Water treatment device and operating method thereof

Abstract

A method according to the present disclosure is a method for operating a water treatment device provided with: an electrolysis device which generates alkaline water and acidic water by electrolysis and which has an electrode capable of switching polarity; a first circulation flow path and a second circulation flow path which are circulation flow paths connected to the electrolysis device and through which the alkaline water and the acidic water generated by the electrolysis device can alternately pass; a water storage tank for storing the treated water generated by the electrolysis device; and a control unit that executes at least two electrolysis steps and a polarity switching step for switching the polarity of the electrodes of the electrolysis device between successive electrolysis steps, and that performs control in the polarity switching step such that acidic water or treated water generated by the electrolysis device flows through the electrolysis device.

Description

Technical Field

[0001] The present disclosure relates to a water treatment device. Background Art

[0002] For example, Patent Document 1 discloses a water treatment device for purifying water by electrolysis. In the water treatment device disclosed in Patent Document 1, Mg dissolved from the anode 2+ ions and OH generated by electrolysis of water in the cathode ﹣ Ions combine to form colloidal particles. Dirt components aggregate in the colloidal particles, and the aggregated dirt components are filtered to purify water.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document: Japanese Patent Application Publication No. 2003-80261 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In a water treatment apparatus utilizing electrolysis, it is required to suppress consumption of electrodes used for electrolysis.

[0008] Therefore, an object of the present disclosure is to solve the above-mentioned problems and to provide a water treatment device and an operating method thereof that can suppress consumption of electrodes.

[0009] Means for solving problems

[0010] A method according to one embodiment of the present disclosure is a method for operating a water treatment device, the water treatment device comprising: an electrolysis device that generates alkaline water and acidic water by electrolysis and has electrodes capable of switching polarity; a first circulation flow path and a second circulation flow path that are circulation flow paths connected to the electrolysis device and capable of alternately passing alkaline water and acidic water generated by the electrolysis device; a water storage tank that stores treated water generated by the electrolysis device; and a control unit, wherein the control unit performs at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between consecutive electrolysis steps, the electrolysis step comprising the following steps: supplying raw water to the electrolysis device; generating alkaline water and acidic water by electrolysis of the raw water and passing the water to the first circulation flow path or the second circulation flow path; and passing the generated alkaline water and acidic water to the water storage tank and storing them as treated water, the control unit controlling in the polarity switching step such that the acidic water or treated water generated by the electrolysis device passes to the electrolysis device.

[0011] A water treatment device according to one embodiment of the present invention comprises: an electrolysis device that generates alkaline water and acidic water by electrolysis and has electrodes capable of switching polarity; a first circulation flow path and a second circulation flow path that are circulation flow paths connected to the electrolysis device and capable of alternately passing alkaline water and acidic water generated by the electrolysis device; a water storage tank that stores the alkaline water and acidic water generated by the electrolysis device as treated water; and a control unit, the control unit executing at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between consecutive electrolysis steps, and the control unit controls in the electrode polarity switching step such that the acidic water or treated water generated by the electrolysis device passes into the electrolysis device.

[0012] Effects of the Invention

[0013] According to the water treatment device and the operating method thereof disclosed in the present invention, it is possible to suppress consumption of electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A This is a schematic diagram of the water treatment device in Embodiment 1.

[0015] Figure 1B is a schematic diagram of the electrodes.

[0016] Figure 2 It is a flow chart of the operation method of the water treatment device.

[0017] Figure 3 This is a flow chart of the water treatment device when executing the first mode.

[0018] Figure 4 This is a diagram showing the flow of water in the first raw water injection mode in the first mode.

[0019] Figure 5 This is a diagram showing the flow of water in the first crystallization treatment mode in the first mode.

[0020] Figure 6 This is a diagram showing the flow of water in the first alkaline water supply mode in the first mode.

[0021] Figure 7 This is a diagram showing the flow of water in the first acidic water supply mode in the first mode.

[0022] Figure 8 This is a diagram showing the flow of water in the first pipe cleaning mode in the first mode.

[0023] Fig. 9 This is a flow chart of the water treatment device when executing the first polarity switching step.

[0024] Fig. 10A This is a diagram showing the flow of water in the first acidic water flow pattern in the first polarity switching step.

[0025] Fig. 10B 1 is a diagram showing the flow of water in the first acidic water discharge mode in the first polarity switching step.

[0026] Fig. 10C 1 is a diagram showing the flow of water in the first acidic water discharge mode in the first polarity switching step.

[0027] Fig.11 This is a flow chart when the water treatment device executes the second mode.

[0028] Fig.12 1 is a diagram showing the flow of water in the second raw water injection mode in the second mode.

[0029] Fig.13 It is a diagram showing the flow of water in the second crystallization treatment mode in the second mode.

[0030] Fig.14 This is a diagram showing the flow of water in the second alkaline water supply mode in the second mode.

[0031] Fig.15 This is a diagram showing the flow of water in the second acidic water supply mode in the second mode.

[0032] Fig.16 This is a diagram showing the flow of water in the second pipe cleaning mode in the second mode.

[0033] Fig.17 This is a flow chart of the water treatment device when executing the second polarity switching step.

[0034] Fig.18 It is a diagram showing the flow of water in the second acidic water flow pattern in the second polarity switching step.

[0035] Fig.19 This is a schematic diagram of a water treatment device in Embodiment 2.

[0036] Fig. 20 It is a flow chart of the operation method of the water treatment device.

[0037] Fig.21 This is a flow chart of the water treatment device when executing the first polarity switching step.

[0038] Fig. 22 It is a diagram showing the flow of water in the treated water supply pattern in the first polarity switching step.

[0039] Fig.23 It is a diagram showing the flow of water in the treated water flow pattern in the first polarity switching step.

[0040] Fig.24This is a flow chart of the water treatment device when executing the second polarity switching step.

[0041] Fig.25 It is a diagram showing the flow of water in the treated water supply pattern in the second polarity switching step.

[0042] Fig.26 It is a diagram showing the flow of water in the treated water flow pattern in the second polarity switching step. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. In addition, the present disclosure is not limited to the embodiments.

[0044] (Implementation Method 1)

[0045] In Embodiment 1, a water softening device that generates soft water from hard water will be described as an example of the water treatment device 2 of the present disclosure. Figure 1A This is a schematic diagram of the water treatment device 2 in the first embodiment.

[0046] The water treatment device 2 is a device for removing metal ions, which are hardness components, from water by electrolysis. The metal ions here refer to calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ). The water treatment device 2 in the first embodiment is a water softening device that produces soft water by removing metal ions from hard water and separating them, thereby reducing the concentration (hardness) of metal ions in the hard water to below a predetermined concentration. As a definition of hard water and soft water, for example, the definition of WHO can be used. That is, hardness less than 120 mg / L can be defined as soft water, and hardness greater than or equal to 120 mg / L can be defined as hard water.

[0047] Figure 1A The water treatment device 2 shown includes raw water flow paths 4A and 4B, batch treatment tanks 6A and 6B, circulation flow paths 8A and 8B, a pump 10, an electrolysis device 12, pH sensors 14A and 14B, a separation device 16, an intermediate tank 18, a water storage tank 20, and a control unit 21. The water treatment device 2 also includes valves 22A and 22B, a valve 24, a valve 26, valves 28A and 28B, a valve 30, and a valve 32 as various valves.

[0048] The raw water flow paths 4A and 4B are flow paths for supplying raw water to the batch tanks 6A and 6B, respectively. The raw water is, for example, hard water. The upstream side of the raw water flow paths 4A and 4B is connected to a water source (not shown), and the downstream side is connected to the batch tanks 6A and 6B. Valves 22A and 22B are provided in the raw water flow paths 4A and 4B, respectively. By opening and closing the valves 22A and 22B, the flow / stop of water from the raw water flow paths 4A and 4B to the batch tanks 6A and 6B is controlled, respectively. The valves 22A and 22B may also be solenoid valves.

[0049] The batch tanks 6A and 6B are tanks for storing water for batch processing. The batch tanks 6A and 6B are provided with float sensors 60A and 60B, respectively, which can detect the amount of stored water. The batch tanks 6A and 6B are connected to circulation channels 8A and 8B, respectively.

[0050] The circulation flow paths 8A and 8B are two circulation flow paths connected to the batch tanks 6A and 6B. The circulation flow paths 8A and 8B extend downstream from the batch tanks 6A and 6B, respectively, and merge into one flow path at a location connected to the valve 24. The circulation flow paths 8A and 8B that have become one flow path are connected to the electrolysis device 12 via the pump 10 and the valve 26.

[0051] The water supply / stop from the batch tanks 6A and 6B to the electrolysis device 12 is controlled by opening and closing the valves 24 and 26. The valves 24 and 26 may be valves opened and closed by motor drive. The water supply from the batch tanks 6A and 6B to the downstream side is performed by driving the pump 10 provided between the valves 24 and 26.

[0052] The electrolysis device 12 is a device that generates alkaline water and acidic water by electrolyzing water supplied through the circulation paths 8A and 8B. The electrolysis device 12 includes two electrodes 50 and 51 and a diaphragm (not shown) disposed between the two electrodes 50 and 51. By applying a voltage between the two electrodes 50 and 51, water is electrolyzed to generate alkaline water and acidic water. The polarity of the electrodes 50 and 51 can be switched between a + electrode (anode) and a - electrode (cathode). When the electrode 50 is a + electrode, the electrode 51 is a - electrode, and when the electrode 50 is a - electrode, the electrode 51 is a + electrode. In Embodiment 1, the electrolysis device 12 is a bipolar structure having a plurality of electrodes 50 and a plurality of electrodes 51.

[0053] Figure 1B Schematic diagram of electrodes 50 and 51. Figure 1B As shown, the electrodes 50 and 51 respectively have a main body 50A and 51A and a catalyst layer 50B and 51B coated on the main body 50A and 51A. The main body 50A and 51A are, for example, a plate-shaped member of titanium (Ti) with a thickness of 0.5 mm. The catalyst layer 50B and 51B are formed of a precious metal such as platinum (Pt) with a thickness of 0.2 μm. When electrolysis is performed, the catalyst layer 50B and 51B dissolves into water and is consumed.

[0054] On the downstream side of the electrolysis device 12 , circulation flow paths 8A and 8B are connected as two flow paths.

[0055] The circulation channels 8A and 8B connected to the downstream side from the electrolysis device 12 can alternately pass alkaline water and acidic water generated by the electrolysis device 12. When alkaline water passes through the circulation channel 8A, acidic water passes through the circulation channel 8B, and when acidic water passes through the circulation channel 8A, alkaline water passes through the circulation channel 8B.

[0056] The circulation flow path 8A connected to the downstream side from the electrolysis device 12 is provided with a valve 28A and a pH sensor 14A in the middle, and is connected to the batch treatment tank 6A. Similarly, the circulation flow path 8B connected to the downstream side from the electrolysis device 12 is provided with a valve 28B and a pH sensor 14B in the middle, and is connected to the batch treatment tank 6B. By opening and closing the valves 28A and 28B, water flow / water stop from the electrolysis device 12 to the batch treatment tanks 6A and 6B is controlled respectively. The valves 28A and 28B may be valves opened and closed by motor drive.

[0057] The circulation flow paths 8A and 8B having the above-mentioned structure respectively constitute circulation flow paths that return from the batch treatment tanks 6A and 6B via the electrolysis device 12 to the batch treatment tanks 6A and 6B. The circulation flow paths 8A and 8B of the first embodiment merge at a location from the valve 24 to the electrolysis device 12 to constitute a single flow path. Compared with the case where the circulation flow paths 8A and 8B do not merge but are independent flow paths, only one pump 10 is required, and the device structure of the water treatment device 2 can be simplified.

[0058] The pH sensors 14A and 14B are sensors for detecting pH values, which are parameters of water flowing through the circulation flow paths 8A and 8B, respectively.

[0059] The valve 26 provided at the portion where the circulation flow paths 8A and 8B merge to form one flow path is connected to the flow path 34 in addition to the circulation flow paths 8A and 8B. The flow path 34 is connected to the separation device 16.

[0060] The separator 16 is a device for separating crystals of a metal component from water supplied from the flow path 34. The separator 16 of the first embodiment is a cyclone type separator for separating solids such as crystals contained in water by centrifugal separation.

[0061] The separation device 16 is connected to two flow paths, namely, a flow path 36 and a flow path 38. The flow path 36 is a flow path through which water after crystals are separated by the separation device 16 passes. The flow path 38 is a drainage flow path through which drainage containing crystals separated by the separation device 16 passes, and extends to the outside of the water treatment device 2 system.

[0062] The flow path 36 through which the water from which the crystals are separated passes is connected to the valve 30. The flow path 40 and the flow path 41 are connected to the valve 30.

[0063] The flow path 40 is connected to the intermediate tank 18. The intermediate tank 18 is a tank for temporarily storing water passed from the flow path 40. The flow / stop of water from the separation device 16 to the intermediate tank 18 via the flow paths 36 and 40 is controlled by opening and closing the valve 30. The valve 30 may be a valve that is opened and closed by a motor drive.

[0064] The flow path 41 is a bypass flow path for connecting the batch tanks 6A and 6B to the separator 16 without passing through the electrolysis device 12. Two flow paths 41A and 41B are connected to the flow path 41, and the flow paths 41A and 41B are connected to the valves 28A and 28B, respectively.

[0065] The intermediate tank 18 is connected to a CO 2 Supply line 42. CO 2 The supply line 42 is used to supply CO to the water stored in the intermediate tank 18. 2 Gas piping. Through CO 2 Supply line 42 supplies CO 2 Gas, thereby reducing the turbidity of the water stored in the intermediate tank 18. 2 A valve 32 is provided in the middle of the supply line 42, and the CO 2 Supply / stop of gas The valve 32 may be a solenoid valve.

[0066] The intermediate tank 18 is further connected to a flow path 44 . The flow path 44 is connected to the water storage tank 20 .

[0067] The water storage tank 20 is a tank for storing treated water after the softening treatment is completed. The treated water stored in the water storage tank 20, that is, soft water, can be supplied to a faucet or the like for use by end users.

[0068] A pressure sensor (not shown) is provided in the water storage tank 20. The pressure sensor detects a decrease in pressure accompanying consumption of treated water, and thus the amount of water stored in the water storage tank 20 can be detected.

[0069] The control unit 21 is a component that controls each component of the water treatment device 2. The control unit 21 is electrically connected to each component of the water treatment device 2, and performs opening and closing control of each valve, on / off control of the pump 10, on / off control of the electrolysis device 12, on / off control of the separation device 16, etc. The control unit 21 is composed of, for example, a microcomputer including a processor and a memory storing a computer program executed by the processor.

[0070] Here, the dissolution of the catalyst layers 50B and 51B of the electrodes 50 and 51 will be described in more detail. When the catalyst layers 50B and 51B of the electrodes 50 and 51 are platinum (Pt), the catalyst layers 50B and 51B are dissolved according to the following formula 1.

[0071] (Formula 1)Pt+4Cl ﹣ +4H + →H 4 (PtCl 4 )

[0072] As shown in Formula 1, in Cl ﹣ The ion-rich environment promotes the dissolution of Pt. ﹣ The elution of Pt is suppressed in an environment with few ions. In addition, it is known that the elution of Pt is promoted when the polarity of the electrodes 50 and 51 is switched compared to the case of constant current electrolysis. This is considered to be because the elution of Pt is easily generated when Pt in a reduced state is rapidly converted to an oxidized state.

[0073] Next, the operating method of the water treatment device 2 will be described. Figure 2 2 is a flow chart of the operation method of the water treatment device 2. Figure 2 As shown, the control unit 21 of the first embodiment performs at least two electrolysis steps and a polarity switching step between consecutive electrolysis steps in the operation method of the water treatment device 2 .

[0074] In the electrolysis step, raw water is electrolyzed to generate treated water. In the polarity switching step, the polarity of the electrodes 50, 51 of the electrolysis device 12 is switched, and the anode and the cathode are exchanged. As the electrolysis step, there are different first modes and second modes, and the control unit 21 alternately repeats the first mode and the second mode. As the polarity switching step, there are different first polarity switching steps and second polarity switching steps, and the control unit 21 performs the first polarity switching step between the first mode and the second mode, and performs the second polarity switching step between the second mode and the first mode.

[0075] In the first mode (S1) and the second mode (S2), in order to perform electrolysis, the control unit 21 applies a constant current to the electrodes 50 and 51 of the electrolysis device 12. Specifically, in the first mode, a positive constant current is applied to the electrode 50, and a negative constant current is applied to the electrode 51, and in the second mode, a negative constant current is applied to the electrode 50, and a positive constant current is applied to the electrode 51. That is, in the first mode and the second mode, the positive and negative currents of the currents applied to the respective electrodes 50 and 51 are maintained.

[0076] On the other hand, in the first polarity switching step (S3) and the second polarity switching step (S5), in order to switch the polarity of the electrodes 50 and 51, the control unit 21 reverses the direction of the current applied to the electrodes 50 and 51, and reverses the positive and negative of the current value. Therefore, the first polarity switching step includes a step of changing the value of the constant current in the first mode (S1) to the value of the constant current in the second mode (S2). In addition, the second polarity switching step includes a step of changing the value of the constant current in the second mode to the value of the constant current in the first mode.

[0077] In the first embodiment, the control unit 21 sequentially executes the first mode (S1), the first polarity switching step (S3), and the second mode (S2). Next, the control unit 21 determines whether to terminate the operation (S4). If it is not terminated (No in S4), the control unit 21 executes the second polarity switching step (S5) and returns to the process before step S1. If it is terminated (Yes in S4), the control unit 21 terminates the operation. The control unit 21 can determine whether to terminate the operation based on the operation time, the amount of treated water generated, or the user's instruction input, for example.

[0078] First, use Figure 3 as well as Figures 4 to 8 , the first mode is described. Figure 3 This is a flowchart when the first mode is executed using the water treatment device 2. Figures 4 to 8 It means according to Figure 3 The flowchart shown is a schematic diagram of the flow of water, etc. when the first mode is executed.

[0079] (First raw water injection mode)

[0080] like Figure 3 As shown, the control unit 21 first executes the first raw water injection mode (S10). The first raw water injection mode is a mode in which hard water as raw water is injected into the water treatment device 2 when the water treatment device 2 starts to operate. Specifically, the control unit 21 generates Figure 4 The flow is controlled in the manner shown. Figure 4 In the following drawings, arrows are used to indicate the flow of water, and no flow of water is generated in the flow path without arrows. In addition, the state of valve opening is indicated by shading, and the state of valve closing is indicated by blackening.

[0081] The control unit 21 opens the valve 22A to allow the raw water to pass through the raw water flow path 4A. By allowing the raw water to pass through the raw water flow path 4A, the raw water flows through the raw water flow path 4A to flow to the batch tank 6A and is stored in the batch tank 6A. At this time, the control unit 21 controls so that the valve 22B is closed.

[0082] The control unit 21 uses the float sensor 60A ( Figure 1A) determines whether a predetermined amount (e.g., 10 L) of raw water has been introduced into the batch processing tank 6A. If it is determined that a predetermined amount of raw water has been introduced into the batch processing tank 6A, the control unit 21 closes the valve 22A and executes the first crystallization processing mode (S11).

[0083] (First crystallization treatment mode)

[0084] Figure 5 The first crystallization treatment mode is shown. The control unit 21 controls to supply the raw water stored in the batch tank 6A to the electrolysis device 12. Specifically, the control unit 21 opens the valve 24 while driving the pump 10 to pass water from the batch tank 6A to the circulation flow path 8A, and opens the valve 26 to pass water to the electrolysis device 12. At this time, the control unit 21 controls the opening and closing of the valve 24 to stop the water supply from the batch tank 6B to the downstream side.

[0085] The control unit 21 also drives the electrolysis device 12 to electrolyze the raw water supplied from the batch treatment tank 6A, thereby generating alkaline water and acidic water.

[0086] In the first crystallization treatment mode, the electrolysis device 12 is controlled so that, of the alkaline water and the acidic water generated by the electrolysis device 12 , the alkaline water passes through the circulation flow path 8A, and the acidic water passes through the circulation flow path 8B.

[0087] The control unit 21 controls the opening and closing of the valve 28A so that the alkaline water passing through the circulation flow path 8A returns to the batch treatment tank 6A, and controls the opening and closing of the valve 28B so that the acidic water passing through the circulation flow path 8B returns to the batch treatment tank 6B. Figure 5 The flow is shown by the arrows.

[0088] According to the above operation, while the raw water in the batch tank 6A is consumed, the alkaline water of about half of the consumed amount is stored again in the batch tank 6A, so the water storage amount is finally reduced, and the pH value detected by the pH sensor 14A increases. On the other hand, since the acidic water is stored in the batch tank 6B, the water storage amount increases, and the pH value detected by the pH sensor 14B is maintained at a low value. In the first embodiment, the generated acidic water can have a pH value of pH 1.0 or more, preferably pH 2.0 or more and pH 4.0 or less.

[0089] In the circulation flow path 8A including the batch treatment tank 6A, the mixed water of the raw water and the alkaline water is circulated while the electrolysis is continuously performed by the electrolysis device 12, and the pH value also continuously increases.

[0090] Here, the Ca contained in the raw water 2+ Mg 2+The metal ions are electrophoresed from the anode (acidic water) to the cathode (alkaline water) through the diaphragm by electrolysis, so the hardness of the acidic water is reduced. ﹣ In alkaline water, the hardness of the water is reduced by the following reactions of Formula 2 to Formula 4.

[0091] (Formula 2) OH ﹣ +HCO 3 ﹣ →H 2 O+CO 3 2﹣

[0092] (Formula 3)Ca 2+ +CO 3 2﹣ →CaCO 3

[0093] (Formula 4)Mg 2+ +2OH ﹣ →Mg(OH) 2

[0094] As shown in Formula 2, the OH contained in alkaline water ﹣ With HCO in water 3 ﹣ (bicarbonate ions) to generate water and CO 3 2﹣ (carbonate ion). CO generated in the reaction of formula 2 3 2﹣ As shown in Formula 3, 2+ reaction, thereby producing insoluble CaCO 3 (calcium carbonate). As shown in Formula 4, Mg 2+ With the OH contained in alkaline water ﹣ The reaction produces insoluble Mg(OH) 2 (Magnesium hydroxide). Along with CaCO 3 and Mg(OH) 2 The metal ions in the alkaline water are crystallized and precipitated, and the concentration of the metal ions in the alkaline water is reduced, so the hardness of the alkaline water is also reduced. As a result, the hardness of both the acidic water and the alkaline water is reduced.

[0095] By continuously supplying alkaline water to the circulation flow path 8A and circulating it, the reactions of the above-mentioned Formulae 2 to 4 can be continuously caused, and the metal ions in the alkaline water can be crystallized and precipitated, thereby reducing the hardness of the raw water.

[0096] In addition, on the anode (acidic water) side, along with the electrolysis of water as the basic reaction, the reaction of the following formula 5 occurs as a side reaction, whereby chloride ions (Cl﹣ ) concentration decreased.

[0097] (Formula 5)2Cl ﹣ →Cl 2

[0098] Therefore, the concentration of chloride ions in acidic water is lower than that in hard water as raw water. In addition, the concentration of chloride ions in acidic water is lower than that in alkaline water. For example, the concentration of chloride ions in acidic water is less than 15% of the concentration of chloride ions in alkaline water.

[0099] The control unit 21 ends the first crystallization treatment mode at a predetermined time, and executes the next first alkaline water supply mode (S12). For example, the control unit 21 may end the first crystallization treatment mode after a predetermined time has passed.

[0100] (First alkaline water delivery mode)

[0101] Figure 6 The first alkaline water supply mode is shown. The control unit 21 controls to supply the alkaline water stored in the batch tank 6A to the intermediate tank 18 via the separator 16. Specifically, the control unit 21 drives the pump 10 while opening the valve 24 to allow water to flow from the batch tank 6A to the circulation flow path 8A, and opens the valve 26 to allow water to flow from the circulation flow path 8A to the flow path 34.

[0102] The control unit 21 separates the crystals contained in the alkaline water by centrifugal separation by operating the separation device 16. The separation device 16 allows the alkaline water from which the crystals have been separated to pass through the flow path 36, and allows the wastewater containing the crystals to pass through the flow path 38 for drainage.

[0103] The control unit 21 opens the valve 30 so that the alkaline water after the crystal separation passing through the flow path 36 passes through the flow path 40. As a result, the alkaline water flows into the intermediate tank 18 through the flow path 40.

[0104] The alkaline water supplied to the intermediate tank 18 may contain CaCO which cannot be separated by the separation device 16. 3 The control unit 21 controls the opening and closing of the valve 32 as needed, so that the CO 2 Supply line 42 supplies CO 2 , thereby supplying CO to the intermediate tank 18 2 Thus, the reaction of the following formula 6 is promoted.

[0105] (Formula 6)CaCO 3 +CO 2 +H 2 O→Ca(HCO 3 ) 2

[0106] As crystalline CaCO 3 With CO 2 and H 2 O reaction, thereby producing soluble Ca(HCO 3 ) 2 This reaction can dissolve the crystals in water and reduce the turbidity of the treated water. 2+ , the reaction formula is omitted.

[0107] According to the above operation, the amount of alkaline water stored in the intermediate tank 18 increases, while the amount of alkaline water stored in the batch tank 6A decreases. The control unit 21 of the first embodiment continues the first alkaline water supply mode until the amount of water stored in the batch tank 6A is exhausted. The control unit 21 can use the float sensor 60A ( Figure 1A ) to determine whether the entire amount of water stored in the batch processing tank 6A is exhausted. When it is determined that the water stored in the batch processing tank 6A is exhausted, the control unit 21 stops the first alkaline water supply mode and executes the next first acidic water supply mode (S13).

[0108] (First acidic water delivery mode)

[0109] Figure 7 The control unit 21 controls the acidic water stored in the batch tank 6B to be supplied to the intermediate tank 18 via the separator 16. The separator 16 is operated in the first alkaline water supply mode, whereas the separator 16 is stopped in the first acidic water supply mode.

[0110] like Figure 7 As shown, the control unit 21 opens the valve 24 to allow water to flow from the batch tank 6B to the circulation flow path 8B, and opens the valve 26 to allow water to flow from the circulation flow path 8B to the flow path 34 while driving the pump 10 .

[0111] The controller 21 does not operate the separator 16, and allows the acidic water reaching the separator 16 to pass directly to the flow path 36. The controller 21 further opens the valve 30, and allows the acidic water flowing into the flow path 36 to pass to the flow path 40. Thus, the acidic water passes into the intermediate tank 18 through the flow path 40.

[0112] Since alkaline water is already stored in the intermediate tank 18, alkaline water and acidic water are mixed in the intermediate tank 18. The mixed water of alkaline water and acidic water is neutralized, and the pH value becomes a value close to neutral. As described above, the hardness of alkaline water and acidic water both decreases, so the hardness of the mixed water also decreases. As a result, the mixed water stored in the intermediate tank 18 is soft water with a pH value close to neutral and low hardness.

[0113] According to the above operation, the amount of mixed water stored in the intermediate tank 18 increases, while the amount of acidic water stored in the batch tank 6B decreases. The control unit 21 of the first embodiment continues the first acidic water supply mode until the amount of acidic water in the batch tank 6B decreases to a predetermined amount (e.g., 2 L). The control unit 21 may use the float sensor 60B ( Figure 1A ) to determine whether the specified amount of water stored in the batch tank 6B is exhausted. When it is determined that the water stored in the batch tank 6B has decreased to the specified amount, the control unit 21 stops the first acidic water supply mode and executes the next first pipe cleaning mode (S14).

[0114] (First pipe cleaning mode)

[0115] Figure 8 The control unit 21 controls the acidic water remaining in the batch tank 6B to return to the batch tanks 6A and 6B via the separator 16 and the bypass flow paths 41, 41A and 41B.

[0116] Specifically, the control unit 21 opens the valve 24 while driving the pump 10 to allow water to flow from the batch tank 6B to the circulation flow path 8B, and opens the valve 26 to allow water to flow from the circulation flow path 8B to the flow path 34. The control unit 21 does not operate the separation device 16, and allows the acidic water reaching the separation device 16 to pass directly to the flow path 36.

[0117] The control unit 21 also controls the opening and closing of the valve 30 so that the acidic water passing through the flow path 36 flows to the flow path 41 and the flow paths 41A and 41B. The control unit 21 also controls the opening and closing of the valves 28A and 28B so that the acidic water passing through the flow paths 41A and 41B flows to the batch treatment tanks 6A and 6B through the circulation flow paths 8A and 8B.

[0118] Thus, the Figure 8 The flow of acidic water shown in FIG. 1 can remove scale (CaCO ) attached to the inner wall surface of each pipe by flowing acidic water in each pipe. 3 ) is dissolved in acidic water to clean the pipes.

[0119] According to the above operation, the acid water storage amount of batch tank 6A increases, and the acid water storage amount of batch tank 6B decreases. When a predetermined amount (for example, 1 L) of acid water is passed into batch tank 6B, control unit 21 ends the first pipe cleaning mode.

[0120] By executing the above steps S10 to S14, the execution of the first mode is completed. Acidic water remains in the batch treatment tank 6B. In this state, the first polarity switching step (S3) is executed.

[0121] Reference Fig. 9 and Figure 10A to Figure 10C , the first polarity switching step is explained. Fig. 9 This is a flow chart of the water treatment device 2 when executing the first polarity switching step. Figure 10A to Figure 10C It is a diagram showing the flow of water in the first polarity switching step.

[0122] (First acidic water flow mode)

[0123] like Fig. 9 As shown, the control unit 21 first executes the first acidic water flow mode (S30). The first acidic water flow mode is a mode in which acidic water is flowed in order to pre-fill the electrolysis device 12 with acidic water before the positive and negative polarities of the electrodes 50 and 51 are reversed. Specifically, the control unit 21 generates the following Fig. 10A The acidic water used in the first acidic water flow mode is the acidic water generated in the first mode.

[0124] The control unit 21 opens the valve 24 while driving the pump 10, so that water flows from the batch treatment tank 6B to the circulation flow path 8B, and opens the valve 26 so that water flows from the circulation flow path 8B to the electrolysis device 12. The control unit 21 does not operate the electrolysis device 12, so that the acidic water reaching the electrolysis device 12 passes directly without being electrolyzed, and flows water to the circulation flow paths 8A and 8B. The control unit 21 also controls the opening and closing of the valves 28A and 28B, so that the acidic water from the electrolysis device 12 flows to the batch treatment tanks 6A and 6B through the circulation flow paths 8A and 8B.

[0125] (First current reversal mode)

[0126] When a predetermined time has passed since the start of the first acidic water flow mode (S30), the control unit 21 executes the first current reversal mode (S31). The first current reversal mode is a mode in which acidic water is flowed to the electrolysis device 12 and the positive and negative current values ​​applied to the electrolysis device 12 are reversed.

[0127] The acidic water flow in the first current reversal mode is performed continuously with the acidic water flow in the first acidic water flow mode. That is, during the first acidic water flow mode and the first current reversal mode, the control unit 21 controls the valves 24 and 26 to maintain the connection between the batch tank 6B and the electrolysis device 12.

[0128] While the acidic water is continuously passed, the control unit 21 reverses the positive and negative currents applied to the electrodes 50 and 51 of the electrolysis device 12. The control unit 21 reverses the current applied to the electrode 50 from positive to negative, and reverses the current applied to the electrode 51 from negative to positive. Through such actions, the polarity of the electrode 50 is switched from the anode to the cathode, and the polarity of the electrode 51 is switched from the cathode to the anode.

[0129] Since a predetermined time (e.g., 5 seconds) has passed since the start of the first acidic water flow mode, the control unit 21 can execute the first current reversal mode in a state where the acidic water fills the electrolysis device 12. Therefore, at the moment of polarity switching, the electrodes 50 and 51 are in contact with the acidic water and are in an environment with a low concentration of chloride ions. Therefore, the dissolution of the catalyst layers 50B and 51B of the electrodes 50 and 51 can be suppressed.

[0130] Furthermore, by passing the acidic water through the electrolysis device 12 , scale attached to the electrodes 50 , 51 can be removed.

[0131] According to the above operation, the amount of acidic water stored in the batch tank 6A increases, and the amount of acidic water stored in the batch tank 6B decreases. When the control unit 21 passes the acidic water in the batch tank 6B for a predetermined time (e.g., 10 seconds), it stops the first current reversal mode and executes the next first acidic water discharge mode (S32).

[0132] Considering the water flow mode to be executed, the control unit 21 controls the first acidic water supply mode (S13) in addition to the first pipe cleaning mode (S14) so ​​that the amount of water flowing in the first acidic water supply mode (S30) and the first current reversal mode (S31) remains in the batch treatment tank 6B.

[0133] (First acidic water drainage mode)

[0134] Next, the control unit 21 executes the first acidic water discharge mode ( S32 ) and performs control so that the acidic water remaining in the batch treatment tanks 6A and 6B is discharged through the separator 16 .

[0135] like Fig. 10B As shown, the control unit 21 opens the valve 24 while driving the pump 10 to allow water to flow from the batch treatment tank 6B to the circulation flow path 8B, and opens the valve 26 to allow water to flow from the circulation flow path 8B to the flow path 34. The control unit 21 does not operate the separation device 16, and allows the acidic water reaching the separation device 16 to pass directly and flow to the flow path 38 for drainage. Fig. 10C As shown, when the drainage of the batch tank 6B is completed, the control unit 21 drives the pump 10 and opens the valve 24 to allow water to flow from the batch tank 6A to the circulation flow path 8A, and opens the valve 26 to allow water to flow from the circulation flow path 8A to the flow path 34. The control unit 21 does not operate the separator 16, and allows the acidic water reaching the separator 16 to pass directly to the flow path 38 for drainage. When the drainage of the batch tank 6A is completed, the control unit 21 stops the first acidic water drainage mode. In addition, the batch tank 6A and the batch tank 6B may be drained in this order.

[0136] By executing the above steps S30 to S32, the first polarity switching step (S3) is completed. When the polarity of the electrodes 50, 51 is switched, the batch tanks 6A, 6B and the circulation channels 8A, 8B in the first mode (S1) are replaced.

[0137] When the polarity of the electrodes 50 and 51 is switched, the water treatment device 2 of the first embodiment switches the batch treatment tanks 6A and 6B and the circulation flow paths 8A and 8B used in the first mode, and executes the second mode which is the same as the softening water treatment. Specifically, after executing the first mode, the control unit 21 executes the second mode according to Fig.11 The flowchart shown implements the second mode.

[0138] like Fig.11 As shown, the control unit 21 sequentially executes the second raw water injection mode (S20), the second crystallization treatment mode (S21), the second alkaline water supply mode (S22), the second acidic water supply mode (S23), and the second pipe cleaning mode (S24) in the second mode.

[0139] Figure 12 to Figure 16 The flow of water in each mode of steps S20 to S24 is shown. Fig.12 Indicates the second raw water injection mode, Fig.13 represents the second crystallization processing mode, Fig.14 Indicates the second alkaline water delivery mode. Fig.15 Indicates the second acidic water delivery mode. Fig.16 Indicates the second pipe cleaning mode.

[0140] like Figure 12 to Figure 16 As shown, the second mode is different from the first mode in that only the batch processing tanks 6A and 6B and the circulation flow paths 8A and 8B are exchanged.

[0141] like Fig.12 As shown, in the second raw water injection mode (S20), raw water is injected into the batch processing tank 6B. Fig.13 As shown, in the second crystallization treatment mode (S21), the raw water stored in the batch treatment tank 6B is supplied to the electrolysis device 12 for electrolysis, and the generated alkaline water is passed into the circulation flow path 8B to circulate in the circulation flow path 8B including the batch treatment tank 6B, and the acidic water is passed into the circulation flow path 8A to be stored in the batch treatment tank 6A. Fig.14 As shown, in the second alkaline water supply mode (S22), the alkaline water stored in the batch treatment tank 6B is supplied to the separation device 16 to separate the crystals, and the alkaline water after the crystal separation is supplied to the intermediate tank 18. Fig.15 As shown, in the second acidic water supply mode (S23), the acidic water stored in the batch treatment tank 6A is supplied to the intermediate tank 18 via the separator 16 to be mixed with the alkaline water. Fig.16 As shown, in the second pipe cleaning mode (S24), the acidic water remaining in the batch treatment tank 6A is made to flow to the bypass flow path 41, the flow path 41A, and the flow path 41B via the separator 16, thereby cleaning each pipe.

[0142] As in the first mode, Fig.13 In the second crystallization treatment mode (S21) shown, alkaline water is circulated in the circulation flow path 8B while electrolysis is performed by the electrolysis device 12. As a result, the pH value of the water flowing in the circulation flow path 8B is increased while the metal components contained in the water are crystallized, thereby reducing the hardness of the raw water.

[0143] By executing the above steps S20 to S24, the execution of the second mode is completed. Acidic water remains in the batch treatment tank 6A. In this state, the second polarity switching step (S5) is executed.

[0144] Reference Fig.17 and Fig.18 , the second polarity switching step of electrodes 50 and 51 is described. Fig.17 This is a flow chart of the water treatment device 2 when executing the second polarity switching step. Fig.18 It is a diagram showing the flow of water in the second acidic water flow pattern in the second polarity switching step.

[0145] like Fig.17 As shown, the control unit 21 sequentially executes the second acidic water flow mode ( S50 ), the second current reversal mode ( S51 ), and the second acidic water drainage mode ( S52 ) in the second polarity switching step.

[0146] like Fig.18 As shown, the second polarity switching step is different from the first polarity switching step in that only the electrodes 50, 51, the batch processing tanks 6A, 6B, and the circulation flow paths 8A, 8B are exchanged.

[0147] In the second acidic water flow mode (S50), the control unit 21 causes the acidic water stored in the batch tank 6A to flow into the electrolysis device 12. In the second current reversal mode (S51), the control unit 21 reverses the positive and negative current values ​​applied to the electrodes 50 and 51 of the electrolysis device 12 while passing the acidic water, thereby reversing the positive and negative polarities of the electrodes 50 and 51. In the second acidic water discharge mode (S52), the control unit 21 discharges the acidic water remaining in the batch tanks 6A and 6B (see Fig. 10B as well as Fig. 10C ).

[0148] Similar to the first polarity switching step (S3), in the second polarity switching step (S5), the polarities of the electrodes 50 and 51 are switched. Thus, the batch tanks 6A and 6B and the circulation channels 8A and 8B used in the second mode are switched again, and the first mode is executed.

[0149] like Figure 2 As shown, the control unit 21 performs the first mode (S10 to S14) and the second mode (S20 to S24) alternately with the polarity switching steps (S3, S5) interposed therebetween, thereby continuously producing soft water.

[0150] (Summarize)

[0151] The above description is summarized to describe the features of the present disclosure.

[0152] The water treatment device 2 of embodiment 1 passes acidic water in the polarity switching step (S3, S5) of the electrodes 50 and 51. Through the electrolysis reaction of water, the chloride ion concentration of the acidic water is lower than the chloride ion concentration of the raw water and the alkaline water. Therefore, by passing acidic water in the polarity switching step, the consumption of the catalyst layers 50B and 51B of the electrodes 50 and 51 can be suppressed. Since the chloride ion concentration of the acidic water is lower than the chloride ion concentration of the treated water, the consumption of the catalyst layers 50B and 51B of the electrodes 50 and 51 can be further suppressed compared to the case where the treated water is passed. In addition, since the acidic water dissolves the scale attached to the electrodes 50 and 51, the life of the electrodes 50 and 51 can be further extended by passing the acidic water.

[0153] [Effect]

[0154] According to the water treatment device 2 and the operating method thereof according to the first embodiment, the following effects can be achieved.

[0155] As described above, the method of the present embodiment is an operation method of the water treatment device 2. The water treatment device 2 includes an electrolysis device 12, a first circulation flow path (circulation flow path 8A), a second circulation flow path (circulation flow path 8B), a water storage tank (intermediate tank 18), and a control unit 21. The electrolysis device 12 generates alkaline water and acidic water by electrolysis, and has electrodes 50 and 51 whose polarity can be switched. The circulation flow paths 8A and 8B are circulation flow paths connected to the electrolysis device 12, and can alternately pass the alkaline water and acidic water generated by the electrolysis device 12. The intermediate tank 18 stores the treated water generated by the electrolysis device 12. The control unit 21 performs at least two electrolysis steps (S1, S2) and a polarity switching step (S3, S5) of switching the polarity of the electrodes 50, 51 of the electrolysis device 12 between consecutive electrolysis steps. The electrolysis step includes a step (S11, S21) of supplying raw water to the electrolysis device 12. The electrolysis step includes steps of generating alkaline water and acidic water by electrolysis of raw water and passing the water to the circulation flow path 8A or the circulation flow path 8B (S11, S21). The electrolysis step includes steps of transferring the generated alkaline water and acidic water to the intermediate tank 18 and storing them as treated water (S12-S13, S22-S23). The control unit 21 controls in the polarity switching step (S3, S5) such that the acidic water or treated water generated by the electrolysis device 12 passes to the electrolysis device 12 (S30-S31, S50-S51).

[0156] With such a structure, the concentration of chloride ions in the acidic water generated by electrolysis is lower than the concentration of chloride ions in the raw water. Therefore, the control unit 21 can switch the polarity of the electrodes 50 and 51 while the electrodes 50 and 51 are in contact with the acidic water with a low chloride ion concentration. Therefore, the dissolution of the catalyst layers 50B and 51B can be suppressed, the consumption of the electrodes 50 and 51 can be suppressed, and the life of the electrodes 50 and 51 can be extended.

[0157] In the method of the present embodiment, the control unit 21 performs control in the polarity switching step ( S3 , S5 ) so that the acidic water flows through the electrolysis device 12 .

[0158] With such a structure, the acidic water can dissolve the scale attached to the electrodes 50 and 51. Therefore, the life of the electrodes 50 and 51 can be further extended.

[0159] In the method of the present embodiment, the control unit 21 performs control so that the acidic water is discharged from the water treatment device 2 after passing through the electrolysis device 12 .

[0160] With such a configuration, it is possible to suppress the acidic water containing scale components from contaminating the raw water supplied in the subsequent electrolysis step.

[0161] In the method of this embodiment, the water treatment device 2 further includes a first valve (valve 24, 26, 28A) that can be opened and closed and a second valve (valve 24, 26, 28B) that can be opened and closed. The valves 24, 26, 28A are provided in the circulation flow path 8A, and when opened, the circulation flow path 8A is connected to the electrolysis device 12. The valves 24, 26, 28B are provided in the circulation flow path 8B, and when opened, the circulation flow path 8B is connected to the electrolysis device 12. The control unit 21 controls in the polarity switching step (S3, S5) so that the valve provided in the flow path through which the acidic water flows is opened.

[0162] With such a structure, the flow of acidic water can be controlled by opening and closing the valves 24, 26, 28A, and 28B. Therefore, the flow of acidic water can be easily performed in coordination with the polarity switching step.

[0163] In the method of this embodiment, the control unit 21 reverses the positive and negative currents applied to the electrodes 50 and 51 of the electrolysis device 12 after opening the valves 24, 26, and 28A or the valves 24, 26, and 28B in the polarity switching step (S3, S5).

[0164] With such a configuration, when the electrolysis device 12 is filled with acidic water having a low chloride ion concentration, the positive and negative directions of the current applied to the electrodes 50 and 51 can be reversed. Therefore, the electrodes 50 and 51 can be prevented from coming into contact with water having a high chloride ion concentration that promotes dissolution of the catalyst layers 50B and 51B.

[0165] In the method of the present embodiment, the control unit 21 performs control so that the acidic water passes through the circulation flow path 8A or the circulation flow path 8B before the polarity switching step ( S3 , S5 ).

[0166] According to such a configuration, in the step ( S14 , S24 ) of passing the acidic water separately from the polarity switching step, scale adhering to the circulation flow paths 8A and 8B can be dissolved to clean the pipes.

[0167] The water treatment device 2 of this embodiment includes an electrolysis device 12, circulation flow paths 8A, 8B, a water storage tank (intermediate tank 18), and a control unit 21. The electrolysis device 12 generates alkaline water and acidic water by electrolysis, and has electrodes 50, 51 that can switch polarity. The circulation flow paths 8A, 8B are circulation flow paths connected to the electrolysis device 12, and can allow the alkaline water and acidic water generated by the electrolysis device 12 to pass alternately. The intermediate tank 18 stores the alkaline water and acidic water generated by the electrolysis device 12. The control unit 21 performs at least two electrolysis steps (S1, S2) and a polarity switching step (S3, S5) of switching the polarity of the electrodes 50, 51 of the electrolysis device 12 between consecutive electrolysis steps. The control unit 21 controls in the polarity switching step (S3, S5) so that the acidic water or treated water generated by the electrolysis device 12 is passed to the electrolysis device 12 (S30-S31, S50-S51).

[0168] With such a structure, the polarity of electrodes 50 and 51 can be switched while electrodes 50 and 51 are in contact with water having a low chloride ion concentration. Therefore, elution of catalyst layers 50B and 51B can be suppressed, consumption of electrodes 50 and 51 can be suppressed, and the life of electrodes 50 and 51 can be extended.

[0169] In the water treatment device 2 of the present embodiment, the control unit 21 performs control so that the acidic water flows into the electrolysis device 12 in the polarity switching step ( S3 , S5 ).

[0170] With such a structure, the acidic water can dissolve the scale attached to the electrodes 50 and 51. Therefore, the life of the electrodes 50 and 51 can be further extended.

[0171] In addition, in Embodiment 1, an example is described in which the operation is terminated after the second mode (Yes in S4 ), but the present invention is not limited to this. For example, the operation may be terminated after the first mode.

[0172] In addition, in Embodiment 1, an example in which acidic water generated in the water treatment device 2 is introduced in the polarity switching step is described, but the present invention is not limited thereto. For example, acidic water or treated water generated by other devices may be introduced. In this case, the concentration of chloride ions is preferably lower than that of the raw water supplied to the water treatment device 2.

[0173] In the first embodiment, the example in which acidic water is passed through both circulation passages 8A and 8B downstream of electrolysis device 12 in the first acidic water passing mode is described, but the present invention is not limited thereto. For example, acidic water may be passed through only one of circulation passages 8A and 8B.

[0174] In addition, in Embodiment 1, the control unit 21 may execute the step of passing acidic water into the electrolysis device 12 to clean the electrolysis device 12 before the polarity switching step (S3, S5). In this case, in the polarity switching step, the first acidic water flow mode (S30) and the second acidic water flow mode (S50) may not be executed, and the flow of acidic water and the reversal of current may be started at the same time. With such a structure, it is also possible to suppress the electrodes 50, 51 from contacting with water having a high concentration of chloride ions.

[0175] (Implementation Method 2)

[0176] A water treatment device 102 according to Embodiment 2 of the present disclosure will be described. In Embodiment 2, differences from Embodiment 1 will be mainly described, and overlapping descriptions with Embodiment 1 will be omitted. In Embodiment 2, configurations identical or equivalent to those in Embodiment 1 are described with the same reference numerals.

[0177] Fig.19 FIG. 1 is a schematic diagram of a water treatment device 102 in Embodiment 2 of the present disclosure. Fig.19 As shown, in the second embodiment, the water treatment device 102 is different from the first embodiment in that it includes a valve 203 and a flow path 204 for connection.

[0178] The valve 203 is provided in the flow path 44, that is, between the intermediate tank 18 and the water storage tank 20. The valve 203 is connected to the flow path 41 via the flow path 204. In the connection between the flow path 204 and the flow path 41, for example, a valve (not shown) that inhibits the flow direction of water toward the valve 30 may be provided. The intermediate tank 18 is connected to the batch treatment tanks 6A, 6B and the circulation flow paths 8A, 8B via the flow path 44, the valve 203, the flow path 204, and the flow path 41, and is thereby connected to the electrolysis device 12. With such a structure, the treated water stored in the intermediate tank 18 can be returned to the batch treatment tanks 6A, 6B.

[0179] The flow and stop of water from the intermediate tank 18 to the batch tank 6A or the batch tank 6B is controlled by opening and closing the valve 203. The valve 203 may be a valve that is opened and closed by a motor drive.

[0180] Next, the operating method of the water treatment device 102 will be described. Fig. 20 This is a flowchart of the method of operating the water treatment device 102.

[0181] like Fig. 20As shown, in the operation method of the water treatment device 102, the control unit 21 executes steps S101 to S105. The first mode (S101) and the second mode (S102) in the operation method of the water treatment device 102 are shared with the first mode (S1) and the second mode (S2) in Embodiment 1, respectively. On the other hand, the operation method of the water treatment device 102 is different from the operation method of the water treatment device 2 in Embodiment 1 in that in the polarity switching step (S103, S105), treated water is passed instead of acidic water.

[0182] The control unit 21 executes the first mode (S101). After the first mode ends, the control unit 21 discharges the acidic water in the batch processing tanks 6A and 6B and executes the first polarity switching step (S103). Therefore, when the control unit 21 starts the first polarity switching step, the batch processing tanks 6A and 6B are empty.

[0183] Next, refer to Figure 21 to Figure 23 , the first polarity switching step is explained. Fig.21 This is a flow chart of the water treatment device 102 when executing the first polarity switching step. Fig. 22 It is a diagram showing the flow of water in the first treated water supply pattern in the first polarity switching step. Fig.23 It is a diagram showing the flow of water in the first treated water flow pattern in the first polarity switching step.

[0184] (First treated water delivery mode)

[0185] like Fig.21 As shown, the control unit 21 first executes the first treated water delivery mode (S60). The first treated water delivery mode is a mode in which the treated water is returned from the intermediate tank 18 to the batch treatment tank 6B. Specifically, the control unit 21 generates Fig. 22 The treated water used in the first treated water supply mode is soft water with a reduced concentration of chloride ions produced in the first mode.

[0186] like Fig. 22 As shown, the control unit 21 opens the valve 203 to pass water from the intermediate tank 18 to the flow path 204, and opens the valve 28B to pass water from the flow path 41 and the flow path 41B to the batch treatment tank 6B. The treated water is stored in the batch treatment tank 6B. At this time, the control unit 21 controls so that the valve 28A is closed.

[0187] (First treated water flow mode)

[0188] When a predetermined time has passed since the start of the first treated water supply mode, the control unit 21 executes the first treated water flow mode (S61). The first treated water flow mode is a mode in which treated water is supplied to the electrolysis device 12 in order to pre-fill the electrolysis device 12 with treated water before the polarity of the electrodes 50 and 51 is reversed. Specifically, the control unit 21 generates Fig.23 The flow is controlled in the manner shown.

[0189] The control unit 21 opens the valve 24 while driving the pump 10, so that water flows from the batch treatment tank 6B to the circulation flow path 8B, and opens the valve 26 so that water flows from the circulation flow path 8B to the electrolysis device 12. The control unit 21 does not operate the electrolysis device 12, so that the treated water reaching the electrolysis device 12 is not electrolyzed but directly passes through the circulation flow path 8B. The control unit 21 also controls the opening and closing of the valve 28B so that the treated water from the electrolysis device 12 passes through the circulation flow path 8B to the batch treatment tank 6B. At this time, the control unit 21 controls so that the valve 28A is closed.

[0190] (First current reversal mode)

[0191] When a predetermined time has passed since the start of the first acidic water flow mode, the control unit 21 executes the first current reversal mode (S62). The first current reversal mode is a mode in which the treated water is passed through the electrolysis device 12 and the positive and negative current values ​​applied to the electrolysis device 12 are reversed.

[0192] The flow of treated water in the first current reversal mode and the flow of treated water in the first treated water flow mode are performed continuously. That is, during the first treated water flow mode and the first current reversal mode, the control unit 21 controls the valves 24 and 26 to maintain the connection between the batch treatment tank 6B and the electrolysis device 12.

[0193] While the treated water is continuously flowing, the control unit 21 reverses the positive and negative currents applied to the electrodes 50 and 51 of the electrolysis device 12. The control unit 21 reverses the current applied to the electrode 50 from positive to negative, and reverses the current applied to the electrode 51 from negative to positive. Through such an action, the polarity of the electrode 50 is switched from the anode to the cathode, and the polarity of the electrode 51 is switched from the cathode to the anode.

[0194] Since a predetermined time (e.g., 5 seconds) has passed since the first treated water flow mode started, the control unit 21 can execute the first current reversal mode in a state where the treated water fills the electrolysis device 12. Therefore, at the moment of polarity switching, the electrodes 50 and 51 are in contact with the treated water and are in an environment with a low concentration of chloride ions. Therefore, the dissolution of the catalyst layers 50B and 51B of the electrodes 50 and 51 can be suppressed.

[0195] This operation can maintain the amount of treated water stored in the batch tank 6B and suppress the treated water from flowing into the batch tank 6A. The controller 21 ends the first current reversal mode after passing the treated water through the batch tank 6B for a predetermined time (eg, 10 seconds).

[0196] By executing the above steps S60 to S62, the execution of the first polarity switching step (S103) is completed. When the first polarity switching step is completed, the treated water is stored in the batch tank 6B. Therefore, the treated water is stored in the batch tank 6B supplied with raw water in the next electrolysis step, i.e., the second mode (S102). Therefore, the treated water introduced in the first polarity switching step can be used as raw water in the second mode.

[0197] Next, the control unit 21 executes the second mode (S102). After the second mode ends, the control unit 21 discharges the acidic water in the batch processing tanks 6A and 6B and executes the second polarity switching step (S105). Therefore, when the control unit 21 starts the second polarity switching step, the batch processing tanks 6A and 6B are empty.

[0198] Next, refer to Figure 24 to Figure 26 , the second polarity switching step is explained. Fig.24 This is a flow chart of the water treatment device 102 when executing the second polarity switching step. Fig.25 It is a diagram showing the flow of water in the second treated water supply pattern in the first polarity switching step. Fig.26 It is a diagram showing the flow of water in the second treated water flow pattern in the first polarity switching step.

[0199] like Fig.24 As shown, the control unit 21 sequentially executes the second treated water delivery mode (S70), the second treated water flow mode (S71), and the second current reversal mode (S72) in the second polarity switching step.

[0200] like Fig.25 and Fig.26 As shown, the second polarity switching step is different from the first polarity switching step (S103) in that only the electrodes 50, 51, the batch tanks 6A, 6B, and the circulation channels 8A, 8B are exchanged.

[0201] In the second treated water supply mode (S70), the control unit 21 supplies the treated water stored in the intermediate tank 18 to the batch treatment tank 6A. In the second treated water flow mode (S71), the control unit 21 flows the treated water stored in the batch treatment tank 6A to the electrolysis device 12. In the second current reversal mode (S72), the control unit 21 reverses the positive and negative current values ​​applied to the electrodes 50 and 51 of the electrolysis device 12 while flowing the treated water, thereby reversing the positive and negative polarities of the electrodes 50 and 51.

[0202] Similar to the first polarity switching step ( S103 ), in the second polarity switching step ( S105 ), the polarities of the electrodes 50 , 51 are switched.

[0203] When the second current reversal mode is completed, the treated water is stored in the batch treatment tank 6A. Therefore, the treated water in the batch treatment tank 6A can be used as raw water in the next electrolysis step, that is, the first mode (S101).

[0204] [Effect]

[0205] According to the water treatment device 102 and the operating method thereof in Embodiment 2, the following effects can be achieved.

[0206] As described above, in the method of the present embodiment, the control unit 21 performs control in the polarity switching step ( S103 , S105 ) so that the treated water flows into the electrolysis device 12 .

[0207] With such a structure, the concentration of chloride ions in the treated water is lower than that in the raw water because the acidic water with a low chloride ion concentration is mixed with the alkaline water. Therefore, the control unit 21 can switch the polarity of the electrodes 50 and 51 while the electrodes 50 and 51 are in contact with the treated water with a low chloride ion concentration. Therefore, the dissolution of the catalyst layers 50B and 51B can be suppressed, the consumption of the electrodes 50 and 51 can be suppressed, and the life of the electrodes 50 and 51 can be extended.

[0208] In the method of this embodiment, the water treatment device 102 further includes a first tank (batch tank 6A) provided in the circulation flow path 8A and a second tank (batch tank 6B) provided in the circulation flow path 8B. The control unit 21 controls in the polarity switching step (S103, S105) such that the treated water introduced into the electrolysis device 12 is injected into the tank that stores raw water in the next electrolysis step, among the batch tank 6A and the batch tank 6B.

[0209] With such a structure, the treated water introduced in the polarity switching step can be reused in the electrolysis step. Therefore, the amount of soft water that can be generated by the water treatment device 2 increases.

[0210] In the method of this embodiment, the water treatment device 102 further includes a connecting flow path (flow path 204) connecting the intermediate tank 18 and the electrolysis device 12, and a third valve (valve 203) that can be opened and closed and is provided in the flow path 204. In the polarity switching step (S103, S105), the control unit 21 controls so that the valve 203 is opened.

[0211] With such a configuration, the treated water stored in the intermediate tank 18 can be easily sent to the electrolysis device 12 through the circulation flow path 8A or the circulation flow path 8B.

[0212] In the method of the present embodiment, the control unit 21 opens the valve 203 in the polarity switching step ( S103 , S105 ) and then reverses the positive and negative directions of the current applied to the electrodes 50 , 51 of the electrolysis device 12 .

[0213] With such a configuration, the positive and negative directions of the current applied to the electrodes 50 and 51 can be reversed in a state where the electrolysis device 12 is filled with treated water having a low chloride ion concentration.

[0214] The water treatment device 102 of this embodiment further includes a flow path 204 connecting the intermediate tank 18 and the electrolysis device 12, and an openable and closable valve 203 provided on the flow path 204. The control unit 21 controls the valve 203 to open in the polarity switching step (S103, S105).

[0215] With such a structure, the treated water stored in the intermediate tank 18 can be easily transported to the electrolysis device 12 .

[0216] In addition, the first mode may also include a first acidic water cleaning mode in which acidic water is passed into the electrolysis device 12 after the first pipe cleaning mode. Similarly, the second mode may also include a second acidic water cleaning mode in which acidic water is passed into the electrolysis device 12 after the second pipe cleaning mode. For example, in the first acidic water cleaning mode, the control unit 21 may generate the following Fig. 10A In the second acidic water cleaning mode, the control unit 21 can generate the following Fig.18 By adopting such a pattern, even in the operation method in which the treated water is passed in the electrode switching step, the scale attached to the electrodes 50 and 51 can be removed.

[0217] The method in the first embodiment is a method for operating a water treatment device, which includes: an electrolysis device that generates alkaline water and acidic water by electrolysis and has electrodes that can switch polarity; a first circulation flow path and a second circulation flow path, which are circulation flow paths connected to the electrolysis device and can alternately pass alkaline water and acidic water generated by the electrolysis device; a water storage tank that stores treated water generated by the electrolysis device; and a control unit, wherein the control unit performs at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between consecutive electrolysis steps, and the electrolysis step includes the following steps: supplying raw water to the electrolysis device; generating alkaline water and acidic water by electrolysis of the raw water, and passing the water to the first circulation flow path or the second circulation flow path; and conveying the generated alkaline water and acidic water to the water storage tank to be stored as treated water, and the control unit controls in the polarity switching step so that the acidic water or treated water generated by the electrolysis device passes to the electrolysis device.

[0218] As a method according to a second aspect, in the method according to the first aspect, the control unit performs control in the polarity switching step so that the acidic water flows through the electrolysis device.

[0219] As a method according to a third aspect, in the method according to the second aspect, the control unit performs control so as to discharge the acidic water from the water treatment device after passing the acidic water through the electrolysis device.

[0220] As a method in a fourth embodiment, in the method in the second or third embodiment, the water treatment device further includes: a first valve, which can be opened and closed, and is arranged in a first circulation flow path, and when opened, the first circulation flow path is connected to the electrolysis device; and a second valve, which can be opened and closed, and is arranged in a second circulation flow path, and when opened, the second circulation flow path is connected to the electrolysis device, and the control unit controls in a polarity switching step so that the valve of the first valve and the second valve arranged in the flow path for acidic water to flow is opened.

[0221] As a method of a fifth aspect, in the method of the fourth aspect, the control unit inverts the positive and negative of the current applied to the electrodes of the electrolysis device after opening the first valve or the second valve in the polarity switching step.

[0222] As a method according to a sixth aspect, in the method according to the first aspect, the control unit performs control in the polarity switching step so that the treated water flows through the electrolysis device.

[0223] As a method in the seventh embodiment, in the method in the sixth embodiment, the water treatment device also has a first tank arranged in the first circulation flow path and a second tank arranged in the second circulation flow path, and the control unit controls in the polarity switching step so that the treated water passed into the electrolysis device is injected into the tank of the first tank and the second tank, which stores raw water in the next electrolysis step.

[0224] As a method in the eighth embodiment, in the method in the sixth or seventh embodiment, the water treatment device also has: a connecting flow path, which connects the water storage tank and the electrolysis device; and a third valve, which can be opened and closed and is arranged in the connecting flow path, and the control unit controls the third valve to open in the polarity switching step.

[0225] As a method according to a ninth aspect, in the method according to the eighth aspect, the control unit inverts the positive and negative directions of the current applied to the electrodes of the electrolysis device after opening the third valve in the polarity switching step.

[0226] As a method according to a tenth aspect, in the method according to any one of the first to ninth aspects, the control unit performs control so that the acidic water passes through the first circulation flow path or the second circulation flow path before the polarity switching step.

[0227] The water treatment device in the eleventh embodiment comprises: an electrolysis device, which generates alkaline water and acidic water by electrolysis and has electrodes capable of switching polarity; a first circulation flow path and a second circulation flow path, which are circulation flow paths connected to the electrolysis device and can allow the alkaline water and acidic water generated by the electrolysis device to flow alternately; a water storage tank, which stores the alkaline water and acidic water generated by the electrolysis device as treated water; and a control unit, which performs at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between consecutive electrolysis steps, and the control unit controls in the electrode polarity switching step so that the acidic water or treated water generated by the electrolysis device flows into the electrolysis device.

[0228] As a water treatment apparatus according to a twelfth aspect, in the water treatment apparatus according to the eleventh aspect, the control unit performs control so that the acidic water flows into the electrolysis device in the polarity switching step.

[0229] As a water treatment device in the thirteenth embodiment, in the water treatment device in the eleventh embodiment, it also has: a connecting flow path, which connects the water storage tank with the electrolysis device; and a third valve, which can be opened and closed and is arranged on the connecting flow path, and the control unit controls in a polarity switching step so that the third valve is opened.

[0230] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art, and such changes and modifications are to be construed as being included therein as long as they do not depart from the scope of the present invention as defined in the appended claims.

[0231] Possibility of Industrial Application

[0232] The water treatment device of the present disclosure can be used as a water softening device.

[0233] Description of Reference Numerals

[0234] 2: water treatment device; 4A, 4B: raw water flow path; 6A, 6B: batch treatment tanks; 8A, 8B: circulation flow path; 10: pump; 12: electrolysis device; 18: intermediate tank; 20: water storage tank; 22A, 22B: valve; 24: valve; 26: valve; 28A, 28B: valve; 50: electrode; 51: electrode; 102: water treatment device; 203: valve; 204: flow path; S1: first mode; S2: second mode; S3: first polarity switching step; S5: second polarity switching step.

Claims

1. A method for operating a water treatment device, the water treatment device comprising: an electrolysis device that generates alkaline water and acidic water by electrolysis and has electrodes capable of switching polarity; a first circulation flow path and a second circulation flow path that are circulation flow paths connected to the electrolysis device and capable of alternately passing alkaline water and acidic water generated by the electrolysis device; and a water storage tank that stores treated water generated by the electrolysis device; and a control unit, wherein The control unit performs at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between the consecutive electrolysis steps. The electrolysis step comprises the following steps: supplying raw water to the electrolysis device; generating alkaline water and acidic water by electrolysis of raw water, and passing the water into the first circulation flow path or the second circulation flow path; as well as The generated alkaline water and acidic water are sent to the water storage tank and stored as treated water. The control unit performs control in the polarity switching step so that the acidic water or the treated water generated by the electrolysis device flows into the electrolysis device.

2. The method according to claim 1, wherein: The control unit performs control in the polarity switching step so that the acidic water flows into the electrolysis device.

3. The method according to claim 2, wherein: The control unit performs control so as to discharge the acidic water from the water treatment device after passing the acidic water through the electrolysis device.

4. The method according to claim 2, wherein: The water treatment device further comprises: a first valve which can be opened and closed and is disposed in the first circulation flow path, and when opened, the first circulation flow path is connected to the electrolysis device; and a second valve which can be opened and closed and is disposed in the second circulation flow path, and when opened, the second circulation flow path is connected to the electrolysis device. The control unit performs control in the polarity switching step so that the valve provided in the flow path through which the acidic water flows, of the first valve and the second valve, is opened.

5. The method according to claim 4, wherein: In the polarity switching step, the control unit reverses the positive and negative directions of the current applied to the electrodes of the electrolysis device after opening the first valve or the second valve.

6. The method according to claim 1, wherein: The control unit performs control in the polarity switching step so that the treated water flows into the electrolysis device.

7. The method according to claim 6, wherein: The water treatment device further comprises: a first tank disposed in the first circulation flow path; and a second tank disposed in the second circulation flow path. The control unit controls in the polarity switching step so that the treated water passed into the electrolysis device is poured into the tank that stores raw water in the next electrolysis step, of the first tank and the second tank.

8. The method according to claim 6, wherein: The water treatment device further comprises: a connecting flow path connecting the water storage tank and the electrolysis device; and a third valve which can be opened and closed and is disposed in the connecting flow path. The control unit performs control in the polarity switching step so as to open the third valve.

9. The method according to claim 8, wherein: In the polarity switching step, the control unit reverses the positive and negative directions of the current applied to the electrodes of the electrolysis device after opening the third valve.

10. The method according to any one of claims 1 to 9, wherein: The control unit controls the flow of acidic water to the first circulation flow path or the second circulation flow path before the polarity switching step.

11. A water treatment device, wherein: The water treatment device comprises: An electrolysis device that generates alkaline water and acidic water by electrolysis and has electrodes capable of switching polarity; A first circulation flow path and a second circulation flow path, which are circulation flow paths connected to the electrolysis device and can alternately pass alkaline water and acidic water generated by the electrolysis device; a water storage tank for storing the alkaline water and acidic water generated by the electrolysis device as treated water; as well as Control Department, The control unit performs at least two electrolysis steps and a polarity switching step of switching the polarity of the electrodes of the electrolysis device between the consecutive electrolysis steps. The control unit performs control in the step of switching the polarity of the electrodes so that the acidic water or the treated water generated by the electrolysis device flows into the electrolysis device.

12. The water treatment device according to claim 11, wherein: The control unit performs control in the polarity switching step so that the acidic water flows into the electrolysis device.

13. The water treatment device according to claim 11, wherein: The water treatment device further comprises: a connecting flow path connecting the water storage tank and the electrolysis device; and a third valve which can be opened and closed and is disposed in the connecting flow path. The control unit performs control in the polarity switching step so as to open the third valve.

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