JP7528872B2 - Ultraviolet sterilization device - Google Patents

Description

The technical field of this specification relates to ultraviolet sterilization devices.

Some sterilization devices use ultraviolet light to kill bacteria contained in water. Traditionally, mercury lamps have often been used as a source of ultraviolet light. In recent years, semiconductor light-emitting elements that emit ultraviolet light have come to be used instead of mercury lamps.

For example, Patent Document 1 discloses a technology for sterilizing water by ultraviolet light emitted by an ultraviolet light-emitting element while water is flowing inside a cylindrical housing (paragraph [0009] of Patent Document 1). The mounting part 5 for mounting the ultraviolet light irradiation device is located at the axial end of the cylindrical housing. From the viewpoints of the light distribution directionality of the ultraviolet light-emitting element and heat dissipation due to heat generation, an external illumination type structure in which ultraviolet light is irradiated from outside the sterilization chamber is mainstream.

JP 2017-104773 A

The ultraviolet rays emitted from the ultraviolet irradiation device are directional, but spread out radially. For this reason, the intensity of the ultraviolet rays is somewhat lower in areas far from the ultraviolet irradiation device. In other words, the sterilization effect is somewhat lower in areas far from the ultraviolet irradiation device.

In the ultraviolet irradiation module described in Patent Document 1, it is difficult to sufficiently sterilize water in the peripheral area of the second end face 2 facing the mounting portion 5 to which the ultraviolet irradiation device is attached. In other words, sufficient sterilization efficiency cannot be obtained. The sterilization efficiency is generally the product of the ultraviolet illuminance and the irradiation time.

The problem that the technology of this specification aims to solve is to provide an ultraviolet sterilization device that is equipped with ultraviolet light emitting elements and aims to achieve strong ultraviolet illuminance and long irradiation time.

The ultraviolet sterilization device in the first aspect has an ultraviolet light-emitting element, a sterilization chamber capable of containing water to be sterilized by ultraviolet light emitted by the ultraviolet light-emitting element and having an inner surface, an inflow pipe for inflowing water into the inside of the sterilization chamber, a flow path for communicating the inflow pipe with the sterilization chamber, and an inflow port which is an opening that opens on the inner surface when the flow path reaches the inner surface of the sterilization chamber. The ultraviolet light-emitting element is arranged along the inner surface. The light irradiation surface of the ultraviolet light-emitting element faces the inside of the inner surface. When viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface, the length of the inflow port along the circumference of the inner surface is longer than twice the length of the inflow port in a direction parallel to the axial direction of the central axis of the inner surface. The inner surface is cylindrical with a curved surface. When viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface, the tangent of the flow path at the inflow port does not pass through the central axis of the inner surface.

In this ultraviolet sterilization device, the distance between the sterilization chamber and the ultraviolet light-emitting element is short. Therefore, the intensity of the ultraviolet light inside the sterilization chamber is sufficiently high. In addition, the water to be sterilized inside the sterilization chamber flows in a spiral shape, so the water stays inside the sterilization chamber for a sufficiently long time. Therefore, the sterilization efficiency of this ultraviolet sterilization device is high.

This specification provides an ultraviolet sterilization device that is equipped with ultraviolet light emitting elements and aims to achieve strong ultraviolet illuminance and long irradiation time.

1 is a schematic diagram of an ultraviolet sterilization device 100 according to a first embodiment. FIG. 2 is a cross-sectional view showing the II-II cross section of FIG. 1. FIG. 2 is a cross-sectional view showing a cross section taken along line III-III of FIG. FIG. 2 is a diagram showing an inlet 113 of the ultraviolet sterilization device 100 of the first embodiment. FIG. 2 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 200 in a modified example of the first embodiment. FIG. 2 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 300 in a modified example of the first embodiment. FIG. 4 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 400 in a modified example of the first embodiment. FIG. 2 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 500 in a modified example of the first embodiment. FIG. 6 is a diagram showing an inlet 613 of an ultraviolet sterilization device 600 in a modified example of the first embodiment. FIG. 7 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 700 in a modified example of the first embodiment.

Specific embodiments will be described below with reference to the drawings, using an ultraviolet sterilization device as an example. However, the technology of this specification is not limited to these embodiments. The device may have a structure different from the embodiments.

(First embodiment)
1. Ultraviolet sterilization device Fig. 1 is a schematic diagram of an ultraviolet sterilization device 100 of a first embodiment. Fig. 2 is a cross-sectional view showing a cross section taken along line II-II in Fig. 1. As shown in Figs. 1 and 2, the ultraviolet sterilization device 100 has a housing 110, an inlet pipe 111, an outlet pipe 112, and an ultraviolet irradiator 120.

The housing 110 houses the ultraviolet irradiation unit 120. The housing 110 has a sterilization chamber SR1, an inlet pipe 111, and an outlet pipe 112. The inlet pipe 111 is a pipe for allowing the water to be sterilized to flow into the inside of the sterilization chamber SR1. The outlet pipe 112 is a pipe for allowing the water to be sterilized to flow out of the sterilization chamber SR1.

The housing 110 houses the sterilization chamber SR1. The housing 110 has an inner surface 110a, an end surface 110b, and an end surface 110c. The sterilization chamber SR1 is a space surrounded by the inner surface 110a, the end surface 110b, and the end surface 110c. The sterilization chamber SR1 has an inner surface 110a, an end surface 110b, and an end surface 110c. The inner surface 110a, the end surface 110b, and the end surface 110c face toward the inside of the sterilization chamber SR1. The sterilization chamber SR1 can temporarily store water to be sterilized inside. The inner surface 110a is a cylindrical inner surface. The end surfaces 110b and 110c are planes perpendicular to the central axis (cylinder axis direction) of the inner surface 110a. The end surface 110c is located in a position facing the end surface 110b. The length of the cylinder in the axial direction of the sterilization chamber SR1 is longer than the diameter of the cylinder of the sterilization chamber SR1.

The ultraviolet irradiation unit 120 irradiates ultraviolet rays toward the inside of the sterilization chamber SR1. The ultraviolet irradiation unit 120 is arranged near the inner surface 110a of the housing 110 and adjacent to the inner surface 110a. The ultraviolet irradiation unit 120 is a unit in which a plurality of ultraviolet light-emitting elements 121 are arranged in a row. The ultraviolet light-emitting elements 121 emit ultraviolet rays for sterilizing water. The ultraviolet irradiation unit 120 is arranged along the inner surface 110a of the housing 110. The row of the ultraviolet light-emitting elements 121 is arranged parallel to the central axis of the inner surface 110a. In other words, the row of the ultraviolet light-emitting elements 121 is arranged parallel to the longitudinal direction of the cylinder of the housing 110. In this way, the ultraviolet light-emitting elements 121 are arranged along the inner surface 110a. The two rows of the ultraviolet irradiation units 120 are arranged facing each other across the central axis of the inner surface 110a. Therefore, the direction in which the light distribution of the ultraviolet light-emitting element 121 has maximum output is the direction from the ultraviolet light-emitting element 121 toward the central axis of the inner surface 110a. The light irradiation surface of the ultraviolet light-emitting element 121 faces inwardly of the inner surface 110a. The ultraviolet light-emitting element 121 has a peak wavelength of, for example, 200 nm or more and 300 nm or less.

Of the materials constituting the inner surface 110a of the housing 110, it is preferable that the material in the area of the ultraviolet irradiation section 120 is transparent to ultraviolet light.

The outer diameter of the housing 110 is, for example, 50 mm or more and 100 mm or less. The length of the housing 110 in the central axis direction is, for example, 100 mm or more and 200 mm or less.

The inlet pipe 111 is a pipe for introducing water into the sterilization chamber SR1. The inlet pipe 111 is connected to the sterilization chamber SR1. Water before sterilization flows through the inlet pipe 111.

The outflow pipe 112 is a pipe for discharging the water inside the sterilization chamber SR1 to the outside. The outflow pipe 112 is connected to the sterilization chamber SR1. The sterilized water flows through the outflow pipe 112.

2. Inlet Fig. 3 is a cross-sectional view showing a cross section taken along line III-III in Fig. 1. Fig. 3 shows a cross section perpendicular to the axial direction of the central axis of the inner side surface 110a. As shown in Fig. 3, the housing 110 has a flow path C1 and an inlet 113. The flow path C1 is a through hole that reaches the inner side surface 110a from the cylindrical outer side surface of the housing 110. The flow path C1 communicates between the inlet pipe 111 and the sterilization chamber SR1. The flow path C1 has a straight pipe portion that is connected to the inlet 113.

The inlet 113 is an opening that opens into the inner surface 110a when the flow path C1 reaches the inner surface 110a of the sterilization chamber SR1. The inlet 113 is provided on the side of the end face 110c. The inlet 113 may also be located on the side of the end face 110b. If the length between the end face 110b and the end face 110c is L1, the distance between the end face 110b and the inlet 113 is (1/8)·L or less.

As shown in FIG. 3, the direction Kx of flow path C1 is a direction that does not pass through the central axis of the inner surface 110a of the housing 110. Furthermore, when viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface 110a, the tangent of flow path C1 at the inlet 113 does not pass through the central axis of the inner surface 110a. For this reason, water flowing from flow path C1 into the sterilization chamber SR1 collides with the inner surface 110a of the housing 110 and generates a flow that rotates around the central axis of the inner surface 110a. In other words, as shown by arrow K2 in FIG. 3, the water convects along the inner surface 110a. In reality, the water flows in a spiral shape, as shown in FIG. 1.

As shown in FIG. 3, the inner surface 110a and the flow path C1 are continuous. Furthermore, at the boundary surface between the inner surface 110a and the flow path C1, the housing 110 has a smooth connection surface without any steps.

Figure 4 is a diagram showing the inlet 113 of the ultraviolet sterilization device 100 of the first embodiment. The inlet 113 is an opening where the inner surface 110a of the housing 110 and the flow path C1 join together. As shown in Figure 4, the shape of the inlet 113 is a rectangle along the inner surface 110a. Since the inner surface 110a is a cylindrical inner surface, the inlet 113 has a rectangular shape formed on the cylindrical inner surface. The circumferential length (path) W1 of the inlet 113 along the inner surface 110a is longer than the axial length H1 of the central axis of the inner surface 110a of the inlet 113.

The length (path) W1 of the inlet 113 in the circumferential direction along the inner surface 110a and the length H1 of the inlet 113 in the axial direction of the central axis of the inner surface 110a satisfy the following formula.
H1 < W1

Preferably, the following formula is satisfied:
2.H1 < W1

Here, length W1 is the length of inlet 113 along the circumference of inner surface 110a when viewed in a cross section perpendicular to the axial direction of the central axis of inner surface 110a of housing 110. Length H1 is the length of inlet 113 in a direction parallel to the axial direction of the central axis of inner surface 110a of housing 110.

3. Sterilization Here, a sterilization method using the ultraviolet sterilization device 100 will be described. First, the ultraviolet light-emitting element 121 of the ultraviolet irradiation unit 120 is turned on, and the ultraviolet light-emitting element 121 irradiates ultraviolet light. Next, water to be treated is introduced into the sterilization chamber SR1 from the inlet pipe 111. Here, as shown in Figures 1 and 3, the water remains inside the sterilization chamber SR1 while drawing a spiral in the direction of the arrow K2. Then, the water is irradiated with ultraviolet light while moving in a spiral shape inside the sterilization chamber SR1, and is sterilized.

4. Effects of the First Embodiment 4-1. Irradiation Distance The distance from the ultraviolet light emitting element 121 of the ultraviolet irradiation unit 120 to the center of the sterilization chamber SR1 is approximately equal to the inner diameter of the inner surface 110a of the sterilization chamber SR1. The farthest distance of the area where water is present that is sterilized by the ultraviolet sterilization device 100 is approximately equal to the inner diameter of the sterilization chamber SR1. Therefore, the irradiation intensity of the ultraviolet light in this ultraviolet sterilization device 100 is sufficiently high. Therefore, the sterilization efficiency of this ultraviolet sterilization device 100 is high.

4-2. Irradiation time The water is irradiated with ultraviolet light while moving in a spiral shape inside the sterilization chamber SR1. Therefore, the distance that the water moves inside the sterilization chamber SR1 is sufficiently longer than the length of the sterilization chamber SR1. Here, the length of the sterilization chamber SR1 is the distance between end face 110b and end face 110c. Therefore, the time that the water to be sterilized remains inside the sterilization chamber SR1 is sufficiently long. Therefore, the sterilization efficiency of this ultraviolet sterilization device 100 is high.

4-3. Cooling of the Light-Emitting Element The ultraviolet irradiating unit 120 is disposed in a position close to the inner surface 110a of the housing 110. Therefore, the heat generated by the ultraviolet emitting element 121 is absorbed by the water to be sterilized. In other words, the ultraviolet emitting element 121 of the ultraviolet irradiating unit 120 is cooled by the water to be sterilized.

5. Modification 5-1. Number of openings FIG. 5 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 200 in a modification of the first embodiment. The ultraviolet sterilization device 200 has a housing 210 and an ultraviolet irradiator 120. The housing 210 has two inlets 213 on the inner side 210a. Of course, the housing 210 has a flow path C2 at each of the inlets 213. The flow paths 213 and C2 are rotationally symmetric with respect to the central axis of the inner side 210a of the housing 210. That is, when one of the flow paths 213 and C2 is rotated 180° around the central axis of the inner side 210a, it overlaps with the other flow path 213 and C2. In this way, the ultraviolet sterilization device 200 has two inlets 213 and a flow path C2. The ultraviolet sterilization device may also have three or more inlets and flow paths. That is, the ultraviolet sterilization device has multiple inlets and multiple flow paths.

5-2. Position of the inlet FIG. 6 is a diagram showing a cross-sectional structure of the ultraviolet sterilization device 300 in a modified example of the first embodiment. The ultraviolet sterilization device 300 has a housing 310 and an ultraviolet irradiation unit 120. The housing 310 has an inlet 313 and a flow path C3. The direction Ky of the flow path C3 is a direction that does not pass through the central axis of the inner side surface 310a of the housing 310. The distance T1 between the center line of the flow path C3 and the central axis of the inner side surface 310a of the housing 310 is smaller than the inner diameter R1 of the inner side surface 310a of the housing 310. When viewed in a cross section perpendicular to the axial direction of the central axis of the inner side surface 310a, the distance T1 between the center line of the flow path C3 and the central axis of the inner side surface 310a of the housing 310 and the inner diameter R1 of the inner side surface 310a of the housing 310 may satisfy the following formula.
(1/2)・R1 ≦ T1 ≦ R1

Of course, the closer the distance T1 is to the inner diameter R1, the more efficiently the water will move in a spiral. If the flow path is curved, the distance T1 is the distance between the tangent to the flow path at the inlet and the central axis of the inner surface. If the inner surface is not a cylindrical inner surface, the distance R1 is the shortest distance between the central axis of the inner surface and the inner surface.

5-3. When the flow path is curved FIG. 7 is a diagram showing a cross-sectional structure of the ultraviolet sterilization device 400 in a modified example of the first embodiment. The ultraviolet sterilization device 400 has a housing 410 and an ultraviolet irradiation unit 120. The housing 410 has an inner side 410a, a flow path C4, and an inlet 413. When viewed in a cross section perpendicular to the central axis of the inner side 410a, the flow path C4 is curved so that the closer to the inlet 413, the closer to the central axis of the inner side 410a. Even in this case, when viewed in a cross section perpendicular to the axial direction of the central axis of the inner side 410a, the tangent of the flow path C4 at the inlet 413 does not pass through the central axis of the inner side 410a.

5-4. When the flow path passes through the inside of the housing FIG. 8 is a diagram showing a cross-sectional structure of an ultraviolet sterilization device 500 in a modified example of the first embodiment. The ultraviolet sterilization device 500 has a housing 510 and an ultraviolet irradiation unit 120. The housing 510 has an inner side 510a, a flow path C5, and an inlet 513. The flow path C5 has a flow path C5a and a flow path C5b. The inlet 513 is located between the flow path C5b and the inner side 510a of the housing 510. The flow path C5a communicates with the flow path C5b. The flow path C5a is a pipe that connects from the inlet pipe 111 to the flow path C5b. The flow path C5a is arranged inside the housing 510 parallel to the central axis of the inner side 510a. The flow path C5a is provided inside the housing 510. The flow path C5b is provided from the flow path C5a to the inlet 513. In this way, the flow path C5 does not necessarily have to penetrate the housing 510 from the outside to the inside.

5-5. Orientation of the inlet FIG. 9 is a diagram showing the inlet 613 of the ultraviolet sterilization device 600 in the modified example of the first embodiment. The ultraviolet sterilization device 600 has a housing 610 and an ultraviolet irradiation unit 120. The housing 610 has an inner surface 610a, a flow path C6, and an inlet 613. The closer the flow path C6 is to the inlet 613, the farther it is from the end face 610c. In other words, the flow path C6 has a shape close to a part of a spiral. The direction Kz passing through the center line of the flow path C6 is not parallel to the end face 610c. Even in this case, the water moves in a spiral shape inside the sterilization chamber SR1. In addition, the inlet 613 has a shape that is farther away from the end face 610c as it moves downstream from the flow path C6.

5-6. Ultraviolet ray irradiation section FIG. 10 is a diagram showing a cross-sectional structure of an ultraviolet ray sterilization device 700 in a modified example of the first embodiment. The ultraviolet ray sterilization device 700 has a housing 710 and an ultraviolet ray irradiation section 120. The housing 710 has an inner side surface 710a, a flow path C1, and an inlet 113. The ultraviolet ray irradiation section 120 has an irradiation surface 120a. The irradiation surface 120a is a light extraction surface of the ultraviolet ray irradiation section 120. In the ultraviolet ray sterilization device 700, the irradiation surface 120a of the ultraviolet ray irradiation section 120 constitutes a part of the inner side surface of the sterilization chamber SR1. That is, the inner side surface of the sterilization chamber SR1 is constituted by the inner side surface 710a of the housing 710 and the irradiation surface 120a of the ultraviolet ray irradiation section 120. It is preferable that the inner side surface 710a and the irradiation surface 120a are continuous surfaces. It is also preferable that there is no step between the inner side surface 710a and the irradiation surface 120a.

5-7. Inner surface The inner surface 110a is not limited to a cylindrical inner surface. The inner surface may have a curved surface and a flat surface. However, since the inner surface is a cylindrical inner surface, the central axis of the cylindrical shape can be determined.

5-8. Reflective Film The inner surface 110a of the housing 110 may be provided with a reflective film that reflects ultraviolet light.

5-9. Combinations The above modifications may be freely combined.

(Additional Note)
The ultraviolet sterilization device in the first aspect has an ultraviolet light-emitting element, a sterilization chamber capable of containing water to be sterilized by ultraviolet light emitted by the ultraviolet light-emitting element and having an inner side, an inflow pipe for inflowing water into the sterilization chamber, a flow path for communicating the inflow pipe with the sterilization chamber, and an inflow port which is an opening that opens on the inner side when the flow path reaches the inner side of the sterilization chamber. The ultraviolet light-emitting element is disposed along the inner side. The light irradiation surface of the ultraviolet light-emitting element faces inwardly of the inner side. When viewed in a cross section perpendicular to the axial direction of the central axis of the inner side, the length of the inflow port along the circumference of the inner side is longer than the length of the inflow port in a direction parallel to the axial direction of the central axis of the inner side.

In the second embodiment of the ultraviolet sterilization device, when viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface, the tangent to the flow path at the inlet does not pass through the central axis of the inner surface.

The ultraviolet sterilization device in the third aspect has an ultraviolet irradiation section in which ultraviolet light emitting elements are arranged in a row. The light irradiation surface of the ultraviolet irradiation section forms part of the inner surface of the sterilization chamber.

In the fourth embodiment of the ultraviolet sterilization device, the flow path is curved so that the closer it is to the inlet, the closer it is to the central axis of the inner surface when viewed in a cross section perpendicular to the central axis of the inner surface.

In the fifth aspect of the ultraviolet sterilization device, the flow path has a straight pipe portion that is connected to the inlet.

In the sixth aspect of the ultraviolet sterilization device, the sterilization chamber has an inner surface, a first end face, and a second end face. The inlet is provided on the side of the first end face. The second end face faces the first end face. The flow path is farther from the first end face as it approaches the inlet.

The ultraviolet sterilization device in the seventh aspect has a housing that houses a sterilization chamber. The flow path has a first flow path provided inside the housing and a second flow path provided from the first flow path to the inlet.

In the ultraviolet sterilization device of the eighth aspect, when viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface, the distance T1 between the tangent to the flow path at the inlet and the central axis of the inner surface, and the shortest distance R1 between the central axis of the inner surface and the inner surface are expressed by the following formula: (1/2) · R1 ≦ T1
Meet the following.

The ultraviolet sterilization device in the ninth aspect has multiple flow paths and multiple inlets.

100... Ultraviolet sterilization device 110... Housing 110a... Inner surface 110b... End surface 110c... End surface 111... Inlet pipe 112... Outlet pipe 113... Inlet port 120... Ultraviolet irradiator 121... Ultraviolet light emitting element SR1... Sterilization chamber

Claims (8)

An ultraviolet light emitting element;
a sterilization chamber capable of containing water to be sterilized by ultraviolet light emitted by the ultraviolet light-emitting element and having an inner surface;
an inlet pipe for injecting water into the sterilization chamber;
a flow path for communicating the inlet pipe with the sterilization chamber;
an inlet which is an opening that opens onto the inner surface when the flow path reaches the inner surface of the sterilization chamber;
having
The ultraviolet light emitting element is
disposed along the inner surface,
The light irradiation surface of the ultraviolet light emitting element is
facing inwardly of the inner surface;
The length of the inlet along the circumference of the inner surface when viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface,
More than twice the length of the inlet in a direction parallel to the axial direction of the central axis of the inner surface ,
The inner surface is cylindrical and has a curved surface.
When viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface, a tangent to the flow path at the inlet does not pass through the central axis of the inner surface.
Including ultraviolet sterilization equipment. The ultraviolet sterilization device according to claim 1,
The ultraviolet light emitting device has an ultraviolet light emitting unit arranged in a row,
The light irradiation surface of the ultraviolet ray irradiation unit is
forming a portion of the inner surface of the sterilization chamber. The ultraviolet sterilization device according to claim 1 or 2 ,
The flow path is
When viewed in a cross section perpendicular to the central axis of the inner surface,
The ultraviolet sterilization device includes a curved portion that approaches the central axis of the inner surface as it approaches the inlet. The ultraviolet sterilization device according to claim 1 or 2 ,
The flow path is
An ultraviolet sterilization device having a straight pipe portion connected to the inlet. The ultraviolet sterilization device according to any one of claims 1 to 4 ,
The sterilization chamber comprises:
The inner surface, a first end surface, and a second end surface,
The inlet is
The first end surface is provided on the side of the first end surface.
The second end surface is
facing the first end surface,
The flow path is
The ultraviolet sterilization device includes a device that is farther away from the first end surface as it approaches the inlet. The ultraviolet sterilization device according to any one of claims 1 to 5 ,
A housing for accommodating the sterilization chamber,
The flow path is
A first flow path provided inside the housing;
a second flow path provided from the first flow path to the inlet;
Including ultraviolet sterilization equipment. The ultraviolet sterilization device according to any one of claims 1 to 6 ,
When viewed in a cross section perpendicular to the axial direction of the central axis of the inner surface,
A distance T1 between a tangent to the flow passage at the inlet and a central axis of the inner surface;
The shortest distance R1 between the central axis of the inner surface and the inner surface;
is expressed by the following formula: (1/2) R1 ≦ T1
An ultraviolet sterilization device including: The ultraviolet sterilization device according to any one of claims 1 to 7 ,
An ultraviolet sterilization device having a plurality of the flow paths and a plurality of the inlets.

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