JP6075030B2 - Pure water production equipment - Google Patents

Description

  The present invention includes a dechlorination device that removes chlorine components contained in raw water, a reverse osmosis membrane module that separates permeate water from supply water from which chlorine components have been removed by the dechlorination device, and desalting the permeate water. The present invention relates to a pure water production apparatus including an electrodeionization stack for obtaining demineralized water.

  In semiconductor manufacturing processes, electronic component cleaning, medical instrument cleaning, and the like, high-purity pure water that does not contain impurities is used. When manufacturing this kind of pure water, a pure water manufacturing apparatus may be used. An activated carbon filter as a dechlorination device that removes chlorine components contained in raw water as a pure water production device, and a reverse osmosis membrane module that separates permeate from raw water (feed water) from which chlorine components have been removed by the activated carbon filter (Hereinafter also referred to as “RO membrane module”), and an electrodeionization stack (hereinafter also referred to as “EDI stack”) that obtains demineralized water by desalting the permeated water separated by the reverse osmosis membrane module. An apparatus for producing pure water is known (see, for example, Patent Document 1).

  The RO membrane module is configured by housing a single or a plurality of RO membrane elements in a pressure vessel, but in recent years, RO membranes for producing pure water are generally polyamide-based RO membranes. . Polyamide-based RO membranes have a higher salt removal rate and water permeability coefficient than those of other materials. However, when the supply water contains a chlorine component, oxidative degradation tends to proceed. Therefore, in a pure water manufacturing apparatus, generally, chlorine components contained in raw water such as tap water are previously removed by an activated carbon filter, and pretreated supply water is supplied to the RO membrane module.

JP 2006-255650 A

  In the pure water manufacturing apparatus described in Patent Document 1, supply water from which chlorine components have been removed is supplied to the RO membrane module. Therefore, it is expected that the life of the RO membrane module is extended by suppressing the oxidative deterioration of the RO membrane. On the other hand, in the water sampling standby state of the pure water production apparatus, there is a possibility that the supply water from which the chlorine component has been removed stays in the primary side of the RO membrane module, and bacteria will propagate on the surface of the RO membrane. When the growth of bacteria progresses, the RO membrane may be clogged by biofouling, so that the growth of bacteria inside the RO membrane module is suppressed while providing a dechlorination device such as an activated carbon filter. An apparatus for producing pure water that can be used is desired.

  An object of this invention is to provide the pure water manufacturing apparatus which can suppress the proliferation of the bacteria inside a reverse osmosis membrane module, providing a dechlorination apparatus.

The present invention provides a dechlorination device for removing chlorine components contained in raw water, a reverse osmosis membrane module for separating permeate from feed water from which chlorine components have been removed by the dechlorination device, and separation by the reverse osmosis membrane module An electrodeionization stack for demineralizing the permeated water to obtain demineralized water, a feed water line for circulating the feed water from which chlorine components have been removed by the dechlorination apparatus to the reverse osmosis membrane module, and the reverse osmosis A permeate line for circulating the permeated water separated by the membrane module to the electrodeionization stack, a demineralization line for sending the demineralized water obtained by the electrodeionization stack toward a demand point, and the reverse osmosis membrane A discharge line for distributing supply water staying on the primary side of the module toward the outside of the system, and a supply line staying on the primary side of the reverse osmosis membrane module are discharged from the discharge line to the outside of the system. And discharging means for feeding processing feasible to, a second circulation water line for returning the water which has passed through the desalting compartments of the electrodeionization stack to the upstream side of the reverse osmosis membrane module, wherein the electrodeionization stack A second circulation means capable of executing a process of sending out the water that has passed through the desalting chamber to the upstream side of the reverse osmosis membrane module, and a predetermined time after the standby state in which the desalted water is not supplied to the demand point A control unit that controls the discharging means to discharge the supply water staying on the primary side of the reverse osmosis membrane module to the outside of the system via the discharge line when it has passed , the control unit comprising: In the case where a predetermined time has elapsed since the standby state in which demineralized water is not supplied to the demand point, water that has passed through the demineralization chamber of the electrodeionization stack is passed through the second circulating water line to the reverse osmosis membrane. Mo The second circulation means is controlled so as to be returned to the upstream side of the module, and the discharge means is controlled so that the supply water staying on the primary side of the reverse osmosis membrane module is discharged outside the system via the discharge line. about the water purifying system to run a second step of.

  A first circulating water line for returning the permeated water separated by the reverse osmosis membrane module to the upstream side of the reverse osmosis membrane module; and the permeated water separated by the reverse osmosis membrane module. A first circulation means capable of performing processing to send back to the upstream side, and the control unit, when a predetermined time has passed since the standby state in which demineralized water is not supplied to the demand point, The first circulation means is controlled so that the permeated water separated by the reverse osmosis membrane module is returned to the upstream side of the reverse osmosis membrane module via the first circulating water line and the primary of the reverse osmosis membrane module. It is preferable to execute the first step of controlling the discharge means so that the supply water staying on the side is discharged out of the system through the discharge line.

  A supply water storage tank that is provided upstream of the reverse osmosis membrane module in the supply water line and stores the supply water; and a water level measurement unit that measures a water level of the supply water stored in the supply water storage tank; A supply water valve provided upstream of the supply water storage tank in the supply water line and opening and closing the supply water line, and the control unit measures by the water level measuring means during normal operation of the apparatus When the water level of the supply water stored in the supplied water storage tank is lower than the first water level, the supply water valve is controlled to be in an open state, and the supply water stays on the primary side of the reverse osmosis membrane module Is stored in the supply water storage tank measured by the water level measuring means during the operation of controlling the discharging means so as to be discharged out of the system through the discharge line. It is preferable that the feed water valve is controlled to be opened when the water level falls below the second water level higher than the first water level.

  Further, the apparatus further includes a temperature measuring unit that measures the temperature of the feed water or the temperature of the outside air, and the control unit becomes in a standby state as the temperature of the feed water or the outside air measured by the temperature measuring unit is higher. It is preferable to set so as to shorten the predetermined time from the start, or to control to increase the discharge time for discharging the supply water through the discharge line.

  A second circulating water line for returning water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module; and water that has passed through the demineralization chamber of the electrodeionization stack. A second circulation means capable of executing a process for sending it back to the upstream side of the osmosis membrane module, an electrical conductivity measurement means for measuring the electrical conductivity of the permeated water flowing through the permeate line, and an alarm And a control means, wherein the control unit passes through the permeate line when a first time has elapsed since the start of execution of the first step and there is a request to send pure water. The electrical conductivity of the water is measured, and when the electrical conductivity of the permeated water exceeds a predetermined conductivity threshold, control is performed so as to perform notification by the notification means, and subsequently, With starting energization It shifts the demineralized water obtained through the serial electrodeionization stack to the third step of returning to the upstream of the reverse osmosis membrane module via the second circulating water line is preferable.

  A second circulating water line for returning water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module; and water that has passed through the demineralization chamber of the electrodeionization stack. A second circulating means capable of executing a process for sending it back to the upstream side of the osmotic membrane module, an electrical characteristic detecting means for measuring the specific resistance of the permeated water flowing through the permeated water line, and a notification for alarming. And a control unit, wherein the control unit circulates the permeate line through the permeate line when a first time has elapsed from the start of the execution of the first step and there is a request to send pure water. When the specific resistance of the permeated water falls below a predetermined specific resistance threshold value, control is performed so as to perform notification by the notification means, and then energization to the electrodeionization stack is started. And the electrical discharge It shifts the demineralized water obtained through the Nsutakku the third step of returning to the upstream of the reverse osmosis membrane module via the second circulating water line is preferable.

  ADVANTAGE OF THE INVENTION According to this invention, while providing a dechlorination apparatus, the demineralized water manufacturing apparatus which can suppress the reproduction of bacteria inside a reverse osmosis membrane module can be provided.

It is a whole block diagram of the pure water manufacturing apparatus 1 which concerns on one Embodiment. It is a flowchart which shows the process sequence of operation | movement of the pure water manufacturing apparatus. It is a flowchart which shows the process sequence of operation | movement of the pure water manufacturing apparatus.

  The pure water manufacturing apparatus 1 which concerns on one Embodiment of this invention is demonstrated referring drawings. FIG. 1 is an overall configuration diagram of a pure water production apparatus 1 according to an embodiment. The pure water production apparatus 1 according to the present embodiment is applied to, for example, a pure water production apparatus that produces demineralized water from raw water (for example, tap water). The desalted water produced by the pure water production apparatus is sent as pure water to a demand location or the like. In the pure water production apparatus of the present embodiment, supplying pure water to a demand location or the like is also referred to as “water sampling”.

  As shown in FIG. 1, a pure water production apparatus 1 according to this embodiment includes an activated carbon filter 2 as a dechlorination apparatus, a prefilter 3, a raw water tank 4 as a supply water storage tank, and a discharge means. Pressurizing pump 5, inverter 6, first RO membrane module 11 and second RO membrane module 12 as reverse osmosis membrane modules, EDI stack 20 as electrodeionization stack, control unit 30, and notification as notification means Unit 31, input operation unit 32, and DC power supply device 33.

  The pure water production apparatus 1 includes a raw water replenishment valve 61 as a supply water valve, a first flow path switching valve 62 as a first circulation means, a second flow path switching valve 63 as a second circulation means, Third flow path switching valve 64, demineralized water return valve 65, first RO valve 101 to fourth RO valve 104, first EDI valve 201 to sixth EDI valve 206, water level sensor 41 as water level measuring means, and in the tank Electrical conductivity sensor 42, in-tank temperature sensor 43 as temperature measuring means, first electrical conductivity sensor 51 as electrical conductivity measuring means, pressure sensor 52, first flow sensor 53, and second flow rate The sensor 54, the 2nd electrical conductivity sensor 55, the 3rd flow sensor 56, and the 4th flow sensor 57 are provided.

  In FIG. 1, the electrical connection path is omitted, but the control unit 30 performs the raw water supply valve 61, the first flow path switching valve 62, the second flow path switching valve 63, the water level sensor 41, and the electric conductivity in the tank. Sensor 42, tank internal temperature sensor 43, first electrical conductivity sensor 51, second electrical conductivity sensor 55, pressure sensor 52, first flow sensor 53, second flow sensor 54, third flow sensor 56, and fourth flow rate. The sensor 57 is electrically connected. Moreover, in this embodiment, the 3rd flow-path switching valve 64, the desalted water return valve 65, the 1st RO valve 101-the 4th RO valve 104, and the 1st EDI valve 201-the 6th EDI valve 206 switch an open / close state by manual operation. Or the valve opening degree can be adjusted.

  The pure water production apparatus 1 includes a raw water line L1 as a supply water line, a first permeate water line L2 and a second permeate water line L3 as permeate water lines, a first RO concentrated water return line L5, and a discharge line. As a first RO concentrated water discharge line L41, a second RO concentrated water return line L6, a second RO permeate return line L7 as a first circulating water line, a second RO permeate discharge line L42, and a desalted water line L8 A demineralized water return line L9, an EDI concentrated water return line L10, an EDI concentrated water discharge line L43, and an EDI electrode water discharge line L44 as a second circulating water line are provided. The “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a radial path, and a pipeline.

  Raw water W1 (supply water) flows through the raw water line L1. The raw water line L1 is a line through which the raw water W1 is circulated to the activated carbon filter 2 and the first RO membrane module 11. The raw water line L1 is a line through which raw water W1 from which the chlorine component has been removed by the activated carbon filter 2 is circulated. The raw water line L1 includes a first raw water line L11 and a second raw water line L12.

  The first raw water line L11 is a line connecting a supply source (not shown) of the raw water W1 and the raw water tank 4. The upstream end of the first raw water line L11 is connected to a supply source (not shown) of the raw water W1. Further, the downstream end of the first raw water line L <b> 11 is connected to the raw water tank 4.

  The first raw water line L11 is provided with a raw water replenishment valve 61, an activated carbon filter 2, a prefilter 3, and a raw water tank 4 in order from the upstream side. The raw water supply valve 61 is a valve capable of opening and closing the first raw water line L11. The raw water supply valve 61 is electrically connected to the control unit 30. The opening / closing operation of the raw water supply valve 61 is controlled by a flow path opening / closing signal from the control unit 30.

  The activated carbon filter 2 is a device that removes chlorine components (mainly residual chlorine) contained in the raw water W1. The activated carbon filter 2 has a filter medium bed made of activated carbon in a pressure tank. The activated carbon filter 2 purifies the raw water W1 by decomposing and removing chlorine components contained in the raw water W1, and adsorbing and removing organic components and capturing suspended substances.

  The prefilter 3 is a filter that removes fine particles contained in the raw water W1 filtered by the activated carbon filter 2. The prefilter 3 is configured by accommodating a filter element in a housing. As the filter element, for example, a nonwoven fabric filter element or a thread wound filter element having a filtration accuracy of 1 to 50 μm is used. The raw water tank 4 is a tank for storing raw water W1 purified through the activated carbon filter 2 and the prefilter 3 as supply water.

  The second raw water line L12 is a line connecting the raw water tank 4 and the first RO membrane module 11. The upstream end of the second raw water line L12 is connected to the raw water tank 4. Further, the downstream end of the second raw water line L12 is connected to the primary inlet port (the inlet of the raw water W1) of the first RO membrane module 11.

  The second raw water line L12 is provided with a pressurizing pump 5, a first RO valve 101, and a first RO membrane module 11 in order from the upstream side. The first RO valve 101 is provided between the pressurizing pump 5 and the first RO membrane module 11 in the second raw water line L12. The first RO valve 101 is a valve capable of adjusting the flow rate of the raw water W1 flowing through the second raw water line L12.

  The pressurizing pump 5 is a device that sucks the raw water W1 flowing through the second raw water line L12 and pumps the raw water W1 toward the first RO membrane module 11. The pressurizing pump 5 can execute a process of sending the raw water W1 staying on the primary side of the first RO membrane module 11 so as to be discharged out of the apparatus (outside the system) from the first RO concentrated water discharge line L41. The pressurizing pump 5 is supplied with driving power whose frequency is converted from the inverter 6. The pressurizing pump 5 is driven at a rotational speed corresponding to the frequency of the supplied driving power (hereinafter also referred to as “driving frequency”).

  The inverter 6 is an electric circuit (or a device having the circuit) that supplies driving power whose frequency is converted to the pressure pump 5. The inverter 6 is electrically connected to the control unit 30. A command signal is input to the inverter 6 from the control unit 30. The inverter 6 outputs driving power having a driving frequency corresponding to the command signal (current value signal or voltage value signal) input by the control unit 30 to the pressurizing pump 5.

  The first RO membrane module 11 is composed of the raw water W1 from which chlorine components have been removed by the activated carbon filter 2 and pumped by the pressure pump 5, the first permeated water W2 from which dissolved salts have been removed, and the concentrated salt from which dissolved salts have been concentrated. Separated into water W3. The first RO membrane module 11 is configured by accommodating a single or a plurality of spiral RO membrane elements in a pressure vessel (vessel). Examples of the RO membrane used in the RO membrane element include a crosslinked aromatic polyamide composite membrane. Examples of RO membrane elements composed of a crosslinked aromatic polyamide composite membrane include: Toray Industries, Inc .: model name “TMG20-400”, Eunjin Chemical Co., Ltd .: model name: “RE8040-BLF”, Nitto Denko Corporation: model name: “ESPA1” Are commercially available, and these elements can be suitably used.

  The first RO concentrated water return line L5 is a line for returning a part of the concentrated water W3 separated by the first RO membrane module 11 to the raw water tank 4. The first RO concentrated water return line L5 includes an upstream first RO concentrated water return line L51 and a downstream first RO concentrated water return line L52.

  The upstream end of the upstream first RO concentrated water return line L51 is connected to the primary outlet port (the outlet of the concentrated water W3) of the first RO membrane module 11. The downstream end of the upstream first RO concentrated water return line L51 is branched into a downstream first RO concentrated water return line L52 and a first RO concentrated water discharge line L41 at a branch portion J11.

  The upstream end of the downstream first RO concentrated water return line L52 is connected to the branch portion J11. The downstream end of the downstream first RO concentrated water return line L52 is connected to the raw water tank 4. A second RO valve 102 is provided in the downstream first RO concentrated water return line L52. The 2nd RO valve 102 is a valve which can adjust the flow volume of the concentrated water W3 which distribute | circulates the downstream 1st RO concentrated water return line L52.

  The 1st RO concentrated water discharge line L41 is a line which distribute | circulates so that the remainder of the concentrated water W3 isolate | separated by the 1st RO membrane module 11 may be discharged | emitted out of the apparatus from the middle of the 1st RO concentrated water return line L5. The first RO concentrated water discharge line L41 is also a line through which the raw water W1 staying on the primary side of the first RO membrane module 11 flows toward the outside of the apparatus (outside the system). The upstream end of the first RO concentrated water discharge line L41 is connected to the branch portion J11. The downstream side of the first RO concentrated water discharge line L41 is connected or opened to a drain pit (not shown), for example. The first RO concentrated water discharge line L41 is provided with a third RO valve 103. The third RO valve 103 is a valve capable of adjusting the waste water flow rate of the concentrated water W3 discharged to the outside of the apparatus via the first RO concentrated water discharge line L41.

  The first permeate line L <b> 2 is a line through which the first permeate W <b> 2 separated by the first RO membrane module 11 flows to the second RO membrane module 12. The upstream end of the first permeate line L2 is connected to the secondary port (the outlet of the first permeate W2) of the first RO membrane module 11. The downstream end of the first permeate line L2 is connected to the primary inlet port (the inlet of the first permeate W2) of the second RO membrane module 12.

  The second RO membrane module 12 is composed of the first permeated water W2 separated by the first RO membrane module 11 and pumped by the pressurizing pump 5, and the second permeated water W4 from which dissolved salts are removed from the first permeated water W2. And the concentrated water W5 in which the dissolved salts are concentrated. The second RO membrane module 12 is configured by accommodating a single or a plurality of spiral RO membrane elements in a pressure vessel (vessel). In the first RO membrane module 11, the same RO membrane element as that of the second RO membrane module 12 can be used.

  The second RO concentrated water return line L6 is a line for returning the concentrated water W5 separated by the second RO membrane module 12 to the raw water tank 4. The upstream end of the second RO concentrated water return line L6 is connected to the primary outlet port (concentrated water outlet) of the second RO membrane module 12. The downstream end of the second RO concentrated water return line L6 is connected to the raw water tank 4. A fourth RO valve 104 is provided in the second RO concentrated water return line L6. The fourth RO valve 104 is a valve capable of adjusting the flow rate of the concentrated water W3 flowing through the second RO concentrated water return line L6.

  The second permeated water line L3 is a line through which the second permeated water W4 separated by the second RO membrane module 12 flows through the EDI stack 20. The second permeate line L3 includes a front-stage permeate line L31, a middle-stage permeate line L32, a desalting chamber inflow line L321, a concentration chamber inflow line L322, and an electrode chamber inflow line L323.

  The upstream end of the front-stage permeate line L31 is connected to the secondary port (the outlet of the second permeate W4) of the second RO membrane module 12. The downstream end of the front-stage permeate line L31 is connected to the middle-stage permeate line L32 and the second RO permeate return line L7 via the first flow path switching valve 62.

  The first flow path switching valve 62 allows the second permeated water W4 separated by the second RO membrane module 12 to flow toward the EDI stack 20 via the middle-stage permeated water line L32 (water sampling side flow path). ) Or a valve that can be switched to a flow path (circulation side flow path and drain side flow path) that flows toward the third flow path switching valve 64 via the second RO permeate return line L7. The first flow path switching valve 62 sends out the second permeated water W4 separated by the second RO membrane module 12 to the upstream side of the first RO membrane module 11 via the second RO permeated water return line L7. It is a valve capable of executing processing. The first flow path switching valve 62 is configured by, for example, an electric or electromagnetic three-way valve. The first flow path switching valve 62 is electrically connected to the control unit 30. The switching of the flow path in the first flow path switching valve 62 is controlled by a flow path switching signal from the control unit 30.

  The second RO permeated water return line L7 is a line for returning the second permeated water W4 separated by the second RO membrane module 12 to the raw water tank 4 on the upstream side of the first RO membrane module 11. The second RO permeate return line L7 includes an upstream second RO permeate return line L71 and a downstream second RO permeate return line L72.

  The upstream end of the upstream second RO permeate return line L71 is connected to the first flow path switching valve 62. The downstream end of the upstream second RO permeate return line L71 is connected to the third flow path switching valve 64.

  The third flow path switching valve 64 allows the second permeated water W4 flowing through the upstream second RO permeate return line L71 to flow toward the raw water tank 4 via the downstream second RO permeate return line L72. This is a valve that can be switched to a channel (circulation side channel) or a channel (drainage side channel) that circulates so as to be discharged to the outside of the apparatus via the second RO permeated water discharge line L42. The third flow path switching valve 64 is a valve that can be manually switched between open and closed states.

  The upstream end of the downstream second RO permeate return line L72 is connected to the third flow path switching valve 64. The downstream end of the downstream second RO permeate return line L72 is connected to the raw water tank 4.

  The second RO permeate discharge line L42 is a line through which the second permeate W4 separated by the second RO membrane module 12 joins the second RO permeate return line L7 and is discharged out of the apparatus. The upstream end of the second RO permeate discharge line L42 is connected to the third flow path switching valve 64. The downstream side of the third flow path switching valve 64 is connected or opened to a drainage pit (not shown), for example.

  The second RO permeated water discharge line L42 is joined to the first RO concentrated water discharge line L41 at the connection portion J12. The connection part J12 is arrange | positioned rather than the 3rd RO valve 103 in the 1st RO concentrated water discharge line L41. The portion of the second RO permeated water discharge line L42 on the downstream side of the connection portion J12 is common to the portion of the first RO concentrated water discharge line L41 on the downstream side of the connection portion J12.

  The upstream end of the middle permeate line L32 is connected to the first flow path switching valve 62. The downstream end of the middle-stage permeate line L32 is branched into a desalting chamber inflow line L321, a concentration chamber inflow line L322, and an electrode chamber inflow line L323 at a branch portion J4.

  The downstream ends of the desalination chamber inflow line L321, the enrichment chamber inflow line L322, and the electrode chamber inflow line L323 are the primary ports of the EDI stack 20 (each inlet side of the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23). )It is connected to the.

  The EDI stack 20 desalinates the second permeated water W4 separated from the first permeated water W2 by the second RO membrane module 12, and passes through water (water that has passed through the desalting chamber 21) W6 and concentrated water W7. This is a water treatment device for obtaining electrode water W8. The EDI stack 20 is electrically connected to the DC power supply device 33. A DC voltage is input from the DC power supply device 33 to the EDI stack 20. The EDI stack 20 is energized and operated by the DC voltage input from the DC power supply device 33. As the passing water W6 obtained in the EDI stack 20, the desalted water obtained by passing through the desalination chamber 21 (described later) of the EDI stack 20 in a state where the EDI stack 20 is energized, or the EDI stack 20 There is second permeated water that passes through the desalting chamber 21 of the EDI stack 20 while the second permeated water W4 separated by the second RO membrane module 12 is left as it is when the energization of the second RO membrane module 12 is stopped.

  The DC power supply device 33 applies a DC voltage between the pair of electrodes of the EDI stack 20. The DC power supply device 33 is electrically connected to the control unit 30. The DC power supply device 33 outputs a DC voltage to the EDI stack 20 in response to the command signal input by the control unit 30.

  In the EDI stack 20, a cation exchange membrane and an anion exchange membrane (not shown) are alternately arranged between a pair of electrodes. The inside of the EDI stack 20 is partitioned into a desalting chamber 21, a concentration chamber 22, and an electrode chamber 23 by these ion exchange membranes. The desalting chamber 21 is filled with an ion exchanger (not shown). As the ion exchanger filled in the desalting chamber 21, for example, an ion exchange resin, an ion exchange fiber, or the like is used. In FIG. 1, a plurality of desalting chambers 21, concentration chambers 22, and electrode chambers 23 partitioned inside the EDI stack 20 are schematically shown.

  A desalting chamber inflow line L321 through which the second permeated water W4 flows is connected to the inlet side of the desalting chamber 21. On the outlet side of the desalting chamber 21, a desalting water line L <b> 8 through which the desalted water W <b> 6 discharged from the desalting chamber 21 is removed is connected. A concentrating chamber inflow line L322 through which the second permeated water W4 flows is connected to the inlet side of the concentrating chamber 22. An EDI concentrated water return line L10 that circulates the concentrated water W7 that has been concentrated and discharged is connected to the outlet side of the concentration chamber 22. An electrode chamber inflow line L323 through which the second permeated water W4 flows is connected to the inlet side of the electrode chamber 23. An electrode water discharge line L44 through which the electrode water W8 flows is connected to the outlet side of the electrode chamber 23.

  A first EDI valve 201 is provided in the desalination chamber inflow line L321. A second EDI valve 202 is provided in the concentration chamber inflow line L322. A third EDI valve 202 is provided in the electrode chamber inflow line L323. The first EDI valve 201 is a valve capable of adjusting the flow rate of the second permeated water W4 flowing through the demineralization chamber inflow line L321 (that is, the flow rate of the demineralized water W6 flowing through the demineralization chamber 21). The second EDI valve 202 is a valve capable of adjusting the flow rate of the second permeated water W4 flowing through the concentration chamber inflow line L322 (that is, the flow rate of the concentrated water W7 flowing through the concentration chamber 22). The third EDI valve 203 is a valve capable of adjusting the flow rate of the second permeated water W4 flowing through the electrode chamber inflow line L323 (that is, the flow rate of the electrode water W8 flowing through the electrode chamber 23).

  The second permeated water W4 flowing through the second permeated water line L3 flows into each of the desalting chamber 21, the concentration chamber 22, and the electrode chamber 23. Residual ions contained in the second permeated water W4 are captured by an ion exchanger (not shown) filled in the desalting chamber 21 to become desalted water W6. The desalted water W6 is sent to the demand point via the desalted water line L8 (described later). Further, residual ions captured by the ion exchanger in the desalting chamber 21 move to the concentration chamber 22 by the applied electric energy. And the water containing a residual ion is discharged | emitted as the concentrated water W7 from the concentration chamber 22 via the EDI concentrated water return line L10 and the EDI concentrated water discharge line L43 (after-mentioned). The second permeated water W4 that has flowed into the electrode chamber 23 is discharged out of the apparatus as electrode water W8 from the electrode chamber 23 via the EDI electrode water discharge line L44.

  The desalted water line L8 is a line that sends the desalted water W6 obtained in the EDI stack 20 as pure water toward the demand point. The demineralized water line L8 includes an upstream demineralized water line L81 and a downstream demineralized water line L82.

  The upstream end of the upstream demineralized water line L81 is connected to the secondary port of the EDI stack 20 (the outlet side of the demineralized chamber 21). The downstream end of the upstream demineralized water line L81 is connected to the downstream demineralized water line L82 and the demineralized water return line L9 (described later) via the second flow path switching valve 63.

  The second flow path switching valve 63 is a flow path (water sampling side flow path) for sending the desalted water W6 obtained in the desalination chamber 21 of the EDI stack 20 toward the demand point via the downstream desalted water line L82. ) Or a valve that can be switched to a flow path (circulation side flow path) that circulates toward the raw water tank 4 via the desalted water return line L9. The second flow path switching valve 63 performs a process of sending the passing water W6 that has passed through the desalination chamber 21 of the EDI stack 20 so as to be returned to the upstream side of the first RO membrane module 11 via the desalted water return line L9. It is a viable valve. The second flow path switching valve 63 is configured by, for example, an electric or electromagnetic three-way valve. The second flow path switching valve 63 is electrically connected to the control unit 30. Switching of the flow path in the second flow path switching valve 63 is controlled by a flow path switching signal from the control unit 30.

  The second flow path switching valve 63 performs a process of sending the demineralized water W6 obtained in the EDI stack 20 from the demineralized water line L8 to the demand point by being switched to the water sampling side flow path by the control unit 30. It functions as an executable sending means.

  An upstream end portion of the downstream demineralized water line L <b> 82 is connected to the second flow path switching valve 63. The downstream end of the downstream desalted water line L82 is connected to a device or the like (not shown) at the demand point.

  The demineralized water return line L9 is a raw water on the upstream side of the first RO membrane module 11 from the middle of the demineralized water line L8 from the passing water W6 (demineralized water, second permeated water) that has passed through the demineralized chamber 21 of the EDI stack 20. It is a line that returns to the tank 4. In the present embodiment, the upstream end of the desalted water return line L9 is connected to the second flow path switching valve 63. The downstream end of the desalted water return line L9 is connected to the raw water tank 4. The desalted water return line L <b> 9 returns the desalted water W <b> 6 obtained in the desalting chamber 21 of the EDI stack 20 to the raw water tank 4.

  A desalted water return valve 65 is provided in the desalted water return line L9. The desalted water return valve 65 is a valve capable of adjusting the flow rate of the desalted water W6 flowing through the desalted water return line L9.

  The EDI concentrated water return line L10 is a line that joins the concentrated water W7 discharged from the concentration chamber 22 of the EDI stack 20 to the desalted water return line L9 and returns it to the raw water tank 4. The upstream end of the EDI concentrated water return line L10 is connected to the secondary port of the EDI stack 20 (the outlet side of the concentration chamber 22). The downstream end of the EDI concentrated water return line L10 is connected to the raw water tank 4.

  The EDI concentrated water return line L10 is joined to the demineralized water return line L9 at the connection J13. The connecting portion J13 is disposed between the raw water tank 4 and the desalted water return valve 65 in the desalted water return line L9. The portion downstream of the connection portion J13 in the EDI concentrated water return line L10 is common to the portion from the connection portion J13 to the raw water tank 4 in the desalted water return line L9. A fifth EDI valve 205 is provided on the upstream side of the connection portion J13 in the EDI concentrated water return line L10.

  The EDI concentrated water discharge line L43 is a line through which the concentrated water W7 discharged from the concentration chamber 22 of the EDI stack 20 is circulated so as to be discharged out of the apparatus from the middle of the EDI concentrated water return line L10. The upstream end portion of the EDI concentrated water discharge line L43 is connected to the connection portion J9. The connecting portion J9 is disposed between the concentrating chamber 22 and the fifth EDI valve 205 in the EDI concentrated water return line L10. The downstream side of the EDI concentrated water discharge line L43 is connected or opened to a drain pit (not shown), for example. A sixth EDI valve 206 is provided in the EDI concentrated water discharge line L43.

  The electrode water discharge line L44 is a line through which the electrode water W8 discharged from the electrode chamber 23 of the EDI stack 20 is circulated out of the apparatus. The upstream end of the electrode water discharge line L44 is connected to the electrode chamber 23 of the EDI stack 20. The electrode water discharge line L44 is joined to the EDI concentrated water discharge line L43 at the connection portion J10. The connecting portion J10 is disposed on the downstream side of the sixth EDI valve 206 in the EDI concentrated water discharge line L43. A portion of the electrode water discharge line L44 on the downstream side of the connection portion J10 is common to a portion of the EDI concentrated water discharge line L43 on the downstream side of the connection portion J10.

  The water level sensor 41 is a device that measures the water level of the raw water W1 stored in the raw water tank 4. The water level sensor 41 is disposed on the lower side inside the raw water tank 4. Further, the water level sensor 41 is electrically connected to the control unit 30. The water level of the raw water tank 4 measured by the water level sensor 41 is transmitted to the control unit 30 as a detection signal. In the present embodiment, the water level sensor 41 is a continuous level sensor, and for example, a capacitive sensor, a pressure sensor, an ultrasonic sensor, or the like is used. FIG. 1 shows an example in which a pressure sensor is provided on the outer wall surface near the bottom of the raw water tank 4 as the water level sensor 41. The water level sensor 41 is not limited to a continuous level sensor, and may be a level switch, for example. The level switch is a preset liquid level position detector, and is configured to detect, for example, a plurality of liquid level positions. As the level switch, for example, a float type or an electrode type is used.

  The in-tank electrical conductivity sensor 42 is a device that measures the electrical conductivity of the raw water W1 stored in the raw water tank 4. The in-tank electrical conductivity sensor 42 is disposed on the lower side inside the raw water tank 4.

  The 1st electrical conductivity sensor 51 is an apparatus which measures the electrical conductivity of the 2nd permeated water W4 which distribute | circulates the 2nd permeated water line L3. The first electrical conductivity sensor 51 is connected to the second permeated water line L3 at the connection portion J1. The connection portion J1 is disposed between the second RO membrane module 12 and the first flow path switching valve 62 in the second permeated water line L3. The 2nd electrical conductivity sensor 55 is an apparatus which measures the electrical conductivity of the desalted water W6 which distribute | circulates the desalted water line L8. The second electrical conductivity sensor 55 is connected to the demineralized water line L8 at the connection portion J6. The connecting portion J6 is disposed between the EDI stack 20 and the fourth EDI valve 204 in the desalted water line L8.

  The in-tank electrical conductivity sensor 42, the first electrical conductivity sensor 51, and the second electrical conductivity sensor 55 are electrically connected to the control unit 30. The electrical conductivity of the raw water W1 measured by the in-tank electrical conductivity sensor 42, the electrical conductivity of the second permeated water W4 measured by the first electrical conductivity sensor 51, and the second electrical conductivity sensor 55 were measured. The electrical conductivity of the desalted water W6 is transmitted to the control unit 30 as a detection signal.

  The in-tank temperature sensor 43 is a device that measures the temperature of the raw water W1 stored in the raw water tank 4. The tank internal temperature sensor 43 is disposed on the lower side of the raw water tank 4. The tank internal temperature sensor 43 is electrically connected to the control unit 30. The temperature of the raw water W1 measured by the tank temperature sensor 43 is transmitted to the control unit 30 as a detection signal.

  The first flow rate sensor 53 is a device that measures the flow rate of the second permeated water W4 flowing through the second permeated water line L3. The first flow rate sensor 53 is connected to the second permeated water line L3 at the connection portion J3. The connecting portion J3 is disposed between the second RO membrane module 12 and the first flow path switching valve 62 in the second permeated water line L3. The second flow rate sensor 54 is a device that measures the flow rate of the desalted water W6 that flows through the desalted water line L8. The second flow rate sensor 54 measures the flow rate of the water flowing through the desalting chamber 21 by measuring the flow rate of the desalted water W6 flowing through the desalted water line L8. The second flow rate sensor 54 is connected to the desalted water line L8 at the connection portion J5. The connecting portion J5 is disposed between the EDI stack 20 and the fourth EDI valve 204 in the desalted water line L8.

  The third flow rate sensor 56 is a device that measures the flow rate of the second permeated water W4 flowing through the concentration chamber inflow line L322. The third flow rate sensor 56 measures the flow rate of the water flowing through the concentration chamber 22 by measuring the flow rate of the second permeated water W4 flowing through the concentration chamber inflow line L322. The third flow sensor 56 is connected to the enrichment chamber inflow line L322 at the connection portion J7. The connecting portion J7 is disposed between the EDI stack 20 and the second EDI valve 202 in the concentration chamber inflow line L322. The fourth flow rate sensor 57 is a device that measures the flow rate of the second permeated water W4 flowing through the electrode chamber inflow line L323. The fourth flow rate sensor 57 measures the flow rate of the water flowing through the electrode chamber 23 by measuring the flow rate of the second permeated water W4 flowing through the electrode chamber inflow line L323. The fourth flow rate sensor 57 is connected to the electrode chamber inflow line L323 at the connection portion J8. The connecting portion J8 is disposed between the electrode chamber 23 of the EDI stack 20 and the third EDI valve 203 in the electrode chamber inflow line L323.

  The first flow sensor 53, the second flow sensor 54, the third flow sensor 56, and the fourth flow sensor 57 are electrically connected to the control unit 30. The flow rate of the second permeate water W4 measured by the first flow rate sensor 53, the flow rate of the desalted water W6 measured by the second flow rate sensor 54, the flow rate of the second permeate water W4 measured by the third flow rate sensor 56, and The flow rate of the second permeated water W4 measured by the fourth flow rate sensor 57 is transmitted to the control unit 30 as a detection signal.

  The pressure sensor 52 is a device that measures the pressure of the second permeated water W4 flowing through the second permeated water line L3. The pressure sensor 52 is connected to the second permeated water line L3 at the connection portion J2. The pressure sensor 52 is electrically connected to the control unit 30. The connecting portion J2 is disposed between the second RO membrane module 12 and the first flow path switching valve 62. The pressure of the second permeated water W4 measured by the pressure sensor 52 is transmitted to the control unit 30 as a detection signal.

  The notification unit 31 notifies a predetermined alarm. The notification unit 31 is electrically connected to the control unit 30. The notification is, for example, one or more of display, sound, light emission, and the like. That is, the notification unit 31 includes one or more of a display device (liquid crystal display or the like), a buzzer, a speaker, a lamp, and the like.

  The input operation unit 32 is an input interface that receives input operations of a user or an administrator for selection related to the operation mode of the device (for example, selection of operation / stop, release of alarm, etc.) and various settings related to the operation conditions of the device. It is. The input operation unit 32 includes an operation panel that combines a display and button switches, a touch panel that directly operates on the display, and the like. The input operation unit 32 is electrically connected to the control unit 30. Information input from the input operation unit 32 is transmitted to the control unit 30.

  Next, the control unit 30 will be described. The control unit 30 is configured by a microprocessor (not shown) including a CPU and a memory. In the control unit 30, various programs for controlling the pure water production apparatus 1 are stored in the memory of the microprocessor. Further, the memory of the microprocessor includes, for example, threshold values for the electrical conductivity of the second permeated water W4 and the desalted water W6, and threshold values for the flow rates of the desalted water W6, the concentrated water W7, and the electrode water W8 discharged from the EDI stack 20. The data etc. are stored.

  In the control unit 30, the CPU of the microprocessor executes various controls described later according to a predetermined program read from the memory. In the control unit 30, an integrated timer unit for managing time measurement and the like is incorporated in the microprocessor.

  The control unit 30 controls to execute the first process and the third process. The control unit 30 performs control so that the first step is executed when a predetermined standby duration (predetermined time) has elapsed since the standby state in which the desalinated water W6 is not supplied to the demand point.

  The first step executed by the control unit 30 refers to the second permeated water W4 separated by the first RO membrane module 11 and the second RO membrane module 12 via the second RO permeated water return line L7 (first circulating water line). The first flow path switching valve 62 (first circulation means) is controlled so as to be returned to the upstream side of the first RO membrane module 11, and the raw water W1 staying on the primary side of the first RO membrane module 11 is concentrated in the first RO. In this step, the pressurization pump 5 is controlled so as to be discharged out of the apparatus (outside the system) via the water discharge line L41.

  Specifically, in the first step, the first flow path switching valve 62 is circulated in a state where the third flow path switching valve 64 is set as a circulation side flow path and the third RO valve is set to be open. The second permeated water W4 separated by the first RO membrane module 11 and the second RO membrane module 12 is returned to the raw water tank 4 by switching to the side flow path and driving the pressure pump 5. Further, in the first step, by driving the pressurizing pump 5, the raw water W1 staying on the primary side of the first RO membrane module 11 is passed through the upstream first RO concentrated water return line L51 and the first RO concentrated water discharge line L41. To the outside of the system (outside the system).

  When the first time has elapsed from the start of the execution of the first step and there is a request for water supply of pure water, the control unit 30 supplies the electricity of the second permeated water W4 flowing through the second permeated water line L3. Start measuring conductivity. When the electrical conductivity of the second permeated water W4 flowing through the second permeated water line L3 exceeds a predetermined first conductivity threshold (conductivity threshold), the control unit 30 performs notification by the notification unit 31. To control. Here, the predetermined first conductivity threshold is, for example, reverse osmosis of standard water quality water under predetermined operating conditions (operating pressure, recovery rate, water temperature, etc.) using an RO membrane module that does not deteriorate or block. The electric conductivity value of the permeated water obtained when the membrane treatment is performed is set. The control unit 30 continues to energize the EDI stack 20 and controls to move to the third step.

  The third step executed by the control unit 30 refers to the desalted water return line L9 (second circulation) in the state where the EDI stack 20 is energized while the desalted water W6 obtained by passing through the EDI stack 20 is used. This is a step of returning to the upstream side of the first RO membrane module 11 via the water line. Specifically, in the third step, while the EDI stack 20 is energized, the first flow path switching valve 62 is switched to the water sampling side flow path, and the second flow path switching valve 63 is switched. By switching to the circulation side flow path and driving the pressurizing pump 5, the desalted water W6 obtained through the EDI stack 20 is returned to the raw water tank 4 through the desalted water return line L9.

  In addition, at the start of the third step, the control unit 30 sets the time during which the flow rate of the water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 exceeds a predetermined first set value, respectively. If the operation continues for 2 hours, the EDI stack 20 is controlled to start operation (that is, energization). Further, the control unit 30 determines that the time during which any one of the flow rates of water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 falls below a predetermined second set value is less than the second time. When the third time is continued for a long time, control is performed so that the notification by the notification unit 31 is executed. The predetermined first set value of the flow rate is normally set to a different flow rate value for each chamber (desalting chamber 21, concentration chamber 22, and electrode chamber 23). The same applies to the predetermined second set value of the flow rate.

  The reason why the predetermined setting value of the flow rate of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 is used as a condition for starting the operation of the EDI stack 20 is that the desalted water W6, the concentration This is because when there is no flow rate equal to or higher than a predetermined value in the water W7 and the electrode water W8, the risk of scale generation or the like increases on the surface of the ion exchange membrane or the electrode.

  As the predetermined first set value of the flow rate, for example, a lower limit flow rate value at which the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 function normally and no risk of scale generation or the like occurs is set. As the predetermined second set value of the flow rate, for example, an upper limit flow rate value in which the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 function normally and a risk of scale generation or the like occurs is set. Note that the predetermined first set value and the predetermined second set value of the flow rate set for the desalting chamber 21 may be the same value. The same applies to the predetermined first set value and the predetermined second set value of the flow rate set for the concentration chamber 22 and the electrode chamber 23, respectively.

  In addition, when the fourth time has elapsed since the operation of the EDI stack 20 has started, the control unit 30 has a case where the electrical conductivity of the desalted water W6 flowing through the desalted water line L8 is lower than a predetermined second conductivity threshold value. The second flow path switching valve 63 is controlled so that the supply of the demineralized water W6 to the demand point by the second flow path switching valve 63 is started. The control unit 30 controls the notification unit 31 to perform notification when the electrical conductivity of the desalted water W6 flowing through the desalted water line L8 exceeds a predetermined third conductivity threshold value.

  As the predetermined second conductivity threshold value, for example, the electrical conductivity value of pure water that is continuously required at the demand point is set. As the predetermined third conductivity threshold value, for example, an upper limit electric conductivity value that is temporarily allowed at a demand point is set.

  The predetermined second conductivity threshold value and the predetermined third conductivity threshold value may be different values or the same value. In this embodiment, the case where the predetermined second conductivity threshold and the predetermined third conductivity threshold are the same value will be described. In the following description, the predetermined second conductivity threshold and the predetermined third conductivity will be described. The rate threshold will be described as a predetermined second conductivity threshold.

  Here, the control part 30 is the forced execution of the circulation process which consists of a 3rd process regarding the alerting | reporting by the alerting | reporting part 31, the forced start of the supply of the desalinated water W6 to a demand location, or the desalted water W6 to a demand location. The notification by the notification unit 31 is executed so that the user can select forcible stop of the supply. As a result, the user can sample water (forcibly start the supply of demineralized water to the demand location), circulate (forcibly execute the circulation process consisting of the third step), and wait (supply of the demineralized water to the demand location). Can be selected and executed by operating the input operation unit 32.

  The control unit 30 controls the raw water replenishing valve 61 to be in an open state when the water level of the raw water W1 measured by the water level sensor 41 is lower than the first water level during normal operation of the apparatus. Further, the control unit 30 controls the pressurizing pump 5 so that the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged out of the apparatus (outside the system) via the first RO concentrated water discharge line L41. During the execution of the operation, the raw water supply valve 61 is controlled to be opened when the water level of the raw water W1 measured by the water level sensor 41 is lower than the second water level higher than the first water level. As a result, the operation of controlling the pressurization pump 5 so that the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged out of the apparatus (outside the system) via the first RO concentrated water discharge line L41 is being executed. In order to prevent the raw water tank 4 from becoming empty, the water level of the raw water W1 is maintained at or above the second water level.

  The control unit 30 starts an operation of discharging the raw water W1 staying on the primary side of the first RO membrane module 11 after the apparatus enters a standby state as the temperature of the raw water W1 measured by the tank temperature sensor 43 increases. Set to shorten the standby duration until Alternatively, the control unit 30 discharges the raw water W1 staying on the primary side of the first RO membrane module 11 via the first RO concentrated water discharge line L41 as the temperature of the raw water W1 measured by the tank temperature sensor 43 increases. Control the discharge time to be longer.

  Moreover, the control part 30 performs a 1st process, when there exists a water supply request | requirement from a demand location in a standby state. When there is a request for pure water from the demand point during sampling, the control unit 30 controls the pure water production apparatus 1 to continue sampling, and the request for pure water is sent from the demand point during sampling. When there is not, it controls so that the pure water manufacturing apparatus 1 may transfer to a standby state. Further, the control unit 30 stops the operation of the pure water production apparatus 1 when the operation switch of the pure water production apparatus 1 is OFF (stopped) during sampling.

  In addition, the control unit 30 performs control so as to shift to a sampling operation when sampling is selected on the selection screen for selecting sampling, circulation, or standby displayed on the notification unit 31 or the input operation unit 32. Then, when circulation is selected, control is performed so as to shift to a circulation operation, or when standby is selected, control is performed so as to shift to a standby state.

  Next, operation | movement of the pure water manufacturing apparatus 1 which concerns on this embodiment is demonstrated. 2 and 3 are flowcharts showing the processing procedure of the operation of the pure water production apparatus 1. FIG. The operation of the pure water production apparatus 1 is started when the operation switch is turned on (operation). The process of the flowchart shown in FIG.2 and FIG.3 is repeatedly performed during the driving | operation of the pure water manufacturing apparatus 1. FIG.

  In step ST105 shown in FIG. 2, after the pure water production apparatus 1 is turned on and the operation switch is turned on, the control unit 30 starts the supply of the raw water W1 during the normal operation of the apparatus. Is set to the first water level. Thereby, the control part 30 is controlled so that the raw | natural water replenishment valve 61 will be in an open state, when the water level of the raw | natural water W1 measured by the water level sensor 41 is less than a 1st water level at the time of the normal driving | operation of an apparatus. Therefore, the water level of the raw water W1 stored in the raw water tank 4 is maintained at or above the first water level.

  In step ST110, the pure water manufacturing apparatus 1 first enters a standby state. In step ST111, the control unit 30 sets the standby duration based on the temperature of the raw water W1 measured by the tank temperature sensor 43. This standby continuation time is a threshold time from when the apparatus enters a standby state until the start of the first step, that is, the operation of discharging the raw water W1 staying on the primary side of the first RO membrane module 11. Specifically, the control unit 30 sets the standby continuation time until the stagnant water starts to be discharged as the temperature of the raw water W1 measured by the tank temperature sensor 43 increases. This is because the higher the temperature of the raw water W1, the more likely the bacteria will propagate.

  For example, when the temperature of the raw water W1 is in the range of 15 ° C. to 25 ° C., the control unit 30 sets the standby duration as 24 hours. When the temperature of the raw water W1 is higher than 25 ° C., the control unit 30 sets the standby duration to 16 hours shorter than 24 hours, and when the temperature of the raw water W1 is lower than 15 ° C. Sets the standby duration to 32 hours longer than 24 hours.

  In step ST112, the control unit 30 determines whether or not the standby duration has elapsed since entering the standby state. If it is determined that the standby duration has elapsed since entering the standby state (YES), the process proceeds to step ST113. If it is determined that the standby duration has not elapsed since the standby state has been reached (NO), the process proceeds to step ST120.

  In step ST120, the control unit 30 determines whether or not there is a request to send pure water from the demand point before the standby duration has elapsed. If it is determined that there is a request for pure water from the demand point before the standby duration has elapsed (YES), the process proceeds to step ST130. If it is determined that there is no request for pure water from the demand point before the standby duration has elapsed (NO), the process repeats step ST120.

  Upon receiving a water supply request from the demand point during the standby state, in step ST130, the control unit 30 activates the device and starts executing the first step. Specifically, under the state where the third flow path switching valve 64 is set as the circulation side flow path, the control unit 30 returns the second permeated water W4 to the raw water tank 4 so that the first flow path switching valve is returned. 62 is switched to the circulation side flow path. In this state, the control unit 30 drives the pressurizing pump 5. As a result, the second permeated water W4 separated by the second RO membrane module 12 is returned to the raw water tank 4 via the second RO permeated water return line L7. The first process started in step ST130 is a preparation process before starting the sampling of pure water, and aims to restore the water quality of the second permeated water W4 that has deteriorated during the standby state to a predetermined water quality. It is said.

  In step ST140, the control unit 30 determines whether or not a first time (for example, 60 seconds) has elapsed since the execution of the first step was started. If it is determined that the first time has elapsed since the start of the first step (YES), the process proceeds to step ST150. If it is determined that the first time has not elapsed since the execution of the first process has started (NO), the process returns to step ST140 and the first process is continued.

  In step ST150, the control unit 30 determines that the electrical conductivity value (EC value) of the second permeated water W4 is a predetermined first conductivity threshold value (EC value) at the time when the first time has elapsed since the start of the first process. For example, it is determined whether it is less than 15 μS / cm). When it determines with the electrical conductivity value of the 2nd permeated water W4 exceeding a 1st conductivity threshold value (NO), a process progresses to step ST151, and after alert | reporting an alarm, it progresses to step ST160. When it is determined that the electrical conductivity value of the second permeated water W4 is lower than the first conductivity threshold value (YES), the process proceeds to step ST160 as it is.

  In step ST160, the control unit 30 starts executing the third step. Specifically, the control unit 30 switches the first flow path switching valve 62 to the water sampling side flow path, and sets the second flow path switching valve 63 to the circulation side flow so as to return the desalted water W6 to the raw water tank 4. Switch to the road. In this state, the control unit 30 drives the pressurizing pump 5. Thereby, the desalinated water W6 obtained in the EDI stack 20 is returned to the raw water tank 4 through the desalted water return line L9.

  As described above, the second permeated water W4 having poor water quality can be returned to the upstream side of the first RO membrane module 11 by performing the first step and the third step at the time of starting the apparatus, and the water quality Can be returned to the upstream side of the first RO membrane module 11. After step ST160, the process proceeds to step ST210.

  In step ST210 shown in FIG. 3, at the start of the third step, the control unit 30 sets the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 to a predetermined first level. It is determined whether or not the set value is exceeded. If it is determined that the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 exceed the predetermined first set values (YES), the process proceeds to step ST220. Transition. When it is determined that the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 do not exceed the predetermined first set values (NO), the process is performed in step ST211. Migrate to

  In step ST220, the control unit 30 sets the second time during which the flow rate of each of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 exceeds a predetermined first set value (for example, 5 seconds) It is determined whether or not the operation has continued. If the time during which the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 exceed the predetermined first set values continues for the second time (YES), the process Proceed to ST230. When the time when the flow rate of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 exceeds the predetermined first set value does not continue for the second time (NO), the process is performed as a step. Return to ST210.

  In step ST <b> 230, the control unit 30 transmits a command signal that causes the EDI stack 20 to output a DC voltage to the DC power supply device 33. Thereby, the EDI stack 20 is energized and the operation of the EDI stack 20 is started.

  If it is determined in step ST210 that the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 do not exceed the predetermined first set values (NO), step ST210 is performed. In ST211, the control unit 30 determines whether any of the flow rates of water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 is below a predetermined second set value. To do. When it is determined that any one of the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 is below a predetermined second set value (YES), the processing is performed. The process proceeds to step ST212. When it is determined that any one of the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 does not fall below the predetermined second set value (NO), the processing is performed. Return to step ST210.

  In step ST212, the control unit 30 sets the time during which the flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22, and the electrode chamber 23 of the EDI stack 20 are less than a predetermined second set value for a third time (for example, 10 seconds) It is determined whether or not the operation has been continued. When the time during which the respective flow rates of water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 are lower than a predetermined second set value continues for a third time (YES), It progresses to step ST213. When the time during which the respective flow rates of the water flowing through the desalination chamber 21, the concentration chamber 22 and the electrode chamber 23 of the EDI stack 20 are less than the predetermined second set value does not continue for the third time (NO), It returns to step ST211.

  In step ST213, the control part 30 alert | reports the warning of abnormal flow from the alerting | reporting part 31. Thereafter, the process returns to step ST210.

  In step ST240, the control unit 30 determines whether or not a fourth time (for example, 60 seconds) has elapsed since the operation of the EDI stack 20 was started. If it is determined that the fourth time has elapsed since the operation of the EDI stack 20 was started (YES), the process proceeds to step ST250. If it is determined that the fourth time has not elapsed since the operation of the EDI stack 20 was started (NO), the process repeats step ST240.

  In step ST250, the control unit 30 determines that the electric conductivity (EC value) of the demineralized water W6 flowing through the demineralized water line L8 is a predetermined second when a fourth time has elapsed since the operation of the EDI stack 20 was started. It is determined whether or not a conductivity threshold value (for example, 1 μS / cm) is exceeded. When the electrical conductivity of the desalted water flowing through the desalted water line L8 is lower than the predetermined second conductivity threshold (YES), the process proceeds to step ST260. When the electrical conductivity of the desalted water W6 flowing through the desalted water line L8 exceeds a predetermined second conductivity threshold value (NO), the process proceeds to step ST251.

  In step ST260, the control unit 30 starts collecting pure water and supplies demineralized water W6 to a demand point or the like. Specifically, the control unit 30 switches the second flow path switching valve 63 to the water sampling side flow path so as to supply the desalted water W6 to the demand point. Thereby, the desalinated water W6 obtained by the EDI stack 20 is sent out to be supplied to the demand point via the desalted water line L8. Thereby, pure water sampling is performed toward the demand point.

  In step ST270, the control unit 30 determines whether or not there is a request to send pure water from the demand point during sampling. If it is determined that there is no request for pure water from the demand point during sampling (YES), the process proceeds to step ST110, and the pure water production apparatus 1 is in a standby state (that is, ends sampling). ) When it is determined that there is a request for pure water from the demand point during sampling (NO), the process proceeds to step ST280.

  In step ST280, the control part 30 determines whether the operation switch of the pure water manufacturing apparatus 1 is OFF (stop). When the operation switch of the pure water production apparatus 1 is OFF (stop) (YES), the operation of the pure water production apparatus 1 is stopped, and the process ends. When the operation switch of the pure water production apparatus 1 is ON (operation) (NO), the process returns to step ST270 and continues to collect pure water.

  When the electrical conductivity of the demineralized water W6 flowing through the demineralized water line L8 in step ST250 exceeds a predetermined second conductivity threshold value (NO), in step ST251, the control unit 30 notifies a water quality abnormality alarm. 31.

  In step ST252, the control unit 30 collects water (forcibly starts supply of demineralized water to the demand point), circulates (forcibly executes the circulation step consisting of the third step), and waits (for removal to the demand point). A selection screen for allowing the user to make a selection about the forced stop of the supply of salt water is displayed on the notification unit 31 or the input operation unit 32, and control is performed so that the input operation unit 32 can enter an input. Thereby, when the electrical conductivity of the desalted water W6 flowing through the desalted water line L8 exceeds a predetermined second conductivity threshold, the user selects any one of water sampling, circulation, and standby to produce pure water. The device 1 can be operated.

  In step ST253, the control unit 30 determines whether or not water sampling is selected on the selection screen displayed on the notification unit 31 or the input operation unit 32. When sampling is selected (YES), the process proceeds to step ST260 and starts sampling. When sampling is not selected (NO), the process proceeds to step ST254.

  In step ST254, the control unit 30 determines whether or not circulation is selected on the selection screen displayed on the notification unit 31 or the input operation unit 32. If circulation is selected (YES), the process proceeds to step ST230 and energizes the EDI stack 20. If circulation is not selected (NO), the process proceeds to step ST110, and the pure water production apparatus 1 enters a standby state.

  Here, if it is determined that the standby duration has elapsed since the standby state in step ST112 (YES), the first step (intermittent operation) is executed in steps ST113 to ST117. The first step executed here is to prevent the bacteria from growing on the surface of the RO membrane by periodically discharging the accumulated water in the first RO membrane module 11 during the standby state of the apparatus. It is aimed.

  First, in step ST113, the control unit 30 sets the water level of the raw water tank 4 that starts the supply of the raw water W1 to the second water level before starting the execution of the first process (before starting the execution of the intermittent operation). Set to. The second water level is a higher water level than the first water level.

  In step ST114, execution of the first step is started. Specifically, the control unit 30 supplies the second permeated water W4 to the raw water tank 4 in a state where the third flow path switching valve 64 is set to the circulation side flow path and the third RO valve 103 is set to open. The first flow path switching valve 62 is switched to the circulation side flow path so as to return to the flow path. In this state, the control unit 30 drives the pressurizing pump 5. Thereby, the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged out of the apparatus (outside the system) via the upstream first RO concentrated water return line L51 and the first RO concentrated water discharge line L41. At the same time, the second permeated water W4 separated by the second RO membrane module 12 is returned to the raw water tank 4 via the second RO permeated water return line L7. As described above, by performing the first step, the second permeated water W4 on the downstream side of the second RO membrane module 12 is returned to the upstream side of the first RO membrane module 11, while returning to the primary side of the first RO membrane module 11. The staying raw water W1 can be discharged out of the apparatus.

  Here, the control unit 30 replenishes the raw water when the water level of the raw water W1 measured by the water level sensor 41 is lower than the second water level higher than the first water level during the execution of the first step for discharging the stagnant water. Control is performed so that the valve 61 is opened. Accordingly, during the execution of the first step, the water level of the raw water W1 is maintained at the second water level or higher so that the raw water tank 4 does not become empty.

  In step ST115, the control unit 30 determines whether or not a first time (for example, 60 seconds) has elapsed since the execution of the first step was started. If it is determined that the first time has elapsed since the start of the first step (YES), the process proceeds to step ST116. If it is determined that the first time has not elapsed since the execution of the first process has started (NO), the process returns to step ST115 and the first process is continued.

  In step ST116, the control unit 30 determines whether or not there is a request to send pure water from the demand point when the first time has elapsed since the start of the first process. If it is determined that there is a request for pure water from the demand point (YES), the process proceeds to step ST117. When it determines with there being no request | requirement of the pure water supply from a demand location (NO), a process transfers to step ST116.

  In step ST117, when receiving a water supply request from the demand point during the standby state, the control unit 30 sets the water level of the raw water W1 to start water supply to the first water level in preparation for normal operation of the apparatus. Then, a process transfers to step ST150 and starts the measurement of the electrical conductivity value (EC value) of the 2nd permeated water W4. Thereafter, the process starts the sampling of pure water through the execution of the third step.

  According to the pure water manufacturing apparatus 1 which concerns on this embodiment mentioned above, the following effects are show | played, for example.

  The pure water production apparatus 1 according to the present embodiment includes a dechlorination apparatus 2, a first RO membrane module 11 and a second RO membrane module 12, an EDI stack 20, a raw water line L1, a first permeate water line L2, and a second. Permeate water line L3, demineralized water line L8, first RO concentrated water discharge line L41 through which raw water W1 staying on the primary side of the first RO membrane module 11 circulates outside the apparatus, and primary of the first RO membrane module 11 A pressure pump 5 capable of executing a process of sending out the supply water W1 staying on the side from the first RO concentrated water discharge line L41 to the outside of the apparatus, and a standby state in which the desalted water W6 is not supplied to the demand point. When the standby duration time has elapsed, the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged out of the apparatus via the first RO concentrated water discharge line L41. And a control unit 30 for controlling the pressurizing pump 5 to so that, a.

  Therefore, even if the standby state of the apparatus is for a long time, the raw water W1 staying on the primary side of the first RO membrane module 11 can be periodically discharged out of the apparatus. Thereby, propagation of bacteria inside the first RO membrane module 11 can be suppressed.

  Moreover, in this embodiment, the control part 30 is the 2nd permeation | transmission isolate | separated with the 2nd RO membrane module 12 when standby | waiting continuation time passes since it will be in the standby state which does not supply demineralized water W6 to a demand location. The raw water W1 that controls the first flow path switching valve 62 to return the water W4 to the upstream side of the first RO membrane module 11 through the second RO permeate return line L7 and stays on the primary side of the first RO membrane module 11 The first step of controlling the pressurizing pump 5 so as to be discharged out of the apparatus through the first RO concentrated water discharge line L41 is performed.

  Therefore, by performing the first step, the second permeated water W4 downstream of the second RO membrane module 12 is retained on the primary side of the first RO membrane module 11 while being returned to the upstream side of the first RO membrane module 11. The raw water W1 can be discharged out of the apparatus. Thereby, the raw water W1 staying on the primary side of the first RO membrane module 11 can be replaced with the second permeated water W4, so that the propagation of bacteria inside the first RO membrane module 11 can be further suppressed.

  In the present embodiment, the raw water tank 4 that stores the raw water W1, the water level sensor 41 that measures the water level of the raw water W1 stored in the raw water tank 4, and the raw water supply valve 61 that opens and closes the raw water line L1 are provided. The control unit 30 is configured so that the raw water supply valve 61 is opened when the water level of the raw water W1 stored in the raw water tank 4 measured by the water level sensor 41 during the normal operation of the apparatus is lower than the first water level. The water level sensor 41 during the operation of controlling the pressurizing pump 5 to control and discharge the raw water W1 staying on the primary side of the first RO membrane module 11 to the outside of the apparatus through the first RO concentrated water discharge line L41. Control is performed so that the raw water supply valve 61 is opened when the water level of the raw water W1 stored in the raw water tank 4 measured by the above is lower than the second water level higher than the first water level.

  Therefore, the water level of the raw water W1 stored in the raw water tank 4 can be maintained at the second water level. Thereby, even if the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged during execution of the first step, the raw water tank 4 is prevented from becoming empty. Therefore, the pressurizing pump 5 can efficiently discharge the raw water W1 staying on the primary side of the first RO membrane module 11 using the raw water W1 stored in the raw water tank 4.

  Moreover, in this embodiment, the tank internal temperature sensor 43 which measures the temperature of the raw | natural water W1 is further provided, and the control part 30 will be in a standby state, so that the temperature of the raw | natural water W1 measured by the tank internal temperature sensor 43 is high. Control is performed so as to shorten the standby duration after the start. Therefore, even when the temperature in the system is high, such as in summer, the raw water W1 staying on the primary side of the first RO module can be discharged out of the apparatus before the propagation of bacteria progresses.

  Moreover, in this embodiment, the control part 30 distribute | circulates the 2nd permeated water line L3, when 1st time passes after starting execution of a 1st process and there exists a water supply request | requirement of a pure water. The electrical conductivity of the second permeated water W4 is measured, and when the electrical conductivity of the second permeated water W4 flowing through the second permeated water line L3 exceeds a predetermined conductivity threshold, the notification by the notification unit 31 is executed. To control. Subsequently, the control unit 30 starts energizing the EDI stack 20, and sends the desalted water W6 obtained through the EDI stack 20 to the upstream side of the first RO membrane module 11 via the desalted water return line L9. Shift to the third step to return.

  Therefore, since the electrical conductivity of the second permeated water W4 is measured only when there is a request for water supply of pure water, an alarm of water quality abnormality may be used unnecessarily during the operation of discharging stagnant water. Absent. In addition, when there is a request to send pure water and the quality of the second permeated water W4 flowing through the second permeated water line L3 is poor, a warning is given by the notifying unit 31. Therefore, it is possible to make the user recognize that the second permeated water W4 having poor water quality is produced, and to promote maintenance such as cleaning and replacement of the RO membrane module. Moreover, the water quality of the desalted water W6 can be recovered while returning the desalted water W6 from the EDI stack 20 to the upstream side of the first RO membrane module 11 by executing the third step.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms. For example, in the above-described embodiment, the notification by the notification unit 31 is executed based on the electrical conductivity measured by the first conductivity sensor 51, but the present invention is not limited to this. For example, you may comprise so that the alerting | reporting part 31 may perform based on the specific resistance measured by an electrical property detection means.

  For example, in the case where electrical characteristic detection means (specific resistance sensor) for measuring the specific resistance of the second permeated water W4 flowing through the second permeated water line L3 is provided, the control unit 30 has a request for supplying pure water. When the specific resistance of the second permeated water W4 flowing through the second permeated water line L3 is measured, and the specific resistance of the second permeated water W4 exceeds a predetermined specific resistance threshold value, the notification by the notification unit 31 is performed. It can be controlled to execute. The control unit 30 starts energizing the EDI stack 20 and returns the desalted water W6 obtained through the EDI stack 20 to the upstream side of the first RO membrane module 11 via the desalted water return line L9. It is possible to shift to the third step.

  Moreover, in the said embodiment, although it controlled to perform a 1st process when standby | waiting continuation time passed after becoming a standby state, it is not restrict | limited to this. The control may be performed so that the second step is executed when the standby duration time has elapsed since the standby state was reached. The second step refers to the passing water W6 (second permeate) that has passed through the desalination chamber 21 of the EDI stack 20 in the state where the energization to the EDI stack 20 is stopped, and the desalted water return line L9 (second circulation). The second flow path switching valve 63 (second circulation means) is controlled so as to be returned to the upstream side of the first RO membrane module 11 via the water line), and the raw water staying on the primary side of the first RO membrane module 11 This is a step of controlling the pressure pump 5 so as to discharge W1 to the outside of the apparatus (outside the system) via the first RO concentrated water discharge line L41.

  Specifically, in the second step, in a state where the energization to the EDI stack 20 is stopped, the second flow path switching valve 63 is set to the circulation side flow path, and the third RO valve 103 is set to open. By driving the pressurizing pump 5 under the condition, the passing water W6 (second permeated water) that has passed through the EDI stack 20 is returned to the raw water tank 4 via the desalted water return line L9. At the same time, the raw water W1 staying on the primary side of the first RO membrane module 11 is discharged out of the apparatus (outside the system) via the first RO concentrated water discharge line L41.

  Moreover, in the said embodiment, the tank internal temperature sensor 43 which measures the temperature of the raw | natural water W1 stored in the raw | natural water tank 4 is provided, and the control part 30 is based on the temperature of the raw | natural water W1 measured by the tank internal temperature sensor 43. Although the standby duration after the standby state is set, the present invention is not limited to this. For example, an outside air temperature sensor that measures the temperature of the outside air may be provided, and the control unit 30 may set a standby duration after the standby state is reached based on the temperature of the outside air measured by the outside air temperature sensor.

  Moreover, in the said embodiment, the control part 30 is controlled so that standby | waiting continuation time after becoming a standby state may be shortened, so that the temperature of the raw | natural water W1 measured by the tank internal temperature sensor 43 is high. However, it is not limited to this. For example, the control unit 30 increases the discharge time for discharging the raw water W1 through the first RO concentrated water discharge line L41 (discharge line) as the temperature of the raw water W1 measured by the tank temperature sensor 43 increases. You may control. In this case, the progress of breeding can be suppressed even under temperature conditions where the breeding speed of the bacteria is increased by discharging a large amount of the raw water W1 staying on the primary side of the first RO membrane module 11.

  Moreover, in the said embodiment, although the reverse osmosis membrane module was set as the structure which has arrange | positioned the 1st RO membrane module 11 and the 2nd RO membrane module 12 in series in two steps, it is not restrict | limited to this. The reverse osmosis membrane module may be constituted by one stage of only the first RO membrane module 11.

1 Pure water production equipment 2 Activated carbon filter (dechlorination equipment)
4 Raw water tank (supply water storage tank)
5 Pressure pump (discharge means)
11 First RO membrane module (reverse osmosis membrane module)
12 Second RO membrane module (reverse osmosis membrane module)
20 EDI stack (Electrodeionization stack)
21 Desalination room 30 Control part 31 Notification part (notification means)
41 Water level sensor (water level measuring means)
43 Tank temperature sensor (temperature measuring means)
51 1st electrical conductivity sensor (electrical conductivity measuring means)
61 Raw water supply valve (valve)
62 1st flow-path switching valve (1st circulation means)
63 Second flow path switching valve (second circulation means)
L1 Raw water line (supply water line)
L2 1st permeate line (permeate line)
L3 Second permeate line (permeate line)
L7 Second RO permeate return line (first circulating water line)
L8 Demineralized water line L9 Demineralized water return line (second circulating water line)
L41 1st RO concentrated water discharge line (discharge line)
W1 Raw water (supply water)
W2 First permeate (permeate)
W4 Second permeated water (permeated water)
W6 passing water, desalted water (water that passed through the desalting chamber)

Claims (6)

A dechlorination device for removing chlorine components contained in raw water,
A reverse osmosis membrane module for separating permeate from the feed water from which the chlorine component has been removed by the dechlorination device;
An electrodeionization stack for obtaining desalted water by desalting the permeated water separated by the reverse osmosis membrane module;
A feed water line for circulating the feed water from which the chlorine component has been removed by the dechlorination device to the reverse osmosis membrane module;
A permeate line for circulating permeate separated by the reverse osmosis membrane module to the electrodeionization stack;
A demineralized water line for sending demineralized water obtained in the electrodeionization stack toward a demand point;
A discharge line for circulating the supply water staying on the primary side of the reverse osmosis membrane module toward the outside of the system;
A discharge means capable of performing a process of sending out the supply water staying on the primary side of the reverse osmosis membrane module so as to be discharged out of the system from the discharge line;
A second circulating water line for returning water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
A second circulation means capable of performing a process of sending out the water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
In a case where a predetermined time has passed since the deionized water is not supplied to the demand point, the supply water staying on the primary side of the reverse osmosis membrane module is discharged out of the system through the discharge line. A control unit for controlling the discharging means ,
When a predetermined time has elapsed since the control unit has been in a standby state in which deionized water is not supplied to the demand point, the water that has passed through the demineralization chamber of the electrodeionization stack passes through the second circulating water line. The second circulation means is controlled to return to the upstream side of the reverse osmosis membrane module, and the supply water staying on the primary side of the reverse osmosis membrane module is discharged out of the system through the discharge line. water purifying system to run a second step of controlling the discharging means. A first circulating water line for returning the permeated water separated by the reverse osmosis membrane module to the upstream side of the reverse osmosis membrane module;
A first circulation means capable of performing a process of sending the permeated water separated by the reverse osmosis membrane module so as to return it to the upstream side of the reverse osmosis membrane module;
When a predetermined time has elapsed since the control unit has entered a standby state in which demineralized water is not supplied to the demand location, the control unit passes the permeated water separated by the reverse osmosis membrane module through the first circulating water line. The discharge means controls the first circulation means to return to the upstream side of the osmosis membrane module and discharges the supply water staying on the primary side of the reverse osmosis membrane module to the outside through the discharge line. The pure water manufacturing apparatus according to claim 1, wherein the first step of controlling the water is executed. A supply water storage tank that is provided upstream of the reverse osmosis membrane module in the supply water line and stores the supply water;
Water level measuring means for measuring the water level of the supply water stored in the supply water storage tank;
Provided on the upstream side of the supply water storage tank in the supply water line, and a supply water valve for opening and closing the supply water line,
The control unit is configured to open the supply water valve when a supply water level stored in the supply water storage tank measured by the water level measurement unit during a normal operation of the apparatus is lower than a first water level. And measured by the water level measuring means during the operation of controlling the discharging means so as to discharge the supply water staying on the primary side of the reverse osmosis membrane module out of the system through the discharging line. The pure of Claim 1 or 2 which controls so that the said water supply valve will be in an open state, when the water level stored in the said water storage tank falls below the 2nd water level higher than the said 1st water level. Water production equipment. Temperature measuring means for measuring the temperature of the feed water or the temperature of the outside air,
The control unit is set to shorten the predetermined time after entering the standby state as the temperature of the feed water or the temperature of the outside air measured by the temperature measuring unit is higher, or via the discharge line. The pure water manufacturing apparatus according to any one of claims 1 to 3 , wherein the discharge time for discharging the supply water is controlled to be long. A second circulating water line for returning water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
A second circulation means capable of performing a process of sending out the water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
Electrical conductivity measuring means for measuring the electrical conductivity of the permeated water flowing through the permeated water line;
A notification means for reporting a warning;
The control unit measures the electrical conductivity of the permeated water flowing through the permeate line when a first time has elapsed since the start of the first step and when there is a request for water supply of pure water. When the electric conductivity of the permeated water exceeds a predetermined conductivity threshold value, control is performed so as to perform notification by the notification means, and subsequently, energization of the electrodeionization stack is started and the electrodeionization is started. The pure water manufacturing apparatus of Claim 2 which transfers to the 3rd process of returning the desalted water obtained by passing an ion stack to the upstream of the said reverse osmosis membrane module via the said 2nd circulating water line. A second circulating water line for returning water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
A second circulation means capable of performing a process of sending out the water that has passed through the demineralization chamber of the electrodeionization stack to the upstream side of the reverse osmosis membrane module;
Electrical characteristic detection means for measuring the specific resistance of the permeate flowing through the permeate line;
A notification means for reporting a warning;
The control unit measures the specific resistance of the permeate flowing through the permeate line when a first time has elapsed since the start of the first step and when there is a request for water supply of pure water, When the specific resistance of the permeated water is lower than a predetermined specific resistance threshold value, control is performed so as to perform notification by the notification means, and energization to the electrodeionization stack is subsequently started and the electrodeionization stack is started. The deionized water production apparatus according to claim 2, wherein the demineralized water obtained by passing the water is transferred to a third step of returning the demineralized water to the upstream side of the reverse osmosis membrane module via the second circulating water line.

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