JP4869881B2 - Ion exchange apparatus and ion exchange method - Google Patents

Description

  The present invention relates to an ion exchange device and an ion exchange method using the ion exchange device. More specifically, the present invention is suitably used for producing pure water used for cleaning water for boiler feed water, electronic parts, and the like. The present invention relates to an ion exchange device and an ion exchange method using the ion exchange device.

  Typical examples of conventional ion exchange devices and ion exchange methods include a two-bed / three-column ion exchange device and a mixed bed ion exchange device. The two-bed / three-column ion exchange device includes, for example, a cation exchange column filled with a strongly acidic cation exchange resin, an anion exchange column filled with a strongly basic anion exchange resin, and a desorption placed between both of them. For example, after ion exchange of cations such as calcium ions, magnesium ions and sodium ions in the raw water with hydrogen ions of the strongly acidic cation exchange resin in the cation exchange tower using the downward flowing water of the raw water, In the acid, the carbonate ion is decarboxylated as carbon dioxide gas, and then the anion such as sulfate ion and chlorine ion in the raw water and silica are converted to the hydroxide ion and ion of the strongly basic anion exchange resin by the downward flowing water in the anion exchange tower. It is exchanged to produce pure water. When each of the ion exchange resins is regenerated, for example, a cocurrent regeneration system in which each regenerant is passed in the same direction as each regenerant, or each regenerant is passed through. There is a counter-current regeneration system that allows liquid to flow in the opposite direction.

  On the other hand, the mixed bed type ion exchange apparatus includes an ion exchange tower having a packed bed composed of a mixed ion exchange resin layer in which a strongly acidic cation exchange resin and a strongly basic anion exchange resin are mixed. High-purity pure water is produced by simultaneously exchanging cations and anions in raw water with high efficiency in an ion exchange tower with water. When each ion exchange resin is regenerated, the mixed ion exchange resin layer is backwashed and separated in the same column. Due to the specific gravity difference of each ion exchange resin, a strong basic anion exchange resin layer is formed in the upper layer and a strong acidity is formed in the lower layer. After forming the cation exchange resin layer, the respective regenerants are passed through each ion exchange resin layer to regenerate both ion exchange resins individually. This regeneration operation may be performed in the same column, or each ion exchange resin may be individually extracted in another column and may be individually regenerated in each column.

  However, in the case of the conventional two-bed / three-column ion exchange apparatus, the tower structure is a three-column structure including a cation tower, a decarbonation tower, and an anion tower. There was a problem that it would be expensive. On the other hand, in the case of a mixed bed type ion exchange apparatus, only one ion exchange tower is required and the apparatus itself can be reduced in size, but a strongly acidic cation exchange resin and a strongly basic anion exchange resin are mixed. Therefore, a so-called clamping phenomenon may occur in which both ion exchange resins adhere to each other to form a mixed resin lump. This mixed resin mass is difficult to completely separate by the backwash separation operation during regeneration, and the mixed resin mass is present in both the strongly acidic cation exchange resin layer and the strongly basic anion exchange resin layer after separation by the backwash separation operation. Therefore, even if the regeneration operation is performed, the mixed resin lump existing in each layer becomes defective in regeneration, or the mixed resin lump is reversely regenerated in each layer. When mixing operation is performed in this state, for example, a strongly acidic cation exchange resin reversely regenerated to the sodium type releases sodium, and a strongly basic anion exchange resin reversely regenerated to the chloride ion type releases the chloride ion type. However, these impurities released near the tower outlet are not removed, and the purity of the treated water is lowered.

  Even in the absence of such a clamping phenomenon, in a mixed bed type ion exchange apparatus, it is necessary to backwash and separate the mixed ion exchange resin layer before passing the regenerant, and after passing the regenerant, Since it is necessary to mix the ion exchange resin separated again, there is a problem that the regeneration process becomes complicated and the regeneration time and the amount of drainage increase. In the case of a mixed bed type, since the backwash separation operation is performed in the ion exchange tower in the regeneration step, the height of the tower becomes high because the space above which the ion exchange resin develops during backwashing is required in the upper layer of the packed bed, There was a problem that it was not always possible to reduce the size of the apparatus. In addition, when the regeneration operation is performed in a separate tower, a separate regeneration tower is required, and an increase in the size of the apparatus cannot be avoided.

  As an ion exchange device that prevents mixed ion exchange resin clamping, for example, there is also a multilayer ion exchange device in which a strongly basic anion exchange resin layer is laminated on a strongly acidic cation exchange resin layer and descending water flows. In the case of this device, the ion exchange resin on the upstream side gradually enters the ion exchange resin layer on the downstream side by passing water, so that the ion exchange resin that has entered the other resin layer during regeneration is reversely regenerated by the other regenerant. However, there was a problem that sufficient purity could not be obtained during water flow. If backwashing for separation is performed before regeneration in order to solve this problem, there are problems such as an increase in regeneration wastewater and downsizing of the apparatus as in the mixed bed type ion exchange tower. In addition, since both ion exchange resins are laminated in contact with each other, reverse regeneration due to the mutual regenerant occurs near the interface between both ion exchange resin layers, and there is a problem that sufficient purity cannot be obtained. It was.

Therefore, the apparatus can be made compact by using the ion exchange apparatus as one tower, and strongly acidic cations formed in the same tower in order to prevent the upstream ion exchange resin from entering the downstream resin layer. Ion exchange in which water to be treated is passed through each layer of the exchange resin layer and strongly basic anion exchange resin layer, and a regenerant is passed through each ion exchange resin layer in the direction opposite to the direction of water to be treated. An apparatus used in the method, wherein a partition plate is provided between the strongly basic anion exchange resin layer and the strongly acidic cation exchange resin layer, which allows the water to be treated to flow but prevents the flow of each ion exchange resin. There is known an ion exchange device configured as described above. In such an apparatus, in order to prevent silica leaks or reverse regeneration parts that occur during regeneration from affecting the quality of the treated water, the regenerant comes into contact with other resin layers during the regeneration of each ion exchange resin layer. In order to avoid this, the supporting water is made to flow in the other resin layer in the same direction or in the opposite direction with respect to the regenerant. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 10-137751

  However, when the partition plate is provided in this way to separate the resin and the regenerant inlet / outlet pipe is installed near the upper part of the partition plate, the regenerant inlet / outlet pipe is embedded in the upper ion exchange resin layer. Therefore, when the lower ion exchange resin layer is regenerated, the regenerant supplied from the regenerant inlet / outlet pipe reversely regenerates the ion exchange resin near the regenerator inlet / outlet pipe. There are problems in that sufficient purity cannot be obtained and ion exchange capacity decreases. On the other hand, when the inlet / outlet pipe of the regenerant is installed near the lower part of the partition plate, the influence on the upper ion exchange layer is reduced, but the treated water side of the upper part of the lower ion exchange layer is reversely regenerated. Therefore, the influence on the purity of the treated water is further increased. In order to prevent such reverse regeneration to the lower ion exchange resin when the regenerant is passed through the upper ion exchange layer, the regenerant is supplied to the upper ion exchange layer from the regenerant inlet / outlet pipe near the partition plate. At the same time as draining, the regenerant of the upper ion exchange resin layer reverses the lower ion exchange resin layer by passing ion exchange water as support water from the regenerant inlet / outlet pipe through the lower ion exchange resin layer from the bottom of the tower. There are ways to prevent playback. However, there is a gap in the vicinity of the lower part of the partition plate where the regenerant inlet / outlet pipe is arranged in consideration of the swelling of the ion exchange resin. For this reason, since the regenerant used during regeneration and supporting water cause turbulent flow in the space in the vicinity of the partition plate, the water in the space in the vicinity of the partition plate becomes a mixed layer in which the regenerant and water are mixed. . When this admixture layer also comes into contact with the ion exchange resin layer of the lower resin layer through which the regenerant does not pass, the lower resin layer is reversely regenerated. For this reason, the purity of the treated water may be reduced, or the ion exchange capacity may be reduced. In order to alleviate this, means for increasing the flow rate of the supporting water compared to the flow rate of the regenerant is taken, but there is a problem that the amount of drainage during regeneration increases.

  The present invention has been made to solve the above-described problems, and an ion exchange device capable of efficiently producing high-purity water without increasing the size of the ion exchange device or increasing the amount of drainage, and the ion exchange. An object of the present invention is to provide an ion exchange method using an apparatus.

  The ion exchange apparatus of the present invention is provided between two types of ion exchange resin layers, a cation exchange resin layer and an anion exchange resin layer formed by laminating in the same tower, and the two types of ion exchange resin layers. An ion exchange apparatus provided with a partition plate configured to prevent the flow of ion exchange resin, but provided with an inlet / outlet pipe of a regenerant near the upper portion of the partition plate. The entire inlet / outlet pipe of the agent is covered with a support material that does not retain the ion exchange capability.

  In addition, the ion exchange method of the present invention includes two types of ion exchange resin layers, a cation exchange resin layer and an anion exchange resin layer, which are formed by being laminated in the same tower, and the two types of ion exchange resin layers. Although the distribution of the water to be treated is allowed, a partition plate configured to block the flow of the ion exchange resin, an inlet / outlet pipe of the regenerant near the upper part of the partition plate, and the entire inlet / outlet pipe of the regenerant An ion exchange method using an ion exchange device comprising: a support material that does not retain the ion exchange capacity to cover, and a water flow step for passing water to be treated in an upward flow to each layer of the ion exchange resin layer, and each ion When alternately performing the regeneration step in which the regenerant is passed through the exchange resin layer in a descending flow, the water flow step and the regeneration step alternately, the regenerant is first passed through the upper layer and then the regenerant into the lower layer. Ascending circulating water flowing through and downflow regeneration It is characterized in that to perform.

  According to the ion exchange apparatus and the ion exchange method of the present invention, by covering the inlet / outlet pipe of the regenerant with the support material, it is possible to suppress the generation of the mixed layer caused by the turbulent flow caused by the other regenerant and the support water. By preventing reverse regeneration of the ion exchange layer on the side where the regenerant does not pass through the layer, high-purity water can be efficiently produced without increasing the size of the apparatus and increasing the amount of drainage.

  Here, as the cation exchange resin that can be used in the present invention, a strong acid cation exchange resin, a weak acid cation exchange resin, or a cation exchange resin obtained by mixing these can be used. An anion exchange resin, a weakly basic anion exchange resin, or an anion exchange resin obtained by mixing them can be used.

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. In addition, in each figure, FIGS. 1-2 is a conceptual diagram which shows embodiment of the ion exchange apparatus of this invention, respectively, FIG. 3 is a flow which shows the principal part of the pure water manufacturing apparatus to which the ion exchange apparatus shown in FIG. 1 is applied. FIG.

(First embodiment)
As shown in FIG. 1, the ion exchange apparatus 10 shown in FIG. 1 includes a tower body 11, an upper layer 12 formed of a strongly acidic cation exchange resin in the tower body 11, and a strong base in the tower body 11. A lower layer 13 made of anionic anion exchange resin, a partition plate 14 for partitioning the upper and lower layers 12 and 13 in the lateral direction, an inlet / outlet pipe 15 provided in the vicinity of the upper portion of the partition plate 14 in parallel therewith, and an inlet / outlet pipe And a support material 16 that does not retain the ion exchange capability covering the upper part 15 and is configured to perform upward flow water and downward flow regeneration.

  The strongly acidic cation exchange resin of the upper layer 12 is supported by the partition plate 14, and the strongly basic anion exchange resin of the lower layer 13 is supported by the second partition plate 17 provided in the lower part of the tower body 11 in parallel with the partition plate 14. It is supported. Therefore, since the strong acid cation exchange resin of the upper layer 12 is partitioned from the lower layer 13 by the partition plate 14, the strong acid cation exchange resin of the upper layer 12 is not mixed with the strongly basic anion exchange resin of the lower layer 13. Further, a slight gap is formed between the upper surface of the strongly basic anion exchange resin of the lower layer 13 and the partition plate 14 corresponding to the amount of swelling during regeneration. In addition, a third partition plate 18 is provided in the upper part of the tower body 11 in parallel with the partition plate 14, and the upper surface of the third partition plate 18 and the strong acid cation exchange resin layer 12 is a strongly basic anion exchange resin. Similarly, a slight gap corresponding to the amount that swells during reproduction is formed. In the present invention, the gap formed below each partition plate is a slight gap corresponding to the amount of swelling during reproduction as described above, and the meaning of the gap in each embodiment described later is also the same.

  In addition, each of the partition plates 14, 17, and 18 is formed by uniformly distributing a large number of communication means communicating the upper and lower spaces over the entire surface, and the water to be treated and the regenerant are circulated through these communication means, Each ion exchange resin and support material are configured so as not to circulate.

  The inflow pipe 11A into which the raw water flows is connected to the tower bottom of the tower body 11, the outflow pipe 11B of the treated water is connected to the top of the tower, and the raw water flows into the tower body 11 from the inflow pipe 11A. , The strongly basic anion exchange resin of the lower layer 13, the support material 16, and the strongly acidic cation exchange resin of the upper layer 12 are passed through the rising water in this order for ion exchange, and treated water from which impurity ions are removed flows out. It flows out of the tube 11B.

  Further, a second outflow pipe 11C from which the regeneration waste liquid of the strongly basic anion exchange resin in the lower layer 13 flows out is connected to the inflow pipe 11A at the bottom of the tower main body 11, and an acid regenerant is connected to the outflow pipe 11B at the top of the tower. Is connected to the second inflow pipe 11D. Further, an external pipe 15A is connected to the inlet / outlet pipe 15 in the tower body 11, and an alkali regenerant flows from the outer pipe 15A and is distributed and supplied to the entire strongly basic anion exchange resin in the lower layer 13 through the inlet / outlet pipe 15. In addition, the acid regeneration waste liquid from the strong acid cation exchange resin of the upper layer 12 is discharged from the external pipe 15A through the inlet / outlet pipe 15.

  Therefore, at the time of regeneration, the acid regenerant is supplied from the second inflow pipe 11D, flows into the top space of the tower body 11, and is dispersed throughout the upper surface of the strongly acidic cation exchange resin of the upper layer 12 through the third partition plate 18. Then, the upper layer 12 and the support material 16 are sequentially passed in a descending flow, and are discharged from the external pipe 15 </ b> A via the inlet / outlet pipe 15. Simultaneously with the injection of the acid regenerant, ion exchange water is supplied as support water from 11A, flows into the lower space of the tower body 11, and is dispersed on the entire lower surface of the strongly basic anion exchange resin of the lower layer 13 through the second partition plate 17. Then, the lower layer 13 and the support material 16 are sequentially passed in an upward flow, and are discharged from the external pipe 15 </ b> A simultaneously with the acid regenerant via the inlet / outlet pipe 15. Further, the alkali regenerant flows into the lowermost part of the support material 16 via the inlet / outlet pipe 15 and is dispersed throughout the upper surface of the strongly basic anion exchange resin of the lower layer 13 via the partition plate 14, and flows downward in the lower layer 13. The alkali regeneration waste liquid passes through the second partition plate 17 and is discharged from the second outflow pipe 11C.

  As the regeneration order, the strong acid cation exchange resin of the upper layer 12 positioned on the water flow outlet side is regenerated first, and the strong base anion exchange resin of the lower layer 13 positioned on the water flow inlet side is regenerated later. is there. Thus, the amount of impurity anions such as chloride ions in the treated water can be reduced by regenerating the strongly acidic cation exchange resin of the upper layer 12 on the water outlet side first. For example, when the strongly basic anion exchange resin as the lower layer 13 is regenerated first, the regenerating agent of the strongly acidic cation exchange resin as the upper layer 12 to be regenerated later has the greatest influence on the purity of the treated water. In the case where the regenerant is hydrochloric acid, the ionic form is partly changed to the chloride ion form. Accordingly, the chloride ions are gradually desorbed into the water flow, thereby increasing the amount of impurity anions in the treated water.

  However, when the upper layer 12 is regenerated first and the lower layer 13 is regenerated later, for example, a strongly basic anion exchange resin that has become a chloride ion type is subjected to chlorination as described above in order to regenerate the lower layer thereafter. The amount of the product ion type strongly basic anion exchange resin is reduced, and the amount of impurities in the treated water is reduced as compared with the above regeneration order. In the case where the upper layer 12 is regenerated first and the lower layer 13 is regenerated later, the strongly acidic cation exchange resin of the regenerated upper layer 12 is contacted with sodium hydroxide, which is the regenerant of the lower layer 13, and its ionic type. Will be partly sodium type, but this sodium type resin will be located in the lower layer (upstream side of the water flow) of the strongly acidic cutin exchange resin and will have little effect on reducing the conductivity of the treated water. Become.

  Further, in this embodiment, since the support material 16 is provided, the ion exchange resin of the upper layer 12 exists away from the inlet / outlet pipe 15 and is not easily affected by contamination of the regenerant of the ion exchange resin of the lower layer 13. It has become. Furthermore, since the vicinity of the inlet / outlet pipe of the regenerant is covered with a support material rather than a space, at the same time as the regenerant is discharged from the upper layer 12 to the external pipe 15A via the inlet / outlet pipe 15 when the ion exchange resin of the upper layer 12 is regenerated. 11A is supplied with ion-exchanged water as supporting water, flows into the lower space of the tower body 11, and is dispersed on the entire lower surface of the strongly basic anion exchange resin of the lower layer 13 through the second partition plate 17, and the lower layer 13 and the supporting material In the process of passing water 16 in an upward flow in order and discharging from the external pipe 15A simultaneously with the acid regenerating agent via the inlet / outlet pipe 15, the lower layer 13 is not mixed even if the flow rate of the supporting water is small. The ion exchange resin is not regenerated in reverse. The material of the support material used here is not particularly limited as long as it is a material that is not altered by the regenerant, and examples thereof include a support material made of a material that does not retain ion exchange ability such as glass and Teflon (registered trademark) resin. It is better that the shape is uniform, but it is not particularly limited to a spherical shape or a pellet shape. Particularly preferable support materials include, for example, uniform granular glass beads such as unibeads and unibeads super (above, trade name, manufactured by Union Co., Ltd.).

  In addition, the size of the support material may be as small as the ion exchange resin stacked in the same chamber does not enter the gap between the support materials. The size is preferably the same as that of the exchange resin. Specifically, the average particle diameter of the support material is preferably 0.3 to 2.0 mm, and particularly preferably 1.0 to 1.4 mm. Further, since the support 16 is in the same chamber as the strong acid cation exchange resin of the upper layer 12, even when a water flow operation, a regeneration operation, or the like is performed, the inlet / outlet pipe 15 is always covered and the strong acid cation of the upper layer is covered. It is preferable that the specific gravity of the exchange resin is heavier than that of the ion exchange resin so that the exchange resin does not directly contact the inlet / outlet pipe. The specific gravity is preferably 1.3 or more, and particularly preferably 2.5 or more.

  Next, the ion exchange method of the present invention using the ion exchange device 10 will be described. When the raw water is treated in the water flow process, the raw water flows up into the tower main body 11 from the inflow pipe 11A at the bottom of the tower, and the entire lower surface of the lower layer 13 made of a strongly basic anion exchange resin through the second partition plate 17. To disperse. The lower layer 13 is moved by a piston by the feed pressure of the raw water to come into contact with the partition plate 14 to form a fixed layer. In this state, while the raw water flows, anions such as sulfate ions and chloride ions in the raw water are strongly basic. Removed by anion exchange resin. Thereafter, the raw water is dispersed on the entire lower surface of the support material 16 via the partition plate 14, and, like the lower layer 13, the upper layer 12 made of a strong acid cation exchange resin moves and is fixed in contact with the third partition plate 18. In this state, cations such as calcium ions, magnesium ions, and sodium ions are removed by the strongly acidic cation exchange resin while the treated water after the removal of anions is passed through in this state. This treated water flows out from the outflow pipe 11B as high-purity pure water via the third partition plate 18, and is supplied to the next step.

  When each ion exchange resin reaches the flow-through point due to the raw water treatment, each ion exchange resin is regenerated in a regeneration step. For this purpose, first, the strongly acidic cation exchange resin of the upper layer 12 located on the water outlet side is regenerated countercurrently without backwashing each ion exchange resin layer. That is, for example, a hydrochloric acid aqueous solution is supplied as an acid regenerant in a downward flow from the second inflow pipe 11D at the top of the tower, and supporting water is supplied into the tower body 11 in an upward flow from the bottom of the tower. As a result, the acid regenerant is dispersed throughout the upper layer 12 via the second partition plate 18, and the acid regenerant passes through the entire upper layer 12 in a downward flow. During this flow, the strongly acidic cation exchange resin is regenerated. The During this time, since the supporting water is passed upward from the tower bottom, the supporting water prevents the acid regenerant from entering the lower layer 13. Then, the acid regeneration waste liquid merges with the supporting water in the inlet / outlet pipe 15 and is discharged from the external pipe 15A. After countercurrent regeneration of the strongly acidic cation exchange resin of the upper layer 12, pure water is supplied from the top of the tower instead of the acid regenerant, and water is passed from both the top and bottom of the tower body 11 to strongly acidify the upper layer 12. The cation exchange resin is extruded and washed, and the washing waste liquid is discharged from the inlet / outlet pipe 15 and the external pipe 15A.

  After the washing operation of the upper layer, the strongly basic anion exchange resin of the lower layer 13 located on the water inlet side is regenerated countercurrently. That is, for example, a sodium hydroxide solution is supplied as an alkali regenerator in a downward flow from the external pipe 15A in the straight body portion, and supporting water is supplied in a downward flow from the second inlet pipe 11D at the top of the tower into the tower body 11. As a result, the alkali regenerant flows from the inlet / outlet pipe 15 into the lowermost portion of the support member 16, joins with the support water, and passes through the partition plate 14 to the entire strongly basic anion exchange resin in the lower layer 13 in a downward flow. . While the alkali regenerant passes through the lower layer 13, the strongly basic anion exchange resin is efficiently regenerated by the alkali regenerator. When the counter-current regeneration operation of the strong basic anion exchange resin is completed, the pure water is continuously flowed down from the inlet / outlet pipe 15 to wash the strong basic anion exchange resin in the lower layer 13 and the regeneration operation is completed. After that, the water flow process and the regeneration process are repeated without performing a backwash operation, and the raw water is treated by an ion exchange reaction to produce pure water.

  In this regeneration operation, the regenerant and the support water generate turbulent flow at the junction, and form a mixed layer in which the regenerant and the support water are mixed. As this admixture layer becomes larger (thicker), the surrounding ion exchange resin cannot be sufficiently regenerated, or the other ion exchange resin (support water side) that is not targeted for regeneration is contaminated. Making it small (thin) is important in ion exchange resins that perform AC regeneration. In particular, when the upper layer 12 is regenerated, since the regenerant and the supporting water are in opposite directions, the admixed layer tends to become large due to the collision. In this embodiment, by providing the supporting material 16 By reducing the size of the admixture layer and promoting the regeneration of the surrounding ion exchange resin or preventing the contamination, the overall regeneration efficiency can be improved.

  Therefore, in this embodiment, without performing the back washing operation of both ion exchange resin layers after the end of water flow, the respective regenerants are added in the direction opposite to the direction in which the water to be treated is passed through both ion exchange resin layers. In order to perform so-called countercurrent regeneration, which passes through the liquid, it can be regenerated as it is without disturbing the ion-type arrangement formed in the ion exchange resin layer at the end of water flow, and the lowest layer remaining at the end of water flow The regenerative ion exchange resin can be effectively utilized and the regeneration efficiency can be improved.

  As described above, according to the present embodiment, the strongly acidic cation exchange resin and the strongly basic anion exchange resin are accommodated in one tower, so that the apparatus is compact compared with the conventional two-bed / three-column ion exchange apparatus. Can be

  In this embodiment, the strongly acidic cation exchange resin layer and the strongly basic anion exchange resin layer that are independent from each other in the same column are regenerated countercurrently, so that the water outlet side of each of the upper and lower ion exchange resins is always fresh. It is possible to regenerate with an appropriate regenerant, and the leakage of impurity ions to the treated water can be greatly reduced. In addition, the strongly acidic cation exchange resin and the strongly basic anion exchange resin are divided into upper and lower layers 12 and 13 by the partition plate 14 and are formed as individual ion exchange resin layers, respectively. As in the exchange apparatus, there is no regeneration failure due to clamping and no reverse regeneration portion remains in each of the layers 12 and 13, and consequently there is no leakage of impurity ions such as silica leaks, and high-purity treated water can be produced. .

  Further, according to the present embodiment, the raw water first comes into contact with the strongly basic anion exchange resin in an upward flow and is ion-exchanged in a slightly alkaline atmosphere, so that nonionic silica such as colloidal silica is dissolved by alkali. And can be efficiently removed in the form of ions. Moreover, since it is upward circulation water in this embodiment, the upper layer 12 is laminated | stacked on the partition material 14 in the state laminated | stacked on the support material 16 at the time of completion | finish of water flow, and the lower layer 13 is water flow in the state laminated | stacked. While the state of compaction at the time is gradually released, it descends to the partition plate 17. Further, in the regeneration process, it is regenerated in a state where it is supported by the respective partition plates 14 and 17, and each ion exchange resin layer is fixed to each partition plate 14 and 17 in a consolidated state even if the water flow process and the regeneration process are repeated. Therefore, it is possible to prevent an increase in pressure loss during water flow and liquid flow.

Furthermore, according to the present embodiment, the presence of the support material 16 makes it possible to suppress the mixed layer formed by the regenerant and the support water, thereby preventing contamination of the ion exchange resin in the regeneration operation. Thus, the regeneration can be performed reliably, and the regeneration efficiency as a whole can be improved, whereby the regeneration time can be shortened and the amount of wastewater discharged can be reduced.

  In the embodiment shown in FIG. 1, as shown in the flow of FIG. 3 to be described later, water to be treated in which raw water is subjected to reverse osmosis membrane treatment to remove most of hardness components such as calcium and magnesium in the raw water in advance. It is suitable when softened water or demineralized water obtained by treating raw water with a known ion exchange device is treated as water to be treated.

(Second Embodiment)
The ion exchange tower 20 shown in FIG. 2 is different from the case of the ion exchange apparatus 10 shown in FIG. 1 in that the vertical relationship between the strongly acidic cation exchange resin layer and the strongly basic anion exchange resin layer is reversed and each ion exchange resin. The type of the regenerant is also configured to perform upward flow water and counter flow regeneration in accordance with the ion exchange apparatus 10 of FIG. 1 except that the vertical relationship is changed in reverse. The reference numerals are also the same as in FIG.

  The support material 26 used here may be the same as that in the first embodiment, but has a higher specific gravity than the ion exchange resin because it is in the same chamber as the strong base anion exchange resin of the upper layer 22. It is preferable that The specific gravity is preferably 1.3 or more, and particularly preferably 2.5 or more.

  Next, an ion exchange method according to the present invention using the ion exchange device 20 will be described. When the raw water is treated in the water flow process, the raw water flows in an upward flow from the inflow pipe 21A at the bottom of the tower into the tower main body 21 and passes through the second partition plate 27 over the entire lower surface of the lower layer 23 made of a strongly acidic cation exchange resin. scatter. The lower layer 23 is moved by a piston due to the feed pressure of the raw water to come into contact with the partition plate 24 to form a fixed layer. In this state, cations such as calcium ions, magnesium ions and sodium ions in the raw water pass while the raw water passes through. It is removed by a strongly acidic cation exchange resin. Thereafter, the raw water is dispersed over the entire lower surface of the support member 26 via the partition plate 24, and the upper layer 22 made of this strongly basic anion exchange resin is moved in a piston manner to contact the third partition plate 28, as in the lower layer 23. In this state, the anion such as sulfate ion and chlorine ion and silica are removed by the strongly basic anion exchange resin while the treated water after removal of the anion is passed through. This treated water flows out from the outflow pipe 21B as high-purity pure water via the third partition plate 28, and is supplied to the next step.

  When each ion exchange resin reaches the flow-through point due to the raw water treatment, each ion exchange resin is regenerated in a regeneration step. For this purpose, first, the strongly basic anion exchange resin in the upper layer 22 located on the water outlet side is regenerated countercurrently without backwashing each ion exchange resin layer. That is, for example, an aqueous sodium hydroxide solution is supplied as an alkali regenerator in a downward flow from the second inflow pipe 21D at the top of the tower, and support water is supplied in an upward flow from the bottom of the tower into the tower body 21. As a result, the alkali regenerant is dispersed throughout the upper layer 22 via the second partition plate 28, and the alkali regenerant passes through the entire upper layer 22 in a downward flow. During this flow, the strongly basic anion exchange resin is regenerated. Is done. During this time, since the supporting water is passed in an upward flow from the bottom of the tower, the supporting water prevents the alkali regenerant from entering the lower layer 23. Then, the alkali regeneration waste liquid merges with the supporting water in the inlet / outlet pipe 25 and is discharged from the external pipe 25A. After countercurrent regeneration of the strongly basic anion exchange resin in the upper layer 22, pure water is supplied from the top of the tower instead of the alkali regenerant, and water is passed from both the top and bottom of the tower body 21 to strengthen the upper layer 22. Cleaning operation of the basic anion exchange resin is performed, and the cleaning waste liquid is discharged from the inlet / outlet pipe 25 and the outer pipe 25A.

  After the upper layer washing operation, the strongly acidic cation exchange resin in the lower layer 23 located on the water inlet side is regenerated countercurrently. That is, as an acid regenerating agent, for example, an aqueous hydrochloric acid solution is supplied in a downward flow from the external pipe 25A in the straight body portion, and supporting water is supplied in a downward flow from the top of the tower. As a result, the acid regenerant flows from the inlet / outlet pipe 25 to the lowermost part of the support member 26, joins with the support water, and passes through the partition plate 24 to the entire strongly acidic cation exchange resin in the lower layer 23 in a downward flow. While the acid regenerant passes through the lower layer 23, the strongly acidic cation exchange resin is efficiently regenerated. When the counter-current regeneration operation of the strong acid cation exchange resin is completed, the pure water is continuously flowed down from the inlet / outlet pipe 25, the strong acid cation exchange resin in the lower layer 23 is washed, and the regeneration operation is terminated. After that, the water flow process and the regeneration process are repeated without performing a backwash operation, and the raw water is treated by an ion exchange reaction to produce pure water.

  Therefore, according to the present embodiment, it is possible to expect the effect of the upward circulation water and the downward flow regeneration of the ion exchange device 10 shown in FIG. Furthermore, according to the present embodiment, the raw water is passed in the order of a strong acidic cation exchange resin and a strong basic anion exchange resin in an upward flow, and the raw water does not come into direct contact with the strong basic anion exchange resin. When treating raw water containing a large amount of hardness components such as magnesium ions in the raw water, these hardness components are removed by the strongly acidic cation exchange resin of the lower layer 23, and in the strongly basic anion exchange resin of the upper layer 22. No poorly soluble hydroxide such as magnesium hydroxide is produced.

  Further, the present invention described with reference to the first and second embodiments also has the following various effects exhibited by the conventional single tower type ion exchange device.

  (1) Since a strongly acidic cation exchange resin and a strongly basic cation exchange resin are packed in one tower, the number of towers can be minimized, the ion exchange apparatus can be made compact, and the installation cost and installation area can be reduced. It can be greatly reduced.

  (2) Even though both ion exchange resins are packed in one tower, without mixing both ion exchange resins as in the past, in order to perform water flow and regeneration while maintaining the laminated state of both ion exchange resins, In order to perform countercurrent regeneration without causing regeneration failure due to clamping phenomenon due to both ion exchange resins as occurs in conventional mixed bed ion exchangers, mixed bed ion exchangers are used for silica in treated water. Rather better. That is, in the mixed bed type ion exchange apparatus, since the ion exchange resin is mixed after the regeneration, the silica-type strongly basic anion exchange resin remaining by the regeneration is dispersed and averaged in the entire resin layer, and the treated water is Silica leak is determined by this averaged silica-type fraction, but since the present invention is countercurrent regeneration, the outflow side of the treated water is completely regenerated and the silica leak is extremely small.

  (3) When the laminated strong acid cation exchange resin and strong base anion exchange resin are regenerated, the regeneration operation itself is performed in an ideal state because countercurrent regeneration is performed without backwashing after passing water. It is possible to maximize the amount of H-type strongly acidic cation exchange resin or OH-type strongly basic anion exchange resin produced after regeneration per the amount of regenerant used, and to increase the processing capacity.

  (4) When regenerating the laminated ion exchange resin, when water is passed from the strongly acidic cation exchange resin to the strongly basic anion exchange resin, the strongly acidic cation exchange resin is regenerated after regenerating the strongly basic anion exchange resin. When the water is regenerated and water is passed from the strongly basic anion exchange resin to the strongly acidic cation exchange resin, both the ion exchange resins are coated such that the strong acid anion exchange resin is regenerated after the strong acid cation exchange resin is regenerated. Even if the regenerant of one ion exchange resin to be regenerated later comes into contact with the other ion exchange resin that has been regenerated earlier, it is regenerated in the reverse order of passing the treated water. Since the salt mold is located at the most upstream part, it is possible to prevent the purity of the treated water from being affected at all.

  (5) Even if water passage and regeneration are repeatedly performed by partitioning both ion exchange resins with a partition plate, stable ion exchange operation can be performed without mixing both ion exchange resins.

  Moreover, FIG. 3 shows the figure which applied the ion exchange apparatus 10 shown, for example in FIG. 1 to the pure water manufacturing apparatus as mentioned above. In the case of this pure water production device, the ion exchange device 10 is disposed downstream of the reverse osmosis membrane device 30 and the reverse osmosis membrane device 30 removes fine particles in the raw water and removes most of the hardness component. The permeated water is configured to flow into the ion exchange device 10. By disposing the ion exchange device 10 on the downstream side of the reverse osmosis membrane device 30 in this way, the ion exchange resin layer does not increase in pressure loss due to accumulation of fine particles, and further, a strongly basic anion exchange resin. Magnesium hydroxide or the like is not generated in the layer, and stable operation can be performed over a long period of time.

  By installing the reverse osmosis membrane device in this way, the water to be treated is treated by the reverse osmosis membrane device, and the ion exchange resin layer is accumulated by the accumulation of fine particles by the flow in which the permeated water is treated by the ion exchange tower used in the present invention. It can prevent obstacles such as an increase in pressure loss, and also generates precipitates such as magnesium hydroxide in the strong basic anion exchange resin layer even when the strong basic anion exchange resin is contacted first. In this way, high-purity treated water can be obtained.

  In addition, although not shown in figure, in processing the to-be-processed water containing calcium hydrogencarbonate or magnesium hydrogencarbonate, after processing to-be-processed water first with the dealkalization softening device which combined weakly acidic cation exchange resin and the decarbonation tower, It can also be processed in each ion exchange column of the present invention. When the water to be treated is passed through an H-type weakly acidic cation exchange resin, calcium ions and magnesium ions corresponding to the bicarbonate ions are ion-exchanged, and the bicarbonate ions become free carbonates. Therefore, most of the free carbonic acid can be removed by treating it with a decarboxylation tower. By adopting such a treatment method, hydrogen carbonate ions can be removed from the ion load of the ion exchange tower of the present invention, and pure water can be obtained at a lower cost. In addition, since the regeneration efficiency of the weakly acidic cation exchange resin is good, a regeneration waste solution obtained by regenerating the strongly acidic cation exchange resin in the ion exchange tower of the present invention can be used for the regeneration.

In addition, when two ion exchange apparatuses used in the present invention are installed, for example, the use efficiency of each ion exchange resin can be increased by operating by the merry-go-round method, and pure water can be produced continuously and efficiently.
3 illustrates the ion exchange device 10 disposed on the downstream side of the reverse osmosis membrane device 30, but the other ion exchange devices shown in FIG. 2 are also applied to the pure water production apparatus shown in FIG. can do.

It is a block diagram which shows one Embodiment of the ion exchange apparatus of this invention. It is a block diagram which shows other embodiment of the ion exchange apparatus of this invention. It is a flowchart which shows the principal part of the pure water manufacturing apparatus to which the ion exchange apparatus shown in FIG. 1 is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 ... Ion exchange apparatus, 11, 21 ... Tower body, 12, 22 ... Upper layer (ion exchange resin layer), 13, 23 ... Lower layer (ion exchange resin layer), 14, 24 ... Partition plate, 15, 25 ... In / out pipe, 16, 26 ... support material, 17, 27 ... second partition plate, 18, 28 ... third partition plate

Claims (3)

Two types of ion exchange resin layers, a cation exchange resin layer and an anion exchange resin layer formed by laminating in the same tower, and the flow of water to be treated provided between the two types of ion exchange resin layers are allowed. Is a partition plate configured to prevent the flow of the ion exchange resin, and an ion exchange device provided with an inlet / outlet pipe of the regenerant near the upper portion of the partition plate,
The upper layer of the ion exchange resin layer is made of a strongly basic anion exchange resin, and the lower layer is made of a strongly acidic cation exchange resin. The treated water is passed through each layer in an upward flow, and the regenerant is lowered to each ion exchange resin layer. When the flow of the water to be treated and the flow of the regenerant are alternately performed, the regenerant is first passed to the upper layer and then the regenerant to the lower layer. Ascending circulating water passed through, used for ion exchange by downflow regeneration,
The entire ion exchange tube of the regenerant is not covered with ion exchange capability, and has a specific gravity of 1.3 or more and is covered with a support material heavier than the ion exchange resin in the same chamber. .   The ion exchange apparatus according to claim 1, wherein the support material has an average particle diameter of 1.0 to 1.4 mm. Two types of ion exchange resin layers, a cation exchange resin layer and an anion exchange resin layer formed by laminating in the same tower, and the flow of water to be treated provided between the two types of ion exchange resin layers are allowed. However, the partition plate configured to prevent the flow of the ion exchange resin, the regenerant inlet / outlet pipe in the vicinity of the upper portion of the partition plate, without maintaining the ion exchange ability to cover the entire inlet / outlet pipe of the regenerant, An ion exchange method using an ion exchange apparatus comprising a support material having a specific gravity of 1.3 or more and heavier than the ion exchange resin in the same chamber,
The upper layer of the ion exchange resin layer consists of a strongly basic anion exchange resin, and the lower layer consists of a strongly acidic cation exchange resin ,
The water-flowing process comprises: a water-passing process for passing water to be treated through each of the ion-exchange resin layers in an upward flow; and a regeneration process for flowing a regenerant in a downward flow through each of the ion-exchange resin layers. When alternately performing the step and the regeneration step, the regenerating agent is first passed through the upper layer, and then each step is performed by ascending circulating water and descending flow regeneration for passing the regenerating agent to the lower layer. Ion exchange method.

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