Fluid sterilization apparatus

Abstract

To provide a fluid sterilization apparatus capable of suppressing the accumulation of foreign matter near the periphery of a window.SOLUTION: A fluid sterilization apparatus according to an embodiment comprises a tubular portion, a light source having a base provided inside the tubular portion and emitting ultraviolet light, a holding portion facing the base, and a window provided between the base and the holding portion and transmitting the ultraviolet light emitted from the light source. The window comprises a peripheral region and a central region inside the peripheral region. The holding portion presses the peripheral region of the window against the base side. In the direction along the central axis of the tubular portion, when a distance between the base and an end on the side opposite to the base of the holding potion is defined as Ha (mm), and a distance between the base and the surface on the side opposite to the base side in the central region of the window is defined as Hb (mm), the following equation is satisfied: Ha (mm)≤Hb (mm).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to a fluid sterilization device. [Background technology]

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

[0003] Such fluid sterilization devices may also be used to sterilize bacteria or inactivate viruses contained in seawater, groundwater, etc. However, seawater, groundwater, etc. contain foreign matter such as sand, dead microorganisms, and inorganic salts. Therefore, when a fluid sterilization device is used for such purposes, foreign matter may adhere to the window.

[0004] Foreign matter adhering to a window can be removed, for example, using a removal device. However, even if foreign matter adhering to a window is removed using a removal device, the foreign matter may not be expelled to the outside of the window and may instead accumulate near the periphery of the window. When foreign matter accumulates near the periphery of the window, the amount of ultraviolet light irradiated onto the fluid may decrease. A decrease in the amount of ultraviolet light irradiated onto the fluid may reduce the effectiveness of sterilizing bacteria or inactivating viruses.

[0005] Therefore, there has been a demand for the development of a fluid sterilization device that can prevent foreign matter from accumulating near the periphery of the window. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-069166 [Patent Document 2] Japanese Patent Application Publication No. 2017-051290 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a fluid sterilizing device that can prevent foreign matter from accumulating near the periphery of the window. [Means for solving the problem]

[0008] A fluid sterilization device according to an embodiment includes a cylindrical portion; a light source having a base disposed inside the cylindrical portion and irradiating ultraviolet light; a holding portion facing the base; and a window disposed between the base and the holding portion and transmitting the ultraviolet light irradiated from the light source. The window has a peripheral region and a central region inside the peripheral region. The holding portion presses the peripheral region of the window against the base. When the distance between the base and the end of the holding portion opposite the base in a direction along the central axis of the cylindrical portion is Ha (mm), and the distance between the base and the surface of the window in the central region opposite the base is Hb (mm), the following equation is satisfied. Ha (mm) ≦ Hb (mm) [Effects of the Invention]

[0009] According to an embodiment of the present invention, a fluid sterilizing device can be provided that can prevent foreign matter from accumulating near the periphery of a window. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic perspective view illustrating a fluid sterilizing device according to an embodiment of the present invention. [Figure 2] 2 is a schematic cross-sectional view of the fluid sterilization device in FIG. 1 in a direction intersecting the central axis of the cylindrical portion. FIG. [Figure 3] FIG. 2 is a schematic perspective view illustrating a foreign matter removal unit and a holding unit. [Figure 4]4 is a schematic partial cross-sectional view of the foreign matter removal unit and the holding unit in FIG. 3, as viewed from the direction of line AA. [Figure 5] 10A and 10B are schematic cross-sectional views illustrating a window and a holding portion according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, similar components are designated by the same reference numerals, and detailed explanations will be omitted as appropriate. In this specification, sterilization includes not only sterilization of bacteria but also inactivation of viruses. Furthermore, sterilization includes not only sterilization but also sterilization.

[0012] FIG. 1 is a schematic perspective view illustrating a fluid sterilizing device 1 according to this embodiment. FIG. 2 is a schematic cross-sectional view of the fluid sterilization device 1 in FIG. 1 in a direction intersecting the central axis of the tubular part 2. As shown in FIG. In FIG. 2, to avoid complexity, only the cylindrical portion 2, the supply portion 3, the discharge portion 4, the light source 5, the window 6, the foreign matter removal portion 7, and the holding portion 8 are shown.

[0013] As shown in FIGS. 1 and 2, the fluid sterilization device 1 includes, for example, a tube section 2, a supply section 3, a discharge section 4, a light source 5, a window 6, a foreign matter removal section 7, a holding section 8, and a controller 9. For example, the light source 5, the window 6, the foreign matter removal unit 7, and the holding unit 8 can be provided inside the cylindrical portion 2. For example, the supply unit 3, the discharge unit 4, and the controller 9 can be provided outside the cylindrical portion 2.

[0014] The cylindrical portion 2 has a cylindrical shape and is open at both ends. The openings at both ends of the cylindrical portion 2 are closed by lids 21. The lids 21 can be detachably attached to the cylindrical portion 2 using fastening members such as bolts, for example.

[0015] The tubular portion 2 is, for example, a cylindrical tube. Ultraviolet light is irradiated into the interior of the tubular portion 2 from a light source 5. In this case, if some of the irradiated ultraviolet light passes through the tubular portion 2 and leaks to the outside, the processing capacity of the fluid sterilization device 1 will decrease. For this reason, the tubular portion 2 can be made of a material that does not transmit ultraviolet light and has a high reflectivity for ultraviolet light.

[0016] Furthermore, the cylindrical portion 2 is preferably made of a material that is highly resistant to ultraviolet light and to the fluid 301a to be sterilized. For example, the cylindrical portion 2 can be made of stainless steel. In this case, if the material of the cylindrical portion 2 is stainless steel containing 8 wt% or more of Ni (nickel), corrosion resistance to the fluid 301a, such as seawater, which is prone to corrosion, can be improved.

[0017] If the cylindrical portion 2 contains a material with high reflectivity for ultraviolet rays, ultraviolet rays incident on the inner surface of the cylindrical portion 2 can be easily reflected toward the fluid 301a. This makes it possible to improve the efficiency of use of ultraviolet rays emitted from the light source 5. If the efficiency of use of 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. Reducing the number of light-emitting elements 51 and discharge lamps allows for the light source 5 to be made smaller, less expensive, and more energy-efficient.

[0018] The interior of the tube portion 2 serves as a flow path for the fluid 301a to be sterilized. Therefore, the fluid 301a comes into contact with the inner surface of the tube portion 2. Here, the fluid 301a may be seawater, groundwater, or the like. Seawater, groundwater, or the like contains foreign matter such as sand, microbial corpses, and inorganic salts. Therefore, when seawater, groundwater, or the like comes into contact with the inner surface of the tube portion 2, the foreign matter may adhere to the inner surface of the tube portion 2. If the foreign matter adheres to the inner surface of the tube portion 2, the reflectivity of the fluid to ultraviolet light may decrease. A decrease in reflectivity reduces the intensity of the reflected light (ultraviolet light) irradiated onto the fluid 301a, which may result in a decrease in the sterilization effect. In this case, disassembling the fluid sterilization device 1 to remove the foreign matter adhered to the inner surface of the tube portion 2 is time-consuming and labor-intensive, and also reduces the operational availability of the fluid sterilization device 1.

[0019] Therefore, the surface roughness (arithmetic mean roughness) Ra of the inner surface 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. This makes it possible to prevent foreign matter from adhering to the inner surface of the cylindrical portion 2 and improve the reflectance against ultraviolet light. For example, the inner surface of the cylindrical portion 2 can be buffed so that the surface roughness Ra of the inner surface of the cylindrical portion 2 falls within the above-mentioned range.

[0020] Alternatively, the inner surface of the cylindrical portion 2 may be buffed and then electropolished to bring the surface roughness Ra of the inner surface of the cylindrical portion 2 into the aforementioned range. By performing electropolishing after buffing, it is possible to remove dirt from the metal surface of the inner surface of the cylindrical portion 2 or to prevent the adhesion of dirt. Furthermore, by performing electropolishing after buffing, the Fe (iron) contained in the metal surface of the inner surface of the cylindrical portion 2 is dissolved, thereby increasing the proportion of Cr (chromium) on the metal surface. As a result, even if the metal surface of the inner surface of the cylindrical portion 2 is scratched, the passive film on the metal surface can be regenerated, making the inner surface more susceptible to self-repair.

[0021] The tubular portion 2 can be mounted on a base 23 via, for example, a plurality of stands 22. The base 23 can be mounted on, for example, the floor of the location where the fluid sterilization device 1 is installed. The installation of the fluid sterilization device 1 is not limited to the example shown. For example, the fluid sterilization device 1 can also be mounted on a wall or ceiling of the installation location. Furthermore, although FIG. 1 illustrates a case where the tubular portion 2 extends vertically, the tubular portion 2 may extend horizontally or may extend in a direction inclined relative to the horizontal.

[0022] The supply unit 3 is provided on one end side of the cylindrical unit 2 . The supply unit 3 includes, for example, a supply pipe 31 , a flange 32 , and a seal member 33 .

[0023] The supply pipe 31 is, for example, a cylindrical pipe. For example, one end of the supply pipe 31 can be provided on the side surface of the cylindrical portion 2. The inside of the supply pipe 31 is in communication with the inside of the cylindrical portion 2. The material of the supply pipe 31 can be, for example, the same as the material of the cylindrical portion 2.

[0024] The flange 32 is plate-shaped and is provided at the end of the supply pipe 31 opposite to the cylindrical portion 2. A supply source of the fluid 301a can be connected to the flange 32 via a seal member 33.

[0025] The discharge portion 4 is provided on the other end side of the cylindrical portion 2. The discharge portion 4 includes, for example, a discharge pipe 41, a flange 42, and a seal member 43.

[0026] The discharge pipe 41 is, for example, a cylindrical pipe. For example, one end of the discharge pipe 41 can be provided on the side surface of the tubular portion 2. The inside of the discharge pipe 41 is in communication with the inside of the tubular portion 2. The material of the discharge pipe 41 can be, for example, the same as the material of the tubular portion 2.

[0027] Flange 42 is plate-shaped and is provided at the end of discharge pipe 41 opposite to the cylindrical portion 2. A tank or the like that stores sterilized fluid 301b can be connected to flange 42 via seal member 43.

[0028] The light source 5 irradiates the fluid 301a flowing inside the tubular portion 2 with ultraviolet light through the window 6. The light source 5 can be provided at least either near the supply unit 3 or near the discharge unit 4. The light source 5 illustrated in FIG. 2 is provided near both the supply unit 3 and the discharge unit 4. If the light source 5 is provided near both the supply unit 3 and the discharge unit 4, the amount of ultraviolet light irradiated onto the fluid 301a flowing inside the tubular portion 2 can be increased. This improves the sterilization effect. Furthermore, the area inside the tubular portion 2 that is irradiated with ultraviolet light can be increased. Therefore, for example, even if the length of the tubular portion 2 in the direction along the central axis is increased, the predetermined sterilization effect can be maintained, thereby improving the processing capacity.

[0029] If the light source 5 is provided either near the supply unit 3 or near the discharge unit 4, the configuration of the fluid sterilizer 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 costs, and the like.

[0030] As shown in FIG. 2, the light source 5 includes, for example, a light emitting element 51, a substrate 52, a base 53, and a stand .

[0031] The light-emitting element 51 is provided on the surface 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 changed as appropriate depending on the processing capacity required of the fluid sterilization device 1. When multiple light-emitting elements 51 are provided, the multiple light-emitting elements 51 can be connected in series.

[0032] There are no particular limitations on the light emitting element 51 as long as it is an element that irradiates ultraviolet light. The light emitting element 51 can be, for example, a light emitting diode or a laser diode.

[0033] 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, the ultraviolet light can be easily absorbed by the DNA or RNA of bacteria or viruses. Therefore, 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.

[0034] The substrate 52 has a plate shape and can be provided on the bottom surface of a recess 53a of the base 53, which will be described later. A wiring pattern can be provided on the substrate 52. The material of the substrate 52 is preferably one that is resistant to ultraviolet light. The material of the substrate 52 can be, for example, ceramics such as aluminum oxide. The substrate 52 can also 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 ceramics or the like, or the substrate 52 is a metal core substrate, it can achieve resistance to ultraviolet light and high heat dissipation properties.

[0035] The base 53 is, for example, plate-shaped and has a recess 53a that opens on the surface opposite to the end side of the tubular portion 2. 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 dissipating heat generated in the light-emitting element 51 to the outside. For this reason, the base 53 is preferably made of a material with high thermal conductivity. The base 53 can be made of, for example, a metal such as an aluminum alloy or stainless steel.

[0036] 3, which will be described later, a plurality of holes 53b are provided in the region between the periphery of the base 53 and the opening of the recess 53a. The plurality of holes 53b penetrate between the surface of the base 53 where the recess 53a opens and the surface of the base 53 opposite to the surface where the recess 53a opens.

[0037] Although the light source 5 has been described above as including a light-emitting element 51 that irradiates ultraviolet light, the light source 5 is not limited to this. For example, the light source 5 may be one that includes a discharge lamp that irradiates ultraviolet light. For example, the light source 5 may also be one that includes a low-pressure mercury lamp or a barrier discharge lamp. In this case, for example, the light source 5 may be a low-pressure mercury lamp that irradiates ultraviolet light with a peak wavelength of 254 nm, or a low-pressure mercury lamp that irradiates ultraviolet light with peak wavelengths of 185 nm and 254 nm.

[0038] Stand 54 is rod-shaped and is provided between base 53 and lid 21. Stand 54 supports base 53, window 6, foreign matter removal unit 7, and holding unit 8 inside cylindrical unit 2. Stand 54 can be made of metal such as aluminum alloy or stainless steel, for example.

[0039] The controller 9 controls the turning on and off of the light emitting element 51. If the light source 5 includes a discharge lamp, the controller 9 controls the turning on and off of the discharge lamp. The controller 9 includes, for example, a lighting circuit and a power supply. As shown in FIG. 1 , the controller 9 can be provided in the cylindrical portion 2, for example. The controller 9 can also be provided in a position separated from the cylindrical portion 2. A terminal block 9a electrically connected to the controller 9 and the light source 5 can also be provided.

[0040] The window 6 is plate-shaped and has a peripheral region and a central region inside the peripheral region. The surface of the central region opposite the base 53 side can be a substantially flat surface. The window 6 is provided between the base 53 and the holding part 8. The window 6 is provided, for example, on the surface of the base 53 where the recess 53a opens. A sealing member 55 such as an O-ring can be provided between the peripheral region of the window 6 and the base 53. The opening of the recess 53a is sealed liquid-tight by the window 6 and the sealing member 55.

[0041] The window 6 faces the light source 5. The window 6 is made of a material that can transmit ultraviolet light emitted from the light source 5 and is resistant to ultraviolet light and the fluid 301a. The window 6 is made of, for example, quartz glass or a fluororesin that transmits ultraviolet light.

[0042] As will be described later, the blade 73a of the remover 73 comes into contact with the surface of the window 6 opposite to the light source 5. Therefore, it is preferable that the surface roughness Ra of the surface of the window 6 opposite to the light source 5 is 0.2 μm or less. In this way, the water wheel 71 provided with the remover 73 can rotate smoothly.

[0043] Ultraviolet light emitted from the light source 5 is irradiated onto the fluid 301a flowing inside the tubular portion 2 through the window 6. A portion of the ultraviolet light irradiated onto the inside of the tubular portion 2 is reflected by the inner surface of the tubular portion 2, and the reflected ultraviolet light is irradiated onto the fluid 301a. Therefore, the fluid 301a flowing inside the tubular portion 2 is sterilized by the ultraviolet light.

[0044] In this case, an anti-reflection film can be provided on the surface of the window 6 facing the light source 5. If an anti-reflection film is provided, it is possible to prevent the ultraviolet light emitted from the light-emitting element 51 from being reflected by the window 6 and becoming less irradiated onto the fluid 301a. In other words, it is possible to improve the utilization efficiency of the ultraviolet light emitted from the light-emitting element 51.

[0045] In addition, an anti-fouling film can be provided on the surface of the window 6 opposite the light source 5 side (the surface that comes into contact with the fluid 301a). As mentioned above, the fluid 301a may contain foreign matter. If foreign matter adheres to the window 6, it becomes difficult for the ultraviolet light emitted from the light emitting element 51 to pass through the window 6. If an anti-fouling film is provided, it is possible to prevent foreign matter from adhering to the window 6.

[0046] However, even if an antifouling film is provided on the window 6, if there is a relatively large amount of foreign matter, the foreign matter may adhere to the window 6. Moreover, over time, the foreign matter may adhere to the window 6. When the foreign matter adheres to the window 6, disassembling the fluid sterilization device 1 to remove the foreign matter adhered to the window 6 takes time and effort, and also reduces the operational rate of the fluid sterilization device 1. Therefore, the fluid sterilization device 1 is provided with a foreign matter removal section 7 that removes foreign matter adhering to the window 6 and prevents foreign matter from adhering to the window 6.

[0047] 2, for example, one foreign substance removal unit 7 can be provided for each window 6. The foreign substance removal unit 7 is provided on the side of the window 6 opposite the light source 5 side. The foreign substance removal unit 7 faces the window 6.

[0048] FIG. 3 is a schematic perspective view illustrating the foreign matter removal unit 7 and the holding unit 8. As shown in FIG. FIG. 4 is a schematic partial cross-sectional view of the foreign matter removal unit 7 and the holding unit 8 in FIG. 3, as viewed from the direction of line AA. As shown in FIGS. 3 and 4, the foreign matter removal unit 7 includes, for example, a water wheel 71, a support unit 72, and a removal unit 73.

[0049] The water turbine 71 rotates due to the reaction force generated when the fluid 301a passes through the multiple blades 71a of the water turbine 71. The water turbine 71 is a reaction water turbine. The water turbine 71 illustrated in FIG. 3 is a propeller water turbine, which is an example of a reaction water turbine. The central axis of rotation of the water turbine 71 can be approximately coaxial with the central axis of the tubular portion 2.

[0050] The water turbine 71 has, for example, a plurality of blades 71 a, a ring 71 b, an arm 71 c, and a boss 71 d. For example, the plurality of blades 71 a, the ring 71 b, the arm 71 c, and the boss 71 d can be integrally formed. The water turbine 71 can be made of, for example, a metal such as an aluminum alloy or stainless steel.

[0051] The blades 71a are arranged, for example, on the outer surface of the ring 71b at predetermined intervals.

[0052] The ring 71b has, for example, a circular ring shape. In a direction intersecting the central axis of the cylindrical portion 2, the inner surface of the ring 71b is located outward from the side surface of the recess 53a of the base 53. Therefore, when the ultraviolet light emitted from the light source 5 is incident on the inner surface of the ring 71b, it is possible to prevent a decrease in the amount of ultraviolet light irradiated onto the fluid 301a.

[0053] The arm 71c is provided on the opposite side of the ring 71b from the light source 5 side. A plurality of arms 71c can be provided. For example, the plurality of arms 71c can be provided at positions that are rotationally symmetrical about the central axis of rotation of the water wheel 71. The number of arms 71c can be changed as appropriate depending on the dimensions of the ring 71b in the direction intersecting with the central axis of the cylindrical portion 2, etc.

[0054] The arm 71c extends between the ring 71b and the boss 71d. One end of the arm 71c is provided at the end of the ring 71b opposite to the light source 5 side. The other end of the arm 71c is provided on the side surface of the boss 71d.

[0055] The boss 71d extends along the central axis of the cylindrical portion 2. The boss 71d is provided inside the ring 71b. The central axis of the boss 71d can be the central axis of rotation of the water turbine 71. 4, the boss 71d has a through hole extending in a direction along the central axis of the boss 71d. A sliding bearing 71d1 can be provided in the through hole of the boss 71d.

[0056] The support portion 72 rotatably supports the water turbine 71 via a sliding bearing 71d1. As shown in FIGS. 3 and 4, the support portion 72 includes, for example, a stand 72a, a beam 72b, and a support shaft 72c.

[0057] As shown in Figures 3 and 4, the stand 72a is rod-shaped and extends in a direction along the central axis of the tube portion 2. One end of the stand 72a is provided at the end of the holder 8 opposite the light source 5 side. A plurality of stands 72a may be provided. The stand 72a may be made of metal such as an aluminum alloy or stainless steel, for example.

[0058] The beam 72b is provided at the end of the stand 72a opposite to the holding portion 8 side. The beam 72b is rod-shaped and extends in a direction intersecting the central axis of the cylindrical portion 2. The beam 72b can be provided, for example, approximately parallel to the surface of the window 6 opposite to the light source 5 side. The beam 72b can be formed from, for example, a metal such as an aluminum alloy or stainless steel.

[0059] The support shaft 72c is, for example, rod-shaped and extends between the beam 72b and the window 6 in a direction along the central axis of the cylindrical portion 2. The central axis of the support shaft 72c can be approximately coaxial with the central axis of the cylindrical portion 2. The vicinity of one end of the support shaft 72c is provided in the center portion of the beam 72b. A gap is provided between the other end of the support shaft 72c and the window 6. The support shaft 72c can be formed from, for example, an aluminum alloy, stainless steel, or other metal.

[0060] As shown in Figures 3 and 4, the removal unit 73 is provided on the water wheel 71. The removal unit 73 is provided on the side of the window 6 opposite the light source 5. When the fluid 301a flows inside the tube portion 2, the removal unit 73 rotates together with the water wheel 71 to remove foreign matter adhering to the window 6 or to prevent foreign matter from adhering to the window 6.

[0061] It is possible to provide at least one removal unit 73. The foreign matter removal unit 7 illustrated in Figures 3 and 4 is provided with two removal units 73. For example, the two removal units 73 can be provided at symmetrical positions on either side of the support shaft 72c.

[0062] The removal portion 73 includes, for example, a blade 73a, a support portion 73b, and a biasing portion 73c.

[0063] The blade 73a has, for example, a plate-like shape and extends in one direction. For example, the blade 73a extends along the window 6, and one end contacts the surface of the window 6 opposite the base 53 side in the central region. In the thickness direction of the blade 73a, the dimension of the end of the blade 73a on the window 6 side is smaller than the dimension of the end of the blade 73a opposite the window 6 side. For example, the thickness direction dimension of the end of the blade 73a on the window 6 side decreases toward the tip. For example, the thickness direction dimension of the end of the blade 73a on the window 6 side can be 0.5 mm or less. For example, the end of the blade 73a on the window 6 side can be sharpened. For example, the end of the blade 73a on the window 6 side can be sloped or tapered. For example, the slope angle can be approximately 10° to 60°.

[0064] Holes 73a1 and 73a2 that penetrate the blade 73a in the thickness direction may be provided near the end of the blade 73a opposite the window 6. For example, in the direction in which the blade 73a extends, hole 73a1 may be provided near one end of the blade 73a, and hole 73a2 may be provided near the other end of the blade 73a.

[0065] The blade 73a is preferably formed from a material that is resistant to the fluid 301a and ultraviolet rays, has low water absorption, is non-sticky, has a low coefficient of friction, is insulating, and is heat resistant. For example, the blade 73a can be formed from a fluororesin such as PTFE (polytetrafluoroethylene). If the blade 73a contains a fluororesin and has a sharp end on the window 6 side, the blade 73a can move smoothly even in the fluid 301a, which does not allow the use of a lubricant.

[0066] Furthermore, it is preferable that the Rockwell hardness of the blade 73a is equal to or less than HR 120. This can improve the wear resistance of the blade 73a.

[0067] The support portion 73b is rod-shaped and can be provided as a pair. The pair of support portions 73b are provided on the water turbine 71 and are movable in a direction along the central axis of the tubular portion 2. The support portion 73b can be provided on an arm 71c of the water turbine 71 so as to be slidable in a direction along the central axis of the tubular portion 2, for example. For example, the support portion 73b can be provided on the arm 71c via a sliding bearing 71c1.

[0068] A pin 73b1 extending in a direction intersecting the direction in which the support portion 73b extends can be provided near the end of the support portion 73b on the window 6 side. The pin 73b1 provided on one support portion 73b can be provided inside a hole 73a1 in the blade 73a. The pin 73b1 provided on the other support portion 73b can be provided inside a hole 73a2 in the blade 73a. The support portion 73b and the pin 73b1 can be made of a metal such as stainless steel.

[0069] In this case, as shown in FIG. 4 , the hole 73a2 extends, for example, along the window 6. For example, the hole 73a2 can be an elongated hole extending in the direction in which the blade 73a extends. In this way, the blade 73a can be rotated around the pin 73b1 provided inside the hole 73a1. That is, the pair of supports 73b provided with the pin 73b1 move the blade 73a toward the window 6, and the blade 73a can be rotated around the pin 73b1 provided inside the hole 73a1 so as to follow the surface of the window 6. Therefore, when the blade 73a rotates along the surface of the window 6, it is possible to prevent a gap from being formed between the end of the blade 73a and the surface of the window 6. As a result, it is possible to prevent the occurrence of an area in which foreign matter adhering to the window 6 cannot be removed.

[0070] The biasing portion 73c is provided between the water wheel 71 and the blade 73a, and presses the blade 73a against the window 6 by elastic force. The biasing portion 73c biases the blade 73a toward the window 6 via, for example, a pair of support portions 73b. The biasing portion 73c can be provided, for example, between the pair of support portions 73b and the arm 71c of the water wheel 71. The biasing portion 73c can be, for example, a leaf spring. The biasing portion 73c is formed, for example, from stainless steel, spring steel, or the like.

[0071] As shown in FIG. 4, the holding portion 8 is, for example, plate-shaped. The holding portion 8 faces the base 53. A hole 8a is provided in the central portion of the holding portion 8, penetrating the thickness direction. A window 6 is exposed inside the hole 8a. When viewed from a direction along the central axis of the tubular portion 2, the shape of the holding portion 8 is, for example, a ring. The dimension (outer diameter dimension) of the holding portion 8 in a direction intersecting the central axis of the tubular portion 2 can be, for example, approximately the same as the dimension (outer diameter dimension) of the base 53.

[0072] The holding portion 8 holds the window 6 by pressing the peripheral region of the window 6 against the base 53. Therefore, when viewed from the direction along the central axis of the cylindrical portion 2, the hole 8a is located inside the peripheral edge of the window 6.

[0073] Furthermore, holder 8 is detachably attached to base 53 using a plurality of bolts. In this case, if the heads of the plurality of bolts protrude from the end of holder 8 on the side opposite to base 53, ultraviolet light irradiated through window 6 is more likely to be incident on the heads of the plurality of bolts. When ultraviolet light irradiated through window 6 is incident on the heads of the plurality of bolts, the amount of ultraviolet light irradiated on fluid 301a is reduced accordingly.

[0074] 4, threaded holes are provided in the holder 8, and the holder 8 is attached to the base 53 by bolts inserted from the side of the base 53. In this way, the heads of the multiple bolts are positioned on the side of the base 53, so that ultraviolet light irradiated through the window 6 can be prevented from entering the heads of the multiple bolts.

[0075] 3, a plurality of holes 8b are provided near the periphery of the holder 8. The plurality of holes 8b penetrate the holder 8 between one surface and the other surface in the thickness direction. The holes 8b communicate with the holes 53b in the base 53 of the light source 5. The holes 53b and 8b function as nozzle holes that supply the fluid 301a to the blades 71a of the water turbine 71.

[0076] 3, it is preferable that each of the holes 8b overlaps with a blade 71a of the water turbine 71 when viewed from the direction along the central axis of the tubular portion 2. In this way, the fluid 301a can be efficiently supplied to the blades 71a from the holes 8b. This allows the water turbine 71 to rotate smoothly, and ultimately allows the removal unit 73 to efficiently remove foreign matter.

[0077] It is also preferable that the positional relationship between the holes 8b and the blades 71a overlapping the holes 8b be substantially the same for each of the multiple holes 8b when viewed from the direction along the central axis of the tubular portion 2. In this way, the amount of fluid 301a supplied to each of the multiple blades 71a is the same, which makes the rotation of the water turbine 71 smoother and ultimately allows the removal unit 73 to remove foreign matter more efficiently.

[0078] In addition, if multiple wings 71a are arranged outside the holding portion 8 and the base 53 in a direction intersecting the central axis of the tubular portion 2, the multiple holes 8b in the holding portion 8 and the multiple holes 53b in the base 53 can be omitted.

[0079] As described above, the rotational movement of the blade 73a causes foreign matter adhering to the window 6 to be peeled off from the window 6. The foreign matter peeled off from the window 6 moves toward the peripheral edge of the window 6 as the blade 73a rotates, and is then expelled from the peripheral edge of the window 6 to the outside.

[0080] As described above, the holder 8 is provided in the peripheral region of the window 6. Therefore, if foreign matter that has moved to the peripheral side of the window 6 hits the edge of the hole 8a of the holder 8, the foreign matter is prevented from being discharged. If the foreign matter that is prevented from being discharged accumulates near the peripheral edge of the window 6, the accumulated foreign matter may prevent ultraviolet light from being irradiated onto the fluid 301a. If ultraviolet light is prevented from being irradiated onto the fluid 301a, the sterilization effect may be reduced.

[0081] 4, when the distance between the base 53 and the end of the holding part 8 on the opposite side to the base 53 side in the direction along the central axis of the cylindrical part 2 is set to Ha (mm), and the distance between the base 53 and the surface of the window 6 in the central region on the opposite side to the base 53 side is set to Hb (mm), the relationship "Ha (mm) ≦ Hb (mm)" is satisfied. In the case of the holding part 8 illustrated in FIG. 4, "Ha (mm) <Hb(mm)」としている。

[0082] In this way, there are no protrusions near the periphery of the window 6, and foreign matter that has moved to the periphery of the window 6 is smoothly discharged to the outside of the window 6. Therefore, it is possible to prevent foreign matter from accumulating near the periphery of the window 6.

[0083] For example, as shown in FIG. 4, the peripheral region of the window 6 can be inclined in a direction approaching the base 53 as it approaches the periphery. For example, an inclined portion 6a can be provided in the peripheral region of the window 6. Furthermore, the retaining portion 8 can be provided with an inclined portion 8c that comes into contact with the inclined portion 6a. The inclined portion 8c is inclined in a direction away from the base 53 as it approaches the center of the hole 8a. As shown in FIG. 4, the inclined portions 6a and 8c can be in direct contact with each other. Furthermore, a sheet made of a material such as a fluororesin can be sandwiched between the inclined portions 6a and 8c.

[0084] FIG. 5 is a schematic cross-sectional view illustrating a window 16 and a holding portion 18 according to another embodiment. As shown in FIG. 5, the thickness of the peripheral region of window 16 can be smaller than the thickness of the central region of window 16. For example, a step 16a can be provided in the peripheral region of window 16. In window 16, the inclined portion 6a of window 6 described above can be replaced with step 16a. In retaining portion 18, the inclined portion 8c of retaining portion 8 described above can be replaced with step 18c. As shown in FIG. 5, step 16a and step 18c can be in direct contact with each other. Alternatively, a sheet made of a fluororesin or the like can be sandwiched between step 16a and step 18c.

[0085] In this embodiment as well, when the distance between the base 53 and the end of the holding portion 18 on the opposite side to the base 53 side in the direction along the central axis of the tubular portion 2 is Ha (mm), and the distance between the base 53 and the surface of the window 16 in the central region on the opposite side to the base 53 side is Hb (mm), the relationship "Ha (mm) ≦ Hb (mm)" is satisfied. In the case of the holding portion 18 illustrated in FIG. 5, "Ha (mm) <Hb(mm)」としている。

[0086] In this way, there are no protruding objects near the periphery of the window 16, and foreign matter that has moved to the periphery of the window 16 is smoothly discharged to the outside of the window 16. Therefore, it is possible to prevent foreign matter from accumulating near the periphery of the window 16.

[0087] Furthermore, although the above description has been given of a case where the foreign matter removal unit 7 is provided, the holder 8 and window 6, or the holder 18 and window 16, can also be applied when the foreign matter removal unit 7 is not provided. For example, if there is a protrusion near the periphery of the window 6 or window 16, stagnation is likely to occur in the flow of the fluid 301a. When stagnation occurs, foreign matter is likely to remain, and there is a risk that the foreign matter will interfere with the irradiation of ultraviolet light to the fluid 301a.

[0088] As described above, if the retaining portion 8 and the window 6, or the retaining portion 18 and the window 16 are used, there will be no protrusions near the periphery of the window 6 or the window 16, which will prevent stagnation from occurring. Therefore, it will be possible to prevent foreign matter from accumulating near the periphery of the window 6 or the window 16.

[0089] However, if the foreign matter removal unit 7 is provided, the rotating blade 73a can peel off foreign matter adhering to the window 6 or window 16, and furthermore, the peeled off foreign matter can be moved to the peripheral edge side of the window 6 or window 16. Therefore, if the foreign matter removal unit 7 is provided, it is possible to more effectively prevent foreign matter from accumulating near the peripheral edge of the window 6 or window 16.

[0090] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0091] 1 fluid sterilization device, 2 cylindrical portion, 5 light source, 6 window, 6a inclined portion, 7 foreign body removal portion, 8 holding portion, 8a hole, 8c inclined portion, 16 window, 16a step, 18 holding portion, 18c step, 51 light emitting element, 53 base, 53b hole, 71 water wheel, 71a blade, 73a blade, 301a fluid

Claims

1. a cylindrical portion; a light source having a base provided inside the cylindrical portion and irradiating ultraviolet light; a holding portion facing the base; a window provided between the base and the holder, the window transmitting the ultraviolet light irradiated from the light source; Equipped with the window has a peripheral region and a central region inward of the peripheral region; the holding portion presses the peripheral region of the window toward the base; A fluid sterilization device that satisfies the following formula, where Ha (mm) is the distance between the base and the end of the holding part opposite the base side in a direction along the central axis of the cylindrical part, and Hb (mm) is the distance between the base and the surface of the window in the central region opposite the base side. Ha (mm)≦Hb (mm)

2. 2. The fluid sterilizing device according to claim 1, wherein the peripheral region of the window is inclined in a direction approaching the base as it approaches the peripheral edge.

3. 2. The fluid sterilization device of claim 1, wherein the thickness of the peripheral region of the window is less than the thickness of the central region of the window.

4. a water wheel provided inside the cylindrical portion; a blade provided on the water wheel and contacting the surface of the window opposite to the base side in the central region; The fluid sterilizing device according to any one of claims 1 to 3, further comprising:

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