JP2001137859A - Electric regeneration type pure water production device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric regeneration type pure water production device improved such that not only a desalting room but also a concentration room and/or an electrode room are electrically stable, and the quality o treated water is stabilized without further lowering it and also power consumption can further be more reduced. SOLUTION: In the electric regeneration type pure water production device which is constituted of plural set of desalting rooms 81... and concentration rooms 91... which are successively formed while alternately arranging an anion exchange membrane and a cation exchange membrane between an anode room 3 provided with an anode 2 and a cathode room 5 provided with a cathode 4, and is constituted so that an ion exchange filling matter A obtained by adding a conductive material (a) to a mixture of a cation exchange body and an anion exchange body is stored in the desalting room 81, the conductive material (a) and/or a mixture (b) of the cation exchange body and the anion exchange body are stored in the concentration rooms 91 and/or the electrode rooms 3, 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric regeneration type pure water producing apparatus.

[0002]

2. Description of the Related Art Hitherto, an electric regeneration type pure water producing apparatus which combines an ion exchanger and an ion exchange membrane and utilizes the action of electrodialysis has been proposed. This device was invented by paying attention to the fact that a water-containing ion exchanger is a good conductor, and is basically sandwiched between an anion exchange membrane and a cation exchange membrane of an electrodialysis device. The deionization chamber is filled with an ion exchanger. Then, the water to be desalinated is circulated while applying a voltage to the desalination chamber to obtain pure water. According to the electric regeneration type pure water production apparatus, there is an advantage that a regenerating agent required in the case of a pure water production method using an ion exchange resin is not required.

In Japanese Patent Application Laid-Open No. 9-24374, the applicant of the present invention discloses a method for producing an electric regeneration type pure water in which an electrolyte solution is added to the water to be treated in an anode chamber, a cathode chamber, and a concentrating chamber, An electric regeneration type pure water production apparatus is proposed in which a conductive substance is added to a mixture of a cation exchanger and an anion exchanger. According to such a method and apparatus, even when the number of built-in chambers of the desalting chamber and the concentrating chamber is increased, without changing the voltage application condition, the treated water is stabilized without lowering the water quality, and Power consumption can be reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to further improve the apparatus described in Japanese Patent Application Laid-Open No. 9-24374 so that not only in the desalting chamber, but also in the concentrating chamber and / or the electrode chamber. It is an object of the present invention to provide an electric regeneration type pure water production apparatus which is stable and therefore stabilized without further lowering the quality of treated water, and which can further reduce power consumption.

[0005]

That is, the gist of the present invention is that an anion exchange membrane and a cation exchange membrane are alternately arranged between an anode chamber having an anode and a cathode chamber having a cathode. It consists of a plurality of sets of desalination chambers and concentration chambers, and the desalination chamber contains an ion exchanger packing in which a conductive substance is added to a mixture of a cation exchanger and an anion exchanger. An electric regeneration type pure water production apparatus, characterized in that a concentrating chamber and / or an electrode chamber contain a conductive substance (a) and / or a mixture of a cation exchanger and an anion exchanger (b). It exists in the electric regeneration type pure water production equipment.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic vertical vertical sectional front view of an example of the electric regeneration type pure water production apparatus of the present invention.

[0007] The basic configuration of the gas regeneration type pure water production apparatus (1) of the present invention is the same as that of the apparatus described in Japanese Patent Application Laid-Open No. 9-24374, and an anode chamber (3) having an anode (2). A plurality of sets of desalination chambers (81) formed by alternately arranging an anion exchange membrane (61) and a cation exchange membrane (71) between the cathode and the cathode chamber (5) having the cathode (4). ), (82)
And a concentration chamber (91), (92),.

That is, a desalting chamber (81) is formed between the anion exchange membrane (61) and the cation exchange membrane (71). Similarly, the anion exchange membrane (62) and the cation exchange membrane are formed. A second desalting chamber (82) is formed sandwiched between (72). In this way, the anion exchange membrane (A) and the cation exchange membrane (C) are alternately arranged, and in the case of the illustrated apparatus, five desalting chambers are formed. On the other hand, the cation exchange membrane (7
A first concentrating chamber (91) is formed between the cation exchange membrane (7) and the anion exchange membrane (62).
A second concentrating chamber (92) is formed sandwiched between 2) and the anion exchange membrane (63). Thus, in the case of the illustrated apparatus, four concentrating chambers are formed. Each of the five desalting chambers contains an ion exchanger packing (A) obtained by adding a conductive substance to a mixture of a cation exchanger and an anion exchanger.

As the ion-exchange membrane for forming the above-mentioned desalting chamber and concentrating chamber, those used in ordinary electrodialysis equipment are used. For example, trade name "Selemion (Asahi Glass Co., Ltd.)" And commercially available products such as Neosepta (Tokuyama Corporation) and Aciplex (Asahi Kasei Corporation).

As the ion exchanger filled in the desalting chamber, an anion exchange resin and a cation exchange resin used for a desalination treatment at the time of ordinary pure water production can be used. It is advantageous to use ion exchange fibers having a large specific surface area and an efficient ion exchange reaction. Specific examples of such ion-exchange fibers include those obtained by introducing an ion-exchange group into a composite fiber of a polystyrene-based fiber and an auxiliary agent, those obtained by introducing an ion-exchange group into a polyvinyl alcohol fiber base, and polyolefin-based fibers. A commercially available product such as one obtained by irradiating the product with radiation and introducing an ion exchange group using radiation graft polymerization can be used.

[0011] The ion exchange resin is appropriately selected from ion exchange resins used in ordinary pure water production.
For example, as the strongly acidic cation exchange resin, “Diaion (registered trademark of Mitsubishi Chemical Corporation) SK1B”, “PK2
08 "and the like, and examples of the strongly basic anion exchange resin include" Diaion SA10A "and" PA316 ".

The above-mentioned ion exchanger may be used in any of a regeneration type and a salt type, but it is preferable to use a regeneration type in order to speed up the rise of water quality.

The conductive material to be added to the mixture of the cation exchanger and the anion exchanger is preferably a conductive fiber when the ion exchange packing is an ion exchange fiber.
Examples of the conductive fibers include, in addition to carbon fibers, composite fibers obtained by kneading carbon black into synthetic fibers such as nylon, acrylic, and polyester, and synthetic fibers whose surfaces are coated with carbon black. Specific examples of such conductive fibers include “Antron” (manufactured by DuPont), “Ultron” (manufactured by Monsanto), and “SA”.
-7 "," Barrel II "(Toray)," Beltron "
There are commercially available products such as (Kanebo), "Mega II" (Unitika) and "Metalian" (Teijin).

The conductive fibers are uniformly mixed with the ion exchange fibers to form a nonwoven fabric. In this case, the mixing ratio does not adversely affect the exchange capacity of the ion-exchange fiber and provides a high conductivity, so that the exchange capacity of the ion-exchange fiber can be improved.
It is appropriately determined in consideration of the properties of the conductive fiber and the like, but is usually 20 to 70% by weight, preferably 30 to 60%, and most preferably about 50%. When the ion-exchange packing is an ion-exchange resin, a conductive material such as small-grain graphite and small-grain activated carbon is mixed and used.

In the apparatus of the present invention, the concentrating chamber and / or the electrode chamber may further contain the conductive substance (a) and / or the mixture of the cation exchanger and the anion exchanger (b).

The conductive substance (a) used in the concentrating chamber and / or the electrode chamber is selected under the same conditions as in the desalting chamber, and is better than the cation exchanger and the anion exchanger in a wet state. A conductive substance that is conductive, particularly carbon fiber, is preferably used. As the mixture (b) of the cation exchanger and the anion exchanger used in the concentration chamber and / or the electrode chamber, the same mixture of the cation exchanger and the anion exchanger as in the desalting chamber is used. Is done.

It is preferable that the conductive substance (a) and / or the above-mentioned mixture (b) be contained in a concentration chamber rather than an electrode chamber. Of course, it may be accommodated in both rooms. Also,
The conductive substance (a) is more preferably used than the above-mentioned mixture (b). Needless to say, the mixture (b) may be used by adding the conductive substance (a) to the mixture as in the case of the ion exchanger packing contained in the desalting chamber.

The apparatus of the present invention is used as follows. To each of the five desalting chambers, water to be treated (deionized water) is supplied from an inflow pipe (131) in parallel. The treated water (deionized water) flows out of the outflow pipe (132). The water to be treated is supplied to the four concentrating chambers in parallel with the inflow pipe (141).
Supplied from The water to be treated supplied to each concentrating chamber is concentrated and discharged from the outlet pipe (142) as concentrated water.
The water to be treated is supplied to the inflow pipe (12
From 1), they are introduced into the anode chamber (3), from the inflow pipe (123) into the cathode chamber (5), and discharged from the outflow pipe (122) and the outflow pipe (124), respectively.

When a direct current is passed from the anode (2) and the cathode (4) while the water to be treated is flowing through each of the above-mentioned flow paths, impurity ions in the water to be treated in each of the desalting chambers are filled with the ion-exchanger packing material. The pure water is produced by being trapped and removed by the anion exchange group and the cation exchange group of (A), and the impurity ions trapped in the ion exchanger packing (A) are also the membrane of the desalting chamber. It is electrodialyzed by the anion exchange membrane and the cation exchange membrane, moves to the adjacent concentration chamber, is concentrated, and is discharged from the outlet pipe (142).

In the apparatus of the present invention, the conductive substance (a) and / or the mixture of the cation exchanger and the anion exchanger (b) are provided not only in the desalination chamber but also in the concentration chamber and / or the electrode chamber.
Is filled, so that a more electrically stable result is obtained. Therefore, it is possible to stabilize the treated water without deteriorating the water quality and to further reduce the power consumption. Also, in the apparatus of the present invention,
According to the description of JP-A-74, an electrolyte solution can be added to the water to be treated in the anode chamber, the cathode chamber and the concentration chamber.

[0021]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 8 and Comparative Examples 1 and 2 This is an electric regeneration type pure water production apparatus having a structure as shown in FIG. 1, wherein the apparatus comprises 45 desalination chambers and 44 enrichment chambers ( The experiment was carried out using the apparatus (A) and the apparatus (B) having 90 desalting chambers and 89 concentrating chambers, respectively. The desalting chamber is 390 mm long, 130 mm wide and 2 mm thick, and the enrichment chamber is 390 mm long, 130 mm wide and 2 m thick.
m.

As the anion exchange membrane, Selemion AM
D [manufactured by Asahi Glass Co., Ltd., Selemion is a registered trademark of the company] is used, and its dimensions are 390 mm long and 130 mm wide. As the cation exchange membrane, Selemion CMD (manufactured by Asahi Glass Co., Ltd.) is used, and its dimensions are 390 mm in length and 130 mm in width.

As the ion exchanger packing in the desalting chamber, styrene-
Strongly acidic cation-exchange fiber in which a sulfonate of divinylbenzene is uniformly dispersed (Nichibi's IEF-
SC ") and a strongly basic anion exchange fiber (" IEF-SA "manufactured by Nichibi Co., Ltd.) obtained by adding a trimethylammonium group to the main chain of polyvinyl alcohol. A conductive fiber ("Bertron" manufactured by Kanebo Co., Ltd.) was mixed at a ratio of 50%, and then formed into a nonwoven fabric.

As shown in Table 1 below, the conductive substance (a) and / or the cation exchanger and the anion exchanger were placed in the concentration chamber and / or the electrode chamber of the apparatus constructed as described above. The mixture (b) was contained.

As the conductive substance (a), a nonwoven fabric of carbon fiber ("Donacarbo S223" manufactured by Donac) was used.

As the mixture (b) of the cation exchanger and the anion exchanger, the strongly acidic cation exchange fiber (“IEF-SC” manufactured by Nichibi Co., Ltd.) and the strongly basic anion exchange fiber (Co., Ltd.) The same amount of both ion-exchange fibers of Nichibi's "IEF-SA") is mixed in the same amount at the exchange capacity, and 50% of polyester fibers are mixed as inert synthetic fibers into a mixed state and then used as a nonwoven fabric. did.

[0028]

[Table 1]

As the water to be treated, RO (reverse osmosis membrane) treated water (electric conductivity: 20 μS / cm) of Yokohama City Water was used. Water to be treated was passed from the inflow pipe (131) to the desalination chamber at an LV of 25 m / h. Similarly, the water to be treated was supplied to both electrode chambers and the concentration chamber at the same flow rate as the supply rate to the desalination chamber. A DC voltage of 600 V was applied to the electrode plates of both electrode chambers simultaneously with the passage of water, and the resistivity of the treated water flowing out of the desalting chamber was measured.
The results are shown in FIGS.

[0030]

According to the present invention described above, it is electrically stable not only in the desalting chamber but also in the concentrating chamber and / or the electrode chamber. In addition, an improved electric regeneration type pure water production apparatus is provided which can further reduce the power consumption, and the industrial value of the present invention is great.

[Brief description of the drawings]

FIG. 1 is a schematic vertical front view of an example of an electric regeneration type pure water production apparatus according to the present invention.

FIG. 2 is a specific resistivity (MΩ · c) of treated water with respect to the elapsed days of water passage obtained in Examples 1 and 2 and Comparative Examples 1 and 2.
Graph showing change in m)

FIG. 3 shows the specific resistivity (MΩ · c) of treated water with respect to the elapsed days of water passage obtained in Examples 3 and 4 and Comparative Examples 1 and 2.
Graph showing change in m)

FIG. 4 shows the specific resistivity (MΩ · c) of treated water with respect to the elapsed days of water passage obtained in Examples 5 and 6 and Comparative Examples 1 and 2.
Graph showing change in m)

FIG. 5 shows the specific resistivity (MΩ · c) of treated water with respect to the elapsed days of water passage obtained in Examples 7 and 8 and Comparative Examples 1 and 2.
Graph showing change in m)

[Explanation of symbols]

1: Electrodialysis tank main body 2: Anode 3: Anode compartment 4: Cathode 5: Cathode compartment 61: Anion exchange membrane 71: Cation exchange membrane 81: Demineralization compartment 91: Concentration compartment 121: Anode compartment side inlet pipe 122: Anode room side outflow tube 123: Cathode room side inflow tube 124: Cathode room side outflow tube 131: Demineralization room side inflow tube 132: Demineralization room side outflow tube 142: Concentration room side inflow tube 142: Concentration room side outflow tube a : Conductive substance A: Ion exchanger packing in which a conductive substance is added to a mixture of a cation exchanger and an anion exchanger

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA17 KB01 KB11 MA13 MA14 PB02 4D025 AA03 BA06 BA08 BA13 BA22 BA25 DA05 DA06 4D061 DA03 DB13 EA02 EB01 EB13 EB17 EB20 EB22

Claims (3)

[Claims] 1. A plurality of sets of a desalting chamber and a concentrating chamber which are sequentially formed by alternately arranging an anion exchange membrane and a cation exchange membrane between an anode chamber having an anode and a cathode chamber having a cathode. In a desalination chamber, an electric regeneration pure water production apparatus containing an ion exchanger packing in which a conductive substance is added to a mixture of a cation exchanger and an anion exchanger is housed. // Conductive substance (a) in electrode chamber
And / or a mixture of a cation exchanger and an anion exchanger (b). 2. The device of claim 1, wherein the conductive material is more conductive in the wet state than the cation and anion exchangers. 3. The device according to claim 2, wherein the conductive substance is carbon fiber.