JP2022073930A - Fluid sterilizer - Google Patents

Abstract

To provide a fluid sterilizer capable of suppressing the adhesion of foreign matters.SOLUTION: A fluid sterilizer according to an embodiment includes: a cylindrical part; a feed head provided at one end of the cylindrical part; a discharge head provided at the other end of the cylindrical part and having a hole penetrating between an end surface on the cylindrical part side and an end surface on the side opposite to the cylindrical part side; a substrate provided inside the hole of the discharge head; a light emitting element provided on the surface of the substrate on the cylindrical part side and capable of emitting ultraviolet rays; and a window provided in the discharge head and facing the light emitting element. The surface roughness Ra of the inner surface of the cylindrical part is 50 nm (nanometer) or less.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a fluid sterilizer.

There is a fluid sterilizer that sterilizes a fluid such as water by irradiating it with ultraviolet rays. For example, a fluid sterilizer having a cylinder through which a fluid flows and a light source provided at the end of the cylinder and irradiating the inside of the cylinder with ultraviolet rays has been proposed. In this case, a part of the ultraviolet rays emitted from the light source is directly applied to the fluid flowing inside the cylinder portion. In addition, the ultraviolet rays emitted from the light source and incident on the inner surface of the cylinder portion propagate while repeating reflection inside the cylinder portion.

Such a fluid sterilizer can also be used for sterilizing seawater, groundwater, etc., for example. However, seawater and groundwater contain foreign substances such as sand, dead microorganisms, and inorganic salts. Therefore, when the fluid sterilizer is used for such an application, foreign matter may adhere to the wetted portion of the fluid sterilizer and the sterilization effect may be reduced.

For example, if foreign matter adheres to the inner surface of the cylinder, the reflectance decreases. When the reflectance is lowered, the intensity of the reflected light (ultraviolet rays) applied to the fluid is lowered, so that the bactericidal effect is reduced. Further, when foreign matter adheres to the window provided between the light source and the flow path, a part of the ultraviolet rays radiated from the light source toward the fluid is shielded from light, so that the bactericidal effect is reduced.

In this case, if the fluid sterilizer is disassembled to remove the adhered foreign matter, it takes time and effort, and the operational availability of the fluid sterilizer is also low.
Therefore, it has been desired to develop a fluid sterilizer capable of suppressing the adhesion of foreign substances.

Japanese Unexamined Patent Publication No. 2018-69166 Japanese Unexamined Patent Publication No. 2017-051290

An object to be solved by the present invention is to provide a fluid sterilizer capable of suppressing the adhesion of foreign substances.

The fluid sterilizer according to the embodiment includes a cylinder portion; a supply head provided at one end of the cylinder portion; and an end surface on the cylinder portion side provided at the other end portion of the cylinder portion, and the said. An end surface opposite to the cylinder side, a discharge head having a hole penetrating between the discharge head; a substrate provided inside the hole of the discharge head; and a surface of the substrate on the cylinder side. It is provided with a light emitting element capable of irradiating ultraviolet rays; a window provided on the discharge head and facing the light emitting element. The surface roughness Ra of the inner surface of the tubular portion is 50 nm (nanometers) or less.

According to the embodiment of the present invention, it is possible to provide a fluid sterilizer capable of suppressing the adhesion of foreign matter.

It is a schematic sectional drawing for exemplifying the fluid sterilization apparatus which concerns on this embodiment.

Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, similar components are designated by the same reference numerals and detailed description thereof will be omitted as appropriate.

FIG. 1 is a schematic cross-sectional view for illustrating the fluid sterilizer 1 according to the present embodiment.
As shown in FIG. 1, the fluid sterilizer 1 includes, for example, a cylinder portion 2, a cover 3, a supply head 4, a discharge head 5, a light source 6, a window 7, a cooling portion 8, and a scraper 9.

The tubular portion 2 has a cylindrical shape, and both end portions are open. The tubular portion 2 can be, for example, a cylindrical tube. Ultraviolet rays are irradiated from the light source 6 to the inside of the tubular portion 2, but if a part of the irradiated ultraviolet rays passes through the tubular portion 2 and leaks to the outside, the processing capacity of the fluid sterilizer 1 is lowered. Therefore, it is preferable that the tubular portion 2 is made of a material that does not transmit ultraviolet rays and has a high reflectance to ultraviolet rays. For example, the tubular portion 2 can be formed of a metal having a high reflectance to ultraviolet rays.

If the tubular portion 2 contains a metal having a high reflectance to ultraviolet rays, the ultraviolet rays incident on the inner surface of the tubular portion 2 can be easily reflected toward the fluid 301a. Therefore, it is possible to improve the utilization efficiency of the ultraviolet rays emitted from the light source 6. If the utilization efficiency of ultraviolet rays can be improved, the number of light emitting elements 61 can be reduced. If the number of light emitting elements 61 is reduced, the size of the light source 6 can be reduced, the cost can be reduced, and energy can be saved.

Further, the internal space of the tubular portion 2 becomes a flow path of the fluid 301a to be sterilized. Therefore, the fluid 301a comes into contact with the inner surface of the tubular portion 2. Here, the fluid 301a may be seawater, groundwater, or the like. For example, when seawater comes into contact with the inner surface of the tubular portion 2 containing metal, corrosion may occur. Therefore, it is preferable that the tubular portion 2 is made of a metal having corrosion resistance against a liquid that is easily corroded such as seawater. For example, if the tubular portion 2 is made of stainless steel containing 8 wt% or more of Ni (nickel), it is possible to improve the reflectance to ultraviolet rays and the corrosion resistance to a liquid that is easily corroded such as seawater. As the stainless steel, for example, SUS304 or SUS316 can be used.

In addition, seawater and groundwater contain foreign substances such as sand, dead microorganisms, and inorganic salts. Since the fluid 301a comes into contact with the inner surface of the tubular portion 2, if the fluid 301a contains a foreign substance, the foreign substance tends to adhere to the inner surface of the tubular portion 2. If foreign matter adheres to the inner surface of the tubular portion 2, the reflectance to ultraviolet rays may decrease. When the reflectance is lowered, the intensity of the reflected light (ultraviolet rays) applied to the fluid 301a is lowered, so that the bactericidal effect may be reduced.
In this case, if the fluid sterilizer 1 is disassembled to remove the foreign matter adhering to the inner surface of the tubular portion 2, it takes time and effort, and the operational availability of the fluid sterilizer 1 is also lowered.

According to the findings obtained by the present inventor, the surface roughness (arithmetic mean roughness) Ra of the inner surface of the tubular portion 2 is in the range of 50 nm (nanometers) or less, preferably 3 nm (nanometers) or more, and 50 nm (). If the range is set to the range of nanometers or less, it is possible to suppress the adhesion of foreign matter to the inner side surface of the tubular portion 2, and it is possible to improve the reflectance to ultraviolet rays. For example, by buffing the inner surface of the tubular portion 2, the surface roughness Ra of the inner surface of the tubular portion 2 can be within the range of the above numerical value.

The cover 3 has a cylindrical shape, and the ends on both sides are open. The cover 3 can be, for example, a cylindrical tube. The tubular portion 2 is housed in the internal space of the cover 3. The material of the cover 3 is not particularly limited as long as it has a certain degree of rigidity. The material of the cover 3 can be, for example, a metal such as stainless steel. The cover 3 can be fixed to, for example, the supply head 4 and the discharge head 5. The method of fixing the cover 3 is not particularly limited. For example, one end of the cover 3 can be provided inside the recess or groove provided in the supply head 4, and the other end of the cover 3 can be provided inside the recess or groove provided in the discharge head 5. .. Further, for example, flanges may be provided at the ends on both sides of the cover 3, one flange may be fixed to the supply head 4 with a screw or the like, and the other flange may be fixed to the discharge head 5 with a screw or the like.
The cover 3 is not always necessary and can be omitted. However, if the cover 3 is provided, it is possible to suppress the external force from directly acting on the tubular portion 2.

The supply head 4 is provided at one end of the tubular portion 2. A seal member (not shown) may be provided between the supply head 4 and the end of the tubular portion 2. The seal member is sealed so that the space between the supply head 4 and the cylinder portion 2 is liquid-tight. The seal member can be, for example, an O-ring or the like.

The supply head 4 has, for example, a columnar shape and has a hole 4a penetrating between an end surface on the cylinder portion 2 side and an end surface on the side opposite to the cylinder portion 2 side. The opening of the hole 4a on the cylinder portion 2 side is connected to the internal space of the cylinder portion 2. The opening on the side of the hole 4a opposite to the tubular portion 2 side becomes the supply port 4a1. A supply source of the fluid 301a can be connected to the supply port 4a1 via a pipe. Further, a filter, a straightening vane, or the like can be provided inside the hole 4a.

The material of the supply head 4 is not particularly limited as long as it is resistant to the fluid 301a and ultraviolet rays. The material of the supply head 4 can be, for example, a metal such as stainless steel. As described above, when the fluid 301a is a liquid such as seawater that is prone to corrosion, it is preferable that the supply head 4 is made of stainless steel containing 8 wt% or more of Ni. By doing so, it is possible to suppress the occurrence of corrosion in the supply head 4 even when sterilizing seawater or the like.

The discharge head 5 is provided at the other end of the tubular portion 2. A seal member (not shown) can be provided between the discharge head 5 and the end of the cylinder 2. The seal member is sealed so that the space between the discharge head 5 and the cylinder portion 2 is liquid-tight. The seal member can be, for example, an O-ring or the like.

The discharge head 5 has, for example, a columnar shape and has holes 5a and holes 5b.
The opening of the hole 5a on the cylinder portion 2 side is connected to the internal space of the cylinder portion 2. The opening on the side of the hole 5a opposite to the tubular portion 2 side is the discharge port 5a1 provided on the side surface of the discharge head 5. The sterilized fluid 301b is discharged from the discharge port 5a1. A tank or the like in which the sterilized fluid 301b is stored can be connected to the discharge port 5a1 via a pipe.
Further, the hole 5a is a curved flow path. The hole 5a has a flow path 5a2 substantially parallel to the end surface of the discharge head 5 on the tubular portion 2 side, and a flow path 5a3 extending in the axial direction of the discharge head 5.

The flow path 5a2 is open to the end surface of the discharge head 5 on the tubular portion 2 side. Further, the window 7 is exposed on the inner wall of the flow path 5a2. The flow path 5a2 is, for example, a disk-shaped space.
One end of the flow path 5a3 is connected to the vicinity of the peripheral edge of the flow path 5a2. A discharge port 5a1 is connected to the other end of the flow path 5a3. The flow path 5a3 is, for example, a cylindrical space.

The ultraviolet rays emitted from the light source 6 enter the flow path 5a2 through the window 7. Therefore, the fluid 301a flowing through the flow path 5a2 is sterilized by ultraviolet rays. Further, a part of the ultraviolet rays incident on the flow path 5a2 is irradiated to the internal space of the tubular portion 2. A part of the ultraviolet rays irradiated to the internal space of the cylinder portion 2 is reflected on the inner surface of the cylinder portion 2. Therefore, the fluid 301a flowing inside the tubular portion 2 is sterilized by ultraviolet rays.

The holes 5b are open to the end surface of the discharge head 5 on the side opposite to the tubular portion 2 side and the flow path 5a2. That is, the discharge head 5 has holes (holes 5b and 5a) penetrating between the end surface on the cylinder portion 2 side and the end surface on the side opposite to the cylinder portion 2 side.
The hole 5b is provided with, for example, a convex portion 63b of the holder 63, a substrate 62, and a light emitting element 61.

The material of the discharge head 5 is not particularly limited as long as it is resistant to the fluids 301a and 301b and ultraviolet rays. The material of the discharge head 5 can be, for example, a metal such as stainless steel. As described above, when the fluids 301a and 301b are liquids that are prone to corrosion such as seawater, it is preferable that the discharge head 5 is made of stainless steel containing 8 wt% or more of Ni. By doing so, it is possible to suppress the occurrence of corrosion in the discharge head 5 even when sterilizing seawater or the like.

The light source 6 is detachably provided on the discharge head 5.
The light source 6 has, for example, a light emitting element 61, a substrate 62, and a holder 63.
The light emitting element 61 is provided on the surface of the substrate 62 on the cylinder portion 2 side. The light emitting element 61 irradiates the window 7 with ultraviolet rays. At least one light emitting element 61 can be provided. When a plurality of light emitting elements 61 are provided, the plurality of light emitting elements 61 can be connected in series. The light emitting element 61 is not particularly limited as long as it is an element that generates ultraviolet rays. The light emitting element 61 may be, for example, a light emitting diode or a laser diode.

The peak wavelength of the ultraviolet rays emitted from the light emitting element 61 is not particularly limited as long as it has a bactericidal effect. However, if the peak wavelength is 255 nm to 290 nm, the bactericidal effect can be improved. Therefore, it is preferable to use a light emitting element 61 capable of irradiating ultraviolet rays having a peak wavelength of 255 nm to 290 nm.

The substrate 62 has a plate shape and is provided on the end surface of the convex portion 63b on the tubular portion 2 side. A wiring pattern can be provided on the substrate 62. The material of the substrate 62 is preferably resistant to ultraviolet rays. The material of the substrate 62 can be, for example, ceramics such as aluminum oxide. The substrate 62 may be a metal plate whose surface is covered with an inorganic material (metal core substrate). If the material of the substrate 62 is ceramics or the like, or if the substrate 62 is a metal core substrate, resistance to ultraviolet rays and high heat dissipation can be obtained.

The holder 63 can be detachably provided on the discharge head 5. The light emitting element 61 has a longer life than that of a discharge lamp or the like, but the luminous efficiency decreases as the lighting time becomes longer. It is also conceivable that the light emitting element 61 may fail to turn off the light. If the holder 63 is detachably provided on the discharge head 5, the light emitting element 61 can be easily replaced.

The holder 63 has, for example, a flange 63a and a convex portion 63b. The flange 63a and the convex portion 63b can be integrally formed.
The flange 63a has a plate shape and is provided on the end surface of the discharge head 5 on the side opposite to the tubular portion 2 side. The flange 63a is attached to the discharge head 5 using, for example, a fastening member such as a screw.

The convex portion 63b is provided on the surface of the flange 63a on the cylinder portion 2 side. The convex portion 63b protrudes from one surface of the flange 63a and is provided inside the hole 5b of the discharge head 5. A substrate 62 on which a light emitting element 61 is mounted can be provided on the end surface of the convex portion 63b on the tubular portion 2 side. Further, the convex portion 63b can have a function of determining the position of the light emitting element 61 with respect to the discharge head 5. For example, the side surface of the convex portion 63b can be brought into contact with the inner wall of the hole 5b of the discharge head 5. In this way, the position of the light emitting element 61 with respect to the discharge head 5 can be determined.

Further, since the hole 5b of the discharge head 5 and the flow path 5a2 are partitioned by the window 7, the discharge head 5 (light source 6) can be attached and detached even when the fluid 301a is present in the flow path 5a2. Therefore, it is possible to improve maintainability.

Further, the holder 63 has a function of releasing the heat generated in the light emitting element 61 to the outside. Therefore, the holder 63 is preferably formed from a material having high thermal conductivity. The holder 63 can be formed of, for example, a metal such as aluminum, copper, or stainless steel. Further, heat radiation fins may be provided on the end surface of the holder 63 on the side opposite to the cylinder portion 2 side, the side surface, and the like.

The window 7 has a plate shape, and is provided, for example, on the inner wall of the hole 5b of the discharge head 5 so as to be liquidtight. That is, the window 7 is provided with the discharge head 5, and one surface of the window 7 is exposed to the flow path 5a2 provided in the discharge head 5. The planar shape of the window 7 can be, for example, a quadrangle. If the planar shape of the window 7 is quadrangular, it is easy to bring the scraper 9 into contact with the entire surface of the window 7. Therefore, it becomes easy to remove the foreign matter adhering to the window 7.

The window 7 faces the light emitting element 61. A space 5b1 can be provided between the window 7 and the light emitting element 61. The window 7 is made of a material that is capable of transmitting ultraviolet rays and has resistance to ultraviolet rays and the fluid 301a. The window 7 is formed of, for example, quartz or a fluororesin that transmits ultraviolet rays.

Further, an antireflection film may be provided on the surface of the window 7 on the light emitting element 61 side. If the antireflection film is provided, it is possible to prevent the ultraviolet rays emitted from the light emitting element 61 from being reflected by the window 7 and becoming difficult to be irradiated to the fluid 301a. That is, it is possible to improve the utilization efficiency of the ultraviolet rays emitted from the light emitting element 61.

Further, an antifouling film may be provided on the surface of the window 7 on the tubular portion 2 side. As described above, the fluid 301a may contain foreign matter. When a foreign substance adheres to the window 7, it becomes difficult for the ultraviolet rays emitted from the light emitting element 61 to pass through the window 7. If the antifouling film is provided, it is possible to prevent foreign matter from adhering to the window 7.

The cooling unit 8 can be provided, for example, on the side of the holder 63 opposite to the light emitting element 61 side. The cooling unit 8 is, for example, a fan that supplies air to the holder 63. When the holder 63 is provided with heat radiation fins, the cooling unit 8 can be a fan that supplies air to the heat radiation fins. Further, the cooling unit 8 may supply the liquid to the flow path provided in the holder 63, for example. That is, the cooling unit 8 may be an air-cooled type or a liquid-cooled type.

The cooling unit 8 may be omitted depending on the number of light emitting elements 61, the amount of heat generated, the temperature and the flow rate of the fluid 301a, and the like. However, if the cooling unit 8 is provided, it is difficult for the temperature of the light emitting element 61 to exceed the maximum junction temperature even if the number of light emitting elements 61 and the applied power are increased.

Further, if the cooling unit 8 is provided, the temperature of the light emitting element 61 is unlikely to exceed the maximum junction temperature even if the temperature of the fluid 301a rises or the flow rate of the hot fluid 301a increases. Therefore, the range of the fluid 301a that can be handled can be expanded.

Here, since the fluid 301a comes into contact with the surface of the window 7 on the cylinder 2 side, if the fluid 301a contains foreign matter, the foreign matter tends to adhere to the surface of the window 7 on the cylinder 2 side. When foreign matter adheres to the window 7, it becomes difficult for the ultraviolet rays emitted from the light source 6 to enter the flow path 5a2. Therefore, the bactericidal effect may be reduced.

As described above, if the antifouling film is provided on the surface of the window 7 on the tubular portion 2 side, it is possible to suppress the adhesion of foreign matter. However, even if the antifouling film is provided, it may be difficult to suppress the adhesion of foreign matter when the amount of foreign matter contained in the fluid 301a is large.

In this case, if the fluid sterilizer 1 is disassembled to remove the foreign matter adhering to the window 7, it takes time and effort, and the operational availability of the fluid sterilizer 1 is also low.
Therefore, the fluid sterilizer 1 is provided with a scraper 9 for removing foreign matter adhering to the window 7.

The scraper 9 can be provided on the discharge head 5. A seal member 10 can be provided between the scraper 9 and the discharge head 5. The seal member 10 is sealed so that the space between the scraper 9 and the discharge head 5 is liquid-tight.

The scraper 9 can be made movable along the surface of the window 7 in a state of being in contact with the surface of the window 7 on the tubular portion 2 side. For example, one end 9a of the scraper 9 can be brought into contact with the surface of the window 7 on the cylinder 2 side. For example, the other end 9b of the scraper 9 can be exposed from the discharge head 5. For example, the scraper 9 can be made movable in a direction orthogonal to the central axis of the tubular portion 2.
If such a scraper 9 is provided, foreign matter adhering to the window 7 can be scraped off.

The scraper 9 may be moved by, for example, by an operator or by using a drive device such as a motor or an air cylinder. The removal of the foreign matter by the scraper 9 can be performed, for example, depending on the amount of the attached foreign matter, or can be performed periodically.

The material of the scraper 9 is not particularly limited as long as it is resistant to the fluid 301a and ultraviolet rays. The material of the scraper 9 can be, for example, a metal such as stainless steel. As described above, when the fluid 301a is a liquid such as seawater that is prone to corrosion, it is preferable to form the scraper 9 from stainless steel containing 8 wt% or more of Ni. By doing so, it is possible to suppress the occurrence of corrosion in the scraper 9 even when sterilizing seawater or the like.

Although some embodiments of the present invention have been exemplified above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, and the like can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof. In addition, each of the above-described embodiments can be implemented in combination with each other.

1 fluid sterilizer, 2 cylinder, 4 supply head, 5 discharge head, 6 light source, 7 window, 9 scraper, 61 light emitting element, 63 holder, 63b convex part, 301a fluid, 301b fluid

Claims (3)

With the cylinder part;
With a supply head provided at one end of the cylinder;
A discharge head provided at the other end of the cylinder and having a hole penetrating between the end surface on the cylinder side and the end surface on the side opposite to the cylinder side;
With the substrate provided inside the hole of the discharge head;
With a light emitting element provided on the surface of the substrate on the cylinder side and capable of irradiating ultraviolet rays;
A window provided on the discharge head and facing the light emitting element;
Equipped with
A fluid sterilizer having a surface roughness Ra of the inner surface of the cylinder portion of 50 nm (nanometers) or less. The fluid sterilizer according to claim 1, wherein the tubular portion is made of stainless steel containing 8 wt% or more of Ni (nickel). The fluid sterilizer according to claim 1 or 2, further comprising a scraper that can move along the surface of the window in contact with the surface of the window on the tubular portion side.

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