JP7709925B2 - Microbubble generator - Google Patents

Description

This specification relates to a microbubble generating device.

Patent document 1 discloses a fine bubble generator including a tank having a supply port and a discharge port, a target member housed in the tank and having a through hole, a supply path for supplying the liquid to the supply port, a discharge path for discharging the liquid stored in the tank from the discharge port to a liquid tank, a fine bubble generating nozzle provided in the discharge path for generating fine bubbles by reducing the pressure of the liquid in which the gas is pressurized and dissolved, one or more liquid level electrodes extending vertically inside the tank and outside the target member and capable of detecting whether the liquid level in the tank is equal to or higher than a predetermined liquid level, and an electrode cover provided to cover at least one of the one or more liquid level electrodes. The liquid supplied from the supply path to the supply port is configured to collide with the target member and be stored in the tank through the through hole or the outside of the target member. When the electrode cover is viewed along the extension direction of the at least one liquid level electrode of the one or more liquid level electrodes, the electrode cover does not cover the entire circumference of the at least one liquid level electrode of the one or more liquid level electrodes.

JP 2013-111504 A

In the microbubble generator, the gas contained in the liquid in the tank rises through the liquid, generating bubbles on the liquid surface. For this reason, droplets may be scattered above the liquid surface due to the bursting of bubbles. If droplets scattered from the liquid surface adhere to the level electrode, slime may form on the level electrode. If slime forms on the level electrode, the liquid level of the tank may be erroneously detected. For this reason, in the microbubble generator of Patent Document 1, an electrode cover is provided to cover at least one of the one or more level electrodes in order to prevent droplets scattered from the liquid surface from adhering to the level electrode. However, the electrode cover of Patent Document 1 cannot prevent droplets scattered from the liquid surface from adhering to the level electrode in the part of the entire circumference of at least one of the one or more level electrodes that is not covered by the electrode cover. For this reason, the adhesion of droplets to at least one of the one or more level electrodes cannot be appropriately suppressed. This specification provides a technology that can appropriately suppress the adhesion of droplets to at least one of one or more liquid level electrodes.

The microbubble generating device disclosed in this specification includes a tank having a supply port and a discharge port, a mixing case housed in the tank and pressurizing and dissolving the gas in the tank in the liquid flowing into the tank, a supply path for supplying the liquid to the supply port, an introduction path for introducing the liquid supplied to the supply port into the mixing case, an exhaust path for discharging the liquid stored in the tank from the exhaust port to a liquid tank, a microbubble generating nozzle provided in the exhaust path for generating microbubbles by reducing the pressure of the liquid in which the gas is pressurized and dissolved, one or more liquid level electrodes extending vertically inside the tank and outside the mixing case and capable of detecting whether the liquid level in the tank is equal to or higher than a predetermined liquid level, and an electrode cover provided to cover at least one of the one or more liquid level electrodes. The mixing case is provided with an outlet portion from which the liquid flows out. The liquid supplied from the supply passage to the supply port is introduced into the mixing case through the introduction passage and flows out of the mixing case from the outflow section, so that the liquid is stored in the tank. When the electrode cover is viewed along the extension direction of the at least one liquid level electrode among the one or more liquid level electrodes, the electrode cover covers the entire circumference of the at least one liquid level electrode among the one or more liquid level electrodes.

According to the above configuration, the electrode cover can suppress droplets scattered from the liquid surface from adhering to at least one of the one or more liquid level electrodes around the entire circumference of the at least one of the one or more liquid level electrodes. Therefore, it is possible to appropriately suppress the adhesion of droplets to at least one of the one or more liquid level electrodes.

In one or more embodiments, the fine bubble generating device may further include a pressure pump provided in the supply path, a gas introduction mechanism capable of introducing gas into the tank, and a control device. The control device may be configured to perform a fine bubble generating operation including a pressurized liquid supply operation in which the pressure pump is driven to pressurize and supply the liquid from the supply path to the supply port, and the liquid in which the gas is pressurized and dissolved is supplied to the liquid tank from the outlet through the discharge path, and a gas introduction operation in which the gas introduction mechanism is operated to introduce the gas into the tank. When the lowest liquid level among the predetermined liquid levels detected by the one or more liquid level electrodes is set as a lower limit liquid level, during the fine bubble generating operation, if the liquid level in the tank is detected to be lower than the lower limit liquid level during the gas introduction operation, the control device may be configured to stop the gas introduction operation and perform only the pressurized liquid supply operation to raise the liquid level in the tank. The lower end of the electrode cover may be located at a position lower than the lower limit liquid level.

When the lower end of the electrode cover is located at a position lower than the liquid level in the tank, the electrode cover prevents gas contained in the liquid in the tank from rising through the liquid and entering the inside of the electrode cover. In this case, inside the electrode cover, the generation of bubbles on the liquid surface is suppressed, and the scattering of droplets above the liquid surface is suppressed. According to the above configuration, during the execution of the fine bubble generating operation, the lower end of the electrode cover is always located at a position lower than the liquid level in the tank. Therefore, during the execution of the fine bubble generating operation, inside the electrode cover, the generation of bubbles on the liquid surface is always suppressed, and the scattering of droplets above the liquid surface is always suppressed. Therefore, according to the above configuration, the adhesion of droplets to at least one of the one or more liquid level electrodes can be more appropriately suppressed. In this specification, the "inside of the electrode cover" means the side of the electrode cover that covers the liquid level electrode.

In one or more embodiments, the one or more level electrodes may include a first level electrode capable of detecting whether the liquid level in the tank is equal to or higher than a first level, and a second level electrode capable of detecting whether the liquid level in the tank is equal to or higher than a second level higher than the first level. The lower limit liquid level may be the first liquid level. In the fine bubble generating operation, when the liquid level in the tank is detected to be equal to or higher than the second liquid level while the gas introduction operation is stopped, the control device may be configured to start the gas introduction operation to lower the liquid level in the tank.

According to the above configuration, the control device uses the first and second level electrodes to control the operation of the gas introduction mechanism so that the tank's liquid level transitions between the first and second liquid levels. The lower end of the electrode cover that covers at least one of the one or more liquid level electrodes is located at a position lower than the first liquid level. According to the above configuration, in a fine-bubble generating device that uses two liquid level electrodes to control the tank's liquid level, scattering of droplets inside the electrode cover is always suppressed. Therefore, in a fine-bubble generating device that uses two liquid level electrodes to control the tank's liquid level, adhesion of droplets to at least one of the one or more liquid level electrodes can be appropriately suppressed.

In one or more embodiments, the electrode cover may be provided to cover the second level electrode of the one or more level electrodes.

When the control device controls the operation of the gas introduction mechanism so that the liquid level in the tank fluctuates between the first liquid level and the second liquid level, the first liquid level electrode is frequently immersed in the liquid, so slime is relatively unlikely to form on the first liquid level electrode. On the other hand, the second liquid level electrode is hardly immersed in the liquid, so slime is relatively likely to form on the second liquid level electrode. According to the above configuration, the electrode cover is provided to cover the second liquid level electrode. This makes it possible to appropriately suppress the adhesion of liquid droplets to the second liquid level electrode, which is relatively prone to slime.

In one or more embodiments, the one or more level electrodes may include only a third level electrode capable of detecting whether the liquid level in the tank is equal to or higher than a third level. The electrode cover may be provided to cover the third level electrode. The lower limit liquid level may be the third liquid level. When the control device detects that the liquid level in the tank is lower than the lower limit liquid level during the fine bubble generating operation and stops the gas introduction operation, the control device may be configured to maintain the gas introduction operation stopped for a predetermined time after the gas introduction operation is stopped, and to start the gas introduction operation after the predetermined time has elapsed.

According to the above configuration, the control device uses the third level electrode to control the operation of the gas introduction mechanism so that the liquid level in the tank is maintained at or above the third level. The lower end of the electrode cover that covers at least one of the one or more level electrodes is located at a position lower than the third level. According to the above configuration, in a fine-bubble generator that uses one level electrode to control the liquid level in the tank, scattering of droplets inside the electrode cover is always suppressed. Therefore, in a fine-bubble generator that uses one level electrode to control the liquid level in the tank, adhesion of droplets to at least one of the one or more level electrodes can be appropriately suppressed.

In one or more embodiments, the third liquid level may be higher than a lower end of the mixing case. The lower end of the electrode cover may be lower than a lower end of the mixing case.

The liquid supplied to the tank is stored according to the shape of the outer surface of the mixing case and the shape of the inner surface of the tank. Therefore, the horizontal cross-sectional area of the liquid stored in the tank is relatively large at a position lower than the bottom end of the mixing case and relatively small at a position higher than the bottom end of the mixing case. Therefore, the amount of gas rising in the liquid per unit area is relatively small at a position lower than the bottom end of the mixing case and relatively large at a position higher than the bottom end of the mixing case. According to the above configuration, the electrode cover extends to a position where the amount of gas rising in the liquid per unit area is relatively small. Therefore, the electrode cover can further prevent the gas contained in the liquid in the tank from rising in the liquid and entering the inside of the electrode cover.

In one or more embodiments, when the gas introduction operation is performed during the fine bubble generation operation while the pressurized liquid supply operation is being performed, the control device may be configured to interrupt the pressurized liquid supply operation when the gas introduction operation starts, and to resume the interrupted pressurized liquid supply operation when the gas introduction operation is stopped.

If the pressurized liquid supply operation is not interrupted when the gas introduction operation is performed, it is necessary to adjust the amount of gas supplied to the tank in the gas introduction operation so that it exceeds the amount of gas consumed from the tank in the pressurized liquid supply operation, which can complicate processing. According to the above configuration, the pressurized liquid supply operation is interrupted when the gas introduction operation is performed, so there is no need to adjust the amount of gas supplied to the tank in the gas introduction operation and the amount of gas consumed from the tank in the pressurized liquid supply operation, simplifying processing.

In one or more embodiments, when the gas introduction operation is performed during the pressurized liquid supply operation in the fine bubble generation operation, the control device may be configured to perform the gas introduction operation without interrupting the pressurized liquid supply operation.

When the pressurized liquid supply operation is interrupted to perform the gas introduction operation, the fine bubbles generated in the liquid in the liquid tank during the pressurized liquid supply operation may disappear while the gas introduction operation is being performed, and it may not be possible to continue to stably generate fine bubbles in the liquid in the liquid tank. With the above configuration, there is no need to interrupt the pressurized liquid supply operation to perform the gas introduction operation, and the pressurized liquid supply operation can be performed continuously. With the above configuration, it is possible to continue to stably generate fine bubbles in the liquid in the liquid tank.

In one or more embodiments, the electrode cover may be seamlessly and integrally formed with a portion of the mixing case.

In the manufacturing process of a microbubble generator, it is sometimes desirable to reduce the number of parts. With the above configuration, the number of parts can be reduced compared to when the electrode cover and the mixing case are provided separately.

In one or more embodiments, the liquid may be water. The liquid tank may be a bathtub that a user uses to bathe.

According to the above configuration, in a micro-bubble generating device that generates micro-bubbles in the water in a bathtub used by a user for bathing, it is possible to appropriately suppress adhesion of droplets to at least one of one or more liquid level electrodes.

1 is a diagram showing a schematic configuration of a hot water device 2 of a first embodiment; FIG. 2 is an exploded view of the tank 52 included in the hot water device 2 of the first embodiment. FIG. 13 is a view of the tank lower portion 522 of the first or second embodiment as viewed from above along the axis A. 1 is a view of the tank lower portion 522 and the case body 40 of the first or second embodiment as viewed from above along the axis A. FIG. 4A to 4C are diagrams illustrating an example of the flow of water in a tank 52 according to the first embodiment. FIG. 11 is a rear view of the electrode unit 54 and the mixing case 4 of the first or third embodiment. 13 is a bottom view of the electrode unit 54 and the case lid 44 of the first or third embodiment. FIG. 10A to 10C are diagrams illustrating examples of the flow of water flowing out of the first outlet portion 404a in the first to third embodiments. A diagram showing a schematic example of water flow in the bathtub adapter 132 of Examples 1 to 3. A diagram showing another example of water flow in the bathtub adapter 132 of Examples 1 to 3. 3 is a diagram showing a schematic example of a water flow in the hot water device 2 of the first embodiment. FIG. 5A to 5C are diagrams illustrating another example of the water flow in the hot water device 2 of the first embodiment. 4 is a flowchart of a process executed by a control device 150 during a fine bubble generating operation of the hot water device 2 of the first embodiment. 10 is a diagram showing a schematic diagram of still another example of the water flow in the hot water device 2 of the first embodiment. FIG. FIG. 13 is a diagram showing a schematic configuration of a water heating device 2A of a second embodiment. FIG. 11 is an exploded view of a tank 72 included in a water heating device 2A of a second embodiment. FIG. 13 is a rear view of the electrode unit 754 and the mixing case 4 of the second embodiment. FIG. 11 is a bottom view of an electrode unit 754 and a case lid 44 according to a second embodiment. 13 is a flowchart of a process executed by a control device 150 during a fine bubble generating operation of a hot water device 2A of a second embodiment. FIG. 13 is a diagram showing a schematic configuration of a water heating device 2B of a third embodiment. 13 is a flowchart of a process executed by a control device 150 during a fine bubble generating operation of a water heating device 2B of a third embodiment. 13 is a diagram illustrating an example of the flow of water in a water heating device 2B of a third embodiment. FIG.

(Example)
1, the hot water device 2 of this embodiment includes a heat source unit 10, an air pressurized dissolution unit 50, a bathtub adapter 132, and a control device 150. The hot water device 2 heats water supplied from a water supply source 200 such as a tap, and can supply the water heated to a desired temperature to a faucet 250 installed in a kitchen or the like, or to a bathtub 130 installed in a bathroom. The hot water device 2 can also generate fine air bubbles in the water in the bathtub 130 that a user uses for bathing.

(Configuration of heat source unit 10)
The heat source unit 10 includes a first heat source unit 12, a second heat source unit 14, a water supply passage 16, a hot water outlet passage 18, a bypass passage 20, a bypass servo 22, a hot water inlet passage 24, a hot water filling valve 26, a water volume sensor 28, a forward circulation passage 30, a return circulation passage 32, a bathtub circulation pump 34, and a water flow switch 36.

The upstream end of the water supply passage 16 is connected to the water supply source 200, and the downstream end of the water supply passage 16 is connected to the first heat source unit 12. The upstream end of the hot water outlet passage 18 is connected to the first heat source unit 12, and the downstream end of the hot water outlet passage 18 is connected to a faucet 250. The first heat source unit 12 is a combustion heat source unit that heats water, for example, by burning gas. The first heat source unit 12 heats the water flowing in from the water supply passage 16 and sends the heated water to the hot water outlet passage 18.

The upstream end of the bypass passage 20 is connected to the water supply passage 16, and the downstream end of the bypass passage 20 is connected to the hot water outlet passage 18. The bypass servo 22 is provided at the point where the bypass passage 20 connects to the water supply passage 16. The bypass servo 22 can adjust the ratio of the flow rate of water flowing from the water supply passage 16 to the hot water outlet passage 18 via the first heat source unit 12 and the flow rate of water flowing from the water supply passage 16 to the hot water outlet passage 18 via the bypass passage 20 by adjusting the opening degree of the built-in valve body. By adjusting the opening degree of the bypass servo 22, the hot water outlet passage 18 downstream of the point where the bypass passage 20 connects is supplied with water whose temperature has been adjusted to the desired temperature by mixing high-temperature water flowing from the first heat source unit 12 and low-temperature water flowing from the bypass passage 20 at a desired ratio. The hot water outlet passage 18 downstream of the point where the bypass passage 20 connects is provided with an outlet hot water temperature thermistor 18a that detects the temperature of the water in the hot water outlet passage 18.

The upstream end of the molten metal pouring passage 24 is connected to the molten metal outlet passage 18 downstream of the point where the bypass passage 20 is connected, and the downstream end of the molten metal pouring passage 24 is connected to the circulation return passage 32. The molten metal filling valve 26 is provided in the molten metal pouring passage 24 and opens and closes the molten metal pouring passage 24. The molten metal filling valve 26 is normally kept in a closed state. The water volume sensor 28 is provided in the molten metal pouring passage 24 and detects the amount of water flowing through the molten metal pouring passage 24.

The upstream end of the circulation return path 32 is connected to the heat source return path 60 (details will be described later) of the air pressurized dissolution unit 50, and the downstream end of the circulation return path 32 is connected to the second heat source device 14. The upstream end of the circulation outward path 30 is connected to the second heat source device 14, and the downstream end of the circulation outward path 30 is connected to the heat source outward path 68 (details will be described later) of the air pressurized dissolution unit 50. The second heat source device 14 is a combustion heat source device that heats water by, for example, burning gas. The second heat source device 14 heats the water flowing in from the circulation return path 32 and sends the heated water to the circulation outward path 30. A circulation return path thermistor 32a that detects the temperature of the water in the circulation return path 32 is provided near the upstream end of the circulation return path 32. A circulation outward path thermistor 30a that detects the temperature of the water in the circulation outward path 30 is provided near the downstream end of the circulation outward path 30.

The bathtub circulation pump 34 is provided in the circulation return path 32 downstream of the connection point of the hot water supply path 24, and sends water in the circulation return path 32 toward the second heat source unit 14. The water flow switch 36 is provided in the circulation return path 32 between the bathtub circulation pump 34 and the second heat source unit 14, and detects whether water is flowing in the circulation return path 32.

(Configuration of the air pressurized dissolving unit 50)
The air pressurization dissolution unit 50 includes a tank 52, a heat source return path 60, a heat source outward path 68, a tank return path 74, a tank outward path 64, a connecting passage 66, a first three-way valve 80, a second three-way valve 82, a check valve 84, a tank water supply valve 86, a first pressurization pump 88, a second pressurization pump 90, a tank circulation path 92, a tank circulation pump 94, and a gas introduction mechanism 96.

(Configuration of Tank 52)
The tank 52 can store water therein. The tank 52 is also used to generate air-dissolved water by pressurizing and dissolving air in water.

2, the tank 52 includes a tank upper part 520 and a tank lower part 522. The tank upper part 520 includes an electrode installation part 540, a first water supply port 74a, and a second water supply port 74b. The tank lower part 522 includes a case installation part 550, a drainage port 64a, and a circulation opening 92a (see FIG. 3). The tank upper part 520 and the tank lower part 522 are fixed to each other by screws (not shown). The tank upper part 520 and the tank lower part 522 have an inner surface of a substantially cylindrical shape centered on an axis A along the vertical direction. The mixing case 4 is accommodated inside the tank 52. The mixing case 4 includes a case body 40, a stirring part 42, a case lid 44, and an introduction pipe 46. The electrode unit 54 is installed in the electrode installation part 540.

As shown in FIG. 3, the drain outlet 64a and the circulation opening 92a are provided on the underside of the tank lower part 522 and open downward. Therefore, the water stored in the tank 52 is configured to be guided along the inner side surface of the tank 52 to the drain outlet 64a and the circulation opening 92a. In this embodiment, when the tank lower part 522 is viewed from above along the axis A, the drain outlet 64a and the circulation opening 92a are positioned so as not to overlap with the axis A.

As shown in FIG. 4, when the tank lower portion 522 and the case body 40 are viewed from above along the axis A, the drain port 64a (see FIG. 3) is positioned so as to be hidden by the case body 40. Also, when the tank lower portion 522 and the case body 40 are viewed from above along the axis A, a portion of the circulation opening 92a is positioned between the inner surface of the tank lower portion 522 and the outer surface of the first side wall portion 402 described below.

(Configuration of Case Body 40)
2, the case body 40 includes a first bottom plate portion 400 having a substantially circular plate shape extending in the horizontal direction, a first side wall portion 402 extending upward from the peripheral portion of the first bottom plate portion 400, a plurality of outlet portions 404 formed by cutting out the upper end portion of the first side wall portion 402, and a plate-like member 406 and a plurality of mounting members 408 provided on the first side wall portion 402. In this embodiment, the first bottom plate portion 400, the first side wall portion 402, the plate-like member 406, and the plurality of mounting members 408 are formed integrally without seams. The first side wall portion 402 is formed in a substantially cylindrical shape centered on the axis A.

As shown in FIG. 4, the plate-like member 406 and the multiple mounting members 408 abut against the case installation portion 550 of the tank lower portion 522 from above. Therefore, the case main body 40 is supported on the tank lower portion 522 via the plate-like member 406 and the multiple mounting members 408.

In this embodiment, four outflow sections 404 are provided. Therefore, in this embodiment, the outflow sections 404 may be divided into a first outflow section 404a, a second outflow section 404b, a third outflow section 404c, and a fourth outflow section 404d.

The multiple mounting members 408 are provided at a predetermined angular interval along the circumferential direction of the axis A. In this embodiment, three multiple mounting members 408 are provided. For this reason, in this embodiment, the multiple mounting members 408 may be classified as a first mounting member 408a, a second mounting member 408b, and a third mounting member 408c. The first mounting member 408a, the second mounting member 408b, and the third mounting member 408c are provided at 90° intervals along the circumferential direction of the axis A.

The plate-shaped member 406 is a flat plate having an approximately sector-shaped shape centered on the axis A. The plate-shaped member 406 is provided along the horizontal direction. The plate-shaped member 406 is provided along the circumferential direction of the axis A within a predetermined angular range (for example, within an angular range of 70°) of the entire circumference of the first side wall portion 402. The plate-shaped member 406 protrudes from the outer surface of the first side wall portion 402 toward the radial outside of the axis A. In addition, when the case body 40 is viewed from above along the axis A, the portion of the first side wall portion 402 where the plate-shaped member 406 is provided overlaps with the entire portion of the first side wall portion 402 where the first outlet portion 404a is provided. In addition, when the case body 40 is viewed from above along the axis A, the distance in the circumferential direction of the axis A from the centroid of the plate-shaped member 406 to the centroid of the first outlet portion 404a is smaller than the distance in the circumferential direction of the axis A from the centroid of the plate-shaped member 406 to the centroid of the drainage port 64a, and is also smaller than the distance in the circumferential direction of the axis A from the centroid of the plate-shaped member 406 to the centroid of the circulation opening 92a.

As shown in FIG. 5, the plate-shaped member 406 is disposed below the first outlet 404a and above the drain outlet 64a and the circulation opening 92a. The vertical distance from the plate-shaped member 406 to the first outlet 404a is smaller than the vertical distance from the plate-shaped member 406 to the drain outlet 64a, and is also smaller than the vertical distance from the plate-shaped member 406 to the circulation opening 92a.

(Configuration of the stirring unit 42)
2, the stirring section 42 includes a second bottom plate portion 420 having a substantially circular plate shape extending horizontally, a second side wall portion 422 extending upward from the peripheral portion of the second bottom plate portion 420, an insertion tube 424 and a fitting member 426 provided along the tangential direction of the second side wall portion 422, and a flange portion 428 protruding radially outward from the upper portion of the second side wall portion 422. In this embodiment, the second bottom plate portion 420, the second side wall portion 422, the insertion tube 424, the fitting member 426, and the flange portion 428 are formed integrally without any seams. The second side wall portion 422 is formed in a substantially cylindrical shape centered on the axis A.

As shown in FIG. 5, the flange portion 428 abuts against the upper end of the first side wall portion 402 of the case body 40 from above. Therefore, the stirring portion 42 is supported by the case body 40 via the flange portion 428. When the stirring portion 42 is supported by the case body 40, the insertion tube 424 fits into a portion of the fourth outlet portion 404d of the case body 40, and the fitting member 426 fits into a portion of the first outlet portion 404a.

The stirring section 42 further includes a jetting outlet 425 formed in the second bottom plate section 420. The second bottom plate section 420 is disposed at a position spaced apart from the first bottom plate section 400 of the case body 40 in the up-down direction. The outer diameter of the second side wall section 422 is smaller than the inner diameter of the first side wall section 402 of the case body 40. As a result, a gap is provided between the stirring section 42 and the case body 40, which connects the jetting outlet 425 and the multiple outflow sections 404.

(Configuration of case lid 44)
As shown in FIG. 2, the case cover 44 includes an upper plate portion 440 having a substantially circular plate shape extending in the horizontal direction, an expanded diameter portion 442 connected to the peripheral portion of the upper plate portion 440 and expanding radially outward of the axis A as it extends downward, a side plate portion 444 extending downward from the lower end of the expanded diameter portion 442, and an electrode cover 446 provided on the side plate portion 444 and extending in the vertical direction. In this embodiment, the upper plate portion 440, the expanded diameter portion 442, the side plate portion 444, and the electrode cover 446 are integrally formed without any seams. The electrode cover 446 is formed in a shape that follows the inner surfaces of the tank upper portion 520 and the tank lower portion 522. In addition, the upper plate portion 440 is provided with a communicating air hole (not shown).

As shown in FIG. 5, the case lid 44 is provided to cover the upper part of the case body 40 and the stirring part 42. The space between the case lid 44 and the stirring part 42 is sealed with a sealing member (not shown). Therefore, the case lid 44 prevents water introduced into the inside of the stirring part 42 from passing between the case lid 44 and the stirring part 42 and flowing out to the outside of the mixing case 4. In addition, the case lid 44 prevents water from splashing above the tank 52 when it flows out from the multiple outflow parts 404 of the case body 40.

(Configuration of the introduction pipe 46)
The inlet pipe 46 is attached to the agitator 42 by being inserted into the insertion pipe 424 of the agitator 42. The inlet pipe 46 is provided so as to communicate the first water supply port 74a and the second water supply port 74b of the tank upper portion 520 with the inside of the agitator 42. Therefore, the inlet pipe 46 can introduce water supplied to the first water supply port 74a and the second water supply port 74b of the tank upper portion 520 into the inside of the agitator 42.

(Configuration of electrode unit 54)
As shown in FIG. 2, the electrode unit 54 includes a high water level electrode 54a, a low water level electrode 54b, and an earth electrode 54c. The high water level electrode 54a, the low water level electrode 54b, and the earth electrode 54c extend vertically inside the tank 52 and outside the mixing case 4. When the high water level electrode 54a and the low water level electrode 54b come into contact with the water surface stored in the tank 52, a current flows between the high water level electrode 54a and the low water level electrode 54b, and an ON signal is output to the control device 150. That is, each of the high water level electrode 54a and the low water level electrode 54b is configured to be able to detect whether the water level in the tank 52 is equal to or higher than a predetermined water level. Hereinafter, the water level in the tank 52 detected by the low water level electrode 54b may be referred to as the "first water level". The water level in the tank 52 detected by the high water level electrode 54a may be referred to as the "second water level". The lower end of the high water level electrode 54a is higher than the lower end of the low water level electrode 54b. Therefore, the second water level is higher than the first water level.

As shown in FIG. 6, the high water level electrode 54a is covered by the electrode cover 446. On the other hand, the low water level electrode 54b and the earth electrode 54c are not covered by the electrode cover 446. The lower end of the electrode cover 446 is located lower than the lower end of the high water level electrode 54a, the lower end of the low water level electrode 54b, and the lower end of the earth electrode 54c. In addition, the lower end of the electrode cover 446 is located lower than the lower end of the mixing case 4.

As shown in FIG. 7, when the electrode cover 446 is viewed from below, the electrode cover 446 covers the entire circumference of the high water level electrode 54a.

(Water flow in tank 52)
As shown in FIG. 5, the water supplied from the first water supply port 74a and the second water supply port 74b is introduced into the inside of the stirring unit 42 through the introduction pipe 46. The water introduced into the inside of the stirring unit 42 flows downward while swirling in a spiral shape inside the stirring unit 42. When the water swirls inside the stirring unit 42, a large negative pressure is generated near the center of the stirring unit 42. Therefore, the air that has accumulated at the top of the tank 52 is taken into the inside of the stirring unit 42 through the air communication hole (not shown) of the case lid 44. The air taken into the inside of the stirring unit 42 is caught in the water swirling inside the stirring unit 42. As a result, the air is dissolved in the water, and air-dissolved water is generated. The air-dissolved water generated inside the stirring unit 42 is sprayed from the spray port 425 toward the first bottom plate portion 400 of the case body 40. The air-dissolved water ejected from the ejection port 425 collides with the first bottom plate portion 400, changes direction, flows upward through the gap formed between the second side wall portion 422 and the first side wall portion 402, and flows out of the mixing case 4 from the multiple outlet portions 404 of the case body 40. The air-dissolved water that flows out from the multiple outlet portions 404 flows downward through the gap formed between the inner surface of the tank 52 and the first side wall portion 402, and is stored in the tank 52. The solid arrows in FIG. 5 indicate the flow of water.

As shown in FIG. 8, the air-dissolved water flowing out of the multiple outlets 404 collides with the plate-shaped member 406 when flowing downward through the gap formed between the inner surface of the tank 52 and the first side wall 402. The air-dissolved water that collides with the plate-shaped member 406 changes direction to flow horizontally along the plate-shaped member 406. When the plate-shaped member 406 changes direction of the air-dissolved water, the air-dissolved water is decelerated. Therefore, if undissolved air is mixed in the air-dissolved water, the undissolved air is separated from the air-dissolved water by the deceleration of the air-dissolved water. The air separated from the air-dissolved water returns to the upper part of the tank 52. As a result, in the hot water device 2 of this embodiment, the amount of undissolved air contained in the air-dissolved water that is guided to the drain outlet 64a (see FIG. 3) and the circulation opening 92a (see FIG. 3) can be reduced. Note that the solid arrows in FIG. 8 indicate the flow of water.

(Configuration of each water channel in the air pressure dissolution unit 50)
As shown in FIG. 1, one end of the heat source return line 60 is connected to the communication passage 66, and the other end of the heat source return line 60 is connected to the circulation return line 32 of the heat source unit 10. The communication passage 66 connects the first three-way valve 80 and the second three-way valve 82. The first three-way valve 80 is connected to the communication passage 66, the first bathtub water passage 62, and the tank outward line 64. The first three-way valve 80 can be switched between a first communication state (see FIG. 14) in which the tank outward line 64 and the first bathtub water passage 62 are connected, a second communication state (see FIG. 1) in which the tank outward line 64 and the communication passage 66 are connected, and a third communication state (see FIG. 11, FIG. 12) in which the first bathtub water passage 62, the tank outward line 64, and the communication passage 66 are connected. The upstream end of the tank outgoing line 64 is connected to the tank 52 via a drain port 64a, and the downstream end of the tank outgoing line 64 is connected to the first three-way valve 80. The tank outgoing line 64 is provided with a check valve 84 that allows water to flow from the tank 52 to the first three-way valve 80 and prohibits water from flowing from the first three-way valve 80 to the tank 52. One end of the first bathtub water passage 62 is connected to the first three-way valve 80, and the other end of the first bathtub water passage 62 is connected to the bathtub adapter 132.

One end of the heat source outgoing line 68 is connected to the circulation outgoing line 30 of the heat source unit 10, and the other end of the heat source outgoing line 68 is connected to the second three-way valve 82. The second three-way valve 82 is connected to the communication passage 66, the heat source outgoing line 68, and the second bathtub water passage 70. The second three-way valve 82 can switch between a fourth communication state (see FIG. 14) in which the second bathtub water passage 70 and the communication passage 66 are connected, and a fifth communication state (see FIG. 1, FIG. 11, FIG. 12) in which the heat source outgoing line 68 and the second bathtub water passage 70 are connected. One end of the second bathtub water passage 70 is connected to the second three-way valve 82, and the other end of the second bathtub water passage 70 is connected to the bathtub adapter 132.

The upstream end of the tank return line 74 is connected to the heat source outward line 68, and the downstream end of the tank return line 74 is connected to the tank 52 via the first water supply port 74a. The tank water supply valve 86 is provided in the tank return line 74 and opens and closes the tank return line 74. The tank water supply valve 86 is normally closed. The first pressurizing pump 88 and the second pressurizing pump 90 are provided in the tank return line 74 between the tank water supply valve 86 and the tank 52. The first pressurizing pump 88 and the second pressurizing pump 90 pressurize the water in the tank return line 74 and send it toward the tank 52. In the tank return line 74, the first pressurizing pump 88 is located upstream of the second pressurizing pump 90.

The upstream end of the tank circulation path 92 is connected to the tank 52 via the circulation opening 92a, and the downstream end of the tank circulation path 92 is connected to the tank 52 via the second water supply port 74b. The tank circulation pump 94 is provided in the tank circulation path 92. The tank circulation pump 94 draws water from the tank 52 into the tank circulation path 92 via the circulation opening 92a, and discharges water from the tank circulation path 92 into the tank 52 via the second water supply port 74b.

(Configuration of Gas Introducing Mechanism 96)
The gas introduction mechanism 96 is provided in the tank circulation path 92 upstream of the tank circulation pump 94. The gas introduction mechanism 96 includes a water inlet pipe 98, a water outlet pipe 100, a Venturi tube 102, a gas introduction path 104, and a gas introduction valve 106. Water flows into the water inlet pipe 98 from the upstream side of the tank circulation path 92. The water outlet pipe 100 causes water to flow out to the downstream side of the tank circulation path 92. The Venturi tube 102 communicates the water inlet pipe 98 and the water outlet pipe 100. The diameter of the Venturi tube 102 is smaller than the diameters of the water inlet pipe 98 and the water outlet pipe 100. The water flowing through the gas introduction mechanism 96 is decompressed to a pressure lower than atmospheric pressure when it flows from the water inlet pipe 98 to the Venturi tube 102, and is pressurized to the original pressure when it flows from the Venturi tube 102 to the water outlet pipe 100. The upstream end of the gas introduction path 104 (hereinafter, also referred to as a gas introduction port 104a) is open to the atmosphere, and the downstream end is connected to the Venturi tube 102. The gas introduction valve 106 is provided in the gas introduction path 104 and opens and closes the gas introduction path 104. When water flows through the gas introduction mechanism 96, if the gas introduction valve 106 is open, air is sucked into the gas introduction path 104 from the gas introduction port 104a, and the air is mixed with the water flowing through the Venturi tube 102. The air introduced through the gas introduction path 104 flows into the tank 52 together with the water flowing through the tank circulation path 92. The gas introduction valve 106 is normally in a closed state.

(Configuration of bathtub adaptor 132)
Next, the bathtub adaptor 132 provided on the wall 130a of the bathtub 130 will be described with reference to Figures 9 and 10. Figure 9 shows the flow of water in the bathtub adaptor 132 when water flows from the first bathtub water channel 62 toward the bathtub 130 and from the bathtub 130 toward the second bathtub water channel 70 (for example, the state of Figure 14). Figure 10 shows the flow of water in the bathtub adaptor 132 when water flows from the bathtub 130 toward the first bathtub water channel 62 and from the second bathtub water channel 70 toward the bathtub 130 (for example, the state of Figure 12).

The bathtub adapter 132 has a first water passage 136 and a second water passage 138. The first water passage 136 is connected to the first bathtub water passage 62, and the second water passage 138 is connected to the second bathtub water passage 70. The first water passage 136 branches into a first discharge passage 136a and a first suction passage 136b. The first discharge passage 136a is connected to a first discharge port 134a provided on the front surface 132a of the bathtub adapter 132. The water discharged from the first discharge port 134a into the bathtub 130 is discharged in front of the wall portion 130a of the bathtub 130, that is, in a direction perpendicular to the wall portion 130a of the bathtub 130. The first discharge passage 136a is provided with a backflow prevention portion 140a that prevents water from flowing from the bathtub 130 toward the first bathtub water passage 62, and a fine bubble generating nozzle 142 that is arranged upstream of the backflow prevention portion 140a (on the first bathtub water passage 62 side). The fine bubble generating nozzle 142 reduces the pressure of the water passing through the fine bubble generating nozzle 142. The first suction passage 136b is connected to a first suction port 134b provided on the front surface 132a of the bathtub adapter 132. The first suction passage 136b is provided with a backflow prevention portion 140b that prevents water from flowing from the first bathtub water passage 62 toward the bathtub 130.

The second water passage 138 branches into a second discharge passage 138a and a second suction passage 138b. The second suction passage 138b is connected to a second suction port 134c provided on the front surface 132a of the bathtub adapter 132. The second suction passage 138b is provided with a check valve 140c that prevents water from flowing from the second bathtub water passage 70 toward the bathtub 130. The second discharge passage 138a is connected to a second discharge port 134d provided on the lower surface 132b of the bathtub adapter 132. The water discharged from the second discharge port 134d is discharged downward, that is, in a direction parallel to the wall portion 130a of the bathtub 130. The second discharge passage 138a is provided with a check valve 140d that prevents water from flowing from the bathtub 130 toward the second bathtub water passage 70.

(Configuration of the control device 150)
The control device 150 shown in Fig. 1 controls the operation of each component of the heat source unit 10 and the air pressurized dissolution unit 50. The control device 150 is configured to be able to communicate with a remote control 154 that can be operated by a user. The control device 150 includes a memory 152, and is capable of storing various settings input by the user, such as the set temperature and set water volume for the water filling operation, and the set temperature for the reheating operation. The user can use the remote control 154 to instruct the start and end of the water filling operation, reheating operation, and fine bubble generation operation, which will be described later.

(Bath filling operation)
The water filling operation starts when the user instructs the remote control 154 to start the water filling operation. Alternatively, the water filling operation may start when the user sets the start time of the water filling operation on the remote control 154 and the control device 150 determines that the start time of the water filling operation has arrived. When the water filling operation starts, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third communication state and the fifth communication state, respectively (see Figs. 11 and 12). When the water filling operation starts, the control device 150 opens the water filling valve 26 and starts heating by the first heat source unit 12. As a result, as shown in Fig. 11, water adjusted to the set temperature flows from the hot water outlet path 18 through the hot water supply path 24 into the circulation return path 32. The water that flows into the circulation return path 32 branches into a flow toward the upstream side (i.e., the heat source return path 60) and a flow toward the downstream side (i.e., the second heat source unit 14). Water flowing from the circulation return line 32 to the heat source return line 60 flows into the bathtub 130 via the communication passage 66, the first three-way valve 80, the first bathtub water passage 62, and the bathtub adapter 132. Water flowing from the circulation return line 32 to the second heat source unit 14 flows into the bathtub 130 via the circulation forward line 30, the heat source forward line 68, the second three-way valve 82, the second bathtub water passage 70, and the bathtub adapter 132. The control device 150 waits until the accumulated water volume detected by the water volume sensor 28 reaches the set water volume for the bath filling operation. The accumulated water volume here means the accumulated water volume detected by the water volume sensor 28 since the bath filling operation started. When the accumulated water volume reaches the set water volume, the control device 150 closes the bath filling valve 26 and ends the heating of water by the first heat source unit 12. Thereafter, the control device 150 notifies the user via the remote control 154 that the water filling operation has been completed, and ends the water filling operation.

(Reheating operation)
The reheating operation starts when the user instructs the start of the reheating operation on the remote control 154. Alternatively, the reheating operation may start when the control device 150 determines that the temperature detected by the circulation return thermistor 32a does not reach the set temperature after the first heat source unit 12 has finished heating the water during the bath filling operation. When starting the reheating operation, the control device 150 sets the first three-way valve 80 to the third communication state and the second three-way valve 82 to the fifth communication state (see Figures 11 and 12). From this state, the control device 150 drives the bathtub circulation pump 34 and starts heating the water by the second heat source unit 14. As a result, as shown in Figure 12, the water in the bathtub 130 is sent to the second heat source unit 14 via the bathtub adapter 132, the first bathtub water passage 62, the first three-way valve 80, the communication passage 66, the heat source return path 60, and the circulation return path 32. The water heated by the second heat source unit 14 is returned to the bathtub 130 via the circulation outward path 30, the heat source outward path 68, the second three-way valve 82, the second bathtub water passage 70, and the bathtub adapter 132. When the temperature detected by the circulation return thermistor 32a becomes equal to or higher than the set temperature, the control device 150 stops the bathtub circulation pump 34 and ends the heating of water by the second heat source unit 14. The control device 150 then notifies the user via the remote control 154 that the reheating operation has been completed, and ends the reheating operation.

(Fine bubble generation operation)
The fine bubble generating operation is started when the user instructs the start of the fine bubble generating operation on the remote control 154. In addition, in the hot water device 2 of this embodiment, the fine bubble generating operation is also automatically started after the above-mentioned water filling operation is completed. In other words, the fine bubble generating operation is executed in conjunction with the execution of the water filling operation. When starting the fine bubble generating operation, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third communication state and the fifth communication state, respectively (see Figures 11 and 12). In addition, the control device 150 sets the tank water supply valve 86 to an open state. From this state, the control device 150 executes the process shown in Figure 13.

In S2, the control device 150 drives the tank circulation pump 94. This causes water to circulate between the tank 52 and the tank circulation path 92.

In S4, the control device 150 starts the first air introduction operation. Specifically, the control device 150 opens the gas introduction valve 106. During the first air introduction operation, air is introduced into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92.

In S6, the control device 150 starts the pressurized water supply operation. Specifically, as shown in FIG. 14, the control device 150 sets the first three-way valve 80 to the first communication state, sets the second three-way valve 82 to the fourth communication state, and drives the bathtub circulation pump 34, the first pressurized pump 88, and the second pressurized pump 90. During the pressurized water supply operation, water from the bathtub 130 is supplied to the tank 52 via the bathtub adapter 132, the second bathtub water passage 70, the second three-way valve 82, the communication passage 66, the heat source return path 60, the circulation return path 32, the second heat source unit 14, the circulation outward path 30, the heat source outward path 68, and the tank return path 74. At this time, water pressurized by the first pressurized pump 88 and the second pressurized pump 90 is supplied from the tank return path 74 to the tank 52. As a result, air is pressurized and dissolved in the water inside the tank 52. The water with the air dissolved under pressure is then supplied to the bathtub 130 from the tank 52 via the tank outflow path 64, the first three-way valve 80, the first bathtub water path 62, and the bathtub adapter 132. At this time, the water with the air dissolved under pressure is depressurized to below atmospheric pressure as it passes through the fine bubble generating nozzle 142 of the first discharge path 136a of the bathtub adapter 132, and is pressurized to atmospheric pressure as it is sprayed into the bathtub 130, generating fine bubbles in the water in the bathtub 130.

In S8, the control device 150 determines whether the water level of the tank 52 falls below the first water level based on the detection signal from the low water level electrode 54b. In this embodiment, the amount of air introduced into the gas introduction mechanism 96 when the gas introduction valve 106 is open is greater than the amount of air in the fine bubbles generated in the water of the bathtub 130. Therefore, when the gas introduction valve 106 is open, the amount of air in the tank 52 increases and the water level of the tank 52 falls. If the water level of the tank 52 is equal to or greater than the first water level (NO), processing proceeds to S12. If the water level of the tank 52 falls below the first water level (YES), processing proceeds to S10.

In S10, if the first air introduction operation is being performed, the control device 150 stops the first air introduction operation. Specifically, the control device 150 closes the gas introduction valve 106. This stops the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92. With the gas introduction valve 106 closed, no air is supplied to the tank 52, so the amount of air in the tank 52 decreases and the water level of the tank 52 rises. Note that in this embodiment, the tank circulation pump 94 continues to be driven even while the gas introduction valve 106 is closed. This promotes the flow of water in the tank 52 and promotes the pressurized dissolution of air into the water in the tank 52.

In S12, the control device 150 determines whether the water level of the tank 52 is equal to or higher than the second water level based on the detection signal from the high water level electrode 54a. If the water level of the tank 52 is below the second water level (if NO), the process proceeds to S16. If the water level of the tank 52 is equal to or higher than the second water level (if YES), the process proceeds to S14.

In S14, if the first air introduction operation is stopped, the control device 150 starts the first air introduction operation. This resumes the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92.

In S16, the control device 150 determines whether the operation time of the fine bubble generating operation has reached the set time. Here, the operation time of the fine bubble generating operation is the elapsed time since the start of the fine bubble generating operation. In the hot water device 2 of this embodiment, when the fine bubble generating operation is performed independently without being linked to the execution of the water filling operation, the set time is set to, for example, 10 minutes. In contrast, when the fine bubble generating operation is performed in conjunction with the execution of the water filling operation, the set time is set to, for example, 30 minutes. If the operation time has not reached the set time (NO), the process returns to S8. When the operation time has reached the set time (YES), the process proceeds to S18.

In S18, the control device 150 stops the pressurized water supply operation. Specifically, the control device 150 stops the bathtub circulation pump 34, the first pressurized pump 88, and the second pressurized pump 90.

In S20, if the first air introduction operation is being performed, the control device 150 stops the first air introduction operation.

In S22, the control device 150 stops the tank circulation pump 94. This stops the circulation of water between the tank 52 and the tank circulation path 92. After S22, the processing in FIG. 13 ends.

In this way, in the hot water device 2 of this embodiment, the control device 150 is configured to control the operation of the gas introduction mechanism 96 during fine bubble generation operation using the high water level electrode 54a and the low water level electrode 54b so that the water level of the tank 52 changes between the first water level and the second water level. Furthermore, in the fine bubble generation operation, when the first gas introduction operation is performed during the pressurized water supply operation, the control device 150 is configured to perform the first gas introduction operation without interrupting the pressurized water supply operation.

Example 2
As shown in Fig. 15, the hot water apparatus 2A of this embodiment has a configuration substantially similar to that of the hot water apparatus 2 of Example 1. In the hot water apparatus 2A, the air pressurization dissolution unit 50 has a tank 72 instead of the tank 52. In addition, in the hot water apparatus 2A, when performing the fine bubble generating operation, the control device 150 performs the process shown in Fig. 19 instead of the process shown in Fig. 13. The following describes the differences between the tank 72 and the tank 52, and the differences between the process shown in Fig. 19 and the process shown in Fig. 13.

(Differences between tank 72 and tank 52)
16 , the tank 72 includes a tank upper part 720 in place of the tank upper part 520. The tank upper part 720 includes an electrode installation part 740 in place of the electrode installation part 540. An electrode unit 754 is installed in the electrode installation part 740 in place of the electrode unit 54.

The electrode unit 754 includes a single water level electrode 754a and an earth electrode 754b. The single water level electrode 754a and the earth electrode 754b extend vertically inside the tank 72 and outside the mixing case 4. When the single water level electrode 754a comes into contact with the surface of the water stored in the tank 72, a current flows between the single water level electrode 754a and the earth electrode 754b, and an ON signal is output to the control device 150. That is, the single water level electrode 754a is configured to be able to detect whether the water level in the tank 72 is equal to or higher than a predetermined water level. Hereinafter, the water level in the tank 72 detected by the single water level electrode 754a may be referred to as the "third water level". The lower end of the single water level electrode 754a is located higher than the lower end of the mixing case 4. Therefore, the third water level is located higher than the lower end of the mixing case 4.

As shown in FIG. 17, the single water level electrode 754a is covered by the electrode cover 446. On the other hand, the earth electrode 754b is not covered by the electrode cover 446. The lower end of the electrode cover 446 is located lower than the lower end of the single water level electrode 754a and the lower end of the earth electrode 754b. In addition, the lower end of the electrode cover 446 is located lower than the lower end of the mixing case 4.

As shown in FIG. 18, when the electrode cover 446 is viewed from below, the electrode cover 446 covers the entire circumference of the single water level electrode 754a.

(Differences between the process shown in FIG. 19 and the process shown in FIG. 13)
In the process shown in Fig. 19, after S6, the process proceeds to S32. In S32, the control device 150 determines whether the water level of the tank 72 falls below the third water level based on the presence or absence of an ON signal output from the single water level electrode 754a. If the water level of the tank 72 is equal to or higher than the third water level (if NO), the process repeats S32. If the water level of the tank 72 falls below the third water level (if YES), the process proceeds to S10. Then, after S10, the process proceeds to S34.

In S34, the control device 150 starts timing the time for the water level to rise using a built-in timer (not shown). After S34, the process proceeds to S36.

In S36, the control device 150 determines whether the water level rise time, which began to be timed in S34, exceeds a first predetermined time (e.g., 90 seconds). If the water level rise time is equal to or less than the first predetermined time (NO), the process repeats S36. If the water level rise time exceeds the first predetermined time (YES), the process proceeds to S38.

In S38, the control device 150 ends the measurement of the water level rise time using a built-in timer (not shown). After S38, the process proceeds to S14.

In this way, in the hot water device 2A, the control device 150 is configured to control the operation of the gas introduction mechanism 96 using a single water level electrode 754a during fine bubble generation operation so that the water level of the tank 72 is maintained at or above the third water level. Furthermore, when the first gas introduction operation is performed during the pressurized water supply operation during fine bubble generation operation, the control device 150 is configured to perform the first gas introduction operation without interrupting the pressurized water supply operation.

Example 3
As shown in FIG. 20, the hot water device 2B of this embodiment has a configuration substantially similar to that of the hot water device 2 of the first embodiment. In the hot water device 2B, the air pressure dissolution unit 50 has a tank 352 instead of the tank 52. The tank 352 does not have the circulation opening 92a in the tank 52. The tank 352 has a third water supply port 374 instead of the first water supply port 74a and the second water supply port 74b in the tank 52. The downstream end of the tank return line 74 is connected to the third water supply port 374. In addition, in the hot water device 2B, the air pressure dissolution unit 50 has a gas introduction path 300 and an air pump 302 instead of the tank circulation path 92, the tank circulation pump 94, and the gas introduction mechanism 96. The upstream end of the gas introduction path 300 (hereinafter also referred to as the gas introduction port 300a) is open to the atmosphere, and the downstream end is connected to the tank 52. The air pump 302 is provided in the gas introduction path 300. When the air pump 302 is driven, air is introduced into the tank 52 through the gas introduction path 300.

In addition, in the hot water device 2B, when performing the fine bubble generating operation, the control device 150 executes the process shown in FIG. 21 instead of executing the process shown in FIG. 13.

As shown in FIG. 21, in S52, the control device 150 starts the second air introduction operation. Specifically, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the second communication state and the fifth communication state (see FIG. 20), respectively, and then drives the air pump 302. During the second air introduction operation, air is introduced into the tank 352 through the gas introduction path 300.

In S54, the control device 150 determines whether the water level of the tank 352 falls below the first water level based on the detection signal from the low water level electrode 54b. When the second air introduction operation is performed while the pressurized water supply operation described below is stopped, the amount of air in the tank 352 increases, causing the water level of the tank 352 to fall. If the water level of the tank 352 is equal to or higher than the first water level (NO), processing proceeds to S60. If the water level of the tank 352 falls below the first water level (YES), processing proceeds to S56.

In S56, if the second air introduction operation is being performed, the control device 150 stops the second air introduction operation. Specifically, the control device 150 stops the air pump 302. This stops the introduction of air into the tank 352.

In S58, if the pressurized water supply operation is stopped, the control device 150 starts the pressurized water supply operation. Specifically, as shown in FIG. 22, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the first communication state and the fourth communication state, respectively, and drives the bathtub circulation pump 34, the first pressurized pump 88, and the second pressurized pump 90. This promotes the pressurized dissolution of air into the water in the tank 352, and starts the supply of air-dissolved water from the tank 352 to the bathtub 130. Note that when the second air introduction operation is stopped, no air is supplied to the tank 352, so the amount of air in the tank 352 decreases and the water level of the tank 352 rises.

In S60, the control device 150 determines whether the water level of the tank 352 is equal to or higher than the second water level based on the detection signal from the high water level electrode 54a. If the water level of the tank 352 is below the second water level (if NO), processing proceeds to S66. If the water level of the tank 352 is equal to or higher than the second water level (if YES), processing proceeds to S62.

In S62, if the second air introduction operation is stopped, the control device 150 starts the second air introduction operation. This restarts the introduction of air into the tank 352.

In S64, if the pressurized water supply operation is being performed, the control device 150 stops the pressurized water supply operation. This stops the supply of air-dissolved water from the tank 352 to the bathtub 130. In addition, because the second air introduction operation is performed with the pressurized water supply operation stopped, the water level in the tank 352 drops.

In S66, the control device 150 determines whether the operation time of the microbubble generating operation has reached the set time. If the operation time has not reached the set time (NO), the process returns to S54. If the operation time has reached the set time (YES), the process proceeds to S68.

In S68, the control device 150 stops pressurized water supply operation if the pressurized water supply operation is in progress.

In S70, if the second air introduction operation is being performed, the control device 150 stops the second air introduction operation. After S70, the processing in FIG. 21 ends.

In this way, in the hot water device 2B, the control device 150 is configured to control the operation of the air pump 302 during the fine bubble generating operation, using the high water level electrode 54a and the low water level electrode 54b, so that the water level of the tank 352 changes between the first water level and the second water level. Furthermore, when the second air introduction operation is performed during the fine bubble generating operation while the pressurized water supply operation is being performed, the control device 150 is configured to interrupt the pressurized water supply operation when the second air introduction operation starts, and to resume the interrupted pressurized water supply operation when the second air introduction operation is stopped.

In addition, in the hot water device 2B, the tank 352 may be equipped with the electrode unit 754 of Example 2 instead of the electrode unit 54. In this case, the control device 150 may be configured to control the operation of the air pump 302 using a single water level electrode 754a in the fine bubble generating operation so that the water level of the tank 352 is maintained at or above the third water level. In this case, the control device 150 may also be configured to interrupt the pressurized water supply operation at the start of the second air introduction operation and resume the interrupted pressurized water supply operation when the second air introduction operation is stopped in the fine bubble generating operation when the second air introduction operation is performed during the pressurized water supply operation.

(Modification)
In the above-described hot water device 2 (or hot water device 2A, hot water device 2B), air is introduced into the tank 52 (or tank 72, tank 352), but instead of air, gas such as carbon dioxide, hydrogen, oxygen, etc. may be introduced into the tank 52 (or tank 72, tank 352). In this case, a gas-filled tank (not shown) filled with gas may be connected to the gas inlet 104a of the gas inlet path 104 (or the gas inlet 300a of the gas inlet path 300).

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the heat source unit 10 is connected to the faucet 250, and the air pressure dissolution unit 50 is connected to the bathtub 130. In another embodiment, the heat source unit 10 may be connected to another heat utilization location, and the air pressure dissolution unit 50 may be connected to another liquid tank.

In the above-mentioned hot water device 2 (or hot water device 2A), the drain outlet 64a and the circulation opening 92a are provided on the underside of the tank lower part 522 and open downward. In another embodiment, the drain outlet 64a and the circulation opening 92a do not have to be provided on the underside of the tank lower part 522 and do not have to open downward. For example, at least one of the drain outlet 64a and the circulation opening 92a may be provided on the side of the tank lower part 522 and may open horizontally.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the plate-shaped member 406 is seamlessly and integrally formed with the first side wall portion 402. In another embodiment, the plate-shaped member 406 may be provided separately from the first side wall portion 402.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the plate-shaped member 406 is arranged along the horizontal direction. In another embodiment, the plate-shaped member 406 does not have to be arranged along the horizontal direction. For example, the plate-shaped member 406 may be arranged along a plane that is inclined with respect to the horizontal direction.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the plate-like member 406 is a flat plate having an approximately sector shape centered on the axis A. In another embodiment, the plate-like member 406 does not have to have an approximately sector shape centered on the axis A, and does not have to be a flat plate. For example, the plate-like member 406 may be a flat plate having an approximately circular shape centered on the axis A, or a plate having an approximately sector shape centered on the axis A and curving upward toward the circumferential end of the axis A.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the plate-shaped member 406 abuts against the case mounting portion 550 of the tank lower portion 522 from above. That is, the plate-shaped member 406 protrudes radially outward of the axis A beyond the inner surface of the tank lower portion 522. In another embodiment, the plate-shaped member 406 does not have to protrude radially outward of the axis A beyond the inner surface of the tank lower portion 522.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the electrode cover 446 is seamlessly and integrally formed with the upper plate portion 440, the enlarged diameter portion 442, and the side plate portion 444. In another embodiment, the electrode cover 446 may be provided separately from the upper plate portion 440, the enlarged diameter portion 442, and the side plate portion 444. In yet another embodiment, a part of the electrode cover 446 may be formed by the inner surface of the tank 52 (or the tank 72, the tank 352), and the remaining part of the electrode cover 446 may be seamlessly and integrally formed with the upper plate portion 440, the enlarged diameter portion 442, and the side plate portion 444. In this case, when the electrode cover 446 is viewed from below, the electrode cover 446 may cover the entire circumference of the high water level electrode 54a (or a single water level electrode 754a).

In the above-mentioned hot water device 2 (or hot water device 2B), the electrode cover 446 covers only the high water level electrode 54a. In another embodiment, the electrode cover 446 may cover at least one of the high water level electrode 54a, the low water level electrode 54b, and the earth electrode 54c. For example, the electrode cover 446 may cover both the high water level electrode 54a and the low water level electrode 54b.

In the above-described hot water device 2A, the electrode cover 446 covers only the single water level electrode 754a. In another embodiment, the electrode cover 446 may cover both the single water level electrode 754a and the earth electrode 754b.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), water level electrodes for detecting the water level in the tank 52 (or tank 72, tank 352) may be provided other than the high water level electrode 54a and the low water level electrode 54b (or a single water level electrode 754a).

The length of the high water level electrode 54a and the low water level electrode 54b (or the single water level electrode 754a) in the above-mentioned hot water device 2 (or the hot water device 2A, the hot water device 2B) may be changed as appropriate. That is, the first water level and the second water level (or the third water level) in the above-mentioned hot water device 2 may be changed as appropriate.

In the above-mentioned hot water device 2 (or hot water device 2A), the gas introduction mechanism 96 is disposed upstream of the tank circulation pump 94 in the tank circulation path 92. In another embodiment, the gas introduction mechanism 96 may be disposed downstream of the tank circulation pump 94 in the tank circulation path 92.

In the above-mentioned hot water device 2 (or hot water device 2A), the downstream end of the tank circulation path 92 is connected to the tank return path 74 downstream of the second pressure pump 90. In another embodiment, the downstream end of the tank circulation path 92 does not need to be connected to the tank return path 74, and may be provided separately from the tank return path 74 for the tank 52 (or tank 72).

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), a set amount of water is stored in the bathtub 130 during the bath filling operation based on the accumulated water amount detected by the water amount sensor 28. In another embodiment, the hot water device 2 (or hot water device 2A, hot water device 2B) may be configured to be provided with a water level sensor capable of detecting the water level of the bathtub 130, for example, and to store water at the set water level in the bathtub 130 during the bath filling operation based on the water level of the bathtub 130 detected by the water level sensor.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the user may be able to switch via the remote control 154 whether or not to execute the fine bubble generating operation in conjunction with the execution of the water filling operation.

In the above-mentioned hot water device 2 (or hot water device 2A, hot water device 2B), the control device 150 ends the fine bubble generating operation when the operating time of the fine bubble generating operation reaches the set time (YES in S16 of FIG. 13, YES in S16 of FIG. 19, or YES in S66 of FIG. 21). In another embodiment, the control device 150 may end the fine bubble generating operation even if the operating time of the fine bubble generating operation has not reached the set time. For example, the control device 150 may end the fine bubble generating operation when the user instructs the end of the fine bubble generating operation via the remote control 154.

The first predetermined time in the hot water device 2A and the set time for stopping the fine bubble operation in the hot water device 2 (or the hot water device 2A, the hot water device 2B) may be changed as appropriate.

(Correspondence)
As described above, in one or more embodiments, the hot water device 2 (or the hot water device 2A, the hot water device 2B) (an example of a fine bubble generator) includes the tank 52 (or the tank 72, the tank 352) having the first water supply port 74a (or the third water supply port 374) (an example of a supply port) and the drain port 64a (an example of a drain port), the mixing case 4 that is accommodated in the tank 52 (or the tank 72, the tank 352) and pressurizes and dissolves air (an example of gas) in the tank 52 (or the tank 72, the tank 352) in water (an example of a liquid) flowing into the tank 52 (or the tank 72, the tank 352), the tank return path 74 (an example of a supply path) that supplies water to the first water supply port 74a (or the third water supply port 374), the introduction pipe 46 (an example of an introduction path) that introduces water supplied to the first water supply port 74a and the second water supply port 74b (or the third water supply port 374) into the mixing case 4, and the tank 52 (or , tank 72, tank 352) from the drain 64a to the bathtub 130 (an example of a liquid tank), a fine bubble generating nozzle 142 provided in the tank forward path 64 and generating fine bubbles by reducing the pressure of the water in which air is pressurized and dissolved, a high water level electrode 54a and a low water level electrode 54b (or a single water level electrode 754a) (an example of one or more liquid level electrodes) that extend vertically inside the tank 52 (or the tank 72, tank 352) and outside the mixing case 4 and can detect whether the water level in the tank 52 (or the tank 72, tank 352) is equal to or higher than a predetermined water level, and an electrode cover 446 provided to cover the high water level electrode 54a (or a single water level electrode 754a) (an example of at least one of the one or more liquid level electrodes). The mixing case 4 is provided with a plurality of outflow parts 404 from which water flows out. Water supplied from the tank return line 74 to the first water supply port 74a (or the third water supply port 374) is introduced into the mixing case 4 through the inlet pipe 46, and flows out of the mixing case 4 from the multiple outlets 404, so that the water is stored in the tank 52 (or the tank 72 or the tank 352). When the electrode cover 446 is viewed from below (an example of a view along the extension direction of at least one of the one or more liquid level electrodes), the electrode cover 446 covers the entire circumference of the high water level electrode 54a (or the single water level electrode 754a).

According to the above configuration, the electrode cover 446 can suppress water droplets (an example of liquid droplets) scattered from the water surface (an example of a liquid surface) from adhering to the high water level electrode 54a (or the single water level electrode 754a) around the entire circumference of the high water level electrode 54a (or the single water level electrode 754a). This makes it possible to appropriately suppress the adhesion of water droplets to the high water level electrode 54a (or the single water level electrode 754a).

In one or more embodiments, the hot water device 2 (or the hot water device 2A, the hot water device 2B) further includes a first pressure pump 88 and a second pressure pump 90 (examples of pressure pumps) provided in the tank return line 74, a gas introduction mechanism 96 (or an air pump 302) (example of a gas introduction mechanism) capable of introducing air into the tank 52 (or the tank 72, the tank 352), and a control device 150. The control device 150 is configured to be capable of performing fine bubble generating operations including a pressurized water supply operation (an example of a pressurized liquid supply operation) in which the control device 150 drives the first pressurizing pump 88 and the second pressurizing pump 90 to pressurize and supply water from the tank return line 74 to the first water supply port 74a (or the third water supply port 374), and supplies water in which air has been pressurized and dissolved to the bathtub 130 from the drain outlet 64a via the tank forward line 64, and a first gas introduction operation (or a second gas introduction operation) in which air is introduced into the tank 52 (or tank 72, tank 352) by operating the gas introduction mechanism 96 (or air pump 302). When the first water level (or boundary water level), which is the lowest of the predetermined water levels detected by the high water level electrode 54a and the low water level electrode 54b (or a single water level electrode 754a), is set as the lower limit water level, if the water level in the tank 52 (or the tank 72, the tank 352) is detected to be lower than the lower limit water level during the first gas introduction operation (or the second gas introduction operation) in the fine bubble generation operation, the control device 150 stops the first gas introduction operation (or the second gas introduction operation) and performs only the pressurized water supply operation to raise the water level in the tank 52 (or the tank 72, the tank 352). The lower end of the electrode cover 446 is located lower than the lower end of the low water level electrode 54b (or the lower end of the single water level electrode 754a). That is, the lower end of the electrode cover 446 is located lower than the lower limit water level.

When the lower end of the electrode cover 446 is located lower than the water level in the tank 52 (or tank 72, tank 352), the electrode cover 446 prevents air contained in the water in the tank 52 (or tank 72, tank 352) from rising through the water and entering the inside of the electrode cover 446. In this case, inside the electrode cover 446, foam generation on the water surface is suppressed, and water droplets are suppressed from scattering above the water surface. According to the above configuration, during the execution of the fine bubble generation operation, the lower end of the electrode cover 446 is always located lower than the water level in the tank 52 (or tank 72, tank 352). Therefore, during the execution of the fine bubble generation operation, foam generation on the water surface is always suppressed inside the electrode cover 446, and water droplets are always suppressed from scattering above the water surface. Therefore, according to the above configuration, the adhesion of water droplets to the high water level electrode 54a (or a single water level electrode 754a) can be more appropriately suppressed.

In one or more embodiments, the one or more water level electrodes include a low water level electrode 54b (an example of a first liquid level electrode) capable of detecting whether the water level in the tank 52 (or the tank 352) is equal to or higher than a first water level (an example of a first liquid level), and a high water level electrode 54a (an example of a second liquid level electrode) capable of detecting whether the water level in the tank 52 (or the tank 352) is equal to or higher than a second water level (an example of a second liquid level) that is higher than a lower limit water level. The lower limit water level is the first water level. In the fine bubble generating operation, when the water level in the tank 52 (or the tank 352) is detected to be equal to or higher than the second water level while the first gas introduction operation (or the second gas introduction operation) is stopped, the control device 150 is configured to start the first gas introduction operation (or the second gas introduction operation) to lower the water level in the tank 52 (or the tank 352).

According to the above configuration, the control device 150 uses the low water level electrode 54b and the high water level electrode 54a to control the operation of the gas introduction mechanism 96 (or the air pump 302) so that the water level of the tank 52 (or the tank 352) transitions between the first water level and the second water level. The lower end of the electrode cover 446 covering the high water level electrode 54a is located lower than the lower end of the low water level electrode 54b (an example of a position lower than the first water level). According to the above configuration, in the hot water device 2 (or the hot water device 2B) that uses the low water level electrode 54b and the high water level electrode 54a (an example of two water level electrodes) to control the water level of the tank 52 (or the tank 352), the scattering of water droplets inside the electrode cover 446 is always suppressed. Therefore, in a hot water device 2 (or a hot water device 2B) that uses a low water level electrode 54b and a high water level electrode 54a to control the water level of a tank 52 (or a tank 352), adhesion of droplets to the high water level electrode 54a can be appropriately suppressed.

In one or more embodiments, the electrode cover 446 is provided to cover the high water level electrode 54a out of the low water level electrode 54b and the high water level electrode 54a.

When the control device 150 controls the operation of the gas introduction mechanism 96 (or the air pump 302) so that the water level of the tank 52 (or the tank 352) fluctuates between the first water level and the second water level, the low water level electrode 54b is frequently immersed in water, so slime is relatively unlikely to form on the low water level electrode 54b. On the other hand, the high water level electrode 54a is hardly immersed in water, so slime is relatively likely to form on the high water level electrode 54a. According to the above configuration, the electrode cover 446 is provided to cover the high water level electrode 54a. This makes it possible to appropriately suppress the adhesion of water droplets to the high water level electrode 54a, which is relatively prone to slime.

In one or more embodiments, the one or more water level electrodes include only a single water level electrode 754a (an example of a third water level electrode) capable of detecting whether the water level in the tank 72 (or the tank 352) is equal to or higher than the third water level (an example of the third water level). The electrode cover 446 is provided to cover the single water level electrode 754a. The lower limit water level is the third water level. When the control device 150 detects that the water level in the tank 72 (or the tank 352) is lower than the lower limit water level and stops the first gas introduction operation (or the second gas introduction operation) during the fine bubble generation operation, the control device 150 is configured to maintain the first gas introduction operation (or the second gas introduction operation) stopped until a first predetermined time has elapsed since the first gas introduction operation (or the second gas introduction operation) was stopped, and to start the first gas introduction operation (or the second gas introduction operation) after the first predetermined time has elapsed.

According to the above configuration, the control device 150 uses a single water level electrode 754a to control the operation of the gas introduction mechanism 96 (or air pump 302) so that the water level of the tank 72 (or tank 352) is maintained at or above the third water level. The lower end of the electrode cover 446 covering the single water level electrode 754a is located lower than the lower end of the single water level electrode 754a (an example of a position lower than the third liquid level). According to the above configuration, in the hot water device 2B that uses a single water level electrode 754a (an example of one liquid level electrode) to control the water level of the tank 72 (or tank 352), the scattering of water droplets inside the electrode cover 446 is always suppressed. Therefore, in the hot water device 2A (or hot water device 2B) that uses a single water level electrode 754a to control the water level of the tank 72 (or tank 352), the adhesion of water droplets to the single water level electrode 754a can be appropriately suppressed.

In one or more embodiments, the third water level is higher than the bottom end of the mixing case 4. The bottom end of the electrode cover 446 is lower than the bottom end of the mixing case 4.

The water supplied to the tank 72 (or tank 352) is stored according to the shape of the outer surface of the mixing case 4 and the shape of the inner surface of the tank 72 (or tank 352). Therefore, the horizontal cross-sectional area of the water stored in the tank 72 (or tank 352) is relatively large at a position lower than the lower end of the mixing case 4 and relatively small at a position higher than the lower end of the mixing case 4. Therefore, the amount of air rising in the water per unit area is relatively small at a position lower than the lower end of the mixing case 4 and relatively large at a position higher than the lower end of the mixing case 4. According to the above configuration, the electrode cover 446 extends to a position where the amount of air rising in the water per unit area is relatively small. Therefore, the electrode cover 446 can further suppress the air contained in the water in the tank 72 (or tank 352) from rising in the water and entering the inside of the electrode cover 446.

In one or more embodiments, when the second gas introduction operation is performed during the fine bubble generation operation while the pressurized water supply operation is being performed, the control device 150 is configured to interrupt the pressurized water supply operation when the second gas introduction operation starts, and to resume the interrupted pressurized water supply operation when the second gas introduction operation stops.

If the pressurized water supply operation is not interrupted when the gas introduction operation is performed, the amount of air supplied to the tank 352 in the gas introduction operation must be adjusted to exceed the amount of air consumed from the tank 352 in the pressurized water supply operation, which can complicate processing. According to the above configuration, the pressurized water supply operation is interrupted when the second gas introduction operation is performed, so there is no need to adjust the amount of air supplied to the tank 352 in the second gas introduction operation and the amount of air consumed from the tank 352 in the pressurized water supply operation, simplifying processing.

In one or more embodiments, when the first gas introduction operation is performed during the fine bubble generation operation while the pressurized water supply operation is being performed, the control device 150 is configured to perform the first gas introduction operation without interrupting the pressurized water supply operation.

When the pressurized water supply operation is interrupted to perform the gas introduction operation, the fine bubbles generated in the water of the bathtub 130 by the pressurized water supply operation may disappear while the gas introduction operation is being performed, and it may not be possible to continue to stably generate fine bubbles in the water of the bathtub 130. With the above configuration, there is no need to interrupt the pressurized water supply operation to perform the first gas introduction operation, and the pressurized water supply operation can be performed continuously. With the above configuration, it is possible to continue to stably generate fine bubbles in the water of the bathtub 130.

In one or more embodiments, the electrode cover 446 is seamlessly and integrally formed with the case lid 44 (an example of part of a mixing case).

In the manufacturing process of the hot water device 2 (or the hot water device 2A, the hot water device 2B), it may be desirable to reduce the number of parts. With the above configuration, the number of parts can be reduced compared to when the electrode cover 446 and the mixing case 4 are provided separately.

In one or more embodiments, the liquid is water. The liquid reservoir is a bathtub 130 in which a user bathes.

The above configuration allows the hot water device 2 (or the hot water device 2A, the hot water device 2B) that generates fine bubbles in the water of the bathtub 130 that the user uses for bathing to appropriately suppress adhesion of water droplets to the high water level electrode 54a (or the single water level electrode 754a).

Although the embodiments have been described in detail above, they are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above. The technical elements described in this specification or drawings are technically useful either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful.

2, 2A, 2B: hot water device 4: mixing case 10: heat source unit 12: first heat source unit 14: second heat source unit 16: water supply line 18: hot water outlet line 18a: hot water outlet temperature thermistor 20: bypass line 22: bypass servo 24: hot water supply line 26: valve 28: water volume sensor 30: circulation forward line 30a: circulation forward line thermistor 32: circulation return line 32a: circulation return line thermistor 34: bathtub circulation pump 36: water flow switch 40: case body 42: stirring section 44: case lid 46: introduction pipe 50: air pressure dissolving unit 52, 72, 352: tank 54, 754: electrode unit 54a: high water level electrode 54b: low water level electrode 54c, 754b: earth electrode 60: heat source return line 62 : First bath water passage 64 : Tank outward passage 64a : Drain port 66 : Communication passage 68 : Heat source outward passage 70 : Second bath water passage 74 : Tank return passage 74a : First water supply port 74b : Second water supply port 80 : First three-way valve 82 : Second three-way valve 84 : Check valve 86 : Tank water supply valve 88 : First pressure pump 90 : Second pressure pump 92 : Tank circulation passage 92a : Circulation opening 94 : Tank circulation pump 96 : Gas introduction mechanism 98 : Water inlet pipe 100 : Water outlet pipe 102 : Venturi tube 104 : Gas introduction passage 104a : Gas introduction port 106 : Gas introduction valve 130 : Bath 130a : Wall portion 132 : Bath adapter 132a : Front surface 132b : Bottom surface 134a : First discharge port 134b : First suction port 134c : Second suction port 134d : Second discharge port 136 : First water passage 136a : First discharge passage 136b : First suction passage 138 : Second water passage 138a : Second discharge passage 138b : Second suction passage 140a, 140b, 140c, 140d : Non-return section 142 : Fine bubble generating nozzle 150 : Control device 152 : Memory 154 : Remote control 200 : Water supply source 250 : Faucet 300 : Gas introduction passage 300a : Gas introduction port 302 : Air pump 374 : Third water supply port 400 : First bottom plate section 402 : First side wall section 404 : Multiple outlet sections 404a : First outlet section 404b : Second outflow portion 404c : Third outflow portion 404d : Fourth outflow portion 406 : Plate-shaped member 408 : Multiple mounting members 408a : First mounting member 408b : Second mounting member 408c : Third mounting member 420 : Second bottom plate portion 422 : Second side wall portion 424 : Insertion tube 425 : Spout port 426 : Fitting member 428 : Flange portion 440 : Upper plate portion 442 : Expanded diameter portion 444 : Side plate portion 446 : Electrode cover 520, 720 : Tank upper portion 522 : Tank lower portion 540, 740 : Electrode installation portion 550 : Case installation portion 754a : Single water level electrode

Claims (10)

a tank having a supply inlet and a discharge outlet;
a mixing case accommodated in the tank and pressurizing and dissolving the gas in the tank into the liquid flowing therein;
a supply channel for supplying the liquid to the supply port;
an introduction passage for introducing the liquid supplied to the supply port into the inside of the mixing case;
a discharge path for discharging the liquid stored in the tank from the discharge port to a liquid tank;
a fine bubble generating nozzle provided in the discharge path for generating fine bubbles by reducing the pressure of the liquid in which the gas is pressurized and dissolved;
One or more liquid level electrodes extending vertically inside the tank and outside the mixing case, capable of detecting whether the liquid level in the tank is equal to or higher than a predetermined liquid level;
and an electrode cover provided to cover at least one of the one or more liquid level electrodes,
The mixing case is provided with an outlet through which the liquid flows out,
The liquid supplied from the supply passage to the supply port is introduced into the mixing case through the introduction passage and flows out of the mixing case from the outflow portion, so as to be stored in the tank,
a micro-bubble generating device, wherein when the electrode cover is viewed along the extension direction of the at least one of the one or more liquid level electrodes, the electrode cover covers the entire circumference of the at least one of the one or more liquid level electrodes. A pressure pump provided in the supply path;
A gas introduction mechanism capable of introducing gas into the tank;
and a control device,
The control device includes:
a pressurized liquid supply operation in which the pressurizing pump is driven to pressurize and supply the liquid from the supply path to the supply port, and the liquid in which the gas is pressurized and dissolved is supplied from the discharge port to the liquid tank via the discharge path;
The gas introduction mechanism is operated to introduce the gas into the tank, and the gas introduction operation is performed to include a fine bubble generating operation.
When the lowest liquid level among the predetermined liquid levels detected by the one or more liquid level electrodes is defined as a lower limit liquid level,
In the fine bubble generating operation, when it is detected that the liquid level in the tank is lower than the lower limit liquid level during the gas introduction operation, the control device stops the gas introduction operation and performs only the pressurized liquid supply operation to raise the liquid level in the tank,
The fine-bubble generating device according to claim 1 , wherein a lower end of the electrode cover is located lower than the lower limit liquid level. the one or more level electrodes include a first level electrode capable of detecting whether or not the liquid level in the tank is equal to or higher than a first level, and a second level electrode capable of detecting whether or not the liquid level in the tank is equal to or higher than a second level that is higher than the first level,
the lower limit liquid level is the first liquid level,
The fine-bubble generating device of claim 2, wherein, during the fine-bubble generating operation, if it is detected that the liquid level in the tank is equal to or higher than the second liquid level while the gas introduction operation is stopped, the control device starts the gas introduction operation to lower the liquid level in the tank. The microbubble generator of claim 3, wherein the electrode cover is provided to cover the second liquid level electrode among the one or more liquid level electrodes. the one or more level electrodes include only a third level electrode capable of detecting whether or not the liquid level in the tank is equal to or higher than a third level;
the electrode cover is provided to cover the third level electrode,
the lower limit liquid level is the third liquid level,
The fine-bubble generating device of claim 2, wherein the control device is configured to, when detecting that the liquid level in the tank is lower than the lower limit liquid level during the fine-bubble generating operation and stopping the gas introduction operation, maintain the gas introduction operation stopped for a predetermined time after the gas introduction operation is stopped, and start the gas introduction operation after the predetermined time has elapsed. The third liquid level is at a position higher than a lower end of the mixing case,
The fine-bubble generating device according to claim 5 , wherein the lower end of the electrode cover is located lower than the lower end of the mixing case. The fine bubble generating device according to any one of claims 2 to 6, wherein the control device is configured to interrupt the pressurized liquid supply operation at the start of the gas introduction operation and resume the interrupted pressurized liquid supply operation at the stop of the gas introduction operation when the gas introduction operation is performed during the fine bubble generating operation. The fine bubble generating device according to any one of claims 2 to 6, wherein the control device is configured to execute the gas introduction operation without interrupting the pressurized liquid supply operation when the gas introduction operation is executed during the fine bubble generating operation. The microbubble generator according to any one of claims 1 to 8, wherein the electrode cover is seamlessly and integrally formed with a part of the mixing case. the liquid is water,
The fine bubble generating device according to claim 1 , wherein the liquid tank is a bathtub used by a user for bathing.