JP5806038B2 - Electric deionized water production equipment - Google Patents

Description

  The present invention relates to an electric deionized water production apparatus, and more particularly to a configuration for suppressing scale generation in a concentration chamber.

Conventionally, as an apparatus for producing deionized water, an apparatus that performs deionization by passing water to be treated through an ion exchanger is known. In such an apparatus, when the ion exchange group of the ion exchanger is saturated and the desalting performance is lowered, it is necessary to regenerate the ion exchanger with a chemical such as acid or alkali. Specifically, the anion and cation adsorbed on ion exchange groups, acid or alkali from the H ⁺ and OH ^- and replacing processing is required. In recent years, in order to eliminate such disadvantages in operation, an electric deionized water production apparatus that does not require regeneration by a drug has been put into practical use.

  The electric deionized water production apparatus is an apparatus that combines electrophoresis and electrodialysis. A general electric deionized water production apparatus includes a demineralization chamber, a pair of concentration chambers disposed on both sides of the demineralization chamber, an anode chamber disposed outside one of the concentration chambers, and a concentration of the other. And a cathode chamber disposed outside the chamber. The desalting chamber has an anion exchange membrane and a cation exchange membrane arranged opposite to each other, and an ion exchanger (anion exchanger and / or cation exchanger) filled between the exchange membranes. The electric deionized water production apparatus may be abbreviated as “EDI”.

In order to produce deionized water (treated water) by EDI configured as described above, water to be treated is introduced into the demineralized chamber with a DC voltage applied between the electrodes provided in the anode chamber and the cathode chamber, respectively. Pass water. The ionic component in the water to be treated is adsorbed by the ion exchanger in the demineralization chamber and subjected to deionization (demineralization) treatment. Specifically, anion components (Cl ⁻ , CO ₃ ²⁻ , HCO ₃ ⁻ , SiO _2, etc.) are adsorbed by the anion exchanger in the desalting chamber, or cation components (Na ⁺ , Ca ² ) by the cation exchanger. ⁺ , Mg ^2+, etc.) are adsorbed. In the desalting chamber, a dissociation reaction of water occurs due to the applied voltage, and hydrogen ions and hydroxide ions are generated (H ₂ O → H ⁺ + OH ⁻ ). The anion component adsorbed on the anion exchanger is exchanged with the hydroxide ion and released from the anion exchanger, and the cation component adsorbed on the cation exchanger is exchanged with the hydrogen ion and released from the cation exchanger. The released anion component (or cation component) travels through the anion exchanger (or cation exchanger) to the anion exchange membrane (or cation exchange membrane), is electrodialyzed on the membrane, and is concentrated water flowing through the concentration chamber. To be discharged.

  As described above, in the electric deionized water production apparatus, hydrogen ions and hydroxide ions continuously act as a regenerant (acid or alkali) for regenerating the ion exchanger. For this reason, the regeneration by the medicine is basically unnecessary, and the continuous operation can be performed without the regeneration of the ion exchanger by the medicine.

In such an electric deionized water production apparatus, when water to be treated containing a large amount of hardness components such as calcium and magnesium is treated, anion exchange is performed among the hydroxide ions generated by the water dissociation reaction in the demineralization chamber. Since excess that has not been used for body regeneration is discharged to the concentration chamber through the anion exchange membrane, the pH in the concentration chamber may locally rise to generate a hardness scale. That is, hydrogen carbonate ions (HCO ₃ ⁻ ) contained in the concentrated water react with hydroxide ions to become carbonate ions (CO ₃ ²⁻ ), and further react with calcium concentrated in the concentration chamber to become calcium carbonate. Magnesium concentrated in the concentration chamber reacts directly with hydroxide ions to become a hardness scale such as magnesium hydroxide. In particular, the pH in the vicinity of the anion exchange membrane that transmits hydroxide ions increases, and scale is generated on the surface of the anion exchange membrane.

  When the hardness scale is generated, not only does the electrical resistance increase at the generated portion, leading to an increase in power consumption, but it may also cause a biased flow of current and reduce the quality of the treated water. Further, the scale grown over a long period of time erodes into the ion exchange membrane and eventually breaks the ion exchange membrane, causing even more serious problems.

  Therefore, as one of the methods for suppressing the generation of scale as described above, Patent Document 1 discloses that scale generation is performed by filling the concentration chamber with an anion exchanger and supplying water containing free carbonic acid to the concentration chamber. An operation method of an electric deionized water production apparatus that can suppress the increase in pH in the concentration chamber and reduce the pH in the concentration chamber is disclosed.

Specifically, excess hydroxide ions discharged from the desalination chamber into the concentration chamber are captured by the anion exchanger in the concentration chamber, and the concentrated water flowing through the concentration chamber contains free carbonic acid (CO ₂ ). The free carbonic acid reacts with hydroxide ions in the anion exchanger to form hydrogencarbonate ions (HCO ₃ ⁻ ). Even when bicarbonate ions react with hardness components in concentrated water to form calcium bicarbonate or magnesium bicarbonate, they do not precipitate like calcium carbonate or magnesium hydroxide. Occurrence is suppressed. In addition, hydrogen carbonate ions released into the concentrated water react with hydrogen ions that move from the other chamber on the opposite side of the demineralization chamber of the concentration chamber to the concentration chamber through the cation exchange membrane. Since it becomes carbonic acid and can react again with the hydroxide ions in the anion exchanger in the concentration chamber, the increase in pH in the concentration chamber can be mitigated.

By the way, in order to produce deionized water (treated water) having a high specific resistance value with an electric deionized water production device, cation removal by cation exchanger and anion removal by anion exchanger are repeated alternately. It is effective to perform multistage processing in which either one is at least two stages or more. For example, in the case of each one-stage treatment in which cation removal is first performed on the water to be treated and then anion removal is performed, only the cation component is first removed by the cation exchanger, so that Only the anion component remains in the water to be treated. However, since the electrical neutrality is maintained in water, hydrogen ions equivalent in amount to the removed cation component are released instead of the removed cation component in the water to be treated in the cation removal unit. Therefore, in the subsequent stage of the cation removing part from which the cation component has been removed to some extent, the hydrogen ions become excessive and it becomes difficult for the cation components (for example, Mg ²⁺ , Ca ²⁺ , Na ⁺ ) to be adsorbed to the cation exchanger. As a result, the cation component leaks into the treated water. In such a case, leakage into the treated water can be prevented by performing a multi-stage treatment in which cation removal is performed as described above, followed by anion removal, and further cation removal.

On the other hand, electrolysis (electrode reaction) of water occurs in the anode chamber and the cathode chamber of the electric deionized water production apparatus, and hydrogen ions and hydroxide ions are also generated by this reaction (2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ / 2H ₂ O + 2e ⁻ → H ₂ + 2OH ⁻ ). Therefore, hydrogen ions generated in the anode chamber and hydroxide ions generated in the cathode chamber can also be used for regeneration of the ion exchanger.

  In Patent Document 2, a sub-desalting chamber is provided adjacent to at least one of the two electrode chambers in addition to the main desalting chamber, and the water to be treated that has circulated through the sub-desalting chamber is circulated to the main desalting chamber. And / or the apparatus which distribute | circulates the to-be-processed water which distribute | circulated the main desalination chamber to the sub-desalination chamber is disclosed. As for the secondary desalting chamber, the secondary desalting chamber adjacent to the anode chamber becomes a demineralizing chamber and a cathode chamber for removing cations by the regenerant (hydrogen ions and hydroxide ions) generated by the electrode reaction as described above. Since adjacent sub-desalting chambers function as a desalting chamber for removing anions, multistage treatment can be realized by passing water through these sub-desalting chambers before and after the main desalting chamber.

Japanese Patent No. 4363587 JP 2009-297670 A

  As in the invention described in Patent Document 1 described above, an anion exchanger is filled in the concentration chamber of the electric deionized water production apparatus, and water containing free carbonic acid is supplied to the concentration chamber to suppress scale formation. be able to.

However, when water to be treated having a higher ion load, particularly water to be treated having a high concentration of silica (SiO ₂ ) in addition to hardness components (Mg ²⁺ , Ca ²⁺ ), is described in Patent Document 1. Even if the method is implemented, a scale may still be generated.

  Moreover, in the case of the apparatus described in Patent Document 2, even if the water to be treated has an ion load equivalent to that described in Patent Document 1, depending on the arrangement of the desalting chamber and the concentration chamber and the water flow method, Even if the method as described in Patent Document 1 is performed, scale generation may still not be suppressed.

  For example, as shown in FIG. 13, two sets of main desalting chambers 103, 106 and 104, 108 are disposed between the anode chamber 101 and the cathode chamber 102. A concentrating chamber 105 is disposed adjacent to the anode chamber 101 between the anode chamber 101 and the pair of main desalting chambers 103 and 106, and the main desalting chamber 106 is disposed between the main desalting chamber 103 and the concentrating chamber 105. Arranged adjacent to each other. A concentrating chamber 107 is disposed adjacent to the main desalting chamber 103 between the main desalting chamber 103 and another set of main desalting chambers 104 and 108, and the main desalting chamber 108 is disposed in the main desalting chamber 104 and the concentrating chamber. 107 are arranged adjacent to them. Further, between the cathode chamber 102 and the main desalting chamber 104, a concentration chamber 109 is disposed adjacent to the main desalting chamber 104, and a sub-desalting chamber 110 is disposed adjacent to them between the cathode chamber 102 and the concentration chamber 109. The The anode chamber 101 and the main desalting chambers 103 and 104 are filled with at least a cation exchanger K, and the main desalting chambers 106 and 108, the sub-desalting chamber 110 and the cathode chamber 102 are at least anion exchanged. Body A is filled. The concentration chambers 105, 107, and 109 are also filled with an anion exchanger. Further, the membrane disposed on the anode side with respect to each of the concentrating chambers 105, 107, and 109 is a cation exchange membrane, and the membrane disposed on the cathode side is an anion exchange membrane. Between the main desalting chambers 103 and 106, between the main desalting chambers 104 and 108, and between the cathode chamber 102 and the auxiliary desalting chamber 110, an anion exchange membrane or an anion exchange membrane and a cation exchange membrane are bonded together. One of the bipolar films having the above structure is disposed.

In the case of the EDI configured as described above, the water to be treated having a high silica concentration in addition to the hardness components (Mg ²⁺ , Ca ²⁺ ) is first passed through the sub-demineralization chamber 110 to form anions in the water to be treated. Among the components, strongly acidic anion components such as Cl 2 ⁻ which are easily adsorbed by the anion exchanger are discharged to the concentration chamber 109. Next, the water to be treated that has passed through the secondary desalting chamber 110 passes through each of the main desalting chambers 103 and 104. At this time, the cation component including the hardness component is captured by the cation exchanger in each of the main desalting chambers 103 and 104, and is further discharged to each of the concentration chambers 107 and 109 through the cation exchange membrane on the cathode side. In addition, the water to be treated that has passed through the main desalting chambers 103 and 104 is passed through the other main desalting chambers 106 and 108 for processing. At this time, among the anion components in the water to be treated, anion components such as silica that are difficult to be adsorbed by the anion exchanger are captured by the anion exchangers of the main desalting chambers 106 and 108, and further the anion exchange membrane on the anode side It passes through the concentrating chambers 105 and 107.

  In the case of such a method, in the second concentration chamber 107 from the right in FIG. 13, the cation component mainly containing hardness from the main desalting chamber 103 is concentrated, and at the same time from the main desalting chamber 108, one stage. Since only an anion component such as silica that has hardly been desalted enters and concentrates in the sub-desalting chamber 110 of the eye, excessive hydroxide ions are also discharged at the same time. Therefore, even if water containing free carbonic acid is supplied to the concentration chamber 107, an effect that can alleviate all hydroxide ions discharged from the sub-desalination chamber 108 to the concentration chamber 107 is not obtained, and the hardness component Since silica and silica are concentrated to a high concentration in the same concentration chamber, scales such as magnesium silicate are easily generated.

  Furthermore, as shown in FIG. 13, in the case of an apparatus that operates by passing water to be treated in parallel through a plurality of main demineralization chambers 103, 104, the treatment to be passed through the plurality of main demineralization chambers 103, 104. Since all of the water is concentrated in one sub-desalting chamber 110 and then distributed to each main desalting chamber, the sub-desalting chamber 110 is loaded with ionic components more than the main desalting chambers 103 and 104. The amount increases and the desired water quality may not be obtained. Therefore, in order to obtain a desired water quality, a larger current value is required. In this case, power consumption during operation is significantly increased, which is not preferable.

  Therefore, the present invention provides an electric deionized water production apparatus that can suppress the generation of scale in the concentrating chamber even during long-term continuous operation and can obtain treated water with good water quality by multistage treatment. Objective.

  In this situation, the present inventor has intensively studied. As a result, in the electric deionized water production apparatus, scale generation is required unless the calcium and magnesium hardness components and silica are combined and concentrated at a high concentration in one concentration chamber. It has been found that it can be remarkably suppressed, and the present invention has been completed.

In order to obtain the effects as described above, one aspect of the present invention is:
An electric deionized water production apparatus in which a desalting chamber and a concentration chamber are arranged between an anode and a cathode, and an anode side and a cathode side of each chamber are partitioned by an ion exchange membrane,
An enrichment chamber disposed between the anode and the cathode, in which the cation component and the anion component in the water to be treated are concentrated, and the first cation exchange membrane as the ion exchange membrane partitioning the anode side and the ion exchange membrane partitioning the cathode side A first concentration chamber having a first anion exchange membrane as
A first anion removal desalting chamber disposed adjacent to the cathode side of the first concentration chamber and filled with at least an anion exchanger;
A first cation removal desalting chamber disposed adjacent to the anode side of the first concentration chamber and filled with at least a cation exchanger;
A second anion removing desalting that is disposed between the first cation removing desalting chamber and the anode or between the first anion removing desalting chamber and the cathode and is filled with at least an anion exchanger. Room,
A second concentration chamber disposed adjacent to the anode side of the second anion removal desalting chamber and having a second anion exchange membrane as an ion exchange membrane for partitioning the cathode side;
Contains
The first anion removal demineralization chamber, the first cation removal demineralization chamber, and the second anion removal demineralization chamber are such that the water to be treated is a first anion removal demineralization chamber, a first cation. Passing in order of removal desalting chamber and second anion removing desalting chamber, or first cation removing desalting chamber, first anion removing desalting chamber, second anion removing desalting chamber In order to pass in the order of
The first concentrating chamber and the second concentrating chamber so that the concentrated water flowing out from one of the first concentrating chamber and the second concentrating chamber does not become water flowing into the other concentrating chamber. A water inflow line and an outflow line are formed in each chamber.

  In such an embodiment, since it is possible to perform an operation in which the hardness component and silica are not concentrated to a high concentration in the concentration chamber, scale generation in the concentration chamber is suppressed even in a long-term continuous operation, and the multistage treatment is preferable. Treated water with quality can be obtained.

  In addition, any number of desalting chambers and concentrating chambers for configuring the apparatus of the above aspect can be stacked via a regenerative ion exchange membrane or an intermediate ion exchange membrane, so that the ion load is higher. Even when processing a larger flow rate, the same treated water quality can be obtained with low power consumption.

  As described above, according to the present invention, electric deionized water production that can suppress the generation of scale in the concentration chamber even during long-term continuous operation and can obtain treated water with good water quality by multistage treatment. An apparatus can be provided.

The figure which showed the apparatus aspect by the basic concept of this invention. The figure which showed the deformation | transformation aspect of the apparatus of FIG. The figure which showed the deformation | transformation aspect of the apparatus of FIG. The figure which showed the deformation | transformation aspect of the apparatus of FIG. BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of EDI (electric deionized water manufacturing apparatus) by the 1st Embodiment (Example 1) of this invention. The schematic block diagram of EDI by the 2nd Embodiment of this invention. The schematic block diagram of EDI by the 3rd Embodiment of this invention. The schematic block diagram of EDI by the 4th Embodiment of this invention. The schematic block diagram of EDI by the 5th Embodiment of this invention. The schematic block diagram of EDI by the 6th Embodiment (Example 2) of this invention. The schematic block diagram of the comparative example 1 compared with EDI of the form of FIG. The schematic block diagram of the comparative example 1 compared with EDI of the form of FIG. It is a schematic block diagram of the conventional EDI.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an apparatus aspect according to the basic concept of the present invention will be described.

  FIG. 1 is a diagram showing an apparatus according to the basic concept of the present invention. The EDI shown in this figure includes a first demineralization chamber 3, a first concentration chamber 4, a second demineralization chamber 5, and a first demineralization chamber 5 between an anode chamber 1 having an anode and a cathode chamber 2 having a cathode. 3 desalting chambers 6 and second concentrating chambers 7 are arranged in the direction between the electrodes. The anode chamber 1 and the second desalting chamber 5 are filled with a cation exchanger, and the cathode chamber 2, the first desalting chamber 3, the first concentration chamber 4 and the third desalting chamber 6 are anion exchanged. The body is filled.

  A first desalting chamber 3 is disposed adjacent to the cathode chamber 2 side of the first concentrating chamber 4, and a wall portion that partitions both the chambers 3 and 4 is constituted by a first anion exchange membrane 8. A second desalting chamber 5 is disposed adjacent to the anode chamber 1 side of the first concentrating chamber 4, and a wall portion that partitions the two chambers 4 and 5 is constituted by a first cation exchange membrane 9. Hereinafter, an aggregate of these three chambers 3, 4, and 5 will be referred to as a first unit A.

  Further, a third desalting chamber 6 is disposed on the anode chamber 1 side of the second desalting chamber 5, and a second concentration chamber 7 is disposed on the anode chamber 1 side of the third desalting chamber 6. A wall portion that is disposed adjacent to and separates the chambers 6 and 7 is constituted by a second anion exchange membrane 10. Hereinafter, the aggregate of these two chambers 6 and 7 will be referred to as a second unit B.

  The flow path P1 communicates the supply source of the water to be treated and the upper part of the first desalination chamber 3, and the flow path P2 is the lower part of the first desalination chamber 3 and the lower part of the second desalination chamber 5. The flow path P3 communicates the upper part of the second desalting chamber 5 and the upper part of the third desalting chamber 6, and the flow path P4 is connected to the lower part of the third desalting chamber 6. Yes. Thus, the water to be treated passes through the flow path P1, the first demineralization chamber 3, the flow path P2, the second demineralization chamber 5, the flow path P3, the third demineralization chamber 6, and the flow path P4 in this order. As it is, deionized water is sent out of the system. That is, in this embodiment, the anion removing desalting chamber (first desalting chamber 3), the cation removing desalting chamber (second desalting chamber 5), and the anion removing desalting chamber (third desalting chamber). Deionization is performed by flowing the water to be treated in the order of 6).

  Furthermore, the flow path Q1 connects the upper part of each of the first and second concentration chambers 4 and 7 to the same source of treated water that has flowed into the flow path P1, and the flow path Q2 Connected to the lower part of the first concentrating chamber 4, the flow path Q <b> 3 is connected to the lower part of the second concentrating chamber 7. Thereby, the same treated water that has flowed into the flow path P1 is supplied to the first concentration chamber 4 and the second concentration chamber 7 through the flow path Q1 different from the flow path P1. The treated water that has passed through the first concentrating chamber 4 is referred to as first concentrated water, the treated water that has passed through the second concentrating chamber 7 is referred to as second concentrated water, and each concentrated water is an electric current. It is discharged outside the system where there is no flow. However, the water that passes through the concentration chambers 4 and 7 and becomes the concentrated water is not necessarily the same, and the treated water does not have to flow into and out of the concentration chambers 4 and 7 at the same time. It is sufficient that the first concentration chamber 4 and the second concentration chamber 7 are not connected by a serial flow path. In addition to the water to be treated, the water that flows into each of the concentrating chambers 4 and 7 is not limited to the water to be treated because treated water or water that has flowed out of any desalting chamber (intermediate treated water) can be used. . That is, the first concentrating chamber 4 and the second concentrating chamber 4 are prevented from flowing into the other concentrating chamber from the concentrating water flowing out from one of the first concentrating chamber 4 and the second concentrating chamber 7. It is only necessary that an inflow line and an outflow line of water be provided in each of the concentration chambers 7.

  In addition, it is common to use the to-be-processed water which permeate | transmitted RO (reverse osmosis) membrane, ie, RO permeated water, for the to-be-processed water deionized by EDI in order not to impair the performance of an ion exchange membrane. Is.

  Next, the operation of the present invention will be described.

In the above apparatus aspect, when the water to be treated is water to be treated having a high silica concentration in addition to the hardness components (Mg ²⁺ , Ca ²⁺ ), the first desalting chamber 3 has anions in the water to be treated. The component is adsorbed on the anion exchanger and electrophoresed to the anode side while repeatedly exchanging with hydroxide ions generated by the electrolysis of water, and passes through the anion exchange membrane 8 on the anode side to be adjacent to the first concentration. It enters chamber 4 and is concentrated.

The treated water (RO permeated water) flowing through the first desalting chamber 3 includes Ca ²⁺ , Mg ²⁺ , Na ⁺ , K ⁺ , Cl ⁻ , carbonic acid components (free carbonic acid, HCO ₃ ^−, etc.), SiO ₂ (Silica often takes a special form, so it is displayed differently from general ions). Ion-selective ion exchangers, even of the same sign of the ions there are differences depending on the type, the non-dissociation of silica, other anions (Cl ^- strongly acidic anion and weakly acidic carbonate components, etc.) It is known that it is less likely to be adsorbed on the ion exchanger. Therefore, in the first desalting chamber 3, strong acid anions such as Cl ⁻ are first adsorbed rather than the anionic silica, and in the anion species moving from the first desalting chamber 3 to the first concentration chamber 4. Silica is less than other anionic components.

The cation component in the for-treatment water that has flowed into the first desalting chamber 3 passes through the first desalting chamber 3 and enters the second desalting chamber 5 via the flow path P2. In the second desalting chamber 5, cations having hardness components such as Ca ²⁺ and Mg ²⁺ are mainly adsorbed on the cation exchanger and are repeatedly exchanged with hydrogen ions generated by electrolysis of water toward the cathode side. It is electrophoresed, passes through the cation exchange membrane 9 on the cathode side, enters the first concentration chamber 4 and is concentrated. From the above, the first concentrated water, which is the water to be treated flowing in the first concentrating chamber 4, contains a relatively large amount of hardness component but has a small amount of silica, thereby suppressing scale generation. Is done.

  The treated water that has passed through the second desalting chamber 5 enters the third desalting chamber 6 via the flow path P3. In the third desalting chamber 6, anion components such as silica that have not been adsorbed in the first desalting chamber 3 are adsorbed by the anion exchanger and exchanged with hydroxide ions generated by electrolysis of water. Electrophoresis to the anode side is repeated, passes through the anion exchange membrane 10 on the anode side, enters the second concentration chamber 7 and is concentrated. Since the ionic component of hardness is removed in the second desalting chamber 5 in the previous stage, the second concentrated water which is the treated water flowing in the second concentrating chamber 7 is relatively hard. The components are reduced, and anionic components such as silica that have not been adsorbed in the first desalting chamber 3 are concentrated. For this reason, since the high-concentration hardness component and silica can be prevented from being present at the same time, scale generation is suppressed. On the other hand, the water to be treated that has passed through the third desalting chamber 6 is sent out of the system through the flow path P4 as demineralized water (treated water) containing almost no hardness component and silica.

The anion exchanger in the first desalting chamber 3 through which the water to be treated is first passed is an anion exchange with low silica adsorption performance so that silica is not captured by the first desalting chamber 3. The body is desirable. For example, type II strong basic anion exchanger, medium basic anion exchanger, weak basic anion exchanger and the like can be mentioned. As a result, the first-stage anion removal demineralization chamber is removed from the concentration chamber sandwiched between the first-stage cation removal demineralization chamber and the first-stage anion removal demineralization chamber. The amount of silica discharged can be significantly reduced.

  Although the basic apparatus mode of the present invention and the operation and effect of the present invention have been described above, the first unit A and the second unit B can be arranged between the anode chamber 1 and the cathode chamber 2 in an arbitrary number of units. May be arranged.

  For example, when one or more first units A in the embodiment of FIG. 1 are arranged in series adjacent to each other, the first desalting chamber 3 and the second desalting chamber 5 are adjacent to each other, As shown in FIG. 2, the chambers 3 and 5 are preferably partitioned by a wall made of an ion exchange membrane. Further, the adjacent first desalting chamber 3 and second desalting chamber 5 are ion exchange membranes (referred to as first intermediate ion exchange membranes 11) arranged at intermediate positions in one desalting chamber. Two small desalting chambers formed by dividing one desalting chamber can be used. This first intermediate ion exchange membrane 11 is an anion exchange membrane, a cation exchange membrane or an ion exchange membrane of a bipolar membrane, in other words, an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane.

  Further, the second desalting chamber 5 of the first unit A and the third desalting chamber 6 of the second unit B are adjacent to each other, but as shown in FIG. It is good to partition with the wall comprised with the exchange membrane. In the second desalting chamber 5 and the third desalting chamber 6, one desalting is performed by an ion exchange membrane (referred to as a second intermediate ion exchange membrane 12) disposed at an intermediate position in one desalting chamber. Two small desalting chambers formed by dividing the chamber can be used. The second intermediate ion exchange membrane 12 is also an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane.

  In the embodiment of FIG. 1, when one or more second units B are arranged adjacent to each other in series, the third desalting chamber 6 and the second concentrating chamber 7 are adjacent to each other. As shown in FIG. 2, the chambers 6 and 7 may be partitioned by a wall formed of an ion exchange membrane. Further, when one or more second units B are arranged in series adjacent to each other between the second unit B and the cathode chamber 2, as shown in FIG. And the second concentration chamber 7 are adjacent to each other, and the third desalting chamber 6 and the second concentration chamber 7 are adjacent to each other. Also in these cases, as shown in FIG. 3, the chambers 3 and 7 and the chambers 6 and 7 are preferably partitioned by walls made of ion exchange membranes.

  Such an ion exchange membrane interposed between the first desalting chamber 3 and the second concentrating chamber 7 and between the third desalting chamber 6 and the second concentrating chamber 7 is filled in the desalting chamber. An ion exchange membrane (referred to as a regenerative ion exchange membrane) having a function of supplying a regenerant (hydrogen ion or hydroxide ion) that regenerates the ion exchanger being used is preferable. When the first desalting chamber 3 and the third desalting chamber 6 are filled with an anion exchanger, the ion exchange membrane between the first desalting chamber 3 and the second concentrating chamber 7 is a hydroxide. The first regeneration ion exchange membrane 13 can supply ions into the first desalting chamber 3, and the ion exchange membrane between the third desalting chamber 6 and the second concentrating chamber 7 contains hydroxide ions. It is preferable that the second regenerated ion exchange membrane 14 be supplied into the third desalting chamber 6.

  In the embodiment of FIG. 1, the second unit B includes a third desalting chamber 6 and a second concentration chamber 7. As shown in FIG. 4, the second unit B includes a fourth desalting chamber. Chamber 16 may be included. Specifically, the fourth desalting chamber 16 is arranged adjacent to the second concentrating chamber 7 on the anode chamber 1 side of the second concentrating chamber 7, and the wall portion that partitions the two chambers 7, 16 is The second cation exchange membrane 17 is used. This additional configuration can further improve the deionization capacity.

  Some of the EDI embodiments using the above aspects are listed below.

(First embodiment)
FIG. 5 is a schematic diagram showing an EDI apparatus according to the first embodiment.

  The EDI according to this embodiment includes one first unit A and one second unit B, which are arranged as in the above-described aspect of FIG. In addition, as in the embodiment of FIG. 3, a flow path line for sequentially passing the water to be treated through the first to third demineralization chambers 3, 5, and 6 for deionization, 6 and a flow path line through which the ionic components discharged from the 6 to the first and second concentration chambers 4 and 7 flow in the water to be treated. The direction of the flow of water passing through the first concentration chamber 4 is opposed to the flow of water passing through the second desalting chamber 5 filled with the cation exchanger. Moreover, about the concentrated water which each passed through the 1st and 2nd concentration chambers 4 and 7, if it is outside the apparatus to which an electric current is not given, it can be made to merge.

  Further, in the present embodiment, the second desalting chamber 5 of the first unit A is disposed adjacent to the anode chamber 1. A cation exchange membrane or a bipolar membrane is used as the ion exchange membrane forming the partition wall between the second desalting chamber 5 and the anode chamber 1. The membrane here is a membrane containing at least a cation exchanger, so that hydrogen ions generated by the electrode reaction in the anode chamber 1 are supplied as a regenerant for the cation exchanger in the second desalting chamber 5. Can do.

  Further, the third desalting chamber 6 of the second unit B is arranged adjacent to the cathode chamber 2. An anion exchange membrane or a bipolar membrane is used as the ion exchange membrane that forms the partition wall between the third desalting chamber 6 and the cathode chamber 2. The membrane here is a membrane containing at least an anion exchanger, so that hydroxide ions generated by the electrode reaction in the cathode chamber 2 are supplied as a regenerant for the anion exchanger in the third desalting chamber 6. can do.

(Second Embodiment)
FIG. 6 is a schematic view showing an EDI apparatus according to the second embodiment.

  The EDI of this embodiment is obtained by adding another second unit B between the third desalting chamber 6 and the cathode chamber 2 to the EDI of the first embodiment shown in FIG. (One first unit A and two second units B). A second regenerative ion exchange membrane 14 is disposed between the third desalting chamber 6 of the second unit B and the second concentration chamber 7 of the added second unit B. Further, an ion exchange membrane that forms a partition wall between the added third third desalting chamber 6 of the second unit B and the cathode chamber 2 is provided with an anion for the purpose of supplying a regenerant similar to the first embodiment. Exchange membranes or bipolar membranes are used.

  To-be-treated water is passed from one direction to one first concentrating chamber 4 and two second concentrating chambers 7, and the to-be-treated water passes through the first demineralizing chamber in a different flow path. After sequentially passing through the third and second desalting chambers 5, water is passed through the two third desalting chambers 6 from the same direction. In this way, since the treated water that has passed through the second desalting chamber 5 is simultaneously treated in the third desalting chamber 6 of the two chambers, the third desalting chamber is the same as the current value used in the EDI of the first embodiment. The capacity of the deanion treatment in the salt chamber 6 is doubled with respect to the first embodiment.

(Third embodiment)
FIG. 7 is a schematic view showing an EDI apparatus according to the third embodiment.

  The EDI of this embodiment is obtained by adding another first unit A between the anode chamber 1 and the second desalting chamber 5 to the EDI of the second embodiment shown in FIG. Yes (two first units A, two second units B). A first intermediate ion exchange membrane 11 is arranged between the second desalting chamber 5 of the first unit A and the first desalting chamber 3 of the added first unit A. Further, the ion exchange membrane forming the partition wall between the added second desalting chamber 5 of the first unit A and the anode chamber 1 is provided with a cation for the purpose of supplying a regenerant similar to the first embodiment. Exchange membranes or bipolar membranes are used.

  The treated water is passed through the two first concentrating chambers 4 and the two second concentrating chambers 7 from the same direction. In another flow path, the water to be treated passes through the two first demineralization chambers 3 from the same direction, and further passes through the two second demineralization chambers 5 from the same direction. Water is passed through the desalting chamber 6 from the same direction. In this way, the water to be treated is simultaneously treated in the first desalting chamber 3 of the two chambers, and the treated water that has passed through the second desalting chamber 5 is simultaneously treated in the third desalting chamber 6 of the two chambers. Therefore, even if it is the same as the electric current value used by EDI of 1st Embodiment, it becomes possible to process a 2 times amount of to-be-treated water with respect to 1st Embodiment.

(Fourth embodiment)
FIG. 8 is a schematic view showing an EDI apparatus according to the fourth embodiment.

  The EDI of this embodiment is obtained by adding another second unit B between the anode chamber 1 and the second concentrating chamber 7 to the aspect of FIG. 2 described above (first unit A). One and two second units B). A third regenerative ion exchange membrane 15 is disposed between the second concentration chamber 7 of the second unit B and the third desalting chamber 6 of the added second unit B. Further, the ion exchange membrane that forms the partition wall between the second concentrating chamber 7 of the added second unit B and the anode chamber 1 has a cation exchange membrane to keep the anion component in the concentrating chamber 7. It is used. An ion exchange membrane that forms a partition wall between the first desalting chamber 3 and the cathode chamber 2 of the first unit A is provided with an anion exchange membrane for the purpose of supplying a regenerant similar to the first embodiment. Or a bipolar membrane is used.

  The treated water is passed through the one first concentrating chamber 4 and the two second concentrating chambers 7 from the same direction. The water to be treated passes through the first demineralization chamber 3 and the second demineralization chamber 5 sequentially in a different flow path, and then passes through the two third demineralization chambers 6 from the same direction.

  According to the present embodiment, as in the embodiment of FIG. 2, the second intermediate ion disposed at an intermediate position in one desalting chamber with respect to the adjacent second desalting chamber 5 and third desalting chamber 6. Two small desalting chambers formed by dividing one desalting chamber by the exchange membrane 12 can be used. The second intermediate ion exchange membrane 12 is an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane.

  Furthermore, in this embodiment, it is possible to eliminate the ion exchange membrane installed between the anode chamber 1 and the second concentration chamber 7 adjacent to the anode chamber 1 and combine them into one chamber.

(Fifth embodiment)
FIG. 9 is a schematic view showing an EDI apparatus according to the fifth embodiment.

  The EDI of this embodiment is obtained by adding another first unit A between the cathode chamber 2 and the first desalting chamber 3 to the EDI of the fourth embodiment shown in FIG. Yes (two first units A, two second units B). A first intermediate ion exchange membrane 11 is arranged between the first desalting chamber 3 of the first unit A and the second desalting chamber 5 of the added first unit A. Further, the ion exchange membrane forming the partition wall between the first desalting chamber 3 and the cathode chamber 2 of the added first unit A has an anion for the purpose of supplying a regenerant similar to the first embodiment. Exchange membranes or bipolar membranes are used.

  The treated water is passed through the two first concentrating chambers 4 and the two second concentrating chambers 7 from the same direction. In another flow path, the water to be treated passes through the two first demineralization chambers 3 from the same direction, and further passes through the two second demineralization chambers 5 from the same direction. Water is passed through the desalting chamber 6 from the same direction. Such a configuration also provides the same effects as those of the third embodiment shown in FIG. Further, similarly to the fourth embodiment, the anode chamber 1 and the second concentrating chamber 7 adjacent to the anode chamber 1 can be combined into one chamber.

(Sixth embodiment)
FIG. 10 is a schematic view showing an EDI apparatus according to the sixth embodiment.

  The EDI of this embodiment is provided with the first unit A and the second unit B of the mode shown in FIG. The second unit B includes a third desalting chamber 6, a second concentrating chamber 7, and a fourth desalting chamber 16, and the first unit A is disposed between the first unit A and the cathode chamber 2. Are arranged adjacent to the unit A. Therefore, as shown in FIG. 10, the second desalting chamber 5, the first concentrating chamber 4, the first desalting chamber 3, and the fourth desalting chamber 16 from the anode chamber 1 side toward the cathode chamber 2. The second concentration chamber 7 and the third desalting chamber 6 are arranged in this order. The first desalting chamber 3 of the first unit A and the fourth desalting chamber 16 of the second unit B are adjacent to each other through the second intermediate ion exchange membrane 12.

  However, in the embodiment described so far, the anion removal desalting chamber (first desalting chamber 3), the cation removing desalting chamber (second desalting chamber 5), and the anion removing desalting chamber (third The desalting chamber 6) and the cation removing desalting chamber (fourth desalting chamber 16) were deionized by flowing the water to be treated in this order. However, in this embodiment, the order is changed. Yes. That is, in this embodiment, the cation removing desalting chamber (second desalting chamber 5), the anion removing desalting chamber (first desalting chamber 3), and the cation removing desalting chamber (fourth desalting chamber). The water to be treated flows in the order of the chamber 16) and the anion removal desalting chamber (third desalting chamber 6). On the other hand, the flow of the concentrated water is the same as the form described so far, and the water to be treated flows into the first concentration chamber 4 and the second concentration chamber 7 together to become the concentrated water. The first concentrating chamber 4 and the second concentrating chamber 7 are connected in parallel so as to flow out.

  In the embodiment described so far, the water to be treated was sequentially passed through three demineralization chambers such as the anion exchanger demineralization chamber, the cation exchanger demineralization chamber, and the anion exchanger demineralization chamber. In the embodiment, a cation exchanger demineralization chamber is added to a stage preceding the first stage anion exchanger demineralization chamber. Therefore, the further improvement of the deionization processing capability is possible.

  In the present embodiment, the first unit A and the adjacent second unit B are shown one by one. However, the number of units is arbitrary, for example, the first unit A and this unit It is also possible to install two adjacent second units B.

  In addition, the order of flowing the water to be treated into each desalting chamber is reversed from the above order, that is, the anion removing desalting chamber (third desalting chamber 6) and the cation removing desalting chamber (fourth desalting chamber). The same effect can be obtained by flowing the water to be treated in the order of the salt chamber 16), the anion removing desalting chamber (first desalting chamber 3), and the cation removing desalting chamber (second desalting chamber 5). can get.

  Various embodiments have been described above, but any configuration other than the above embodiments can be used as long as the configuration includes the basic aspect of the apparatus shown in FIG.

  For example, the water flowing into each of the concentrating chambers 4 and 7 is not limited to the water to be treated because treated water or water flowing out of any desalting chamber (intermediate treated water) can be used in addition to the water to be treated. .

  Further, the water that passes through the concentration chambers 4 and 7 and becomes the concentrated water is not necessarily the same, and the water to be treated does not have to flow into and out of the concentration chambers 4 and 7 at the same time. It is sufficient that the first concentration chamber 4 and the second concentration chamber 7 are not connected by a serial flow path. That is, the first concentrating chamber 4 and the second concentrating chamber 4 are prevented from flowing into the other concentrating chamber from the concentrating water flowing out from one of the first concentrating chamber 4 and the second concentrating chamber 7. It is only necessary that an inflow line and an outflow line of water be provided in each of the concentration chambers 7.

[Example]
Next, the effects of the present invention will be examined in comparison with some examples and comparative examples.

  As an apparatus according to the present invention, EDI (Example 1) in the first embodiment shown in FIG. 5 and EDI (Example 2) in the sixth embodiment shown in FIG. 10 were prepared. As a comparative example to be compared with these, EDI (Comparative Example 1) having the same configuration as the apparatus shown in FIG. 5 except that the flow of concentrated water is changed in series, and the flow of concentrated water is changed in series in the same manner. Except for this, EDI (Comparative Example 2) having the same configuration as the apparatus shown in FIG. 10 was prepared. Using these, the effect of the present invention was confirmed. The EDIs of Comparative Example 1 and Comparative Example 2 are shown in FIGS. 11 and 12, respectively.

  In Example 1 (FIG. 5) and Comparative Example 1 (FIG. 11), the first regenerative ion exchange membrane 13 is a bipolar membrane, and the second desalting chamber 5 is adjacent to the anode chamber 1 through a cation exchange membrane. The third desalting chamber 6 is adjacent to the cathode chamber 2 via an anion exchange membrane.

  In both Example 1 and Comparative Example 1, the water to be treated is a deionization chamber for anion removal (first demineralization chamber 3) filled with an anion exchanger, and a cation removal deionization filled with a cation exchanger. Water is passed in this order through the salt chamber (second desalting chamber 5) and the anion removing desalting chamber (third desalting chamber 6) filled with the anion exchanger. However, regarding the concentrated water, in Example 1, the water to be treated before passing through the first desalting chamber 3 is simultaneously passed through the first concentrating chamber 4 and the second concentrating chamber 7. Then, the water is passed through the second concentration chamber 7 and the first concentration chamber 4 in this order.

  In Example 2 (FIG. 10) and Comparative Example 2 (FIG. 12), the second intermediate ion exchange membrane 12 is a bipolar membrane, and the second desalting chamber 5 is adjacent to the anode chamber 1 through the cation exchange membrane. The third desalting chamber 6 is adjacent to the cathode chamber 2 via an anion exchange membrane.

  In both Example 2 and Comparative Example 2, the water to be treated is a cation removing desalting chamber (second desalting chamber 5) filled with a cation exchanger, and an anion removing desiccation chamber filled with an anion exchanger. A salt chamber (first desalting chamber 3), a cation removing desalting chamber (fourth desalting chamber 16) filled with a cation exchanger, and an anion removing desalting chamber (filled with an anion exchanger) Water is passed through the third desalting chamber 6) in this order. However, with respect to the concentrated water, in Example 2, water to be treated is passed through the first concentration chamber 4 of the unit A and the second concentration chamber 7 of the adjacent unit B to the second desalting chamber 5 of the unit A. Although water is allowed to pass simultaneously, in Comparative Example 2, the water is passed through the second concentrating chamber 7 and the first concentrating chamber 4 in this order.

The specifications of the electric deionized water production apparatus in Examples 1 and 2 and Comparative Examples 1 and 2, the water flow rate, the specifications of the feed water, etc. are as follows. CER is an abbreviation for cation exchange resin, and AER is an anion exchange resin.
・ Anode chamber: dimension 300 × 80 × 5 mm CER filling ・ Cathode chamber: dimension 300 × 80 × 5 mm AER filling ・ First desalting chamber of Example 1 and Comparative Example 1: dimension 300 × 80 × 10 mm II type AER filling Example 1, second desalting chamber of comparative example 1: dimension 300 × 80 × 10 mm CER filling • Example 1, third desalting chamber of comparative example 1: dimension 300 × 80 × 30 mm AER filling Example 2, first desalting chamber of comparative example 2: dimensions 300 × 80 × 10 mm CER filling, Example 2, second desalting chamber of comparative example 2: dimensions 300 × 80 × 10 mm Type II AER filling / implementation Example 2, third desalting chamber of comparative example 2: dimensions 300 × 80 × 10 mm CER filling, Example 2, fourth desalting chamber of comparative example 2: dimensions 300 × 80 × 30 mm AER filling, each concentrating chamber : 300 x 80 x 5 mm AER filling / treatment water flow rate: 60 L / h
・ Flow rate of concentrated water: 20 L / h
・ Flow rate of electrode water: 10L / h
・ Supply water to desalination chamber (treated water): RO permeated water 15 ± 1 μS / cm
・ Water supplied to the concentration chamber: RO permeate 15 ± 1 μS / cm
-Supply water to the electrode chamber: pure water (<0.1 μS / cm)
-Applied current value: 2.5A
The apparatuses of Examples 1 and 2 and Comparative Examples 1 and 2 were operated for 2000 hours, and the treated water quality (treated water specific resistance, treated water silica concentration) and operating voltage were compared. In addition, after the operation was stopped, the device was disassembled and the presence or absence of scale generation in the concentration chamber was compared. The results are shown in Table 1.

  In Examples 1 and 2, compared with Comparative Examples 1 and 2, there was no significant difference in specific resistance value, but good treated water having a low silica concentration was obtained. This is because in Examples 1 and 2, no scale was generated in the concentration chamber, but in Comparative Examples 1 and 2, scale was generated in the concentration chamber. This is thought to be caused by the occurrence of crystallization. Actually, the operating voltages of Examples 1 and 2 were clearly higher than those of Comparative Examples 1 and 2.

DESCRIPTION OF SYMBOLS 1 Anode chamber, 2 Cathode chamber, 3 1st desalination chamber, 4 1st concentration chamber 5 2nd desalination chamber, 6 3rd desalination chamber, 7 2nd concentration chamber 8 1st anion exchange Membrane, 9 First cation exchange membrane 10 Second anion exchange membrane, 11 First intermediate ion exchange membrane 12 Second intermediate ion exchange membrane, 13 First regenerated ion exchange membrane 14 Second regenerated ion exchange membrane , 15 3rd regeneration ion exchange membrane 16 4th desalting chamber, 17 2nd cation exchange membrane A, A-1 1st unit, B 2nd unit P1, P2, P3, P4 flow path, Q1 , Q2, Q3 flow path

Claims (14)

An electric deionized water production apparatus in which a desalting chamber and a concentration chamber are arranged between an anode and a cathode, and an anode side and a cathode side of each chamber are partitioned by an ion exchange membrane,
A concentration chamber disposed between the anode and the cathode, in which cation components and anion components in the water to be treated containing hardness and silica are concentrated; a cation exchange membrane as an ion exchange membrane partitioning the anode side; A first concentration chamber having an anion exchange membrane as an ion exchange membrane separating the sides;
A first anion removal desalting chamber disposed adjacent to the cathode side of the first concentrating chamber and filled with at least an anion exchanger;
A first cation removing desalination chamber disposed adjacent to the anode side of the first concentrating chamber and filled with at least a cation exchanger;
A second anion disposed between the first cation removing desalting chamber and the anode or between the first anion removing desalting chamber and the cathode and filled with at least an anion exchanger. A desalting chamber for removal;
A second concentration chamber disposed adjacent to the anode side of the second anion removal desalting chamber and having an anion exchange membrane as an ion exchange membrane for partitioning the cathode side;
Contains
The first anion removal demineralization chamber, the first cation removal demineralization chamber, and the second anion removal demineralization chamber are such that water to be treated is the first anion removal demineralization chamber, Passing in order of the first cation removing desalting chamber and the second anion removing desalting chamber, or the first cation removing desalting chamber, the first anion removing desalting chamber, It is communicated in series so as to pass in the order of the second anion removal desalting chamber,
The first concentrating chamber and the second concentrating chamber so that the concentrated water flowing out from one of the first concentrating chamber and the second concentrating chamber does not become water flowing into the other concentrating chamber. An electric deionized water production apparatus characterized in that a water inflow line and an outflow line are formed in each of the chambers. Between the first anion removing desalting chamber and the cathode, the second anion removing desalting chamber and the second concentration chamber are provided,
The first anion-removing desalting chamber and the second concentrating chamber are supplied with a hydroxide ion for regenerating an anion exchanger as a regenerant to the first anion-removing desalting chamber. 2. The electric deionized water production apparatus according to claim 1, which is adjacent to each other through a regenerated ion exchange membrane. Two or more second units including the second anion removing desalting chamber and the second concentrating chamber are provided adjacent to each other between the first anion removing desalting chamber and the cathode. ,
The second anion removal demineralization chamber in one second unit and the second concentration chamber in the other second unit are transferred to the second anion removal demineralization chamber. 3. The electric deionized water production apparatus according to claim 1, wherein the apparatus is adjacent to each other through a second regenerative ion exchange membrane that supplies hydroxide ions that regenerate water as a regenerant. Two or more first units including the first anion removing desalting chamber, the first concentrating chamber, and the first cation removing desalting chamber are provided adjacent to each other;
The first cation removal desalting chamber in one of the first units is connected to another through an intermediate ion exchange membrane that is an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane. The electric deionization production apparatus according to any one of claims 1 to 3, wherein the apparatus is adjacent to the first anion removal demineralization chamber in the first unit. Between the first cation removing desalting chamber and the anode, the second anion removing desalting chamber and the second concentrating chamber are provided,
The second anion-removing desalination chamber is a first cation-removing desalination chamber through a second intermediate ion-exchange membrane that is an ion-exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane. The electric deionized water production apparatus according to claim 1, wherein Two or more second units including the second anion removing desalting chamber and the second concentrating chamber are provided adjacent to each other between the first cation removing desalting chamber and the anode. ,
The second concentration chamber in one of the second units and the second anion removal desalting chamber in the other second unit are transferred to the second anion removal desalting chamber. The electric deionized water production apparatus according to claim 5, which is adjacent to each other through a third regenerated ion exchange membrane for supplying hydroxide ions for regenerating water as a regenerant. Two or more first units including the first anion removing desalting chamber, the first concentrating chamber, and the first cation removing desalting chamber are provided adjacent to each other;
The first anion removal desalting chamber in one of the first units is connected to another through an intermediate ion exchange membrane that is an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane. The electric deionization production apparatus according to claim 1, wherein the electric deionization production apparatus is adjacent to the first cation removal demineralization chamber in the first unit. The second unit including the second anion removing desalting chamber and the second concentrating chamber includes a second cation removing desalting chamber filled with at least a cation exchanger, and The second cation removal desalting chamber is adjacent to the anode side of the second concentration chamber via a cation exchange membrane;
The first anion removal demineralization chamber, the first cation removal desalination chamber, the second anion removal demineralization chamber, and the second cation removal demineralization chamber are composed of water to be treated. Passing in order of the first anion removal desalting chamber, the first cation removing desalting chamber, the second anion removing desalting chamber, the second cation removing desalting chamber, or The first cation removing demineralization chamber, the first anion removing demineralizing chamber, the second cation removing demineralizing chamber, and the second anion removing demineralizing chamber pass in order. The electric deionized water production apparatus according to claim 1, wherein the electric deionized water production apparatus is connected to the electric deionized water. The second anion removing desalting chamber, the second concentrating chamber, and the second cation removing desalting chamber are provided between the first cation removing desalting chamber and the anode. Two or more second units are provided adjacent to each other,
The second cation removal desalting chamber in one second unit is connected to the other through a third intermediate ion exchange membrane which is an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane. The electric deionized water production apparatus according to claim 8, which is adjacent to the second anion removal demineralization chamber in the second unit. The second anion removing desalting chamber, the second concentration chamber, and the second cation removing desalting chamber are provided between the first anion removing desalting chamber and the cathode. A second unit is provided ,
Before SL desalting compartment first anion removal, through the fourth intermediate ion exchange membrane is an ion exchange membrane comprising at least one anion exchange membrane and a cation exchange membrane, wherein before the SL second unit first The apparatus for producing electric deionized water according to claim 8, which is adjacent to the cation removal demineralization chamber. The second anion removing desalting chamber, the second concentration chamber, and the second cation removing desalting chamber are provided between the first anion removing desalting chamber and the cathode. Two or more second units are provided adjacent to each other,
The second deionization chamber for removing anions in one second unit is connected to the other through a third intermediate ion exchange membrane that is an ion exchange membrane comprising at least one of an anion exchange membrane and a cation exchange membrane. 11. The electric deionized water production apparatus according to claim 8, wherein the apparatus is adjacent to the second cation removing demineralization chamber in the second unit.   The anion exchanger filled in the first anion removal desalting chamber is an anion exchanger having lower silica adsorption performance than the anion exchanger filled in the second anion removal desalting chamber. The electric deionized water production apparatus according to any one of claims 1 to 11, wherein the apparatus is an electric deionized water production apparatus. The anion exchanger filled in the first anion-removing desalting chamber is at least one of type II strong basic anion exchanger, medium basic anion exchanger, and weak basic anion exchanger. electrodeionization water producing apparatus according to any one of claims 1 1 2, characterized in that it comprises.   The electric deionized water production apparatus according to any one of claims 1 to 13, wherein the first concentration chamber and the second concentration chamber are filled with at least an anion exchanger.

Images