JP7700936B2 - Fluid sterilizer - 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 using ultraviolet light emitted from a light source such as an LED (see, for example, Patent Document 1). In devices that use such light sources, a heat dissipation structure is important to prevent deterioration due to an increase in the temperature of the light source and a decrease in the amount of light.

According to Patent Document 1, the heat generated by the light source is efficiently dissipated by a heat sink provided in the light source module device, and is also conducted to the cylinder that serves as the sterilizing section of the fluid in the fluid sterilization device, and is dissipated by the fluid as well.

JP 2020-89462 A

However, according to Patent Document 1, a heat sink is used to dissipate heat from the light source, and the size of the heat sink is large, so it is not suitable for miniaturizing the fluid sterilization device. Also, in order to efficiently dissipate heat from the cylinder to the fluid, the cylinder is required to have high thermal conductivity, which narrows the range of materials that can be selected for the cylinder, which may hinder weight reduction, etc.

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 can be made small and lightweight while having a structure that can effectively dissipate heat generated by the light source.

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 section 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 in which a light source that emits ultraviolet light is housed in a base having an opening surface covered with a film-like or plate-like ultraviolet light-transmitting member, and which irradiates the ultraviolet light emitted from the light source and transmitted through the ultraviolet light-transmitting member into the flow path; a cooling member in contact with the base and exposed to the flow path, for dissipating heat of the light source to the fluid to cool the light source; and a sealing part arranged in a position in contact with the ultraviolet light-transmitting member, wherein the ultraviolet light-transmitting member is fixed by being sandwiched between the sealing part and the base.
[2] The fluid sterilization device described in [1] above, wherein the sealing part is sandwiched between the cooling member and the ultraviolet light transmitting member and is subjected to compression.
[3] The fluid sterilization device according to [1] or [2] above, wherein the base accommodates a light-emitting element as the light source and a substrate on which the light-emitting element is mounted.
[4] The fluid sterilization device according to any one of [1] to [3] above, wherein the ultraviolet light transmitting member is a waterproof film or a quartz glass plate.
[5] The fluid sterilization device according to any one of [1] to [5] above, wherein the flow path portion has a tubular member therein for partitioning the flow path, one end of the tubular member in the longitudinal direction faces the inlet and the other end faces the ultraviolet light irradiation module, the fluid flowing in from the inlet passes inside the tubular member and then flows out from the outlet through a region on the outside of the tubular member where the cooling member is exposed, and light emitted from the ultraviolet light irradiation module is irradiated onto the inside of the tubular member.
[6] The fluid sterilization device described in [5] above, wherein the longitudinal position of the flow path portion is farther from the outlet than the cooling member, the tubular member has a hole for allowing the fluid flowing inside the tubular member to flow to the outside of the tubular member, and the area of the hole is larger than the areas of the inlet and the outlet.
[7] The fluid sterilization device described in [5] or [6] above, wherein the cylindrical member is made of fluororesin.
[8] The fluid sterilization device according to any one of [5] to [7] above, wherein the end of the tubular member on the inlet 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.
[9] The fluid sterilization device described in any one of [1] to [8] above, wherein the flow path portion is made of resin.

The present invention provides a fluid sterilization device that sterilizes fluids such as water by irradiating them with ultraviolet light, and that can be made compact and lightweight while having a structure that can effectively dissipate heat generated by the light source.

FIG. 1 is a perspective view of a fluid sterilizing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the fluid sterilization device taken along its length. FIG. 3 is a perspective view of a cooling member included in the fluid sterilization device. Figure 4(a) is a side view of a tubular member included in the fluid sterilization device, and Figure 4(b) is a cross-sectional view of the tubular member taken along line AA in Figure 4(a). FIG. 5 is a plan view of a diffusion plate included in the fluid sterilization device.

[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. Fig. 2 is a cross-sectional view of the fluid sterilization device 1 taken along its longitudinal direction.

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 tube 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, an ultraviolet light irradiation module 11 fixed to one end of the length of the flow path tube 10 for irradiating ultraviolet light into the flow path 101, and an annular (cylindrical) cooling member 12 provided inside the flow path tube 10 and exposed to the flow path 101 for dissipating heat from a light source contained in the ultraviolet light irradiation module 11 to the fluid to cool the light source.

The flow path tube 10 has an opening 104 at one end in its longitudinal direction (left-right direction in FIG. 2) for fitting the ultraviolet light irradiation module 11. The inlet 102 is provided at the end of the flow path tube 10 opposite the opening 104, and the outlet 103 is provided on the side of the flow path tube 10. The inlet 102 and outlet 103 of the flow path tube 10 have a tubular shape that protrudes outward so that a tube for flowing a fluid can be connected, for example, as shown in FIG. 1 and FIG. 2. The shape of the flow path tube 10 is typically a circular tube shape as shown in FIG. 1.

The ultraviolet light irradiation module 11 has a light-emitting element 111 as a light source that emits ultraviolet light, a substrate 112 having wiring on which the light-emitting element 111 is mounted, and a base 113 that houses the light-emitting element 111 and the substrate 112.

The base 113 has a protrusion 114 that protrudes toward the light extraction side, and this protrusion 114 is fitted inside the opening 104 of the flow tube 10, thereby fixing the ultraviolet light irradiation module 11 to one end of the flow tube 10. Since the base 113 is fitted closely to the flow tube 10, it has a shape that corresponds to the shape of the flow tube 10. Furthermore, the shape of the protrusion 114 is typically annular. For example, if the flow tube 10 has a circular tube shape, the planar shape of the base 113 (the shape seen from the flow tube 10 side) is circular, and the protrusion 114 has an annular shape.

In the ultraviolet light irradiation module 11, the light emitting element 111 and the substrate 112 are housed in a recess 115 in the base 113, and the opening of the recess 115 is covered with a waterproof film 116. This seals the space in which the light emitting element 111 of the ultraviolet light irradiation module 11 is mounted, preventing the intrusion of fluids. In addition, the ultraviolet light emitted from the light emitting element 111 is extracted through the waterproof film 116.

The ultraviolet light emitted by the ultraviolet light irradiation module 11 (light emitting element 111) 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 ultraviolet light in the wavelength range called UV-C (less than 280 nm) (hereinafter referred to as UVC light), of which UVC light is preferred as it has the highest bactericidal effect.

The light-emitting element 111 is, for example, an LED chip (Light Emitting Diode) or an LD chip (Laser Diode) that emits ultraviolet light, and may be equipped with a lens for adjusting the light distribution.

The waterproof film 116 is made of a material that transmits the ultraviolet light emitted by the light-emitting element 111, such as a fluororesin. Alternatively, instead of the waterproof film 116, a plate made of a material that transmits the ultraviolet light emitted by the light-emitting element 111, such as a quartz glass plate, may be used.

The method of fixing the ultraviolet light irradiation module 11 to the flow tube 10 is not particularly limited. In the example shown in FIG. 1, the ultraviolet light irradiation module 11 has a protrusion 115 on the side of the base 113, and the flow tube 10 has a linear hole 105 bent into an L shape for passing the protrusion 115. When the ultraviolet light irradiation module 11 is inserted into the opening 104 of the flow tube 10 and then twisted in the circumferential direction, the protrusion 115 enters the bent part of the hole 105, and the ultraviolet light irradiation module 11 is fixed to the flow tube 10 by the restoring force of the sealing parts 151 to 153 (described later) that are compressed by inserting the ultraviolet light irradiation module 11 into the flow tube 10. The ultraviolet light irradiation module 11 may be fixed to the flow tube 10 by other methods such as screwing.

Figure 3 is a perspective view of the cooling member 12. The cooling member 12 has both a sealing function to prevent leakage of fluid from the interface between the flow path tube 10 and the ultraviolet light irradiation module 11, and a cooling function to cool the light emitting element 111 by releasing heat from the light emitting element 111 into the fluid. In order to enhance the cooling effect, the cooling member 12 is preferably made of a material with high thermal conductivity such as aluminum, copper, or stainless steel. In addition, in order to effectively exert the cooling effect, it is preferable that the cooling member 12 has a higher thermal conductivity than the flow path tube 10, which also comes into contact with the fluid.

The cooling member 12 is installed inside the protrusion 114 of the flow path tube 10 and the ultraviolet light irradiation module 11, in contact with the protrusion 114. The cooling member 12 is sealed between the flow path tube 10 and the protrusion 114 by annular sealing parts 151, 152 such as O-rings, preventing leakage of fluid from the interface between the flow path tube 10 and the protrusion 114.

Specifically, along the longitudinal direction of the flow tube 10 (the insertion direction of the ultraviolet light irradiation module 11), the flow tube 10 and the cooling member 12 sandwich the sealing part 151, and the cooling member 12 and the base 113 of the ultraviolet light irradiation module 11 sandwich the sealing part 152. When the ultraviolet light irradiation module 11 is inserted into the flow tube 10, the sealing parts 151 and 152 are compressed, producing a sealing effect. Also, as shown in FIG. 2, a waterproof film 116 may be sandwiched and fixed between the sealing part 152 and the base 113.

The outer side surface 121 of the annular cooling member 12 is in contact with the inner side surface of the protrusion 114 of the base 113, and heat generated in the light emitting element 111 is transferred to the cooling member 12 via the substrate 112 and base 113. In addition, the inner side surface 122 of the cooling member 12 is exposed to the flow path 101, and thus comes into contact with the fluid flowing through the flow path 101, and can transfer the heat of the cooling member 12 to the fluid. Therefore, the cooling member 12 can be used to effectively release the heat generated in the light emitting element 111 to the fluid. In other words, the light emitting element 111 can be cooled by the cooling member 12.

Since the cooling member 12 can effectively dissipate heat generated by the light emitting element 111 to the fluid, there is no need to use the flow passage tube 10 for heat dissipation, and the flow passage tube 10 does not need to have a high thermal conductivity. For this reason, in the fluid sterilization device 1, there is a wide range of materials to choose from for the flow passage tube 10, and for example, a lightweight resin can be used as the material for the flow passage tube 10 to reduce the weight of the fluid sterilization device 1. For example, the specific gravity of aluminum is 2.7 and the specific gravity of polycarbonate resin is 1.2, and by using polycarbonate resin as the material for the flow passage tube 10 instead of aluminum, which has excellent thermal conductivity, the weight of the fluid sterilization device 1 can be significantly reduced.

As shown in FIG. 2, the flow path pipe 10 may have a cylindrical member 13 therein that defines the flow path 101. One end of the cylindrical member 13 in the longitudinal direction faces the inlet 102, and the other end faces the ultraviolet light irradiation module 11.

The fluid flowing in from the inlet 102 passes through the inside of the cylindrical member 13 (the area surrounded by the inside side 131 of the cylindrical member 13), then flows out from the outlet 103 through the area where the cooling member 12 is exposed on the outside of the cylindrical member 13 (the area between the outside side 132 of the cylindrical member 13 and the inner surface of the flow path tube 10). Then, the light emitted from the ultraviolet light irradiation module 11 is irradiated to the inside of the cylindrical member 13. In this way, by using the cylindrical member 13, the flow path 101 can be divided into a section inside the cylindrical member 13 where ultraviolet light is irradiated and a section outside the cylindrical member 13 where the cooling member 12 is cooled, and the fluid can be sterilized and the light emitting element 111 can be cooled efficiently.

The cylindrical member 13 has holes 133 for allowing the fluid flowing inside the cylindrical member 13 to flow to the outside of the cylindrical member 13. Since the position of the holes 133 in the longitudinal direction of the flow path tube 10 is farther from the outlet 103 than the cooling member 12, the fluid that passes through the holes 133 passes through the area where the cooling member 12 is exposed, removes heat from the cooling member 12, and then reaches the outlet 103.

Figure 4(a) is a side view of the cylindrical member 13. Figure 4(b) is a cross-sectional view of the cylindrical member 13 when cut along the cutting line A-A shown in Figure 4(a). There may be one or more holes 133. In the example shown in Figure 4, four holes 133 are provided at equal intervals along the circumferential direction of the cylindrical member 13. In order to suppress 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 133 (the total area of the holes 133 when multiple holes 133 are provided) is larger than the areas of the inlet 102 and the outlet 103.

The cylindrical member 13 is preferably made of a material that has high resistance to and reflectance against ultraviolet light, such as a fluororesin, in order to efficiently reflect the ultraviolet light emitted from the ultraviolet light irradiation module 14 at the inner surface 131 and effectively sterilize the fluid. Examples of such fluororesins include PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), PVF (polyvinyl fluoride), and PVDF (polyvinylidene fluoride).

In particular, by using PTFE, which has excellent reflectivity to UVC light, as the material for the cylindrical member 13, the fluid can be effectively sterilized using the ultraviolet light irradiation module 11 that emits UVC light.

In addition, because the cylindrical member 13 blocks most of the ultraviolet light that reaches the inner surface of the flow path tube 10, deterioration of the flow path tube 10 due to exposure to ultraviolet light can be suppressed. For example, even if a resin that is not highly resistant to ultraviolet light is used as the material for the flow path tube 10, a decrease in lifespan can be suppressed.

The cylindrical member 13 has a simple cylindrical shape, so that commercially available general-purpose fluororesin pipes can be used almost as is, and costs can be kept low even when expensive fluororesin is used as the material.

In particular, PTFE, a fluororesin with excellent reflectivity to UVC light, has an extremely high melt viscosity and cannot be processed by normal melt processing, and in order to process it into the desired shape, it must be cut from a block produced by compressing and sintering PTFE powder, resulting in very high material and processing costs. If a general-purpose PTFE pipe could be used, cutting from a PTFE block would not be necessary, and using PTFE as the material for the cylindrical member 13 would have a greater effect in reducing manufacturing costs.

The end of the tubular member 13 on the inlet 103 side, i.e., the fluid inlet of the tubular member 13, is preferably covered by a flat diffusion plate 14 as shown in FIG. 2.

Figure 5 is a plan view of the diffusion plate 14. The diffusion plate 14 has a number of holes 141 through which fluid passes, located away from its center, and diffuses the fluid that flows in from the inlet 102. The holes 141 are not provided in the center of the diffusion plate 14, but are provided near the outer periphery of the diffusion plate 14 or in a position that is in contact with the outer periphery, so that the fluid that passes through the holes 141 flows near the inner side surface 131 of the cylindrical member 13.

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 14 to cause the fluid to flow near the side surface 131 (inner wall) of the tubular member 13, the flow rate near the side surface 131 of the tubular member 13 can be relatively increased, and the difference in flow rate between near the center of the tubular member 13 and near the side surface 131 can be reduced. This averages out the residence time of the fluid in the flow path 101, reducing the variation in the ultraviolet light irradiation time due to differences in the fluid flow path, and enabling efficient sterilization.

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 total area of the holes 141 is larger than the area of the inlet 102 and the outlet 103. In addition, in order to allow the fluid to flow as evenly as possible near the side surface 131 of the cylindrical member 13, it is preferable that the multiple holes 141 are arranged at equal intervals along the circumferential direction of the diffusion plate 14.

To improve sterilization efficiency, the diffusion plate 14, like the cylindrical member 13, is preferably made of a fluororesin that reflects the light emitted from the ultraviolet light irradiation module 11. In particular, by using PTFE as the material for the diffusion plate 14, sterilization can be effectively performed using the ultraviolet light irradiation module 11 that emits UVC light.

In addition, when the diffusion plate 14 is used, the diffusion plate 14 blocks most of the ultraviolet light that travels toward the periphery of the inlet 102 of the flow path tube 10, so that the cylindrical member 13 and the diffusion plate 14 can more effectively prevent deterioration of the flow path tube 10 due to exposure to ultraviolet light.

The method of fixing the diffusion plate 14 to the fluid sterilization device 1 is not particularly limited. For example, as shown in FIG. 2, the diffusion plate 14 can be fixed by sandwiching it between the inner surface of the flow tube 10 and the end of the cylindrical member 13. By inserting the ultraviolet light irradiation module 11 into the opening 104 of the flow tube 10, the cylindrical member 13 is pushed in, and the diffusion plate 14 is sandwiched and fixed between the inner surface of the flow tube 10 and the end of the cylindrical member 13. In this case, if an annular seal part 153 such as an O-ring that surrounds the diffusion plate 14 is used, the seal part 153 is sandwiched between the inner surface of the flow tube 10 and the end of the cylindrical member 13 together with the diffusion plate 14, and the cylindrical member 13 is reliably fixed by its restoring force, and the fluid flowing in from the inlet 102 can be prevented from flowing directly outside the cylindrical member 13.

In addition, a diffusion member having a three-dimensional shape may be used instead of the flat diffusion plate 14, 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.

(Effects of the embodiment)
According to the fluid sterilization device 1 of the above embodiment, the light emitting element 111 can be effectively cooled using the cooling member 12. The cooling member 12 fits inside the flow passage tube 10, and since the cooling function of the cooling member 12 is high, it is not necessary to use a large cooling component such as a heat sink, so that the fluid sterilization device 1 can be made smaller. Furthermore, by using the cooling member 12, the light emitting element 111 can be cooled by dissipating heat into the fluid even if the flow passage tube 10 does not have a high thermal conductivity, so that the material of the flow passage tube 10 can be selected with a wide range, and for example, a lightweight resin can be used as the material of the flow passage tube 10 to reduce the weight of the fluid sterilization device 1.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made 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 104 Opening 11 Ultraviolet light irradiation module 111 Light emitting element 113 Base 114 Protrusion 12 Cooling member 13 Cylindrical member 133 Hole 14 Diffusion plate 141 Hole

Claims (8)

a flow path portion having a flow path for flowing a fluid to be sterilized, an inlet for causing the fluid to flow into the flow path, and an outlet for causing the fluid to flow out of the flow path;
an ultraviolet light irradiation module that contains a light source that emits ultraviolet light in a base whose opening surface is covered with a film-like or plate-like ultraviolet light transmitting member, and irradiates the ultraviolet light emitted from the light source and transmitted through the ultraviolet light transmitting member into the flow path;
a cooling member that is in contact with the base and exposed to the flow path, for dissipating heat from the light source to the fluid to cool the light source;
A sealing part arranged at a position in contact with the ultraviolet light transmitting member;
Equipped with
the ultraviolet light transmitting member is fixed by being sandwiched between the sealing part and the base,
The sealing part is sandwiched between the cooling member and the ultraviolet light transmitting member and is subjected to compression.
Fluid sterilizer. The base accommodates a light-emitting element as the light source and a substrate on which the light-emitting element is mounted.
2. The fluid disinfection device of claim 1 . The ultraviolet light transmitting member is a waterproof film or a quartz glass plate.
A fluid sterilization device according to claim 1 or 2 . The flow path portion has a cylindrical member therein for partitioning the flow path,
One end of the cylindrical member in a longitudinal direction faces the inlet, and the other end faces the ultraviolet light irradiation module,
the fluid that flows in from the inlet passes through the inside of the tubular member, then flows out from the outlet through a region of the tubular member where the cooling member is exposed,
The light emitted from the ultraviolet light irradiation module is irradiated onto the inside of the cylindrical member.
The fluid sterilizing device according to any one of claims 1 to 3 . the tubular member has a hole for allowing the fluid flowing inside the tubular member to flow to the outside of the tubular member, the position of the flow path portion in the longitudinal direction being farther from the outlet than the cooling member, and the area of the hole is larger than the areas of the inlet and the outlet.
5. A fluid disinfection device according to claim 4 . The cylindrical member is made of a fluororesin.
A fluid sterilization device according to claim 4 or 5 . The end of the cylindrical member on the inlet 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.
A fluid sterilizing device according to any one of claims 4 to 6 . The flow path portion is made of resin.
A fluid sterilizing device according to any one of claims 1 to 7 .

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