JP4049170B2 - Method for producing deionized water production apparatus - Google Patents

Description

  The present invention relates to a deionized water production apparatus for producing pure water or ultrapure water used for pharmaceutical production, semiconductor production, boiler water for power generation and the like.

  As a method for producing deionized water, a general method is to obtain deionized water by flowing water to be treated through a packed bed of ion exchange resin and adsorbing and removing impurity ions on the ion exchange resin. Here, a method of regenerating the ion exchange resin having reduced adsorption capacity using an acid or alkali is employed. However, this method has a problem that the waste liquid of acid and alkali used for regeneration is discharged, and therefore, a deionized water production method that does not require regeneration is desired.

  From such a viewpoint, in recent years, a self-regenerating electrodialysis deionized water production method combining an ion exchange resin and an ion exchange membrane has attracted attention. In this method, a mixture of an anion exchanger and a cation exchanger is placed in a desalting chamber of an electrodialysis apparatus in which an anion exchange membrane and a cation exchange membrane are alternately arranged, and water to be treated is placed in the desalting chamber. This is a method for producing deionized water by applying voltage while flowing and performing electrodialysis. In this method, since the ion exchange resin in a wet state is generally contained in the desalting chamber, the adhesion between the ion exchange resins or between the ion exchange resin and the ion exchange membrane is insufficient, and the thickness of the desalting chamber is increased. However, there is a drawback in that the resistance increases when trying to reduce the membrane use area.

As a method for compensating for these drawbacks, in Japanese Patent Publication No. 4-72567 and Japanese Patent Publication No. 6-20513, the width of the desalting chamber is about 0.762 to 10.16 cm (≈0.3 to 4 inches), It has been proposed that the thickness be about 0.127 to 0.635 cm (≈0.05 to 0.25 inch) to prevent an increase in resistance. However, in this method, since the thickness of the desalting chamber is thin, it is difficult to fill the ion-exchanger into the desalting chamber, and the amount of produced water per unit area is low.
Japanese Patent Publication No. 4-72567 Japanese Patent Publication No. 6-20513

  The present invention relates to a self-regenerative electrodialysis deionized water production apparatus that combines an ion exchanger and an ion exchange membrane, and does not increase in resistance even if the thickness of the desalting chamber is increased, and the prior art has Another object of the present invention is to provide a deionized water production apparatus that does not have the above-described drawbacks and can stably obtain pure water over a long period of time.

In the present invention, a cation exchange membrane and an anion exchange membrane are alternately arranged between a cathode and an anode, and an ion exchanger is accommodated in a desalting chamber of an electrodialysis tank in which a desalting chamber and a concentration chamber are formed. In the deionized water production apparatus, a pressure of 0.1 to 20 kg / cm ² is generated between the ion exchanger accommodated in the desalting chamber and the cation exchange membrane and anion exchange membrane partitioning the desalting chamber. There is provided a deionized water production apparatus characterized in that the deionized water is produced.

  The present invention accommodates an ion exchanger in a desalting chamber of an electrodialysis tank in which a cation exchange membrane and an anion exchange membrane are alternately arranged between a cathode and an anode to form a desalting chamber and a concentrating chamber. A method for producing a deionized water production apparatus, comprising: drying an ion exchanger accommodated in a demineralization chamber; In the accommodating step, the amount of the ion exchanger accommodated in the demineralization chamber is the volume when taken out from the demineralization chamber after the deionized water is produced. Provided is a method for producing a deionized water production apparatus having an amount of 103 to 170% of the volume of the desalting chamber.

  According to the deionized water production apparatus of the present invention, the electrical resistance can be reduced by increasing the adhesion between the ion exchangers housed in the demineralization chamber of the electrodialysis tank (to each other) and the ion exchange membrane, The thickness of the desalination chamber can be increased. Therefore, an apparatus with a small membrane use area and a large production water volume is obtained.

  In the present invention, the state of the ion exchanger is changed in advance and accommodated in the desalting chamber of the electrodialysis tank, or the state is changed after being accommodated in the desalting chamber. Hereinafter, in this specification, the state of the ion exchanger will be described by the following terms. The “use state” is a state when the ion exchanger is accommodated in the desalting chamber and used for electrodialysis, and is in a state of being balanced with the environment at the time of use. The “contracted state” refers to a state in which the apparent volume of the ion exchanger is contracted by some method. “Free state” refers to a state that is in equilibrium with the environment in which it is used but is not constrained by a desalting chamber.

  In the present invention, the thickness of the desalting chamber is 0.2 cm or more, preferably 0.7 cm or more. If the thickness of the desalting chamber is less than 0.2 cm, the effect of reducing the area of the membrane used is not clear, and it is difficult to fill the ion exchanger, which is not preferable. On the other hand, if the thickness exceeds 80.0 cm, the effect of reducing the area of the film used is large, but it is also not preferable because the increase in resistance is also large. Especially, it is especially preferable that the thickness of the desalting chamber is 1.1 cm or more and 30.0 cm or less because the resistance increase is small and the effect of reducing the area of the membrane used is large.

The pressure generated between the ion exchanger accommodated or filled in the desalting chamber and the cation exchange membrane and the anion exchange membrane partitioning the desalting chamber is in the range of 0.1 to 20 kg / cm ² . When the pressure is less than 0.1 kg / cm ² , the adhesion between the ion exchangers or between the ion exchanger and the ion exchange membrane is not sufficient, the resistance increases, and a short path for treated water can be obtained and obtained. Since the purity of water falls, it is not preferable. On the other hand, if the pressure is higher than 20 kg / cm ² , the adhesion between the ion exchangers or between the ion exchanger and the ion exchange membrane is sufficient, but the amount of treated water decreases or the ion exchange membrane used is damaged. Is not preferable. Especially, it is preferable that the said pressure is 0.5-10 kg / cm < ² >, especially 0.8-2 kg / cm < ² >.

  In the present invention, as a preferable means for generating pressure between the packing body filled in the desalting chamber and the ion exchange membrane, (1) the volume of the ion exchanger accommodated in the desalting chamber is smaller than that of the regenerative type. The ion exchanger in a free state is stored in the desalting chamber with a volume of the ion exchanger regeneration type larger than that of the desalting chamber, and the ion exchanger is made to pass water and energize. And (2) means for increasing the pressure by accommodating the ion exchanger in the desalting chamber and mechanically reducing the volume of the desalting chamber.

  In the means of (1) above, the ion exchanger accommodated in the desalting chamber accommodates an amount of 103 to 170% with respect to the desalting chamber volume when converted to the ion exchanger regeneration type volume in the free state. It is preferable. If this amount is less than 103%, the adhesion of the accommodated ion exchanger is not good, which is not preferable. On the other hand, when the amount is larger than 170%, the adhesion is good, but the pressure loss when water is passed increases, which is not preferable. In particular, the amount of the ion exchanger is particularly preferably 111 to 150%.

  As a method of reducing the volume of the ion exchanger from the regenerative type, (a) a method of reducing the moisture content by drying, or (b) a method of changing the counter ion to an ion species other than the regenerative type and making it a load type , (C) or a method of immersing in an organic solvent and replacing the solvent, etc. (d) The method of (a) in which the moisture content is reduced by drying, and the load type by changing the counter ion to an ion species other than the regenerative type (B) is a preferred method because it can be easily applied regardless of the type and structure of the ion exchanger and has a large effect of increasing the volume.

  When the moisture content is reduced by drying, the moisture content (weight) is preferably reduced to 1 to 30%. If the moisture content is less than 1%, drying takes time, which is not preferable. If the moisture content is greater than 30%, the effect of increasing the volume is reduced when water is passed through and energized, such being undesirable. A moisture content of 5 to 15% is particularly preferable because drying is easy and the effect of increasing the volume during water flow and energization is large. As the type of counter ion at the time of drying, Na type is preferable in the case of a cation exchanger, and Cl type is preferable in the case of an anion exchanger because it is thermally stable. The drying temperature is preferably 30 to 80 ° C. If the temperature is less than 30 ° C., drying takes time, and if the temperature is higher than 80 ° C., the ion exchange group is decomposed, which is not preferable.

In the case of a method in which the counter ion is changed to an ion species other than the regenerative type to make it a load type, the Na type is particularly preferable for the cation exchanger and the Cl type is particularly preferable for the anion exchanger as described above. In addition, monovalent counter ions such as K-type and Li-type are preferably used in the case of a cation exchanger, and NO ₃ type is preferably used in the case of an anion exchanger. In this regard, in the case of a divalent or higher counter ion such as a Ca type, Al type, or SO ₄ type, conversion to a regenerative type is not easy.

  Next, in the method (2) in which the ion exchanger is accommodated in the desalting chamber and the pressure is increased by mechanically reducing the volume of the desalting chamber, the chamber between the desalting chamber and the ion exchange membrane is used. It is preferable to reduce the volume of the desalting chamber by 5 to 60% by volume by introducing a spacer that contracts due to pressure, filling the ion exchanger, and compressing by applying pressure from the outside. If the desalting chamber volume to be reduced is less than 5% by volume, the adhesion of the accommodated ion exchanger is not good, which is not preferable. On the other hand, if the volume of the desalting chamber to be reduced is larger than 60% by volume, the adhesion is good, but the pressure loss when water is passed increases, which is not preferable. As the material for the shrinking spacer, a foamed sheet of polyethylene, polypropylene, polystyrene or the like is preferably used.

  In the present invention, examples of the ion exchanger accommodated in the desalting chamber include ion exchange resins, ion exchange fibers, processed products thereof, and the like. The porous ion exchanger adhered to is a preferable ion exchanger from the viewpoints of ion exchange performance and durability. In particular, a porous ion exchanger sheet is preferable because it has good adhesion between ion exchange resins and can be easily accommodated in a desalting chamber.

  As for the porosity when the ion exchanger is accommodated in the desalting chamber, the continuous porosity involved in the passage of the liquid is preferably 5% by volume or more. If the porosity is less than 5% by volume, the flow rate of the liquid decreases and the pressure loss increases, which is not preferable. When the porosity is 10 to 40%, water permeability is good, desalting performance is excellent, and treated water with high purity is particularly preferable. In addition, this porosity is a value at the time of accommodating an ion exchanger in a desalting chamber, water flow, and electricity supply.

  As the ion exchanger, at least a cation exchanger, an anion exchanger, a mixture thereof, or a porous molded product thereof can be used. Moreover, the structure which combined the domain (area | region) of the cation exchanger and the domain (area | region) of the anion exchanger may be sufficient. In this case, various shapes can be used for each domain in contact with the ion exchange membrane. For example, a sea island shape, a layer shape, a mosaic shape, a lattice shape, or the like can be used. In particular, sea islands and layers are preferred because they can be easily stored in the dilution chamber and can be efficiently desalted. However, the ratio of the cation exchanger to the anion exchanger used as a whole may be a ratio of the cation exchanger / anion exchanger = 20/80 to 80/20 in the total ion exchange capacity ratio. preferable.

  When a porous ion exchanger is used as the ion exchanger, the weight fraction of the binder polymer is preferably 20% or less. If the weight fraction is larger than 20%, the surface of the ion exchange resin particles is covered with a binder polymer, so that the adsorptivity is lowered, and the porosity is lowered, so that the flow rate of the liquid to be treated is reduced and the pressure loss is increased. Absent. Among these, the weight fraction is preferably 1 to 5%. The binder polymer is preferably a thermoplastic polymer or a solvent-soluble polymer from the viewpoint of the production method of the porous ion exchanger.

  As such a binder polymer, the following can be preferably used. First, examples of the thermoplastic polymer include low density polyethylene, linear low density polyethylene, ultra high molecular weight high density polyethylene, polypropylene, polyisobutylene, 1,2-polybutadiene, vinyl acetate, ethylene-vinyl acetate copolymer, and solvent. Examples of the soluble polymer include natural rubber, butyl rubber, polyisoprene, polychloroprene, styrene-butadiene rubber, nitrile rubber, vinyl chloride-fatty acid vinyl ester copolymer, and the like.

  The thickness of the porous sheet in which the ion exchange resin is bound using the binder polymer is 50% to 100% of the thickness of the desalting chamber when the porous sheet is accommodated in the desalting chamber in a reduced volume form. preferable. If this thickness is less than 50% of the desalting chamber thickness, it is not preferable because it does not adhere to the ion exchange membrane when water is passed through or energized. If the thickness is greater than 100%, it cannot be accommodated in the desalting chamber, which is not preferable. It is particularly preferable when the thickness of the porous sheet with the volume reduced is 70 to 90% of the thickness of the desalting chamber.

  The following method is preferred as a method for binding an ion exchange resin to a porous sheet using a binder polymer. That is, (a) a method in which ion exchange resin particles and a binder polymer are kneaded with heat and then formed into a sheet by thermoforming such as a flat plate press; (b) a binder polymer solution is applied to the surface of the ion exchange resin particles and the solvent is evaporated. (C) a method of extracting a pore-forming agent after heating and molding the binder polymer and pore-forming agent and ion-exchange resin particles, and (d) a binder polymer solution in which the pore-forming agent is dispersed in an ion-exchange resin. For example, a method of extracting a pore-forming agent after being applied to the particle surface and cured. Among these, after the ion exchange resin particles and the binder polymer of (a) are heat-kneaded, the sheet is formed by thermoforming such as a flat plate press, and the binder polymer, pore former and the ion exchange resin particles of (c) are heated. The method of extracting the pore-forming agent after the mixed molding is preferable from the viewpoints of molding processability and specific resistance of the resulting porous ion exchanger.

  The ion exchange group of the ion exchanger has a sulfonic acid type that is a strong acid as a cation exchange group, and a quaternary ammonium salt type or a pyridinium salt type that is a strong base as an anion exchange group. It is preferable from the viewpoint of stability. The ion exchange capacity of the ion exchanger is preferably 0.5 to 7 meq / g dry resin. If the ion exchange capacity is lower than 0.5 meq / g dry resin, ion adsorption and desalting are not sufficiently performed in the desalting chamber, and the purity of the treated water may be lowered, which is not preferable. In the case where the ion exchange capacity is 1 to 5 meq / g dry resin, a product with high treated water purity is obtained, and the performance stability is excellent, which is particularly preferable.

As an apparatus for producing deionized water in the present invention, for example, JP-A-3-186400, JP-A-2-277526, JP-A-5-64726, US Pat. No. 4,632,745 and US Pat. It is preferable to use an electrodialysis tank having the following configuration, which is described in the specification of US Pat. No. 5,425,866. In the electrodialysis tank, a plurality of cation exchange membranes and anion exchange membranes are preferably arranged alternately through a chamber frame between an anode chamber having an anode and a cathode chamber having a cathode. A desalting chamber partitioned by an anion exchange membrane and a cathode side partitioned by a cation exchange membrane and a concentration chamber partitioned by a cation exchange membrane on the cathode side and partitioned by an anion exchange membrane are alternately preferred. 2 to 50 sets are formed. The thickness of the frame-like chamber frame having an opening at the center interposed between the cation exchange membrane and the anion exchange membrane defines the thicknesses of the desalting chamber and the concentration chamber. The thickness of the chamber frame of the desalting chamber and the concentration chamber is not necessarily the same. As the ion exchange membrane, either a homogeneous system or a heterogeneous system can be used. In order to increase the mechanical strength, a reinforced fabric or a non-woven fabric can be used. In order to keep the thickness of the concentrating chamber at a predetermined thickness, a net-like spacer (spacer) is preferably inserted and arranged. Desalination can be performed by flowing the water to be treated in the desalting chamber and flowing an electric current while flowing water for discharging the concentrated salts in the concentration chamber. A voltage of about 4 to 20 V is preferably applied to each unit cell, and the current density is preferably 0.00001 to 0.05 A / cm ² .

FIG. 1 is a diagram schematically showing an example of the seed electrodialysis tank. In FIG. 1, A is an anion exchange membrane and K is a cation exchange membrane. As shown in the figure, both the ion exchange membrane A and the cation exchange membrane K are disposed in the electrodialysis tank 1 in the desalination chamber frames D ₁ , D ₂ , D ₃ ... Dn and the concentration chamber frames C ₁ , C ₂ , C ₃ ... Cn are arranged at predetermined intervals, whereby the anode chamber 2, the concentration chambers S ₁ , S _2. Sn, desalting chambers R ₁ , R ₂ ... Rn and cathode chamber 3 are configured. The desalting chambers R ₁ , R _2, ... Rn are filled with Yin Yang ion exchange resin. Spacers N ₁ , N ₂ , N ₃ ... Nn are inserted into the concentration chamber.

In FIG. 1, reference numeral 4 denotes an anode, and 5 denotes a cathode, and a predetermined voltage is applied between both electrodes during operation. As a result, the anion component in the liquid to be treated introduced from the conduit 6 to the desalting chambers R ₁ , R ₂ ... Rn permeates through the anion exchange membrane A to the concentration chamber on the anode side, while the liquid to be treated. The cation component therein permeates and transfers through the cation exchange membrane K to the concentration chamber on the cathode side, and the liquid to be treated itself is deionized and discharged through the conduit 7. Further, the concentrated liquid is introduced into each of the concentrating chambers S ₁ , S ₂ ... Sn through the introduction pipe 8, where the positive and negative ions permeated and transferred as described above are collected and discharged from the conduit 9 as a concentrated liquid.

  The cations in the water to be treated that are captured by the cation exchanger in the desalination chamber are given driving force by the electric field and are exchanged via the cation exchanger in contact with the captured cation exchanger. It reaches the membrane and passes through the membrane and moves to the concentration chamber. Similarly, the anion in the water to be treated captured by the anion exchanger moves to the concentration chamber via the anion exchanger and the anion exchange membrane. For this reason, if the cation exchanger and the anion exchanger are gathered within a certain range to form an aggregation region, the number of contact points between the same type of ion particles is remarkably increased, so that the movement of ions is facilitated. Since ion performance improves, it is further more preferable.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, of course, this invention is not limited to these Examples.

Example 1
A sulfonic acid type (H type) cation exchange resin (trade name: Diaion SK-1B, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 4.5 meq / g dry resin, and A quaternary ammonium salt type (OH type) anion exchange resin (trade name: Diaion SA-10A, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 3.5 meq / g dry resin. After drying with hot air at a temperature of 50 ° C. to a moisture content of 8% by weight, the mixture was mixed at a cation exchange resin / anion exchange resin = 44/56 (weight ratio in the dry state), and the ion exchange capacity ratio was 50 / 50 mixture.

This dry ion exchange resin mixture was filled in a desalting chamber of a vertical electrodialysis tank having a desalting chamber thickness of 1.2 cm and a concentrating chamber thickness of 0.2 cm at a volume filling rate of 60 minutes. After the pre-energization treatment for 24 hours with water, the specific resistance in 10 μS / cm water was measured and found to be 1051 Ω · cm at a current density of 0.0025 A / cm ² . Using such an electrodialysis tank, deionized water was produced as follows. Electrodialysis tanks are cation exchange membranes (strongly acidic heterogeneous membrane, thickness 500 μm, ion exchange capacity 4.5 meq / g dry resin) and anion exchange membranes (strongly basic heterogeneous membrane, thickness 500 μm, ion exchange capacity) 3.5 milliequivalent / gram dry resin) was placed through a desalting chamber frame (made of polypropylene with a thickness of 1.2 cm) and concentrated chamber frame (made of polypropylene with a thickness of 0.2 cm) and tightened, and the filter press type dialysis tank ( As the concentrating chamber, an effective area of 507 cm ² (13 cm wide, 39 cm long) × 5 pairs consisting of a polypropylene net having an intersection thickness of 0.2 cm was used.

When water having an electric conductivity of 5 μS / cm was used as raw water and desalting was performed at a current density of 0.004 A / cm ² (voltage = 5 V per unit cell), treated water having an electric conductivity of 0.062 μS / cm was 0.4 m. ^It was stably obtained at a production rate of ³ / h. In this case, the effective membrane use area per 1 m ³ / h of produced water was 1.27 m ² . After the measurement, the ion exchange resin in the desalting chamber was taken out, and the volume of the ion exchange resin mixture in the free state was measured to be 122% of the volume of the desalting chamber. Moreover, when the measurement apparatus shown in FIG. 2 was used, the same dry ion exchanger as in this example was put into the metal container 10 shown in FIG. 2 at the same volume filling rate, and the generated pressure was measured by passing water. Was 2.1 kg / cm ² . In FIG. 2, 11 is a metal plate, 12 is a water inlet, 13 is a water outlet, 14 is a load cell, and 15 is a dry ion exchanger.

Example 2
Sodium sulfonate type (Na type) cation exchange resin (trade name: Diaion SK-1B, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 4.5 meq / g dry resin, and A quaternary ammonium salt type (Cl type) anion exchange resin (product name: Diaion SA-10A, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 3.5 meq / g dry resin. After drying with hot air at a temperature of 50 ° C. to a moisture content of 8% by weight, mixing is carried out at a cation exchange resin / anion exchange resin = 44/56 (weight ratio in the dry state), and the ion exchange capacity ratio is 50/50. A mixture of

3% by weight of linear low density polyethylene (manufactured by Dow Chemical Company, trade name: Affinity SM-1300) was mixed with this mixture and kneaded at a temperature of 120 to 130 ° C. The obtained kneaded material was thermoformed at a temperature of 130 ° C. with a flat plate press to obtain a porous ion exchanger sheet-like material having a thickness of 0.6 cm. The porosity of the continuous voids of this porous sheet was 23% by volume. The porous ion exchange sheet was accommodated in a desalting chamber of an electrodialysis tank having the same configuration as that of Example 1 except that the thickness of the desalting chamber was 0.8 cm, and the volume filling rate was 54%. When the specific resistance in water at 10 μS / cm was measured after the pre-energization treatment for 24 hours with water, it was 1164 Ω · cm at a current density of 0.0025 A / cm ² .

After measuring the specific resistance, deionized water was produced. As the electrodialysis tank, the same electrodialysis tank as in Example 1 was used except for the thickness of the desalination chamber. When water having an electric conductivity of 5 μS / cm was used as raw water and desalting was performed at a current density of 0.004 A / cm ² (voltage = 5 V per unit cell), treated water having an electric conductivity of 0.060 μS / cm was 0.45 m. ^It was stably obtained at a production rate of ³ / h. In this case, the effective area of membrane use per 1 m ³ / h of produced water was 1.13 m ² . After the operation, the ion exchange sheet in the desalting chamber was taken out, and the volume in the free state was measured. As a result, it was 111% of the desalting chamber volume. Further, when the same dry ion exchanger sheet as in this example was passed through the metal container 10 of the measuring apparatus shown in FIG. 2 at the same volume filling rate and the generated pressure was measured, the pressure was 1.2 kg / cm ^2. Met.

Example 3
Sodium sulfonate type (Na type) cation exchange resin (trade name: Diaion SK-1B, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 4.5 meq / g dry resin, and A quaternary ammonium salt type (Cl type) anion exchange resin (product name: Diaion SA-10A, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 3.5 meq / g dry resin. It was dried with hot air at a temperature of 50 ° C. to adjust the water content to 8% by weight. Each ion-exchange resin was mixed with 3% by weight of linear low-density polyethylene (manufactured by Dow Chemical Company, trade name: Affinity SM-1300) and kneaded at a temperature of 120 to 130 ° C. Each obtained kneaded material was thermoformed at a temperature of 130 ° C. with a flat plate press to obtain a porous cation exchanger sheet and a porous anion exchanger sheet having a thickness of 0.6 cm. The porosity of continuous voids of the obtained porous cation exchanger sheet was 24% by volume, and the porosity of the porous anion exchanger sheet was 23% by volume.

Using these porous ion exchanger sheet-like materials, a combination of a cation exchanger domain (region) and an anion exchanger domain (region) having the shape shown in FIGS. In the same electrodialysis tank as in Example 2, the desalting chamber having a thickness of 0.8 cm was filled at a volume filling rate of 66%. 3 (a) is a plan view, FIG. 3 (b) is a cross-sectional view taken along line YY in FIG. 3 (a), and in FIG. 3, reference numeral 16 denotes an anion exchanger domain, and reference numeral 17 denotes a cation exchanger domain. Is shown. When the specific resistance in water of 10 μS / cm was measured after 60 minutes of water flow and 24 hours of pre-energization treatment, it was 911 Ω · cm at a current density of 0.0025 A / cm ² .

After measuring the specific resistance, deionized water was produced. The same electrodialysis tank as used in Example 2 was used as the electrodialysis tank. When water having an electric conductivity of 5 μS / cm was used as raw water and desalting was performed at a current density of 0.004 A / cm ² (voltage = 5 V per unit cell), treated water having an electric conductivity of 0.057 μS / cm was 0.47 m. ^It was stably obtained at a production rate of ³ / h. In this case, the effective area of membrane use per 1 m ³ / h of produced water was 1.08 m ² . After the measurement, the ion exchange resin in the desalting chamber was taken out and the volume was measured. As a result, the volume was 134% of the volume of the desalting chamber. Further, when the same dry ion exchanger as in the present example was put into the metal container 10 of the measuring apparatus shown in FIG. 2 with the same volume filling rate and the generated pressure was measured by passing water, the pressure was 4.2 kg / cm ² . there were.

Example 4
Sodium sulfonate type (Na type) cation exchange resin (trade name: Diaion SK-1B, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 4.5 meq / g dry resin, and A quaternary ammonium salt type (Cl type) anion exchange resin (product name: Diaion SA-10A, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 3.5 meq / g dry resin. It was dried with hot air at a temperature of 50 ° C. to adjust the water content to 8% by weight. Each ion exchange resin was mixed with 3% by weight of 1,2-polybutadiene (RB-820, manufactured by Nippon Synthetic Rubber Co., Ltd.) and kneaded at a temperature of 120 to 130 ° C. Each obtained kneaded material was thermoformed at a temperature of 130 ° C. with a flat plate press to obtain a porous cation exchanger sheet and a porous anion exchanger sheet having a thickness of 0.6 cm. The porosity of continuous voids of the obtained porous cation exchanger sheet was 24% by volume, and the porosity of the porous anion exchanger sheet was 23% by volume.

A combination of the cation exchanger domain (region) and the anion exchanger domain (region) having the shape shown in FIGS. 4 (a) to 4 (b) using these both porous ion exchanger sheets. Was filled in a desalting chamber having a thickness of 0.8 cm at a volume filling rate of 55%. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along the line ZZ in FIG. 4A. In FIG. 4, reference numeral 16 denotes an anion exchanger domain, and reference numeral 17 denotes a cation exchanger. Shows the domain. When the specific resistance in 10 μS / cm of water was measured after 60 minutes of water flow and 24 hours of pre-energization, it was 1206 Ω · cm when the current density was 0.0025 A / cm ² , and the undried state was the same. A value lower than 1362 Ω · cm when the regenerative ion exchange resin was measured in a cell was obtained.

After measuring the specific resistance, deionized water was produced. The same electrodialysis tank as that used in Example 2 was used. When water having an electric conductivity of 5 μS / cm was used as raw water and desalting was performed at a current density of 0.004 A / cm ² (voltage = 5 V per unit cell), treated water having an electric conductivity of 0.057 μS / cm was 0.46 m. ^It was stably obtained at a production rate of ³ / h. In this case, the effective area of membrane use per 1 m ³ / h of produced water was 1.10 m ² . After the measurement, the ion exchange resin in the desalting chamber was taken out and the volume was measured. As a result, it was 113% of the volume of the desalting chamber. Further, the same dry ion exchanger as in this example was put in the metal container 10 of the measuring apparatus shown in FIG. 2 with the same volume filling rate, and the generated pressure was measured by passing water. The pressure was 1.3 kg / cm ² . there were.

《Comparative example》
A sulfonic acid type (H type) cation exchange resin (trade name: Diaion SK-1B, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 4.5 meq / g dry resin, and A quaternary ammonium salt type (OH type) anion exchange resin (trade name: Diaion SA-10A, manufactured by Mitsubishi Chemical Corporation) having a particle size of 400 to 600 μm and an ion exchange capacity of 3.5 meq / g dry resin. After regenerating with hydrochloric acid and sodium hydroxide aqueous solution, the mixture was mixed with cation exchange resin / anion exchange resin = 40/60 (volume ratio in a wet state) to obtain a mixture having an ion exchange capacity ratio of 50/50.

This wet regenerated ion exchange resin mixture is filled 100% by volume filling rate into the desalting chamber of the electrodialysis tank having the same configuration as in Example 1 except that the width of the desalting chamber is 0.8 cm, When the specific resistance in 10 μS / cm of water was measured after 60 minutes of water flow and 24 hours of pre-energization treatment, it was 1362 Ω · cm at a current density of 0.0025 A / cm ² . After measuring the specific resistance, deionized water was produced. The same electrodialysis tank as in Example 1 was used except that the thickness of the desalting chamber was different. When water having an electric conductivity of 5 μS / cm was used as raw water and desalting was performed at a current density of 0.005 A / cm ² (voltage = 5 V per unit cell), treated water having an electric conductivity of 0.07 μS / cm was 0.04 m. ^It could only be obtained at a production rate of ³ / h. When the amount of treated water was increased, the conductivity increased and the amount of treated water could not be increased. In this case, the effective membrane use area per 1 m ³ / h of produced water was a large value of 12.68 m ² .

The figure which shows typically the example of 1 aspect of a self-regenerative type electrodialysis apparatus. The figure which shows the outline of the apparatus which measured the generated pressure by the water flow of a dry ion exchanger in a present Example. The figure which shows the example of the aspect of the porous ion exchange resin body which comprised the yin and yang porous ion exchanger sheet-like material in the shape of an island (used in Example 3). The figure which shows the example of an aspect of the porous ion exchange resin body which comprised the yin-yang both porous ion exchanger sheet-like material in the multilayer form (used in Example 4).

Explanation of symbols

A Anion exchange membrane K Cation exchange membrane 1 Container (electrodialysis tank)
2 Anode chamber 3 Cathode chamber 4 Anode 5 Cathode S ₁ , S ₂ ... Sn Concentration chamber R ₁ , R ₂ ... Rn Desalination chamber D ₁ , D ₂ , D _{3. 1} , C ₂ , C ₃ ... Cn Concentration chamber frame N ₁ , N ₂ , N ₃ ... Nn Spacer 6 Liquid to be treated introduction pipe 7 Deionized water conduit 8 Concentrate introduction pipe 9 Concentration conduit 10 Metal container DESCRIPTION OF SYMBOLS 11 Metal plate 12 Water inlet 13 Water outlet 14 Load cell 15 Dry ion exchanger 16 Anion exchanger domain 17 Cation exchanger domain

Claims (4)

  Deionization in which an ion exchanger is accommodated in a desalination chamber of an electrodialysis tank in which a cation exchange membrane and an anion exchange membrane are alternately arranged between a cathode and an anode to form a desalination chamber and a concentration chamber A method for producing a water production apparatus, wherein the ion exchanger accommodated in the desalting chamber is dried, then accommodated in the desalting chamber, and passed through the desalting chamber to increase the ion exchange volume. The amount of the ion exchanger accommodated in the demineralization chamber is the same as the volume of the demineralization chamber when the deionized water is taken out from the demineralization chamber. A method for producing a deionized water production apparatus, characterized in that the amount is 103 to 170% of the volume. In the ion exchanger accommodating step, by passing water through the desalting chamber, 0 is placed between the ion exchanger accommodated in the desalting chamber and the cation exchange membrane and the anion exchange membrane partitioning the desalting chamber. The method for producing deionized water production apparatus according to claim 1, wherein a pressure of 1 to ²⁰ kg / cm ² is generated.   3. The ion exchanger storage step, wherein the ion exchanger stored in the desalting chamber is dried in a moisture content of 30% by weight or less and then stored in the desalting chamber. Manufacturing method of deionized water manufacturing apparatus. The method for producing a deionized water production apparatus according to claim 1, 2 or 3, further comprising a step of inserting and arranging a net-like spacer in the concentration chamber.

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