JP2023091796A - Water softening device - Google Patents

Abstract

To provide a water softening device capable of detecting a timing of polarity inversion operation and performing the polarity inversion operation at an appropriate timing.SOLUTION: A water softening device 1 includes a water softening tank 3, a neutralization tank 4, an electrolysis tank 9, a detection section 27, and a control section 26. The detection section 27 detects a voltage, and the control section 26 controls electrode regeneration processing of the electrolysis tank 9 based on the voltage detected by the detection section 27. In resin regeneration processing, when the voltage detected by the detection section 27 is lower than a first reference value, the resin regeneration processing is continued or shifted to water softening processing, and, when the voltage detected by the detection section 27 is equal to or higher than the first reference value, the resin regeneration processing is stopped and shifted to electrode regeneration processing. And in the electrode regeneration processing, when the voltage detected by the detection section 27 is equal to or higher than a second reference value, the electrode regeneration processing is continued, and, when the voltage detected by the detection section 27 is lower than the second reference value, the electrode regeneration processing is stopped and shifted to the resin regeneration processing or the water softening processing.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water softening device.

Many conventional water softeners using cation exchange resins have been proposed. For example, a cation exchange resin (strongly acidic ion exchange resin) having sodium ions as functional groups is used to obtain soft water by ion-exchanging calcium ions and magnesium ions, which are hardness components contained in raw water, into sodium ions. Are known.

By the way, the ion exchange capacity of the cation exchange resin decreases or disappears with continued use. That is, after all sodium ions, which are functional groups of the cation exchange resin, are exchanged with calcium ions and magnesium ions, which are hardness components, ion exchange becomes impossible. Therefore, it is necessary to regenerate the cation exchange resin to enable ion exchange again.

An example of the regeneration treatment is a treatment in which regenerated water such as saturated saline is passed through a cation exchange resin. In such a regeneration treatment, it is necessary to periodically replenish salt according to the amount of soft water used, and replenishment of salt is troublesome. In addition, since a large amount of salt is used, it causes environmental problems.

Therefore, as a method for regenerating a cation exchange resin without using salt, a method of using a weakly acidic cation exchange resin and regenerating the cation exchange resin with acidic electrolyzed water generated by electrolysis is known (for example, patent Reference 1). The weakly acidic cation exchange resin has hydrogen ions (hydrogen ions) at the end of the functional group, and softens the raw water by exchanging hardness components (e.g., calcium ions, magnesium ions) in the raw water with hydrogen ions. ing. Water softened by the weakly acidic cation exchange resin becomes acidic because hydrogen ions are released instead of hardness components. In order to neutralize this, a weakly acidic cation exchange resin is sometimes used in combination with a weakly basic anion exchange resin. That is, the weakly basic anion exchange resin neutralizes the softened raw water by adsorbing the hydrogen ions and anions contained in the water softened by the weakly acidic cation exchange resin. As a method for regenerating a weakly basic anion exchange resin, a method using alkaline electrolyzed water produced by electrolysis is known (see, for example, Patent Document 2).

Japanese Unexamined Patent Application Publication No. 2011-30973 JP 2010-142674 A

In such a conventional water softening device, an electrolytic cell that generates hydrogen ions for regenerating the weakly acidic cation exchange resin and hydroxide ions for regenerating the weakly basic anion exchange resin by electrolysis of water is provided. used. During operation of the electrolytic cell, hydroxide ions produced at the cathode react with calcium ions or magnesium ions in water, and solids (scale) are deposited mainly on the cathode. Since the scale deposited in the electrolytic cell increases the operating voltage of the electrolytic cell, it causes an increase in the power consumption of the water softening device. Therefore, it is necessary to perform a polarity reversal operation in which the voltage applied to the electrodes of the electrolytic cell is reversed to remove the solids. However, since the electrode is consumed by performing the pole reversal, it is necessary to perform the pole reversal operation at an appropriate timing, but there is a problem that it is difficult to detect the timing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water softening apparatus capable of detecting the timing of the polarity reversal operation and performing the polarity reversal operation at an appropriate timing.

In order to achieve this object, the water softening apparatus according to the present invention comprises a water softening tank for softening raw water with a weakly acidic cation exchange resin, and A neutralization tank that neutralizes with an ion exchange resin, an electrolytic tank that generates acidic electrolyzed water and alkaline electrolyzed water, a detector that detects the voltage of the electrolytic tank, and an electrode of the electrolytic tank based on the voltage detected by the detector. and a control unit that controls the reproduction process. The control unit detects the voltage detected by the detection unit during resin regeneration processing in which at least one of regeneration of the weakly acidic cation exchange resin using acidic electrolyzed water and regeneration of the weakly basic anion exchange resin using alkaline electrolyzed water is performed. is less than the first standard value, the resin regeneration process is continued or shifted to the water softening process, and when the voltage detected by the detection unit is the first standard value or more, the resin regeneration process is stopped. Proceed to electrode regeneration processing. If the voltage detected by the detection unit during the electrode regeneration process is equal to or higher than the second reference value, the electrode regeneration process is continued, and if the voltage detected by the detection unit is less than the second reference value, electrode regeneration is performed. After finishing the treatment, the resin regeneration treatment or water softening treatment is started. This achieves the intended purpose.

According to the present invention, it is possible to provide a water softening device capable of detecting the timing of the polarity reversal operation and performing the polarity reversal operation at an appropriate timing.

FIG. 1 is a conceptual diagram showing the configuration of a water softening device according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing the state of each component during the resin regeneration treatment of the water softening device. FIG. 3 is a diagram showing the state of each component during the electrode regeneration treatment of the water softener. FIG. 4 is a diagram showing a state during operation of the water softening device.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention. Also, each drawing described in the embodiment is a schematic drawing, and the ratios of sizes and thicknesses of constituent elements in each drawing do not necessarily reflect actual dimensional ratios.

(Embodiment 1)
A water softening device 1 according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram showing the configuration of a water softening device 1 according to Embodiment 1 of the present invention. Note that FIG. 1 conceptually shows each element of the water softening device 1 .

(overall structure)
The water softening device 1 is a device that generates neutral soft water from externally supplied raw water containing hardness components. The raw water is water (water to be treated) introduced into the apparatus from the inflow port 2, and is, for example, city water or well water. Raw water contains hardness components (eg calcium or magnesium ions).

Specifically, as shown in FIG. 1, the water softening device 1 includes an inlet 2, a water softening tank 3 (first water softening tank 3a and second water softening tank 3b), and a neutralization tank 4 (second It comprises a first neutralization tank 4 a and a second neutralization tank 4 b ), a water intake 5 and a regeneration device 6 .

In addition, the water softening device 1 includes a plurality of on-off valves (on-off valves 51 to 55, on-off valves 61 to 66, on-off valves 71, on-off valves 72, on-off valves 81, and on-off valves 82) and a plurality of Channels (channels 30 to 36, first supply channel 41, first bypass channel 42, first recovery channel 43, second supply channel 45, second bypass channel 46, second recovery channel 47 , a water supply channel 48, and a water supply channel 49), the details of which will be described later. In addition, a plurality of channels (channels 30 to 36, first supply channel 41, first bypass channel 42, first recovery channel 43, second supply channel 45, second bypass channel 46, second Pipes such as pipes, for example, are used as the recovery channel 47, the water supply channel 48, and the water supply channel 49).

((Inlet, water intake, and channels 30 to 34))
The inflow port 2 is connected to a raw water supply source and a flow path 30 . The inlet 2 is an opening through which raw water is introduced into the device.

The water intake port 5 is an opening through which neutral soft water treated by the water softening tank 3 and the neutralizing tank 4 is discharged out of the apparatus. In the water softening device 1 , the softened water can be taken out from the water intake 5 by the pressure of the raw water flowing in from the inlet 2 .

The inlet 2 to the water intake 5 are connected in this order by a channel 30, a channel 31, a channel 32, a channel 33, and a channel .

The channel 30 is a channel that connects the inlet 2 to the first water softening tank 3a. That is, the flow path 30 is a flow path that guides raw water containing hardness components from the inlet 2 to the first water softening tank 3a.

The flow path 31 is a flow path that connects the first water softening tank 3a to the first neutralization tank 4a. That is, the flow path 31 is a flow path that guides the acidic soft water (first soft water) softened in the first water softening tank 3a to the first neutralization tank 4a.

The channel 32 is a channel that connects the first neutralization tank 4a to the second water softening tank 3b. That is, the flow path 32 is a flow path that guides the first soft water neutralized in the first neutralization tank 4a (first neutralized soft water) to the second water softening tank 3b.

The flow path 33 is a flow path that connects the second water softening tank 3b to the second neutralization tank 4b. That is, the flow path 33 is a flow path that guides the acidic soft water (second soft water) softened in the second water softening tank 3b to the first neutralization tank 4a.

The flow path 34 is a flow path that connects the second neutralization tank 4b to the water intake port 5. As shown in FIG. That is, the flow path 34 is a flow path that guides the second soft water (second neutralized soft water) neutralized in the first neutralization tank 4 a to the intake port 5 .

In summary, in the water softening device 1, in the water softening process, the raw water supplied from the outside passes through the inlet 2, the flow path 30, the first water softening tank 3a, the flow path 31, the first neutralization tank 4a, the flow path 32, the second softening tank 3b, the channel 33, the second neutralizing tank 4b, the channel 34, and the water intake 5, and discharged as neutral soft water.

((water softening tank))
The water softening tank 3 softens raw water containing hardness components by the action of the weakly acidic cation exchange resin 7 . Specifically, the water softening tank 3 exchanges cations (calcium ions, magnesium ions), which are hardness components contained in flowing water (raw water), with hydrogen ions. become The water softening tank 3 is equipped with a weakly acidic cation exchange resin 7 having hydrogen ions at the ends of functional groups.

The water softening tank 3 is composed of, for example, a cylindrical container filled with a weakly acidic cation exchange resin 7 . The water softening tank 3 includes a first water softening tank 3a and a second water softening tank 3b.

The first water softening tank 3a is filled with a first weakly acidic cation exchange resin 7a. The first water softening tank 3a is connected to the flow path 30 on the upstream side and connected to the flow path 31 on the downstream side.

The second water softening tank 3b is filled with a second weakly acidic cation exchange resin 7b. The second water softening tank 3b is connected to the flow path 32 on the upstream side and connected to the flow path 33 on the downstream side.

Also, the first water softening tank 3a and the second water softening tank 3b have the same channel length, the same channel cross-sectional area, and the same volume of the weakly acidic cation exchange resin 7. As shown in FIG. As a result, since the first water softening tank 3a and the second water softening tank 3b can be configured with the same member, the cost of the water softening device 1 can be reduced.

In the following description, the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin 7b will be described as the weakly acidic cation exchange resin 7 unless it is necessary to distinguish between them.

The weakly acidic cation exchange resin 7 is an ion exchange resin having hydrogen ions at the terminal of functional groups. The weakly acidic cation exchange resin 7 adsorbs cations (calcium ions, magnesium ions), which are hardness components contained in raw water to be passed, and releases hydrogen ions. As the weakly acidic cation exchange resin 7, there is no particular limitation, and general-purpose resins can be used. As the weakly acidic cation exchange resin 7, a resin in which hydrogen ions (H+), which are counter ions of carboxyl groups, are cations such as metal ions and ammonium ions (NH4+) may be used.

((Neutralization tank))
The neutralization tank 4 neutralizes the pH of the soft water (acidified soft water) containing hydrogen ions coming out of the water softening tank 3 by the action of the weakly basic anion exchange resin 8 to make neutral soft water. . Specifically, since the neutralization tank 4 absorbs hydrogen ions and anions contained in the soft water flowing from the water softening tank 3, the pH of the soft water increases and the water can be neutralized.

The neutralization tank 4 is equipped with a weakly basic anion exchange resin 8 .

The neutralization tank 4 is composed of, for example, a cylindrical container filled with a weakly basic anion exchange resin 8 . Moreover, the neutralization tank 4 is comprised including the 1st neutralization tank 4a and the 2nd neutralization tank 4b.

The first neutralization tank 4a is configured by, for example, filling a cylindrical container with a first weakly basic anion exchange resin 8a. The first neutralization tank 4a is connected to the flow path 31 on the upstream side and connected to the flow path 32 on the downstream side.

The second neutralization tank 4b is filled with a second weakly basic anion exchange resin 8b. The second neutralization tank 4b is connected to the flow path 33 on the upstream side and connected to the flow path 34 on the downstream side.

The first neutralization tank 4a and the second neutralization tank 4b have the same channel length, channel cross-sectional area, and volume of weakly basic anion exchange resin 8 . As a result, since the first neutralization tank 4a and the second neutralization tank 4b can be configured with the same member, the cost of the water softening device 1 can be reduced.

In the following description, the first weakly basic anion exchange resin 8a and the second weakly basic anion exchange resin 8b are referred to as the weakly basic anion exchange resin 8 when there is no particular need to distinguish between the two. explain.

The weakly basic anion exchange resin 8 neutralizes the hydrogen ions contained in the water that is passed through it to produce neutral water. The weakly basic anion exchange resin 8 is not particularly limited, and a general-purpose one can be used, and examples thereof include a free base type anion exchange resin. The weakly basic anion exchange resin 8 is regenerated using alkaline electrolyzed water in a resin regeneration treatment to be described later.

((playback device))
The regeneration device 6 is a device that regenerates the weakly acidic cation exchange resin 7 in the water softening tank 3 and regenerates the weakly basic anion exchange resin 8 in the neutralization tank 4 . Specifically, the regeneration device 6 includes an electrolytic cell 9, an acidic electrolyzed water storage tank 19, an acidic electrolyzed water circulation pump 23, an alkaline electrolyzed water storage tank 21, an alkaline electrolyzed water circulation pump 24, a trapping section 25, It includes a control unit 26 and a detection unit 27 . In the regeneration device 6 , the first supply channel 41 , the first recovery channel 43 , the first recovery channel 43 , the first recovery channel 43 , the A second supply channel 45 and a second recovery channel 47 are connected to each other.

((Electrolyzer))
The electrolytic cell 9 produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin 7 and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin 8 by electrolyzing water. By generating acidic electrolyzed water and alkaline electrolyzed water in the electrolytic cell 9, when the water softening performance of the water softening device 1 has deteriorated, regeneration treatment can be performed. In addition, the electrolytic cell 9 is configured so that the energization state of the anode 11 and the cathode 15 can be controlled by a control section 26 which will be described later. Further, the voltage of the electrolytic cell 9 is detected by the detection unit 27, which will be described later, during resin regeneration processing and electrode regeneration processing.

The electrolytic cell 9 comprises a diaphragm 10 , an anode compartment 14 and a cathode compartment 18 .

The electrolytic cell 9 is separated into an anode chamber 14 and a cathode chamber 18 by a diaphragm 10 provided inside.

The diaphragm 10 separates the interior of the electrolytic cell 9 into an anode chamber 14 and a cathode chamber 18 . The diaphragm 10 suppresses mixing of the acidic electrolyzed water generated in the anode chamber 14 and the alkaline electrolyzed water generated in the cathode chamber 18 . As a result, the hydrogen ions in the acidic electrolyzed water and the hydroxide ions in the alkaline electrolyzed water can be suppressed from being consumed by the neutralization reaction, so that the weakly acidic cation exchange resin 7 and the weakly basic anion exchange resin 8 are regenerated. Efficiency reduction can be suppressed.

In addition, the diaphragm 10 can also suppress a decrease in regeneration efficiency of the other ion exchange resin when the regeneration of one ion exchange resin ends first. Specifically, when there is no diaphragm 10, an environment in which acidic electrolyzed water and alkaline electrolyzed water are easily mixed is created. For example, when regeneration of the weakly acidic cation exchange resin 7 is completed before regeneration of the weakly basic anion exchange resin 8, hydrogen in the acidic electrolyzed water used for regeneration of the weakly acidic cation exchange resin 7 is The ions react with hydroxide ions in the alkaline electrolyzed water, and neutralization consumes the hydroxide ions. That is, when the diaphragm 10 is not provided, if the regeneration of one ion-exchange resin is completed first, the efficiency of regeneration of the other ion-exchange resin tends to decrease. However, by separating the inside of the electrolytic cell 9 into the anode chamber 14 and the cathode chamber 18 by the diaphragm 10, even when the regeneration of one ion exchange resin is completed, the other ion exchange resin can be regenerated. Mixing with electrolyzed water can be suppressed. Therefore, the diaphragm 10 can also suppress a decrease in regeneration efficiency of one ion exchange resin when regeneration of the other ion exchange resin is completed first.

As the diaphragm 10, for example, a fluorine-based porous membrane can be used. As the porous membrane used for the diaphragm 10, in addition to the fluorine-based porous membrane, a generally used porous membrane such as a hydrocarbon-based porous membrane may be used. Fluorine-based porous membrane is used in the water softening device 1 because of its superiority.

The anode chamber 14 is a part where acidic electrolyzed water is produced during electrolysis of water. Anode chamber 14 includes anode 11 , first intake port 12 , and first outlet port 13 .

The anode 11 produces hydrogen ions by electrolyzing water. Therefore, in the anode chamber 14 provided with the anode 11, the hydrogen ion concentration of the water increases, and the water becomes acidic electrolyzed water. A platinum electrode, for example, can be used as the anode 11 .

The first water intake port 12 is an opening through which the acidic electrolyzed water stored in the acidic electrolyzed water reservoir 19 is introduced into the anode chamber 14 through the water supply channel 48 . The first water intake 12 is connected to the water supply channel 48 .

The first outlet 13 is an opening for supplying acidic electrolyzed water containing hydrogen ions generated at the anode 11 to the water softening tank 3 through the first supply flow path 41 . The first outlet 13 is connected to the first supply channel 41 .

The cathode chamber 18 is a portion where alkaline electrolyzed water is generated during electrolysis of water. Cathode chamber 18 includes cathode 15 , second intake port 16 , and second outlet port 17 .

The cathode 15 produces hydroxide ions by electrolyzing water. Therefore, in the cathode chamber 18 provided with the cathode 15, the hydroxide ion concentration of water increases, and alkaline electrolyzed water is obtained. A platinum electrode, for example, can be used as the cathode 15 .

The second water intake port 16 is an opening through which the alkaline electrolyzed water stored in the alkaline electrolyzed water storage tank 21 is introduced into the cathode chamber 18 through the water supply channel 49 . The second water intake 16 is connected to the water supply channel 49 .

The second discharge port 17 is an opening for supplying alkaline electrolyzed water containing hydroxide ions generated at the cathode 15 to the neutralization tank 4 through the second supply flow path 45 . The second outlet 17 is connected to the second supply channel 45 .

That is, the electrolytic cell 9 uses the anode 11 to electrolyze the water that flows in from the first water intake port 12 (the water that is supplied from the acidic electrolyzed water storage tank 19), thereby producing acidic electrolyzed water in the anode chamber 14. It is generated and discharged from the first ejection port 13 . In addition, the electrolytic cell 9 uses the cathode 15 to electrolyze the water flowing in from the second water intake 16 (the water supplied from the alkaline electrolyzed water storage tank 21), thereby producing alkaline electrolyzed water in the cathode chamber 18. It is generated and discharged from the second outlet 17 .

It should be noted that, up to this point, the case where the anode 11 is energized so as to have a higher potential than the cathode 15 (positive electrolysis) has been described. On the other hand, when current is applied to the anode 11 so that the cathode 15 has a high potential (reverse electrolysis), alkaline electrolyzed water is produced in the anode chamber 14 and acidic electrolyzed water is produced in the cathode chamber 18 . In the water softening apparatus 1, the electrolytic cell 9 performs positive electrolysis during the resin regeneration treatment, and performs reverse electrolysis during the electrode regeneration treatment.

((Acidic Electrolyzed Water Storage Tank and Alkaline Electrolyzed Water Storage Tank))
The acidic electrolyzed water storage tank 19 is connected to the first recovery channel 43 on the upstream side, and is connected to the water supply channel 48 on the downstream side. The acidic electrolyzed water reservoir 19 is a tank or container equipped with an air vent valve 20 . The acidic electrolyzed water storage tank 19 secures and stores water to be circulated in the acidic electrolyzed water circulation channel 40 (see FIG. 2) when the weakly acidic cation exchange resin 7 is regenerated.

By storing the acidic electrolyzed water in the acidic electrolyzed water storage tank 19 , it is possible to control the total amount of the acidic electrolyzed water flowing through the acidic electrolyzed water circulation flow path 40 . For example, by increasing the volume of the acidic electrolyzed water storage tank 19, the ion concentration in the acidic electrolyzed water circulation channel 40 can be reduced when the amount of ions in the acidic electrolyzed water circulation channel 40 is constant. Due to the decrease in the concentration of cations such as hardness components, the equilibrium of the reaction in the weakly acidic cation exchange resin 7 is on the side of the regeneration reaction (the reaction in which the hardness components are desorbed from the weakly acidic cation exchange resin 7 and hydrogen ions are adsorbed). , it is possible to improve the regeneration efficiency. In addition, by reducing the volume of the acidic electrolyzed water storage tank 19, when the amount of ions (cations such as hardness components) in the acidic electrolyzed water circulation channel 40 is constant, the ions in the acidic electrolyzed water circulation channel 40 Concentration can be increased. Due to the increase in the ion concentration of the acidic electrolyzed water, the solution resistance during electrolysis in the electrolytic cell 9 is reduced. Therefore, it is possible to reduce the applied voltage applied by the electrolytic cell 9, and it is possible to reduce the power consumption. In other words, the performance of the water softening device 1 can be improved by using the acidic electrolyzed water reservoir 19 having a volume suitable for the purpose.

The air vent valve 20 extracts gas contained in the acidic electrolyzed water so that the gas does not accumulate in the acidic electrolyzed water circulation flow path 40 .

The alkaline electrolyzed water storage tank 21 is connected to the second recovery channel 47 on the upstream side, and is connected to the water supply channel 49 on the downstream side. The alkaline electrolyzed water storage tank 21 is a tank or container equipped with an air vent valve 22 . The alkaline electrolyzed water storage tank 21 secures and stores water to be circulated in the alkaline electrolyzed water circulation channel 44 (see FIG. 2) when the weakly basic anion exchange resin 8 is regenerated.

By storing the alkaline electrolyzed water in the alkaline electrolyzed water storage tank 21 , it is possible to control the total amount of the alkaline electrolyzed water flowing through the alkaline electrolyzed water circulation flow path 44 . For example, by increasing the volume of the alkaline electrolyzed water storage tank 21, the ion concentration in the alkaline electrolyzed water circulation channel 44 can be reduced when the amount of ions in the alkaline electrolyzed water circulation channel 44 is constant. The decrease in the anion concentration tilts the equilibrium of the reaction in the weakly basic anion exchange resin 8 toward the regeneration reaction side, which makes it possible to increase the regeneration efficiency. In addition, by reducing the volume of the alkaline electrolyzed water storage tank 21, the ion concentration in the alkaline electrolyzed water circulation channel 44 can be increased when the amount of ions in the alkaline electrolyzed water circulation channel 44 is constant. Due to the increase in the ion concentration of the alkaline electrolyzed water, the solution resistance during electrolysis in the electrolytic cell 9 is reduced. Therefore, it is possible to reduce the applied voltage applied by the electrolytic cell 9, and it is possible to reduce the power consumption. That is, the performance of the water softening device 1 can be improved by using the alkaline electrolyzed water storage tank 21 having a volume suitable for the purpose.

The air vent valve 22 extracts gas contained in the alkaline electrolyzed water so that the gas does not accumulate in the alkaline electrolyzed water circulation flow path 44 .

((Acidic electrolyzed water circulation pump and alkaline electrolyzed water circulation pump))
The acidic electrolyzed water circulation pump 23 is a device that circulates water in the acidic electrolyzed water circulation channel 40 (see FIG. 2) during the resin regeneration process by the regeneration device 6 . The acidic electrolyzed water circulation pump 23 is provided in a water supply channel 48 that communicates and connects between the acidic electrolyzed water reservoir 19 and the first water intake 12 .

The acidic electrolyzed water circulation pump 23 makes it possible to control the flow rate of the acidic electrolyzed water flowing through the acidic electrolyzed water circulation flow path 40 . For example, when the generation rate of hydrogen ions in the electrolytic cell 9 is constant, increasing the flow rate of the acidic electrolyzed water reduces the hydrogen ion concentration (increases the pH). Further, when the flow rate of the acidic electrolyzed water is decreased, the hydrogen ion concentration increases (the pH decreases). That is, by adjusting the flow rate of the acidic electrolyzed water with the acidic electrolyzed water circulation pump 23, the hydrogen ion concentration in the acidic electrolyzed water supplied to the weakly acidic cation exchange resin 7 can be adjusted. Therefore, hydrogen ions can be supplied according to the state of the weakly acidic cation exchange resin 7, and the performance of the water softening device 1 can be improved.

The alkaline electrolyzed water circulation pump 24 is a device that circulates water in the alkaline electrolyzed water circulation flow path 44 (see FIG. 2) during the resin regeneration process by the regeneration device 6 . The alkaline electrolyzed water circulation pump 24 is provided in a water supply channel 49 that communicates between the alkaline electrolyzed water storage tank 21 and the second water intake port 16 .

The alkaline electrolyzed water circulation pump 24 makes it possible to control the flow rate of the alkaline electrolyzed water flowing through the alkaline electrolyzed water circulation channel 44 . For example, when the generation rate of hydroxide ions in the electrolytic cell 9 is constant, increasing the flow rate of the alkaline electrolyzed water reduces the hydroxide ion concentration. Also, when the flow rate of the alkaline electrolyzed water is reduced, the hydroxide ion concentration increases. That is, by adjusting the flow rate of the alkaline electrolyzed water with the alkaline electrolyzed water circulation pump 24, the hydroxide ion concentration in the alkaline electrolyzed water supplied to the weakly basic anion exchange resin 8 can be adjusted. Therefore, hydroxide ions can be supplied according to the state of the weakly basic anion exchange resin 8, and the performance of the water softening device 1 can be improved.

By providing the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 independently of each other instead of using one pump, the flow rate of acidic electrolyzed water capable of supplying hydrogen ions suitable for regeneration of the weakly acidic cation exchange resin 7 It is possible to individually set the flow rate of the alkaline electrolyzed water capable of supplying hydroxide ions suitable for regeneration of the weakly basic anion exchange resin 8 .

The acidic electrolyzed water circulating pump 23 and the alkaline electrolyzed water circulating pump 24 are connected to a control unit 26 to be described later so as to communicate wirelessly or by wire.

((capturing part))
The capture unit 25 is provided in the second supply channel 45 after the electrolytic bath 9 and before the second neutralization bath 4b.

The capture unit 25 separates solids contained in the alkaline electrolyzed water supplied from the electrolytic cell 9 . A solid is a reaction product that is precipitated by a reaction between hardness components in the alkaline electrolyzed water and hydroxide ions generated by the cathode 15 in the cathode chamber 18 of the electrolytic cell 9 . For example, when the hardness component contained in the alkaline electrolyzed water is magnesium ions, magnesium hydroxide is generated. If solids precipitated during the resin regeneration treatment are not removed, they accumulate in the neutralization tank 4, and hardness components are eluted from the solids, increasing the soft water hardness during the water softening treatment, that is, reducing the water softening performance. . Therefore, by separating the precipitates in the trapping section 25, it is possible to suppress the inflow and accumulation of the precipitates in the second neutralization tank 4b, thereby suppressing the deterioration of the water softening performance during the water softening process.

The capturing part 25 may take any form as long as it can separate the reaction product with the hardness component contained in the alkaline electrolyzed water supplied from the electrolytic cell 9 . Examples thereof include a form using a cartridge type filter, a filtration layer using granular filter media, a cyclone type solid-liquid separator, or a hollow fiber membrane.

((control part))
The control unit 26 controls a water softening process for softening raw water containing hardness components. In addition, the control unit 26 controls resin regeneration processing of the weakly acidic cation exchange resin 7 in the water softening tank 3 and the weakly basic anion exchange resin 8 in the neutralization tank 4 . Furthermore, the control unit 26 controls electrode regeneration processing for regenerating the electrolytic cell 9 . In addition, the control unit 26 controls switching among the water softening process, the resin regeneration process, and the electrode regeneration process of the water softening device 1 . At this time, the control unit 26 controls the anode 11, the cathode 15, the acidic electrolyzed water circulation pump 23, the alkaline electrolyzed water circulation pump 24, the on-off valves 51 to 55, the on-off valves 61 to 66, the on-off valve 71, the on-off valve 72, The operation of the on-off valve 81 and the on-off valve 82 is controlled, the water softening process, the resin regeneration process, and the electrode regeneration process are switched, and each process is executed.

Specifically, the control unit 26 compares the voltage detected by the detection unit 27 with a first reference value or a second reference value, which will be described later, to perform the water softening process, the resin regeneration process, and the electrode regeneration process. determine the switching.

Note that the control unit 26 has a computer system having a processor and memory. The computer system functions as a controller by the processor executing the program stored in the memory. Although the program executed by the processor is recorded in advance in the memory of the computer system here, it may be recorded in a non-temporary recording medium such as a memory card and provided, or may be provided through a telecommunication line such as the Internet. may be provided through

((Detector))
The detector 27 detects the voltage in the electrolytic cell 9 during the resin regeneration process and the electrode regeneration process. Also, the detection unit 27 is connected to the control unit 26 . That is, based on the voltage detected by the detection unit 27, the control unit 26 can determine switching between the water softening process, the resin regeneration process, and the electrode regeneration process.

((acidic electrolyzed water circulation channel, alkaline electrolyzed water circulation channel))
Next, with reference to FIG. 2, the acidic electrolyzed water circulation channel 40 and the alkaline electrolyzed water circulation channel 44 formed during the resin regeneration treatment of the water softening device 1 will be described. FIG. 2 is a diagram showing the state of each component during the resin regeneration treatment of the water softening device 1. As shown in FIG.

The acidic electrolyzed water circulation flow path 40, as shown in FIG. It is a flow path that flows through the first water softening tank 3 a and returns to the acidic electrolyzed water storage tank 19 for circulation. More specifically, in the acidic electrolyzed water circulation channel 40, the water sent from the acidic electrolyzed water storage tank 19 by the acidic electrolyzed water circulation pump 23 flows through the water supply channel 48, the first water intake 12, the anode chamber 14, and the first outlet. Outlet 13, first supply channel 41, on-off valve 63, second water softening tank 3b, first bypass channel 42, on-off valve 65, first water softening tank 3a, first recovery channel 43, on-off valve 61, It is a flow path that circulates and circulates in order of the acidic electrolyzed water storage tank 19 .

The first supply channel 41 is a channel that connects the first outlet 13 to the channel 33 . That is, the first supply channel 41 is a channel for supplying acidic electrolyzed water from the first outlet 13 to the downstream side of the second water softening tank 3b. The first supply channel 41 is connected to the channel 33 between the second water softening tank 3b and the on-off valve 54. As shown in FIG. The on-off valve 54 is provided between the connecting point of the second bypass flow path 46 and the flow path 33 and the second water softening tank 3b. Thereby, mixing of the acidic electrolyzed water flowing through the first supply channel 41 and the alkaline electrolyzed water flowing through the second recovery channel 47 can be suppressed. An on-off valve 63 is installed in the first supply channel 41 .

The first bypass flow path 42 is a flow path that bypasses the first neutralization tank 4a and connects the flow path 32 to the flow path 31 . That is, the first bypass flow path 42 is a flow path that bypasses the first neutralization tank 4a and supplies the acidic electrolyzed water that has flowed through the second water softening tank 3b to the first water softening tank 3a. Thereby, the acidic electrolyzed water can be supplied from the second water softening tank 3b to the downstream side of the first water softening tank 3a. By providing the first bypass channel 42, the resin regeneration process can be performed without circulating the acidic electrolyzed water in the first neutralization tank 4a existing between the first water softening tank 3a and the second water softening tank 3b. can proceed. An on-off valve 65 is installed in the first bypass flow path 42 .

The first recovery channel 43 is a channel that connects the channel 30 to the acidic electrolyzed water reservoir 19 . That is, the first recovery channel 43 is a channel for recovering the acidic electrolyzed water containing the hardness component that has flowed out of the water softening tank 3 due to the resin regeneration treatment of the water softening tank 3 to the acidic electrolyzed water storage tank 19 . An on-off valve 61 is installed in the first recovery channel 43 .

The water supply channel 48 is a channel that connects the acidic electrolyzed water reservoir 19 to the first water intake 12 . An acidic electrolyzed water circulation pump 23 is provided in the water supply channel 48 . That is, the water supply channel 48 is a channel for supplying the acidic electrolyzed water stored in the acidic electrolyzed water storage tank 19 to the anode chamber 14 of the electrolytic cell 9 using the acidic electrolyzed water circulation pump 23 . An on-off valve 71 is installed in the water supply channel 48 .

Here, the state of each channel for circulating water in the acidic electrolyzed water circulation channel 40 will be described.

An on-off valve 54 is installed in the channel 33 downstream of the first supply channel 41 and upstream of the first bypass channel 42 . By closing the on-off valve 54 and opening the on-off valve 63, the first supply flow path 41 is connected to the downstream side of the second water softening tank 3b. As a result, the acidic electrolyzed water from the anode chamber 14 of the electrolytic bath 9 can be supplied to the second water softening bath 3b.

An on-off valve 52 is installed in the channel 31 downstream of the first bypass channel 42 and upstream of the second recovery channel 47 . In addition, an on-off valve 53 is installed on the downstream side of the second bypass flow path 46 and the upstream side of the first bypass flow path 42 in the flow path 32 . By closing the on-off valve 52 and the on-off valve 53 and opening the on-off valve 65, the first bypass flow flows upstream of the second water softening tank 3b and downstream of the first water softening tank 3a. The path 42 will be in a state of communication and connection. As a result, the acidic electrolyzed water that has flowed through the second water softening tank 3b can be supplied to the first water softening tank 3a.

An on-off valve 51 is installed in the channel 30 downstream of the inlet 2 and upstream of the first recovery channel 43 . By closing the on-off valve 51 and the on-off valve 52 and opening the on-off valve 61, the first recovery passage 43 is connected to the upstream side of the first water softening tank 3a. As a result, in the water softening device 1, the water (acidic electrolyzed water containing hardness components) that has flowed through the first water softening tank 3a and the second water softening tank 3b can be recovered to the acidic electrolyzed water storage tank 19. Become.

An on-off valve 71 is installed in the water supply channel 48 on the downstream side of the acidic electrolyzed water storage tank 19 (position between the acidic electrolyzed water storage tank 19 and the acidic electrolyzed water circulation pump 23). Water can be stored in the acidic electrolyzed water storage tank 19 by closing the on-off valve 71 . On the other hand, water can be supplied to the water supply channel 48 by opening the on-off valve 71 .

On the other hand, in the alkaline electrolyzed water circulation passage 44, as shown in FIG. 2 (black arrow), the water sent out from the alkaline electrolyzed water storage tank 21 by the alkaline electrolyzed water circulation pump 24 flows into the electrolytic cell 9 and the second neutralization tank 4b. , and the first neutralization tank 4a, and return to the alkaline electrolyzed water storage tank 21 for circulation. More specifically, the alkaline electrolyzed water circulation channel 44 sends water from the alkaline electrolyzed water storage tank 21 by the alkaline electrolyzed water circulation pump 24 through the water supply channel 49, the second intake port 16, the cathode chamber 18, and the second outlet. Outlet 17, second supply channel 45, capture unit 25, on-off valve 64, second neutralization tank 4b, second bypass channel 46, on-off valve 66, first neutralization tank 4a, second recovery channel 47, It is a channel that circulates through the on-off valve 62 and the alkaline electrolyzed water reservoir 21 in this order.

The second supply channel 45 is a channel that connects the second outlet 17 to the channel 34 . That is, the second supply channel 45 is a channel for supplying alkaline electrolyzed water from the electrolytic bath 9 to the downstream side of the second neutralizing bath 4b. An on-off valve 64 is installed in the second supply channel 45 .

The second bypass flow path 46 is a flow path that bypasses the second water softening tank 3b and connects the flow path 33 to the flow path 32 . That is, the second bypass flow path 46 is a flow path that bypasses the second water softening tank 3b and supplies the alkaline electrolyzed water that has flowed through the second neutralization tank 4b to the downstream side of the first neutralization tank 4a. . An on-off valve 66 is installed in the second bypass flow path 46 .

The second recovery channel 47 is a channel that connects the channel 31 to the alkaline electrolyzed water storage tank 21 . That is, the second recovery channel 47 is a channel for recovering the alkaline electrolyzed water that has passed through the first neutralization tank 4 a into the alkaline electrolyzed water storage tank 21 . An on-off valve 62 is installed in the second recovery channel 47 .

The water supply channel 49 is a channel that connects the alkaline electrolyzed water storage tank 21 to the second water intake port 16 . An alkaline electrolyzed water circulation pump 24 is provided in the water supply channel 49 . That is, the water supply channel 49 uses the alkaline electrolyzed water circulation pump 24 to supply the acidic electrolyzed water stored in the alkaline electrolyzed water storage tank 21 from the second water intake 16 to the cathode chamber 18 of the electrolytic cell 9. is. An on-off valve 72 is installed in the water supply channel 49 .

Here, the state of each channel for circulating water in the alkaline electrolyzed water circulation channel 44 will be described.

An on-off valve 54 is installed in the channel 34 downstream of the second supply channel 45 and upstream of the second bypass channel 46 . In addition, an on-off valve 55 is installed in the flow path 34 upstream of the water intake 5 and downstream of the second neutralization tank 4b. By closing the on-off valve 54 and the on-off valve 55 and opening the on-off valve 64, the second supply flow path 45 is connected to the downstream side of the second neutralization tank 4b. As a result, the alkaline electrolyzed water from the cathode chamber 18 of the electrolytic cell 9 can be supplied to the second neutralization cell 4b.

An on-off valve 53 is installed in the channel 32 downstream of the second bypass channel 46 and upstream of the second water softening tank 3b. In addition, by closing the on-off valve 52, the on-off valve 53, and the on-off valve 54 and opening the on-off valve 66, The second bypass channel 46 is in a state of being connected. As a result, the alkaline electrolyzed water that has flowed through the second neutralization tank 4b can be supplied to the first neutralization tank 4a.

By closing the on-off valve 52 and opening the on-off valve 62, the second recovery passage 47 is connected to the upstream side of the first neutralization tank 4a. As a result, in the water softening device 1, the water (alkaline electrolyzed water containing anions) that has flowed through the first neutralization tank 4a and the second neutralization tank 4b can be recovered into the alkaline electrolyzed water storage tank 21. Become.

In addition, an on-off valve 72 is installed in the water supply channel 49 on the downstream side of the alkaline electrolyzed water storage tank 21 (position between the alkaline electrolyzed water storage tank 21 and the alkaline electrolyzed water circulation pump 24). Water can be stored in the alkaline electrolyzed water storage tank 21 by closing the on-off valve 72 . On the other hand, water can be supplied to the water supply channel 49 by opening the on-off valve 72 .

Further, by closing the on-off valve 51 and the on-off valve 55, the circulation of water to the acidic electrolyzed water circulation channel 40 and the alkaline electrolyzed water circulation channel 44 can be started, while the on-off valve 51 and the on-off valve 55 are opened. By doing so, the circulation of water to the acidic electrolyzed water circulation channel 40 and the alkaline electrolyzed water circulation channel 44 can be stopped.

((Anode Chamber Electrolyzed Water Drainage Channel, Cathode Chamber Electrolyzed Water Drainage Channel))
Next, the anode chamber electrolyzed water drainage channel 90 and the cathode chamber electrolyzed water drainage channel 92 formed during the electrode regeneration treatment of the water softening device 1 will be described with reference to FIG. FIG. 3 is a diagram showing the state of each component during the electrode regeneration treatment of the water softening device 1. As shown in FIG.

As shown in FIG. 3 (white arrow), the anode chamber electrolyzed water drainage channel 90 is configured to send the water stored in the acidic electrolyzed water storage tank 19 by the acidic electrolyzed water circulation pump 23 to the electrolytic tank 9 and the first supply. It is a channel that flows through the channel 41 and the channel 35 and is discharged to the outside of the apparatus.

The channel 35 is a channel connected to the first supply channel 41 between the on-off valve 63 and the electrolytic cell 9 . One end of the channel 35 is open to the outside of the device. In other words, the channel 35 is a channel for discharging the electrolyzed water delivered from the anode chamber 14 to the outside of the apparatus.

As shown in FIG. 3 (black arrow), the water stored in the alkaline electrolyzed water storage tank 21 is pumped out of the cathode chamber electrolyzed water drainage channel 92 by the alkaline electrolyzed water circulation pump 24 to flow through the electrolytic cell 9 and the second supply. It is a flow path that flows through the flow paths 45 and 36 and is discharged to the outside of the apparatus.

The channel 36 is a channel connected to the second supply channel 45 between the on-off valve 64 and the electrolytic bath 9 . One end of the channel 36 is open to the outside of the device. In other words, the channel 36 is a channel for discharging the electrolyzed water sent from the cathode chamber 18 to the outside of the apparatus.

((on-off valve))
A plurality of on-off valves (on-off valve 51 to on-off valve 55, on-off valve 61 to on-off valve 66, on-off valve 71, on-off valve 72, on-off valve 81, and on-off valve 82) are provided in each flow path, and each The channel is switched between an "open" state and a "closed" state. In addition, a plurality of on-off valves (on-off valves 51 to 55, on-off valves 61 to 66, on-off valves 71, on-off valves 72, on-off valves 81, and on-off valves 82) are connected to the control unit 26 wirelessly or They are communicably connected by wire.

The above is the configuration of the water softening device 1 .

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

((Water softening treatment, resin regeneration treatment and electrode regeneration treatment))
Next, the water softening treatment, resin regeneration treatment, and electrode regeneration treatment of the water softening device 1 will be described with reference to FIG. FIG. 4 is a diagram showing the state during operation of the water softening device 1. As shown in FIG.

In the water softening treatment, the regeneration treatment, and the drainage treatment, the control unit 26, as shown in FIG. 81, on-off valve 82, anode 11, cathode 15, acidic electrolyzed water circulating pump 23, alkaline electrolyzed water circulating pump 24, and detector 27 are switched and controlled to be in the respective flow states and operating states.

Here, "ON" in FIG. 4 indicates a state in which the corresponding on-off valve is "opened", a state in which the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are operating, and a state in which the detection unit 27 is operating. state respectively. “ON (positive electrolysis)” is a state (positive electrolysis state) in which current is applied so that the anode 11 is at a high potential with respect to the cathode 15 . “ON (reverse electrolysis)” is a state (reverse electrolysis state) in which current is applied so that the potential of the cathode 15 is higher than that of the anode 11 . Blanks indicate a state in which the corresponding on-off valve is "closed", a state in which the anode 11 and the cathode 15 are not energized, a state in which the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are stopped, and a state in which the detection unit 27 is Each indicates a non-operating state.

((Water softening treatment))
The operation of the water softening device 1 during the water softening process will be described with reference to the column "during water softening process" in FIGS. 1 and 4. FIG.

In the water softening apparatus 1, as shown in FIG. 4, during the water softening process, the on-off valve 55 provided at the water intake 5 is opened while the on-off valves 51 to 54 are open. As a result, raw water containing hardness components flows in from the outside and flows through the water softening tank 3 and the neutralization tank 4, so that the water softening device 1 receives softened water (medium water) from the water intake 5. soft water) can be taken out. At this time, the on-off valves 61 to 66, the on-off valve 71, the on-off valve 72, the on-off valve 81, and the on-off valve 82 are all closed. Further, the operations of the anode 11, the cathode 15, the acidic electrolyzed water circulation pump 23, the alkaline electrolyzed water circulation pump 24, and the detection unit 27 are also stopped.

Specifically, as shown in FIG. 1, in the water softening process, the pressure of city water causes the raw water supplied from the inflow port 2 to pass through the flow path 30 and be supplied to the first water softening tank 3a. . The raw water supplied to the first water softening tank 3a flows through the first weakly acidic cation exchange resin 7a provided in the first water softening tank 3a. At this time, cations, which are hardness components in the raw water, are adsorbed by the action of the first weakly acidic cation exchange resin 7a, and hydrogen ions are released (ion exchange is performed). Then, the raw water is softened by removing the cations from the raw water. The softened water contains many hydrogen ions that have been exchanged with hardness components and flowed out, so that it is acidified to become acidic water with a low pH (first soft water). Here, 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 used to soften temporary hardness components (for example, carbonic acid such as calcium carbonate). The pH tends to decrease more easily than water containing a large amount of salt). Since water softening does not progress easily when the pH is lowered, the water that has flowed through the first water softening tank 3a is passed through the first neutralizing tank 4a for neutralization.

The softened water further flows through the channel 31 and flows into the first neutralization tank 4a. In the first neutralization tank 4a, hydrogen ions contained in the softened water are adsorbed by the action of the first weakly basic anion exchange resin 8a. That is, since hydrogen ions are removed from the water softened by the first water softening tank 3a, the lowered pH is raised and neutralized. Therefore, compared with the case where the water softened in the first water softening tank 3a is directly softened in the second water softening tank 3b, the water softening treatment in the second water softening tank 3b proceeds more easily.

The water neutralized by the first neutralization tank 4a (first neutralized soft water) further flows through the flow path 32 and flows into the second water softening tank 3b. In the second water softening tank 3b, the second weakly acidic cation exchange resin 7b adsorbs cations, which are hardness components, and releases hydrogen ions. The second water softening tank 3b exchanges the hardness components that could not be removed in the first water softening tank 3a with hydrogen ions possessed by the second weakly acidic cation exchange resin 7b. That is, the water flowing into the second water softening tank 3b is further softened to become soft water (second soft water).

The second soft water flows through the channel 33 and flows into the second neutralization tank 4b. In the second neutralization tank 4b, hydrogen ions contained in the inflowing second soft water are adsorbed by the action of the second weakly basic anion exchange resin 8b. In other words, since the hydrogen ions are removed from the second soft water, the lowered pH increases, and the second soft water becomes neutral soft water (neutralized second soft water) that can be used as domestic water. The neutralized second soft water can flow through the flow path 34 and be taken out from the water intake 5 .

That is, in the water softening process, raw water flows through the first water softening tank 3a, the first neutralizing tank 4a, the second water softening tank 3b, and the second neutralizing tank 4b in this order. As a result, the raw water containing the hardness component flows out of the first water softening tank 3a before the pH of the raw water decreases due to the water softening treatment in the first water softening tank 3a, and is neutralized in the first neutralization tank 4a. It is softened in the second water softening tank 3b and neutralized in the second neutralization tank 4b. Therefore, compared with the case where the water softening tank 3 and the neutralizing tank 4 are configured individually, the decrease in pH of the water flowing through the water softening tank 3, that is, the acidification can be suppressed. 3 (particularly the second water softening tank 3b) is easily exchanged with the hydrogen ions retained by the weakly acidic cation exchange resin. Therefore, it is possible to improve the water softening performance.

Then, in the water softening device 1, when the time specified by the control unit 26 comes or when the water softening process exceeds a predetermined time, the resin regeneration process is executed.

((resin regeneration treatment))
Next, the operation of the regenerating device 6 of the water softening device 1 during resin regeneration processing will be described in order with reference to FIG.

In the water softening device 1, the water softening tank 3 filled with the weakly acidic cation exchange resin 7 loses or loses its cation exchange capacity with continued use. That is, after all hydrogen ions, which are functional groups of the cation exchange resin, are exchanged with calcium ions or magnesium ions, which are hardness components, ion exchange becomes impossible. In such a state, hardness components come to be contained in the treated water. Therefore, in the water softening device 1, it is necessary to perform a resin regeneration treatment for the water softening tank 3 and the neutralization tank 4 by the regenerating device 6. FIG.

When the on-off valves 51 to 55, the on-off valve 81, and the on-off valve 82 are closed and the on-off valves 61 to 66, the on-off valve 71, and the on-off valve 72 are opened during the resin regeneration process, 2, an acidic electrolyzed water circulation channel 40 and an alkaline electrolyzed water circulation channel 44 are formed.

When the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are operated, the water stored in the acidic electrolyzed water storage tank 19 and the alkaline electrolyzed water storage tank 21 flows into the acidic electrolyzed water circulation channel 40 and the alkaline electrolyzed water circulation channel 44. cycle through each.

In addition, the electrolytic cell 9 energizes the anode 11 so that the potential is high with respect to the cathode 15 (positive electrolysis). As a result, during electrolysis, hydrogen ions are generated at the anode 11 and acidic electrolyzed water is generated at the anode chamber 14 . On the other hand, hydroxide ions are generated at the cathode 15 and alkaline electrolyzed water is generated at the cathode chamber 18 .

Further, by operating the detection unit 27, it becomes possible to detect the voltage of the electrolytic cell 9 during the resin regeneration process.

The acidic electrolyzed water generated in the anode chamber 14 of the electrolytic cell 9 flows from the first discharge port 13 through the first supply channel 41 and is sent into the second water softening tank 3b, where the second weakly acidic cation exchange inside The resin 7b is circulated. Then, the acidic electrolyzed water that has flowed through the second water softening tank 3b flows through the first bypass channel 42, is sent into the first water softening tank 3a, and flows through the first weakly acidic cation exchange resin 7a inside. do. That is, by passing acidic electrolyzed water through the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin 7b, the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin The cations (hardness components) adsorbed on 7b cause an ion exchange reaction with hydrogen ions contained in the acidic electrolyzed water. As a result, the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin 7b are regenerated.

After that, the acidic electrolyzed water that has flowed through the first weakly acidic cation exchange resin 7 a contains cations and flows into the first recovery channel 43 . That is, the acidic electrolyzed water containing cations that has flowed through the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin 7b passes through the first bypass flow path 42 and the first recovery flow path 43 to produce an acidic It is recovered in the electrolyzed water storage tank 19 .

In this way, the acidic electrolyzed water circulation flow path 40 is located most downstream from the inlet of the raw water, and has the second weakly acidic cation exchange resin 7b with a small amount of adsorption of hardness components for the second water softening. A first soft water having a first weakly acidic cation exchange resin 7a that is circulated from the downstream side of the tank 3b and is located upstream and adsorbs more hardness components than the second weakly acidic cation exchange resin 7b. It is constructed so as to flow into the downstream side of the gasification tank 3a. That is, the acidic electrolyzed water circulation flow path 40 circulates the acidic electrolyzed water sent from the electrolytic tank 9 to the second water softening tank 3b, and then sends it to the first water softening tank 3a through the first bypass flow path 42. , and flows through the first water softening tank 3 a , collects it in the acidic electrolyzed water storage tank 19 , and then flows into the electrolytic tank 9 from the first intake port 12 . As a result, during the regeneration process, the acidic electrolyzed water discharged from the anode chamber 14 of the electrolytic cell 9 flows into the second water softening tank 3b, which has a smaller adsorption amount of hardness components than the first water softening tank 3a. Then, acidic electrolyzed water containing hardness components is discharged from the second water softening tank 3b to the first water softening tank 3a. Regeneration of the second weakly acidic cation exchange resin 7b in the second water softening tank 3b consumes less hydrogen ions in the acidic electrolyzed water than in the first water softening tank 3a, so regeneration of the first water softening tank 3a Compared to , the decrease in hydrogen ion concentration can be suppressed. Therefore, it is possible to prevent acidic electrolyzed water containing a large amount of hydrogen ions from flowing into the first water softening tank 3a and readsorption of hardness components in the first water softening tank 3a. Therefore, it is possible to suppress the deterioration of the regeneration processing efficiency and shorten the regeneration time.

Also, the acidic electrolyzed water circulation flow path 40 circulates the acidic electrolyzed water sent from the electrolysis tank 9 from the downstream side of the first water softening tank 3a and the second water softening tank 3b to the first water softening tank 3a and the second water softening tank 3b. It is a route that introduces water into the water softening tank 3b and causes it to flow out from the upstream side of the water softening tank 3 where the amount of adsorbed hardness components is greater than that on the downstream side. Note that the downstream side refers to the downstream side in the flow path during the water softening process.

On the other hand, the alkaline electrolyzed water generated in the cathode chamber 18 of the electrolytic cell 9 is fed from the second discharge port 17 through the second supply channel 45 and the trapping portion 25 into the second neutralization cell 4b, whereupon the internal first It flows through di-weakly basic anion exchange resin 8b. Then, the alkaline electrolyzed water that has flowed through the second neutralization tank 4b flows through the second bypass flow path 46, is sent into the first neutralization tank 4a, and displaces the first weakly basic anion exchange resin 8a inside. circulate. That is, by passing alkaline electrolyzed water through the first weakly basic anion exchange resin 8a and the second weakly basic anion exchange resin 8b, the first weakly basic anion exchange resin 8a and the second weakly basic The anions adsorbed on the anion exchange resin 8b undergo an ion exchange reaction with hydroxide ions contained in the alkaline electrolyzed water. This regenerates the first weakly basic anion exchange resin 8a and the second weakly basic anion exchange resin 8b.

After that, the alkaline electrolyzed water that has passed through the second weakly basic anion exchange resin 8 b contains anions and flows into the second recovery channel 47 . That is, the alkaline electrolyzed water containing anions that has passed through the first weakly basic anion exchange resin 8a and the second weakly basic anion exchange resin 8b passes through the second bypass channel 46 and the second recovery channel 47. is collected in the alkaline electrolyzed water storage tank 21.

In this way, the alkaline electrolyzed water circulation flow path 44 is located most downstream from the raw water inlet, and has a second weakly basic anion exchange resin 8b with a small amount of anion adsorption. Circulating from the downstream side of the sum tank 4b and having the first weakly basic anion exchange resin 8a located upstream and adsorbing more anions than the second weakly basic anion exchange resin 8b It was configured to flow into the downstream side of the first neutralization tank 4a. That is, the alkaline electrolyzed water circulation flow path 44 circulates the alkaline electrolyzed water sent from the electrolytic tank 9 to the second neutralization tank 4b, and then sends it to the first neutralization tank 4a through the second bypass flow path 46. , and flows through the first neutralization tank 4a, recovers it in the alkaline electrolyzed water storage tank 21, and then flows into the electrolytic tank 9 from the second intake port 16. As a result, during the regeneration treatment, alkaline electrolyzed water flows into the second neutralization tank 4b, which has a smaller amount of anions adsorbed than the first neutralization tank 4a, and alkaline electrolyzed water containing anions is produced. It is discharged from the second neutralization tank 4b to the first neutralization tank 4a. In the regeneration of the second weakly basic anion exchange resin 8b in the second neutralization tank 4b, the consumption of hydroxide ions in the alkaline electrolyzed water is less than in the first neutralization tank 4a. Compared to the regeneration of 4a, the decrease in hydroxide ion concentration can be suppressed. Therefore, alkaline electrolyzed water containing a large amount of hydroxide ions can be prevented from flowing into the first neutralization tank 4a and re-adsorbing anions in the first neutralization tank 4a. Therefore, it is possible to suppress the deterioration of the regeneration processing efficiency and shorten the regeneration time.

Also, the alkaline electrolyzed water circulation flow path 44 circulates the alkaline electrolyzed water sent from the electrolysis tank 9 from the downstream side of the first neutralization tank 4a and the second neutralization tank 4b to the first neutralization tank 4a and the second neutralization tank 4b. It is introduced into tank 4b and discharged from the upstream side of each neutralization tank where the amount of anions adsorbed is larger than that on the downstream side. As a result, the alkaline electrolyzed water flows in from the downstream side where the amount of adsorbed anion components is smaller, and the neutralization tank 4 is regenerated. In regeneration of the weakly basic anion exchange resin 8 on the downstream side, the consumption of hydroxide ions in the alkaline electrolyzed water is less than that on the upstream side, so reduction in the hydroxide ion concentration of the alkaline electrolyzed water can be suppressed. Therefore, it is possible to suppress the anions contained in the alkaline electrolyzed water coming from the downstream side from re-adsorbing on the upstream side. Therefore, it is possible to suppress the deterioration of the regeneration processing efficiency of the neutralization tank 4 and shorten the regeneration time. Note that the downstream side refers to the downstream side in the flow path during the water softening process.

During the period of the resin regeneration process, the detector 27 detects the voltage of the electrolytic cell 9 . The voltage of the electrolytic cell 9 detected by the detector 27 is compared with the first reference value to determine whether to proceed to the electrode regeneration process. Note that the first reference value is set to a predetermined voltage value. The predetermined voltage value may be set, for example, from the viewpoint of power consumption. When the voltage value is low, power consumption can be reduced.

Specifically, when the voltage of the electrolytic cell 9 detected by the detector 27 is less than the first reference value, the controller 26 continues the resin regeneration process. In addition, when the detected voltage is less than the first reference value, and when a certain time (for example, 7 hours) has passed since the start of the resin regeneration process (when the anode 11 and the cathode 15 started operating), the control unit 26 ends the resin regeneration process and shifts to the water softening process.

Further, when the voltage of the electrolytic cell 9 detected by the detection unit 27 is equal to or higher than the first reference value, the control unit 26 terminates the resin regeneration process and shifts to the electrode regeneration process.

((Electrode regeneration treatment))
Next, the operation during electrode regeneration processing by the regeneration device 6 of the water softening device 1 will be described in order with reference to the column "during electrode regeneration processing" in FIGS. 3 and 4. FIG.

During the resin regeneration treatment, when the electrolytic cell 9 is operating, hardness components (calcium ions or magnesium ions) in the water are deposited as solids (scales) on the cathode 15 . Since the solid deposited on the cathode 15 is a non-conductor, it increases the operating voltage of the electrolytic cell 9 and increases the power consumption during the resin regeneration process. Therefore, it is necessary to regenerate the electrode to remove the solid deposited on the cathode 15 .

During the electrode regeneration process, the on-off valves 51 to 55 and the on-off valves 61 to 66 are closed, and the on-off valves 71, 72, 81 and 82 are opened. In this way, as shown in FIG. 3, an anode chamber electrolyzed water drainage channel 90 and a cathode chamber electrolyzed water drainage channel 92 are formed.

When the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are operated, the water stored in the acidic electrolyzed water storage tank 19 and the alkaline electrolyzed water storage tank 21 flows into the electrolytic cell 9 .

In the electrode regeneration treatment, the controller 26 energizes the anode 11 so that the cathode 15 has a high potential (reverse electrolysis). Therefore, the electrolytic cell 9 electrolyzes the water that has flowed into the electrolytic cell, producing alkaline electrolyzed water in the anode chamber 14 and producing acidic electrolyzed water in the cathode chamber 18 .

At this time, the acidic electrolyzed water generated in the cathode chamber 18 can dissolve solids deposited on the cathode 15 . Therefore, by performing the electrode regeneration process, the voltage of the electrolytic cell 9 detected by the detection unit 27 decreases.

During the period of the electrode regeneration process, the detector 27 detects the voltage of the electrolytic cell 9 . The control unit 26 compares the voltage of the electrolytic cell 9 detected by the detection unit 27 with the second reference value, and determines the end of the electrode regeneration process. In addition, the second reference value is set to a predetermined voltage value according to the degree of dissolution of the solid deposited on the cathode 15 . As the predetermined voltage value, for example, a value higher than the voltage at the beginning of the resin regeneration treatment may be set as the second reference value. In this case, a certain amount of the solid deposited on the cathode 15 can be dissolved. Further, it is more preferable to set the voltage at the beginning of the resin regeneration treatment as the second reference value. In this case, most of the solid deposited on the cathode 15 can be dissolved.

Specifically, when the voltage of the electrolytic cell 9 detected by the detector 27 is equal to or higher than the second reference value, the controller 26 continues the electrode regeneration process.

On the other hand, when the voltage of the electrolytic cell 9 is less than the second reference value, the control unit 26 terminates the electrode regeneration process and shifts to resin regeneration process or water softening process. Specifically, when the electrode regeneration process is started before a certain period of time (for example, 7 hours) has passed since the start of the resin regeneration process, the process shifts to the resin regeneration process. On the other hand, when a certain period of time (for example, 7 hours) has already passed since the start of the resin regeneration process when the electrode regeneration process is started, the water softening process may be started.

As described above, the water softening device 1 repeatedly performs the water softening process, the resin regeneration process, and the electrode regeneration process.

As described above, according to the water softening device 1 according to Embodiment 1, the following effects can be obtained.

(1) The water softening device 1 includes a water softening tank 3 , a neutralization tank 4 , an electrolytic tank 9 , a detector 27 and a controller 26 . The water softening tank 3 softens raw water containing hardness components with a weakly acidic cation exchange resin 7 . The neutralization tank 4 neutralizes the pH of the softened water that has passed through the water softening tank 3 with a weakly basic anion exchange resin 8 . The electrolytic cell 9 produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin 7 and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin 8 . The detector 27 detects the voltage of the electrolytic cell 9 . The control unit 26 controls the detection unit 27 during the resin regeneration process in which at least one of regeneration of the weakly acidic cation exchange resin 7 using acidic electrolyzed water and regeneration of the weakly basic anion exchange resin 8 using alkaline electrolyzed water is performed. If the detected voltage is less than the first reference value, the resin regeneration process is continued or shifted to water softening process, and if the voltage detected by the detection unit 27 is equal to or higher than the first reference value, the resin regeneration process is started. When the voltage detected by the detection unit 27 is equal to or higher than the second reference value during the electrode regeneration processing, the electrode regeneration processing is continued, and the voltage detected by the detection unit 27 is changed to the second reference value. When it becomes less than the reference value, the electrode regeneration process is ended, and the process shifts to resin regeneration process or water softening process.

As a result, it is possible to prevent the voltage from rising above the first reference value due to scale generated in the electrolytic cell 9 during the resin regeneration process. Therefore, it is also possible to determine the start and end of the electrode regeneration process and the transition to the resin regeneration process or the water softening process. That is, it becomes possible to detect the timing of the electrode regeneration process and perform the polarity inversion operation at an appropriate timing. Therefore, since the electrode is not excessively regenerated, consumption of the electrode is suppressed, and the water softening device 1 can be used for a long period of time.

(Embodiment 2)
The water softening apparatus 1a according to Embodiment 2 of the present invention detects the voltage of the electrolytic cell 9 by the detection unit 27a at a timing after the end of the resin regeneration process and before the start of the water softening process, and detects the voltage of the electrode regeneration process. It is different from the first embodiment in that it determines the implementation. Other configurations are the same as those of the water softening device 1 according to the first embodiment. In the following, repetitive explanations of the contents already explained in the first embodiment will be omitted as appropriate, and differences from the first embodiment will be mainly explained.

((Detector))
The detection unit 27a detects the voltage of the electrolytic cell 9 after the end of the resin regeneration process and before the start of the water softening process. Further, the detection unit 27a detects the voltage of the electrolytic cell 9 during the electrode regeneration process. Also, the detection unit 27 a is connected to the control unit 26 . That is, based on the voltage detected by the detection unit 27a, the control unit 26 can determine switching between the water softening process, the resin regeneration process, and the electrode regeneration process.

((Water softening treatment, resin regeneration treatment, and electrode regeneration treatment))
((Water softening treatment))
In the water softening device 1a, the on-off valve 55 provided at the water intake 5 is opened while the on-off valves 51 to 54 are open during the water softening process. As a result, raw water containing hardness components flows in from the outside and flows through the water softening tank 3 and the neutralization tank 4. soft water) can be taken out.

Then, in the water softening device 1a, when the time specified by the control unit 26 comes or when the water softening process exceeds a predetermined time, the resin regeneration process is executed.

((resin regeneration treatment))
The resin regeneration treatment may be terminated after a certain period of time (for example, 7 hours) from the start of the resin regeneration treatment (when the anode 11 and the cathode 15 start operating). The fixed time can be arbitrarily set depending on the water quality of the installation area, the hardness of the raw water, the properties of the resin, and the like.

After the end of the resin regeneration process and before the start of the water softening process, the detector 27 a detects the voltage of the electrolytic cell 9 . When the voltage of the electrolytic cell 9 detected by the detection unit 27a is less than the first reference value, the control unit 26 does not shift to electrode regeneration processing, but shifts to water softening processing. On the other hand, when the voltage of the electrolytic cell 9 detected by the detector 27a is equal to or higher than the first reference value when the resin regeneration process is completed, the controller 26 performs the electrode regeneration process and the water softening process in parallel.

((Electrode regeneration treatment and water softening treatment))
The operations of the water softening apparatus 1a for resin regeneration and water softening will be described in order with reference to the columns "during water softening" and "during resin regeneration" in FIG.

When the control unit 26 shifts from the resin regeneration process to the electrode regeneration process and the water softening process, the on-off valves 61 to 66 are closed, and the on-off valves 51 to 55, the on-off valve 71, the on-off valve 72, and the on-off valve are closed. 81 and the on-off valve 82 are opened. That is, an anode chamber electrolyzed water drainage channel 90 and a cathode chamber electrolyzed water drainage channel 92 are formed.

When the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are operated, the water stored in the acidic electrolyzed water storage tank 19 and the alkaline electrolyzed water storage tank 21 flows into the electrolytic cell 9 . Further, the alkaline electrolyzed water and the acidic electrolyzed water electrolyzed by the electrolytic cell 9 are drained from the channels 35 and 36 .

In the electrode regeneration treatment, the controller 26 energizes the anode 11 so that the cathode 15 has a high potential (reverse electrolysis). Thereby, alkaline electrolyzed water can be generated in the anode chamber 14 and acidic electrolyzed water can be generated in the cathode chamber 18 .

At this time, the acidic electrolyzed water generated in the cathode chamber 18 can dissolve solids deposited on the cathode 15 . Therefore, by performing the electrode regeneration process, the voltage of the electrolytic cell 9 detected by the detection unit 27a decreases.

The detector 27a detects the voltage of the electrolytic cell 9 during the period of the electrode regeneration process. The control unit 26 compares the voltage of the electrolytic cell 9 detected by the detection unit 27a with the second reference value, and determines the end of the electrode regeneration process. In addition, the second reference value is set to a predetermined voltage value according to the degree of dissolution of the solid deposited on the cathode 15 . As the predetermined voltage value, for example, a value higher than the voltage at the beginning of the resin regeneration treatment may be set as the second reference value. In this case, a certain amount of the solid deposited on the cathode 15 can be dissolved. Further, it is more preferable to set the voltage at the beginning of the resin regeneration treatment as the second reference value. In this case, most of the solid deposited on the cathode 15 can be dissolved.

Specifically, when the voltage of the electrolytic cell 9 detected by the detector 27a is equal to or higher than the second reference value, the controller 26 continues the electrode regeneration process.

On the other hand, when the voltage of the electrolytic cell 9 is less than the second reference value, the controller 26 terminates the electrode regeneration process. At the end of the electrode regeneration process, the on-off valve 71, the on-off valve 72, the on-off valve 81, and the on-off valve 82 are closed, and the energization to the anode 11 and the cathode 15 is stopped. Also, the operation of the acidic electrolyzed water circulation pump 23, the alkaline electrolyzed water circulation pump 24, and the detection unit 27 is stopped. Since the time required for the water softening process is longer than the time required for the electrode regeneration process, the water softening process is continued.

As described above, the water softening device 1a repeatedly performs the water softening process, the resin regeneration process, and the electrode regeneration process.

As described above, according to the water softening device 1 according to the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

(2) The water softening device 1 a includes a water softening tank 3 , a neutralization tank 4 , an electrolytic tank 9 , a detector 27 and a controller 26 . The water softening tank 3 softens raw water containing hardness components with a weakly acidic cation exchange resin 7 . The neutralization tank 4 neutralizes the pH of the softened water that has passed through the water softening tank 3 with a weakly basic anion exchange resin 8 . The electrolytic cell 9 produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin 7 and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin 8 . The detector 27 a detects the voltage of the electrolytic cell 9 . The control unit 26 performs at least one of regeneration of the weakly acidic cation exchange resin 7 using acidic electrolyzed water and regeneration of the weakly basic anion exchange resin 8 using alkaline electrolyzed water. If the voltage detected by the detection unit 27a is less than the first reference value before starting the softening process, the electrode regeneration process is not performed, and the water softening process is performed.

According to such a configuration, after the water softening treatment and the resin regeneration treatment are performed as a set, it is possible to determine whether to shift to the electrode regeneration treatment. It is possible to shift to water softening treatment without performing regeneration treatment. Therefore, control can be performed so that excessive electrode regeneration processing is not performed. Therefore, consumption of the electrodes can be suppressed, and the water softening device 1a can be used for a long period of time. Moreover, since the detection unit 27a detects the voltage of the electrolytic cell 9 when the resin regeneration process is completed, the detection unit 27a does not need to operate all the time. Therefore, it is possible to extend the life of the detection unit 27a.

(3) In the water softening device 1, when the voltage detected by the detection unit 27 is equal to or higher than the first reference value, the electrode regeneration process and the water softening process are executed in parallel.

According to such a configuration, the electrode regeneration treatment and the water softening treatment can be performed in parallel. Therefore, since the water softening treatment can be performed promptly after the resin regeneration treatment, the time during which the water softening treatment can be performed can be lengthened.

(4) In the water softening device 1, when the voltage detected by the detection unit 27 becomes less than the second reference value during the electrode regeneration process, the electrode regeneration process is terminated.

With such a configuration, it is possible to determine the end of the electrode regeneration process that has been performed in parallel with the water softening process. Therefore, it is possible to determine the end of the electrode regeneration process at an appropriate timing, so that the consumption of the electrodes can be suppressed, and the water softening device 1a can be used for a long period of time.

(Embodiment 3)
The water softening apparatus 1b according to Embodiment 3 of the present invention detects the voltage of the electrolytic cell 9 by the detecting unit 27 at the timing after the end of the resin regeneration process and before the start of the water softening process, and the voltage of the electrolytic cell 9 is It is different from the second embodiment in that when it is equal to or greater than the first reference value, the electrode regeneration treatment and the water softening treatment are not performed in parallel, and only the electrode regeneration treatment is performed. Other configurations are the same as those of the water softening device 1a according to the second embodiment. In the following, repetitive explanations of the contents already explained in the second embodiment will be omitted as appropriate, and differences from the second embodiment will be mainly explained.

((Water softening treatment, resin regeneration treatment, and electrode regeneration treatment))
((Water softening treatment))
In the water softening device 1b, the on-off valve 55 provided at the water intake 5 is opened while the on-off valves 51 to 54 are open during the water softening process. As a result, raw water containing hardness components flows in from the outside and flows through the water softening tank 3 and the neutralizing tank 4. soft water) can be taken out.

Then, in the water softening device 1b, when the time period specified by the control unit 26 comes or when the water softening process exceeds a predetermined time, the resin regeneration process is performed.

((resin regeneration treatment))
The resin regeneration treatment may be terminated after a certain period of time (for example, 7 hours) from the start of the resin regeneration treatment (when the anode 11 and the cathode 15 start operating). The fixed time can be arbitrarily set depending on the water quality of the installation area, the hardness of the raw water, the properties of the resin, and the like.

After the end of the resin regeneration process and before the start of the water softening process, the detector 27 a detects the voltage of the electrolytic cell 9 . When the voltage of the electrolytic cell 9 detected by the detection unit 27a is less than the first reference value, the control unit 26 does not shift to the electrode regeneration process, but shifts to the water softening process. On the other hand, when the voltage of the electrolytic cell 9 detected by the detection unit 27a is equal to or higher than the first reference value when the resin regeneration process is completed, the control unit 26 shifts to the electrode regeneration process.

((Electrode regeneration treatment))
The operation of the water softening device 1b for resin regeneration and water softening will be described in order with reference to the column "during resin regeneration" in FIG.

When the control unit 26 shifts from the resin regeneration process to the electrode regeneration process, the on-off valves 51 to 55 and the on-off valves 61 to 66 are closed, and the on-off valves 71, 72, 81, Then, the on-off valve 82 is opened. Then, an anode chamber electrolyzed water drainage channel 90 and a cathode chamber electrolyzed water drainage channel 92 are formed.

Then, when the acidic electrolyzed water circulation pump 23 and the alkaline electrolyzed water circulation pump 24 are operated, the water stored in the acidic electrolyzed water storage tank 19 and the alkaline electrolyzed water storage tank 21 flows into the electrolytic tank 9, and further flows into the flow path. 35 and flow path 36.

In the electrode regeneration treatment, the controller 26 energizes the anode 11 so that the cathode 15 has a high potential (reverse electrolysis). Thereby, alkaline electrolyzed water can be generated in the anode chamber 14 and acidic electrolyzed water can be generated in the cathode chamber 18 .

At this time, the acidic electrolyzed water generated in the cathode chamber 18 can dissolve solids deposited on the cathode 15 . As a result, the voltage of the electrolytic cell 9 detected by the detection unit 27a decreases.

The detector 27a detects the voltage of the electrolytic cell 9 during the period of the electrode regeneration process. The control unit 26 compares the voltage of the electrolytic cell 9 detected by the detection unit 27a with the second reference value, and determines the end of the electrode regeneration process. In addition, the second reference value is set to a predetermined voltage value according to the degree of dissolution of the solid deposited on the cathode 15 . As the predetermined voltage value, for example, a value higher than the voltage at the beginning of the resin regeneration treatment may be set as the second reference value. In this case, a certain amount of the solid deposited on the cathode 15 can be dissolved. Further, it is more preferable to set the voltage at the beginning of the resin regeneration treatment as the second reference value. In this case, most of the solid deposited on the cathode 15 can be dissolved.

Specifically, when the voltage of the electrolytic cell 9 detected by the detector 27a is equal to or higher than the second reference value, the controller 26 continues the electrode regeneration process.

On the other hand, when the voltage of the electrolytic cell 9 is less than the second reference value, the controller 26 terminates the electrode regeneration process and shifts to the water softening process. At the end of the electrode regeneration process, the on-off valve 71, the on-off valve 72, the on-off valve 81, and the on-off valve 82 are closed, and the energization to the anode 11 and the cathode 15 is stopped. Also, the operation of the acidic electrolyzed water circulation pump 23, the alkaline electrolyzed water circulation pump 24, and the detection unit 27a is stopped. Then, the on-off valves 51 to 55 are opened to shift to the water softening process.

As described above, the water softening device 1 repeatedly performs the water softening process, the resin regeneration process, and the electrode regeneration process.

As described above, according to the water softening device 1 according to the third embodiment, in addition to the effects (2) to (4) of the second embodiment, the following effects can be obtained.

(5) In the water softening device 1, when the voltage detected by the detection unit 27 is equal to or higher than the first reference value, the electrode regeneration process is performed, and then the water softening process is performed.

According to such a configuration, when the voltage of the electrolytic cell 9 becomes equal to or higher than the first reference value during the resin regeneration process, the electrode regeneration process is performed, and then the water softening process is performed. Therefore, the electrode regeneration process and the water softening process are not performed at the same time, and the control of the water softening device 1 can be simplified.

The present invention has been described above based on the embodiments. Those skilled in the art will understand that these embodiments are merely examples, and that various modifications can be made to combinations of each component or each treatment process, and such modifications are also within the scope of the present invention. I am where I am.

In the water softening device 1 according to Embodiment 1, the water softening tank 3 and the neutralizing tank 4 are two each, but the number is not limited to this. For example, it may be one each. This simplifies the device configuration. Also, for example, each may be three or more. This increases the number of times that water softening and neutralization are alternately performed during the water softening process, so that the water softening performance can be further improved.

In addition, in the water softening device 1 according to Embodiment 1, the channel lengths and channel cross-sectional areas of the first water softening tank 3a and the second water softening tank 3b are equal, but this is not the only option. For example, the channel length or the channel cross-sectional area may be different, or both the channel length and the channel cross-sectional area may be different. Even in this way, the same effect as in the first embodiment can be obtained.

Further, in the water softening device 1 according to Embodiment 1, the first weakly acidic cation exchange resin 7a filled in the first water softening tank 3a and the second weak Although the volumes of the acidic cation exchange resins 7b are assumed to be equal, this is not the only option. For example, the volumes of the first weakly acidic cation exchange resin 7a and the second weakly acidic cation exchange resin 7b may be different, or different kinds of weakly acidic cation exchange resins 7 may be used. Thereby, the water softening performance can be adjusted, and the water softening device 1 having the water softening performance suitable for the purpose can be obtained.

Further, in the water softening apparatus 1 according to Embodiment 1, the channel lengths and channel cross-sectional areas of the first neutralization tank 4a and the second neutralization tank 4b are equal, but this is not the only option. For example, the channel length or the channel cross-sectional area may be different, or both the channel length and the channel cross-sectional area may be different. be done.

Further, in the water softening apparatus 1 according to Embodiment 1, the first weakly basic anion exchange resin 8a filled in the first neutralization tank 4a and the second Although the volumes of the weakly basic anion exchange resins 8b are assumed to be equal, this is not the only option. For example, the first weakly basic anion exchange resin 8a and the second weakly basic anion exchange resin 8b may have different volumes, or different types of weakly basic anion exchange resins 8 may be used. . However, the volume of the second weakly basic anion exchange resin 8b filled in the second neutralization tank 4b adsorbs the hydrogen ions released from the second water softening tank 3b, It is sufficient if the volume is sufficient to convert the inflowing acidic soft water to neutral soft water. Thereby, the water softening performance can be adjusted, and the water softening device 1 having the water softening performance suitable for the purpose can be obtained.

Further, in the water softening device 1 according to Embodiment 1, the acidic electrolyzed water is circulated in the order of the second water softening tank 3b and the first water softening tank 3a, but this is not the only option. For example, the acidic electrolyzed water may be circulated through the first water softening tank 3a and the second water softening tank 3b in this order. Furthermore, in the water softening apparatus 1 according to Embodiment 1, the acidic electrolyzed water is circulated from the downstream side of the water softening tank 3, but it may be circulated from the upstream side. Also in this way, the water softening tank 3 can be regenerated.

Further, in the water softening device 1 according to Embodiment 1, the acidic electrolyzed water is circulated in the order of the second water softening tank 3b and the first water softening tank 3a, but this is not the only option. For example, a first playback device and a second playback device having functions equivalent to those of the playback device 6 may be used to carry out playback processing through independent distribution channels. Thereby, the regeneration treatment of the first water softening tank 3a and the second water softening tank 3b can be performed independently, and the time required for the regeneration treatment can be shortened.

Further, in the water softening device 1 according to Embodiment 1, the alkaline electrolyzed water is circulated in the order of the second neutralization tank 4b and the first neutralization tank 4a, but this is not the only option. For example, the alkaline electrolyzed water may be circulated through the first neutralization tank 4a and the second neutralization tank 4b in this order. Furthermore, in the water softening device 1 according to Embodiment 1, the acidic electrolyzed water is circulated from the downstream side of the neutralization tank 4, but it may be circulated from the upstream side. Even in this way, the neutralization tank 4 can be regenerated.

Moreover, in the water softening device 1 according to Embodiment 1, the alkaline electrolyzed water is circulated in the order of the second neutralization tank 4b and the first neutralization tank 4a, but this is not the only option. For example, a first playback device and a second playback device having functions equivalent to those of the playback device 6 may be used to carry out playback processing through independent distribution channels. Thereby, the regeneration treatment of the first neutralization tank 4a and the second neutralization tank 4b can be performed independently, and the time required for the regeneration treatment can be shortened.

Further, in the water softening device 1 according to Embodiment 1, the regeneration process is executed when the time period specified by the control unit 26 has come or when the water softening process has exceeded a certain period of time. It is not limited to this. For example, an ion concentration detector is provided on the downstream side of the second neutralization tank 4b and the upstream side of the on-off valve 55, and the ion concentration detector detects the ion concentration (e.g., hardness) of the soft water flowing through the flow path 34. component concentration) is always detected, and not only when the time period specified by the control unit 26 comes or when the water softening process exceeds a certain time, but also when the ion concentration exceeds a preset reference value You may make it perform a reproduction|regeneration process. Accordingly, it is possible to determine whether to perform the regeneration process based on the ion concentration of the water after it has flowed through the second neutralization tank 4b. Therefore, the state of the weakly acidic cation exchange resin 7 in the water softening tank 3 can be determined more accurately, and the weakly acidic cation exchange resin 7 and the weakly basic anion exchange resin 8 can be regenerated at appropriate timing. It can be carried out.

The water softener according to the present invention can be applied to a water purifier installed at a place of use (POU: Point of Use) or a water purifier installed at a building entrance (POE: Point of Entry).

Reference Signs List 1, 1a, 1b water softening device 2 inlet 3 water softening tank 3a first water softening tank 3b second water softening tank 4 neutralization tank 4a first neutralization tank 4b second neutralization tank 5 water intake 6 regenerator 7 Weakly acidic cation exchange resin 7a First weakly acidic cation exchange resin 7b Second weakly acidic cation exchange resin 8 Weakly basic anion exchange resin 8a First weakly basic anion exchange resin 8b Second weakly basic anion Exchange resin 9 Electrolytic bath 10 Diaphragm 11 Anode 12 First water intake port 13 First discharge port 14 Anode chamber 15 Cathode 16 Second water intake port 17 Second discharge port 18 Cathode chamber 19 Acidic electrolyzed water reservoir 20 Air vent valve 21 Alkaline electrolyzed water Water tank 22 Air vent valve 23 Acidic electrolyzed water circulation pump 24 Alkaline electrolyzed water circulation pump 25 Capturing part 26 Control part 27 Detection part 27a Detection part 30, 31, 32, 33, 34, 35, 36 Channel 40 Acidic electrolyzed water circulation channel 41 Second One supply channel 42 First bypass channel 43 First recovery channel 44 Alkaline electrolyzed water circulation channel 45 Second supply channel 46 Second bypass channel 47 Second recovery channel 48, 49 Water supply channel 51, 52, 53, 54, 55, 61, 62, 63, 64, 65, 66, 71, 72, 81, 82 On-off valve 90 Anode chamber electrolyzed water drainage channel 92 Cathode chamber electrolyzed water drainage channel

Claims (5)

a water softening tank for softening raw water with a weakly acidic cation exchange resin;
a neutralization tank for neutralizing the pH of soft water that has passed through the water softening tank with a weakly basic anion exchange resin;
an electrolytic cell for producing acidic electrolyzed water and alkaline electrolyzed water;
a detection unit that detects the voltage of the electrolytic cell;
a control unit that controls the electrode regeneration process of the electrolytic cell based on the voltage detected by the detection unit;
with
The control unit
At the time of resin regeneration treatment for performing at least one of regeneration of the weakly acidic cation exchange resin using the acidic electrolyzed water and regeneration of the weakly basic anion exchange resin using the alkaline electrolyzed water,
when the voltage detected by the detection unit is less than the first reference value, continuing the resin regeneration process or transitioning to the water softening process;
when the voltage detected by the detection unit is equal to or higher than the first reference value, the resin regeneration process is stopped and the electrode regeneration process is started;
During the electrode regeneration treatment,
if the voltage detected by the detection unit is equal to or higher than a second reference value, continuing the electrode regeneration process;
A water softening device that terminates the electrode regeneration process and shifts to the resin regeneration process or the water softening process when the voltage detected by the detection unit is less than a second reference value. a water softening tank for softening raw water with a weakly acidic cation exchange resin;
a neutralization tank for neutralizing the pH of soft water that has passed through the water softening tank with a weakly basic anion exchange resin;
an electrolytic cell for producing acidic electrolyzed water and alkaline electrolyzed water;
a detection unit that detects the voltage of the electrolytic cell;
a control unit that controls the electrode regeneration process of the electrolytic cell based on the voltage detected by the detection unit;
with
After completion of a resin regeneration treatment for performing at least one of regeneration of the weakly acidic cation exchange resin using the acidic electrolyzed water or regeneration of the weakly basic anion exchange resin using the alkaline electrolyzed water and the water softening treatment before the start of
The control unit
A water softening device that, when the voltage detected by the detection unit is less than a first reference value, does not shift to the electrode regeneration process, but shifts to the water softening process. The control unit
3. The water softening device according to claim 2, wherein the electrode regeneration process and the water softening process are performed in parallel when the voltage detected by the detection unit is equal to or higher than the first reference value. 3. The water softening device according to claim 2, wherein when the voltage detected by the detection unit is equal to or higher than the first reference value, the water softening process is performed after the electrode regeneration process. The water softening device according to claim 3 or 4, wherein the electrode regeneration process is terminated when the voltage detected by the detection unit becomes less than a second reference value during the electrode regeneration process.

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