JPH11114558A - Hot water circulating bathtub device having ultraviolet sterilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently sterilize hot water with UV over a long period by preventing the contamination of a reflecting cylinder with a photocatalyst and to sterilize the hot water more effectively by using the photocatalyst in sterilizing the hot water. SOLUTION: This hot water circulating bathtub device is provided with a heating means, a circulating pump, a filter tank and a UV sterilizer 1. The sterilizer 1 is furnished with a casing 3 contg. a watertight cylindrical liq. passage 6, a UV lamp 2 for irradiating the liq. with UV and a reflecting cylinder 7 for reflecting the UV radiated from the lamp 2. The hot water passing through the passage 6 is irradiated with the UV from the lamp 2, the UV emitted from the lamp 2 is reflected by the cylinder 7 to irradiate the hot water, and the hot water is sterilized. Further, a photocatalyst is deposited on the inner face of the reflecting cylinder 7 provided in the passage 6, and the adhesion of foreign matter to the inner face of the cylinder 7 is prevented by the photocatalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water circulating bath apparatus for circulating hot water in a bath to keep the bath water clear, and more particularly to a hot water circulating bath apparatus for irradiating hot water with ultraviolet rays for sterilization.

[0002]

2. Description of the Related Art An apparatus has been developed which circulates hot water in a bathtub and irradiates the circulation path with ultraviolet rays for sterilization. This hot water circulation type bathtub apparatus circulates hot water to the ultraviolet sterilizer 1 shown in FIG. In the ultraviolet sterilizer 1 of this figure, a watertight ultraviolet lamp 2 is disposed in a watertight liquid passage 6 provided in a casing 3. The liquid passage 6 opens the inlet 4 and the outlet 5 to circulate hot water in the bathtub. On the outside of the ultraviolet lamp 2 and on the inside of the liquid passage 6,
The reflecting tube 7 is provided to reflect the ultraviolet rays emitted from the ultraviolet lamp 2 to efficiently sterilize the fluid.

[0003]

In the ultraviolet sterilizer of this structure, the ultraviolet light emitted from the ultraviolet lamp is reflected by the reflecting tube, so that the ultraviolet light emitted from the ultraviolet lamp can be efficiently irradiated to the hot water. For this reason, there is a feature that hot water can be more efficiently sterilized with an ultraviolet lamp. However,
The ultraviolet sterilizer having this structure has a drawback that the surface is gradually soiled by the circulated warm water and the reflectance is reduced. In particular, in an ultraviolet sterilizer of a hot-water circulating bathtub apparatus that continuously circulates hot water for 24 hours, the reflection tube gradually becomes dirty, the reflectance of ultraviolet rays is reduced, and the bactericidal efficiency is greatly reduced.

[0004] Furthermore, there is a disadvantage that the stain on the dirty reflecting tube cannot be easily removed. This is because it is necessary to open the casing and take out the reflecting tube in order to reliably remove the dirt from the reflecting tube and clean the reflecting tube. In order to take out the reflecting tube from the casing, it is necessary to remove the hose connected to the ultraviolet sterilizer and open the casing lid. Therefore, the user cannot take out the reflecting tube by himself. Only a professional repairer can remove the dirt from the reflector tube. For this reason, there is a disadvantage that maintenance is troublesome and expensive.

Further, with the casing opened,
We cannot easily take out reflector tube. In particular, it takes time and effort to take out the reflection tube inserted without any gap so as to be in close contact with the inner surface of the casing. Furthermore, the reflecting tube having a structure in which the reflecting tube is bent into a metal plate without being formed into a pipe shape and is adhered to the inner surface of the casing by its elasticity can be easily inserted into the liquid passage of the casing. ,
It is extremely difficult to remove. This is because it is elastically close to the inner surface of the casing. The reflecting tube of this structure
Even if the casing is opened, it cannot be easily removed, and it is necessary to bend the metal plate inward and remove it from the inner surface of the casing.

The present invention has been developed with the object of solving such disadvantages. An important object of the present invention is to prevent the reflecting tube from being stained and to efficiently apply hot water to ultraviolet light for a long period of time. An object of the present invention is to provide a hot water circulation bathtub apparatus having an ultraviolet sterilizer capable of sterilizing.

Further, another important object of the present invention is to use a photocatalyst for preventing contamination of a reflecting tube together with sterilization of warm water,
An object of the present invention is to provide a hot water circulation bathtub apparatus having an ultraviolet sterilizer capable of more effectively sterilizing hot water.

[0008]

According to the present invention, a hot water circulating bath apparatus having an ultraviolet sterilizer according to the present invention comprises a heating means 12 for heating hot water to a set temperature, and a circulating pump 10 for circulating hot water in the bath 9. A filtration tank 11 for clarifying hot water circulated by a circulation pump 10, and an ultraviolet sterilizer 1 for irradiating the circulated hot water with ultraviolet rays for sterilization.

The ultraviolet sterilizer 1 is disposed at the center or almost at the center of the cylindrical liquid passage 6 having a water-tight cylindrical liquid passage 6 therein, and passes through the liquid passage 6. And an elongate ultraviolet lamp 2 that irradiates the liquid to be irradiated with ultraviolet light, and is disposed substantially all around the inner surface of the cylindrical liquid passage 6 so as to reflect ultraviolet light radiated from the ultraviolet lamp 2 to the entire circumference. And a reflecting cylinder 7 which is not provided. The ultraviolet sterilizer 1 irradiates the liquid passing through the liquid passage 6 with ultraviolet light of the ultraviolet lamp 2, and further reflects the ultraviolet light emitted from the ultraviolet lamp 2 by the reflecting cylinder 7 to irradiate the liquid in the liquid passage 6.

[0010] Furthermore, a photocatalyst is attached to the inner surface of the reflecting cylinder 7 provided in the liquid passage 6 of the ultraviolet sterilizer 1. The photocatalyst prevents foreign substances from adhering to the inner surface of the reflecting tube 7 and irradiates the same with ultraviolet rays to sterilize hot water.

In the hot water circulation type bathtub apparatus according to a second aspect of the present invention, the reflection tube 7 of the ultraviolet sterilizer 1 is formed by bending the elastically deformable metal plate 22 into a cylindrical shape and inserting it into the inner surface of the liquid passage 6. I do. The metal plate 22 is expanded by its own elasticity, and is mounted in close contact with the inner surface of the liquid passage 6.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples illustrate a hot-water circulating bath apparatus for embodying the technical idea of the present invention, and the present invention does not specify a hot-water circulating bath apparatus as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However, the members described in the claims are not limited to the members of the embodiments.

The hot water circulation type bathtub apparatus shown in FIG. 2 includes a circulation pump 10, a filtration tank 11, a heating means 12, and an ultraviolet sterilizer 1 in a hot water circulation path connected to a bathtub 9 via a circulation pipe 8. And are connected.

The circulation pump 10 is operated continuously for 24 hours to draw hot water in the bathtub 9 and forcibly circulate the hot water in the hot water circulation path. The circulation pump 10 has a suction side connected to a suction port opened in the bathtub 9, and a filtration tank 11, a heating means 12, and the ultraviolet sterilizer 1 connected in series to a discharge side. This hot water circulation type bathtub apparatus circulates hot water pressurized by a circulation pump 10 from a filtration tank 11 to a heating means 12 and from the heating means 12 to an ultraviolet sterilizer 1 to a bathtub 9.

The filtering tank 11 filters the warm water in the bath 9 clear. The filtration tank 11 contains a filter medium for clarifying hot water. As the filter medium, one obtained by crushing natural stone into granules or one obtained by crushing natural stone and sintering it in a porous manner can be used. This filter media provides a comfortable environment for the propagation of microorganisms,
Aerobic microorganisms parasitize. Microorganisms eat ammonia and proteins contained in warm water as food and decompose. Therefore, sweat and dirt in the warm water are effectively removed by the microorganisms, and the warm water is kept clear. In the filtration tank 11, when foreign matter is deposited and the amount of circulating hot water is reduced, the fining action is reduced.

The device shown in FIG. 2 has a primary filter 13 connected to the suction side of the circulation pump 10. The primary filter 13 filters warm water sucked into the circulation pump 10 to remove foreign substances such as hair and organic soft bodies. The primary filter 13 is a filter medium for physically filtering hot water, for example,
Built-in filter media such as open-cell synthetic resin foam, non-woven fabric, filter paper and wire mesh.

As the heating means 12, an electric heater or a burner heating means can be used. These heating means 12 are controlled by a temperature sensor for detecting the temperature of the hot water, and heat the hot water to a constant temperature. FIG. 3 shows a heating means 12 for heating hot water with a heater. The heater shown in this figure includes a heating pipe 14 which is a metal pipe such as stainless steel, and a ceramic heater 15.
Is embedded in a casting metal 16 such as aluminum. In the casting metal 16, two heating tubes 14 are embedded in parallel, and a ceramic heater 15 is embedded between the heating tubes 14.
The two heating tubes 14 are connected in series via a U-shaped hose or pipe, and heat the hot water to be passed inside. The heaters shown in these figures have a simple structure, and have a feature of efficiently heating hot water.

As shown in FIG. 4 to FIG. 6, the ultraviolet sterilizer has a plastic casing 3 having a water-tight tubular liquid passage 6 formed therein, and a center or a center of the tubular liquid passage 6. An elongated ultraviolet lamp 2 is provided substantially at the center and irradiates the liquid passing through the liquid passage 6 with ultraviolet light, and a reflecting tube 7 reflects ultraviolet light radiated from the ultraviolet lamp 2 over the entire circumference. I have.

The casing 3 includes a casing body 17 and
And a lid 18 for closing the opening of the casing body 17. The casing body 17 includes the ultraviolet lamp 2.
And a connecting portion 17B provided above and below the main body and having an inflow port 4 and a discharge port 5.

The main body portion 17A has an overall shape of an ultraviolet ray so that a cylindrical elongate ultraviolet lamp 2 is inserted at the center or almost the center, and a liquid passage is formed between the ultraviolet ray lamp 2 and the cylindrical body. It has a cylindrical shape with a larger inside diameter than the lamp 2. The connecting portions 17B are provided above and below the main body portion 17A, extend in the lateral direction, and have a liquid inlet 4 and a liquid outlet 5.
Are provided.

The casing body 17 and the lid 18 are integrally formed of a synthetic resin. The synthetic resin for molding the casing body 17 is polyethylene, nylon, EVA,
Synthetic resins such as polypropylene, vinyl chloride, and polypropylene can be used.

The casing body 17 shown in FIG. 5 and FIG.
The upper end is opened so that the ultraviolet lamp 2 can be inserted into the liquid passage 6 and held in a fixed position. The opening at the upper end is formed with a female screw on the inner surface, and the lid 18 is screwed and fixed to the female screw. At the bottom of the casing body 17, a table 19 on which the quartz glass tube 2A of the ultraviolet lamp 2 is mounted is provided.

The lid 18 has a male screw on the outer periphery of the lower end,
A central hole is opened through the center up and down. A flange is provided at the upper end of the outer male screw on the outer periphery. An O-ring 20 is inserted into the lower surface of the flange. The male screw portion of the lid 18 is screwed into the upper end of the casing main body 17 and the O-ring 20 between the upper end of the casing main body 17 and the flange forms the casing main body 17.
And the lid 18 are connected in a watertight manner.

The quartz glass tube 2A of the ultraviolet lamp 2 is inserted into the center hole of the lid 18 in a watertight manner. Therefore, an annular groove is provided in the center hole so as to be vertically separated. An O-ring 21 is fitted into the annular groove, and the O-ring 21 is tightly connected to the outer periphery of the quartz glass tube 2A and is connected in a watertight manner.

The ultraviolet lamp 2 comprises a quartz glass tube 2A and a lamp 2B. The lamp 2B emits ultraviolet light by discharging in a cylindrical shape. The lamp 2B is inserted freely into and out of the quartz glass tube 2A.

The casing body 17 made of synthetic resin
Is a reflecting cylinder 7 that reflects ultraviolet light on the inner surface of the main body 17A.
Is inserted and installed in place. The reflecting tube 7 reflects ultraviolet rays radiated from the ultraviolet lamp 2 to the entire circumference. Therefore, the reflecting cylinder 7 is provided in close contact with the inner surface of the main body 17A, and is disposed all around the ultraviolet lamp 2, that is, all around the inner surface of the cylindrical liquid passage 6.

The reflecting cylinder 7 disposed inside the liquid passage 6 having a watertight structure does not require a watertight structure. The reflecting cylinder 7
A metal plate 22 having a photocatalyst adhered to the surface is optimal. In particular, the metal plate 22 of the reflecting tube 7 is optimally a thin stainless steel plate having a mirror-finished surface with a photocatalyst attached thereto. However, instead of a stainless steel plate, a thin metal plate made of titanium, shinchu, copper or the like with a photocatalyst attached thereto can also be used. The thickness of the reflecting cylinder 7 is preferably 0.1 to 1 m.
m.

As the photocatalyst attached to the surface of the metal plate 22 serving as the reflecting cylinder 7, any one that has a sterilizing effect by irradiating ultraviolet rays can be used. The optimal photocatalyst is titanium oxide.
The photocatalyst, which is titanium oxide, is applied to a metal plate 2
2 is immersed, dried, heated in a firing furnace, and sintered on the surface of the metal plate 22. The photocatalyst attached to the metal plate 22 by this method is extremely strongly attached. However, the present invention does not specify a method for attaching a photocatalyst to the reflecting cylinder. The photocatalyst is
It can be attached to the surface of the reflecting tube by any method currently used or developed in the future, such as applying and attaching to the surface of a metal plate via a binder.

The metal plate 22 with the photocatalyst attached thereto is cut into a rectangular shape as shown in FIG. 7 and then curved into a cylindrical shape as shown in FIG. 8 to form a casing body 17 as shown in FIGS.
Insert This method is advantageous in that the photocatalyst can be attached to the flat metal plate 22, so that the photocatalyst can be attached efficiently. However, after the metal plate is bent into a cylindrical shape, the photocatalyst can be attached. The reflection tube 7 inserted into the casing body 17 is expanded by its own elasticity,
Adhere to the inner surface of To replace the reflecting tube 7, the metal plate 2
2 is bent inward to make the reflecting tube 7 thinner, and the radius of curvature thereof is made smaller than that of the casing body 17 to be taken out.

As described above, the ultraviolet disinfection apparatus 1 in which the flat metal plate 22 is elastically attached to the casing body 17 comprises:
There is a feature that the reflection cylinder 7 can be mass-produced inexpensively. In particular,
There is a feature that the reflecting tube 7 can be attached to a fixed position in close contact with the inner surface of the casing main body 17 without accurately adjusting the outer shape of the reflecting cylinder 7 to the inner diameter of the casing main body 17.

Further, the metal plate 22 shown in FIG. 7 and FIG.
In the figure, a passage recess 23 is provided at the upper edge and the lower edge.
As shown in FIGS. 5 and 6, these passage recesses 23 are formed by bending the metal plate 22 into a cylindrical shape and inserting the metal plate 22 into the casing body 17. Are arranged such that the passage recesses 23 abut against the inflow port 4. These passage recesses 23 are provided so as to be almost equal to or slightly larger in opening area of the inlet 4 and the outlet 5 so that the hot water can smoothly pass therethrough without blocking the inlet 4 and the outlet 5. ing. The reflecting cylinder 7 having this structure is configured such that portions other than the passage recess 23 at the upper and lower edges are connected to the connecting portion 17B from the main body portion 17A of the casing main body 17.
To lengthen the entire length of the reflecting tube 7. As described above, the ultraviolet sterilizer that can lengthen the entire length of the reflecting tube 7 is:
There is a feature that the area of reflecting the ultraviolet rays on the inner surface of the reflecting cylinder 7 is widened and the hot water circulating more efficiently can be sterilized.

Further, the metal plate 22 shown in FIG. 7 and FIG.
A plurality of positioning recesses 24 are provided on the lower edge. As shown in FIGS. 5 and 6, these positioning concave portions 24 are used when the metal plate 22 is bent into a cylindrical shape and inserted into the casing body 17.
It is inserted into the positioning protrusion 25 provided on the inner surface of the casing body 17. The reflecting cylinder 7 has a positioning concave portion 24 and a positioning convex portion 2.
Via 5 the casing body 17 is held in the correct position. As described above, the reflecting cylinder 7 held at the fixed position of the casing main body 17 can reliably move the passage recesses 23 at the upper and lower edges to the discharge port 5 and the inflow port 4 without causing displacement in the casing main body 17. It has the feature that it can be positioned to smoothly circulate hot water.

In the above embodiment, the reflecting cylinder 7 is constituted by the metal plate 22. However, the hot water circulation type bathtub apparatus of the present invention
The reflecting cylinder does not necessarily need to be made of a metal plate. A photocatalyst may be attached to the surface of the metal cylinder to form a reflection cylinder.
The reflecting tube is attached to the main body with an outer diameter being a cylindrical shape equal to the inner diameter of the main body. The reflecting tube inserted into the main body is held at a fixed position, for example, by pushing it with a lid. further,
The reflecting tube can be held in a fixed position by closely contacting the inner surface of the main body.

As shown in FIG. 9, the ultraviolet sterilizer can be a casing 3 in which the main body 17A and the connecting portion 17B are separately formed of a synthetic resin. In the ultraviolet sterilizer 1, the main body 17A and the connecting portion 17B are watertightly connected to each other to form the casing 3 having the liquid passage 6 therein. The casing body 17 shown in this figure is composed of three parts. The main body 17A is formed in a cylindrical shape having flanges 26 at both ends so that the main body 17A can be connected to the connecting portion 17B without water leakage. The connection portion 17B has a flange 26 formed at a connection portion with the main body portion 17A. The main body portion 17A and the connecting portion 17B are watertightly connected by sandwiching an O-ring 27 between the flanges 26. Casing 3 connected in this state
Since the O-ring 27 is connected by sandwiching the O-ring 27 with the flange 26, water leakage can be reduced as compared with a structure in which the opening end of the metal cylinder is pressed with packing. This is because the flange 26 of the main body 17A and the connecting portion 17B can be directly connected by the screw 28.

[0036]

The hot water circulation type bathtub apparatus having the ultraviolet sterilizer of the present invention has a feature that it can effectively prevent the reflection tube of the ultraviolet sterilizer from being stained and efficiently sterilize the hot water with ultraviolet rays for a long period of time. This is because the hot water circulation bathtub apparatus of the present invention has a photocatalyst attached to the inner surface of the reflecting cylinder provided in the liquid passage of the ultraviolet sterilizer. The reflecting cylinder having the photocatalyst adhered to the surface exhibits a strong bactericidal power when irradiated with ultraviolet rays, and can effectively prevent foreign substances from adhering to the inner surface of the reflecting cylinder. As described above, the reflection tube whose surface is prevented from being stained by the photocatalyst maintains the reflectance of ultraviolet rays high, thereby preventing the reflection efficiency of the reflection tube from lowering. Therefore, this ultraviolet sterilizer has a feature that it can efficiently reflect ultraviolet rays over a long period of time and effectively sterilize warm water with ultraviolet rays without deteriorating the sterilizing effect. In addition, since the work of removing the dirt from the reflecting tube can be reduced to a minimum, it also has a feature of saving labor and cost for maintenance.

Further, the photocatalyst attached to the surface of the reflecting tube of the ultraviolet sterilizer is used not only for preventing the reflecting tube from being stained but also for sterilizing hot water. In other words, the photocatalyst effectively prevents the surface of the reflecting tube from being stained with strong sterilizing power when irradiated with ultraviolet rays, and also sterilizes hot water circulating in the ultraviolet sterilizer. For this reason, the hot water circulation type bathtub apparatus of the present invention is excellent in sterilizing hot water circulating more effectively by the synergistic effect of the sterilizing power of the ultraviolet light emitted from the ultraviolet lamp and the sterilizing power of the photocatalyst irradiated with the ultraviolet light. Also has features.

Further, the hot water circulation type bathtub apparatus according to the second aspect can mirror-polish the surface of the reflecting tube of the ultraviolet sterilizer in a simple, easy and ideal state, and attaches a photocatalyst to the surface of the reflecting tube. There are features that can be done. This is because the ultraviolet sterilizer of this hot-water circulating bathtub apparatus is configured such that a metal plate that is elastically deformed is bent into a cylindrical shape and inserted into the liquid passage to form a reflecting tube. In this way, the reflecting tube, which is formed by bending the metal plate into a cylindrical shape, can be mirror-polished on its surface in a state where it is spread in a planar shape, and can adhere a photocatalyst. Therefore, the surface can be extremely easily mirror-polished to an ideal state, and the photocatalyst can be efficiently attached, and the UV sterilizing apparatus can have high UV sterilizing efficiency and can be mass-produced at low cost. Prepare.

In particular, an ultraviolet sterilizer using a metal plate elastically adhered to the reflecting cylinder can be mass-produced at low cost, but cannot be easily removed from the casing.
This type of ultraviolet sterilizer can be used in an ideal state if it can prevent a decrease in the reflectance of the reflecting tube. The present invention uses a photocatalyst to prevent the reflection tube from being stained, and by maintaining a high reflectance of the reflection tube for ultraviolet rays for a long period of time, eliminates the need to remove the reflection tube from the casing and remove surface contamination. It is a realization of a hot water circulation type bathtub device having an ideal ultraviolet sterilizer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a conventional ultraviolet sterilizer.

FIG. 2 is a schematic cross-sectional view of a hot water circulation type bathtub apparatus having an ultraviolet sterilizer according to an embodiment of the present invention.

3 is a sectional perspective view showing a heating means of the hot water circulation type bathtub apparatus shown in FIG. 2;

FIG. 4 is a perspective view showing an ultraviolet sterilizer of the hot-water circulation type bathtub apparatus shown in FIG. 2;

FIG. 5 is a sectional view of the ultraviolet sterilizer shown in FIG. 4;

FIG. 6 is a sectional view of the ultraviolet sterilizer shown in FIG. 4;

FIG. 7 is a plan view of a metal plate constituting a reflecting tube of the ultraviolet sterilizer shown in FIG. 5;

8 is a perspective view showing a state in which the metal plate shown in FIG.

FIG. 9 is a sectional view showing another example of the ultraviolet sterilizer.

[Explanation of symbols]

1. Ultraviolet sterilizer 2. Ultraviolet lamp 2A: Quartz glass tube
2B Lamp 3 Casing 4 Inlet 5 Outlet 6 Liquid passage 7 Reflector tube 8 Circulation pipe 9 Bath tub 10 Circulation pump 11 Filtration tank 12 Heating means 13 Primary filter 14 Heating pipe 15 ... Ceramic heater 16 ... Cast metal 17 ... Casing body 17A ... Main body
17B ... connecting part 18 ... lid 19 ... base 20 ... O-ring 21 ... O-ring 22 ... metal plate 23 ... passage concave part 24 ... positioning concave part 25 ... positioning convex part 26 ... flange 27 ... O-ring 28 ... screw

Claims (2)

[Claims] A heating means (12) for heating hot water to a set temperature and a circulation pump (1) for circulating hot water in a bathtub (9).
0), a filtration tank (11) for clarifying hot water circulated by a circulation pump (10), and an ultraviolet sterilizer (1) for irradiating ultraviolet light to the circulated hot water to sterilize the hot water circulation bathtub An ultraviolet sterilizer (1) having a casing (3) having a cylindrical liquid passage (6) having a water-tight structure therein and a center or substantially center of the cylindrical liquid passage (6). Disposed, liquid passage
(6) An elongated ultraviolet lamp (2) for irradiating ultraviolet light to the liquid passing therethrough, and a cylindrical liquid passage so as to reflect ultraviolet light radiated from the ultraviolet lamp (2) all around.
(6) with a reflecting tube (7) arranged on the entire circumference of the inner surface,
The liquid passing through the liquid passage (6) is irradiated with ultraviolet light from the ultraviolet lamp (2), and the ultraviolet light emitted from the ultraviolet lamp (2) is reflected by the reflecting tube (7) to remove the liquid in the liquid passage (6). In a hot water circulation type bathtub apparatus having an ultraviolet sterilizer configured to irradiate, a photocatalyst is attached to an inner surface of a reflection tube (7) disposed in a liquid passage (6) of the ultraviolet sterilizer (1), A hot water circulating bath apparatus having an ultraviolet sterilizer, wherein the apparatus is configured to prevent foreign matter from adhering to the inner surface of the reflecting tube (7) by a photocatalyst. 2. A metal plate (22), wherein a reflecting tube (7) is elastically deformed.
Is bent into a cylindrical shape and inserted into the inner surface of the liquid passage (6), and the metal plate (22) is expanded by its own elasticity and is mounted in close contact with the inner surface of the liquid passage (6). A hot water circulating bath apparatus having the ultraviolet sterilizer according to claim 1.