JP5105036B2 - Dual water distribution system - Google Patents

Description

In the present invention, when the raw water consisting of groundwater, industrial tap water, tap water is subjected to microfiltration or ultrafiltration using a partial membrane filtration device, it is essential to maintain the filtration membrane surface as a central function of filtration. The present invention relates to a system that guarantees permanent filtration while automatically and efficiently cleaning a membrane surface without using a special cleaning device.

In recent years, membrane filters are mainly used as water purification near the point of use. Along with the evolution of actual usage, small and compact ones are mainly in the form of faucet direct connection or under sink.
However, all of the membrane filters used for them are disposable types in which the filter cartridge is replaced when the filter is clogged. On the other hand, in the purified water classified into medium and large scale, the backwashing operation is performed manually or automatically by sensing the filtration flow rate or the filtration differential pressure for the degree of clogging of the membrane filter.
According to this method, a back pressure pressurizing pump, an air bubbling device, a backwash water discharge and a rinsing step are required, and as a result, the device becomes complicated and energy loss is not always practical.
In order to avoid these problems, a system that incorporates a partial filtration, that is, a cross-flow filtration mechanism, may be adopted as the structure of the water filtration device, which requires the installation of a circulation pump and a circulation tank, as well as flushing and discharge of concentrated water. Such complicated processes have been pointed out as disadvantages such as energy loss and reduction in water recovery rate.

Furthermore, as a system that efficiently supplies water while using a membrane filtration process, when water is filtered using a reverse osmosis membrane filter in the water supply system, each of untreated water, circulating water, and filtered water is passed through a water supply pipe. A method of sending directly to the place of use (see Patent Document 1) has been proposed.
However, in this proposed method, clogging is likely to occur, and a method for controlling the cleaning of the reverse osmosis membrane is unsolved and impractical.
On the other hand, when filtered water and untreated water are used at the same time, it is necessary to study technically, such as whether or not the filtration mechanism of the reverse osmosis membrane that requires high pressure can operate stably.

Further, a method has been proposed in which well water and groundwater are treated with a reverse osmosis membrane filter, the treated water is used for clean water, and the concentrated water is used for irrigation (see Patent Document 2). In this method, each water is once stored in a tank and operated, but the method of maintaining the pressure on the primary side is unknown, and the effectiveness of the reverse osmosis membrane filtration mechanism itself is questionable, and directly It is not practical in that it requires extra equipment such as a tank because it is not used.
As described above, at present, the filtration membrane surface is automatically cleaned during use in any method, and the membrane filtration device is practically used almost permanently or without replacement of the filtration membrane over a long period of time. I can't do it.

JP 2000-319944 A JP-A-5-7873

In view of the situation as described above, the present invention adopts a filtration membrane that is used for normal water treatment, does not require a special backwashing step and apparatus, and can perform water treatment with membrane use efficiency of 100%. It is to propose.

As a result of diligent research in order to achieve the above-mentioned object from such a viewpoint, the present inventors have alternated between membrane-passing water (not using circulating water) and permeating water in partial membrane filtration (also referred to as cross-flow filtration). Surprisingly, the present inventors have found a method that does not require a special backwashing process and apparatus and can perform water treatment with a use efficiency of 100%.
That is, when water purification treatment is performed by the conventional membrane filtration method, the filtered water is once stored in the filtered water tank and connected to the tap to the point of use, and is also circulated in the membrane filtration system as circulating water.
Furthermore, a method has generally been adopted in which a predetermined point in time is determined and the permeated water from the filtered water tank is reversely passed to perform reverse water washing or flushing and washing the circulating water side at a high membrane surface flow rate.

In the conventional membrane filtration method, the above method is an established method, but as a result of intensive studies on the circulating water used here, the present system is a system directly connected to a faucet as it is in a usual usage mode. When running as an outflow, it was found that the degree of contamination on the surface of the filtration membrane was lower than in the case of circulating water for a certain time in the membrane filtration system.
This has the effect of cleaning the membrane surface when passing through the membrane surface, and shows the effect of increasing the opportunity for membrane surface cleaning when used alternately with membrane permeated water. I noticed that. Inferring from this result, the filtration membrane surface is kept normal and a stable water purification effect is obtained over a long period of time, rather than special reverse water flow or reverse pressure water flow cleaning and / or flushing cleaning with high flux circulating water. I found a direction that I can do.
Based on this hint, the inventors have intensively studied and set certain conditions for this alternate use, and found that this water treatment method can be surely executed, and have reached the present invention.

The gist of the present invention is that when supplying the inflow-side primary water of the partial membrane filtration device, a pipe line having the membrane surface passing water as an out-of-system flow path is provided, and combined with the permeation-side secondary water system pipe line. It is based on a dual supply and distribution system characterized by arranging at least one faucet that can be controlled by each. Here, control refers to a faucet that can be opened and closed including automatic control or manual operation.
Also, the permeate side secondary water system pipe line is provided with an open / close valve set to open and close based on the differential pressure derived from the permeate side secondary water output pressure and the inflow side primary water receiving pressure, and the permeate side secondary water system Permeated water can be passed by disposing a discharge valve operated by a check timer in the branch line for measuring the water pressure on the permeated water line between the water pressure measuring point of the pipe and the open / close valve. Can be controlled.
In the opening / closing control of the opening / closing valve, when the opening / closing valve operated by the differential pressure stops the passage of secondary water on the permeate side, the partial membrane filtration device is separated when the discharge valve is opened by the check timer. The filtered water that has permeated through the membrane is released by opening the open / close valve via differential pressure monitoring that occurs when the permeated water side pipe water pressure measurement branch pipe is discharged through the discharge valve. It is set as follows.

On the other hand, a tap water receiving tank is provided in the permeate side secondary water pipe, and a water level sensor is provided in the receiving tank, and when the inflow is below a preset water level, drinking water is supplied from the water supply to the water receiving tank. I can do it.
Based on the differential pressure shown above, the operation can be displayed when the valve is opened and closed and / or the timer is operated, and the operation including an alarm can be displayed on the operation display.
On the other hand, it has a booster pump that operates with a detection width determined based on the differential pressure derived from the permeate side secondary water output pressure and the inflow side primary water receiving pressure at the raw water inlet pressure, and starts and stops membrane filtration. It can also be set to operate in conjunction with the pressure difference inside.

As the filtration membrane, an ultrafiltration membrane filter having a molecular weight cut off of 50,000 or more and 500,000 or less can be adopted, and a microfiltration membrane filter having a blocking pore diameter of 0.2 μm or less can be adopted as the filtration membrane .
The filtration membrane referred to in the present invention is preferably a microfiltration membrane, an ultrafiltration membrane, or the like that has a normal tap water pressure, that is, about 200 to 500 kPa , and allows sufficient water permeation at room temperature.
That is, including a case receiving the assistance of a booster pump, filtration with a flux of 50 L / m ² / hr or more at normal temperature under a differential pressure of 1 MPa or less, preferably 20 L / m ² / hr or more under a differential pressure of 100 kPa. Use a membrane. Outside this specification range, if normal water for daily use is used from one or more faucets, filtration membranes are frequently clogged.
As the shape of the filtration membrane, particularly in the case of an ultrafiltration membrane having a small fractional molecular weight, it is preferable that the skin layer, that is, the separation / fractionation membrane part is thin or finely creped with an asymmetric membrane, but this limits the present invention. is not.

On the other hand, considering that the membrane surface is washed by using the membrane surface passing water as miscellaneous water, it is desirable that the membrane surface is smooth and the pores on the membrane surface are finer.
The form of the membrane filter module may be any type such as a hollow fiber membrane module, a spiral module, and a tubular filter module. In addition, the materials constituting the separation membrane are inorganic materials, metals, alloys, metal oxides and their sintered bodies (ceramics), glass, carbonaceous, polymeric organic materials such as cellulose, regenerated cellulose, cellulose derivatives, and cellulose organic acids. Esters, cellulose acetate, cellulose esters, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyacrylonitrile, polyacrylic acid and its derivatives, poly Examples include ether, polyphenyl ether, polyester, polycarbonate, polyurethane, polyamide and derivatives thereof, and polyimide.

However, these may be any examples as main examples, but in view of contamination of the film surface by an organic substance contained in a trace amount in water, it is more preferable to be hydrophilic than hydrophobic. However, even a hydrophobic material that has been subjected to a hydrophilic treatment by γ-ray treatment, a hydrophilic group graph, or the like can be used without any problem. The hollow fiber membrane can be produced by any method such as a dry method, a wet method, a dry-wet method, a melting method, etc. However, the wet method is preferable in consideration of the production of the asymmetric membrane.
The differential pressure switch according to the present invention is, for example, an assembly that uses a Bourdon tube that receives two different pressures and a single microswitch to open and close an electric circuit when a differential pressure value is set in advance.

The present invention is based on the fact that tap water is injected using a press-in pump when tap water pressure of tap water, tap water pressure of industrial tap water, or ground water, underground water, surface water, etc. is used as raw water. A booster pump is used when water pressure is insufficient when using raw water or when membrane separation is controlled using a two-stage pump.
The primary water flowing into the apparatus of the present invention is, as described above, tap water, industrial tap water, ground water, underground water, surface water, etc., but miscellaneous water using membrane surface water is based on drinking water standards. If it is necessary to comply, the raw water must meet at least the standards recognized as drinking water.

As the press-fitting pump and booster pump according to the present invention, those used for a relatively low-viscosity liquid such as a mechanical pump, a vortex pump, and a reciprocating pump are used.
The water level sensor referred to in the present invention refers to, for example, a so-called float switch in which a float detects a rise / fall of a liquid level and performs a switch operation. That is, in this case, a fixed lower limit liquid level detection position of the water receiving tank is determined, the instrument is set, the float is lowered by the lowering of the liquid level, and the magnet at the end of the arm connects the open / close valve contact of the water supply water supply pipe. Open. In this float switch, a reed switch is enclosed in the stem, and the switch is operated by a magnetic force in the float.

These water level sensors are installed in the water receiving tank, but may be horizontal or vertical. However, it is necessary to use one that complies with the Food Sanitation Law.
There are two types of open / close valves according to the present invention, one that opens and closes by a signal from a differential pressure switch and one that opens and closes by a timer. And they are activated via a controller if necessary.
Any of the above methods or systems can be assembled into an apparatus.
Examples of raw water that can be used as the inflow side primary water of the present invention include groundwater, underground water, surface water, industrial tap water, and tap water.

In the present invention, when the primary water (raw water) on the inflow side is used after being subjected to microfiltration or ultrafiltration using a partial membrane filtration device, the filtration membrane surface is automatically and efficiently used without using a special cleaning device. The present invention proposes a partial membrane filtration device that can be cleaned and used permanently and always automatically cleans the membrane surface only during normal operation.
That is, when water purification treatment is performed by the conventional partial membrane filtration method, the filtered water is once stored in the filtered water tank and connected to the tap to the point of use, and is also circulated in the membrane filtration system as circulating water. . Furthermore, a method has generally been adopted in which a predetermined point in time is determined and the filtered water from the filtered water tank is reversely passed to perform reverse water washing or flushing and washing the circulating water side at a high membrane surface flow rate.
According to the method of the present invention, the filtration membrane is always kept clean in a normal use state without worrying about these cares.

Hereinafter, the embodiment and configuration of the present invention and the state of their cooperation will be specifically described with reference to FIGS.
FIG. 1 is a flowchart showing the basic idea of the present invention. It is a schematic diagram in which inflow side primary water (raw water) pressurized by a pump is introduced into a partial membrane filtration device to obtain membrane surface passing water and membrane permeating water. That is, inflow side primary water pressurized by a pump (hereinafter also abbreviated as raw water) (8) is introduced into the partial membrane filtration device (13). The introduced raw water moves through the surface of the filtration membrane (1) to the membrane surface passing water side conduit (4) and is pressed into one or more faucets (6) at the point of use. On the other hand, the filtered water and permeated water that have permeated through the separation membrane (1) are filled in the faucet (7) at the point of use through the permeated water side conduit (3).
When the faucet (7) is opened in this state, membrane permeated water, that is, purified water, is supplied as drinking water and other domestic water for cooking. On the other hand, when the faucet (6) is opened, raw water that is not membrane-filtered is supplied as it is and used as water for miscellaneous purposes such as watering and toilet water. This state is referred to as “two-way water distribution” in the present invention. The water that one person needs in one day consists of the above-mentioned clean water and miscellaneous water, and the ratio is said to be between about 1:10 to 1:30.

Accordingly, if the faucets (6) and (7) are used alternately, the surface of the filtration membrane is wiped and washed with water passing through the membrane when the faucet (6) is used, and the membrane is opened when the faucet (7) is opened, that is, when the membrane is filtered. Adhering dirt and accumulated dirt staying on the surface are usually removed.
Surprisingly, the present inventors have confirmed that a stable dual supply / distribution state is ensured by this mechanism, and that the water purification treatment by the partial membrane filtration device is stable and lasts for a long time without requiring a special membrane washing process. did. The present invention proposes a device for making this system more stable.
That is, it is intended to provide means for protecting the filtration membrane when the faucet (7) is opened and purified water on the permeate side is continuously used and the faucet (6) is hardly used.

In FIG. 2, water pressure measurement points are provided in each of the membrane permeate water side pipe and the inflow water side pipe, and the open / close valve (12) of the permeate water side pipe (3) is closed and separated based on the differential pressure. Prevent overcontamination of the membrane. On the other hand, a discharge valve (10) operated by a check timer is provided in the permeated water side pipe water pressure measurement branch pipe (11) branched from the permeated water side pipe (3), and the differential pressure is set at regular intervals. It is an explanatory schematic diagram of a system for checking and opening the on-off valve (12) through the differential pressure switch (9) when the differential pressure is equal to or lower than a preset differential pressure.
That is, the differential pressure switch (9) between the water pressure measurement point (a) of the permeate water side pipe (3) and the water pressure measurement point (b) of the inflow water side pipe, and the signal of this differential pressure switch (9) Open / close valve (12) of the permeate side pipe as a secondary water side valve that opens and closes directly, and a discharge valve (10) that is provided between point (a) and the open / close valve (12) and that operates with a timer. This is a dual water supply device provided with a permeated water side pipe water pressure measurement branch pipe (11) to prepare for an accident caused by a sudden blockage of a filtration membrane.

In this system, when the differential pressure between (a) and (b) exceeds a preset value, the on-off valve (12) is closed, and thereafter the membrane filtration is stopped. Thereafter, when the miscellaneous water of the faucet (6) is used, the filtration surface is washed. Then, when the discharge valve (10) operated by the check timer is opened, the filtration surface is sufficiently cleaned, the filtrate passes through the separation membrane (1), and the permeate passes through the permeate side pipe. The pressure difference between (a) and (b) caused by being discharged from the branch line (11) for water pressure measurement via the discharge valve (10) has recovered to a state where it does not exceed a preset value. In this case, the open / close valve (12) is opened by a signal from the differential pressure switch (9), and the permeated water can be obtained again from the water tap (7).
FIG. 3 is a schematic diagram showing a system in which the water passing through the membrane surface of the partial membrane filtration device and the permeated water are connected to a tap water receiving tank.
That is, a pipe line having a water tap (6) is directly connected to the membrane surface passing water outlet side of the partial membrane filtration device, and the membrane permeated water outlet side is further connected to a tap water receiving tank (14). The original water supply device is shown.
Also in this system, a permeated water side pipe water pressure measurement branch pipe (11) having a differential pressure switch (9), an on-off valve (12) and a discharge valve (10) is installed, and an accident due to a sudden blockage of the filtration membrane. It is preferable to prepare for.

Fig. 4 shows that the water supply from the system passing through the membrane surface of the partial membrane filtration device and the membrane permeated water (sometimes simply referred to as permeated water) are connected to a tap water receiving tank, and the filtered water supply cannot catch up. When the water level of a water tank falls, it is a schematic diagram of the system which supplies water with the valve | bulb act | operated by a water level sensor.
That is, a dual supply system in which a pipe line having a water tap (6) is directly connected to the membrane surface passing water outlet side of the partial membrane filtration apparatus and the permeate outlet side is connected to a tap water receiving tank (14). In the water distribution system, a differential pressure switch (9) is disposed between the filtered water outlet vicinity (a) and the raw water inlet (b). In a water treatment system in which a valve (12) that opens and closes in response to a signal from the differential pressure switch (9) is provided in a pipe line downstream from the pressure detection point (a) at the filtered water outlet, water supply water is supplied to a water receiving tank (14). A water level sensor (16) for sending a signal to the open / close valve (20) of the pipe (15) is provided, and the valve (12) is closed to stop the inflow from the partial membrane filtration device, or the water treatment system to the water receiving tank (14). When supply from (5) cannot catch up and the water level in the water receiving tank (14) falls below the preset water level, the valve (20) of the water supply pipe (15) is opened in the water receiving tank (14) and received from the water supply. The dual water supply apparatus with which water is supplied to the water tank (14) is shown.

It should be noted that when the water receiving tank (14) is full, the water supply from the water supply pipe and the water treatment system is set to be stopped by another control system. .
FIG. 5 is a schematic diagram in which water pressure measurement points are provided in each of the permeate water side pipe and the inflow water side pipe, the permeate water valve is stopped based on the differential pressure, and the signal lamp (17) blinks. .
That is, the outlet of the membrane surface passing water (5) and the outlet of the permeated water (2) of the partial membrane filtration device (13) are directly connected to the pipes (3) and (4) having the faucets (7) and (6), respectively. In the two-way water supply system, the signal lamp (17) blinking by the signal of the differential pressure switch (9) between the vicinity (a) of the permeated water (2) and the vicinity of the inflow water inlet (b) is provided with a faucet (7 ), And a warning is issued when the filter membrane is blocked. At this point, the faucet (7) is closed to stop use.
Thereafter, only the miscellaneous water of the faucet (6), that is, the water passing through the membrane surface, is continuously washed, and even if the faucet (7) is opened, the signal lamp (17) is activated by the signal from the differential pressure switch (9). Make sure that it does not light up, and use the permeated water from the faucet (7). The signal lamp (17) may be a buzzer for notifying abnormality.

FIG. 6 is a schematic diagram in which a water pressure measurement point is provided in each of the permeate water side pipe and the inflow water side pipe, and a booster pump that operates based on the differential pressure is provided in the inflow water side pipe. That is, a differential pressure switch (9) comprising pressures in the vicinity of the permeate water side secondary water outlet (a) and the inflow water side primary water inlet (b) is arranged, and the booster is operated by a signal of the differential pressure switch (9). The pump (18) is provided in a pipe line in the vicinity of the pressure detection point (b) at the inlet of the water supply water pipe (19) having a constant water pressure or an industrial tap water pipe.
Usually, the membrane filtration is performed by the booster pump (18). When the differential pressure between (a) and (b) becomes a certain value or more, the booster pump (18) is stopped and the water pressure of the water supply or industrial Only the water passing through the membrane from the faucet (6) is supplied with tap water pressure.
Hereinafter, the present invention will be further described with reference to examples.

A water purifier was installed that used industrial tap water as raw water and was introduced into a water treatment device (cross-flow ultrafiltration membrane separation device) after being boosted by a booster pump. The ultrafiltration membrane filter used here is a cylindrical module having a membrane area of 50 m ² composed of an internal pressure type hollow fiber membrane having a molecular weight cut off of 80,000 and a blocking pore diameter of 0.005 μm made of polyvinylidene fluoride. is there.
The permeated water side outlet of this water purifier was extended by a pipe line and directly connected to three water taps (faucet) pipes for purified water. On the other hand, the membrane surface passing water outlet (one-way in this example, not circulating) was also extended by pipes and directly connected to six water taps (faucets) for miscellaneous water.

A water pressure measurement point (a) was provided near the permeate outlet and a water pressure measurement point (b) was provided near the raw water inlet, and a differential pressure switch was attached between (a) and (b). Furthermore, a permeated water side pipe opening / closing valve that opens and closes directly connected to the signal of the differential pressure switch on the permeated water side pipe line, is provided between the point (a) and the open / close valve, and is operated manually or every 6 hours with a timer. A permeated water side pipe water pressure measuring branch pipe having a discharge valve for discharging purified water for 10 seconds was provided.
In this system, when the pressure difference between (a) and (b) exceeded 300 kPa , the permeated water side pipe opening / closing valve was set to close.

In the water treatment apparatus set under the above conditions, turbidity 9 (mg / l), pH 6.9, hardness CaCO ₃ 98 (mg / l) evaporation residue 210 (mg / l), chloride ion Cl35 (mg / l) , Iron Fe0.3 (mg / l), COD4.2 (mg / l), Chromaticity (degree) 13, Industrial tap water with a water pressure of 100 kPa is injected, 3 purified water taps are fully opened, membrane surface One miscellaneous water faucet at the outlet of the passing water was opened and the raw water was treated at an initial pressure of 250 kPa .
Next, the constant flow valve on the raw water inlet side was adjusted so that the faucet side faucet was closed and the amount of water discharged from the purified water faucet was 4.0 m ³ for 1 hour. When water continuously passed in this state, the permeated water side pipe opening / closing valve was automatically closed after 34 hours and the operation of the water treatment apparatus was stopped.
Subsequently, the three faucets on the miscellaneous water side were fully opened and 10 m ³ of continuous water was discharged per hour. After 6 hours, the permeated water side pipe opening / closing valve was automatically opened and water could be discharged from the purified water faucet. became.
After this test operation, when this system was further continuously used for one year or more in the form of alternate use of purified water and miscellaneous water, stable purified water and miscellaneous water were obtained. In addition, the purified water obtained satisfied all 50 water quality standards in periodic water quality tests.

Ten external pressure hollow fiber microfiltration membrane modules (membrane area 20 m ² ) made of hydrophilic polyethylene with a blocking hole diameter of 0.1 μm, having an outer diameter of 1000 mm, a raw water inlet at the lower part of the raw water side, and a raw water outlet and a filtration at the upper part on the opposite side of 180 ° respectively. A partial membrane filtration device provided with a water outlet was installed.
This processing apparatus was directly connected to a pipe having a water tap (faucet) for miscellaneous water on the raw water outlet side, and a tap water receiving tank pipe was connected to the filtrate (permeate) outlet side. On the other hand, a tap water supply pipe is naturally connected to the tap water receiving tank, and a water level sensor for sending a signal for controlling the open / close valve of the water supply pipe is provided in the receiving tank.

Also, a differential pressure switch is arranged between the water pressure measurement point (a) near the filtrate outlet and the water pressure measurement point (b) near the raw water inlet, and a valve that opens and closes according to the signal of the differential pressure switch is connected to the filtrate outlet. A filtered water pipe was provided downstream from the pressure detection point (a). Thus, when the valve is closed in the water supply line from the filtrate outlet of the water treatment device to the water receiving tank and the flow from the partial membrane filtration device to the water receiving tank is stopped, or the amount of water flow from the water treatment device to the water receiving tank When the water level falls below a preset water level in preparation for a change in water, a water treatment system was completed so that the water supply water supply pipe valve was opened in the water receiving tank and water was supplied from the water supply to the water receiving tank.

In this partial membrane filtration device, turbidity 9 (mg / l), pH 6.9, hardness CaCO ₃ 98 (mg / l), evaporation residue 210 (mg / l), chloride ion Cl35 (mg / l), iron Fe0 .3 (mg / l), COD 0.11 (mg / 1), chromaticity (degree) 2 and electrical conductivity (mS / m) 15 groundwater at a raw water feed pressure of 100 kPa and a membrane permeate flow rate of 5 m ³ / The membrane filtered water was sent to the water receiving tank after being adjusted to the time, and it was used on a daily basis by using a choke water faucet on the raw water outlet side as needed for chores. The water quality of the membrane permeated water (membrane filtered water) supplied to the water receiving tank stably satisfied the tap water quality standard.

When the water receiving tank (14) was full, the water supply from the water supply pipe and the water treatment system was set up to be stopped by a separately prepared control system. The details are omitted because normal means are used.
The water treatment system on a daily amount of 2,000m ³ of domestic water but the water supply of office that requires a (drinking water, service water together) are performed more than one year, without the need for most use of tap water ( The operation is stable.

As described above, while supplying purified water that meets tap water quality standards using a partial membrane filtration method using various water sources, the membrane surface is washed with circulating water that has not been subjected to membrane filtration treatment to stabilize membrane filtration. According to the present invention, it is possible to use rationally separated water, and it is convinced that the utility of the present invention is industrially significant.

FIG. 1 is a flowchart showing the basic idea of the present invention. It is the schematic diagram by which the water flow pressurized with the pump is introduce | transduced into a partial membrane filtration apparatus, and membrane surface passing water and permeated water are obtained. Fig. 2 provides water pressure measurement points on the permeate side pipe and the influent side pipe, and operates the permeate side pipe on the basis of the differential pressure. It is explanatory drawing schematic diagram of the system canceled using a check timer via a differential pressure switch. FIG. 3 is a schematic diagram showing a water supply system in which water passing through the membrane surface of the partial membrane filtration device and permeate water are connected to a tap water receiving tank. Fig. 4 shows the operation of the water level sensor when the supply of filtered water from the membrane surface of the partial membrane filtration device and the permeated water are connected to the tap water receiving tank, and the supply of filtered water cannot catch up and the water level in the receiving tank drops. It is a schematic diagram of the system which supplies water with the valve which performs. FIG. 5 is a schematic diagram in which water pressure measurement points are provided in each of the permeate water side pipe and the inflow water side pipe, the permeate water valve is stopped based on the differential pressure, and the signal lamp blinks. FIG. 6 is a schematic diagram in which a water pressure measurement point is provided in each of the permeate water side pipe and the inflow water side pipe, and a booster pump that operates based on the differential pressure is provided in the inflow water side pipe.

DESCRIPTION OF SYMBOLS 1 Separation membrane 2 Membrane permeate (also referred to as permeate) side of separation membrane module 3 Permeate conduit of separation membrane module 4 Membrane surface passing water side conduit 5 Membrane surface passage water side 6 of separation membrane module Membrane surface passage water side Faucet (water tap) directly connected to the pipeline
7 Faucet (water tap) directly connected to the permeate pipe
8 Inflow water inlet having water pressure 9 Differential pressure switch 10 Permeated water side pipe pressure measuring valve for discharge outside system operated by timer 11 Permeated water side pipe pressure measuring pipe for discharge 12 Permeated water side pipe opening / closing source Valve 13 Partial membrane filtration device 14 Water supply tank 15 Water supply pipe 16 Water level sensor 17 Signal lamp 18 Booster pump 19 Water supply water 20 Water supply pipe open / close valve 21 Constant flow valve a Permeate water side pipe pressure measurement part b Membrane surface passing water side pipe Pressure measurement unit

Claims (8)

When supplying the inflow side primary water of the partial membrane filtration device, a pipe line that uses the water passing through the membrane surface as an out-of-system flow path is provided, and in combination with the permeate side secondary water line, at least one controllable unit is provided. A faucet is installed, and a permeate-side secondary water system pipe line is provided with an open / close valve set to open and close based on the differential pressure derived from the permeate-side secondary water output pressure and the inflow-side primary water receiving pressure. A discharge valve operated by a check timer is arranged in the branch line for measuring the permeated water side pipe water pressure, which is provided between the water pressure measuring point of the side secondary water system pipe line and the on-off valve,
In the opening / closing control of the opening / closing valve, the passage stop of the secondary water of the permeation side by the opening / closing valve operated by the differential pressure,
When the discharge valve is opened by the check timer, filtered water that has permeated through the separation membrane of the partial membrane filtration device is discharged from the permeate-side pipe water pressure measurement branch pipe through the discharge valve. By opening the on-off valve through the differential pressure monitoring that occurs by
Two-way water distribution system characterized by setting to be canceled. 2. The dual supply and distribution system according to claim 1, wherein an operation display is performed based on the differential pressure when the valve is opened and / or closed and a timer is activated. The dual supply and distribution system according to claim 2, wherein an operation including an alarm is displayed on the operation display. 4. The dual supply and distribution system according to claim 1, wherein a tap water receiving tank is provided in the permeate-side secondary water pipeline. 5. 5. The dual supply and distribution system according to claim 4, wherein a water level sensor is provided in the water receiving tank, and drinking water is supplied to the water receiving tank from a water supply or the like when the inflow is below a preset water level. It has a booster pump that operates with a detection width determined based on the differential pressure derived from the pressure on the permeate side secondary water output pressure and the inflow side primary water receiving pressure at the raw water inlet, and starts and stops membrane filtration in the pipeline. The dual supply and distribution system according to any one of claims 1 to 5, wherein the dual supply and distribution system is set to operate in conjunction with a pressure difference. The dual supply and distribution system according to any one of claims 1 to 6, wherein an ultrafiltration membrane filter having a fractional molecular weight of 50,000 to 500,000 is used as the filtration membrane . The dual water supply and distribution system according to any one of claims 1 to 6, wherein a microfiltration membrane filter having a blocking pore diameter of 0.2 µm or less is used as the filtration membrane.

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