JP2012200640A - Drinking water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drinking water supply system which can provide drinking water with high water quality by suppressing contamination of microorganisms, rust or the like.SOLUTION: The drinking water supply system includes a water clarification means Sa for clarifying water, a circulation line Sb for circulating water clarified at a downstream side of the water clarification means Sa to a supplying pipe Sc, water quality detecting means s2, s5 for detecting water quality of water flowing in the circulation line Sb and a monitoring means for keeping water quality constant. Preferably, in the circulation line Sb, water circulates between clarified water tanks 8a, 8b for storing water and the supplying pipe Sc. Preferably, the water quality detecting means are electric conductivity sensors s2, s5.

Description

  The present invention relates to a drinking water supply system that provides water as drinking water.

Conventionally, in general households, business establishments, etc., tap water and well water are used for drinking by removing chlorine and organic substances with activated carbon using a small water purifier.
Commercial mineral water is shipped using activated carbon to remove chlorine and organic substances and adjust minerals.

On the other hand, tap water may not be suitable for drinking in ordinary households, business establishments, etc. in emerging countries, and drinking barrel water (about 20 liters) is purchased from specialists for drinking water.
Schools and dormitories in emerging countries often draw water, but are not suitable for drinking. Similarly, they purchase drinking barrel water from specialists and use it as drinking water.
As prior art documents related to the present application, there are the following Patent Documents 1 and 2.

JP 2009-74279 A JP-A-6-71249

By the way, when using a water purifier in a general household, a business office, etc., when there is a period when it is not used for travel or the like, there is an inconvenience that microorganisms and bacteria are generated on the activated carbon. In addition, the water purifier must be replaced in an appropriate period, and may take time and forget the replacement time.
As described above, the water purifier has a problem in managing the non-use period and a problem that the filter must be replaced in an appropriate period.

On the other hand, when barrel water is purchased and drunk at ordinary households or business establishments in emerging countries, microorganisms and fungi may be generated in the barrel water after a certain period. In addition, the barrel water itself may be contaminated in the barrel.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a drinking water supply system that can suppress the mixing of microorganisms, rust, and the like and can provide high-quality drinking water.

In order to achieve the above-mentioned object, the drinking water supply system according to the first aspect of the present invention is the water purification means for purifying water and the purified water downstream of the water purification means with respect to the supply destination piping. A circulation line through which water is circulated, a water quality detection means for detecting the quality of water flowing through the circulation line, and a monitoring means for keeping the water quality constant are provided.
According to the first aspect of the present invention, even if microorganisms, rust, or the like is present in the supply destination pipe, the circulating water can be monitored to keep the water quality constant.

The drinking water supply system according to the second aspect of the present invention is the drinking water supply system according to the first aspect of the present invention, wherein the circulation line is a purified water tank for storing the purified water, and the purified water tank and a supply pipe. The water is circulated between the two.
According to the second aspect of the present invention, since the water purification tank for storing water is provided in the circulation line, it is possible to cope with a sudden change in flow rate.

The drinking water supply system according to the third aspect of the present invention is the drinking water supply system according to the first or second aspect of the present invention, wherein the water quality detection means is a conductivity sensor.
According to the third aspect of the present invention, since the water quality detection means is a conductivity sensor, a system can be constructed with low cost and high accuracy.

A drinking water supply system according to a fourth aspect of the present invention is the drinking water supply system according to any one of the first to third aspects, further comprising a first filtration means for filtering water upstream from the water purification tank. And the said monitoring means is returning the water which circulates through the said circulation line to the entrance of the said 1st filtration means according to the water quality.
According to the fourth aspect of the present invention, even if bacteria or the like is contained in the water returning from the supply destination pipe, it can be removed by the first filtering means, so that safe water can be supplied to the supply destination.

The drinking water supply system according to the fifth aspect of the present invention is the drinking water supply system according to the fourth aspect of the present invention, wherein the first filtering means is any one of RO membrane, NF membrane, UF membrane, or a combination thereof. is there.
According to the fifth aspect of the present invention, bacteria can be removed from water.

A drinking water supply system according to a sixth aspect of the present invention is the drinking water supply system according to the fourth or fifth aspect of the present invention, comprising: a filter dirt detection means for detecting dirt in the first filtration means; and a first filtration means. When the dirt is detected, a filter dirt removing means for removing the dirt by flowing back to the first filtering means is provided.
According to the sixth aspect of the present invention, dirt on the first filtering means can be detected and removed.

In the drinking water supply system according to the seventh aspect of the present invention, in the drinking water supply system according to any one of the first to sixth aspects of the present invention, if the water quality is abnormal, contact the administrator's mobile phone or terminal device. And / or an abnormal communication means for sounding an alarm or turning on a warning light.
According to the seventh aspect of the present invention, the administrator can immediately recognize and respond to abnormalities in the quality of drinking water with high safety.

A drinking water supply system according to an eighth aspect of the present invention is the drinking water supply system according to any one of the first to seventh aspects, wherein the circulation line is provided with disinfection means using ozone or / and ultraviolet rays. Yes.
According to the eighth aspect of the present invention, water circulating in the circulation line can be disinfected.

A drinking water supply system according to a ninth aspect of the present invention is the drinking water supply system according to any one of the fourth to eighth aspects, further comprising a second filtration means using activated carbon upstream of the first filtration means. Yes.
According to the ninth aspect of the present invention, chlorine, organic matter and the like can be removed by the second filtration means.

A drinking water supply system according to a tenth aspect of the present invention is the drinking water supply system according to any one of the first to ninth aspects, wherein the supply destination pipe is a reverse return pipe.
According to the tenth aspect of the present invention, water can flow smoothly in the supply destination piping.

A drinking water supply system according to an eleventh aspect of the present invention is the drinking water supply system according to any one of the first to ninth aspects, wherein the supply destination pipe is branched with a plurality of substantially equal flow resistances. Piping is formed.
According to the eleventh aspect of the present invention, water can flow smoothly in the supply destination pipe.

  ADVANTAGE OF THE INVENTION According to this invention, mixing with microorganisms, rust, etc. can be suppressed, and the drinking water supply system which can provide a good quality drinking water is realizable.

It is a block diagram which shows the whole structure of the drinking water supply system which concerns on embodiment of this invention. It is a conceptual diagram which shows the structure of the user's piping of embodiment. It is a figure which shows the flow of the tap water of the stationary mode at the time of stationary in the drinking water supply system of embodiment by a thick line. It is a figure which shows the flow of the tap water of the steady mode where the usage-amount of the water of embodiment increased, with a thick line. It is a figure which shows the flow of the tap water of the repurification mode which stops the circulation of the water of the supply block of embodiment, and purifies water with a thick line. It is a figure which shows the flow of the tap water of the washing | cleaning mode of the sand filtration apparatus of the filtration block of embodiment, and an activated carbon adsorber with a thick line.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a configuration diagram showing the overall configuration of a drinking water supply system according to an embodiment of the present invention.
The drinking water supply system S according to the embodiment is a system that supplies tap water, well water, and the like that are not suitable for drinking to users (suppliers) such as schools and hotels as drinking water that is suitable for drinking.
In the following description, it is assumed that tap water that is not suitable for drinking is supplied to the drinking water supply system S through the water pipe Is.

  The drinking water supply system S includes a filtering block Sa that uses drinking water that is not suitable for drinking supplied from the water pipe Is and drinking water that is suitable for drinking, and the drinking water produced by the filtering block Sa is used by the school of the user (supplier). , Hotels, etc. O. And a supply block Sb that is circulated and supplied to a U (point of use) pipe Sc. The drinking water supply system S is controlled by a control unit (monitoring means) (not shown).

  The filtration block Sa of the drinking water supply system S includes first and second raw water tanks 1a and 1b for storing tap water supplied through the water pipe Is, and a sand filtration device 2 for removing large foreign substances from the tap water, Activated carbon adsorber 3 provided with activated carbon that adsorbs chlorine, organic matter, etc. in tap water, MF filter 4 provided with MF membrane (microfiltration membrane) that removes fine foreign substances in tap water, and these A treated water tank 5 for storing treated water treated in Step 1, a prefilter 6 such as an MF membrane for filtering treated water, and a membrane unit 7 provided with a first filtration filter 7a and a second filtration filter 7b. It has. The MF membrane (microfiltration membrane) separates suspended matter and colloidal particles contained in water with high accuracy.

The first and second filtration filters 7a and 7b are each composed of one of RO membrane (reverse osmosis membrane), NF membrane (nanofiltration membrane), UF membrane (ultrafiltration membrane), or a combination thereof. Yes.
The RO membrane (reverse osmosis membrane) is a semipermeable membrane that allows water to pass through but hardly allows ions or low-molecular substances to pass through.
The NF membrane (nanofiltration membrane) is selective to elements and ions and cuts low-molecular impurities and microorganisms.
The UF membrane (ultrafiltration membrane) performs molecular level sieving according to the pore size of the membrane and the molecular size of the substance to be removed in water.
In the steady mode, the first filtration filter 7a is mainly used by the control of the control unit, and the second filtration filter 7b is controlled by a valve (not shown) so that a minimum (minimum) flow rate flows. Note that the roles of the first filtration filter 7a and the second filtration filter 7b may be exchanged periodically or at an arbitrary period under the control of the control unit.

The first and second raw water tanks 1a and 1b, the sand filtration device 2, the activated carbon adsorber 3, the MF filter 4, the treated water tank 5, the prefilter 6, and the membrane unit 7 are arranged in order of the pipe I through which tap water flows. It is connected to the.
The first raw water tank 1a is a tank for storing tap water from the water pipe Is, and the second raw water tank 1b is a buffer tank and a backup tank for the first raw water tank 1a.

Between the first and second raw water tanks 1a and 1b and the sand filtration device 2, the tap water supplied from the water pipe Is and stored in the first and second raw water tanks 1a and 1b is sent to the sand filtration device 2. First and second raw water pumps p1 and p2 are provided.
The first raw water pump p1 is a pump that is operated when the water in the first raw water tank 1a is sent to the sand filtration device 2 in the steady mode, and the second raw water pump p2 is a backup or sand for the first raw water pump p1. It is used for reverse flow (arrows β1 and β2 in FIG. 6) when the filtration device 2 and the activated carbon adsorber 3 are washed.

That is, the second raw water pump p2 supplies the tap water to the sand filtration device 2 as shown by the arrow β1 in FIG. 6 through the pipes I1 and I2 when the sand filtration device 2 is washed. In addition, when the activated carbon adsorber 3 is washed, the second raw water pump p2 supplies tap water to the sand filtration device 2 through the pipes I1 and I3 as indicated by an arrow β2 in FIG.
Between the treated water tank 5 and the pre-filter 6, first and second high-pressure pumps p3 and p4 are provided. The second high pressure pump p4 is used as a backup for the first high pressure pump p3, and is operated when the first high pressure pump p3 fails. Note that the first and second high-pressure pumps p3 and p4 may be alternately used for operation and backup.

Hereinafter, other symbols of the filtration block Sa will be described.
Reference numerals d1 to d20 are valves that allow the flow in the pipe I to pass or stop by opening and closing.
Reference numerals g1 to g4 are check valves that allow the flow of the pipe I in the direction of the arrow while preventing the flow in the direction of the opposite arrow.
Reference numeral n <b> 1 is a viewing window or a check valve that allows the backflow (see arrow β <b> 1 in FIG. 6) of the sand filtration device 2 to be washed and washed.
Reference numeral n2 is a viewing window or a check valve for viewing the backflow when the activated carbon adsorber 3 is cleaned by backflow (see arrow β2 in FIG. 6).

Reference numeral c1 indicates that the water in the supply block Sb is closed when the water in the supply block Sb satisfies a predetermined water quality as drinking water to prevent the supply block Sb from returning to the treated water tank 5, while the water in the supply block Sb Is a control valve that opens to permit the return from the supply block Sb to the treated water tank 5 when the predetermined water quality as drinking water is not satisfied.
The filtration block Sa includes pressure gauges t1 to t4 that measure the pressure of the water flow in the pipe I as flow sensors in the pipe I, and a flow meter r1 that measures the flow rate of the water flow in the pipe I. ing.

Next, the supply block Sb of the drinking water supply system S will be described.
The supply block Sb is connected to the filtration block Sa and the pipe I.
The supply block Sb includes first and second water purification tanks 8a and 8b that store drinking water made by the filtration block Sa, an ozonizer 9 that supplies ozone (O ₃ ) to drinking water flowing in the pipe I, and a beverage A UV (Ultra Violet) sterilization apparatus 10 for sterilizing water and a filter 11 provided with an MF membrane (microfiltration membrane) for removing foreign matters mixed in drinking water circulating from the user's piping Sc are provided. Yes.

The 1st water purification tank 8a is a tank which stores the drinking water supplied from the filtration block Sa, and the 2nd water purification tank 8b is a tank for buffers and a backup of the 1st water purification tank 8a.
Between the first and second water purification tanks 8a and 8b and the UV sterilizer 10, inverter-controlled first and second water supply pumps p5 and p6 are provided.

The inverter-controlled first water supply pump p5 is a pump that sends drinking water in the first water purification tank 8a to the UV sterilizer 10 or the user's (supplier) pipe Sc. The inverter-controlled second water supply pump p6 is This is a pump used for backup of the first water supply pump p5.
The first water supply pump p5 drastically reduces the amount of drinking water used at night, so that the drinking water flow rate is set to the minimum (minimum) flow rate by inverter control. In this way, “dead water” is not generated by always creating a flow. Thereby, it is possible to reduce power consumption.

  The supply block Sb is provided with a control valve c2. The control valve c2 is controlled to close when the drinking water circulating to the supply block Sb does not satisfy the predetermined water quality and to allow the return from the supply block Sb to the treated water tank 5, while the supply block When the drinking water of Sb satisfies the predetermined water quality, the valve is opened and the circulation in the supply block Sb is continued.

Reference numerals b1 to b12 are valves that pass or stop the flow of the pipe I by opening and closing.
Reference numerals g5 to g7 are check valves that permit the flow of the pipe I in the direction of the arrow while preventing the flow in the direction of the opposite arrow.
The supply block Sb includes pressure gauges t5 and t6 that measure the pressure of the flow of drinking water in the pipe I.

  The supply block Sb has, as sensors, a PH meter s1 that measures the PH value of drinking water flowing through the piping I of the user (supplier) to the piping Sc, and the conductivity of the drinking water in the piping I of the outbound route. Conductivity meter s2 for measurement, residual chlorine measuring device s3 for measuring residual chlorine in drinking water in outgoing pipe I, fine particle meter s4 for measuring fine particles of drinking water in outgoing pipe I, and user (supply And a conductivity meter s5 for measuring the conductivity of the drinking water in the pipe I on the return path from the previous pipe Sc.

  The fact that the drinking water in the pipe I of the supply block Sb is contaminated is that the pure water has a low conductivity, so that the control unit conducts the drinking water in the pipe I measured by the conductivity meter s5 in the return path. It can be determined by determining whether or not the difference between the rate and the conductivity of the drinking water in the pipe I measured by the forward conductivity meter s2 is equal to or greater than an allowable value indicating the degree of contamination.

Supply of ozone (O ₃ ) by the ozonizer 9 is performed when the control unit determines that the measured value of the fine particle meter s4 is larger than the allowable value indicating the degree of contamination and the amount of fine particles in the drinking water has increased, or the return line I When the control unit determines that the difference between the conductivity of the drinking water in the pipe and the conductivity of the drinking water in the outgoing pipe I is greater than the allowable value indicating the degree of contamination, the valve b3 and / or the valve b5 This is performed by opening the valve and bubbling from below the first water purification tank 8a and / or the second water purification tank 8b.

FIG. 2 is a conceptual diagram showing the configuration of the user's piping Sc.
The piping I in the forward path of the supply block Sb in the drinking water supply system S is connected to the user's piping Sc at an incoming connection point Iin (see FIG. 1), and the drinking water in the supply block Sb flows into the user's piping Sc. On the other hand, the return pipe I of the supply block Sb is connected to the user's pipe Sc at the outlet connection point Iot (see FIG. 1), and the drinking water passing through the user's pipe Sc flows into the return pipe I. .

The user's piping Sc is provided over a single floor or a plurality of floors, and a drinking faucet (not shown) is provided at a single or a plurality of predetermined locations.
The user's piping Sc has a length from the incoming connection point Iin through the main piping Sc0, first piping Sc1, main piping Sc9 to the outgoing connection point Iot, and from the incoming connection point Iin to the main piping Sc0, second piping. This is a reverse return pipe having a length equal to the length from the main pipe Sc9 to the outlet connection point Iot. A faucet for supplying drinking water is disposed in the first pipe Sc1 and the second pipe Sc2.

That is, the user's piping Sc passes through the first piping Sc1 from the incoming connection point Iin, and the flow resistance of the pipeline from the incoming connection point Iin to the outgoing piping I2 through the second piping Sc2. The flow resistance of the pipe line leading to the connection point Iot, that is, the flow resistance of the first pipe Sc1 and the second pipe Sc2 is set equal or substantially equal.
Therefore, the drinking water flowing into the user's piping Sc from the incoming connection point Iin flows and stays uniformly in any of the pipes (the first piping Sc1 and the second piping Sc2) of the user's piping Sc (so-called dead water and There will be no). Therefore, the drinking water flowing through the user's piping Sc can maintain the water quality.

Here, in FIG. 2, the user's piping Sc has been described by exemplifying the case where the first and second pipings Sc1 and Sc2 are two branch pipes. However, the user's piping Sc may be a single pipe. A pipe having an arbitrary number of branch pipes for reverse return may be used.
In addition, the user's piping Sc is adjusted by appropriately adjusting the diameter of each branch pipe (first and second pipes Sc1 and Sc2) branching from the main pipe Sc0, and the branch pipes from the incoming connection point Iin to the outgoing connection point Iot. If the flow resistance of the flow, that is, the flow resistance of each branch pipe (the first and second pipes Sc1, Sc2) is adjusted to be equal or substantially equal, etc., it is possible to suppress the retention of drinking water (generation of dead water) in the pipeline. It is not always necessary to use a reverse return pipeline. However, the reverse return conduit is more desirable because it has a simple configuration and is easy to install.

<Operation of drinking water supply system S>
Next, the operation of the drinking water supply system S will be described.
First, the steady mode of the operation state at the time of stationary of the drinking water supply system S will be described.
FIG. 3 is a diagram showing a flow of tap water in a steady mode at a steady time in the drinking water supply system S by a bold line.
Normally, the filtration block Sa has the valves d1, d2, d5, d7, d11, d13, d16, d17, d19 opened by the control unit, and the first raw water pump p1 and the first high pressure pump p3 are connected. Be operational. In addition, the valves of other filtration blocks Sa such as the regulating valve c1 are closed.

Thereby, the tap water from the water pipe Is is stored in the first and second raw water tanks 1a and 1b. The second raw water tank 1b is used as a buffer tank and a backup tank.
The water in the first raw water tank 1a passes through the valves d5 and d7, the first raw water pump p1 and the check valve g1, and flows into the sand filtration device 2, and is sand-filtered by the sand filtration device 2 to remove foreign matters. . The water filtered by the sand filter 2 flows through the valve d11 to the activated carbon adsorber 3, and the activated carbon adsorber 3 adsorbs chlorine (Cl ₂ ), organic matter, and the like to the activated carbon. The water that has passed through the activated carbon adsorber 3 flows through the valve d13 to the MF filter 4 and is filtered to remove fine particles.

The water filtered by the MF filter 4 flows through the valve d16 to the treated water tank 5 and is stored.
Water in the treated water tank 5 is filtered by the pre-filter 6 through the valve d17, the first high-pressure pump p3, the check valve g3, and the valve d19.
The water that has passed through the prefilter 6 is filtered by the membrane unit 7 (7a, 7b), and then flows into the first water purification tank 8a and / or the second water purification tank 8b of the supply block Sb.

Normally, the second water purification tank 8b of the supply block Sb is used as a buffer, and the second water supply pump p6 is not used.
Then, the control unit opens the valves b1, b2, b4, b7, b10, b11, b12 and the regulating valve c2, and the first feed water pump p5 is operated.
The valves of the other supply blocks Sb are closed by the control unit.

  The water supplied from the filtration block Sa is stored in the first water purification tank 8a and / or the second water purification tank 8b. In FIG. 3, the case where it stores by the 1st water purification tank 8a and the 2nd water purification tank 8b is shown. In addition, the 2nd water purification tank 8b plays the role of a buffer tank and a backup tank at the time of steady state.

The water stored in the first water purification tank 8a flows through the valve b4, the first water supply pump p5, the valve b7, the check valve g5, and the valve b10 to the UV sterilizer 10, and in the UV sterilizer 10, ultraviolet rays are used. Sterilized.
The water sterilized by the UV sterilization apparatus 10 flows through the valve b11 and the check valve g7 from the incoming connection point Iin to the user's piping Sc as drinking water.

Drinking water that has flowed out of the user's piping Sc through the outlet connection point Iot is filtered by the filter 11 through the valve b12, and then returned to the first water purification tank 8a through the adjustment valve c2.
As described above, the water supplied from the filtration block Sa is supplied to the first water purification tank 8a, and after flowing into the user's piping Sc, is returned to the first water purification tank 8a and circulated.

Next, a case where the amount of water used has increased from the steady state of FIG. 3 will be described with reference to FIG. FIG. 4 is a diagram illustrating a flow of tap water in a steady mode in which the amount of water used is increased by a bold line.
In the steady state of FIG. 3, when the flow rate measured by the flow meter r1 increases and the amount of water used increases, the control unit sets the second raw water tank 1b for the buffer of the filtration block Sa and the supply block Sb. A second water purification tank 8b for buffer is newly used. In this case, since the flow rate is large, the control unit operates the backup second raw water pump p2 and the second high-pressure pump p4 for the filtration block Sa and also operates the backup second feed water pump p6 for the supply block Sb. .

At this time, the control unit opens the valves d6, d8, d8a, d18, d20 of the filtration block Sa, and opens the valves b6, b8 of the supply block Sb to obtain the state shown in FIG.
In addition, in FIG. 4, although the case where the 2nd raw | natural water tank 1b, the 2nd purified water tank 8b, the 2nd raw | natural water pump p2, the 2nd high pressure pump p4, and the 2nd feed water pump p6 were used was illustrated suitably according to a state Of course, use can be arbitrarily selected by the control unit.

<Maintenance of drinking water quality>
In steady mode (including when the amount of water used is large), circulating water (drinking water) is sterilized by the UV sterilizer 10 during circulation and filtered by the filter 11 after flowing into the user's piping Sc. And a constant water quality is maintained.
As for the quality of the circulating water, the PH value is measured by the PH meter s1, the conductivity is measured by the conductivity meters s2 and s5, and the residual chlorine is measured by the residual chlorine measuring device s3. Further, the fine particles contained in the water circulating in the fine particle meter s4 are measured.

  When the control unit recognizes that the residual chlorine measured by the residual chlorine measuring device s3 exceeds the set allowable value, the control unit performs cleaning described later to enhance the adsorption function of the activated carbon. In this case, the water stored in the first and second water purification tanks 8a and 8b is discarded until the residual chlorine value reaches the allowable value, and the water whose residual chlorine value is within the allowable value is circulated. You may comprise.

When the fine particles measured by the fine particle meter s4 deviate from the allowable value, or / and when the difference in the electric conductivity measured by the conductivity meters s2 and s5 deviates from the allowable value, the control unit operates the ozonizer 9 and The valves b3 and b5 are opened, ozone (O ₃ ) is supplied to the water in the first and second water purification tanks 8a and 8b, and microorganisms are removed and organic substances are decomposed by ozone.

  In addition, when the difference in the conductivity measured by the residual chlorine measuring device s3 and the particle meter s4 and the conductivity measured by the conductivity meters s2 and s5 each deviates from the allowable value, the abnormality communication means of the control unit causes the drinking water supply system. You may contact the S administrator's mobile phone, send an e-mail to the administrator's terminal device, sound an alarm with an alarm device, or turn on an alarm lamp to notify that effect.

<Purification by circulating water circulation>
Even if ozone (O ₃ ) is supplied, if the difference in the fine particles measured by the fine particle meter s4 deviates from the allowable value, or / and the difference in the electric conductivity measured by the conductivity meters s2 and s5 is within the allowable value. In the case of deviation, the control unit uses an abnormal communication means to contact the administrator's mobile phone of the drinking water supply system S, send an e-mail to the administrator's terminal device, or issue an alarm with an alarm device. Notify the administrator to that effect by sounding or turning on a warning light.

  At the same time, as shown in FIG. 5, the control unit closes the regulating valve c2 to stop the circulation of the water in the supply block Sb and opens the regulating valve c1 to regulate the water circulating in the supply block Sb. It returns to the treated water tank 5 of the filtration block Sa from the valve c1. In addition, FIG. 5 is a figure which shows the flow of the tap water of the repurification mode which stops the circulation of the water of the supply block Sb, and purifies water with a thick line.

  The water returned to the treated water tank 5 is filtered by the pre-filter 6 and filtered by the membrane unit 7 and supplied to the first and second water purification tanks 8a and 8b. At this time, the first raw water pump p1 is stopped and the valve d16 is closed, and the supply of the tap water from the first raw water tank 1a to the treated water tank 5 is stopped.

  The valve d16 may be closed and the supply of the tap water from the first raw water tank 1a to the treated water tank 5 may be continued. However, since the purification of the water circulating through the supply block Sb proceeds more quickly when the supply of the tap water from the first raw water tank 1a to the treated water tank 5 is stopped, the tap water from the first raw water tank 1a is advanced. It is more desirable to stop the supply to the treated water tank 5.

  When the fine particles measured by the fine particle meter s4 are within the allowable value and the difference in conductivity measured by the conductivity meters s2 and s5 is within the allowable value, the adjustment valve c1 is closed. Then, the regulating valve c2 and the valve d16 are opened, the first raw water pump p1 is put into an operating state, and the steady mode of FIG. 3 is restored.

<Detection and cleaning of clogging of purifier>
Next, the sand filtration device 2, which is a purification device of the filtration block Sa, the activated carbon adsorber 3, the MF filter 4, the prefilter 6, and the removal of dirt on the membrane unit 7, and the filter 11 which is a purification device of the supply block Sb. The removal of dirt will be described.
The dirt of the sand filtration device 2 and the activated carbon adsorber 3 is such that the difference between the pressure value measured by the pressure gauge t1 and the pressure value measured by the pressure gauge t2 exceeds the allowable value in the steady mode shown in FIG. In this case, the control unit determines that the sand filtration device 2 and / or the activated carbon adsorber 3 is clogged due to contamination.

  Note that the difference between the flow rate of water measured by the flow meter r1 upstream of the sand filter 2 and the flow rate of water measured by a flow meter (not shown) downstream of the activated carbon adsorber 3 exceeds the allowable value. It may be determined whether or not the sand filtration device 2 and / or the activated carbon adsorber 3 is clogged due to contamination.

FIG. 6 is a diagram showing the flow of tap water in the cleaning mode of the sand filtration device 2 and the activated carbon adsorber 3 of the filtration block Sa with a bold line.
In this case, the control unit closes the valves d7 and d8a, stops the first raw water pump p1, the first high-pressure pump p3, and the first feed water pump p5, and pauses the steady mode. At the same time, the control unit opens the valves d5, d8, d9, d10, d12, and d14, operates the second raw water pump p2, and shifts to the purification mode.

  Thereby, the water in the first raw water tank 1a flows through the valves d5 and d8, the second raw water pump p2 and the check valve g2 to the pipes I1 and I2, and from the valve d9 to the sand filtration device 2 as shown in FIG. It flows backward in the opposite direction to the steady mode (arrow β1 in FIG. 6). By the reverse flow, the dirt of the sand filter 2 is removed, and the dirt of the sand filter 2 is discharged through the pipe I2 and the valve d10.

At the same time, the water in the first raw water tank 1a flows through the valves d5 and d8, the second raw water pump p2 and the check valve g2 to the pipes I1 and I3, and from the valve d12 to the activated carbon adsorber 3 as shown in FIG. It flows in the opposite direction to the mode (arrow β2 in FIG. 6). By the reverse flow, the dirt on the activated carbon adsorber 3 is removed, and the dirt on the activated carbon adsorber 3 is discharged through the pipe I3 and the valve d14.
In addition, in the said description, although the dirt of the sand filtration apparatus 2 and the dirt of the activated carbon adsorber 3 were detected together, the case where the sand filtration apparatus 2 and the activated carbon adsorber 3 were backwashed simultaneously and washed was illustrated, The sand filtration device 2 and the activated carbon adsorber 3 may be configured to individually detect the dirt by upstream and downstream pressures, flow rates, and the like, and perform cleaning individually.

  Similarly, when the upstream pressure gauge t2 and the downstream pressure gauge t3 exceed the allowable value, or the difference between the flow values measured by the flow meters provided upstream and downstream (not shown) If the MF filter 4 is clogged, the control unit suspends the steady mode in FIG. 3 and makes the MF filter flow backward in the opposite direction to the steady mode. The vessel 4 can be cleaned.

  Similarly, the pre-filter 6 of the filtration block Sa, the first and second filtration filters 7a and 7b of the membrane unit 7, and the filter 11 of the supply block Sb are also provided with a pressure gauge (not shown) provided at the upstream and downstream, respectively. If the pressure value or / and the flow rate difference of the flow meter (filter contamination detection means) exceeds an allowable value, it is assumed that clogging has occurred and the pump (not shown) is directed in the opposite direction to the steady mode of FIG. Washing is performed by backflow using a filter dirt removing means).

In addition, when each said clogging does not recover even if it wash | cleans, a control part will contact the mobile phone of the administrator of the drinking water supply system S by an abnormal communication means, or it will be electronic to a terminal device of a manager. Notify the administrator by sending an e-mail, sounding an alarm with an alarm, or turning on an alarm light.
Note that the prefilter 6 of the filtration block Sa, the first and second filtration filters 7a and 7b of the membrane unit 7, and the filter 11 of the supply block Sb may be individually detected by detecting clogging. These may be combined as appropriate to detect clogging and wash.

According to the drinking water supply system S of the embodiment, even if there are microorganisms or rust in the water supply pipe (user's pipe Sc) of a user (supply destination) such as a school, a hotel, etc., the circulating water is monitored and the water quality is monitored. Can be kept constant. Further, by using conductivity sensors (conductivity meters s2, s5) as water quality detection means, a system can be constructed with low cost and high accuracy.
In addition, the first and second filtration filters 7a and 7b of the membrane unit 7 are each composed of either a RO membrane, an NF membrane, a UF membrane, or a combination thereof, so that bacteria can be removed from the water. it can.

Furthermore, since a filtration means using activated carbon is provided in front of the membrane unit 7, chlorine, organic matter, etc. can be removed.
In addition, even if bacteria or the like is contained in the circulating water returned from users (suppliers) such as schools and hotels, it can be removed and disinfected with the ozonizer 9, UV sterilizer 10, and filter 11, so safe water can be supplied to the user. Can be supplied.

  Furthermore, when the water quality deteriorates, the circulation is stopped, and the contaminants can be removed again by the prefilter 6 and the membrane unit 7, so that safe water can be supplied to the user without human intervention. In addition, if the water quality deteriorates, the administrator is notified by mobile phone, e-mail, alarm, warning light, etc., so the administrator can immediately recognize and respond to abnormalities in the quality of safe drinking water. .

Moreover, since the drinking water supply system S is connected to user's piping Sc, such as a reverse return, circulating water flows smoothly without staying, and generation | occurrence | production of microorganisms and mixing of the rust of piping Sc are suppressed.
Therefore, it is possible to realize a drinking water supply system that can suppress the mixing of microorganisms, rust, and the like and provide high-quality drinking water.

In the above embodiment, the case where two first and second raw water tanks 1a and 1b and two first and second water purification tanks 8a and 8b are provided is exemplified, but three or more may be provided. Moreover, each of the raw water tank and the water purification tank may be one.
Moreover, in the said embodiment, although the case where the 1st, 2nd water purification tanks 8a and 8b were provided was illustrated, you may comprise without providing a water purification tank.

Note that the administrator's terminal device described in the above embodiment may be a portable information terminal as long as it is capable of electronic contact, and is not particularly limited.
In addition, although tap water was illustrated in the said embodiment, warm water, such as well water and a hot spring, may be sufficient and water other than tap water may be applied. In addition, the water of a claim shall include warm water.

2 Sand filter (water purification means)
3 Activated carbon adsorber (second filtration means, water purification means)
4 MF filter (water purification means)
6 Pre-filter (water purification means)
7 Membrane unit (first filtration means, water purification means)
8a 1st water purification tank (water purification tank)
8b 2nd water purification tank (water purification tank)
9 Ozonizer (disinfection means)
10 UV sterilizer (disinfection means)
S drinking water supply system s2, s5 conductivity meter (water quality detection means, conductivity sensor)
Sa filtration block (water purification means)
Sb supply block (circulation line)
Sc piping (supplier piping)

Claims (11)

Water purification means for purifying water;
A circulation line through which the purified water is circulated on the downstream side of the water purification means with respect to a supply pipe;
Water quality detection means for detecting the quality of the water flowing through the circulation line;
A drinking water supply system comprising: monitoring means for keeping the water quality constant. The drinking water supply system according to claim 1, wherein the circulation line is configured to circulate the water between a purified water tank that stores the purified water, and the purified water tank and a supply destination pipe. .   The drinking water supply system according to claim 1 or 2, wherein the water quality detection means is a conductivity sensor. It has the 1st filtration means which filters water upstream from the said water purification tank, The said monitoring means returns the water which circulates through the said circulation line to the entrance of the said 1st filtration means according to the water quality, It is characterized by the above-mentioned. The drinking water supply system according to any one of claims 1 to 3.   The drinking water supply system according to claim 4, wherein the first filtration means is any one of RO membrane, NF membrane, UF membrane, or a combination thereof. Filter dirt detecting means for detecting dirt in the first filtering means;
The drinking water supply according to claim 4 or 5, further comprising: filter dirt removing means for removing the dirt by causing the first filtration means to flow backward when the dirt of the first filtering means is detected. system. 7. The apparatus according to any one of claims 1 to 6, further comprising an abnormality communication means for contacting an administrator's mobile phone or terminal device and / or sounding an alarm or turning on a warning light when the water quality is abnormal. The drinking water supply system as described in any one of them. The drinking water supply system according to any one of claims 1 to 7, wherein the circulation line includes disinfecting means using ozone and / or ultraviolet rays. The drinking water supply system according to any one of claims 4 to 8, further comprising a second filtering unit using activated carbon upstream of the first filtering unit. The drinking water supply system according to any one of claims 1 to 9, wherein the supply destination pipe is a reverse return pipe. The drinking water supply system according to any one of claims 1 to 9, wherein the supply destination pipe is formed with a plurality of branch pipes branching with substantially equal flow resistance.

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