JP2018030077A - Sterilization device of flowing water, and sterilization method of flowing water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sterilization device of flowing water having an enhanced sterilization efficiency of UV light.SOLUTION: A sterilization device of flowing water includes a straight pipe 20 to partition a processing passage 16, a light source (first light source 41 or second light source 42) that is installed on at least one end of both ends (upstream side end 21, downstream side end 22) of the straight pipe 20 and emits UV light toward the processing passage 16 in the axial direction of the straight pipe 20, and a bubble generator 50 that is installed upstream of the processing passage 16 and mixes bubbles 70 with water flowing into the processing passage 16. The device may further include a window member (first window member 25 or second window member 26) to separate the light source from the processing passage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a running water sterilization apparatus and a running water sterilization method, and more particularly to a technique for sterilizing running water by irradiating ultraviolet light.

  It is known that ultraviolet light has a sterilizing ability, and an apparatus for irradiating ultraviolet light is used for sterilization treatment in medical or food processing sites. In addition, an apparatus for continuously sterilizing a fluid by irradiating a fluid such as water with ultraviolet light is also used. As such a device, for example, a device in which an ultraviolet LED is arranged on the inner wall of a pipe end of a flow path formed of a straight tubular metal pipe can be cited (for example, see Patent Document 1).

JP 2011-16074 A

  It is desirable to be able to irradiate ultraviolet light with high efficiency to the flowing water in the straight tubular channel.

  The present invention has been made in view of these problems, and one of exemplary purposes thereof is to provide a running water sterilization apparatus and a running water sterilization method with improved sterilization efficiency.

  A flowing water sterilizer according to an aspect of the present invention is provided on at least one of a straight pipe that divides a processing flow path and both ends of the straight pipe, and irradiates ultraviolet light in the axial direction of the straight pipe toward the processing flow path. A light source, and a bubble generator that is provided upstream of the processing channel and mixes bubbles with water flowing into the processing channel.

  According to this aspect, by mixing bubbles in the water flowing through the straight tubular processing channel, the volume occupied by water in the processing channel can be reduced, and the transmittance of ultraviolet light in the processing channel can be increased. it can. Further, the ultraviolet light is scattered, reflected, and refracted by the bubbles, so that the illuminance distribution of the ultraviolet light in the processing flow path can be made uniform and the occurrence of irradiation unevenness can be suppressed. Furthermore, it is possible to prevent the adhesion of dirt to the wall surface in the processing channel by using a shock wave when bubbles are crushed.

  The light source may be provided at least at the downstream end of the straight pipe.

  You may further provide the window member which divides between a light source and a process flow path.

  You may further provide the deaeration apparatus which is provided downstream from a process flow path and removes a bubble from the water which flows out out of a process flow path.

  The straight pipe may have at least an inner wall surface made of polytetrafluoroethylene (PTFE).

  Another aspect of the present invention is a running water sterilization method. The method includes a step of mixing bubbles with water flowing into a processing flow path partitioned by a straight pipe, and a step of irradiating ultraviolet light in the axial direction of the straight pipe toward water containing bubbles flowing through the processing flow path. .

  According to this aspect, by mixing bubbles in the water flowing through the straight tubular processing channel, the volume occupied by water in the processing channel can be reduced, and the transmittance of ultraviolet light in the processing channel can be increased. it can. Further, the ultraviolet light is scattered, reflected, and refracted by the bubbles, so that the illuminance distribution of the ultraviolet light in the processing flow path can be made uniform and the occurrence of irradiation unevenness can be suppressed. Furthermore, it is possible to prevent the adhesion of dirt to the wall surface in the processing channel by using a shock wave when bubbles are crushed.

  According to the present invention, it is possible to improve the sterilization ability by increasing the irradiation efficiency of ultraviolet light.

It is sectional drawing which shows schematically the structure of the running water sterilizer which concerns on embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

  Drawing 1 is a figure showing roughly the composition of running water sterilizer 10 concerning an embodiment. The running water sterilizer 10 includes a straight pipe 20, an inflow pipe 31, an outflow pipe 32, a first light source 41, a second light source 42, a bubble generator 50, and a deaeration device 60. The flowing water sterilizer 10 is used for mixing the bubbles 70 with the water flowing through the processing flow path 16 defined by the straight pipe 20 and irradiating the water mixed with the bubbles 70 with ultraviolet light to perform sterilization.

The straight pipe 20 includes an upstream end 21, a downstream end 22, an inflow port 23, an outflow port 24, a first window member 25, and a second window member 26. The straight pipe 20 extends in the axial direction from the upstream end 21 toward the downstream end 22 and has, for example, a length of three times or more the inner diameter. The upstream end 21 is provided with a first window member 25 that transmits ultraviolet light from the first light source 41, and an inflow port 23 is provided in the vicinity of the first window member 25. The downstream end 22 is provided with a second window member 26 that transmits ultraviolet light from the second light source 42, and an outlet 24 is provided in the vicinity of the second window member 26. First window member 25 and the second window member 26 are quartz (SiO _2), sapphire _{(Al 2 O} 3), consisting of members which has higher transmission in the amorphous fluororesin such ultraviolet light.

  An inflow pipe 31 extending in a direction intersecting or orthogonal to the axial direction of the straight pipe 20 is attached to the inflow port 23. An outflow pipe 32 extending in a direction intersecting or perpendicular to the axial direction of the straight pipe 20 is attached to the outflow port 24. A first branch pipe 33 is provided in the middle of the inflow pipe 31, and the bubble generator 50 is connected via the first branch pipe 33. A second branch pipe 34 is provided in the middle of the outflow pipe 32, and a deaeration device 60 is connected through the second branch pipe 34.

  The straight pipe 20 is made of, for example, polytetrafluoroethylene (PTFE) which is a perfluorinated resin. PTFE is a chemically stable material and is excellent in durability, heat resistance and chemical resistance. PTFE is a material having a high reflectivity of ultraviolet light. Therefore, by configuring the straight tube 20 with PTFE, the ultraviolet light emitted from the first light source 41 and the second light source 42 can be propagated in the axial direction of the straight tube 20 while being reflected by the inner wall surface 18.

  The straight pipe 20 may not be entirely made of PTFE, and the inner wall surface 18 that defines the processing flow path 16 may be made of PTFE. For example, the straight pipe 20 may be configured by attaching a PTFE liner to the inner surface of a pipe made of another resin material or metal material. The inflow pipe 31 and the outflow pipe 32 may be made of the same material as that of the straight pipe 20, or may be made of a material different from that of the straight pipe 20.

  The first light source 41 and the second light source 42 are so-called UV-LED (Ultra Violet-Light Emitting Diode) light sources including light emitting elements that emit ultraviolet light. It is preferable that the light emitting element included in the light source emits ultraviolet light having a central wavelength or peak wavelength in the range of about 200 nm to 350 nm and having a high bactericidal efficiency in the vicinity of 260 nm to 270 nm. As such an ultraviolet light LED, for example, one using aluminum gallium nitride (AlGaN) is known.

  The first light source 41 is disposed in the first light source chamber 11 defined between the upstream end 21 and the first window member 25. The first light source 41 is arranged so as to irradiate ultraviolet light in the axial direction toward the processing channel 16 through the first window member 25. The second light source 42 is disposed in the second light source chamber 12 defined between the downstream end 22 and the second window member 26. The second light source 42 is disposed so as to irradiate ultraviolet light in the axial direction toward the processing channel 16 through the second window member 26. For example, the first light source 41 and the second light source 42 are mounted on a substrate whose base material is copper (Cu), aluminum (Al), or the like.

  The first light source 41 and the second light source 42 may include an adjustment mechanism for adjusting the light distribution angle of the light emitting element. For example, when the directivity angle or orientation angle of the light emitting element included in the light source is 60 degrees or more, 90 degrees or more, or 120 degrees or more, the adjustment mechanism adjusts the emission angle so that the orientation angle becomes 30 degrees or less. To. The adjustment mechanism may be constituted by a transmission type optical system such as a lens, or may be constituted by a reflection type optical system such as a concave mirror. By using such an adjustment mechanism, the incident angle of the ultraviolet light incident on the inner wall surface 18 of the processing channel 16 can be made to be 75 degrees or more. In particular, when the inner wall surface 18 is made of PTFE, the present inventors know that the reflectance on the surface becomes very high when the incident angle to the PTFE is 70 degrees or more. Therefore, by adjusting the alignment angle of the ultraviolet light by the adjusting mechanism, it is possible to propagate the ultraviolet light having a higher intensity far.

The bubble generating device 50 generates bubbles 70 in the water flowing into the processing channel 16 from the inlet 23 and mixes the bubbles 70 with the water flowing through the processing channel 16. The bubble size generated by the bubble generator 50 is not particularly limited, but is preferably a bubble size that can effectively scatter ultraviolet light, so-called millibubbles (bubble diameter: about 0.1 mm to several mm), It may be a microbubble (bubble diameter: about 1 μm to 100 μm). The component of the bubble 70 generated by the bubble generator 50 is not particularly limited, and may be nitrogen (N ₂ ), oxygen (O ₂ ), carbon dioxide (CO ₂ ), or air containing these. The deaeration device 60 removes the bubbles 70 contained in the water flowing out from the outlet 24 so that the water in which the bubbles 70 are reduced or removed flows out from the outflow pipe 32.

  According to the above configuration, the flowing water sterilizer 10 mixes the bubbles 70 with the water flowing through the treatment channel 16 and irradiates the water containing the bubbles 70 with ultraviolet light. Since the transmittance of ultraviolet light is higher in air than in water, the transmittance of ultraviolet light traveling in the axial direction can be increased by increasing the volume ratio of bubbles in the processing channel and decreasing the volume ratio of water. Can be increased. In addition, the ultraviolet light is scattered, reflected, and refracted by the bubbles 70 to uniformize the illuminance distribution of the ultraviolet light in the processing flow path 16, thereby causing uneven irradiation that causes a portion where the amount of ultraviolet light irradiation is partially insufficient. Can be prevented. By suppressing the irradiation unevenness, it is possible to prevent water that has not been sufficiently sterilized from partially passing through and to enhance the sterilizing effect.

  According to the present embodiment, it is possible to prevent dirt from adhering to the inner wall surface 18 of the processing channel 16 by using a shock wave when the bubbles 70 are crushed, and to suppress a decrease in the irradiation intensity of ultraviolet light. In the present embodiment, since a window member having a relatively small opening corresponding to the water flow cross-sectional area of the straight pipe 20 is used, there is a possibility that the irradiation intensity of ultraviolet light may be greatly reduced due to local contamination of the window member. . However, the first window member 25 is located in the vicinity of the inlet 23 where the direction of water flow changes in an L shape, and many bubbles 70 are formed on the inner surface of the first window member 25 due to turbulent flow accompanying the change in water flow. Therefore, the dirt on the inner surface of the first window member 25 is effectively removed by the collision and collapse of the bubble 70. Similarly, since the second window member 26 is provided at the end of the axially extending flow path, many of the bubbles 70 from the processing flow path 16 toward the outlet 24 collide with the second window member 26, and the second window member 26 The dirt on the inner surface of 26 is effectively removed. As described above, according to the present embodiment, it is possible to effectively remove the dirt on the window member through which the ultraviolet light is transmitted, and it is possible to suppress a decrease in the ultraviolet light irradiation intensity due to the dirt on the window member.

  In the above, this invention was demonstrated based on the Example. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, and various modifications are possible, and such modifications are within the scope of the present invention. It is a place.

  In the above-mentioned embodiment, the case where the 1st light source 41 and the 2nd light source 42 were each provided in the both ends of the straight tube 20 was shown. In a modification, a light source may be provided only in either one of the both ends of the straight tube 20. For example, only the first light source 41 may be provided, or only the second light source 42 may be provided. When providing a light source in any one of them, it may be preferable to provide only the second light source 42. This is because the second window member 26 has a higher dirt removal effect by the bubbles 70 than the position of the first window member 25. The running water sterilizer may be configured not to include the deaerator 60. In this case, the water containing the bubbles 70 may flow out from the outflow pipe 32 to the outside.

  In the above-mentioned embodiment, it demonstrated as an apparatus for irradiating ultraviolet light to water and performing a sterilization treatment. In a modified example, this apparatus may be used for a purification treatment for decomposing organic substances contained in water by irradiation with ultraviolet light.

  DESCRIPTION OF SYMBOLS 10 ... Running water sterilizer, 16 ... Processing flow path, 18 ... Inner wall surface, 20 ... Straight pipe, 21 ... Upstream side end, 22 ... Downstream side end, 23 ... Inlet, 24 ... Outlet, 25 ... 1st Window member, 26 ... second window member, 41 ... first light source, 42 ... second light source, 50 ... bubble generator, 60 ... deaerator, 70 ... air bubbles.

Claims (6)

A straight pipe that divides the processing flow path;
A light source that is provided at at least one of both ends of the straight pipe and irradiates ultraviolet light in the axial direction of the straight pipe toward the processing flow path;
A flowing water sterilizer, comprising a bubble generator provided upstream of the processing channel and mixing bubbles with water flowing into the processing channel.   The running water sterilizer according to claim 1, wherein the light source is provided at least at a downstream end of the straight pipe.   The running water sterilizer according to claim 1, further comprising a window member that partitions between the light source and the processing flow path.   The flowing water sterilizer according to any one of claims 1 to 3, further comprising a deaeration device that is provided downstream of the processing channel and removes bubbles from water flowing out of the processing channel. .   5. The running water sterilizer according to claim 1, wherein at least an inner wall surface of the straight pipe is made of polytetrafluoroethylene (PTFE). Mixing air bubbles with water flowing into a processing channel defined by a straight pipe;
Irradiating ultraviolet light in the axial direction of the straight pipe toward the water containing bubbles flowing through the treatment flow path.

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