Fluid sterilization device

Abstract

To provide a fluid sterilization device that achieves uniformly high sterilization effect for fluids such as water and air flowing within the tube.SOLUTION: A fluid sterilization device includes a cylindrical device main body 1, an inflow-side connection part 2, an outflow-side connection part 3, a conical flow straightener 4 incorporated inside the device main body 1, a flow straightening plate 6 having a fluid passage hole 5 arranged so as to be connected to the flow straightener in a circumferential shape near the inner wall of the tube, an ultraviolet light transmission plate 7 positioned at the center of the flow straightening plate, a deep ultraviolet LED 8 incorporated adjacent to the ultraviolet light transmission plate, a mirror surface 14, and an electrical control part 15. Although it is described that the device is installed on the upstream side, a device with the same configuration can be installed on the downstream side as well, and the use of both devices can further enhance sterilization effects.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides a fluid sterilization device that inactivates viruses and disinfects general bacteria in fluids such as water and air flowing through pipes installed in manufacturing plants, various facilities, offices, and ordinary homes. To use this device, if the target fluid is water, installing this fluid sterilization device in the water supply pipe will inactivate and disinfect viruses contained in the water flowing through the pipe, thereby providing clean water. Furthermore, when delivering water from a water purification plant or factory water storage tank, it does not rely on chemical sterilization methods such as chlorine agents, and physical sterilization like the present invention does not pose a safety hazard, allowing for the provision of high-quality water. Furthermore, if the target fluid is air, for example, connecting this fluid sterilization device to the ceiling pipe that brings outdoor air into the building will effectively inactivate and disinfect viruses in the air, allowing clean and safe air to be brought into the room. [Background technology]

[0002] Generally, sterilization of water or air flowing through pipes has not been widely practiced until now. Furthermore, there have been few indoor air supply devices with additional functions such as sterilization. However, there will continue to be concerns about the spread of various viruses and bacteria in daily life. Furthermore, when the target fluid is water, ensuring safe water is an important infrastructure element in general drinking water and food and beverage factories. Furthermore, when the target fluid is air, this invention is an invention that implements measures for air supply to indoor spaces. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-141292 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-121319 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a fluid sterilization device 1 includes a cylindrical body 5 having a flow path through which a fluid to be sterilized flows in an axial direction, a light source 3 having an ultraviolet LED that emits ultraviolet light toward the fluid, and a rectifying unit 8 provided inside the cylindrical body 5 on the side of an inlet 5a through which the fluid flows and rectifies the flow of the fluid. The rectifying unit 8 is composed of a plurality of rectifying plates 8A, 8B that are spaced apart from each other in the axial direction and each have a plurality of holes through which the fluid passes. The rectifying unit is composed of at least a first rectifying plate provided closest to the inlet and a second rectifying plate provided downstream of the first rectifying plate in the flow path. The main selling point of Patent Document 1 is the configuration of the rectifying plates. However, a problem with Patent Document 1 is that while the fluid is straightened immediately after passing through the first and second straightening plates located immediately after the inlet, the laminar flow becomes disrupted and turbulent near the LED light source irradiation position, far from the straightening plates, where the outflow direction changes perpendicular to the inflow direction, resulting in an uneven flow rate. This leads to a problem of increased sterilization performance due to differences in flow rate within the pipe, resulting in a reduced sterilization effect. Another problem is increased flow path resistance when the flow path changes direction at a right angle. Patent Document 2 also describes a technology for improving the efficiency of sterilizing fluids using ultraviolet light. The solution is a fluid sterilization device that includes a flow path for the fluid and a light source that irradiates ultraviolet light toward the fluid flowing through the flow path. The flow path may include a straight pipe extending longitudinally, and the fluid may flow through the flow path in a laminar flow state. The light source may irradiate ultraviolet light so that the ultraviolet light intensity near the center of the cross section of the flow path perpendicular to the longitudinal direction is higher than the ultraviolet light intensity around the center. In their own research, they found that when irradiating ultraviolet light into a straight tubular flow path to perform a sterilization treatment, laminar flow achieved approximately seven times the sterilization efficiency than turbulent flow. Furthermore, since fluids in laminar flow generally have a velocity distribution in which the flow velocity is fastest near the center and slowest near the inner wall of the tube, they stated that by increasing the intensity of ultraviolet light near the center in accordance with this velocity distribution, it is possible to effectively irradiate the fluid flowing inside the flow path with ultraviolet light and improve sterilization efficiency.In the case of Patent Document 2 mentioned above, the diameter of the tube into which the fluid flows within the flow path is smaller than that of the tube body, and is positioned at the center of the tube body, i.e., the position where the flow velocity is usually greatest, and the element that emits ultraviolet light is configured to irradiate the fluid near the inner wall of the tube body, which has a slower flow velocity.The problem is that the irradiated light is weak near the center where the flow velocity within the tube is fast, and the irradiated illuminance is strongest near the inner wall of the tube body, where the flow velocity is slower, which is a completely opposite arrangement.

[0005] The present invention was conceived in view of the above and aims to solve the problems described in Prior Art Documents 1 and 2. Specifically, the inflow and outflow directions are not perpendicular but are collinear, and the flow velocity of the inflowing fluid varies depending on the cross-sectional position within the tube, i.e., the maximum flow velocity is near the center of the tube. The flow is regulated and uniformly dispersed by a flow straightening section located near the inner wall of the tube. Furthermore, by circumferentially arranging the fluid passage holes near the inner wall of the cylindrical device body, the flow velocity, which is typically fastest near the center of the tube, can be equalized, forming a laminar flow within the tube. With the above configuration, by irradiating the fluid with deep ultraviolet light parallel to the flow of the fluid, which has been equalized to form a laminar flow, the fluid can be uniformly irradiated, thereby improving the sterilization effect. Furthermore, by providing a mirror-finish inner wall surface of the device body, the light reflection effect can be used to achieve a higher sterilization effect. The deep-ultraviolet LEDs used in the present invention have a wavelength of 220-300 nm. University research institutes and companies have demonstrated that their inactivation and sterilization effects against the novel coronavirus and all common bacteria are over 99% under certain conditions, as reported in papers. Users of the fluid sterilization device of the present invention can provide a sterilization device with a sterilization function using physical means that are safe for the human body by adding the device to the middle of a piping path for a fluid flowing through a pipe. For example, if the target fluid is water, connecting the device to the middle of a piping system that supplies water from a water storage tank to a specified location allows for the supply of sterilized, clean, and safe water to the desired location. Furthermore, if the target fluid is air, for example, when outdoor air is supplied to a room through a piping system in the ceiling, sterilization is performed inside the device, which is connected to the middle of the piping. [Means for solving the problem]

[0006] When the target fluid is water, the fluid sterilization device of the present invention can easily perform its sterilization function by adding it to the middle of the piping when supplying water to food and beverage factories, water purification plants, medical and nursing care facilities, etc. Furthermore, when the target fluid is air, it can be used as a device that can perform sterilization while ventilating in rooms of large facilities, food and beverage factories, precision equipment factories, medical and nursing care institutions, livestock houses such as poultry farms, general offices, and indoor spaces in homes. Furthermore, the fluid sterilization device of the present invention can be effectively used as a means of solving problems that require reliable inactivation and sterilization measures against highly infectious viruses and common bacteria. An embodiment of the fluid sterilization device of the present invention will be described. The fluid sterilization device of the present invention is a device comprising: a cylindrical device main body 1 having a hollow interior and openings on the inlet and outlet sides through which fluid can flow; an inlet-side connection part 2; an outlet-side connection part 3; a conical rectifying part 4 incorporated inside the device main body 1; a rectifying plate 6 arranged perpendicular to the device main body at a position connected to the rectifying part 4 and having a plurality of fluid passage holes 5 arranged circumferentially near the inner wall of the device main body 1; a deep-ultraviolet LED 8 attached adjacent to an ultraviolet-transmitting plate 7 at the front of the rectifying plate 6, which emits irradiation light parallel to the fluid flow direction toward the downstream side, a mirror surface 14 on the inner wall of the device main body 1; and an electrical control unit 15. The downstream side of the device main body 1 also has the same configuration as described above, that is, it is composed of a conical rectifier 9 incorporated inside the device main body 1, a rectifier plate 11 that is perpendicular to the device main body at a position connected to the rectifier 9 and has a plurality of fluid passage holes 10 arranged circumferentially at a position close to the inner wall of the device main body, a deep-ultraviolet LED 13 attached adjacent to an ultraviolet-transmitting plate 12 at the front part of the rectifier plate 11 that emits irradiation light parallel to the fluid flow direction toward the upstream side at the center of the rectifier plate 11, a mirror surface 14 provided on the inner wall of the device main body 1, and an electrical control unit 15 that electrically controls the deep-ultraviolet LED 8 and the deep-ultraviolet LED 13. Furthermore, when sterilization is performed only from the upstream side to the downstream side within the device main body 1, or when sterilization is performed by irradiating from the downstream side to the upstream side, it is also possible to operate both the upstream side and the downstream side simultaneously. [Effects of the Invention]

[0007] According to the present invention, for example, when the fluid is water, the water passing through the piping from the inlet-side connection 2 is equalized by the rectifier 4 attached to the cylindrical device body 1, which equalizes the difference in flow velocity across the cross section of the pipe, and flows through the fluid passage holes 5 arranged on the circumference of the rectifier plate 6 near the inner wall of the device body 1, thereby forming a laminar flow with a nearly uniform flow velocity within the device body. Light emitted from the deep-ultraviolet LED 8 strikes the fluid downstream toward the fluid, thereby sterilizing bacteria contained in the fluid. Furthermore, by providing a mirror surface 14 on the inner wall surface of the device body, the light emitted from the deep-ultraviolet LED 8 is amplified by the reflection effect of the mirror surface, thereby sterilizing the water evenly and effectively. Furthermore, when the target fluid is air, the same process as for water is carried out to inactivate and sterilize viruses and bacteria contained in the air. Furthermore, in the sterilization space within the mirror surface 14 inside the device body 1, which has a cross-section larger than the cross-sectional areas of the inlet and outlet connectors, the fluid velocity slows inversely proportional to the cross-sectional area, improving the sterilization effect of the deep-UV LED. Furthermore, the cross-sectional flow velocity distribution of a fluid passing through the fluid passage holes near the inner wall of the device body is typically a parabola with the fastest velocity at the center of the tube, so the flow velocity near the inner wall of the tube, where the velocity is lowest, increases, and the flow velocity within the tube is equalized. By providing multiple circumferential fluid passage holes near the inner wall of the device body, the fluid within the device body is irradiated with deep UV light while passing through in a laminar flow with a nearly uniform flow velocity, improving the sterilization effect. Furthermore, by configuring the downstream side in the same way as the upstream side, a synergistic effect between the upstream and downstream sides is achieved, further enhancing the sterilization effect. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front cross-sectional view of a fluid sterilization device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a partially enlarged front cross-sectional view of a fluid sterilization device according to an embodiment of the present invention; [Figure 3] 1 is a side cross-sectional view of a fluid sterilization device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0009] A fluid sterilization device according to an embodiment of the present invention will be described below with reference to Figures 1 to 3. In all the following drawings, the dimensions and proportions of each component are shown differently as appropriate to facilitate understanding. [Example]

[0010] As shown in Figures 1 to 3, in this embodiment of the fluid sterilization device of the present invention, when the target fluid is water, for example, the water passing through the piping from the inlet-side connector 2 flows through a rectifier 4 in the device body 1 and a plurality of fluid passage holes 5 circumferentially provided in a rectifier plate 6 connected thereto, while equalizing the difference in flow velocity across the cross section of the pipe. Light emitted from deep-ultraviolet LEDs 8 that passes through an ultraviolet-transmitting plate 7 midway through the flow is irradiated onto the water flowing inside a cylindrical pipe having a mirrored inner wall 14, thereby achieving uniform and effective sterilization. Furthermore, when the target fluid is air, the same process as that described above for water is used to inactivate and sterilize viruses and bacteria contained in the air. [Industrial Applicability]

[0011] In industrial applications, when the fluid is water, the fluid sterilization device is connected to the piping of the water supply route in facilities requiring purified water, such as water purification facilities, food and beverage factories, and medical and nursing care facilities. Furthermore, when the fluid is air, the device is installed indoors in large facilities where many people gather, in the ceilings of food and beverage companies, medical and welfare facilities, research institutes, precision equipment factories, poultry farms, general offices, and household rooms. By connecting the fluid sterilization device to the piping that draws and supplies outdoor air indoors, it is possible to inactivate and sterilize viruses floating in the air, thereby supplying purified air indoors. Reference symbols: Device body 1, inlet side connection portion 2, outlet side connection portion 3, rectification portion 4, fluid passage hole 5, rectification plate 6, ultraviolet-transmitting plate 7, deep-ultraviolet LED 8, rectification portion 9, fluid passage hole 10, rectification plate 11, ultraviolet-transmitting plate 12, deep-ultraviolet LED 13, mirror portion 14, and electrical control portion 15.

Claims

1. a flow straightening unit disposed inside the body parallel to the flow path and regulating the flow to guide the fluid close to the inner wall of the tube; a flow straightening plate disposed downstream of the flow straightening unit and perpendicular to the tube; an ultraviolet light transmitting plate disposed near the center of the flow straightening plate; an LED for sterilization that transmits the ultraviolet light transmitting plate and emits light toward the downstream side in a direction parallel to the flow of the fluid; a plurality of fluid passage holes disposed circumferentially near the cylindrical inner wall of the flow straightening plate; and an electrical control unit.

2. 2. The fluid sterilization device according to claim 1, wherein the LED of the sterilization means irradiated toward the fluid in the cylindrical device body is a deep ultraviolet LED that emits light with a wavelength in the range of 220 to 300 nm.

3. The fluid sterilization device according to claim 1 or 2, wherein the cross-sectional area of ​​the flow path inside the cylindrical device body is larger than the cross-sectional area of ​​the inlet-side connecting portion or the outlet-side connecting portion.

4. 4. The fluid sterilization device according to claim 1, 2, or 3, wherein the inner surface of the cylindrical device body is formed as a mirror surface.

5. The fluid sterilization device according to claim 1, 2, 3, and 4, characterized in that it comprises a straightening plate disposed inside the cylindrical device body and on the downstream side of the flow path perpendicular to the tube, an ultraviolet-transmitting plate disposed near the center of the straightening plate, an LED for sterilization that transmits the ultraviolet-transmitting plate and emits light toward the upstream direction in a direction parallel to the flow of the fluid, a plurality of fluid passage holes disposed circumferentially near the cylindrical inner wall of the straightening plate, and a straightening section that regulates the flow inside the device body and guides the fluid from near the inner wall of the tube toward the center of the tube.

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