JP6936644B2 - Fluid sterilizer - Google Patents

Description

The present invention relates to a fluid sterilizer.

It is known that ultraviolet rays have a sterilizing ability, and devices that irradiate ultraviolet rays are used for sterilizing treatment in medical and food processing sites. In addition, a device for continuously sterilizing a fluid by irradiating a fluid such as water with ultraviolet rays is also used. As such a device, for example, a device in which an ultraviolet light emitting diode is arranged at an end of a container formed of a straight tubular pipe has been devised (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-233712

However, in the above-mentioned device, since the flow of the fluid flowing into the pipe constituting the container is not positively controlled, an asymmetric flow velocity distribution with respect to the central axis of the pipe occurs. Therefore, a fast flow flowing out of the pipe may occur in a relatively short time. Bacteria contained in such a fast flow may flow out of the apparatus without being exposed to ultraviolet rays for a sufficient time, which may contribute to a decrease in bactericidal performance.

The present invention has been made in view of these problems, and one of its exemplary purposes is to provide a new technique for improving the sterilization efficiency of a fluid by ultraviolet rays.

In order to solve the above problems, the fluid sterilizer according to an embodiment of the present invention includes a treatment flow path in which the passing fluid is sterilized, a light source that irradiates ultraviolet rays toward the treatment flow path, and a treatment flow path. It is provided with a housing to be used and a reflection-suppressing substance that is filled around the treatment flow path and suppresses the reflection of ultraviolet rays incident on the treatment flow path. The treatment flow path is composed of a transmissive member that transmits ultraviolet rays, and the antireflection substance has a higher refractive index than air.

According to this aspect, the reflection of ultraviolet rays incident on the treatment flow path can be suppressed as compared with the case where the periphery of the treatment flow path is air.

The housing has an inflow path through which the fluid flows into the treatment flow path and an outflow path through which the fluid flows out from the treatment flow path, and the treatment flow path may communicate with the inflow path and the outflow path in a non-linear manner. good. The non-linear communication is a case where the inflow path and the outflow path are not communicated with each other at the shortest distance, for example, when the processing flow path includes a curved path or a turnaround path. As a result, the distance until the fluid flowing in from the inflow path reaches the outflow path can be lengthened, so that the fluid flowing in the processing flow path can be irradiated with sufficient ultraviolet rays.

The inflow path may be an outer peripheral surface of the housing and may be formed in a direction intersecting the longitudinal direction of the housing.

The processing flow path may be formed in a spiral shape. As a result, a processing flow path having a long path can be arranged in a compact housing.

The permeation member may be made of an amorphous fluororesin or an inorganic material.

The antireflection substance may be a liquid having a refractive index of 1.3 or more.

The light source may be a semiconductor light emitting device that emits ultraviolet rays having a center wavelength or a peak wavelength in the range of 200 nm to 350 nm. As a result, the size of the light source can be made compact, and the degree of freedom of arrangement is increased.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, the sterilization efficiency of a fluid by ultraviolet rays can be improved.

It is sectional drawing which shows the schematic structure of the fluid sterilizer which concerns on a reference example. It is sectional drawing which shows the schematic structure of the fluid sterilizer which concerns on 1st Embodiment. It is sectional drawing which shows the schematic structure of the fluid sterilizer which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate. Moreover, the configuration described below is an example, and does not limit the scope of the present invention at all.

(Reference example)
First, the fluid sterilizer according to the reference example will be described. FIG. 1 is a cross-sectional view showing a schematic configuration of a fluid sterilizer 100 according to a reference example.

The fluid sterilizer 100 includes a straight pipe 104 that partitions the processing flow path 102, and a light source 106 that irradiates the inside of the straight pipe 104 with ultraviolet rays. The straight pipe 104 is provided with an inflow path 110 extending in the radial direction of the straight pipe 104 at one end 108 and an outflow path 114 extending in the radial direction of the straight pipe 104 at the other end 112. .. The other end 112 is provided with a window 116 for transmitting ultraviolet rays from the light source 106.

In the fluid sterilizer 100, the fluid flowing in from the inflow path 110 flows through the processing flow path 102 in the axial direction of the straight pipe 104 and flows out from the outflow path 114. Since the inflow path 110 is directly attached to the side of the straight pipe 104, the fluid flow is turbulent in the vicinity of one end 108.

Specifically, the fluid flowing in from the inflow path 110 collides with the side wall of the straight pipe 104 facing the inflow path 110 immediately after the inflow, and causes a fast flow with a rebounding force. That is, the speed of the fluid flowing from the inflow path 110 near the side wall on which the inflow path 110 of the straight pipe 104 is formed becomes relatively high. As a result, as shown in FIG. 1, an asymmetric velocity distribution is generated with respect to the central axis of the straight pipe 104, and it becomes difficult to efficiently act the ultraviolet rays from the light source 106 on the fluid. In particular, bacteria that ride on a fast stream flow out without being sufficiently exposed to ultraviolet rays, which can cause a significant decrease in bactericidal performance.

Therefore, the fluid sterilizer according to each of the following embodiments has been devised in view of the fluid sterilizer 100 according to the reference example.

(First Embodiment)
FIG. 2 is a cross-sectional view showing a schematic configuration of the fluid sterilizer 10 according to the first embodiment. The fluid sterilizer 10 includes a processing flow path 12 in which the passing fluid is sterilized, a light source 14 that irradiates the processing flow path 12 with ultraviolet rays L, and a tubular housing 16 that houses the processing flow path 12. A reflection-suppressing substance 18 that suppresses the reflection of ultraviolet rays L incident on the treatment flow path 12 and is filled around the treatment flow path 12.

The housing 16 has an inflow path 20 in which the fluid flows into the processing flow path 12 and an outflow path 22 in which the fluid flows out from the processing flow path 12. The inflow path 20 and the outflow path 22 are outer peripheral surfaces of the housing 16 and are formed so as to intersect with each other in the longitudinal direction of the housing 16. The processing flow path 12 is connected to the housing 16 in the vicinity of each of the inflow path 20 and the outflow path 22. Further, the space between the housing 16 and the processing flow path 12 filled with the reflection inhibitor 18 has a watertight structure with respect to the outside of the housing 16. Therefore, the fluid flowing through the processing flow path 12 and the reflection inhibitor 18 do not mix.

The housing 16 is made of a metal material or a resin material, and it is desirable that the housing 16 is made of a material having a high reflectance of ultraviolet rays. For example, the inner peripheral surface 16a of the housing 16 may be made of mirror-polished aluminum (Al) or polytetrafluoroethylene (PTFE), which is a fully fluorinated resin. By constructing the housing 16 with these materials, the ultraviolet rays emitted by the light source 14 can be reflected by the inner peripheral surface 16a and propagated in the longitudinal direction of the housing 16. In particular, PTFE is a chemically stable material and has a high reflectance of ultraviolet rays, and is therefore suitable as a material for the housing 16.

Inside the housing 16, a window portion 17 that transmits ultraviolet rays emitted from the light source 14 is provided. The window portion 17 separates the space provided with the light source 14 from the space provided with the processing flow path 12. The window portion 17 is partially or wholly composed of a member having a high ultraviolet transmittance such as _{quartz (SiO 2} ), sapphire (Al ₂ O _{3), and an amorphous fluororesin.}

The processing flow path 12 according to the present embodiment communicates the inflow path 20 and the outflow path 22 in a non-linear manner. The non-linear communication is a case where the inflow path 20 and the outflow path 22 are not communicated with each other at the shortest distance, that is, a case where the inflow path 20 and the outflow path 22 are communicated in a detour (detour). For example, the processing flow path 12 may include a curved path or a turning path (crank path). The processing flow path 12 according to the present embodiment is formed in a spiral shape, and the diameter of the flow path is about 8 to 15 mm.

As a result, the distance until the fluid flowing in from the inflow path 20 reaches the outflow path 22 can be lengthened, so that the fluid flowing in the processing flow path 12 can be irradiated with sufficient ultraviolet rays. Further, by making the processing flow path 12 thin and long with respect to the internal space of the housing 16, it becomes easy to level the velocity distribution in the processing flow path 12.

Further, by forming the processing flow path 12 into a spiral shape, a processing flow path having a long path can be arranged in the compact housing 16. When the processing flow path 12 is spiral, the flow velocity of the fluid tends to be faster toward the outer peripheral portion (the speed of the fluid is slower toward the inner peripheral portion). However, at the same time, the moving distance of the flowing water becomes long, so that the bias of the velocity distribution in the processing flow path 12 is reduced. Further, the direction of the spiral (clockwise or counterclockwise) may be reversed in the middle of the processing flow path 12 to form the flow path. As a result, the fluid that has passed through the outer peripheral portion of the spiral processing flow path 12 passes through the inner peripheral portion from the middle, and the bias of the velocity distribution in the processing flow path 12 is further reduced.

The processing flow path 12 is composed of a transmissive member that transmits ultraviolet rays. Specifically, it is composed of an _{inorganic material such as glass, quartz (SiO 2} ), and sapphire (Al ₂ O ₃ ), and a member having a high ultraviolet transmittance such as an amorphous fluorine-based resin. Such a transmissive member has a refractive index of 1.3 to 1.5 or more, and has a higher refractive index than air. Therefore, the ultraviolet rays that have passed through the air are repeatedly reflected on the surface of the processing flow path 12 due to the difference in refractive index between the air and the transmitting member. Therefore, the proportion of the ultraviolet rays emitted from the light source 14 that reach the inflow path 20 side of the processing flow path 12 decreases, and the sterilization efficiency of the fluid decreases.

Therefore, in the fluid sterilizer 10 according to the present embodiment, the periphery of the treatment flow path 12 is filled with a reflection inhibitor 18 having a refractive index higher than that of air. Since the reflection-suppressing substance 18 according to the present embodiment is water (refractive index 1.33), the reflection of ultraviolet rays L incident on the treatment flow path 12 is compared with the case where the periphery of the treatment flow path 12 is air. Can be suppressed.

The antireflection substance 18 may be a substance other than water, which is transparent to the wavelength range of ultraviolet rays, and may be a liquid having a refractive index of 1.3 or more, or a solid such as glass or resin. The refractive index of the reflection inhibitor 18 is preferably within ± 0.3, preferably within ± 0.2, and more preferably within ± 0.1 of the refractive index of the members constituting the processing flow path 12.

When the reflection inhibitor 18 is a liquid, the space inside the housing 16 can be easily filled, and the surface of the processing flow path 12 can be reliably covered. Further, since the reflection inhibitor 18 is constantly irradiated with ultraviolet rays emitted from the light source 14, the growth of bacteria is suppressed without replacement. In the fluid sterilizer 10 according to the present embodiment, a filling hole 16b for filling the reflection inhibitor 18 is provided in a part of the housing 16. When the fluid sterilizer 10 is used, the reflection inhibitor 18 is first filled inside the housing 16 through the filling holes 16b, the filling holes 16b are sealed, and then the fluid to be sterilized flows into the processing flow path 12.

The light source 14 is a semiconductor light emitting device that emits ultraviolet rays whose center wavelength or peak wavelength is in the range of 200 nm to 350 nm. The light source 14 according to the present embodiment is an LED (Light Emitting Diode) that emits ultraviolet rays, and preferably emits ultraviolet rays in the vicinity of 260 nm to 290 nm, which is a wavelength having high sterilization efficiency. As such an ultraviolet LED, for example, one using aluminum gallium nitride (AlGaN) is known. As a result, the size of the light source that emits ultraviolet rays can be made compact, and the degree of freedom of arrangement is increased.

(Second Embodiment)
FIG. 3 is a cross-sectional view showing a schematic configuration of the fluid sterilizer 30 according to the second embodiment. The fluid sterilizer 30 according to the present embodiment has substantially the same configuration as the fluid sterilizer 10 according to the first embodiment except that an ultraviolet lamp is used as a light source, and the same configuration has the same reference numerals. The description will be omitted as appropriate.

In the fluid sterilizer 30, a straight tubular ultraviolet lamp 32 is arranged so as to penetrate the central portion of the spirally formed processing flow path 12. Since the ultraviolet rays emitted from the ultraviolet lamp 32 enter the processing flow path 12 via the reflection suppressing substance 18, the reflection on the surface of the processing flow path 12 is suppressed.

Although the present invention has been described above with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or substituted. Those are also included in the present invention. Further, it is also possible to appropriately rearrange the combinations and the order of processing in each embodiment based on the knowledge of those skilled in the art, and to add modifications such as various design changes to the embodiments. Additional embodiments may also be included within the scope of the invention.

In the above-described first embodiment, the light source is provided near the end on the outflow path side of the housing, but the light source may be provided near the end on the inflow path side of the housing. Further, the light source may be provided both near the end of the housing on the outflow path side and near the end of the housing on the inflow path side.

10 Fluid sterilizer, 12 Treatment flow path, 14 Light source, 16 Housing, 16a Inner peripheral surface, 17 Window, 18 Reflection inhibitor, 20 Inflow path, 22 Outflow path.

Claims (8)

A processing flow path in which the passing fluid is sterilized, and
A light source that irradiates ultraviolet rays toward the processing flow path,
A housing for accommodating the processing flow path and
A reflection-suppressing substance that suppresses the reflection of ultraviolet rays incident on the treatment flow path, which is filled around the treatment flow path, is provided.
The processing flow path is composed of a transmissive member that transmits ultraviolet rays.
The antireflection substance has a higher refractive index than air and has a higher refractive index.
A fluid sterilizer characterized in that the space filled with the antireflection substance has a watertight structure with respect to the outside of the housing and the treatment flow path. A processing flow path in which the passing fluid is sterilized, and
A light source that irradiates ultraviolet rays toward the processing flow path,
A housing for accommodating the processing flow path and
A reflection-suppressing substance that suppresses the reflection of ultraviolet rays incident on the treatment flow path, which is filled around the treatment flow path, is provided.
The light source is provided at the longitudinal end of the housing and is provided.
The processing flow path is composed of a transmissive member that transmits ultraviolet rays.
The antireflection substance has a higher refractive index than air and has a higher refractive index.
A fluid sterilizer characterized in that the space filled with the antireflection substance has a watertight structure with respect to the outside of the housing. The housing has an inflow path through which the fluid flows into the processing flow path and an outflow path through which the fluid flows out from the processing flow path.
The fluid sterilizer according to claim 1 or 2 , wherein the treatment flow path communicates the inflow path and the outflow path in a non-linear manner. The fluid sterilizer according to claim 3 , wherein the inflow path is an outer peripheral surface of the housing and is formed in a direction intersecting the longitudinal direction of the housing. The fluid sterilizer according to any one of claims 1 to 4 , wherein the treatment flow path is formed in a spiral shape. The fluid sterilizer according to any one of claims 1 to 5 , wherein the permeation member is made of an amorphous fluororesin or an inorganic material. The fluid sterilizer according to any one of claims 1 to 6 , wherein the antireflection substance is a liquid having a refractive index of 1.3 or more. The fluid sterilizer according to any one of claims 1 to 7 , wherein the light source is a semiconductor light emitting device that emits ultraviolet rays having a center wavelength or a peak wavelength in the range of 200 nm to 350 nm.

Images