JP3963032B2 - Ion exchange device and polishing filter - Google Patents

Description

【００４７】
比較例１としてポリッシングフィルタ１１ａ、１１ｂを取付けない場合は、Ｎａリーク量０．５ｍｇ／ｌ、電気伝導率０．５ｍＳ／ｍであったが、ポリッシングフィルタ１１ａ、１１ｂを取付けた実施例１ではＮａリーク量０．０５ｍｇ／ｌ、電気伝導率０．０５ｍＳ／ｍとなった。
【図面の簡単な説明】
【図１】実施形態のイオン交換装置の系統図である。
【図２】実施形態のポリッシングフィルタの断面図である。
【符号の説明】
１ａ 陽イオン交換塔
１ｂ 陰イオン交換塔
２ａ 陽イオン交換樹脂層
２ｂ 陰イオン交換樹脂層
３ａ、３ｂ フリーボード
４ａ、４ｂ、６ａ、６ｂ、２３、２４ ストレーナ
５ａ、５ｂ、７ａ、７ｂ 支持板
８ａ、８ｂ 被処理液入口配管
９ａ、９ｂ 被処理液路
１０ａ、１０ｂ 洗浄排液路
１１ａ、１１ｂ ポリッシングフィルタ
１２ａ、１２ｂ 処理液出口配管
１３ａ、１３ｂ 処理液路
１４ａ、１４ｂ 洗浄水路
１５ａ、１５ｂ 薬注路
１６ａ、１６ｂ 排液路
１７ 脱炭酸塔
２０ ケーシング
２１、２２ 接続部
２５ａ、２５ｂ 樹脂層
２６ 隔壁
２７、２８ フランジ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a countercurrent regeneration type ion exchange device, and more particularly to an ion exchange device with a polishing filter and a polishing filter.
[0002]
[Prior art]
In ion exchange devices such as pure water devices and softening devices, counter-current regeneration type ion exchange devices in which the flow direction during ion exchange and the flow direction of regenerant during regeneration are reversed are regenerated with a small amount of regenerant. Widely used as a device that can. In such a countercurrent regenerative ion exchange apparatus, raw water is flowed from top to bottom, the regenerant is flown from bottom to top, and raw water is flowed from bottom to top, and the regenerant is flown from top to bottom. There are two types. In either case, the purity of the treated water is likely to decrease because the resin layer is disturbed when the liquid passing direction changes during ion exchange and regeneration.
[0003]
In other words, in the counter-current regeneration type, in which the raw water is flowed downward from above, the ion exchange resin layer receives the upward force of the regenerant flow during regeneration, so the ions at the bottom (treated water outlet side) The exchange resin is lifted and a gap is formed in the lower part. In particular, when the ion exchange resin comes into contact with the regenerant regardless of ionicity, the gap becomes larger because it contracts due to osmotic pressure.
[0004]
For this reason, when the flow of the regenerant stops after the regeneration, the ion exchange resin may be fluidized, and the ion exchange resin of the intermediate portion or more that is not sufficiently regenerated may be mixed into the lower resin layer. Thus, if a resin that is not sufficiently regenerated is mixed into the ion exchange resin layer on the treated water outlet side, the purity of treated water at the time of ion exchange decreases.
[0005]
As countermeasures, ( i ) a method of supplying lift-down water for pressing the ion exchange resin downward after regeneration, ( ii ) a method of filling the ion exchange resin as densely as possible to prevent gaps, etc. have been implemented. Yes.
However, in the above method ( i ) , since water flows in the direction opposite to regeneration and extrusion, the cleaning effect of the ion exchange resin is deteriorated, and a valve for supplying lift-down water is necessary and controlled. The relationship becomes complex and water consumption increases. In the method ( ii ) , problems such as an increase in the differential pressure and difficulty in discharging the inflowing turbidity occur.
[0006]
In addition, in the method of ion exchange by flowing raw water in an upward flow from the bottom, the ion exchange resin layer receives the upward force of the raw water flow during water flow, so the ion exchange resin at the bottom (raw water inlet side) is lifted A gap is formed in the lower part. In particular, in the case of a strong acid or strongly basic ion exchange resin, an ion exchange reaction occurs and contracts by contact with raw water, so that the gap becomes large.
[0007]
Therefore, when the operation is stopped in the middle of water sampling, the ion exchange resin settles downward and fluidizes, and the ion exchange resin below the intermediate part that is not sufficiently regenerated is sufficiently regenerated. May be mixed into the exchange resin layer. In this way, when a resin in which the ion exchange resin layer on the treated water outlet side is not sufficiently regenerated is mixed, the purity of the treated water at the time of ion exchange decreases.
[0008]
Conventionally, as described above, ( i ) a method of supplying lift-down water for pressing the ion exchange resin downward when the operation is stopped, and ( ii ) filling the ion exchange resin as densely as possible so as not to generate a gap. Methods are implemented.
However, in this case as well, in the case of the downward flow, the method ( i ) requires a valve for supplying the lift-down water, which complicates the control relationship and increases the amount of pure water used. Further, in the method ( ii ) , problems such as an increase in differential pressure, difficulty in discharging the inflowing turbidity, and an increase in cracking of the ion exchange resin occur.
[0009]
On the other hand, in the combination of a cation exchange tower-decarbonation tower-anion exchange tower-cation exchange tower-anion exchange tower as in a 4-bed 5-tower pure water apparatus, An apparatus for regenerating countercurrent by passing a regenerant through a positive or anion exchange column in the previous stage is known, and it is said that high-purity deionized water can be obtained with a small amount of regenerant used.
[0010]
However, such an apparatus requires two columns each for cation or anion exchange resin, each of which requires valves, piping, and a control system, making the apparatus larger and more complex, and also complicated to operate and control. There are problems such as becoming.
[0011]
[Problems to be solved by the invention]
The problem of the present invention is that, with a simple apparatus and operation, the ion-exchange resin is not densely packed in the tower, thereby allowing the resin to be cleaned by developing the resin without increasing the differential pressure, and with little regeneration. It is to obtain an ion exchange apparatus capable of obtaining a high-purity ion exchange treatment liquid with a drug amount.
The second object of the present invention is to obtain a polishing filter for an ion exchange device that can be attached to an ion exchange tower to form the ion exchange device described above and can be attached to a conventional ion exchange device.
[0012]
[Means for Solving the Problems]
The present invention provides the following ion exchange device and polishing filter.
(1) and a cation exchange column packed with a cation-exchange resins to have a freeboard,
An anion exchange tower packed with an anion exchange resin so as to have a free board;
A small amount of resin of the same type as the resin packed in the cation exchange column or anion exchange column is packed tightly between the double strainers, and the treatment solution outlet side port of each cation exchange column and anion exchange column First and second polishing filters attached to the pipes ;
The cation exchange column and the anion exchange column are respectively passed through the first and second polishing filters in an upward flow or a downward flow for ion exchange, and a regenerant is passed in the opposite direction. And an ion exchange device having a piping system provided for regeneration .
(2) A polishing filter used as the first or second polishing filter of the ion exchange device according to (1 ) above ,
A casing having a connection to the treatment liquid outlet side pipe of the ion exchange tower;
A polishing filter for an ion exchange device, comprising: a cation exchange resin layer or an anion exchange resin layer closely packed between double strainers provided in the casing.
[0013]
Ion exchanger of the present invention is one used in JunmizuSo 置等, cation exchange column packed with a cation exchange resin, and having an anion exchange column packed with an anion exchange resin.
[0014]
These cation exchange column and anion exchange column are filled with a cation or anion exchange resin so as to have a free board (backwash space). The free board is preferably about 1/5 to 1/20 of the cation or anion exchange resin layer. This cation or anion exchange tower has the same structure as that conventionally used for pure water equipment, softening equipment, etc., and has strainers on the inflow side and outflow side of raw water so that it can be passed through the resin layer. And Already it is also possible to use existing cation or anion exchange column that is used as a cation or anion exchange column as cation or anion exchange column of the present invention.
[0015]
The above cation or anion exchange column in the present invention, so that each perform a counter-current regeneration, ion exchange and passed through the liquid to be treated in upflow or downflow process liquid flow during ion exchange A piping system is provided so as to perform regeneration by passing the regenerant in the reverse direction, that is, downward flow or upward flow. That is, when performing ion exchange upwardly flowing water, subjected to downward flow regeneration, when the ion exchange downward circulation water to perform reproduction upflow, cation exchange column and an anion exchange column Pipes are provided at the upper and lower parts of each . In both cases of upward circulating water and upward flow regeneration, water and liquid flow are performed at such a flow rate that a fixed bed is formed by pressing at least a part of the resin layer on the upper side of the cation exchange column and anion exchange column. Configured as follows.
[0016]
In the present invention, the ion exchange treatment liquid is taken out from the cation exchange column and the anion exchange column as described above, and the first and second polishing filters are attached to the respective pipes into which the regenerant is injected. The polishing filters used as the first and second polishing filters are provided in the casing having the connection portions on both sides connected to the treatment liquid outlet side pipes of the cation exchange column and the anion exchange column. A double strainer provided to face each other is provided, and a cation or anion exchange resin is closely packed between the double strainers.
[0017]
As the ion exchange resin, the same kind of resin as that filled in the positive or negative ion exchange column is filled. That is, when packed with a cation exchange resin to the cation exchange column packed with the same cation exchange resin, when filled with an anion exchange resin to the anion exchange column and an anion exchange resin. Cation or anion exchange resin amount to fill the polishing filter 1 / 10-1 / 50 cation or anion exchange resin quantity charged into positive or negative ion exchange column, preferably of the order of 1 / 20th to / 30 Capacity.
[0018]
The structure of the strainer is not limited as long as it allows liquid to pass through, but a strainer having a low liquid passing resistance is used. The resin is densely packed between double strainers so that no gap is formed and the resin does not flow when the resin contracts. A buffer material such as a sponge may be provided to absorb the change in the volume of the resin. The liquid passing direction of the resin layer and the installation direction of the polishing filter are arbitrary. The thickness of the resin layer in the liquid passing direction is 5 to 30 cm, preferably about 10 to 20 cm. In this resin layer, the flow area of the strainer is determined so that the liquid flow speed is 5 to 50 times, preferably 10 to 20 times the liquid flow speed in the positive or anion exchange column.
[0019]
The above-mentioned polishing filter is attached so as to be inserted into the respective treatment liquid outlet side pipes of the cation exchange column and the anion exchange column to form an ion exchange device. In this ion exchange device, a regenerant (acid or alkali in the case of a deionized water device or salt in the case of a softening device) is passed through a polishing filter in an upward or downward flow through a cation exchange column and an anion exchange column. Regeneration is performed, and ion exchange is performed by passing the liquid to be treated in the reverse direction.
[0020]
In this case, since the entire amount of the regenerant is passed through the polishing filter with respect to the total amount of the cation exchange resin or anion exchange resin, the polishing filter is completely regenerated. Since then regenerant is liquid passage from each treatment liquid outlet cation exchange column and an anion exchange column, the resin layer of the treatment liquid outlet side is reproduced in a state close to complete regeneration, as opposite regeneration incomplete state It becomes.
[0021]
When ion exchange is performed by passing in the opposite direction after regeneration, the liquid to be treated is subjected to ion exchange treatment by passing through the resin layer from the inlet side if there is no disturbance of the resin layer by switching the liquid passing direction. It flows out as a high-purity treatment liquid on the outlet side. However, when the resin layer moves due to the reversal of the liquid passing direction, the resin layer is partially disturbed, so that a part of the incompletely regenerated resin may be mixed into the resin layer on the outlet side of the treatment liquid.
[0022]
In this case, ions leak from the incompletely regenerated portion on the outlet side, and the purity of the processing solution is lowered. In the present invention, the treatment liquid having such a lowered purity removes ions leaked when passing through the polishing filter, thereby obtaining a high-purity ion exchange treatment liquid. Since there is no disturbance of the resin layer in the polishing filter, there is no decrease in purity due to ion leakage. The disturbance of the resin layer in the cation exchange column and an anion exchange column can be minimized by a freeboard in the range, cationic Therefore using polishing filter having a resin layer of small volume It becomes possible to remove leaked ions in each of the exchange column and the anion exchange column.
[0023]
As described above, in the present invention, by installing a polishing filter on each treatment liquid side of the cation exchange column and the anion exchange column, the cation exchange resin or the anion exchange resin in the column expands, and the column outlet Even if the treated water purity decreases, the polishing filter can increase the purity, so that it is not necessary to densely fill the resin in the cation exchange column and the anion exchange column, and the increase in the differential pressure can be eliminated. . In addition, since the density is not filled, the development rate of backwashing of the resin can be increased, so that the discharge by backwashing of turbidity flowing into the cation exchange resin layer and the anion exchange resin layer is improved.
[0024]
Cation and anion exchange resins are filled in the polishing filters, for contacting the first and regenerant to regenerate the resin cation or anion exchange tower during reproduction, respectively, will be in contact with the high purity regenerant, Further, since the amount of cation or anion exchange resin in the polishing filter is small compared to the amount of resin in the tower, the regeneration level is increased, and thus the purity of the treated water is improved. Since the amount of extrusion water after regeneration is also large relative to the amount of filled resin, there is no need to worry about residual regenerant.
[0025]
Since the polishing filter of the present invention is attached to the front piping of the cation or anion exchange column and does not require a valve, it can be easily attached to an existing apparatus for use. A valve is not required, but a simple shut-off valve can be provided for repair, inspection, etc.
[0026]
【The invention's effect】
In the ion exchange apparatus of the present invention, a small amount of a cation or anion exchange resin is provided on each treatment solution outlet side of a cation exchange column and an anion exchange column filled with a cation or anion exchange resin so as to have a free board. Since the densely packed polishing filter is installed, it is possible to clean the resin by spreading the cation or anion exchange resin closely in the tower without increasing the differential pressure by simple equipment and operation. And a high-purity ion exchange treatment liquid can be obtained with a small amount of the regenerant.
[0027]
In the polishing filter of the present invention, since the cation or anion exchange resin is closely packed between the double filters in the casing, it can be easily attached to the cation and anion exchange tower to form the above ion exchange apparatus. And a polishing filter for an ion exchange device that can be attached to an existing ion exchange device.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system diagram of a pure water apparatus according to an embodiment, and FIG. 2 is a cross-sectional view of a polishing filter.
[0029]
FIG. 1 shows a counter-current regeneration type pure water apparatus in which ion exchange is carried out with downward circulating water to perform upward flow regeneration, 1a is a cation exchange tower, 1b is an anion exchange tower, The cation exchange resin layer 2a and the anion exchange resin layer 2b are formed so as to leave the free boards 3a and 3b in the tower by filling the cation exchange resin and the anion exchange resin, respectively. The free boards 3a and 3b have a capacity of 1/5 to 1/20 of the positive and anion exchange resin layers 2a and 2b. Support plates 5a and 5b having strainers 4a and 4b and support plates 7a and 7b having strainers 6a and 6b are provided on the upper and lower portions of the ion exchange towers 1a and 1b to support the resin layers 2a and 2b. .
[0030]
Ion exchange column 1a, the top of 1b have the liquid to be treated inlet pipe 8a, 8b are provided, the pump P _1a, respectively, P _1b, the valve V _1a, the liquid to be treated path 9a with a V _1b, 9b; and valves Cleaning drainage channels 10a and 10b having V _2a and V _2b are connected. Treatment liquid outlet pipes 12a and 12b having polishing filters 11a and 11b are provided below the ion exchange towers 1a and 1b, and treatment liquid paths 13a and 13b having valves V _3a and V _3b ; pumps P _2a and P drain path having and valve V _6a, a V _{6b; 2b,} the valve V _4a, washing water passage 14a having a V _4b, 14b; pump P _3a, P _3b, the valve V _5a, Kusurichuro 15a having a V _5b, 15b 16a and 16b are connected. The processing liquid path 13a and the liquid path 9b to be processed communicate with each other via the decarbonation tower 17.
[0031]
As shown in FIG. 2, the polishing filters 11a and 11b are provided in a cylindrical casing 20 having connection portions 21 and 22 connected to the treatment liquid outlet pipes 12a and 12b at both ends, and a double cylinder concentric with the casing 20. A resin layer that is densely filled with 1/10 to 1/50 of the ion exchange resin of the resin layers 2a and 2b between the strainers 23 and 24 provided in a shape. 25a and 25b are formed. A partition wall 26 is provided so as to oppose the upstream connection portion 21, whereby a flow path is formed in the order of the connection portion 21, the strainer 23, the resin layers 25 a and 25 b, the strainer 24, and the connection portion 22. Flanges 27 and 28 for connecting to the processing liquid outlet pipes 12a and 12b are formed in the connection parts 21 and 22, respectively. The lid 29 integrated with the connecting portion 21 is fixed to the flange 30 of the casing 20 with bolts 31. The partition wall 26 is fixed to the strainers 23 and 24 by screws 33 through packings 32.
[0032]
The polishing filters 11a and 11b are attached so as to be inserted into the treatment liquid outlet pipes 12a and 12b of the ion exchange towers 1a and 1b in FIG. 1 to form an ion exchange device. The ion exchange towers 1a and 1b may be existing or newly installed. In this case, it is not necessary to provide an operation valve in the pipes 12a and 12b, but it is possible to provide a shut-off valve for repair and inspection.
[0033]
In the ion exchange apparatus configured as described above, the pumps P _1a and P _1b are driven (others are stopped), and the valves V _1a , V _3a , V _1b , and V _3b are opened (others are closed) to perform ion exchange. I do. At this time, raw water is supplied to the cation exchange tower 1 from the liquid channel 9a to be treated, passes through the resin layer 2a in a downward flow, is subjected to cation exchange, and cations in the raw water are removed. The processing liquid whose purity has been lowered due to disturbance in the lower part of the resin layer 2a enters the polishing filter 11a from the processing liquid outlet pipe 12a and passes through the resin layer 25a, thereby undergoing cation exchange and removing remaining cations. .
[0034]
The treatment liquid in the treatment liquid path 13a is decarboxylated in the decarbonation tower 17, enters the anion exchange tower 1b from the liquid path 9b to be treated, passes through the resin layer 2b in the downward flow, undergoes anion exchange, and anions are obtained. Removed. The treatment liquid whose purity has been lowered due to the disturbance in the lower part of the resin layer 2b enters the polishing filter 11b from the treatment liquid outlet pipe 12b and passes through the resin layer 25b, thereby undergoing anion exchange, and the remaining anions are removed. . Thereby, it is taken out from the processing liquid passage 13b as the final processing liquid (pure water).
[0035]
Regeneration is performed with upward flow by switching the flow path. First, as backwashing, the pumps P _2a and P _2b are started (others are stopped), the valves V _4a , V _4b , V _2a and V _2b are opened (the others are closed), and the polishing filter 11a is passed through the washing channels 14a and 14b. , 11b through which the cleaning water is introduced into the ion exchange towers 1a and 1b, flowing in an upward flow, and the resin layers 2a and 2b are developed and cleaned, and the cleaning drainage is discharged from the cleaning drainage channels 10a and 10b. Take out. Thereby, the turbidity rejected by the resin layers 2a and 2b is removed. Finally, the cleaning is finished with the resin layers 2a and 2b pressed against the upper support plates 5a and 5b.
[0036]
Thereafter, the pumps P _3a , P _3b are started (others are stopped), the valves V _5a , V _5b , V _2a , V _2b are opened (the others are closed), and the polishing filters 11a, 11b are opened from the drug injection channels 15a, 15b. Then, a regenerant (acid or alkali) is introduced into the ion exchange towers 1a and 1b and passed in an upward flow, and regeneration is performed with the resin layers 2a and 2b pressed upward. A part of the resin in the lower layer may be fluidized. At this time, since the amount of the regenerant passes through the polishing filters 11a and 11b, the amount of the resin layer 2a or 2b and the total amount of the resin layer 2a or 2b and 25a or 25b is completely regenerated. The resins 2a and 2b are sequentially regenerated from the bottom, and the exchange zone gradually moves upward.
[0037]
When the prescribed amount of regenerant is dispensed, pure water is injected through the same route and extrusion is performed. Thereafter, the pumps P _2a and P _2b are started (the others are stopped), the valves V _4a , V _4b , V _2a and V _2b are opened, and pure water is passed through to wash upward. After washing with upward flow for a certain period of time, pumps P _1a and P _1b are started (others are stopped), and valves V _1a , V _1b , V _6a and V _6b are opened (others are closed) and downward flow Wash with. At this time, the resin layers 2a and 2b move downward, or at that time, the resin layers 2a and 2b are slightly disturbed, and the resin of the incompletely reproduced portion may be mixed into the lower layer portions of the resin layers 2a and 2b. Although there is no influence on the resin layers 25a and 25b. After downflow cleaning for a predetermined time, the valves V _6a and V _6b are closed, the valves V _3a and V _3b are opened, and the same ion exchange process as described above is performed.
[0038]
In each of the above operations, the polishing filters 11a and 11b are always filled with the resin and do not flow, so that the ion exchange process can be performed in a completely regenerated state. For this reason, it is possible to deionize a treatment liquid whose purity is lowered due to the disturbance of the resin layers 2a and 2b to obtain a high-purity treatment liquid. At this time, the disturbance generated in the resin layers 2a and 2b can be minimized by setting the free board capacity within the above range. For this reason, the resin layers 25a and 25b having the resin amount increase the purity of the treatment liquid. It becomes possible to recover. When the volume of the resin layers 25a, 25b is reduced due to crushing or the like, or when the performance is reduced, the bolts 31 are loosened to remove the lid 29, and the screws 33 are further loosened to remove the partition wall 26 and the packing 32 to replenish the resin. Or replace. Further, the polishing filters 11a and 11b themselves may be removed from the piping and replaced with new ones.
[0039]
The above embodiment is an example of performing ion exchange with the downward flowing liquid and performing upward flow regeneration. However, in the case of an ion exchange apparatus that performs ion exchange with the upward flowing liquid and performs downward flow regeneration, the ion exchange tower The flow path and piping system connected to 1a and 1b are turned upside down, the processed liquid inlet pipes 8a and 8b and the processed liquid paths 9a and 9b are connected to the lower part, and the processing liquid outlet having the polishing filters 11a and 11b on the upper part. The pipes 12a and 12b, the treatment liquid paths 13a and 13b, the cleaning water paths 14a and 14b, and the chemical injection paths 15a and 15b are configured to communicate with each other. The configuration and operation in this respect are the same as in the conventional case. In order to spread and wash the resin layers 2a and 2b (back washing), it is preferable to connect a washing water channel to the lower part.
[0040]
In such an ion exchange apparatus, the resin layers 25a and 25b are completely regenerated by supplying the regenerant to the ion exchange towers 1a and 1b through the polishing filters 11a and 11b, and regenerating by passing the liquid downward. The resin layers 2a and 2b are sequentially regenerated from the top. After regeneration, the flow is switched to the upward flow, the resin layer is pushed up, and ion exchange is performed in the upward flow. When the resin layer is pushed up, a slight disturbance occurs in the resin layers 2a and 2b. The decrease in the purity due to the disturbance is caused by the fact that the purity is recovered by passing the treatment liquid through the polishing filters 11a and 11b. It is the same.
[0041]
In the above ion exchange apparatus, by installing the polishing filters 11a and 11b on the treatment liquid side of the ion exchange towers 1a and 1b, the ion exchange resin layers 2a and 2b in the tower are developed, and the treated water purity at the tower outlet is developed. However, since the purity can be increased by the polishing filters 11a and 11b, it is not necessary to densely fill the resin in the ion exchange towers 1a and 1b, and the increase in the differential pressure can be eliminated. Moreover, since it does not pack densely, the backwashing development rate of the resin can be increased, and the discharge by backwashing of the suspended matter flowing into the ion exchange resin layers 2a and 2b is improved.
[0042]
Since the ion exchange resin layers 25a and 25b filled in the polishing filters 11a and 11b first come into contact with the regenerant that regenerates the resin layers 2a and 2b in the ion exchange towers 1a and 1b at the time of regeneration, the regenerant has high purity. In addition, since the amount of ion exchange resin in the polishing filters 11a and 11b is smaller than the amount of resin in the ion exchange towers 1a and 1b, the regeneration level is increased, thereby improving the purity of the treated water. Since the amount of extrusion water after regeneration is also large relative to the amount of filled resin, there is no need to worry about residual regenerant.
[0043]
Further, the polishing filters 11a and 11b are attached to the pipes in front of the ion exchange towers 1a and 1b and do not require a valve. Therefore, the polishing filters 11a and 11b can be easily attached to an existing apparatus and used. A valve is not required, but a simple shut-off valve can be provided for repair, inspection, etc.
[0044]
As described above, the ion exchange apparatus has a small amount of the ion exchange resin layer 25a on the treatment liquid outlet side of the ion exchange columns 1a and 1b in which the ion exchange resin layers 2a and 2b are formed so as to have the free boards 3a and 3b. Since the polishing filters 11a and 11b packed closely with 25b are installed, the differential pressure can be increased with a simple apparatus and operation without packing the ion exchange resin into the ion exchange towers 1a and 1b. In addition, the resin can be washed by developing the resin, and a high-purity ion exchange treatment liquid can be obtained with a small amount of the regenerant.
[0045]
【Example】
Examples and comparative examples will be described below.
Example 1 and Comparative Example 1
In the ion exchange apparatus of FIG. 1, ion exchange was performed under the conditions shown in Table 1.
[0046]
[Table 1]

[0047]
When the polishing filters 11a and 11b were not attached as Comparative Example 1, the Na leak amount was 0.5 mg / l and the electrical conductivity was 0.5 mS / m. In Example 1 where the polishing filters 11a and 11b were attached, Na was used. The leakage amount was 0.05 mg / l, and the electric conductivity was 0.05 mS / m.
[Brief description of the drawings]
FIG. 1 is a system diagram of an ion exchange apparatus according to an embodiment.
FIG. 2 is a cross-sectional view of the polishing filter of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a Cation exchange tower 1b Anion exchange tower 2a Cation exchange resin layer 2b Anion exchange resin layer 3a, 3b Free board 4a, 4b, 6a, 6b, 23, 24 Strainer 5a, 5b, 7a, 7b Support plate 8a, 8b Processed liquid inlet pipes 9a, 9b Processed liquid paths 10a, 10b Washing drain paths 11a, 11b Polishing filters 12a, 12b Processed liquid outlet pipes 13a, 13b Processed liquid paths 14a, 14b Washing water paths 15a, 15b Chemical injection paths 16a , 16b Drainage path 17 Decarbonation tower 20 Casing 21, 22 Connection part 25a, 25b Resin layer 26 Partition 27, 28 Flange

Claims (2)

And a cation exchange column packed with a cation exchange resins so as to have a free board,
An anion exchange tower packed with an anion exchange resin so as to have a free board;
A small amount of resin of the same type as the resin packed in the cation exchange column or anion exchange column is packed tightly between the double strainers, and the treatment solution outlet side port of each cation exchange column and anion exchange column First and second polishing filters attached to the pipes ;
The cation exchange column and the anion exchange column are respectively passed through the first and second polishing filters in an upward flow or a downward flow for ion exchange, and a regenerant is passed in the opposite direction. And an ion exchange device having a piping system provided for regeneration . A polishing filter used as the first or second polishing filter of the ion exchange device according to claim 1 ,
A casing having a connection to the treatment liquid outlet side pipe of the ion exchange tower;
A polishing filter for an ion exchange device, comprising: a cation exchange resin layer or an anion exchange resin layer closely packed between double strainers provided in the casing.

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