JPH10314732A - Device and method for bath water filtration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the viable count in bath water to the low level and carry out the stabilized operation for a long period of time by returning filtrate for bath water filtered by a membrane separating device with a filtration unit stored in an outer container to a bath water purification system or to the inside of a bathtub. SOLUTION: A stock solution introduction opening 3a of an outer container 3 of a membrane separating device 2 is connected with a circulating flow path on the downstream side of a biological filter tank of a bath water purification system 20 through a stock solution feed piping 11 provided with a pump P11 and a valve V11, and the bath water passed through the biological filtration tank is introduced as a stock solution in the pressurized state into the outer container 3, and the flow rate of bath water is controlled. Then a filtrate introduction opening 3b of the outer container 3 is connected with a sterilization device of the bathtub purification system 20 through a filtrate return piping 12 provided with a valve V12, and the filtrate filtered by a filtration unit 4 of the membrane separating device 2 is returned into a circulating flow path of the bath water purification system 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath water filtration apparatus and method for filtering bath water used in a bath water purification system. It is an object of the present invention to provide a bath water filtration apparatus and method capable of performing stable operation of the apparatus and reducing operation costs.

[0002]

2. Description of the Related Art In recent years, a bath water purification system called a 24-hour bath has been widely used. FIG. 4 shows an example of this type of bath water purification system. The bath water purification system 20 shown here includes a bath 21, a purification device 22 for purifying bath water in the bath 21, and a purification device 22. And a circulation flow path 23 which is a circulation means for returning the purified water treated by the purification process to the bathtub 21. Purification device 2
2 has a pre-filter 25, a biological filtration tank 26, a sterilizer 27, and a heating tank 28,
As 5, a glass filter or the like is used, and as the biological filtration tank 26, a filter material made of ceramic or the like and filled with aerobic bacteria adhered thereto is used. Further, as the sterilizing device 27, a device configured to be capable of performing a sterilizing process by irradiating the bath water with ultraviolet rays, injecting ozone, or the like is used. The heating tank 28 is provided with a heater for heating and sterilizing bath water.

In this bath water purification system 20, the bath water is always kept at a temperature at which it can be bathed by a heat retaining means (not shown), and the bath water is passed through a pre-filter 25 and a biological filtration tank 26 to suspend the bath water. After removing suspended substances and soluble organic substances, and subsequently passing through a sterilizing device 27 and a heating tank 28 for sterilizing treatment, it is returned to the bathtub 21 and can be reused. This system has advantages such as the ability to reduce the water cost and prevent the bathtub from becoming dirty by reusing the bathwater while appropriately purifying it.

[0004]

In the bath water purification system described above, the purification is performed so that a large number of viable bacteria do not remain in the bath water returned to the bath tub 21 through the circulation channel 23. It is desired to further improve the sterilizing effect of the sterilizing device 27 and the heating tank 28 of the device 22. In particular, since it has been pointed out that a large number of bacteria of the genus Legionella known as pathogenic bacteria may remain in the bath water, a means for more efficiently removing microorganisms in the circulating water in the circulation channel 23 has been strongly desired. I have. Therefore, in order to improve the sterilizing effect, it has been considered to increase the ultraviolet intensity, the ozone injection amount, and the like of the sterilizing device 27, and to increase the heating temperature in the heating tank 28. In this case,
There is a problem that the energy consumption of electric power and the like increases, and the operating cost rises.

[0005] In order to solve this problem, as a means for removing microorganisms from bath water, a device using a separation membrane which can be operated at a relatively low cost has been studied. As a separation membrane used in this type of apparatus, a membrane having a membrane pore diameter smaller than that of a microorganism such as a bacterium, for example, 1 μm or less, so that the microorganism can be removed from bath water is used. However, an apparatus using a separation membrane often becomes inoperable in a short time due to clogging of the membrane, and has a problem that a large amount of labor and cost are required for maintenance. The present invention has been made in view of the above circumstances, and can keep the number of viable bacteria in bath water used in a bath water purification system low, and can perform stable operation for a long period of time, and furthermore, operating cost is low. An object of the present invention is to provide a bath water filtration device that can be reduced.

[0006]

A bath water filtration device according to the present invention comprises a membrane separation device having a filtration unit having a separation membrane for filtering bath water used in a bath water purification system housed in an outer container; It has a return means for returning the filtrate filtered by the membrane separation device into the bath water purification system or the bathtub. Further, a gas-liquid mixed fluid comprising a back-washing means for back-flowing the washing water to the separation membrane of the filtration unit, and a diffuser tube having a diffuser port for flowing a gas-liquid mixed fluid obtained by mixing gas and cleaning water toward the filtration unit. Preferably, a supply means is provided. The air diffuser is preferably disposed below the filtration unit in the outer container, and the filtration unit is preferably disposed with the longitudinal direction of the separation membrane oriented substantially horizontally. Further, it is preferable that the flow rate of the bath water introduced into the membrane separation device is adjustable. Further, a hollow fiber membrane may be used as the separation membrane of the filtration unit. Further, it is preferable that the above-mentioned bath water filtration device is provided so as to be detachable from the bath water purification system. The bath water filtration method of the present invention is characterized in that a part of the bath water circulated by the circulating means of the bath water purification system is filtered by a membrane separation device in which a filtration unit having a separation membrane is housed in an outer container. The filtrate filtered by the above is returned to the bath water purification system. In addition, if necessary, a backwashing step in which washing water is intermittently supplied to the filtrate side of the filtration unit in a pressurized state to flow back to the separation membrane of the filtration unit, and a gas-liquid mixture of washing water and gas. It is desirable for the stable operation of the bath water filtration device to perform a bubbling step of supplying the mixed fluid to the membrane separation device and vibrating the separation membrane of the filtration unit. The flow rate of the bath water filtered by the membrane separation device is preferably 0.2 to 10% of the amount of the bath water used in the bath water purification system per minute.

[0007]

1 to 3 show an example of a bath water filtration device according to the present invention. In FIG. 1, reference numeral 1 denotes a bath water filtration device of this example. The bath water filtration device 1 includes a membrane separation device 2 for filtering bath water used in a bath water purification system 20, and a membrane separation device 2 It has a filtrate return pipe 12 as return means for returning the filtrate filtered by the filter to the bath water purification system 20. The membrane separation device 2 has one or a plurality of filtration units 4 housed in an outer container 3. The outer container 3 includes a stock solution inlet 3a for introducing a stock solution, which is water to be treated, into the outer container 3, a filtrate outlet 3b for drawing the filtrate filtered by the filtration unit 4 from the outer container 3, A stock solution outlet 3c for discharging the stock solution to the outside of the outer container 3 and a gas-liquid mixed fluid inlet 3d for introducing a gas-liquid mixed fluid for cleaning the filtration unit into the outer container 3 are provided.

The filtration unit 4 includes a cylindrical support 5
A separation membrane module in which the separation membrane 6 is housed is used. It is preferable that the separation membrane 6 be composed of a large number of hollow fiber membranes. As the hollow fiber membrane, various porous ones can be used. For example, cellulose type, polyolefin type, polyvinyl alcohol type, PM
Materials composed of various materials such as MA-based and polysulfone-based materials may be used. Among them, materials having high elongation such as polyethylene and polypropylene are preferable. Although not particularly limited, it is preferable to use a hollow fiber membrane having a pore size of 0.01 to 1 μm, preferably 0.1 to 0.2 μm, and a membrane area of 0.5 to ⁵ m ^2. .

The support 5 is made of a synthetic resin or the like.
A window 5a through which the undiluted solution flows is formed on the side surface. At both ends of the support 5, filtrate collecting chambers 7, which are flow paths for the filtrate having passed through the separation membrane 6, are formed. Support 5
Is provided with a filtrate outlet 5b for discharging the filtrate in the filtrate collecting chamber 7.

The filtrate collecting chambers 7 at both ends of the support 5 have
Both ends of the separation membrane 6 are inserted, and the gap between the separation membrane 6 and the support 5 is filled with a sealing material, and the separation membrane 6 is focused on the support while maintaining the open state of the end. 5, and the filtrate collecting chamber 7 is liquid-tightly partitioned from the outside. The sealing material is a material in which an epoxy resin, an unsaturated polyester resin, polyurethane, or the like is liquefied and filled in the gap between the separation membrane 6 and the support 5 and cured. The support 5 has two ends 2
A filtrate pipe 8 communicating the two filtrate collection chambers 7, 7 is provided, and the filtrate in the filtrate collection chamber 7 at one end where the filtrate outlet 5 b is not provided is passed through the filtrate pipe 8 to the other end. The liquid flows into the filtrate collecting chamber 7 on the side, and can be discharged therefrom through the filtrate discharge port 5b. Filtrate outlet 5b
Is connected to the filtrate outlet 3b of the outer container 3 via the line 4a, and discharges the filtrate in the filtrate collecting chambers 7, 7 to the outside of the outer container 3 through the line 4a and the outlet 3b. You can do it. The filtration unit 4 is preferably disposed in the outer container 3 with the longitudinal direction of the separation membrane 6 oriented substantially horizontally.

A gas-liquid mixed fluid obtained by mixing a gas such as air and cleaning water flows into the membrane separation device 2 toward the filtration unit 4, and a diffuser tube 9 having a diffuser port for cleaning the filtration unit 4. Is provided. This gas-liquid mixed fluid supply means 10 is
A diffuser pipe 9 provided therein, a cleaning water supply pipe 14 provided with a valve V14 for sending cleaning water into the diffuser pipe 9, a pipe 9a connecting these, and a cleaning water in the pipe 14 And a gas supply source 15 for supplying a gas to the apparatus.

The air diffuser 9 is a hollow body having a number of air diffusers 91 formed therein. The air diffuser 9 is disposed in the outer container 3 and below the filtration unit 4, and is provided through a pipe 9a. Is connected to the gas-liquid mixture inlet 3d. The diffuser 9
It is preferable to use a filter whose length is substantially equal to the length of the separation membrane 6 of the filtration unit 4. It is preferable that the air diffuser 9 is disposed along the longitudinal direction of the separation membrane 6 because the gas-liquid mixed fluid can efficiently contact the entire separation membrane 6.

The cleaning water supply pipe 14 has one end connected to a cleaning water supply source (not shown) and the other end connected to a gas-liquid mixed fluid inlet 3 d of the outer container 3. In conduit 14,
A gas supply source 15 is connected via the pipe 16, supplies gas such as air to the cleaning water in the pipe 14 through the pipe 16, and converts the cleaning water supplied from the cleaning water supply source into a gas. The gas can be sent to the air diffuser 9 as a gas-liquid mixed fluid mixed with the gas. As the gas supply source 15, a general-purpose air pump or ejector may be used.

The undiluted solution inlet 3a of the outer container 3 of the membrane separation device 2 having the above-described structure is connected to the undiluted solution supply line 11 having the pump P11 and the valve V11 to connect the undiluted solution to the biological filtration tank 26 of the bath water purification system 20. The bath water is connected to the downstream circulation flow path 23 and can be introduced into the outer container 3 in a pressurized state using the bath water that has passed through the biological filtration tank 26 as a stock solution. In this device, it is preferable that the flow rate of the bath water introduced into the outer container 3 can be adjusted by using a pump whose flow rate can be arbitrarily adjusted as the pump P11. The filtrate outlet 3b of the outer container 3 is connected to the valve V
The filtrate filtrated by the filtration unit 4 of the membrane separation device 2 is connected to the sterilization device 27 of the bath water purification system 20 via the filtrate return line 12 having It can be returned inside. The undiluted solution outlet 3c having a valve V13 is connected to the undiluted solution outlet 3c of the outer container 3.
The stock solution in the outer container 3 can be discharged to the outside of the system through the pipe 13.

The washing water supply line 14 and the filtrate return line 12 are connected by a pump (not shown) and a back washing water supply line 17 having a valve V17, and a washing water supply source (not shown). ), A backwashing water flow path 18 is formed as a backwashing means from the washing water supply line 14, the backwashing water supply line 17, and the filtrate return line 12 to the gas-liquid mixed fluid inlet 3d. The cleaning water supplied from the supply source can be sent under pressure to the filtrate side of the filtration unit 4 through the flow path 18. Further, the undiluted solution discharge line 13 may be provided with a heating device 19 for subjecting the discharged water flowing in the line 13 to heat sterilization.

It is preferable that the bath water filtering apparatus 1 having the above-described configuration can be detachably attached to the bath water purification system 20.

Next, the bath water filtration method of the present invention will be described with reference to the case where the above-mentioned bath water filtration device 1 is used. First, the valve V11 of the stock solution supply line 11 and the filtrate return line 12
The valve V12 is opened and the pump P11 is operated, and a part of the bath water in the circulation flow path 23 of the bath water purification system 20 is discharged from the membrane separation device 2 as a stock solution through the stock solution supply pipe 11 in a pressurized state. It is introduced into the container 3. The flow rate of the undiluted solution introduced into the outer container 3 is preferably 0.2 to 10%, preferably 2 to 3%, per minute with respect to the bath water used in the bath water purification system 20. It is. this is,
If the flow rate is less than 0.2%, the effect of keeping the number of viable bacteria in the bath water returned to the bathtub 21 low is insufficient, and if the flow rate exceeds 10%, the pores of the separation membrane 6 of the membrane separation device 2 are reduced. This is because the flux is easily reduced due to the blockage.

The flow rate of the undiluted solution may be set with respect to the flow rate of the circulating water in the circulation flow path 23 of the bath water purification system 20. It is desirable to set it to 5 to 40%. If the flow rate is less than 2%, the effect of keeping the number of viable bacteria in the bath water returned to the bathtub 21 low is insufficient. If the flow rate exceeds 85%, the membrane pores of the separation membrane 6 of the membrane separation device 2 are blocked. Flux reduction is likely to occur. Further, the flow rate of the stock solution may be set to a value corresponding to the specific growth rate of the microorganism to be removed under the condition. Specific examples of the flow rate of the undiluted solution introduced into the membrane separation device 2 include the following. The amount of bath water used in the bath water purification system 20 is 200 l, and when the bath water is circulated in the circulation passage 23 as circulating water at a flow rate of 15 to 25 l / min, the bath water in the circulation passage 23 is reduced by one minute. 0.4 corresponding to 0.2 to 10% of the amount of bath water per
The solution is supplied to the membrane separation device 2 through the stock solution supply line 11 at a flow rate of ２０20 l / min.

The bath water introduced into the outer container 3 of the membrane separation device 2 permeates the separation membrane 6 of the filtration unit 4 and is collected in the filtrate collecting chamber 7 as a filtrate from which suspended substances and microorganisms have been removed. The filtrate is returned into the bath water purification system 20 through the filtrate outlet 5b and the filtrate return line 12.

When performing the above-mentioned filtration operation, the valve V13 of the undiluted solution discharge line 13, the valve V14 of the washing water supply line 14, and the valve V17 of the backwashing water supply line 17 are kept closed. Further, if necessary, the valve V13 of the undiluted solution discharge line 13 may be appropriately opened to discharge the undiluted solution in the outer container 3 which has been concentrated by filtration to the outside of the system. deep.

When the suspended substances such as microorganisms in the undiluted solution are deposited on the separation membrane 6 of the filtration unit 4 by filtration and the filtration resistance increases and the flux decreases, the separation membrane is cleaned by the following washing method. Wash 6 and restore flux. The cleaning method described below includes a backwashing step and a bubbling step. First, the following backwashing step is performed. After stopping the pump P11 of the stock solution supply line 11 and stopping the supply of the stock solution to the membrane separation device 2, the valve V of the filtrate return line 12 is stopped.
12 is closed, and the valve V17 of the backwash water supply line 17 and the valve V13 of the stock solution discharge line 13 are opened.

By this operation, washing water supplied from a supply source (not shown) is introduced into the filtrate side of the separation membrane 6 of the filtration unit 4 through the backwash water flow path 18 in a pressurized state. And the sediment on the separation membrane 6 is peeled off. As this washing water, city water, industrial water, a filtrate stored in advance, or the like may be used, and among them, city water is particularly preferable. This is because the city water contains a large amount of chlorine, so that the growth of microorganisms in the washing wastewater can be suppressed. The washing water that flows back through the separation membrane 6 and comes out of the separation membrane 6 is discharged to the outside of the system through the undiluted solution outlet 3c and the undiluted solution discharge line 13 together with the separated material.

Subsequently, the following bubbling step is performed.
First, the valve V17 of the backwash water supply line 17 is closed,
After the supply of the washing water to the filtrate side of the filtration unit 4 is stopped, the valve V14 of the washing water supply pipe 14 is opened, and the washing water is introduced into the pipe 14. At the same time, a gas such as air supplied from the gas supply source 15 is supplied into the cleaning water supply pipe 14 through the pipe 16 and mixed with the cleaning water in the pipe 14 to form a gas-liquid mixed fluid. Through the outer container 3
Supply within. The gas-liquid mixed fluid supplied into the outer container 3 flows upward in the outer container 3 and is discharged out of the system through the undiluted liquid discharge line 13.

In the course of the gas-liquid mixed fluid flowing through the outer container 3, the gas contained in this fluid is converted into air bubbles to form the separation membrane 6.
And vibrates the separation membrane 6 to separate the deposits adhered to the membrane surface by rubbing of the hollow fiber membranes constituting the separation membrane 6 or relative flow of the washing water. At the same time,
The cleaning water in the gas-liquid mixture fluid applies a high shearing force to the deposit on the separation membrane 6, and further promotes peeling of the deposit.

At this time, since the filtration unit 4 is disposed in the outer container 3 with the longitudinal direction of the separation membrane 6 oriented substantially horizontally, the filtration unit 4 is supplied from the air diffuser 9 and gas-liquid mixture rising vertically upward. The gas in the fluid hits the separation membrane 6 from the vertical direction, whereby a shear force is efficiently applied to the deposit on the separation membrane 6 and the separation of the deposit from the membrane is promoted. On the other hand, when the longitudinal direction of the separation membrane 6 is inclined with respect to the horizontal direction, the gas hits the separation membrane 6 not vertically but in an inclined direction, and is added vertically upward by the buoyancy of the gas. The shearing force does not efficiently act on the sediment, and the air flows along the separation membrane immediately after hitting the separation membrane 6, and the contact time between the air and the separation membrane 6 is shortened, so that the deposition is performed. The effect of peeling an object is likely to be insufficient.

The above two-step washing operation is preferably repeated at an appropriate frequency, preferably about once every 30 minutes to 1 hour for stable operation. Also,
It is sufficient that the time required for the above-mentioned washing operation is 2-3 minutes. Further, the flow rate of the washing water used for this washing operation is substantially the same as the flow rate of the bath water introduced into the membrane separation device 2, for example, when the flow rate of the bath water is 0.4 to 20 l / min,
It is preferably 0.4 to 20 l / min.

In the bath water filtration device 1 having the above-described configuration, the membrane separation device 2 having the separation membrane 6 is provided.
An effect sufficient to remove microorganisms such as bacteria belonging to the genus Legionella from the bath water used in the bath water purification system can be obtained. Therefore, the number of viable bacteria in the bath water of the bath water purification system can be kept low, and the safety thereof can be further ensured.

Further, since the gas-liquid mixed fluid supply means 10 for flowing the gas-liquid mixed fluid toward the filtration unit 4 is provided, the separation membrane 6 is vibrated by the gas in the gas-liquid mixed fluid during the cleaning operation. A strong shearing force is applied to the deposit on the separation membrane 6 by the cleaning water in the fluid, and the deposit on the separation membrane 6 can be efficiently peeled off, and a high cleaning effect can be obtained.
Accordingly, it is possible to suppress a decrease in the permeation flux due to blockage of the pores of the separation membrane 6 and the like, to enable more stable operation, to facilitate maintenance, and to reduce the operation cost. In addition, since the backwash water flow path 18 for backflowing the washing water to the separation membrane 6 is provided, it is possible to efficiently remove the deposits on the separation membrane when performing the washing operation, thereby enabling a more stable operation. it can.

Further, by disposing the air diffuser 9 below the filtration unit 4 in the outer container 3 and disposing the filtration unit 4 so that the longitudinal direction of the separation membrane 6 is substantially horizontal,
The shearing force exerted by the gas in the gas-liquid mixed fluid on the sediment on the separation membrane 6 can be increased, and the cleaning efficiency when cleaning the separation membrane 6 can be increased.

Further, by providing the flow rate of the bath water to be introduced into the membrane separation device 2 arbitrarily adjustable, the flow rate of the bath water to be treated by the membrane separation device 2 can be reduced within a range where the effect of removing microorganisms is not reduced. Can be set, membrane separation device 2
In this case, it is possible to suppress a decrease in the permeation flux due to clogging of the pores of the separation membrane 6 and the like, thereby enabling more stable operation.

Further, by making the bath water filtration device 1 detachably attachable to the bath water purification system 20, it can be easily applied to the existing bath water purification system 20. it can.

In the above bath water filtration method, only a part of the circulating water circulated in the bath water purification system 20 is passed through the membrane separation device 2, so that the membrane pores of the separation membrane 6 are blocked in the membrane separation device 2. The flux is hardly reduced, and a sufficient effect for removing microorganisms in the circulating water can be obtained. Therefore, the number of viable bacteria in the bath water in the bath water purification system 20 can be kept low, its safety can be made more reliable, stable operation can be performed for a long time, and operation costs can be reduced.

Further, by performing a bubbling step of flowing the gas-liquid mixed fluid toward the filtration unit 4, the separation membrane 6
The upper deposit can be efficiently removed, and a high cleaning effect can be obtained. Accordingly, it is possible to suppress a decrease in the permeation flux due to blockage of the pores of the separation membrane 6 and the like, thereby enabling more stable operation. Further, by performing the backwashing step of backflowing the washing water to the separation membrane of the filtration unit, a more stable operation can be performed.

A solution such as hypochlorite is supplied to the undiluted solution supply line 11 of the bath water filtration device 1.
It is preferable to provide a chlorine supply means for supplying the solution into the inside and increasing the chlorine concentration in the stock solution in the stock solution supply pipe 11. Thus, the oxidative decomposition of organic substances in the stock solution introduced into the membrane separation device 2 can be advanced, and the number of viable bacteria in the stock solution can be reduced. Therefore, the effect of removing microorganisms by the membrane separation device 2 can be ensured, and a decrease in permeation flux caused by the adsorption of organic substances to the separation membrane 6 can be prevented, so that a more stable operation can be performed. Further, by providing a flocculant adding means for adding a flocculant to the stock solution in the stock solution supply pipe 11, the suspended matter in the stock solution supplied to the membrane separation device 2 is agglomerated. It is possible to reduce the aqueous property and the adhesion to the separation membrane, prevent the separation membrane 6 from being clogged in the membrane separation device 2, and enable a stable operation.

Further, in the above example, the undiluted solution supply line 11 of the bath water filtration device 1 is connected to the circulation flow path 23 downstream of the biological filtration tank 26 of the bath water purification system 20, and the filtrate return line 1 is connected.
2 is connected to the sterilizer 27, but the bath water filtration device of the present invention is not limited to this, and the pipeline 11 and the pipeline 1 are not limited thereto.
2 may be connected to another part of the circulation channel 23 or may be directly connected to the bathtub 21. Further, in the above-described example, the gas-liquid mixed fluid supply means 10 has the air diffuser 9. However, the present invention is not limited to this.
And the gas-liquid mixed fluid supply means may be configured so that the gas-liquid mixed fluid introduced from the gas-liquid mixed fluid inlet 3 d directly reaches the filtration unit 4.

[0036]

As described above, the bath water filtration device of the present invention is provided with a membrane separation device having a separation membrane, so that a sufficient effect can be obtained for removing microorganisms in the bath water used in the bath water purification system. be able to. Therefore, the number of viable bacteria in the bath water used in the bath water purification system can be kept low, and its safety can be further ensured. Further, by providing a gas-liquid mixed fluid supply means for flowing the gas-liquid mixed fluid toward the filtration unit and a backwashing means for backflowing the cleaning water to the separation membrane, a strong shearing is performed on the sediment on the separation membrane during the cleaning operation. By applying force, the deposits on the separation membrane can be efficiently peeled off, and a high cleaning effect can be obtained. Therefore, it is possible to suppress a decrease in the permeation flux due to blockage of the pores of the separation membrane and the like, to enable more stable operation, to facilitate maintenance, and to reduce the operation cost. Further, by providing the flow rate of the bath water introduced into the membrane separation device arbitrarily adjustable, the flow rate of the bath water to be treated by the membrane separation device can be set low within a range that does not reduce the microorganism removing effect. In addition, it is possible to suppress a decrease in the permeation flux due to blockage of the membrane pores of the separation membrane in the membrane separation device, thereby enabling more stable operation.

In the method for filtering bath water of the present invention,
Since only a part of the circulating water circulated in the bath water purification system is passed through the membrane separation device, it is difficult for the flux to decrease due to blockage of the separation membrane in the membrane separation device. Can be raised. Therefore, the number of viable bacteria in the bath water in the bath water purification system can be kept low, the safety thereof can be made more reliable, stable operation can be performed for a long time, and the operating cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a bath water filtration device of the present invention.

FIG. 2 is a sectional view showing a filtration unit of the bath water filtration device shown in FIG.

FIG. 3 is a flowchart showing a bath water filtration device shown in FIG. 1 and a bath water purification system to which the device is connected.

FIG. 4 is a flowchart showing an example of a bath water purification system.

[Explanation of symbols]

1 ... bath water filtration device, 2 ... membrane separation device, 3 ... outer container,
4 ... filtration unit, 6 ... separation membrane, 10 ... gas-liquid mixed fluid supply means, 12 ... filtrate return pipe (return means), 18.
..Backwash water channel (backwash means), 20 bath water purification system, 21 bathtub, 22 purifier, 23 circulation channel (circulator)

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 65/02 520 B01D 65/02 520 (72) Inventor Michio Sugano 2-3-1 Kyobashi, Chuo-ku, Tokyo Inside Mitsubishi Rayon Co., Ltd. 72) Inventor Kenji Wataru 4-160 Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture Mitsubishi Rayon Co., Ltd. Product Development Laboratory

Claims (10)

[Claims] 1. A bath water purification system comprising a bath, a purifying device for purifying bath water in the bath, and a circulating means for returning the bath water purified by the purifying device to the bath tub. A bath water filtration device for filtering, wherein a membrane separation device containing a filtration unit having a separation membrane for filtering the bath water in an outer container, and a filtrate filtered by the membrane separation device, the bath water purification system or A bath water filtration device having a return means for returning the water to a bathtub. 2. The bath water filtration device according to claim 1,
A bath water filtration device comprising backwash means for backwashing the washing water to the separation membrane of the filtration unit. 3. The gas-liquid mixed fluid according to claim 1 or 2, further comprising an air diffuser having an air diffuser port through which a gas-liquid mixed fluid obtained by mixing gas and washing water flows toward the filtration unit. A bath water filtration device provided with a supply unit. 4. The bath water filtration device according to claim 3,
A bath water filtration device, wherein an air diffuser is arranged below a filtration unit in an outer container, and the filtration unit is arranged with the longitudinal direction of the separation membrane oriented substantially horizontally. 5. The bath water filtration device according to claim 1, wherein a flow rate of the bath water introduced into the membrane separation device is adjustable. 6. The bath water filtration device according to claim 1, wherein the separation membrane of the filtration unit is a hollow fiber membrane. 7. A bath water used in a bath water purification system comprising a bath tub, a purifying device for purifying bath water in the bath tub, and a circulating means for returning the bath water purified by the purifying device to the bath tub. A bath water filtration method for filtering, wherein a part of the bath water circulated by a circulating means of the bath water purification system is filtered by a membrane separation device in which a filtration unit having a separation membrane is housed in an outer container. A bath water filtration method, comprising returning the filtrate filtered by the separation device to the bath water purification system. 8. The bath water filtration method according to claim 7,
A bath water filtration method comprising intermittently supplying a washing water to a filtrate side of a filtration unit in a pressurized state and flowing back to a separation membrane of the filtration unit. 9. The bath water filtration method according to claim 7, wherein a gas-liquid mixed fluid obtained by mixing the cleaning water and the gas is intermittently supplied to the membrane separation device, and the separation membrane of the filtration unit is vibrated. A bath water filtration method comprising performing a bubbling step. 10. The bath water filtration method according to claim 7, wherein a flow rate of the bath water to be filtered by the membrane separation device is used per minute for the bath used in the bath water purification system. A bath water filtration method characterized in that the amount of water is 0.2 to 10%.