Mist generating device and mist generating system equipped with same

Abstract

To provide a mist generating device which can generate a mist efficiently and can accumulate the generated mist in a mist accumulation space in water section devices.SOLUTION: A mist generating device (1) for supplying a mist to water section devices includes: a mist generating device body (8); a water accumulation part (12) which is provided in the mist generating device body for accumulating water to be the mist; a water supply valve (30) for controlling the supply and stop of the water to the water accumulation part; an ultrasonic oscillator (18) which is provided in the water accumulation part and generates the mist by emitting ultrasonic waves to a water surface of the water accumulated in the water accumulation part; and a control part (26) for controlling the water supply valve and the ultrasonic oscillator. The control part controls the water supply valve so that a water level of the water accumulated in the water accumulation part is kept in a proper range.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a mist generator, and more particularly to a mist generator that supplies mist to plumbing equipment, and a mist generating system including the same. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2008-018130 (Patent Document 1) describes a bathtub sauna device in which mist is pumped into the bathtub body covered with a bathtub lid, creating a sauna space within the bathtub body, allowing users to enjoy a sauna bath inside the bathtub body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-018130 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the bathtub sauna device described in Patent Document 1 requires a bathtub lid to be placed on top of the bathtub body to create a sauna space inside the bathtub body, which restricts the user's position and prevents them from feeling fully comfortable. In other words, to retain mist inside the bathtub body without a bathtub lid, a large amount of mist must be pumped into the bathtub body. However, a mist generator that generates a large amount of mist would be very large and expensive.

[0005] Therefore, an object of the present invention is to provide a mist generating device that can efficiently generate mist and retain the generated mist in the mist retention space of a plumbing device, and a mist generating system equipped with the same. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a mist generating device that supplies mist to plumbing equipment, comprising a mist generating device main body, a water storage section provided within the mist generating device main body and storing water to be made into mist, a water supply valve that controls the supply and stop of water to the water storage section, an ultrasonic vibrator provided within the water storage section that irradiates ultrasonic waves toward the surface of the water stored in the water storage section to generate mist, and a control section that controls the water supply valve and the ultrasonic vibrator, wherein the control section controls the water supply valve so that the water level of the water stored in the water storage section is maintained within an appropriate range.

[0007] In the present invention configured as described above, a water storage section for storing water to be turned into mist is provided within the mist generator body, and an ultrasonic vibrator irradiates ultrasonic waves toward the surface of the stored water. This converts the water stored in the water storage section into mist, generating mist. While ultrasonic vibrators are widely used to generate mist, the inventors discovered that the amount of mist generated is strongly dependent on the distance between the ultrasonic vibrator and the water surface onto which the ultrasonic waves are irradiated. Specifically, it became clear that the amount of mist generated significantly decreases when the distance from the ultrasonic vibrator to the water surface deviates from the optimum value.

[0008] According to the present invention configured as described above, the control unit controls the water supply valve so that the water level in the water storage unit is maintained within an appropriate range, so the water level in the water storage unit is always maintained within an appropriate range, and the ultrasonic vibrator can efficiently generate mist. This makes it possible to generate a large amount of mist and supply it to plumbing equipment without using a large-scale device.

[0009] In the present invention, an overflow section is preferably provided within the mist generating device body, and the control section sets the water level in the water storage section to the overflow level by controlling the water supply valve so that water introduced through the water supply valve flows out from the overflow section.

[0010] The inventors of the present invention discovered that the optimum range of water levels in the water storage unit for efficient mist generation is very narrow. In contrast, water level sensors, such as float switches, commonly used in plumbing equipment have relatively low detection accuracy, and it became clear that such sensors cannot provide sufficient water level accuracy. According to the present invention configured as described above, the control unit controls the water supply valve so that the introduced water flows out of the overflow unit. This allows the water level in the water storage unit to be accurately set to the overflow level based on the height of the overflow unit, and the water level in the water storage unit can be reliably maintained within the optimum range.

[0011] In the present invention, preferably, the control unit maintains the water level in the water storage unit at the overflow level for a predetermined period of time by continuing to allow water to flow out of the overflow unit for a predetermined period of time while the ultrasonic vibrator is activated to generate mist within the mist generating device main body.

[0012] Even if the water level in the water storage section is initially set within the appropriate range, when mist is being generated, the water in the water storage section turns into mist, causing the water level to gradually drop and fall outside the appropriate range. According to the present invention configured as described above, the control section continues to cause water to flow out of the overflow section for a predetermined period while mist is being generated, so that the water level in the water storage section can be maintained within the appropriate range even when mist is being generated.

[0013] In the present invention, the control unit preferably opens the water supply valve when or before the ultrasonic vibrator is activated to allow water to flow out from the overflow portion.

[0014] When supplying mist to plumbing equipment, the mist generator must be started up so that a large amount of mist can be supplied quickly, since the supplied mist has not accumulated yet. According to the present invention configured as described above, the control unit causes water to flow out of the overflow section when or before the ultrasonic vibrator is started, so that the water level in the water reservoir is set to the appropriate level when mist supply begins, enabling a large amount of mist to be supplied at the start of supply.

[0015] In the present invention, the control unit is preferably configured to be able to perform overflow control, which continues to allow water to flow out of the overflow unit, and maintenance control, which maintains the water level in the water storage unit within a predetermined range below the overflow level, and the control unit performs overflow control for a predetermined period of time while the ultrasonic vibrator is operating, and then performs maintenance control.

[0016] According to the present invention configured in this manner, the control unit performs overflow control, which continues to allow water to flow out of the overflow section, for a predetermined period of time, and then performs maintenance control, which maintains the water level in the water storage section within a predetermined range.Therefore, overflow control is performed at the beginning of operation of the mist generating device, making it possible to generate a large amount of mist, while subsequent maintenance control can suppress the generation of wasted water.

[0017] In the present invention, it is preferable that the device further includes a water level sensor that detects the water level in the water storage section, and in maintenance control, when the water level sensor detects that the water level in the water storage section has dropped to a predetermined water level, the control section raises the water level in the water storage section by opening the water supply valve for a predetermined period of time.

[0018] According to the present invention configured as described above, for example, the rate of water level decline in the water storage section may decrease due to aging of the ultrasonic vibrator, and if the water level decline is estimated from the operating time of the ultrasonic vibrator, a discrepancy will occur between the actual water level and the estimated water level. On the other hand, if the water level after refilling is detected using a water level sensor, the set water level will be significantly off due to errors in the water level sensor. In contrast, with the present invention configured as described above, after a water level decline is detected, the water supply valve is opened for a predetermined time to raise the water level in the water storage section, thereby enabling relatively accurate detection of the lowered water level and relatively accurate setting of the water level after refilling. In other words, by setting the predetermined time for opening the water supply valve to the time it takes for the water level in the water storage section to rise to approximately the overflow level, variation in the water level after refilling can be sufficiently suppressed even if the accuracy of the water level sensor is insufficient.

[0019] In the present invention, the control unit is preferably configured to be able to set a preparation mode, and when the preparation mode is set, the control unit opens the water supply valve without operating the ultrasonic vibrator, thereby causing water to flow out of the overflow section and setting the water level in the water storage section to the overflow level.

[0020] According to the present invention configured in this manner, the control unit is configured to be able to set the preparation mode, so that the water level in the water storage unit can be set to the overflow level before the ultrasonic vibrator is activated, and a sufficient amount of mist can be generated immediately after the mist generating device is started.

[0021] The present invention also provides a mist generating system, characterized by comprising the mist generating device of the present invention and plumbing equipment having a mist retention space in which the mist ejected from the mist generating device is retained. [Effects of the Invention]

[0022] According to the mist generating device of the present invention and the mist generating system equipped with the same, mist can be generated efficiently and the generated mist can be retained in the mist retention space of the plumbing equipment. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view of a mist generating system in which a mist generating device according to a first embodiment of the present invention is applied to a bathtub apparatus, which is a plumbing device. [Figure 2] 1 is a side cross-sectional view of a mist generating system according to a first embodiment of the present invention. [Figure 3] 1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 4] 1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 5]1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 6] 1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 7] 1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 8] 1A and 1B are diagrams showing the state of the mist generator according to the first embodiment of the present invention from the start of mist ejection until the mist is retained in the entire mist retention space. [Figure 9] 3A and 3B are diagrams showing a method for measuring the temperature of the mist and the temperature in the room before the supply of the mist begins in the mist generator according to the first embodiment of the present invention. [Figure 10] 3A and 3B are diagrams showing a method for measuring the temperature of the mist and the temperature in the room before the supply of the mist begins in the mist generator according to the first embodiment of the present invention. [Figure 11] 3A and 3B are diagrams showing a method for measuring the temperature of the mist and the temperature in the room before the supply of the mist begins in the mist generator according to the first embodiment of the present invention. [Figure 12] FIG. 3 is a diagram showing an example of the measurement results of mist temperature by the mist generating device according to the first embodiment of the present invention. [Figure 13] FIG. 1 is a diagram showing the range of temperature difference between the temperature of mist supplied from the mist discharge passage to the mist accumulation space and the temperature in the room where the plumbing equipment is used before the supply of mist begins in the mist generating device according to the first embodiment of the present invention. [Figure 14] 1 is a schematic diagram of a mist particle size measuring device in a mist generating device according to a first embodiment of the present invention. [Figure 15] 1 is a schematic diagram of a particle size distribution measuring device in a mist generating device according to a first embodiment of the present invention. [Figure 16]2 shows an example of particle size distribution data measured by a particle size distribution measuring device in the mist generating device according to the first embodiment of the present invention. [Figure 17] 4 is a diagram illustrating the relationship between the difference in intensity and particle size in the mist generator according to the first embodiment of the present invention. FIG. [Figure 18] FIG. 1 is a diagram showing a box-shaped observation device for observing the state inside a virtual retention space in the mist generating device according to the first embodiment of the present invention. [Figure 19] FIG. 3 is a diagram showing a comparison of the state of mist in a virtual retention space for different combinations of temperature difference and Sauter mean particle diameter in the mist generator according to the first embodiment of the present invention. [Figure 20] 1 is a diagram showing a determination device for determining whether mist is accumulating in the mist accumulation space inside the bathtub main body in the mist generator according to the first embodiment of the present invention. FIG. [Figure 21] 1 is a vertical cross-sectional view of a mist generator main body and a mist discharge passage of a mist generator according to a first embodiment of the present invention. FIG. [Figure 22] 1 is a perspective cross-sectional view of a mist generator main body and a mist discharge passage of a mist generator according to a first embodiment of the present invention. FIG. [Figure 23] 1 is a perspective view of a main body of a mist generator according to a first embodiment of the present invention, with a mist discharge passage removed. FIG. [Figure 24] 1 is a perspective cross-sectional view showing the internal structure of a mist generator main body of a mist generator according to a first embodiment of the present invention. [Figure 25] 1 is a perspective cross-sectional view of a mist generator main body and a mist discharge passage of a mist generator according to a first embodiment of the present invention, viewed obliquely from below. FIG. [Figure 26] 5 is a flowchart showing a control procedure performed by a control unit in the mist generating device according to the first embodiment of the present invention. [Figure 27] 3A to 3C are diagrams showing the state inside the tank in chronological order in the mist generating device according to the first embodiment of the present invention. [Figure 28]FIG. 10 is a perspective view of a mist generating system including a mist generating device according to a second embodiment of the present invention. [Figure 29] FIG. 10 is a perspective view of a mist generating system including a mist generating device according to a third embodiment of the present invention. [Figure 30] FIG. 10 is a perspective view of a mist generating system including a mist generating device according to a fourth embodiment of the present invention. [Figure 31] FIG. 10 is a perspective view of a mist generating system including a mist generating device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, a mist generating device according to an embodiment of the present invention and a mist generating system including the same will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a mist generating system in which a mist generating device according to a first embodiment of the present invention is applied to a bathtub apparatus, which is a plumbing device, and Fig. 2 is a side cross-sectional view of the mist generating system according to the first embodiment of the present invention.

[0025] As shown in FIG. 1, a bathtub apparatus 2, a plumbing device incorporating a mist generator 1 according to a first embodiment of the present invention, is installed in a bathroom 3. The bathroom 3 is a box-shaped space that forms a somewhat sealed interior space 5 because water is used inside. The water includes water that is warmer than the outside air temperature (room temperature) and heated water (so-called hot water). An operating unit 28 for operating the mist generator 1 is installed in the bathroom 3. In this embodiment, the combination of the mist generator 1 and the bathtub apparatus 2 functions as a mist generating system.

[0026] The operating unit 28 can also control the water storage and temperature settings for the bathtub apparatus 2. The operating unit 28 may have an operating function for setting the temperature of the mist to be supplied, an operating function for setting the particle size of the mist to be supplied, and so on. The operating unit 28 may be installed outside the bathroom 3, or may be a remote control or other remote operating unit. The bathtub apparatus 2 is equipped with a water supply device 7 that supplies water. The bathtub apparatus 2 further includes a bathtub main body 6 that forms a mist retention space 4 that receives the mist supplied from the mist generating device 1. Examples of plumbing equipment to which the mist generating device 1 of this embodiment can be applied include bathrooms, toilets, washrooms, kitchens, and the like. In this case, the mist generating device 1 is installed to supply mist to the bathtub main body, bathroom wash area floor, shower room, hand-washing bowl, washbasin bowl, kitchen sink, and other plumbing equipment. The bathroom 3 is not limited to a room where only the bathtub main body 6 is installed, but may also include a toilet, hand-washing device, washbasin, or a combination thereof.

[0027] The bathtub body 6 forms a mist retention space 4 that is open upward toward the indoor space 5 in which the bathtub body 6 of the bathtub apparatus 2 is placed. The bathtub body 6 is a bathtub (hot tub) that is designed to store water in the internal mist retention space 4. The bathtub body 6 is formed in a rectangular shape 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.

[0028] The mist retention space 4 is a space formed in a roughly rectangular parallelepiped shape inside the bathtub main 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 mist retention space 4, allowing user A to bathe in a seated position. As will be described later, in FIG. 2, mist is retained above the water B in the mist retention space 4 (a mist retention layer C is formed). The mist retention space 4 extends up to the upper end 6a of the bathtub main body 6 and is open at the top. The mist generator 1 of this embodiment is configured to retain mist in the mist retention space 4 even when a bathtub lid covering the top surface of the mist retention space 4 is not placed on the bathtub main body 6.

[0029] It is also possible to retain only mist without storing water B in the mist retention space 4. The shape of the bathtub body 6 is not limited to the box-like shape shown 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 mist 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. Furthermore, the upper edge 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 upper edge of the bathtub body 6 may be shaped to extend diagonally upward or downward, to have a bow-like shape with a portion concave downward, or to form an approximately right angle in side view.

[0030] The mist generator 1 comprises a mist generator main body 8 in which mist is generated, and a mist discharge passage 10 that discharges the mist into a mist accumulation space in the bathtub main body 6, which is open at the top. Mist is generated from heated water inside the mist generator main body 8. The mist generator main body 8 is located on the short side portion 6e of the bathtub main body 6. A platform-like portion is formed on the top of the short side portion 6e on which the mist generator main body 8 is placed.

[0031] Inside the mist generator main body 8 is a tank 12, which serves as a water storage section for storing water to be made into mist. Connected to this tank 12 are a water supply channel 14, which supplies water from a water supply source, and a drain channel 16, which drains water from the tank 12 to a drain pipe. Inside the tank 12 are provided an ultrasonic vibrator 18, a heater 20, a float switch 21, which serves as a water level sensor, and a water temperature gauge 22, which serves as water temperature detection means. Furthermore, outside the tank 12 is provided an indoor temperature gauge 24, which serves as air temperature detection means. The ultrasonic vibrator 18 and heater 20 are controlled by a control unit 26.

[0032] A rectangular parallelepiped tank 12 is formed within the mist generator main body 8, and a water supply channel 14 and a drain channel 16 are connected to the side wall of the mist generator main body 8. A mist discharge passage 10 is also connected to the side wall of the mist generator main body 8. Furthermore, a water supply channel on / off valve 30 is provided in the water supply channel 14 to open and close the water supply channel 14. A drain channel on / off valve 32 is provided in the drain channel 16 to open and close the drain channel 16. The specific structure within the mist generator main body 8 will be described later.

[0033] The ultrasonic vibrator 18 is attached to the bottom surface of the tank 12 facing upward and is configured to irradiate ultrasonic waves toward the surface of the water stored in the tank 12. When ultrasonic waves are irradiated by the ultrasonic vibrator 18, a liquid column is formed on the water surface of the tank 12 vertically above the ultrasonic vibrator 18, and a mist (fog) of finely divided water with a predetermined particle size is generated around this liquid column. The ultrasonic vibrator 18 is electrically connected to the control unit 26, and the particle size of the generated mist can be changed by adjusting the ultrasonic oscillation output, frequency, etc. of the ultrasonic vibrator 18. In this embodiment, five ultrasonic vibrators 18 are arranged in a straight line inside the tank 12.

[0034] The control unit 26 is configured to heat the water in the tank 12 by passing an electric current through the heater 20, thereby controlling the temperature of the water in the tank 12 to a predetermined temperature. For example, the heater 20 can heat supplied water (e.g., room temperature of about 20°C) to 60°C or higher, which is above room temperature. Also, for example, the control unit 26 can control the temperature of water once heated to 60°C or higher by the heater 20 so that the temperature difference between the room temperature and the water temperature is a predetermined temperature. Thus, in the mist generator main body 8, the temperature of the water heated to 60°C or higher is controlled, and mist is generated from the temperature-controlled water. Note that the present invention can also be configured so that water heated to 60°C or higher in a water heater is supplied to the mist generator main body 8, and mist is generated from that water.

[0035] The control unit 26 heats the water in the tank 12 to a temperature above room temperature, generating mist that creates an updraft at a temperature above room temperature, and has the function of controlling the temperature of the mist so that the mist can easily stagnate depending on the particle size and other conditions of the mist. Since the water is heated to 60°C or above, it is also possible to take measures to suppress the growth of at least some bacteria (e.g., Legionella). The step of the heater 20 temporarily heating the water (or mist) to 60°C or above may be omitted, and instead of this step, other bacteria suppression means, such as a sterilization means using UV light or a sterilization means that adds a sterilizing agent, may be provided.

[0036] The present invention can also be configured such that the heater 20 is provided at a position higher than the water level in the tank 12 and the mist generated from the water is heated. In this case, the heater 20 can heat the mist generated from the water to 60°C or higher. Furthermore, for example, the control unit 26 can control the temperature of the mist heated by the heater 20 to 60°C or higher so that the temperature difference between the temperature of the mist and room temperature becomes a predetermined temperature.

[0037] 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 mist generator main body 8 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 the supply of mist begins (before the mist generator 1 is operated), the temperature of the air in the indoor space 5 and the temperature of the air in the mist retention space 4 are assumed to be approximately equal or relatively close to each other, so the control unit 26 can estimate the temperature of the air in the indoor space 5 measured by the indoor temperature measuring device 24 as the temperature of the air in the mist retention space 4.

[0038] The control unit 26 is also configured to control the water supply line opening / closing valve 30, which is a water supply valve, and the ultrasonic vibrator 18. The float switch 21 detects the water level in the tank 12, and when the water level in the tank 12 drops to a predetermined level, it detects this and outputs a detection signal to the control unit 26. Based on the detection signal from the float switch 21, the control unit 26 controls the water supply line opening / closing valve 30 so that the water level of the water stored in the tank 12 is maintained within an appropriate range. The control of the water supply line opening / closing valve 30 by the control unit 26 will be described later.

[0039] The control unit 26 has a built-in CPU, memory, etc., and generates mist based on a predetermined control program recorded in the memory, etc. The control unit 26 is electrically connected to the ultrasonic vibrator 18, heater 20, water temperature measuring instrument 22, indoor temperature measuring instrument 24, operation unit 28, etc. The control unit 26 is also electrically connected to and controls a water supply line opening / closing valve 30 provided in the water supply line 14 and a drainage line opening / closing valve 32 provided in the drainage line.

[0040] The mist discharge passage 10 discharges the mist generated by the mist generator main body 8 toward the room in which the bathtub main body 6 is located, allowing it to flow into the mist accumulation space 4 within the bathtub main body 6, which is open at the top. As shown by the cross-section of the flow path in Figure 2, the mist discharge passage 10 is a passage extending from the mist generator main body 8 to the upper part of one end of the mist accumulation space 4. The opening of the mist discharge passage 10 is formed in a horizontally elongated rectangular shape along the short side portion 6e of the bathtub main body 6. The opening is formed to have a width that spans almost the entire short side portion 6e. The mist discharge passage 10 is located above the water overflow portion 6c within the bathtub main body 6. In this embodiment, this overflow portion 6c is the overflow surface 6b of the bathtub main body 6. As a variant, the overflow portion 6c may be an overflow port provided within the bathtub main body 6.

[0041] The mist generator 1 is configured to supply mist at a flow rate of, for example, 0.03 mL / min to 1.5 mL / min to a 1 L (liter) mist retention space 4. For example, the mist generator 1 supplies mist at a flow rate of 11 mL / min to a bathtub main body 6 having a mist retention space 4 with a volume of 330 L. The flow rate (supply amount) of mist can be controlled by the number, output, and direction of ultrasonic wave irradiation of the ultrasonic vibrators 18, the water level in the tank 12, or the shape of the flow path in the mist generator main body 8 and the mist discharge passage 10, etc.

[0042] In the mist generator main body 8, heated mist is generated, and the temperature of the mist is controlled to make it easier for the mist to remain in the mist retention space 4. This will now be described. The mist generator 1 is configured so that the temperature difference between the mist supplied from the mist discharge passage 10 to the mist retention space 4 and the room temperature where the bathroom appliance is used before mist supply begins is 0°C or more, allowing the mist supplied from the mist discharge passage 10 to remain in the mist retention space 4 of the bathtub body 6. The mist generator 1 is also 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 discharged from the mist discharge passage 10, which corresponds to the particle size of the mist. This type of mist supply may be achieved without using the room temperature gauge 24 (i.e., without relying on the measurement results of the room temperature gauge 24) by presetting the temperature of the water supplied to the mist generator body 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 generator 1 is 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 generator 1 generates heated mist and controls the particle size of the mist, making it easier for the mist to remain in the mist retention space 4.

[0043] Next, the operation of the mist generating device according to the first embodiment of the present invention will be described with reference to FIGS. 3 to 8 are diagrams showing the state from when mist starts to be ejected until the mist accumulates throughout the mist accumulation space 4. The basic structure of the mist generating device 1 shown in Figures 3 to 8 is almost the same as the basic structure of the mist generating device 1 shown in Figure 2, so the same reference numerals as in Figure 2 will be used in the description of Figures 3 to 8.

[0044] As shown in Figure 2, in the standby state before the mist generator 1 starts operating, water at approximately 38°C is stored in the lower half of the mist 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 mist retention space 4 are approximately the same temperature. In addition, in the standby state, the water supply channel on-off valve 30 and the drain channel on-off valve 32 are closed, and there is no water in the tank 12. The ultrasonic vibrator 18 and heater 20 are stopped.

[0045] 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 measuring device 24 measures the air temperature in the indoor space 5, and the measured air temperature in the indoor space 5 is input to the control unit 26. The control unit 26 then opens the water supply line valve 30 to supply water from the water supply line 14 into the tank 12. The drainage line valve 32 remains closed. When a predetermined amount of water is stored in the tank 12, the water supply line valve 30 is closed. 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 is 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 discharge passage 10 to the mist retention space 4 and the temperature in the bathroom 3 before mist supply begins is 0°C or higher. Next, the control unit 26 activates the ultrasonic vibrator 18 to generate mist within the tank 12 .

[0046] FIG. 3 shows the state immediately after the supply of mist from the mist discharge passage 10 into the mist retention space 4 begins. The mist generated in the mist generator main body 8 is supplied from the mist discharge passage 10 to the mist retention space 4 in the bathtub main body 6. The mist naturally overflows from the mist discharge passage 10 and, as shown by arrow F1, is supplied into the mist 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 stirring, diffusing, or rising, within the mist retention space 4.

[0047] Figure 4 shows the state approximately several seconds after the start of mist supply. The supply of mist from the mist supply unit 10 to the retention space 4 continues. The supplied mist has begun to accumulate above the surface of the water B and in a lower part of the retention space 4. The force of the updraft trying to raise the mist does not exceed the weight of the mist supplied from the mist supply unit 10, making it easier for the mist to accumulate in the retention space 4. Therefore, the mist accumulates in a relatively low part of the retention space 4. The mist is gradually supplied and added from the mist supply unit 10 side, and gradually moves from the mist supply unit 10 side toward the opposite short side above the water surface or bottom of the retention space 4.

[0048] 5 shows a state in which the mist has reached the opposite short side of the bathtub main body 6 from the state in FIG. 4. The supply of mist from the mist supply unit 10 to the retention space 4 continues.

[0049] FIG. 6 shows the state after about 10 seconds have passed since the start of mist supply. As shown in Figure 6, after the rising cloud R (for example, a collection of mist of a predetermined density that rises beyond the overflow surface 6b, which is the upper edge of the bathtub main body 6) rises to a height within a range of approximately 5 cm to approximately 30 cm above the overflow surface 6b, some of the mist floats or dissipates, while the force of gravity on the majority of the mist becomes greater than the force exerted on the mist from the rising air current, and the mist gradually descends again toward the retention space 4 within the bathtub main body 6, and some of the mist evaporates and disappears during its movement.

[0050] As shown in Figure 7, more mist is supplied into the retention space 4 than in the state shown in Figure 6, and the mist descending from the rising cloud R returns to and remains in the retention space 4. Note that the mist device 1 may also form a mist retention layer C without forming a rising cloud of mist.

[0051] FIG. 8 shows the state after about 20 seconds have passed since the start of mist supply. Mist continues to be supplied from the mist discharge passage 10 to the mist retention space 4, and the mist supplied into the mist retention space 4 accumulates up to a portion close to the top of the mist retention space 4 (the upper end 6a of the bathtub main body 6). The mist mainly accumulates in the mist retention space 4 in an area above the water surface of the water B and below the top of the mist retention space 4. The mist either falls into the water B and is absorbed, or forms droplets that adhere to the wall of the bathtub main body 6 and disappear, or diffuses beyond the edge of the upper end 6a of the bathtub main body 6. The time it takes for the mist to disappear varies depending on the particle size of the mist. While the mist disappears or diffuses in this way, new mist is supplied before it disappears or diffuses, forming a mist retention layer in the retention space 4. In other words, the mist flows slowly within the mist retention space 4 but does not diffuse from the mist retention space 4, forming a stable retention layer C. The retention layer C is formed above the water surface of water B when mist of a certain density or higher exists within a unit space. 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. Due to the presence of the retention layer, it appears as if the mist is filled up to the top of the mist retention space 4.

[0052] The retention boundary surface 66 on the upper side of the retained mist is formed below height position M1 (Figure 2), which is the height of the overflow surface 6b of the bathtub body 6 (height position M0 (Figure 2)) 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 is present in the air at a concentration above a certain level, and air layer J, where the mist is present in the air at a concentration below a certain level. Because the mist moves to some extent while retaining its position, 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.

[0053] 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 (Figure 2)) that is 100 mm to 200 mm higher than the height of the overflow surface 6b of the bathtub main body 6 (height position M0). When 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 position above the bathtub, that is, the warm bathing effect up to a height higher than the bathtub. While the mist generator 1 is operating (in use), mist is supplied into the bathtub main body 6 and the mist continues to accumulate. The mist generating device 1 is 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.

[0054] Next, with reference to Figures 9 to 11, we will explain how to measure the temperature of the mist supplied from the mist discharge passage 10 to the mist retention space 4, and the temperature of the room in which the bathtub apparatus 2 is used before the supply of mist begins. 9 to 11 are diagrams showing methods for measuring the temperature of the mist and the temperature inside the room before the supply of the mist begins.

[0055] The temperature of the mist supplied from the mist discharge passage 10 to the mist retention space 4 is measured using 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 mist 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.

[0056] The virtual retention space 34 is formed to mimic the shape of the actual mist retention space 4 while being smaller in 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 sink in the case of a washbasin, or a kitchen sink in the case of a kitchen. The virtual retention space 34 is, for example, a rectangle with short sides of 120 mm and long sides of 300 mm when viewed from above, and a cuboid 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-sensing element 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.

[0057] 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 φ4.5 mm x 50 mm. 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 (measurement method) is performed, no air conditioning or other ventilation that would create airflow in the room is supplied.

[0058] Next, FIG. 12 shows an example of the measurement results of the mist temperature. In Fig. 12, the vertical axis represents the temperature (mist atmosphere temperature) [°C] measured by the K-type thermocouple 36 in the virtual retention space 34, and the horizontal axis represents the elapsed time [s] from the start of measurement. As shown in Fig. 12, the temperature measured by the K-type thermocouple 36 begins to rise when the mist generator 1 of this embodiment starts to supply mist into the virtual retention space 34 of the box-shaped device 35, and after a sufficient amount of time (e.g., 2500 [s]) it becomes an approximately constant value. In this embodiment, the mist atmosphere temperature T1 (43°C in the example of Fig. 12), which is the highest temperature when the measured temperature stops increasing, is defined as the temperature of the mist supplied from the mist generator 1 to the mist retention space 4.

[0059] In the example of measuring mist ambient temperature shown in FIG. 12, the room temperature at the start is T0 = -5°C, and the initial temperature of the mist generated in the mist generator main body 8 is 60°C. The temperature of the mist supplied from the mist discharge passage 10 to the mist retention space 34 is slightly reduced, and this temperature is measured as the mist ambient temperature. After mist supply begins, the temperature in the virtual retention space 34 increases over time, and the temperature increase converges to a substantially constant value T1. If mist supply from the mist generator 1 continues, the value to which the temperature measured in the virtual retention space 34 converges will be the temperature of the mist supplied from the mist discharge passage 10 to the virtual retention space 34. Therefore, it is assumed that the temperature of the mist actually supplied from the mist discharge passage 10 to the mist retention space 4 will be the temperature of the mist measured in the virtual retention space 34 (mist ambient temperature).

[0060] Next, a method for measuring the temperature in a room where the plumbing equipment is used before mist supply begins will be described. The temperature in the room where the plumbing equipment is used before mist supply begins is measured by a room temperature K thermocouple 50 (FIGS. 9 to 11) located outside the virtual retention space 34 in the room where the plumbing equipment is used. The room temperature K thermocouple 50 outside the virtual retention space 34 is located in the same room space as the box-shaped device 35 and simulates the room temperature measuring device 24. Therefore, the temperature measured by the room temperature K thermocouple 50 corresponds to the room temperature measured by the room 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 room 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 side wall in the direction along the short side and 150 mm inward from the side wall at one end of the virtual retention space 34 in the direction along the long side, as viewed from above. The room temperature K thermocouple 50 is fixed outside the virtual retention space 34 by a support portion 38 extending outside the virtual retention space 34. The temperature of the room where the plumbing appliance 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 in the virtual retention space. The room temperature K thermocouple 50 is not limited to this location, and may be placed in a position outside and near the mist generator main body 8. Furthermore, since the room temperature K thermocouple 50 only needs to measure the temperature of the room where the plumbing appliance is used before mist supply begins, the K thermocouple 36 placed inside the virtual retention space 34 may measure the air temperature in the virtual retention space 34 before mist supply begins.

[0061] 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 discharge passage 10 to the mist 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 discharge passage 10 to the mist retention space 4 can be determined based on the temperature of the room where the plumbing equipment is used before the mist is supplied. 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 is supplied.

[0062] In FIG. 13, the vertical axis represents the mist temperature (°C), and the horizontal axis represents the room temperature (°C). Furthermore, line C1 in FIG. 13 is the line where the temperature difference between the mist temperature and the room temperature is 0°C. Therefore, the area above line C1 is the range where the temperature difference is 0°C or more. Furthermore, line C2 is the line where the temperature difference between the mist temperature and the room temperature is 100°C. The mist generator 1 is configured to achieve a temperature difference between 0°C and 100°C. By being able to set a relatively high mist temperature, where the temperature difference is up to 100°C, the cleaning properties of the mist and its ability to easily remove dirt 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 (for example, 100°C), it changes into water vapor and the mist droplets disappear, so the temperature of the mist supplied from the mist discharge passage 10 is kept below 100°C (shown by the area below line C5).

[0063] Furthermore, the mist generator 1 is 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 the plumbing equipment.

[0064] Furthermore, the mist generator main body 8 and mist discharge passage 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.

[0065] Also, in Figure 13, if the mist temperature is set to 35 degrees or higher (shown by line D1) and 45 degrees or lower (shown 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.

[0066] Next, a device and method for measuring the particle size of the mist supplied from the mist discharge passage 10 will be described with reference to FIGS. Figure 14 is a schematic diagram of a mist particle size measuring device. As shown in Figure 14, mist particle size measuring device 37 includes a box-shaped device 39 that sets up virtual retention space 34 of the same size and shape as described above, and a particle size distribution measuring device 53. A 20 mm x 20 mm square opening 52 is formed in the side wall of this box-shaped device 39, i.e., near the center of the side wall of virtual retention space 34, and a lid 55 is attached to this opening 52.

[0067] 15, the particle size distribution measuring device 53 includes a particle size measuring laser 54, and the particle size measuring laser 54 is arranged so that a measurement region E of the particle size measuring laser is located near and in front of the opening 52. The particle size measuring laser 54 is arranged so that the laser light of the particle size measuring laser 54 is parallel to the long side of the virtual retention space 34 in a top view. 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 away from the opening 52. The particle size distribution measuring device 53 includes a measurement lens 56, and the measurement lens 56 is configured to detect diffracted and scattered light of the laser light.

[0068] First, with the lid 55 attached to the opening 52, mist is started to be supplied into the virtual retention space 34. The mist supply port from the mist discharge passage 10 is not shown. One minute after the start of mist supply, the lid 55 is opened, and the mist is allowed 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 when the transmittance of the particle size measurement laser 54 is 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 Corporation. Particle size distribution data is measured 10 times and recorded on a PC. The 10 particle size distribution data are averaged on the PC.

[0069] FIG. 16 shows an example of particle size distribution data measured by the particle size distribution measuring device 53. In FIG. 16, the left vertical axis shows frequency [%], the right vertical axis shows cumulative [%], and the horizontal axis shows particle size [μm]. For example, a 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 the 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.

[0070] The mist generator 1 is configured so that the particle size of the majority of the mist supplied from the mist discharge passage 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.

[0071] The mist generator 1 is configured so that the particle size of the majority of the mist supplied from the mist discharge passage 10 is 3.6 μm or more and 20 μm or less. To minimize the effects on measurement of a small number of large-sized particles and small-sized 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.

[0072] The mist generator 1 is configured so that the particle size of the majority of the mist supplied from the mist discharge passage 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.

[0073] 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]. In Figure 17, the preferable ranges for particle size and temperature difference ΔT are indicated by dotted regions. The mist generator 1 can set a predetermined temperature difference between the mist temperature and the room temperature in a range of 0°C to 100°C. As mentioned above, the temperature difference can be changed to a range of 0°C to 60°C, 0°C to 45°C, etc.

[0074] The mist generator 1 is 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 can be calculated as 45.3 mm / s using the following formula. 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=9.8m / s2 , μ=1.8X10-5N·sec / m 2 (15℃) V(∞)=(2ρgr 2 ) / (9μ)=1.2×10 8 r 2 The terminal velocity v(∞) is proportional to the square of the radius of the water droplet. Note that this formula is applicable in the range of Re<1, i.e., r<0.1mm.

[0075] 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 mist retention space in approximately 10 seconds (for example, the distance from the mist discharge passage 10 to the bottom of the mist retention space 4 is 45 cm) and disappears. In other words, the mist will remain for at least 10 seconds from the time the mist is supplied until it disappears. If the mist remains for approximately 10 seconds in this way, 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 larger than 40 μm, the average time until the mist disappears becomes shorter, making it less likely that a mist retention layer will form due to the disappearance of the mist.

[0076] The mist generator 1 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 particle size of the mist 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 mist retention space 4, further reducing the proportion of mist that falls to the bottom of the mist retention space 4 relatively quickly.

[0077] The mist generator 1 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 particle size of the mist 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 mist retention space 4. This allows the mist to remain in the mist retention space 4 for a longer period of time, and further reduces the proportion of mist that falls to the bottom of the mist retention space 4 relatively quickly.

[0078] The mist generator 1 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 discharge passage 10 that is not retained in the mist retention space 4 and diffuses outside the mist retention space 4, while increasing the proportion of mist that is retained in the mist retention space 4, allowing the mist to be retained efficiently in the mist retention space 4.

[0079] The mist generator 1 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 can further reduce the proportion of mist that diffuses outside the mist retention space 4 without being retained within the mist retention space 4, and further increase the proportion of mist that is retained within the mist retention space 4, allowing the mist to be retained within the mist retention space 4 more efficiently.

[0080] The mist generator 1 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 that diffuses outside the mist retention space 4 without being retained within the mist retention space 4, and further increases the proportion of mist that is retained within the mist retention space 4, allowing the mist to be retained within the mist retention space 4 more efficiently.

[0081] Next, the relationship between the temperature difference, particle size, and the state of mist in 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 in the virtual retention space. Figure 19 shows a comparison of the state of mist in the virtual retention space 58 for nine combinations of temperature difference and Sauter mean particle size.

[0082] As shown in FIG. 19, the state of mist in a virtual retention space 58 can be measured using a box-shaped observation device 55 that corresponds to the shape of an assumed plumbing device. The box-shaped observation device 55 is equipped with a virtual retention space 58 that simulates the shape of the mist retention space of an assumed plumbing device, and a camera 62 that observes and records the state of mist in the virtual retention space 58. As shown in FIG. 18, the virtual retention space 58 of the box-shaped observation device 55 has short sides of 120 mm, long sides of 300 mm, and a height of 240 mm. The virtual retention space 58 does not have a ceiling surface and is open upward. 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 having a width of 70 mm and a height of 40 mm 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 discharge passage 10.

[0083] Figure 19 shows a comparison of nine patterns of stagnation states, taken by camera 62, when mist with a predetermined particle size and temperature difference is supplied from the mist discharge passage 10. In 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 discharge passage 10, and the horizontal axis indicates the temperature difference ΔT between the temperature of the mist and the temperature inside the room.

[0084] Pattern example A in Figure 19 shows the state of mist 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 starts 15°C). In pattern example A, the mist supplied from the mist discharge passage 10 falls to the bottom and disappears relatively quickly within virtual retention space 58, so the mist does not remain within virtual retention space 58. This photograph was taken two minutes after the start of mist supply. Therefore, in pattern example A, a mist retention layer C that forms a retention boundary surface 66 on the upper surface is not formed within virtual retention space 58.

[0085] 19 shows the state of the mist when the Sauter mean particle size of the mist is 50 μm to 60 μm and the temperature difference is 25° C. (mist temperature is 40° C. and the room temperature before the mist supply starts is 15° C.) In pattern example B, the mist supplied from the mist discharge passage 10 falls relatively quickly toward the bottom within the virtual retention space 58 and disappears, so the mist does not remain within the virtual retention space 58.

[0086] 19 shows the state of the mist 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.) In pattern example C, the mist supplied from the mist discharge passage 10 also falls relatively quickly toward the bottom within the virtual retention space 58 and disappears, so the mist does not remain within the virtual retention space 58.

[0087] Pattern example D in Figure 19 shows the state of mist 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 starts 15°C). In pattern example D, the mist supplied from the mist discharge passage 10 forms a stagnation layer C in the virtual stagnation 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. On the other hand, the updraft caused by the temperature difference is also small. As a result, the mist stagnates and forms a stagnation layer in the virtual stagnation space 58, forming a stagnation boundary surface 66 on its upper surface.

[0088] Pattern example E in Figure 19 shows the state of mist when the Sauter mean particle diameter 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). In pattern example E, mist supplied from the mist discharge passage 10 forms a highly concentrated stagnation layer C in the virtual retention space 58. Because the mist particle diameter 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, but the fall of the mist is suppressed, causing the mist to remain stagnate for a relatively long time. Therefore, a stagnation layer C of mist is formed in the virtual retention space 58, forming a stagnation boundary surface 66 on its upper surface.

[0089] Pattern example F in Figure 19 shows the state of mist when the Sauter mean particle diameter 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). In pattern example F, the mist supplied from the mist supply unit forms a highly concentrated stagnation layer C in the virtual retention space 58. Because the mist particle diameter 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 the mist continues to be maintained. Therefore, a mist stagnation layer is formed in the virtual retention space 58, forming a retention boundary surface 66 on the 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 area of the virtual retention space 58, it is considered that the retention boundary surface 66 is formed.

[0090] Pattern example G in Figure 19 shows the state of mist 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). In pattern example G, the mist supplied from the mist discharge passage 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 fall speed is even slower. Therefore, the mist is lighter 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.

[0091] Pattern example H in Figure 19 shows the state of mist 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). In pattern example G, the mist supplied from the mist discharge passage 10 diffuses in a floating manner 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 stronger updraft. Therefore, a mist stagnation layer C that forms a retention boundary surface 66 on its upper surface is not formed within the virtual retention space 58.

[0092] Pattern example I in Figure 19 shows the state of mist 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). In pattern example I, the mist supplied from the mist discharge passage 10 diffuses in a floating manner 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.

[0093] 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 such that a stagnant boundary surface 66 has been formed) in the mist stagnant space 4 (or virtual stagnant space, etc.) within the bathtub body 6.

[0094] As shown in Figure 20, the internal transmittance measured inside the mist retention space 4 in the bathtub body 6 using a transmittance measuring device 68 is compared with the external transmittance measured outside the mist retention space 4. If the internal transmittance is lower than the external transmittance, it can be determined that mist is retained inside the mist retention space 4. More specifically, if the internal transmittance / external transmittance is less than 1, it can be determined that mist is retained inside the mist retention space 4.

[0095] 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 mist 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 horizontally at a position 150 mm below the upper end of the mist retention space 4 (for example, a depth position that is approximately 30% of the depth of the mist retention space 4). The first laser device 70 and the first transmittance measuring device 72 are disposed near the center of the mist retention space 4 when viewed from above. The transmittance is measured by measuring the intensity of the laser light measured by the first transmittance measuring device 72 relative to the intensity of the laser light emitted from the first laser device 70.

[0096] The transmittance measuring device 68 further includes a second laser device 74 disposed outside the mist 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 apart horizontally at a position 150 mm above the upper end of the mist retention space 4 (for example, relative to the upper end of the mist retention space 4, a position symmetrical to the first laser device 70 and first transmittance measuring device 72). The first laser device 70 and the first transmittance measuring device 72 are disposed near the center of the mist retention space 4 when viewed from above. 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. The transmittance measuring device 68 has a first laser device 70 and a first transmittance measuring device 72 arranged inside the mist retention space 4, but these devices may also be arranged in a virtual retention space such as the one described above instead of the mist retention space 4 to virtually measure the predicted transmittance. In this case, a second laser device 74 and a second transmittance measuring device 76 are arranged outside the virtual retention space.

[0097] More specifically, the device configuration involves oscillating laser light emitted from a Keyence digital fiber amplifier FS-N11MN through a Keyence FU-77TZ (first laser device 70 or second laser device 74) and receiving it at 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.

[0098] For example, as shown in pattern example E in Fig. 19, when mist is retained inside the mist retention space 4, the internal transmittance decreases. On the other hand, the mist is mainly retained inside the mist 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 mist retention space 4.

[0099] 19, when the mist does not accumulate inside the mist accumulation 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 is 1, and it is not determined that the mist is accumulating inside the mist accumulation space 4.

[0100] As shown in pattern example I in Figure 19, when mist diffuses from inside the mist retention space 4 to the outside, it is thought that both the internal transmittance and the external transmittance will have similar values with slightly low transmittance. Therefore, internal transmittance / external transmittance = 1, and it is not determined that mist is retained inside the mist retention space 4.

[0101] Next, with reference to Figs. 21 to 25, the specific structures of the mist generator main body 8 and the mist discharge passage 10 of the mist generator 1 according to the first embodiment of the present invention will be described. Figure 21 is a vertical cross-sectional view of the mist generator main body 8 and mist discharge passage 10 of the mist generator 1 according to this embodiment. Figure 22 is a perspective cross-sectional view of the mist generator main body 8 and mist discharge passage 10. Figure 23 is a perspective view of the mist generator main body 8 with the mist discharge passage 10 removed. Figure 24 is a perspective cross-sectional view showing the internal structure of the mist generator main body 8. Figure 25 is a perspective cross-sectional view of the mist generator main body 8 and mist discharge passage 10 as viewed obliquely from below.

[0102] As shown in Figures 21 and 22, the mist generator main body 8 of the mist generator 1 is formed in a roughly rectangular box shape, with the water to be turned into mist stored in its lower part, forming a water storage section called tank 12. A recess 12a is provided in the bottom of tank 12, and an ultrasonic vibrator 18 is attached to the bottom surface of this recess 12a, facing vertically upward. With this structure, the ultrasonic vibrator 18 irradiates ultrasonic waves toward the water surface W of the water stored in tank 12, forming a liquid column LC above the water surface W vertically above the ultrasonic vibrator 18. In this way, the irradiation of ultrasonic waves forms a liquid column LC above the water surface W of the tank 12, and mist is generated around this liquid column LC in the internal space of the mist generator main body 8.

[0103] As shown in FIG. 24, five recesses 12a are arranged in the longitudinal direction of the mist generator main body 8 at the bottom of the tank 12, and an ultrasonic vibrator 18 is provided at the bottom of each recess 12a. That is, the five ultrasonic vibrators 18 are arranged in a straight line at the bottom of the mist generator main body 8. Furthermore, partition walls 8b extending in the short side direction are provided between each recess 12a (ultrasonic vibrators 18) to separate the interior of the mist generator main body 8. Furthermore, a heater 20 is arranged at the bottom of the tank 12 so as to extend in the longitudinal direction of the mist generator main body 8. This heater 20 is arranged so as to extend parallel to the arrangement direction of the five ultrasonic vibrators 18. When the mist generator 1 is operating, the heater 20 heats the water in the tank 12 to a predetermined temperature.

[0104] Furthermore, as shown in Figure 21, an opening is provided at the top of one side of the mist generator main body 8, and a mist discharge passage 10 is attached to cover this opening. The mist discharge passage 10 is attached to one side of the mist generator main body 8 and is a duct with a roughly rectangular cross section that extends vertically downward from the mist generator main body 8. The upper end of the mist discharge passage 10 communicates with the interior of the mist generator main body 8 at the side, and a mist discharge outlet 10a facing vertically downward is provided at the lower end. As a result, mist generated in the internal space of the mist generator main body 8 flows into the mist discharge passage 10 and is discharged from the mist discharge outlet 10a at the lower end of the mist discharge passage 10.

[0105] Meanwhile, an intake passage 8e is provided at the upper end of the mist generator main body 8, on the opposite side from the mist discharge passage 10. This intake passage 8e is formed on the top surface of the mist generator main body 8 and opens vertically upward. That is, the interior space of the mist generator main body 8 is connected to the outside air via the intake passage 8e. The intake passage 8e is also provided on the top surface of the mist generator main body 8, and a ceiling surface 8a is formed vertically above the ultrasonic vibrator 18. This ceiling surface 8a is inclined so that it is higher on the side of the mist generator main body 8 facing the mist discharge passage 10 and lower on the side facing the intake passage 8e. That is, the ceiling surface 8a is inclined in the portion vertically above the ultrasonic vibrator 18 where the liquid column LC is formed, but is generally horizontal near the mist discharge passage 10. Due to the inclination of this ceiling surface 8a, the mist generated within the mist generator main body 8 is guided toward the mist discharge passage 10.

[0106] Furthermore, a step is provided between the inclined portion of the ceiling surface 8a and the generally horizontal portion, and this step constitutes a damming portion 8c. That is, when the liquid column LC formed on the water surface W or droplets LD separated from the liquid column LC hit the inclined ceiling surface 8a and cause water droplets to adhere to the ceiling surface 8a, the damming portion 8c prevents the adhered water droplets from flowing toward the mist discharge passage 10 (shown by imaginary lines in FIG. 21).

[0107] Furthermore, as shown in Fig. 25, a generally dome-shaped guide wall 8d is provided on the ceiling surface 8a adjacent to the blocking portion 8c. The guide wall 8d is configured with a dome shape that is higher in the center and is provided above each ultrasonic transducer 18. That is, the water blocked by the blocking portion 8c flows left and right along the guide wall 8d, then flows along the inner wall surface of the mist generator main body 8 and the partition wall 8b (Fig. 24) into the tank 12 (shown by imaginary lines in Fig. 25). The water that flows down from the blocking portion 8c along the partition wall 8b flows down between the ultrasonic transducers 18, preventing the flowing water from interfering with the formation of the liquid column LC.

[0108] Next, as shown in Figures 23 and 24, a water supply section 9 and a drainage section 11 are provided at one end of the mist generator main body 8. The water supply section 9 has a water supply channel connection section 9a to which a water supply channel 14 (Figure 2) is connected, and a water supply chamber 9b into which water supplied from this water supply channel connection section 9a flows. Water that flows into the water supply chamber 9b flows into a tank 12 inside the mist generator main body 8, and as shown in Figure 24, the water supply chamber 9b and the tank 12 are connected through a communication passage 9c below a partition wall 8b provided adjacent to the water supply chamber 9b.

[0109] Because the lower end of partition wall 8b is located below the water surface W of tank 12, communicating passage 9c is always submerged while mist generator 1 is in operation. That is, water supply chamber 9b of water supply unit 9 is in communication with the inside of tank 12 through communicating passage 9c below the water surface W of tank 12. In this way, water supply unit 9 is in communication with the inside of tank 12 through communicating passage 9c below the water surface W of tank 12. For this reason, when water flows into water supply chamber 9b from water supply channel connection portion 9a, rippling of the water surface W in tank 12 can be suppressed.

[0110] Furthermore, as shown in Figures 23 and 24, the drainage unit 11 has a drainage channel connection portion 11a connected to the drainage channel 16 (Figure 2), a drainage chamber 11b provided adjacent to this drainage channel connection portion 11a, and an overflow portion 11c provided between the drainage channel connection portion 11a and the drainage chamber 11b. The drainage chamber 11b is connected to the inside of the tank 12 through a passage (not shown) below the water level W. The overflow portion 11c is a weir extending horizontally to separate the drainage chamber 11b and the drainage channel connection portion 11a. When the water level in the drainage chamber 11b exceeds the height of the overflow portion 11c, the water in the drainage chamber 11b is discharged to the drainage channel connection portion 11a. Furthermore, since the tank 12 and the drainage chamber 11b are connected by a passage below the water level W, the maximum water level in the tank 12 is determined by the height of the overflow portion 11c.

[0111] Next, the control of the water supply passage opening / closing valve 30 by the control unit 26 will be described with reference to FIGS. Fig. 26 is a flowchart showing the control procedure of the water supply passage opening / closing valve 30 and the like by the control unit 26. Fig. 27 is a diagram showing the state inside the tank 12 in chronological order. The flowchart shown in Fig. 26 is executed by the control unit 26 when the mist generator 1 of this embodiment is started up.

[0112] First, when a user operates the start switch (not shown) of the operation unit 28 (Fig. 1), the processing of the flowchart shown in Fig. 26 is started, and step S1 is executed. In step S1, the control unit 26 sends a control signal to the water supply line on-off valve 30 (Fig. 2), causing it to open. When the water supply line on-off valve 30 is opened, water that has passed through the water supply line on-off valve 30 flows into the tank 12, as shown in column A of Fig. 27. A constant flow valve (not shown) is provided upstream of the water supply line on-off valve 30, and the flow rate (L / min) of water flowing into the tank 12 via the water supply line on-off valve 30 is adjusted to a predetermined flow rate. As water flows into the tank 12, the water level in the tank 12 rises.

[0113] Next, in step S2, it is determined whether the float switch 21 (FIG. 2) has detected the first water level TL1. The processing of step S2 is repeatedly executed until the float switch 21 detects the first water level TL1. As shown in column B of FIG. 27, when the water level in the tank 12 rises and the float switch 21 detects the first water level TL1, the processing in the flowchart shown in FIG. 26 proceeds to step S3.

[0114] In step S3, the control unit 26 starts energizing the heater 20 (Fig. 24). That is, the first water level TL1 is set to a water level at which the heater 20, which is located at the bottom of the tank 12, is fully immersed in the water accumulated in the tank 12, thereby preventing the heater 20 from running dry. If the supply of water continues after the float switch 21 detects the first water level TL1, the float switch 21 will detect a second water level TL2 (column B in Fig. 27) that is higher than the first water level TL1.

[0115] In step S4, it is determined whether a first predetermined time has elapsed since the float switch 21 detected the second water level TL2. The process of step S4 is repeatedly executed until the first predetermined time has elapsed since the float switch 21 detected the second water level TL2. This first predetermined time is set so that the water level in the tank 12 exceeds the overflow level determined by the height of the overflow portion 11c (FIG. 24) before the first predetermined time has elapsed after the float switch 21 detected the second water level TL2. That is, the water level in the tank 12 exceeds the height of the overflow portion 11c and overflows, as shown in column C of FIG. 27, before the first predetermined time has elapsed, and water is discharged from the drainage channel connection portion 11a. For example, it is preferable to set the second water level TL2 and the water flow rate so that the first predetermined time is approximately 10 seconds.

[0116] When the first predetermined time has elapsed after the float switch 21 detects the second water level TL2, step S5 is executed. In step S5, the control unit 26 sends a control signal to the water supply line on-off valve 30 to close it. This sets the water level in the tank 12 to the overflow level determined by the height of the overflow section 11c. The height of the water surface W at this overflow level corresponds to the appropriate water level at which mist can be generated most efficiently when the ultrasonic vibrator 18 is activated.

[0117] In this embodiment, the water supply line on-off valve 30 is controlled so as to close when a first predetermined time has elapsed after the float switch 21 detects the second water level TL2. In contrast, as a modified example, the present invention can also be configured so that the water supply line on-off valve 30 closes when a predetermined time has elapsed after the float switch 21 detects the first water level TL1. In this case, the predetermined time until the water supply line on-off valve 30 is closed is set longer than the first predetermined time, so that the water level in the tank 12 exceeds the overflow water level.

[0118] Next, in step S6, it is determined whether the water temperature in the tank 12 has reached a predetermined temperature (e.g., 60°C). That is, the control unit 26 determines whether the water temperature in the tank 12 has reached the predetermined temperature based on the detection signal from the water temperature measuring device 22 (Fig. 2). The processing of step S6 is repeatedly executed until the water temperature in the tank 12 reaches the predetermined temperature, and once the predetermined temperature is reached, the processing in the flowchart proceeds to step S7 (row D in Fig. 27). Thereafter, the control unit 26 controls the heater 20 so that the water temperature in the tank 12 is always maintained near the predetermined temperature while mist is being generated.

[0119] When the water temperature in the tank 12 reaches a predetermined temperature, the control unit 26 executes step S7 to activate the ultrasonic vibrator 18 and begin generating mist. Next, in step S8, the control unit 26 sends a signal to the water supply line on-off valve 30 to open it. The control unit 26 then executes overflow control from step S7 onward, allowing water to continue flowing out over the overflow section 11c. That is, when the ultrasonic vibrator 18 is activated in step S7, mist is generated, and the water in the tank 12 begins to decrease. Immediately after, or simultaneously with, this, the control unit 26 opens the water supply line on-off valve 30 to allow water to flow into the tank 12. Because the flow rate of water flowing in due to the opening of the water supply line on-off valve 30 is greater than the amount of water lost due to the water being converted into mist, the water in the tank 12 continues to flow out of the drainage line connection section 11a over the overflow section 11c during overflow control (see column E in FIG. 27 ).

[0120] During overflow control, the water in the tank 12 continues to overflow beyond the overflow portion 11c, maintaining the water level in the tank 12 precisely at the overflow level (the height of the overflow portion 11c). This maintains the water level in the tank 12 precisely at the appropriate overflow level for mist generation during overflow control, enabling the mist generator body 8 to generate mist most efficiently. Therefore, the mist generator 1 can generate mist at a high flow rate immediately after startup, quickly filling the mist retention space 4 in the bathtub body 6 where mist had not previously accumulated. Alternatively, overflow control can be initiated by opening the water supply line valve 30 immediately before starting the ultrasonic vibrator 18. Furthermore, the present invention can be configured such that overflow from the overflow portion 11c is essentially continuous during overflow control by controlling the water supply line valve 30 to repeatedly open and close in short bursts (e.g., every few seconds).

[0121] Next, in step S9, it is determined whether a second predetermined time has elapsed since the ultrasonic vibrator 18 was activated in step S7 and mist generation began, i.e., whether the second predetermined time has elapsed since overflow control began. If the second predetermined time has not elapsed, the process of step S9 is repeated and overflow control continues. For example, the second predetermined time can be set to approximately 3 minutes. This second predetermined time is preferably set to a time sufficient to fill the mist retention space 4 (inside the bathtub body 6 in this embodiment) with mist after the mist generator 1 is activated.

[0122] When the second predetermined time has elapsed, the process in the flowchart proceeds to step S10, and maintenance control is executed from step S10 onwards. In the maintenance control, the water level in the tank 12 is maintained within a predetermined range below the overflow level. In step S10, the control unit 26 sends a signal to the water supply passage on-off valve 30 to close it and stop the water supply (F in FIG. 27). By stopping the water supply, water no longer flows into the tank 12, but the ultrasonic vibrator 18 is activated and mist generation continues, causing the water level in the tank 12 to drop.

[0123] Next, in step S11, it is determined whether or not the float switch 21 has detected that the water level in the tank 12 has dropped to the second water level TL2. If the water level in the tank 12 has dropped to the second water level TL2, the process proceeds to step S12; if the water level has not dropped, the process of step S11 is repeated. As shown in line G of FIG. 27, when the water level in the tank 12 drops to the second water level TL2, in step S12, the control unit 26 opens the water supply passage opening / closing valve 30 to resume water supply.

[0124] Next, in step S13, it is determined whether a third predetermined time has elapsed since the water supply was resumed in step S12. The process in step S13 is repeatedly executed until the third predetermined time has elapsed. Once the third predetermined time has elapsed, the process in the flowchart proceeds to step S14. The third predetermined time for supplying water to the tank 12 is preferably set so that the water level in the tank 12 rises from a state in which it has dropped to the second water level TL2 to a state in which it is close to the overflow level. As a result, the maintenance control from step S10 onward maintains the water level in the tank 12 in a range between the overflow level and the second water level TL2. Because the maintenance control maintains the water surface W in the tank 12 between the overflow level and the second water level TL2, mist can be generated relatively efficiently by operating the ultrasonic vibrator 18. In addition, mist is generated with maximum efficiency through overflow control, and a sufficient amount of mist remains inside the bathtub body 6, so even if the mist generation efficiency is slightly reduced due to maintenance control, a sufficient amount of mist can be maintained inside the bathtub body 6.

[0125] In reality, even during maintenance control, overflow from the overflow section 11c may occur due to an error in detecting the second water level TL2 by the float switch 21 or an error in the flow rate of water flowing into the tank 12. However, during maintenance control, water is supplied to the tank 12 to an extent that does not cause a large amount of overflow, thereby preventing the generation of wasted water. In step S13, the system checks whether the third predetermined time has elapsed based on the time elapsed since the water supply was resumed, but it may also check the time elapsed since the float detection was switched from OFF to ON. In this case, the predetermined time is set so that the water level rises close to the overflow level.

[0126] Once the third predetermined time has elapsed, the process proceeds to step S14, where it is determined whether or not the user has performed an operation to stop the mist generator 1. If the user has not performed an operation to stop the mist generator 1, the process returns to step S10, and the supply of water to the tank 12 is stopped (row H in FIG. 27). Thereafter, the process of steps S10 → S11 → S12 → S13 → S14 → S10 is repeatedly executed, and maintenance control continues, until the user performs an operation to stop the mist generator 1.

[0127] On the other hand, if the user performs an operation to stop the mist generator 1 while maintenance control is continuing, the process in the flowchart moves from step S14 to S15. In step S15, the control unit 26 sends a control signal to the water supply passage opening / closing valve 30 to stop the water supply, and also stops the supply of electricity to the heater 20. Next, in step S16, the control unit 26 sends a control signal to the drainage channel opening / closing valve 32 (Fig. 2) to open it, and ends the processing of the flowchart shown in Fig. 26. As a result, the water stored in the tank 12 is drained into the drainage channel 16 through the drainage channel opening / closing valve 32, and the mist generator 1 returns to its initial state (section I in Fig. 27).

[0128] The operation unit 28 (FIG. 1) is also provided with a preparation mode setting switch (not shown). When the user operates this preparation mode setting switch to set the preparation mode, the control unit 26 opens the water supply passage on-off valve 30 without operating the ultrasonic vibrator 18, thereby causing water to flow out of the overflow section 11c and setting the water level in the tank 12 to the overflow level. Specifically, when the preparation mode is set, the control unit 26 executes the flowchart shown in FIG. 26 up to step S6, and puts the mist generator 1 into standby mode. Next, when the user operates the start switch of the mist generator 1, the process from step S6 onwards is executed, and mist is discharged from the mist generator 1. This allows the user to enjoy a mist bath immediately after starting the mist generator 1, without having to wait for water to be supplied to the tank 12.

[0129] According to the mist generator 1 of the first embodiment of the present invention, the control unit 26 controls the water supply valve (steps S10 to S13 in FIG. 26) so that the water level stored in the tank 12, which is the water storage unit, is maintained within an appropriate range, so that the height of the water surface W in the tank 12 is always maintained within an appropriate range, and mist can be generated efficiently by the ultrasonic vibrator 18. This makes it possible to generate a large amount of mist and supply it to plumbing equipment without using a large-scale device.

[0130] Furthermore, according to the mist generating device 1 of this embodiment, the control unit 26 controls the water supply line opening / closing valve 30, which is a water supply valve, so that the introduced water flows out from the overflow section 11c (columns C and E in Figure 27), so that the water level in the tank 12 can be accurately set to the overflow water level depending on the height of the overflow section 11c, and the water level W of the tank 12 can be reliably set to an appropriate value.

[0131] Furthermore, according to the mist generating device 1 of this embodiment, the control unit 26 continues to cause water to flow out of the overflow section 11c for a predetermined period of time while mist is being generated (steps S7 to S9 in Figure 26), so that the water level in the tank 12 can be maintained at an appropriate value even while mist is being generated.

[0132] Furthermore, according to the mist generating device 1 of this embodiment, the control unit 26 causes water to flow out of the overflow section 11c when the ultrasonic vibrator 18 is started (steps S7 and S8 in Figure 26), so that when the supply of mist begins, the water level in the tank 12 is set to an appropriate water level, and a large amount of mist can be supplied when the supply begins.

[0133] Furthermore, according to the mist generating device 1 of this embodiment, the control unit 26 performs overflow control (steps S7 to S9 in Figure 26) to continue flowing water out of the overflow section 11c for a predetermined period of time, and then performs maintenance control (steps S10 to S13 in Figure 26) to maintain the water level in the tank 12 within a predetermined range.Therefore, overflow control is performed in the early stages of operation of the mist generating device 1, enabling the generation of a large amount of mist, while subsequent maintenance control can suppress the generation of wasted water.

[0134] Furthermore, with the mist generator 1 of this embodiment, a drop in the water level is detected by the float switch 21, which is a water level sensor, so even if the accuracy of the float switch 21 is insufficient, it is possible to prevent the water level in the tank 12 from dropping too low. Furthermore, with the mist generator 1 of this embodiment, after a drop in the water level is detected, the water supply line on-off valve 30 is opened for a predetermined time to raise the water level in the tank 12, so the water level after water is replenished can be set with relatively high accuracy. In other words, by setting the predetermined time for opening the water supply line on-off valve 30 to the time it takes for the water level in the tank 12 to rise to approximately the overflow level, it is possible to sufficiently suppress variation in the water level after water is replenished, even if the accuracy of the float switch 21 is insufficient.

[0135] Furthermore, according to the mist generating device 1 of this embodiment, the control unit 26 is configured to be able to set the preparation mode, so that the water level in the tank 12 can be set to the overflow level before the ultrasonic vibrator 18 is activated, and a sufficient amount of mist can be generated immediately after the mist generating device 1 is started up.

[0136] Next, a mist generating system equipped with a mist generator according to a second embodiment of the present invention will be described with reference to Fig. 28. This embodiment differs from the first embodiment described above in that the plumbing equipment to which the mist generator is applied is the floor of a bathroom wash area. Fig. 28 is a perspective view of a mist generating system equipped with a mist generator according to a third embodiment of the present invention.

[0137] As shown in Figure 28, a mist generating system 102 equipped with a mist generator 1 according to the second embodiment of the present invention is installed in a bathroom 3. The mist generating system 102 is provided with a water supply device 107. The mist generating system 102 further includes a washing area floor body 106 that forms a mist retention space 104 that receives the mist supplied from the mist generator 1.

[0138] The washing area floor body 106 forms a mist retention space 104 that is open upward toward the indoor space 5 in which the mist generating system 102 is used. The washing area floor body 106 is formed by the bathroom wall, the outer wall of the bathtub body, the bathroom door, etc., and is designed to allow water to flow inside the mist retention space 104. With this structure, the washing area floor body 106 is designed to allow mist to retain in the mist retention space 104. The retention space 104 is formed, for example, up to the upper end of the bathtub body 6, which defines the wall of the washing area floor body 106.

[0139] The mist generator 1 is used in a mist generating system 102. The mist generator 1 is configured so that the temperature difference between the mist supplied to the mist retention space 104 and the temperature of the room in which the mist generating system 102 is used before the mist supply begins is 0°C or more, and so that the supplied mist is retained in the mist retention space 104 of the washing area floor body 106. Figure 28 shows an example of a mist retention layer C that forms a retention boundary surface 66 on its upper surface.

[0140] According to the second embodiment of the present invention configured as described above, heated mist is retained in the mist retention space 104 of the washing area floor body 106. For example, the heated mist can warm the washing area floor body 106, thereby heating the washing area floor and the mist retention space 104. The heated mist can also allow a user to take a mist bath in the mist retention space 104. Furthermore, for example, the heated mist can warm the washing area floor body 106 and make it easier to clean or remove dirt adhering to the washing area floor body 106 with relatively high cleaning performance.

[0141] Next, a mist generating system equipped with a mist generator according to a third embodiment of the present invention will be described with reference to Fig. 29. The mist generating system of this embodiment differs from the above-described embodiments in that the plumbing equipment to which the mist generator is applied is a shower room. Fig. 29 is a perspective view of a mist generating system equipped with a mist generator according to the third embodiment of the present invention.

[0142] As shown in Figure 29, the mist generating system according to the third embodiment applies a mist generator 1 according to the third embodiment of the present invention to a shower room 203, which is a plumbing fixture. The shower room 203 is formed in the shape of a rectangle with sides of approximately 0.8 to 2 meters, with a semicircular area added to it, when viewed from above, forming a relatively small room. A shower room apparatus 202 provided in the shower room 203 is provided with a supply device 207 that supplies water. The shower room apparatus 202 further comprises a shower room main body 206 that forms a mist retention space 204 that receives the mist supplied from the mist generation device 1. The shower room 203 is not limited to a room in which only the supply device 207 is provided, and may also comprise a toilet, hand-washing equipment, a sink, or a combination of these.

[0143] The shower room main body 206 forms a mist retention space 204 that is open upward toward the indoor space 205 where the shower room apparatus 202 is used. The shower room main body 206 is formed by the shower room walls, shower room door, etc., and is designed to allow water to flow into the mist retention space 204 inside. This structure allows mist to be retained in the shower room main body 206. Note that this embodiment demonstrates that the mist retention space 204 can be defined even if the boundary between the indoor space 205 of the shower room 203 and the mist retention space 204 is not clearly defined by the structure. The boundary between the indoor space 205 and the mist retention space 204 is set at a different position, taking into account the mist supply capacity of the mist generator 1. The mist retention space 204 can be arbitrarily set as a space for storing mist, taking into account the mist supply capacity of the mist generator 1. Such mist retention space 204 is a retention space that is open upward toward the indoor space 205. Note that this is not limited to this embodiment, and even if the boundary between the indoor space 205 and the mist retention space 204 is not clearly defined by the structure, the mist retention space 204 can be set with the same purpose. The retention space 204 is formed, for example, to the height of the face of a seated user (or, for example, to a height of about one-third of the total height of the interior space of the shower room).

[0144] The mist generator 1 is configured so that the temperature difference between the mist supplied to the mist retention space 204 and the temperature of the shower room before the mist supply begins is 0°C or more, and the supplied mist is retained within the mist retention space 204 of the shower room main body 206. Figure 29 shows an example of a mist retention layer C that forms a retention boundary surface 66 on its upper surface.

[0145] According to the structure of the third embodiment configured in this manner, heated mist is retained within the mist retention space 204 of the shower room main body 206. For example, the heated mist can warm the shower room main body 206, thereby heating the shower room floor and the mist retention space 204. The heated mist also allows the user to take a mist bath in the mist retention space 204. Furthermore, by retaining the heated mist at a relatively high position, the user can take a mist bath while sitting in the chair 208 inside the mist retention space 204 or while standing. Furthermore, for example, the heated mist can warm the shower room main body 206 and also easily clean or remove dirt adhering to the shower room main body 206 with relatively high cleaning performance.

[0146] Next, a mist generating system equipped with a mist generator according to a fourth embodiment of the present invention will be described with reference to Figure 30. The fourth embodiment differs from the above-described embodiments in that the mist generating device according to the present invention is applied to a washbasin, which is a plumbing fixture. Figure 30 is a perspective view of a mist generating system equipped with a mist generator according to the fourth embodiment of the present invention.

[0147] As shown in Figure 30, a washbasin device 302, which is a plumbing device that uses a mist generating device 1 according to the fourth embodiment of the present invention, is installed on a counter or the like in a washroom 303. The washbasin device 302 is provided with a supply device 307 that supplies water. The washbasin device 302 further includes a washbasin main body 306 that forms a mist retention space 304 that receives the mist supplied from the mist generating device 1.

[0148] The washbasin body 306 forms a mist retention space 304 that is open upward toward the indoor space 305 in which the washbasin device 302 is used. The washbasin body 306 is designed to store water in the internal mist retention space 304. With this structure, the washbasin body 306 allows mist to be retained in the mist retention space 304. The retention space 304 is formed, for example, up to the upper end of the washbasin body 306.

[0149] The mist generator 1 is used in a washbasin 302. The mist generator 1 is configured so that the temperature difference between the mist supplied to the mist retention space 304 and the room temperature in which the washbasin 302 is used before the mist supply begins is 0°C or more, and the supplied mist is retained in the mist retention space 304 of the washbasin body 306. Figure 30 shows an example of a mist retention layer C that forms a retention boundary surface 66 on its upper surface.

[0150] According to the structure of the fourth embodiment configured as described above, heated mist is retained in the mist retention space 304 of the washbasin body 306. For example, by retaining the heated mist in the mist retention space 304 of the washbasin body 306 and having the user apply the mist to a part of the body, such as the face, hands, or feet, the user can obtain moisturizing, improved cleansing performance, a warm bath, beauty effects, etc. The heated mist also allows the user to take a mist bath on a part of the body in the mist retention space 304. For example, the heated mist not only warms the washbasin body 306 but also makes it easier to clean or remove dirt adhering to the mist retention space 304 of the washbasin body 306 with relatively high cleaning performance.

[0151] Next, a mist generating system equipped with a mist generator according to a fifth embodiment of the present invention will be described with reference to Figure 31. The fifth embodiment differs from the above-described embodiments in that the mist generator according to the present invention is applied to a kitchen sink apparatus, which is a plumbing appliance. Figure 31 is a perspective view of a kitchen sink apparatus to which the mist generator according to the fifth embodiment of the present invention is applied.

[0152] As shown in Figure 31, a kitchen sink apparatus 402, which is a plumbing fixture employing a mist generator 1 according to the fifth embodiment of the present invention, is installed in a kitchen 403. The kitchen sink apparatus 402 is provided with a supply device 407 that supplies water. The kitchen sink apparatus 402 further includes a kitchen sink main body 406 that forms a mist retention space 404 that receives the mist supplied from the mist generator 1. The retention space 404 is formed up to the upper end of the kitchen sink main body 406, for example.

[0153] Kitchen sink body 406 forms mist retention space 404 that is open upward toward indoor space 405 in which kitchen sink device 402 is used. Kitchen sink body 406 is designed to allow water to be stored inside mist retention space 404. With this structure, kitchen sink body 406 allows mist to be retained inside mist retention space 404.

[0154] Mist generator 1 is configured so that the temperature difference between the mist supplied to mist retention space 404 and the room temperature where the plumbing appliance is used before the mist supply begins is 0°C or more, and the supplied mist is retained within mist retention space 404 in kitchen sink body 406. Figure 31 shows an example of mist retention layer C that forms retention boundary surface 66 on its upper surface.

[0155] According to the structure of the fifth embodiment configured as described above, heated mist is retained in the mist retention space 404 of the kitchen sink body 406. For example, by retaining the heated mist in the mist retention space 404 of the kitchen sink body 406 and directing the mist at dishes, appliances, etc., the objects to be washed are warmed, and dirt adhering thereto can be washed with relatively high cleaning performance. Furthermore, by directing the heated mist at the objects to be washed, dirt can be easily removed, even if it does not completely clean them. Furthermore, by retaining the heated mist in the mist retention space 404 of the kitchen sink body 406, the user can work while warming their hands and fingers inside the kitchen sink body 406. Furthermore, for example, the heated mist can warm the kitchen sink body 406 and easily clean or remove dirt adhering to the mist retention space 404 inside the kitchen sink body 406 with relatively high cleaning performance.

[0156] Although the preferred embodiment of the present invention has been described above, various modifications can be made to the above-described embodiment. [Explanation of symbols]

[0157] 1. Mist generator 2 Bathtub equipment 3 bathroom 4 Mist retention space 5 Indoor space 6 Bathtub body 6a Upper end 6d Long side part 6e Short side part 6f Drainage pan 8 Mist generator body 8a Ceiling surface 8b Partition wall 8c Dammed section 8d Guidance wall 8e Intake passage 9 Water supply section 9a Water supply line connection 9b Water supply room 9c communication path 10 Mist discharge passage 10a Mist outlet 11 Drainage section 11a Drainage channel connection 11b Drain room 11c Overflow section 12 Tank (water storage section) 12a Recess 14 Water supply channel 16 Drainage Channel 18 Ultrasonic transducer 20 Heater 21 Float switch (water level sensor) 22 Water temperature measuring instrument 24 Indoor temperature measuring instrument 26 Control Unit 28 Control section 30 Water supply channel opening / closing valve (water supply valve) 32 Drainage channel opening / closing valve 102 Mist generation system 203 Shower Room 302 Washroom equipment 402 Kitchen sink equipment

Claims

1. A mist generator that supplies mist to plumbing equipment, A mist generator body; a water storage section provided within the mist generating device body, which stores water to be turned into mist; a water supply valve that controls the supply and stop of water to the water storage section; an ultrasonic vibrator provided in the water storage section and configured to irradiate ultrasonic waves toward the surface of the water stored in the water storage section to generate mist; a control unit that controls the water supply valve and the ultrasonic vibrator, the control unit controls the water supply valve so that the water level stored in the water storage unit is maintained within an appropriate range; An overflow section is provided within the mist generating device body, and the control section sets the water level in the water storage section to an overflow level by controlling the water supply valve so that water introduced through the water supply valve flows out of the overflow section.

2. The mist generating device of claim 1, wherein the control unit, while activating the ultrasonic vibrator to generate mist within the mist generating device body, continues to allow water to flow out of the overflow section for a predetermined period of time, thereby maintaining the water level in the water storage section at the overflow level for a predetermined period of time.

3. 3. The mist generating device according to claim 1, wherein the control unit opens the water supply valve when or before the ultrasonic vibrator is activated, causing water to flow out of the overflow portion.

4. The control unit is configured to be able to perform overflow control, which continues to cause water to flow out of the overflow section, and maintenance control, which maintains the water level in the water storage section within a predetermined range below the overflow level, and the control unit performs the overflow control for a predetermined period of time while the ultrasonic vibrator is operating, and then performs the maintenance control. A mist generating device as described in any one of claims 1 to 3.

5. The mist generating device of claim 4 further comprises a water level sensor for detecting the water level in the water storage section, and in the maintenance control, when the water level sensor detects that the water level in the water storage section has dropped to a predetermined water level, the control section opens the water supply valve for a predetermined period of time to raise the water level in the water storage section.

6. The mist generating device of any one of claims 1 to 5, wherein the control unit is configured to be able to set a preparation mode, and when the preparation mode is set, the control unit opens the water supply valve without operating the ultrasonic vibrator, thereby causing water to flow out of the overflow section and setting the water level in the water storage section to the overflow level.

7. A mist generator according to any one of claims 1 to 6; a plumbing device having a mist retention space for retaining the mist discharged from the mist generator; A mist generating system comprising:

Images