Fluid sterilization device

Abstract

The objective is to provide a fluid sterilization device that can suppress the reduction in the amount of ultraviolet light incident on the fluid, even when equipped with a water turbine with blades. [Solution] The fluid sterilization apparatus according to the embodiment comprises: a cylindrical portion having a space through which a fluid flows; a light source provided inside the cylindrical portion for irradiating ultraviolet light; a window provided inside the cylindrical portion, facing the side of the light source to which the ultraviolet light is irradiated, and transmitting the ultraviolet light irradiated from the light source; a water turbine provided inside the cylindrical portion, which is rotated by the fluid flowing through the space; and blades provided on the water turbine that contact the window. The water turbine has a frame portion provided with a plurality of blades, located in the space between the light source and the inner wall of the cylindrical portion in a direction intersecting the central axis of the cylindrical portion; a boss provided on the side of the light source opposite to the window side in a direction along the central axis of the cylindrical portion; and an arm with one end provided on the frame portion and the other end provided on the boss.

Description

Technical Field

[0001] Embodiments of the present invention relate to a fluid sterilization device.

Background Art

[0002] There is a fluid sterilization device that irradiates a fluid such as water with ultraviolet light to sterilize bacteria or inactivate viruses contained in the fluid. For example, a fluid sterilization device has been proposed that includes a cylindrical portion through which a fluid flows, a window provided near an end of the cylindrical portion, and a light source that irradiates ultraviolet light into the cylindrical portion through the window.

[0003] Here, such a fluid sterilization device may also be used, for example, when sterilizing bacteria or inactivating viruses contained in seawater or groundwater. However, seawater, groundwater, etc. contain foreign substances such as sand, dead microorganisms, and inorganic salts. Therefore, when the fluid sterilization device is used for such applications, foreign substances may adhere to the window.

[0004] In this case, if the fluid sterilization device is disassembled to remove the foreign substances adhering to the window, it takes time and effort, and the operation rate of the fluid sterilization device also decreases.

[0005] For example, if a waterwheel is provided with blades that contact the window and the waterwheel is rotated by the fluid flowing inside the cylindrical portion, the rotating blades can remove the foreign substances adhering to the window. That is, by flowing the fluid inside the cylindrical portion, it is possible to perform both continuous treatment of the fluid with ultraviolet light and removal of foreign substances adhering to the window by the rotating blades.

[0006] However, since the blades are provided on the ultraviolet light emission side of the window, the ultraviolet light emitted through the window enters the waterwheel where the blades are provided, the rotating shaft of the waterwheel, and the support portion that supports the rotating shaft of the waterwheel. When ultraviolet light enters these elements, the amount of light of the ultraviolet light incident on the fluid decreases by that amount, so there is a risk that the sterilization effect cannot be improved.

[0007] Therefore, there was a need for the development of a fluid sterilization device that could suppress the reduction in the amount of ultraviolet light incident on the fluid, even when equipped with a water turbine with blades. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2018-069166 [Patent Document 2] Japanese Patent Publication No. 2017-051290 [Overview of the project] [Problems that the invention aims to solve]

[0009] The problem that the present invention aims to solve is to provide a fluid sterilization device that can suppress the reduction in the amount of ultraviolet light incident on the fluid, even when the device is equipped with a water turbine that has blades. [Means for solving the problem]

[0010] The fluid sterilization apparatus according to the embodiment comprises: a cylindrical portion having a space through which a fluid flows; a light source provided inside the cylindrical portion for irradiating ultraviolet light; a window provided inside the cylindrical portion, facing the side of the light source to which the ultraviolet light is irradiated, and transmitting the ultraviolet light irradiated from the light source; a water turbine provided inside the cylindrical portion, which is rotated by the fluid flowing through the space; and blades provided on the water turbine that contact the window. The water turbine has a frame portion provided with a plurality of blades, located in the space between the light source and the inner wall of the cylindrical portion in a direction intersecting the central axis of the cylindrical portion; a boss provided on the side of the light source opposite to the window side in a direction along the central axis of the cylindrical portion; and an arm, one end of which is provided on the frame portion and the other end of which is provided on the boss. [Effects of the Invention]

[0011] According to embodiments of the present invention, even when a water turbine equipped with blades is provided, a fluid sterilization device can be provided that can suppress a decrease in the amount of ultraviolet light incident on the fluid. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic perspective view illustrating the fluid sterilization apparatus according to this embodiment. [Figure 2] Figure 1 is a schematic cross-sectional view of the fluid sterilization device, taken in a direction intersecting the central axis of the cylindrical section. [Figure 3] This is a schematic perspective view illustrating the light source, window, and foreign object processing section. [Figure 4] This is a schematic perspective view illustrating the processing unit. [Figure 5] This is a schematic perspective view illustrating a waterwheel. [Modes for carrying out the invention]

[0013] The embodiments will be illustrated below with reference to the drawings. In each drawing, similar components are denoted by the same reference numerals, and detailed explanations will be omitted as appropriate. Furthermore, in this specification, sterilization includes not only the killing of bacteria but also the inactivation of viruses. Furthermore, sterilization includes not only disinfection but also detoxification.

[0014] Figure 1 is a schematic perspective view illustrating the fluid sterilization apparatus 1 according to this embodiment. Figure 2 is a schematic cross-sectional view of the fluid sterilization device 1 in Figure 1, taken in a direction intersecting the central axis of the cylindrical section 2. Note that, to avoid complexity, the controller 8 is omitted from Figure 2. Figure 3 is a schematic perspective view illustrating the light source 5, window 6, and foreign object processing unit 7.

[0015] As shown in Figures 1 and 2, the fluid sterilization device 1 includes, for example, a cylindrical section 2, a supply section 3, a discharge section 4, a light source 5, a window 6, a foreign matter processing section 7, and a controller 8. For example, the light source 5, the window 6, and the foreign object treatment unit 7 can be provided inside the cylindrical portion 2. For example, the supply unit 3, the discharge unit 4, and the controller 8 can be provided outside the cylindrical portion 2.

[0016] The controller 8 controls the lighting and extinguishing of the light emitting element 51 provided on the light source 5. When a discharge lamp is provided in the light source 5, the controller 8 controls the lighting and extinguishing of the discharge lamp. The controller 8 includes, for example, a lighting circuit and a power source. As shown in FIG. 1, the controller 8 can be provided, for example, in the cylindrical portion 2. The controller 8 can also be provided at a position separated from the cylindrical portion 2. The controller 8 and the light source 5 can be electrically connected via wiring, for example. Also, the wiring electrically connected to the controller 8 and the wiring electrically connected to the light source 5 can be separable using, for example, a connector 8a or the like.

[0017] The cylindrical portion 2 has a cylindrical shape and the ends on both sides are open. The openings at the ends on both sides of the cylindrical portion 2 are blocked by the lid 21. The lid 21 can be detachably provided on the cylindrical portion 2 using a fastening member such as a bolt, for example.

[0018] The cylindrical portion 2 has a space inside through which the fluid 301a flows. The cylindrical portion 2 is, for example, a cylindrical tube. Ultraviolet rays are irradiated from the light source 5 to the fluid 301a flowing inside the cylindrical portion 2. In this case, if a part of the irradiated ultraviolet rays leaks outside through the cylindrical portion 2, the processing ability of the fluid sterilization device 1 decreases. Therefore, the cylindrical portion 2 can be formed from a material that does not transmit ultraviolet rays and has a high reflectance for ultraviolet rays.

[0019] Also, the cylindrical portion 2 is preferably formed from a material having high resistance to ultraviolet rays and high resistance to the fluid 301a that is the object of sterilization. For example, the cylindrical portion 2 can be formed from stainless steel. In this case, if the material of the cylindrical portion 2 is stainless steel containing 8 wt% or more of Ni (nickel), the corrosion resistance against the fluid 301a in which corrosion is likely to occur, such as seawater, can be improved.

[0020] If the cylindrical portion 2 contains a material with a high reflectivity to ultraviolet rays, it becomes easier to reflect the ultraviolet rays incident on the inner wall of the cylindrical portion 2 toward the fluid 301a. Therefore, the utilization efficiency of the ultraviolet rays irradiated from the light source 5 can be improved. If the utilization efficiency of the ultraviolet rays can be improved, it becomes possible to reduce the number of light-emitting elements 51 and discharge lamps provided in the light source 5. If the number of the light-emitting elements 51 and discharge lamps is reduced, miniaturization, cost reduction, energy saving, etc. of the light source 5 can be achieved.

[0021] Also, the internal space of the cylindrical portion 2 serves as a flow path for the fluid 301a to be sterilized. Therefore, the fluid 301a comes into contact with the inner wall of the cylindrical portion 2. Here, the fluid 301a may be seawater, groundwater, or the like. Seawater, groundwater, etc. contain foreign substances such as sand, dead microorganisms, and inorganic salts. So, when seawater, groundwater, etc. come into contact with the inner wall of the cylindrical portion 2, foreign substances may adhere to the inner wall of the cylindrical portion 2. When foreign substances adhere to the inner wall of the cylindrical portion 2, the reflectivity to ultraviolet rays may decrease. When the reflectivity decreases, the intensity of the reflected light (ultraviolet rays) irradiated to the fluid 301a decreases, so there is a risk that the sterilization effect, etc. may decrease. In this case, if the fluid sterilizer 1 is disassembled to remove the foreign substances adhering to the inner wall of the cylindrical portion 2, it takes time and effort, and the operability of the fluid sterilizer 1 also decreases.

[0022] Therefore, the surface roughness (arithmetic mean roughness) Ra of the inner wall of the cylindrical portion 2 is set to 50 nm (nanometers) or less, preferably 3 nm (nanometers) or more and 50 nm (nanometers) or less. By doing so, it is possible to suppress the adhesion of foreign substances to the inner wall of the cylindrical portion 2 and improve the reflectivity to ultraviolet rays. For example, the inner wall of the cylindrical portion 2 can be buff-polished so that the surface roughness Ra of the inner wall of the cylindrical portion 2 falls within the above-mentioned range.

[0023] Alternatively, the inner wall of the cylindrical section 2 may be buffed and then electropolished so that the surface roughness Ra of the inner wall of the cylindrical section 2 falls within the aforementioned range. Performing electropolishing after buffing removes dirt from the metal surface of the inner wall of the cylindrical section 2 or suppresses the adhesion of dirt. Furthermore, performing electropolishing after buffing dissolves the Fe (iron) contained in the metal surface of the inner wall of the cylindrical section 2, thereby increasing the proportion of Cr (chromium) on the metal surface. As a result, even if the metal surface of the inner wall of the cylindrical section 2 is scratched, the passive film on the metal surface can be regenerated, making the inner wall more easily self-repaired.

[0024] The cylindrical section 2 can be mounted on the base 23, for example, via a plurality of stands 22. The base 23 can be mounted, for example, on the floor of the location where the fluid sterilization device 1 is installed. Note that the installation of the fluid sterilization device 1 is not limited to the examples given. For example, the fluid sterilization device 1 can also be mounted on the wall or ceiling of the installation location. In addition, although Figure 1 illustrates the case where the cylindrical section 2 extends in the vertical direction, the cylindrical section 2 may extend in the horizontal direction, or it may extend in a direction inclined with respect to the horizontal direction.

[0025] The supply unit 3 is provided on one end side of the cylindrical portion 2. The supply unit 3 includes, for example, a supply pipe 31 and a flange 32.

[0026] The supply pipe 31 is, for example, a cylindrical pipe. For example, one end of the supply pipe 31 can be provided on the outer wall of the cylindrical section 2. The internal space of the supply pipe 31 is in communication with the internal space of the cylindrical section 2. The material of the supply pipe 31 can be, for example, the same as the material of the cylindrical section 2.

[0027] The flange 32 is plate-shaped and is provided at the end of the supply pipe 31 opposite to the cylindrical portion 2. A fluid supply source 301a can be connected to the flange 32 via a sealing member.

[0028] The discharge section 4 is provided on the other end side of the cylindrical section 2. The discharge section 4 includes, for example, a discharge pipe 41 and a flange 42.

[0029] The discharge pipe 41 is, for example, a cylindrical pipe. For example, one end of the discharge pipe 41 can be provided on the outer wall of the cylindrical section 2. The internal space of the discharge pipe 41 is in communication with the internal space of the cylindrical section 2. The material of the discharge pipe 41 can be, for example, the same as the material of the cylindrical section 2.

[0030] The flange 42 is plate-shaped and is provided at the end of the discharge pipe 41 opposite to the cylindrical section 2. A tank containing sterilized fluid 301b can be connected to the flange 42 via a sealing member.

[0031] The light source 5 irradiates the fluid 301a flowing through the internal space of the cylindrical section 2 with ultraviolet light through the window 6. The light source 5 can be provided, for example, near the supply section 3 and near the discharge section 4. In the example shown in Figure 2, the light source 5 is provided near both the supply section 3 and the discharge section 4. By providing the light source 5 near both the supply section 3 and the discharge section 4, the amount of ultraviolet light irradiated onto the fluid 301a flowing inside the cylindrical section 2 can be increased. This improves the sterilization effect. Furthermore, the area irradiated with ultraviolet light inside the cylindrical section 2 can be enlarged. Therefore, for example, even if the length of the cylindrical section 2 along its central axis is increased, the predetermined sterilization effect can be maintained, thus improving the processing capacity.

[0032] Furthermore, if the light source 5 is located near either the supply unit 3 or the discharge unit 4, the configuration of the fluid sterilization device 1 can be simplified and manufacturing costs can be reduced. Therefore, the number of light sources (5) can be changed as appropriate depending on the required sterilization effect, processing capacity, manufacturing cost, etc.

[0033] As shown in Figures 2 and 3, the light source 5 comprises, for example, a light-emitting element 51, a substrate 52, and a base 53. The light-emitting element 51 is provided on the side of the substrate 52 facing the window 6. The light-emitting element 51 irradiates ultraviolet light toward the window 6. At least one light-emitting element 51 can be provided. The number of light-emitting elements 51 can be appropriately changed according to the processing capacity required for the fluid sterilization device 1. If multiple light-emitting elements 51 are provided, the multiple light-emitting elements 51 can be connected in series.

[0034] The light-emitting element 51 is not particularly limited as long as it is an element that emits ultraviolet light. The light-emitting element 51 can be, for example, a light-emitting diode or a laser diode.

[0035] The peak wavelength of the ultraviolet light emitted from the light-emitting element 51 is not particularly limited as long as it has a sterilizing effect. However, if the peak wavelength is 300 nm or less, it becomes easier for the ultraviolet light to be absorbed by the DNA or RNA of bacteria and viruses. For this reason, the light-emitting element 51 can be, for example, a light-emitting diode that emits ultraviolet light with a peak wavelength of 200 nm to 300 nm.

[0036] The substrate 52 is plate-shaped and can be provided on the bottom surface of the recess 53a of the base 53, which will be described later. A wiring pattern can be provided on the substrate 52. Preferably, the material of the substrate 52 is resistant to ultraviolet light. The material of the substrate 52 can be, for example, a ceramic such as aluminum oxide. Alternatively, the substrate 52 can be a metal core substrate in which the surface of a metal plate is covered with an inorganic material. If the material of the substrate 52 is a ceramic or the like, or if the substrate 52 is a metal core substrate, resistance to ultraviolet light and high heat dissipation can be obtained.

[0037] The base 53, for example, is plate-shaped and has a recess 53a that opens on the side facing the window 6. The recess 53a can be provided in the central region of the base 53. A substrate 52 on which the light-emitting element 51 is mounted can be provided inside the recess 53a. The base 53 has the function of holding the substrate 52 on which the light-emitting element 51 is mounted and the function of releasing the heat generated in the light-emitting element 51 to the outside. For this reason, it is preferable that the base 53 be formed from a material with high thermal conductivity. The base 53 can be formed from a metal such as an aluminum alloy or stainless steel.

[0038] Furthermore, as shown in Figure 2, the periphery of the base 53 (the side of the base 53) is separated from the inner wall of the cylindrical portion 2 in a direction intersecting the central axis of the cylindrical portion 2. The space between the periphery of the base 53 and the inner wall of the cylindrical portion 2 becomes a flow path for the fluid 301a.

[0039] In the above description, a light source 5 equipped with a light-emitting element 51 that emits ultraviolet light has been described, but the light source 5 is not limited to this. For example, the light source 5 may be equipped with a discharge lamp that emits ultraviolet light. For example, the light source 5 may be equipped with a low-pressure mercury lamp or a barrier discharge lamp. In this case, for example, it may be a low-pressure mercury lamp that emits ultraviolet light with a peak wavelength of 254 nm, or a low-pressure mercury lamp that emits ultraviolet light with peak wavelengths of 185 nm and 254 nm.

[0040] As shown in Figures 2 and 3, the light source 5 is supported by a stand 54 located inside the cylindrical portion 2. The stand 54 is located on the side of the light source 5 opposite to the window 6 side. For example, the stand 54 extends between the base 53 and the lid 21. For example, one end of the stand 54 can be fixed to the side of the base 53 opposite to the window 6 side. For example, the other end of the stand 54 can be fixed to the lid 21.

[0041] Furthermore, as shown in Figure 2, the stand 54 can be cylindrical in shape, and its central axis can be approximately coaxial with the central axis of the cylindrical portion 2. As will be described later, the boss 72e of the water turbine 72 is rotatably supported by the stand 54.

[0042] Furthermore, as shown in Figure 2, the stand 54 may also have a hole that passes through between its two ends. For example, the stand 54 may be a cylindrical tube or the like. This would make the stand 54 lighter. Also, if the stand 54 has a through hole, the wiring electrically connected to the light source 5 can be routed through the through hole in the stand 54. This makes it easier to electrically connect the light source 5 and the controller 8 using wiring.

[0043] Stand 54 can be made from a metal such as aluminum alloy or stainless steel.

[0044] Window 6 is plate-shaped and faces the side of the light source 5 that is irradiated with ultraviolet light. The surface of the central region of window 6 opposite to the base 53 can be a substantially flat surface. Window 6 is detachably attached to the base 53 by a member 6a that presses against the vicinity of the periphery of window 6. Member 6a is, for example, cylindrical and is attached to the base 53 using fasteners such as screws. The end of member 6a opposite to the base 53 is provided with a protruding portion 6a1 that contacts the surface of window 6 opposite to the base 53. The protruding portion 6a1 is, for example, annular and protrudes inward from member 6a. When member 6a is attached to the base 53, the vicinity of the periphery of window 6 is pressed toward the base 53 by the protruding portion 6a1. As a result, window 6 is fixed to the base 53 by member 6a. Member 6a can be made from a metal such as aluminum alloy or stainless steel.

[0045] Furthermore, a sealing member 6b, such as an O-ring, can be provided between the peripheral region of the surface of the window 6 facing the base 53 and the base 53. If a sealing member 6b is provided, the opening of the recess 53a of the base 53 can be sealed to be liquid-tight by the window 6 and the sealing member 6b.

[0046] The window 6 is made of a material that can transmit ultraviolet light irradiated from the light source 5 and is resistant to ultraviolet light and fluid 301a. For example, the window 6 may be made of quartz glass or a fluororesin that transmits ultraviolet light.

[0047] Furthermore, as will be described later, the blade 71a of the processing unit 71 comes into contact with the side of the window 6 opposite to the side facing the light source 5. For this reason, it is preferable that the surface roughness Ra of the side of the window 6 opposite to the side facing the light source 5 be 0.2 μm or less. In this way, the water turbine 72 equipped with the processing unit 71 can be rotated smoothly.

[0048] Ultraviolet light emitted from the light source 5 is irradiated through the window 6 onto the fluid 301a flowing through the internal space of the cylindrical section 2. In addition, some of the irradiated ultraviolet light is reflected by the inner wall of the cylindrical section 2, and the reflected ultraviolet light irradiates the fluid 301a. As a result, the fluid 301a flowing through the internal space of the cylindrical section 2 is efficiently sterilized by the ultraviolet light.

[0049] In this case, an anti-reflective coating can be provided on the side of the window 6 facing the light source 5. If an anti-reflective coating is provided, it is possible to suppress the reflection of ultraviolet light emitted from the light-emitting element 51 by the window 6, which would otherwise make it difficult for the fluid 301a to be irradiated. In other words, the utilization efficiency of ultraviolet light emitted from the light-emitting element 51 can be improved.

[0050] Furthermore, an anti-fouling film can be provided on the side of window 6 opposite to the light source 5 (the side that comes into contact with the fluid 301a). As mentioned above, the fluid 301a may contain foreign matter. If foreign matter adheres to window 6, ultraviolet light emitted from the light-emitting element 51 will have difficulty passing through window 6. If an anti-fouling film is provided, it is possible to suppress the adhesion of foreign matter to window 6.

[0051] However, even if window 6 is equipped with an anti-fouling film, foreign matter may adhere to window 6 if the amount of foreign matter is relatively large. Also, foreign matter may adhere to window 6 over time. If foreign matter adheres to window 6, disassembling the fluid sterilization device 1 to remove the foreign matter attached to window 6 is time-consuming and laborious, and also reduces the operating rate of the fluid sterilization device 1.

[0052] Therefore, the fluid sterilization device 1 is equipped with a foreign matter processing unit 7 that removes foreign matter adhering to the window 6 or suppresses the adhesion of foreign matter to the window 6.

[0053] As shown in Figures 2 and 3, the foreign matter processing unit 7 can be provided, for example, one unit per window 6. The foreign matter processing unit 7 includes, for example, a processing unit 71 and a water turbine 72.

[0054] The processing unit 71 is located on the water turbine 72. When the fluid 301a flows through the inside of the cylindrical section 2, the processing unit 71 rotates together with the water turbine 72 to remove foreign matter adhering to the window 6 or to prevent foreign matter from adhering to the window 6.

[0055] Figure 4 is a schematic perspective view illustrating the processing unit 71. As shown in Figure 4, the processing unit 71 includes, for example, a blade 71a, a support portion 71b, a biasing portion 71c, and a beam 71d.

[0056] At least one blade 71a can be provided. The processing unit 71 illustrated in Figure 4 is provided with two blades 71a. When providing multiple blades 71a, for example, the multiple blades 71a can be positioned so as to be rotationally symmetrical with respect to the rotational axis 72f of the water turbine 72.

[0057] The blade 71a has a shape that is, for example, plate-like and extends in one direction. For example, the blade 71a extends along the side of the window 6 opposite to the side of the light source 5, and one end contacts the side of the window 6 opposite to the side of the light source 5. In the thickness direction of the blade 71a, the dimension of the end of the blade 71a on the window 6 side is smaller than the dimension of the end of the blade 71a opposite to the side of the window 6. For example, the thickness dimension of the blade 71a near the end on the window 6 side decreases towards the tip. For example, the area near the end of the blade 71a on the window 6 side can be made pointed.

[0058] The blade 71a is preferably made from a material that has resistance to fluid 301a and ultraviolet rays, low water absorption, non-stick properties, low coefficient of friction, insulating properties, and heat resistance. For example, the blade 71a can be made from a fluororesin such as PTFE (polytetrafluoroethylene). If the blade 71a contains a fluororesin and the end of the blade 71a on the window 6 side is pointed, the blade 71a can rotate smoothly even in fluid 301a where a lubricant cannot be used.

[0059] The support portion 71b is rod-shaped and a pair can be provided for one blade 71a. One end of the pair of support portions 71b is provided on the blade 71a. The pair of support portions 71b are provided on the beam 71d and are movable in a direction along the rotational axis 72f of the water turbine 72. The support portions 71b can be slidably provided on the beam 71d, for example, via a sliding bearing provided on the beam 71d. The support portions 71b can be formed from a metal such as stainless steel.

[0060] The biasing portion 71c can be provided, for example, at least one for each blade 71a. The biasing portion 71c is provided, for example, between the beam 71d and the blade 71a, and presses the blade 71a against the window 6 by elastic force. The biasing portion 71c can be, for example, a leaf spring. The biasing portion 71c can be formed from, for example, stainless steel or spring steel.

[0061] The beam 71d is rod-shaped and extends along the side of the window 6 opposite to the light source 5. As shown in Figure 2, when viewed from a direction along the central axis of the cylindrical section 2, the end of the beam 71d is located between the inner wall of the cylindrical section 2 and the base 53 of the light source 5. As shown in Figures 2 to 4, holes 71d1 for attaching the connection part 72d of the water turbine 72 are provided near both ends of the beam 71d. The beam 71d can be made from a metal such as aluminum alloy or stainless steel.

[0062] The water turbine 72 rotates due to the fluid 301a flowing through the space inside the cylindrical section 2. For example, the water turbine 72 rotates due to the reaction force generated when the fluid 301a passes through the multiple blades 72a of the water turbine 72. The water turbine 72 is a reaction turbine. The water turbine 72 illustrated in Figures 2 and 3 is a propeller turbine, which is an example of a reaction turbine. The rotation axis 72f of the water turbine 72 can be approximately coaxial with the central axis of the cylindrical section 2.

[0063] Figure 5 is a schematic perspective view illustrating the water turbine 72. As shown in Figure 5, the turbine 72 has, for example, multiple blades 72a, a frame 72b, arms 72c, connecting parts 72d, and a boss 72e. For example, the multiple blades 72a, frame 72b, arms 72c, connecting parts 72d, and boss 72e can be formed integrally. The turbine 72 can be made from, for example, an aluminum alloy or a metal such as stainless steel.

[0064] As described above, in the direction intersecting the central axis of the cylindrical portion 2, the space between the periphery of the light source 5 (base 53) and the inner wall of the cylindrical portion 2 becomes a flow path for the fluid 301a. Therefore, as shown in Figure 2, a frame portion 72b with multiple wings 72a is provided in the space between the periphery of the light source 5 (base 53) and the inner wall of the cylindrical portion 2.

[0065] The multiple blades 72a are arranged at predetermined intervals on the side (outer part) of the frame 72b, on the inner wall side of the cylindrical part 2. The multiple blades 72a are plate-shaped and inclined with respect to the direction along the rotational axis 72f of the water turbine 72.

[0066] The fluid 301a flows in the space between the periphery of the light source 5 (base 53) and the inner wall of the cylindrical part 2 in a direction along the central axis of the cylindrical part 2 (in a direction along the rotational axis 72f of the water turbine 72). Therefore, if a plurality of blades 72a inclined with respect to the direction along the rotational axis 72f of the water turbine 72 are provided in this space, the fluid 301a will collide with each surface of the plurality of blades 72a from the inclined direction. As a result, the kinetic energy of the fluid 301a can be converted into the rotation of the water turbine 72.

[0067] Furthermore, when the fluid 301a flowing through the internal space of the cylindrical section 2 flows into the space between the periphery of the light source 5 (base 53) and the inner wall of the cylindrical section 2, the flow velocity of the fluid 301a increases. Therefore, if multiple blades 72a are provided in the space between the periphery of the light source 5 (base 53) and the inner wall of the cylindrical section 2, the rotational force of the water turbine 72 can be increased, or the rotational speed of the water turbine 72 can be increased. As a result, the blades 71a provided on the water turbine 72 can efficiently remove foreign matter and suppress the adhesion of foreign matter.

[0068] The angle of inclination between the direction along the rotational axis 72f of the water turbine 72 and the surface of the blade 72a that strikes the fluid 301a can be obtuse. In this case, reducing the angle of inclination or increasing the number of blades 72a can increase the force that rotates the water turbine 72, but it will increase the resistance to the flow of the fluid 301a. Therefore, the angle of inclination and the number of blades 72a can be appropriately changed according to the processing conditions of the fluid 301a (for example, the flow rate and velocity of the fluid 301a flowing inside the cylindrical section 2).

[0069] The frame portion 72b is, for example, cylindrical. As shown in Figure 2, in the direction along the central axis of the cylindrical portion 2, the end of the frame portion 72b is located closer to the light source 5 than the side of the window 6 opposite to the light source 5 (the ultraviolet emission surface). In this way, ultraviolet rays irradiated through the window 6 can be prevented from entering the frame portion 72b and the multiple wings 72a. In other words, ultraviolet rays irradiated through the window 6 can be prevented from being blocked by the frame portion 72b and the multiple wings 72a.

[0070] Multiple arms 72c can be provided. These multiple arms 72c can be positioned, for example, in a rotationally symmetrical manner with respect to the rotation axis 72f of the water turbine 72. The multiple arms 72c connect the frame portion 72b, on which multiple blades 72a are provided, to the boss 72e. The arms 72c can, for example, be rod-shaped and bent. Alternatively, they can be L-shaped, with one end provided on the outer side of the boss 72e. The other end of the arm 72c can be provided, for example, at one end of the frame portion 72b in a direction along the rotation axis 72f of the water turbine 72. The number of arms 72c can be appropriately changed depending on the dimensions (e.g., diameter) of the frame portion 72b in a direction intersecting the rotation axis 72f of the water turbine 72.

[0071] Multiple connection parts 72d can be provided. These multiple connection parts 72d can be positioned, for example, to be rotationally symmetrical with respect to the rotational axis 72f of the water turbine 72. The multiple connection parts 72d detachably connect the frame portion 72b, on which the multiple blades 72a are provided, to the processing section 71 (beam 71d). The connection part 72d is, for example, rod-shaped, with one end provided at the end of the frame portion 72b opposite to the side on which the arm 72c is provided. A male screw can be provided near the other end of the connection part 72d. The other end of the connection part 72d is inserted, for example, into a hole 71d1 in the beam 71d of the processing section 71 and secured using a nut or the like. Therefore, the processing section 71 on which the blades 71a are provided and the water turbine 72 can be detachably connected.

[0072] The boss 72e is, for example, cylindrical and extends along the rotational axis 72f of the water turbine 72. The central axis of the boss 72e becomes the rotational axis 72f of the water turbine 72. The boss 72e can be rotatably mounted on the stand 54 of the light source 5, for example, via a radial sliding bearing 72e1. The boss 72e can be mounted, for example, between the base 53 of the light source 5 and the collar 54a provided on the stand 54. Thrust sliding bearings can also be provided between the boss 72e and the base 53, and between the boss 72e and the collar 54a.

[0073] As shown in Figure 2, the boss 72e is located on the side of the light source 5 opposite to the window 6, in the direction along the central axis of the cylindrical portion 2. In other words, the boss 72e is not located in the area irradiated with ultraviolet light. Therefore, since the ultraviolet light irradiated through the window 6 is not blocked by the boss 72e, it is possible to suppress the reduction in the amount of ultraviolet light irradiated onto the fluid 301a. Furthermore, if the boss 72e is located on the side of the light source 5 opposite to the window 6, then the arm 72c is also located on the side of the light source 5 opposite to the window 6. Therefore, the ultraviolet light irradiated through the window 6 is not blocked by the arm 72c, thus suppressing a decrease in the amount of ultraviolet light irradiated onto the fluid 301a.

[0074] Furthermore, as shown in Figure 2, in the direction along the central axis of the cylindrical portion 2, the frame portion 72b, which is provided with multiple wings 72a, is located on the side of the window 6 opposite to the light source 5 (the ultraviolet emission surface) that is closer to the light source 5. Also, in the direction intersecting the central axis of the cylindrical portion 2, the frame portion 72b, which is provided with multiple wings 72a, is located in the space between the light source 5 (base 53) and the inner wall of the cylindrical portion 2. In other words, the frame portion 72b, which is provided with multiple wings 72a, is located in a region that is less likely to be irradiated with ultraviolet light. Therefore, since the ultraviolet light irradiated through the window 6 is less likely to be blocked by the frame portion 72b, the reduction in the amount of ultraviolet light irradiated onto the fluid 301a can be further suppressed.

[0075] Although a portion of the connection portion 72d is located in the area irradiated with ultraviolet light, the connection portion 72d is rod-shaped, which allows for a small light-receiving area. Therefore, even if ultraviolet light enters a portion of the connection portion 72d, the reduction in the amount of ultraviolet light irradiated onto the fluid 301a is minimal.

[0076] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other.

[0077] The following are additional notes regarding the embodiments described above.

[0078] (Note 1) A cylindrical section having a space through which fluid flows; A light source that emits ultraviolet light is provided inside the cylindrical portion; A window is provided inside the cylindrical portion, facing the side of the light source to which the ultraviolet light is irradiated, and which transmits the ultraviolet light irradiated from the light source; A water turbine is provided inside the cylindrical portion and rotates due to the fluid flowing through the space; The turbine is provided with blades that come into contact with the window; It is equipped with, The aforementioned water turbine is A frame portion having multiple wings is located in the space between the light source and the inner wall of the cylindrical portion, in a direction intersecting the central axis of the cylindrical portion; In the direction along the central axis of the cylindrical portion, the boss provided on the side of the light source opposite to the window side; An arm with one end provided on the frame and the other end provided on the boss; A fluid sterilization device having the following features.

[0079] (Note 2) The fluid sterilization apparatus according to Appendix 1, wherein, in a direction along the central axis of the cylindrical portion, the frame portion on which the plurality of wings are provided is located on the side of the window that is opposite to the side of the light source.

[0080] (Note 3) Inside the cylindrical portion, the light source is further provided with a stand on the side opposite to the window side. The boss is a fluid sterilization device according to Appendix 1 or 2, which is rotatably supported on the stand.

[0081] (Note 4) The fluid sterilization apparatus described in Appendix 3, wherein the central axis of the stand is substantially coaxial with the central axis of the cylindrical portion.

[0082] (Note 5) The stand is a fluid sterilization device according to appendix 3 or 4, having a hole that penetrates between the ends on both sides. [Explanation of Symbols]

[0083] 1 Fluid sterilization device, 2 Cylinder section, 5 Light source, 6 Window, 7 Foreign matter processing section, 51 Light-emitting element, 53 Base, 54 Stand, 71 Processing section, 71a Blade, 72 Water turbine, 72a Wing, 72b Frame section, 72c Arm, 72d Connection section, 72e Boss, 301a Fluid

Claims

1. A cylindrical section having a space through which fluid flows; A light source that emits ultraviolet light is provided inside the cylindrical portion; A window is provided inside the cylindrical portion, facing the side of the light source to which the ultraviolet light is irradiated, and which transmits the ultraviolet light irradiated from the light source; A water turbine is provided inside the cylindrical portion and rotates due to the fluid flowing through the space; The turbine is provided with blades that come into contact with the window; It is equipped with, The aforementioned water turbine is A frame portion having multiple wings is located in the space between the light source and the inner wall of the cylindrical portion, in a direction intersecting the central axis of the cylindrical portion; In the direction along the central axis of the cylindrical portion, the boss provided on the side of the light source opposite to the window side; An arm having one end provided on the frame and the other end provided on the boss; A fluid sterilization device having the following features.

2. The fluid sterilization apparatus according to claim 1, wherein, in a direction along the central axis of the cylindrical portion, the frame portion on which the plurality of wings are provided is located on the side of the window that is opposite to the side of the light source.

3. Inside the cylindrical portion, the light source is further provided with a stand on the side opposite to the window side. The fluid sterilization apparatus according to claim 1 or 2, wherein the boss is rotatably supported on the stand.

4. The fluid sterilization apparatus according to claim 3, wherein the central axis of the stand is substantially coaxial with the central axis of the cylindrical portion.

5. The fluid sterilization apparatus according to claim 3, wherein the stand has a hole that penetrates between the ends on both sides.

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