JP2003145164A - Electric deionized water production apparatus and deionized water production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric deionized water production apparatus and a deionized water production method wherein the scale is prevented from being generated in the concentration chamber during long continuous operation by solving a problem of scale generation from an aspect of the structure of a concentration chamber in the electric deionized water production apparatus. SOLUTION: In this deionized water production method, a desalting chamber is formed by filling ion exchange bodies into the desalting chamber partitioned by a cation exchange membrane disposed on one side and an anion exchange membrane disposed on the other side, concentration chambers are installed on both the sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane, the desalting chambers and the concentration chamber are disposed between an anode chamber with an anode and a cathode chamber with a cathode, and water to be treated is made to flow into the desalting chamber while applying a voltage and concentrated water is made to flow into the concentration chamber, thereby removing impurity ions in the water to be treated to produce deionized water. The concentration chamber is formed by laminating and filling a reticulated cation conducting spacer and a reticulated anion conductive spacer alternately in the inlet and outlet direction of the concentrated water.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the field of semiconductor manufacturing,
The present invention relates to a scale generation prevention type electric deionized water manufacturing apparatus and a deionized water manufacturing method used in various fields such as pharmaceutical manufacturing, power generation fields such as nuclear power and thermal power, food industry and laboratory facilities.

[0002]

2. Description of the Related Art As a method for producing deionized water, a method of deionizing water by passing through water to be treated through an ion exchange resin has been conventionally known. In this method, when the ion exchange resin is saturated with ions, It is necessary to regenerate with chemicals, and in order to eliminate such disadvantages in processing operation, a method for producing deionized water by an electric deionization method, which does not require regeneration with chemicals, has been established and has been put to practical use. There is.

This electric deionized water producing apparatus is divided into a cation exchange membrane on one side and an anion exchange membrane on the other side 1.
One chamber is filled with an ion exchanger to form a desalting chamber, and concentration chambers are provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane. It is arranged between an anode chamber provided with a cathode and a cathode chamber provided with a cathode.The treated water flows into the desalting chamber while applying a voltage, and the concentrated water flows into the concentration chamber to receive the treated water. Impurity ions in the treated water are removed to obtain deionized water.

In recent years, cation exchange membranes and anion exchange membranes are alternately arranged apart from each other, and the space formed by the cation exchange membrane and the anion exchange membrane is filled with every other ion exchanger to form a desalting chamber. In place of the conventional type electric deionized water producing device, a power saving type electric deionized water producing device has been developed in which the structure of the desalting chamber is drastically modified. This power-saving type electric deionized water producing device is partitioned by a cation exchange membrane on one side, an anion exchange membrane on the other side, and an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane. The two small desalting chambers are filled with an ion exchanger to form a desalting chamber. Concentration chambers are provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane. The chamber is arranged between an anode chamber with an anode and a cathode chamber with a cathode.The water to be treated is introduced into one of the small desalination chambers while applying a voltage, and then the small desalination chamber is supplied. The outflow water of the salt chamber flows into the other small demineralization chamber, and the concentrated water flows into the concentration chamber to remove impurity ions in the water to be treated to obtain deionized water. According to the electric deionized water producing apparatus having such a structure, the ion exchanger filled in at least one of the two small desalting chambers is, for example, only the anion exchanger or only the cation exchanger. Can be used as a single ion exchanger or a mixed exchanger of anion exchanger and cation exchanger, and the electrical resistance can be reduced for each type of ion exchanger, and the optimum thickness for obtaining high performance can be obtained. Can be set.

On the other hand, when the hardness of the water to be treated flowing into such an electric deionized water producing apparatus is high, scales such as calcium carbonate and magnesium hydroxide are generated in the concentration chamber of the electric deionized water producing apparatus. . When the scale occurs, the electric resistance at that portion increases, and it becomes difficult for current to flow. That is, it is necessary to increase the voltage in order to pass the same current value as when there is no scale generation.
Power consumption increases. In addition, the current density in the concentrating chamber varies depending on the place where the scale is attached, and the current becomes nonuniform in the demineralizing chamber. Further, if the scale adhesion amount further increases, the water flow differential pressure also rises, the voltage further rises, and when the maximum voltage value of the device is exceeded, the current value decreases. In this case, the current value required for ion removal cannot be applied, resulting in deterioration of treated water quality. Furthermore, the grown scale erodes even into the ion exchange membrane and eventually breaks the ion exchange membrane.

[0006]

As one of the measures for solving such a problem, there is a method of flowing water to be treated having low hardness into an electric deionized water producing apparatus. In the water to be treated having such a low hardness, the solubility product is not reached in the concentrating chamber, so that the scale cannot be generated. However, in practice, even when the water to be treated having such low hardness is passed through, scales such as calcium carbonate and magnesium hydroxide may be generated in the concentrating chamber. In this case, similar to the above, serious problems occur. The generation of such a scale is a serious problem that is similarly observed in the conventional electric deionized water manufacturing apparatus and the power-saving electric deionized water manufacturing apparatus. On the other hand, in a concentrating chamber defined by a cation exchange membrane and an anion exchange membrane of a conventional electric deionized water production system, a mesh-like cation conducting spacer is provided on the cation exchange membrane side and a mesh-like anion conducting membrane is provided on the anion exchange membrane side. Methods of filling spacers are known. According to this method, it is possible to secure the flow path in the concentrating chamber and reduce the voltage. However, it is not sufficient in terms of prevention of scale generation, and the serious problem of scale generation on the cation-conducting spacer and the anion-conducting spacer has not been solved yet.

[0007] Therefore, the object of the present invention is to solve the problem of scale generation from the structure of the concentrating chamber of the electric deionized water producing apparatus, not from the measures to be taken from the water to be treated, and even in long-term continuous operation. An object of the present invention is to provide an electric deionized water producing apparatus and a deionized water producing method in which no scale is generated in the concentrating chamber.

[0008]

Under such circumstances, the inventors of the present invention have made earnest studies, and as a result, as a result, a mesh-like structure was formed in the concentrating chamber of the electric deionized water manufacturing apparatus in the flowing direction of the concentrated water. If the cation-conducting spacers and the mesh-shaped anion-conducting spacers are alternately stacked and filled, the turbulent flow generation effect due to the mesh shape of the spacers and the inflow and outflow directions of the concentrated water of the cation-conducting spacers and the anion-conducting spacers The present invention has been completed by discovering that the concentration gradient of carbonate ions and calcium ions in concentrated water can be greatly reduced due to the effect of being alternately stacked, and that no scale is generated in the concentration chamber even during long-term continuous operation. Came to.

That is, according to the present invention (1), a desalting chamber is constructed by filling an ion exchanger into a chamber defined by the cation exchange membrane on one side and the anion exchange membrane on the other side. An electric deionization system is provided in which concentration chambers are provided on both sides of the deionization chamber through anion exchange membranes, and the deionization chamber and the concentration chamber are arranged between an anode chamber having an anode and a cathode chamber having a cathode. In the ionized water production apparatus, the concentration chamber is an electrical deionization device in which mesh-like cation-conducting spacers and mesh-like anion-conducting spacers are alternately stacked and filled in the concentrated water inflow and outflow directions. Is provided. By adopting such a configuration, in the mesh-shaped anion-conducting spacer region of the concentrating chamber, the anions that have permeated the anion-exchange membrane do not move into the concentrated water, but pass through the highly-conductive anion-conducting spacer and move to the cation-exchange membrane. , Move to concentrated water for the first time here. Similarly, in the mesh-shaped cation-conducting spacer region, the cations that have permeated the cation-exchange membrane do not move into the concentrated water, but pass through the cation-conducting spacer having high conductivity and move to the anion-exchange membrane, where it is first introduced into the concentrated water. Moving. Therefore, in the concentrating chamber, for example, the concentration gradient of carbonate ions, calcium ions, etc. in the liquid is greatly reduced, and collision in the high concentration portion is avoided. Further, as described above, the ions transferred to the cation exchange membrane or the anion exchange membrane are sufficiently agitated by the turbulent flow generation effect due to the network shape of the spacers, so that the accumulation of scale in the concentrating chamber is hindered and the carbon dioxide is further increased. Scales such as calcium are less likely to occur.

In addition, the present invention (2) comprises two cation exchange membranes, one side cation exchange membrane, the other side anion exchange membrane, and an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane. A small desalting chamber is filled with an ion exchanger to form a desalting chamber. Concentration chambers are provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane. In an electric deionized water producing apparatus arranged between an anode chamber having an anode and a cathode chamber having a cathode,
The concentrating chamber provides an electric deionized water manufacturing apparatus in which reticulated cation-conducting spacers and reticulated anionic-conducting spacers are alternately stacked and filled in the inflow / outflow direction of concentrated water. It is a thing. By adopting such a configuration, the same effect as that of the above invention can be obtained even in the power-saving type electric deionized water producing apparatus. Further, among the two small desalting chambers, at least one desalting chamber is filled with a single ion exchanger such as an anion exchanger alone or a cation exchanger alone or an anion exchanger and a cation exchange chamber. It can be used as a mixed exchanger of the body, and the electric resistance can be reduced for each type of ion exchanger, and the thickness can be set to an optimum thickness for obtaining high performance. Further, the concentrating chamber has higher conductivity, the current density can be made uniform throughout the inlet side to the outlet side of the desalting chamber, and the power consumption can be further reduced.

Further, in the present invention (3), the ion exchanger filled in one of the small deionization chambers partitioned by the intermediate ion exchange membrane and the anion exchange membrane on the other side is an anion exchanger, The ion exchanger filled in the other small desalting chamber partitioned by the one side cation exchange membrane and the intermediate ion exchange membrane is a mixture of a cation exchanger and an anion exchanger, A deionized water producing apparatus is provided. By adopting such a configuration, in addition to exhibiting the same effect as the above-mentioned invention, water to be treated containing a large amount of anion component,
In particular, water to be treated containing a large amount of weakly acidic components such as silica and carbonic acid can be sufficiently treated.

The present invention (4) provides the electric deionized water producing apparatus according to (1) to (3), wherein the concentration chamber has a thickness of 0.2 to 8.0 mm. Is. By adopting such a configuration, the electric resistance is reduced and
It is possible to prevent the generation of scale and to determine the optimum thickness of the concentration chamber without increasing the water differential pressure.

In the present invention (5), a deionization chamber is constructed by filling an ion exchanger in a chamber defined by the cation exchange membrane on one side and the anion exchange membrane on the other side. A concentration chamber is provided on both sides of the desalination chamber via an anion exchange membrane, and these desalination chamber and concentration chamber are arranged between an anode chamber having an anode and a cathode chamber having a cathode, and a voltage is applied. While injecting the water to be treated into the demineralizing chamber and flowing the concentrated water into the concentrating chamber to remove the impurity ions in the water to be treated to obtain deionized water, the concentrating chamber has a net-like cation. The present invention provides a method for producing deionized water, in which conductive spacers and mesh-like anion conductive spacers are formed by alternately stacking and filling them in the inflow and outflow directions of concentrated water. By adopting such a configuration, the same effect as that of the invention (1) can be obtained.

Further, the present invention (6) comprises two cation exchange membranes, one side cation exchange membrane and the other side anion exchange membrane, and an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane. A small desalting chamber is filled with an ion exchanger to form a desalting chamber. Concentration chambers are provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane. It is arranged between an anode chamber provided with an anode and a cathode chamber provided with a cathode, and water to be treated is introduced into one of the small desalination chambers while applying a voltage, and then the outflow water of the small desalination chamber is supplied to the other. In the method for obtaining deionized water by flowing the concentrated water into the small demineralization chamber and flowing the concentrated water into the concentrating chamber to obtain deionized water, the concentrating chamber comprises a net-like cation-conducting spacer. The mesh-shaped anion conductive spacers are aligned with the flowing direction of concentrated water. There is provided a method for producing deionized water in which is stacked filled in. By adopting such a configuration, the same effect as that of the invention (2) can be obtained.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric deionized water producing apparatus according to this embodiment will be described with reference to FIG. Figure 1
FIG. 1 is a schematic diagram showing an example of an electric deionized water producing apparatus. As shown in FIG. 1, the cation exchange membranes 3, the intermediate ion exchange membranes 5 and the anion exchange membranes 4 are spaced apart from each other and alternately arranged, and ion exchange is performed in the space formed by the cation exchange membranes 3 and the intermediate ion exchange membranes 5. The body 8 is filled to form the first small desalting chambers d ₁ , d ₃ , d ₅ and d ₇ , and the intermediate ion exchange membrane 5
The space formed by the anion exchange membrane 4 is filled with the ion exchanger 8 to form the second small desalting chambers d ₂ , d ₄ , d ₆ and d ₈ , and the first small desalting chamber d ₁ is formed. Demineralization chamber D in the second small desalination chamber d _2.
1 , a desalination chamber D ₂ in the first small desalination chamber d ₃ and the second small desalination chamber d ₄ , and a desalination chamber D in the first small desalination chamber d ₅ and the second small desalination chamber d _6.
3 , the first small desalination chamber d ₇ and the second small desalination chamber d ₈ in the desalination chamber D ₄
And The portion filled with the ion exchanger 8a formed of the anion exchange membrane 4 and the cation exchange membrane 3 located adjacent to the desalting chambers D ₂ and D ₃ is the concentration chamber 1 for flowing the concentrated water. These are installed side by side and from the left in the figure, a desalting chamber D ₁ , a concentrating chamber 1, a desalting chamber D ₂ , a concentrating chamber 1, a desalting chamber D ₃ ,
A concentrating chamber 1 and a desalting chamber D ₄ are formed. Further, on the left side of the desalting chamber D ₁ , the cathode chamber 2a is passed through the cation exchange membrane 3 and the desalting chamber D _{4 is}
Anode chambers 2b are provided on the right side of the above through the anion exchange membrane 4. In the two small desalination chambers adjacent to each other via the intermediate ion exchange membrane 5, the treated water outflow line 1 of the second small desalination chamber 1
2 is connected to the untreated water inflow line 13 of the first small desalination chamber.

Such a desalting chamber is, as shown in FIG.
Two frame bodies 21, 22 and three ion exchange membranes 3, 5, 4
A deionization module 20 formed by
That is, the cation exchange membrane 3 is formed on one surface of the first frame 21.
To seal the inner space of the first frame 21 with an ion exchanger, and then seal the intermediate ion exchange membrane 5 to the other surface of the first frame 21 to form the first small desalting chamber. Form. Next, the second frame body 22 is sealed so as to sandwich the intermediate ion exchange membrane 5,
The inner space of the second frame 22 is filled with an ion exchanger, and then the anion exchange membrane 4 is sealed on the other surface of the second frame 22 to form a second small desalting chamber. The ion exchanger filled in the first desalting chamber and the second small desalting chamber is not particularly limited, but the second small desalting chamber into which the water to be treated first flows is filled with an anion exchanger, Then, the first small desalting chamber into which the outflow water of the second small desalting chamber flows is filled with a mixed ion exchanger of an anion exchanger and a cation exchanger so that treated water containing a large amount of anion components, particularly It is preferable in that the water to be treated containing a large amount of weakly acidic components such as silica and carbonic acid can be sufficiently treated. Reference numeral 23 is a rib for reinforcing the frame.

In the concentrating chamber 1, mesh-like cation-conducting spacers and mesh-like anion-conducting spacers are alternately stacked and filled in the inflow / outflow direction of the concentrated water. The method for laminating these mesh-shaped ion-conducting spacers is not particularly limited, and includes two beds of an anion-conducting spacer and a cation-conducting spacer, and a compound bed of a plurality of anion-conducting spacers and cation-conducting spacers alternately laminated. Either may be used.
The mesh-shaped ion-conducting spacer to be filled in the concentrating chamber is not particularly limited and has a two-dimensional or three-dimensional mesh structure, and when filled in the concentrating chamber, the water flow differential pressure is within the allowable range. The turbulent flow can be applied to the concentrated water while maintaining the above, and it has an ion-exchange group.
And a graft-polymerizable monomer which has an ion-exchange group or can be converted into an ion-exchange group on the surface of the cross-linking network.

In the ion conductive spacer using a cross-linking network of polyolefin type polymers, the polyolefin type polymer is not particularly limited, and examples thereof include polypropylene, polyethylene and polyethylene terephthalate.
As shown in FIG. 2, the shape of the oblique mesh is such that an infinite number of wire rods are oriented at an interval m and a front side wire rod 32 in which an innumerable number of wires are oriented at an interval n intersect at each intersection as shown in the figure. A plain weave diagonal mesh 30 integrally formed is exemplified. The distance m between the front-side wires and the distance n between the back-side wires may be the same or different, but they are usually the same.
Further, the thickness w of the oblique net 30 is substantially the same as the thickness of the concentrating chamber when one is filled in the concentrating chamber. The polymerizable monomer to be graft-polymerized on the surface of the cross network 30 can be selected from polymerizable monomers having an ion exchange group or convertible to an ion exchange group. Include sulfone groups, carboxyl groups, etc.,
Examples of the anion exchange group include a quaternary ammonium group and a tertiary amine group. Although there is no particular limitation on the mesh size of the crossed net having the ion exchange group introduced,
It is 0%, preferably 30 to 70%. If the openings are too large, electrical conduction cannot be obtained between the ion exchange membranes on both sides that partition the concentration chamber, ions do not move, and the ion concentration gradient in the concentrated water cannot be reduced. on the other hand,
If the mesh size is too small, the water flow differential pressure of the concentrated water is undesirably increased. The oblique net with the ion-exchange groups introduced is packed in the concentrating chamber with the mesh facing the ion-exchange membranes on both sides. Even if the packing amount is one,
Any of the filling in which a plurality of sheets are stacked may be used. Further, the diagonal mesh may be twill weave in addition to the mesh shown in FIG. 2, and the mesh shape may be a rhombus, a quadrangle, a circle, an ellipse, or the like. In the case of a plain weave diagonal net having a square mesh shape, one side of the square is about 0.5 to 5.0 mm, preferably about 1.0 to 3.0 mm.

The concentration chamber 1 is, for example, as shown in FIG.
Anion exchange membrane 4 on one side and cation exchange membrane 3 on the other side
Then, it is manufactured by sandwiching the mesh-shaped ion-conducting spacers 81 and 82 cut into a standard size. In FIG. 3, the mesh-shaped ion-conducting spacer is composed of two laminated floors 8 a including an anion-conducting spacer 81 on the upper side and a cation-conducting spacer 82 on the lower side. That is, two beds of one cation-conducting spacer 81 and one anion-conducting spacer 82 of the same size as the cation-conducting spacer 81 are laminated in the concentrating chamber of the flat plate-type electric deionized water manufacturing apparatus. When filling,
The vertical and horizontal dimensions of the ion-conducting spacer formed of two beds are the same as those of the ion exchange membranes 3 and 4 on both sides, and the thickness dimension w is the thickness in the concentration chamber. In the concentrating chamber 1, the order of the ion-conducting spacers stacked and filled in the inflow / outflow direction of the concentrated water is not particularly limited, and the reticulated cation-conducting spacers and the reticulated anion-conducting spacers are arranged from the concentrated water inlet side. The spacers may be ordered, or the mesh-shaped anion conductive spacers and the mesh-shaped cation conductive spacers may be sequentially arranged.
Further, the end face portions of the different ion conductive spacers are not particularly limited as long as a large gap is not formed, and the end faces are brought into contact with or brought close to each other to be stacked and filled. Thus, if the mesh-shaped cation-conducting spacers and anion-conducting spacers are uniformly stacked and packed in the concentrating chamber defined by both ion-exchange membranes, the electrical conductivity between the ion-exchange membranes on both sides of the concentrating chamber is defined. It is possible to obtain electrical continuity, transfer ions, and reduce the ion concentration gradient in the concentrated water. Further, the effect of reducing the ion concentration is further enhanced by the effect of generating turbulence due to the mesh shape of the spacer. On the other hand, the thickness of the concentrating chamber is 0.2 to 8.0 mm, preferably 0.5 to 5.0 mm, more preferably 0.8 to 2.
It is 5 mm. If the thickness of the concentrating chamber is less than 0.2 mm, even if the mesh-shaped cation-conducting spacers and the mesh-shaped anion-conducting spacers are alternately stacked and filled in the concentrated water inflow / outflow direction, It becomes difficult to obtain the effect of preventing scale generation, and water flow differential pressure tends to occur. On the other hand, if it exceeds 8.0 mm, the electric resistance increases and the power consumption increases.

The electric deionized water producing apparatus is usually
It is operated as follows. That is, between the cathode 6 and the anode 7
To the treated water inflow line 11
As the treated water flows in, it is concentrated from the concentrated water inflow line 15.
Condensed water flows in, and cathode water inflow line 17a, anode water flow
Cathode water and anode water respectively flow in from the inlet line 17b.
It The treated water flowing in from the treated water inflow line 11 is
2 small desalination chamber d₂, D_Four, D₆, D₈Flow down, ion exchange
Impurity ions are removed when passing through the packed bed of the replacement body 8.
It Further, through the treated water outflow line 12 of the second small desalination chamber.
The effluent discharged from the treated water inflow line 13 of the first small desalination chamber
Through the first small desalination chamber d₁, D₃, D_Five, D ₇Downflow,
Here, too, impurities are generated when passing through the packed bed of the ion exchanger 8.
Ion is removed and deionized water is deionized water outflow line 1
Obtained from 4. In addition, inflow from the concentrated water inflow line 15
The concentrated water that has risen rises in each concentrating chamber 1, and the cation exchange membrane 3 and
And impurity ions that move through the anion exchange membrane 4
The ion conduction space inside the concentrating chamber, as described below.
The impurity ions moving through the sensor are received and
Concentration chamber outflow line 1 as concentrated water with concentrated pure ions
6 and then from the cathode water inflow line 17a.
The entered cathode water flows out from the cathode water outflow line 18a,
The anode water flowing in from the anode water inflow line 17b is the anode water.
It flows out from the outflow line 18b. By the above operation
Thus, the impurity ions in the water to be treated are electrically removed.

Next, the action of preventing scale generation in the concentrating chamber of the electric deionized water producing apparatus of the present invention will be described with reference to FIGS. FIG. 4 is a diagram more simply showing the electric deionized water production apparatus of FIG. 1, and FIGS. 5 and 6 are diagrams for explaining movement of impurity ions in the concentration chamber of the electric deionized water production apparatus of FIG. Are shown respectively. In FIG. 4, the second small desalting chambers d ₂ , d ₄ , d ₆ into which the water to be treated first flows
Is filled with anion exchanger (A), and the first small desalting chambers d ₁ , d ₃ and d ₅ into which the outflow water of the second small desalting chamber flows are mixed ions of a cation exchanger and an anion exchanger. Exchanger (M)
The four concentrating chambers 1 are alternately filled with a mesh-shaped anion-conducting spacer single bed (A) and a mesh-shaped cation-conducting spacer single bed (C) in order along the water flow direction of the desalting chamber. Floor-filled.

In FIG. 5, in the single bed region 1a of the reticulated anion conducting spacer of the concentrating chamber 1, anions such as carbonate ions permeating the anion exchange membrane a do not move into the concentrated water,
It moves to the cation exchange membrane c through the anion-conducting spacer A having high conductivity, and moves to the concentrated water for the first time at the contact portion 101 between the anion-conducting spacer A and the cation membrane c (arrow pointing right in FIG. 5). Therefore, anions such as carbonate ions are discharged from the concentration chamber 1 while being electrically attracted to the cation exchange membrane c. That is, with respect to anions such as carbonate ions in the anion-conducting spacer single-bed region 1a, the concentration gradient in the concentrated water is distributed as indicated by the symbol X in FIG. On the other hand, in the single bed region 1a of the anion conductive spacer, cations such as calcium ions that have permeated the cation exchange membrane c move in the concentrated water. Therefore, at the portion where the concentration of calcium ions is the highest, the carbonate ion, which is a counter ion that forms the scale, moves in the single-bed portion of the anion-conducting spacer, so that scale is difficult to generate.

Similarly, in the cation-conducting spacer single bed region 1b of the concentrating chamber 1, cations such as calcium ions having permeated through the cation-exchange membrane c do not move into the concentrated water, pass through the cation-conducting spacer C having high conductivity, and pass through the anion. The cation-conducting spacer C and the anion membrane a move to the exchange membrane a.
The contact portion 102 moves to the concentrated water for the first time (in FIG. 5, leftward arrow). Therefore, cations such as calcium ions are discharged from the concentration chamber 1 while being electrically attracted to the anion exchange membrane a. That is, for the cations such as calcium ions in the single bed region 1b of the cation conductive spacer, the concentration gradient in the concentrated water is distributed as indicated by the symbol Y in FIG. On the other hand, anion exchange membrane a
Anions such as carbonate ions that permeate through the solution migrate in concentrated water. For this reason, in the portion where the concentration of carbonate ions is highest, the calcium ion, which is a counter ion forming the scale, moves in the single-bed portion of the cation-conducting spacer, so that scale is difficult to generate. Furthermore, since the ion-conducting spacer filled in the concentrating chamber has a mesh-like shape, the flow of the concentrated water is likely to be turbulent, and the concentration gradient of carbonate ions, calcium ions, etc. can be greatly reduced, and the ion-exchange membrane can be used. Since it has the effect of scraping off the scale component that tends to adhere to the surface, the generation of scale is further suppressed.
Such ion transfer is the same for magnesium ions, hydrogen ions, and hydroxide ions. Further, by stacking the anion conductive spacer single bed region 1a and the cation conductive spacer single bed region 1b inside the concentration chamber,
The anions that have moved to the portion filled with the cation-conducting spacer are transmitted through the anion-exchange membrane having high conductivity and reach the single-bed region 1a of the anion-conducting spacer, rather than moving in the concentrated water having low conductivity, where the conductivity is increased. High anion exchanger. This ion movement mode is the same for cations. That is, almost no ions move through the concentrated water to the vicinity of the facing ion exchange membrane,
Most of the ions move through the cation conducting spacer and the anion conducting spacer to the vicinity of the facing ion exchange membrane. 5 and 6, in the concentrating chamber 1, a cation exchange membrane a and an anion exchange membrane c, and a net-like cation-conducting spacer single bed area 1a or a net-like anion-conducting spacer single bed area 1b. There is a gap between them,
This is provided to make it easier to understand the stacked state of the ion conductive spacers, and in reality, it is in a close contact state,
There is no such gap.

In the conventional electric deionized water production apparatus, the current applied for the purpose of regenerating the ion exchanger promotes the electrolysis of water, and the concentration chamber filled with the network spacer which does not show the ion conductivity. Causes a pH shift on the surface of the ion exchange membrane, the pH is high in the vicinity of the anion exchange membrane, the pH is low in the vicinity of the cation exchange membrane, and as shown in FIG. 7, both carbonate ions and calcium ions are in contact with each other with a high concentration gradient. Therefore, scale was likely to be generated on the surface of the anion exchange membrane on the concentration chamber side. However, in this example, as described above, in the concentrated water near the surface of the anion exchange membrane a where the cation concentration in the concentrated water seems to be the highest,
Since there is no high concentration of anion such as carbonate ion, there is no case where the carbonate ion and the calcium ion are combined to produce calcium carbonate in the concentrating chamber (Fig. 6).
reference). Therefore, even if the electric deionized water producing apparatus of this example is continuously operated for a long time, no scale is generated in the concentrating chamber.

Further, the concentrating chamber 1 has an ion conducting spacer 8a.
Since the cation exchange membranes 3 and the anion exchange membranes 4 located on both sides are electrically conducted by the homogeneous and close packing, the conductivity is enhanced, and the current density is uniform over the entire inlet side to the outlet side of the desalting chamber. And can reduce power consumption.

In the present invention, the flow directions of the water to be treated in the first small desalting chamber and the second small desalting chamber are not particularly limited, and in addition to the above embodiment, the first small desalting chamber and The flow directions in the two small desalting chambers may be different. The small desalination chamber into which the water to be treated flows is, in addition to the above-described embodiment, first, the water to be treated is caused to flow into the first small desalination chamber, and after flowing down, the outflow of the first small desalination chamber. Water may be allowed to flow into the second small desalting chamber. Also, the flow direction of the concentrated water is appropriately determined.

Another electric deionized water producing apparatus according to the embodiment of the present invention will be described with reference to FIG. The electric deionized water production apparatus 100 of FIG. 8 is a form in which the intermediate ion exchange membrane in the power-saving electric deionized water production apparatus 10 shown in FIG. Is one pass. That is, in the electric deionized water producing apparatus 100, the cation exchange membrane 10 on one side is
A desalting chamber 104 is formed by filling a chamber defined by the anion exchange membranes 102 on the first and other sides with an ion exchanger 103.
Concentration chambers 105 are provided on both sides of the desalination chamber 104 via the cation exchange membrane 101 and the anion exchange membrane 102, and the desalination chamber 104 and the concentration chamber 105 are provided with an anode chamber having an anode 110 and a cathode having a cathode 109. It is arranged between the chambers, and while water is applied to the desalination chamber 104 while applying voltage,
In the method of flowing the concentrated water into the concentrating chamber 105 to remove the impurity ions in the water to be treated to obtain the deionized water, the concentrating chamber 105 adopts the same configuration as that of the above-described embodiment, and thus has the same function. Produce an effect. In addition, reference numeral 111 is a treated water inflow line, 114 is a deionized water outflow line, 1
15 is a concentrated water inflow line, 116 is a concentrated water outflow line,
Reference numeral 117 represents an electrode water inflow line, and 118 represents an electrode water outflow line. Further, the form of the electric deionized water producing apparatus of the present invention is not particularly limited, spiral type,
Examples include concentric circle type and flat plate type.

The water to be treated used in the method for producing deionized water of the present invention is not particularly limited, and examples thereof include well water, tap water, sewage, industrial water, river water, and cleaning drainage of semiconductor devices in semiconductor manufacturing plants. Alternatively, there may be mentioned permeated water obtained by performing reverse osmosis membrane treatment of water recovered from the concentrating chamber, or water that has been used at points of use such as semiconductor manufacturing plants and has not been subjected to reverse osmosis membrane treatment. When using a part of the treated water supplied in this way as concentrated water,
It is preferable to use the water to be treated supplied to the desalting chamber and the concentrated water to be supplied to the concentrating chamber after softening them, since the scale generation can be further suppressed. The softening method is not particularly limited, but a softener using a sodium-type ion exchange resin or the like is preferable.

[0029]

EXAMPLES Example 1 An electric deionized water producing apparatus having the same configuration as that shown in FIG. 8 and having six deionization modules arranged in parallel was used under the following apparatus specifications and operating conditions. The water to be treated is permeated water of reverse osmosis membrane for industrial use, and its hardness is 200 μgCaC.
It was O ₃ / l. Further, a part of the water to be treated was used as concentrated water and electrode water. Driving time is 4000 hours,
The presence or absence of scale generation in the concentration chamber after 4000 hours was observed. Table 1 shows the operating conditions for obtaining treated water having a resistivity of 17.9 MΩ-cm 2 at the same time.

(Operating conditions) -Electric deionized water production device; trial EDI-Demineralization chamber; width 300 mm, height 600 mm, thickness 3 mm-ion exchange resin filled in the deionization chamber; anion exchange resin (A ) And cation exchange resin (K) mixed ion exchange resin (mixing ratio by volume ratio is A: K = 1: 1) -concentration chamber; width 300 mm, height 600 mm, thickness 1 mm-concentration chamber-filled ion conductive spacer; 4 beds in which mesh-shaped cation-conducting spacer single beds and mesh-shaped anion-conducting spacer single beds are alternately laminated along the inflow / outflow direction of concentrated water ・ Flow rate of the whole device; 1 m ³ / h

Example 2 Under the following equipment specifications and operating conditions, an electric deionized water production system was constructed in which three deionization modules (six small deionization chambers) were arranged in parallel with the same construction as in FIG. The equipment was used.
Industrial water reverse osmosis membrane permeate was used as the water to be treated, and its hardness was 200 μg CaCO ₃ / l. Further, a part of the water to be treated was used as concentrated water and electrode water. Driving time is 4
It was 000 hours, and the presence or absence of scale generation in the concentrating chamber after 4000 hours was observed. Table 1 shows the operating conditions for obtaining treated water with a resistivity of 17.9 MΩ-cm at the same time.
Shown in.

(Operating conditions) -Electric deionized water production device; trial EDI-intermediate ion exchange membrane; anion exchange membrane-first small desalting chamber; width 300 mm, height 600 mm, thickness 3 mm-first small Ion exchange resin filled in the desalting chamber; mixed ion exchange resin of anion exchange resin (A) and cation exchange resin (K) (mixing ratio is A: K = 1: 1 by volume ratio) ・ Second small desalting chamber Width 300 mm, height 600 mm, thickness 8 mm-Second small desalting chamber filled ion exchange resin; anion exchange resin-concentration chamber; width 300 mm, height 600 mm, thickness 1 mm-concentration chamber filled ion conductive spacer; mesh-like Cation-conducting spacer single beds and mesh-like anion-conducting spacer single beds were alternately laminated along the inflow / outflow direction of concentrated water. Flow rate of the entire device: 1 m ³ / h

Comparative Example 1 The same procedure as in Example 1 was carried out except that instead of the mesh-shaped ion conductive spacer, a mesh spacer having no ion conductivity was filled in the concentration chamber. The operation time was 4000 hours, and the presence or absence of scale generation in the concentrating chamber after 4000 hours was observed. In addition, the resistivity at the same time is 17.9 MΩ
Table 1 shows the operating conditions for obtaining -cm 2 of treated water. The mesh spacer having no ion conductivity is the one before introduction of the ion exchange group, which is obtained in the manufacturing process of the mesh ion conductive spacer used in Example 1.

Comparative Example 2 The same procedure as in Example 2 was carried out except that the concentration chamber was filled with a mesh spacer having no ion conductivity instead of the mesh ion conductive spacer. The operation time was 4000 hours, and the presence or absence of scale generation in the concentrating chamber after 4000 hours was observed. In addition, the resistivity at the same time is 17.9 MΩ
Table 1 shows the operating conditions for obtaining -cm 2 of treated water. The mesh spacer having no ion conductivity is the one before introduction of the ion exchange group, which is obtained in the manufacturing process of the mesh ion conductive spacer used in Example 1.

[0035]

[Table 1] ────────────────────────────────────                    Example 1 Example 2 Comparative Example 1 Comparative Example 2 ────────────────────────────────────  Average applied voltage 100 80 150 130  (V)  Current (A) 2 2 2 2 2  No scale after 4000 hours No Yes Yes Yes  Situation ────────────────────────────────────

[0036]

EFFECTS OF THE INVENTION According to the present invention, the problem of scale generation can be solved from the structural aspect of the concentrating chamber of the electric deionized water manufacturing apparatus, not even from the measures to be taken from the water to be treated, and even in long-term continuous operation. , Stable operation can be performed without the occurrence of scale in the concentrating chamber. In addition, the conductivity in the concentration chamber is increased, the current density can be made uniform over the entire inlet side to the outlet side of the desalting chamber, and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electric deionized water production apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating the shape of a diagonal network.

FIG. 3 is a diagram illustrating the structures of a desalination chamber module and a concentration chamber.

FIG. 4 is a schematic view of the electric deionized water producing apparatus of FIG. 1.

FIG. 5 is a diagram for explaining movement of impurity ions in the concentrating chamber.

FIG. 6 is a diagram showing a concentration gradient of impurity ions in a concentrating chamber.

FIG. 7 is a diagram showing a concentration gradient of impurity ions in a concentrating chamber (conventional type) filled with a mesh spacer having no ion conductivity.

FIG. 8 is a schematic diagram of an electric deionized water producing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

D, D ₁ ~D _4, 104 desalting _{d 1, d 3, d 5} , d 7 first small depletion chambers _{d 2, d 4, d 6} , d 8 second small depletion chamber 1,105 concentrated Chamber 2 Electrode chamber 3, 101 Cation membrane 4, 102 Anion membrane 5 Intermediate ion exchange membrane 6, 109 Cathode 7, 110 Anode 8, 103 Ion exchanger 8a Laminated floor 10 of single cation conductive spacer and single anionic conductive spacer, 100 Electric Deionized Water Production Equipment 11, 111 Treated Water Inflow Line 12 Treated Water Outflow Line 13 of Second Small Desalination Chamber 13 Treated Water Inflow Line 14, 114 Deionized Water Outflow Line 15 , 115 Concentrated water inflow line 16, 116 Concentrated water outflow line 17a, 17b, 117 Electrode water inflow line 18a, 18b, 118 Electrode water outflow line 20 Deionization module 30 Diagonal net 101 Carbonate ion is first in concentrated water Point 102 calcium ions that move Te is first moved to the concentrate water

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Osamu Kawaguchi             Olga 1-2-8 Shinsuna, Koto-ku, Tokyo             Within the corporation F-term (reference) 4D006 GA17 HA42 JA04A JA04Z                       JA30Z JA43B JA44Z KA26                       KA31 KB11 MA03 MA13 MA14                       PA01 PB02 PC01 PC11 PC31                       PC32 PC33 PC42                 4D061 DA01 DB13 EA02 EA09 EB01                       EB04 EB13 EB19 FA08

Claims (6)

[Claims] 1. A desalting chamber is formed by filling a chamber defined by a cation exchange membrane on one side and an anion exchange membrane on the other side with an ion exchanger, and a desalting chamber is formed through the cation exchange membrane and the anion exchange membrane. In the electric deionized water manufacturing apparatus, which is provided with a concentrating chamber on both sides of the demineralizing chamber, the demineralizing chamber and the concentrating chamber are arranged between an anode chamber equipped with an anode and a cathode chamber equipped with a cathode.
The concentrating chamber is formed by alternately filling the mesh-shaped cation-conducting spacers and the mesh-shaped anion-conducting spacers in a stack in the inflow and outflow directions of the concentrated water. Manufacturing equipment. 2. Ion exchange into two small desalting chambers defined by a cation exchange membrane on one side, an anion exchange membrane on the other side, and an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane. A desalting chamber is formed by filling the body, and a concentrating chamber is provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane, and the desalting chamber and the concentrating chamber serve as an anode chamber equipped with an anode. In the electric deionized water producing apparatus arranged between the cathode chambers provided with a cathode, the concentrating chamber has a net-like cation-conducting spacer and a net-like anion-conducting spacer in the inflow and outflow directions of the concentrated water. On the other hand, an electric deionized water manufacturing apparatus characterized by being formed by alternately stacking and filling. 3. The ion exchanger filled in one of the small desalting chambers defined by the intermediate ion exchange membrane and the anion exchange membrane on the other side is an anion exchanger, and the cation exchange membrane on the one side. 3. The electrical deionizer according to claim 2, wherein the ion exchanger filled in the other small desalting chamber partitioned by the intermediate ion exchange membrane is a mixture of a cation exchanger and an anion exchanger. Ion water production equipment. 4. The concentration chamber has a thickness of 0.2 to 8.0 mm.
The electric deionized water production apparatus according to claim 1, wherein 5. A desalting chamber is constituted by filling a chamber defined by the cation exchange membrane on one side and the anion exchange membrane on the other side with an ion exchanger, and the desalting chamber is formed through the cation exchange membrane and the anion exchange membrane. Concentration chambers are provided on both sides of the deionization chamber, and these deionization chamber and concentration chamber are arranged between an anode chamber equipped with an anode and a cathode chamber equipped with a cathode, and the desalination chamber is treated while voltage is applied. In the method of flowing deionized water by injecting concentrated water into the concentrating chamber by flowing water into the concentrating chamber to obtain deionized water, the concentrating chamber comprises a net-like cation conducting spacer and a net-like anion. A method for producing deionized water, characterized in that the ion-conducting spacers are formed by alternately stacking and filling them in the inflow / outflow direction of the concentrated water. 6. Ion exchange into two small desalting chambers defined by a cation exchange membrane on one side, an anion exchange membrane on the other side and an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane. A desalting chamber is formed by filling the body, and a concentrating chamber is provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane, and the desalting chamber and the concentrating chamber serve as an anode chamber equipped with an anode. It is placed between cathode chambers equipped with a cathode, and the water to be treated flows into one small desalination chamber while applying a voltage, and then the outflow water of the small desalination chamber flows into the other small desalination chamber. At the same time, the concentrated water flows into the concentrating chamber to remove the impurity ions in the water to be treated to obtain deionized water. In the concentrating chamber, the reticulated cation conducting spacer and the reticulated anionic conducting spacer are used. Are formed by alternately stacking and filling the flow direction of concentrated water. What is claimed is: 1. A method for producing deionized water, comprising: