JP2003326269A - Electric regenerative demineralizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric regenerative demineralizer which prevents the deformation of membranes due to a pressure difference and prevents the membrane deterioration due to the contact of the channelling membranes with each other between respective chambers. <P>SOLUTION: This electric regenerative demineralizer has a cathode chamber 2 and an anode chamber 4, cation exchange membranes 6 and anion exchange membranes 5 are partially alternately arranged between both chambers, desalting chambers 7 and concentration chambers 8 are formed by using the ion exchange membranes and chamber frames, and ion exchangers 9 are packed at least in the desalting chambers 7 among the above chambers. Further, concentration chamber-splitting plates 30 made of a conductive substance having the rigidity in the interior thereof are disposed on one or more of the concentration chambers 8, and the chamber frames are formed on the concentration chambers 8 provided with the concentration chamber-splitting plates 30 in such a manner that introduced concentrated water flows through both surfaces of the concentration chamber-splitting plates 30. The concentration chamber- splitting plates 30 are disposed nearly on the central part in the plate thickness direction of the chamber frames constituting the concentration chambers 8 and are incorporated into the chamber frames and, in the ion exchangers 9, ion exchange groups are preferably introduced by a radiation graft polymerization method. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric regenerative desalination apparatus, and more particularly, to an electric regenerative desalination apparatus which prevents partial flow due to deformation of a membrane due to pressure difference in each chamber and reduction of desalination efficiency. Regarding the device.

[0002]

2. Description of the Related Art A conventional method for producing pure water is to pass water in an inlet of a desalting chamber through a container filled with an ion exchange resin and exchange the ions in the water in the inlet of the desalting chamber for H ⁺ and OH ⁻ ions. An ion exchange method for producing pure water is known. However, in this ion exchange method, when the exchange capacity of the ion exchange resin is saturated, an acid,
It is necessary to regenerate the ion exchange capacity using alkali. The regeneration operation of the ion exchange resin is complicated, and a large amount of acid,
There is a problem that careful storage and handling of the alkali are required and the equipment becomes large. On the other hand, in recent years, an electric regeneration type desalination apparatus has been developed which regenerates an ion exchanger by electricity and continuously produces pure water. This is as shown in FIG.
This is a device for removing the ionic components in 0 by moving it to the outlet water 13 of the concentrating chamber and the catholyte and anolyte with a DC power supply applied to both ends of the device, and has a cathode chamber 2 having a cathode 1 and an anode 3. A desalting chamber 7 and a concentrating chamber 8 formed by alternately arranging anion exchange membranes 5 and cation exchange membranes 6 are provided between the anode chamber 4 and the cathode chamber 2 and the anode chamber 4, and at least desalination chamber is provided. The chamber 7 is filled with an ion exchanger 9.

The cathode chamber inlet water 14 is supplied to the cathode chamber 2, and the anode chamber 4 is supplied.
To the anode chamber inlet water 16 and to the concentration chamber 8 to the concentration chamber inlet water 12
By introducing a desalting chamber inlet water 10 into the desalting chamber 7 and applying a direct current between the cathode 1 and the anode 3, the ion content contained in the desalting chamber inlet water 10 is ion-exchanged. Anions move through the surface of the body 9 in the direction of electric potential, anions permeate the anion exchange membrane 5, and cations permeate the cation exchange membrane 6 to concentrate water in the concentrating chamber 8 and catholyte and anode in the cathodic chamber 2. The water 10 is transferred to the anolyte in the chamber 4 and the deionization chamber inlet water 10 is deionized and purified water 1
1 is manufactured. Since the ion exchanger 9 filled in the desalting chamber 7 is continuously regenerated by H ⁺ and OH ⁻ generated by hydrolyzation, regeneration work with an acid or an alkali is not necessary, and thus pure water is obtained. 11 can be continuously manufactured. The demineralizing chamber inlet water 10 is usually city water, industrial water, or the like, and water from which hardness components have been removed by a reverse osmosis membrane or the like is used.

The concentration chamber inlet water 12 may be branched from the demineralization chamber inlet water 10 and supplied to the concentration chamber 8, or water of a quality that can be used as concentrated water may be introduced from the outside. Well, it may be supplied using a concentrated water pump (not shown). When the concentration chamber inlet water 12 is supplied to the concentration chamber 8 using a concentrated water pump, a part of the concentration chamber outlet water 13, the cathode chamber outlet water 15, and the anode chamber outlet water 17 is circulated and used to It is also possible to operate by increasing the flow rate of the water 12. In addition, in order to reduce the electrical resistance in the concentrated water,
A method of adding an electrolyte from the outside is also used. The cathode chamber inlet water 14 and the anode chamber inlet water 16 may be the same as the concentrating chamber inlet water 12, respectively, or the desalting chamber inlet water 1
0 or pure water 11 may be used or may be separately supplied from the outside.

Further, as shown in FIG. 6, as another form of the electric regenerative desalting apparatus, a first desalting chamber group 20 for roughly desalting ions in the desalting chamber inlet water 10 and further desalting There is also an electric regeneration type desalination apparatus having a second desalination chamber group 21 for performing salt treatment. In this type of electric regenerative desalination device,
By disposing the concentrating chamber between the desalting chamber group 20 and the second desalting chamber group 21, the first desalting chamber group and the second desalting chamber group are divided. In the first desalination chamber group, the treated water 19 that has been subjected to the crude desalination treatment is introduced into the second desalination chamber group through the internal pipe of the apparatus or the external pipe of the apparatus, and is further desalted to be pure. It is supplied to the outside as water 11. In this case, the second
The same water as the inlet water of the concentrating chamber adjacent to the first desalting chamber group may be supplied to the concentrating chamber adjacent to the desalting chamber group, or another water may be used. . As another example of water, the concentrated water outlet water adjacent to the first deionization chamber group may be
Used as the concentration chamber inlet water adjacent to the desalination chamber group, or the concentration chamber outlet water adjacent to the second desalination chamber group as the concentration chamber inlet water adjacent to the first desalination chamber group, or It is possible to supply water suitable for concentrated water from the outside.

In the above-mentioned electric regeneration type desalination apparatus,
Since the pressures of concentrated water, polar solution, and treated water supplied to the concentrating chamber, the polar chamber, and the desalting chamber are different, the ion exchange membrane provided between the desalting chamber, the concentrating chamber, and the polar chamber is deformed. Therefore, problems such as film burning due to contact between the membranes, liquid not being uniformly supplied to each desalting chamber and concentrating chamber, and one-way flow in the same desalting chamber may occur. This caused problems with the regenerative desalination equipment, decreased flow rate, and degraded performance. In addition, a first desalination chamber group for performing crude desalination and a second desalination chamber group for further desalting the water treated in the first desalination chamber group are provided as one electric regenerative desalination unit. In the electric regeneration type desalination device incorporated in the apparatus, the pressure difference between the first and second desalination chamber groups also causes the deformation of the membrane, and in addition to the above-mentioned problems, Since the pressure of the desalination chamber group is high, the second desalination chamber group is crushed, which causes a problem that the pressure loss of the second desalination chamber group becomes high.

In order to prevent such deformation of the membrane due to the pressure difference between the chambers, a lattice-shaped chamber frame is used as the chamber frame forming the desalting chamber, the concentrating chamber, and the polar chamber. Measures such as reducing the deformation of the ion exchange membrane are taken.
(For example, JP-A-7-100391). However, in such a method, there is a problem that the effective desalination area is reduced by the lattice for preventing the deformation of the membrane, and it takes time to fill the ion exchanger because of the lattice.
Further, as shown in FIG. 7, in the electric regenerative desalination apparatus having the first desalination chamber group and the second desalination chamber group, the first desalination chamber group and the second desalination chamber group A method of eliminating the influence of the pressure difference between the first desalination chamber group and the second desalination chamber group by arranging a rigid partition wall between the partition walls may be adopted. Therefore, electrodes and polar chambers are required on both sides of the partition wall, which causes a problem that the device becomes large and assembly is troublesome.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and prevents the membrane from being deformed due to the pressure difference generated between the desalting chamber, the concentrating chamber and the polar chamber. It is an object of the present invention to provide an electric regenerative desalination device capable of preventing film burning or the like due to contact of one-flow membranes between demineralization chambers and concentration chambers, which is a cause of troubles in the desalination device. To do.

[0009]

In order to solve the above-mentioned problems, the present invention has a cathode chamber having a cathode and an anode chamber having an anode, and a cation exchange membrane and a cation exchange membrane are provided between the both electrode chambers. At least a part of the anion exchange membranes are alternately arranged, and a desalting chamber and a concentrating chamber are formed by using these ion exchange membranes and a chamber frame, and at least the desalting chamber among the existing chambers is ion-exchanged. An electric regenerative desalination apparatus in which a body is filled, wherein one or more of the concentrating chambers is provided with a concentrating chamber dividing plate made of a rigid conductive material, and An electric regenerative desalination device characterized in that a chamber frame is formed in a concentrating chamber equipped with a chamber dividing plate so that concentrated water to be introduced flows on both sides of the concentrating chamber dividing plate. is there.

Further, according to the present invention, a cathode chamber having a cathode and an anode chamber having an anode are provided, and between the both electrode chambers,
At least a part of cation exchange membranes and anion exchange membranes are alternately arranged, and a desalting chamber and a concentrating chamber are formed by using these ion exchange membranes and chamber frames, and at least desalting of the existing chambers. The chamber is filled with an ion exchanger, and the desalination chamber further includes a first desalination chamber group for roughly desalting the water to be treated and treated water treated in the first desalination chamber group. An electric regenerative desalination apparatus which is divided into a second desalination chamber group for desalination through a concentrating chamber, wherein the first desalination chamber group and the second desalination chamber group are separated from each other. Inside the concentrating chamber, a concentrating chamber dividing plate made of a rigid conductive material is provided, and the concentrated water introduced into the concentrating chamber dividing plate is provided with the concentrating chamber dividing plate. The electric regenerating desalination device is characterized in that a chamber frame is formed so as to flow on both sides of the plate.

In the electric regenerating type desalination apparatus, the concentration chamber dividing plate is arranged substantially in the center of the chamber frame forming the concentration chamber in the plate thickness direction and is incorporated in the chamber frame. Well, the ion exchanger is an ion exchanger having ion exchange groups introduced by a radiation graft polymerization method, and the shape thereof may be a non-woven fabric, a woven fabric, a net-like sheet, and the rigidity is high. The conductive material is, for example, a metal such as a titanium plate, a titanium plate whose surface is plated with platinum, or the like,
Also, a metal conductive plastic or the like which has been subjected to some kind of treatment is used.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor has proposed that an electrode is provided by interposing a conductive plate (a bipolar electrode) having much higher rigidity than an ion exchange membrane in the concentration chamber, preferably in the vicinity of the central portion in the thickness direction. The inventors have found that it is possible to reduce the film deformation due to the pressure between the chambers without reducing the area, and have completed the present invention. And according to this invention, the 1st desalination-chamber group which performs crude desalination and the 2nd desalination-chamber group which further desalinates the water processed by the 1st desalination chamber group are one unit. Even when incorporated in an electric regeneration type desalination apparatus, a conductive plate having much higher rigidity than the ion exchange membrane is provided in the concentration chambers adjacent to both the first desalination chamber group and the second desalination chamber group. By interposing the (double electrode), it is possible to reduce the membrane deformation due to the pressure difference generated between the first desalination chamber group and the second desalination chamber group without increasing the number of electrodes and electrode chambers therebetween. It is possible. As described above, in the present invention, desalting is performed by incorporating a concentration chamber dividing plate made of a conductive substance having a much higher rigidity than the ion exchange membrane, for example, a metal plate such as titanium or a conductive plastic into the concentration chamber. By suppressing the deformation of the membrane due to the pressure difference generated between the chambers without reducing the chamber area, it is possible to prevent an increase in flow channel pressure loss or prevent drift and improve the performance.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of the electric regeneration type desalination apparatus of the present invention. The same configuration as the configuration shown in FIG. A cathode chamber 2 having a cathode 1 and an anode chamber 4 having an anode 3 are arranged to face each other, and an anion exchange membrane 5 and a cation exchange membrane 6 are alternately arranged between the cathode chamber 2 and the anode chamber 4. As a result, a demineralizing chamber 7 and a concentrating chamber 8 are formed. In the concentrating chamber 8, a concentrating chamber dividing plate 30 made of a conductive material is provided, and concentrated water is concentrated by the concentrating chamber dividing plate 3.
The concentrating chamber 8 is formed so as to flow on both sides of 0. Desalination room 7
An electric regeneration type desalination apparatus is configured by filling the ion exchanger 9 with the ion exchanger 9. Further, it is desirable to fill the concentrating chamber 8 and the bipolar chambers 2 and 4 with the ion exchanger 9.

The cathode chamber inlet water 14 is supplied to the cathode chamber 2, and the anode chamber 4 is supplied.
To the anode chamber inlet water 16 and to the concentration chamber 8 to the concentration chamber inlet water 12
By introducing a desalting chamber inlet water 10 into the desalting chamber 7 and applying a direct current between the cathode 1 and the anode 3, the ion content contained in the desalting chamber inlet water 10 is ion-exchanged. Anions move through the surface of the body 9 in the direction of electric potential, anions permeate the anion exchange membrane 5, and cations permeate the cation exchange membrane 6 to concentrate water in the concentrating chamber 8, cathode water in the cathode chamber 2, and anode. It moves to the anode water in the chamber 4 and is discharged to the outside of the system, and the deionization chamber inlet water 10 is deionized to produce pure water 11. Since the ion exchanger filled in the desalting chamber 7 is continuously regenerated by H ⁺ and OH ⁻ generated by hydrolyzation, no regeneration work by acid or alkali is necessary. Water 11
Can be continuously manufactured. The chamber adjacent to the cathode chamber and the cathode chamber may be a desalting chamber or a concentrating chamber.

When the desalting chamber is adjacent to the cathode chamber, the ion exchanger to be filled in the cathode chamber is preferably a cation exchanger, and when the concentrating chamber is adjacent to the anion exchanger. desirable. When the desalting chamber is adjacent to the anode chamber,
The ion exchanger to be filled in the anode chamber is preferably an anion exchanger, and is preferably a cation exchanger when the concentrating chambers are adjacent to each other. Further, FIG. 2 is a schematic configuration diagram showing another example of the electric regenerative desalination apparatus of the present invention.
This is an example in which the concentration chamber dividing plate 30 is incorporated in the concentration chamber 8 adjacent to 0 and the second desalting chamber group 21. The method for incorporating the concentrating chamber dividing plate 30 is not particularly limited as long as its function is satisfied, but as one example thereof, in the present invention, as shown in FIG. 3, the concentrating chamber dividing plate is composed of two concentrating chamber dividing plates. And was used as one concentrating chamber. Here, both may be completely divided. In this case, it is naturally necessary to supply water to both sides.

[0016]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 In this example, an experiment of desalting was performed according to the flow chart of the test apparatus shown in FIG. As the demineralizing chamber inlet water 10, the concentrating chamber inlet water 1, the cathode chamber inlet water 14, and the anode chamber inlet water 16, Fujisawa city water pretreated with an activated carbon filter safety filter and a reverse osmosis membrane device was used. The water quality is a specific resistance of 0.20 MΩ · cm and a calcium concentration of 0.75 mg /
L and magnesium concentration were 0.22 mg / L.

In the experiment, an electric regenerative desalting apparatus having the structure shown in FIG. 1 was used in the test apparatus of FIG. 4, the flow rate of the demineralizing chamber inlet water 10 was 1 m ³ / h, and the flow rate of the concentrating chamber inlet water 12 was 360 L. /
h, the flow rate of the cathode chamber inlet water 14 and the flow rate of the anode chamber inlet water 16 are respectively 40 L / h, the concentration chamber dividing plate 30 is
Using a titanium plate with platinum plating on the surface, 1.
A DC current of 2 A was applied to the cathode 1 and the anode 3 for operation. The electric regeneration type desalination device has an electrode area of 0.256 m ² ,
There are 10 desalting chambers and 9 concentrating chambers. Cathode chambers and anode chambers are provided at both ends. Anion exchangers and cation exchangers are placed inside the desalting chambers and concentration chambers, and cations are placed inside the cathode chambers. The exchanger is filled with an anion exchanger in the anode chamber. As a result of operating under the above conditions, the specific resistance of pure water 11 was 14.8 MΩ · cm, and pure water having a higher specific resistance than Comparative Example 1 could be obtained.

As Comparative Example 1, an electric regenerating desalination apparatus having the structure shown in FIG. 5 was used for the electric regenerating desalination apparatus in FIG. 4, and the concentration chamber partition plate was not used. Same as As a result, pure water 1 having a specific resistance of 10.4 MΩ · cm
1 was produced continuously. From this result, in Example 1, since the concentration chamber dividing plate was placed in the concentration chamber, the amount of deformation of the membrane due to the pressure difference in each chamber was reduced, and the desalination chamber inlet water 10 was evenly distributed to each desalination chamber. Was introduced. As shown in the first embodiment,
By incorporating the concentrating chamber dividing plate 30 in the concentrating chamber 8, the influence of the pressure between the chambers can be reduced, and the flow rate of the desalting chamber inlet water 10 between the chambers can be made uniform, thereby improving the desalination performance. Improved.

Example 2 In Example 2, an electric regenerative desalination apparatus having the structure shown in FIG. 2 was used in the test apparatus shown in FIG. Desalination chamber inlet water 1
The flow rate of 0 is 1 m ³ / h and the flow rate of the water 12 at the inlet of the concentrating chamber is 68
0 L / h, cathode chamber inlet water 14 flow rate and anode chamber inlet water 16
Flow rate of 40 L / h for each of the concentrating chamber dividing plates 30
Uses a titanium plate with platinum plating on the surface,
A DC current of 1.2 A was applied to the cathode 1 and the anode 3 for operation. Electric regenerative desalination equipment has an electrode area of 0.256 m
² , 8 in the first and second desalination chamber groups, 17 in the concentration chamber
A cathode chamber and an anode chamber are provided at both ends, and anion exchanger and cation exchanger are provided in the desalting chamber and the concentration chamber, a cation exchanger is provided in the cathode chamber, and an anion exchange is provided in the anode chamber. The body is filled.

As a result of operating under the above conditions, the specific resistance of the pure water 11 was about 17.5 MΩ · cm, the water quality was improved as compared with Comparative Example 2, and the first desalination chamber group and the second desalination chamber were used. The pressure loss of each chamber group was about 0.05 MPa, and the desalting chamber inlet water 10 could be supplied at a supply pressure of about 0.1 MPa. Further, the flow rate of the outlet water 13 of the concentrating chamber adjacent to each of the first desalting chamber group 20 and the second desalting chamber group 21 is
The concentration chamber outlet water 13 adjacent to the first desalting chamber group 20 is 320 L / h, and the concentration chamber outlet water 13 adjacent to the second desalting chamber group 21 is 360 L / h. However, the imbalance of the flow rate was largely eliminated compared with 2.

As Comparative Example 2, an electric regenerative desalination apparatus having the structure shown in FIG. 6 was used in the electric regenerative desalination apparatus of FIG. 4, and other conditions were used in Example 2 without using a concentrating chamber dividing plate. Same as As a result, pure water 11 having a specific resistance of about 16.5 MΩ · cm could be continuously produced. However, while the pressure loss in the first desalination chamber group is approximately 0.05 MPa, the pressure loss in the second desalination chamber group is approximately 0.12 MPa, and the supply pressure of the desalination chamber inlet water 10 is approximately 0.2 MPa was required. Further, the flow rate of the outlet water 13 of the concentrating chamber adjacent to the first desalting chamber group and the outlet water 13 of the concentrating chamber adjacent to the second desalting chamber group
Of the concentration chamber outlet water 13 adjacent to the second desalination chamber group was about 440 L / h, the concentration of the concentration water adjacent to the first desalination chamber group was Room outlet water 13
The flow rate was about 240 L / h, which was a considerable imbalance.

[0022]

According to the electric regeneration type desalination apparatus of the present invention,
As described above, in the electric regenerative desalination device that removes the ion components in the water to be treated to produce pure water, by incorporating the concentration chamber dividing plate (double electrode) made of a conductive substance in the concentration chamber, , It is possible to suppress the influence of the membrane deformation etc. due to the pressure difference in each chamber, which makes it possible to prevent the membrane deformation due to the pressure difference without reducing the electrode plate area, and ensure stable operation. It is possible to make an electric regenerator that can

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an electric regeneration type desalination apparatus of the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the electric regeneration type desalination apparatus of the present invention.

FIG. 3 is an explanatory view showing a method of incorporating the concentrating chamber dividing plate used in the present invention.

FIG. 4 is a flowchart of the test apparatus used in the examples.

FIG. 5 is a schematic configuration diagram showing another example of a conventional electric regeneration desalination apparatus.

FIG. 6 is a schematic configuration diagram showing another example of a conventional electric regeneration desalination apparatus.

FIG. 7 is a schematic configuration diagram showing another example of a conventional electric regenerative desalination apparatus.

[Explanation of symbols]

1: Cathode, 2: Cathode chamber, 3: Anode, 4: Anode chamber, 5: Anion exchange membrane, 6: Cation exchange membrane, 7: Deionization chamber, 8:
Concentration chamber, 9: ion exchanger, 10: water in the desalting chamber, 1
1: Pure water, 12: Concentration chamber inlet water, 13: Concentration chamber outlet water,
14: cathode chamber inlet water, 15: cathode chamber outlet water, 16: anode chamber inlet water, 17: anode chamber outlet water, 19: first desalting chamber outlet water, 20: first desalting chamber group, 21 : Second desalination chamber group,
30: Concentration chamber dividing plate

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Claims (4)

[Claims] 1. A cathode chamber having a cathode and an anode chamber having an anode, and at least a part of a cation exchange membrane and an anion exchange membrane are alternately arranged between the both electrode chambers, and these ions are An electric regenerative desalination apparatus in which a desalting chamber and a concentrating chamber are formed using an exchange membrane and a chamber frame, and at least the desalting chamber among the existing chambers is filled with an ion exchanger. At least one of the concentrating chambers is provided with a concentrating chamber dividing plate made of a rigid conductive material therein, and the concentrating chamber provided with the concentrating chamber dividing plate is provided with concentrated water to be introduced. An electric regeneration type desalination apparatus, wherein a chamber frame is formed so as to flow on both sides of the concentrating chamber division plate. 2. A cathode chamber having a cathode and an anode chamber having an anode, and at least a part of a cation exchange membrane and an anion exchange membrane are alternately arranged between the two electrode chambers, and these ions are A desalting chamber and a concentrating chamber are formed using an exchange membrane and a chamber frame, and at least the desalting chamber among the existing chambers is filled with an ion exchanger, and the desalting chamber is filled with water to be treated. Is divided into a first desalting chamber group for roughly desalting the water and a second desalting chamber group for further desalting the treated water treated in the first desalting chamber group. An electric regeneration type desalination device in which the inside of the concentrating chamber separating the first desalting chamber group and the second desalting chamber group is divided into a concentrating chamber made of a rigid conductive material. The concentrated water to be introduced into the concentrating chamber having the plate and the concentrating chamber dividing plate flows on both sides of the concentrating chamber dividing plate. An electric regeneration type desalination device characterized in that a chamber frame is formed. 3. The concentrating chamber dividing plate is arranged in a substantially central portion in a plate thickness direction of a chamber frame forming the concentrating chamber and is incorporated in the chamber frame. Alternatively, the electric regenerative desalination apparatus according to 2 above. 4. The ion exchanger is an ion exchanger in which an ion exchange group is introduced by a radiation graft polymerization method, and the shape thereof is a non-woven fabric, a woven fabric, or a net-like sheet. The electric regenerative desalination apparatus according to 1, 2, or 3.