JP2001079553A - Method for packing ion exchanger in electric deionizer, and electric deionizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively pack an ion exchanger in the concentration chamber of an electric deionizer and to obtain good deionization efficiency by contracting the exchanger by drying and then packing the exchanger. SOLUTION: When deionized water is produced, plural anion-exchange membranes 13 and cation-exchanger membranes 15 are alternately arranged between an anode 11 and a cathode 12 to alternately form an concentration chamber 15 and a desalting chamber 16, and an ion exchanger 10A is packed in the chamber 16 and an ion exchanger 10B in the chamber 15 to constitute an electric deionizer which is widely used. In this case, the exchanger 10B is dried and then packed in the chamber 15. As the drying method in this dry packing, the exchanger is preferably vacuum-dried by a vacuum pump, and the volumetric contraction of the exchanger 10B is preferably controlled to 70-90%. Otherwise, the exchanger 10B is dipped in an electrolyte soln. prior to the vacuum drying and contracted in form of salt to adjust its volumetric contraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for filling an ion exchanger in an electrodeionization apparatus and an electrodeionization apparatus, and more particularly, to a method for forming a plurality of anion exchange membranes and cation exchange membranes between a cathode and an anode. Are alternately arranged to form an enrichment chamber and a desalination chamber alternately, and a method for effectively filling the enrichment chamber of the electrodeionization apparatus with an ion exchanger and filling the ion exchanger with such a method. To an improved electrodeionization device.

[0002]

2. Description of the Related Art Conventionally, semiconductor manufacturing plants, liquid crystal manufacturing plants,
In the production of deionized water used in various industries or research facilities such as the pharmaceutical industry, the food industry, and the electric power industry, as shown in FIG. 1, a plurality of anions are exchanged between electrodes (anode 11 and cathode 12). The membrane 13 and the cation exchange membrane 14 are alternately arranged to form the concentration chamber 15 and the desalination chamber 16 alternately. The mixed ion exchange resin of the anion exchange resin and the cation exchange resin, An electrodeionization apparatus filled with an ion exchanger 10A such as a fiber is frequently used, and an electrodeionization apparatus filled with an ion exchanger 10B in a concentration chamber 15 is also known (Japanese Patent Publication No. 7-1658).
No. 7, "Clean Technology 1998.10", pp. 62-65). In FIG. 1, reference numeral 17 denotes an anode chamber,
18 is a cathode chamber.

[0003] The electrodeionization apparatus is capable of efficient desalination treatment and does not require regeneration like an ion exchange resin.
Complete continuous water sampling is possible, and an excellent effect that extremely high-purity water is obtained is exhibited.

Conventionally, in such an electrodeionization apparatus, various proposals have been made for a method of filling an ion exchanger into a desalting chamber, and a method of drying and shrinking the ion exchanger to fill the deionization chamber ( Hereinafter, referred to as “dry filling”) has also been proposed. In USP 5,203,976,
Although a method of filling the desalting chamber as a slurry with the ion exchanger (hereinafter referred to as “slurry filling”) is described, the method of filling the concentration chamber with the ion exchanger is not disclosed.

[0005] The concentration chamber and the desalination chamber of the electrodeionization apparatus are
Since it is partitioned by an ion-exchange membrane, which is difficult to impart sufficient strength and rigidity to itself as a partition material, sufficient pressure is also generated from the enrichment chamber side to prevent the enrichment chamber from deforming Is needed.

[0006]

However, it is practically difficult to arrange a spacer net or the like in an enrichment chamber in an electrodeionization apparatus in which an ion exchanger is also filled in the enrichment chamber. It was difficult to generate sufficient pressure. When the pressure from the enrichment chamber side is insufficient and the enrichment chamber loses the pressure of the desalination chamber and is pressed and deformed, the substantial volume of the desalination chamber increases, and the packing density of the ion exchanger on the desalination chamber side Is reduced, and the degree of adhesion between the ion exchangers is deteriorated, so that ion transfer is impaired, and the quality of deionized water obtained is reduced.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and effectively fills an enrichment chamber with an ion exchanger so as to obtain a good deionization efficiency. An object is to provide an electrodeionization device.

[0008]

According to the present invention, there is provided a method for filling an ion exchanger of an electrodeionization apparatus, comprising the steps of:
In a method for filling an ion exchanger in the concentration chamber of an electrodeionization apparatus comprising a concentration chamber and a desalination chamber formed by a plurality of ion exchange membranes, the ion exchanger may be filled after drying and shrinking the ion exchanger. Features.

The electrodeionization apparatus of the present invention is an electric deionization apparatus in which a concentration chamber and a desalination chamber are formed by a plurality of ion exchange membranes between a cathode and an anode, and the concentration chamber is filled with an ion exchanger. In the deionization device, the ion exchanger is filled after drying and shrinking.

In accordance with the present invention, the filling of the ion exchanger into the concentrating chamber is performed by drying and shrinking the ion exchanger so that sufficient pressure is also generated from the concentrating chamber side to prevent deformation of the concentrating chamber. Can be. For this reason, the packing density of the ion exchanger in the deionization chamber is sufficiently maintained, and the degree of adhesion between the ion exchangers is increased. The movement is promoted, the removal rate is improved, and deionized water of high water quality (high specific resistance) can be obtained.

On the other hand, when the ion exchanger in the concentration chamber is filled with slurry, it is difficult to generate sufficient pressure from the concentration chamber side, and high-quality deionized water cannot be obtained.

According to the present invention, when the ion exchanger in the concentrating chamber is dry-filled, if the ion exchanger in the desalting chamber is also dry-filled, insufficient expansion due to expansion from both chambers may cause water leakage. Therefore, it is preferable that the ion exchanger in the concentration chamber is dry-filled and the ion exchanger in the desalination chamber is slurry-filled.

[0013]

Embodiments of the present invention will be described below in detail.

The basic structure of the electrodeionization apparatus of the present invention is the same as that of the electrodeionization apparatus shown in FIG.

In the present invention, in such an electrodeionization apparatus, the ion exchanger in the concentration chamber is filled by dry filling. As a drying method of this dry filling, it is preferable to dry under reduced pressure using a vacuum pump. At this time, the volume shrinkage of the ion exchanger (the ratio of the volume after drying shrinkage to the volume before drying) is 70. About 90% is desirable. If the volume shrinkage exceeds 90%, the effect of the present invention by dry filling cannot be sufficiently obtained, and
If it is less than 0%, the filling density of the resin becomes too high,
Because the resin deformation and the water resistance when passing water are too large,
Not preferred. Before performing the drying under reduced pressure, the ion exchanger may be immersed in an electrolyte solution such as about 0.1 to 50% by weight of an NaCl aqueous solution to be shrunk in a salt form to adjust the volume shrinkage. good.

The ion exchanger dried and shrunk in this way is preferably weighed in advance in an amount corresponding to the volume of each concentrating chamber, so that the ion exchanger can be uniformly filled, and is thus preferable.

In the present invention, an ion exchange resin, an ion exchange fiber or the like can be used as an ion exchanger filled in the concentration chamber. Examples of the ion exchange resin include “650C” and “550A” manufactured by Dow Chemical Company. "SK1B", "SA10A", "SSA10" or the like manufactured by Mitsubishi Chemical Corporation can be used, and these can be mixed or used alone according to the purpose.

In the present invention, when the ion-exchanger is filled also in the desalting chamber, the same ion-exchange resin or ion-exchange fiber as described above can be used as the ion-exchanger.

When filling the desalting chamber with an ion exchanger,
As described above, in order to prevent water leakage due to expansion from both the desalting chamber and the concentrating chamber, a method of filling the ion exchanger into the desalting chamber uses an aqueous NaCl solution of about 0.1 to 50% by weight. It is preferable to use slurry filling.

[0020]

The present invention will be described more specifically with reference to comparative examples and examples.

In the following comparative examples and examples,
Water (conductivity: 10 μS / cm) obtained by sequentially treating tap water with an activated carbon tower, a reverse osmosis membrane separator, and a membrane deaerator was used as feed water for the electrodeionization apparatus.

As the ion exchangers in the desalting chamber of the electrodeionization apparatus, cation exchange resin "650C" manufactured by Dow Chemical Co. and anion exchange resin "SSA" manufactured by Mitsubishi Chemical Corporation are used.
10 "and a cation exchange resin" 650C "manufactured by Dow Chemical Co. and an anion exchange resin" 550 "manufactured by Mitsubishi Chemical Corporation as ion exchangers in the concentration chamber.
A "mixed at 4: 6. "CMB" and "AHA" manufactured by Tokuyama Corporation were used as the ion exchange membrane. The cells of the desalting chamber and the concentrating chamber of the electrodeionization apparatus were 187 mm in width, 795 mm in height, and 2.5 mm in thickness, and had three demineralizing chambers and four concentrating chambers.

Comparative Example 1 Each of the deionization chamber and the concentration chamber was filled with the ion exchanger by 1
The ion exchanger was immersed in an aqueous solution of 0% by weight of NaCl, and transferred to each cell as it was by slurry filling to produce an electrodeionization apparatus. Supply water is passed through this electrodeionization apparatus at a flow rate of 80 L / hr in the desalting chamber, a recovery rate of 80%, and an operation current of 0.5 A. The ratio of the produced water (deionized water) after 3 days of operation Measure resistance, Na concentration and Cl concentration,
The results are shown in Table 1.

Example 1 In Comparative Example 1, the ion exchanger in the concentration chamber was filled by immersing the ion exchanger in a 10% by weight aqueous solution of NaCl, washing with pure water, further treating with methanol, and reducing the pressure with a vacuum pump. An electrodeionization apparatus was manufactured in the same manner as above except that drying and filling were performed after drying and adjusting the volume shrinkage to 82%. The supplied water was passed through this electrodeionization apparatus under the same operating conditions as in Comparative Example 1, and the measurement results of the specific resistance, Na concentration, and Cl concentration of the produced water (deionized water) after 3 days of operation were shown in Table 1. Indicated.

[0025]

[Table 1]

Table 1 shows that according to the present invention, the specific resistance of the produced water can be improved.

[0027]

As described above in detail, according to the present invention, the ion exchanger can be effectively filled in the concentration chamber of the electrodeionization apparatus, and deionized water having good water quality can be obtained. Moreover, by employing the dry filling of the present invention,
The assembly accuracy of the electrodeionization apparatus is also improved, which is extremely advantageous industrially.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of an electrodeionization apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10A, 10B Ion exchanger 11 Anode 12 Cathode 13 Anion exchange membrane 14 Cation exchange membrane 15 Concentration room 16 Demineralization room 17 Anode room 18 Cathode room

Claims (2)

[Claims] 1. A method for filling an ion exchanger in an enrichment chamber of an electrodeionization apparatus comprising a concentration chamber and a desalination chamber formed by a plurality of ion exchange membranes between a cathode and an anode. A method for filling an ion exchanger in an electrodeionization apparatus, comprising filling the ion exchanger after drying and shrinking the ion exchanger. 2. An electrodeionization apparatus in which a concentration chamber and a desalination chamber are formed between a cathode and an anode by a plurality of ion exchange membranes, and the concentration chamber is filled with an ion exchanger. An electrodeionization device characterized in that the exchanger is filled after drying and shrinking.