JP6514851B2 - Deionized water production equipment - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a deionized water production apparatus, and more particularly to a deionized water production apparatus having a plurality of frames stacked one on another to form chambers through which liquid flows.

  Deionized water production apparatuses that remove ions in water by passing water through an ion exchanger, that is, deionize, are known (Patent Documents 1 to 3). An electric deionization water production apparatus is an apparatus combining electrophoresis and electrodialysis. The deionized water production apparatus has a deionization chamber, a concentration chamber adjacent to the deionization chamber, an anode chamber, and a cathode chamber. The deionization chamber and the concentration chamber are disposed between the anode chamber and the cathode chamber. The deionization chamber and the concentration chamber are each formed of a frame having an opening for containing an ion exchanger, and a pair of ion exchange membranes sandwiching the frame. These frames are stacked on one another in the direction of current flow.

In order to produce deionized water (hereinafter also referred to as treated water) by the deionized water production apparatus having the above-described configuration, a DC voltage is applied between the electrodes provided in the anode chamber and the cathode chamber. Pass water through the deionization chamber as it is. The ion exchanger in the deionization chamber captures the ionic components in the water. At the same time as the capture of the ionic component, the dissociation reaction of water occurs at the interface of the anion exchanger and the cation exchanger, and as a result, hydrogen ions and hydroxide ions are generated (H ₂ O → H ⁺ + OH ⁻ ). The ion component trapped in the ion exchanger is exchanged with this hydrogen ion and hydroxide ion and released from the ion exchanger. The liberated ionic component is again trapped on the ion exchanger. The ionic component moves toward the concentration chamber by the action of voltage while repeating the trapping on the ion exchanger and the liberation from the ion exchanger. The ion component transferred to the concentration chamber is discharged together with the concentrated water flowing through the concentration chamber.

  Patent Document 2 discloses adjusting the thickness of the deionization chamber from the viewpoint of controlling the hydrogen ion index (pH) of treated water. Patent Document 3 discloses a deionized water production apparatus having a second small demineralization chamber into which water to be treated flows and a first small deionization chamber into which water having passed through the second small deionization chamber flows. ing. The first small desalting chamber contains a mixture of cation and anion exchangers. The second small desalting chamber contains an anion exchanger. In Patent Document 3, in view of electrical resistance and current efficiency, it is preferable that the thickness of the first small deionization chamber is 0.8 to 8 mm, and the thickness of the second small deionization chamber is 5 to 15 mm. It suggests that there is.

JP, 2013-34920, A JP 2001-113281 A JP 2001-239270 A

  At present, in order to make the deionization treatment more efficient, the flow rate of water flowing into the deionization chamber is being increased. However, as the flow rate of water is increased, anion components, particularly carbonic acid components, which are poorly sequestered to the ion exchanger, can not be removed completely and remain in water.

  In order to improve the removal performance of the anion component, the time for which the anion component in water is in contact with the anion exchanger in the deionization chamber (hereinafter, may be simply referred to as "contact time") may be increased. For this purpose, it is conceivable to increase the thickness of the deionization chamber containing the anion exchanger, that is, the thickness of the frame. In the present specification, the thickness of the frame means the thickness in the stacking direction of the frame.

  The inventor of the present application has found a problem that when the thickness of the frame is increased, the shape accuracy of the frame may be reduced. If the accuracy of the shape of the frame, in particular the flatness of the surface of the frame, is reduced, unexpected gaps may occur between the frames. This can cause a problem that liquid in the room leaks from the gap formed between the frames.

  Therefore, it is desirable to improve the removal performance of the anion component by increasing the thickness of the deionization chamber containing the anion exchanger, and to obtain a deionization water producing device capable of suppressing the fluid leakage from the deionization chamber. .

  The deionized water production apparatus in one form comprises a plurality of frames and an ion exchange membrane. Each frame has an opening. The plurality of frames are stacked on one another. The ion exchange membrane is provided in some of the regions between the frames. The ion exchange membranes separate the openings of adjacent frames from one another to form a chamber through which the liquid passes. At least two of the plurality of frames are adjacent to one another such that the openings of the at least two frames jointly form a first deionization chamber. That is, the openings of the at least two frames are not separated by the ion exchange membrane. The first deionization chamber is filled with an anion exchanger.

  By forming one first deionization chamber with at least two frames instead of increasing the thickness of each frame, the thickness of the first deionization chamber can be maintained while maintaining the shape accuracy of the frames. It can be enlarged. Since the shape accuracy of the frames is maintained, leakage of liquid from between the stacked frames is suppressed. Moreover, the removal performance of the anion component in water can be improved by enlarging the thickness of the 1st deionization chamber with which the anion exchanger was filled.

  According to the present invention, the removal performance of the anion component can be improved, and the fluid leakage from the deionization chamber can be suppressed.

It is a typical sectional view of a deionized water manufacture device concerning a 1st embodiment. It is a typical disassembled perspective view of the deionization process part which concerns on 1st Embodiment, and the concentration chamber adjacent to a deionization process part. FIG. 3 (A) is a schematic plan view of a first deionization chamber frame, and FIG. 3 (B) is a schematic plan view of a second deionization chamber frame. It is a schematic plan view of a frame for concentration chambers. It is a typical sectional view of the deionization processing part concerning the 1st comparative example. The relation between the operation time of the deionized water production apparatus and the conductivity of the treated water is shown. The relationship between the operating time of a deionized water production apparatus and the carbonic acid removal rate is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The deionized water production apparatus according to the following embodiment relates to an electric deionized water production apparatus including a pair of electrodes to which a voltage is particularly applied.

  FIG. 1 is a schematic cross-sectional view of the deionized water production apparatus according to the first embodiment. The deionized water production apparatus 100 according to the present embodiment includes at least one deionization unit 108 and a plurality of concentration chambers 114. FIG. 2 is a schematic exploded perspective view of the deionization processing unit 108 and the concentration chamber 114 adjacent to the deionization processing unit 108. At least one deionization unit 108 and a plurality of concentration chambers 114 are disposed between the cathode chamber 116 and the anode chamber 118.

  In the present embodiment, the deionized water production apparatus 100 has three deionized treatment sections 108. Alternatively, the deionized water production system 100 may have one or more deionizers 108. The concentration chambers 114 may be disposed on both sides of each deionization unit 108. When a plurality of deionization units 108 are present, the concentration chambers are disposed between the deionization units 108 and between the deionization units 108 and the electrode chambers 116 and 118. Instead of the example shown in FIG. 1, the deionization processing unit 108 and the cathode chamber 116 may be adjacent to each other, and the deionization processing unit 108 and the anode chamber 118 may be adjacent to each other. That is, the deionized water production apparatus may not have the concentration chamber 114 between the cathode chamber 116 and the deionization processing unit 108 and between the anode chamber 118 and the deionization processing unit 108.

  Each deionization unit 108 may have a first deionization chamber 110 and a second deionization chamber 112. The first deionization chamber 110 is adjacent to the second deionization chamber 112. A concentration chamber 114 is disposed on the side opposite to the second deionization chamber 112 of the first deionization chamber 110. Further, another concentration chamber 114 is disposed on the opposite side of the second deionization chamber 112 to the first deionization chamber 110.

  Each of the above-described chambers 110, 112, 114, 116, 118 is disposed between the plurality of frames 130, 132, 134, 136, 138 stacked on one another and the frames 130, 132, 134, 136, 138 The ion exchange membranes 120, 122, 124, 126, 128 are formed. Each frame 130, 132, 134, 136, 138 has an opening 160 for forming each chamber 110, 112, 114, 116, 118. Specifically, a space partitioned from the outside is formed by closing the opening formed in the frame with a pair of ion exchange membranes. This partitioned space forms each of the above-mentioned chambers. In the cathode chamber 116 and the anode chamber 118, each chamber may be formed by closing the opening formed in the frame with the ion exchange membrane and the end plates 136 and 138.

  End plates 104 and 106 are provided outside the frames 136 and 138 forming the cathode chamber 116 and the anode chamber 118. The end plates 104 and 106 press the laminated body which consists of several frame 130, 132, 134, 136, 138 laminated | stacked mutually from the both sides. The end plates 104, 106 may be fastened together, for example by bolts.

  The deionized water production apparatus 100 according to this embodiment includes a frame 136 for a cathode chamber, a frame 134 for a concentration chamber, a frame 130 for a first deionization chamber, and a second deionization chamber And a frame 138 for the anode chamber. A first ion exchange membrane 120 is provided between the concentration chamber frame 134 and the second deionization chamber frame 132. The first ion exchange membrane 120 separates the opening 160 of the concentration chamber frame 134 from the opening 160 of the second deionization chamber frame 132 from each other. The first ion exchange membrane 120 may be, for example, a cation exchange membrane.

  A second ion exchange membrane 122 is provided between the first deionization chamber frame 130 and the concentration chamber frame 134. The second ion exchange membrane 122 separates the opening 160 of the second concentration chamber frame 134 from the opening 160 of the first deionization chamber frame 130. The second ion exchange membrane 122 may be, for example, an anion exchange membrane. As described above, the first ion exchange membrane 120 disposed on the cathode side of the deionization unit 108 is a cation exchange membrane, and the second ion exchange membrane disposed on the anode side of the deionization unit 108 Preferably, 122 is an anion exchange membrane.

  A third ion exchange membrane 124 is provided between the first deionizing chamber frame 130 and the second deionizing chamber frame 132. The third ion exchange membrane 124 may be, for example, a bipolar membrane. The bipolar membrane is an ion exchange membrane in which an anion exchange membrane and a cation exchange membrane are joined together and integrated. The bipolar membrane is characterized in that the dissociation reaction of water is greatly promoted at the interface between the anion exchange membrane and the cation exchange membrane. It is preferable that the anion exchange membrane of the bipolar membrane faces the first deionization chamber 110 side. Thereby, a rise in the operating voltage of the deionized water production apparatus 100 can be suppressed. As a result, the durability to operation at high current is improved.

  The openings 160 of the concentration chamber frame 134 disposed between the deionization units 108 adjacent to each other are closed by the first ion exchange membrane 120 and the second ion exchange membrane 122. The opening 160 of the concentration chamber frame 134 disposed between the deionization processing unit 108 and the cathode chamber 116 is closed by the first ion exchange membrane 120 and another ion exchange membrane 126. Further, the opening 160 of the concentration chamber frame 134 disposed between the deionization processing unit 108 and the anode chamber 118 is closed by the second ion exchange membrane 122 and another ion exchange membrane 128. There is.

  An ion exchanger is filled in the first and second deionization chambers 110 and 112. Preferably, an anion exchanger is filled in the first deionization chamber 110. The anion exchanger may be packed in a single bed form in the first deionization chamber 110. Anion exchangers capture the anion component in water. Preferably, the second ionizing chamber 112 is filled with a cation exchanger. The cation exchanger may be packed in a single bed form in the second deionization chamber 112. Cation exchangers capture the cationic component in water. A cation exchange resin and an anion exchange resin can be used as a cation exchanger and an anion exchanger, respectively.

  A first supply passage 142 which allows liquid to flow into the second deionization chamber 112 is in communication with the second deionization chamber 112. The liquid flowing out of the second deionization chamber 112 is preferably introduced into the first deionization chamber 110 through the first discharge path 152, the intermediate path 159 and the second supply path 140. The liquid flowing into the first deionization chamber 110 is discharged to the outside through the second discharge passage 150. The liquid discharged to the outside through the second discharge path 150 is the treated water deionized in the first and second deionized chambers 110 and 112.

  The water to be treated flowing into the second deionization chamber 112 may be water which has permeated the two-stage reverse osmosis membrane (RO membrane) 102, and may be decarbonated water or softened water. May be. Instead of this, the water to be treated flowing into the second deionization chamber 112 may be water which has permeated through the RO membrane of one stage, may be water which has not been decarbonated, or may be water which has not been softened. In this case, the liquid flowing into the second deionization chamber 112 may be permeated water that has permeated through the RO membrane of one stage.

  The liquid is applied to the first and second deionization chambers 110 and 112 in a state where a DC voltage is applied between the cathode plate 117 installed in the cathode chamber 116 and the anode plate 119 installed in the anode chamber 118. Passed through. The ion exchanger in the deionization chamber 110, 112 captures the ion component in the liquid. At the same time as the capture of the ion component, a water dissociation reaction occurs at the interface of the ion exchanger, and as a result, hydrogen ions and hydroxide ions are generated. The ion component trapped in the ion exchanger is exchanged with this hydrogen ion and hydroxide ion and released from the ion exchanger. The liberated ionic component is again trapped on the ion exchanger. The ionic component moves into the concentration chamber 114 by the action of voltage while repeating the trapping on the ion exchanger and the liberation from the ion exchanger.

  Concentrated water is supplied to each concentration chamber 114 through a supply passage 144 for the concentration chamber. The concentrated water having passed through the concentration chamber 114 is discharged through the concentration chamber discharge path 154. The ion component transferred from the deionization chamber 110, 112 to the concentration chamber 114 is discharged to the outside together with the concentrated water. An anion exchanger is preferably packed in a single bed form in each concentration chamber 114 in order to suppress the generation of scale.

  Electrode water (anode water or cathode water) is supplied to the cathode chamber 116 and the anode chamber 118. These electrode waters generate hydrogen ions and hydroxide ions by electrolysis near the electrodes. In order to reduce the electrical resistance of the deionized water production apparatus 100, it is preferable that the cathode chamber 116 and the anode chamber 118 be filled with an ion exchanger, respectively. Specifically, the cathode chamber 116 is preferably filled with an anion exchanger in a single bed form, and the anode chamber 118 is preferably filled with a cation exchanger in a single bed form.

  In the present embodiment, the two frames 130 are adjacent to each other such that the openings 160 of the two frames 130 jointly form the first deionization chamber 110. In other words, no ion exchange membrane is provided between these two frames 130. Alternatively to this embodiment, the three frames may be adjacent to one another such that the openings of the at least three frames together form a first deionization chamber.

  The thickness of the first deionization chamber 110 is increased without increasing the thickness of each frame 130 by the openings 160 of at least two of the frames 130 jointly forming one chamber (first deionization chamber). Can be increased. Since it is not necessary to increase the thickness of the single frame 130, the shape accuracy of the frame 130 can be improved. In particular, by maintaining the flatness of the surface of the frame 130 at a high level, the frames 130 adjacent to each other are in close contact with each other. Thereby, the leakage of the liquid from between at least two frames 130 forming the first deionization chamber 110 is suppressed.

  In addition, since the thickness of the first deionization chamber 110 filled with the anion exchanger can be increased, the contact time in which the anion component in water, particularly the carbonate component, contacts the anion exchanger can be lengthened. Thereby, the removal rate of the anion component in water improves.

  The second deionization chamber 112 containing the cation exchanger mainly removes the cation component in the water. The cationic component in water, particularly the hardness component such as calcium component and magnesium component, may precipitate as magnesium hydroxide or calcium carbonate, particularly in the alkaline region. In order to suppress the precipitation of these cation components, it is preferable to flow water into the second deionization chamber 112 that accommodates the cation exchanger, before the first deionization chamber 110 that accommodates the anion exchanger. In particular, the hydrogen ion index (pH) of the water in the second deionization chamber 112 containing the cation exchanger is neutral to acidic due to the hydrogen ions generated in the water dissociation reaction proceeding in the bipolar membrane 124. Has shifted to Therefore, the cation component in water can be removed while suppressing the precipitation of the hardness component. As a result, it is possible to prevent the occurrence of scale caused by calcium component and magnesium component.

  The deionized water production apparatus 100 may have one or more reverse osmosis membranes 102 upstream of the deionization chambers 110 and 112. In addition, the deionized water production apparatus 100 may be provided with a separate carbon dioxide removal facility for removing the carbonic acid component in water upstream or downstream of the deionization chambers 110 and 112. Thereby, before the raw water flows into the deionization chamber 110, 112, it is possible to reduce the ion component and the carbonic acid component in the raw water.

  In the deionized water production apparatus 100 according to this embodiment, as described above, the removal efficiency of the anion component in water, in particular, the carbonate component is improved. Thus, there may not be a separate carbon dioxide removal facility upstream or downstream of the deionization chamber to remove carbonic acid in the water. Furthermore, since precipitation of the hardness component can be suppressed, the two-stage RO film may be replaced with a single-stage RO film, and the softening device may not be installed.

  Each frame 130, 132, 134, 136, 138 is preferably formed from a plastic material, in particular an injection moldable plastic material. A frame made of an injection molded plastic material changes due to heat contraction after injection molding. The larger the size of the frame, in particular the thickness of the frame, the more the frame is deformed by this heat shrinkage. Therefore, the prevention of liquid leakage by suppressing the increase in thickness of each frame is particularly significant for a frame made of an injection moldable plastic material.

  The thickness of each frame 130, 132, 134, 136, 138 is in the range of 4 to 15 mm from the viewpoint of forming the frames 130, 132, 134, 136, 138 having high flatness by injection molding. Is preferred. Even in this case, the thickness of the first deionization chamber 110 can be made 15 mm or more by the openings 160 of at least two frames 130 jointly forming one first deionization chamber 110. it can. The thickness of the first deionization chamber 110 may be, for example, in the range of 15 to 30 mm. From the viewpoint of the manufacturing accuracy of the plurality of frames 130, 132, 134, 136, 138 stacked on one another, the thickness of the plurality of frames 130, 132, 134, 136, 138 is 1000 mm or less. preferable.

  FIG. 3 is a schematic plan view of a frame for a deionization chamber. FIG. 3A shows a frame 130 for a first deionization chamber. FIG. 3B shows the frame 132 for the second deionization chamber. FIG. 4 is a schematic plan view of a frame 134 for a concentration chamber.

  Each frame 130, 132, 134 may be comprised of a plate having a substantially rectangular opening 160 formed therein. First to sixth through holes 161 to 166 are formed around the opening 160 of each frame 130, 132, 134. In addition, the annular gasket which surrounds the opening 160 or through-hole 161-166 of each frame 130, 132, 134 may be provided. The gasket improves the function of preventing the liquid from leaking from the inside of the opening 160 or the through holes 161-166.

  The first through holes 161 of the frames 130, 132, 134 communicate with each other to form a second supply passage 140. The second through holes 162 of the frames 130, 132, 134 communicate with each other to form a first supply passage 142. The third through holes 163 of the frames 130, 132, 134 communicate with each other to form a second discharge path 150. The fourth through holes 164 of the frames 130, 132, 134 communicate with each other to form a first discharge passage 152. The fifth through holes 166 of the frames 130, 132, 134 communicate with each other to form a supply passage 144 for supplying a liquid into the concentration chamber. The sixth through holes 165 of the frames 130, 132, 134 communicate with each other to form a discharge passage 154 for discharging the liquid from the concentration chamber.

  The frame 130 for the first deionization chamber has a groove 180 for communicating the first through hole 161 with the opening 160 in order to introduce the liquid from the second supply passage 140 into the first deionization chamber 110. Have. In addition, the frame 130 for the first deionization chamber is a groove that causes the opening 160 to communicate with the third through hole 163 in order to discharge the liquid from the inside of the first deionization chamber 110 to the second discharge path 150. It has 181.

  The frame body 132 for the second deionization chamber has a groove 182 for communicating the second through hole 162 with the opening 160 in order to introduce the liquid from the first supply passage 142 into the second deionization chamber 112. Have. In addition, the second deionization chamber frame 132 is a groove connecting the opening 160 to the fourth through hole 164 in order to discharge the liquid from the second deionization chamber 112 to the first discharge path 152. It has 183.

  The concentration chamber frame 134 has a groove 185 communicating the fifth through hole 166 with the opening 160 in order to introduce the liquid from the concentrated water supply path 144 into the concentration chamber 114. Further, the concentration chamber frame 134 has a groove 184 for connecting the opening 160 to the sixth through hole 165 in order to discharge the liquid from the concentration chamber 114 to the concentrated water discharge path 154.

  As described above, the frames 130, 132, and 134 may have the same shape as each other except for the shapes of the grooves 180 to 185. Further, the frame 136 for the cathode chamber and the frame 138 for the anode chamber may have the same shape as the above-mentioned frame. However, the frame in the vicinity of the end plates 104 and 106 may not need the supply passages 140, 142 and 144 or the discharge passages 150, 152 and 154. In this case, those frames may not have through holes corresponding to the supply or discharge paths.

  Preferably, at least two of the frames 130 forming the first deionization chamber 110 have the same shape as one another. Specifically, the shapes of the openings 160, the through holes 161 to 166, and the grooves 180 and 181 formed in the at least two frames 130 for the first deionization chamber are identical to each other, and the first deionization is performed. The thickness of the at least two frames 130 for the ion chamber may be identical to one another. Thereby, the at least two frames 130 for the first deionization chamber can be molded with the same mold.

  In each frame 130, 132, 134, 136, 138, a central member 170, 172, 174 in which an opening 160 is formed, a peripheral member in which grooves 180 to 185 and through holes 161 to 166 are formed (central member 170, Parts other than 172 and 174) may be composed of separate parts. In this case, the frames 130, 132, 134, 136, 138 are formed by attaching the peripheral members to the central member.

  At least two of the plurality of frames 130, 132, 134, 136, 138 may have the same shape as each other except for the peripheral members. Specifically, the thickness of each frame and the shape of the opening of each frame are preferably identical to each other. Thereby, at least the central member of the frame can be formed into the same shape. As a result, in particular the central part of at least two frames can be molded with the same mold. If a plurality of frames can be manufactured with a common mold, the manufacturing cost of the deionized water manufacturing apparatus can be reduced. In one example, the frame 130 for the first deionization chamber may have the same shape as the frame 132 for the second deionization chamber, except for the peripheral members. In another example, the frame 130, 132 for the first or second deionization chamber has the same shape as the frame 134, 136, 138 for the concentration chamber, the cathode chamber or the anode chamber except for the peripheral members. It may be.

  If the number of frames 130, 132, 134, 136, 138 stacked on one another is too large, even if the frames are pressed by the end plates 104, 106, the pressing force does not act evenly on each frame, and from within the room Liquid may leak. Therefore, it is preferable to set an upper limit on the number of frame bodies stacked one on another from the viewpoint of preventing the liquid from leaking from the room. Hereinafter, experimental results on liquid leakage will be described for the deionized water production apparatus according to the first embodiment and the deionized water production apparatus according to the second embodiment.

  The first and second embodiments have the same configuration as the deionized water production apparatus shown in FIG. However, in both embodiments, the number of deionization units 108 is different from each other. Table 1 shows the number of deionization units 108, the number of first deionization chambers 110, the number of second deionization chambers 112, the number of concentration chambers 114, and the number of cathode chambers for the first and second embodiments. The number 116, the number of anode chambers 118 and the total number of frames 130, 132, 134, 136, 138 are shown. It should be noted that in both embodiments, the first deionization chamber 110 is composed of two frames 130.

  In both embodiments, the shapes of the frames 130, 132, 134, 136 and 138 are identical to each other. The length in the vertical direction of each frame is 450 mm, the length in the horizontal direction of each frame is 280 mm, and the thickness of each frame is 10 mm. The longitudinal length of the opening 160 of each frame is 300 mm, and the lateral length of the opening 160 is 150 mm.

  A laminated body in which a plurality of frames 130, 132, 134, 136, and 138 are stacked on one another is pressed together by the end plates 104 and 106. In addition, the first and second deionization chambers 110 and 112, the concentration chamber 114, the cathode chamber 116 and the anode chamber 118 were filled with water, and the second discharge passage 150 and the discharge passage 154 for concentrated water were closed. Then, a water pressure of 0.6 MPa was applied to the respective chambers from the first supply passage 142 and the supply passage 144 for concentrated water. In this state, the deionized water production apparatus was maintained for 30 minutes.

  When the total number of frames was 75 (first example), no water leak from each room was detected. On the other hand, when the total number of frames was 83 (second example), a leak of 23 mL of water per hour was detected. Therefore, the total number of frames constituting the deionized water production apparatus may be preferably 80 or less, more preferably 75 or less. However, the upper limit of the number of frames may vary depending on the size of the frames, the experimental conditions, and the like. Therefore, it should be noted that the present invention is not necessarily limited to the above upper limit value.

  In order to improve the throughput of treated water per unit time, it is advantageous to increase the flow rate of the liquid flowing into the deionization chambers 130 and 132. However, as the flow rate of the liquid increases, the deionization performance may be degraded. In order to suppress the decrease in the deionization performance, it is preferable to increase the contact time to the ion exchanger contained in the deionization chamber by increasing the thickness (volume) of the deionization chamber.

  The inventor of the present application has found that the deionization performance of the deionization chamber containing the anion exchanger drops more than the deionization performance of the deionization chamber containing the cation exchanger when the flow rate of the liquid increases. Discovered that. Here, as described above, there may be an upper limit on the total number of frames 130, 132, 134, 136, 138 stacked on one another. Therefore, it is preferable to make the thickness of the first deionization chamber 110 containing an anion exchanger larger than the thickness of the second deionization chamber 112 containing a cation exchanger. Preferably, the thickness of the first deionization chamber 110 in the stacking direction of the frame is in the range of 1.5 times to 3 times the thickness of the second deionization chamber 112. More preferably, as described in detail below, the thickness of the first deionization chamber 110 in the stacking direction of the frame is twice the thickness of the second deionization chamber 112. Thereby, the deionization performance of the anion component by the deionization chamber which accommodates an anion exchanger can be improved, maintaining the deionization performance of the cation component by the deionization chamber which accommodates a cation exchanger.

  Hereinafter, experimental results on the deionization performance of the deionized water production apparatus according to the first embodiment and the deionized water production apparatus according to the first comparative example will be described. The deionized water production apparatus in the first embodiment has eighteen deionization units 108.

  The deionized water production apparatus according to the first comparative example has the same configuration as that of the deionized water production apparatus according to the first embodiment except for the configuration of the deionized water treatment unit. FIG. 5 is a schematic cross-sectional view of a deionization treatment unit provided in the deionized water production apparatus according to the first comparative example. The deionization processing unit 708 of the first comparative example has a first deionization chamber 710 and a second deionization chamber 712. In the deionization processing unit 708 of the first comparative example, the first deionization chamber 710 and the second deionization chamber 712 are each formed of one frame body 730 732.

  In both the first embodiment and the first comparative example, the third ion exchange membranes 124, 724 disposed between the first deionization chamber 110, 710 and the second deionization chamber 112, 712 are bipolar. It is a membrane. In both the first embodiment and the first comparative example, the ion exchange membranes 122 and 722 of the first deionization chamber 110 and 710 on the opposite side to the third ion exchange membranes 124 and 724 are anion exchange membranes. In both the first embodiment and the first comparative example, the ion exchange membranes 120 and 720 on the side opposite to the third ion exchange membrane 124 and 724 of the second deionization chamber 112 and 712 are cation exchange membranes. In both the first embodiment and the first comparative example, the first deionization chamber 110, 710 accommodates the anion exchanger in a single bed form, and the second deionization chamber 112, 712 comprises a single bed of cation exchanger. Contain in form.

  Table 2 shows the number of deionization units 108 and 708, the number of first deionization chambers 110 and 710, and the number of second deionization chambers 112 and 712 for the first example and the first comparative example. , The number of concentration chambers, the number of cathode chambers, the number of anode chambers and the total number of frames. It should be noted that in the first embodiment, the first deionization chamber 110 is composed of two frames 130.

  As described above, in consideration of the existence of the upper limit value in the number of frame bodies, the total number of frame bodies in the first embodiment and the first comparative example is made to coincide with each other. In the first comparative example, the shape of each frame is the same as the frame in the first embodiment. That is, the length in the vertical direction of each frame is 450 mm, the length in the horizontal direction of each frame is 280 mm, and the thickness of each frame is 10 mm. The longitudinal length of the opening of each frame is 300 mm, and the lateral length of the opening is 150 mm.

For the first embodiment and the first comparative example, the flow rate of the water to be treated flowing into the deionization chambers 110, 112, 710, and 712 was 3600 L / h. The flow rate of the concentrated water flowing into the concentration chamber was 360 L / h. The flow rate of the electrode water flowing into the cathode chamber and the anode chamber was 20 L / h, respectively. Further, the current value applied between the cathode plate installed in the cathode chamber and the anode plate installed in the anode chamber was 2.5A. The water to be treated flowing into the deionization chamber is water which has permeated the RO membrane 102 of one stage. Just before flowing into the second deionization chamber 112, 712, the conductivity of the water to be treated is 8 μS / cm, the carbonation concentration is 10 mg CO ₂ / L, the hardness concentration is 1 mg CaCO ₃ / L, and the sodium concentration Was 1 mg Na / L.

  Table 3 shows the fluid flow space velocity throughout the first deionization chamber and the fluid flow space velocity across the second deionization chamber under the above conditions. Here, the water passage space velocity is defined by the flow velocity of the liquid divided by the volume of the chamber. The reciprocal of the space water flow rate in a certain chamber means the contact time to the ion exchanger filled in the certain chamber. In the first embodiment, the volume of the first deionization chamber 110 is twice the volume of the second deionization chamber 112. Therefore, the water passage space velocity in the first deionization chamber 110 is 1/2 of the water passage space velocity in the second deionization chamber 112.

  FIG. 6 is a graph showing the relationship between the operating time of the deionized water production apparatus and the conductivity of the treated water discharged through the deionization chamber. FIG. 7 shows a graph showing the relationship between the operation time of the deionized water production apparatus and the carbonic acid removal rate of the treated water. When the deionized water production apparatus was operated for about 500 hours or more, in the deionized water production apparatus in the first comparative example, the conductivity of the treated water increased and the carbon dioxide removal rate of the treated water decreased. On the other hand, in the deionized water production apparatus according to the first embodiment, the conductivity of the treated water was substantially constant, and the carbonic acid removal rate of the treated water also maintained a substantially constant value. As described above, in the deionized water production apparatus of the first embodiment, it is possible to improve the carbonic acid removal rate while suppressing the decrease in the removal rate of the ionic component.

Incidentally, looking at Table 3 above, the water passing space velocity of the fluid in the second deionization chamber in the first embodiment is based on the water passing space velocity of the fluid in the second deionization chamber in the first comparative example. It is getting bigger. Therefore, in the deionized water production apparatus of the first embodiment, the contact time to the cation exchanger is smaller. Nevertheless, the deionized water production apparatus in the first example exhibited the same removal performance of cationic components as the deionized water production apparatus in the first comparative example. It is believed that this is due to the fact that the deionization performance of the deionization chamber containing the cation exchanger does not decrease as much as the flow rate increases. Therefore, the flow passage space velocity of the fluid in the first deionization chamber 110 is made relatively small from the viewpoint that the upper limit value may exist in the total number of the frame members, that is, the thickness of all the frame members, and the second deionization It is preferable to make the water flow space velocity of the fluid in the chamber 112 relatively large. Preferably, the fluid passage space velocity of the fluid in the first deionization chamber 110 is 150 to 300 h ⁻¹ and the fluid passage velocity of the liquid in the second deionization chamber 112 is 300 to 600 h ⁻¹ . It may be. More preferably, the flow through space velocity of the fluid in the second deionization chamber 112 is twice the flow through space velocity of the liquid in the first deionization chamber 110. These water passage space velocities can be adjusted by the flow rate of the liquid flowing into the deionization chambers 110 and 112 and the volume ratio of the first deionization chamber 110 to the second deionization chamber 112.

As described above, the deionized water production apparatus according to the present embodiment may not have a separate decarbonation facility to improve the carbon dioxide removal rate. The deionized water production apparatus according to the present embodiment can also perform decarboxylation of water having a carbonate concentration of 3 mg CO ₂ / L to ₂₀ mg CO ₂ / L. In addition, the deionized water production apparatus according to the present embodiment may preferably have one RO membrane. Deionized water producing apparatus according to this _embodiment, it is possible to perform the de-ionized water having a hardness concentration of 0.5mgCaCO ₃ / L~2mgCaCO 3 / L.

  Furthermore, the deionized water production apparatus of the present embodiment may not have an ion exchange membrane between at least two frames 130 forming the first deionized chamber 110. Therefore, the number of ion exchange membranes can be reduced. Since the ion exchange membrane is generally expensive, the deionized water production apparatus of this embodiment is also advantageous from the viewpoint of production cost.

  Although the preferred embodiments of the present invention have been presented and described in detail, it is understood that the present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the invention. I want to be

DESCRIPTION OF SYMBOLS 100 Deionization water production apparatus 108 Deionization process part 110,112 Deionization chamber 114 Concentration chamber 116 Cathode chamber 118 Anode chamber 120, 122, 124, 126, 128 Ion exchange membrane 130, 132, 134, 136, 138 Frame body

Claims (10)

A plurality of frames, each having an opening, formed from an injection moldable plastic material and laminated to each other;
An anode disposed at one end of the plurality of frames along the stacking direction of the plurality of frames;
A cathode disposed at the other end of the plurality of frames along the stacking direction;
An ion exchange membrane provided in some of the regions between the frames and separating the openings of adjacent frames from one another to form a chamber through which the liquid passes;
The chamber includes a chamber constituting a deionization processing unit, and a concentration chamber disposed on both sides in the stacking direction across the deionization processing unit,
At least two frames of the plurality of frames are adjacent to each other so that the openings of the at least two frames jointly form one first deionization chamber that constitutes the deionization treatment unit. Yes,
The first deionization chamber is filled with an anion exchanger,
The thickness of the frame is in the range of 4 to 15 mm,
The deionized water producing apparatus, wherein a thickness of the first deionization chamber along the stacking direction is 15 mm or more, and is larger than a thickness of the concentration chamber along the stacking direction.   The deionized water production apparatus according to claim 1, wherein the at least two frames forming the first deionized chamber have the same shape. The deionization processing unit includes the first deionization chamber and a second deionization chamber adjacent to the first deionization chamber.
The deionized water production apparatus according to claim 1 or 2 , wherein the second deionized chamber is filled with a cation exchanger. In the deionization processing unit, the ion exchange membrane disposed on the side opposite to the second deionization chamber of the first deionization chamber is an anion exchange membrane,
The said ion exchange membrane arrange | positioned on the said deionization process part on the opposite side to the said 1st deionization chamber of the said 2nd deionization chamber is a cation exchange membrane of Claim 3 which is a cation exchange membrane. Ion water production equipment. Wherein the deionization unit, having the second is to channel flow into the outflow liquid to the first deionization chamber deionized chamber, deionized water producing apparatus according to claim 3 or 4. The ion exchange membrane that separates the first deionization chamber and the second deionization chamber in the deionization processing unit is a bipolar membrane in which a cation exchange membrane and an anion exchange membrane are joined to each other,
The deionized water production apparatus according to any one of claims 3 to 5 , wherein the anion exchange membrane of the bipolar membrane faces the first deionization chamber side. The thickness of the first deionization chamber in the stacking direction, the a second range 1.5 times to 3 times the thickness of the deionization compartment, in any one of claims 3 6 Deionized water production apparatus as described. The water passing space velocity of the first deionization chamber liquid is 150~300h ^-1, water passing space velocity of liquid in the second deionization compartment is 300~600h ^-1, claim 3 The deionized water production apparatus according to any one of 7 . A plurality of frames, each having an opening, formed of an injection moldable plastic material and stacked on each other, and an anode disposed at one end of the plurality of frames along the stacking direction of the plurality of frames And a cathode disposed at the other end of the plurality of frames along the stacking direction, provided in some of the regions between the frames adjacent to form a chamber through which the liquid passes And a method of deionizing a liquid using a deionized water production apparatus having an ion exchange membrane for separating the openings of the frame from each other,
The chamber includes a chamber constituting a deionization processing unit, and a concentration chamber disposed on both sides in the stacking direction across the deionization processing unit,
At least two frames of the plurality of frames are adjacent to each other so that the openings of the at least two frames jointly form one first deionization chamber that constitutes the deionization treatment unit. Yes,
The first deionization chamber is filled with an anion exchanger,
The thickness of the frame is in the range of 4 to 15 mm,
The thickness of the first deionization chamber along the stacking direction of the plurality of frames is 15 mm or more, and is larger than the thickness of the concentration chamber along the stacking direction,
The first flow rate of liquid in the first deionization chamber is 150 to 300 h ^-1 and the flow rate of liquid in the second deionization chamber is 300 to 600 h ^-1 . A method comprising flowing a liquid through the first and second deionization chambers. A plurality of frames, each having an opening, formed of an injection moldable plastic material and stacked on each other, and an anode disposed at one end of the plurality of frames along the stacking direction of the plurality of frames And a cathode disposed at the other end of the plurality of frames along the stacking direction, provided in some of the regions between the frames adjacent to form a chamber through which the liquid passes And an ion exchange membrane for separating the openings of the frame from each other, wherein the chamber is a chamber disposed in the deionization processing section, and a concentration disposed on both sides in the stacking direction across the deionization processing section. A method of producing a deionized water production apparatus, comprising:
At least two frames of the plurality of frames are adjacent to each other so that the openings of the at least two frames jointly form one first deionization chamber that constitutes the deionization treatment unit. ,
Filling the first deionization chamber with an anion exchanger;
The thickness of the frame is in the range of 4 to 15 mm, the thickness of the first deionization chamber along the stacking direction is 15 mm or more, and the thickness of the concentration chamber along the stacking direction is larger Method for producing deionized water production apparatus.

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