Fluid sterilizer

Abstract

To provide a fluid sterilizer having enhanced sterilization effect.SOLUTION: A fluid sterilizer includes: a flow passage pipe 100, which is formed shaped like a cylinder defining a flow passage space for fluid passage and which has an inlet 101 formed near a first end and an outlet 102 formed near a second end; a light source unit 110 disposed at at least one of a location near the inlet 101 and a location near the outlet 102 and emitting ultraviolet light into the flow passage space. In the flow passage pipe 100 a constricted portion 106 is formed which is narrow in the middle along the axial direction of the flow passage space. The light source unit 110 includes a plurality of light-emitting elements 141 that radiate ultraviolet light. Optical axes 144 of the plurality of light-emitting elements 141 are set at different angles so as to face the constricted portion 106.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 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] Patent Document 1 describes a water sterilization device using an LED that emits ultraviolet light, in which a plurality of ultraviolet LEDs are arranged at the end of a flow path tube through which water flows, and ultraviolet light is emitted from each ultraviolet LED in the axial direction of the flow path tube.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration disclosed in Patent Document 1, the optical axes of the plurality of ultraviolet LEDs are all arranged to be parallel to the axial direction of the flow path tube. However, since there are fast-flowing and slow-flowing parts of water in the flow path tube, it is not sufficient to increase the ultraviolet intensity for the fast-flowing part of water, and there is room for improvement to improve the sterilization effect.

[0006] The present invention has been made in view of such a background, and aims to provide a fluid sterilization device with an improved sterilization effect.

Means for Solving the Problems

[0007] One aspect of the present invention is a flow path tube formed in a cylindrical shape that forms a flow path space through which a fluid flows, and having an inlet formed near the first end and an outlet formed near the second end; a light source unit disposed at at least one of near the inlet and near the outlet, and irradiating ultraviolet light into the flow path space; the flow path tube forms a constricted portion that is constricted and thinned in an intermediate portion in the axial direction of the flow path space; the light source unit has a plurality of light emitting elements that emit ultraviolet light; in the fluid sterilization device, the optical axes of the plurality of light emitting elements are set at different angles so as to face the constricted portion.

Effect of the Invention

[0008] In the fluid sterilization device of the above aspect, since both the fluid and ultraviolet light are concentrated in the constricted portion of the flow path space, the sterilization effect can be improved in the constricted portion.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0010] The fluid sterilization device includes a flow path tube formed in a cylindrical shape that forms a flow path space through which the fluid flows, the flow path tube having an inlet formed near the first end and an outlet formed near the second end, and a light source unit disposed at at least one of the vicinity of the inlet and the vicinity of the outlet to irradiate ultraviolet light into the flow path space. The flow path tube forms a constricted portion that is constricted and thinned at an intermediate portion in the axial direction within the flow path space. The light source unit has a plurality of light emitting elements that emit ultraviolet light, and the optical axes of the plurality of light emitting elements are set at different angles so as to face the constricted portion.

[0011] According to this, since both the fluid and the ultraviolet light are concentrated in the constricted portion of the flow path space, the sterilization effect can be improved in the constricted portion.

[0012] In the above fluid sterilization device, the light source unit has a first light source unit disposed near the inlet and a second light source unit disposed near the outlet. The optical axes of the plurality of light emitting elements of the first light source unit are set at different angles so as to face the constricted portion, and the optical axes of the plurality of light emitting elements of the second light source unit are set at different angles so as to face the constricted portion.

[0013] Thereby, since both the ultraviolet light from the first light source unit and the ultraviolet light from the second light source unit are concentrated in the constricted portion of the flow path space, the sterilization effect can be further improved in the constricted portion.

[0014] In the above fluid sterilization device, for example, if the light source unit has a mounting substrate on which a plurality of light emitting elements are mounted, and the portion of the mounting substrate on which the plurality of light emitting elements are mounted is formed in a concave shape so that the optical axes of the plurality of light emitting elements are set at different angles from each other, the installation angles of the plurality of light emitting elements themselves can be made different from each other, so that the optical axes of the plurality of light emitting elements can be set at different angles from each other.

[0015] In the above-described fluid sterilization device, for example, if the light source unit includes at least one light-emitting element and has a plurality of light source elements installed at the same angle as the optical axis of the light-emitting element, and the installation angles of the plurality of light source elements are set to different angles from each other, the optical axes of the light-emitting elements of each light source element will be at different angles respectively. Therefore, the optical axes of the plurality of light-emitting elements can be set to different angles from each other.

[0016] In the above-described fluid sterilization device, the flow path tube has a first large-diameter portion located near the first end and having an inlet formed therein, a second large-diameter portion located near the second end and having an outlet formed therein, and a small-diameter portion formed between the first large-diameter portion and the second large-diameter portion and having a smaller diameter than the first large-diameter portion and the second large-diameter portion. Thereby, a constricted and narrowed portion is formed in the middle in the axial direction of the flow path space.

[0017] In the above-described fluid sterilization device, since the first large-diameter portion, the second large-diameter portion, and the small-diameter portion are arranged coaxially with each other, it is possible to effectively concentrate and flow the fluid through the constricted and narrowed portion of the flow path space.

[0018] In the above-described fluid sterilization device, the small-diameter portion has a first tapered portion that gradually decreases in diameter from the first large-diameter portion side toward the second large-diameter portion side, and a second tapered portion that gradually decreases in diameter from the second large-diameter portion side toward the first large-diameter portion side. Thereby, even if the middle of the flow path space is constricted and narrowed, the flow of the fluid in the flow path space can be made smooth.

[0019] In the above-described fluid sterilization device, the optical axis of the first light source unit and the optical axis of the second light source unit pass through the small-diameter portion without intersecting the inner wall of the flow path tube. Thereby, ultraviolet light can be concentrated and irradiated to the constricted and narrowed portion of the flow path space, so that the sterilization effect can be further improved.

[0020] In the above fluid sterilization device, the inlet is arranged such that the inflow direction of the fluid flowing in is offset with respect to the center of the flow path tube. As a result, the fluid flowing in from the inlet forms a spiral flow, so that the residence time of the fluid in the flow path space becomes longer and the irradiation time of ultraviolet light on the fluid becomes longer. As a result, the sterilization efficiency can be improved.

[0021] In the above fluid sterilization device, the flow path tube is formed of a material including one selected from the group consisting of stainless steel, titanium, aluminum, iron, polyvinyl chloride, polyethylene, polytetrafluoroethylene, and quartz. When a material with a high reflectivity of ultraviolet light is not used for the flow path tube in this way, it is difficult for the intensity of ultraviolet light to be uniform over the entire flow path space. However, by constricting and narrowing the middle of the flow path space, both the fluid and ultraviolet light can be concentrated at the constricted and narrowed part of the flow path space. Therefore, the sterilization effect can be improved even if a material with a high reflectivity of ultraviolet light is not used for the flow path tube.

[0022] In the above fluid sterilization device, the light source unit has a light emitting element that emits ultraviolet light, a column portion provided so as to protrude from the end surface 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 and housing the light emitting element. The storage portion is formed so as to extend radially outward from the tip of the column portion over the entire circumference of the tip of the column portion. As a result, a large exposed area (in other words, cooling area) of the storage portion in the flow path space can be ensured, so that the light emitting element housed in the storage portion can be efficiently cooled by the fluid.

[0023] (Embodiment 1) 1. Outline of the configuration of the fluid sterilization device 1 FIG. 1 is a diagram schematically showing the configuration of the fluid sterilization device 1 in the present embodiment. As shown in FIG. 1, the fluid sterilization device in the present embodiment has a flow path tube 100 and two light source units 110. The light source unit 110 also has an LED package 140, a column portion 120, and a storage portion 130.

[0024] The fluid sterilization device 1 in this embodiment is a device that flows fluid from the inlet 101 of the flow path pipe 100 into the flow path space inside the flow path pipe 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 gas and liquid, a mixture of gas and 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 solvents, etc.

[0025] 2. Details of each component of the fluid sterilization device 1 Next, each component of the fluid sterilization device 1 will be described in detail.

[0026] 2-1. Structure of the flow path pipe 100 The flow path pipe 100 is cylindrical and has a cylindrical space inside. This space is the flow path space through which the fluid to be sterilized flows. One light source unit 110 is provided at each of both ends. Also, an inlet 101 is provided on the side wall of one end side (the left side in FIG. 1) in the axial direction of the flow path pipe 100, and an outlet 102 is provided on the side wall of the other end side (the right side in FIG. 1). Hereinafter, the end on the inlet 101 side of the flow path pipe 100 is referred to as the first end, and the end on the outlet 102 side of the flow path pipe 100 is referred to as the second end.

[0027] Among the light source units 110 respectively arranged at both ends of the flow path pipe 100, the light source unit arranged closer to the inlet 101 is the first light source unit 110A, and the light source unit arranged closer to the outlet is the second light source unit 110B. Hereinafter, the first light source unit 110A and the second light source unit 110B will be simply referred to as the light source unit 110 without distinguishing their names.

[0028] The material of the flow path tube 100 is metal such as stainless steel, titanium, aluminum, iron, resin materials such as polyvinyl chloride, polyethylene, and PTFE (polytetrafluoroethylene), glass such as quartz glass, etc. The material of the flow path tube 100 may be one in which 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 (polytetrafluoroethylene), etc. Glass is, for example, quartz glass, soda-lime glass, borosilicate glass, lead glass, etc., and is a material that is transparent to ultraviolet light and has a low reflectivity of ultraviolet light. Also, it may be one in which 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.

[0029] Fig. 2(a) is a diagram showing the position of the inlet 101, and Fig. 2(b) is a diagram showing the position of the outlet 102. Figs. 2(a) and 2(b) are cross-sectional views of a cross-section cut along a plane perpendicular to the central axis of the flow path tube 100, viewed from the first end side toward the second end side.

[0030] As shown in Fig. 2(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 center O of the flow path tube 100. That is, the central axis L1 of the inlet 101 is displaced so as not to pass through the center 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 in the flow path tube 100 as shown in Fig. 3. The tangential direction of the spiral flow on the central axis L1 of the inlet 101 is the direction of the central axis L1 of the inlet 101.

[0031] As shown in Fig. 2(b), the outlet 102 is also arranged with its outflow direction offset with respect to the center O of the flow path tube 100. That is, the central axis L2 of the outlet 102 is displaced so as not to pass through the center O of the flow path tube 100. As a result, a spiral flow can be maintained also on the outlet 102 side, and the tangential direction of the spiral flow on the central axis L2 of the outlet 102 is in the direction of the central axis L2 of the outlet 102.

[0032] As shown in Fig. 1, the flow path tube 100 has a shape in which the middle in the axial direction (the left - right direction in Fig. 1) is constricted and becomes thinner. Specifically, the flow path tube 100 has a first large - diameter portion 103, a second large - diameter portion 104, and a small - diameter portion 105. The first large - diameter portion 103 is located closer to the first end of the flow path tube 100. An inlet 101 is formed in the first large - diameter portion 103. The second large - diameter portion 104 is located closer to the second end of the flow path tube 100. An outlet 102 is formed in the second large - diameter portion 104.

[0033] The small - diameter portion 105 is formed between the first large - diameter portion 103 and the second large - diameter portion 104, and has a smaller diameter than the first large - diameter portion 103 and the second large - diameter portion 104. The first large - diameter portion 103, the second large - diameter portion 104, and the small - diameter portion 105 are arranged coaxially with each other.

[0034] The small - diameter portion 105 has a minimum - diameter portion 105a, a first tapered portion 105b, and a second tapered portion 105c. The minimum - diameter portion 105a is the portion with the smallest diameter among the small - diameter portion 105. The first tapered portion 105b is formed between the first large - diameter portion 103 and the minimum - diameter portion 105a, and gradually decreases in diameter from the first large - diameter portion 103 toward the minimum - diameter portion 105a. The second tapered portion 105c is formed between the second large - diameter portion 104 and the minimum - diameter portion 105a, and gradually decreases in diameter from the second large - diameter portion 104 toward the minimum - diameter portion 105a.

[0035] Since the wall thickness of the flow path tube 100 is configured to be substantially constant, the flow path space also has a shape in which the middle in the axial direction is constricted and becomes thinner. In other words, a constricted and thinner narrow portion 106 is formed in the middle in the axial direction of the flow path space.

[0036] In this embodiment, the small-diameter portion 105 of the flow channel pipe 100 has a shape that is symmetric with respect to the axial direction of the flow channel pipe 100 (left-right symmetric in FIG. 1). Therefore, the constriction portion 106 of the flow channel space also has a shape that is symmetric with respect to the axial direction of the flow channel pipe 100 (left-right symmetric in FIG. 1).

[0037] 2-2. Configuration of the light source unit 110 The light source unit 110 includes a column portion 120, a storage portion 130, and an LED package 140. The storage portion 130 stores the LED package 140. Hereinafter, the light source unit 110 provided on the first end side will be described, but the light source unit 110 provided on the second end side has the same configuration.

[0038] As shown in FIG. 1, the column portion 120 protrudes in the axial direction of the flow channel pipe 100 from the first end side to the second end side of the flow channel pipe 100 and has a frustum-shaped portion. The central axis of the column portion 120 coincides with the central axis of the flow channel pipe 100. That is, the central axis of the column portion 120 is arranged coaxially with the central axis of the flow channel pipe 100.

[0039] The inclination angle (angle with respect to the bottom surface) of the side surface of the frustum is, for example, 30 to 70°. The large-diameter-side end of the column portion 120 is connected to the first end of the flow channel pipe 100, and the small-diameter-side end is connected to the storage portion 130.

[0040] The shape of the column portion 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 of a pyramid shape may be used. However, a frustum shape is preferred for forming a spiral flow. Also, the entire column portion 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, among the column portion 120, the tip-side portion connected to the storage portion 130 may be cylindrical, and the base-side portion connected to the first end of the flow channel pipe 100 may be frustum-shaped.

[0041] As shown in FIG. 4, the storage portion 130 that stores the LED package 140 has a glass plate 132, a pedestal portion 133, and a mounting substrate 135.

[0042] The pedestal portion 133 is a bottomed cylindrical member with an open front end surface, and the bottom surface is connected to the tip of the column portion 120. The central axis of the pedestal portion 133 coincides with the central axis of the column portion 120. That is, the central axis of the pedestal portion 133 is arranged coaxially with the central axis of the column portion 120. As described above, the central axis of the column portion 120 is arranged coaxially with the central axis of the flow path tube 100. Therefore, the central axis of the pedestal portion 133 is also arranged coaxially with the central axis of the flow path tube 100.

[0043] Inside the pedestal portion 133, the mounting substrate 135 is arranged at the bottom, and the LED package 140 is mounted on the mounting substrate 135. A glass plate 132 is provided on the front end surface of the pedestal portion 133, sealing the internal space of the pedestal portion 133. The glass plate 132 is a material that transmits ultraviolet light from the LED package 140, such as quartz or sapphire. By providing a photocatalytic film that transmits ultraviolet light on the surface of the glass plate 132, it is possible to suppress the growth of miscellaneous bacteria on the glass plate 132 or prevent organic matter stains. 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, etc.

[0044] 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. That is, the outer diameter of the pedestal portion 133 is larger than the outer diameter of the tip of the column portion 120. Therefore, the bottom surface of the pedestal portion 133 will be exposed to the flow path space except for the region connected to the column portion 120.

[0045] On the outer edge of the bottom surface of the pedestal portion 133, a peripheral wall 136 protruding toward the first end side is formed. As a result, a recess 134 that is recessed more than the peripheral wall 136 is formed in the portion of the bottom surface of the pedestal portion 133 surrounded by the peripheral wall 136. The recess 134 is provided to retain fluid as much as possible near the bottom surface of the pedestal portion 133. The pedestal portion 133 can be cooled by the fluid that stays near the bottom surface of the pedestal portion 133. That is, the heat-generating LED package 140 can be cooled via the pedestal portion 133.

[0046] In the present embodiment, the peripheral wall 136 is provided over the entire circumference of the bottom surface of the pedestal portion 133, but it may be provided only on a part of the bottom surface of the pedestal portion 133. By providing the peripheral wall 136 only on a part of the bottom surface of the pedestal portion 133, the formation of an air pocket in the recess 134 can be suppressed and the cooling efficiency can be improved.

[0047] 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, when viewed in the central axis direction of the flow path tube 100, it is preferable that the recess 134 is located at a position overlapping the LED package 140. The pedestal portion 133 can be cooled more efficiently by the fluid that stays near the bottom surface of the pedestal portion 133. That is, the heat-generating LED package 140 can be cooled more efficiently via the pedestal portion 133.

[0048] In the present embodiment, the pedestal portion 133 is a bottomed cylindrical member, but any shaped member may be used as long as it is bottomed cylindrical. For example, it may be a bottomed rectangular tube-shaped (polygonal box-shaped) member. However, from the viewpoint of generating a spiral flow, it is preferable to use a bottomed cylindrical shape as in the present embodiment.

[0049] The materials of the column portion 120 and the pedestal portion 133 are preferably metal materials with high thermal conductivity such as stainless steel and aluminum. Titanium may be used as the material of the column portion 120 and the pedestal portion 133, and the surface may be oxidized to form a photocatalytic film. According to this, the breeding of various bacteria on the column portion 120 and the pedestal portion 133 can be suppressed.

[0050] The LED package 140 is mounted on the mounting substrate 135. A plurality of LED packages 140 may be mounted on one mounting substrate 135, and two are shown in FIGS. 1 and 4. As shown in FIG. 4, the LED package 140 has an LED 141, an LED substrate 142 on which the LED 141 is mounted, and a lens 143 that seals the LED 141.

[0051] The LED 141 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. Although one LED 141 is shown in one LED package 140 in FIG. 4, a plurality of LEDs 141 may be provided in one LED package 140. The configuration of the LED 141 is not limited, and it may be either a face-up type or a flip-chip type.

[0052] The LED package 140 is preferably mounted in a region outside the column portion 120 when viewed from the central axis direction of the flow path tube 100. Since fluid can be brought into contact with the region on the bottom surface of the pedestal portion 133 that extends in the axial direction of the LED package 140, the storage portion 130 can be efficiently cooled. That is, the heat-generating LED package 140 can be efficiently cooled.

[0053] In this embodiment, the LED package 140 having the LED 141 is mounted on the mounting substrate 135, but the LED 141 may be directly mounted on the mounting substrate 135.

[0054] A hole 111 penetrating in the axial direction is provided in the center of the column portion 120 and the storage portion 130. The 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 135 passes. The wiring cable is drawn into the mounting substrate 135 through the hole 111.

[0055] The mounting substrate 135 is a substrate on which the LED package 140 is mounted. In the present embodiment, the mounting substrate 135 is formed of aluminum. The mounting substrate 135 may be a glass epoxy substrate such as FR-4 or CEM3, or a flexible substrate made of polyimide or the like. Various processes such as drilling may be performed on the mounting substrate 135.

[0056] As shown in FIG. 4, the mounting surface of the mounting substrate 135 on which the LED package 140 is mounted is formed in a concave shape that is recessed from the glass plate 132 side toward the column portion 120 side. In the present embodiment, the mounting surface forms a gently parabolic (in other words, mortar-shaped) curved surface. The mounting surface is most deeply recessed at a portion that intersects the central axis of the pedestal portion 133 (hereinafter referred to as the central portion of the mounting surface).

[0057] In FIG. 4, the mounting substrate 135 is a plate-shaped member with a constant thickness, but the mounting substrate 135 may be a member with a non-constant thickness. That is, in FIG. 4, the mounting surface is formed in a concave shape because the mounting substrate 135 itself is curved in a plate shape, but the back surface of the mounting substrate 135 (that is, the surface opposite to the mounting surface) may be formed in a flat shape and only the mounting surface may be formed in a concave shape.

[0058] In the present embodiment, on the mounting surface of the mounting substrate 135, two LED packages 140 are arranged at equal intervals along a virtual circle centered on the central portion of the mounting surface.

[0059] A circuit forming member (not shown) electrically connected to the LED package 140 is mounted on the mounting substrate 135. The circuit forming member is a drive circuit for causing the LED 141 to emit light, a connector header for connecting the drive circuit and a power cable, and the like. As other electronic components (not shown), a thermistor for measuring the temperature of the mounting substrate 135, a connector header for connecting the thermistor to a power cable, and the like are provided on the mounting substrate 135.

[0060] 2-3. Optical axis 144 of LED141 The optical axis 144 of the LED 141 is the axis in the stacking direction of the semiconductor layers for emitting ultraviolet light in the ultraviolet light emitted by the LED 141, that is, the axis perpendicular to the main surface of the element substrate on which the semiconductor layers are stacked. The optical axis 144 is, for example, the axis located at the center in the irradiation range of the ultraviolet light of the LED 141 having a predetermined light distribution characteristic.

[0061] The optical axis 144 may be a virtual line extending in the direction in which the luminous intensity of the ultraviolet light is maximized from the LED 141 in the irradiation range of the ultraviolet light, but it is not limited to this depending on the configuration of the LED 141. In the present embodiment, the optical axis 144 of the LED 141 is on the perpendicular line to the portion of the mounting surface where the LED 141 is mounted.

[0062] As described above, the mounting surface is formed in a concave shape recessed from the side of the glass plate 132 toward the side of the column portion 120, and the LED 141 is arranged on a virtual circle centered on the center portion of the mounting surface. Therefore, the optical axis 144 of the LED 141 is inclined with respect to the central axis of the pedestal portion 133 so as to intersect the central axis of the pedestal portion 133.

[0063] As described above, the central axis of the pedestal portion 133 is arranged coaxially with the central axis of the flow path tube 100. Therefore, the optical axis 144 of the LED 141 is inclined with respect to the central axis of the pedestal portion 133 so as to intersect the central axis of the flow path tube 100.

[0064] In the present embodiment, as shown in FIG. 1, the direction of the optical axis 144 of the LED 141 (specifically, the shape of the mounting surface of the mounting substrate 135 and the position of the light source portion 110) is set so that the optical axis 144 of the LED 141 passes through the small-diameter portion 105 of the flow path tube 100 without intersecting the inner wall of the flow path tube 100.

[0065] As a result, the optical axes 144 of the respective LEDs 141 are set at different angles from each other and are set to face the constricted portion 106 of the flow path space. In the present embodiment, the optical axes 144 of the respective LEDs 141 intersect with each other at the constricted portion 106 of the flow path space. In the present embodiment, the optical axes 144 of the respective LEDs 141 intersect with each other on the central axis of the flow path space and at the central position in the axial direction of the flow path space.

[0066] 3. Regarding the flow path of the fluid Next, the flow path of the fluid in the flow path space will be described. FIG. 3 is a diagram schematically showing the flow path of the fluid in the vicinity of the first end of the flow path tube 100. As shown in FIG. 3, the fluid that has entered the flow path space in the flow path tube 100 from the inlet 101 hits the side surface of the frustum-shaped portion of the column portion 120. However, since the side surface is inclined, it is reflected in the axial direction, and a flow toward the storage portion 130 is formed. Therefore, the fluid can be efficiently brought into contact with the storage portion 130, and the cooling efficiency can be improved.

[0067] Since the outer diameter of the pedestal portion 133 is larger than the outer diameter of the tip of the column portion 120, the fluid can be brought into contact with the bottom surface of the pedestal portion 133 (the left side surface in FIG. 3). In particular, the fluid contacts the region on the axial extension of the LED package 140 on the bottom surface of the pedestal portion 133. Therefore, the pedestal portion 133 can be efficiently cooled.

[0068] Since the peripheral wall 136 is provided on the bottom surface of the pedestal portion 133 and there is a recess 134 surrounded by the peripheral wall 136, the fluid tends to stay on the back surface of the pedestal portion 133. Therefore, heat can be efficiently conducted from the bottom surface of the pedestal portion 133 to the fluid, and the cooling efficiency can be improved.

[0069] Since the inflow port 101 is offset, as shown in FIG. 3, a flow is formed that swirls around the column portion 120. Since the column portion 120 has a shape that becomes thinner from the first end side to the second end side, the fluid swirls around the column portion 120 and moves from the first end side to the second end side. Therefore, a spiral flow is formed in the flow path space. By forming a spiral flow, the residence time of the fluid in the flow path space is increased, and the irradiation time of ultraviolet light on the fluid is increased, so that the sterilization efficiency can be improved.

[0070] Moreover, a constricted portion 106 that is constricted and thinned is formed in the middle of the flow path space, and the optical axes 144 of the respective LEDs 141 are set to face the constricted portion 106. Therefore, the fluid in the flow path space flows concentratedly into the constricted portion 106, and the fluid in the constricted portion 106 is irradiated with ultraviolet light concentratedly. That is, both the fluid and the ultraviolet light are concentrated in the constricted portion 106. Therefore, since the fluid in the flow path space is efficiently irradiated with ultraviolet light, the sterilization efficiency can be improved.

[0071] In the light source unit 110 on the side of the outflow port 102, since the column portion 120 has a shape that becomes thinner from the second end side to the first end side, the fluid flowing from the first end side to the second end side can be reflected in the radial direction of the flow path tube 100 by the column portion 120. Therefore, the residence time of the fluid can be lengthened in the vicinity of the storage portion 130 on the side of the outflow port 102, so that the storage portion 130 can be efficiently cooled.

[0072] 5. Summary of Effects As described above, according to the fluid sterilization device in the present embodiment, the flow path tube 100 forms a constricted portion 106 that is constricted and thinned in the intermediate portion in the axial direction of the flow path space, and the light source unit 110 has a plurality of LEDs 141 that emit ultraviolet light. The optical axes of the plurality of LEDs 141 are set at different angles so as to face the constricted portion 106.

[0073] According to this, since both the fluid and the ultraviolet light are concentrated in the constricted portion 106 of the flow path space, the sterilization effect can be improved in the constricted portion 106.

[0074] In this embodiment, in the light source units 110 respectively arranged at both ends of the flow path tube 100, the optical axes of the plurality of LEDs 141 are set at different angles so as to face the constricted portion 106. As a result, the ultraviolet light from the light source units 110 converges on the constricted portion 106 from both ends of the flow path tube 100. Therefore, compared with the case where the ultraviolet light from the light source units 110 converges on the constricted portion 106 only from one end of the flow path tube 100, the sterilization effect can be further improved in the constricted portion 106.

[0075] Specifically, the portion of the mounting substrate 135 of the light source unit 110 where the plurality of LEDs 141 are mounted is formed in a concave shape so that the optical axes of the plurality of LEDs 141 are set at different angles from each other. Thereby, the installation angles of the plurality of LEDs 141 can be set at different angles from each other, so that the optical axes of the plurality of LEDs 141 can also be set at different angles from each other.

[0076] In this embodiment, the flow path tube 100 has a first large-diameter portion 103 near the first end, a second large-diameter portion 104 near the second end, and a small-diameter portion 105 between the first large-diameter portion 103 and the second large-diameter portion 104, thereby forming a constricted portion 106 in the flow path space.

[0077] Since the first large-diameter portion 103, the second large-diameter portion 104, and the small-diameter portion 105 are arranged coaxially with each other, the fluid can be effectively concentrated and flowed through the constricted portion 106.

[0078] The small-diameter portion 105 has a first tapered portion 105b that gradually decreases in diameter from the first large-diameter portion 103 side toward the second large-diameter portion 104 side, and a second tapered portion 105c that gradually decreases in diameter from the second large-diameter portion 104 side toward the first large-diameter portion 103 side. Thereby, even if a constricted portion 106 that is constricted and thinned is formed in the middle of the flow path space, the flow of the fluid in the flow path space can be made smooth.

[0079] According to the fluid sterilization device in this embodiment, the optical axis 144 of the light source unit 110 passes through the small-diameter portion 105 without intersecting the inner wall of the flow path tube 100. Thereby, since ultraviolet light can be concentrated and irradiated on the constricted portion 106 of the flow path space, the sterilization effect can be further improved.

[0080] According to the fluid sterilization device in this embodiment, the inlet 101 is arranged such that the inflow direction of the inflowing fluid is offset with respect to the center of the flow path tube 100. Thereby, since the fluid flowing in from the inlet 101 forms a spiral flow, the residence time of the fluid in the flow path space becomes longer and the irradiation time of ultraviolet light on the fluid becomes longer. As a result, the sterilization efficiency can be improved.

[0081] According to the fluid sterilization device in this embodiment, the flow path tube 100 is formed of a material including one selected from the group consisting of stainless steel, titanium, aluminum, iron, polyvinyl chloride, polyethylene, polytetrafluoroethylene, and quartz. In this way, when a material with a high reflectivity of ultraviolet light is not used for the flow path tube 100, it is difficult for the intensity of ultraviolet light to be uniform over the entire flow path space. However, by forming the constricted portion 106 in the flow path space, both the fluid and ultraviolet light can be concentrated on the constricted portion 106. Therefore, the sterilization effect can be improved even if a material with a high reflectivity of ultraviolet light is not used for the flow path tube.

[0082] According to the fluid sterilization device in this embodiment, in the light source unit 110, the column portion 120 is provided so as to protrude from the first end of the flow path tube 100 toward the second end side, and the storage portion 130 provided at the tip of the column portion 120 is formed so as to spread radially outward from the tip of the column portion 120 over the entire circumference of the tip of the column portion 120. Thereby, since a large exposed area (in other words, cooling area) of the storage portion 130 in the flow path space can be ensured, the LED 141 accommodated in the storage portion 130 can be efficiently cooled by the fluid.

[0083] (Embodiment 2) In the above-described Embodiment 1, one light source unit 110 is provided at each end of the flow path tube 100. However, in this embodiment, as shown in FIG. 5, a plurality (specifically, three) of light source units 110 are provided at each end of the flow path tube 100.

[0084] At each of both ends of the flow path tube 100, one of the plurality of light source units 110 is arranged on the central axis of the flow path tube 100, and the other light source units 110 are arranged away from the central axis of the flow path tube 100.

[0085] In the above-described Embodiment 1, the central axis of the pedestal portion 133 of the light source unit 110 (in other words, the central axis of the storage portion 130) is arranged coaxially with the central axis of the flow path tube 100. In contrast, in this embodiment, in the light source unit 110 arranged on the central axis of the flow path tube 100 among the plurality of light source units 110, the central axis 151 of the pedestal portion 133 is set coaxially with the central axis of the flow path tube 100, and in the light source unit 110 arranged away from the central axis of the flow path tube 100, the central axis 151 of the pedestal portion 133 is inclined with respect to the central axis of the flow path tube 100 so as to intersect the central axis of the flow path tube 100 in the flow path space (in other words, it is non-parallel to the central axis of the flow path tube 100).

[0086] In the above-described Embodiment 1, the mounting surface of the mounting substrate 135 is formed in a concave shape that is recessed from the glass plate 132 side toward the column portion 120 side. However, in this embodiment, the mounting surface of the mounting substrate 135 is formed in a planar shape orthogonal to the central axis of the pedestal portion 133. Therefore, the angle of the optical axis of the LED 141 becomes the same as the angle of the central axis of the pedestal portion 133 (in other words, it becomes parallel to the central axis of the pedestal portion 133).

[0087] That is, in this embodiment, in each light source unit 110, the storage portion 130, which is a light source element including at least one LED 141, is installed at the same angle as the optical axis of the LED 141 stored therein. And the installation angles of the storage portions 130 of each light source unit 110 are set to different angles from each other.

[0088] As a result, among the plurality of light source units 110, in the light source unit 110 disposed on the central axis of the flow path tube 100, the optical axis of the LED 141 is set parallel to the central axis of the flow path tube 100. In the light source unit 110 disposed away from the central axis of the flow path tube 100, the optical axis of the LED 141 is inclined with respect to the central axis of the flow path tube 100 so as to intersect the central axis of the flow path tube 100 in the flow path space (in other words, it is non-parallel to the central axis of the flow path tube 100).

[0089] In the present embodiment, the direction of the optical axis of the LED 141 (specifically, the angle of the central axis of the pedestal portion 133 and the position of the light source unit 110) is set so that the optical axis of the LED 141 passes through the small-diameter portion 105 of the flow path tube 100 without intersecting the inner wall of the flow path tube 100 in each light source unit 110.

[0090] As a result, the optical axis of the LED 141 is set at different angles for each of the plurality of light source units 110 and is set to face the constricted portion 106 of the flow path space. In the present embodiment, the central axes 151 of the respective pedestal portions 133 intersect each other at the constricted portion 106 of the flow path space. In the present embodiment, the central axes 151 of the respective pedestal portions 133 intersect each other on the central axis of the flow path space and at the central position in the axial direction of the flow path space.

[0091] Also in the present embodiment, similar to the first embodiment, a constricted portion 106 that is constricted and narrowed is formed in the middle of the flow path space, and the optical axis 144 of each LED 141 is set to face the constricted portion 106. Therefore, the fluid in the flow path space concentrates and flows through the constricted portion 106, and the fluid in the constricted portion 106 is intensively irradiated with ultraviolet light. That is, both the fluid and the ultraviolet light concentrate on the constricted portion 106. Therefore, since the fluid in the flow path space is efficiently irradiated with ultraviolet light, the sterilization efficiency can be improved.

[0092] In the above-described Embodiment 1, the mounting substrate 135 on which a plurality of LEDs 141 are mounted is formed in a concave shape, so that the installation angles of the plurality of LEDs 141 are set at different angles from each other. In contrast, in the present embodiment, there are a plurality of storage portions 130 each of which is a light source element including at least one LED 141, and the installation angles of the plurality of storage portions 130 are set at different angles from each other. Thereby, also in the present embodiment, similarly to Embodiment 1 above, the optical axes of the plurality of LEDs 141 can be set at different angles from each other.

[0093] (Other Modification Forms) In the above-described embodiment, the flow path tube 100 itself has a shape that is constricted and narrowed, so that the constriction portion 106 is formed in the flow path space inside the flow path tube 100. However, the manner of forming the constriction portion 106 is not limited to this. For example, the outer diameter of the flow path tube 100 may be constant, and the constriction portion 106 may be formed in the flow path space by the inner diameter changing in a large diameter, small diameter, and large diameter manner from the first end side to the second end side.

[0094] In the above-described Embodiment 1, the optical axes 144 of the respective LEDs 141 intersect with each other on the central axis of the flow path space and at the central position in the axial direction of the flow path space. However, the position where the optical axes 144 of the respective LEDs 141 intersect with each other may be appropriately changed according to the light distribution characteristics of the respective LEDs 141, the characteristics of the flow of the fluid in the flow path space, and the like.

[0095] In the above-described Embodiment 2, the central axes 151 of the respective pedestal portions 133 intersect with each other on the central axis of the flow path space and at the central position in the axial direction of the flow path space. However, the position where the central axes 151 of the respective pedestal portions 133 intersect with each other may be appropriately changed according to the light distribution characteristics of the respective LEDs 141, the characteristics of the flow of the fluid in the flow path space, and the like.

[0096] In the above-described embodiment, 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 of 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. Similarly in this case, the sterilization efficiency can be improved by providing a reflecting member on the end face of the first end side. As the reflecting member, PTFE (polytetrafluoroethylene), stainless steel, titanium, etc. can be used.

[0097] In the above-described embodiment, the light source unit 110 is arranged in the flow path space, but the light source unit 110 may be arranged outside the flow path space. For example, a glass plate 132 may be arranged at the end of the flow path tube 100, and the light source unit 110 may be arranged so as not to protrude into the flow path space. Also, in the light source unit 110, a configuration may be adopted in which the peripheral wall 136 is not provided and the recess 134 is not formed.

Explanation of Reference Numerals

[0098] 100 Flow path tube 101 Inlet 102 Outlet 103 First large-diameter portion 104 Second large-diameter portion 105 Small-diameter portion 105b First tapered portion 105c Second tapered portion 106 Narrow portion 110 Light source unit (first light source unit, second light source unit) 110A First light source unit 110B Second light source unit 130 Storage portion (light source element) 141 LED (light-emitting element) 144 Optical axis

Claims

1. A flow path tube formed in a cylindrical shape that forms a flow path space through which a fluid flows, having an inlet formed near the first end and an outlet formed near the second end; A light source unit disposed at at least one of near the inlet and near the outlet, for irradiating ultraviolet light into the flow path space; and is provided with, The flow path tube forms a constricted portion that is constricted and thinned at an intermediate portion in the axial direction of the flow path space, The light source unit has a plurality of light emitting elements that emit ultraviolet light, A fluid sterilization device in which the optical axes of the plurality of light emitting elements are set at different angles so as to face the constricted portion.

2. The light source unit has a first light source unit disposed near the inlet and a second light source unit disposed near the outlet, The optical axes of the plurality of light emitting elements of the first light source unit are set at different angles so as to face the constricted portion, The fluid sterilization device according to claim 1, wherein the optical axes of the plurality of light emitting elements of the second light source unit are set at different angles so as to face the constricted portion.

3. The light source unit has a mounting substrate on which the plurality of light emitting elements are mounted, The fluid sterilization device according to claim 1, wherein a portion of the mounting substrate on which the plurality of light emitting elements are mounted is formed in a concave shape so that the optical axes of the plurality of light emitting elements are set at different angles from each other.

4. The light source unit has a plurality of light source elements including at least one of the light emitting elements and installed at the same angle as the optical axis of the light emitting element, The fluid sterilization device according to claim 1, wherein the installation angles of the plurality of light source elements are set at different angles from each other.

5. The flow path tube is, A first large diameter portion located near the first end and having the inlet formed therein, A second large diameter portion located near the second end and having the outlet formed therein, The fluid sterilization device according to claim 1, further comprising a small diameter portion formed between the first large diameter portion and the second large diameter portion and having a smaller diameter than the first large diameter portion and the second large diameter portion.

6. The fluid sterilization device according to claim 5, wherein the first large diameter portion, the second large diameter portion, and the small diameter portion are arranged coaxially with each other.

7. The fluid sterilization device according to claim 5, further comprising a first tapered portion that gradually decreases in diameter from the small diameter portion toward the second large diameter portion side and a second tapered portion that gradually decreases in diameter from the second large diameter portion side toward the first large diameter portion side.

8. The fluid sterilization device according to claim 5, wherein the optical axes of the plurality of light-emitting elements pass through the small-diameter portion without intersecting the inner wall of the flow path tube.

9. The fluid sterilization device according to claim 1, wherein the inlet is arranged such that the inflow direction of the inflowing fluid is offset with respect to the center of the flow path tube.

10. The fluid sterilization device according to claim 1, wherein the flow path tube is formed of a material containing one selected from the group consisting of stainless steel, titanium, aluminum, iron, polyvinyl chloride, polyethylene, polytetrafluoroethylene, and quartz.

11. The light source unit a light-emitting element that emits ultraviolet light; a column portion provided so as to protrude from 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 and housing the light-emitting element, The fluid sterilization device according to any one of claims 1 to 10, wherein the storage portion is formed so as to extend radially outward from the tip of the column portion over the entire circumference of the tip of the column portion.

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