JP2023146778A - Ultraviolet lamp - Google Patents

Abstract

To provide an ultraviolet lamp capable of suppressing a rise in a temperature of a light source without increasing a size of a device.SOLUTION: An ultraviolet lamp has a space containing fluid to be irradiated with ultraviolet light, a light source for irradiating ultraviolet light toward the space, a metal support member for supporting the light source, a supply pipe defining a supply channel for supplying fluid to the space, and a discharge pipe defining a discharge channel for discharging the fluid in the space. At least one of the supply pipe and the discharge pipe is made of metal. The support member is in contact with the metallic supply pipe or the metallic discharge pipe.SELECTED DRAWING: Figure 2

Description

The present invention relates to an ultraviolet irradiation device that irradiates a fluid with ultraviolet rays.

It is widely known that fluids such as liquids can be sterilized using ultraviolet light. For example, Patent Document 1 describes a fluid sterilization device that irradiates ultraviolet rays in the axial direction to a flow path extending in the axial direction to sterilize the fluid flowing inside the flow path.

Specifically, the fluid sterilization device described in Patent Document 1 includes a light source including a semiconductor light emitting element that emits ultraviolet rays, and a casing having a flow path through which a fluid to be sterilized flows in the axial direction. The light source is housed in a case disposed at one end of the housing in the axial direction. The housing is made of stainless steel and has a tapered structure in which the cross-sectional area of the flow path gradually increases from one end to the other end. The tapered structure has an inclination that matches the orientation angle of the semiconductor light emitting device. Further, a rectifying means for adjusting the flow of fluid is provided at the other end of the housing. Furthermore, the case states that a heat dissipation fan may be provided.

In Patent Document 1, the casing has a tapered structure with an inclination that matches the orientation angle of the semiconductor light emitting element, so that ultraviolet rays can reach a position far from the light source, and the fluid whose flow is adjusted by a rectifying means. It is said that by irradiating ultraviolet rays to the fluid, the sterilizing effect can be enhanced because the fluid is evenly irradiated with ultraviolet rays. Furthermore, the temperature rise of the light source due to its use is suppressed by using a heat dissipation fan.

JP2019-98055A

However, the fluid sterilization device described in Patent Document 1 requires a heat dissipation fan and a device for driving the heat dissipation fan in order to suppress the rise in temperature of the light source, resulting in a problem that the device becomes large. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ultraviolet irradiation device that can suppress a rise in the temperature of a light source without increasing the size of the device.

An ultraviolet irradiation device according to an embodiment of the present invention is an ultraviolet irradiation device for irradiating a fluid with ultraviolet rays, and includes a space in which the fluid to be irradiated with ultraviolet rays is housed, and a space in which the ultraviolet rays are directed toward the space. A light source for irradiation, a metal support member that supports the light source, a supply pipe that defines a supply channel for supplying fluid to the space, and a discharge channel for discharging the fluid from the space. at least one of the supply pipe and the discharge pipe is made of metal, and the support member is in contact with the supply pipe made of metal or the discharge pipe made of metal. .

According to the present invention, it is possible to provide an ultraviolet irradiation device that can suppress a rise in the temperature of a light source without increasing the size of the device.

FIGS. 1A and 1B are diagrams showing the configuration of an ultraviolet irradiation device according to an embodiment. FIG. 2 is a cross-sectional perspective view of the ultraviolet irradiation device. FIG. 3 is a cross-sectional view of the ultraviolet irradiation device. FIGS. 4A and 4B are graphs showing changes in the temperature of the light source depending on the material of the discharge pipe.

Hereinafter, an ultraviolet irradiation device according to an embodiment of the present invention will be described in detail with reference to the attached drawings. In the following description, an example will be described in which the ultraviolet irradiation device is applied to a sterilization device for sterilizing fluid.

(Configuration of ultraviolet irradiation device)
1A, B, 2, and 3 are diagrams showing the configuration of an ultraviolet irradiation device 100 according to this embodiment. FIG. 1A is a perspective view of the ultraviolet irradiation device 100, and FIG. 1B is a plan view. FIG. 2 is a cross-sectional perspective view of the ultraviolet irradiation device 100. FIG. 3 is a cross-sectional view of the ultraviolet irradiation device 100.

As shown in FIGS. 1A, B, 2, and 3, the ultraviolet irradiation device 100 is a device for irradiating a flowing fluid with ultraviolet rays, and includes a space S1 in which a fluid to be irradiated with ultraviolet rays is accommodated; A light source 120 for irradiating ultraviolet rays toward the space S1, a metal support member 130 that supports the light source 120, a supply pipe 140 that defines a supply channel S2 for supplying fluid to the space S1, It has a discharge pipe 150 that defines a discharge flow path S3 for discharging the fluid of S1. Note that in this embodiment, the ultraviolet irradiation device 100 further includes a cover 160 that mainly covers the first wall 111 of the storage wall 110.

Space S1 is defined by storage wall 110. The storage wall 110 defines a space S1 for accommodating a fluid and reflects the ultraviolet rays emitted from the light source 120. The storage wall 110 may be one member or may be two or more members. In this embodiment, the storage wall 110 has two members: a first wall 111 and a second wall 112. Examples of the shape of the space S1 defined by the storage wall 110 (the first wall 111 and the second wall 112) include a spherical shape, a cylindrical shape, a prismatic shape, and other shapes. In this embodiment, the shape of the space S1 defined by the storage wall 110 (the first wall 111 and the second wall 112) is approximately spherical. The first wall 111 defines one generally hemispherical shape of the space S1, and the second wall 112 defines the other generally hemispherical shape of the space S1. Note that in this embodiment, the first wall 111 also defines a part of the supply flow path S2, which will be described later, and the second wall 112 also defines a part of the discharge flow path S3, which will be described later. In this embodiment, the first wall 111 is arranged on the upstream side in the fluid flow direction, and the second wall 112 is arranged on the downstream side in the fluid flow direction. The substantially spherical space S1 is formed by joining the first wall 111 and the second wall 112.

The materials for the first wall 111 and the second wall 112 are not particularly limited as long as they can perform the above functions. The materials of the first wall 111 and the second wall 112 may be the same or different. In this embodiment, the first wall 111 and the second wall 112 are made of the same material. The material of the first wall 111 and the second wall 112 is preferably polytetrafluoroethylene (PTFE) from the viewpoint of efficiently reflecting ultraviolet rays. The inner diameter of the storage wall 110 is not particularly limited, but is, for example, about 20 to 60 mm. By setting the inner diameter of the storage wall 110 to approximately 20 to 60 mm, the fluid within the storage wall 110 can be sufficiently sterilized even when only one UV-C LED is used as the light source 120. A supply channel S2 and a discharge channel S3 are connected to the space S1.

The supply pipe 140 defines a supply channel S2 for supplying fluid to the space S1. On the downstream side of the supply pipe 140, a first sealing member (not shown) such as an O-ring is disposed in a part of the region between the supply pipe 140 and the first wall 111 to prevent liquid leakage. . Moreover, in this decimal form, the supply pipe 140 is in contact with the cover 160 by being screwed together (not shown). The material of the supply pipe 140 is not particularly limited as long as it can perform the above function. Examples of materials for the supply pipe 140 include nickel-plated brass, polypropylene (PP), acrylonitrile-butadiene rubber-styrene copolymer (ABS resin), polystyrene, acrylonitrile-styrene copolymer (AS resin), polyacetal ( POM) and polyvinyl chloride (PVC). In this embodiment, the material of supply pipe 140 is polypropylene.

The supply channel S2 supplies fluid to the inside of the storage wall 110 (space S1). One end of the supply channel S2 is open to the space S1. That is, the opening of the supply channel S2 to the space S1 is the supply port 141. It is preferable that the supply channel S2 is arranged so as to be able to smoothly supply fluid into the interior of the storage wall 110 (space S1) along the inner surface of the storage wall 110. In the present embodiment, at the connection between the inner surface of the supply channel S2 and the inner surface of the storage wall 110 in the cross section including the center of gravity of the space S1 along the flow direction of the fluid in the supply channel S2, the supply channel S2 A part of the inner surface of is arranged smoothly and continuously with the inner surface of the storage wall 110 so as to coincide with a tangent to the inner surface of the storage wall 110 at the connecting portion. In this embodiment, the supply channel S2 is configured by a part of the storage wall 110 (first wall 111) and the supply pipe 140.

The discharge pipe 150 defines a discharge flow path S3 for discharging the fluid inside the space S1. On the upstream side of the discharge pipe 150, a second sealing member 152 is disposed in a partial area between the supply pipe 140 and the first wall 111 to prevent liquid leakage. In this embodiment, the second sealing member 152 is an O-ring. Furthermore, the discharge pipe 150 is connected to the support member 130 by screwing together. The material of the discharge pipe 150 is not particularly limited as long as it can perform the above function. Examples of materials for the discharge tube 150 include nickel-plated brass, brass, copper, and aluminum. In this embodiment, the material of the discharge pipe 150 is nickel-plated brass. Nickel-plated brass as a material for the discharge pipe 150 is preferable because it is less susceptible to dissimilar metal corrosion. Therefore, at least one of the supply pipe 140 and the discharge pipe 150 is made of metal. Here, "at least one of the supply pipe 140 and the discharge pipe 150 is made of metal" means that only the supply pipe 140 may be made of metal, only the discharge pipe 150 may be made of metal, and the supply pipe 140 and the discharge pipe 150 may be made of metal. 150 means that both may be made of metal. The support member 130 and the discharge pipe 150 made of metal are screwed into contact with each other.

The discharge channel S3 discharges the fluid inside the storage wall 110 (space S1). One end of the discharge channel S3 opens into the space S1. That is, the opening of the discharge channel S3 to the space S1 is the discharge port 151. It is preferable that the discharge flow path S3 is disposed inside the storage wall 110 (space S1) so that the fluid can be smoothly discharged along the wall of the storage wall 110. In the present embodiment, the discharge flow path is formed at the connection portion between the inner surface of the discharge flow path S3 and the inner surface of the storage wall 110 in the cross section including the center of gravity of the storage wall 110 along the flow direction of the fluid in the discharge flow path S3. A part of the inner surface of S3 is arranged smoothly and continuously with the inner surface of the storage wall 110 so as to coincide with a tangent to the inner surface of the storage wall 110 at the connection portion. In this embodiment, the discharge flow path S3 is configured by a part of the storage wall 110 (second wall 112) and the discharge pipe 150.

Support member 130 supports light source 120. In this embodiment, support member 130 covers a portion of storage wall 110 and supports discharge pipe 150. A recess 131 in which the light source 120 is placed is arranged in the support member 130. The support member 130 is made of metal in order to efficiently transfer the heat generated by the light source 120 to the exhaust pipe 150. The material of the support member 130 is not particularly limited as long as it can exhibit the above function. Examples of materials for support member 130 include metals such as aluminum, brass, and copper. In this embodiment, the material of the support member 130 is aluminum from the viewpoint of heat dissipation and manufacturing cost. Further, the support member 130 is in contact with the exhaust pipe 150 in order to efficiently transfer the heat generated by the light source 120 to the exhaust pipe 150. The method of contact between the support member 130 and the discharge pipe 150 is not particularly limited. In this embodiment, the support member 130 and the discharge pipe 150 are in contact with each other through screwing. Thereby, the contact area between the support member 130 and the discharge pipe 150 is increased, and the heat generated by the light source 120 is efficiently transferred to the discharge pipe 150. In this embodiment, since aluminum is susceptible to dissimilar metal corrosion, the discharge pipe 150 that defines the discharge flow path S3 that comes into contact with the fluid is formed of nickel-plated brass, thereby eliminating corrosion caused by the light source 120. Heat is escaping.

The cover 160 covers all of the first wall 111 and a part of the second wall 112, and supports the supply pipe 140. More specifically, the cover 160 covers the reservoir wall in conjunction with the support member 130. In this embodiment, the first wall 111 and the second wall 112 are fixed by fixing the support member 130 and the cover 160. The material of the cover 160 is not particularly limited as long as it can perform the above functions. Examples of materials for the cover 160 include metals such as aluminum, stainless steel, brass, and copper, polypropylene (PP), acrylonitrile-butadiene rubber-styrene copolymer (ABS resin), polystyrene, acrylonitrile-styrene copolymer (AS resin), etc. ), polyacetal (POM), polyvinyl chloride (PVC), and other resins. In this embodiment, the material of cover 160 is polypropylene.

The light source 120 irradiates the fluid inside the storage wall 110 (space S1) with ultraviolet light. The light source 120 may directly irradiate the fluid in the space S1 with ultraviolet rays, or may irradiate the fluid in the space S1 with ultraviolet rays through other members such as windows or mirrors. In this embodiment, a window 123 that transmits ultraviolet rays is arranged in a part of the storage wall 110, and the light source 120 irradiates the space S1 with ultraviolet rays through the window 123.

The type of light source 120 is not particularly limited as long as it can emit ultraviolet rays. Examples of light source 120 include a light emitting diode (LED), a mercury lamp, a metal halide lamp, a xenon lamp, and a laser diode (LD). In this embodiment, light source 120 is a light emitting diode (LED). The wavelength of the ultraviolet light emitted by the light source 120 is not particularly limited. From the viewpoint of effective sterilization, the wavelength of the ultraviolet light emitted by the light source 120 is preferably 200 nm or more and 350 nm or less, more preferably 200 nm or more and 280 nm or less. That is, the ultraviolet rays emitted from the light source 120 are preferably ultraviolet C waves (UVC). Examples of commercially available light sources 120 include NCSU334A (Nichia Corporation), which is an ultraviolet light emitting diode with a peak wavelength of 280 nm. Further, other examples of ultraviolet light emitting diodes having a peak wavelength of 280 nm include KLARAN (Asahi Kasei Corporation) and ZEU110BEAE (Stanley Electric Corporation).

The position of the light source 120 is not particularly limited as long as it can irradiate the fluid in the space S1 with ultraviolet rays. The light source 120 may be placed on the first wall 111 or the second wall 112. In this embodiment, the light source 120 is placed on the second wall 112 side. More specifically, the light source 120 is arranged inside a recess 131 provided in the support member 130 so that the generated heat is easily transferred to the support member 130. Further, the light source 120 is arranged so that its optical axis does not intersect with either the supply port 141 or the discharge port 151.

The window 123 is arranged as a part of the wall surface of the storage wall 110 (second wall 112), and transmits the ultraviolet rays emitted from the light source 120 into the inside of the storage wall 110 (space S1). The material for the window 123 is not particularly limited as long as it can transmit ultraviolet rays and has the necessary strength. From the viewpoint of improving sterilization performance, the material of the window 123 is preferably a material that transmits ultraviolet rays having a wavelength of 200 nm or more and 830 nm or less. Examples of materials for the window 123 include quartz glass, sapphire glass, barium fluoride, and calcium fluoride.

Further, the shape of the window 123 is not particularly limited as long as it allows the ultraviolet rays emitted from the light source 120 to reach the space S1, and may be flat or shaped to match the inner surface of the storage wall 110. In this embodiment, the window 123 has a flat plate shape and is arranged to cover a recess provided in the second wall 112. The outer diameter of the window 123 is not particularly limited as long as it allows the ultraviolet rays emitted from the light source 120 to reach the space S1. For example, the outer diameter of the window 123 is preferably 20 to 50% of the inner diameter of the storage wall 110. By increasing the outer diameter of the window 123, a wide range of the space S1 can be directly irradiated with ultraviolet rays. On the other hand, by reducing the outer diameter of the window 123, it is possible to increase the proportion of the ultraviolet reflecting surface occupying the inner surface of the space S1. Further, in this embodiment, the third sealing member 124 is arranged in a part of the area between the window 123 and the second wall 112 to prevent liquid leakage.

(How to use the ultraviolet irradiation device and how to cool the light source)
Next, a method of using the ultraviolet irradiation device 100 and a method of cooling the light source 120 according to the present embodiment will be described.

With ultraviolet light emitted from the light source 120, a fluid to be sterilized (for example, water) is introduced into the space S1 from the supply port 141, and the fluid in the space S1 is taken out from the discharge port 151. At this time, the fluid introduced into the supply port 141 does not directly move to the discharge port 151, but stays in the space S1 while rotating in a spiral shape. Note that the fluid may be moved by pressurizing the supply port 141 (supply channel S2) side, or the fluid may be moved by reducing the pressure on the discharge port 151 (discharge channel S3) side. The ultraviolet light emitted from the light source 120 is reflected by the inner surface of the storage wall 110.

Here, the light source 120 is placed on a metal support member 130. Further, the metal discharge pipe 150 defines a discharge flow path S3. The metal support member 30 and the metal discharge pipe 150 are in contact with each other. Furthermore, fluid flows through the discharge channel S3 defined by the discharge pipe 150. Therefore, the heat generated by the light source 120 is transmitted to the support member 130, the discharge pipe 150, and the fluid in this order. Note that in this embodiment, since the support member 130 is made of metal and the discharge pipe 150 is made of metal, the heat generated by the light source 120 is quickly transmitted to the fluid via the discharge pipe 150. . As a result, the heat generated by the light source 120 is quickly removed, so that an increase in the temperature of the light source 120 can be suppressed.

Note that in the above example, the support member 130 is in contact with the discharge pipe 150, but the support member 130 may be in contact with a metal supply pipe 140. In this case, the supply pipe 140 is preferably made of nickel-plated brass, and the discharge pipe 150 may be made of resin. Further, the supply pipe 140 and the discharge pipe 150 may be made of metal or may be formed of nickel-plated brass.

(experiment)
Here, the temperature of the light source 120 and the change in temperature due to differences in the material of the discharge pipe 150 (or the supply pipe 140) were investigated. In this experiment, the support member 130 was in contact with the discharge pipe 150. The material of the discharge tube 150 is polypropylene or electroless nickel plated brass.

FIG. 4A is a graph showing the relationship between the fluid flow rate and the temperature of the light source 120 in the ultraviolet irradiation device 100 with one light source 120 turned on, and FIG. 4B is a graph showing the relationship between the fluid flow rate and the temperature of the light source 120 in the ultraviolet irradiation device 100 with one light source 120 turned on. 2 is a graph showing the relationship between the flow rate of the light source 120 and the temperature of the light source 120. The horizontal axes in FIGS. 4A and 4B indicate the fluid flow rate, and the vertical axes indicate the temperature of the light source 120. The triangular symbols in FIGS. 4A and 4B show the results when the exhaust pipe 150 is constructed of nickel-plated brass, and the square symbols represent the results when the exhaust pipe 150 is constructed from polypropylene. ing. As the light source 120, NCSU434B (Nichia Chemical Industries, Ltd.), which is an ultraviolet light emitting diode with a peak wavelength of 280 nm, was used, and the driving current of the light source was 500 mA.

As shown by the triangular symbols in FIGS. 4A and 4B, when the discharge pipe 150 was made of metal, no large fluctuations in the temperature of the light source 120 were observed even when the flow rate was increased. Further, from the comparison between the square symbol and the triangular symbol, regardless of the number of light sources 120, the ultraviolet irradiation device 100 having the metal discharge pipe 150 is better than the ultraviolet ray irradiation device having the resin discharge pipe 150. The temperature of the light source 120 was low. This is considered to be because in the ultraviolet irradiation device 100 having the metal discharge pipe 150, the heat generated by the light source 120 is dissipated to the fluid flowing in the discharge channel S3 via the support member 130 and the discharge pipe 150. . That is, it is considered that the aluminum support member 130 and the exhaust pipe 150 functioned as a heat sink.

On the other hand, as shown by the square symbols in FIGS. 4A and 4B, the temperature of the light source 120 was high in the ultraviolet irradiation device having the discharge pipe 150 made of resin. This is considered to be because the heat generated by the light source 120 and conducted to the support member 130 was not enveloped by the fluid flowing in the discharge channel S3 via the discharge pipe 150. In other words, it was thought that this was because the resin discharge pipe 150 did not function as a heat sink.

Furthermore, although no particular results are shown, no dissimilar metal corrosion occurred in the ultraviolet irradiation device 100 according to the present embodiment in which the discharge pipe 150 was made of nickel-plated brass.

(effect)
According to the present invention, the heat of the light source 120 is efficiently dissipated into the fluid via the metal support member 130 and the metal supply pipe 140 or the metal discharge pipe 150, so that the temperature of the light source 120 can be prevented from increasing. It can be suppressed.

The ultraviolet irradiation device according to the present invention is useful, for example, in sterilizing purified water, agricultural water, food washing water, various washing waters, bath water, pool water, and the like.

100 Ultraviolet irradiation device 110 Storage wall 111 First wall 112 Second wall 123 Window 124 Third sealing member 120 Light source 130 Support member 131 Recess 140 Supply pipe 141 Supply port 150 Discharge pipe 151 Discharge port 152 Second sealing member 160 Cover S1 Space S2 Supply channel S3 Discharge channel

Claims (4)

An ultraviolet irradiation device for irradiating a fluid with ultraviolet rays,
a space containing the fluid to which ultraviolet rays are irradiated;
a light source for irradiating ultraviolet light toward the space;
a metal support member that supports the light source;
a supply pipe defining a supply flow path for supplying fluid to the space;
and a discharge pipe defining a discharge flow path for discharging fluid in the space,
At least one of the supply pipe and the discharge pipe is made of metal,
The support member is in contact with the metal supply pipe or the metal discharge pipe,
Ultraviolet irradiation device. The ultraviolet irradiation device according to claim 1, wherein the support member is made of aluminum. The ultraviolet irradiation device according to claim 1 or 2, wherein the metal is nickel-plated brass. The ultraviolet irradiation device according to any one of claims 1 to 3, wherein the support member and the metal supply pipe or the metal discharge pipe are screwed into contact with each other.