by the central axis L1 of the inlet 101 and the central axis O is 90 degrees. It does not necessarily have to be 90 degrees, but 80 - 100 degrees is preferable.

[0026] As shown in Fig. 4(b), the outlet 102 is also arranged such that the outflow direction is offset with respect to the central axis O of the flow path tube 100. That is, the flow path central axis (hereinafter simply referred to as the central axis of the outlet 102) L2, which is the central axis of the flow path region of the outlet 102, coincides with a direction parallel to the line intersecting the central axis O of the flow path tube 100 and not intersecting the central axis O of the flow path tube 100. When viewed in cross-section as shown in Fig. 4(b), the central axis L2 of the outlet 102 is displaced by Y2 in the Y direction so as not to pass through the central axis O of the flow path tube 100. As a result, a spiral flow can also be maintained on the outlet 102 side, and the tangential direction of the spiral flow is the direction of the central axis L2 of the outlet 102. Y1 and Y2 may be different, but it is preferably as close as possible, and particularly preferably the same value.

[0027] The more detailed positions, shapes, and sizes of the inlet 101 and the outlet 102 will be described later.

[0028] 2 - 2. Configuration of the light source unit 110 The light source unit 110 has an LED package 140, a column part 120, and a storage part 130. Hereinafter, the light source unit 110a provided on the first end part 100a side will be described, but the light source unit 110b provided on the second end part 100b side has the same configuration.

[0029] As shown in FIG. 1, the column part 120 protrudes from the first end toward the second end of the flow path pipe 100 and has a frustum-shaped portion. The central axis of the column part 120 coincides with the central axis of the flow path pipe 100. The inclination angle (angle with respect to the bottom surface) of the side surface of the frustum is, for example, 30 to 70°. One end on the thicker side of the column part 120 is connected to the first end of the flow path pipe 100, and one end on the thinner side is connected to the storage part 130.

[0030] Note that the shape of the column part 120 is not limited to a frustum shape, and any shape may be used as long as it becomes thinner toward the second end side. A stepwise thinning shape may be used, but a continuously thinning shape is preferred. For example, a frustum-shaped pyramid may be used. However, a frustum shape is preferred for forming a spiral flow. Also, the entire column part 120 does not have to be a frustum, and a part may be a frustum and the other part may be a cylinder. For example, as shown in FIG. 1, the tip side connected to the storage part 130 may be cylindrical, and the other part may be frustum-shaped.

[0031] The storage part 130 is connected to the tip of the column part 120. The storage part 130 stores the LED package 140. The storage part 130 has a glass plate 132, a pedestal part 133, and a substrate 135.

[0032] The pedestal portion 133 is in the shape of a cylindrical box with an open top, and its outer bottom surface is connected to the tip of the column portion 120. A substrate 135 is disposed on the bottom surface inside the box, and an LED package 140 is mounted on the substrate 135. A glass plate 132 is provided on the top surface of the box, sealing the inside of the box. The glass plate 132 is made of a material that transmits ultraviolet light from the LED package 140, such as quartz or sapphire. A photocatalytic film that transmits ultraviolet light may be provided on the surface of the glass plate 132 to suppress the growth of germs on the glass plate 132 or prevent contamination by organic substances. The glass plate 132 is not limited to a flat plate and may be lens-shaped. For example, it may be a TIR lens, a fly-eye lens, a Fresnel lens, or the like.

[0033] As shown in FIG. 1, the pedestal portion 133 is formed so as to extend radially outward from the tip of the column portion 120 over the entire circumference of the tip of the column portion 120. Therefore, the back surface of the pedestal portion 133 will be in contact with the flow path space except for the region connected to the column portion 120.

[0034] The pedestal portion 133 has a peripheral wall 136 that protrudes toward the first end side in the outer peripheral region of its back surface, and has a recess 134 surrounded by the back surface of the pedestal portion 133 and the peripheral wall 136. In Embodiment 1, it is not necessary to provide the peripheral wall 136 over the entire circumference, and it is preferable to provide it partially. If it is provided over the entire circumference, an air pocket may form in the recess 134, deteriorating the cooling efficiency. Also, the peripheral wall 136 is preferably provided outside the LED package 140 when viewed in the central axis direction of the flow path tube 100. That is, it is preferable that the LED package 140 is located within the region of the recess 134. The pedestal portion 133 can be cooled more efficiently.

[0035] In Embodiment 1, the pedestal portion 133 is in the shape of a cylindrical box, but any shape may be used as long as it is box-shaped. For example, it may be in the shape of a regular square column box (square shape). However, from the point of generating a spiral flow, it is preferable to use a cylindrical box shape as in Embodiment 1.

[0036] The materials of the column part 120 and the pedestal part 133 are preferably high thermal conductivity metal materials such as SUS and aluminum, or high heat dissipation resins mixed with thermal conductive fillers. Also, titanium may be used and the surface may be oxidized to form a photocatalytic film. It is possible to suppress the growth of miscellaneous bacteria in the column part 120 and the pedestal part 133.

[0037] The LED package 140 is mounted on the substrate 135. A plurality of LED packages 140 may be mounted, and in FIG. 1, two are mounted. The LED package 140 has an LED, a substrate on which the LED is mounted, and a lens that seals the LED.

[0038] The LED is a light emitting element that emits ultraviolet light. The wavelength of the ultraviolet light is preferably 250 to 285 nm, which is a wavelength with high sterilization efficiency. A plurality of LEDs may be provided in one LED package 140.

[0039] The LED package 140 is preferably mounted in a region outside the column part 120 when viewed from the central axis direction of the flow path tube 100. Since fluid can be brought into contact with the region directly below the LED package 140 on the back surface of the pedestal part 133, the storage part 130 can be efficiently cooled.

[0040] In the first embodiment, the packaged LED package 140 is mounted on the substrate 135, but the LED may be directly mounted on the substrate 135.

[0041] A continuous through hole 111 is provided at the center of the column part 120 and the storage part 130. This hole 111 is a hole through which a wiring cable that supplies power to the LED package 140 and circuit components on the mounting substrate passes. The wiring cable is drawn into the mounting substrate through this hole 111.

[0042] 3. Positions, shapes, and sizes of the inlet 101 and the outlet 102 The position, shape, and size of the inlet 101 are configured such that the fluid flowing in from the inlet 101 circulates around the column portion 120. This facilitates the formation of a spiral flow of the fluid. Specifically, the position, shape, and size of the inlet 101 may be set to satisfy the following conditions.

[0043] As shown in FIG. 3, let the cross-sectional area of the flow path region of the inlet 101 in a cross-section perpendicular to the central axis L1 of the inlet 101 be S1. Further, as shown in FIG. 4(a), let the cross-sectional area in the direction perpendicular to the central axis O of the flow path tube 100 for the ring-shaped region between the housing portion 130 of the light source portion 110a and the inner wall surface of the flow path tube 100 be S2.

[0044] At this time, it is preferable to configure such that S1 is 0.8 times or more and 1.2 times or less of S2. More preferably, S1 is 0.9 times or more and 1.1 times or less of S2.

[0045] By configuring S1 and S2 in this way, the flow rate of the fluid flowing into the flow path tube 100 from the inlet 101 per unit time and the flow rate of the fluid passing through the ring-shaped region per unit time become substantially equal. Therefore, the pressure loss can be reduced.

[0046] Also, as shown in FIG. 3, it is preferable that the extension line of the central axis L1 of the inlet 101 is provided at a position where it does not interfere with the light source portion 110a. Further, when viewed from the direction of the central axis L1 of the inlet 101, the ratio of the region where the flow path region of the inlet 101 and the light source portion 110a interfere with respect to the flow path region of the inlet 101 is preferably 90% or more. More preferably, it is 95% or more.

[0047] By setting in this way, the fluid flowing into the flow path tube 100 smoothly flows into the region of the side surface of the column portion 120, and a flow path that rotates around the column portion 120 is easily formed. Therefore, the pressure loss can be reduced. Also, a spiral flow can be easily formed.

[0048] As shown in FIG. 3, for the region surrounded by the side surface of the column portion 120, the back surface of the storage portion 130, the extended surface of the back surface of the storage portion 130, the inner wall surface of the flow path tube 100, and the end surface on the first end portion 100a side of the flow path tube 100, the cross-sectional area of one side cross-section among the cross-sections in the plane including the central axis O of the flow path tube 100 is defined as S3. At this time, it is preferable that S3 is configured to be 0.8 times or more and 1.2 times or less of S1. More preferably, S3 is 0.9 times or more and 1.1 times or less of S1.

[0049] By configuring S1 and S3 in this way, the flow rate of the fluid flowing into the flow path tube 100 from the inlet 101 per unit time and the flow rate of the fluid circulating around the column portion 120 per unit time become substantially equal. Therefore, the pressure loss can be reduced.

[0050] In addition, although the position, shape, and size of the inlet 101 have been described above, it is also preferable that the position, shape, and size of the outlet 102 are set in the same manner. That is, the position, shape, and size of the outlet 102 may be configured such that the fluid flowing out from the outlet 102 circulates around the column portion 120. Also, the inlet 101 and the outlet 102 may have different shapes and sizes.

[0051] Also, as long as it is within the range satisfying the above, the cross-sectional shape of the flow path region of the inlet 101 and the outlet 102 does not have to be circular, but in order to further reduce the pressure loss, it is preferably circular.

[0052] 4. Regarding the fluid flow path Regarding the flow path of the fluid flowing in the flow path tube 100, it will be described with reference to FIG. 5. FIG. 5(a) is a diagram schematically showing the flow path on the first end portion 100a side (inlet 101 side) of the flow path tube 100, and FIG. 5(b) is a diagram schematically showing the flow path on the second end portion 100b side (outlet 102 side) of the flow path tube 100.

[0053] As shown in Fig. 5(a), the fluid that enters the flow path space in the flow path tube 100 from the inlet 101 flows around the column part 120 of the light source part 110a. This is because the inlet 101 is offset from the central axis O of the flow path tube 100, and the position, shape, and size of the inlet 101 are set to go around the periphery of the column part 120. When viewed in the direction of the central axis O of the flow path tube 100 and in the direction from the first end part 100a to the second end part 100b, the fluid flows in a counterclockwise rotation.

[0054] The fluid that circulates around the column part 120 hits the side surface of the frustum-shaped part of the column part 120. Therefore, the fluid is reflected in the axial direction due to the inclination of the side surface, and a flow path toward the storage part 130 is formed. Therefore, the fluid can be efficiently brought into contact with the storage part 130, and the cooling efficiency can be improved.

[0055] Also, since the pedestal part 133 is formed so as to spread radially outward from the tip of the column part 120 over the entire circumference of the tip of the column part 120, the back surface of the pedestal part 133 can be brought into contact with the fluid. In particular, the fluid contacts the area directly below the LED package 140 on the back surface of the pedestal part 133. Therefore, the pedestal part 133 can be efficiently cooled.

[0056] In addition, since the peripheral wall 136 is provided on the back surface of the pedestal part 133 and there is a recessed part 134 surrounded by the peripheral wall 136, the fluid tends to stay on the back surface of the pedestal part 133. Therefore, heat can be efficiently conducted from the back surface of the pedestal part 133 to the fluid, and the cooling efficiency can be improved.

[0057] Thereafter, the fluid flows in the central axis direction while rotating around the central axis O in the ring-shaped region between the storage part 130 and the inner wall surface of the flow path tube 100. As a result, a spiral flow F1 is formed. By making it the spiral flow F1, the residence time of the fluid in the flow path space becomes longer, and the irradiation time of ultraviolet light to the fluid becomes longer, so that the sterilization efficiency can be improved.

[0058] On the other hand, on the second end portion 100b side, as shown in Fig. 5(b), the spiral flow F2 is maintained. This is because a clean spiral flow F1 is formed on the first end portion 100a side, and there is little breakdown of the spiral flow F1 even at a distance. Therefore, also on the second end portion 100b side, the irradiation time of ultraviolet light becomes longer, and the sterilization efficiency can be improved.

[0059] Also, on the second end portion 100b side, in the ring-shaped region between the housing portion 130 of the light source portion 110b and the inner wall surface of the flow path tube 100, the fluid passes in the direction of the central axis O while rotating around the central axis O. Then, the fluid flows out from the outlet 102 while circulating around the column portion 120 of the light source portion 110b. The outlet 102 is also offset from the central axis O of the flow path tube 100, similar to the inlet 101, and the position, shape, and size of the outlet 102 are set so as to circulate around the column portion 120. Therefore, the fluid can flow out smoothly from the outlet 102, and the pressure loss can be reduced.

[0060] Also, a part of the fluid circulating around the column portion 120 of the light source portion 110b is reflected by the side surface of the column portion 120, and a flow path F0 is formed leading to the housing portion 130 of the light source portion 110b. Therefore, the housing portion 130 of the light source portion 110b can be efficiently cooled.

[0061] 5. Summary As described above, in the fluid sterilization apparatus according to Embodiment 1, the flow path direction of the inlet 101 is made to coincide with the direction toward a position offset from the central axis O of the flow path tube 100, and further, the position, shape, and size of the inlet 101 are configured such that the fluid flowing in from the inlet 101 circulates around the column portion 120. Also, since the housing portion 130 is formed so as to extend radially outward from the tip of the column portion 120 over the entire circumference of the tip of the column portion 120, a ring-shaped region is formed between the housing portion 130 of the light source portion 110 and the inner wall surface of the flow path tube 100. The fluid passes through the ring-shaped region while rotating around the axis. As a result, a clean spiral flow can be easily formed.

[0062] (Embodiment 2) FIG. 6 is a diagram schematically showing the configuration of the light source unit 210 of the fluid sterilization apparatus according to Embodiment 2. As shown in FIG. 6(a), the light source unit 210 has a column portion 220 and a storage portion 230. The column portion 220 has the same configuration as the column portion 120 in Embodiment 1. The storage portion 230 has a configuration in which the pedestal portion 133 of the storage portion 130 in Embodiment 1 is replaced with a pedestal portion 233, and the other configurations are the same as those of the storage portion 130. The pedestal portion 233 has a configuration in which the peripheral wall 136 is removed from the pedestal portion 133, and the outer peripheral region of the back surface of the pedestal portion 233 is flat.

[0063] In Embodiment 2, the effect of retaining the fluid on the back surface of the storage portion 230 by the peripheral wall 136 cannot be obtained, but other effects can be obtained in the same manner as in Embodiment 1.

[0064] In Embodiment 2, in the light source unit 210 on the side of the inlet 101, a groove 237 may be provided on the back surface (the back surface of the pedestal portion 233) of the storage portion 230 so as to guide the fluid from the center side to the outer peripheral side of the back surface of the storage portion. Alternatively, a wall-like protrusion may be provided instead of the groove 237.

[0065] FIGS. 6(b) and (c) are cross-sectional views showing the cross-section at VI-VI in FIG. 6(a). FIG. 6(b) shows the case where a spiral groove 237 is provided on the back surface of the pedestal portion 233. The center of the spiral is the center of the column portion 220. By providing such a spiral groove 237, the contact time between the fluid and the storage portion 230 becomes longer, so that it can be cooled efficiently. In addition, a flow path that spirals toward the outer periphery of the back surface of the storage portion 230 can be formed, and the fluid passing between the inner wall of the flow path tube 100 and the storage portion 230 is likely to form a spiral flow.

[0066] FIG. 6(c) shows the case where a radial groove 237 is provided on the back surface of the pedestal portion 233. By providing such a groove 237, the fluid can be guided to the outer periphery.

[0067] Also, in the light source unit 210 on the outlet 102 side, grooves 237 may be provided as shown in FIGS. 6(b) and 6(c). The storage unit 230 can be efficiently cooled. Further, the fluid that has passed between the inner wall of the flow path pipe 100 and the storage unit 230 can be guided to the column part 220 side, and then a smooth flow path can be formed toward the outlet 102 side by reflection by the column part 220.

[0068] (Embodiment 3) FIG. 7 is a diagram schematically showing the configuration of the light source unit 410 of the fluid sterilization device in Embodiment 3. The light source unit 410 has a column part 420 and a storage unit 130. The column part 420 is cylindrical as shown in FIG. 7. Other configurations are the same as those of the column part 120 in Embodiment 1. The storage unit 130 is the same as that in Embodiment 1.

[0069] In Embodiment 3, since the column part 420 is a cylinder, there is no effect of directing the fluid toward the storage unit 430 side, but other effects can be obtained in the same manner as in Embodiment 1.

[0070] (Embodiment 4) FIG. 8 is a diagram schematically showing the configuration of the light source unit 510 of the fluid sterilization device in Embodiment 4. The light source unit 510 has a column part 420 and a storage unit 230. The column part 420 is the same as the column part 420 in Embodiment 3 and is cylindrical. The storage unit 230 has the same configuration as the storage unit 230 in Embodiment 2, and has a configuration in which there is no peripheral wall 136 in the outer peripheral region on the back surface of the pedestal part 233.

[0071] In Embodiment 4, there is no effect of directing the fluid toward the storage unit 230 side or the effect of retaining the fluid on the back surface of the storage unit 230, but other effects can be obtained in the same manner as in Embodiment 1.

[0072] Note that also in Embodiment 4, similar to FIGS. 6(b) and 6(c) of Embodiment 2, grooves may be provided on the back surface of the storage unit 230 to guide the fluid from the center side to the outer peripheral side of the back surface of the storage unit.

[0073] (Modification 1 of Embodiment 1) FIG. 9 is a diagram schematically showing the configuration of the fluid sterilization apparatus in Modification 1 of Embodiment 1. As shown in FIG. 9, the fluid sterilization apparatus in Modification 1 has a light intensity sensor 600 at the center of the flow path tube 100. Other configurations are the same as those of the fluid sterilization apparatus in Embodiment 1.

[0074] The light intensity sensor 600 is a sensor that detects the intensity of ultraviolet light in the central part within the flow path tube 100. For example, the outputs of the two light source units 110 are controlled so that the intensity of ultraviolet light in the central part becomes equal to or higher than a predetermined value.

[0075] Also, the light intensity sensor 600 also serves as a rectifying plate. The light intensity sensor 600 is provided on the inner wall of the flow path tube 100 and is a wall-like protrusion protruding toward the central axis side of the flow path tube 100. The light intensity sensor 600 is in the form of a wall along the direction of the spiral flow, thereby maintaining the spiral flow in the central part of the flow path tube 100.

[0076] (Modification 2 of Embodiment 1) FIG. 10 is a diagram schematically showing the configuration of the fluid sterilization apparatus in Modification 2 of Embodiment 1. As shown in FIG. 10, the fluid sterilization apparatus in Modification 2 has a configuration in which a spiral groove 700 is provided on the inner wall of the flow path tube 100, and other configurations are the same as those of the fluid sterilization apparatus in Embodiment 1. By providing the spiral groove 700 in the flow path tube 100, it becomes easy to maintain a spiral flow in the flow path space, and the sterilization efficiency can be improved.

[0077] (Other Modifications) In the fluid sterilization apparatuses according to Embodiments 1 to 5, the light source units 110 are provided on each of the inlet 101 side and the outlet 102 side. However, when the flow path tube 100 is short, etc., the light source unit 110 may be provided only on the inlet 101 side. In this case, a reflecting member that reflects ultraviolet light is arranged on the end face on the second end side, and the sterilization efficiency can be improved by irradiating the fluid with the reflected light of the ultraviolet light by this reflecting member. Also, the light source unit 110 may be provided only on the outlet 102 side. Also in this case, the sterilization efficiency can be improved by providing a reflecting member on the end face on the first end side. As the reflecting member, PTFE, SUS, Ti, etc. can be used. Also, a resin such as fluorine-coated vinyl chloride may be used.

Explanation of Reference Numerals

[0078] 100: Flow path tube 101: Inlet 102: Outlet 110, 110a, 110b, 210, 310, 410, 510: Light source unit 111: Hole 120: Column portion 130: Storage portion 132: Glass plate 133: Pedestal portion 134: Concave portion 135: Substrate 136: Peripheral wall 140: LED package

Claims

1. A fluid sterilization device having a flow path tube that forms a flow path space for flowing a fluid, an inlet being formed in a side wall on a first end side, and an outlet being formed on a second end side, and a light source unit disposed at a position near the inlet in the flow path space and emitting ultraviolet light toward the second end side, wherein the light source unit has a light emitting element that emits ultraviolet light, a column portion provided so as to protrude from an end surface of the first end of the flow path tube toward the second end side, and a storage portion provided at a tip of the column portion and housing the light emitting element, wherein the storage portion is formed so as to spread radially outward from the tip of the column portion over the entire circumference of the tip of the column portion, the central axis of the flow path of the inlet coincides with a direction parallel to a line intersecting the central axis of the flow path tube and not intersecting the central axis of the flow path tube, and the position, shape, and size of the inlet are configured such that the fluid flowing in from the inlet circulates around the column portion. A fluid sterilization device.

2. The fluid sterilization device according to claim 1, wherein a cross-sectional area S1 perpendicular to the central axis of the flow path of the inlet in the flow path region of the inlet is 0.8 times or more and 1.2 times or less of a cross-sectional area S2 perpendicular to the central axis of the flow path tube in a ring-shaped region formed between the storage portion and the inner wall surface of the flow path tube.

3. The fluid sterilization device according to claim 1, wherein an extension line of the central axis of the flow path of the inlet is provided at a position that does not interfere with the light source unit.

4. The fluid sterilization device according to claim 1, wherein a ratio of a region where the flow path region of the inlet and the light source unit interfere with respect to the flow path region of the inlet, as viewed in the central axis direction of the flow path of the inlet, is 90% or more and 100% or less.

5. The fluid sterilization device according to claim 4, wherein the flow path region of the inlet and the column portion are configured not to interfere with each other as viewed in the central axis direction of the flow path of the inlet.

6. The fluid sterilization device according to claim 1, wherein a cross-sectional area S3 of one side cross-section among cross-sections including the central axis of the flow path tube in a region surrounded by a side surface of the column portion, a back surface of the storage portion, an extended surface of the back surface of the storage portion, an inner wall surface of the flow path tube, and an end surface of the first end is 0.8 times or more and 1.2 times or less of a cross-sectional area S1 perpendicular to the central axis of the flow path of the inlet in the flow path region of the inlet.

7. Furthermore, it has a second light source unit that is disposed at a position from the outlet in the flow path space and emits ultraviolet light toward the first end side. The outlet is formed in the side wall on the second end side. The second light source unit includes: a second light emitting element that emits ultraviolet light; a second column portion provided so as to protrude from the end surface of the second end of the flow path tube toward the first end side; and a second storage portion provided at the tip of the second column portion and housing the second light emitting element. The second storage portion is formed so as to extend radially outward from the tip of the second column portion over the entire circumference of the tip of the second column portion. The central axis of the flow path of the outlet coincides with a direction parallel to the line intersecting the central axis of the flow path tube and not intersecting the central axis of the flow path tube. The fluid sterilization device according to claim 1, wherein the position, shape, and size of the outlet are configured such that the fluid flowing out from the outlet circulates around the column portion.

8. The cross-sectional area S4 perpendicular to the central axis direction of the flow path of the outlet with respect to the flow path region of the outlet is configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S5 perpendicular to the central axis of the flow path tube with respect to the ring-shaped region formed between the second storage portion and the inner wall surface of the flow path tube. The fluid sterilization device according to claim 7.

9. The fluid sterilization device according to claim 7, wherein the ratio of the region where the flow path region of the outlet and the second light source unit interfere with respect to the flow path region of the outlet, as viewed from the central axis direction of the flow path of the outlet, is configured to be 90% or more and 100% or less.

10. Of the cross section including the central axis of the flow path tube of the region surrounded by the side surface of the second column portion, the back surface of the second storage portion, the extension surface of the back surface of the second storage portion, the inner wall surface of the flow path tube, and the end surface of the second end, the cross-sectional area S6 of one side cross section is configured to be 0.8 times or more and 1.2 times or less of the cross-sectional area S4 perpendicular to the central axis direction of the flow path of the outlet with respect to the flow path region of the outlet. The fluid sterilization device according to claim 7.

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