JP7802271B2 - Mist generating device and bathtub device equipped with same - Google Patents

Description

The present invention relates to a mist generator, and in particular to a mist generator used in a bathtub system.

As shown in Patent Document 1, a bathtub sauna device for sauna bathing has been known in the past. This type of bathtub sauna device includes a bathtub lid that is attached to the top of the bathtub body to create a sauna space using mist.

Japanese Patent Application Laid-Open No. 2008-018130 JP 2014-057952 A

However, bathtub sauna devices such as those shown in Patent Document 1 require a bathtub lid to create the sauna space, which restricts the user's position, reducing comfort and reducing convenience for the user.

In response to this, as shown in Patent Document 2, an ultrasonic atomization unit has been proposed, which controls the water temperature in the atomization tank so as not to increase, so that the mist does not easily disperse due to rising air currents.

However, if such an ultrasonic atomization unit is adopted, the problem arises that the mist will diffuse if the mist temperature is increased, and ultimately, to prevent the mist from diffusing, it becomes necessary to provide a bathtub lid as shown in Patent Document 1.

The present invention was made to solve the problems of the prior art mentioned above, and aims to provide a mist generator that allows heated mist to remain in a retention space that is open at the top.

In order to solve the above-mentioned problems, one embodiment of the present invention is a mist generating device for use in a bathtub body, comprising a mist generating unit that generates mist from heated water whose temperature has been controlled, or that generates temperature-controlled mist by heating mist generated from water, and a mist supply unit that supplies the mist generated by the mist generating unit into the bathtub body, which forms a retention space with an open top, and is characterized in that the mist generating unit and the mist supply unit are configured so that the mist supplied from the mist supply unit is retained in the retention space of the bathtub body.
In one embodiment of the present invention, the mist generator and the mist supply unit are configured so that the mist supplied from the mist supply unit is retained in the retention space of the bathtub body. This allows heated mist to remain in the retention space with an open top. This eliminates the need for a lid on the bathtub body, improving convenience. Furthermore, the user can warm up with the mist inside the bathtub body without a lid, improving user comfort. Furthermore, because the user can warm up with the mist inside the bathtub body, the user can enjoy a mist bath without feeling pressured and with reduced physical strain compared to immersion in water. Furthermore, the heat is transmitted to the user more slowly than when immersed in water, reducing the strain on the user's body.

In one embodiment of the present invention, the mist generating section preferably includes a water temperature detecting means for detecting the water temperature.
In one embodiment of the present invention, the mist generator includes a water temperature detector that detects the water temperature, allowing for more accurate water temperature control. This allows the mist generator and mist supply unit to more reliably retain the heated mist within the retention space of the bathtub body.

In one embodiment of the present invention, preferably, the mist generating unit controls the temperature of water heated to 60°C or higher and generates mist from the temperature-controlled water, or heats mist generated from water to 60°C or higher and controls the temperature of the heated mist.
In one embodiment of the present invention configured in this manner, by heating the water or mist to 60°C or higher, the effects of at least some bacteria (e.g., Legionella) can be suppressed even if bacteria are contained in the water.

In one embodiment of the present invention, the retention boundary surface on the upper side of the retained mist is preferably formed below a height position obtained by adding a height equivalent to the depth of the bathtub body to the height of the overflow surface of the bathtub body.
In one embodiment of the present invention configured in this manner, the retention boundary surface on the upper side of the retained mist is formed below a height position obtained by adding a height equivalent to the depth of the bathtub body to the height of the overflow surface of the bathtub body, thereby preventing the retention boundary surface from being formed at a position that is too high, thereby increasing the comfort of the user.

In one embodiment of the present invention, the upper boundary surface of the retained mist is preferably formed above the height position of the overflow surface of the bathtub body.
In one embodiment of the present invention configured in this manner, the retention boundary surface on the upper side of the retained mist is formed above the height position of the overflow surface of the bathtub body, making it easier for a user sitting in the bathtub body to take a mist bath up to the upper part of their body, and also making it possible to warm the user's body up to a level higher than the water level at which water is normally poured, thereby further increasing the user's comfort.

In the present invention, the upper retention boundary surface of the retained mist is preferably formed below a height position obtained by adding a value between 100 mm and 200 mm to the height of the overflow surface of the bathtub body.
In one embodiment of the present invention configured in this manner, the retention boundary surface on the upper side of the retained mist is formed below a height position obtained by adding a value between 100 mm and 200 mm to the height of the overflow surface of the bathtub body, so that the retention boundary surface is more likely to be formed below the position of the face of a user sitting in the bathtub body, further increasing the comfort of the user.

In the present invention, the mist supply section is preferably disposed above the overflow section of the bathtub main body.
In one embodiment of the present invention configured in this manner, the mist supply section is positioned above the water overflow section within the bathtub body, thereby preventing water within the bathtub body from entering upstream from the mist supply section as a flow of sewage.

In the present invention, the overflow portion of the water in the bathtub body is preferably the overflow surface of the bathtub body.
In one embodiment of the present invention configured in this manner, the mist supply section is positioned above the water overflow surface in the bathtub body, thereby preventing water in the bathtub body from entering upstream from the mist supply section as sewage.

In the present invention, preferably, the mist generator further includes temperature detection means for detecting the temperature in the bathroom in which the bathtub body is placed.
In one embodiment of the present invention configured in this manner, the mist generating device further includes a temperature detection means for detecting the temperature in the bathroom in which the bathtub body is placed. Therefore, the mist generating unit can generate heated mist according to the temperature in the bathroom in which the bathtub body is placed, and the mist generating unit and the mist supply unit can more reliably retain the heated mist within the retention space of the bathtub body.

In the present invention, the mist supply section preferably includes a mist supply port section that opens downward.
In one embodiment of the present invention, the mist supply unit has a mist supply port that opens downward. This reduces the distance the mist needs to travel to reach the bathtub body compared to when the mist supply port opens sideways or upward. This prevents the mist from experiencing temperature changes, such as a drop in temperature, before reaching the bathtub body, making it difficult to adjust the temperature of the mist that reaches the bathtub body. This allows the heated mist to more easily stagnate in the retention space above the bathtub body. Furthermore, for example, the mist supply unit has a mist supply port that opens downward, which prevents water in the bathtub body from flowing upstream from the mist supply unit as wastewater.

In the present invention, preferably, the bathtub apparatus comprises the mist generating device and the bathtub main body that forms the retention space that receives the mist supplied from the mist supply section of the mist generating device.
Furthermore, one embodiment of the present invention is a bathtub apparatus characterized by comprising a mist generating device according to one embodiment of the present invention and the bathtub main body that forms the retention space that receives the mist supplied from the mist supply section of the mist generating device.

In the present invention, the mist generating section and the mist supply section of the mist generating device are preferably arranged on the short side of the bathtub main body.
In one embodiment of the present invention, the mist generating unit and mist supply unit of the mist generator are located on the short sides of the bathtub body, so that the mist supplied from the mist supply unit is supplied relatively evenly in the left-right direction of the short sides in the retention space within the bathtub body, preventing disruption of the mist retention. Furthermore, the mist is supplied in a relatively uniform flow in the left-right direction of the short sides, and this mist travels along the long sides, making it easier to create a visual effect that gives the user a soothing effect and a luxurious feel.

The mist generating device of the present invention allows heated mist to remain in a retention space that is open at the top.

1 is a perspective view of a bathtub apparatus equipped with a mist generating device according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating the structure of a bathtub apparatus equipped with a mist generating device according to a first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 5A to 5C are diagrams illustrating the mist supply operation from the mist generating device according to the first embodiment of the present invention. 1 is a top view of a measuring device for measuring, in a virtual retention space, the temperature of mist supplied to the retention space from a mist supply unit of a mist generating device according to a first embodiment of the present invention. FIG. 1 is a front view of a measuring device for measuring, in a virtual retention space, the temperature of mist supplied to the retention space from a mist supply unit of a mist generating device according to a first embodiment of the present invention. FIG. 1 is a side view of a measuring device for measuring, in a virtual retention space, the temperature of mist supplied to the retention space from a mist supply unit of a mist generating device according to a first embodiment of the present invention. FIG. 4A and 4B are diagrams showing changes in mist ambient temperature due to mist supplied from the mist generating device according to the first embodiment of the present invention. A figure showing the range of temperature difference between the temperature of the mist supplied to the retention space from the mist supply unit of the mist generating device according to the first embodiment of the present invention and the temperature in the room where the plumbing equipment is used before the supply of mist begins. 1 is a perspective view of a device for measuring the particle size of mist supplied from a mist supply unit of a mist generating device according to a first embodiment of the present invention. FIG. 1 is a top view of a device for measuring the particle size of mist supplied from a mist supply unit of a mist generating device according to a first embodiment of the present invention. FIG. FIG. 3 is a diagram showing an example of particle size distribution data obtained by measuring the particle size of the mist supplied from the mist supply unit of the mist generator according to the first embodiment of the present invention using a particle size distribution measuring device. FIG. 10 is a diagram showing the relationship between the temperature difference between the mist temperature and the room temperature and the particle size of the mist supplied from the mist supply unit of the mist generator according to the first embodiment of the present invention. 1 is a perspective view of an observation device for observing a state in which mist supplied from a mist supply unit of a mist generating device according to a first embodiment of the present invention is supplied to a virtual retention space. FIG. 10 is a diagram comparing the state in which mist supplied from the mist supply unit of the mist generating device according to the first embodiment of the present invention is supplied to a virtual retention space, depending on the temperature difference and the particle size of the mist. FIG. FIG. 2 is a diagram showing a transmittance measuring device for determining whether mist supplied from the mist supply unit of the mist generator according to the first embodiment of the present invention is stagnating. 1 is a diagram showing the difference between mist bathing using mist supplied from the mist supply unit of the mist generating device according to the first embodiment of the present invention and a normal bathtub bath, in terms of heat flux and the passage of time. FIG. This figure shows the results of measuring a user's skin temperature after 10 minutes of bathing in a mist bath using mist supplied from the mist supply unit of the mist generating device of the first embodiment of the present invention, and in a normal bathtub bath. FIG. 10 is a perspective view of a bathtub apparatus equipped with a mist generating device according to a second embodiment of the present invention. FIG. 10 is a side view of a bathtub apparatus equipped with a mist generating device according to a second embodiment of the present invention.

The following describes in detail the embodiments of the present invention disclosed in this specification, with reference to the accompanying drawings. Many improvements and other embodiments of the present invention will be apparent to those skilled in the art from the following description. Therefore, the following description should be construed as merely illustrative, and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and/or function thereof may be substantially changed without departing from the spirit of the present invention.

A bathtub apparatus, which is a plumbing device equipped with a mist generating device according to a first embodiment of the present invention, will now be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a bathtub apparatus equipped with a mist generating device according to a first embodiment of the present invention, and FIG. 2 is a side view of the bathtub apparatus equipped with a mist generating device according to the first embodiment of the present invention.
As shown in FIGS. 1 and 2 , a bathtub apparatus 2, which is a plumbing device equipped with a mist generating device 1 according to the first embodiment of the present invention, is installed in a bathroom 3. Plumbing devices are devices equipped with a water discharge device for use in bathrooms, bathroom washbasin floors, toilets, washrooms, kitchens, and the like. The mist generating device 1 is used in plumbing devices such as the bathtub itself, the bathroom washbasin floor, the shower room, the hand-washing bowl, the washbasin bowl, and the kitchen sink. The bathroom 3 is a box-shaped space that forms a somewhat sealed interior space 5 for water use. The water includes water at a temperature higher than the outside air temperature (room temperature) and heated water (so-called hot water). An operating unit 28 for operating the mist generating device 1 is installed in the bathroom 3. The operating unit 28 can also be used to store water in the bathtub apparatus 2 and set the temperature. The operating unit 28 may have operating functions for setting the temperature of the mist to be supplied, the particle size of the mist to be supplied, and the like. The operating unit 28 may be installed outside the bathroom 3 or may be a remote operating unit such as a remote control. The bathtub apparatus 2 is equipped with a water supply device 7. The bathtub apparatus 2 also includes a bathtub body 6 that forms a retention space 4 that receives mist supplied from a mist supply unit (described later) of the mist generating device 1.

The bathtub body 6 forms a retention space 4 that is open upward toward the interior space 5 in which the bathtub body 6 of the bathtub device 2 is placed. The bathtub body 6 is a bathtub (hot tub) that can store water in the internal retention space 4. The bathtub body 6 is rectangular when viewed from above, with long side portions 6d formed on the long sides of the rectangle and short side portions 6e formed on the short sides. The short side portions 6e are shorter in width than the long side portions 6d.
The retention space 4 is a space formed in a roughly rectangular parallelepiped shape inside the bathtub body 6. As shown in FIG. 2 , when user A takes a bath, water B at 34°C to 45°C is stored in the lower part of the retention space 4, allowing user A to bathe while seated. As described below, in FIG. 2 , mist is retained above the water B in the retention space 4 (a mist retention layer C is formed). The retention space 4 extends to the upper end 6a of the bathtub body 6 and is open on the top side. The bathtub body 6 does not have a lid covering the top surface of the retention space 4, allowing mist to be retained in the retention space 4, as described below. Note that the retention space 4 may retain mist without storing water B. The shape of the bathtub body 6 is not limited to the box-like shape described in the embodiment, and may be any shape that can form a retention space. For example, the bathtub body 6 may be circular or elliptical in top view, with a bowl-shaped retention space formed inside. The bottom of the bathtub body 6 may be angled to allow the user to assume a posture similar to a lying or sitting position, and may or may not have a step on the bottom. The top of the wall of the bathtub body 6 does not need to be horizontal at a constant height, but may be formed to vary in height. For example, the top of the wall of the bathtub body 6 may be shaped to extend diagonally upward or downward in side view, to have a bow-like shape with a portion concave downward, or to form an approximately right angle.

The mist generator 1 is used in a bathtub unit 2, which is a plumbing device. The mist generator 1 includes a mist generator 8 that generates mist and a mist supply unit 10 that supplies mist into the bathtub main body 6.

The mist generating unit 8 generates mist from water that has been heated and temperature-controlled, or generates temperature-controlled mist by heating mist generated from water. The mist generating unit 8 is located on the short side portion 6e of the bathtub body 6. A platform-shaped portion is formed at the top of the short side portion 6e on which the mist generating unit 8 is placed.

The mist generating unit 8 includes a tank 12 that stores water therein, a water supply channel 14 that supplies water from a water source to the tank 12, a drainage channel 16 that drains water from the tank 12 to a drain pipe, an ultrasonic vibrator 18 provided at the bottom inside the tank 12, a heater 20 provided at the bottom inside the tank 12, a water temperature gauge 22 that serves as a water temperature detection means provided inside the tank 12, an indoor temperature gauge 24 that serves as an air temperature detection means provided outside the tank 12, and a control unit 26 that controls the ultrasonic vibrator 18 and heater 20.

The tank 12 is formed in a rectangular parallelepiped shape. A water supply channel 14 and a drain channel 16 are connected to the side wall at the bottom of the tank 12. A mist supply unit 10 is connected to the side wall near the center of the tank 12. The water supply channel 14 is provided with a water supply channel on-off valve 30 that opens and closes the water supply channel 14. The drain channel 16 is provided with a drain channel on-off valve 32 that opens and closes the drain channel 16.

The ultrasonic vibrator 18 generates ultrasonic waves in the water in the tank 12, vibrating the water on the surface and breaking it into fine particles from the surface, generating mist (fog) of a predetermined particle size. The ultrasonic vibrator 18 is electrically connected to the control unit 26, and the particle size of the mist generated can be changed by adjusting the ultrasonic oscillation output, frequency, etc. of the ultrasonic vibrator 18. The ultrasonic vibrator 18 may be replaced with another device that generates mist of a predetermined particle size, such as a mist generator using steam, a mist generator using pressure spray, or a mist generator using arc discharge. In addition, although one ultrasonic vibrator 18 is provided in the tank 12 in this embodiment, multiple ultrasonic vibrators 18 may also be provided in the tank 12.

The control unit 26 has a function of heating the water in the tank 12 using the heater 20 and a function of controlling the temperature of the water in the tank 12. For example, the heater 20 can heat water from the supply water temperature (e.g., room temperature, about 20°C) to 60°C or higher, which is above room temperature. Furthermore, for example, the control unit 26 can control the temperature of water once heated to 60°C or higher by the heater 20, thereby raising or lowering the temperature so that a predetermined temperature difference (described below) is 0°C or higher. Thus, the mist generating unit 8 controls the temperature of water heated to 60°C or higher and generates mist from the temperature-controlled water. The mist generating unit 8 may also generate mist from water heated to 60°C or higher in a water heater and then supplied to the mist generating unit 8. The mist generating unit 8 heats the water in the tank 12 to a temperature above room temperature and generates mist that generates an updraft at a temperature above room temperature, adjusting the temperature of the mist according to the mist particle size and other conditions, and controls the mist to easily stagnate. Since the water is heated to 60°C or higher, it is also possible to take measures to suppress the growth of at least some bacteria (e.g., Legionella). Note that the step of the heater 20 temporarily heating the water (or mist) to 60°C or higher may be omitted, and instead of this step, other bacteria suppression means, such as a sterilization means using UV light or a sterilization means adding a sterilizing agent, may be provided. In this case, the heater 20 can heat the water (or mist) to a temperature below 60°C.
The heater 20 may be provided at a position higher than the water level in the tank 12 and heat the mist generated from the water. In this case, the heater 20 can heat the mist generated from the water to 60°C or higher. For example, the control unit 26 can control the temperature by raising or lowering the temperature of the mist in the tank 12 so that the mist heated by the heater 20 to 60°C or higher has a predetermined temperature difference of 0°C or higher, as described below. In this case, the mist generating unit 8 heats the mist generated from the water to 60°C or higher and controls the temperature of the heated mist.
The heater 20 may heat the mist generated from the water in a state where the heater 20 is provided at a position lower than the water level in the tank 12. In this case, a duct is provided to pass the mist from the tank 12 to the heater 20, which is provided at a position lower than the water level in the tank 12, and the mist that is supplied to the heater 20 through this duct is heated by the heater 20. The downstream side of this duct is connected to the mist supply unit 10 or the tank 12, and the mist heated by the heater 20 is returned to the mist supply unit 10 or the tank 12.

The water temperature measuring device 22 detects the temperature of the water in the tank 12. The control unit 26 is electrically connected to the water temperature measuring device 22, and the control unit 26 can recognize the temperature of the water in the tank 12.
The indoor temperature measuring device 24 detects the temperature of the air outside the tank 12 in the indoor space 5 where the bathtub main body 6 is placed. The control unit 26 is electrically connected to the indoor temperature measuring device 24, allowing the control unit 26 to recognize the temperature of the air in the indoor space 5. Note that before mist supply begins (before the mist generating unit 8 is driven), the air temperature in the indoor space 5 and the air temperature in the retention space 4 are assumed to be approximately equal or relatively close to each other, so the control unit 26 can estimate the air temperature in the indoor space 5 measured by the indoor temperature measuring device 24 as the air temperature in the retention space 4.

The control unit 26 has a built-in CPU, memory, etc., and controls connected devices to generate mist based on a predetermined control program stored in the memory, etc. The control unit 26 is electrically connected to the ultrasonic vibrator 18, heater 20, water temperature measuring device 22, indoor temperature measuring device 24, operation unit 28, etc. The control unit 26 is also electrically connected to the water supply line opening/closing valve 30 provided in the water supply line 14 and the drainage line opening/closing valve 32 provided in the drainage line, and can control these.

The mist supply unit 10 supplies mist generated by the mist generation unit 8 into the bathtub body 6, which forms a retention space 4 that opens upward toward the room in which the bathtub body 6 is placed. As shown in the cross-section of the flow path in Figure 2, the mist supply unit 10 forms a flow path that extends linearly from the mist generation unit 8 to the top of one end of the retention space 4. When viewed from the front (from the retention space 4 side), the opening of the mist supply unit 10 is formed as a horizontally elongated rectangle along the short side 6e of the bathtub body 6. The opening is formed to have a width that spans almost the entire short side 6e. The mist supply unit 10 is located above the water overflow area 6c in the bathtub body 6. In this embodiment, this overflow area 6c is the overflow surface 6b of the bathtub body 6. Alternatively, the overflow area 6c may be an overflow port provided in the bathtub body 6. The mist supply unit 10 is also located on the short side 6e of the short side of the bathtub body 6. A platform-shaped portion on which the mist supply unit 10 is positioned is formed at the top of the short side portion 6e. The mist supply unit 10 has a supply rate per volume ranging from 0.03 mL/min·L to 1.5 mL/min·L. For example, the mist supply unit 10 can supply mist at a rate of 11 mL/min per unit time to the 330 L retention space 4 of the bathtub main body 6. Furthermore, the mist supply unit 10 can supply mist at a rate of 6 mL/min per unit time to a 4.32 L retention space 4, such as a virtual retention space for measuring temperature differences and particle sizes, or to other plumbing equipment. The mist supply rate can be controlled by the number, output, and direction of ultrasonic irradiation of the ultrasonic transducers 18, the water level in the mist generation unit 8, or the shape of the flow paths within the mist generation unit 8 and the mist supply unit 10.

The mist generating unit 8 and the mist supplying unit 10 generate heated mist and control the temperature of the mist, making it easier for the mist to remain in the retention space 4. This will be described below.
The mist generating unit 8 and the mist supply unit 10 are configured so that the temperature difference between the mist supplied from the mist supply unit 10 to the retention space 4 and the room temperature where the bathroom appliance is used before mist supply begins is 0°C or more, so that the mist supplied from the mist supply unit 10 is retained in the retention space 4 of the bathtub body 6. Furthermore, the mist generating unit 8 and the mist supply unit 10 of the mist generator 1 are configured to create a temperature difference such that the force of the rising air current caused by the temperature difference to lift the mist does not exceed the weight of the mist supplied from the mist supply unit 10, which corresponds to the particle size of the mist. This type of mist supply may be achieved without using the room temperature measuring device 24 (without relying on the measurement results of the room temperature measuring device 24) by presetting the temperature of the water supplied to the mist generating unit 8, the heating temperature of the heater 20, or the frequency of the ultrasonic vibrator 18 according to the expected temperature range of the air in the room space 5. Alternatively, this type of mist supply may be achieved by adjusting the settings at the time of supply. The mist generating unit 8 and the mist supplying unit 10 are configured so that the temperature difference is preferably 100° C. or less, more preferably 60° C. or less, and even more preferably 45° C. or less. The mist generating unit 8 and the mist supplying unit 10 generate heated mist and control the particle size of the mist, making it easier for the mist to remain in the retention space 4.

Next, the operation of the mist generating device according to the first embodiment of the present invention will be described with reference to FIGS. 2 and 3 to 8. FIG.
3 to 8, the mist generator 1 is incorporated into the upper part of the bathtub main body 6 of the bathtub equipment 2 so as to appear to be nearly one unit with the bathtub main body 6. The basic structure of the mist generator 1 shown in Figures 3 to 8 is nearly the same as the basic structure of the mist generator 1 shown in Figure 2, so the same reference numerals as in Figure 2 will be used in the explanation of Figures 3 to 8.

As shown in Figure 2, in the standby state before the mist generator 1 begins operation, water at approximately 38°C is stored in the lower half of the retention space 4 of the bathtub body 6. The air temperature in the interior space 5 of the bathroom 3 and the air temperature in the retention space 4 are approximately the same temperature. The water supply channel on-off valve 30 and the drain channel on-off valve 32 are closed. There is no water in the tank 12. The ultrasonic vibrator 18 and heater 20 are stopped.

The user operates the operating unit 28 to start controlling the mist supply from the mist generator 1. Before mist supply begins, the indoor temperature gauge 24 measures the air temperature in the indoor space 5, and the control unit 26 recognizes the air temperature in the indoor space 5. The control unit 26 opens the water supply line on-off valve 30 to supply water from the water supply line 14 into the tank 12. The drain line on-off valve 32 remains closed. When a predetermined amount of water has accumulated in the tank 12, the water supply line on-off valve 30 opens. Next, the control unit 26 activates the heater 20 to heat the water from the supplied water temperature to 60°C or higher. After the water has been heated to 60°C or higher, the control unit 26 adjusts the temperature of the water in the tank 12 by starting and stopping the heater 20 so that the temperature difference between the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 and the temperature in the bathroom 3 where the bathtub apparatus 2 is used before mist supply begins is 0°C or higher. The control unit 26 then activates the ultrasonic vibrator 18 to generate mist within the tank 12.

FIG. 3 shows a state immediately after the mist supply unit 10 starts supplying mist into the retention space 4 .
The mist generated in the tank 12 is supplied from the mist supply unit 10 to the retention space 4 in the bathtub body 6. The mist naturally overflows from the mist supply unit 10 and, as shown by arrow F1, is supplied into the retention space 4 while freely falling due to its own weight. In this way, the mist is prevented from moving in any direction other than downward. Therefore, the mist is prevented from moving, such as by stirring, diffusing, or rising, within the retention space 4.

FIG. 4 shows the state after about 10 seconds have passed since the start of mist supply.
The supply of mist from the mist supply unit 10 to the retention space 4 continues. The supplied mist begins to stagnate above the surface of the water B and in a lower portion of the retention space 4. Because the temperature difference between the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 and the temperature of the indoor space 5 in which the bathtub apparatus 2 is used before the mist supply began is set to 0°C or more, the temperature of the mist makes it difficult for the mist to generate an updraft strong enough to overcome its own weight. Therefore, the mist stagnates in a relatively low portion of the retention space 4.

FIG. 5 shows the state after about 30 seconds have passed since the start of mist supply.
The mist continues to be supplied from the mist supply unit 10 to the retention space 4. The mist supplied into the retention space 4 gradually increases, and the mist gradually becomes retained in higher parts of the retention space 4.

FIG. 6 shows the state after about one minute has passed since the start of mist supply.
The mist continues to be supplied from the mist supply unit 10 to the retention space 4. The amount of mist supplied into the retention space 4 gradually increases, and the mist begins to accumulate in higher parts of the retention space 4.

FIG. 7 shows the state after about 1 minute and 30 seconds have passed since the start of mist supply.
The mist continues to be supplied from the mist supply unit 10 to the retention space 4. The mist supplied into the retention space 4 further increases, and the mist is retained up to a portion of the retention space 4 close to the top (the upper end 6a of the bathtub body 6).

FIG. 8 shows the state after about two minutes have passed since the start of mist supply.
The mist continues to be supplied from the mist supply unit 10 to the retention space 4. The mist supplied into the retention space 4 remains near the top of the retention space 4 (the upper end 6a of the bathtub body 6). The mist remains primarily in the retention space 4 in an area above the water surface of the water B and below the top of the retention space 4. Some of the mist falls into the water B and is absorbed, or forms droplets that adhere to the wall of the bathtub body 6, or flows over the edge of the upper end 6a of the bathtub body 6. While some of the mist disappears or diffuses, the majority of the mist remains in the retention space 4. In other words, the mist flows slowly within the retention space 4 but does not diffuse from the retention space 4, forming a stable retention layer C. The retention layer C is formed when mist of a certain density or higher exists within a unit space above the water surface of the water B. The retention layer appears as a white cloud. The retention layer is formed so that the mist density is relatively high at the bottom and relatively low at the top. The presence of the retention layer makes it appear as if the retention space 4 is filled with mist up to the top.

The retention boundary surface 66 on the upper side of the retained mist is formed below height M1, which is the height of the overflow surface 6b of the bathtub body 6 (height position M0) plus the height equivalent to the depth L1 of the bathtub body 6. The retention boundary surface 66 indicates the boundary region between retention layer C, where the mist has a concentration above a certain level in the air, and air layer J, where the mist has a concentration below a certain level in the air. Because the mist moves to some extent while retaining, the retention boundary surface 66 is defined as an area that has some height in the vertical direction and also as an area that spreads horizontally. The overflow surface 6b of the bathtub body 6 is the lowest part of the side wall of the bathtub body 6, i.e., the part that overflows first when water accumulates up to the upper limit of the bathtub body 6.

Furthermore, the retention boundary surface 66 on the upper side of the retained mist is formed above the height position M0 of the overflow surface 6b of the bathtub main body 6. Furthermore, the retention boundary surface 66 on the upper side of the retained mist is formed below a height position (height position M2 to height position M3) obtained by adding a value between 100 mm and 200 mm to the height (height position M0) of the overflow surface 6b of the bathtub main body 6. If the retention boundary surface 66 is positioned higher than the height of the overflow surface 6b of the bathtub main body 6, the user can enjoy the mist bathing effect up to a height above the bathtub, i.e., the warm bathing effect up to a height higher than the bathtub. While the mist generator 8 is operating (in use), mist is supplied into the bathtub main body 6 and the mist continues to stagnate.
The mist generating unit 8 and the mist supply unit 10 are configured to specify the temperature difference between the mist temperature and the room temperature, the particle size of the mist, the amount of mist supplied, etc., so that the height position of the stagnation boundary surface 66 is at the specified height position as described above.

Next, referring to Figures 9 to 11, we will explain how to measure the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 and the temperature of the room in which the bathtub apparatus 2 is used before the supply of mist begins.
The temperature of the mist supplied from the mist supply unit 10 to the retention space 4 can be measured by a box-shaped device 35 that corresponds to the shape of the expected plumbing equipment. The box-shaped device 35 includes a virtual retention space 34 that simulates the shape of the retention space of the expected plumbing equipment, and a K-type thermocouple 36 that is placed in the center of the virtual retention space 34 and measures the temperature.
The virtual retention space 34 is formed to mimic the shape of the actual retention space 4 but at a smaller size. The size and shape of the virtual retention space are determined based on the anticipated plumbing equipment, such as a bathtub in the case of a bathtub apparatus 2, a bathroom wash area floor, a shower room, a washbasin in the case of a washbasin, or a kitchen sink in the case of a kitchen. For example, the virtual retention space 34 forms a rectangle with short sides of 120 mm and long sides of 300 mm when viewed from above, and a rectangular parallelepiped with a height of 120 mm and long sides of 300 mm when viewed from the front. The virtual retention space 34 of the box-shaped apparatus 35 is open, with its ceiling omitted. A temperature sensor of a K-type thermocouple 36 is positioned at the center of the virtual retention space 34 to measure the air temperature within the virtual retention space 34. The K thermocouple 36 is located 60 mm inward from the sidewall along the short side, 150 mm inward from the sidewall along the long side, and 60 mm above the bottom in the height direction, as viewed from above. For example, the temperature-sensing part of the K thermocouple measures 4.5 mm in diameter and 50 mm in length. The K thermocouple 36 is electrically connected to a temperature logger (not shown). For example, measurement data from the K thermocouple 36 (model L-TN-4-K, manufactured by AS ONE Corporation) is measured and recorded using a temperature logger (NR-TH08, manufactured by Keyence Corporation, NR-500 series), and the temperature logger information is recorded on a computer. The water used to generate the mist is tap water, and the quality of the water used to generate the mist is based on that of tap water. Furthermore, in the room where each measurement method is performed, no air conditioning or other ventilation that would create airflow within the room is supplied.

As shown in Figure 12, the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 is determined by the mist ambient temperature T1 (e.g., 43°C), which is the maximum temperature when the temperature rise has almost stopped after a sufficient amount of time (e.g., 2500 seconds) has passed since the mist supply unit 10 of this embodiment started to supply mist to the virtual retention space 34 in the box-shaped device 35.
In FIG. 12 , the vertical axis represents the temperature (mist ambient temperature) [°C] measured by the K thermocouple 36 in the virtual retention space 34, and the horizontal axis represents the elapsed time [s] from the start of measurement. FIG. 12 shows an example of a measurement of the mist ambient temperature. In this measurement example, the room temperature at the start is T0 = −5°C, and the initial mist temperature generated by the mist generation unit 8 is 60°C. The temperature of the mist supplied to the retention space from the mist supply unit 10 is slightly lowered, and this temperature is measured as the mist ambient temperature. After mist supply begins, the temperature in the virtual retention space 34 rises over time, and the temperature rise converges to a substantially constant value T1. If mist supply from the mist supply unit 10 continues, the value to which the temperature of the mist in the virtual retention space 34 converges is the temperature of the mist supplied from the mist supply unit 10 to the virtual retention space 34. Therefore, it is assumed that the temperature of the mist actually supplied from the mist supply unit 10 to the retention space 4 will be the temperature of the mist obtained in the virtual retention space 34 (mist ambient temperature).

Next, we will explain how to measure the temperature in a room where a plumbing device is used before mist supply begins. The temperature in the room where the plumbing device is used before mist supply begins is measured by a room temperature K thermocouple 50 located outside the virtual retention space 34 within the room where the plumbing device is used. The room temperature K thermocouple 50 outside the virtual retention space 34 is located in the same indoor space as the box-shaped device 35 and simulates the indoor temperature measuring device 24. Therefore, the temperature measured by the room temperature K thermocouple 50 corresponds to the indoor temperature measured by the indoor temperature measuring device 24. In simulations using a virtual retention space, the temperature measured by this room temperature K thermocouple 50 is used as the indoor temperature. The room temperature K thermocouple 50 is located at the height of the top of the virtual retention space 34, 60 mm outward from the sidewall in the direction along the short side and 150 mm inward from the sidewall at one end of the virtual retention space 34 in the direction along the long side, when viewed from above. The room temperature K thermocouple 50 is fixed outside the virtual retention space 34 by a support portion 38 that extends outside the virtual retention space 34. The temperature of the room where the plumbing equipment is used is measured by the room temperature K thermocouple 50 before mist supply to the virtual retention space 34 begins. The room temperature K thermocouple is the same K thermocouple as the K thermocouple 36 inside the virtual retention space. The room temperature K thermocouple 50 is not limited to this location and can be placed in a position outside and near the mist generation unit 8. Furthermore, since the room temperature K thermocouple 50 only needs to measure the temperature of the room where the plumbing equipment is used before mist supply begins, the K thermocouple 36 placed inside the virtual retention space 34 may measure the air temperature inside the virtual retention space 34 before mist supply begins.

Next, referring to Figure 13, we will explain the range of temperature difference (shown by the dotted area in Figure 13) between the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 and the temperature in the room where the plumbing equipment is used before the mist supply begins.
As described above, the temperature of the mist supplied from the mist supply unit 10 to the retention space 4 and the room temperature where the plumbing equipment is used before the mist supply begins can be determined. Therefore, the temperature difference between these mist temperatures and the room temperature can be determined. By setting this temperature difference to 0°C or more, the temperature of the mist adjusted after heating can be set to the same temperature as or higher than the room temperature before the mist supply begins.
In Figure 13, the vertical axis represents the mist temperature (°C), and the horizontal axis represents the room temperature (°C). Furthermore, line C1 is shown where the temperature difference between the mist temperature and the room temperature is 0°C. Therefore, the range where the temperature difference is 0°C or more is shown above line C1. Figure 13 also shows line C2 where the temperature difference between the mist temperature and the room temperature is 100°C. The mist generation unit 8 and mist supply unit 10 of the mist generator 1 are configured to achieve a temperature difference between 0°C and 100°C. By being able to set a relatively high mist temperature, with a temperature difference of up to 100°C, the cleaning properties and dirt removal ability of the mist can be improved when using mist to clean the bathtub body 6 of a bathroom fixture. For example, relatively high cleaning performance can be achieved by using high-temperature mist close to the boiling point of water. Furthermore, when the mist reaches its boiling temperature (e.g., 100°C), it changes into water vapor and the mist droplets disappear, so the temperature of the mist supplied from the mist supply unit 10 is kept below 100°C (shown by the area below line C5).

Furthermore, the mist generation unit 8 and mist supply unit 10 of the mist generator 1 are configured so that the temperature difference is between 0°C and 60°C. Line C3 is shown where the temperature difference between the mist temperature and the room temperature is 60°C. By limiting the use of relatively high-temperature mist that results in a temperature difference of up to 60°C, the cleaning properties of the mist can be improved while further reducing the risk of burns when using mist to clean the bathtub body 6 of a plumbing appliance.

Furthermore, the mist generation unit 8 and mist supply unit 10 of the mist generator 1 are configured so that the temperature difference is between 0°C and 45°C. Line C4 is shown, where the temperature difference between the mist temperature and the room temperature is 45°C. By using a relatively low-temperature mist with a temperature difference of up to 45°C, the possibility of users of plumbing equipment being burned by the mist can be virtually eliminated.

Furthermore, in Figure 13, if the mist temperature is set to 35 degrees or higher (indicated by line D1) and 45 degrees or lower (indicated by line D2), the temperature can be set to about the user's body temperature or warmer, while almost eliminating the possibility of the user being burned by the mist.

Next, a device and a method for measuring the particle size of the mist supplied from the mist supply unit 10 will be described with reference to FIG.
The mist particle size measuring device 37 includes a box-shaped device 39 that sets up a virtual retention space 34 of the same size and shape as described above, and a particle size distribution measuring device 53. A square opening 52 measuring 20 mm x 20 mm is formed in the side wall of this box-shaped device 39, i.e., near the center of the side wall of the virtual retention space 34, and a lid 55 is attached to this opening 52.

As shown in FIG. 15, the particle size distribution measuring device 53 is equipped with a particle size measuring laser 54 arranged so that the measurement region E of the particle size measuring laser is located near and in front of the opening 52. When viewed from above, the particle size measuring laser 54 is arranged so that the laser light from the particle size measuring laser 54 is parallel to the long side of the virtual retention space 34. The measurement region E, through which the laser light emitted from the particle size measuring laser 54 passes, is located in front of the opening 52. The measurement region E is located 150 mm from the opening 52. The particle size distribution measuring device 53 further includes a measurement lens 56 to detect the diffracted and scattered light of this laser light.

With the lid 55 attached to this opening, mist begins to be supplied into the virtual retention space 34. The mist supply port from the mist supply unit 10 is not shown. One minute after the mist supply begins, the lid 55 is opened, allowing the mist to leak toward the measurement area E of the particle size measurement laser 54. The scattered light distribution is measured using the measurement lens 56 with the particle size measurement laser 54 having a transmittance of 60% to 90%. For example, the particle size measurement laser 54 and measurement lens 56 are the LDSA-SPR1500A, an Aerotrac LDSA-SPR series spray particle size distribution measurement device manufactured by Microtrac Bell Co., Ltd. Particle size distribution data is measured 10 times and recorded on a PC. The 10 particle size distribution data are averaged on the PC. Figure 16 shows an example of particle size distribution data measured by the particle size distribution measurement device 53. In Figure 16, the left vertical axis represents frequency [%], the right vertical axis represents cumulative [%], and the horizontal axis represents particle size [μm]. For example, the PC analyzes the particle size distribution data obtained in this way and obtains the 20th percentile particle size G and Sauter mean particle size H of this particle size distribution data as particle size data. The Sauter mean particle size indicates the particle size having the same surface area to volume ratio as the total volume of all particles relative to the total surface area of all particles. By determining the average particle size using the Sauter mean particle size, the influence of a small number of large particle sizes on the measurement value can be suppressed.

The mist generating unit 8 and other components are configured so that the particle size of the majority of the mist supplied from the mist supply unit 10 is 3.1 μm or more and 40 μm or less. To minimize the effects on measurement of a small number of large particles and small particles at the upper and lower limits of this range, the particle size of the mist is specified to satisfy the conditions that the Sauter mean particle size of the mist is 40 μm or less and the Sauter mean particle size of the mist is 3.1 μm or more.
The mist generating unit 8 and other components are configured so that the particle size of the majority of the mist supplied from the mist supply unit 10 is 3.6 μm or more and 20 μm or less. To minimize the effects on measurement of a small number of large-diameter particles and small-diameter particles at the upper and lower limits of this range, the particle size of the mist is specified to satisfy the conditions that the average of the Sauter mean particle size and the Sauter mean particle size of the mist is 3.6 μm or more and the Sauter mean particle size of the mist supplied from the mist supply unit is 20 μm or less.
The mist generating unit 8 and other components are configured so that the particle size of the majority of the mist supplied from the mist supply unit 10 is 4.1 μm or more and 10 μm or less. To reduce the influence of a small number of large-diameter particles or small-diameter particles at the upper and lower limits of this range, the particle size of the mist is specified to satisfy the condition that the Sauter mean particle size of the mist is 4.1 μm or more and 10 μm or less.

Next, the relationship between the temperature difference and the particle size will be described with reference to FIG.
In Figure 17, the vertical axis represents particle size [µm], and the horizontal axis represents temperature difference ΔT [°C]. The preferred ranges for particle size and temperature difference ΔT are indicated by dotted areas in Figure 17. The mist generation unit 8 and mist supply unit 10 can set a predetermined temperature difference between the mist temperature and the room temperature in a range of 0°C or more and 100°C or less. As described above, the temperature difference can be changed to 0°C or more and 60°C or less, 0°C or more and 45°C or less, etc.

The mist generating unit 8 and the mist supplying unit 10 are configured so that the Sauter mean particle size of the mist is 40 μm or less. Therefore, the particle size of most of the mist is 40 μm or less.
If the mist particle size is 40 μm, the terminal velocity v is calculated as 45.3 mm/s. The method for calculating the terminal velocity v of the water droplets can be expressed as follows. If the molecular viscosity coefficient of air is μ and the radius of the water droplet (half the mist particle size) is r, then ρ = 103 kg/m ^-3 , g = 9.8 m/s ² , μ = 1.8X10 ^-5 N・sec/m ² (15°C),
The terminal velocity v(∞) is proportional to the square of the radius of the water droplet. Note that this formula is applicable to the range Re<1, i.e., r<0.1 mm.
If the mist particle size is 40 μm and the terminal velocity of the mist is 45.3 mm/s, it is assumed that the supplied mist reaches the bottom of the retention space in approximately 10 seconds (for example, the distance from the mist supply unit 10 to the bottom of the retention space 4 is 45 cm) and disappears. In other words, the mist will remain for at least 10 seconds from the time of supply until it disappears. If the mist remains for approximately 10 seconds in this manner, new mist can be supplied during this time, making it easier to maintain the mist retention layer C. In Figure 17, when the Sauter mean particle size is greater than 40 μm, the average time until the mist disappears becomes shorter, making it more difficult for a mist retention layer to form due to the disappearance of the mist.

The mist generation unit 8 and mist supply unit 10 may be configured so that the Sauter mean particle size of the mist is 20 μm or less. In this case, the particle size of the majority of the mist is 20 μm or less. If the mist particle size is 20 μm, the terminal velocity v is calculated to be 11.3 mm/s, and it will take at least approximately 40 seconds for the supplied mist to reach the bottom of the retention space 4, further reducing the proportion of mist that falls to the bottom of the retention space 4 relatively quickly.

The mist generation unit 8 and mist supply unit 10 may be configured so that the Sauter mean particle size of the mist is 10 μm or less. In this case, the particle size of the majority of the mist is 10 μm or less. If the mist particle size is 10 μm, the terminal velocity v is calculated to be 2.8 mm/s, and it will take at least approximately 160 seconds for the supplied mist to reach the bottom of the retention space 4. This allows the mist to remain in the retention space 4 for a longer period of time, and further reduces the proportion of mist that falls to the bottom of the retention space 4 relatively quickly.

The mist generation unit 8 and the mist supply unit 10 may be configured so that the Sauter mean particle size of the mist is 3.1 μm or more. In this case, the particle size of the majority of the mist is 3.1 μm or more. This reduces the proportion of mist supplied from the mist supply unit 10 that diffuses outside the retention space 4 without being retained within the retention space 4, while increasing the proportion of mist that is retained within the retention space 4, allowing the mist to be retained efficiently within the retention space 4.

The mist generation unit 8 and the mist supply unit 10 may be configured so that the Sauter mean particle size of the mist is 3.6 μm or more. In this case, the particle size of the majority of the mist is 3.6 μm or more. This further reduces the proportion of mist supplied from the mist supply unit 10 that is not retained within the retention space 4 and diffuses outside the retention space 4, while further increasing the proportion of mist that is retained within the retention space 4, allowing the mist to be retained more efficiently within the retention space 4.

The mist generation unit 8 and the mist supply unit 10 may be configured so that the Sauter mean particle size of the mist is 4.1 μm or more. In this case, the particle size of the majority of the mist is 4.1 μm or more. This further reduces the proportion of mist supplied from the mist supply unit 10 that diffuses outside the retention space 4 without being retained within the retention space 4, and further increases the proportion of mist that is retained within the retention space 4, allowing the mist to be retained more efficiently within the retention space 4.

Next, the relationship between temperature difference, particle size, and the state of mist within the virtual retention space 58 will be further explained with reference to Figures 18 and 19. Figure 18 shows a box-shaped observation device for observing the state within the virtual retention space. Figure 19 compares the state of mist within the virtual retention space 58 for nine combinations of temperature difference and Sauter mean particle size.

As shown in Figure 19, the state of mist within a virtual retention space 58 can be measured using a box-shaped observation device 55 that corresponds to the shape of the expected plumbing equipment. The box-shaped observation device 55 is equipped with a virtual retention space 58 that simulates the shape of the retention space of the expected plumbing equipment, and a camera 62 that observes and records the state of the mist within the virtual retention space 58. As shown in Figure 18, the virtual retention space 58 of the box-shaped observation device 55 forms a rectangular parallelepiped with short sides of 120 mm, long sides of 300 mm, and a height of 240 mm in a perspective view. The virtual retention space 58 is open upward, with no ceiling surface. One side wall of the virtual retention space 58 of the box-shaped observation device 55 is formed by a transparent plate 60, and the interior of the virtual retention space 58 can be observed and recorded using a camera 62 positioned diagonally above the box-shaped observation device 55. A supply port 64 measuring 70 mm in width and 40 mm in height is formed at a position 120 mm high on the side wall on the short side of the virtual retention space 58 of the box-shaped observation device 55. This supply port 64 is connected to the mist supply unit 10.

19, mist with a predetermined particle size and temperature difference is supplied from the mist supply unit 10, and photographs of the stagnation state taken by the camera 62 are shown for comparison in nine patterns. In the photographs of each pattern, the position where the stagnation boundary surface is expected to occur is indicated by a dotted line for reference.
In FIG. 19, the vertical axis indicates the Sauter mean particle diameter of the mist supplied from the mist supply unit 10, and the horizontal axis indicates the temperature difference ΔT between the temperature of the mist and the temperature inside the room.
In pattern example A of Figure 19, when the Sauter mean particle size of the mist is 50 μm to 60 μm and the temperature difference is 5°C (mist temperature 20°C and room temperature before mist supply begins 15°C), the mist supplied from mist supply unit 10 falls relatively quickly to the bottom within virtual retention space 58 and disappears, resulting in no mist remaining within virtual retention space 58. This photograph was taken two minutes after mist supply began. Therefore, no mist retention layer C has been formed within virtual retention space 58, forming retention boundary surface 66 on its upper surface.

In pattern example B of Figure 19, when the Sauter mean particle size of the mist is 50 μm to 60 μm and the temperature difference is 25°C (mist temperature 40°C and room temperature before mist supply starts 15°C), the mist supplied from the mist supply unit 10 falls relatively quickly to the bottom within the virtual retention space 58 and disappears, so the mist does not remain within the virtual retention space 58.
In pattern example C of Figure 19, when the Sauter mean particle size of the mist is 50 μm to 60 μm and the temperature difference is 45°C (mist temperature 60°C and room temperature before mist supply starts 15°C), the mist supplied from the mist supply unit 10 falls relatively quickly to the bottom within the virtual retention space 58 and disappears, so the mist does not remain within the virtual retention space 58.

In pattern example D in Figure 19, when the Sauter mean particle size of the mist is 4 μm to 8 μm and the temperature difference is 5°C (mist temperature 20°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit 10 forms a stagnation layer C in the virtual retention space 58, although the concentration is somewhat low. Because the mist particle size is relatively small, the terminal velocity is also relatively small and the falling speed is slow. Meanwhile, the updraft caused by the temperature difference is also small. As a result, the mist stagnates and forms a stagnation layer in the virtual retention space 58, forming a stagnation boundary surface 66 on its upper surface.

In pattern example E in Figure 19, when the Sauter mean particle size of the mist is 4 μm to 8 μm and the temperature difference is 25°C (mist temperature 40°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit 10 forms a highly concentrated stagnation layer C within the virtual retention space 58. Because the mist particle size is relatively small, the terminal velocity is also relatively low and the fall speed is slow. A slight updraft is also generated due to the temperature difference. Here, the force of the updraft caused by the temperature difference to lift the mist does not exceed the weight of the mist, while suppressing the fall of the mist and causing the mist to remain stagnate for a relatively long time. Therefore, a stagnation layer C of mist is formed within the virtual retention space 58, forming a stagnation boundary surface 66 on its upper surface.

In pattern example F in Figure 19, when the Sauter mean particle size of the mist is 4 μm to 8 μm and the temperature difference is 45°C (mist temperature 60°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit forms a highly concentrated stagnation layer C within the virtual retention space 58. Because the mist particle size is relatively small, the terminal velocity is also relatively small, and the fall speed is slow. Furthermore, the updraft caused by the temperature difference is slightly stronger than when the temperature difference is 25°C. However, the force of the updraft caused by the temperature difference to lift the mist still does not exceed the weight of the mist, suppressing the fall of the mist and causing the mist to remain stagnant for a relatively long time. Because the updraft is somewhat stronger, there are areas where the mist appears to float up from the stagnation layer C, but overall the stagnation layer C of mist continues to be maintained. Therefore, a stagnation layer of mist is formed within the virtual retention space 58, forming a stagnation boundary surface 66 on its upper surface. Even if there are areas where the mist is rising locally, if the retention boundary surface 66 is maintained over more than half of the virtual retention space 58, it is considered that the retention boundary surface 66 is formed.

In pattern example G of Figure 19, when the Sauter mean particle size of the mist is 1.2 μm and the temperature difference is 5°C (mist temperature 20°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit 10 diffuses and floats up within the virtual retention space 58. The updraft caused by the temperature difference is relatively small. However, because the mist particle size is even smaller, the terminal velocity is even smaller and the falling speed is even slower. Therefore, the mist is light in weight and diffuses with a slight updraft. Therefore, no mist stagnation layer C is formed within the virtual retention space 58, forming a retention boundary surface 66 on its upper surface.
In pattern example H of Figure 19, when the Sauter mean particle size of the mist is 1.2 μm and the temperature difference is 25°C (mist temperature 40°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit 10 diffuses and floats up within the virtual retention space 58. Because the mist particle size is even smaller, the terminal velocity is also smaller and the falling speed is even slower. Furthermore, the updraft caused by the temperature difference is even stronger. Therefore, the mist is lighter and is diffused by the stronger updraft. Therefore, a mist stagnation layer C that forms a retention boundary surface 66 on the upper surface is not formed within the virtual retention space 58.
In pattern example I of Figure 19, when the Sauter mean particle size of the mist is 1.2 µm and the temperature difference is 45°C (mist temperature 60°C and room temperature before mist supply begins 15°C), the mist supplied from the mist supply unit 10 diffuses and floats up within the virtual retention space 58. Because the mist particle size is even smaller, the terminal velocity is even smaller and the falling speed is even slower. Furthermore, the updraft caused by the temperature difference is even stronger. Therefore, the mist is lighter and is diffused by the even stronger updraft. Therefore, a mist stagnation layer C that forms a retention boundary surface on the upper surface is not formed within the virtual retention space 58.

Next, referring to Figure 20, we will explain a device and method for determining whether mist is in a stagnant state (whether a mist stagnant layer C has formed on the upper surface that forms a stagnant boundary surface 66) in the stagnant space 4 (or virtual stagnant space, etc.) within the bathtub body 6.
20, the internal transmittance measured inside the retention space 4 in the bathtub body 6 using a transmittance measuring device 68 is compared with the external transmittance measured outside the retention space 4. If the internal transmittance is lower than the external transmittance, it can be determined that mist is accumulating inside the retention space 4. More specifically, if the internal transmittance/external transmittance is less than 1, it can be determined that mist is accumulating inside the retention space 4.

For example, as shown in pattern example E in Fig. 19, when mist is retained inside the retention space 4, the internal transmittance decreases. On the other hand, the mist mainly remains inside the retention space 4, and the external transmittance measured above the retention boundary surface 66 is relatively high. Therefore, the internal transmittance/external transmittance is less than 1, and it is determined that mist is retained inside the retention space 4.
19, when the mist does not remain inside the retention space 4 and the mist mainly falls and disappears, both the internal transmittance and the external transmittance remain relatively high. Therefore, the internal transmittance/external transmittance = 1, and it is not determined that the mist is remaining inside the retention space 4.
19, when mist diffuses from the inside of the retention space 4 to the outside, the internal transmittance and external transmittance are both considered to be similar values with slightly low transmittance. Therefore, the internal transmittance/external transmittance ratio is 1, and it is not determined that mist is retained inside the retention space 4.

Next, the transmittance measuring device 68 will be described with reference to FIG.
The transmittance measuring device 68 includes a first laser device 70 disposed inside the retention space 4 and a first transmittance measuring device 72 that receives a laser. The first laser device 70 and the first transmittance measuring device 72 are disposed 150 mm apart in the horizontal direction at a position 150 mm below the upper end of the retention space 4 (for example, a depth position that is about 30% of the depth of the retention space 4). The first laser device 70 and the first transmittance measuring device 72 are disposed near the center of the retention space 4 when viewed from above. The intensity of the laser light measured by the first transmittance measuring device 72 is measured relative to the intensity of the laser light emitted from the first laser device 70, and the transmittance is measured.
The transmittance measuring device 68 further includes a second laser device 74 disposed outside the retention space 4 and a second transmittance measuring device 76 that receives the laser. The second laser device 74 and the second transmittance measuring device 76 are disposed 150 mm above the upper end of the retention space 4 (e.g., relative to the upper end of the retention space 4, symmetrical to the first laser device 70 and the first transmittance measuring device 72), and are spaced 150 mm apart horizontally. The first laser device 70 and the first transmittance measuring device 72 are disposed near the center of the retention space 4 in a top view. The intensity of the laser light measured by the second transmittance measuring device 76 is measured relative to the intensity of the laser light emitted from the second laser device 74, and the transmittance is measured. Note that the transmittance measuring device 68 has the first laser device 70 and the first transmittance measuring device 72 disposed inside the retention space 4. However, these devices may be disposed in a virtual retention space such as that described above instead of the retention space 4 to virtually measure the transmittance. In this case, a second laser device 74 and a second transmittance measuring device 76 are placed outside the virtual retention space.
More specifically, the device configuration involves laser light emitted from a Keyence digital fiber amplifier FS-N11MN, passing through a Keyence FU-77TZ (first laser device 70 or second laser device 74) and received by a Keyence FU-77TZ (first transmittance measuring device 72 or second transmittance measuring device 76). The received light is returned to the fiber amplifier FS-N11MN, which outputs a voltage of, for example, 1-5 V depending on the light intensity. The output voltage is measured using a Keyence NR-500 series NR-HA08 and scaled to a value between 0 and 100% on a PC. Transmittance data is measured, for example, at a sampling period of 100 ms. For example, within 15 minutes of starting to supply mist at a nearly constant rate, transmittance data is averaged over the first 30 seconds that can be determined to be in a steady state.

Next, the difference in how heat is transferred to the user during mist bathing and normal bathing will be described with reference to Figures 21 and 22.
Figure 21 shows the heat flux transmitted over time from the water to a user sitting in the bathtub body 6 of bathtub equipment 2 when the user takes a bath by crawling into a bathtub filled with 40°C water up to the normal bathing level (the water level that is above the user's armpits and below the user's shoulders when bathing, for example, 450 mm when bathing), the heat flux transmitted to the user when the same bathtub body 6 is filled with 40°C mist (mist atmosphere state), the heat flux transmitted to the user when the same bathtub body 6 is filled with 43°C mist (mist atmosphere state), and the heat flux transmitted to the user when the same bathtub body 6 is filled with 45°C mist (mist atmosphere state). The vertical axis represents heat flux [W/ ^m2 ], and the horizontal axis represents time [s] from the start of bathing. The heat flux [W/ ^m2 ] is measured by placing a measuring device at the center of the back of an average-sized user and measuring the heat flux transmitted to the user. The mist atmosphere state indicates a state in which the bathtub body 6 is sufficiently filled with mist.
When a user bathes in 40°C water from time 0 [S], the heat flux rises sharply at the beginning. This shows that the thermal stimulus given to the user at the start of bathing is large. On the other hand, when a mist bath is taken, the initial rise in heat flux is relatively suppressed and rises gradually. This shows that the thermal stimulus given to the user at the start of bathing is smaller than when taking a bath in a bath.
Furthermore, when a user bathes in water at 40°C and when they take a mist bath using mist at 40°C, the heat flux is lower with the mist at 40°C, and the user feels a lower temperature. Bathing in mist at 40°C can warm the user's body gently with low stimulation.

Furthermore, as shown in Figure 21, the heat flux acting on a user is comparable when bathing in 40°C water and when mist bathing with 43°C mist. Figure 22 shows the results of measuring the user's skin temperature after 10 minutes of bathing or mist bathing. It can be seen that users experience approximately the same warmth when bathing in 40°C water and when mist bathing with 43°C mist. Thus, mist bathing reduces the irritation caused by heated water at the start of bathing, allowing for a gentler bathing experience. For example, a user bathing in 43°C water feels very hot and can only bathe for a short time, whereas a user bathing in 43°C mist feels slightly cooler and can therefore remain immersed for a longer period of time compared to water of the same temperature. Furthermore, compared to water, mist gives the user a slightly lower temperature sensation, allowing the user's body to warm up gradually at a slightly slower rate, with less strain on the user's body due to the warming. Mist bathing also puts less strain on the user's body due to the water pressure, and as there is no pressure on the body like with water, it is possible to enjoy mist bathing for long periods of time. Furthermore, mist bathing gives the user the visual effect of an open-air bath, with the surface of the water covered in mist, providing a sense of luxury and healing to the user.

Next, the effects of the configuration of this embodiment will be described.
In the first embodiment of the present invention, the mist generator 8 and mist supply unit 10 are configured so that the mist supplied from the mist supply unit 10 is retained in the retention space 4 of the bathtub body 6. This allows the heated mist to remain in the retention space 4, which is open at the top of the bathtub body 6. This eliminates the need for a user lid, improving convenience, and also improves user comfort, as the user can warm up with the mist inside the bathtub body 6 without a lid. Furthermore, because the user can be warmed by the mist inside the bathtub body 6, the user can enjoy a mist bath without feeling any pressure or strain on the body compared to when immersed in water. Furthermore, the heat is transmitted to the user more slowly than when immersed in water, reducing the strain on the body.

In the first embodiment of the present invention configured in this manner, the mist generation unit 8 is equipped with a water temperature detection means for detecting the water temperature, allowing for more reliable control of the water temperature. Therefore, the mist generation unit 8 and the mist supply unit 10 can more reliably retain the heated mist within the retention space 4 of the bathtub body 6.

In the first embodiment of the present invention configured as described above, by heating the water or mist to 60°C or higher, even if bacteria are present in the water, the effects of at least some of the bacteria (e.g., Legionella) can be suppressed.

In the first embodiment of the present invention configured in this manner, the retention boundary surface 66 on the upper side of the retained mist is formed below the height position obtained by adding the height equivalent to the depth of the bathtub body 6 to the height of the overflow surface 6b of the bathtub body 6, thereby preventing the retention boundary surface 66 from being formed at a position that is too high, thereby increasing user comfort.

In the first embodiment of the present invention, which is configured in this manner, the retention boundary surface 66 on the upper side of the retained mist is formed above the height position of the overflow surface 6b of the bathtub main body 6, making it easier for a user sitting in the bathtub main body 6 to enjoy mist bathing up to the upper part of their body, and also making it possible to warm the user's body up to a level higher than the water level at which water is normally poured, further increasing the user's comfort.

In the first embodiment of the present invention configured in this manner, the retention boundary surface 66 on the upper side of the retained mist is formed below a height position that is between 100 mm and 200 mm above the height of the overflow surface 6b of the bathtub main body 6. This makes it easier for the retention boundary surface 66 to be formed below the face of a user sitting in the bathtub main body 6, further increasing user comfort.

In the first embodiment of the present invention configured in this manner, the mist supply unit 10 is positioned above the water overflow area within the bathtub body 6, preventing the water within the bathtub body 6 from flowing upstream from the mist supply unit 10 as wastewater.

In the first embodiment of the present invention configured in this manner, the mist supply unit 10 is positioned above the water overflow surface 6b within the bathtub body 6, thereby preventing water within the bathtub body 6 from entering upstream from the mist supply unit 10 as sewage.

In the first embodiment of the present invention configured in this manner, the mist generator 1 further includes an indoor temperature measuring device 24 that detects the air temperature in the bathroom where the bathtub body 6 is placed. This allows the mist generation unit 8 to generate heated mist according to the air temperature in the bathroom where the bathtub body 6 is placed, and the mist generation unit 8 and mist supply unit 10 can more reliably retain the heated mist within the retention space 4 of the bathtub body 6.

The first embodiment of the present invention is a bathtub apparatus characterized by comprising the mist generator of the first embodiment of the present invention and a bathtub main body 6 that forms a retention space 4 that receives mist supplied from the mist supply unit 10 of the mist generator 1.

In the first embodiment of the present invention configured as described above, the mist generation unit 8 and mist supply unit 10 of the mist generator 1 are positioned on the short sides of the bathtub body 6, so the mist supplied from the mist supply unit 10 is supplied relatively evenly in the left-right direction of the short sides in the retention space 4 within the bathtub body 6, preventing disruption of the mist retention. Furthermore, a relatively uniform flow of mist is supplied in the left-right direction of the short sides, and this mist travels along the long sides, making it easier to create a visual effect that gives the user a soothing effect and a sense of luxury.

Next, a mist generator 101 according to a second embodiment of the present invention will be described with reference to Figures 23 and 24. The mist generator 101 of the second embodiment differs from the first embodiment described above in that the mist supply unit has a mist supply port facing downward. Here, only the differences between the second embodiment of the present invention and the first embodiment will be described, and similar parts will be designated by the same reference numerals in the drawings and will not be described again.
FIG. 23 is a perspective view of a bathtub apparatus equipped with a mist generating device according to the second embodiment of the present invention, and FIG. 24 is a side view of a bathtub apparatus equipped with a mist generating device according to the second embodiment of the present invention.
24, the retention boundary surface 66 in the second embodiment is formed in the same manner as the retention boundary surface 66 in the first embodiment, but due to space limitations, reference numerals M0, M1, M2, M3, L1, etc., which are used to describe the position where the retention boundary surface 66 is formed, are omitted. In the second embodiment, the reference numerals M0, M1, M2, M3, L1, etc., which are used to describe the position where the retention boundary surface 66 is formed, are also referred to in the description of the retention boundary surface 66 in the first embodiment and in the description of FIG. 2, etc.

As shown in Figures 23 and 24, a bathtub apparatus 2, which is a plumbing device equipped with a mist generator 101 according to the second embodiment of the present invention, is installed in a bathroom 3. Plumbing devices are devices equipped with a water discharge device for use in bathrooms, bathroom wash area floors, toilets, washrooms, kitchens, etc. The mist generator 101 is a mist generator used in plumbing devices such as the bathtub body, bathroom wash area floor, shower room, hand wash bowl, wash basin bowl, and kitchen sink.

The mist generator 101 is used in a bathtub unit 2, which is a plumbing device. The mist generator 101 includes a mist generator 108 that generates mist and a mist supply unit 110 that supplies mist into the bathtub main body 6.

The mist generating unit 108 is attached to the wall W of the bathroom 3, at a height higher than the height of the bathtub main body 6. The mist generating unit 108 is located above the short side portion 6e of the upper edge of the bathtub main body 6. The mist generating unit 108 is spaced apart from the bathtub main body 6. That is, the mist generating unit 108 is not directly attached to the bathtub main body 6, and a gap space is formed between the bottom surface of the mist generating unit 108 and the short side portion 6e. While the mist generating unit 108 is spaced apart from the bathtub main body 6, as a variant, the mist generating unit 108 may be arranged so as to contact or be attached to the bathtub main body 6. Note that the mist generating unit 108 in the second embodiment has essentially the same components and functions as the mist generating unit 8 in the first embodiment, except for its location. Therefore, similar parts will be given the same reference symbols in the drawings, and descriptions will be omitted or given briefly, with the differences being mainly described.

The mist generating unit 108 includes a water supply channel 14 that supplies water from a water source to the tank 12, a drainage channel 16 that drains water from the tank 12 to a drain pipe, an ultrasonic vibrator 18 provided at the bottom inside the tank 12, a heater 20 provided at the bottom inside the tank 12, a water temperature gauge 22 that serves as a water temperature detection means provided inside the tank 12, an indoor temperature gauge 24 that serves as an air temperature detection means provided outside the tank 12, and a control unit 26 that controls the ultrasonic vibrator 18 and heater 20.

The tank 12 is attached to the front side of the wall W (inside the bathroom 3). A water supply channel 14 and a drain channel 16 are connected to the side wall at the bottom of the tank 12. A mist supply unit 110 is connected to the side wall near the center of the tank 12. The water supply channel 14 extends from the front side of the wall W to the back side (outside the bathroom 3). The drain channel 16 extends from the front side of the wall W to the back side. The control unit 26 is provided on the back side of the wall W.

The mist supply unit 110 supplies the mist generated by the mist generation unit 108 into the bathtub body 6, which is a retention section that forms the retention space 4 with an upwardly open opening facing the room in which the bathtub body 6 is placed. The mist supply unit 110 is located above the short side portion 6e of the short side of the bathtub body 6. As shown in the cross section of the flow path in Figure 24, the mist supply unit 110 includes a mist supply flow path 111 that extends laterally from the mist generation unit 108 to the top of one end of the retention space 4, and a mist supply port 113 that is connected to the downstream end of the mist supply flow path 111 and opens downward.

The mist supply flow path 111 extends substantially horizontally from the vertical center of the tank 12. Alternatively, the mist supply flow path 111 may extend from the top of the tank 12. Alternatively, the mist supply flow path 111 may extend diagonally downward from the mist generating unit 108 toward the retention space 4. Furthermore, the mist supply flow path 111 may form a flow path that curves from sideways to downward in an arc, in conjunction with the downward-facing mist supply port 113. When viewed from the front (from the retention space 4 side), the mist supply flow path 111 forms a horizontally elongated rectangular flow path (e.g., flow path cross section). The bottom surface 111a of the mist supply flow path 111 extends flat and parallel to the left-right direction of the short side portion 6e of the bathtub body 6 (the depth direction of the paper in Figure 24) and also extends flat and parallel to the front-to-back direction of the short side portion 6e. A vertical wall 111b is formed on the front side of the mist supply flow path 111 on the retention space 4 side, and the mist passing through the mist supply section 110 is guided downward by the vertical wall 111b.

The mist supply port 113 extends downward from the downstream end of the mist supply flow path 111. The mist supply port 113 forms a duct-like flow path extending downward. The mist supply port 113 forms an opening that opens downward. When viewed from the front of the opening (when viewed from below the mist supply port 113 upward), the mist supply port 113 forms a horizontally long rectangular flow path (e.g., flow path cross section). The width of the mist supply port 113 in the left-right direction (depth direction in the plane of FIG. 24) is the same as the width of the mist supply flow path 111 in the left-right direction (depth direction in the plane of FIG. 24). The width of the mist supply port 113 in the left-right direction may be different from the width of the mist supply flow path 111. The width of the mist supply port 113 in the left-right direction is shorter than the width of the short side portion 6e in the left-right direction. The left-right width of the mist supply port 113 may be the same as the width of almost the entire short side portion 6e, for example, the left-right width of the retention space 4 of the short side portion 6e. Alternatively, the left-right width of the mist supply port 113 may be about half the entire left-right width of the retention space 4 of the short side portion 6e.

The lower end 113a of the mist supply port 113 extends parallel to the left-right direction of the short side portion 6e of the bathtub body 6 (the depth direction of the paper in Figure 24). The lower end 113a is located above the retention space 4, inside the bathtub body 6, from the short side portion 6e. The mist supply port 113 is located above the retention space 4. The mist supply port 113 extends vertically downward. The mist supply port 113 may also extend diagonally downward. An imaginary line N along the opening direction of the mist supply port 113 extends into the space inside the short side portion 6e of the bathtub body 6, for example, into the retention space 4.

The lower end 113a of the mist supply port 113 is located above the water overflow portion 6c within the bathtub body 6. This prevents water within the bathtub body 6 from flowing upstream from the mist supply port 113 as sewage. The lower end 113a of the mist supply port 113 may also be located below the upper end of the stagnation boundary surface 66. In this embodiment, this overflow portion 6c is the overflow surface 6b of the bathtub body 6, and the lower end 113a of the mist supply port 113 is located above the short side portion 6e of the bathtub body 6. Alternatively, the overflow portion 6c may be an overflow port provided within the bathtub body 6. Therefore, the lower end 113a of the mist supply port 113 may be located above the overflow port provided within the bathtub body 6 and below the short side portion 6e.

The length of the mist supply port 113, for example, the length from the bottom of the mist supply flow path 111 to the lower end 113a, is variable. The lower end 113a of the mist supply port 113 is located, for example, at a position higher than 0 mm above the overflow portion 6c, or at a position higher than 50 mm above the overflow portion 6c. The lower end 113a is also located, for example, at a height lower than 400 mm above the short side portion 6e, or at a height lower than 100 mm above the short side portion 6e. Therefore, the lower end 113a of the mist supply port 113 is positioned within a height range, for example, higher than 0 mm above the overflow portion 6c and lower than 400 mm above the short side portion 6e. More preferably, the lower end 113a of the mist supply port 113 is positioned at a height within a range, for example, at least 50 mm above the overflow portion 6c and no more than 100 mm above the short side portion 6e. Positioning the lower end 113a of the mist supply port 113 as described above allows the mist to travel a relatively short distance from the lower end 113a to the retention space 4, making it easier to control the temperature and other aspects of the mist supplied to the retention space 4. Furthermore, it prevents the mist from diffusing before it is supplied to the retention space 4. Positioning the lower end 113a of the mist supply port 113 at a height greater than 0 mm above the overflow portion 6c as described above prevents the water in the bathtub body 6 from entering the upper side as sewage before overflowing from the overflow portion 6c, even when the overflow portion 6c is located lower than the upper edge of the bathtub body 6. Furthermore, as described above, the lower end 113a of the mist supply port 113 is preferably positioned at a height more than 50 mm above the height of the overflow portion 6c, thereby further preventing water from inside the bathtub body 6 from flowing upstream from the lower end 113a as wastewater.

As a variant, the mist supply port 113 may be formed as an opening on the lower side of the mist supply flow path 111, opening downward. Such a lower-side opening mist supply port 113 forms an opening that does not protrude downward from the mist supply flow path 111 as a duct-like flow path. When viewed from the front of the opening (when viewed from below the lower-side opening mist supply port 113 to the top), the lower-side opening mist supply port 113 forms a horizontally elongated rectangular flow path (flow path cross section). The left-right width of the lower-side opening mist supply port 113 is the same as the left-right width of the mist supply flow path 111. The left-right width of the lower-side opening mist supply port 113 is shorter than the left-right width of the short side portion 6e. The left-right width of the mist supply port 113 of the lower opening may be the same as the width of almost the entire short side portion 6e, for example, the left-right width of the retention space 4 at the short side portion 6e. The left-right width of the mist supply port 113 of the lower opening may also be approximately half the overall left-right width of the retention space 4. The left-right edges of the mist supply port 113 of the lower opening extend parallel to the left-right directions of the short side portions 6e of the bathtub body 6. The mist supply port 113 of the lower opening is located higher in the retention space 4 inside the bathtub body 6 than the short side portions 6e. The mist supply port 113 of the lower opening opens vertically downward, but may also open diagonally downward toward the retention space 4. The mist supply port 113 at the lower opening is located above the water overflow portion 6c in the bathtub body 6, and the mist supply port 113 at the lower opening is located above the short side portion 6e of the bathtub body 6.

Again, in this embodiment, the mist supply unit 110 has a supply rate per volume ranging from 0.03 mL/min·L to 1.5 mL/min·L. The mist supply unit 110 can supply mist at a rate of 11 mL/min per unit time to the 330 L retention space 4 of the bathtub main body 6. Furthermore, the mist supply unit 110 can supply mist at a rate of 6 mL/min per unit time to a 4.32 L retention space 4, such as a virtual retention space for measuring temperature differences and particle size, or to other plumbing equipment. The mist supply rate can be controlled by the number of ultrasonic vibrators 18, their output, the direction in which the ultrasonic waves are emitted, the water level in the mist generation unit 108, or the shape of the flow paths in the mist generation unit 108 and the mist supply unit 110.

The mist generation unit 108 and mist supply unit 110 generate heated mist and control the temperature of the mist, making it easier for the mist to remain in the retention space 4. The following explains this. The mist generation unit 108 and mist supply unit 110 are configured so that the temperature difference between the temperature of the mist supplied from the mist supply unit 110 to the retention space 4 and the temperature of the room where the plumbing equipment is used before the mist supply begins is 0°C or more, allowing the mist supplied from the mist supply unit 110 to remain in the retention space 4 of the bathtub body 6. Furthermore, the mist generation unit 108 and mist supply unit 110 of the mist generator 101 are configured to create a temperature difference such that the force of the rising air current caused by the temperature difference, which tends to lift the mist, does not exceed the weight of the mist supplied from the mist supply unit 110, which is determined by the particle size of the mist. This type of mist supply can be achieved without using the indoor temperature gauge 24 (without relying on the measurement results of the indoor temperature gauge 24) by presetting the temperature of the water supplied to the mist generation unit 108, the heating temperature of the heater 20, or the frequency of the ultrasonic vibrator 18 according to the expected temperature range of the air in the indoor space 5. Alternatively, this type of mist supply can be achieved by adjusting the settings at the time of supply. The mist generation unit 108 and the mist supply unit 110 are configured so that the temperature difference is preferably 100°C or less, more preferably 60°C or less, and even more preferably 45°C or less. The mist generation unit 108 and the mist supply unit 110 generate heated mist and control the particle size of the mist, making it easier for the mist to remain in the retention space 4.

The operation, various measurement methods, actions (effects), etc. of the mist generator 101 of the second embodiment are basically the same as the operation, various measurement methods, actions (effects), etc. of the mist generator 1 of the first embodiment. Therefore, for parts that overlap with the operation, various measurement methods, actions (effects), etc. of the first embodiment, please refer to the explanation of the first embodiment, and explanations of the second embodiment will be omitted.

In the second embodiment of the present invention configured as described above, the mist supply unit 110 has a mist supply port 113 that opens downward. This reduces the distance the mist supplied from the mist supply port 113 of the mist supply unit 110 travels to reach the bathtub body 6, making it relatively short compared to when the mist supply port 113 of the mist supply unit 110 opens sideways or upward. This prevents the mist from undergoing changes such as a drop in temperature before reaching the bathtub body 6, making it difficult to adjust the temperature of the mist reaching the bathtub body 6. This makes it easier for heated mist to remain in the retention space 4, which is open above the bathtub body 6. Furthermore, for example, because the mist supply unit 110 has a mist supply port 113 that opens downward, it is possible to prevent water in the bathtub body 6 from flowing upstream from the mist supply unit 110 as sewage.

1 Mist generating device 2 Bathtub device 4 Retention space 6 Bathtub body 6b Overflow surface 6c Overflow section 8 Mist generating section 10 Mist supply section 24 Indoor temperature measuring instrument 101 Mist generating device 110 Mist supply section 113 Mist supply port section A User B Water C Retention layer

Claims (13)

A mist generator for use in a bathtub body,
a mist generating unit that generates mist;
A mist supply unit supplies the mist generated by the mist generating unit into the bathtub body, which forms a retention space with an open top,
The mist generating unit and the mist supply unit are configured so that the mist supplied from the mist supply unit is retained in the retention space of the bathtub body ,
The mist generating unit generates mist that is supplied from the mist supply unit and retained in the retention space at a temperature equal to or warmer than the user's body temperature, i.e., 35°C or higher . The mist generator according to claim 1, wherein the mist generating unit includes a water temperature detection means for detecting the water temperature. The mist generator according to claim 1 or 2, wherein the mist generating unit generates mist from water whose temperature has been controlled by heating, or controls the temperature of mist generated from water by heating it. The mist generator according to any one of claims 1 to 3, wherein the mist generating unit controls the temperature of water heated to 60°C or higher and generates mist from the temperature-controlled water, or heats mist generated from water to 60°C or higher and controls the temperature of the heated mist. A mist generator as described in any one of claims 1 to 4, wherein the upper retention boundary surface of the retained mist is formed below a height position obtained by adding a height equivalent to the depth of the bathtub body to the height of the overflow surface of the bathtub body. The mist generator of claim 5, wherein the upper boundary of the retained mist is formed above the height of the overflow surface of the bathtub body. The mist generator described in claim 5 or 6, wherein the upper retention boundary surface of the retained mist is formed below a height position obtained by adding a value between 100 mm and 200 mm to the height of the overflow surface of the bathtub body. The mist generator according to any one of claims 1 to 7, wherein the mist supply unit is positioned above the water overflow area within the bathtub body. The mist generator according to claim 8, wherein the overflow portion of the water in the bathtub body is the overflow surface of the bathtub body. The mist generator according to any one of claims 1 to 9, further comprising a temperature detection means for detecting the temperature inside the bathroom in which the bathtub body is placed. A mist generator as described in any one of claims 1 to 10, wherein the mist supply unit has a mist supply port that opens downward. A bathtub device,
A mist generator according to any one of claims 1 to 11;
A bathtub apparatus comprising: a bathtub body that forms the retention space that receives the mist supplied from the mist supply unit of the mist generating device. The bathtub apparatus according to claim 12, wherein the mist generating unit and the mist supply unit are arranged on the short side of the bathtub body.