Water softening device

Abstract

The water softening device is provided with: water softening tanks (3, 5) that soften raw water containing a hardness component by means of a weakly acidic cation exchange resin (33) to generate acidic soft water; neutralization tanks (4, 6) for neutralizing the pH of the acidic soft water that has passed through the soft water tanks (3, 5) by means of a weakly alkaline anion exchange resin (34) to generate neutralized soft water; and a control unit (15) that controls a regeneration step, which is a step for regenerating at least one of the weakly acidic cation exchange resin (33) and the weakly alkaline anion exchange resin (34). The control unit (15) is provided with an adsorption amount determination unit for determining the adsorption amount of the hardness component in the soft water tanks (3, 5) on the basis of the hardness of the raw water, the amount of the raw water introduced into the soft water tanks (3, 5), and the hardness of the water introduced into the soft water tanks (3, 5), and the control unit (15) determines the adsorption amount of the hardness component in the soft water tanks (3, 5) on the basis of the adsorption amount of the hardness component determined by the adsorption amount determination unit during the regeneration step. The regeneration step is controlled such that the regeneration step is continued when the hardness component adsorption amount is equal to or greater than a reference value, and the regeneration step is ended when the hardness component adsorption amount is less than the reference value.

Description

Technical Field

[0001] The invention relates to a water softening device. Background Art

[0002] In conventional water softening devices, weakly acidic cation exchange resins have hydrogen ions at the ends of functional groups, and hardness components (e.g., calcium ions or magnesium ions) in raw water are exchanged with hydrogen ions to soften raw water. As a method for regenerating cation exchange resins without using salt, a method for regenerating cation exchange resins using acidic electrolyzed water generated by electrolysis is known (e.g., see Patent Document 1).

[0003] Water softened by a weakly acidic cation exchange resin becomes acidic because hydrogen ions are released from the weakly acidic cation exchange resin in place of the hardness component in the soft water. In order to neutralize the hydrogen ions, a weakly acidic cation exchange resin is sometimes used in combination with a weakly basic anion exchange resin. As a method for regenerating a weakly basic anion exchange resin, a method using alkaline electrolyzed water generated by electrolysis is known (for example, see Patent Document 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-30973

[0007] Patent Document 2: Japanese Patent Application Publication No. 2010-142674 Summary of the invention

[0008] In such a water softening device, since water cannot be softened during the regeneration of the ion exchange resin, the regeneration process of the ion exchange resin must be completed at night when the water softening process is less necessary. Therefore, it is required to shorten the time required to complete the regeneration process.

[0009] The time required to complete the regeneration process is mainly determined by the amount of hardness components adsorbed on the ion exchange resin and the electrolytic water concentration of the acidic electrolytic water and alkaline electrolytic water generated by electrolysis. The electrolytic water concentration is one of the factors that determine the durability of the electrode, and it mainly depends on the current value applied to the electrode. If a high current is applied to the electrode to increase the electrolytic water concentration, the time taken to complete the regeneration process can be shortened, but the durability of the electrolytic cell is significantly reduced, so it is not practical. Therefore, there is a problem that it is difficult to complete the regeneration process in a short time while suppressing the applied current value applied to the electrolytic cell, and solving this problem is the first issue.

[0010] In addition, in the conventional water softening device, bicarbonate ions are adsorbed on the weakly basic ion exchange resin when the raw water is softened. The adsorbed bicarbonate ions are released into the alkaline electrolyzed water used in the regeneration when the weakly basic anion exchange resin is regenerated. Since the released bicarbonate ions consume the hydroxide ions in the alkaline electrolyzed water and the hydrogen ions in the acidic electrolyzed water, the hydroxide ion concentration in the alkaline electrolyzed water and the hydrogen ion concentration in the acidic electrolyzed water are reduced, and there is a problem that the regeneration efficiency of the weakly basic anion exchange resin and the weakly acidic cation exchange resin is reduced. Solving this problem becomes the second subject.

[0011] In the conventional water softening device, it is required to solve at least one of the above-mentioned first problem and the second problem.

[0012] Therefore, the present invention provides a water softening device that solves at least one of the first and second problems described above and can suppress a decrease in the water softening performance.

[0013] Furthermore, as a softening device for coping with the first problem, the softening device of the present invention comprises: a softening tank for softening raw water containing hardness components by using a weakly acidic cation exchange resin to generate acidic soft water; a neutralization tank for neutralizing the pH, i.e., the hydrogen ion concentration index, of the acidic soft water that has passed through the softening tank by using a weakly basic anion exchange resin to generate neutralized soft water; and a control unit for controlling a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin. The control unit comprises an adsorption amount determination unit for determining the amount of hardness component adsorption in the softening tank based on the hardness of the raw water, the amount of raw water passed through the softening tank, and the hardness of water after passing through the softening tank. During the regeneration process, the control unit controls the execution of the regeneration process in such a manner that the regeneration process is continued when the amount of hardness component adsorption is greater than a reference value, and the regeneration process is terminated when the amount of hardness component adsorption is less than the reference value, based on the amount of hardness component adsorption determined by the adsorption amount determination unit.

[0014] In addition, as a softening device for coping with the first problem, the softening device of the present invention comprises: a softening tank, which uses a weakly acidic cation exchange resin to soften raw water containing hardness components to generate acidic soft water; a neutralization tank, which uses a weakly basic anion exchange resin to neutralize the pH of the acidic soft water that has passed through the softening tank to generate neutralized soft water; an electrolytic cell, which generates acidic electrolyzed water for regenerating the weakly acidic cation exchange resin and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin; and a control unit, which controls a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin. The control unit includes: an adsorption amount determination unit, which determines the amount of hardness component adsorbed to the soft water tank based on the hardness of the raw water, the amount of raw water passed into the soft water tank, and the hardness of the water after passing through the soft water tank; and a main regeneration time calculation unit, which calculates the main regeneration time required for the regeneration process required to remove the hardness component based on the hardness component adsorption amount. The control unit determines the time consumed by the regeneration process based on the comparison between a specified reference time and the main regeneration time.

[0015] Moreover, as a softening device for coping with the second problem, the softening device of the present invention comprises: a softening tank, which uses a weakly acidic cation exchange resin to soften raw water containing hardness components to generate acidic soft water; a neutralization tank, which uses a weakly basic anion exchange resin to neutralize the pH of the acidic soft water that has passed through the softening tank to generate neutralized soft water; an electrolytic cell, which generates acidic electrolyzed water and alkaline electrolyzed water; and a control unit, which controls a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin. The control unit includes: a hardness storage unit that stores the hardness component concentration of raw water containing hardness components; an adsorption amount calculation unit that calculates the amount of ions adsorbed to at least one of the soft water tank and the neutralization tank based on the hardness component concentration of the raw water, the amount of raw water passed into the soft water tank, and the hardness of the water after passing through the soft water tank; a removal amount calculation unit that calculates the amount of ions that can be removed from at least one of the soft water tank and the neutralization tank based on the amount of hydrogen ions in the acidic electrolyzed water and the amount of hydroxide ions in the alkaline electrolyzed water obtained by operating the electrolytic cell for a specified time; and a process management unit that implements a regeneration process based on a comparison between the ion adsorption amount and the ion removal amount.

[0016] According to the water softening device of the present invention, it is possible to provide a water softening device that solves at least one of the first and second problems described above and can suppress a decrease in the water softening performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a conceptual diagram showing the structure of the water softening device according to the first embodiment.

[0018] Figure 21 is a diagram showing the structure of a water softening flow path of the water softening device according to the first embodiment.

[0019] Figure 3 It is a structural diagram showing a regeneration circulation flow path of a softening tank and a regeneration circulation flow path of a neutralization tank in a water softening device according to a first embodiment.

[0020] Figure 4 It is a structural diagram showing a regeneration flow path cleaning flow path of the water softening device according to the first embodiment.

[0021] Figure 5 It is a structural diagram showing the electrolytic cell cleaning flow path of the water softening device according to the first embodiment.

[0022] Figure 6 It is a structural diagram showing a capture unit cleaning flow path of the water softening device according to the first embodiment.

[0023] Figure 7 It is a diagram showing a control method of the water softening device according to the first embodiment.

[0024] Figure 8 This is a functional block diagram of the water softening device according to the first embodiment.

[0025] Fig. 9 This is a schematic diagram showing the resin regeneration rate and the reaction exchange efficiency along with the passage of regeneration time in the water softening device according to the first embodiment.

[0026] Fig.10 This is a conceptual diagram showing the structure of a water softening device according to a second embodiment.

[0027] Fig.11 It is a structural diagram showing a water softening flow path of a water softening device according to a second embodiment.

[0028] Fig.12 It is a structural diagram showing a regeneration circulation flow path of a softening tank and a regeneration circulation flow path of a neutralization tank in a water softening device according to a second embodiment.

[0029] Fig.13 It is a diagram showing the structure of a regeneration flow path cleaning flow path of a water softening device according to a second embodiment.

[0030] Fig.14 It is a structural diagram showing an electrolytic cell cleaning flow path of a water softening device according to a second embodiment.

[0031] Fig.15 It is a diagram showing the structure of a capture unit washing flow path of a water softening device according to a second embodiment.

[0032] Fig.16 This is a functional block diagram of the water softening device according to the second embodiment.

[0033] Fig.17 It is a diagram showing a control method of the water softening device according to the second embodiment.

[0034] Fig.18 This is a flowchart of the regeneration time determination method of the water softening device according to the second embodiment.

[0035] Fig.19 This is a conceptual diagram showing the structure of a water softening device according to a third embodiment.

[0036] Fig. 20 It is a structural diagram showing a water softening flow path of a water softening device according to a third embodiment.

[0037] Fig.21 It is a structural diagram showing a regeneration circulation flow path of a softening tank and a regeneration circulation flow path of a neutralization tank in a water softening device according to a third embodiment.

[0038] Fig. 22 This is a functional block diagram of a water softening device according to a third embodiment.

[0039] Fig.23 It is a diagram showing a control method of the water softening device according to the third embodiment.

[0040] Fig.24 This is a flowchart showing a control method of the water softening device according to the third embodiment. DETAILED DESCRIPTION

[0041] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiments are examples of specific implementations of the present invention and do not limit the technical scope of the present invention. In addition, the figures described in the embodiments are schematic figures, and the size and thickness ratios of the components in the figures do not necessarily reflect the actual size ratios.

[0042] (First embodiment)

[0043] Reference Figure 1 A water softening device 1 according to a first embodiment of the present invention will be described. Figure 1 1 is a conceptual diagram showing the structure of a water softening device 1 according to a first embodiment of the present invention. Figure 1 , each element of the water softening device 1 is conceptually shown.

[0044] <1. Overall structure>

[0045] The softening device 1 is a device for generating neutral soft water from raw water containing hardness components supplied from the outside. It should be noted that raw water refers to water (treatment target water) introduced into the device from the inlet 2, such as city water or well water. Raw water contains hardness components (such as calcium ions or magnesium ions). By using the softening device 1 to perform softening treatment, neutral soft water with reduced hardness can be obtained, and soft water can be used even in areas where the hardness of raw water is high.

[0046] Specifically, if Figure 1 As shown, the water softening device 1 includes an inlet 2 , a softening tank, a neutralization tank, a water intake port 7 , a regeneration device 8 , and a control unit 15 .

[0047] The water softening device 1 includes a drain port 13 , a plurality of on-off valves (on-off valves 18 to 23 ), and a plurality of flow path switching valves (flow path switching valves 24 to 27 ). Details of these will be described later.

[0048] <2. Inlet and water intake>

[0049] The inlet 2 is connected to a raw water supply source and is an opening for introducing raw water into the water softening device 1 .

[0050] The water intake port 7 is an opening for supplying softened water flowing through the water softening device 1 to the outside of the device. In the water softening device 1, softened water can be taken out from the water intake port 7 by the pressure of raw water flowing in from the inlet port 2.

[0051] In the softening process of the softening treatment in the softening device 1, raw water supplied from the outside flows in the order of the inlet 2, the flow path 28, the first soft water tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second soft water tank 5, the flow path 31, the second neutralization tank 6, the flow path 32 and the water intake 7, and is discharged as neutral soft water.

[0052] <3. Soft water tank>

[0053] The soft water tank (the first soft water tank 3 and the second soft water tank 5) softens raw water containing hardness components under the action of the weakly acidic cation exchange resin 33. Specifically, in the soft water tank, cations (calcium ions or magnesium ions) as hardness components contained in the circulating water (raw water) are exchanged with hydrogen ions, so that the hardness of the raw water is reduced and the raw water is softened. In the softening device 1 of the present embodiment, the first soft water tank 3 and the second soft water tank 5 are provided as soft water tanks.

[0054] The first soft water tank 3 softens the raw water flowing in from the inlet 2. The first soft water tank 3 includes a flow path switching valve 24. Details of the flow path switching valve will be summarized and described later.

[0055] The second soft water tank 5 softens the water that has flowed through the first neutralization tank 4 described later. The second soft water tank 5 includes a flow path switching valve 26 .

[0056] The first soft water tank 3 and the second soft water tank 5 are respectively filled with weakly acidic cation exchange resin 33 .

[0057] The weakly acidic cation exchange resin 33 is an ion exchange resin having hydrogen ions at the ends of the functional groups. The weakly acidic cation exchange resin 33 adsorbs cations (calcium ions or magnesium ions) as hardness components contained in the raw water passed through, and releases hydrogen ions. The soft water treated by the weakly acidic cation exchange resin 33 contains a large amount of hydrogen ions released in exchange with the hardness components. That is, the soft water flowing out of the first soft water tank 3 and the second soft water tank 5 is soft water (acidic soft water) that contains a large amount of hydrogen ions and is acidified.

[0058] Since the functional groups of the weakly acidic cation exchange resin 33 have hydrogen ions at their terminals, the weakly acidic cation exchange resin 33 can be regenerated using acidic electrolyzed water in the regeneration treatment described below. At this time, the cations taken in as hardness components during the water softening treatment are released from the weakly acidic cation exchange resin 33.

[0059] There is no particular limitation on the weakly acidic cation exchange resin 33, and a general-purpose material can be used. For example, a material having a carboxyl group (-COOH) as an exchange group can be used. In addition, a hydrogen ion (H ＋ ) can also become metal ions or ammonium ions (NH4 ＋ ) and other cations.

[0060] <4. Neutralization tank>

[0061] The neutralization tank (the first neutralization tank 4 and the second neutralization tank 6) neutralizes the pH (hydrogen ion concentration index) of the soft water (acidified soft water) containing hydrogen ions discharged from the soft water tank under the action of the weakly basic anion exchange resin 34, and becomes neutral soft water. Specifically, the neutralization tank adsorbs hydrogen ions contained in the soft water from the soft water tank together with anions, so that the pH of the soft water increases and can become neutral soft water. In the softening water device 1 in this embodiment, the first neutralization tank 4 and the second neutralization tank 6 are provided as neutralization tanks.

[0062] The first neutralization tank 4 neutralizes the acidic soft water flowing through the first soft water tank 3. The first neutralization tank 4 includes a flow path switching valve 25.

[0063] The second neutralization tank 6 neutralizes the acidic soft water flowing through the second soft water tank 5. The second neutralization tank 6 includes a flow path switching valve 27.

[0064] The first neutralization tank 4 and the second neutralization tank 6 are respectively filled with a weakly basic anion exchange resin 34 .

[0065] The weakly basic anion exchange resin 34 neutralizes hydrogen ions contained in the water passed therethrough to generate neutral water. The weakly basic anion exchange resin 34 can be regenerated using alkaline electrolyzed water in a regeneration process described later.

[0066] The weakly basic anion exchange resin 34 is not particularly limited, and a general-purpose material can be used. For example, a material in a free base form can be mentioned.

[0067] <5. Regeneration device>

[0068] The regeneration device 8 is a device for regenerating the weakly acidic cation exchange resin 33 filled in the first soft water tank 3 and the second soft water tank 5 and regenerating the weakly basic anion exchange resin 34 filled in the first neutralization tank 4 and the second neutralization tank 6 .

[0069] The regeneration device 8 includes an electrolytic cell 9, a capture unit 10, a first water pump 11, and a second water pump 12. In addition, the regeneration device 8 is connected to the second soft water tank 5, the second neutralization tank 6, the flow path 28, and the flow path 29, respectively, with a first supply flow path 35, a second supply flow path 36, a first recovery flow path 37, and a second recovery flow path 38. Details of each flow path are described later. It should be noted that the first supply flow path 35, the second supply flow path 36, the first recovery flow path 37, the second recovery flow path 38, the neutralization tank bypass flow path 42, and the soft water tank bypass flow path 44 form the soft water tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40 described later.

[0070] <5.1 Electrolytic Cell>

[0071] The electrolytic tank 9 generates and discharges acidic electrolytic water and alkaline electrolytic water by electrolyzing the incoming water (water supplied from the inlet 2) using a pair of electrodes 41 (electrode 41a and electrode 41b) provided inside. More specifically, at the electrode 41a which becomes the anode during electrolysis in the regeneration process, hydrogen ions are generated by electrolysis, and acidic electrolytic water is generated. In addition, at the electrode 41b which becomes the cathode during electrolysis in the regeneration process, hydroxide ions are generated by electrolysis, and alkaline electrolytic water is generated. In addition, the electrolytic tank 9 supplies the acidic electrolytic water to the first soft water tank 3 and the second soft water tank 5 via the first supply flow path 35 and the neutralization tank bypass flow path 42, and supplies the alkaline electrolytic water to the first neutralization tank 4 and the second neutralization tank 6 via the second supply flow path 36 and the soft water tank bypass flow path 44. The acidic electrolyzed water generated by the electrolytic cell 9 is used in the regeneration of the weakly acidic cation exchange resin 33 in the first soft water tank 3 and the second soft water tank 5, and the alkaline electrolyzed water generated by the electrolytic cell 9 is used in the regeneration of the weakly basic anion exchange resin 34 in the first neutralization tank 4 and the second neutralization tank 6, as described later. It should be noted that the electrolytic cell 9 is configured so that the power supply state of the pair of electrodes 41 can be controlled by the control unit 15 described later.

[0072] <5.2 Water supply pump>

[0073] The first water pump 11 is used to pump acidic electrolyzed water through the soft water tank regeneration circulation flow path 39 (see FIG. 1 ) during the regeneration process performed by the regeneration device 8. Figure 3 ) circulation device. The first water supply pump 11 is provided in the first recovery flow path 37 connecting the first soft water tank 3 and the electrolytic tank 9. The reason for such a configuration is that it is easy to circulate the acidic electrolyzed water in the soft water tank regeneration circulation flow path 39 using only the first water supply pump 11.

[0074] The second water pump 12 is used to make the alkaline electrolyzed water flow through the neutralization tank regeneration circulation flow path 40 (see Figure 3 The second water pump 12 is provided in the second recovery flow path 38 connecting the first neutralization tank 4 and the electrolytic tank 9. The reason for such a configuration is that it is easy to circulate the alkaline electrolyzed water in the neutralization tank regeneration circulation flow path 40 using only the second water pump 12.

[0075] The first water pump 11 and the second water pump 12 are connected to a control unit 15 to be described later in a wireless or wired manner so as to be communicable.

[0076] <5.3 Capture part>

[0077] The capturing unit 10 is provided in the second supply flow path 36 which connects the electrolytic tank 9 and the second neutralization tank 6 in communication with each other.

[0078] The capture unit 10 captures the precipitate contained in the alkaline electrolyzed water sent from the electrolytic cell 9. The precipitate refers to the reaction product generated by the reaction of the cations, that is, the hardness components, released from the first soft water tank 3 and the second soft water tank 5 during the regeneration process in the electrolytic cell 9 with the alkaline electrolyzed water. More specifically, during the electrolysis of water in the electrolytic cell 9, the hardness components (for example, calcium ions or magnesium ions) released from the first soft water tank 3 and the second soft water tank 5 during the regeneration process move to the cathode (electrode 41b) side. Since alkaline electrolyzed water is generated on the cathode side, the hardness components react with the alkaline electrolyzed water to form precipitates. For example, when the hardness component is calcium ion, it is mixed with the alkaline electrolyzed water to cause a reaction to produce calcium carbonate or a reaction to produce calcium hydroxide. And the precipitate from the hardness component is captured as a precipitate by the capture unit 10 provided in the second supply flow path 36. The precipitate from the hardness component is captured by the capture unit 10, so that the precipitate can be prevented from flowing into the second neutralization tank 6 and accumulating. Therefore, when the softening treatment is restarted after the regeneration treatment is completed, the hardness of the soft water sent from the second neutralization tank 6 can be prevented from increasing due to the ionization of the precipitate accumulated in the second neutralization tank 6 and the hydrogen ions released from the first soft water tank 3 and the second soft water tank 5.

[0079] In addition, during the regeneration process, the alkaline electrolyzed water from which the precipitate from the hardness component has passed through the capture unit 10 is electrolyzed again by the electrolytic cell 9 after flowing through the second neutralization tank 6 and the first neutralization tank 4, and is again supplied as alkaline electrolyzed water to the regeneration of the weakly basic anion exchange resin 34. At this time, the acidic electrolyzed water contains less hardness components than when the capture unit 10 is not provided. That is, by capturing the precipitate with the capture unit 10, the hardness of the acidic electrolyzed water is reduced, so that the hardness components flowing into the first soft water tank 3 and the second soft water tank 5 can be reduced, and the reduction in the regeneration efficiency of the weakly acidic cation exchange resin 33 can be suppressed.

[0080] It should be noted that “the hardness component reacts” includes not only the state in which all the hardness components react, but also the state in which unreacted components or components that do not exceed the solubility product are included.

[0081] The capturing unit 10 may be in any form as long as it can separate the precipitate produced by the reaction of the hardness component and the alkaline electrolyzed water. For example, a box-type filter, a filter layer using a granular filter material, a cyclone-type solid-liquid separator, a hollow fiber membrane, etc. may be used.

[0082] A cartridge filter is a generally used mechanism for the capturing unit 10. The cartridge filter may be a depth filter such as a wire wound filter, a surface filter such as a pleated filter or a membrane filter, or a combination of these.

[0083] The capturing unit 10 includes an on-off valve 22 and a capturing unit drain port 14 .

[0084] The on-off valve 22 is a valve for controlling drainage from the capture unit 10, and is provided, for example, at the lower portion of the capture unit 10. By opening the on-off valve 22, water in the capture unit 10 can be drained from the capture unit drainage port 14 to the outside of the device.

[0085] The capture unit drain port 14 is an opening for draining water in the capture unit 10 to the outside of the device. By opening the on-off valve 22 provided upstream of the capture unit drain port 14, the water in the capture unit 10 can be drained to the outside of the device from the capture unit drain port 14.

[0086] <6. On / off valve and flow path switching valve>

[0087] A plurality of on-off valves (on-off valves 18 to 23 ) are provided in each flow path, and switch between an “open” state and a “closed” state in each flow path.

[0088] The plurality of on-off valves (on-off valve 18 , on-off valve 19 , on-off valve 21 , and on-off valve 23 ) start or stop the flow of water to each flow path by opening and closing the valves.

[0089] The on-off valve 20 and the on-off valve 22 are opened during the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process described later, and the regeneration circulation water is discharged to the outside of the device.

[0090] A plurality of flow path switching valves (flow path switching valves 24 to 27) are respectively provided in the first soft water tank 3, the first neutralization tank 4, the second soft water tank 5, and the second neutralization tank 6. The plurality of flow path switching valves each have three openings. The first opening is an inflow and outflow port through which water can flow in and out, the second opening is an inflow port that does not function as an outflow port but functions as an inflow port, and the third opening is an outflow port that does not function as an inflow port but functions as an outflow port. The plurality of flow path switching valves are each always "open" at the inflow and outflow ports, and depending on the direction of water flow, when either the inflow port or the outflow port is "open", the other is "closed". By providing the flow path switching valves 24 to 27, the number of on-off valves required for each flow path in the water softening device 1 can be reduced, and the cost of the water softening device 1 can be reduced.

[0091] In addition, the plurality of on-off valves (on-off valves 18 to 23 ) and the plurality of flow path switching valves (flow path switching valves 24 to 27 ) are respectively connected to a control unit 15 to be described later in a wireless or wired manner so as to be communicable.

[0092] <7. Drainage outlet>

[0093] The drain port 13 is an opening provided at the end of the drain flow path 54, and is an opening for discharging water in the device to the outside of the device during the regeneration path cleaning process and the electrolytic cell cleaning process. An on-off valve 20 is provided upstream of the drain port 13, and by opening the on-off valve 20, water can be discharged from the drain port 13.

[0094] <8.Flow path>

[0095] The bypass flow path 53 is a flow path connecting the inlet 2 and the water intake port 7, and the flow path is provided with an on-off valve 18. Through the bypass flow path 53, the user of the water softening device 1 can obtain raw water from the water intake port 7 regardless of the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture part cleaning process.

[0096] <9. Water softening flow path>

[0097] Reference Figure 2 The softening flow path 43 formed during the water softening step of the water softening device 1 will be described. Figure 2 1 is a diagram showing the structure of the water softening flow path 43 of the water softening device 1 .

[0098] Softening flow path 43 (in Figure 2 43 is a flow path for softening raw water. The raw water flowing through the softening flow path 43 becomes neutral soft water and is discharged from the water intake port 7 to the outside of the device.

[0099] The softening water flow path 43 is formed by the inlet 2 , the flow path 28 , the first softening water tank 3 , the flow path 29 , the first neutralization tank 4 , the flow path 30 , the second softening water tank 5 , the flow path 31 , the second neutralization tank 6 , the flow path 32 , and the water intake port 7 .

[0100] The flow path 28 is a flow path connected from the inlet 2 to the first soft water tank 3. That is, the flow path 28 is a flow path that guides the raw water containing hardness components from the inlet 2 to the first soft water tank 3.

[0101] The flow path 29 is a flow path connecting the first soft water tank 3 to the first neutralization tank 4. That is, the flow path 29 is a flow path for guiding the water softened in the first soft water tank 3 to the first neutralization tank 4.

[0102] The flow path 30 is a flow path connecting the first neutralization tank 4 to the second soft water tank 5. That is, the flow path 30 is a flow path for guiding the water neutralized in the first neutralization tank 4 to the second soft water tank 5.

[0103] The flow path 31 is a flow path connecting the second soft water tank 5 to the second neutralization tank 6. That is, the flow path 31 is a flow path for guiding the water softened in the second soft water tank 5 to the second neutralization tank 6.

[0104] The flow path 32 is a flow path connected from the second neutralization tank 6 to the water intake port 7. That is, the flow path 32 is a flow path that guides the softened raw water from the second neutralization tank 6 to the water intake port 7.

[0105] like Figure 2 As shown, an on-off valve 19 is provided on the flow path 28 on the downstream side of the inlet 2 and the upstream side of the first soft water tank 3. In addition, an on-off valve 18 is provided on the bypass flow path 53. And, by closing the on-off valve 18 and opening the on-off valve 19, the first soft water tank 3 is connected to the inlet 2. In addition, the flow path switching valve 24 is switched to connect the first soft water tank 3 with the first neutralization tank 4, the flow path switching valve 25 is switched to connect the first neutralization tank 4 with the second soft water tank 5, the flow path switching valve 26 is switched to connect the second soft water tank 5 with the second neutralization tank 6, and the flow path switching valve 27 is switched to connect the second neutralization tank 6 with the water intake 7. Thus, a softening water flow path 43 is formed which connects the inlet 2 to the flow path 28, the first softening tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second softening tank 5, the flow path 31, the second neutralization tank 6, the flow path 32 and the water intake 7. At this time, the on-off valve 20, the on-off valve 21 and the on-off valve 23 are closed.

[0106] <10. Regeneration circulation flow path>

[0107] Next, refer to Figure 3 The softening tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40 formed during the regeneration process of the water softening device 1 will be described. Figure 3 1 is a diagram showing the structure of the softening tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40 of the water softening device 1 .

[0108] First, the soft water tank regeneration circulation flow path 39 will be described.

[0109] The soft water tank regeneration circulation flow path 39 is a flow path for acidic electrolyzed water to flow during the regeneration process to regenerate the first soft water tank 3 and the second soft water tank 5, and is as follows: Figure 3 As indicated by (white arrows), the water delivered by the first water delivery pump 11 flows through the electrolytic tank 9 , the second soft water tank 5 , and the first soft water tank 3 and returns to the electrolytic tank 9 for circulation.

[0110] Specifically, the soft water tank regeneration circulation flow path 39 is composed of the first supply flow path 35 connecting the electrolytic tank 9 , the second soft water tank 5 , the first soft water tank 3 and the first water supply pump 11 , the neutralization tank bypass flow path 42 and the first recovery flow path 37 .

[0111] The first supply flow path 35 is a flow path that is connected from the downstream side of the electrolytic cell 9 to the downstream side of the second soft water tank 5 , and is a flow path that supplies acidic electrolyzed water from the electrolytic cell 9 to the second soft water tank 5 .

[0112] The neutralization tank bypass flow path 42 is a flow path that bypasses the first neutralization tank 4 and communicates from the upstream side of the second soft water tank 5 to the downstream side of the first soft water tank 3 , and is a flow path that supplies acidic electrolyzed water from the second soft water tank 5 to the first soft water tank 3 .

[0113] The first recovery flow path 37 is a flow path connected to the electrolytic cell 9 from the upstream side of the first soft water tank 3, and is a flow path for recovering the acidic electrolyzed water containing hardness components that has passed through the first soft water tank 3 and the second soft water tank 5 to the electrolytic cell 9. The first recovery flow path 37 is provided with a first water supply pump 11.

[0114] In addition, the soft water tank regeneration circulation flow path 39 is a flow path that introduces the acidic electrolyzed water sent out from the electrolytic tank 9 from the downstream sides of the first soft water tank 3 and the second soft water tank 5, respectively, and causes the acidic electrolyzed water to flow out from the upstream sides of the first soft water tank 3 and the second soft water tank 5, respectively, where the adsorption amount of hardness components is greater than that of the downstream side of the soft water tank.

[0115] It should be noted that in the above description, the downstream side (or upstream side) refers to the downstream side (or upstream side) in the flow path during the water softening treatment.

[0116] Next, the neutralization tank regeneration circulation flow path 40 will be described.

[0117] The neutralization tank regeneration circulation flow path 40 is a flow path for alkaline electrolyzed water to flow during the regeneration process to regenerate the first neutralization tank 4 and the second neutralization tank 6, and is as follows: Figure 3 As indicated by (black arrow), the water sent out by the second water sending pump 12 flows through the electrolytic tank 9 , the second neutralization tank 6 , and the first neutralization tank 4 and returns to the electrolytic tank 9 for circulation.

[0118] Specifically, the neutralization tank regeneration circulation flow path 40 is composed of the second supply flow path 36 , the soft water tank bypass flow path 44 , and the second recovery flow path 38 connecting the electrolytic tank 9 , the second neutralization tank 6 , the first neutralization tank 4 , and the second water supply pump 12 .

[0119] The second supply flow path 36 is a flow path that connects from the downstream side of the electrolytic cell 9 to the downstream side of the second neutralization tank 6, and is a flow path for supplying alkaline electrolyzed water from the electrolytic cell 9 to the second neutralization tank 6. The second supply flow path 36 is provided with the capture unit 10, the on-off valve 21, and the on-off valve 23.

[0120] The soft water tank bypass flow path 44 is a flow path that bypasses the second soft water tank 5 and communicates from the upstream side of the second neutralization tank 6 to the downstream side of the first neutralization tank 4 , and is a flow path that supplies alkaline electrolyzed water from the second neutralization tank 6 to the first neutralization tank 4 .

[0121] The second recovery flow path 38 is a flow path connected to the electrolytic cell 9 from the upstream side of the first neutralization tank 4, and is a flow path for recovering the alkaline electrolyzed water that has passed through the first neutralization tank 4 and the second neutralization tank 6 to the electrolytic cell 9. The second recovery flow path 38 is provided with a second water supply pump 12.

[0122] <11. Regeneration flow path and cleaning flow path>

[0123] Next, refer to Figure 4 The regeneration flow path cleaning flow path 45 formed during the regeneration flow path cleaning step of the water softening device 1 will be described. Figure 4 1 is a diagram showing the structure of the regeneration flow path cleaning flow path 45 of the water softening device 1 .

[0124] The regeneration flow path cleaning flow path 45 is a flow path for discharging high hardness water remaining in the flow path to the outside of the device without flowing into the first neutralization tank 4 and the second neutralization tank 6 during the regeneration flow path cleaning process described later. The regeneration flow path cleaning flow path 45 includes a first drainage flow path 46 and a second drainage flow path 47.

[0125] The first drainage flow path 46 is composed of Figure 4 As shown by (white arrow), the first water pump 11, the electrolytic cell 9, the on-off valve 20 and the drain port 13 are connected from the inlet 2. Specifically, the first drain flow path 46 is a flow path that allows the raw water flowing in from the inlet 2 to flow in the order of the flow path 28, the first recovery flow path 37, the first water pump 11, the electrolytic cell 9, the drain flow path 54, the on-off valve 20 and the drain port 13.

[0126] The drainage flow path 54 is a flow path connected to the first supply flow path 35 at one end, and is a flow path connected to the drain port 13 at the other end. The drainage flow path 54 is provided with an on-off valve 20, and the water in the flow path can be discharged to the outside of the device by opening the on-off valve 20, and the drainage from the drain port 13 can be stopped by closing the on-off valve 20.

[0127] The second drainage flow path 47 is composed of Figure 4 As shown by the black arrow, the flow paths connected from the inlet 2 to the first soft water tank 3, the second soft water tank 5, the on-off valve 20 and the drain 13 are formed. Specifically, the second drain flow path 47 is a flow path that allows the raw water flowing in from the inlet 2 to flow in the order of the flow path 28, the first soft water tank 3, the neutralization tank bypass flow path 42, the second soft water tank 5, the first supply flow path 35, the on-off valve 20 and the drain 13.

[0128] It should be noted that it is preferable to control the flow rate of water flowing through the second drainage flow path 47 to be greater than the flow rate of water flowing through the first drainage flow path 46. As a result, the high-hardness water in the second drainage flow path 47, which is the flow path of the soft water tank used in the water softening process, can be preferentially replaced with raw water. Therefore, the influence of high-hardness water at the start of the water softening process can be suppressed.

[0129] <12. Electrolytic cell cleaning flow path>

[0130] Next, refer to Figure 5 The electrolytic cell cleaning flow path 49 formed during the electrolytic cell cleaning step of the water softening device 1 will be described. Figure 5 1 is a diagram showing the structure of the electrolytic cell cleaning flow path 49 of the water softening device 1 .

[0131] The electrolytic tank cleaning flow path 49 is a flow path for removing precipitates caused by hardness components in the electrolytic tank 9 and the neutralization tank regeneration circulation flow path 40 during the electrolytic tank cleaning step described below. The electrolytic tank cleaning flow path 49 includes a first drain flow path 46 and a third drain flow path 50 .

[0132] The third drainage flow path 50 is composed of Figure 5 As shown by the black arrow, the third drainage flow path 50 is composed of the flow paths connected from the inlet 2 to the first soft water tank 3, the second water supply pump 12, the electrolytic cell 9, the on-off valve 21, the capture unit 10, the on-off valve 22, and the capture unit drain port 14. Specifically, the third drainage flow path 50 is a flow path that allows the raw water flowing in from the inlet 2 to flow in the order of the flow path 28, the first soft water tank 3, the flow path 29, the second recovery flow path 38, the second water supply pump 12, the electrolytic cell 9, the second supply flow path 36, the on-off valve 21, the capture unit 10, and the on-off valve 22, and is discharged from the capture unit drain port 14 to the outside of the device.

[0133] More specifically, in the third drainage flow path 50, the raw water flowing in from the inlet 2 flows into the first soft water tank 3 through the flow path 28 and becomes acidic soft water. The generated acidic soft water flows into the electrolytic cell 9 through the flow path 29 and the second recovery flow path 38 by the second water supply pump 12. Thereafter, the acidic soft water flows through the second supply flow path 36 in the order of the on-off valve 21, the capture part 10, and the on-off valve 22, so that the acidic soft water dissolves the precipitate in the capture part 10 and is discharged from the capture part drain port 14 to the outside of the device.

[0134] <13. Capture unit cleaning flow path>

[0135] Next, refer to Figure 6 The capturing unit cleaning flow path 51 formed during the capturing unit cleaning step of the water softening device 1 will be described. Figure 6 1 is a diagram showing the structure of the capture unit washing flow path 51 of the water softening device 1 .

[0136] The capturing part cleaning flow path 51 is a flow path for removing precipitates derived from hardness components precipitated in the capturing part 10 during a capturing part cleaning step described later. The capturing part cleaning flow path 51 includes a fourth drain flow path 52.

[0137] like Figure 6 As shown, the capture part cleaning flow path 51 is composed of the flow paths connected from the inlet 2 to the first soft water tank 3, the first neutralization tank 4, the second soft water tank 5, the second neutralization tank 6, the capture part 10 and the capture part drain port 14. Specifically, the capture part cleaning flow path 51 is a flow path that allows the raw water flowing in from the inlet 2 to flow in the order of the flow path 28, the first soft water tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second soft water tank 5, the flow path 31, the second neutralization tank 6, the second supply flow path 36, the on-off valve 23, the capture part 10 and the on-off valve 22, and is discharged from the capture part drain port 14 to the outside of the device.

[0138] <14. Raw water hardness measuring section and soft water hardness measuring section>

[0139] The raw water hardness measuring unit 60 and the soft water hardness measuring unit 61 (see Figure 1 ) Determine the hardness component in water during the softening process.

[0140] The raw water hardness measuring unit 60 is provided in the flow path 28 connecting the inlet 2 and the first soft water tank 3 , and measures the hardness of raw water flowing through the flow path 28 (ie, the hardness of raw water before softening).

[0141] The soft water hardness measuring unit 61 is provided in the flow path 32 connecting the second neutralization tank 6 and the water intake 7 , and measures the hardness of soft water flowing in the flow path 32 (ie, the hardness of soft water softened by the soft water tank and the neutralization tank).

[0142] Note that, as the raw water hardness measuring unit 60 and the soft water hardness measuring unit 61 , general-purpose components may be used. For example, a detector for measuring the electrical conductivity of liquid or a detector for measuring the amount of TDS (Total Dissolved Solid) contained in water may be used.

[0143] <15. Flow rate measurement unit>

[0144] The flow rate measuring unit 62 (see Figure 1) is provided in the flow path 32 that connects the second neutralization tank 6 and the water intake 7, and measures the flow rate of water flowing in the flow path 32. It should be noted that in the softening process, the water flowing into the first soft water tank 3 is not distributed but circulates in the first neutralization tank 4, the second soft water tank 5 and the second neutralization tank 6. Therefore, the amount of water flowing in the flow path before and after softening can be regarded as substantially the same. That is, the flow rate of water measured by the flow measuring unit 62 can be regarded as the amount of raw water flowing before softening and the amount of soft water flowing after softening.

[0145] <16. First ion concentration measuring unit and second ion concentration measuring unit>

[0146] The first ion concentration measuring unit 56 (see Figure 1 ) is provided on the first supply flow path 35 to measure the ion concentration of the acidic electrolyzed water flowing out of the electrolytic cell 9 and before flowing into the soft water tank (second soft water tank 5) during the resin regeneration process.

[0147] The second ion concentration measuring unit 57 included in the water softening device 1 is provided in the first recovery flow path 37 and measures the ion concentration of the acidic electrolyzed water flowing out of the soft water tank (first soft water tank 3 ) during the resin regeneration step.

[0148] The ion concentration of the acidic electrolyzed water measured by the first ion concentration measuring unit 56 and the second ion concentration measuring unit 57 may be a pH value or a TDS amount. As each measuring unit, a general-purpose pH meter or a TDS detector can be used.

[0149] It should be noted that the ion concentration of the acidic electrolyzed water measured by the first ion concentration measuring unit 56 and the second ion concentration measuring unit 57 may be measured in real time during the resin regeneration process or may be measured at a set time interval, for example, at 30-minute intervals.

[0150] <17. Control Department>

[0151] Reference Figure 8 The functions of the control unit 15 according to the present embodiment will be described. Figure 8 This is a functional block diagram of the water softening device 1 according to the first embodiment.

[0152] The control unit 15 controls the execution of each process of the water softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capturing unit cleaning process, and controls switching between the processes.

[0153] The so-called control of switching between the various processes specifically refers to the switching from the softening process to the regeneration process, the switching from the regeneration process to the regeneration flow path cleaning process, the switching from the regeneration flow path cleaning process to the electrolytic cell cleaning process, the switching from the electrolytic cell cleaning process to the capture part cleaning process, and the switching from the capture part cleaning process to the softening process.

[0154] Furthermore, the control unit 15 controls the on-off valve 20 and the on-off valve 22 to control drainage during the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process.

[0155] Furthermore, the control unit 15 controls the flow path switching valves 24 to 27 , the on-off valve 18 , the on-off valve 19 , the on-off valve 21 , and the on-off valve 23 to switch the flow paths.

[0156] The control unit 15 includes an adsorption amount determination unit 55 , a storage unit 58 , and a calculation unit 59 .

[0157] The adsorption amount determination unit 55 can calculate the amount of hardness component adsorbed to the soft water tank based on the hardness of the raw water measured by the raw water hardness measurement unit 60, the hardness of the soft water measured by the soft water hardness measurement unit 61, and the flow rate of softened water measured by the flow rate measurement unit 62. Specifically, the hardness of the soft water measured by the soft water hardness measurement unit 61 is subtracted from the hardness of the raw water measured by the raw water hardness measurement unit 60, and the value calculated by the subtraction is multiplied by the flow rate of softened water measured by the flow rate measurement unit 62, thereby being able to calculate the amount of hardness component adsorption.

[0158] The storage unit 58 stores the first ion concentration information measured by the first ion concentration measuring unit 56, that is, the ion concentration information of the acidic electrolyzed water before it flows out of the electrolytic cell 9 and flows into the soft water tank in the resin regeneration process. In addition, the storage unit 58 similarly stores the second ion concentration information measured by the second ion concentration measuring unit 57, that is, the ion concentration information after the aforementioned acidic electrolyzed water flows into the soft water tank. It should be noted that the timing at which each ion concentration information is stored in the storage unit 58 corresponds to the timing at which each ion concentration information is measured in the first ion concentration measuring unit 56 or the second ion concentration measuring unit 57.

[0159] The calculation unit 59 calculates a reference difference value (differential ion concentration value) which is the difference between the first ion concentration information and the second ion concentration information stored in the storage unit 58. If the difference in pH value is considered as the difference value here, the difference value is the difference in hydrogen ion concentration before and after the soft water tank, and therefore represents the reaction amount in the exchange reaction between the hardness component adsorbed on the weakly acidic cation exchange resin 33 and the hydrogen ions in the acidic electrolyzed water. Thus, the exchange reaction efficiency of the hardness component and the hydrogen ion in a predetermined time can be calculated. Based on the exchange reaction efficiency calculated by the calculation unit 59, the control unit 15 determines whether to continue or end the regeneration process, and determines the operating status of the electrolytic cell 9.

[0160] The above is the structure of the water softening device 1.

[0161] Next, the operation of the water softening device 1 will be described.

[0162] <18. Water softening step, regeneration step, regeneration flow path cleaning step, electrolytic cell cleaning step, and capture unit cleaning step>

[0163] Next, refer to Figure 7 The water softening step, the regeneration step, the regeneration flow path cleaning step, the electrolytic cell cleaning step, and the capturing portion cleaning step of the water softening device 1 will be described. Figure 7 It is a diagram showing a state of the water softening device 1 during operation.

[0164] In the water softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process and the capture unit cleaning process, the control unit 15 performs the following steps: Figure 7 As shown, the on-off valves 18 to 23 , the flow path switching valves 24 to 27 , the electrode 41 of the electrolytic cell 9 , the first water supply pump 11 , and the second water supply pump 12 are switched and controlled so as to be in respective flow states.

[0165] here, Figure 7 The "on" in the figure indicates that the on-off valve is "open", the electrode 41 is energized, and the water pump is in operation. The blanks indicate that the on-off valve is "closed", the electrode 41 is not energized, and the water pump is stopped.

[0166] in addition, Figure 7 The phrase "from (the number of component A) to (the number of component B)" in the figure indicates that the flow path switching valve connects the flow paths in a direction in which water is fed from component A to component B. For example, the flow path switching valve 24 of the water softening process connects the flow paths in a manner that water can be fed from flow path 28 to flow path 29.

[0167] in addition, Figure 7The "toward (number of component C)" in the figure indicates a state where the flow path switching valve connects the flow path in a direction in which water may be supplied to component C. At this time, although the flow path is connected, it is difficult for water to flow in or out of the soft water tank or the neutralization tank in which the flow path switching valve is installed, so it is extremely difficult for water to be supplied from the flow path switching valve.

[0168] <18.1 Water Softening Process>

[0169] First, refer to Figure 2 as well as Figure 7 The column “during water softening” of FIG. 1 explains the operation during the water softening process performed by the water softening device 1 .

[0170] In the water softening device 1, as Figure 7 As shown, in the softening process, the on-off valve 19 provided in the flow path 28 is opened while the on-off valve 18 is closed. As a result, raw water containing hardness components flows in from the outside. The raw water flows in the first softening tank 3, the first neutralization tank 4, the second softening tank 5, and the second neutralization tank 6 in this order, so that in the softening device 1, softened water (neutral soft water) can be taken out from the water intake port 7.

[0171] At this time, the flow path switching valve 24 is in a connection state where water can be sent from the flow path 28 to the flow path 29, the flow path switching valve 25 is in a connection state where water can be sent from the flow path 29 to the flow path 30, the flow path switching valve 26 is in a connection state where water can be sent from the flow path 30 to the flow path 31, and the flow path switching valve 27 is in a connection state where water can be sent from the flow path 31 to the flow path 32. The on-off valves 20 to 23 are all in a closed state. In addition, the operation of the electrode 41 of the electrolytic cell 9, the first water pump 11, and the second water pump 12 is also stopped.

[0172] Through this control, Figure 1As shown, in the softening process, the raw water is supplied from the inlet 2 to the first soft water tank 3 through the flow path 28 under the pressure of the raw water flowing in from the outside. And the raw water supplied to the first soft water tank 3 flows through the weakly acidic cation exchange resin 33 provided in the first soft water tank 3. At this time, the cations as the hardness components in the raw water are adsorbed by the weakly acidic cation exchange resin 33, and hydrogen ions are released (ion exchange is performed). And by removing the cations from the raw water, the raw water is softened. The softened water contains a large amount of hydrogen ions that flow out in exchange with the hardness components, so it is acidified and becomes acidic water (first soft water) with a low pH. Here, when water containing a large amount of permanent hardness components (for example, sulfates such as calcium sulfate or chlorides such as magnesium chloride) as hardness components is softened, the pH is easily lowered than water containing a large amount of temporary hardness components (for example, carbonates such as calcium carbonate). Since water softening is difficult to proceed in a state where the pH is lowered, the water flowing through the first soft water tank 3 is passed through the first neutralization tank 4 to be neutralized.

[0173] The water softened in the first soft water tank 3 flows through the flow path 29 via the flow path switching valve 24 provided in the first soft water tank 3, and flows into the first neutralization tank 4. In the first neutralization tank 4, hydrogen ions contained in the softened water are adsorbed by the weakly basic anion exchange resin 34. That is, hydrogen ions are removed from the water softened in the first soft water tank 3, so the pH value that has been lowered rises and is neutralized. Therefore, compared with the case where the water softened in the first soft water tank 3 is softened in the second soft water tank 5 as it is, it is easy to make the softening treatment in the second soft water tank 5 progress.

[0174] The water neutralized by the first neutralization tank 4 (neutralized first soft water) flows through the flow path 30 via the flow path switching valve 25 provided in the first neutralization tank 4, and flows into the second soft water tank 5. In the second soft water tank 5, cations as hardness components are adsorbed by the weakly acidic cation exchange resin 33, and hydrogen ions are released. The second soft water tank 5 exchanges the hardness components that cannot be removed by the first soft water tank 3 with the hydrogen ions possessed by the weakly acidic cation exchange resin 33. That is, the water flowing into the second soft water tank 5 is further softened and becomes soft water (second soft water).

[0175] The second soft water flows through the flow path 31 via the flow path switching valve 26 provided in the second soft water tank 5, and flows into the second neutralization tank 6. In the second neutralization tank 6, the hydrogen ions contained in the second soft water flowing in are adsorbed by the weakly basic anion exchange resin 34. That is, the hydrogen ions are removed from the second soft water, and the pH value that has been lowered rises, and becomes neutral soft water (neutralized second soft water) that can be used as domestic water. The neutralized second soft water flows through the flow path switching valve 27 provided in the second neutralization tank 6, and is taken out from the water intake port 7.

[0176] That is, in the softening treatment, the raw water flows through the first softening tank 3, the first neutralization tank 4, the second softening tank 5, and the second neutralization tank 6 in this order. Thus, the raw water containing hardness components flows out of the first softening tank 3 before the pH of the raw water decreases due to the softening treatment in the first softening tank 3, is neutralized in the first neutralization tank 4, is softened in the second softening tank 5, and is neutralized in the second neutralization tank 6. Therefore, compared with the case where the softening tank and the neutralization tank are constituted by monomers, the pH of the water flowing in the softening tank can be suppressed from decreasing, that is, acidification, so that the hardness components are easily exchanged with the hydrogen ions held by the weakly acidic cation exchange resin 33 of the softening tank (particularly the second softening tank 5). Therefore, the softening performance can be improved.

[0177] Then, in the water softening device 1, when the time period determined by the control unit 15 comes or when the water softening process exceeds a constant water volume, the water softening process is terminated and the regeneration process is performed.

[0178] <18.2 Regeneration process>

[0179] Next, refer to Figure 3 as well as Figure 7 The column “at the time of regeneration” will sequentially describe the operations during the regeneration process performed by the regeneration device 8 of the water softening device 1 .

[0180] In the softening device 1, the first softening tank 3 and the second softening tank 5 filled with weakly acidic cation exchange resin 33 have a reduced or lost cation exchange capacity when used continuously. That is, after all the hydrogen ions of the functional groups of the cation exchange resin are exchanged with calcium ions or magnesium ions as hardness components, ion exchange cannot be performed. Even before all the hydrogen ions are exchanged with the hardness components, it is difficult for the ion exchange reaction to occur as the hydrogen ions decrease, so the softening performance is also reduced. When this state is reached, the hardness components are contained in the treated water. Therefore, in the softening device 1, it is necessary to perform a regeneration process of the first softening tank 3, the second softening tank 5, the first neutralization tank 4, and the second neutralization tank 6 using the regeneration device 8.

[0181] During the regeneration process, the control unit 15 closes the on-off valves 19, 20, and 22, and opens the on-off valves 18, 21, and 23. The control unit 15 makes the flow path switching valve 24 a connection state in which water can be delivered from the neutralization tank bypass flow path 42 to the first recovery flow path 37, makes the flow path switching valve 25 a connection state in which water can be delivered from the soft water tank bypass flow path 44 to the second recovery flow path 38, makes the flow path switching valve 26 a connection state in which water can be delivered from the first supply flow path 35 to the neutralization tank bypass flow path 42, and makes the flow path switching valve 27 a connection state in which water can be delivered from the second supply flow path 36 to the soft water tank bypass flow path 44. That is, the first soft water tank 3 and the second soft water tank 5 are in a connected state, and the first neutralization tank 4 and the second neutralization tank 6 are in a connected state. The control unit 15 stops the drainage of the drain port 13 and the capture unit drain port 14. As a result, as Figure 3 As shown in the figure, a soft water tank regeneration circulation flow path 39 and a neutralization tank regeneration circulation flow path 40 are formed respectively.

[0182] When the first water supply pump 11 and the second water supply pump 12 are operated, the acidic electrolyzed water and the alkaline electrolyzed water in the electrolytic tank 9 circulate in the soft water tank regeneration circulation flow path 39 and the neutralization tank regeneration circulation flow path 40, respectively.

[0183] In addition, the control unit 15 energizes the electrolytic cell 9 in such a manner that the anode has a higher potential than the cathode (positive electrolysis). Thus, during electrolysis, hydrogen ions are generated at the anode, and acidic electrolyzed water is generated near the anode. On the other hand, hydroxide ions are generated at the cathode, and alkaline electrolyzed water is generated near the cathode.

[0184] The acidic electrolyzed water generated in the electrolytic cell 9 flows through the first supply flow path 35 and is sent to the second soft water tank 5 through the flow path switching valve 26, and flows through the weakly acidic cation exchange resin 33 inside. In addition, the acidic electrolyzed water that has flowed through the second soft water tank 5 flows through the neutralization tank bypass flow path 42 and is sent to the first soft water tank 3 through the flow path switching valve 24, and flows through the weakly acidic cation exchange resin 33 inside. That is, by passing the acidic electrolyzed water into the weakly acidic cation exchange resin 33, the cations (hardness components) adsorbed on the weakly acidic cation exchange resin 33 and the hydrogen ions contained in the acidic electrolyzed water undergo an ion exchange reaction. As a result, the weakly acidic cation exchange resin 33 is regenerated.

[0185] Then, the acidic electrolyzed water flowing through the first soft water tank 3 contains cations and flows into the first recovery flow path 37. That is, the acidic electrolyzed water containing cations flowing through the weakly acidic cation exchange resin 33 is recovered to the electrolytic cell 9 through the first recovery flow path 37.

[0186] In this way, the soft water tank regeneration circulation flow path 39 is constructed to allow acidic electrolyzed water to flow from the downstream side of the second soft water tank 5, which is a soft water tank located at the most downstream relative to the inlet of raw water and has a weakly acidic cation exchange resin 33 that adsorbs less hardness components than the soft water tank on the upstream side, and to flow into the downstream side of the first soft water tank 3, which is located upstream and has a weakly acidic cation exchange resin 33 that adsorbs more hardness components than the second soft water tank 5.

[0187] That is, the soft water tank regeneration circulation flow path 39 is a flow path that allows the acidic electrolyzed water sent from the electrolytic tank 9 to flow through the second soft water tank 5, then be sent to the first soft water tank 3 through the neutralization tank bypass flow path 42, flow through the first soft water tank 3, and flow into the electrolytic tank 9 through the first recovery flow path 37. Thus, during the regeneration process, the acidic electrolyzed water discharged from the electrolytic tank 9 flows into the second soft water tank 5, which has a smaller adsorption amount of hardness components than the first soft water tank 3, and the acidic electrolyzed water containing hardness components is discharged from the second soft water tank 5 to the first soft water tank 3. In the regeneration of the weakly acidic cation exchange resin 33 of the second soft water tank 5, the consumption of hydrogen ions in the acidic electrolyzed water is less than that of the first soft water tank 3, so that the decrease in hydrogen ion concentration can be suppressed compared with the regeneration of the first soft water tank 3. Therefore, the acidic electrolyzed water containing a large amount of hydrogen ions flows into the first soft water tank 3, and the hardness components can be suppressed from being adsorbed again in the first soft water tank 3. Therefore, a decrease in the regeneration processing efficiency can be suppressed and the regeneration time can be shortened.

[0188] On the other hand, the alkaline electrolyzed water generated near the cathode of the electrolytic cell 9 flows through the second supply flow path 36 and the capture unit 10, and is sent to the second neutralization tank 6 via the flow path switching valve 27, and flows through the weakly basic anion exchange resin 34 inside. In addition, the alkaline electrolyzed water that has flowed through the second neutralization tank 6 flows through the soft water tank bypass flow path 44, and is sent to the first neutralization tank 4 via the flow path switching valve 25, and flows through the weakly basic anion exchange resin 34 inside. That is, by passing the alkaline electrolyzed water into the weakly basic anion exchange resin 34, the anions adsorbed on the weakly basic anion exchange resin 34 undergo an ion exchange reaction with the hydroxide ions contained in the alkaline electrolyzed water. As a result, the weakly basic anion exchange resin 34 is regenerated.

[0189] Then, the alkaline electrolyzed water flowing through the first neutralization tank 4 contains anions and flows into the second recovery flow path 38. That is, the alkaline electrolyzed water containing anions flowing through the weakly basic anion exchange resin 34 is recovered to the electrolytic tank 9 through the second recovery flow path 38.

[0190] In this way, the neutralization tank regeneration circulation flow path 40 is constructed to allow alkaline electrolyzed water to flow from the downstream side of the second neutralization tank 6, which is the neutralization tank located most downstream relative to the inlet of the raw water and has a weakly basic anion exchange resin 34 that adsorbs less anions than the neutralization tank on the upstream side, and to flow into the downstream side of the first neutralization tank 4, which is located upstream and has a weakly basic anion exchange resin 34 that adsorbs more anions than the second neutralization tank 6.

[0191] That is, the neutralization tank regeneration circulation flow path 40 is a flow path in which the alkaline electrolyzed water sent from the electrolytic tank 9 is sent to the first neutralization tank 4 by the soft water tank bypass flow path 44 after circulating in the second neutralization tank 6, circulates in the first neutralization tank 4, and flows into the electrolytic tank 9 via the second recovery flow path 38. Thus, during the regeneration process, the alkaline electrolyzed water flows into the second neutralization tank 6, in which the adsorption amount of anions is less than that of the first neutralization tank 4, and the alkaline electrolyzed water containing anions is discharged from the second neutralization tank 6 to the first neutralization tank 4. In the regeneration of the weakly basic anion exchange resin 34 of the second neutralization tank 6, the consumption of hydroxide ions in the alkaline electrolyzed water is less than that of the first neutralization tank 4, so the reduction of the hydroxide ion concentration can be suppressed compared with the regeneration of the first neutralization tank 4. Therefore, the alkaline electrolyzed water containing a large amount of hydroxide ions flows into the first neutralization tank 4, and the re-adsorption of anions in the first neutralization tank 4 can be suppressed. Therefore, a decrease in the regeneration processing efficiency can be suppressed and the regeneration time can be shortened.

[0192] In addition, in the neutralization tank regeneration circulation flow path 40, the alkaline electrolyzed water sent from the electrolytic tank 9 is introduced into the first neutralization tank 4 and the second neutralization tank 6 from the downstream side of each of the first neutralization tank 4 and the second neutralization tank 6, and flows out from the upstream side where the adsorption amount of anions in each neutralization tank is more than the downstream side. Thus, the alkaline electrolyzed water flows in from the downstream side where the adsorption amount of anion components is less, and the neutralization tank is regenerated. In the regeneration of the weakly basic anion exchange resin 34 on the downstream side, the consumption of hydroxide ions in the alkaline electrolyzed water is less than that on the upstream side, so the reduction of the hydroxide ion concentration of the alkaline electrolyzed water can be suppressed. Therefore, the anions contained in the alkaline electrolyzed water from the downstream side can be suppressed from being re-adsorbed on the upstream side. Therefore, the reduction of the regeneration treatment efficiency of the neutralization tank can be suppressed, and the regeneration time can be shortened. It should be noted that the downstream side refers to the downstream side in the flow path during the softening treatment.

[0193] In the present embodiment, the control unit 15 determines whether to continue or terminate the regeneration process based on the progress of the exchange reaction between the hardness component and the hydrogen ions in the weakly acidic cation exchange resin 33 .

[0194] In the regeneration process, the regeneration rate of the resin is not always proportional to the time elapsed from the start of the regeneration process. Fig. 9 Provide explanation. Fig. 9This is a schematic diagram showing the resin regeneration rate and reaction exchange efficiency of the water softening device 1 according to the first embodiment as the regeneration time passes. It should be noted that the regeneration time is the time elapsed from the start of the regeneration process, and it varies depending on the conditions such as the capacity of the electrolytic cell 9. Fig. 9 The times shown are examples.

[0195] As the resin regeneration progresses, the ease of the exchange reaction between the hardness component and the hydrogen ion changes, and the speed of the resin regeneration also changes. The frequency of the exchange reaction is determined by the concentration difference between the hardness component and the hydrogen ion. When the concentration of the hardness component is significantly lower than the concentration of the hydrogen ion, the exchange reaction is difficult to occur. Specifically, as the regeneration process progresses, the unregenerated resin adsorbing the hardness component decreases. In other words, when the adsorbed hardness per unit resin volume decreases, the desorption rate of the hardness component from the weakly acidic cation exchange resin 33 decreases.

[0196] That is, from the initial stage to the middle stage of the regeneration process, a large amount of hardness components are adsorbed on the weakly acidic cation exchange resin 33, so the exchange reaction efficiency between the hardness components and hydrogen ions is high, but as the regeneration process approaches the end stage, the hardness components adsorbed on the weakly acidic cation exchange resin 33 decrease, so the exchange reaction efficiency between the hardness components and hydrogen ions decreases. For such a weakly acidic cation exchange resin 33, when the regeneration process is continued even when the amount of adsorbed hardness components decreases, the time taken to complete the regeneration of the resin becomes longer. Therefore, in this embodiment, in order to prevent the regeneration time from being prolonged as described above, the regeneration process is performed only in the area with high exchange reaction efficiency.

[0197] Specifically, the amount of hardness component adsorbed to the soft water tank is calculated based on the hardness of the raw water measured by the raw water hardness measuring unit 60, the hardness of the soft water after softening measured by the soft water hardness measuring unit 61, and the water flow rate measured by the flow rate measuring unit 62. The control unit 15 continues the regeneration process when the amount of hardness component adsorption is greater than the reference value, and terminates the regeneration process when it is less than the reference value.

[0198] The reference value refers to the ratio of the amount of hardness component actually adsorbed to the weakly acidic cation exchange resin 33 (actually adsorbed hardness component amount) to the amount of hardness component adsorbable to the weakly acidic cation exchange resin 33 , and in this embodiment, the reference value is 20%.

[0199] In the present embodiment, the reason for setting the reference value to 20% is that the exchange reaction efficiency in the regeneration step can be maintained at a high efficiency of 70% or more.

[0200] The calculation of the exchange reaction efficiency is performed by the calculation unit 59. The calculation unit 59 calculates the exchange reaction efficiency based on the first ion concentration information measured by the first ion concentration measuring unit 56 and stored in the storage unit 58 and the second ion concentration information measured by the second ion concentration measuring unit 57 and stored in the storage unit 58. For example, if the pH of the acidic electrolyzed water before the soft water tank flows in is 2.74 and the pH after the soft water tank flows in is 3.71, the hydrogen ion concentrations are 1.82 mM and 0.19 mM, respectively, and the exchange reaction efficiency can be calculated to be about 89% based on the consumption of hydrogen ions.

[0201] When the actual adsorption amount of the hardness component is 20% or more, the exchange reaction between the hardness component and the hydrogen ion is easy to progress near the resin of the soft water tank, and the exchange reaction efficiency shows a high value. On the other hand, when the regeneration process progresses and the actual adsorption amount of the hardness component is less than 20%, due to the difference in ion concentration between the hardness component and the hydrogen ion, the ease of the hardness component from the weakly acidic cation exchange resin 33 and the adsorption of the hydrogen ion to the weakly acidic cation exchange resin 33 is reduced. That is, the exchange reaction between the hardness component and the hydrogen ion is difficult to occur. That is, when the actual adsorption amount of the hardness component is less than 20%, the regeneration process progresses while maintaining a state of poor exchange reaction efficiency. Therefore, although more than 80% of the resin as a whole of the weakly acidic cation exchange resin 33 is regenerated, a large amount of regeneration time is required to regenerate the remaining 20% ​​of the resin, resulting in a prolonged regeneration process.

[0202] It should be noted that the aforementioned "requirement of a large amount of regeneration time" means that the regeneration time required to reduce the actual adsorption hardness component from 20% to approximately 0% becomes longer than the regeneration time required to reduce the actual adsorption hardness component by 20% within the range of 40 to 100% of the actual adsorption hardness component. In other words, in the regeneration process, when the regeneration process is performed until the resin regeneration rate reaches 80% and the regeneration process is terminated when the regeneration rate exceeds 80%, the regeneration process can be terminated in a time shorter than 80% of the time required for the regeneration process when the regeneration process is performed until the resin regeneration rate reaches approximately 100%.

[0203] Therefore, the control unit 15 performs control to terminate the regeneration process when the regeneration process progresses and the hardness component adsorption amount is less than the reference value. Fig. 9 The resin regeneration rate in refers to the ratio of the weakly acidic cation exchange resin 33 that does not adsorb the hardness component in the weakly acidic cation exchange resin 33 .

[0204] In addition, as a result of in-depth research, it was found that if the exchange reaction efficiency between the hardness component and the hydrogen ion is at least 70%, the resin can be regenerated in the region with high exchange reactivity. In the region where the exchange reaction efficiency is maintained at 70% or more, when the concentration of the hardness ions adsorbed on the resin is compared with the concentration of the hydrogen ions in the acidic electrolyzed water, the concentration of the hydrogen ions is higher. Therefore, according to the adsorption selectivity of the weakly acidic cation exchange resin 33, the hardness ions are easily separated and the hydrogen ions are easily in contact with the unregenerated resin layer, so it is considered that the hydrogen ions are easily adsorbed on the resin. In this embodiment, the second reference value, which is the reference value of the exchange reaction efficiency, is set to 70%.

[0205] It should be noted that the reference value of the hardness component adsorption amount may be changed as long as the exchange reaction efficiency is 70% or more. For example, by setting the reference value of the hardness component adsorption amount to 30% instead of 20%, the amount of hardness component removed from the weakly acidic cation exchange resin 33 from the start of the regeneration process to the end of the regeneration process is reduced, thereby further shortening the regeneration time.

[0206] Then, in the water softening device 1 , the regeneration process is performed based on the above-mentioned control, and when the regeneration process is completed, the process shifts to the regeneration flow path cleaning process.

[0207] It should be noted that when the user wants to obtain soft water during the regeneration process, by opening a faucet (not shown) connected to the water softening device 1, raw water flows from the inlet 2 through the bypass flow path 53 and out of the water intake port 7, so that the raw water can be used even without waiting for the end of the regeneration process.

[0208] <18.3 Regeneration flow path cleaning process>

[0209] Next, refer to Figure 4 as well as Figure 7 The column “Regeneration flow path cleaning” of FIG. 1 sequentially describes the operations of the water softening device 1 during the regeneration flow path cleaning step.

[0210] In the water softening device 1, during the regeneration process, hardness components are released from the first soft water tank 3 and the second soft water tank 5 into the acidic electrolyzed water, and the acidic electrolyzed water is not discharged from the soft water tank regeneration circulation flow path 39 but circulates in the flow path. Therefore, after the regeneration process is completed, the soft water tank regeneration circulation flow path 39 is filled with high-hardness water containing hardness components released from the first soft water tank 3 and the second soft water tank 5. The hardness of this high-hardness water is significantly higher than the hardness of raw water (for example, 450ppm), for example, sometimes rising to about 2000ppm. When the water softening process is transferred to the water softening process in a state where this high-hardness water remains in the water softening device 1, the high-hardness water or the mixed water of raw water and high-hardness water is discharged from the water intake port 7. Therefore, the following problem occurs: when the user of the water softening device 1 performs the water softening process after the regeneration process is completed, not only soft water cannot be obtained immediately after the soft water process starts, but water with a hardness higher than that of raw water is obtained.

[0211] In addition, high-hardness water flows through the weakly acidic cation exchange resin 33 in the first soft water tank 3 and the second soft water tank 5. Although the adsorbed hardness components are replaced with hydrogen ions and regenerated in the regeneration process, the water containing the hardness components flows again, so the hydrogen ions filled by the regeneration process with great difficulty exchange with the hardness components, and the hardness components are adsorbed again in the weakly acidic cation exchange resin 33. Therefore, the hydrogen ions that can be used in the softening of raw water are reduced, and the softening performance is reduced. In order to solve these problems, a regeneration flow path cleaning process is performed to discharge the high-hardness water in the soft water tank regeneration circulation flow path 39.

[0212] During the regeneration flow path cleaning process, the control unit 15 closes the on-off valves 21 to 23 and opens the on-off valves 18 to 20. In addition, the control unit 15 makes the flow path switching valve 24 a connection state in which water can be supplied from the flow path 28 to the neutralization tank bypass flow path 42, makes the flow path switching valve 25 a connection state in which water can be supplied to the soft water tank bypass flow path 44, makes the flow path switching valve 26 a connection state in which water can be supplied from the neutralization tank bypass flow path 42 to the first supply flow path 35, and makes the flow path switching valve 27 a connection state in which water can be supplied to the second supply flow path 36. That is, the first soft water tank 3 and the second soft water tank 5 are in a connected state, the second soft water tank 5 and the drain port 13 are in a connected state, and the electrolytic tank 9 and the drain port 13 are in a connected state. The control unit 15 stops the drainage of the capture unit drain port 14. As a result, as Figure 4 As shown in the figure, the first drain flow path 46 and the second drain flow path 47 are formed. It should be noted that at this time, the operation of the electrode 41, the first water pump 11, and the second water pump 12 is stopped.

[0213] In the regeneration flow path cleaning step, specifically, the on-off valve 19 is opened so that raw water flows from the outside into the first drain flow path 46 and the second drain flow path 47 .

[0214] In the first drainage flow path 46, under the action of the pressure of the raw water flowing in, the high-hardness water in the flow path 28, the first recovery flow path 37, the first water supply pump 11, the electrolytic cell 9 and the first supply flow path 35 is washed away and flows into the drainage flow path 54. The high-hardness water flowing into the drainage flow path 54 is discharged from the drain port 13 to the outside of the device.

[0215] In the second drainage flow path 47, under the action of the pressure of the raw water flowing in, the high hardness water in the flow path 28, the first soft water tank 3, the neutralization tank bypass flow path 42, the second soft water tank 5 and the first supply flow path 35 is washed away and flows into the drainage flow path 54. The high hardness water flowing into the drainage flow path 54 is discharged from the drain port 13 to the outside of the device.

[0216] In this way, by the regeneration flow path cleaning process, the high hardness water in the first drainage flow path 46 and the second drainage flow path 47, which are the main residual parts of the high hardness water after the regeneration process, can be suppressed from flowing into the neutralization tank, and the high hardness water can be replaced with raw water. Therefore, in the regeneration flow path cleaning process, the adsorption of hydrogen ions to the weakly basic anion exchange resin 34 in the neutralization tank can be suppressed, so the consumption of the filled hydroxide ions can be suppressed, and the neutralization performance can be maintained. Therefore, the reduction of the water softening performance caused by the high hardness water can be suppressed.

[0217] Note that the control unit 15 supplies the raw water to each flow path so that the flow rate of the raw water flowing through the second drain flow path 47 is greater than the flow rate of the raw water flowing through the first drain flow path 46 .

[0218] Thus, the high-hardness water in the second drainage flow path 47, which is a flow path including the soft water tank used in the softening process and is a flow path necessary for draining the high-hardness water in the flow path, can be preferentially replaced with raw water. Therefore, the reduction in the softening performance caused by the high-hardness water when the softening process is started can be suppressed. In addition, the amount of water discharged from the first drainage flow path 46, which is a flow path not used in the softening process and is a flow path where the influence of the high-hardness water on the softening process is small even if the high-hardness water remains, can be reduced, thereby preventing useless drainage and suppressing the amount of water required for the regeneration flow path cleaning process.

[0219] In addition, the high-hardness water is discharged to the outside of the device through the flow path that does not include the neutralization tank. That is, the hardness components in the high-hardness water stored in the soft water tank regeneration circulation flow path 39 can be suppressed from being adsorbed to the weakly basic anion exchange resin 34 in the neutralization tank and discharged, thereby preventing the softening performance caused by the high-hardness water generated during the regeneration process from being reduced, and the softening performance can be maintained.

[0220] Furthermore, in the water softening device 1, when the time period determined by the control unit 15 is reached, or when the regeneration flow path cleaning process exceeds a constant time (for example, 1 minute), or when the water flow rate in the regeneration flow path cleaning process exceeds a constant value, the regeneration flow path cleaning process is terminated and the electrolytic cell cleaning process is performed.

[0221] It should be noted that, when the user wants to obtain soft water during the regeneration flow path cleaning process, by opening a faucet (not shown) connected to the water softening device 1, raw water flows from the inlet 2 through the bypass flow path 53 and out of the water intake port 7. Therefore, raw water can be used without waiting for the completion of the regeneration flow path cleaning process.

[0222] <18.4 Electrolytic Cell Cleaning Process>

[0223] Next, refer to Figure 5 as well as Figure 7 The column “During electrolytic cell cleaning” of FIG. 1 sequentially describes the operations of the water softening device 1 during the electrolytic cell cleaning step.

[0224] In the regeneration process, when the electrolytic cell 9 is operated, the hardness components (calcium ions or magnesium ions) in the water are precipitated as solids (scale) at the cathode. The precipitates precipitated at the cathode are non-conductors, which causes the operating voltage of the electrolytic cell 9 to increase, and the power consumption during the regeneration process to increase. Therefore, it is necessary to perform an electrolytic cell cleaning process to remove the precipitates precipitated at the cathode.

[0225] In the electrolytic tank cleaning process, the control unit 15 opens the on-off valves 18 to 22 and closes the on-off valve 23. In addition, the control unit 15 makes the flow path switching valve 24 a connection state in which water can be supplied from the flow path 28 to the flow path 29, makes the flow path switching valve 25 a connection state in which water can be supplied to the soft water tank bypass flow path 44, makes the flow path switching valve 26 a connection state in which water can be supplied to the first supply flow path 35, and makes the flow path switching valve 27 a connection state in which water can be supplied to the second supply flow path 36. That is, the first soft water tank 3 and the electrolytic tank 9 are in a state of communication and connection, the electrolytic tank 9 and the drain port 13 are in a state of communication and connection, and the electrolytic tank 9 and the capture unit drain port 14 are in a state of communication and connection. As a result, Figure 5 As shown, the first drain flow path 46 and the third drain flow path 50 are formed respectively.

[0226] In the electrolytic cell cleaning step, specifically, the on-off valve 19 is opened by the control unit 15 , so that raw water flows from the outside into the first drain flow path 46 and the third drain flow path 50 .

[0227] The raw water that has flowed into the first drainage flow path 46 flows through the flow path 28 , the first recovery flow path 37 , and the first water supply pump 11 , and flows into the electrolytic cell 9 .

[0228] On the other hand, the raw water flowing into the third drainage flow path 50 flows through the flow path 28 , the first soft water tank 3 , the second recovery flow path 38 , and the second water supply pump 12 , and flows into the electrolytic cell 9 .

[0229] In the electrolytic cell cleaning step, the control unit 15 energizes the cathode so that the potential is higher than that of the anode (reverse electrolysis). Therefore, the electrolytic cell 9 electrolyzes the raw water flowing into the electrolytic cell to generate alkaline electrolyzed water near the anode and acidic electrolyzed water near the cathode.

[0230] At this time, the precipitate deposited at the cathode can be dissolved by the acidic electrolytic water generated at the cathode. Therefore, it is possible to suppress the reduction in electrolytic performance caused by the adhesion of the precipitate to the surface of the electrode 41.

[0231] The alkaline electrolyzed water generated by the anode flows through the first supply flow path 35 , flows into the drain flow path 54 , and is discharged to the outside of the device from the drain port 13 .

[0232] On the other hand, the acidic electrolyzed water generated by the cathode dissolves the precipitate precipitated at the cathode, and flows through the second supply flow path 36 and flows into the capture part 10. The acidic electrolyzed water flowing into the capture part 10 can dissolve the precipitate fixed to the capture part 10, so the capture part 10 can be preliminarily cleaned. Therefore, the time required for the capture part cleaning process as the next process can be shortened. In addition, the acidic electrolyzed water is discharged to the outside of the device from the capture part drain port 14 provided at the lower part of the capture part 10.

[0233] That is, in the electrolytic cell cleaning step, the removal of the precipitates in the electrolytic cell 9 and the removal of the precipitates in the capturing section 10 can be performed simultaneously, and the time required from the end of the regeneration step to the start of the water softening step can be shortened.

[0234] Then, in the water softening device 1 , when the time period determined by the control unit 15 comes or when the electrolytic cell cleaning process exceeds a certain time (eg, 5 minutes), the electrolytic cell cleaning process is terminated and the capturing part cleaning process is executed.

[0235] It should be noted that in the third drainage flow path 50, the raw water passes through the first soft water tank 3, and thus the acidic water passes through the capture part 10. Therefore, the capture part 10 is acidic, and the precipitate fixed to the capture part 10 is dissolved by the acidic water. Therefore, the capture part 10 can be preliminarily cleaned, so the time required for the capture part cleaning process as the next process can be shortened. That is, the removal of the precipitate in the electrolytic cell 9 and the removal of the precipitate in the capture part 10 can be performed at the same time, and the time required from the end of the regeneration process to the start of the water softening process can be shortened.

[0236] It should be noted that, when the user wants to obtain soft water during the electrolytic cell cleaning process, by opening a faucet (not shown) connected to the water softening device 1, raw water flows from the inlet 2 through the bypass flow path 53 and flows out from the water intake port 7. Therefore, raw water can be used without waiting for the completion of the electrolytic cell cleaning process.

[0237] <18.5 Capture unit cleaning process>

[0238] Next, refer to Figure 6 as well as Figure 7 The column “When the capturing part is cleaned” of FIG. 1 sequentially describes the operations of the water softening device 1 during the capturing part cleaning step.

[0239] In the regeneration process, high-hardness water containing hardness components released from the first soft water tank 3 and the second soft water tank 5 flows into the electrolytic tank 9. The hardness components move to the cathode side during electrolysis, react with the hydroxide ions generated by the cathode, and become precipitates. A part of the precipitated precipitates is contained in the alkaline electrolytic water released from the electrolytic tank 9, flows in the second supply flow path 36, and is captured by the capture part 10. Therefore, the precipitates are gradually accumulated in the capture part 10 in the regeneration process, so the pressure loss caused by the capture part 10 gradually increases, and the flow rate of the alkaline electrolytic water flowing in the neutralization tank regeneration circulation flow path 40 gradually decreases. Therefore, when the precipitates are left alone, the time required for the regeneration of the weakly basic anion exchange resin 34 of the first neutralization tank 4 and the second neutralization tank 6 is extended, and it is possible that the filling of the hydroxide ions into the weakly basic anion exchange resin 34 cannot be completed. Therefore, it is necessary to perform a capture part cleaning process to remove the precipitates fixed or precipitated in the capture part 10.

[0240] In the capture part cleaning process, the control unit 15 opens the on-off valves 18, 19, 22, and 23 and closes the on-off valves 20 and 21. In addition, the control unit 15 makes the flow path switching valve 24 a connection state in which water can be supplied from the flow path 28 to the flow path 29, makes the flow path switching valve 25 a connection state in which water can be supplied from the flow path 29 to the flow path 30, makes the flow path switching valve 26 a connection state in which water can be supplied from the flow path 30 to the flow path 31, and makes the flow path switching valve 27 a connection state in which water can be supplied from the flow path 31 to the second supply flow path 36. That is, the first soft water tank 3 and the first neutralization tank 4 are in a state of communication and connection, the first neutralization tank 4 and the second soft water tank 5 are in a state of communication and connection, the second soft water tank 5 and the second neutralization tank 6 are in a state of communication and connection, and the second neutralization tank 6 and the capture part drain port 14 are in a state of communication and connection. As a result, Figure 6 The fourth drain flow path 52 is formed as shown.

[0241] In the capture unit cleaning process, specifically, the control unit 15 opens the on-off valve 19 so that raw water flows from the outside into the flow path 28. The raw water flows through the flow path 28, the first soft water tank 3, the flow path 29, the first neutralization tank 4, the flow path 30, the second soft water tank 5, the flow path 31, the second neutralization tank 6, and the second supply flow path 36, and flows into the capture unit 10.

[0242] In the capture part 10, neutral soft water flows in from the side opposite to the water flow direction in the regeneration process. That is, the capture part 10 is backwashed by the inflowing neutral soft water. At this time, a part of the precipitate fixed or precipitated in the capture part 10 is dissolved in advance by the electrolytic cell cleaning process, so the capture part 10 can be easily cleaned by neutral soft water. The neutral soft water containing the precipitate is discharged to the outside of the device from the capture part drain port 14 provided at the lower part of the capture part 10.

[0243] In this way, the capture part 10 can be backwashed, so that the precipitate remaining in the capture part 10 can be removed. Therefore, the clogging of the capture part 10 can be suppressed, and when the regeneration process is performed again, the pressure loss caused by the capture part 10 can be reduced. As a result, the flow rate of the neutralization tank regeneration circulation flow path 40, which is the regeneration flow path including the capture part 10, can be suppressed from decreasing, and the flow rate of the alkaline electrolyzed water can be guaranteed, so the regeneration performance can be guaranteed.

[0244] Then, in the water softening device 1 , when the time period determined by the control unit 15 comes or when the capturing unit washing process exceeds a certain time (eg, 5 minutes), the capturing unit washing process is terminated and the water softening process is performed.

[0245] It should be noted that the flow path from the inlet 2 to the second neutralization tank 6 is the same as the flow path during the softening process. That is, by using the fourth drainage flow path 52, the second neutralization tank 6, which is the neutralization tank at the last stage in the softening process, is filled with softened water. Therefore, by performing the softening process after the capture unit cleaning process using the fourth drainage flow path 52, the user of the softening device 1 can obtain soft water that has been softened and has reduced hardness from the water intake port 7 immediately after the softening process begins.

[0246] It should be noted that, when the user wants to obtain soft water during the capture unit cleaning process, by opening a faucet (not shown) connected to the water softening device 1, raw water flows from the inlet 2 through the bypass flow path 53 and out of the water intake port 7. Therefore, raw water can be used without waiting for the capture unit cleaning process to be completed.

[0247] As described above, in the water softening device 1, the water softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture part cleaning process are repeatedly performed in sequence. By performing the capture part cleaning process immediately before the water softening process, the neutralization tank at the last stage in the water softening process is filled with softened water. Therefore, when the user of the water softening device 1 turns on the faucet, the discharge of high-hardness water from the water intake port 7 can be suppressed, and soft water with stable hardness can be provided from the beginning of the water softening process.

[0248] In addition, by performing the electrolytic cell cleaning process after the regeneration flow path cleaning process, the high-hardness water is discharged outside the device when the pole is changed in the electrolytic cell cleaning process, and the possibility of electrolyzing the high-hardness water can be suppressed. Therefore, the electrolysis of high-hardness water can be suppressed, and the generation of a large amount of scale in the flow path for delivering alkaline electrolyzed water can be suppressed when the pole is changed.

[0249] As described above, according to the water softening device 1 of this embodiment, the following effects can be obtained.

[0250] (1) The water softening device 1 includes: a softening tank for softening raw water containing hardness components by using a weakly acidic cation exchange resin 33 to generate acidic soft water; a neutralization tank for neutralizing the pH of the acidic soft water that has passed through the softening tank by using a weakly basic anion exchange resin 34 to generate neutralized soft water; and a control unit 15 for controlling a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin 33 and the weakly basic anion exchange resin 34. The control unit 15 includes an adsorption amount determination unit 55 for determining the amount of hardness component adsorption in the softening tank based on the hardness of the raw water, the amount of raw water passed through the softening tank, and the hardness of water after passing through the softening tank. The control unit 15 controls the execution of the regeneration process based on the hardness component adsorption amount determined by the adsorption amount determination unit 55 in the regeneration process so that the regeneration process is continued when the hardness component adsorption amount is greater than a reference value, and the regeneration process is terminated when the hardness component adsorption amount is less than the reference value.

[0251] According to this structure, the regeneration process can be terminated at the end of the regeneration when the exchange reaction efficiency between the hardness component adsorbed on the weakly acidic cation exchange resin 33 and the hydrogen ions in the acidic electrolyzed water decreases. Therefore, the regeneration process can be prevented from being prolonged and the regeneration time can be shortened.

[0252] (2) The water softening device 1 may further include an electrolytic tank 9 for generating acidic electrolytic water for regenerating the weakly acidic cation exchange resin 33 and alkaline electrolytic water for regenerating the weakly basic anion exchange resin 34. The reference value may be a value when the exchange reaction efficiency between the hardness component adsorbed in the softening tank and the hydrogen ions in the acidic electrolytic water during the regeneration process is at least 70%.

[0253] According to this structure, the regeneration process can be terminated when the exchange reaction efficiency is less than 70%. That is, the regeneration process can be performed only in the region where the reactivity between the hardness component and the hydrogen ion is high, and the weakly acidic cation exchange resin 33 is not regenerated in the region where the reactivity is low, thereby shortening the regeneration time.

[0254] (3) The water softening device 1 may further include: a first ion concentration measuring unit 56 for measuring the ion concentration of the acidic electrolyzed water flowing into the softening tank during the regeneration process; and a second ion concentration measuring unit 57 for measuring the ion concentration of the acidic electrolyzed water flowing out of the softening tank during the regeneration process. The control unit 15 may include a storage unit 58 for storing the first ion concentration information measured by the first ion concentration measuring unit 56 and the second ion concentration information measured by the second ion concentration measuring unit 57, and a calculation unit 59 for calculating the difference between the first ion concentration information and the second ion concentration information, and calculating the exchange reaction efficiency based on the calculation result of the calculation unit 59.

[0255] According to this configuration, the ion concentration of the acidic electrolyzed water can be measured before and after the soft water tank, and the ion concentration information can be monitored based on the actual value of the measured ion concentration to calculate the real-time exchange reaction efficiency.

[0256] (4) In the water softening device 1, the calculation unit 59 may calculate a differential ion concentration value which is a difference between the first ion concentration information and the second ion concentration information in a predetermined reference time. The control unit 15 may continue the regeneration process when the exchange reaction efficiency calculated based on the differential ion concentration value is greater than the second reference value, and terminate the regeneration process when the exchange reaction efficiency is less than the second reference value.

[0257] Thus, the continuation and termination of the regeneration process can be controlled based on the timing of the decrease in the exchange reaction efficiency between the hardness component and the hydrogen ion in real time. Therefore, the implementation of the regeneration process during the period of low exchange reaction efficiency, which is a factor in prolonging the regeneration time, can be avoided.

[0258] The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that these embodiments are for illustration only, and various modifications can be implemented in the combination of the above-mentioned components or processing flows, and such modifications also belong to the scope of the present invention.

[0259] In addition, those skilled in the art should understand that the combination of the constituent elements or processing flows of this embodiment with the constituent elements or processing flows of other embodiments can also be implemented and belongs to the scope of the present invention.

[0260] It should be noted that, in the softening device 1 of the present embodiment, after the regeneration process is completed, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture part cleaning process are performed in this order, but it is not limited to this. For example, the regeneration flow path cleaning process can also be performed after the electrolytic cell cleaning process, and the capture part cleaning process can be performed as a pre-process of the softening process. Even if the cleaning in the device is performed in this order, the precipitates in the electrolytic cell 9 and the capture part 10 can be removed, and soft water can be filled in the second neutralization tank 6 immediately before the softening process.

[0261] In addition, in the present embodiment, in the regeneration process, the regeneration process is terminated when the hardness component adsorption amount is less than the reference value, but the present invention is not limited thereto. Depending on the use status of the water softening device 1, there is a possibility that an error will occur between the exchange reaction efficiency calculated by the measurement and the actual exchange reaction efficiency due to a decrease in the ion adsorption capacity of the weakly acidic cation exchange resin 33 or a deviation between the calculated hardness adsorption amount and the actual hardness adsorption amount. When the regeneration process is performed in a state where a deviation (error) is generated, there is a possibility that the regeneration process is also performed in a region where the exchange reaction efficiency is reduced, and there is a possibility that the regeneration process is terminated even though the resin is actually regenerated at a higher exchange reaction efficiency.

[0262] Therefore, in the process of implementing a series of operations of the softening device 1 including the regeneration process, a regeneration process for additionally regenerating the weakly acidic cation exchange resin 33 may be included. Specifically, even when the amount of adsorption of the hardness component becomes less than the reference value, control of continuing the regeneration process may be implemented and additional regeneration may be performed m times out of n times (n is an integer greater than or equal to 2, m is an integer greater than or equal to 1, n>m). For example, the resin may be completely regenerated once out of five regeneration processes.

[0263] It should be noted that the additional regeneration refers to a regeneration process in which the operation is performed until the amount of hardness components adsorbed to the weakly acidic cation exchange resin 33 becomes approximately 0%. Thus, even if the water softening device 1 is used for a long time and the weakly acidic cation exchange resin 33 deteriorates and the ion exchange capacity decreases, the amount of hardness components adsorbed to the weakly acidic cation exchange resin 33 can be reduced by regeneration, and the possibility of errors in the calculation of the hardness adsorption amount and the exchange reaction efficiency can be reduced.

[0264] (Second embodiment)

[0265] Next, a second embodiment of the present invention will be described.

[0266] The present invention solves the above-mentioned first conventional problem and provides a water softening device capable of shortening the time required to complete the regeneration process of an ion exchange resin.

[0267] Furthermore, in order to achieve this purpose, the water softening device of the present embodiment comprises: a softening tank, which utilizes a weakly acidic cation exchange resin to soften raw water containing hardness components to generate acidic soft water; a neutralization tank, which utilizes a weakly basic anion exchange resin to neutralize the pH of the acidic soft water that has passed through the softening tank to generate neutralized soft water; an electrolytic tank, which generates acidic electrolyzed water for regenerating the weakly acidic cation exchange resin and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin; and a control unit, which controls a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin. The control unit includes: an adsorption amount determination unit, which determines the amount of hardness component adsorbed to the soft water tank based on the hardness of the raw water, the amount of raw water passed into the soft water tank, and the hardness of the water after passing through the soft water tank; and a main regeneration time calculation unit, which calculates the main regeneration time required for the regeneration process required to remove the hardness component based on the hardness component adsorption amount. The control unit determines the time consumed by the regeneration process based on the comparison between a specified reference time and the main regeneration time.

[0268] According to such a configuration, it is possible to provide a water softening device capable of shortening the time required to complete the regeneration process of the ion exchange resin.

[0269] Hereinafter, the second embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiments are examples of specific implementations of the present invention and do not limit the technical scope of the present invention. In addition, the figures described in the embodiments are schematic figures, and the size and thickness ratio of each component in each figure do not necessarily reflect the actual size ratio.

[0270] Reference Fig.10 A water softening device 101 according to a second embodiment of the present invention will be described. Fig.10 1 is a conceptual diagram showing the structure of a water softening device 101 according to a second embodiment of the present invention. Fig.10 , each element of the water softening device 101 is conceptually shown.

[0271] <1. Overall structure>

[0272] The softening device 101 is a device for generating neutral soft water from raw water containing hardness components supplied from the outside. It should be noted that raw water refers to water (treatment target water) introduced into the device from the inlet 102, such as city water or well water. Raw water contains hardness components (for example, calcium ions or magnesium ions). By using the softening device 101 to perform softening treatment, neutral soft water with reduced hardness can be obtained, and soft water can be used even in areas where the hardness of raw water is high.

[0273] Specifically, if Fig.10As shown, the water softening device 101 includes an inlet 102 , a softening tank, a neutralization tank, a water intake port 107 , a regeneration device 108 , and a control unit 115 .

[0274] The water softening device 101 includes a drain port 113 , a plurality of on-off valves (on-off valves 118 to 123 ), and a plurality of flow path switching valves (flow path switching valves 124 to 127 ). Details of these will be described later.

[0275] <2. Inlet and water intake>

[0276] The inlet 102 is connected to a raw water supply source and is an opening for introducing raw water into the water softening device 101 .

[0277] The water intake 107 is an opening for supplying softened water flowing through the softening device 101 to the outside of the device. In the softening device 101, softened water can be taken out from the water intake 107 by the pressure of raw water flowing in from the inlet 102.

[0278] In the softening process of the softening treatment in the softening device 101, raw water supplied from the outside flows in the order of the inlet 102, the flow path 128, the first soft water tank 103, the flow path 129, the first neutralization tank 104, the flow path 130, the second soft water tank 105, the flow path 131, the second neutralization tank 106, the flow path 132 and the water intake 107, and is discharged as neutral soft water.

[0279] <3. Soft water tank>

[0280] The soft water tank (the first soft water tank 103 and the second soft water tank 105) softens the raw water containing hardness components under the action of the weakly acidic cation exchange resin 133. Specifically, in the soft water tank, cations (calcium ions or magnesium ions) as hardness components contained in the circulating water (raw water) are exchanged with hydrogen ions, so that the hardness of the raw water is reduced and the raw water is softened. In the softening device 101 of this embodiment, the first soft water tank 103 and the second soft water tank 105 are provided as soft water tanks.

[0281] The first soft water tank 103 softens the raw water flowing in from the inlet 102. The first soft water tank 103 includes a flow path switching valve 124. Details of the flow path switching valve will be summarized later.

[0282] The second soft water tank 105 softens the water that has flowed through the first neutralization tank 104 described later. The second soft water tank 105 includes a flow path switching valve 126 .

[0283] The first soft water tank 103 and the second soft water tank 105 are respectively filled with weakly acidic cation exchange resin 133 .

[0284] The weakly acidic cation exchange resin 133 is an ion exchange resin having a hydrogen ion at the end of a functional group. The weakly acidic cation exchange resin 133 adsorbs cations (calcium ions or magnesium ions) as hardness components contained in the raw water passed through, and releases hydrogen ions. The soft water treated by the weakly acidic cation exchange resin 133 contains a large amount of hydrogen ions released in exchange with the hardness components. That is, the soft water flowing out of the first soft water tank 103 and the second soft water tank 105 is soft water (acidic soft water) that contains a large amount of hydrogen ions and is acidified.

[0285] Since the functional groups of the weakly acidic cation exchange resin 133 have hydrogen ions at their ends, the weakly acidic cation exchange resin 133 can be regenerated using acidic electrolyzed water in the regeneration treatment described below. At this time, the cations taken in as hardness components during the water softening treatment are released from the weakly acidic cation exchange resin 133.

[0286] There is no particular limitation on the weakly acidic cation exchange resin 133, and a general-purpose material can be used. For example, a material having a carboxyl group (-COOH) as an exchange group can be used. In addition, a hydrogen ion (H ＋ ) can also become metal ions or ammonium ions (NH4 ＋ ) and other cations.

[0287] <4. Neutralization tank>

[0288] The neutralization tank (the first neutralization tank 104 and the second neutralization tank 106) neutralizes the pH (hydrogen ion concentration index) of the soft water (acidified soft water) containing hydrogen ions released from the soft water tank under the action of the weakly basic anion exchange resin 134, and becomes neutral soft water. Specifically, the neutralization tank adsorbs hydrogen ions contained in the soft water from the soft water tank together with anions, so that the pH of the soft water increases and can become neutral soft water. In the softening water device 101 in this embodiment, the first neutralization tank 104 and the second neutralization tank 106 are provided as neutralization tanks.

[0289] The first neutralization tank 104 neutralizes the acidic soft water flowing through the first soft water tank 103. The first neutralization tank 104 includes a flow path switching valve 125.

[0290] The second neutralization tank 106 neutralizes the acidic soft water flowing through the second soft water tank 105. The second neutralization tank 106 includes a flow path switching valve 127.

[0291] The first neutralization tank 104 and the second neutralization tank 106 are respectively filled with weakly basic anion exchange resin 134 .

[0292] The weakly basic anion exchange resin 134 neutralizes hydrogen ions contained in the water passed through to generate neutral water. The weakly basic anion exchange resin 134 can be regenerated using alkaline electrolyzed water in a regeneration process described later.

[0293] The weakly basic anion exchange resin 134 is not particularly limited, and a general-purpose material can be used. For example, a material in a free base form can be mentioned.

[0294] <5. Regeneration device>

[0295] The regeneration device 108 is a device for regenerating the weakly acidic cation exchange resin 133 filled in the first soft water tank 103 and the second soft water tank 105 and regenerating the weakly basic anion exchange resin 134 filled in the first neutralization tank 104 and the second neutralization tank 106 .

[0296] The regeneration device 108 includes an electrolytic cell 109, a capture unit 110, a first water pump 111, and a second water pump 112. In addition, the regeneration device 108 is connected to the second soft water tank 105, the second neutralization tank 106, the flow path 128, and the flow path 129, respectively, with a first supply flow path 135, a second supply flow path 136, a first recovery flow path 137, and a second recovery flow path 138. Details of each flow path are described later. It should be noted that the first supply flow path 135, the second supply flow path 136, the first recovery flow path 137, the second recovery flow path 138, the neutralization tank bypass flow path 142, and the soft water tank bypass flow path 144 form the soft water tank regeneration circulation flow path 139 and the neutralization tank regeneration circulation flow path 140 described later.

[0297] <5.1. Electrolytic Cell>

[0298] The electrolytic tank 109 generates and discharges acidic electrolytic water and alkaline electrolytic water by electrolyzing the water (water supplied from the inlet 102) by using a pair of electrodes 141 (electrode 141a and electrode 141b) provided inside. More specifically, at the electrode 141a which becomes the anode during electrolysis in the regeneration process, hydrogen ions are generated by electrolysis, and acidic electrolytic water is generated. In addition, at the electrode 141b which becomes the cathode during electrolysis in the regeneration process, hydroxide ions are generated by electrolysis, and alkaline electrolytic water is generated. In addition, the electrolytic tank 109 supplies acidic electrolytic water to the first soft water tank 103 and the second soft water tank 105 via the first supply flow path 135 and the neutralization tank bypass flow path 142, and supplies alkaline electrolytic water to the first neutralization tank 104 and the second neutralization tank 106 via the second supply flow path 136 and the soft water tank bypass flow path 144. The acidic electrolyzed water generated by the electrolytic cell 109 is used in the regeneration of the weakly acidic cation exchange resin 133 in the first soft water tank 103 and the second soft water tank 105, and the alkaline electrolyzed water generated by the electrolytic cell 109 is used in the regeneration of the weakly basic anion exchange resin 134 in the first neutralization tank 104 and the second neutralization tank 106, as described later. It should be noted that the electrolytic cell 109 is configured so that the power supply state of the pair of electrodes 141 can be controlled by the control unit 115 described later.

[0299] <5.2 Water supply pump>

[0300] The first water pump 111 is used to pump acidic electrolyzed water in the soft water tank regeneration circulation flow path 139 (see FIG. 1 ) during the regeneration process performed by the regeneration device 108. Fig.12 ) circulation device. The first water supply pump 111 is provided in the first recovery flow path 137 connecting the first soft water tank 103 and the electrolytic tank 109. The reason for such a configuration is that it is easy to circulate the acidic electrolyzed water in the soft water tank regeneration circulation flow path 139 using only the first water supply pump 111.

[0301] The second water pump 112 is used to pump the alkaline electrolyzed water through the neutralization tank regeneration circulation flow path 140 (see Fig.12 ) circulation device. The second water supply pump 112 is provided in the second recovery flow path 138 connecting the first neutralization tank 104 and the electrolytic tank 109. The reason for such a configuration is that it is easy to circulate the alkaline electrolyzed water in the neutralization tank regeneration circulation flow path 140 using only the second water supply pump 112.

[0302] The first water pump 111 and the second water pump 112 are connected to a control unit 115 to be described later in a wireless or wired manner so as to be communicable.

[0303] <5.3 Capture part>

[0304] The capturing unit 110 is provided in the second supply flow path 136 which connects the electrolytic tank 109 and the second neutralization tank 106 in communication with each other.

[0305] The capture unit 110 captures the precipitate contained in the alkaline electrolyzed water sent from the electrolytic cell 109. The precipitate refers to a reaction product generated by the reaction of the hardness component as the cation released from the first soft water tank 103 and the second soft water tank 105 in the electrolytic cell 109 with the alkaline electrolyzed water. More specifically, during the electrolysis of water in the electrolytic cell 109, the hardness component (for example, calcium ion or magnesium ion) released from the first soft water tank 103 and the second soft water tank 105 in the regeneration process moves to the cathode (electrode 141b) side. Since alkaline electrolyzed water is generated on the cathode side, the hardness component reacts with the alkaline electrolyzed water to form a precipitate. For example, when the hardness component is a calcium ion, it is mixed with the alkaline electrolyzed water to cause a reaction to produce calcium carbonate or a reaction to produce calcium hydroxide. The precipitate from the hardness component is captured as a precipitate by the capture unit 110 provided in the second supply flow path 136. Furthermore, the precipitate from the hardness component is captured by the capture unit 110, thereby preventing the precipitate from flowing into the second neutralization tank 106 and accumulating. Therefore, when the softening treatment is restarted after the regeneration treatment is completed, the hardness of the soft water sent from the second neutralization tank 106 can be prevented from increasing due to the ionization of the precipitate accumulated in the second neutralization tank 106 and the hydrogen ions released from the first soft water tank 103 and the second soft water tank 105.

[0306] In addition, during the regeneration process, the alkaline electrolyzed water from which the precipitate of the hardness component has passed through the capture unit 110 is circulated in the second neutralization tank 106 and the first neutralization tank 104, and then is electrolyzed again by the electrolytic tank 109, and is again supplied as alkaline electrolyzed water to the regeneration of the weakly basic anion exchange resin 134. At this time, the acidic electrolyzed water contains fewer hardness components than when the capture unit 110 is not provided. That is, by capturing the precipitate using the capture unit 110, the hardness of the acidic electrolyzed water is reduced, so that the hardness component flowing into the first soft water tank 103 and the second soft water tank 105 can be reduced, and the reduction in the regeneration efficiency of the weakly acidic cation exchange resin 133 can be suppressed.

[0307] It should be noted that “the hardness component reacts” includes not only the state in which all the hardness components react, but also the state in which unreacted components or components that do not exceed the solubility product are included.

[0308] The capturing unit 110 may be formed in any manner as long as it can separate the precipitate produced by the reaction of the hardness component and the alkaline electrolyzed water. For example, a box-type filter, a filter layer using a granular filter material, a cyclone-type solid-liquid separator, a hollow fiber membrane, etc. may be used.

[0309] A cartridge filter is a generally used mechanism for the capturing unit 110. The cartridge filter may be a depth filter such as a wire wound filter, a surface filter such as a pleated filter or a membrane filter, or a combination of these.

[0310] The capturing unit 110 includes an on-off valve 122 and a capturing unit drain port 114 .

[0311] The on-off valve 122 is a valve for controlling drainage from the capture unit 110, and is provided, for example, at the lower portion of the capture unit 110. By opening the on-off valve 122, water in the capture unit 110 can be drained from the capture unit drainage port 114 to the outside of the device.

[0312] The capture unit drain port 114 is an opening for draining water in the capture unit 110 to the outside of the device. By opening the on-off valve 122 provided upstream of the capture unit drain port 114, the water in the capture unit 110 can be drained to the outside of the device from the capture unit drain port 114.

[0313] <6. On / off valve and flow path switching valve>

[0314] A plurality of on-off valves (on-off valves 118 to 123 ) are provided in each flow path, and switch between an “open” state and a “closed” state in each flow path.

[0315] The plurality of on-off valves (on-off valve 118 , on-off valve 119 , on-off valve 121 , and on-off valve 123 ) start or stop the flow of water to each flow path by opening and closing the valves.

[0316] The on-off valve 120 and the on-off valve 122 are opened during the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process described later, and the regeneration circulation water is discharged to the outside of the device.

[0317] A plurality of flow path switching valves (flow path switching valves 124 to 127) are respectively provided in the first soft water tank 103, the first neutralization tank 104, the second soft water tank 105, and the second neutralization tank 106. The plurality of flow path switching valves each have three openings. The first opening is an inflow and outflow port through which water can flow in and out, the second opening is an inflow port that does not function as an outflow port but functions as an inflow port, and the third opening is an outflow port that does not function as an inflow port but functions as an outflow port. The plurality of flow path switching valves each have an inflow and outflow port that is always "open", and when one of the inflow port and the outflow port is "opened" according to the water flow direction, the other is "closed". By providing the flow path switching valves 124 to 127, the number of on-off valves required for each flow path in the water softening device 101 can be reduced, and the cost of the water softening device 101 can be reduced.

[0318] In addition, the plurality of on-off valves (on-off valves 118 to 123 ) and the plurality of flow path switching valves (flow path switching valves 124 to 127 ) are respectively connected to a control unit 115 to be described later in a wireless or wired manner so as to be communicable therewith.

[0319] <7. Drainage outlet>

[0320] The drain port 113 is an opening provided at the end of the drain flow path 154, and is an opening for discharging water in the device to the outside of the device during the regeneration path cleaning process and the electrolytic cell cleaning process. An on-off valve 120 is provided upstream of the drain port 113, and water can be discharged from the drain port 113 by opening the on-off valve 120.

[0321] <8.Flow path>

[0322] The bypass flow path 153 is a flow path connecting the inlet 102 and the water intake port 107, and the flow path is provided with an on-off valve 118. Through the bypass flow path 153, the user of the water softening device 101 can obtain raw water from the water intake port 107 regardless of the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process.

[0323] <9. Water softening flow path>

[0324] Reference Fig.11 The softening flow path 143 formed during the water softening step of the water softening device 101 will be described. Fig.11 1 is a diagram showing the structure of the water softening flow path 143 of the water softening device 101 .

[0325] Softening flow path 143 (in Fig.11 ) is a flow path for softening raw water. The raw water flowing through the softening flow path 143 becomes neutral soft water and is discharged from the water intake port 107 to the outside of the device.

[0326] The softening water flow path 143 is formed by the inlet 102 , the flow path 128 , the first softening tank 103 , the flow path 129 , the first neutralization tank 104 , the flow path 130 , the second softening tank 105 , the flow path 131 , the second neutralization tank 106 , the flow path 132 , and the water intake 107 .

[0327] The flow path 128 is a flow path connected from the inlet 102 to the first soft water tank 103. That is, the flow path 128 is a flow path that guides the raw water containing hardness components from the inlet 102 to the first soft water tank 103.

[0328] The flow path 129 is a flow path connecting the first soft water tank 103 to the first neutralization tank 104. That is, the flow path 129 is a flow path that guides the water softened by the first soft water tank 103 to the first neutralization tank 104.

[0329] The flow path 130 is a flow path connecting the first neutralization tank 104 to the second soft water tank 105. That is, the flow path 130 is a flow path that guides the water neutralized by the first neutralization tank 104 to the second soft water tank 105.

[0330] The flow path 131 is a flow path connecting the second softening tank 105 to the second neutralization tank 106. That is, the flow path 131 is a flow path that guides the water softened by the second softening tank 105 to the second neutralization tank 106.

[0331] The flow path 132 is a flow path connecting the second neutralization tank 106 to the water intake port 107. That is, the flow path 132 is a flow path that guides the softened raw water from the second neutralization tank 106 to the water intake port 107.

[0332] like Fig.11 As shown, an on-off valve 119 is provided on the flow path 128 on the downstream side of the inlet 102 and the upstream side of the first soft water tank 103. In addition, an on-off valve 118 is provided on the bypass flow path 153. And, by closing the on-off valve 118 and opening the on-off valve 119, the first soft water tank 103 is connected to the inlet 102. In addition, the flow path switching valve 124 is switched to connect the first soft water tank 103 with the first neutralization tank 104, the flow path switching valve 125 is switched to connect the first neutralization tank 104 with the second soft water tank 105, the flow path switching valve 126 is switched to connect the second soft water tank 105 with the second neutralization tank 106, and the flow path switching valve 127 is switched to connect the second neutralization tank 106 with the water intake port 107. Thus, a softening water flow path 143 is formed which connects the inlet 102 to the flow path 128, the first soft water tank 103, the flow path 129, the first neutralization tank 104, the flow path 130, the second soft water tank 105, the flow path 131, the second neutralization tank 106, the flow path 132 and the water intake 107. At this time, the on-off valves 120, 121 and 123 are closed.

[0333] <10. Regeneration circulation flow path>

[0334] Next, refer to Fig.12 The softening tank regeneration circulation flow path 139 and the neutralization tank regeneration circulation flow path 140 formed during the regeneration process of the water softening device 101 will be described. Fig.12 1 is a diagram showing the structure of a softening tank regeneration circulation flow path 139 and a neutralization tank regeneration circulation flow path 140 of the water softening device 101 .

[0335] First, the soft water tank regeneration circulation flow path 139 will be described.

[0336] The soft water tank regeneration circulation flow path 139 is a flow path for acidic electrolyzed water to flow during the regeneration process to regenerate the first soft water tank 103 and the second soft water tank 105, and is as follows: Fig.12 As indicated by (white arrows), the water delivered by the first water delivery pump 111 flows through the electrolytic tank 109 , the second soft water tank 105 , and the first soft water tank 103 and returns to the electrolytic tank 109 for circulation.

[0337] Specifically, the soft water tank regeneration circulation flow path 139 is composed of the first supply flow path 135 connecting the electrolytic tank 109 , the second soft water tank 105 , the first soft water tank 103 and the first water supply pump 111 , the neutralization tank bypass flow path 142 and the first recovery flow path 137 .

[0338] The first supply flow path 135 is a flow path that is connected from the downstream side of the electrolytic cell 109 to the downstream side of the second soft water tank 105 , and is a flow path that supplies acidic electrolyzed water from the electrolytic cell 109 to the second soft water tank 105 .

[0339] The neutralization tank bypass flow path 142 is a flow path that bypasses the first neutralization tank 104 and communicates with the first soft water tank 103 from the upstream side of the second soft water tank 105 , and is a flow path that supplies acidic electrolyzed water from the second soft water tank 105 to the first soft water tank 103 .

[0340] The first recovery flow path 137 is a flow path connected to the electrolytic cell 109 from the upstream side of the first soft water tank 103, and is a flow path for recovering the acidic electrolyzed water containing hardness components that has passed through the first soft water tank 103 and the second soft water tank 105 to the electrolytic cell 109. The first recovery flow path 137 is provided with a first water supply pump 111.

[0341] In addition, the soft water tank regeneration circulation flow path 139 is a flow path that introduces the acidic electrolyzed water sent out from the electrolytic tank 109 from the downstream side of the first soft water tank 103 and the second soft water tank 105 to the first soft water tank 103 and the second soft water tank 105 respectively, and causes the acidic electrolyzed water to flow out from the upstream side of the first soft water tank 103 and the second soft water tank 105 respectively, where the adsorption amount of hardness components is greater than that of the downstream side of the soft water tank.

[0342] It should be noted that in the above description, the downstream side (or upstream side) refers to the downstream side (or upstream side) in the flow path during the water softening treatment.

[0343] Next, the neutralization tank regeneration circulation flow path 140 will be described.

[0344] The neutralization tank regeneration circulation flow path 140 is a flow path for alkaline electrolyzed water to flow during the regeneration process to regenerate the first neutralization tank 104 and the second neutralization tank 106, and is as follows: Fig.12As indicated by (black arrow), the water sent out by the second water sending pump 112 circulates through the electrolytic tank 109 , the second neutralization tank 106 , and the first neutralization tank 104 and returns to the electrolytic tank 109 .

[0345] Specifically, the neutralization tank regeneration circulation flow path 140 is composed of the second supply flow path 136 connecting the electrolytic tank 109 , the second neutralization tank 106 , the first neutralization tank 104 and the second water supply pump 112 , the soft water tank bypass flow path 144 and the second recovery flow path 138 .

[0346] Second supply flow path 136 is a flow path connected from the downstream side of electrolytic cell 109 to the downstream side of second neutralization tank 106, and is a flow path for supplying alkaline electrolyzed water from electrolytic cell 109 to second neutralization tank 106. Capture unit 110, opening and closing valve 121, and opening and closing valve 123 are provided in second supply flow path 136.

[0347] The soft water tank bypass flow path 144 is a flow path that bypasses the second soft water tank 105 and communicates with the first neutralization tank 104 from the upstream side of the second neutralization tank 106 , and is a flow path that supplies alkaline electrolyzed water from the second neutralization tank 106 to the first neutralization tank 104 .

[0348] The second recovery flow path 138 is a flow path connected to the electrolytic cell 109 from the upstream side of the first neutralization tank 104, and is a flow path for recovering the alkaline electrolyzed water that has passed through the first neutralization tank 104 and the second neutralization tank 106 to the electrolytic cell 109. The second recovery flow path 138 is provided with a second water delivery pump 112.

[0349] <11. Regeneration flow path and cleaning flow path>

[0350] Next, refer to Fig.13 The regeneration flow path cleaning flow path 145 formed during the regeneration flow path cleaning step of the water softening device 101 will be described. Fig.13 1 is a diagram showing the structure of the regeneration flow path cleaning flow path 145 of the water softening device 101 .

[0351] The regeneration flow path cleaning flow path 145 is a flow path for discharging high hardness water remaining in the flow path to the outside of the device without flowing into the first neutralization tank 104 and the second neutralization tank 106 during the regeneration flow path cleaning process described later. The regeneration flow path cleaning flow path 145 includes a first drainage flow path 146 and a second drainage flow path 147.

[0352] The first drainage flow path 146 is composed of Fig.13As shown by (white arrow), the first water pump 111, the electrolytic cell 109, the on-off valve 120 and the drain port 113 are connected from the inlet 102 to each flow path. Specifically, the first drain flow path 146 is a flow path that allows the raw water flowing in from the inlet 102 to flow in the order of the flow path 128, the first recovery flow path 137, the first water pump 111, the electrolytic cell 109, the drain flow path 154, the on-off valve 120 and the drain port 113.

[0353] The drainage flow path 154 is a flow path connected to the first supply flow path 135 at one end, and is a flow path connected to the drain port 113 at the other end. The drainage flow path 154 is provided with an on-off valve 120, and the water in the flow path can be discharged to the outside of the device by opening the on-off valve 120, and the drainage from the drain port 113 can be stopped by closing the on-off valve 120.

[0354] The second drainage flow path 147 is composed of Fig.13 As shown by the black arrow, the flow paths connected from the inlet 102 to the first soft water tank 103, the second soft water tank 105, the on-off valve 120 and the drain 113 are formed. Specifically, the second drain flow path 147 is a flow path that allows the raw water flowing in from the inlet 102 to flow in the order of the flow path 128, the first soft water tank 103, the neutralization tank bypass flow path 142, the second soft water tank 105, the first supply flow path 135, the on-off valve 120 and the drain 113.

[0355] It should be noted that it is preferable to control the flow rate of water flowing through the second drainage flow path 147 to be greater than the flow rate of water flowing through the first drainage flow path 146. Thus, the high-hardness water in the second drainage flow path 147, which is the flow path of the soft water tank used in the water softening process, can be preferentially replaced with raw water. Therefore, the influence of the high-hardness water at the start of the water softening process can be suppressed.

[0356] <12. Electrolytic cell cleaning flow path>

[0357] Next, refer to Fig.14 The electrolytic cell cleaning flow path 149 formed during the electrolytic cell cleaning step of the water softening device 101 will be described. Fig.14 1 is a diagram showing the structure of the electrolytic cell cleaning flow path 149 of the water softening device 101 .

[0358] The electrolytic tank cleaning flow path 149 is a flow path for removing precipitates caused by hardness components in the electrolytic tank 109 and the neutralization tank regeneration circulation flow path 140 during the electrolytic tank cleaning process described later. The electrolytic tank cleaning flow path 149 includes a first drain flow path 146 and a third drain flow path 150 .

[0359] The third drainage flow path 150 is composed of Fig.14As shown by the black arrow, the third drainage flow path 150 is a flow path that is connected from the inlet 102 to the first soft water tank 103, the second water pump 112, the electrolytic cell 109, the on-off valve 121, the capture unit 110, the on-off valve 122, and the capture unit drain port 114. Specifically, the third drainage flow path 150 is a flow path that allows the raw water flowing in from the inlet 102 to flow in the order of the flow path 128, the first soft water tank 103, the flow path 129, the second recovery flow path 138, the second water pump 112, the electrolytic cell 109, the second supply flow path 136, the on-off valve 121, the capture unit 110, and the on-off valve 122, and is discharged from the capture unit drain port 114 to the outside of the device.

[0360] More specifically, in the third drainage flow path 150, the raw water flowing in from the inlet 102 flows into the first soft water tank 103 through the flow path 128 and becomes acidic soft water. The generated acidic soft water is flowed into the electrolytic cell 109 through the flow path 129 and the second recovery flow path 138 by the second water supply pump 112. Thereafter, the acidic soft water is circulated in the order of the on-off valve 121, the capture part 110, and the on-off valve 122 through the second supply flow path 136, and the acidic soft water dissolves the precipitate in the capture part 110 and is discharged from the capture part drainage port 114 to the outside of the device.

[0361] <13. Capture unit cleaning flow path>

[0362] Next, refer to Fig.15 The capturing unit cleaning flow path 151 formed during the capturing unit cleaning step of the water softening device 101 will be described. Fig.15 1 is a diagram showing the structure of the capture unit cleaning flow path 151 of the water softening device 101 .

[0363] The capturing part cleaning flow path 151 is a flow path for removing precipitates derived from hardness components precipitated in the capturing part 110 during a capturing part cleaning step described later. The capturing part cleaning flow path 151 includes a fourth drain flow path 152 .

[0364] like Fig.15 As shown, the capture part cleaning flow path 151 is composed of the respective flow paths connected from the inlet 102 to the first soft water tank 103, the first neutralization tank 104, the second soft water tank 105, the second neutralization tank 106, the capture part 110 and the capture part drain port 114. Specifically, the capture part cleaning flow path 151 is a flow path that allows the raw water flowing in from the inlet 102 to flow in the order of the flow path 128, the first soft water tank 103, the flow path 129, the first neutralization tank 104, the flow path 130, the second soft water tank 105, the flow path 131, the second neutralization tank 106, the second supply flow path 136, the on-off valve 123, the capture part 110 and the on-off valve 122, and is discharged from the capture part drain port 114 to the outside of the device.

[0365] <14. Raw water hardness measuring section and soft water hardness measuring section>

[0366] The raw water hardness measuring unit 160 and the soft water hardness measuring unit 161 (see Fig.10 ) Determine the concentration of hardness components in water during the water softening process.

[0367] The raw water hardness measuring unit 160 is provided in the flow path 128 that connects the inlet 102 and the first soft water tank 103 , and measures the hardness of raw water flowing through the flow path 128 (ie, the hardness of raw water before softening).

[0368] The soft water hardness measuring unit 161 is provided in the flow path 132 connecting the second neutralization tank 106 and the water intake 107 , and measures the hardness of the soft water flowing in the flow path 132 (ie, the hardness of the soft water softened by the soft water tank and the neutralization tank).

[0369] Note that general-purpose components may be used as the raw water hardness measuring unit 160 and the soft water hardness measuring unit 161 . For example, a detector for measuring the electrical conductivity of liquid or a detector for measuring the amount of TDS (Total Dissolved Solid) contained in water may be used.

[0370] <15. Flow rate measurement unit>

[0371] The flow rate measuring unit 162 (see Fig.10 ) is provided in the flow path 132 that connects the second neutralization tank 106 with the water intake 107, and the flow rate flowing in the flow path 132 is measured. It should be noted that in the softening process, the water flowing into the first soft water tank 103 is not distributed but circulated in the first neutralization tank 104, the second soft water tank 105 and the second neutralization tank 106. Therefore, the amount of water flowing in the flow path before and after softening can be regarded as substantially the same. That is, the flow rate of water measured by the flow measuring unit 162 can be regarded as the raw water flow rate before softening and the soft water flow rate after softening.

[0372] <16. Control Department>

[0373] Reference Fig.16 Each function of the control unit 115 according to this embodiment will be described. Fig.16 This is a functional block diagram of a water softening device 101 according to the second embodiment.

[0374] The control unit 115 controls the execution of each process of the water softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capturing unit cleaning process, and controls switching between the processes.

[0375] The so-called control of switching between the various processes, for example, specifically refers to the switching from the softening process to the regeneration process, the switching from the regeneration process to the regeneration flow path cleaning process, the switching from the regeneration flow path cleaning process to the electrolytic cell cleaning process, the switching from the electrolytic cell cleaning process to the capture part cleaning process, and the switching from the capture part cleaning process to the softening process.

[0376] In addition, the control unit 115 controls the on-off valve 120 and the on-off valve 122 to control the drainage during the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture unit cleaning process.

[0377] Furthermore, the control unit 115 controls the flow path switching valves 124 to 127 , the on-off valve 118 , the on-off valve 119 , the on-off valve 121 , and the on-off valve 123 to switch the flow paths.

[0378] The control unit 115 includes an adsorption amount determination unit 155 , a designation unit 156 , a recording unit 157 , a reference time determination unit 158 ​​, a comparison unit 159 , a main regeneration time calculation unit 163 , and a residual adsorption amount determination unit 164 .

[0379] <16.1 Adsorption amount determination section>

[0380] The adsorption amount determination unit 155 calculates the amount of hardness component adsorbed to the weakly acidic cation exchange resin 133 in the soft water tank based on the hardness of the raw water measured by the raw water hardness measurement unit 160, the hardness of the soft water measured by the soft water hardness measurement unit 161, and the flow rate of softened water measured by the flow rate measurement unit 162. Specifically, the hardness of the soft water measured by the soft water hardness measurement unit 161 is subtracted from the hardness of the raw water measured by the raw water hardness measurement unit 160. Then, the value calculated by the subtraction is multiplied by the flow rate of softened water measured by the flow rate measurement unit 162. Thus, the hardness component adsorption amount is calculated.

[0381] In addition, when the cycle of the softening process and the regeneration process is repeated, depending on the setting of the regeneration time, there is a possibility that the weakly acidic cation exchange resin 133 cannot be completely regenerated, and the hardness component may remain in the weakly acidic cation exchange resin 133. In this way, even if the weakly acidic cation exchange resin 133 adsorbs the residual hardness component at the time of the previous regeneration, in order to accurately calculate the amount of the hardness component adsorbed to the weakly acidic cation exchange resin 133, the adsorption amount determination unit 155 cooperates with the residual adsorption amount determination unit 164 described later.

[0382] Specifically, the adsorption amount determination unit 155 calculates the amount of adsorbed hardness component adsorbed by the k-th softening process by subtracting the hardness of the soft water after the water passes through the soft water tank from the hardness of the raw water and multiplying the value obtained by the subtraction by the amount of water. The adsorption amount determination unit 155 adds the residual hardness component adsorption amount after the (k-1)-th regeneration process determined by the residual adsorption amount determination unit 164 (k is an integer greater than or equal to 2) to the calculated amount of adsorbed hardness component adsorbed by the k-th softening process. In this way, the hardness component adsorption amount can be calculated more accurately.

[0383] <16.2 Residual adsorption amount determination section>

[0384] When the cycle of the softening process and the regeneration process is repeatedly performed, the residual adsorption amount determination unit 164 determines the residual hardness component adsorption amount after the (k-1)th regeneration process based on the (k-1)th regeneration time when the adsorption amount determination unit 155 determines the adsorption amount in the kth softening process (k is an integer greater than 2).

[0385] Specifically, the amount of residual hardness component adsorption is determined based on the change in the hardness of soft water after the soft water tank is passed through when the softening process is repeatedly implemented. When the amount of water passed through the soft water tank in the first softening process to make the soft water hardness above the reference value (for example, 30 ppm) is compared with the amount of water passed through the soft water tank in the k-th softening process to make the soft water hardness above the reference value, the amount of water passed through the k-th softening process is less than the amount of water passed through the reference value due to the influence of the amount of residual hardness component adsorption. The reduction ratio when comparing the amount of water passed through the k-th softening process with the amount of water passed through the first softening process without residual hardness component adsorption is considered to be equal to the ratio of the amount of residual hardness component adsorption to the hardness adsorbable amount obtained based on the resin amount of the weakly acidic cation exchange resin 133, and therefore the residual hardness adsorption is determined using the above method. For example, when the water flow exceeding the reference value in the first softening process is 500 L, and the water flow exceeding the reference value in the k-th softening process is 400 L, the water flow in the k-th softening process is 20% less than that in the first softening process. That is, 20% of the adsorbable amount of the resin does not function, so the residual hardness component adsorption amount can also be estimated to be 20%. In this way, by determining the residual hardness component adsorption amount, the k-th regeneration time can be determined with high accuracy based on the (k-1)-th residual hardness component adsorption amount that can be determined by the k-th softening process.

[0386] The information on the residual hardness component adsorption amount determined by the residual adsorption amount determination unit 164 is sent to the adsorption amount determination unit 155 and used for calculation of an accurate hardness component adsorption amount.

[0387] It should be noted that the reference value (third reference value) refers to the amount of hardness component adsorption that can be removed during a predetermined reference time. The predetermined reference time refers to a continuous time period during which the soft water process is less frequently performed, such as 7 hours at night. In other words, the reference value can be said to be the amount of hardness component that can be removed by performing the regeneration process during the time period during which the soft water process is less frequently performed.

[0388] <16.3 Main regeneration time calculation unit>

[0389] The main regeneration time calculation unit 163 calculates the main regeneration time as the time taken for the resin regeneration process based on the relationship between the amount of hardness components adsorbed to the soft water tank calculated by the adsorption amount determination unit 155 and the amount of protons supplied from the electrolytic cell 109. It should be noted that the main regeneration time refers to the time required to remove the hardness components adsorbed to the ion exchange resin from the ion exchange resin and complete the regeneration of the ion exchange resin.

[0390] The calculation method of the main regeneration time of the resin is described. First, in order to regenerate the resin, protons need to be supplied to the soft water tank, and in order to complete the regeneration of the resin, an amount of protons equivalent to the amount of hardness components adsorbed to the weakly acidic cation exchange resin 133 in the soft water tank needs to be supplied to the resin. The amount of protons generated in the electrolytic cell 9 (mol) is derived from the current value (A=C / sec), the Faraday constant (C / mol), the proton generation efficiency (%), and the regeneration time (h). Specifically, it is derived from the following formula (1).

[0391] Proton generation amount (mol) = current value (A = C / sec) × proton generation efficiency (%) × regeneration time (h) × 3600 ÷ Faraday constant (C / mol) (1)

[0392] It should be noted that the current value and the proton generation efficiency are set according to the prescribed electrolysis performance information and thus become fixed values.

[0393] According to 2R-COOH+Ca 2＋ (R―COO)2Ca+2H ＋ relationality,

[0394] When 1 mol of hardness component ions are adsorbed to the weakly acidic cation exchange resin 133, the amount of protons required for regeneration is 2 mol. That is, if the amount of adsorbed hardness component removed is determined, the amount of protons required for regeneration can be calculated, and thus the main regeneration time can be derived.

[0395] As a method for determining the predetermined reference time consumed by the regeneration process, there are a case where the predetermined reference time is pre-set by the designation unit 156, and a case where the predetermined reference time is determined by the reference time determination unit 158 ​​based on the actual state of use to identify a time period with a low possibility of implementing the water softening process. It should be noted that the predetermined reference time refers to a continuous time period during which the frequency of implementing the water softening process is low.

[0396] <16.4 Designated Department>

[0397] The designation unit 156 predetermines a time when the water softening process is not performed, and designates this time as a predetermined reference time in the regeneration process. For example, when the time period when the water softening process is not performed is set from 23:00 to 6:00, the regeneration process is determined to be performed in this time period (7 hours).

[0398] <16.5 Recording Department>

[0399] The recording unit 157 monitors the use status of the water softening device 101 and records the time period in which the water softening process is performed. Information on the recorded time period is sent to the reference time determination unit 158 ​​.

[0400] <16.6 Reference time determination unit>

[0401] The reference time determination unit 158 ​​determines a time period in which the softening process is less frequently performed based on the time period information of the softening process performed recorded in the recording unit 157, and determines to perform the regeneration process in this time period. For example, the usage status of the past month is monitored, and compared with the time period in which the softening process is performed, the time period in which the soft water usage is less is averagely calculated and set as the prescribed reference time.

[0402] It should be noted that the regeneration process is basically carried out continuously without interruption, so a continuous time period is set. Alternatively, when setting a continuous time period, a case where the amount of soft water used is small (for example, less than 5% of the amount of water used in a day, etc.) is judged as an error value, and the time period including the error value is set as the time period for carrying out the regeneration process.

[0403] In addition, when there is little information about the use history of the softening device 101, such as when the softening device 101 is used, the time period when the softening process is not performed is unclear. Therefore, the method for determining the prescribed reference time may be changed according to the information of the actual use state. Specifically, the prescribed reference time may be a time period determined by the reference time determination unit 158, and a prescribed reference time pre-set by the designation unit 156 may be used instead of the time period determined by the reference time determination unit 158.

[0404] <16.7 Comparison section>

[0405] The comparison unit 159 receives the main reproduction time calculated by the main reproduction time calculation unit 163 and the time information on the reproduction process from the designation unit 156 or the reference time determination unit 158, and compares the magnitude relationship between the respective reproduction times.

[0406] When the predetermined reference time determined by the designation unit 156 or the reference time determination unit 158 ​​is longer than the main regeneration time calculated by the main regeneration time calculation unit 163, the main regeneration time is set as the resin regeneration time. The resin regeneration time refers to the time for performing the regeneration process.

[0407] On the other hand, when the main regeneration time calculated by the main regeneration time calculation unit 163 is longer than the prescribed reference time determined by the designation unit 156 or the reference time determination unit 158, the prescribed reference time is set as the resin regeneration time. When the prescribed reference time is used as the resin regeneration time, the adsorbed hardness components cannot be completely removed in one regeneration process. However, in the later stage of the regeneration process, the concentration of the hardness components relative to the concentration of hydrogen ions becomes smaller, and the ion exchange reaction is difficult to occur, so the regeneration efficiency is reduced compared to the initial to middle stage of the regeneration process. In addition, in the period from the initial to middle stage of the regeneration when the regeneration efficiency is high, the regeneration of the resin is completed by about 70% to 80%. Therefore, even if the regeneration process is implemented with the prescribed reference time as the resin regeneration time, the later stage of the regeneration process where the regeneration efficiency is reduced is omitted in most cases, so even if the softening process and the regeneration process are repeatedly performed, the softening performance can be ensured.

[0408] Based on the time taken for the regeneration process determined by the comparison unit 159 , the control unit 115 operates the electrolytic cell 109 to perform the regeneration process.

[0409] In the control unit 115, if the cycle of the softening process and the regeneration process is repeated, there is a possibility that the hardness component adsorbed by the softening process cannot be completely removed when the regeneration process is implemented, and the hardness component in the state of being adsorbed without being completely regenerated remains in the weakly acidic cation exchange resin 133. When the softening process and the regeneration process are repeatedly performed in a state where the hardness component remains, the amount of residual hardness component remaining in the weakly acidic cation exchange resin 133 gradually increases, and there is a possibility that the regeneration efficiency of the weakly acidic cation exchange resin 133 decreases due to the relationship between the hardness component and the hydrogen ion concentration. Specifically, when the amount of residual hardness component adsorption increases, in order to complete the regeneration by taking into account the amount of residual hardness component adsorption, a hydrogen ion concentration higher than the hydrogen ion concentration required to remove the amount of hardness component adsorbed by the first softening process is required. Therefore, it is difficult to completely remove the amount of hardness component adsorbed to the resin in the required regeneration time calculated based on the amount of hardness component actually adsorbed by the first softening process. That is, it is assumed that the regeneration efficiency in the first regeneration process deteriorates as the number of repetitions of the softening process and the regeneration process increases.

[0410] In order to suppress the reduction of regeneration efficiency during such repeated use, the control unit 115 performs the regeneration process at least during the main regeneration time determined by the main regeneration time calculation unit 163 in the m regeneration processes out of n times, even when the amount of hardness component adsorption exceeds the reference value (n is an integer greater than 2, m is an integer greater than 1, n>m). In this way, the hardness components adsorbed on the ion exchange resin can be removed regularly, and substantially all of the ion exchange resin can be regenerated. Therefore, even when the softening process and the regeneration process are repeated for a long time, the reduction of the regeneration efficiency can be suppressed. It should be noted that n and m can be set arbitrarily, for example, n=5, m=1, or n=3, m=2.

[0411] In addition, as another means for suppressing the reduction in regeneration efficiency during repeated use, there is a means for implementing a regeneration process during the main regeneration time when a reduction in regeneration efficiency is detected. Specifically, after the a-th regeneration process is completed, in the (a+1)-th softening process, when the hardness of the soft water measured by the soft water hardness measuring unit 161 exceeds the reference hardness value (for example, 50 ppm), in the (a+1)-th regeneration process, the regeneration process is implemented at least during the main regeneration time calculated by the main regeneration time calculation unit 163. In this way, it is possible to detect a reduction in softening performance and implement the regeneration process during the main regeneration time, so that even when the softening process and the regeneration process are repeatedly implemented, the reduction in softening performance can be suppressed. It should be noted that a is an integer greater than 1.

[0412] The above is the structure of the water softening device 101.

[0413] Next, the operation of the water softening device 101 will be described.

[0414] <17. Water softening step, regeneration step, regeneration flow path cleaning step, electrolytic cell cleaning step, and capture unit cleaning step>

[0415] Next, refer to Fig.17 The water softening step, the regeneration step, the regeneration flow path cleaning step, the electrolytic cell cleaning step, and the capturing portion cleaning step of the water softening device 101 will be described. Fig.17 It is a diagram showing the state of the water softening device 101 during operation.

[0416] In the water softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process and the capture unit cleaning process, the control unit 115 Fig.17 As shown, the on-off valves 118 to 123 , the flow path switching valves 124 to 127 , the electrode 141 of the electrolytic cell 109 , the first water supply pump 111 , and the second water supply pump 112 are switched and controlled so as to be in respective flow states.

[0417] here, Fig.17 The "on" in the figure indicates that the on-off valve is "open", the electrode 141 is energized, and the water pump is in operation. The blanks indicate that the on-off valve is "closed", the electrode 141 is not energized, and the water pump is stopped.

[0418] in addition, Fig.17 The phrase "from (the number of component A) to (the number of component B)" in the figure indicates that the flow path switching valve connects the flow path in a direction in which water is fed from component A to component B. For example, the flow path switching valve 124 of the water softening process connects the flow paths in a manner that water can be fed from flow path 128 to flow path 129.

[0419] in addition, Fig.17 The "toward (number of component C)" in the figure indicates a state where the flow path switching valve connects the flow path in a direction in which water may be supplied to component C. At this time, although the flow path is connected, it is difficult for water to flow in or out of the soft water tank or the neutralization tank in which the flow path switching valve is installed, so it is extremely difficult for water to be supplied from the flow path switching valve.

[0420] <17.1 Water Softening Process>

[0421] First, refer to Fig.11 as well as Fig.17 The column “during water softening” explains the operation during the water softening process performed by the water softening device 101.

[0422] In the water softening device 101, as Fig.17 As shown, in the softening process, the on-off valve 119 provided in the flow path 128 is opened while the on-off valve 118 is closed. As a result, raw water containing hardness components flows in from the outside. The inflowing raw water flows in the order of the first softening tank 103, the first neutralization tank 104, the second softening tank 105, and the second neutralization tank 106, so that in the softening device 101, softened water (neutral soft water) can be taken out from the water intake port 107.

[0423] At this time, the flow path switching valve 124 is in a connection state where water can be sent from the flow path 128 to the flow path 129, the flow path switching valve 125 is in a connection state where water can be sent from the flow path 129 to the flow path 130, the flow path switching valve 126 is in a connection state where water can be sent from the flow path 130 to the flow path 131, and the flow path switching valve 127 is in a connection state where water can be sent from the flow path 131 to the flow path 132. The on-off valves 120 to 123 are all in a closed state. In addition, the operation of the electrode 141 of the electrolytic cell 109, the first water pump 111, and the second water pump 112 are also stopped.

[0424] Through this control, Fig.11 As shown, in the softening process, under the pressure of raw water flowing in from the outside, raw water is supplied from the inlet 102 through the flow path 128 to the first soft water tank 103. And the raw water supplied to the first soft water tank 103 flows through the weakly acidic cation exchange resin 133 provided in the first soft water tank 103. At this time, the cations as hardness components in the raw water are adsorbed by the weakly acidic cation exchange resin 133, and hydrogen ions are released (ion exchange is performed). And by removing the cations from the raw water, the raw water is softened. The softened water contains a large amount of hydrogen ions that flow out in exchange with the hardness components, so it is acidified and becomes acidic water (first soft water) with a low pH. Here, when water containing a large amount of permanent hardness components (for example, sulfates such as calcium sulfate or chlorides such as magnesium chloride) as hardness components is softened, the pH is easily lowered than water containing a large amount of temporary hardness components (for example, carbonates such as calcium carbonate). Since water softening is difficult to proceed in a state where the pH is lowered, the water flowing through the first soft water tank 103 is passed into the first neutralization tank 104 for neutralization.

[0425] The water softened in the first soft water tank 103 flows through the flow path 129 via the flow path switching valve 124 provided in the first soft water tank 103, and flows into the first neutralization tank 104. In the first neutralization tank 104, hydrogen ions contained in the softened water are adsorbed by the weakly basic anion exchange resin 134. That is, hydrogen ions are removed from the water softened in the first soft water tank 103, and the pH value that has been lowered is increased and neutralized. Therefore, compared with the case where the water softened in the first soft water tank 103 is softened in the second soft water tank 105 as it is, it is easy to make the softening process in the second soft water tank 105 progress.

[0426] The water neutralized by the first neutralization tank 104 (neutralized first soft water) flows through the flow path 130 via the flow path switching valve 125 provided in the first neutralization tank 104, and flows into the second soft water tank 105. In the second soft water tank 105, cations as hardness components are adsorbed by the weakly acidic cation exchange resin 133, and hydrogen ions are released. The second soft water tank 105 exchanges the hardness components that cannot be removed by the first soft water tank 103 with the hydrogen ions possessed by the weakly acidic cation exchange resin 133. That is, the water flowing into the second soft water tank 105 is further softened and becomes soft water (second soft water).

[0427] The second soft water flows through the flow path 131 via the flow path switching valve 126 provided in the second soft water tank 105, and flows into the second neutralization tank 106. In the second neutralization tank 106, the hydrogen ions contained in the second soft water flowing in are adsorbed by the weakly basic anion exchange resin 134. That is, the hydrogen ions are removed from the second soft water, and the pH value that has been lowered rises, and becomes neutral soft water (neutralized second soft water) that can be used as domestic water. The neutralized second soft water flows through the flow path switching valve 127 provided in the second neutralization tank 106, and is taken out from the water intake port 107.

[0428] That is, in the softening treatment, the raw water flows in the order of the first softening tank 103, the first neutralization tank 104, the second softening tank 105, and the second neutralization tank 106. Thus, the raw water containing hardness components flows out of the first softening tank 103 before the pH of the raw water decreases due to the softening treatment in the first softening tank 103, is neutralized in the first neutralization tank 104, is softened in the second softening tank 105, and is neutralized in the second neutralization tank 106. Therefore, compared with the case where the softening tank and the neutralization tank are constituted by monomers, the pH of the water flowing in the softening tank can be suppressed from decreasing, that is, acidification, so that the hardness components are easily exchanged with the hydrogen ions held by the weakly acidic cation exchange resin 133 of the softening tank (particularly the second softening tank 105). Therefore, the softening performance can be improved.

[0429] Then, in the water softening device 101, when the time period determined by the control unit 115 comes or when the water softening process exceeds a constant water volume, the water softening process is terminated and the regeneration process is performed.

[0430] <17.2 Regeneration process>

[0431] Next, refer to Fig.12 as well as Fig.17 The column “Regeneration” will sequentially describe the operations during the regeneration process performed by the regeneration device 108 of the water softening device 101.

[0432] In the softening device 101, the first softening tank 103 and the second softening tank 105 filled with weakly acidic cation exchange resin 133 have a reduced or lost cation exchange capacity when used continuously. That is, after all the hydrogen ions of the functional groups of the cation exchange resin are exchanged with calcium ions or magnesium ions as hardness components, ion exchange cannot be performed. Even before all the hydrogen ions are exchanged with the hardness components, it is difficult for the ion exchange reaction to occur as the hydrogen ions decrease, so the softening performance is also reduced. When this state is reached, the hardness components are contained in the treated water. Therefore, in the softening device 101, it is necessary to perform regeneration treatment of the first softening tank 103, the second softening tank 105, the first neutralization tank 104, and the second neutralization tank 106 using the regeneration device 108.

[0433] During the regeneration process, the control unit 115 closes the on-off valves 119, 120, and 122 and opens the on-off valves 118, 121, and 123. The control unit 115 makes the flow path switching valve 124 a connection state in which water can be sent from the neutralization tank bypass flow path 142 to the first recovery flow path 137, makes the flow path switching valve 125 a connection state in which water can be sent from the soft water tank bypass flow path 144 to the second recovery flow path 138, makes the flow path switching valve 126 a connection state in which water can be sent from the first supply flow path 135 to the neutralization tank bypass flow path 142, and makes the flow path switching valve 127 a connection state in which water can be sent from the second supply flow path 136 to the soft water tank bypass flow path 144. That is, the first soft water tank 103 and the second soft water tank 105 are in a state of communication and connection, and the first neutralization tank 104 and the second neutralization tank 106 are in a state of communication and connection. The control unit 115 stops the drainage of the drainage port 113 and the capture unit drainage port 114. Fig.12 As shown in the figure, a soft water tank regeneration circulation flow path 139 and a neutralization tank regeneration circulation flow path 140 are formed respectively.

[0434] When the first water pump 111 and the second water pump 112 are operated, the acidic electrolyzed water and the alkaline electrolyzed water in the electrolytic tank 109 circulate in the soft water tank regeneration circulation flow path 139 and the neutralization tank regeneration circulation flow path 140, respectively.

[0435] In addition, the control unit 115 energizes the electrolytic cell 109 so that the anode has a higher potential than the cathode (positive electrolysis). Thus, during electrolysis, hydrogen ions are generated at the anode, and acidic electrolyzed water is generated near the anode. On the other hand, hydroxide ions are generated at the cathode, and alkaline electrolyzed water is generated near the cathode.

[0436] The acidic electrolyzed water generated in the electrolytic cell 109 flows through the first supply flow path 135 and is sent to the second soft water tank 105 via the flow path switching valve 126, and flows through the weakly acidic cation exchange resin 133 inside. In addition, the acidic electrolyzed water that has flowed through the second soft water tank 105 flows through the neutralization tank bypass flow path 142 and is sent to the first soft water tank 103 via the flow path switching valve 124, and flows through the weakly acidic cation exchange resin 133 inside. That is, by passing the acidic electrolyzed water into the weakly acidic cation exchange resin 133, the cations (hardness components) adsorbed on the weakly acidic cation exchange resin 133 and the hydrogen ions contained in the acidic electrolyzed water undergo an ion exchange reaction. As a result, the weakly acidic cation exchange resin 133 is regenerated.

[0437] Then, the acidic electrolyzed water flowing through the first soft water tank 103 contains cations and flows into the first recovery flow path 137. That is, the acidic electrolyzed water containing cations flowing through the weakly acidic cation exchange resin 133 is recovered to the electrolytic tank 109 via the first recovery flow path 137.

[0438] In this way, the soft water tank regeneration circulation flow path 139 is constructed to allow acidic electrolyzed water to flow from the downstream side of the second soft water tank 105, which is a soft water tank located at the most downstream relative to the inlet of the raw water and is a soft water tank having a weakly acidic cation exchange resin 133 that adsorbs less hardness components than the soft water tank on the upstream side, and to flow into the downstream side of the first soft water tank 103, which is located upstream and has a weakly acidic cation exchange resin 133 that adsorbs more hardness components than the second soft water tank 105.

[0439] That is, the soft water tank regeneration circulation flow path 139 is a flow path that allows the acidic electrolyzed water sent from the electrolytic tank 109 to flow through the second soft water tank 105, then be sent to the first soft water tank 103 through the neutralization tank bypass flow path 142, flow through the first soft water tank 103, and flow into the electrolytic tank 109 through the first recovery flow path 137. Thus, during the regeneration process, the acidic electrolyzed water discharged from the electrolytic tank 109 flows into the second soft water tank 105, which has a smaller adsorption amount of hardness components than the first soft water tank 103, and the acidic electrolyzed water containing hardness components is discharged from the second soft water tank 105 to the first soft water tank 103. In the regeneration of the weakly acidic cation exchange resin 133 in the second soft water tank 105, the consumption of hydrogen ions in the acidic electrolyzed water is less than that in the first soft water tank 103, so that the decrease in hydrogen ion concentration can be suppressed compared with the regeneration of the first soft water tank 103. Therefore, the acidic electrolyzed water containing a large amount of hydrogen ions flows into the first soft water tank 103, and it is possible to suppress the re-adsorption of hardness components in the first soft water tank 103. Therefore, it is possible to suppress a decrease in the regeneration treatment efficiency and shorten the regeneration time.

[0440] On the other hand, the alkaline electrolyzed water generated near the cathode of the electrolytic cell 109 flows through the second supply flow path 136 and the capture unit 110, and is sent to the second neutralization tank 106 via the flow path switching valve 127, and flows through the weakly basic anion exchange resin 134 inside. In addition, the alkaline electrolyzed water that has flowed through the second neutralization tank 106 flows through the soft water tank bypass flow path 144, and is sent to the first neutralization tank 104 via the flow path switching valve 125, and flows through the weakly basic anion exchange resin 134 inside. That is, by passing the alkaline electrolyzed water into the weakly basic anion exchange resin 134, the anions adsorbed on the weakly basic anion exchange resin 134 undergo an ion exchange reaction with the hydroxide ions contained in the alkaline electrolyzed water. As a result, the weakly basic anion exchange resin 134 is regenerated.

[0441] Then, the alkaline electrolyzed water flowing through the first neutralization tank 104 contains anions and flows into the second recovery flow path 138. That is, the alkaline electrolyzed water containing anions flowing through the weakly basic anion exchange resin 134 is recovered to the electrolytic tank 109 via the second recovery flow path 138.

[0442] In this way, the neutralization tank regeneration circulation flow path 140 is constructed to allow alkaline electrolyzed water to flow from the downstream side of the second neutralization tank 106, which is the neutralization tank located most downstream relative to the inlet of the raw water and has a weakly basic anion exchange resin 134 that adsorbs less anions than the neutralization tank on the upstream side, and to flow into the downstream side of the first neutralization tank 104, which is located upstream and has a weakly basic anion exchange resin 134 that adsorbs more anions than the second neutralization tank 106.

[0443] That is, the neutralization tank regeneration circulation flow path 140 is a flow path in which the alkaline electrolyzed water sent from the electrolytic tank 109 flows through the second neutralization tank 106, is sent to the first neutralization tank 104 through the soft water tank bypass flow path 144, flows through the first neutralization tank 104, and flows into the electrolytic tank 109 via the second recovery flow path 138. Thus, during the regeneration process, the alkaline electrolyzed water flows into the second neutralization tank 106, which has a smaller amount of anions adsorbed than the first neutralization tank 104, and the alkaline electrolyzed water containing anions is discharged from the second neutralization tank 106 to the first neutralization tank 104. In the regeneration of the weakly basic anion exchange resin 134 in the second neutralization tank 106, the consumption of hydroxide ions in the alkaline electrolyzed water is less than that in the first neutralization tank 104, so the decrease in the hydroxide ion concentration can be suppressed compared with the regeneration of the first neutralization tank 104. Therefore, alkaline electrolyzed water containing a large amount of hydroxide ions flows into the first neutralization tank 104, and it is possible to suppress the re-adsorption of anions in the first neutralization tank 104. Therefore, it is possible to suppress a decrease in the regeneration treatment efficiency and shorten the regeneration time.

[0444] In addition, in the neutralization tank regeneration circulation flow path 140, the alkaline electrolyzed water sent from the electrolytic tank 109 is introduced into the first neutralization tank 104 and the second neutralization tank 106 from the downstream side of the first neutralization tank 104 and the second neutralization tank 106, and flows out from the upstream side where the adsorption amount of anions in each neutralization tank is more than the downstream side. Thus, the alkaline electrolyzed water flows in from the downstream side where the adsorption amount of anion components is less, and the neutralization tank is regenerated. In the regeneration of the weakly basic anion exchange resin 134 on the downstream side, the consumption of hydroxide ions in the alkaline electrolyzed water is less than that on the upstream side, so the reduction of the hydroxide ion concentration of the alkaline electrolyzed water can be suppressed. Therefore, the anions contained in the alkaline electrolyzed water from the downstream side can be suppressed from being re-adsorbed on the upstream side. Therefore, the reduction of the regeneration treatment efficiency of the neutralization tank can be suppressed, and the regeneration time can be shortened. It should be noted that the downstream side refers to the downstream side in the flow path during the softening treatment.

[0445] <17.2.1 Control method of water softening device>

[0446] Next, use Fig.18 The control performed by the control unit 115 in the above-described configuration will be described. Fig.18 This is a flowchart for determining the regeneration time of the water softening device 101 of the second embodiment. Here, in the flowchart, numbers are assigned with S as the first letter. For example, S1 and the like represent processing steps. However, the size of the numerical value representing the processing step has nothing to do with the processing order.

[0447] Next, the control executed when the regeneration process is determined in the water softening device 101 will be described.

[0448] First, the raw water hardness measuring unit 160 obtains hardness information of raw water ( S001 ).

[0449] Next, the flow rate measuring unit 162 measures the amount of raw water flowing into the soft water tank ( S002 ).

[0450] In addition, the soft water hardness measuring unit 161 obtains hardness information of the soft water after the water flows through the soft water tank ( S003 ).

[0451] Then, based on the information acquired in each step of S001 to S003 , the adsorption amount determination unit 155 determines the amount of hardness component adsorbed to the weakly acidic cation exchange resin 133 in the water softening process ( S004 ).

[0452] Next, the main regeneration time calculation unit 163 derives the main regeneration time as the time required to completely remove the adsorbed hardness component based on the hardness component adsorption amount determined in step S004 and the proton generation amount of the electrolytic cell 109 ( S005 ).

[0453] In the water softening device 101 of this embodiment, the main regeneration time is compared with a predetermined reference time to determine the implementation time of the regeneration process. The predetermined reference time is determined by a pre-set mode (S207) and a mode of setting a time period with a low frequency of the water softening process based on actual usage (S107-S108).

[0454] First, in the mode of presetting the regeneration time ( S207 ), the designation unit 156 sets the time period for regeneration implementation, assuming a time period when the water softening process is not implemented.

[0455] Next, in a mode ( S107 to S108 ) of setting a time period in which the frequency of the water softening process is less frequent based on the actual usage status, the recording unit 157 monitors the actual usage status and records the time period in which the water softening process is performed ( S107 ).

[0456] Then, the reference time determination unit 158 ​​determines a time period when the water softening process is less frequently performed based on the recorded information, and sets this time period as a predetermined reference time ( S108 ).

[0457] Thereafter, the comparison unit 159 compares the main reproduction time with a predetermined reference time ( S309 ).

[0458] As a result of the comparison, when the main reproduction time is longer than the predetermined reference time, the comparison unit 159 sets the predetermined reference time as the reproduction time ( S410 ).

[0459] Then, the control unit 115 drives the electrolytic cell 109 to start the regeneration process ( S411 ).

[0460] On the other hand, when the predetermined reference time is longer than the main reproduction time, the comparison unit 159 sets the main reproduction time as the reproduction time ( S510 ).

[0461] Then, the control unit 115 drives the electrolytic cell 109 to start the regeneration process ( S511 ).

[0462] In the water softening device 101, the regeneration process is performed based on the above-mentioned control, and when the regeneration process is completed, the process shifts to the regeneration flow path cleaning process.

[0463] It should be noted that when the user wants to obtain soft water during the regeneration process, by opening a faucet connected to the softening device 101, raw water flows from the inlet 102 through the bypass flow path 153 and out of the water intake 107, so that raw water can be used even without waiting for the end of the regeneration process.

[0464] <17.3 Regeneration flow path cleaning process>

[0465] Next, refer to Fig.13 as well as Fig.17 The column “Regeneration flow path cleaning” of FIG. 1 sequentially describes the operations of the water softening device 101 during the regeneration flow path cleaning step.

[0466] In the water softening device 101, during the regeneration process, hardness components are released from the first soft water tank 103 and the second soft water tank 5 into the acidic electrolyzed water, and the acidic electrolyzed water is not discharged from the soft water tank regeneration circulation flow path 139 but circulates in the flow path. Therefore, after the regeneration process is completed, the soft water tank regeneration circulation flow path 139 is filled with high-hardness water containing hardness components released from the first soft water tank 103 and the second soft water tank 105. The hardness of this high-hardness water is significantly higher than the hardness of raw water (for example, 450ppm), for example, sometimes rising to about 2000ppm. When the water softening process is transferred to the water softening process in a state where this high-hardness water remains in the water softening device 101, the high-hardness water or the mixed water of raw water and high-hardness water is discharged from the water intake port 107. Therefore, the following problem occurs: when the user of the water softening device 101 performs the water softening process after the regeneration process is completed, not only soft water cannot be obtained immediately after the soft water process is started, but water with a hardness higher than that of raw water is obtained.

[0467] In addition, high-hardness water flows through the weakly acidic cation exchange resin 133 in the first soft water tank 103 and the second soft water tank 105. Although the adsorbed hardness components are replaced with hydrogen ions and regenerated in the regeneration process, the water containing the hardness components flows again, so the hydrogen ions filled by the regeneration process with great difficulty exchange with the hardness components, and the hardness components are adsorbed again in the weakly acidic cation exchange resin 133. Therefore, the hydrogen ions that can be used in the softening of raw water are reduced, and the softening performance is reduced. In order to solve these problems, a regeneration flow path cleaning process is performed to discharge the high-hardness water in the soft water tank regeneration circulation flow path 139.

[0468] During the regeneration flow path cleaning process, the control unit 115 closes the on-off valves 121 to 123 and opens the on-off valves 118 to 120. In addition, the control unit 115 makes the flow path switching valve 124 a connection state in which water can be supplied from the flow path 128 to the neutralization tank bypass flow path 142, makes the flow path switching valve 125 a connection state in which water can be supplied to the soft water tank bypass flow path 144, makes the flow path switching valve 126 a connection state in which water can be supplied from the neutralization tank bypass flow path 142 to the first supply flow path 135, and makes the flow path switching valve 127 a connection state in which water can be supplied to the second supply flow path 136. That is, the first soft water tank 103 and the second soft water tank 105 are in a connected state, the second soft water tank 105 and the drain port 113 are in a connected state, and the electrolytic tank 109 and the drain port 113 are in a connected state. The control unit 115 stops the drainage of the capture unit drain port 114. As a result, Fig.13 As shown in the figure, the first drain flow path 146 and the second drain flow path 147 are formed. It should be noted that at this time, the operation of the electrode 141, the first water pump 111 and the second water pump 112 is stopped.

[0469] In the regeneration flow path cleaning step, specifically, the on-off valve 119 is opened so that raw water flows from the outside into the first drain flow path 146 and the second drain flow path 147 .

[0470] In the first drainage flow path 146, under the action of the pressure of the raw water flowing in, the high-hardness water in the flow path 128, the first recovery flow path 137, the first water supply pump 111, the electrolytic cell 109 and the first supply flow path 135 is washed away and flows into the drainage flow path 154. The high-hardness water flowing into the drainage flow path 154 is discharged from the drain port 113 to the outside of the device.

[0471] In the second drainage flow path 147, under the pressure of the raw water flowing in, the high hardness water in the flow path 128, the first soft water tank 103, the neutralization tank bypass flow path 142, the second soft water tank 105 and the first supply flow path 135 is washed away and flows into the drainage flow path 154. The high hardness water flowing into the drainage flow path 154 is discharged from the drain port 113 to the outside of the device.

[0472] In this way, through the regeneration flow path cleaning process, the high hardness water in the first drainage flow path 146 and the second drainage flow path 147, which are the main high hardness water remaining parts after the regeneration process, can be suppressed from flowing into the neutralization tank, and the high hardness water can be replaced with raw water. Therefore, in the regeneration flow path cleaning process, the adsorption of hydrogen ions to the weakly basic anion exchange resin 134 in the neutralization tank can be suppressed, so the consumption of the filled hydroxide ions can be suppressed, and the neutralization performance can be maintained. Therefore, the reduction of the water softening performance caused by the high hardness water can be suppressed.

[0473] It should be noted that the control unit 115 supplies the raw water to each flow path so that the flow rate of the raw water flowing through the second drain flow path 147 is greater than the flow rate of the raw water flowing through the first drain flow path 146 .

[0474] Thus, the high-hardness water in the second drainage flow path 147, which is a flow path including the soft water tank used in the softening process and is a flow path necessary for draining the high-hardness water in the flow path, can be preferentially replaced with raw water. Therefore, the reduction in the softening performance caused by the high-hardness water when the softening process is started can be suppressed. In addition, the amount of water discharged from the first drainage flow path 146, which is a flow path not used in the softening process and is a flow path where the influence of the softening process on the high-hardness water is small even if it remains, can be reduced, thereby preventing useless drainage and suppressing the amount of water required for the regeneration flow path cleaning process.

[0475] In addition, the high-hardness water is discharged to the outside of the device through the flow path that does not include the neutralization tank. That is, the hardness components in the high-hardness water stored in the soft water tank regeneration circulation flow path 139 can be suppressed from being discharged to the adsorption site of the weakly basic anion exchange resin 134 in the neutralization tank, thereby preventing the softening performance from being reduced due to the high-hardness water generated during the regeneration process, and maintaining the softening performance.

[0476] Furthermore, in the softening device 101, when the time period determined by the control unit 115 is reached, or when the regeneration flow path cleaning process exceeds a constant time (for example, 1 minute), or when the water flow rate in the regeneration flow path cleaning process exceeds a constant value, the regeneration flow path cleaning process is terminated and the electrolytic cell cleaning process is performed.

[0477] It should be noted that, when the user wants to obtain soft water during the regeneration flow path cleaning process, by opening a faucet connected to the water softening device 101, raw water flows from the inlet 102 through the bypass flow path 153 and out of the water intake port 107. Therefore, raw water can be used without waiting for the completion of the regeneration flow path cleaning process.

[0478] <17.4 Electrolytic Cell Cleaning Process>

[0479] Next, refer to Fig.14 as well as Fig.17 The column “During electrolytic cell cleaning” of FIG. 11 describes the operations of the water softening device 101 during the electrolytic cell cleaning step in sequence.

[0480] In the regeneration process, when the electrolytic cell 109 is operated, the hardness components (calcium ions or magnesium ions) in the water are precipitated as solids (scale) at the cathode. The precipitates precipitated at the cathode are non-conductors, which causes the operating voltage of the electrolytic cell 109 to increase, and the power consumption during the regeneration process to increase. Therefore, it is necessary to perform an electrolytic cell cleaning process to remove the precipitates precipitated at the cathode.

[0481] In the electrolytic tank cleaning process, the control unit 115 opens the on-off valves 118 to 122 and closes the on-off valve 123. In addition, the control unit 115 makes the flow path switching valve 124 a connection state in which water can be supplied from the flow path 128 to the flow path 129, makes the flow path switching valve 125 a connection state in which water can be supplied to the soft water tank bypass flow path 144, makes the flow path switching valve 126 a connection state in which water can be supplied to the first supply flow path 135, and makes the flow path switching valve 127 a connection state in which water can be supplied to the second supply flow path 136. That is, the first soft water tank 103 and the electrolytic tank 109 are in a state of communication and connection, the electrolytic tank 109 and the drain port 113 are in a state of communication and connection, and the electrolytic tank 109 and the capture unit drain port 114 are in a state of communication and connection. As a result, Fig.14 As shown, the first drain flow path 146 and the third drain flow path 150 are formed respectively.

[0482] In the electrolytic cell cleaning step, specifically, the on-off valve 119 is opened by the control unit 115 , so that raw water flows from the outside into the first drain flow path 146 and the third drain flow path 150 .

[0483] The raw water that has flowed into the first drainage flow path 146 flows through the flow path 128 , the first recovery flow path 137 , and the first water supply pump 111 , and flows into the electrolytic cell 109 .

[0484] On the other hand, the raw water flowing into the third drainage flow path 150 flows through the flow path 128 , the first soft water tank 103 , the second recovery flow path 138 , and the second water supply pump 112 , and flows into the electrolytic cell 109 .

[0485] In the electrolytic cell cleaning step, the control unit 115 energizes the cathode so that the potential is higher than that of the anode (reverse electrolysis). Therefore, the electrolytic cell 109 electrolyzes the raw water flowing into the electrolytic cell to generate alkaline electrolyzed water near the anode and acidic electrolyzed water near the cathode.

[0486] At this time, the precipitate deposited at the cathode can be dissolved by the acidic electrolytic water generated at the cathode. Therefore, it is possible to suppress the reduction in electrolytic performance caused by the adhesion of the precipitate to the surface of the electrode 141.

[0487] The alkaline electrolyzed water generated by the anode flows through the first supply flow path 135 , flows into the drain flow path 154 , and is discharged to the outside of the device from the drain port 113 .

[0488] On the other hand, the acidic electrolyzed water generated by the cathode dissolves the precipitate precipitated at the cathode, and flows through the second supply flow path 136 and flows into the capture part 110. The acidic electrolyzed water flowing into the capture part 110 can dissolve the precipitate fixed to the capture part 110, so the capture part 110 can be preliminarily cleaned. Therefore, the time required for the capture part cleaning process as the next process can be shortened. In addition, the acidic electrolyzed water is discharged to the outside of the device from the capture part drain port 114 provided at the lower part of the capture part 110.

[0489] That is, in the electrolytic cell cleaning step, the removal of the precipitates in the electrolytic cell 109 and the removal of the precipitates in the capturing unit 110 can be performed simultaneously, and the time required from the end of the regeneration step to the start of the water softening step can be shortened.

[0490] Then, in the water softening device 101, when the time period determined by the control unit 115 comes or when the electrolytic cell cleaning process exceeds a certain time (eg, 5 minutes), the electrolytic cell cleaning process is terminated and the capturing unit cleaning process is executed.

[0491] It should be noted that in the third drainage flow path 150, the raw water passes through the first soft water tank 103, and thus becomes acidic water and passes through the capture part 110. Therefore, the capture part 110 is acidic, and the precipitate fixed to the capture part 110 is dissolved by the acidic water. Therefore, the capture part 110 can be preliminarily cleaned, so the time required for the capture part cleaning process as the next process can be shortened. That is, the removal of the precipitate in the electrolytic cell 109 and the removal of the precipitate in the capture part 110 can be performed at the same time, and the time required from the end of the regeneration process to the start of the water softening process can be shortened.

[0492] It should be noted that, when the user wants to obtain soft water during the electrolytic cell cleaning process, by opening a faucet connected to the water softening device 101, raw water flows from the inlet 102 through the bypass flow path 153 and out of the water intake port 107. Therefore, raw water can be used without waiting for the completion of the electrolytic cell cleaning process.

[0493] <17.5 Capture unit cleaning process>

[0494] Next, refer to Fig.15 as well as Fig.17 The column “When the capturing part is cleaned” of FIG. 11 sequentially describes the operations of the water softening device 101 during the capturing part cleaning step.

[0495] In the regeneration process, high-hardness water containing hardness components released from the first soft water tank 103 and the second soft water tank 105 flows into the electrolytic tank 109. The hardness components move to the cathode side during electrolysis, react with the hydroxide ions generated by the cathode, and become precipitates. A part of the precipitated precipitates is contained in the alkaline electrolytic water released from the electrolytic tank 109, flows in the second supply flow path 136, and is captured by the capture part 110. Therefore, the precipitates are gradually accumulated in the capture part 110 in the regeneration process, so the pressure loss caused by the capture part 110 gradually increases, and the flow rate of the alkaline electrolytic water flowing in the neutralization tank regeneration circulation flow path 140 gradually decreases. Therefore, when the precipitates are left alone, the time required for the regeneration of the weakly basic anion exchange resin 134 of the first neutralization tank 104 and the second neutralization tank 106 is extended, and it is possible that the filling of the weakly basic anion exchange resin 134 with hydroxide ions cannot be completed in the end. Therefore, it is necessary to perform a capturing portion cleaning step of removing the precipitates fixed to or precipitated on the capturing portion 110 .

[0496] In the capture unit washing process, the control unit 115 opens the on-off valves 118, 119, 122, and 123 and closes the on-off valves 120 and 121. In addition, the control unit 115 makes the flow path switching valve 124 a connection state in which water can be supplied from the flow path 128 to the flow path 129, makes the flow path switching valve 125 a connection state in which water can be supplied from the flow path 129 to the flow path 130, makes the flow path switching valve 126 a connection state in which water can be supplied from the flow path 130 to the flow path 131, and makes the flow path switching valve 127 a connection state in which water can be supplied from the flow path 131 to the second supply flow path 136. That is, the first soft water tank 103 and the first neutralization tank 104 are in a state of communication and connection, the first neutralization tank 104 and the second soft water tank 105 are in a state of communication and connection, the second soft water tank 105 and the second neutralization tank 106 are in a state of communication and connection, and the second neutralization tank 106 and the capture part drain port 114 are in a state of communication and connection. Fig.15 The fourth drain flow path 152 is formed as shown.

[0497] In the capture unit cleaning process, specifically, the control unit 115 opens the on-off valve 119 so that raw water flows from the outside into the flow path 128. The raw water flows through the flow path 128, the first soft water tank 103, the flow path 129, the first neutralization tank 104, the flow path 130, the second soft water tank 105, the flow path 131, the second neutralization tank 106, and the second supply flow path 136, and flows into the capture unit 110.

[0498] Neutral soft water flows into the capture part 110 from the side opposite to the water flow direction in the regeneration process. That is, the capture part 110 is backwashed by the inflowing neutral soft water. At this time, a part of the precipitate fixed or precipitated in the capture part 110 is dissolved in advance by the electrolytic cell cleaning process, so the capture part 110 can be easily cleaned by the neutral soft water. The neutral soft water containing the precipitate is discharged to the outside of the device from the capture part drain port 114 provided at the lower part of the capture part 110.

[0499] In this way, the capture part 110 can be backwashed, so that the precipitate remaining in the capture part 110 can be removed. Therefore, the clogging of the capture part 110 can be suppressed, and when the regeneration process is performed again, the pressure loss caused by the capture part 110 can be reduced. As a result, the flow rate of the neutralization tank regeneration circulation flow path 140, which is the regeneration flow path including the capture part 110, can be suppressed from decreasing, and the flow rate of the alkaline electrolyzed water can be guaranteed, so the regeneration performance can be guaranteed.

[0500] Then, in the water softening device 101, when the time period determined by the control unit 115 comes or when the capturing unit washing process exceeds a certain time (eg, 5 minutes), the capturing unit washing process is terminated and the water softening process is performed.

[0501] It should be noted that the flow path from the inlet 102 to the second neutralization tank 106 is the same flow path as the flow path during the softening process. That is, by using the fourth drainage flow path 152, the second neutralization tank 106, which is the neutralization tank at the last stage in the softening process, is filled with softened water. Therefore, by performing the softening process after the capture unit cleaning process using the fourth drainage flow path 152, the user of the softening device 101 can obtain soft water that has been softened and has reduced hardness from the water intake port 107 immediately after the softening process begins.

[0502] It should be noted that, when the user wants to obtain soft water during the capture unit cleaning process, by opening a faucet connected to the water softening device 101, raw water flows from the inlet 102 through the bypass flow path 153 and out of the water intake port 107. Therefore, raw water can be used without waiting for the capture unit cleaning process to be completed.

[0503] As described above, in the softening device 101, the softening process, the regeneration process, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture part cleaning process are repeatedly performed in sequence. By performing the capture part cleaning process immediately before the softening process, the neutralization tank at the last stage in the softening process becomes filled with softened water. Therefore, when the user of the softening device 101 turns on the faucet, the discharge of high-hardness water from the water intake port 107 can be suppressed, and soft water with stable hardness can be provided from the beginning of the softening process.

[0504] In addition, by performing the electrolytic cell cleaning process after the regeneration flow path cleaning process, the high-hardness water is discharged outside the device when the pole is changed in the electrolytic cell cleaning process, and the possibility of electrolyzing the high-hardness water can be suppressed. Therefore, the electrolysis of high-hardness water can be suppressed, and the generation of a large amount of scale in the flow path for delivering alkaline electrolyzed water can be suppressed when the pole is changed.

[0505] As described above, according to the water softening device 101 of this embodiment, the following effects can be obtained.

[0506] (1) The water softening device 101 includes: a softening tank that softens raw water containing hardness components using a weakly acidic cation exchange resin 133 to produce acidic soft water; a neutralization tank that neutralizes the pH of the acidic soft water that has passed through the softening tank using a weakly basic anion exchange resin 134 to produce neutralized soft water; an electrolytic tank 109 that generates acidic electrolyzed water for regenerating the weakly acidic cation exchange resin 133 and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin 134; and a control unit 115 that controls a regeneration step that is a step for regenerating at least one of the weakly acidic cation exchange resin 133 and the weakly basic anion exchange resin 134. The control unit 115 includes: an adsorption amount determination unit 155 that determines the amount of hardness component adsorbed to the soft water tank based on the hardness of raw water, the amount of raw water passed into the soft water tank, and the hardness of water after passing through the soft water tank; and a main regeneration time calculation unit 163 that calculates the main regeneration time required for the regeneration process required to remove the hardness component adsorbed based on the hardness component adsorption amount. The control unit 115 determines the time consumed in the regeneration process based on the comparison between the predetermined reference time and the main regeneration time.

[0507] According to this structure, the resin regeneration time can be determined based on the amount of hardness component adsorbed to the weakly acidic cation exchange resin 133 and the water flow rate, and after setting the upper limit time consumed by the regeneration process per unit cycle of the softening process and the regeneration process, the resin regeneration time based on the amount of adsorbed hardness component can be implemented. Therefore, the time required to complete the regeneration process of the ion exchange resin can be shortened.

[0508] (2) In the water softening device 101 , the control unit 115 may execute the regeneration step at least during the main regeneration time when the amount of hardness component adsorption is equal to or less than a reference value (third reference value) of the amount of hardness component that can be removed in a predetermined reference time.

[0509] According to this structure, in the case where the amount of hardness components adsorbed on the resin is small, the hardness components adsorbed on the resin can be removed even if the implementation time of the regeneration process is less than the prescribed reference time. Therefore, the resin regeneration can be completed in a short time. In the case where the prescribed reference time is set as the regeneration time in advance, the regeneration process is continued after the regeneration of the ion exchange resin is completed, but with this structure, since the regeneration process is implemented during the main regeneration time, it is possible to suppress excessive implementation of the regeneration process. In addition, the burden on the electrolytic cell 109 to which the current is continuously applied when the regeneration process is implemented can be suppressed, and the durability of the electrolytic cell 109 is improved.

[0510] (3) In the water softening device 101 , when the amount of hardness component adsorption is greater than a reference value (third reference value) of the amount of hardness component that can be removed within a predetermined reference time, the control unit 115 may terminate the regeneration step when a predetermined reference time has elapsed.

[0511] According to such a configuration, since the regeneration process is terminated based on a predetermined reference time, it is possible to suppress the time required for the regeneration process from being prolonged.

[0512] (4) In the water softening device 101, the control unit 115 may further include: a recording unit 157 that records the time period during which the water softening process is performed; and a reference time determination unit 158 ​​that determines a time period during which the water softening process is performed less frequently as a predetermined reference time based on the time period during which the water softening process is performed recorded by the recording unit 157. The control unit 115 may determine the time period during which the regeneration process is performed based on the determined predetermined reference time.

[0513] According to this structure, the time consumed by the regeneration process can be set in advance, so the time consumed by the regeneration process can be suppressed from being prolonged. In addition, the regeneration time and the time period for implementing the regeneration process can be set based on the actual use status of the softening device 101. Therefore, a regeneration process that is convenient for the user who uses the softening device 101 can be performed.

[0514] (5) In the water softening device 101 , the control unit 115 may further include a designation unit 156 that designates a preset time as a time when the water softening process is not performed as a predetermined reference time, and determines the designated predetermined reference time as a time period for performing the regeneration process.

[0515] Thus, the time required for the regeneration process can be set in advance, and thus the time required for the regeneration process can be prevented from being prolonged to a time longer than the set time.

[0516] (6) In the water softening device 101, the control unit 115 may perform the regeneration step m times out of n times at least during the main regeneration time even when the hardness component adsorption amount exceeds the reference value (third reference value) when performing the regeneration step multiple times (where n is an integer greater than 2, m is an integer greater than 1, and n>m).

[0517] Thus, when the softening process and the regeneration process are repeated, the relationship between the amount of hardness components remaining in the ion exchange resin and the hydrogen ion concentration during regeneration changes, so it is possible to predict a decrease in regeneration efficiency, but even when the amount of hardness component adsorption exceeds the reference value, the regeneration process can be performed m times out of n times during the main regeneration time. Therefore, the softening process and the regeneration process can be repeatedly performed for a long time while maintaining the softening performance.

[0518] (7) The water softening device 101 may include a soft water hardness measuring unit 161 for measuring the hardness of water after the water passes through the soft water tank. When the hardness measured by the soft water hardness measuring unit 161 at the end of the regeneration process is higher than a reference hardness value that is a target hardness after the regeneration process, the control unit 115 may perform the regeneration process at least during the main regeneration time even when the amount of adsorption of the hardness component exceeds the reference value (third reference value) during the next regeneration process.

[0519] Thus, the water softening performance can be monitored by the soft water hardness measuring unit 161. Therefore, the reduction in regeneration efficiency can be detected, and when the regeneration efficiency is reduced, the regeneration process is performed during the main regeneration time, so that the water softening process and the regeneration process can be repeatedly performed for a long time while maintaining the water softening performance.

[0520] (8) In the water softening device 101, the adsorption amount determination unit 155 may include a residual adsorption amount determination unit 164 that determines the residual hardness component adsorption amount after the (k-1)th regeneration process based on the (k-1)th regeneration time. In addition, the adsorption amount determination unit 155 may determine the hardness component adsorption amount based on the hardness of the raw water, the amount of raw water passed into the soft water tank, the hardness of the water after passing through the soft water tank, and the residual hardness component adsorption amount determined by the residual adsorption amount determination unit 164 (where k is an integer greater than or equal to 2).

[0521] Thus, in the process of repeating the softening process and the regeneration process, the amount of hardness components remaining in the ion exchange resin after the regeneration process is accurately measured, and the amount of adsorbed hardness components can be determined. Therefore, the setting of the regeneration time becomes more accurate.

[0522] The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that these embodiments are for illustration only, and various modifications can be implemented in the combination of the above-mentioned components or processing flows, and such modifications also belong to the scope of the present invention.

[0523] In addition, those skilled in the art should understand that the combination of the constituent elements or processing flows of this embodiment with the constituent elements or processing flows of other embodiments can also be implemented and belongs to the scope of the present invention.

[0524] It should be noted that, in the softening device 101 of the present embodiment, after the regeneration process is completed, the regeneration flow path cleaning process, the electrolytic cell cleaning process, and the capture part cleaning process are performed in this order, but it is not limited to this. For example, the regeneration flow path cleaning process can also be performed after the electrolytic cell cleaning process, and the capture part cleaning process can be performed as a pre-process of the softening process. Even if the cleaning in the device is performed in this order, the precipitates in the electrolytic cell 109 and the capture part 110 can be removed, and soft water can be filled in the second neutralization tank 106 immediately before the softening process.

[0525] (Third Embodiment)

[0526] Next, a third embodiment of the present invention will be described.

[0527] The present invention solves the above-mentioned second conventional problem and provides a water softening device capable of suppressing a decrease in efficiency of a regeneration process of a weakly basic anion exchange resin and a weakly acidic cation exchange resin.

[0528] Furthermore, the water softening device of the present embodiment includes a softening tank, a neutralization tank, an electrolytic tank, and a control unit. The control unit includes a hardness storage unit, an adsorption amount calculation unit, a removal amount calculation unit, and a process management unit. The softening tank softens raw water containing hardness components using a weakly acidic cation exchange resin to generate acidic soft water. The neutralization tank neutralizes the pH of the acidic soft water that has passed through the softening tank using a weakly basic anion exchange resin to generate neutralized soft water. The electrolytic tank generates acidic electrolyzed water and alkaline electrolyzed water. The control unit controls a regeneration process as a process for regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin. The hardness storage unit stores the hardness component concentration of raw water containing hardness components. The adsorption amount calculation unit calculates the amount of ions adsorbed to at least one of the softening tank and the neutralization tank based on the hardness component concentration of the raw water, the amount of raw water passed into the softening tank, and the hardness of the water after passing through the softening tank. The removal amount calculation unit calculates the amount of ions that can be removed from at least one of the softening tank and the neutralization tank based on the amount of hydrogen ions in the acidic electrolyzed water and the amount of hydroxide ions in the alkaline electrolyzed water obtained by operating the electrolytic tank for a predetermined time. The process management unit performs the regeneration process based on the comparison between the ion adsorption amount and the ion removal amount.

[0529] According to the present embodiment, it is possible to provide a water softening device capable of suppressing a decrease in efficiency of the regeneration process of the weakly basic anion exchange resin and the weakly acidic cation exchange resin.

[0530] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following embodiments are examples of specific implementations of the present invention and do not limit the technical scope of the present invention. In addition, the figures described in the embodiments are schematic figures, and the size and thickness ratio of each component in each figure do not necessarily reflect the actual size ratio.

[0531] Reference Fig.19 A water softening device 201 according to a third embodiment of the present invention will be described. Fig.19 2 is a conceptual diagram showing the structure of a water softening device 201 according to a third embodiment of the present invention. Fig.19 , each element of the water softening device 201 is conceptually shown.

[0532] <1. Overall structure>

[0533] The softening device 201 is a device for generating neutral soft water from raw water containing hardness components supplied from the outside. It should be noted that raw water refers to water (treatment target water) introduced into the device from the inlet 202, such as city water or well water. Raw water contains hardness components (for example, calcium ions or magnesium ions). By using the softening device 201 to perform a softening process, neutral soft water with a lower hardness than raw water is obtained, and soft water can be used even in areas where the hardness of raw water is high. It should be noted that the softening of water in the softening device 201 refers to a state in which the amount of hardness components in the softened water is less than the amount of hardness components in the raw water.

[0534] Specifically, if Fig.19 As shown, the water softening device 201 includes an inlet 202 , a softening tank 203 , a neutralization tank 204 , a water intake 205 , a regeneration device 206 , a flow rate measuring unit 251 , and a control unit 213 .

[0535] The water softening device 201 includes a drain port 211 , a plurality of on-off valves (on-off valves 214 to 219 ), and a plurality of flow path switching valves (flow path switching valves 220 to 223 ). Details of these will be described later.

[0536] <2. Inlet and water intake>

[0537] The inlet 202 is connected to a raw water supply source and is an opening for introducing raw water into the water softening device 201 .

[0538] The water intake 205 is an opening for supplying water that has passed through the softening process in the softening device 201 to the outside of the device. The softening device 201 can take out softened water from the water intake 205 under the pressure of raw water flowing in from the inlet 202 .

[0539] In the softening process of the softening process in the softening device 201, raw water supplied from the outside flows in the order of the inlet 202, the flow path 224, the first soft water tank 203a, the flow path 225, the first neutralization tank 204a, the flow path 226, the second soft water tank 203b, the flow path 227, the second neutralization tank 204b, the flow path 228, the flow path 229, the flow measuring unit 251 and the water intake 205, and is discharged as neutral soft water.

[0540] <3. Soft water tank>

[0541] The soft water tank 203 (the first soft water tank 203a and the second soft water tank 203b) softens raw water containing hardness components under the action of the weakly acidic cation exchange resin 230. Specifically, in the soft water tank 203, cations (calcium ions or magnesium ions) as hardness components contained in the circulating water (raw water) are exchanged with hydrogen ions, so that the hardness of the raw water is reduced and the raw water is softened. In the softening device 201 of this embodiment, the first soft water tank 203a and the second soft water tank 203b are provided as the soft water tank 203, and when there is no particular distinction between the two, the two are collectively recorded as the soft water tank 203.

[0542] The first soft water tank 203a softens the raw water flowing in from the inlet 202. The first soft water tank 203a includes a flow path switching valve 220. Details of the flow path switching valve will be summarized and described later.

[0543] The second soft water tank 203 b softens the water that has flowed through the first neutralization tank 204 a described later. The second soft water tank 203 b includes a flow path switching valve 222 .

[0544] The first soft water tank 203 a and the second soft water tank 203 b are respectively filled with weakly acidic cation exchange resin 230 .

[0545] Specifically, the first soft water tank 203a is filled with a first weakly acidic cation exchange resin 230a. The second soft water tank 203b is filled with a second weakly acidic cation exchange resin 230b. It should be noted that, hereinafter, the first weakly acidic cation exchange resin 230a and the second weakly acidic cation exchange resin 230b are described as weakly acidic cation exchange resin 230 when there is no need to distinguish between the two.

[0546] The weakly acidic cation exchange resin 230 is an ion exchange resin having hydrogen ions at the ends of the functional groups. The weakly acidic cation exchange resin 230 adsorbs cations (calcium ions or magnesium ions) as hardness components contained in the raw water passed through, and releases hydrogen ions. The soft water treated by the weakly acidic cation exchange resin 230 contains a large amount of hydrogen ions released in exchange with the hardness components. That is, the soft water flowing out of the first soft water tank 203a and the second soft water tank 203b is soft water (acidic soft water) that contains a large amount of hydrogen ions and is acidified.

[0547] Since the functional groups of the weakly acidic cation exchange resin 230 have hydrogen ions at their ends, the weakly acidic cation exchange resin 230 can be regenerated using acidic electrolyzed water in the regeneration step described below. At this time, the cations taken in as hardness components in the water softening step are released from the weakly acidic cation exchange resin 230.

[0548] There is no particular limitation on the weakly acidic cation exchange resin 230, and a general-purpose material can be used. For example, a material having a carboxyl group (-COOH) as an exchange group can be used. In addition, a hydrogen ion (H ＋ ) can also become metal ions or ammonium ions (NH4 ＋ ) and other cations.

[0549] <4. Neutralization tank>

[0550] The neutralization tank 204 (the first neutralization tank 204a and the second neutralization tank 204b) neutralizes the pH (hydrogen ion concentration index) of the soft water (acidified soft water) containing hydrogen ions released from the soft water tank under the action of the weakly basic anion exchange resin 231, and becomes neutral soft water. Specifically, the neutralization tank 204 adsorbs the hydrogen ions contained in the soft water from the soft water tank 203 together with the anions, so that the pH of the soft water increases and can become neutral soft water. In the softening water device 201 in this embodiment, the first neutralization tank 204a and the second neutralization tank 204b are provided as the neutralization tank 204, and when there is no particular distinction between the two, the two are collectively recorded as the neutralization tank 204.

[0551] The first neutralization tank 204a neutralizes the acidic soft water flowing through the first soft water tank 203a. The first neutralization tank 204a includes a flow path switching valve 221.

[0552] The second neutralization tank 204b neutralizes the acidic soft water flowing through the second soft water tank 203b. The second neutralization tank 204b includes a flow path switching valve 223.

[0553] The first neutralization tank 204a and the second neutralization tank 204b are respectively filled with weakly basic anion exchange resins 231. The first neutralization tank 204a is formed by filling the first weakly basic anion exchange resin 231a in a cylindrical container, for example. The second neutralization tank 204b is formed by filling the second weakly basic anion exchange resin 231b. It should be noted that, hereinafter, the first weakly basic anion exchange resin 231a and the second weakly basic anion exchange resin 231b are described as weakly basic anion exchange resins 231 when there is no need to distinguish between the two.

[0554] The weakly basic anion exchange resin 231 adsorbs hydrogen ions contained in the water passed therein to generate neutral water. The weakly basic anion exchange resin 231 is regenerated using alkaline electrolyzed water in a regeneration step described later.

[0555] The weakly basic anion exchange resin 231 is not particularly limited, and a general-purpose material can be used. For example, a free base type material of a tertiary amine can be mentioned.

[0556] <5. Flow rate measurement unit>

[0557] The flow rate measuring unit 251 of the water softening device 201 detects the flow rate of the neutral soft water flowing out of the second neutralization tank 204b. The flow rate measuring unit 251 is connected to the adsorption amount calculation unit 253 and the control unit 213 described later in a wireless or wired manner so as to be able to communicate. Information related to the detected flow rate of the soft water is used as an adsorption amount calculation unit 253 (see Fig. 22 ) and an input signal of the control unit 213. As the flow measuring unit 251, as long as it is a detector for measuring the flow rate of the water flow, a general-purpose detector such as an impeller type and an ultrasonic type can be used. The flow measuring unit 251 is arranged on the downstream side of the neutralization tank 204, and is arranged on the flow path 229 in the present embodiment. It should be noted that, when a plurality of neutralization tanks 204 are provided, the flow measuring unit 251 is preferably arranged at a position downstream of the neutralization tank 204 in the last stage. It should be noted that the downstream side refers to the downstream side in the softening process.

[0558] <6. Regeneration device>

[0559] The regeneration device 206 is a device for regenerating the weakly acidic cation exchange resin 230 filled in the first soft water tank 203a and the second soft water tank 203b and regenerating the weakly basic anion exchange resin 231 filled in the first neutralization tank 204a and the second neutralization tank 204b.

[0560] The regeneration device 206 includes an electrolytic cell 207, a capture unit 208, a first water pump 209, and a second water pump 210. In addition, the regeneration device 206 is connected to the first supply flow path 232, the second supply flow path 233, the first recovery flow path 234, and the second recovery flow path 235 with respect to the second soft water tank 203b, the second neutralization tank 204b, the flow path 224, and the flow path 225, respectively. The details of each flow path are described later. It should be noted that the first supply flow path 232, the second supply flow path 233, the first recovery flow path 234, the second recovery flow path 235, the neutralization tank bypass flow path 239, and the soft water tank bypass flow path 241 form the soft water tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237 described later.

[0561] <6.1 Electrolytic Cell>

[0562] The electrolytic tank 207 generates acidic electrolyzed water and alkaline electrolyzed water by electrolyzing the water entering the electrolytic tank 207 using a pair of electrodes 238 (electrode 238a and electrode 238b) provided therein. In more detail, at the electrode 238a which becomes the anode during electrolysis in the regeneration process, hydrogen ions are generated by electrolysis, and acidic electrolyzed water is generated. In addition, at the electrode 238b which becomes the cathode during electrolysis in the regeneration process, hydroxide ions are generated by electrolysis, and alkaline electrolyzed water is generated. In addition, the electrolytic tank 207 supplies the generated acidic electrolyzed water to the first soft water tank 203a and the second soft water tank 203b via the first supply flow path 232 and the neutralization tank bypass flow path 239. In addition, the electrolytic tank 207 supplies the generated alkaline electrolyzed water to the first neutralization tank 204a and the second neutralization tank 204b via the second supply flow path 233 and the soft water tank bypass flow path 241. The acidic electrolyzed water generated by the electrolytic cell 207 is used in the regeneration of the weakly acidic cation exchange resin 230 in the first soft water tank 203a and the second soft water tank 203b, and the alkaline electrolyzed water generated by the electrolytic cell 207 is used in the regeneration of the weakly basic anion exchange resin 231 in the first neutralization tank 204a and the second neutralization tank 204b, as described later. It should be noted that the electrolytic cell 207 is configured to be able to control the energization state of the pair of electrodes 238 by the control unit 213 described later.

[0563] The electrolytic cell 207 is provided with a diaphragm as a porous membrane for separating liquids inside the cell. The diaphragm is a membrane that can realize ion movement caused by migration while suppressing the mixing of acidic electrolyzed water and alkaline electrolyzed water caused by convection. Thus, it is possible to suppress the consumption of hydrogen ions in the acidic electrolyzed water and hydroxide ions in the alkaline electrolyzed water due to neutralization reaction, thereby suppressing the reduction of the regeneration efficiency of the weakly acidic cation exchange resin 230 and the weakly basic anion exchange resin 231.

[0564] <6.2 Water supply pump>

[0565] The first water supply pump 209 is a device for circulating the acidic electrolyzed water in the first soft water tank 203a and the second soft water tank 203b during the regeneration process performed by the regeneration device 206. The first water supply pump 209 is provided in the first recovery flow path 234 that connects the first soft water tank 203a and the electrolytic tank 207. The reason for such a configuration is that it is easy to circulate the acidic electrolyzed water using only the first water supply pump 209.

[0566] The second water supply pump 210 is a device for circulating alkaline electrolyzed water in the first neutralization tank 204a and the second neutralization tank 204b during the regeneration process performed by the regeneration device 206. The second water supply pump 210 is provided in the second recovery flow path 235 that connects the first neutralization tank 204a and the electrolytic tank 207. The reason for such a configuration is that it is easy to circulate alkaline electrolyzed water using only the second water supply pump 210.

[0567] In addition, the first water supply pump 209 and the second water supply pump 210 are connected to a control unit 213 described later in a wireless or wired manner so as to be communicable.

[0568] <6.3 Capture part>

[0569] The capture unit 208 is provided in the second supply flow path 233 that connects the electrolytic cell 207 and the second neutralization tank 204b. In other words, the capture unit 208 is provided downstream of the electrolytic cell 207 and upstream of the neutralization tank 204 during the regeneration process.

[0570] The capture unit 208 captures the precipitate contained in the alkaline electrolyzed water sent from the electrolytic cell 207. The precipitate refers to the reaction product generated by the reaction of the cations, that is, the hardness components, released from the first soft water tank 203a and the second soft water tank 203b during the regeneration process in the electrolytic cell 207 with the alkaline electrolyzed water. More specifically, during the electrolysis of water in the electrolytic cell 207, the hardness components (for example, calcium ions or magnesium ions) released from the first soft water tank 203a and the second soft water tank 203b during the regeneration process move from the anode (electrode 238a) side to the cathode (electrode 238b) side via the diaphragm. Since alkaline electrolyzed water is generated on the cathode side, the hardness components react with the alkaline electrolyzed water to form precipitates. For example, when the hardness component is calcium ions, by mixing with the alkaline electrolyzed water, a reaction to produce calcium carbonate or a reaction to produce calcium hydroxide is caused. The precipitate derived from the hardness component is captured as a precipitate by the capture section 208 provided in the second supply flow path 233. By providing the capture section 208 in the second supply flow path 233, which is a flow path on the downstream side of the electrolytic cell 207 and the upstream side of the neutralization tank 204, the precipitate derived from the hardness component can be captured by the capture section 208, and the precipitate can be prevented from flowing into the neutralization tank 204 and accumulating in the neutralization tank 204. In the case where the capture section 208 is not provided on the downstream side of the electrolytic cell 207 and the upstream side of the neutralization tank 204, when the softening process is restarted after the regeneration process is completed, the precipitate accumulated in the neutralization tank 204 reacts with the hydrogen ions in the acidic soft water released from the soft water tank 203 and ionizes. As a result, the soft water sent out from the neutralization tank 204 contains the hardness component again, and thus the hardness increases compared to the hardness when it is released from the soft water tank 203 provided immediately before. By providing the capture portion 208 in the second supply flow path 233 , it is possible to suppress the increase in hardness associated with the accumulation and dissolution of the precipitates.

[0571] In addition, during the regeneration process, the alkaline electrolyzed water in which the precipitate from the hardness component is captured by the capture unit 208 flows through the second neutralization tank 204b and the first neutralization tank 204a, and then is electrolyzed again by the electrolytic tank 207, and is again supplied as alkaline electrolyzed water to the regeneration of the weakly basic anion exchange resin 231. At this time, the acidic electrolyzed water contains less hardness components than when the capture unit 208 is not provided. That is, by capturing the precipitate by the capture unit 208, the hardness of the acidic electrolyzed water is reduced, so that the hardness components flowing into the first soft water tank 203a and the second soft water tank 203b can be reduced, and the reduction in the regeneration efficiency of the weakly acidic cation exchange resin 230 can be suppressed.

[0572] It should be noted that “the hardness component reacts” includes not only the state in which all the hardness components react, but also the state in which unreacted components or components that do not exceed the solubility product are included.

[0573] The capturing unit 208 may be in any manner as long as it can separate the precipitate produced by the reaction of the hardness component and the alkaline electrolyzed water. For example, a box-type filter, a filter layer using a granular filter material, a cyclone-type solid-liquid separator, a hollow fiber membrane, etc. may be used.

[0574] A cartridge filter is a generally used mechanism for the capturing unit 208. As the cartridge filter, a depth filter such as a wire wound filter, a surface filter such as a pleated filter and a membrane filter can be used, or a combination of these can be used.

[0575] The capturing unit 208 includes an on-off valve 218 and a capturing unit drain port 212 .

[0576] The on-off valve 218 is provided at the bottom of the capture unit 208 and controls the discharge of water from the capture unit 208. By opening the on-off valve 218, water in the capture unit 208 can be discharged from the capture unit discharge port 212 to the outside of the device.

[0577] The capture unit drain port 212 is an opening for draining the water in the capture unit 208 to the outside of the device. By opening the on-off valve 218 provided upstream of the capture unit drain port 212, the water in the capture unit 208 can be drained to the outside of the device from the capture unit drain port 212.

[0578] <7. On / off valve and flow path switching valve>

[0579] A plurality of on-off valves (on-off valves 214 to 219 ) are provided in each flow path, and switch between an “open” state and a “closed” state in each flow path.

[0580] The plurality of on-off valves (on-off valve 214 , on-off valve 215 , on-off valve 217 , and on-off valve 219 ) start or stop the flow of water to each flow path by opening and closing the valves.

[0581] The on-off valve 216 and the on-off valve 218 are opened when switching to the water softening process after the completion of the regeneration process, and the regeneration circulating water is discharged to the outside of the device.

[0582] A plurality of flow path switching valves (flow path switching valves 220 to 223) are respectively provided in the first soft water tank 203a, the first neutralization tank 204a, the second soft water tank 203b, and the second neutralization tank 204b. The plurality of flow path switching valves each have three openings. The first opening is an inflow and outflow port through which water can flow in and out, the second opening is an inflow port that does not function as an outflow port for water to flow out but functions as an inflow port for water to flow in, and the third opening does not function as an inflow port for water to flow in but functions as an outflow port for water to flow out. The plurality of flow path switching valves each have an inflow and outflow port that are always "open", and when one of the inflow and outflow ports is "opened" according to the water flow direction, the other is "closed". By providing the flow path switching valves 220 to 223, the number of on-off valves required for each flow path in the water softening device 201 can be reduced, and the cost of the water softening device 201 can be reduced.

[0583] In addition, the plurality of on-off valves (on-off valves 214 to 219 ) and the plurality of flow path switching valves (flow path switching valves 220 to 223 ) are respectively connected to a control unit 213 to be described later in a wireless or wired manner so as to be communicable therewith.

[0584] <8. Drainage outlet>

[0585] The drain port 211 is an opening provided at the end of the drain flow path 243, and is an opening for discharging water in the device during the regeneration process and the softening process to the outside of the device. An on-off valve 216 is provided upstream of the drain port 211, and by opening the on-off valve 216, water can be discharged from the drain port 211. For example, after the regeneration process is completed, the drain port 211 connects the soft water tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237 (see Fig.21 ) is discharged to the outside of the device. Drainage from the drain port 211 can also be performed when switching to the softening process after the regeneration process is completed.

[0586] <9.Flow path>

[0587] The bypass flow path 242 is a flow path that connects the inlet 202 and the flow path 229, and the flow path is provided with an on-off valve 214. Through the bypass flow path 242, raw water can bypass the softening tank 203 and the neutralization tank 204 without passing into the softening tank 203 and the neutralization tank 204, and can be sent to the downstream side of the neutralization tank 204 as untreated water. In addition, through the bypass flow path 242, the user of the softening device 201 can obtain raw water from the water intake port 205 even when the regeneration process is being performed.

[0588] <10. Water softening flow path>

[0589] Reference Fig. 20The softening flow path 240 formed during the water softening step of the water softening device 201 will be described. Fig. 20 1 is a diagram showing the structure of the water softening flow path 240 of the water softening device 201 .

[0590] Softening flow path 240 (in Fig. 20 240 is a flow path for softening raw water. The raw water flowing through the softening flow path 240 becomes neutral soft water and is discharged from the water intake port 205 to the outside of the device.

[0591] The softening flow path 240 is a flow path through which water flows through the inlet 202, flow path 224, the first soft water tank 203a, flow path 225, the first neutralization tank 204a, flow path 226, the second soft water tank 203b, flow path 227, the second neutralization tank 204b, flow path 228, the flow measuring unit 251 and flow path 229, which are routes for passing water to the soft water tank 203 and the neutralization tank 204, and delivers soft water from the water intake 205.

[0592] The flow path 224 is a flow path connected to the first soft water tank 203a from the inlet 202. That is, the flow path 224 is a flow path that guides the raw water containing hardness components from the inlet 202 to the first soft water tank 203a.

[0593] The flow path 225 is a flow path connecting the first soft water tank 203a to the first neutralization tank 204a. That is, the flow path 225 is a flow path that guides the water softened by the first soft water tank 203a to the first neutralization tank 204a.

[0594] The flow path 226 is a flow path connecting the first neutralization tank 204a to the second soft water tank 203b. That is, the flow path 226 is a flow path that guides the water neutralized by the first neutralization tank 204a to the second soft water tank 203b.

[0595] The flow path 227 is a flow path connecting the second soft water tank 203b to the second neutralization tank 204b. That is, the flow path 227 is a flow path that guides the water softened in the second soft water tank 203b to the second neutralization tank 204b.

[0596] The flow path 228 is a flow path connected from the second neutralization tank 204b to the flow path 229. That is, the flow path 228 is a flow path that guides the softened raw water from the second neutralization tank 204b to the flow path 229.

[0597] Flow path 229 connects flow path 228 to water inlet 205 and bypass flow path 242 to water inlet 205. In other words, flow path 229 guides softened raw water from flow path 228 to water inlet 205 and guides raw water from bypass flow path 242 to water inlet 205.

[0598] like Fig. 20 As shown, an on-off valve 215 is provided on the flow path 224 on the downstream side of the inlet 202 and the upstream side of the first soft water tank 203a. And, by closing the on-off valve 214 and opening the on-off valve 215, the first soft water tank 203a is connected to the inlet 202. In addition, the flow path switching valve 220 is switched to connect the first soft water tank 203a with the first neutralization tank 204a, the flow path switching valve 221 is switched to connect the first neutralization tank 204a with the second soft water tank 203b, the flow path switching valve 222 is switched to connect the second soft water tank 203b with the second neutralization tank 204b, and the flow path switching valve 223 is switched to connect the second neutralization tank 204b with the water intake 205. Thus, a softening flow path 240 is formed that connects the inlet 202 to the flow path 224, the first soft water tank 203a, the flow path 225, the first neutralization tank 204a, the flow path 226, the second soft water tank 203b, the flow path 227, the second neutralization tank 204b, the flow path 228, the flow path 229 and the water intake port 205.

[0599] <11. Regeneration circulation flow path>

[0600] Next, refer to Fig.21 The softening tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237 formed during the regeneration process of the water softening device 201 will be described. Fig.21 It is a diagram showing the structure of the softening tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237 of the water softening device 201.

[0601] First, the soft water tank regeneration circulation flow path 236 will be described.

[0602] The soft water tank regeneration circulation flow path 236 is a flow path for acidic electrolyzed water to flow during the regeneration process to regenerate the first soft water tank 203a and the second soft water tank 203b, and is as follows: Fig.21 As indicated by (white arrow), the water delivered by the first water delivery pump 209 flows through the electrolytic tank 207 , the second soft water tank 203 b , and the first soft water tank 203 a and returns to the electrolytic tank 207 for circulation.

[0603] Specifically, the soft water tank regeneration circulation flow path 236 is composed of the first supply flow path 232, the neutralization tank bypass flow path 239 and the first recovery flow path 234, and the electrolytic cell 207, the second soft water tank 203b, the first soft water tank 203a and the first water supply pump 209 are arranged on the soft water tank regeneration circulation flow path 236.

[0604] The first supply flow path 232 is a flow path that communicates from the downstream side of the electrolytic cell 207 in the regeneration process to the downstream side of the second soft water tank 203 b in the water softening process, and is a flow path for supplying acidic electrolyzed water from the electrolytic cell 207 to the second soft water tank 203 b.

[0605] The neutralization tank bypass flow path 239 is a flow path that bypasses the first neutralization tank 204a and connects from the upstream side of the second soft water tank 203b during the water softening process to the downstream side of the first soft water tank 203a, and is a flow path that supplies acidic electrolyzed water from the second soft water tank 203b to the first soft water tank 203a.

[0606] The first recovery flow path 234 is a flow path that is connected to the electrolytic cell 207 from the upstream side of the first soft water tank 203a during the water softening process, and is a flow path that recovers the acidic electrolyzed water containing hardness components that has passed through the first soft water tank 203a and the second soft water tank 203b to the electrolytic cell 207. The first water supply pump 209 is provided in the first recovery flow path 234.

[0607] In addition, the soft water tank regeneration circulation flow path 236 is a flow path that introduces the acidic electrolyzed water sent out from the electrolytic tank 207 from the downstream sides of the first soft water tank 203a and the second soft water tank 203b during the softening process to the first soft water tank 203a and the second soft water tank 203b, and causes the acidic electrolyzed water to flow out from the upstream side where the adsorption amount of hardness components is greater than the downstream side of each soft water tank 203.

[0608] Next, the neutralization tank regeneration circulation flow path 237 will be described.

[0609] The neutralization tank regeneration circulation flow path 237 is a flow path for alkaline electrolyzed water to flow during the regeneration process to regenerate the first neutralization tank 204a and the second neutralization tank 204b, and is as follows: Fig.21 As indicated by (black arrow), the water sent out by the second water sending pump 210 flows through the electrolytic tank 207 , the second neutralization tank 204 b , and the first neutralization tank 204 a and returns to the electrolytic tank 207 for circulation.

[0610] Specifically, the neutralization tank regeneration circulation flow path 237 is composed of the second supply flow path 233, the soft water tank bypass flow path 241 and the second recovery flow path 235, and the electrolytic cell 207, the second neutralization tank 204b, the first neutralization tank 204a and the second water supply pump 210 are arranged on the neutralization tank regeneration circulation flow path 237.

[0611] The second supply flow path 233 is a flow path that communicates from the downstream side of the electrolytic cell 207 during the regeneration process to the downstream side of the second neutralization tank 204b during the water softening process, and is a flow path for supplying alkaline electrolyzed water from the electrolytic cell 207 to the second neutralization tank 204b. The second supply flow path 233 is provided with an on-off valve 217, a capture unit 208, and an on-off valve 219.

[0612] The soft water tank bypass flow path 241 is a flow path that bypasses the second soft water tank 203b and connects from the upstream side of the second neutralization tank 204b during the water softening process to the downstream side of the first neutralization tank 204a, and is a flow path that supplies alkaline electrolyzed water from the second neutralization tank 204b to the first neutralization tank 204a.

[0613] The second recovery flow path 235 is a flow path connected to the electrolytic cell 207 from the upstream side of the first neutralization tank 204a during the water softening process, and is a flow path for recovering the alkaline electrolyzed water that has passed through the first neutralization tank 204a and the second neutralization tank 204b to the electrolytic cell 207. The second recovery flow path 235 is provided with a second water delivery pump 210.

[0614] <12. Control Department>

[0615] Reference Fig. 22 The functions of the control unit 213 according to this embodiment will be described. Fig. 22 This is a functional block diagram of a water softening device 201 according to the third embodiment.

[0616] The control unit 213 controls the execution of the water softening process, the execution of the regeneration process, and the switching between the processes.

[0617] In addition, the control unit 213 controls the on-off valve 216 and the on-off valve 218 to control the drainage in the drainage process.

[0618] The control unit 213 controls the flow path switching valves 220 to 223 , the on-off valve 214 , the on-off valve 215 , the on-off valve 217 , and the on-off valve 219 to switch the flow paths.

[0619] The control unit 213 includes a hardness storage unit 252 , an adsorption amount calculation unit 253 , a removal amount calculation unit 254 , a residual value calculation unit 255 , an integrated value calculation unit 256 , a maximum value determination unit 257 , an estimated value calculation unit 258 , a comparison unit 259 , and a process management unit 260 .

[0620] <12.1 Hardness storage unit>

[0621] The hardness storage unit 252 stores the hardness component concentration of the raw water flowing into the water softening device 201. The hardness component concentration of the raw water may be input as a value corresponding to the region where the water softening device 201 is used or a value of the hardness component concentration measured in advance, or a device capable of measuring the hardness component concentration of the raw water may be provided on the downstream side of the inlet 202, that is, on the flow path 224, and the value measured by the device may be input.

[0622] <12.2 Adsorption amount calculation section>

[0623] The adsorption amount calculation unit 253 calculates the amount of cations adsorbed to the weakly acidic cation exchange resin 230 by the softening process as the adsorption amount (ion adsorption amount). The adsorption amount is calculated by multiplying the amount of raw water subjected to the softening process (the amount of soft water taken out from the water intake port 205) by the hardness component concentration of the raw water. More precisely, the hardness component concentration value removed by the softening process (the difference between the hardness component concentration of the raw water and the hardness component concentration of the soft water) is multiplied by the amount of soft water taken out from the water intake port 205.

[0624] It should be noted that, when raw water having a hardness component concentration similar to that of general domestic water (for example, a hardness component concentration of 250 mg / L or less) is softened, the hardness component concentration of the soft water taken out from the water intake 205 becomes approximately 1% or less compared to the hardness component concentration of the raw water, and can be substantially regarded as "0". Therefore, the hardness component concentration of the raw water can be used as it is in the calculation of the adsorption amount.

[0625] In addition, the amount of anions adsorbed to the weakly basic anion exchange resin 231 becomes an ion equivalent that is substantially equivalent to the hardness component adsorbed to the weakly acidic cation exchange resin 230. Therefore, by calculating the amount of adsorbed hardness component, the amount of adsorbed anions can also be calculated. More specifically, when cations (calcium ions or magnesium ions) as hardness components contained in the raw water introduced in the water softening process are adsorbed to the weakly acidic cation exchange resin 230, an equivalent amount of hydrogen ions is released (for example, 2 mol of hydrogen ions are released for each 1 mol of calcium ions adsorbed). Moreover, the released hydrogen ions are adsorbed together with anions of an equivalent amount in the weakly basic anion exchange resin 231. Therefore, the ion equivalent of the cations adsorbed to the weakly acidic cation exchange resin 230 and the ion equivalent of the anions adsorbed to the weakly basic anion exchange resin 231 become equivalent. However, if the flow rate of raw water exceeds the assumed value during the softening process and neutralization in the weakly basic anion exchange resin 231 is not completed, the adsorption amount of hydrogen ions and anions decreases and becomes less than the ion equivalent of cations adsorbed to the weakly acidic cation exchange resin 230 .

[0626] The adsorption amount calculation unit 253 includes a unit time adsorption amount calculation unit 253a that calculates the adsorption amount per unit time (for example, 1 day) as the unit time adsorption amount. The unit time adsorption amount is calculated by multiplying the amount of raw water that has been subjected to the softening process per unit time, that is, the amount of soft water taken out from the water intake port 205 per unit time by the hardness component concentration of the raw water. More precisely, the hardness component concentration value removed by the softening process (the difference between the hardness component concentration of the raw water and the hardness component concentration of the soft water) is multiplied by the amount of soft water taken out from the water intake port 205 per unit time.

[0627] <12.3 Removal amount calculation section>

[0628] The removal amount calculation unit 254 calculates the amount of cations that can be removed from the weakly acidic cation exchange resin 230 as the removal amount (ion removal amount) based on the operating time of the electrolytic cell 207. Since the weakly acidic cation exchange resin 230 has a high exchange order of hydrogen ions, most of the hydrogen ions that flow into it are consumed by the regeneration of the ion exchange resin. That is, the amount of hydrogen ions generated in the electrolytic cell 207 can be used as the cation removal amount. The amount of hydrogen ions generated (mol) and the amount of hydroxide ions generated (mol) in the electrolytic cell 207 are derived from the current value (A=C / sec), the Faraday constant (C / mol), the generation efficiency (%) and the regeneration time (h). Specifically, it is derived from the following formula (2).

[0629] Generation amount (mol) = current value (A = C / sec) × generation efficiency (%) × regeneration time (h) × 3600 ÷ Faraday constant (C / mol) (2)

[0630] It should be noted that the current value and the generation efficiency are set according to the specified electrolysis performance information and therefore become fixed values. Therefore, if the regeneration time is determined, the generation amount of hydrogen ions supplied from the electrolytic cell 207 can be derived, and the amount of cations that can be removed from the weakly acidic cation exchange resin 230 can be calculated. In other words, the removal amount calculation unit 254 calculates the amount of cations that can be removed from the weakly acidic cation exchange resin 230 by the regeneration process as the removal amount.

[0631] <12.4 Residual value calculation section>

[0632] The residual value calculation unit 255 calculates the amount of cations adsorbed to the weakly acidic cation exchange resin 230 at the end of the regeneration process as a residual value. The residual value is calculated by adding the amount of adsorption of the weakly acidic cation exchange resin 230 caused by the softening process performed after the end of the previous regeneration process to the residual value calculated at the end of the previous regeneration process, and subtracting the amount of removal of the weakly acidic cation exchange resin 230 caused by the regeneration process. It should be noted that in the initial residual value calculation, the residual value at the end of the previous regeneration process is set to "0".

[0633] <12.5 Cumulative value calculation unit>

[0634] The cumulative value calculation unit 256 calculates the cumulative value of the adsorption amount since the end of the previous regeneration process. In other words, the cumulative value of the amount of cations adsorbed to the weakly acidic cation exchange resin 230 through the softening process after the end of the previous regeneration process is calculated. In the calculation, the adsorption amount calculated for the softening process performed after the end of the previous regeneration process may be used, or the amount of raw water subjected to the softening process may be multiplied by the hardness component concentration of the raw water in the same manner as the adsorption amount calculation unit 253.

[0635] <12.6 Maximum value determination section>

[0636] The maximum value determination unit 257 selects the maximum adsorption per unit time among the adsorption per unit time since the end of the previous regeneration process as the maximum value. In other words, the amount of cations adsorbed on the weakly acidic cation exchange resin 230 when the softening treatment amount of raw water in the softening process divided per unit time after the end of the previous regeneration process is the largest is recorded as the maximum value. It should be noted that the softening treatment amount refers to the amount of raw water softened by the softening process.

[0637] <12.7 Estimated value calculation unit>

[0638] The estimated value calculation unit 258 calculates the sum of the residual value calculated by the residual value calculation unit 255, the cumulative value calculated by the cumulative value calculation unit 256, and the maximum value determined by the maximum value determination unit 257, and calculates the estimated value. In other words, the estimated value calculation unit 258 calculates the sum of the maximum values ​​of the current cation amount adsorbed on the weakly acidic cation exchange resin 230 and the cation amount adsorbed on the weakly acidic cation exchange resin 230 when the next softening process is estimated to be performed per unit time as the estimated value. Thus, the cation amount is calculated in view of the softening treatment amount after the previous regeneration process, so the maximum value of the sum of the residual value and the cumulative value at the end of the next softening process can be estimated.

[0639] <12.8 Comparison section>

[0640] The comparison unit 259 compares the amount of cations that can be adsorbed on the weakly acidic cation exchange resin 230 with the estimated value calculated by the estimated value calculation unit 258, and determines whether the estimated value exceeds the amount of cations that can be adsorbed. If the estimated value exceeds the amount of cations that can be adsorbed, there is a possibility that the softening performance will be reduced in the next softening process, and the hardness of the soft water taken out will exceed the established standard (the water taken out is not soft water), so the process management unit 260 described later controls in a manner of performing a regeneration process, and the details will be described later.

[0641] The amount of cations adsorbable to the weakly acidic cation exchange resin 230 (hereinafter referred to as the water softening amount) is proportional to the amount of the ion exchange resin and can therefore be set in advance according to the amount of the weakly acidic cation exchange resin 230 filled in the soft water tank 203 .

[0642] <12.9 Process Management Department>

[0643] The process management unit 260 determines whether to implement the regeneration process every unit period after the softening process ends. Specifically, the regeneration process is implemented when the sum of the residual value and the cumulative value exceeds the removal amount. On the other hand, when the sum of the residual value and the cumulative value is less than the removal amount, the regeneration process is not performed, and the softening process is continued, and the softening process is performed in the next unit period. In this way, the number of times the regeneration process is implemented can be suppressed to the minimum number of times necessary.

[0644] In addition, when the sum of the residual value and the cumulative value is less than the removal amount but the estimated value exceeds the softenable amount, the regeneration process is performed. This can prevent the softening performance from decreasing and the hardness of the soft water taken out from the water intake 205 from increasing due to the sum of the residual value and the cumulative value exceeding the softenable amount in the middle of the next softening process.

[0645] The control unit 213 and the various structures of the control units in other embodiments in this specification can be implemented as hardware by components headed by the CPU (Central Processing Unit) of a computer and mechanical devices, and as software by computer programs, etc., but here they are implemented through their cooperation. Therefore, these functional modules can be implemented in various forms by combining hardware and software.

[0646] The above is the structure of the water softening device 201.

[0647] Next, the operation of the water softening device 201 will be described.

[0648] <13. Water softening process, regeneration process and drainage process>

[0649] Next, refer to Fig.23 The water softening step, the regeneration step, and the drainage step of the water softening device 201 will be described. Fig.23 It is a diagram showing the state of the water softening device 201 during operation.

[0650] In the water softening process, the regeneration process and the drainage process, the control unit 213 Fig.23 As shown, the on-off valves 214 to 219 , the flow path switching valves 220 to 223 , the electrode 238 of the electrolytic cell 207 , the first water supply pump 209 , and the second water supply pump 210 are switched and controlled so as to be in respective flow states.

[0651] here, Fig.23 The "on" in the figure respectively indicates that the on-off valve is "open", the electrode 238 is energized, the water pump is in operation, and the flow meter 251 is energized. The blanks respectively indicate that the on-off valve is "closed", the electrode 238 is not energized, the water pump is stopped, and the flow meter 251 is not energized.

[0652] in addition, Fig.23 The phrase "from (the number of component A) to (the number of component B)" in the figure indicates that the flow path switching valve connects the flow path in a direction in which water is fed from component A to component B. For example, the flow path switching valve 220 of the water softening process connects the flow paths in a manner that water can be fed from flow path 224 to flow path 225.

[0653] <13.1 Water Softening Process>

[0654] First, refer to Fig. 20 as well as Fig.23 The column “during water softening” explains the operation during the water softening process performed by the water softening device 201.

[0655] In the water softening device 201, as Fig.23 As shown, in the softening process, the on-off valve 215 provided in the flow path 224 is opened while the on-off valve 214 is closed. As a result, raw water containing hardness components flows in from the outside. The raw water flows in the order of the first softening tank 203a, the first neutralization tank 204a, the second softening tank 203b, and the second neutralization tank 204b, so that in the softening device 201, softened water (neutral soft water) can be taken out from the water intake port 205.

[0656] At this time, the flow path switching valve 220 is in a connection state where water can be sent from the flow path 224 to the flow path 225, the flow path switching valve 221 is in a connection state where water can be sent from the flow path 225 to the flow path 226, the flow path switching valve 222 is in a connection state where water can be sent from the flow path 226 to the flow path 227, and the flow path switching valve 223 is in a connection state where water can be sent from the flow path 227 to the flow path 228. The on-off valves 216 to 219 are all in a closed state. In addition, the operations of the electrode 238 of the electrolytic cell 207, the first water pump 209, and the second water pump 210 are also stopped.

[0657] Through this control, Fig. 20 As shown, in the softening process, under the pressure of raw water flowing in from the outside, raw water is supplied from the inlet 202 through the flow path 224 to the first soft water tank 203a. And the raw water supplied to the first soft water tank 203a flows through the weakly acidic cation exchange resin 230 provided in the first soft water tank 203a. At this time, the cations as hardness components in the raw water are adsorbed by the weakly acidic cation exchange resin 230, and hydrogen ions are released (ion exchange is performed). And by removing the cations from the raw water, the raw water is softened. The softened water contains a large amount of hydrogen ions that flow out in exchange with the hardness components, so it is acidified and becomes acidic water (first soft water) with a low pH (hydrogen ion concentration index). Here, when water containing a large amount of permanent hardness components (for example, sulfates such as calcium sulfate or chlorides such as magnesium chloride) as hardness components is softened, the pH is easily lowered than water containing a large amount of temporary hardness components (for example, carbonates such as calcium carbonate). Since water softening is difficult to proceed in a state where the pH is lowered, the water flowing through the first soft water tank 203a is passed into the first neutralization tank 204a for neutralization.

[0658] The first soft water flows through the flow path 225 via the flow path switching valve 220 provided in the first soft water tank 203a, and flows into the first neutralization tank 204a. In the first neutralization tank 204a, hydrogen ions contained in the softened water are adsorbed by the weakly basic anion exchange resin 231. That is, hydrogen ions are removed from the water softened by the first soft water tank 203a, and the pH value thus lowered rises and is neutralized. Therefore, compared with the case where the water softened in the first soft water tank 203a is softened in the second soft water tank 203b as it is, it is easy to make the softening process in the second soft water tank 203b proceed.

[0659] The water neutralized by the first neutralization tank 204a (neutralized first soft water) flows through the flow path 226 via the flow path switching valve 221 provided in the first neutralization tank 204a, and flows into the second soft water tank 203b. In the second soft water tank 203b, cations as hardness components are adsorbed by the weakly acidic cation exchange resin 230, and hydrogen ions are released. The second soft water tank 203b exchanges the hardness components that cannot be removed by the first soft water tank 203a with the hydrogen ions possessed by the weakly acidic cation exchange resin 230. That is, the water flowing into the second soft water tank 203b is further softened and becomes soft water (second soft water).

[0660] The second soft water flows through the flow path 227 via the flow path switching valve 222 provided in the second soft water tank 203b, and flows into the second neutralization tank 204b. In the second neutralization tank 204b, the hydrogen ions contained in the second soft water flowing in are adsorbed by the weakly basic anion exchange resin 231. That is, the hydrogen ions are removed from the second soft water, and the pH value that has been reduced rises, and becomes neutral soft water (neutralized second soft water) that can be used as domestic water. The neutralized second soft water flows through the flow path switching valve 223 provided in the second neutralization tank 204b, and flows through the flow path 228, the flow measurement unit 251, and the flow path 229, and is taken out from the water intake port 205.

[0661] That is, in the softening process, the raw water flows in the order of the first softening tank 203a, the first neutralization tank 204a, the second softening tank 203b, and the second neutralization tank 204b. Thus, the raw water containing hardness components flows out of the first softening tank 203a before the pH of the raw water decreases due to the softening process in the first softening tank 203a, is neutralized in the first neutralization tank 204a, is softened in the second softening tank 203b, and is neutralized in the second neutralization tank 204b. Therefore, compared with the case where the softening tank and the neutralization tank are constituted by monomers, the pH of the water flowing in the softening tank can be suppressed from decreasing, that is, acidification, so that the hardness components are easily exchanged with the hydrogen ions retained by the weakly acidic cation exchange resin 230 of the softening tank (particularly the second softening tank 203b). Therefore, the softening performance can be improved.

[0662] In the softening device 201, when the determined time period is reached, when the sum of the residual value and the cumulative value described later is higher than the removal amount, or when the estimated value is equal to the softenable water amount, the softening process is terminated and the regeneration process is executed.

[0663] <13.2 Regeneration process>

[0664] Next, refer to Fig.21 as well as Fig.23 The column “at the time of regeneration” describes the operations during the regeneration process performed by the regeneration device 206 of the water softening device 201 in sequence.

[0665] In the softening device 201, the first soft water tank 203a and the second soft water tank 203b filled with the weakly acidic cation exchange resin 230 have a reduced or lost cation exchange capacity when they are used continuously. That is, after all the hydrogen ions of the functional groups of the cation exchange resin are exchanged with the calcium ions or magnesium ions as the hardness components, ion exchange cannot be performed. When this state is reached, the hardness component is contained in the treated water. In addition, similarly, the first neutralization tank 204a and the second neutralization tank 204b filled with the weakly basic anion exchange resin 231 have a reduced or lost anion exchange capacity and neutralization performance when they are used continuously. When this state is reached, the acidic soft water flowing into the soft water tank cannot be neutralized. Therefore, in the softening device 201, it is necessary to perform a regeneration process of the first soft water tank 203a, the second soft water tank 203b, the first neutralization tank 204a and the second neutralization tank 204b using the regeneration device 206. In the present embodiment, the control unit 213 determines the execution timing of the regeneration process, thereby suppressing the number of executions of the regeneration process.

[0666] During the regeneration process, the control unit 213 closes the on-off valves 215, 216, and 218 and opens the on-off valves 214, 217, and 219. The control unit 213 makes the flow path switching valve 220 a connection state in which water can be sent from the neutralization tank bypass flow path 239 to the first recovery flow path 234, makes the flow path switching valve 221 a connection state in which water can be sent from the soft water tank bypass flow path 241 to the second recovery flow path 235, makes the flow path switching valve 222 a connection state in which water can be sent from the first supply flow path 232 to the neutralization tank bypass flow path 239, and makes the flow path switching valve 223 a connection state in which water can be sent from the second supply flow path 233 to the soft water tank bypass flow path 241. That is, the first soft water tank 203a and the second soft water tank 203b are in a state of communication and connection, and the first neutralization tank 204a and the second neutralization tank 204b are in a state of communication and connection. The control unit 213 stops the drainage of the drainage port 211 and the capture unit drainage port 212. Fig.21 As shown in the figure, the soft water tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237 are formed respectively.

[0667] When the first water supply pump 209 and the second water supply pump 210 are operated, the acidic electrolyzed water and the alkaline electrolyzed water in the electrolytic tank 207 circulate in the soft water tank regeneration circulation flow path 236 and the neutralization tank regeneration circulation flow path 237, respectively.

[0668] In addition, the control unit 213 energizes the electrolytic cell 207 so that the anode has a higher potential than the cathode (positive electrolysis). Thus, during electrolysis, hydrogen ions are generated at the anode, and acidic electrolyzed water is generated near the anode. On the other hand, hydroxide ions are generated at the cathode, and alkaline electrolyzed water is generated near the cathode.

[0669] The acidic electrolyzed water generated in the electrolytic cell 207 flows through the first supply flow path 232 and is sent to the second soft water tank 203b via the flow path switching valve 222, and flows through the weakly acidic cation exchange resin 230 inside. In addition, the acidic electrolyzed water that has flowed through the second soft water tank 203b flows through the neutralization tank bypass flow path 239 and is sent to the first soft water tank 203a via the flow path switching valve 220, and flows through the weakly acidic cation exchange resin 230 inside. That is, by passing the acidic electrolyzed water into the weakly acidic cation exchange resin 230, the cations (hardness components) adsorbed on the weakly acidic cation exchange resin 230 and the hydrogen ions contained in the acidic electrolyzed water undergo an ion exchange reaction. As a result, the weakly acidic cation exchange resin 230 is regenerated.

[0670] Then, the acidic electrolyzed water flowing through the first soft water tank 203a contains cations and flows into the first recovery flow path 234. That is, the acidic electrolyzed water containing cations flowing through the weakly acidic cation exchange resin 230 is recovered to the electrolytic tank 207 via the first recovery flow path 234.

[0671] In this way, the soft water tank regeneration circulation flow path 236 is constructed to allow acidic electrolyzed water to flow from the downstream side of the second soft water tank 203b, which is a soft water tank located at the most downstream side as the inlet relative to the raw water and is a soft water tank having a weakly acidic cation exchange resin 230 that adsorbs less hardness components than the soft water tank on the upstream side, and to flow into the downstream side of the first soft water tank 203a, which is located upstream and has a weakly acidic cation exchange resin 230 that adsorbs more hardness components than the second soft water tank 203b.

[0672] That is, the soft water tank regeneration circulation flow path 236 is a flow path in which the acidic electrolyzed water sent out from the electrolytic tank 207 flows through the second soft water tank 203 b, is sent to the first soft water tank 203 a through the neutralization tank bypass flow path 239, flows through the first soft water tank 203 a, and flows into the electrolytic tank 207 via the first recovery flow path 234.

[0673] Thus, during the regeneration process, first, the acidic electrolyzed water discharged from the electrolytic tank 207 flows into the second soft water tank 203b having a smaller adsorption amount of hardness components than the first soft water tank 203a, and the acidic electrolyzed water containing hardness components is discharged from the second soft water tank 203b to the first soft water tank 203a. In the regeneration of the weakly acidic cation exchange resin 230 in the second soft water tank 203b, the consumption of hydrogen ions in the acidic electrolyzed water is less than that in the first soft water tank 203a, so the reduction in hydrogen ion concentration can be suppressed compared with the regeneration of the first soft water tank 203a. Therefore, the acidic electrolyzed water containing more hydrogen ions flows into the first soft water tank 203a, and the re-adsorption of hardness components in the first soft water tank 203a can be suppressed. Therefore, the reduction in the efficiency of the regeneration process can be suppressed, and the regeneration time can be shortened. It should be noted that the downstream side refers to the downstream side in the flow path during the softening process.

[0674] On the other hand, the alkaline electrolyzed water generated near the cathode of the electrolytic cell 207 flows through the second supply flow path 233 and the capture unit 208, and is sent to the second neutralization tank 204b via the flow path switching valve 223, and flows through the weakly basic anion exchange resin 231 inside. In addition, the alkaline electrolyzed water that has flowed through the second neutralization tank 204b flows through the soft water tank bypass flow path 241, and is sent to the first neutralization tank 204a via the flow path switching valve 221, and flows through the weakly basic anion exchange resin 231 inside. That is, by passing the alkaline electrolyzed water into the weakly basic anion exchange resin 231, the anions adsorbed on the weakly basic anion exchange resin 231 undergo an ion exchange reaction with the hydroxide ions contained in the alkaline electrolyzed water. As a result, the ...

Claims

1. A water softening device, wherein: The water softening device comprises: A soft water tank that softens raw water containing hardness components using a weakly acidic cation exchange resin to produce acidic soft water; A neutralization tank, which uses a weakly basic anion exchange resin to neutralize the pH, i.e., the hydrogen ion concentration index, of the acidic soft water that has passed through the soft water tank to generate neutralized soft water; as well as a control unit that controls a regeneration step as a step of regenerating at least one of the weakly acidic cation exchange resin and the weakly basic anion exchange resin, The control unit includes an adsorption amount determination unit that determines the amount of hardness component adsorption in the soft water tank based on the hardness of the raw water, the amount of the raw water passed into the soft water tank, and the hardness of the water after passing through the soft water tank. During the regeneration process, the control unit controls the regeneration process based on the hardness component adsorption amount determined by the adsorption amount determination unit so as to continue the regeneration process when the hardness component adsorption amount is greater than a reference value and to terminate the regeneration process when the hardness component adsorption amount is less than the reference value.

2. The water softening device according to claim 1, wherein: The water softening device further includes an electrolytic cell for generating acidic electrolyzed water for regenerating the weakly acidic cation exchange resin and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin. The reference value is a value when the exchange reaction efficiency between the hardness component adsorbed in the soft water tank and the hydrogen ions in the acidic electrolyzed water during the regeneration step is at least 70%.

3. The water softening device according to claim 2, wherein: The water softening device also has: a first ion concentration measuring unit for measuring the ion concentration of the acidic electrolyzed water flowing into the soft water tank during the regeneration step; and a second ion concentration measuring unit for measuring the ion concentration of the acidic electrolyzed water flowing out of the soft water tank during the regeneration step; The control unit further comprises: a storage unit configured to store first ion concentration information measured by the first ion concentration measuring unit and second ion concentration information measured by the second ion concentration measuring unit; as well as a calculation unit that calculates a difference between the first ion concentration information and the second ion concentration information, The control unit calculates the exchange reaction efficiency based on the calculation result of the calculation unit.

4. The water softening device according to claim 3, wherein: The calculation unit calculates a differential ion concentration value which is a difference between the first ion concentration information and the second ion concentration information at a predetermined reference time. The control unit continues the regeneration step when the exchange reaction efficiency calculated based on the differential ion concentration value is equal to or greater than a second reference value, The control unit ends the regeneration step when the exchange reaction efficiency calculated based on the differential ion concentration value is smaller than the second reference value.

5. The water softening device according to any one of claims 1 to 3, wherein: When the control unit executes the regeneration process a plurality of times, Even when the amount of adsorption of the hardness component becomes smaller than the reference value, the regeneration step is continued m times out of n times. Here, n is an integer greater than or equal to 2, m is an integer greater than or equal to 1, and n>m.

6. The water softening device according to claim 1, wherein: The water softening device further includes an electrolytic cell for generating acidic electrolyzed water for regenerating the weakly acidic cation exchange resin and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin. The control unit further includes a main regeneration time calculation unit for calculating a main regeneration time required for the regeneration step to remove the hardness component of the hardness component adsorption amount based on the hardness component adsorption amount. The control unit determines a time taken for the regeneration process based on a comparison between a predetermined reference time and the main regeneration time.

7. The water softening device according to claim 6, wherein: The control unit executes the regeneration step at least during the main regeneration time when the hardness component adsorption amount is equal to or less than a third reference value that is an amount of the hardness component that can be removed within the predetermined reference time.

8. The water softening device according to claim 6 or 7, wherein: When the amount of adsorbed hardness component is larger than a third reference value that is an amount of hardness component that can be removed within the predetermined reference time, the control unit ends the regeneration step when the predetermined reference time has expired.

9. The water softening device according to any one of claims 6 to 8, wherein: The control unit further comprises: a recording unit for recording a time period during which the water softening process is performed; and a reference time determination unit that determines a time period during which the softening process is performed less frequently as the predetermined reference time based on the performance time period recorded by the recording unit, The control unit determines a time period for performing the regeneration process based on the determined predetermined reference time.

10. The water softening device according to any one of claims 6 to 8, wherein: The control unit further includes a designation unit that designates a time set in advance as a time when the water softening process is not performed as the predetermined reference time. The control unit determines the designated predetermined reference time as a time period for performing the regeneration process.

11. The water softening device according to claim 8, wherein: When the control unit executes the regeneration process a plurality of times, Even when the hardness component adsorption amount exceeds the third reference value, the regeneration process is performed at least during the main regeneration time m times out of n times, Here, n is an integer greater than or equal to 2, m is an integer greater than or equal to 1, and n>m.

12. The water softening device according to claim 8, wherein: The water softening device further comprises a soft water hardness measuring unit for measuring the hardness of water after the water passes through the soft water tank. When the hardness measured by the soft water hardness measuring unit at the end of the regeneration process is higher than a reference hardness value serving as a target hardness after the regeneration treatment, the control unit performs the regeneration process at least during the main regeneration time during the next regeneration process even if the adsorption amount of the hardness component exceeds the reference value.

13. The water softening device according to claim 6, wherein: The adsorption amount determination unit includes a residual adsorption amount determination unit that determines a residual hardness component adsorption amount after the (k-1)th regeneration process based on the (k-1)th regeneration time, wherein k is an integer greater than or equal to 2. The adsorption amount determination unit determines the hardness component adsorption amount based on the hardness of the raw water, the amount of the raw water passed into the soft water tank, the hardness of the water after passing through the soft water tank, and the residual hardness component adsorption amount determined by the residual hardness component determination unit.

14. The water softening device according to claim 1, wherein: The water softening device also includes an electrolytic cell for generating acidic electrolyzed water and alkaline electrolyzed water. The control unit further comprises: a hardness storage unit that stores a hardness component concentration of raw water containing a hardness component; an adsorption amount calculation unit that calculates the amount of ions adsorbed to at least one of the soft water tank and the neutralization tank based on the hardness component concentration of the raw water, the amount of the raw water passed into the soft water tank, and the hardness of the water after passing through the soft water tank; a removal amount calculation unit that calculates an ion removal amount that can be removed from at least one of the softening tank and the neutralization tank based on an amount of hydrogen ions in the acidic electrolyzed water and an amount of hydroxide ions in the alkaline electrolyzed water obtained by operating the electrolytic tank for a predetermined time; as well as A process management unit performs the regeneration process based on a comparison between the ion adsorption amount and the ion removal amount.

15. The water softening device according to claim 14, wherein: The process management unit performs the regeneration process after the ion adsorption amount reaches the ion removal amount.

16. The water softening device according to claim 14 or 15, wherein: The process management unit does not perform the regeneration process when the ion adsorption amount is smaller than the ion removal amount.

17. The water softening device according to claim 14, wherein: The control unit further comprises: a residual value calculation unit that calculates a residual value as an amount of ion components adsorbed to at least one of the soft water tank and the neutralization tank at the end of the previous regeneration step; a unit time adsorption amount calculation unit that calculates the adsorption amount of the ion component per unit time as the unit time adsorption amount; a cumulative value calculation unit that calculates a cumulative value of the amount of ion adsorption during a non-regeneration period that is a period from the end of the previous regeneration step; as well as a maximum value determination unit that determines a maximum value of the adsorption amount per unit time during the non-regeneration period, The process management unit performs the regeneration process based on comparison of the residual value, the cumulative value, the maximum value, and the ion removal amount.

18. The water softening device according to claim 17, wherein: The process management department has: an estimated value calculation unit that calculates an estimated value that is a sum of the residual value, the cumulative value, and the maximum value; and a comparing unit that compares the water softening amount, which is the amount of the ion component that can be adsorbed to the softening tank and the neutralization tank, with the estimated value, When the estimated value is larger than the water softening amount, the process management unit performs the regeneration process even when the ion adsorption amount does not reach the ion removal amount.

19. The water softening device according to claim 18, wherein: The process management unit performs the regeneration process after the ion adsorption amount reaches the ion removal amount when the estimated value becomes equal to or less than the water softening amount.

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