KR20060134870A - A fine air buble generator and a bath tub system using the same - Google Patents

Abstract

A micro-air bubble generator using a circulation pump with small capacity and bath tub system using the same is provided to allow downsizing of apparatus, to allow lightening of apparatus, to maintain water quality for long term, to reduce maintenance cost, and to allow active circulation of water with large quantity of air bubbles. The micro-air bubble generator using a circulation pump with small capacity and bath tub system using the same comprises: a water inlet(2); a circulation pump(3); a water inhaling pipe(4); a water circulating pipe(7); an air supply pipe(11) connected to the water inlet(2); inner containers established inside the water circulating pipe(7); and a water quality improving device(20) filled with ores(19).

Description

A fine air buble generator and a bath tub system using the same}

1 is an explanatory diagram showing an embodiment of the present invention.

2 is an explanatory diagram showing main parts of the embodiment.

FIG. 3A is an explanatory diagram of a discharge nozzle used in the above embodiment, and FIG. 3B is an explanatory diagram of a filter used in the discharge nozzle.

 4 is an explanatory diagram showing an example of a conventional micro bubble generator.

<Description of Major Codes>

1 Bath 2 Liquid Inlet

3 Circulation Pump 4 Liquid Suction Pipe

6 Liquid return port 7, 7 'liquid return line

11, 14 Air supply piping 17, 18 Inner cylinder

19 Ore 20 Liquid improvement means

Japanese Patent Laid-Open No. 2001-179241

The present invention provides a microbubble generating device capable of generating microbubbles in a low tank by circulating a liquid into and out of a low tank, mixing air into a liquid in a middle of the circulation path, and mixing a gas and a liquid. And a bath system using the same.

Background Art Conventionally, a micro bubble generator is provided in a bathtub to generate micro bubbles while circulating hot water in the bathtub. For example, as shown in FIG. 4, the microbubble generating device includes a liquid suction pipe 4 extending from the liquid suction port 2 installed in the bathtub 1 and reaching the suction side of the circulation pump 3; A venturi mechanism 5 for introducing air into the liquid suction pipe 4 and a liquid reflux pipe 7 extending from the discharge side of the circulation pump 3 to the reflux port 6 of the tub 1; It is provided so that the water of a bathtub can be circulated. Since the venturi mechanism 5 mixes air into the water to dissolve the air, the water is refluxed into the tub 1, so that the microbubbles 8 are large in the tub 1. It is supposed to occur.

Since the microbubble 8 has a function of adhering suspended matter such as when suspended in water, it is kept clean for a long time by removing it from the overflow pipe 9 provided in the tub 1. You can. In addition, since the micro-bubble (8) ruptures fine vibration and ultrasonic waves, it also brings the effect of giving a pleasant stimulus to the person using the water.

In such a microbubble generating device, in order to generate a lot of microbubbles 8, a large amount of air must be mixed in water, and in this case, a large load is placed on the circulation pump 3 in the apparatus shown in FIG. Because of this, problems such as cavitation, air lock, etc. occur, a large and expensive one must be used. However, when such a large and expensive circulation pump is used, not only the cost but also the entire microbubble generating device becomes large, and there is a problem in that the installation space is limited.

Therefore, in order to reduce the load of the circulation pump 3, the apparatus which provided the gas-liquid mixing tank downstream of the circulation pump 3 is proposed. (See Japanese Laid-Open Patent No. 2001-179241)

However, the above-mentioned problem is not sufficiently solved even by the above device, and therefore, development of a better device is required.

In order to solve this problem, the present invention can generate a large amount of microbubbles without using a large and expensive circulation pump, and in addition, an excellent microbubble generator and tub using the same to improve the quality of the refluxed liquid. To provide a system for that purpose.

In order to achieve the above object, the present invention is to take out the liquid in the reservoir to the outside of the reservoir, and then supply air to the liquid to make a mixed state of the gas and the liquid to return to the inside of the reservoir, thereby reducing the microbubble in the reservoir A microbubble generating device comprising: a liquid suction pipe extending from the liquid suction port of the low tank to the suction side of the circulation pump; a liquid reflux pipe extending from the discharge side of the circulation pump to the liquid reflux port of the low tank; An air supply pipe connected in the middle of the liquid reflux pipe, a gas-liquid mixing mechanism which is formed in the middle of the liquid reflux pipe and supplies air to the liquid flowing along the liquid reflux pipe, and is mixed in the middle of the liquid reflux pipe. It is installed on the downstream side than the gas-liquid mixing mechanism, and includes a liquid quality improving means for contacting the refluxed liquid with ore to improve the quality of the liquid. It will be the micro-bubble generating device consisting of a technological base.

In addition, the present invention is the gas-liquid mixing mechanism is formed on the inner side of the liquid reflux pipe, the front end portion is located upstream than the air supply pipe communication port connected to the air supply pipe connected to the liquid reflux pipe, the rear end is the air supply It is placed in a position opposed to the pipe communication port, the first inner cylinder of the shape that becomes narrower toward the rear end, and formed inside the liquid reflux pipe, the front end portion is installed downstream from the air supply pipe communication port, Another technical gist of the micro-bubble generating device including a second inner cylinder of a shape narrowing toward the end is described.

In addition, the present invention is another technical gist of the micro-bubble generating device further comprises a circulation pump air supply pipe connected to the suction side of the purified pump.

In addition, the present invention is further provided with an air regulator in the middle of each of the air supply pipe and the purified pump air supply pipe, the microbubble generation in the middle of the liquid reflux pipe is installed in the reverse side more downstream than the liquid improvement means The device is another technical point.

In addition, the present invention is another technical gist of the micro-bubble generating device in which the granular body of the quartz andesite glass bedrock is filled in the liquid improvement means.

In addition, the present invention is another technical gist of the micro-bubble generating device is formed in a column (column) in which the liquid-improving means is a liquid flows into one end and the liquid flows out to the other end.

In addition, the present invention is installed by connecting the microbubble generating device is connected to the liquid suction port and the liquid return port formed in the tub, the water stored in the tub is circulated through the microbubble generating device, the microbubble in the water refluxed into the tub Another technical gist of a bath system is characterized in that it is generated.

Best Mode for Carrying Out the Invention The best mode for carrying out the present invention will be described below with the accompanying drawings.

1 shows an embodiment in which the microbubble generating device according to the present invention is used for generating microbubbles while circulating water in a bathtub. A liquid suction port 2 is provided at a part of the side wall of the bathtub 1, and a liquid reflux port 6 is provided at another part of the side wall of the bathtub 1. The liquid suction pipe 4 extends from the liquid suction port 2 and is connected to the suction side of the circulation pump 3. In addition, the liquid return pipe 7 extends from the discharge side of the circulation pump 3 and is connected to the liquid return port 6 of the bathtub 1. In addition, a circulation pump air supply pipe 11 is connected to the suction side of the circulation pump 3 with the air regulator 10 interposed therebetween, and water and air sucked into the circulation pump 3 are in the circulation pump 3. Allow to mix at. The part indicated by 12 is a drain pipe for draining water.

In addition, the air supply pipe 14 is connected to the middle of the liquid return pipe 7 with the air regulator 13 interposed therebetween, and a special gas-liquid mixing mechanism 15 is installed at this connection portion. The part indicated by 16 is a drain pipe for draining water.

Referring to the gas-liquid mixing mechanism 15 in more detail, as shown in Figure 2, this portion is installed inside the liquid return pipe (7), the two inner cylinders of the shape that becomes narrower gradually toward the rear ( 17, 18). Among them, the first inner cylinder 17 provided upstream has a wider front end than the communication port 14a of the air supply pipe 14, and the rear end of which narrows is provided in the communication port. It is located in a position opposite to 14a. For this reason, the water flowing into the liquid return pipe 7 in a predetermined pressurized state by the circulation pump 3 is strongly injected from the narrower rear end thereof, and flows from the communication port 14a by the ejector effect. The air to be blown in by itself is injected by the injection force, and the mixture becomes a gas-liquid mixture (hereinafter referred to as "gas-liquid mixture flow"). Here, the terms 'upstream' and 'downstream' are set based on the direction of water flowing along the pipe. Like the river, the water flow is defined as 'upstream' and the opposite is 'downstream'. Side '.

As for the 2nd inner cylinder 18 provided in the downstream of the said 1st inner cylinder 17, the gas-liquid mixture flow is strongly strong in the rear end whose front end part is provided downstream from the said communication port 14a, and the width becomes narrow. It is sprayed, and a gas becomes a fine bubble and a part becomes a gas-liquid mixture stream melt | dissolved in water.

On the other hand, downstream of the portion where the gas-liquid mixing mechanism 15 is installed along the liquid reflux pipe 7, a means for improving the water quality of the refluxed water, and the liquid quality improving means 20 in which the ore 19 is filled therein. ), The gas-liquid mixture flows from above the liquid-improving means 20, flows down the gap between the ore 19, and flows out from below the liquid-improving means 20. The part indicated by 21 is an air vent regulator.

The gas-liquid mixture receives the collision energy generated when it flows while colliding with the ore 19 in the column 20, so that more air is dissolved in water while smaller bubbles are generated or bubbles are splashed. And when the ore contains components such as minerals that have a good effect on the body, the components are eluted to improve the water quality. In addition, dirty substances such as those contained in water are removed between the ores 19.

In addition, the gas-liquid mixture flowing out from the lower portion of the liquid-improving means 20 is discharged from the discharge nozzle 30 installed in the liquid return port 6 of the tub 1 via the liquid return pipe 7 '. 1) Not only the bubbles already discharged to the inside, but also air bubbles already dissolved, the dissolved air appears as fine bubbles. In this regard, the water in the bath 1 is formed by microbubbles (bubbles with an average particle diameter of 2 to 6 µm) generated from gas-liquid mixture flow (circulated at 1.9 liters of air per minute) circulated at a rate of 2.4 liters per minute. (300 liters) The whole becomes a milky white foam bath in 15 minutes.

In addition, the liquid return pipe 7 'is provided with a reverse valve 31 and a pressure gauge 32, and the air regulator 10, which is installed in the electric circulation pump air supply pipe 11 and the air supply pipe (14) 13), the pressure inside the liquid reflux pipes 7 and 7 'is optimal for generating microbubbles and the reflux is smooth. In this regard, an example in which the pressure in the liquid reflux pipe 7 is set to 0.253 MPa (2.5 atmospheres) and the pressure in the liquid reflux pipe 7 'is set to 0.203 MPa (2.0 atmospheres) as an optimal example of pressure balance. Can be mentioned.

Alternatively, as shown in FIG. 3 (a), the discharge nozzle 30 installed in the liquid return port 6 is provided with two filters 33 which maintain a constant interval in the cavity inside thereof. It is possible to discharge finer bubbles. As shown in FIG. 3 (b), the filter 33 has a structure in which the front and rear surfaces of the polyester nonwoven fabric 34 having a predetermined thickness are sandwiched by the SUS316 mesh net 35.

In addition, the nozzle hole 36 of the discharge nozzle 30 has a configuration in which two (or four) small holes having a diameter of 2 mm are drilled.

The bath system using the microbubble generating device of the above configuration has the advantage that the microbubble generating device is compact and does not occupy a place and can be provided at low cost. And since the gas-liquid mixture flows refluxed inside the bathtub 1 contains a lot of air and the bubbles are very fine and rich, a comfortable bathing feeling can be obtained. In addition, even if the water is repeatedly circulated, the water quality is improved every time, so that the water can be kept clean.

In the above embodiment, the arrangement of the first inner cylinder 17 on the upstream side between the two inner cylinders 17 and 18 of the gas-liquid mixing mechanism 15 is the communication port 14a of the air supply pipe 14. When the diameter L is set to 100, it is appropriate to arrange so that the length M of narrowing the rear end portion of the communication hole 14a to be below 70 is 80 to 80 (see Fig. 2). That is, when the M is less than 70, the length of the first inner cylinder 17 coming in below the communicating port 14a is too short, so that water easily escapes from the communicating port 14a. This is because there is a risk that the ejector effect is weakened because the length 17 enters below the communication port 14a is too deep. Among them, it is particularly preferable to set it to 75, in which case it is possible to mix air at a high ratio of air 8 to water 10 by volume ratio.

The balance of the diameters of the rear ends of the two inner cylinders 17 and 18 is also important in generating microbubbles. These dimensions also depend on the inner diameter of the liquid reflux pipe 7, but, for example, when the inner diameter of the liquid reflux pipe 7 is 10 mm, the diameter of the rear end of the first inner cylinder 17 is set to 5 mm, It is appropriate to set the diameter of the rear end of the second inner cylinder 18 to 3 mm. That is, by making the difference of both diameters large and small, the pressure of the gas-liquid mixture flow discharged | emitted from the 2nd inner cylinder 18 can be raised, the mixing ratio of water and air can be raised, and abundant microbubbles can be produced | generated.

In the above example, the ore may be used in any way as the ore 19 to be filled in the liquid quality improving means 20, but the particle size of the ore having an average particle diameter of 8 to 12 mm is particularly suitable.

Alternatively, the ore 19 may be a raw ore, a fired product thereof, or an artificial inorganic material produced artificially.

Among the ores, it is appropriate to contain a lot of silicic acid (SiO₂), especially in the state of improving the water quality, and also to contain it easily in the water. Among them, the amount of silicic acid eluted in the water is increased to contain 50% or more of silicic acid, which is preferable in view of effect. Examples of such ores include quartz andesite glass bedrock, rhyolite and feldspar, and especially, quartz andesite glass bedrock is rich in other mineral components and is optimal.

The quartz andesite glass bedrock is mineralogy and belongs to quartz andesites, and contains a lot of natural glass obtained by rapidly cooling magma (dark field). It is most suitable that it is rich in minerals and has a high content of crystal water of 4% or more (Song Kwang-seok, made by Mineser Fine Co., Ltd.) without being buried under 1000m underground and being weathered as pure igneous rock. That is, since the above-mentioned unweathered crystal water is contained a lot, many mineral components including silicic acid can be eluted at high concentration in water, and the effect can be very excellent.

In addition, the composition example of the said quartz andesite glass bedrock is as showing in following Table 1.

TABLE 1

              (Unit: weight%)

ingredient Yes (1) Yes (2) SiO ₂ 68.00 69.70 Al ₂ O ₃ 15.00 15.10 K ₂ O  3.38  5.10 CaO  2.95  2.24 C  2.74  0.00 Fe ₂ O ₃  2.29  1.64 Na ₂ O  2.22  3.34 B ₂ O ₃  1.91  2.05 MgO  0.80  0.218 TiO ₂  0.165  0.129 BaO  0.157  0.087 F  0.0803  0.103 MnO  0.0672  0.134 Cl  0.0598  0.0451 SrO  0.0505  0.0451 SO ₃  0.0343  0.0138 Rb ₂ O  0.0324  0.0294 P ₂ O5  0.0209  0.0227 ZrO ²  0.0177  0.0154 ZnO  0.00845  0.00556 Y ₂ O ₃  0.00786  0.0107 Ca ₂ O ₃  0.00242  0.00277 CuO  0.00209  0 As ₂ O ₃  0.00199  0.00249 Au ₂ O  0.00  0.00291 NiO  0.00  0.00 PbO  0.00  0.00 Cr ₂ O ₃  0.00  0.00 H ₂ O *  5.64  4.20

*: Number of crystals

In addition, the quartz andesite glass bedrock can bring about an excellent effect by using a mixture of a fired one and an unbaked one at a predetermined temperature section. In other words, the excellent function of the quartz andesite glass bedrock is also provided in the unbaked product, but by combining with the fired products that are fired by changing the firing conditions, all or part of the excellent function of the quartz andesite glass bedrock can be selectively increased. have.

When the quartz andesite glass bedrock is calcined, the firing method may be a conventionally known method, but the firing temperature is preferably set to 300 to 1500 ° C. In other words, if the firing temperature is less than 300 ° C., there is no substantial difference from that of the unfired. On the contrary, if the firing temperature is higher than 1500 ° C., the function of the fired product does not increase any more, and there is a possibility that the function may deteriorate in some cases.

In addition, it is known that the firing temperature and the function of the fired products obtained by the energy sources (petroleum, gas, electricity, heavy oil, coal, coke, sunlight, firewood) for the firing are slightly different. It is more suitable to set to 350-1350 degreeC. Alternatively, the firing time is preferably set to 15 to 180 minutes, and firewood is optimal as an energy source.

In the above example, the filter 33 is provided inside the discharge nozzle 30 in a state in which two sheets are kept at a constant interval. However, it is also possible to sandwich the urethane sponge between the two filters 33. In this way, the filter 33 can be maintained and held stably, which is appropriate. Of course, the configuration of the discharge nozzle 30 is not limited thereto. In addition, the same effect can be obtained even if the filter 33 etc. are provided directly in the liquid return port 6, without providing the said discharge nozzle 30. FIG.

In the above example, the microbubble generator of the present invention is used in a bath system, but the microbubble generator of the present invention is not limited to a bath tub system, but is widely used in leisure facilities, health facilities, etc. Applicable Or it can be used for the water circulation system in the water tank used for breeding and cultivating animals and plants, a washing tank, etc.

Next, the Example of this invention is described with a comparative example.

Example 1

The bathtub 1 (450 liters in volume) provided with the liquid suction opening 2 and the liquid return opening 6 was prepared, and the micro bubble generator of the structure shown in FIG. In addition, the ore 19 was filled with quartz andesite glass bedrock (Song ore, Mincerapine Co., average particle diameter 10mm) inside the liquid-improving means 20. The tank is filled with 300 liters of water, and the microbubble generator is activated to start the water circulation (2.4 liters of water circulation, 1.9 liters of air supply). Three baths were repeated three times for 20 minutes in a pair, and at each end of bathing, the amount of dissolved silicic acid, dissolved ammonia and dissolved oxygen were measured at the same time as sensory evaluation of water smell and water quality.

Example 2

As the ore 19, rhyolite is used. Otherwise, it bathed similarly to the said Example 1, and performed the same evaluation and measurement.

Comparative Example 1

In the conventional apparatus shown in FIG. 4, the liquid quality improvement means 20 which filled Example 2 and the oriental ore 19 in the middle of the liquid reflux piping 7 was used. Other than that was bathed similarly to Example 2, and the same evaluation and measurement were performed.

Comparative Example 2

The conventional apparatus shown in FIG. 4 was used. Otherwise, it bathed similarly to the said Example 2, and performed the same evaluation and measurement.

The result of evaluation and measurement of the said Example 1, 2 and Comparative Examples 1 and 2 was put together in following Tables 2 and 3, and was shown.

[Table 2]

Example 1 Example 2      Smell, water quality After the first bath No smell Soft and not bleeding No smell Mild and not smoky After the second bathing No odor Mild and not moisturizing Smooth skin. No odor Mild and does not leave skin Smooth skin After the third bath No odor Mild and does not leave skin Smooth skin No odor Mild and does not leave skin Smooth skin      Dissolved silicate Existing  3.8 ppm / liter  3.8 ppm / liter After the first bath 17.0 ppm / liter  4.6 ppm / liter After the second bathing 23.0 ppm / liter  4.6 ppm / liter After the third bath 33.0 ppm / liter  4.7 ppm / liter     Dissolved Ammonia Existing  0.0 ppm / liter  0.0 ppm / liter After the first bath  5.8 ppm / liter 23.8 ppm / liter After the second bathing  4.5 ppm / liter 35.1 ppm / liter After the third bath  4.0 ppm / liter 39.7 ppm / liter       Dissolved oxygen (DO) Existing  4.5 mg / liter  4.5 mg / liter After the first bath  9.9 mg / liter  8.5 mg / liter After the second bathing 10.3 mg / liter  9.3 mg / liter After the third bath 10.7 mg / liter  9.5 mg / liter

Table 3

Comparative Example 1 Comparative Example 2      Smell, water quality After the first bath It smells a bit smelly, but the time turned out It smells a bit. When the water was rough After the second bathing Smells mild, but more exposed times The smell is strong. The water quality is hard. After the third bath Smells mild, but more time to rise Intense smell, water quality is rough, more time to float      Dissolved silicate Existing  3.8 ppm / liter  3.8 ppm / liter After the first bath  4.1 ppm / liter  3.8 ppm / liter After the second bathing  4.3 ppm / liter  3.8 ppm / liter After the third bath  4.3 ppm / liter  3.9 ppm / liter      Dissolved Ammonia Existing  0.0 ppm / liter  0.0 ppm / liter After the first bath 24.7 ppm / liter 35.6 ppm / liter After the second bathing 35.9 ppm / liter 41.3 ppm / liter After the third bath 42.8 ppm / liter 57.9 ppm / liter      Dissolved oxygen (DO) Existing  4.5 mg / liter  4.5 mg / liter After the first bath  7.4 mg / liter  4.7 mg / liter After the second bathing  8.1 mg / liter  4.5 mg / liter After the third bath  8.3 mg / liter  4.6 mg / liter

From the above results, Examples 1 and 2 can maintain a good smell and water quality compared to Comparative Examples 1 and 2, or have a large amount of dissolved oxygen, so that a comfortable bathing can be realized. In particular, the quartz andesite glass bedrock is used as the ore 19, rich in silicic acid and oxygen as minerals, excellent in ammonia removal performance, and more comfortable bathing can be realized.

Therefore, in the microbubble generating device according to the present invention, air is supplied from two parts of the liquid circulation path, and in addition, the air supply part on the downstream side of the circulation pump combines two special inner cylinders and has a high ratio by the ejector effect. Since the furnace air can be mixed with the liquid, it is possible to operate even a small-capacity circulation pump, thereby realizing compactness, light weight, and low cost of the device.

In addition, the air is mixed at a high ratio with respect to the liquid, so that the solubility in the liquid is high, and the effect of mixing the gas and the liquid by the two special inner cylinders is further added, so that the microbubbles of the liquid refluxed inside the tank are added. It becomes a very small microbubble (for example, 2-6 micrometers), and becomes more abundant.

In addition, since the mixed flow of gas and liquid refluxed into the tank passes through the liquid quality improving means, not only does it contain microbubbles, but the reflux of the liquid itself is improved, so that the liquid in the tank is not dirty. And the effect of maintaining a good state over a long period of time.

In particular, an air regulator is installed in the middle of each of the circulation pump air supply pipe and the air supply pipe, and a reverse valve is installed downstream from the liquid improvement means in the middle of the liquid return pipe, thereby providing the two air regulators and the reverse. It is possible to easily set the pressure in the upstream pipe and the pressure in the downstream pipe to a predetermined pressure difference from the liquid quality improvement means, and as a result, the reflux of the gas-liquid mixture to the low tank more smoothly. It produces the effect that it can.

In addition, the liquid substance improving means is formed in a column (column) in which liquid flows into one end and liquid flows out to the other end, and by filling the granular body of quartz andesite glass stool in the liquid substance improving means, The collision energy at the time of collision of the granular body and gas-liquid mixture of the glass bed rock increases the air solubility and the rich mineral components (especially silicic acid) contained in the quartz andesite glass bed rock are eluted. The refluxing liquid has the effect of having excellent quality.

In addition, the microbubble generating device is connected to the liquid suction port and the liquid return port formed in the tub, so that the water stored in the tub circulates through the microbubble generating device, the microbubble may be generated in the water refluxed into the tub. The bath system can provide abundant microbubbles, provide a comfortable bathing feeling, and keep the water clean without odors and contamination even if the water is repeatedly circulated.

Claims (8)

In the microbubble generating apparatus which draws out the liquid in a low tank, supplies air to this liquid, makes it the mixed state of a gas, and returns it to the inside of a low tank, and produces | generates a micro bubble in a low tank. A liquid suction pipe extending from the low liquid suction port to the suction side of the circulation pump; A liquid reflux pipe extending from the discharge side of the circulation pump to the liquid reflux port of the tank; An air supply pipe communicating with the liquid reflux pipe; A gas-liquid mixing mechanism which is formed in the middle of the liquid reflux pipe and supplies air to the liquid flowing along the liquid reflux pipe; A liquid quality improving means installed in the middle of the liquid reflux pipe downstream of the gas-liquid mixing mechanism and contacting the refluxed liquid with ore to improve the quality of the liquid; Microbubble generating device, characterized in that comprising a. The gas-liquid mixing mechanism of claim 2, It is formed inside the liquid return pipe, the front end is located upstream than the air supply pipe communication port is connected to the air supply pipe, the rear end is placed in a position opposite to the air supply pipe communication port, A first inner passage having a narrower width toward the rear end portion; A second inner cylinder formed inside the liquid reflux pipe, having a front end disposed downstream from the air supply pipe communication port, and having a narrower width toward the rear end; Microbubble generating device, characterized in that comprising a. The microbubble generating device according to any one of claims 1 and 2, Microbubble generating device, characterized in that further comprising a circulation pump air supply pipe communicating with the suction side of the purified pump. According to claim 3, The air supply pipe and the circulation pump air supply pipe, An air regulator is further provided in each middle, and in the middle of the liquid return pipe, a microbubble generating device, characterized in that a reverse valve is further installed on the downstream side than the liquid-improving means. The liquid quality improving means according to any one of claims 1, 2, and 4, A fine bubble generator, characterized in that the granular body of quartz andesite glass bedrock is filled inside. According to claim 3, The liquid improvement means, A fine bubble generator, characterized in that the granular body of quartz andesite glass bedrock is filled inside. 7. The liquid improvement means according to any one of claims 1, 2, 4 or 6, The micro-bubble generating device, characterized in that formed in a column (column) in which liquid is introduced into one end portion and the liquid flows out the other end portion. The microbubble generating device according to claim 1 is connected to the liquid suction port and the liquid return port formed in the bathtub, so that the water stored in the bathtub circulates through the microbubble generating device and is refluxed into the bathtub. Bath tub system, characterized in that the micro-bubbles are generated.

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