JP3557718B2 - Circulating warm bath - Google Patents

Description

[0001]
[Industrial applications]
TECHNICAL FIELD The present invention relates to a circulating warm water bath for cleaning and sterilizing bath water and circulating the bath water while heating the bath at the same time.
[0002]
[Prior art]
In recent years, circulating warm water baths have been spreading in pursuit of comfort and convenience of life. This circulating warm bath circulates bath water, filters the bath water by a filtration device, purifies the bath water, heats the bath water by providing a heater, and can enter the bath at any time for 24 hours.
[0003]
Therefore, a conventional circulating warm bath will be described. FIG. 2 is a schematic overall view of a conventional circulating warm water bath system. 1 is a bathtub, 2 is a circulation pump for circulating bathwater, 3 is a circulation path, 5 is a filtration device, and a filtering material 4 is filled inside. 6 is a bath water inlet, 7 is a discharge port, 8 is a heater for heating the circulating bath water, 9 is an injector for sucking ozone gas, and 10 is an ozone generator for generating ozone gas.
[0004]
The operation of the conventional circulating warm bath constructed as described above will be described below. The circulation pump 2 rotates to suck the bath water in the bathtub 1 from the suction port 6 and circulation starts. The bath water is transferred to the heater 8 and heated to an appropriate temperature. The heated bath water is transferred to the filtration device 5 via the circulation path 3. The filtration device 5 is filled with a filter material 4 such as sand, ceramic balls or a wound filter having a diameter of 0.2 mm to 2 mm to which bacteria and other microorganisms are fixed. The turbid component is adsorbed on the filter medium 4 and decomposed by other microorganisms, and the bath water is filtered. Zoogloea ramigera, Sphaerotilus natans, and the like are suitable for these bacteria (Fuji Techno Systems, Inc., “Utilization and Application Technical Documents of Microorganisms”, published in July 1975). The filtered and cleaned bath water passes through the injector 9. At this time, the injector 9 sucks the ozone gas generated by the ozone generator 10, so that the ozone gas is mixed with the bath water. The mixed ozone gas sterilizes bacteria and the like growing in the bath water and oxidizes and decomposes the remaining organic matter, so that the bacteria and other microorganisms fixed to the filter medium 4 can further easily decompose the ozone gas. Thus, the filtration performance of the filtration device 5 can be improved. The bath water that has passed through the injector 9 flows back to the bathtub 1. The above-described circulation operation is repeated at appropriate intervals to remove the turbid components of the bath water, thereby purifying the bath, and furthermore, having a sterilizing effect so that the bath can be taken at any time.
[0005]
In addition, a hair catcher or the like is provided at the suction port 6 of the bath water to preliminarily filter relatively large-sized hair, scale, fat, and the like mixed in the bath water, thereby extending the filtration life of the filtration device 5. Some do.
[0006]
[Problems to be solved by the invention]
However, a method of providing a filtering material in a filtering device, capturing dirt, fat, and the like, which are turbid components in the bath water, by the bacteria and microorganisms fixed to the filtering material, and filtering the bath water is based on the method of removing bacteria, microorganisms, and the like. There was a problem that the bathtub water had to be frequently replaced during the first month of operation until it was sufficiently fixed and the decomposition ability was exhibited.
[0007]
Most of these turbid components are negatively charged on the surface (negative zeta potential) and repel each other in bath water to form a uniform emulsion (emulsion), which is dispersed to remove the emulsion. In addition, microfiltration using a hollow fiber membrane with a filtration accuracy of 0.1 μm (which can filter most of 0.1 μm particles) or a special filter with a positive zeta potential is used. A turbid component having a negative potential has to be adsorbed and removed, and there is a problem that the cost of the filter material is high and the maintenance is complicated.
[0008]
Mountain sand, ceramic balls, wound filters, etc. are inexpensive filter media, but their zeta potential is negatively charged, and if these are used as filter media, they repel turbid components in the bath water and almost all turbid components There is also a problem that the water passes through without being filtered.
[0009]
In addition, a method of providing a hair catcher or the like and preliminarily filtering relatively large-sized hair, grime, fat, and the like mixed in the bath water is easily clogged when the bathtub is frequently used. However, there is a problem that the hair catcher and the like must be frequently cleaned or replaced. There is also a problem that germs proliferate in the hair catcher and generate an odor.
[0010]
In addition, when the bath water is back-flushed and backwashed to remove the turbid components trapped by the filter media, bacteria and other microorganisms once fixed to the filter media are also removed at the same time, and the turbid components such as dirt and fat are removed. There was also a problem that the decomposition ability was reduced.
[0011]
Therefore, the present invention solves the above-mentioned conventional problems, and easily filters fine turbid components from the initial stage of operation, does not require a hair catcher, etc., facilitates backwashing work, and has a filter material closing life. It is an object of the present invention to provide a circulating warm water bath which is long, small, easy to maintain, and sanitary.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a circulating pump for circulating bath water in a bath tub, a pair of electrodes provided , and electrolysis of circulated bath water to elute metal ions from each of the electrodes to form a hydroxide. a electrolytic cell for generating, a circulating bath apparatus back into bath with the bath water containing turbidity components are agglomerated and filtered through a filtration apparatus with hydroxide generated in the electrolytic cell, to the respective electrodes The polarity of the applied voltage is switched at regular intervals, and at the time of switching, the application of the voltage is stopped for a predetermined time .
[0013]
It is desirable that a circulation pump be provided between the electrolytic cell and the filtration device. Preferably, the electrode is made of Al, Fe, Ni or an alloy thereof.
[0014]
Further, a control unit for controlling and supplying electric power to the electrolytic cell is provided.
Further, it is desirable to provide a heater for heating the bath water.
[0015]
Further, it is preferable to provide a flow rate detection unit for detecting the flow rate of the bath water.
[0016]
[Action]
The circulating warm water bath of the present invention is provided with a circulating pump that circulates bath water in a bathtub, and a pair of electrodes, which is provided to electrolyze circulated bath water to elute metal ions from each of the electrodes to generate hydroxide. a electrolytic bath, the bath water containing turbidity components are agglomerated to return to the bath and filtered through a filtration apparatus with hydroxide generated in the electrolytic cell, the voltage applied to each of the electrodes at regular intervals Since the polarity is switched and the application of voltage is stopped for a predetermined time at the time of switching , turbid components such as minute scales and fats can be flocculated, filtered with a filtration device and kept in clean bath water. it can. In addition, the electrode life is long, and there is almost no deterioration due to adhesion to the electrode surface.
[0017]
Further, since the circulation pump is provided between the electrolytic cell and the filtration device, the bath water and the hydroxide can be sufficiently mixed, and the aggregation of the turbid component due to the hydroxide can be facilitated.
[0018]
Further, since the electrode is made of Al, Fe, Ni or an alloy thereof, a hydroxide of such a metal can be easily formed.
[0019]
In addition, since the control unit that controls and supplies power to the electrolytic cell is provided, the polarity of the voltage to the electrode provided in the electrolytic cell can be switched, and the power supply can be turned on and off at regular intervals. it can.
[0020]
Further, since the heater for heating the bath water is provided, the bath water can always be kept at an appropriate temperature.
[0021]
Further, since the flow rate detection unit for detecting the flow rate of the bath water is provided, the circulation flow rate of the bath water can be controlled, and the bath water can be effectively filtered.
[0022]
【Example】
Hereinafter, a circulating warm bath according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a schematic overall view of a circulating warm water bath in one embodiment of the present invention. In FIG. 1, 1 is a bathtub, 2 is a circulation pump, 3 is a circulation path, 4 is a filter material, 5 is a filtering device, 6 is a suction port, 7 is a discharge port, 8 is a heater, 11 is a flow rate detection unit, and 12 is An electrolytic cell, 13 is an electrode, 14a and 14b are solenoid valves, 15 is a drainage channel, and 16 is a control unit. The operations and functions of the components having the same reference numerals as those in the conventional example are basically the same, and the description will be omitted. Electric power is supplied from the control unit 16 to the circulation pump 2, the circulation pump 2 rotates, the bath water in the bathtub 1 is sucked, and is transferred from the suction port 6 to the electrolysis tank 12 as shown by an arrow (solid line). The electrolytic cell 12 is formed of a closed container, and a part thereof has an inlet through which bath water flows in and an outlet through which electrolyzed bath water flows out, and a pair of electrodes 13 are provided inside thereof so as to face each other. I have. The electrodes 13 are connected to the control unit 16, respectively. The shape of the electrode 13 may be a plate shape, a mesh shape, or the like, and preferably has a large contact area with bath water. When a DC voltage is applied from the control unit 16, the circulating bath water is electrolyzed, and metal ions are eluted from the anode side to generate hydroxide. The electrode 13 is made of Al, Fe, Ni metal or an alloy thereof, and the anode and the cathode are preferably made of the same metal or alloy. This alloy may be one in which Al, Fe and Ni are independently alloyed with another metal, or one formed of at least two of Al, Fe and Ni. However, it is important to select a metal that forms an alloy that is harmless to the human body. The generated metal ions and metal hydroxides are positively charged with cations and have excellent cohesion, and can easily aggregate turbid components such as dirt and fats charged with anions.
[0024]
The agglomerated turbid components form flocs and have a size of about 40 μm or more, and are mixed and dispersed in the bath water. On the other hand, the positively charged one in the bath water is adsorbed on the cathode side. Since the electrode 13 used here is made of Al, Fe, Ni or an alloy thereof, it easily forms a hydroxide having excellent cohesion and is harmless to the human body. Above all, Al metal is safe for the human body, and the generated zeta potential of the hydroxide is higher than others, so that the zeta potential easily aggregates negative turbid components, and the oxide is stable. This is suitable for the electrode 13 without contaminating the bath water, and there is no possibility of polluting the environment even if the washing water washed with the electrode flows out. Therefore, in this embodiment, the Al electrode 13 is used.
[0025]
The bath water that has passed through the electrolytic cell 12 is stirred and mixed while being transferred through the circulation pump 2 by placing the circulation pump 2 at an appropriate position immediately after or behind the bath water, and the coagulation effect is further enhanced. That is, since the circulating pump 2 uses a turbo-type pump or the like, the impeller rotates during operation, and the rotation of the impeller produces a stirring action of bath water. In order to enhance the coagulation effect, the circulation pump 2 is preferably provided between the electrolytic cell 1 and the filtration device 5, preferably immediately after the electrolytic cell 12. As a result, the time for forming the flocs up to the filtration device 5 can be increased, and the turbid components can be easily aggregated, and the increased turbid components can be efficiently filtered. The bath water containing the turbid component flocs transferred by the circulation pump 2 is controlled by the flow rate detection unit 11 detecting the flow rate and the control unit 16 controlling the rotation speed of the circulation pump 2, and an arrow (solid line). Is sent into the filtration device 5 via the electromagnetic valve 14a as shown by. In the filtration device 5, the bath water flows down the surface of the filtration material 4 filled in the filtration tank, and is filtered there. Here, the flow rate of the bath water is suitably 20 to 30 L / min in the case of ordinary households, and if it is more than this, the coagulation by the metal ions and the metal hydroxide becomes insufficient, or the turbid components are fixed to the filter material 4 and trapped. Bacteria (Zoogloea ramigera, Sphaerotilus natans, etc.) and other microorganisms may be easily detached. If the flow rate is lower than this, when the power applied to the electrolytic bath 12 is constant, the concentration of hydroxide of metal ions contained in the circulated bath water increases, and the surplus water on the bath surface of the bathtub 1 is increased. A metal hydroxide film is formed and is not hygienic. For this reason, the flow rate detection unit 11 always detects the flow rate of the circulating bath water, and sends a signal to the control unit 16 when the flow rate becomes lower than a predetermined flow rate due to clogging of the circulation system path and the like. Can be stopped, and the supply of electric power to the electrolytic cell 12 can be stopped to stop the electrolysis.
[0026]
The floc of the turbid component is adsorbed on the surface of the filter medium 4 or is moored in a large number of gaps between the filter mediums 4 to filter the bath water. The filtering medium 4 is formed of a spherical ceramic ball (for example, composed of silica and alumina) having a diameter of about 0.4 mm to 1 mm, and has a filtering accuracy of about 40 μm capable of physically filtering, and a filtering accuracy of about 40 μm or more. The cloudy components that have formed flocs can be physically filtered. The filtered bath water is heated to an appropriate temperature by the heater 8 through the solenoid valve 14b, and returns to the bathtub 1 again. Here, the control unit 16 controls the rotation speed of the circulation pump 2 so that the flow rate becomes a preset flow rate. Further, the operation of continuously applying a predetermined DC current to the pair of electrodes 13 and thereafter turning off the electrode for a certain period of time, switching the polarity and applying the DC current again for a certain period of time is repeated. This repetitive operation is an effective method for removing the turbid component adhering to the electrode 13 and extending the life of the electrode as described later. The heater 8 is controlled and supplied with electric power necessary to maintain the bath water at a predetermined temperature. Although not shown here, a temperature sensor is provided to detect the temperature of the bath water and control the power supplied to the heater 8.
[0027]
The operation of the circulating warm bath configured as described above will be described below with reference to FIG. FIG. 1 is a schematic structural diagram of a circulating warm water bath. Here, a case where Al is used for the pair of electrodes 13 will be described. When the circulation pump 2 is energized by the control unit 16, the circulation pump 2 starts rotating and starts sucking bath water in the bathtub 1 from the suction port 6 as shown by an arrow (solid line). The predetermined circulation amount of the bath water is determined by the rotation speed of the circulation pump 2 at which the set flow amount is stored in the flow detection unit 11, and the control unit 16 controls the circulation pump 2 so as to reach this rotation speed. The sucked bath water is transferred to the electrolytic cell 12 and electrolyzed, and at the same time, Al ions are eluted to the anode side of the electrode 13. The eluted Al ions react with the hydroxyl groups in the bath water to produce aluminum hydroxide. Aluminum hydroxide generated by this reaction aggregates minute turbid components to form flocs. The bath water containing the flocculated flocs is sent through the circulation path 3, the flow rate is detected by the flow rate detecting unit 11, and is transferred from the solenoid valve 14a to the filtering device 5 as shown by an arrow (solid line). The flocculated floc contained in the transferred bath water is about 40 μm or more and is sufficiently large. Therefore, the filter medium 4 such as sand, ceramic balls or a wound filter, which is usually used, can be sufficiently filtered to clarify the bath water. Can be
[0028]
In addition to the physical filtration, the zeta potential of the floc is slightly positively charged, and the zeta potential of the commonly used filter medium 4 such as a ceramic ball and a wound filter is negatively charged. The turbid component is electrochemically adsorbed by the action of force or van der Waals force, and the bath water can be filtered.
[0029]
As described above, since the turbid components are aggregated to generate flocs having a size of about 40 μm or more, the turbid components can be easily removed only by passing through the filter material 4, and the zeta potential of the flocs is slightly positively charged. Therefore, it can be efficiently removed by being adsorbed on the filter medium 4. In addition, since bacteria and other microorganisms fixed to the filter medium 4 further capture dirt, fat, and the like, which are turbid components in the bath water, it is possible to sufficiently filter even fine shapes. The filtered bath water is transferred from the solenoid valve 14b to the heater 8, heated to an appropriate temperature, and discharged from the outlet 7 into the bathtub 1. The method of forming Al ions and Al hydroxide in bath water to aggregate turbid components by using Al as an electrode as in this embodiment has a high zeta potential compared to other metals and easily aggregates turbid components. Not only can it be used, it has a long life and is harmless to the human body, does not pollute the bath water with Al oxide, and is suitable for a circulating warm water bath.
[0030]
By the way, the anode of the electrode 13 provided in the electrolytic cell 12 is gradually and slightly consumed due to elution of Al ions, and positively charged ions and turbid components adhere to the cathode surface, and the electrode surface is oxidized. . For this reason, if the electrolysis operation is continued without changing the polarity of the electrode 13, the electrolysis current is reduced by the attached component, and the elution amount of Al ions from the anode is reduced. In about one week, the electrolysis operation cannot be continued. Therefore, in this embodiment, the control unit 16 controls the voltage applied to the electrode 13 so that the polarity is switched at regular intervals. As described above, since both the anode 13 and the cathode 13 are made of Al metal, even if the polarity of the electrode 13 is switched, it is possible to generate Al ions from the anode side and easily generate Al hydroxide. it can. At the same time, products such as aluminum oxide formed on the surface of the electrode 13 on the anode side are removed by this polarity switching, and the surface of the electrode 13 always has Al metal exposed. However, when the polarity of the electrode 13 is simply switched, a new substance adheres to the substance that has adhered to the surface of each electrode, so that the electrode life is shortened. In order to prevent this, in the present embodiment, the application of the voltage is stopped for a certain time when the polarity of the electrode 13 is switched, and thereafter the polarity is switched and the application of the voltage is started. When the application of the voltage is stopped for a certain period of time in this way, the deposits that have been electrically attracted by the Coulomb force or the like and adhered to the electrode surface are released from the adsorption and become free. The released and free deposits are separated by the flow of bath water transported in the electrolytic cell 12, and are transported together with the bath water to the filtration device 5 where they are filtered. Thereafter, by switching the polarity of the electrode 13, the polarity can be switched after the electrode surface is cleaned. The time for stopping the application of the voltage may be as long as or less than the energizing time, and the time may be set according to the degree of the turbidity component of the bath water. When the turbidity component is large, the stop time of the voltage application may be shortened, and the polarity switching interval of the electrode 13 may be shortened.
[0031]
Here, a bath water of a normal turbid component having a turbidity of about 3 is circulated, an Al metal having a size of 20 mm × 40 mm × 3 mmt is used for the electrode 13, a current of 60 mA is supplied for about 1 hour and stopped for about 15 minutes. After that, the operation of switching the polarity, turning on electricity for about 1 hour, stopping again for about 15 minutes, and then switching the polarity again and driving for about 1 hour was repeated once a day, and it was possible to use it for about 1 year. Was. The life of the electrode 13 was consumed by elution of Al ions, and was hardly affected by deterioration due to adhesion to the electrode surface.
[0032]
In this embodiment, since the floc of the turbid component is formed in the electrolytic cell 13 in a short time, the diameter of the filter medium 4 to be used can be increased to about 0.4 mm or more, and the bath water having the turbidity of about 3 is used. The time for setting the value to 1 or less is as short as about 1 hour. In the conventional method in which floc is formed by adding a flocculant, the time required for floc formation becomes longer, and the effect is remarkable as compared with about 12 hours to reduce turbidity to 1 or less. Further, although ceramic balls are used as the filter material 4 here, sand, glass balls, a wound filter, or the like may be used without being affected by the material. Even if the filtration accuracy of these filter media 4 is coarse, about 250 μm, most of the flocs are adsorbed by the filter media 4 and filtered. There is no need to use a small one, and the price can be kept low. Further, even if the size of the filter medium 4 is widely distributed, about 0.1 mm to 2 mm in diameter, it does not affect the filtering effect at all. The shape may be any shape such as a sphere or a cubic, as long as it has a large contact area with the bath water and is easy to fix bacteria and microorganisms that capture and degrade turbid components.
[0033]
On the other hand, when the bath water is repeatedly circulated, the turbid component adheres to and accumulates on the surface of the filter material 4 in the filter device 5 to cause clogging, or the turbid component due to bacteria or microorganisms fixed to the filter material 4. Is reduced, and the filtration capacity is significantly reduced. In order to prevent this, in the present embodiment, the inside of the filtration device 5 is washed by a back washing operation (back washing) about twice a day. Therefore, this backwash will be described. The bath water is circulated while being filtered, but at a predetermined time, a timer provided in the control unit 16 is operated, and the control unit 16 transmits a switching signal to the solenoid valve 14a, and causes the passage of the solenoid valve 14a to flow. Switch from AB to BC. Next, a switching signal is transmitted to the electromagnetic valve 14b, and the flow path of the electromagnetic valve 14b is switched from EF to DE. By doing so, the bath water sucked from the bathtub 1 by the circulation pump 2 flows through the electrolytic bath 12 and the flow rate detection unit 11, and reaches the filtration device 5 from the flow path DE of the solenoid valve 14b. By the bath water transferred from the lower part to the upper part of the filter device 5, the filter medium 4 is stirred and floated in the bath water as the wash water, and the filter medium 4 repeatedly collides with each other, and the turbid component adhering to the surface is separated. Then, the filter medium 4 is washed. The bath water containing the turbid component is drained from the drain channel 15. In this way, the backwashing operation is completed, the flow path of the solenoid valve 14a is switched from BC to AB by the switching signal from the control unit 16, and the flow path of the solenoid valve 14b is changed from DE to EF. To return to the original bath water circulation filtration operation.
[0034]
In this embodiment, the heater 8 is provided downstream of the filtration device 5, but may be provided in any circulation path 3 in the circulation warm bath without being limited to this position. You can choose a position that can be easily made. Further, the heater 8 may be directly provided in the bathtub 1 in addition to the above-mentioned flow path. In this case, maintenance of the heater 8 becomes easy, and when the circulation of the bath water is unnecessary, the heating can be performed while the circulation of the bath water is stopped.
[0035]
It is also appropriate to provide an activated carbon tank or the like (not shown) for removing various bacteria and the like generated inside the circulating warm bath. In this case, it is preferable to provide the filter between the filtration device 5 and the heater 8, so that the activated carbon tank and the like not only adsorb and remove various bacteria but also remove soluble organic substances and odor components in the bath water. Can also. On the other hand, if the activated carbon tank is provided between the filtration device 5 and the solenoid valve 14b, and the heater 8 is provided in any place between the activated carbon tank and the flow rate detection unit 11, the heater 8 is energized during the backwashing operation. By heating the backflowing bath water to about 60 to 70 ° C., the activated carbon tank and the inside of the filtration device 5 are simultaneously regenerated and sterilized with hot water, and the heated hot water can be drained from the drainage channel 15. As described above, the electrolytic bath 12 is provided in the circulation path 3 of the bath water, the electrode 13 is eluted to generate a hydroxide, and the generated hydroxide aggregates turbid components to form flocs, which are filtered by the filtration device 5. Is equipped with a hair catcher, etc., so that there is no need to preliminarily remove suspended matters, etc., it is possible to easily filter fine turbid components from the beginning of operation, the filtration speed is fast, hot water regeneration by backwashing operation and hot water Sterilization is possible, and sanitary bath water can be circulated using an inexpensive filter medium 4, and only the bath water that has been sterilized and clarified can be filled in the bath tub.
[0036]
【The invention's effect】
As is clear from the above embodiments, according to the present invention, a circulating pump for circulating bath water in a bath tub, a pair of electrodes are provided, and the circulated bath water is electrolyzed to elute metal ions from the electrodes to form water. a electrolytic cell to produce an oxide, the bath water containing turbidity components are agglomerated to return to the bath and filtered through a filtration apparatus with hydroxide generated in the electrolytic cell, it is applied to the respective electrodes The polarity of the voltage is switched at regular intervals, and when the voltage is switched, the application of the voltage is stopped for a predetermined period of time. Has a long clogging life and can facilitate maintenance. In addition, the electrode life is long and there is almost no deterioration due to adhesion to the electrode surface.
[0037]
In addition, since the circulation pump is provided between the electrolytic cell and the filtration device, fine turbid components can be aggregated in a large shape by metal hydroxide eluted from the electrode.
[0038]
In addition, since the electrode is made of Al, Fe, Ni or an alloy thereof, metal hydroxide is easily formed, and the electrode can be made safe and sanitary.
[0039]
In addition, since the control unit for controlling and supplying power to the electrolytic cell is provided, the polarity of the electrode can be easily switched, and the backwashing operation can be repeatedly performed.
[0040]
In addition, since the heater for heating the bath water is provided, the temperature of the bath water can be freely changed.
[0041]
Further, since the flow rate detecting unit for detecting the flow rate of the bath water is provided, it is possible to prevent the hydroxide of the electrode from being excessively generated in the bath water.
[Brief description of the drawings]
FIG. 1 is a schematic overall view of a circulating hot water bath in one embodiment of the present invention. FIG. 2 is a schematic general view of a conventional circulating hot water bath system.
DESCRIPTION OF SYMBOLS 1 Bathtub 2 Circulation pump 3 Circulation path 4 Filtration material 5 Filtration device 6 Inlet 7 Outlet 8 Heater 9 Injector 10 Ozone generator 11 Flow rate detection part 12 Electrolysis tank 13 Electrodes 14a, 14b Solenoid valve 15 Drainage path 16 Control part

Claims (6)

A circulation pump that circulates bath water in the bath, and an electrolytic bath that is provided with a pair of electrodes and electrolyzes the circulated bath water to elute metal ions from each of the electrodes to generate hydroxides , A circulating warm water bath containing a turbid component agglomerated by a hydroxide generated in an electrolytic cell and returned to the bath by filtering the same with a filtration device, wherein a voltage applied to each of the electrodes is constant. A circulating warm bath characterized in that the polarity is switched every time, and the voltage application is stopped for a predetermined time at the time of switching . The circulating bath according to claim 1, wherein the circulating pump is provided between the electrolytic cell and the filtering device. 3. The circulating bath according to claim 1, wherein the electrode is made of Al, Fe, Ni, or an alloy thereof. The circulating bath according to any one of claims 1 to 3, further comprising a controller configured to control and supply electric power to the electrolytic cell. The circulating bath according to any one of claims 1 to 4, further comprising a heater for heating bath water. The circulating warm water bath according to any one of claims 1 to 5, further comprising a flow rate detection unit for detecting a flow rate of the bath water.

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