JP2018043206A - Electric type deionized water production device and operational method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric type deionized water production device and an operational method thereof, which can solve a problem of the rise of water quality of treatment water, which may occur at the time of device start, while suppressing useless consumption of water or energy.SOLUTION: An electric type deionized water production device 10 includes: a desalination chamber D located between an anode 11 and a cathode 12 and partitioned by an anion exchange membrane a1 and a cation exchange membrane c1; and a pair of concentration chambers C1 and C2 arranged on both sides of the desalination chamber D. The electric type deionized water production device 10 is provided with a controller 3 in which an operation is switched between a first operational mode for storing treatment water obtained by conducting water to be treated to the desalination chamber D and a second operation mode for circulating by refluxing the treatment water obtained by conducting water to be treated to the desalination chamber D or for externally discharging the treatment water. In the second operational mode, an amount of water conducted to the desalination chamber D is less than in the first operational mode, and a current value that flows between the anode 11 and the anode 12 is the same as in the first operational mode or less than in the first operational mode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric deionized water production apparatus and an operation method thereof.

  The electric deionized water production apparatus is arranged between a cation exchange membrane that allows only cations (cations) to pass therethrough and an anion exchange membrane that allows only anions (anions) to pass through, and an ion exchanger (anion exchanger and cation). It is an apparatus comprising as basic components a desalting chamber filled with at least one of the exchangers, and concentrating chambers arranged on both sides of the desalting chamber and outside the cation exchange membrane and the anion exchange membrane, respectively. The desalting chamber is disposed between the anode and the cathode such that an anion exchange membrane is located between the desalting chamber and the anode, and a cation exchange membrane is located between the desalting chamber and the cathode. .

In such an electrical deionized water production apparatus, when water to be treated is passed through the desalting chamber with a DC voltage applied between the anode and the cathode, ionic components in the water to be treated are ions in the desalting chamber. Captured by the exchanger. At the same time, in the desalting chamber, the dissociation reaction of water proceeds due to the potential difference generated at the interface between the ion exchange membrane and the ion exchanger or between the ion exchangers, and hydrogen ions (H ⁺ ) and hydroxide ions ( OH ⁻ ) is produced. Then, the ion component previously captured in the ion exchanger is ion-exchanged by the generated hydrogen ions and hydroxide ions, and is released from the ion exchanger. Of the liberated ionic components, the cations are driven by a direct current to move in the ion exchanger, and further pass through the cation exchange membrane and move to the concentration chamber on the cathode side. Similarly, of the released ionic component, the anion is driven by a direct current and moves in the ion exchanger, and further passes through the anion exchange membrane and moves to the concentration chamber on the anode side. In this way, the ion component in the for-treatment water supplied to the desalting chamber moves to the concentration chamber, and deionized water is obtained from the desalting chamber, and the ion exchanger in the desalting chamber is also regenerated. On the other hand, the ionic component can be discharged to the outside as concentrated water by flowing water into the concentration chamber where the ionic component has moved.

  As described above, in the electric deionized water production apparatus, the process is performed by a plurality of processes including adsorption of impurity ions to the ion exchanger, electrical regeneration of the ion exchanger, and movement of impurity ions to the concentration chamber. Impurity ions in the water are removed. For this reason, compared with the adsorption apparatus using a general ion exchange resin, there exists a tendency for the rise of the quality of the treated water (deionized water) at the time of apparatus start-up to take time. In particular, when the apparatus is stopped after operating for a certain time, it may take a long time for the water quality to rise when the operation is resumed. This is because an electric deionized water production apparatus is arranged with a demineralization chamber in which an ionic component is removed and an ion concentration is reduced, and a demineralization chamber and an ion exchange membrane sandwiched between And a concentration chamber in which the ion concentration is increased by the ion component that has moved, so that when the apparatus is stopped, no voltage is applied between the anode and the cathode. This is because the ion component diffuses from the concentration chamber to the desalting chamber based on the gradient of the ion concentration with the chamber and is adsorbed by the ion exchanger in the desalting chamber. That is, even if the apparatus is started in a state where the impurity ions are adsorbed on the ion exchanger in the desalting chamber, a process for moving the adsorbed impurity ions to the concentration chamber again is required. In one example, it may take several hours to several tens of hours to return to the state before the operation of the apparatus is stopped.

  Considering the above points, as a method of shortening the rise time of water quality at the time of restarting operation, when stopping the operation of the apparatus, water supply to the concentrating chamber is allowed even after the application of DC voltage to the electrode is stopped. It is conceivable to continue and to discharge (blow) water containing a large amount of impurity ions while staying in the concentration chamber. However, this method is not effective when the concentration chamber is filled with an ion exchange resin in order to suppress the generation of scale in the concentration chamber and reduce the operating voltage (see, for example, Patent Document 1). That is, when the ion exchange resin is filled in the concentrating chamber, the ionic components adsorbed on the ion exchange resin in the concentrating chamber are not discharged to the outside even if the above-described blow operation is performed. It is difficult to avoid the problem of rising water quality when restarting operation.

  Therefore, as another method for avoiding the problem of rising water quality, as described in Patent Document 2, even when there is no demand for treated water at the point of use, the treated water is returned to the desalination chamber. By circulating, it can be considered that the electric deionized water production apparatus is continuously operated without stopping the operation.

JP 2001-259646 A JP-A-9-57271

  However, the method described in Patent Document 2 is not preferable from the viewpoint of energy saving because the power consumption associated with the circulating operation of the treated water and the constant operation of the DC power supply cannot be ignored. In addition, it is necessary to discharge the concentrated water that has taken in the ionic components in the concentration chamber during the circulation operation of the treated water, but if the circulation operation of the treated water takes a long time, the amount of discharge cannot be ignored. .

  Accordingly, an object of the present invention is to provide an electric deionized water production apparatus and a method for operating the same, which avoids the problem of rising of the quality of treated water that may occur when the apparatus is started up while suppressing wasteful consumption of energy and water. It is to be.

  In order to achieve the above-described object, the electric deionized water production apparatus of the present invention is located between an anode and a cathode, and is partitioned by an anion exchange membrane on the anode side and a cation exchange membrane on the cathode side. Electrical deionization comprising a demineralization chamber filled with at least one of an exchanger and an anion exchanger, and a pair of concentration chambers arranged on both sides of the demineralization chamber via an anion exchange membrane and a cation exchange membrane A water production apparatus comprising: a first operation mode in which operation of the electric deionized water production apparatus is performed by storing treated water obtained by passing treated water through a desalting chamber in a treated water tank; A control unit for switching the treatment water obtained by passing the treatment water to the desalting chamber to be circulated by refluxing the desalination chamber or switching to the second operation mode for discharging the treated water to the outside; In the second operation mode, the water flow rate to the desalination chamber is the same as in the first operation mode. Even less, the same or not the current value in the first operation mode which flows between the anode and the cathode, or less than the first operation mode.

  Further, the operation method of the electric deionized water production apparatus of the present invention is located between the anode and the cathode, and is partitioned by the anion exchange membrane on the anode side and the cation exchange membrane on the cathode side, and the cation exchanger and the anion An electric deionized water production apparatus comprising a demineralization chamber filled with at least one of an exchanger and a pair of concentration chambers disposed on both sides of the demineralization chamber via an anion exchange membrane and a cation exchange membrane It is an operation method, and is obtained by passing the treated water through the desalting chamber, the first step of storing the treated water obtained by passing the treated water through the desalting chamber in the treated water tank. A second step of circulating the treated water to the desalting chamber and circulating it or discharging the treated water to the outside. In the second step, the amount of water flow to the desalting chamber is set to the first step. The current value flowing between the anode and the cathode is the same as in the first step, or the first process To be smaller than.

  According to such an electrical deionized water production apparatus, the power consumption and the amount of discharged water in the second operation mode (second step) are the same as those in the first operation mode (first step) ( The amount of water passing through the desalting chamber and the current value between the electrodes) can be reduced compared to the case where the second operation mode (second step) is performed. As a result, even when the apparatus is continuously operated in order to avoid the problem of rising water quality of the treated water that may occur at the time of starting the apparatus, the power consumption and the amount of drainage to the outside can be reduced.

  As described above, according to the present invention, it is possible to avoid the problem of rising of the quality of the treated water that may occur when the apparatus is started up while suppressing wasteful consumption of water and energy.

It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on the 1st Embodiment of this invention. It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on the 4th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below is an example for explaining the present invention, and does not limit the present invention.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an electric deionized water production apparatus according to the first embodiment of the present invention. The illustrated configuration is merely an example. For example, the configuration (number, arrangement, etc.) of each room is changed, or a valve, a measuring instrument, or the like is added. Needless to say, it can be appropriately changed according to the performance.

  The electric deionized water production apparatus 10 is a combination of electrophoresis and electrodialysis, and simultaneously performs deionization (desalting) treatment of water to be treated with an ion exchanger and regeneration treatment of the ion exchanger. Device. The electric deionized water production apparatus 10 includes a treated water tank 1 for storing treated water supplied to the electric deionized water production apparatus 10 and treated water produced by the electric deionized water production apparatus 10. A treated water tank 2 for storing (deionized water) is connected.

  The electric deionized water production apparatus 10 includes an anode chamber E1 including an anode 11, a cathode chamber E2 including a cathode 12, a demineralization chamber D provided between the anode chamber E1 and the cathode chamber E2, A pair of concentrating chambers C1 and C2 disposed on both sides of the desalting chamber D, the anode side concentrating chamber C1 adjacent to the desalting chamber D via the anion exchange membrane a1 on the anode 11 side of the desalting chamber D And a pair of concentrating chambers C1 and C2 including the desalting chamber D and the adjacent cathode-side concentrating chamber C2 via the cation exchange membrane c1 on the cathode 12 side of the desalting chamber D. The anode enrichment chamber C1 is adjacent to the anode chamber E1 via the cation exchange membrane c2, and the cathode enrichment chamber C2 is adjacent to the cathode chamber E2 via the anion exchange membrane a2.

  The desalting chamber D is filled with at least one of a cation exchanger and an anion exchanger, and preferably a mixture of a cation exchanger and an anion exchanger. That is, it is preferable that the cation exchanger and the anion exchanger are packed in a so-called mixed bed form. Examples of the cation exchanger include a cation exchange resin, a cation exchange fiber, and a monolithic porous cation exchanger, and the most versatile cation exchange resin is preferably used. Examples of the cation exchanger include weakly acidic cation exchangers and strongly acidic cation exchangers. Examples of the anion exchanger include anion exchange resins, anion exchange fibers, and monolithic porous anion exchangers, and the most general anion exchange resin is preferably used. Examples of the anion exchanger include weakly basic anion exchangers and strong basic anion exchangers.

  The anode-side enrichment chamber C1 and the cathode-side enrichment chamber C2 are provided to take in the anion component and the cation component discharged from the desalting chamber D and discharge them to the outside with concentrated water, respectively. In order to suppress the electric resistance of the electric deionized water production apparatus 10, it is preferable that each of the concentrating chambers C1 and C2 is filled with an ion exchanger.

  The anode chamber E1 accommodates an anode 11 made of a metal net or plate. The cathode chamber E2 contains a cathode 12 made of a metal net or plate. In order to suppress the electric resistance of the electric deionized water production apparatus 1, it is preferable that the anode chamber E1 and the cathode chamber E2 are filled with an ion exchanger.

  The desalting chamber D is connected to the treated water tank 1 via the flow path f1, and is connected to the treated water tank 2 via the flow path f2. The flow path f1 is provided with a pump 13 for delivering the water to be treated. The flow path f2 is provided with a valve 14 and the quality of treated water flowing through the flow path f2 (for example, conductivity, specific resistance, etc.). A water quality meter 15 for measurement is provided. The flow path f1 from the to-be-processed water tank 1 branches in the middle, and is connected also to each concentration chamber C1, C2 and the cathode chamber E2. A flow path f3 for discharging concentrated water supplied through the flow path f1 to the outside is connected to each of the concentration chambers C1 and C2. The cathode chamber E2 is connected to the anode chamber E1 through a flow channel f4, and the anode chamber E1 is connected to a flow channel f5 for discharging electrode water supplied to the anode chamber E1 and the cathode chamber E2 to the outside. ing. The channel f1 may be connected to the anode chamber E1, and the channel f5 may be connected to the cathode chamber E2. Further, a flow path f6 branched from the flow path f2 and connected to the water tank 1 to be treated is provided, and a valve 16 is provided in the flow path f6.

  A flow path f7 is connected to the water tank 1 to be treated, and the water to be treated is preferably water pretreated with a reverse osmosis (RO) membrane or an ion exchange resin (water having a conductivity of 0.1 to 100 μS / cm). ) Is supplied as needed. The treated water tank 2 is connected to a use point via a pipe (not shown), and the treated water in the treated water tank 2 can be supplied to the use point. The treated water tank 2 is provided with a water level meter 17 for measuring the water level in the treated water tank 2.

  Furthermore, the electric deionized water production apparatus 10 has a control unit 3 that switches the operation of the electric deionized water production apparatus 10 to two operation modes. Hereinafter, two operation modes of the electric deionized water production apparatus of the present embodiment, that is, a water sampling operation mode and a circulation operation mode will be described.

  The water sampling operation mode (first operation mode) is an operation mode performed during normal operation of the electric deionized water production apparatus 10. In this water sampling operation mode, the process of storing the treated water obtained by passing the treated water through the desalting chamber D in the treated water tank 2 is performed in order to replenish the treated water used at the use point. Is called.

  When the water sampling operation mode is started, the valve 14 of the flow path f2 is opened, and the valve 16 of the flow path f6 is closed. Then, a constant current operation is performed, that is, a direct current voltage is applied between the anode 11 and the cathode 12 so that a current value flowing between the two electrodes 11 and 12 becomes a predetermined value. By the operation of the pump 13, the water to be treated is supplied from the water tank 1 to be treated through the flow path f1. At this time, a part of the water to be treated is supplied as concentrated water to the anode side concentrating chamber C1 and the cathode side concentrating chamber C2, and similarly, a part of the water to be treated is supplied to the anode chamber E1 and the cathode chamber E2. It is supplied as electrode water. When the water to be treated passes through the desalting chamber D, the cation component and the anion component in the water to be treated are adsorbed and removed by the cation exchanger and the anion exchanger filled in the desalting chamber D, respectively. Thus, the treated water from which the cation component and the anion component have been removed is stored in the treated water tank 2 from the treatment chamber D through the flow path f2 as treated water (deionized water).

On the other hand, in the desalting chamber D, a water dissociation reaction in which water is dissociated into hydrogen ions (H ⁺ ) and hydroxide ions (OH ⁻ ) proceeds continuously. H ⁺ is exchanged with a cation component adsorbed on the cation exchanger, and OH ⁻ is exchanged with an anion component adsorbed on the anion exchanger. Thus, the cation exchanger and the anion exchanger filled in the desalting chamber D are regenerated.

  The cation component liberated from the cation exchanger in the desalting chamber D is attracted to the cathode 12 side by the potential difference between the anode 11 and the cathode 12, passes through the cation exchange membrane c1, and moves to the cathode concentration chamber C2. The cation component moved to the cathode side concentrating chamber C2 is taken into the concentrated water supplied to the cathode side concentrating chamber C2, and is discharged to the outside through the flow path f3 together with the concentrated water. The anion component liberated from the anion exchanger in the desalting chamber D is attracted to the anode side 11 by the potential difference between the anode 11 and the cathode 12, passes through the anion exchange membrane a1, and moves to the anode concentration chamber C1. The anion component that has moved to the anode-side concentration chamber C1 is taken into the concentrated water supplied to the anode-side concentration chamber C1, and is discharged to the outside through the flow path f3 together with the concentrated water.

  The circulation operation mode (second operation mode) is an operation mode performed when the treated water in the treated water tank 2 is not used, for example, when there is no demand for treated water at the use point. In this circulation operation mode, a process is performed in which treated water obtained by passing the treated water through the desalting chamber D is recirculated to the desalting chamber D without being stored in the treated water tank 2.

  In the circulation operation mode, the same desalination treatment as that in the normal operation mode is performed, but when the circulation operation mode is started, the valve 14 of the flow path f2 is closed and the valve 16 of the flow path f6 is opened. . Therefore, the treated water that has flowed out of the desalting chamber D flows from the flow path f2 into the flow path f6, and flows again from the treated water tank 1 into the desalting chamber D through the flow path f1. Thus, the treated water flowing out from the desalting chamber D is returned to the desalting chamber D through the water tank 1 to be treated, whereby the circulating operation of the treated water is performed.

  On the other hand, in the circulation operation mode, the output of the pump 13 is controlled, and the amount of water flow to the desalination chamber D is set to be smaller than that in the water sampling operation mode. Accordingly, the value of the current flowing between the anode 11 and the cathode 12 is set to be the same as or smaller than the water sampling operation mode. As a result, in the circulation operation mode, the pump 13 is compared with the case where the treatment water circulation operation is performed under the same conditions as in the water sampling operation mode (the amount of water passing through the desalination chamber D and the current value between the electrodes 11 and 12). And the current value can be made the same or smaller, and the power consumption of the entire apparatus can be reduced. Further, in the circulation operation mode, since the amount of water flow to the desalination chamber D is reduced, the amount of concentrated water to the concentration chambers C1 and C2 can be reduced, thereby reducing the amount of drainage to the outside. . That is, as a continuous operation for avoiding the problem of rising of the quality of treated water that may occur at the time of starting the device, by operating in the circulating operation mode of the present embodiment, the power consumption of the entire device and the amount of discharged water to the outside are reduced. It becomes possible to reduce.

  The reduction rate of the current value between the electrodes 11 and 12 (ratio of the current value in the circulation operation mode to the current value in the water sampling operation mode) is the reduction rate of the water flow rate to the desalination chamber D (water flow rate in the water sampling operation mode). Is preferably the same as the ratio of the water flow rate in the circulation operation mode). This is because the circulation operation mode has the same current efficiency as the water sampling operation mode and can maintain the same treated water quality.

  Even if there is demand for treated water at the point of use and treated water in the treated water tank 2 is used, the water level in the treated water tank 2 may become nearly full depending on the amount of use. There is. In this case, switching from the water sampling operation mode to the circulation operation mode is performed based on the water level in the treated water tank 2 regardless of whether or not the treated water in the treated water tank 2 is used. Good. That is, when the water level in the treated water tank 2 measured by the water level meter 17 exceeds a predetermined water level, switching from the water sampling operation mode to the circulation operation mode may be performed. The switching from the water sampling operation mode to the circulation operation mode may be performed based on the quality of the treated water obtained. That is, when the water quality of the treated water measured by the water quality meter 15 is lower than the desired water quality, the water sampling operation mode is switched to the circulating operation mode, and the treated water circulation operation is performed until the desired treated water quality is obtained. You may come to do.

  In the embodiment described above, only one desalting chamber is provided, but two or more desalting chambers may be provided. In this case, the desalting chamber and the concentrating chamber are provided alternately via a cation exchange membrane or an anion exchange membrane, the concentrating chamber located closest to the anode side is adjacent to the anode chamber, and the concentrating chamber located closest to the cathode side. Will be adjacent to the cathode chamber. On the other hand, the concentration chamber adjacent to the anode chamber is omitted, the anode chamber and the desalination chamber are adjacent, or the concentration chamber adjacent to the cathode chamber is omitted, and the cathode chamber and the desalination chamber are adjacent. You can also In this case, the anode chamber and the cathode chamber also serve as the concentration chamber, that is, ionic components in the water to be treated removed in the desalting chamber adjacent to the anode chamber or the cathode chamber move to the anode chamber or the cathode chamber. As a result, it is discharged to the outside together with the electrode water. Such a configuration is applicable regardless of the number of desalting chambers, and is also applicable when only one desalting chamber is provided. In any case, each desalting chamber is located between the anode and the cathode, and is partitioned by the anion exchange membrane on the anode side and the cation exchange membrane on the cathode side.

  Further, the desalting chamber may be divided into two in the direction of direct current application by an intermediate ion exchange membrane. In this case, these two small desalting chambers form a series channel, and the small desalting chamber on the anode side adjacent to the anion exchange membrane is filled with at least an anion exchanger, and the cathode adjacent to the cation exchange membrane. The small desalting chamber on the side is filled with at least a cation exchanger. The intermediate ion exchange membrane can be selected in consideration of the quality of the water to be treated and the water quality required for the treated water (deionized water), the type of ion exchanger filled in each small desalting chamber, for example, A single membrane of an anion exchange membrane or a cation exchange membrane or a bipolar membrane may be used.

(Second Embodiment)
FIG. 2 is a schematic configuration diagram of an electric deionized water production apparatus according to the second embodiment of the present invention. Hereinafter, the same reference numerals are given to the same components as those in the first embodiment, the description thereof is omitted, and only the components different from those in the first embodiment will be described.

  This embodiment is a modification in which the circulation path of the treated water in the circulation operation mode is changed with respect to the first embodiment. In the first embodiment, a flow path f6 branched from the flow path f2 connecting the treatment chamber D and the treated water tank 2 and connected to the treated water tank 1 is provided, but in this embodiment, A flow path f8 that connects the treated water tank 2 and the flow path f1 is provided. The flow path f8 is provided with a pump 18 for sending treated water and a valve 19, and in response thereto, a new valve 20 is provided in the flow path f1. In the present embodiment, the valve 14 provided in the flow path f2 is not provided.

  In the water sampling operation mode of the present embodiment, the valve 20 of the flow path f1 is opened, the same operation as that of the first embodiment is performed, and the treated water is stored in the treated water tank 2. On the other hand, in the circulation operation mode, the valve 20 of the flow path f1 is closed and the valve 19 of the flow path f8 is opened. And the operation | movement of the pump 13 stops and the pump 18 operates, and the treated water in the treated water tank 2 flows into the flow path f1. In this way, the treated water flowing out from the desalting chamber D is returned to the desalting chamber D via the treated water tank 2 so that the circulating operation of the treated water is performed.

  Also in the present embodiment, in the circulation operation mode, the water flow rate to the desalination chamber D is set to be smaller than that in the water sampling operation mode so that the power consumption of the entire apparatus and the amount of drainage to the outside are reduced. The value of the current flowing between the anode 11 and the cathode 12 is also set to be the same as or smaller than the water sampling operation mode. In the circulation operation mode of the present embodiment, since the treated water in the treated water tank 2 is supplied to the desalting chamber D as the treated water, the desalting treatment may not be performed in the desalting chamber D. The current value flowing between the electrodes 11 and 12 may be zero.

(Third embodiment)
In the third embodiment of the present invention, when the treated water in the treated water tank 2 is not used, treated water obtained by passing the treated water through the desalting chamber D instead of the circulation operation mode is supplied to the outside. This is different from the first embodiment in that a blow operation mode for discharging is performed. Hereinafter, with reference to Fig.3 (a) and FIG.3 (b), the electrical deionized water manufacturing apparatus of this embodiment is demonstrated. Fig.3 (a) and FIG.3 (b) are schematic which shows the flow-path structure in the water sampling operation mode of the electric deionized water manufacturing apparatus of this embodiment, and a blow operation mode, respectively. Hereinafter, with respect to the same configuration as that of the above-described embodiment, the same reference numerals are given to the drawings and the description thereof will be omitted, and only the configuration different from the above-described embodiment will be described.

  In the present embodiment, unlike the first embodiment, the flow path f6 branched from the flow path f2 is connected to the flow path f1 instead of the water tank 1 to be treated. Accordingly, a valve 21 is newly provided in the flow path f1.

  In the water sampling operation mode of the present embodiment, as shown in FIG. 3A, the valve 21 of the flow path f1 and the valve 14 of the flow path f2 are opened, the valve 16 of the flow path f6 is closed, and the first The same operation as in the embodiment is performed, and the treated water is stored in the treated water tank 2.

  On the other hand, when the blow operation mode (second operation mode) is started, as shown in FIG. 3B, the valve 21 in the flow path f1 and the valve 14 in the flow path f2 are closed, and the valve in the flow path f6. 16 is opened. For this reason, the to-be-treated water supplied from the to-be-treated water tank 1 through the flow path f1 flows into the desalting chamber D through the flow path f6, and passes through the desalting chamber D in the direction opposite to the water sampling operation mode. leak. A part of the treated water that has flowed out of the desalting chamber D flows into the cathode chamber E2, and is discharged to the outside through the flow channel f4 and the anode chamber E1 through the flow channel f5. Into the concentrating chambers C1 and C2 and discharged to the outside through the flow path f3. Thus, the treated water that has flowed out of the desalting chamber D is discharged to the outside through the anode chamber E1, the cathode chamber E2, and the pair of concentrating chambers C1 and C2.

  In the blow operation mode of the present embodiment, similarly to the circulation operation mode of the above-described embodiment, the amount of water flow to the desalting chamber D is set to be smaller than that in the water sampling operation mode, and the anode 11 and the cathode 12 The value of the current flowing between them is set to be the same as or smaller than the water sampling operation mode. Thereby, also in the blow operation mode of the present embodiment, when the treatment water blow operation is performed under the same conditions as the water sampling operation mode (the amount of water passing through the desalination chamber D and the current value between the electrodes 11 and 12). In comparison, the power consumption of the entire apparatus can be reduced, and the amount of drainage to the outside can be reduced. That is, as a continuous operation to avoid the problem of rising of the quality of treated water that may occur at the time of starting the device, by operating in the blow operation mode of the present embodiment, the power consumption of the entire device and the amount of drainage to the outside are reduced. It becomes possible to reduce.

  In addition, in the blow operation mode of this embodiment, since the water flow direction to the desalination chamber D is the opposite direction (counterflow) to the water sampling operation mode, the blow operation mode is performed when the quality of the treated water is reduced. Thus, the ion exchanger filled in the desalting chamber D is regenerated countercurrently, and the regeneration effect of the ion exchanger can be obtained with high efficiency.

(Fourth embodiment)
FIG. 4A and FIG. 4B are schematic views showing flow path configurations in the water sampling operation mode and the blow operation mode of the electric deionized water production apparatus of the present embodiment, respectively. Hereinafter, with respect to the same configuration as that of the above-described embodiment, the same reference numerals are given to the drawings and the description thereof will be omitted, and only the configuration different from the above-described embodiment will be described.

  This embodiment is a modification in which the supply path of the water to be treated to the desalting chamber D in the blow operation mode is changed with respect to the third embodiment. In the third embodiment, a flow path f6 branched from the flow path f2 and connected to the flow path f1 is provided, but in this embodiment, branched from the flow path f2 and connected to the treated water tank 2. A flow path f9 is provided. A valve 22 is provided in the flow path f9.

  In the water sampling operation mode of the present embodiment, as shown in FIG. 4A, the valve 21 of the flow path f1 and the valve 14 of the flow path f2 are opened, the valve 22 of the flow path f9 is closed, and the first The same operation as in the embodiment is performed, and the treated water is stored in the treated water tank 2.

  On the other hand, when the blow operation mode is started, as shown in FIG. 4B, the valve 21 of the flow path f1 and the valve 14 of the flow path f2 are closed, and the valve 22 of the flow path f9 is opened. The operation of the pump 13 is stopped. Here, the flow path f9 connects the treated water tank 2 and the desalting chamber D so that the treated water in the treated water tank 2 is supplied to the desalting chamber D by the head pressure. For this reason, the treated water in the treated water tank 2 flows into the desalting chamber D through the flow path f9 and the flow path f2, and flows out through the desalting chamber D in the direction opposite to the water sampling operation mode. Then, the treated water that has flowed out of the desalting chamber D flows into the cathode chamber E2, and is discharged to the outside through the flow channel f4 and the anode chamber E1 through the flow channel f5, and into the pair of concentration chambers C1 and C2. It flows in and is discharged to the outside through the flow path f3. Thus, the treated water that has flowed out of the desalting chamber D is discharged to the outside through the anode chamber E1, the cathode chamber E2, and the pair of concentrating chambers C1 and C2.

  Also in this embodiment, in the blow operation mode, the water flow rate to the desalination chamber D is set to be smaller than the water sampling operation mode so that the power consumption of the entire apparatus and the amount of drainage to the outside are reduced. The value of the current flowing between the anode 11 and the cathode 12 is also set to be the same as or smaller than the water sampling operation mode. In particular, the blow operation mode of the present embodiment is advantageous in comparison with other embodiments in that a pump is not used because water is supplied using water head pressure. In the blow operation mode of the present embodiment, since the treated water in the treated water tank 2 is supplied as treated water to the desalting chamber D, the desalting treatment may not be performed in the desalting chamber D. The current value flowing between the electrodes 11 and 12 may be zero. Moreover, the regeneration effect of the ion exchanger with which the desalting chamber D was filled can also be acquired similarly to 3rd Embodiment.

  Next, the present invention will be described in more detail with reference to specific examples.

Example 1
In the present embodiment, using the electric deionized water production apparatus shown in FIG. 1, after operating for a certain period of time in the sampling operation mode, the operation is performed for 22 hours in the circulation operation mode, and the sampling operation mode is set. The treated water quality (treated water specific resistance) after switching operation again was measured. As the water to be treated, two-stage RO permeated water having a conductivity of 3 to 4 μS / cm is used. In the circulation operation mode, treated water having a specific resistance value of 18.2 MΩ · cm is obtained in the water sampling operation mode. After that, it started when the water level in the treated water tank became equal to or higher than a predetermined upper limit water level. In the water sampling operation mode, the treatment flow rate (the flow rate of the treated water flowing into the treatment chamber), the concentrated water flow rate, and the electrode water flow rate are 500 L / h, 50 L / h, and 20 L / h, respectively. The treatment flow rate, the concentrated water flow rate, and the electrode water flow rate were 250 L / h, 25 L / h, and 10 L / h, respectively. The operating current (current value flowing between the electrodes) was 2.5 A in both the water sampling operation mode and the circulation operation mode.

(Example 2)
Measurement was performed under the same conditions as in Example 1 except that the operating current in the circulating operation mode was 1.25 A.

(Example 3)
In this embodiment, the electric deionized water production apparatus shown in FIG. 2 is used, the operation current in the circulation operation mode is set to 1.25 A, and the water sampling operation mode and the circulation operation mode are set according to the water level in the treated water tank. The measurement was performed under the same conditions as in Example 1 except that the operation in the circulating operation mode was performed for a total of 22 hours while appropriately switching between and. That is, in the present embodiment, in the circulating operation mode, the treated water in the treated water tank is supplied to the desalting chamber as treated water, so that the water level in the treated water tank becomes equal to or lower than a predetermined lower limit water level. The operation in the circulating operation mode was performed for a total of 22 hours while appropriately switching between the water sampling operation mode and the circulation operation mode so that the water sampling operation mode was executed until the water level reached a predetermined upper limit water level or higher.

Example 4
The same conditions as in Example 3 except that the treatment flow rate, the concentrated water flow rate, and the electrode water flow rate in the circulation operation mode were 50 L / h, 5 L / h, and 1 L / h, respectively, and the operation current in the circulation operation mode was 0 A. The measurement was performed.

(Example 5)
In the present embodiment, the electric deionized water production apparatus shown in FIG. 3 is used, and instead of operating in the circulating operation mode, the operation is performed in the blow operation mode, the treatment flow rate in the blow operation mode, the concentrated water flow rate, and the electrode The measurement was performed under the same conditions as in Example 1 except that the water flow rates were 50 L / h, 40 L / h, and 10 L / h, respectively, and the operating current in the blow operation mode was 0.25 A.

(Example 6)
In the present embodiment, the electric deionized water production apparatus shown in FIG. 4 is used, and the blow operation is performed while appropriately switching between the water sampling operation mode and the blow operation mode according to the water level in the treated water tank, as in the third embodiment. Measurement was performed under the same conditions as in Example 5 except that the operation in the mode was performed for a total of 22 hours.

(Comparative Example 1)
After operating for a certain period of time in the sampling operation mode and obtaining treated water with a specific resistance value of 18.2 MΩ · cm, the operation of the system is stopped for 22 hours instead of 22 hours in the circulation operation mode. Then, measurement was performed under the same conditions as in Example 1 except that the operation in the water sampling operation mode was restarted.

(Comparative Example 2)
Under the same conditions as in Example 1, except that the treatment flow rate, the concentrated water flow rate, and the electrode water flow rate in the circulation operation mode were set to 500 L / h, 50 L / h, and 20 L / h, respectively, as in the water sampling operation mode. Measurements were made.

Actually, in Examples 1 to 6 and Comparative Examples 1 and 2, measurement was performed using an electric deionized water production apparatus provided with five demineralization chambers. The specifications of each chamber common to each example and each comparative example are as follows. Here, CER is an abbreviation for a cation exchange resin and AER is an anion exchange resin.
・ Anode chamber: Dimension 200 × 300 × 8 mm CER filling ・ Cathode chamber: Dimension 200 × 300 × 8 mm AER filling ・ Desalination chamber: Dimension 200 × 300 × 16 mm (5 chambers) AER / CER filling ・ Concentration chamber: Dimension 200 × 300 × 8mm (6 rooms) AER filling

  Table 1 shows the measurement results in Examples 1 to 6 and Comparative Examples 1 and 2, specifically, the treated water specific resistance 10 seconds after the resumption of operation in the water sampling operation mode. For comparison, Table 1 also shows an integrated value (total amount of drainage) of drainage during continuous operation (circulation operation and blow operation), operating current, and pump operating status.

  Compared to Comparative Example 1 in which continuous operation is not performed, in Examples 1 to 6, it was confirmed that good results were obtained regarding the rise of the quality of the treated water. Further, from Table 1, Examples 2 and 4 to 6 are slightly inferior to Examples 1 and 3 in terms of rising water quality of the treated water, but at least the total amount of drainage and power consumption (operating current and pump operating conditions). On the other hand, it turns out that it is better than Examples 1 and 3. Moreover, it turns out that the total drainage amount is reduced significantly compared with the comparative example 2 which performed the continuous operation similarly in all the Examples. Therefore, in Examples 1-6, it was confirmed by performing continuous operation that the problem of the rising of the quality of treated water is avoided, and the total amount of drainage and power consumption can be reduced.

DESCRIPTION OF SYMBOLS 1 Treated water tank 2 Treated water tank 3 Control part 10 Electric deionized water production apparatus 11 Anode 12 Cathode 13,18 Pumps 14, 16, 19, 20-22 Valve 15 Water quality meter 17 Water level meter D Desalination chamber C1 Anode Side enrichment chamber C2 Cathode side enrichment chamber E1 Anode chamber E2 Cathode chamber a1, a2 Anion exchange membrane c1, c2 Cation exchange membrane f1-f9 Channel

Claims (10)

A desalting chamber located between the anode and the cathode, partitioned by the anion exchange membrane on the anode side and the cation exchange membrane on the cathode side, and filled with at least one of a cation exchanger and an anion exchanger; An electric deionized water production apparatus comprising a pair of concentration chambers disposed on both sides of the demineralization chamber via the anion exchange membrane and the cation exchange membrane,
The operation of the electric deionized water production apparatus includes a first operation mode in which treated water obtained by passing the treated water through the demineralization chamber is stored in a treated water tank, and the treated water is dehydrated. A control unit that circulates the treated water obtained by passing the salt water through the desalting chamber, or switches to the second operation mode for discharging the treated water to the outside;
In the second operation mode, the amount of water flow to the desalination chamber is less than that in the first operation mode, and the current value flowing between the anode and the cathode is the same as in the first operation mode, Smaller than the first operation mode,
Electric deionized water production equipment.   The electric deionized water production apparatus according to claim 1, wherein each of the pair of concentration chambers is filled with an ion exchanger.   The desalting chamber is connected to the treated water tank so that the treated water returns to the desalting chamber via the treated water tank storing the treated water in the second operation mode. The electric deionized water production apparatus according to claim 1 or 2.   The desalination chamber is connected to the treated water tank so that the treated water returns to the desalted chamber via the treated water tank in the second operation mode. The electric deionized water production apparatus as described. An anode chamber having the anode and a cathode chamber having the cathode;
In the demineralization chamber, a part of the treated water is discharged to the outside through the anode chamber and the cathode chamber in the second operation mode, and the other part of the treated water is passed through the pair of concentration chambers. The electric deionized water production apparatus according to claim 1, wherein the apparatus is connected to the anode chamber, the cathode chamber, and the pair of concentration chambers so as to be discharged to the outside.   The desalting chamber is connected to the treated water tank so that the treated water in the treated water tank is supplied as the treated water to the desalted chamber in the second operation mode. Item 3. The electric deionized water production apparatus according to Item 1 or 2.   The desalting chamber and the treated water tank are connected so that the treated water in the treated water tank is supplied to the desalting chamber by water head pressure. The electric deionized water production apparatus according to claim 6.   The electricity according to any one of claims 5 to 7, wherein a flow direction of the treated water to the desalting chamber is opposite to each other in the first operation mode and the second operation mode. Type deionized water production equipment.   9. The control unit according to claim 1, wherein the control unit switches from the first operation mode to the second operation mode based on a water level in the treated water tank or a quality of the treated water. Electric deionized water production equipment. A desalting chamber located between the anode and the cathode, partitioned by the anion exchange membrane on the anode side and the cation exchange membrane on the cathode side, and filled with at least one of a cation exchanger and an anion exchanger; An operation method of an electrical deionized water production apparatus comprising a pair of concentration chambers disposed on both sides of the demineralization chamber via the anion exchange membrane and the cation exchange membrane,
A first step of storing treated water obtained by passing treated water through the desalting chamber in a treated water tank;
A second step of circulating the treated water obtained by passing the treated water through the desalting chamber to the desalting chamber for circulation or discharging the treated water to the outside,
In the second step, the amount of water flow to the desalting chamber is less than that in the first step, and the current value flowing between the anode and the cathode is the same as in the first step, Or smaller than the first step,
An operation method of the electric deionized water production apparatus

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