JP7525025B2 - Fluid Sterilization Device - Google Patents

Description

The present invention relates to a fluid sterilization device.

Conventionally, there is known a fluid sterilization device that sterilizes fluids such as water by irradiating them with ultraviolet light (see, for example, Patent Document 1). The fluid sterilization device of Patent Document 1 is equipped with a housing having a flow path through which the fluid to be sterilized flows in the axial direction, an inlet through which the fluid flows, and an outlet through which the fluid flows out, with the inlet provided at one axial end of the housing and a light source module device that emits ultraviolet light attached to the other end of the housing.

In addition, the wavelength of the ultraviolet light emitted by the light source module device is 240 to 380 nm, and stainless steel is listed as a material for the housing whose inner surface is irradiated with the ultraviolet light.

JP 2020-89462 A

In a fluid sterilization device such as that described in Patent Document 1, the material of the housing whose inner surface is irradiated with ultraviolet light is required to be a material such as fluororesin that has excellent resistance to and reflectance against ultraviolet light.

However, fluororesin is an expensive material. In particular, PTFE (polytetrafluoroethylene), a fluororesin with excellent reflectance to ultraviolet light in the UV-C wavelength range (less than 280 nm), which has a high bactericidal effect, has an extremely high melt viscosity and cannot be processed by normal melt processing. To process it into the desired shape, it is necessary to cut it from a block produced by compressing and sintering PTFE powder, which results in very high material and processing costs.

For this reason, if the housing material of a fluid sterilization device such as that described in Patent Document 1 were simply replaced with fluororesin, the sterilization efficiency would increase because the reflectance of the housing to ultraviolet light would increase, but the manufacturing costs would become extremely high.

The object of the present invention is to provide a fluid sterilization device that sterilizes fluids such as water by irradiating them with ultraviolet light, and that uses fluororesin as the material for the flow passage pipes through which the fluid flows, while keeping manufacturing costs down.

In order to achieve the above object, one aspect of the present invention provides the following fluid sterilization device.

[1] A fluid sterilization device comprising: a flow path for flowing a fluid to be sterilized, an inlet for allowing the fluid to flow into the flow path, and an outlet for allowing the fluid to flow out of the flow path; and an ultraviolet light irradiation module that irradiates ultraviolet light into the flow path, wherein the flow path pipe has a cylindrical first portion and a second portion connected to one end of the first portion, the first portion being made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module, the second portion having an attachment portion for attaching the ultraviolet light irradiation module and the inlet or the outlet, and a reflective material made of a fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module is provided along an inner surface of the second portion, which constitutes an inner wall of the flow path, and the reflective material has holes through which the fluid passes.
[2] A fluid sterilization device comprising: a flow path for flowing a fluid to be sterilized, an inlet for allowing the fluid to flow into the flow path, and an outlet for allowing the fluid to flow out of the flow path; and an ultraviolet light irradiation module that irradiates ultraviolet light into the flow path, wherein the flow path pipe has a cylindrical first portion and a second portion connected to one end of the first portion, the first portion being made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module, the second portion having an attachment portion for attaching the ultraviolet light irradiation module and the inlet or the outlet, a reflective material made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module is provided along an inner surface of the second portion, which constitutes an inner wall of the flow path, and the reflective material is installed in a cylindrical region between the ultraviolet light irradiation module and the first portion within the second portion.
[3] A fluid sterilization device as described in [1] above, wherein the area of the hole is larger than the area of the inlet and the outlet.
[4] The fluid sterilization device according to any one of [1] to [3] above, wherein the second part has the outlet, and an end of the first part opposite to the end of the first part on the second part side is covered with a flat diffusion plate having a hole through which the fluid passes at a position away from the center thereof and diffusing the fluid flowing in from the inlet, the diffusion plate being made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module.

The present invention provides a fluid sterilization device that sterilizes fluids such as water by irradiating them with ultraviolet light, and that uses fluororesin as the material for the flow passage pipe through which the fluid flows, while keeping manufacturing costs down.

FIG. 1 is a perspective view of a fluid sterilizing device according to an embodiment of the present invention. 2(a) and (b) are a side view of the fluid sterilizing device as seen in the longitudinal direction and a side view as seen in a direction perpendicular to the longitudinal direction, respectively. FIG. 3 is a cross-sectional view of the fluid sterilization device taken along section line AA shown in FIG. 2(a). FIG. 4(a) is a plan view of a reflective material made of a rectangular sheet, and FIG. 4(b) is a perspective view of the reflective material made of a rectangular sheet rolled into a ring shape. 5A and 5B are a plan view and a cross-sectional view of an example of a diffusion plate. 6A and 6B are a plan view and a cross-sectional view of another example of the diffusion plate.

[Embodiment]
(Configuration of the Fluid Sterilization Device)
Fig. 1 is a perspective view of a fluid sterilization device 1 according to an embodiment of the present invention. Figs. 2(a) and 2(b) are a side view of the fluid sterilization device 1 as seen in the longitudinal direction and in a direction perpendicular to the longitudinal direction, respectively. Fig. 3 is a cross-sectional view of the fluid sterilization device 1 taken along the section line A-A shown in Fig. 2(a).

The fluid sterilization device 1 is a device for sterilizing fluids (mainly liquids such as water) and inhibiting bacterial growth, and is equipped with a flow path 101 for flowing the fluid to be sterilized, a flow path pipe 10 having an inlet 102 for allowing the fluid to flow into the flow path 101, and an outlet 103 for allowing the fluid to flow out of the flow path 101, and an ultraviolet light irradiation module 14 for irradiating ultraviolet light into the flow path 101.

The flow path pipe 10 has a cylindrical first portion 11, a second portion 12 having an outlet 103 connected to one end of the first portion 11, and a third portion 13 having an inlet 102 connected to the other end of the first portion 12. Here, the inner surfaces of the first portion 11, the second portion 12, and the third portion 13, mainly the inner surfaces of the first portion 11 and the second portion 12, form the inner wall of the flow path 101.

The first portion 11 is made of a fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module 14. Therefore, the light emitted from the ultraviolet light irradiation module 14 can be efficiently reflected by the inner surface of the first portion 11 that constitutes the inner wall of the flow path 101. Here, the fluororesin used as the material for the first portion 11 is a fluororesin that has high resistance and reflectance to ultraviolet light, such as PTFE, PFA (perfluoroalkoxyalkane), PVF (polyvinyl fluoride), and PVDF (polyvinylidene fluoride), and is usually white in color.

In particular, by using PTFE, which has excellent reflectance for ultraviolet light in the UV-C wavelength range (less than 280 nm) (hereinafter referred to as UVC light), as the material for the first part 11, sterilization can be effectively performed using the ultraviolet light irradiation module 14 that emits UVC light.

The first part 11 has a simple cylindrical shape, so that a commercially available general-purpose fluororesin pipe or the like can be used almost as is. In addition, in order to further reduce the processing steps of general-purpose products such as pipes, it is preferable that the first part 11 has a cylindrical shape with no irregularities on its inner and outer surfaces.

The second part 12 has an attachment part 121 for attaching the ultraviolet light irradiation module 14, and an outlet port 103. In addition, a sheet-like reflector 17 made of fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module 14 is provided along the inner surface of the second part 12, which is the inner wall of the flow path 101.

The second part 12 has an opening 123 for connecting with the first part 11, and the first part 11 and the second part 12 are connected by fitting one end of the first part 11 inside the opening 123. Here, in order to prevent leakage of fluid from the interface between the first part 11 and the second part 12, it is preferable to use a sealing member such as an O-ring 201 at the overlapping part of the first part 11 and the second part 12.

The ultraviolet light irradiation module 14 is attached to the second part 12, for example, by screwing a heat sink 146 and a cover 147 of the ultraviolet light irradiation module 14 (described later) to the mounting part 121 of the second part 12 using screws 148. Light emitted from the ultraviolet light irradiation module 14 passes through an opening 122 included in the mounting part 121 and is irradiated to the fluid in the flow path 101. Note that the opening 122 is blocked by the ultraviolet light irradiation module 14, so that water does not leak out from the opening 122.

In the example shown in Figures 1 to 3, the outflow pipe 16 is connected to the opening 124 on the outlet 103 side of the second part 12. The outflow pipe 16 is fitted and fixed inside the opening 124, and the opening of the outflow pipe 16 on the opposite side to the opening 124 functions as the outflow port 103. In this case, in order to effectively prevent fluid from leaking from the interface between the second part 12 and the outflow pipe 16, it is preferable to wrap sealing tape or the like around the part of the outflow pipe 16 that is fitted into the opening 124.

The reflective material 17 is provided, for example, by placing a sheet made of fluororesin along the inner surface of the second portion 12, or by applying paint made of fluororesin to the inner surface of the second portion 12. In order to prevent ultraviolet light from leaking out from the gap between the reflective material 17 and the first portion 11, it is preferable that the reflective material 17 is in contact with the end of the first portion 11 without any gaps. The reflective material 17 may be in close contact with the inner surface of the second portion 12, or there may be a gap between the reflective material 17 and the inner surface of the second portion 12.

When the reflective material 17 is a sheet made of fluororesin, it has holes 171 through which the fluid passes. There may be one hole 171, or it may be a collection of multiple holes. In order to prevent a decrease in the flow rate of the fluid in the flow tube 10 and an increase in pressure in the flow tube 10, it is preferable that the area of the hole 171 (or the total area of the holes if it is a collection of multiple holes) is larger than the areas of the inlet 102 and the outlet 103.

The fluororesin that is the material of the reflector 17 can be a fluororesin that reflects the light emitted from the ultraviolet light irradiation module 14, similar to the material of the first part 11. In particular, by using PTFE as the material of the reflector 17, sterilization can be effectively performed using the ultraviolet light irradiation module 14 that emits UVC light.

In addition, because the reflector 17 blocks much of the ultraviolet light directed toward the second portion 12, deterioration of the second portion 12 due to exposure to ultraviolet light can be suppressed. Therefore, the second portion 12 does not need to be resistant to ultraviolet light, and the range of materials that can be selected for the second portion 12 is expanded. For example, polycarbonate can be used as the material for the second portion 12.

In order to efficiently irradiate the light emitted from the ultraviolet light irradiation module 14 into the flow path 101, it is preferable that the opening 122 for taking in the light emitted from the ultraviolet light irradiation module 14 in the second part 12 and the opening 123 for connecting to the first part 11 face each other, in which case the area in the second part 12 where the reflector 17 is placed will be cylindrical. For this reason, a rectangular sheet made of fluororesin can be rolled into a ring shape and placed along the inner surface of the second part 12 to be used as the reflector 17.

In this case, it is preferable that the reflector 17 and the second portion 12 have a misalignment prevention structure that prevents the reflector 17 from misaligning with respect to the second portion 12. For example, it is preferable that the reflector 17 has a notch (cutout) 172 for preventing misalignment. By fitting this notch 172 into a rib (protrusion) 125 provided on the inner surface of the second portion 12, it is possible to prevent the reflector 17 from misaligning with respect to the second portion 12. Note that since the rib 125 of the second portion 12 is not covered by the reflector 17, it is preferable that it is provided on the ultraviolet light irradiation module 14 side where ultraviolet light is less likely to hit.

Figure 4(a) is a plan view of the reflector 17 made of a rectangular sheet, and Figure 4(b) is a perspective view of the reflector 17 made of a rectangular sheet rolled into a ring shape. In the example shown in Figures 4(a) and (b), the hole 171 is a group of four holes.

The light emitted from the ultraviolet light irradiation module 14 usually contains visible light in addition to ultraviolet light. For this reason, by using a material that transmits visible light, such as transparent polycarbonate, for the material of the second part 12, the visible light that leaks through the hole 171 of the reflector 17 and transmits through the second part 12 can be visually recognized, allowing the operation of the ultraviolet light irradiation module 14 to be confirmed.

The third part 13 has a shape that covers the end of the first part 11 on the third part 13 side, and has an inlet 102.

The third part 13 has an opening 131 for connecting with the first part 11, and the first part 11 and the third part 13 are connected by fitting one end of the first part 11 inside the opening 131. Here, in order to prevent leakage of fluid from the interface between the first part 11 and the third part 13, it is preferable to use a sealing member such as an O-ring 202 at the overlapping part of the first part 11 and the third part 13.

In the example shown in Figures 1 to 3, the inlet pipe 15 is connected to the opening 132 on the inlet 102 side of the third part 13. The inlet pipe 15 is fitted and fixed inside the opening 132, and the opening of the inlet pipe 15 opposite the opening 132 functions as the inlet 102. In this case, to effectively prevent fluid from leaking from the interface between the third part 13 and the inlet pipe 15, it is preferable to wrap sealing tape or the like around the part of the inlet pipe 15 that fits into the opening 132.

The functions of the inlet 102 and the outlet 103 in the flow path pipe 10 may be reversed. That is, the fluid may flow into the flow path 101 from the outlet 103 of the second part 12, and the fluid may flow out from the inlet 102 of the third part 13.

When a fluid flows into the flow path 101 from the inlet 102 and flows out from the outlet 103, i.e., when the inlet 102 functions as an inlet and the outlet 103 functions as an outlet, it is preferable that the end of the first part 11 on the third part 13 side (the end opposite the end on the second part 12 side), i.e., the fluid inlet of the first part 11, is covered by a flat diffusion plate 18.

Figures 5(a) and (b) are a plan view and a cross-sectional view of an example of the diffuser plate 18. The cross-section of the diffuser plate 18 shown in Figure 5(b) is a cross-section taken along the cutting line B-B shown in Figure 5(a).

The diffusion plate 18 has holes 181 through which fluid passes, located away from its center, and diffuses the fluid that flows in from the inlet 102. The holes 181 are not provided in the center of the diffusion plate 18, but are provided near the outer periphery of the diffusion plate 18 or in a position that is in contact with the outer periphery, so that the fluid that passes through the holes 181 flows near the inner wall of the first portion 11.

Generally, the flow rate of the fluid flowing through the flow path is slower due to frictional resistance closer to the inner wall of the flow path, and the difference in flow rate with respect to the center of the flow path becomes larger. However, by using the diffusion plate 18 to cause the fluid to flow near the inner wall of the first part 11, the flow rate near the inner wall of the first part 11 can be relatively increased, and the difference in flow rate between near the center and near the inner wall of the first part 11 can be reduced. This averages out the residence time of the fluid in the flow path 101, thereby reducing the variation in the ultraviolet light irradiation time due to differences in the fluid flow path, and enabling efficient sterilization.

In order to allow the fluid to flow as evenly as possible near the inner wall of the first portion 11, it is preferable that the multiple holes 181 are arranged at equal intervals along the circumferential direction of the diffusion plate 18. In addition, in order to prevent a decrease in the flow rate of the fluid in the flow passage pipe 10 and an increase in pressure in the flow passage pipe 10, it is preferable that the area of the hole 181 (the total area of the multiple holes 181 when multiple holes 181 are provided) is larger than the areas of the inlet 102 and the outlet 103.

To improve sterilization efficiency, the diffusion plate 18 is preferably made of a fluororesin that reflects the light emitted from the ultraviolet light irradiation module 14, similar to the material of the first part 11. In particular, by using PTFE as the material of the diffusion plate 18, sterilization can be effectively performed using the ultraviolet light irradiation module 14 that emits UVC light.

In addition, when the diffusion plate 18 is used, the diffusion plate 18 blocks much of the ultraviolet light heading toward the third portion 13, so that deterioration of the third portion 13 due to exposure to ultraviolet light can be suppressed. Therefore, the third portion 13 does not need to be resistant to ultraviolet light, and the range of materials that can be selected for the third portion 13 is expanded. In this case, for example, polycarbonate can be used as the material for the third portion 13.

The method of fixing the diffusion plate 18 to the fluid sterilization device 1 is not particularly limited. For example, as shown in FIG. 3, the diffusion plate 18 can be fixed by sandwiching it between the first part 11 and the third part 13. Here, the part outside the dotted line in FIG. 5(a) is the part sandwiched between the first part 11 and the third part 13.

Figures 6(a) and (b) are a plan view and a cross-sectional view of another example of the diffusion plate 18. The cross-section of the diffusion plate 18 shown in Figure 6(b) is a cross-section taken along the cutting line C-C shown in Figure 6(a).

As shown in Figures 6(a) and (b), the holes 181 in the diffusion plate 18 may be inclined so that they widen toward the outer periphery as they approach the first portion 11 from the third portion 13.

In addition, a diffusion member having a three-dimensional shape may be used instead of the flat diffusion plate 18, but the flat shape is structurally simpler, and therefore manufacturing costs can be reduced when using expensive fluororesin, especially PTFE, which must be cut from a block.

The case 19 has a plate-like portion 191 parallel to the length of the first portion 11 and a plate-like portion 192 that covers the third portion 13, and the first portion 11, second portion 12, and third portion 13 can be fixed by fixing the case 19 to the second portion 12 while pressing the third portion 13 toward the first portion 11 with the plate-like portion 192. In other words, the three parts, the first portion 11, second portion 12, and third portion 13, can be fixed using the case 19.

In the example shown in Figures 1 to 3, the case 19 has a plate-like portion 193 that runs along the surface of the second portion 12 facing the case 19, and the plate-like portion 193 is screwed to the second portion 12 using screws 194, thereby fixing the case 19 to the second portion 12. The case 19 is made of, for example, stainless steel.

As described above, the ultraviolet light irradiation module 14 is attached to the second portion 12 and irradiates ultraviolet light to the fluid flowing through the flow path 101. The ultraviolet light emitted by the ultraviolet light irradiation module 14 is, for example, ultraviolet light in the wavelength range called UV-A (400-315 nm), ultraviolet light in the wavelength range called UV-B (315-280 nm), or the above-mentioned UVC light, and among these, UVC light is preferably used as it has the highest sterilizing effect.

The configuration of the ultraviolet light irradiation module 14 is not particularly limited, but in the example shown in Figures 1 to 3, it includes a light-emitting element 141 that emits ultraviolet light, a wiring board 142 on which the light-emitting element 141 is mounted, a cable 143 connected to the wiring of the wiring board 142 for supplying power and the like from the outside to the light-emitting element 141, a reflector 144 that surrounds the light-emitting element 141, a waterproof sheet 145 installed on the reflector 144 so as to cover the upper part of the light-emitting element 141, a heat sink 146 installed on the back side of the wiring board 142, and a cover 147 that covers and fixes each of these components. The area where the light-emitting element 141 is mounted is sealed to ensure waterproofing, and the light emitted from the light-emitting element 141 is extracted through the waterproof sheet 145.

The light-emitting element 141 includes, for example, an LED chip (Light Emitting Diode) or an LD chip (Laser Diode) that emits ultraviolet light, and a lens for adjusting the light distribution.

A sealing member such as an O-ring 203 is used between the mounting portion 121 of the second part 12 and the cover 147 of the ultraviolet light irradiation module 14 to prevent leakage of fluid from the interface between the second part 12 and the ultraviolet light irradiation module 14.

(Effects of the embodiment)
According to the fluid sterilization device 1 of the above embodiment, a pipe made of a general-purpose fluororesin can be used as the first section 11 of the flow path pipe 10, and a reflective material 17 made of fluororesin is used for the second section 12, thereby making it possible to reduce manufacturing costs while ensuring excellent sterilization efficiency by increasing the reflectance of ultraviolet light on the inner wall of the flow path 101. In particular, when PTFE is used as the fluororesin, cutting from a PTFE block is not required, which makes it even more effective at reducing manufacturing costs.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. Furthermore, the components of the above embodiment can be combined in any manner without departing from the spirit of the invention.

Furthermore, the above-mentioned embodiments do not limit the invention according to the claims. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

REFERENCE SIGNS LIST 1 Fluid sterilization device 10 Flow path pipe 101 Flow path 102 Inlet 103 Outlet 11 First part 12 Second part 121 Mounting part 13 Third part 14 Ultraviolet light irradiation module 15 Inlet pipe 16 Outlet pipe 17 Reflector 171 Hole 18 Diffusion plate 181 Hole 19 Case

Claims (4)

a flow path pipe having a flow path for flowing a fluid to be sterilized, an inlet for allowing the fluid to flow into the flow path, and an outlet for allowing the fluid to flow out of the flow path;
an ultraviolet light irradiation module that irradiates ultraviolet light into the flow path;
Equipped with
the flow passage pipe has a cylindrical first portion and a second portion connected to one end of the first portion,
the first portion is made of a fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module,
the second portion has a mounting portion for mounting the ultraviolet light irradiation module and the inlet or the outlet,
a reflecting material made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module is provided along an inner surface of the second portion that becomes an inner wall of the flow path;
The reflector has holes through which the fluid passes.
Fluid sterilization device. a flow path pipe having a flow path for flowing a fluid to be sterilized, an inlet for allowing the fluid to flow into the flow path, and an outlet for allowing the fluid to flow out of the flow path;
an ultraviolet light irradiation module that irradiates ultraviolet light into the flow path;
Equipped with
the flow passage pipe has a cylindrical first portion and a second portion connected to one end of the first portion,
the first portion is made of a fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module,
the second portion has a mounting portion for mounting the ultraviolet light irradiation module and the inlet or the outlet,
a reflecting material made of a fluororesin that reflects ultraviolet light emitted from the ultraviolet light irradiation module is provided along an inner surface of the second portion that becomes an inner wall of the flow path;
The reflector is disposed in a cylindrical region between the ultraviolet light irradiation module and the first portion in the second portion.
Fluid sterilization device. The area of the hole is larger than the area of the inlet and the outlet.
2. The fluid disinfection device of claim 1. the second portion having the outlet;
an end portion of the first portion opposite to an end portion of the second portion side is covered with a flat diffusion plate having a hole through which the fluid passes at a position away from the center thereof and diffusing the fluid that has flowed in from the inlet;
The diffusion plate is made of a fluororesin that reflects the ultraviolet light emitted from the ultraviolet light irradiation module.
A fluid sterilization device according to any one of claims 1 to 3.