JP2022086033A - Water softening apparatus - Google Patents

Abstract

A water softening apparatus capable of suppressing deterioration in water softening performance caused by hardness components released from a water softening tank during regeneration treatment of the water softening tank. A water softening device (1) includes a water softening tank (3), a neutralization tank (4), an electrolytic tank (12), a water storage tank (15), and a separation section (14). The water softening tank 3 softens raw water containing hardness components with a weakly acidic cation exchange resin 10 . The neutralization tank 4 neutralizes the pH of the softened water that has passed through the water softening tank with the weakly basic anion exchange resin 11 . The electrolytic bath 12 produces acidic electrolyzed water for regenerating the water softening bath 3 and alkaline electrolyzed water for regenerating the neutralizing bath 4 . The water storage tank 15 mixes the acidic electrolyzed water that has passed through the water softening tank 3 and the alkaline electrolyzed water that has passed through the neutralization tank 4 and supplies the mixture to the electrolytic tank 12 . Separation unit 14 is provided in a flow path that communicates electrolytic bath 12 and neutralization bath 4 , and separates deposits caused by hardness components contained in water introduced into electrolytic bath 12 . [Selection drawing] Fig. 1

Description

The present invention relates to a water softening device for obtaining domestic water.

In the conventional water softening device using a weakly acidic cation exchange resin, a method of regenerating the cation exchange resin with acidic electrolyzed water generated by electrolysis is known as a method of regenerating the cation exchange resin without using salt. (See, for example, Patent Document 1). The weakly acidic cation exchange resin has a proton at the end of the functional group and exchanges hardness components (for example, calcium ion and magnesium ion) in the raw water with hydrogen ions to soften the raw water. Then, the hydrogen ions in the water softened by the weakly acidic cation exchange resin are neutralized by being adsorbed by the weakly basic anion exchange resin provided in the subsequent stage of the weakly acidic cation exchange resin. In the conventional water softening device, as a method for regenerating the weakly basic anion exchange resin, a method of regenerating the weakly basic anion exchange resin with alkaline electrolytic water generated by electrolysis is known (for example, Patent Document 2). reference).

Japanese Unexamined Patent Publication No. 2011-30973 Japanese Unexamined Patent Publication No. 2010-142674

In such a conventional water softening device, during the regeneration treatment, the hardness components (for example, calcium ion and magnesium ion) released from the water softening tank react with the alkaline electrolyzed water in the electrolytic cell to form a precipitate. There is. When such a precipitate flows into the neutralization tank and the water softening treatment is restarted in a state where it is accumulated in the neutralization tank, there is a problem that the water softening performance is deteriorated.

The present invention solves the above-mentioned conventional problems, and can suppress the deterioration of the water softening performance caused by the hardness component released from the water softening tank during the regeneration treatment of the water softening tank. It is an object of the present invention to provide a water softening device.

In order to achieve this object, the water softening device according to the present invention includes a water softening tank, a neutralization tank, an electrolytic cell, a water storage tank, and a separation unit. The water softening tank softens the raw water containing the hardness component with a weakly acidic cation exchange resin. The neutralization tank neutralizes the pH of the soft water that has passed through the softening tank with a weakly basic anion exchange resin. The electrolytic cell produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin in the water softening tank and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin in the neutralization tank. In the water storage tank, the acidic electrolyzed water flowing through the softening tank and the alkaline electrolyzed water flowing through the neutralization tank are mixed and supplied to the electrolytic cell. The separation portion is provided in a flow path communicating the electrolytic cell and the neutralization tank, and separates the precipitates caused by the hardness component contained in the water introduced into the electrolytic cell. This will achieve the intended purpose.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a water softening apparatus capable of suppressing a decrease in water softening performance caused by a hardness component released from a water softening tank during a regeneration treatment of the water softening tank. ..

FIG. 1 is a conceptual diagram showing a configuration of a water softening device according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a circulation flow path of the water softening device. FIG. 3 is a block diagram showing a cleaning flow path of the water softening device. FIG. 4 is a diagram showing a state of the water softening device during operation. FIG. 5 is a conceptual diagram showing the configuration of the water softening device according to the second embodiment of the present invention. FIG. 6 is a conceptual diagram showing the configuration of the water softening device according to the third embodiment of the present invention.

The water softening device according to the present invention includes a water softening tank, a neutralization tank, an electrolytic cell, a water storage tank, and a separation unit. In the water softening tank, raw water containing a hardness component and chloride ions is softened with a weakly acidic cation exchange resin. The neutralization tank neutralizes the pH of the soft water that has passed through the softening tank with a weakly basic anion exchange resin. The electrolytic cell produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin in the water softening tank and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin in the neutralization tank. In the water storage tank, the acidic electrolyzed water flowing through the softening tank and the alkaline electrolyzed water flowing through the neutralization tank are mixed and supplied to the electrolytic cell. The separation portion is provided in a flow path communicating the electrolytic cell and the neutralization tank, and separates the precipitates caused by the hardness component contained in the water introduced into the electrolytic cell.

According to such a configuration, when the water softening tank and the neutralization tank are regenerated, the precipitate contained in the alkaline electrolytic water that has passed through the electrolytic cell (due to the hardness component contained in the water introduced into the electrolytic cell). The precipitate) can be separated at the separation portion, and the inflow of the precipitate into the neutralization tank can be reduced. Therefore, when the water softening treatment is restarted after the regeneration treatment is completed, the precipitate flowing into the neutralization tank, which is seen in the conventional water softening apparatus, reacts with the hydrogen ions released from the water softening tank to form a hardness component. It is possible to suppress the occurrence of the phenomenon of formation, and it is possible to reduce the deterioration of the water softening performance due to the dissolution of the precipitate.

Further, the water softening apparatus according to the present invention further includes a control unit for controlling the regeneration treatment of the weakly acidic cation exchange resin in the water softening tank and the weakly basic anion exchange resin in the neutralization tank. After the regeneration process is completed, the electrolytic tank may be repolarized, and the acid electrolyzed water after the repolarization may be circulated to the separation unit and controlled so as to be discharged to the outside of the apparatus. According to such a configuration, since the separation part is washed (dissolution and removal of the precipitate separated at the separation part), the maintenance frequency of the separation part can be reduced, and the water softening device can be used for a long period of time. can do.

Further, in the water softening apparatus according to the present invention, in the control unit, when the ion concentration specified based on the information on the ion concentration of the acidic electrolyzed water after conversion after flowing through the separation unit becomes less than the reference value. In addition, the configuration may be such that the inversion of the electrolytic cell is controlled to be completed. According to such a configuration, the end of the inversion can be controlled based on the ion concentration contained in the acidic electrolyzed water after the inversion. Therefore, the acidic electrolyzed water can be circulated through the separated portion until the hardness component contained in the acidic electrolyzed water after flowing through the separated portion becomes less than the standard value, and the separated portion can be washed (separated precipitates). Dissolution) can be performed more reliably. Therefore, the maintenance frequency of the separated portion can be further reduced, and the water softening device can be used for a long period of time.

Further, in the water softening apparatus according to the present invention, the water storage tank may be further provided with a water storage tank separation unit for separating precipitates caused by the hardness component contained in the water introduced into the tank. According to such a configuration, the precipitate can be separated not only in the separation portion provided between the electrolytic cell and the neutralization tank but also in the water storage tank separation portion, so that the precipitate can be separated more reliably. Therefore, when the water softening treatment is restarted after the regeneration treatment is completed, the precipitates flowing into the neutralization tank, which are seen in the conventional water softening equipment, react with hydrogen ions from the water softening tank to form a hardness component. It is possible to suppress the occurrence of such a phenomenon, and further reduce the deterioration of the water softening performance due to the dissolution of the precipitate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples that embody the present invention, and do not limit the technical scope of the present invention. Further, each figure described in the embodiment is a schematic view, and the ratio of the size and the thickness of each component in each figure does not necessarily reflect the actual dimensional ratio. ..

(Embodiment 1)
The water softening device 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram showing the configuration of the water softening device 1 according to the first embodiment 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 produces city water (raw water containing a hardness component) supplied from the outside as neutral soft water that can be used as domestic water.

Specifically, as shown in FIG. 1, the water softening device 1 includes an inflow port 2 for raw water from the outside, a water softening tank 3, a neutralization tank 4, and an intake port 5 for soft water after treatment. The reproduction device 6 is provided. Further, the regeneration device 6 includes an electrolytic cell 12, a separation unit 14, a water storage tank 15, and a water pump 20. Further, the water softening device 1 includes a first drain port 16, a second drain port 18, a plurality of selection valves (selection valve 17, selection valve 19), and a plurality of on-off valves (on-off valve 27 to on-off valve 34). And the control unit 35.

The inflow port 2 is connected to the city water. The water softening device 1 can take out the water after the water softening treatment from the intake port 5 by the pressure of the city water.

The inflow port 2 to the intake port 5 are connected by a flow path 7, a flow path 8, and a flow path 9. The flow path 7 is a flow path connecting the inflow port 2 to the water softening tank 3. The flow path 8 is a flow path connecting the water softening tank 3 to the neutralization tank 4. The flow path 9 is a flow path connecting the neutralization tank 4 to the intake port 5.

In other words, the flow path 7 is a flow path that guides the raw water containing the hardness component from the inflow port 2 to the softening tank 3. Further, the flow path 8 is a flow path that guides the raw water softened in the softening tank 3 to the neutralization tank 4. The flow path 9 is a flow path that guides the soft water neutralized by the neutralization tank 4 to the water port 5.

That is, in the water softening device 1, in the water softening treatment, the city water supplied from the outside is the inflow port 2, the flow path 7, the water softening tank 3, the flow path 8, the neutralization tank 4, the flow path 9, and the intake port. It is distributed in the order of 5, and is discharged as neutral soft water.

(Soft water tank and neutralization tank)
The water softening tank 3 is filled with a weakly acidic cation exchange resin 10, and the neutralization tank 4 is filled with a weakly basic anion exchange resin 11.

Here, the weakly acidic cation exchange resin 10 is not particularly limited, and a general-purpose resin can be used, and examples thereof include those having a carboxyl group (—COOH) as an exchange group. Further, the hydrogen ion (H +), which is the counter ion of the carboxyl group, may be a cation such as a metal ion or an ammonium ion (NH4 +).

Further, the weak basic anion exchange resin 11 is not particularly limited, and a general-purpose resin can be used, and examples thereof include those having a free base type.

The water softening tank 3 softens the raw water containing the hardness component by the action of the weakly acidic cation exchange resin 10. More specifically, the water softening tank 3 includes a weakly acidic cation exchange resin 10 having a hydrogen ion at the end of the functional group. Since the water softening tank 3 exchanges cations (calcium ion, magnesium ion) which are hardness components contained in the circulating water (raw water) with hydrogen ions, the hardness of the raw water is lowered and the raw water can be softened. .. Further, since the terminal of the functional group of the weakly acidic cation exchange resin 10 is a hydrogen ion, the weakly acidic cation exchange resin 10 can be regenerated by using acidic electrolyzed water in the regeneration treatment described later. At this time, the weakly acidic cation exchange resin 10 releases cations, which are hardness components taken in during the water softening treatment.

Raw water containing a hardness component is passed through the water softening tank 3 from the flow path 7, and by passing through the weakly acidic cation exchange resin 10 filled therein, the raw water containing the hardness component is used as soft water in the flow path 8 Water is passed through the neutralization tank 4. However, the soft water treated with the weakly acidic cation exchange resin 10 contains a large amount of hydrogen ions that have been exchanged with the hardness component.

The neutralization tank 4 neutralizes the pH of soft water (acidified soft water) containing hydrogen ions that has come out of the soft water tank 3 by the action of the weakly basic anion exchange resin 11, and neutral water (neutral). It is to convert to soft water). More specifically, the neutralization tank 4 includes a weakly basic anion exchange resin 11 and adsorbs hydrogen ions contained in the soft water from the soft water tank 3 together with an anions (anions), so that the pH of the soft water is high. Can be made into neutral soft water. Further, the weakly basic anion exchange resin 11 can be regenerated using alkaline electrolyzed water in the regeneration treatment described later.

Soft water containing hydrogen ions is passed through the neutralization tank 4 from the flow path 8 and passes through the weakly basic anion exchange resin 11 filled therein to acidify the water softening tank 3. The soft water is neutralized and passed to the outside as neutral soft water through the flow path 9.

(Reproduction device)
The regeneration device 6 is a device that regenerates the weakly acidic cation exchange resin 10 in the water softening tank 3 and regenerates the weakly basic anion exchange resin 11 in the neutralization tank 4. Specifically, as described above, the regeneration device 6 includes an electrolytic cell 12, a separation unit 14, a water storage tank 15, and a water pump 20. Then, the regeneration device 6 has a first supply flow path 22, a first recovery flow path 23, and a second supply flow flow with respect to the flow path 7, the flow path 8, and the flow path 9 from the inflow port 2 to the intake port 5. The road 24 and the second recovery flow path 25 are connected to each other. Each of the flow paths constitutes a circulation flow path 21 (first circulation flow path 21a, second circulation flow path 21b), which will be described later.

Here, the first supply flow path 22 is a flow path for supplying acidic electrolyzed water from the electrolytic cell 12 to the softening tank 3. The first supply flow path 22 is a flow path that connects the electrolytic cell 12 and the selection valve 17 in communication with the first supply flow path 22a, and the selection valve 17 and the water softening tank 3 in communication with each other. It is composed of one supply flow path 22b. The first recovery flow path 23 is a flow path for recovering water containing a hardness component that has passed through the softening tank 3 to the water storage tank 15. The second supply flow path 24 is a flow path for supplying alkaline electrolyzed water from the electrolytic cell 12 to the neutralization tank 4. The second supply flow path 24 is a flow path that connects the electrolytic cell 12 and the selection valve 19 in communication with the second supply flow path 24a, and the selection valve 19 and the water softening tank 3 in communication with each other. (2) It is composed of a supply flow path 24b. The second recovery flow path 25 is a flow path for recovering the water that has passed through the neutralization tank 4 to the water storage tank 15.

(Electrolytic cell)
The electrolytic tank 12 electrolyzes acidic electrolyzed water and alkaline electrolysis by electrolyzing the incoming water (water supplied from the water storage tank 15) using a pair of electrodes 13 (electrodes 13a and 13b) provided inside. Generates and discharges water. More specifically, in the electrode 13a which becomes an anode during electrolysis, hydrogen ions are generated by electrolysis, and acidic electrolyzed water is generated. Further, in the electrode 13b which becomes a cathode during electrolysis, hydroxide ions are generated by electrolysis, and alkaline electrolyzed water is generated. Then, the electrolytic cell 12 supplies the acidic electrolyzed water to the softening tank 3 via the first supply flow path 22, and supplies the alkaline electrolyzed water to the neutralization tank 4 via the second supply flow path 24. .. Although the details will be described later, the acidic electrolyzed water generated by the electrolytic cell 12 is used for the regeneration of the weakly acidic cation exchange resin 10 in the water softening tank 3, and the alkaline electrolyzed water generated by the electrolytic cell 12 is neutralized. It is used for regeneration of the weakly basic anion exchange resin 11 in the tank 4. The electrolytic cell 12 is configured so that the energization state of the pair of electrodes 13 can be controlled by the control unit 35 described later.

Further, the electrolytic cell 12 is repolarized at the time of cleaning the separation portion 14 described later (at the time of cleaning the separation portion). Here, the inversion is applied by exchanging the anode and the cathode of the pair of electrodes 13. That is, at the electrode 13a which becomes a cathode at the time of pole rotation, hydroxide ions are generated by electrolysis, and the water becomes alkaline electrolyzed water. Further, in the electrode 13b which becomes an anode at the time of pole rotation, hydrogen ions are generated by electrolysis and become acidic electrolyzed water. Therefore, at the time of repolarization, the electrolytic cell 12 supplies the acidic electrolyzed water to the second supply flow path 24a and supplies the alkaline electrolyzed water to the first supply flow path 22a. Although the details will be described later, at the time of turning, the alkaline electrolyzed water sent out from the electrolytic cell 12 flows through the first supply flow path 22a and passes through the selection valve 17 and the first drainage flow path 37 to the first drainage port 16. Is discharged from the device. On the other hand, the acidic electrolyzed water sent out from the electrolytic cell 12 flows through the second supply flow path 24a and flows into the separation section 14 provided on the second supply flow path 24a to wash the separation section 14. After that, the water is discharged to the outside of the device from the second drain port 18 via the selection valve 19 and the second drain flow path 38.

In the electrolytic cell 12, the repolarization is completed after a certain period of time (for example, 5 minutes) has elapsed from the start of the repolarization.

(Water storage tank)
The water storage tank 15 secures and stores water to be circulated in the circulation flow path 21 (see FIG. 2) when the weakly acidic cation exchange resin 10 and the weakly basic anion exchange resin 11 are regenerated. Further, the water storage tank 15 is a mixture of acidic electrolyzed water containing a hardness component that has flowed through the softening tank 3 and alkaline electrolyzed water that has flowed through the neutralizing tank 4 and contains anions, and is supplied to the electrolytic cell 12. be.

Then, the water flowing through the water storage tank 15 is passed through the electrolytic tank 12, electrolyzed in the electrolytic tank 12, becomes acidic electrolytic water and alkaline electrolytic water, and is supplied to the softening tank 3 and the neutralization tank 4, respectively. To. Then, the acidic electrolyzed water and the alkaline electrolyzed water are reused in the softening tank 3 and the neutralizing tank 4, respectively, and then passed (recovered) to the water storage tank 15 again. Therefore, the acidic electrolyzed water and the alkaline electrolyzed water used for the regeneration of the weakly acidic cation exchange resin 10 and the regeneration of the weakly basic anion exchange resin 11 can be reused.

(Water pump)
The water pump 20 is a device that circulates water in the circulation flow path 21 (see FIG. 2) during the regeneration process by the regeneration device 6. The water pump 20 is provided in a water supply flow path 36 that communicates and connects between the water storage tank 15 and the electrolytic cell 12. The water pump 20 is preferably arranged on the upstream side of the electrolytic cell 12 and on the downstream side of the water storage tank 15. This arrangement is because one water pump 20 facilitates circulation of water through the first circulation flow path 21a and the second circulation flow path 21b, which will be described later. Further, the water pump 20 is wirelessly or wiredly connected to the control unit 35 described later.

(Separation part)
The separation unit 14 is provided in the second supply flow path 24a that communicates and connects the electrolytic cell 12 and the selection valve 19. Then, the separation unit 14 separates the precipitate contained in the alkaline electrolyzed water delivered from the electrolytic cell 12. Here, the precipitate is a reaction product produced in the electrolytic cell 12 by the reaction of the hardness component, which is a cation released from the water softening tank during the regeneration treatment of the water softening tank, with the alkaline electrolyzed water. .. More specifically, water is electrolyzed in the electrolytic cell 12, acidic electrolyzed water is obtained on the anode side (electrode 13a), and water is passed through the first supply flow path 22a. Further, on the cathode side (electrode 13b), alkaline electrolyzed water containing anions (for example, hydroxide ions) is obtained, and water is passed through the second supply flow path 24a. Further, while the electrolysis is being performed in the electrolytic cell 12, the hardness components (for example, calcium ions and magnesium ions) released from the water softening tank 3 during the regeneration treatment move to the cathode side. Since alkaline electrolyzed water is generated on the cathode side, the hardness component reacts with the alkaline electrolyzed water to form a precipitate. For example, when the hardness component is calcium ion, mixing with alkaline electrolyzed water causes a reaction that produces calcium carbonate or a reaction that produces calcium hydroxide. Then, the precipitate derived from the hardness component is separated as a precipitate by the separation portion 14 provided on the second supply flow path 24a. Then, by separating the precipitate derived from the hardness component by the separation unit 14, it is possible to prevent the precipitate from flowing into the neutralization tank 4 and accumulating. Therefore, when the water softening treatment is restarted after the regeneration treatment is completed, the precipitate deposited in the neutralization tank 4 reacts with the hydrogen ions released from the water softening tank 3 to form a hardness component, and from the neutralization tank 4. It is possible to suppress an increase in the hardness of the delivered soft water. Further, the alkaline electrolyzed water from which the precipitate derived from the hardness component was separated in the separation unit 14 during the regeneration treatment flows through the neutralization tank 4, is mixed with the acidic electrolyzed water, and then is electrolyzed again in the electrolysis tank 12. It is decomposed and used as acidic electrolyzed water and alkaline electrolyzed water for the regeneration of the weakly acidic cation exchange resin 10 and the regeneration of the weakly basic anion exchange resin 11, respectively. At this time, the acid electrolyzed water contains less hardness component than the case where the city water or the separation portion 14 is not provided. That is, by separating the precipitate in the separation unit 14, the hardness of the acidic electrolyzed water is lowered, so that the hardness component flowing into the water softening tank 3 can be reduced, and the regeneration efficiency of the weakly acidic cation exchange resin 10 can be reduced. Can be suppressed.

In addition, "the hardness component reacts" means not only that all the hardness components react, but also includes a state in which a component that does not react or a component that does not exceed the solubility product is contained.

The form of the separation unit 14 does not matter as long as it can separate the precipitate generated by the reaction between the hardness component and the alkaline electrolyzed water. For example, a cartridge type filter, a filtration layer using a granular filter medium, a cyclone type solid-liquid separator, a hollow fiber membrane, or the like may be used.

As a means generally used as the form of the separation unit 14, a cartridge type filter can be mentioned. As the cartridge type filter, a deep filtration type such as a pincushion filter, a surface filtration type such as a pleated filter and a membrane filter, or a combination thereof can be used.

The spool filter corresponds to a particle size of 1 to 150 micrometers and is mainly used as a pre-filter. There are pleated filters and membrane filters that correspond to a wide particle size of about 0.03 to 100 micrometers, but in particular, when implementing the present invention, those with an accuracy of about 0.5 to 1.5 micrometers should be used. If used, it is preferable to capture the hardness component that precipitates in the regeneration treatment described later. Alkaline electrolyzed water flows through the separation unit 14 in the regeneration treatment described later, and acidic electrolyzed water flows in the cleaning treatment. Therefore, the material of the cartridge type filter is preferably a material having high corrosion resistance to acids and alkalis (for example, polypropylene). ..

The purpose of the granular filter medium used for the filtration layer is to capture and remove the hardness component. However, depending on the presence of particles having a surface potential that adsorbs to the granular filter medium, ions in the raw water, etc. Can also remove particles or chromaticity of 1-10 micrometers. As the granular filter medium, a filter medium suitable for the object to be removed, such as filtered sand and a pellet-shaped fiber filter medium, can be used. The material of the granular filter medium may be, for example, sand, anthracite, garnet, ceramics, granular activated carbon, iron oxyhydroxide, manganese sand, or the like, which has a hardness that does not easily deform under pressure. It is preferable to use a particle size having a particle size of, for example, 0.3 to 5.0 mm and a uniformity coefficient of 1.2 to 2.0.

Further, the multi-layer filtration method in which a plurality of types of filter media having different specific densities are mixed and used is a method in which particles having different sizes are laminated in order from the bottom as a layer to be filtered. In the multi-layer filtration method, it is common to mix particles having a large specific density and a small size and particles having a small specific density and a large size to form a multilayer structure. The multi-layer filtration method is preferable because it has advantages such as high filtration efficiency per unit volume and low head loss as compared with using a single type of filter medium. As the granular filter medium, for example, 0.3 mm of garnet, 0.6 mm of sand and 1.0 mm of anthracite are mixed at a ratio of 2: 1: 1 and used, but turbid particles are used. It is preferable to adjust the mixing ratio and the particle size according to the characteristics.

(On-off valve and selection valve)
A plurality of on-off valves (on-off valve 27 to on-off valve 34) are provided in each flow path, and switch between an "open" state and a "closed" state in each flow path. Further, the selection valve 17 is provided in the first supply flow path 22 and determines the flow direction of the electrolyzed water generated by electrolysis at the electrode 13a of the electrolytic cell 12. Specifically, in the selection valve 17, electrolytic water generated by electrolysis at the electrode 13a flows through the first supply flow path 22 (first supply flow path 22a and first supply flow path 22b) to soften the water tank 3. The flow state up to the above and the flow path state in which the electrolyzed water generated by the electrolysis at the electrode 13a reaches the first drainage port 16 from the first supply flow path 22a via the first drainage flow path 37. Further, the selection valve 19 is provided in the second supply flow path 24, and determines the flow direction of the electrolyzed water generated by electrolysis at the electrode 13b of the electrolytic cell 12. Specifically, in the selection valve 19, electrolytic water generated by electrolysis at the electrode 13b flows through the separation portion 14 and the second supply flow path 24 (second supply flow path 24a and second supply flow path 24b). The flow state leading to the neutralization tank 4 and the flow path of the electrolytic water generated by electrolysis at the electrode 13b from the second supply flow path 24a to the second drainage port 18 via the separation portion 14 and the second drainage flow path 38. Switch between states. Further, the plurality of on-off valves (on-off valve 27 to on-off valve 34), the selection valve 17, and the selection valve 19 are each wirelessly or wiredly connected to the control unit 35 described later.

(Drainage port)
The first drain port 16 and the second drain port 18 are the electrolyzed water (acidic electrolyzed water) that has flowed out of the electrolytic tank 12 during cleaning of the separation portion 14 (during cleaning of the separation portion) and subsequent drainage during cleaning of the separation portion, which will be described later. And alkaline electrolyzed water) to the outside of the device.

The first drainage port 16 flows out of the electrolytic cell 12 at the time of cleaning the separated portion, and discharges the alkaline electrolyzed water flowing through the first supply flow path 22a and the first drainage flow path 37 to the outside of the apparatus. At the time of drainage, the first drainage port 16 sends water from the electrolytic cell 12 and flows through the first supply flow path 22a and the first drainage flow path 37 (water such as alkaline electrolyzed water remaining in the flow path) to the outside of the device. Discharge to.

The second drainage port 18 flows out of the electrolytic cell 12 at the time of cleaning the separation portion, and discharges the acidic electrolyzed water flowing through the second supply flow path 24a, the separation portion 14, and the second drainage flow path 38 to the outside of the apparatus. The second drainage port 18 is sent out from the electrolytic cell 12 at the time of drainage, and the water flowing through the second supply flow path 24a, the separation portion 14, and the second drainage flow path 38 (acidic electrolyzed water remaining in the flow path, etc.) Water) is discharged to the outside of the device.

(Control unit)
The control unit 35 controls the water softening treatment for softening the raw water containing the hardness component. Further, the control unit 35 controls the regeneration treatment of the weakly acidic cation exchange resin 10 in the water softening tank 3 and the weakly basic anion exchange resin 11 in the neutralization tank 4. Further, the control unit 35 controls the inversion of the electrolytic cell 12. Further, the control unit 35 controls switching between the water softening treatment, the regeneration treatment, the cleaning treatment, and the wastewater treatment of the water softening device 1. At this time, the control unit 35 includes an electrode 13, a water pump 20, an on-off valve 27, an on-off valve 28, an on-off valve 29, an on-off valve 30, an on-off valve 31, an on-off valve 32, an on-off valve 33, an on-off valve 34, and a selection valve 17. , And the operation of the selection valve 19 is controlled to switch between the water softening treatment, the regeneration treatment, the cleaning treatment, and the wastewater treatment, and to execute the respective treatments and the repolarization.

(Flow path)
Next, with reference to FIG. 2, the circulation flow path 21 formed during the regeneration process of the water softening device 1 will be described. FIG. 2 is a configuration diagram showing a circulation flow path 21 of the water softening device 1.

Although the description is duplicated, as shown in FIG. 2, in the water softening device 1, the electrolytic cell 12 and the water storage tank 15 constituting the regenerating device 6 are communicated and connected by a water supply flow path 36. Further, in the electrolytic cell 12 and the water storage tank 15, the first supply flow path 22 and the first recovery flow path 23 are provided with respect to the flow path 7, the flow path 8 and the flow path 9 from the inflow port 2 to the intake port 5. It is communicated and connected by the second supply flow path 24 and the second recovery flow path 25, respectively. Then, in the reproduction device 6, the circulation flow path 21 is configured by the combination of the flow paths.

The first supply flow path 22 is a flow path for supplying acidic electrolyzed water from the electrolytic cell 12 to the softening tank 3, and a selection valve 17 and an on-off valve 27 are installed in the flow path. The first supply flow path 22 is formed by a first supply flow path 22a that connects the electrolytic cell 12 and the selection valve 17 in communication, and a first supply flow path 22b that connects the selection valve 17 and the water softening tank 3 in communication. It is composed. That is, the water softening device 1 includes a first supply flow path 22 that draws acidic electrolyzed water from the electrolytic cell 12 and enables water to be sent to the upstream side of the water softening tank 3.

The first recovery flow path 23 is a flow path for recovering water containing a hardness component that has passed through the water softening tank 3 to the water storage tank 15, and an on-off valve 28 is installed in the flow path. That is, the water softening device 1 includes a first recovery flow path 23 that allows the upstream side of the water storage tank 15 to be connected to the downstream side of the water softening tank 3.

The second supply flow path 24 is a flow path for supplying alkaline electrolyzed water from the electrolytic cell 12 to the neutralization tank 4 via the separation unit 14, and a selection valve 19 and an on-off valve 29 are installed in the flow path. ing. The second supply flow path 24 is formed by a second supply flow path 24a that communicates and connects the electrolytic cell 12 and the selection valve 19, and a second supply flow path 24b that communicates and connects the selection valve 19 and the neutralization tank 4. It is composed. That is, the water softening device 1 separates the precipitate derived from the hardness component contained in the alkaline electrolyzed water drawn from the electrolytic tank 12 at the separation unit 14, and the alkaline electrolyzed water from which the precipitate is separated is separated from the neutralizing tank 4. A second supply flow path 24 that enables water to be sent to the upstream side is provided.

The second recovery flow path 25 is a flow path for recovering the water that has passed through the neutralization tank 4 to the water storage tank 15, and an on-off valve 30 is installed in the flow path. That is, the water softening device 1 includes a second recovery flow path 25 that allows the upstream side of the water storage tank 15 to be connected to the downstream side of the neutralization tank 4.

In the circulation flow path 21, the water sent from the water storage tank 15 by the water pump 20 is in the first circulation flow path 21a through which the water softening tank 3 is circulated, and the water sent out from the water storage tank 15 by the water supply pump 20 is in the middle. It includes a second circulation flow path 21b that flows through the Japanese tank 4.

In the first circulation flow path 21a, as shown in FIG. 2 (white arrow), the water sent from the water storage tank 15 by the water pump 20 flows through the electrolytic cell 12 and the water softening tank 3 to the water storage tank 15. It is a flow path that circulates back. More specifically, in the first circulation flow path 21a, the water sent from the water storage tank 15 by the water supply pump 20 is supplied to the water supply flow path 36, the electrolytic cell 12, the first supply flow path 22a, the selection valve 17, and the first supply. It is a flow path that circulates in the order of the flow path 22b, the on-off valve 27, the water softening tank 3, the first recovery flow path 23, the on-off valve 28, and the water storage tank 15.

In the second circulation flow path 21b, as shown in FIG. 2 (black arrow), the water sent from the water storage tank 15 by the water pump 20 flows through the electrolytic cell 12 and the neutralization tank 4 to the water storage tank 15. It is a flow path that circulates back. More specifically, in the second circulation flow path 21b, the water sent from the water storage tank 15 by the water supply pump 20 is supplied to the water supply flow path 36, the electrolytic cell 12, the second supply flow path 24a, the selection valve 19, and the second supply. It is a flow path that circulates in the order of the flow path 24b, the on-off valve 29, the neutralization tank 4, the second recovery flow path 25, the on-off valve 30, and the water storage tank 15.

Here, in order to circulate water in the circulation flow path 21, an on-off valve 31 is installed in the flow path 7 on the downstream side of the inflow port 2. Then, by closing the on-off valve 31 and opening the on-off valve 27, the first supply flow path 22 is communicated and connected to the upstream side of the water softening tank 3. As a result, the acidic electrolyzed water from the electrolytic cell 12 can be supplied to the softening tank 3.

Further, in the flow path 8, an on-off valve 32 is installed on the downstream side of the first recovery flow path 23 and on the upstream side of the second supply flow path 24b. Then, by closing the on-off valve 32 and opening the on-off valve 28, the first recovery flow path 23 is communicated and connected to the downstream side of the water softening tank 3. As a result, the water softening device 1 can recover the water (acidic electrolyzed water containing a hardness component) that has flowed through the water softening tank 3 to the water storage tank 15.

Further, by closing the on-off valve 32 and opening the on-off valve 29, the second supply flow path 24 is communicated and connected to the upstream side of the neutralization tank 4. As a result, the water softening device 1 can supply the alkaline electrolyzed water from the electrolytic cell 12 to the neutralization tank 4.

Further, in the flow path 9, an on-off valve 33 is installed on the downstream side of the neutralization tank 4. Then, by closing the on-off valve 33 and opening the on-off valve 30, the second recovery flow path 25 is communicated and connected to the downstream side of the neutralization tank 4. This makes it possible to recover the water (alkaline electrolyzed water containing anions) that has passed through the second recovery flow path 25 to the water storage tank 15.

Further, in the water supply flow path 36, an on-off valve 34 is installed on the downstream side of the water storage tank 15 (position between the water storage tank 15 and the water supply pump 20). By closing the on-off valve 34, water can be stored in the water storage tank 15. On the other hand, by opening the on-off valve 34, water can be supplied to the water supply flow path 36.

Further, a selection valve 17 is installed in the first supply flow path 22 (first supply flow path 22a and first supply flow path 22b). By switching the selection valve 17, the electrolytic water generated by electrolysis at the electrode 13a flows through the first supply flow path 22a and the first supply flow path 22b to reach the softening tank 3, and the electrode 13a. The electrolyzed water generated by electrolysis can be discharged from the first supply flow path 22a to the outside of the device by the first drainage port 16 via the first drainage flow path 37 described later.

Further, a selection valve 19 is installed in the second supply flow path 24 (second supply flow path 24a and second supply flow path 24b). By switching the selection valve 19, the electrolytic water generated by electrolysis at the electrode 13b flows through the second supply flow path 24a and the second supply flow path 24b to reach the softening tank 3, and the electrode 13b. The electrolyzed water generated by electrolysis can be discharged from the second supply flow path 24a to the outside of the device by the second drainage port 18 via the first drainage flow path 37 described later.

Further, by closing the on-off valve 33, the circulation of water to the circulation flow path 21 can be started, while by opening the on-off valve 33, the circulation of water to the circulation flow path 21 is stopped. Can be done.

Next, with reference to FIG. 3, the cleaning flow path 26 formed during the cleaning treatment of the water softening device 1 will be described. FIG. 3 is a configuration diagram showing a cleaning flow path 26 of the water softening device 1.

Although the description is duplicated, as shown in FIG. 3, the regeneration device 6 is composed of an electrolytic cell 12, a separation unit 14, and a water storage tank 15. The water storage tank 15 is communicated with the flow path 9 by a second recovery flow path 25. Further, the electrolytic cell 12 and the water storage tank 15 are communicated with each other by the water supply flow path 36. The electrolytic cell 12 is communicated with the first drain port 16 by the first supply flow path 22a and the first drainage flow path 37. Further, the electrolytic cell 12 is communicated with the second drainage port 18 by the second supply flow path 24a and the second drainage flow path 38. Then, in the reproduction device 6, the cleaning flow path 26 is configured by the combination of the flow paths.

The first drainage flow path 37 is a flow path for discharging water from the selection valve 17 to the first drainage port 16. That is, the water softening device 1 includes a first drainage flow path 37 that allows water to be drawn from the selection valve 17 to the first drainage port 16 and discharged to the outside of the device.

The second drainage flow path 38 is a flow path for discharging water from the selection valve 19 to the second drainage port 18. That is, the water softening device 1 includes a second drainage flow path 38 that allows water to be drawn from the selection valve 19 to the second drainage port 18 and discharged to the outside of the device.

The cleaning flow path 26 includes a first cleaning flow path 26a and a second cleaning flow path 26b.

In the first cleaning flow path 26a, as shown in FIG. 3 (diagonal arrow and horizontal line arrow), the water introduced from the inflow port 2 is introduced into the flow path 7, the water softening tank 3, the flow path 8, and the neutralization tank 4. The second recovery flow path 25, the water storage tank 15, the water supply flow path 36, and the electrolytic tank 12 are circulated in this order, and after being electrolyzed in the electrolytic tank 12, the first supply flow path 22a, the selection valve 17, are used as alkaline electrolytic water. It is a flow path that flows through the first drainage channel 37 and is discharged to the outside of the device from the first drainage port 16.

In the second cleaning flow path 26b, as shown in FIG. 3 (diagonal arrow and shaded arrow), the water introduced from the inflow port 2 is introduced into the flow path 7, the water softening tank 3, the flow path 8, and the neutralization tank 4. The second recovery flow path 25, the water storage tank 15, the water supply flow path 36, and the electrolytic cell 12 are circulated in this order, and after being electrolyzed in the electrolytic cell 12, the second supply flow path 24a (separation section 14) is used as acidic electrolyzed water. Included), the selection valve 19, and the second drainage channel 38, and the flow path is discharged from the second drainage port 18 to the outside of the device.

(Water softening treatment, regeneration treatment, cleaning treatment, and wastewater treatment)
Next, with reference to FIG. 4, the water softening treatment, the regeneration treatment, the cleaning treatment, and the wastewater treatment of the water softening apparatus 1 starting from the regeneration treatment will be described. FIG. 4 is a diagram showing a state of the water softening device 1 during operation.

In the water softening treatment, the regeneration treatment, the cleaning treatment, and the wastewater treatment, as shown in FIG. 4, the control unit 35 has an on-off valve 27, an on-off valve 28, an on-off valve 29, an on-off valve 30, an on-off valve 31, and an on-off valve 32. , The on-off valve 33, the on-off valve 34, the selection valve 17, the selection valve 19, the electrode 13 of the electrolytic cell 12, and the water pump 20 are switched and controlled so as to be in their respective distribution states. The control unit 35 has a computer system having a processor and a memory. Then, the processor executes a program stored in the memory, so that the computer system functions as a control unit. The program executed by the processor is assumed to be recorded in advance in the memory of the computer system here, but may be recorded in a non-temporary recording medium such as a memory card and provided, or a telecommunications line such as the Internet. May be provided through.

Here, "ON" in FIG. 4 indicates a state in which the corresponding on-off valve is "opened", a state in which the electrode 13 is energized, and a state in which the water pump 20 is operating. The blanks indicate a state in which the on-off valve is "closed", a state in which the electrode 13 is not energized, and a state in which the water pump 20 is stopped. Further, the notation of the selection valve 17 and the selection valve 19 in FIG. 4 refers to the components corresponding to the numbers (reference numerals) (water softening tank 3, neutralization tank 4, first drain port 16 or second drain port 18). And the state where the flow path is opened. The selection valve 17 in the normal state is in a state where the flow path is open to the water softening tank 3, but is left blank if it is not related to other treatments. The selection valve 19 in the normal state is in a state where the flow path is open to the neutralization tank 4, but is left blank if it is not related to other treatments. Further, "ON (reversal)" of the electrode 13 at the time of cleaning the separated portion shown in FIG. 4 indicates a state in which the electrode 13 is reversing.

(Reproduction processing)
First, the operation during the regeneration process by the regeneration device 6 of the water softening device 1 will be described in order with reference to the columns of "at the time of water injection" and "at the time of regeneration" in FIG.

In the water softening apparatus 1, the cation exchange capacity of the water softening tank 3 filled with the weakly acidic cation exchange resin 10 decreases or disappears as the use is continued. 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, the hardness component is contained in the treated water. Therefore, in the water softening device 1, it is necessary to regenerate the water softening tank 3 and the neutralization tank 4 by the regenerating device 6.

Therefore, in the water softening device 1, once in a predetermined period (for example, one day (24 hours)), the control unit 35 specifies a time zone in which the regeneration process is possible, and executes the regeneration process.

First, as shown in FIG. 4, the on-off valve 31 and the on-off valve 28 are opened at the time of water injection. As a result, the water softening device 1 introduces raw water from the inflow port 2 through the water softening tank 3 into the water storage tank 15 by the pressure of the city water. At this time, the on-off valve 27, the on-off valve 32, the on-off valve 29, the on-off valve 33, the on-off valve 30, and the on-off valve 34 are closed. By storing a predetermined amount of water according to the capacity of the water softening device 1 in the water storage tank 15, the regenerating device 6 can secure the amount of water at the time of regenerating.

Next, at the time of regeneration, the on-off valve 31, the on-off valve 32, and the on-off valve 33 are closed, the on-off valve 27, the on-off valve 28, the on-off valve 29, the on-off valve 30, and the on-off valve 34 are opened, and the selection valve is selected. When the water flow direction of 17 is set to the water softening tank 3 direction and the water flow direction of the selection valve 19 is set to the neutralization tank 4 direction, as shown in FIG. 2, the first circulation flow path 21a and the second circulation flow path 21a and the second. Circulation flow paths 21b are formed respectively.

Then, when the electrode 13 of the electrolytic cell 12 and the water pump 20 are operated, the water stored in the water storage tank 15 circulates in each of the first circulation flow path 21a and the second circulation flow path 21b.

At this time, the acidic electrolyzed water generated in the electrolytic cell 12 is sent into the softening tank 3 through the first supply flow path 22 and flows through the weakly acidic cation exchange resin 10 inside. That is, by circulating the acidic electrolyzed water through the weakly acidic cation exchange resin 10, the cations (hardness components) adsorbed on the weakly acidic cation exchange resin 10 are ion-exchanged with the hydrogen ions contained in the acidic electrolyzed water. Cause a reaction. As a result, the weakly acidic cation exchange resin 10 is regenerated. After that, the acidic electrolyzed water flowing through the weakly acidic cation exchange resin 10 contains cations and flows into the first recovery flow path 23. That is, the acidic electrolyzed water containing the cations flowing through the weakly acidic cation exchange resin 10 is recovered in the water storage tank 15 via the first recovery flow path 23.

On the other hand, the alkaline electrolyzed water generated in the electrolytic cell 12 is sent into the neutralization tank 4 through the separation unit 14 provided in the second supply flow path 24 and the second supply flow path 24, and is weakly basic inside. The anion exchange resin 11 is distributed. That is, by circulating the alkaline electrolyzed water through the weakly basic anion exchange resin 11, the anions adsorbed on the weakly basic anion exchange resin 11 exchange ions with the hydroxide ions contained in the alkaline electrolyzed water. Cause a reaction. As a result, the weakly basic anion exchange resin 11 is regenerated. After that, the alkaline electrolyzed water flowing through the weakly basic anion exchange resin 11 contains anions and flows into the second recovery flow path 25. That is, the alkaline electrolyzed water containing anions flowing through the weakly basic anion exchange resin 11 is recovered in the water storage tank 15 via the second recovery flow path 25.

Then, in the water storage tank 15, the acidic electrolyzed water containing cations recovered from the water softening tank 3 and the alkaline electrolyzed water containing anions recovered from the neutralization tank 4 are mixed and neutralized.

At this time, by mixing the acidic electrolyzed water containing cations (hardness component) and the alkaline electrolyzed water containing anions, the hardness component reacts with the hydroxide ions contained in the alkaline electrolyzed water, and the precipitate is formed. However, at least in the initial stage of the regeneration treatment, the amount of hydroxide ions contained in the alkaline electrolyzed water flowing from the neutralization tank 4 is smaller than the amount of the hardness component released from the water softening tank 3, so that the precipitate is formed. Is unlikely to occur. Therefore, the hardness component contained in the neutralized electrolyzed water is sent to the electrolytic cell 12 as it is.

After that, the electrolyzed water mixed in the water storage tank 15 is passed to the electrolytic cell 12 again via the water supply flow path 36. Then, the passed water is electrolyzed again in the electrolytic cell 12.

As described above, water is electrolyzed in the electrolytic cell 12, and a large amount of hydroxide ions are generated by electrolysis in the vicinity of the cathode, so that precipitation is likely to occur. .. That is, the hardness components (for example, calcium ions and magnesium ions) contained in the water supplied from the water storage tank 15 move to the cathode side and react with the hydroxide ions to form a precipitate. Then, the alkaline electrolyzed water containing such a precipitate is sent out to the second supply flow path 24a and flows into the separation unit 14.

In the separation unit 14, the precipitate contained in the alkaline electrolyzed water is separated, and the alkaline electrolyzed water (treated water) from which the hardness component has been removed can be obtained.

Here, the acidic electrolyzed water that was electrolyzed again in the electrolytic cell 12 and the alkaline electrolyzed water that was electrolyzed again in the electrolytic cell 12 and the precipitate was separated by the separation unit 14 are the weakly acidic cation exchange resins 10, respectively. Is used for regeneration and regeneration of the weakly basic anion exchange resin 11.

Here, as a problem that occurs in the neutralization tank of the conventional water softening device, the precipitate formed by the reaction between the hardness component released from the water softening tank and the alkaline electrolyzed water in the electrolytic cell during the regeneration treatment is medium. It sometimes flowed into a Japanese tank and accumulated in a neutralization tank. In other words, when the water softening treatment is restarted with the precipitates deposited in the neutralization tank, it reacts with the hydrogen ions released from the water softening tank and becomes a hardness component, so that the water softening performance deteriorates. Become. However, in the present embodiment, by separating the precipitates generated in the electrolytic cell 12 by the separation unit 14, it is possible to suppress the deposition of the precipitates due to the hardness component inside the neutralization tank 4. can.

Then, in the water softening device 1, when the regeneration process is completed, the electrode 13 is inverted. Further, the on-off valve 27, the on-off valve 28, and the on-off valve 29 are closed, the on-off valve 31 and the on-off valve 32 are opened, and the water flow direction of the selection valve 17 is changed from the water softening tank 3 direction to the first drain port 16 direction. By switching and switching the water flow direction of the selection valve 19 from the neutralization tank 4 direction to the second drain port 18 direction, the cleaning process is started.

(Washing process)
In the water softening device 1, when the regeneration process is completed, the process shifts to the cleaning process. Here, the cleaning treatment is a treatment for cleaning the separation unit 14, in which the pair of electrodes 13 of the electrolytic cell 12 are reversed, and the acidic electrolyzed water generated in the electrolytic cell 12 at the time of conversion is separated into the separation unit 14. This is a treatment for dissolving the precipitate caused by the hardness component separated by the separation unit 14.

Next, the operation during the cleaning process by the water softening device 1 will be described with reference to the column of “during cleaning” in FIG.

In the water softening device 1, as shown in FIG. 4, the on-off valve 30, the on-off valve 31, the on-off valve 32, and the on-off valve 34 are opened in the cleaning process (during cleaning). As a result, the water softening device 1 introduces raw water into the electrolytic cell 12 from the inflow port 2 through the water softening tank 3, the neutralization tank 4, the second recovery flow path 25, and the water storage tank 15 by the pressure of the city water. At this time, the on-off valve 27, the on-off valve 28, the on-off valve 29, and the on-off valve 33 are closed. By circulating the raw water to the softening tank 3, the neutralization tank 4, and the second recovery channel 25, the raw water was circulated to the softening tank 3, the neutralization tank 4, and the second recovery channel 25 during the regeneration process. Electrolyzed water can be replaced with raw water.

Next, when the electrode 13 is inverted, the water flow direction of the selection valve 17 is set to the first drain port 16 direction, and the water flow direction of the selection valve 19 is set to the second drain port 18 direction. As shown in 3, the cleaning flow path 26 is formed. By the repolarization, the electrolytic cell 12 is in a state where the acidic electrolyzed water can be supplied to the second supply flow path 24a and the alkaline electrolyzed water can be supplied to the first supply flow path 22a.

Then, when the electrode 13 of the electrolytic cell 12 and the water supply pump 20 are operated, raw water and electrolyzed water (acidic electrolyzed water, alkaline electrolyzed water) will flow to the cleaning flow path 26.

At this time, the alkaline electrolyzed water generated in the electrolytic cell 12 flows through the first supply flow path 22a and the first drainage flow path 37, and is discharged to the outside of the device from the first drainage port 16.

On the other hand, the acidic electrolyzed water generated in the electrolytic cell 12 is sent to the second drainage flow path 38 through the separation portion 14 provided in the second supply flow path 24a, and is discharged to the outside of the device by the second drainage port 18. To. That is, by circulating the acidic electrolyzed water to the separation unit 14, the precipitate caused by the hardness component captured in the separation unit 14 reacts with the acidic electrolyzed water. As a result, the precipitate caused by the hardness component is dissolved to become a hardness component and is contained in the acidic electrolyzed water. After that, the acidic electrolyzed water flowing through the separation unit 14 contains a hardness component and is discharged to the outside of the device by the second drain port 18. That is, by circulating the acidic electrolyzed water through the separation unit 14 and discharging the circulating acidic electrolyzed water, the separation unit 14 can be washed and the hardness component can be discharged to the outside of the apparatus. As a result, the separation unit 14 can be washed, so that a decrease in the amount of water flow due to clogging of the separation unit 14 can be reduced. In addition, the number of maintenance of the separation unit 14 can be reduced.

Then, in the water softening device 1, when the cleaning process is completed, the repolarization of the electrode 13 is terminated and the operation is stopped. In addition, the on-off valve 31 and the on-off valve 32 are closed to stop the inflow of city water, thereby shifting to wastewater treatment.

The end of the cleaning process is when a certain time (for example, 5 minutes) has elapsed from the start of turning.

(Wastewater treatment)
In the water softening device 1, when the cleaning treatment is completed, the wastewater treatment is started. Here, the wastewater treatment is a treatment for draining the raw water, the acidic electrolyzed water, and the alkaline electrolyzed water remaining in the cleaning flow path 26.

Next, the operation during wastewater treatment by the water softening device 1 will be described with reference to the column of “drainage” in FIG.

In the water softening device 1, as shown in FIG. 4, in the wastewater treatment (during drainage), the on-off valve 27, the on-off valve 28, the on-off valve 29, the on-off valve 31, the on-off valve 32, and the on-off valve 33 are closed to open and close. Open the valve 30. As a result, the inflow of city water from the inflow port 2 is stopped, and the raw water and the neutralization tank remaining in the path from the inside of the softening tank 3 to the water storage tank 15 via the first recovery flow path 23. The raw water remaining in the path from the inside of 4 to the water tank 15 via the second recovery flow path 25 can flow into the water tank 15.

Next, the on-off valve 34 is open, the water pump 20 is operating, and the electrode 13 is stopped. From this, the raw water remaining in the path from the inside of the water storage tank 15 to the electrolytic tank 12 via the water supply flow path 36, the first supply flow path 22a and the first drainage flow path 37 from the inside of the electrolytic tank 12. Alkaline electrolyzed water remaining in the path leading to the first drainage port 16 via the above, and from the inside of the electrolytic tank 12 to the second drainage port 18 via the second supply flow path 24a and the second drainage flow path 38. The electrolyzed water remaining in the route can be discharged to the outside of the device.

By performing the wastewater treatment, it is possible to prevent the inflow of the alkaline electrolyzed water remaining in the cleaning flow path 26 into the softening tank 3 and the inflow of the acidic electrolyzed water remaining in the cleaning flow path 26 into the neutralization tank 4. can.

Then, in the water softening device 1, when the wastewater treatment is completed, the operation of the water pump 20 is stopped. Further, the on-off valve 30 and the on-off valve 34 are closed, and the on-off valve 31, the on-off valve 32, and the on-off valve 33 are opened. Further, the water flow direction of the selection valve 17 is set to the water softening tank 3 direction, and the water flow direction of the selection valve 19 is set to the neutralization tank 4 direction, whereby the water softening treatment is started.

The end of the wastewater treatment is when a certain time (for example, 1 minute) has elapsed from the start of the wastewater treatment.

(Softening treatment)
When the wastewater treatment is completed, the water softening device 1 shifts to the water softening treatment.

Next, the operation during the water softening treatment by the water softening device 1 will be described with reference to the column of “at the time of water softening” in FIG.

In the water softening device 1, as shown in FIG. 4, in the water softening treatment (during water softening), the on-off valve 33 provided in the water intake port 5 is opened with the on-off valve 31 and the on-off valve 32 open. As a result, in the water softening device 1, city water (raw water containing a hardness component) flows from the outside through the water softening tank 3 and the neutralization tank 4, so that the water softened from the intake port 5 (neutral soft water). Can be taken out. At this time, the on-off valve 27, the on-off valve 28, the on-off valve 29, the on-off valve 30, and the on-off valve 34 are all in a closed state. Further, the operation of the electrode 13 of the electrolytic cell 12 and the water pump 20 is also stopped.

Specifically, as shown in FIG. 1, in the softening treatment, the raw water supplied by the pressure of the city water is supplied to the softening tank 3 from the inflow port 2 through the flow path 7. Then, the raw water supplied to the softening tank 3 circulates the weakly acidic cation exchange resin 10 provided in the softening tank 3. At this time, the cations, which are the hardness components of the raw water, are adsorbed by the action of the weakly acidic cation exchange resin 10, and hydrogen ions are released (ion exchange is performed). Then, the raw water is softened by removing cations from the raw water. The softened water further passes through the flow path 8 and proceeds to the neutralization tank 4. In the neutralization tank 4, hydrogen ions contained in the softened water are adsorbed by the action of the weakly basic anion exchange resin 11. That is, since hydrogen ions are removed from the treated soft water, the lowered pH rises to become softened neutral water as domestic water, which can be taken out from the intake port 5 through the flow path 9.

Then, the water softening device 1 executes the regeneration process when the time zone specified by the control unit 35 is reached or when the water softening process exceeds a certain period of time.

As described above, in the water softening device 1, the water softening treatment, the regeneration treatment, the cleaning treatment, and the wastewater treatment are repeatedly executed.

As described above, according to the water softening device 1 according to the first embodiment, the following effects can be enjoyed.

(1) The water softening device 1 includes a water softening tank 3, a neutralization tank 4, an electrolytic cell 12, a water storage tank 15, and a separation unit 14. The water softening tank 3 softens the raw water containing the hardness component with the weakly acidic cation exchange resin 10. The neutralization tank 4 neutralizes the pH of the soft water that has passed through the softening tank with the weakly basic anion exchange resin 11. The electrolysis tank 12 contains acidic electrolyzed water for regenerating the weakly acidic cation exchange resin 10 in the water softening tank 3 and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin 11 in the neutralization tank 4. Generate. The water storage tank 15 mixes the acidic electrolyzed water flowing through the softening tank 3 and the alkaline electrolyzed water flowing through the neutralization tank 4 and supplies the water to the electrolytic cell 12. The separation unit 14 was provided in a flow path communicating the electrolytic cell 12 and the neutralization tank 4, so as to separate the precipitates caused by the hardness component contained in the water introduced into the electrolytic cell 12.

As a result, when the water softening tank 3 and the neutralization tank 4 are regenerated, the precipitate contained in the alkaline electrolytic water that has passed through the electrolytic cell 12 (due to the hardness component contained in the water introduced into the electrolytic cell 12). The precipitate) can be separated by the separation unit 14, and the inflow of the precipitate into the neutralization tank 4 can be reduced. Therefore, when the water softening treatment is restarted after the regeneration treatment is completed, it is possible to prevent the precipitates flowing into the neutralization tank 4 from reacting with hydrogen ions from the water softening tank 3 to form a hardness component. , The deterioration of water softening performance due to the dissolution of precipitates can be reduced.

(2) The water softening device 1 includes a control unit 35 that controls the regeneration process of the weakly acidic cation exchange resin 10 in the water softening tank 3 and the weakly basic anion exchange resin 11 in the neutralization tank 4. Then, after the regeneration process was completed, the control unit 35 turned the electrolytic cell 12 so that the acid electrolyzed water after the turning was circulated to the separation unit 14 and discharged to the outside of the apparatus. As a result, the separation unit 14 is washed (dissolution and removal of the precipitate separated by the separation unit 14), so that the maintenance frequency of the separation unit 14 can be reduced, and the water softening device 1 that can be used for a long period of time can be reduced. Can be.

(Embodiment 2)
Next, the water softening device 1a according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a conceptual diagram showing the configuration of the water softening device 1a according to the second embodiment of the present invention.

The water softening device 1a according to the second embodiment is different from the first embodiment in that the ion concentration detecting section 39 is provided on the downstream side of the separating section 14. That is, in the water softening apparatus 1a according to the second embodiment, when the ion concentration becomes less than the reference value based on the information regarding the ion concentration of the acidic electrolyzed water after the repolarization after flowing through the separation unit 14. It is controlled so as to end the inversion of the electrolytic cell 12. Other than this, the configuration of the water softening device 1a is the same as that of the water softening device 1 according to the first embodiment. Hereinafter, the contents already explained in the first embodiment will be omitted again as appropriate, and the differences from the first embodiment will be mainly described.

As shown in FIG. 5, the water softening device 1a includes an ion concentration detection unit 39 on the second supply flow path 24a at the rear stage of the separation unit 14 and at the front stage of the selection valve 19.

The ion concentration detecting unit 39 detects the ion concentration of the acidic electrolyzed water flowing through the separating unit 14 during the cleaning process. The ion concentration detection unit 39 is wirelessly or wiredly connected to the control unit 35, and the information regarding the detected ion concentration is used as an input signal of the control unit 35.

Here, as the ion concentration detecting unit 39, a general-purpose one can be used, for example, a detector for measuring the electric conductivity of a liquid or TDS (Total Dissolved Solid) contained in water. Examples include detectors that measure the amount of.

Water (pure water) is an insulator that conducts almost no electricity by itself, but it is energized by dissolving (ionizing) various substances. That is, the electric conductivity of the liquid is an index of the amount of ionized substances contained in the liquid. In general city water, it is proportional to the content of calcium ions, magnesium ions, sodium ions, chloride ions, etc., which are abundant in river water or groundwater, which is the water source of city water. In the present embodiment, the TDS represents the total concentration of ions (calcium ion, magnesium ion, chloride ion, hydrogen ion, etc.) contained in the water flowing through the ion concentration detection unit 39 during the cleaning process. In water of the same water system, the electric conductivity and TDS are approximately proportional to each other.

The control unit 35 controls to end the repolarization of the electrolytic cell 12 when the ion concentration specified based on the information on the ion concentration output from the ion concentration detection unit 39 becomes less than the reference value. On the other hand, the control unit 35 controls so that the inversion of the electrolytic cell 12 is continued when the ion concentration is equal to or higher than the reference value. As a result, the control unit 35 can control the end of the turning pole based on the ion concentration contained in the acidic electrolyzed water after the turning pole. Therefore, the acidic electrolyzed water can be circulated through the separation unit 14 until the ion concentration contained in the acidic electrolyzed water after flowing through the separation unit 14 becomes less than the reference value.

Here, the ion concentration specified based on the information on the ion concentration output from the ion concentration detection unit 39 is the acidic electrolyzed water after flowing through the separation unit 14 in a state where there is no precipitate in the separation unit 14. It is the ion concentration of the difference between the contained ion concentration and the ion concentration contained in the acidic electrolyzed water after flowing through the separation unit 14 at the time of cleaning treatment. The reference value is a value that defines the difference in ion concentration so as to be within a predetermined range.

As described above, according to the water softening device 1a according to the second embodiment, the following effects can be enjoyed in addition to the effects (1) and (2) obtained by the first embodiment.

(3) In the water softening device 1a, the control unit 35 has a reference value of the ion concentration specified based on the information on the ion concentration (hardness component concentration) of the acidic electrolyzed water after the inversion after flowing through the separation unit 14. When it became less than, the conversion of the electrolytic cell 12 was controlled to be terminated. This makes it possible to control the end of the inversion based on the information regarding the ion concentration contained in the acidic electrolyzed water after the inversion. Therefore, the acidic electrolyzed water can be circulated through the separation unit 14 until the ion concentration specified based on the information on the ion concentration contained in the acidic electrolyzed water after the inversion becomes less than the reference value, and the separation unit 14 can be circulated. Washing (dissolution of separated precipitates) can be performed more reliably. Therefore, the maintenance frequency of the separation unit 14 can be further reduced, and the water softening device 1a that can be used for a long period of time can be obtained.

(Embodiment 3)
Next, the water softening device 1b according to the third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a conceptual diagram showing the configuration of the water softening device 1b according to the third embodiment of the present invention.

The water softening device 1b according to the third embodiment is different from the first embodiment in that the water storage tank 15 is further provided with the water storage tank separation unit 40. Other than this, the configuration of the water softening device 1b is the same as that of the water softening device 1 according to the first embodiment. Hereinafter, the contents already explained in the first embodiment will be omitted again as appropriate, and the differences from the first embodiment will be mainly described.

As shown in FIG. 6, the water softening device 1b is provided with a water tank separating portion 40 in the vicinity of the outlet of the water tank 15 (the connection portion between the water tank 15 and the water supply flow path 36). That is, in the water softening device 1b, the separation unit 14 and the water storage tank separation unit 40 separate the precipitates caused by the hardness component.

As described above, in the water storage tank 15, although the amount of hydroxide ions contained in the alkaline electrolyzed water is small in the initial stage of the regeneration treatment, the regeneration of the neutralization tank 4 is completed earlier than the regeneration of the softening tank 3. In the latter half of the regeneration process, the amount of hydroxide ions contained in the alkaline electrolyzed water increases. That is, in the latter half of the regeneration treatment, the acidic electrolyzed water containing the hardness component released from the water softening tank 3 and the alkaline electrolyzed water released from the neutralization tank 4 are mixed, and precipitates are likely to be generated. As a result, the hardness components (for example, calcium ions and magnesium ions) released from the water softening tank 3 react with the hydroxide ions from the neutralization tank 4 to form precipitates. Therefore, the water tank separating unit 40 separates the precipitates generated in the water tank 15. As with the separation unit 14, the water storage tank separation unit 40 may be in any form as long as it can separate the precipitate generated by the reaction between the hardness component and the alkaline electrolyzed water. As described above, for example, a cartridge type filter, a filtration layer using a granular filter medium, a cyclone type solid-liquid separator, a hollow fiber membrane, or the like may be used.

Then, the water storage tank 15 supplies the electrolyzed water from which the precipitate is separated by the water storage tank separation unit 40 to the electrolytic cell 12 via the water supply flow path 36. At this time, since the hardness component contained in the electrolyzed water supplied to the electrolytic cell 12 is reduced, the precipitates generated in the electrode 13b of the electrolytic cell 12 are also reduced.

As described above, according to the water softening device 1b according to the third embodiment, the following effects can be enjoyed in addition to the effects (1) and (2) obtained by the first embodiment.

(4) In the water softening device 1b, the water storage tank 15 is further provided with a water storage tank separation unit 40 for separating precipitates caused by hardness components contained in the water introduced into the tank. As a result, the precipitate can be separated not only by the separation unit 14 provided between the electrolytic cell 12 and the neutralization tank 4, but also by the water storage tank separation unit 40, so that the precipitate can be separated more reliably. Therefore, when the water softening treatment is restarted after the regeneration treatment is completed, the precipitate flowing into the neutralization tank 4 reacts with the hydrogen ions from the water softening tank 3 to form a hardness component as in the conventional water softening apparatus. It is possible to suppress the deterioration of the water softening performance due to the dissolution of the precipitate.

(5) The water softening device 1b has a separation unit 14 provided on the downstream side of the electrolytic cell 12 and a water storage tank separation unit 40 provided on the upstream side of the electrolytic cell 12 with respect to the cleaning flow path 26. Configured. As a result, the hardness component contained in the electrolyzed water supplied to the electrolytic cell 12 can be reduced, so that the precipitates generated in the electrolytic cell 12 can be reduced. Therefore, the maintenance frequency of the separation unit 14 can be further reduced, and the water softening device 1b can be used for a long period of time.

The present invention has been described above based on the embodiments. It is understood by those skilled in the art that these embodiments are exemplary and that various modifications are possible for each of these components or combinations of processing processes, and that such modifications are also within the scope of the present invention. I am here.

Further, in the water softening device 1 according to the first embodiment, the regeneration process is executed when the time zone specified by the control unit 35 is reached or when the water softening process exceeds a certain period of time. Not limited to this. For example, an ion concentration detection unit different from the ion concentration detection unit 39 is provided on the downstream side of the second recovery flow path 25 and on the upstream side of the on-off valve 27, and the flow path 9 is circulated by the ion concentration detection unit. The ion concentration (for example, hardness component concentration) of the soft water to be softened is always detected, and the ion concentration is set in advance not only when the time zone specified by the control unit 35 is reached or when the softening treatment exceeds a certain period of time. The reproduction process may be executed when the reference value is exceeded. Thereby, the execution of the regeneration process can be determined based on the ion concentration of the water after flowing through the neutralization tank 4. Therefore, the state of the weakly acidic cation exchange resin 10 in the water softening tank 3 can be determined more accurately, and the weakly acidic cation exchange resin 10 and the weakly basic anion exchange resin 11 can be regenerated at appropriate timings. It can be carried out.

Further, in the water softening apparatus 1 according to the first embodiment, in the cleaning treatment (during cleaning), raw water is flowed from the inflow port 2 to the water softening tank 3, the neutralization tank 4, the second recovery flow path 25, and the water storage tank 15. It was introduced into the electrolytic cell 12 through, but this is not the case. For example, the first recovery flow path 23 may be circulated instead of the second recovery flow path 25. As a result, the acidic electrolyzed water containing the hardness component remaining in the first recovery flow path 23 can be recovered.

Further, in the water softening device 1 according to the first embodiment, the water storage tank 15 may be further provided with an on-off valve and an air vent valve. When the on-off valve provided in the water storage tank 15 is opened during the wastewater treatment, the water in the water storage tank 15 is drained to the outside by the action of the air vent valve. As a result, the time required for wastewater treatment can be shortened.

Further, in the water softening device 1 according to the first embodiment, the first drain port 16 and the second drain port 16 and the second drain port 16 are configured to discharge the electrolyzed water sent from the electrolytic cell 12 to the outside of the device during the cleaning treatment and the waste water treatment. The drainage port 18 is provided, but the present invention is not limited to this. For example, it is preferable to mix and drain the alkaline electrolyzed water drained from the first drain port 16 and the acidic electrolyzed water drained from the second drain port 18. As a result, the acidic electrolyzed water and the alkaline electrolyzed water can be neutralized and drained.

In the water softening device 1 according to the first embodiment, the separating portion 14 is configured to be cleaned, but the present invention is not limited to this. For example, the separation unit 14 may be configured not to be cleaned. As a result, although the above-mentioned effect (2) cannot be obtained, the effects such as simplification of the device configuration, miniaturization of the device, and cost reduction of the device can be enjoyed.

The water softening device according to the present invention can be applied to a place-of-use water purification device (POU: Point of Use) or a building entrance-installed water purification device (POE: Point of Entry).

1 Water softening device 1a Water softening device 1b Water softening device 2 Inflow port 3 Water softening tank 4 Neutralization tank 5 Intake port 6 Regeneration device 7 Flow path 8 Flow path 9 Flow path 10 Weakly acidic cation exchange resin 11 Weak basic yin Ion exchange resin 12 Electrolyte tank 13 Electrode 13a Electrode 13b Electrode 14 Separation part 15 Water storage tank 16 First drainage port 17 Selection valve 18 Second drainage port 19 Selection valve 20 Water supply pump 21 Circulation flow path 21a First circulation flow path 21b Second Circulation flow path 22 First supply flow path 22a First supply flow path 22b First supply flow path 23 First recovery flow path 24 Second supply flow path 24a Second supply flow path 24b Second supply flow path 25 Second recovery flow path Road 26 Cleaning flow path 26a First cleaning flow path 26b Second cleaning flow path 27 On-off valve 28 On-off valve 29 On-off valve 30 On-off valve 31 On-off valve 32 On-off valve 33 On-off valve 34 On-off valve 35 Control unit 36 Water supply flow path 37 1 drainage channel 38 2nd drainage channel 39 Ion concentration detector 40 Water storage tank separation unit

Claims (4)

A water softening tank that softens raw water containing hardness components with a weakly acidic cation exchange resin,
A neutralization tank that neutralizes the pH of the soft water that has passed through the softening tank with a weak basic anion exchange resin, and
An electrolytic cell that produces acidic electrolyzed water for regenerating the weakly acidic cation exchange resin in the water softening tank and alkaline electrolyzed water for regenerating the weakly basic anion exchange resin in the neutralization tank. ,
A water storage tank that mixes the acidic electrolyzed water that has flowed through the water softening tank and the alkaline electrolyzed water that has flowed through the neutralization tank and supplies the water to the electrolyzed tank.
A separation unit provided in a flow path communicating the electrolytic cell and the neutralization tank to separate precipitates caused by the hardness component contained in water introduced into the electrolytic cell.
A water softening device characterized by being provided with. Further, a control unit for controlling the regeneration treatment of the weakly acidic cation exchange resin in the water softening tank and the weakly basic anion exchange resin in the neutralization tank is provided.
The control unit is characterized in that after the completion of the regeneration process, the electrolytic cell is repolarized, and the acid electrolyzed water after the reconversion is circulated to the separation unit and controlled to be discharged to the outside of the apparatus. The water softening device according to claim 1. The control unit rotates the electrolytic cell when the ion concentration specified based on the information on the ion concentration of the acidic electrolyzed water after the conversion after flowing through the separation unit becomes less than the reference value. The water softening apparatus according to claim 2, wherein the water softening apparatus is controlled so as to terminate the above-mentioned. The invention according to any one of claims 1 to 3, wherein the water storage tank further includes a water storage tank separating portion for separating precipitates caused by the hardness component contained in water introduced into the tank. Water softening device.

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