JP2002346568A - Electric regeneration type pure water production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric regeneration type pure water production apparatus, which is electrically stable, therefore stabilizing the water quality of treated water without deteriorating the water quality, and is improved so as to reduce the amount of power consumption. SOLUTION: This electric regeneration type pure water production apparatus is composed of a plurality of sets of demineralization chambers (81), or the like, and concentration chambers (91), or the like, which are sequentially formed between a positive electrode chamber (3) with a positive electrode (2) and a negative electrode chamber (5) with a negative electrode (4) by alternately arranging an anion-exchange membrane and a cation-exchange membrane. A mixture of a cation exchanger and an anion exchanger is housed in the demineralization chamber. The anion exchanger is exclusively housed between the mixture of the ion exchangers and the anion exchange membrane. The cation exchanger is exclusively housed between the mixture of the ion exchangers and the cation exchange membrane.

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.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the stability of the treated water so that the quality of the treated water can be stabilized without deteriorating and the power consumption can be reduced. An object of the present invention is to provide an electric regeneration type pure water producing apparatus.

[0004]

As a result of various studies, the present inventors have surprisingly put a mixture of a cation exchanger and an anion exchanger in a desalting chamber, and It has been found that the above object can be easily achieved by accommodating an ion exchanger of the same ion between the mixture and the ion exchange membrane.

The present invention has been achieved based on the above findings, and the gist of the present invention is to provide an anion exchange membrane and a cation exchange membrane between an anode chamber having an anode and a cathode chamber having a cathode. An electric regeneration type pure water production apparatus comprising a plurality of sets of a desalination chamber and a concentration chamber which are formed alternately and sequentially and in which a mixture of a cation exchanger and an anion exchanger is accommodated. A single anion exchanger is accommodated between the mixture of the ion exchangers and the anion exchange membrane, and a single anion exchanger is accommodated between the mixture of the ion exchangers and the cation exchange membrane. An electric regeneration type pure water production apparatus characterized by comprising a cation exchanger.

[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.

The basic configuration of the gas regeneration type pure water producing apparatus (1) of the present invention is the same as that of the conventional apparatus, and comprises an anode chamber (3) having an anode (2) and a cathode (4). An anion exchange membrane (61) and a cation exchange membrane (7) between the cathode chamber (5).
A plurality of sets of the desalting chambers (81), (82),...
2)...

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). Thus, in the case of the illustrated apparatus, five desalination chambers are formed. On the other hand, the first concentration chamber (91) is sandwiched between the cation exchange membrane (71) and the anion exchange membrane (62).
Is formed, and similarly, a second concentration chamber (92) is formed between the cation exchange membrane (72) and the anion exchange membrane (63). Thus, in the case of the illustrated apparatus, four concentrating chambers are formed. Then, a mixture of a cation exchanger and an anion exchanger (A) is placed in the five desalting chambers.
Are accommodated respectively.

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).

[0010] The desalting chamber contains a mixture of a cation exchanger and an anion exchanger. As such an ion exchanger, an anion exchange resin and a cation exchange resin used in a desalination treatment at the time of ordinary pure water production can be used, but the specific surface area is large and the ion exchange reaction is efficient. It is advantageous to use a suitable ion exchange fiber. As such an ion exchange fiber, specifically,
Ion-exchange groups are introduced into a composite fiber of polystyrene-based fibers and auxiliary agents, ion-exchange groups are introduced into a polyvinyl alcohol fiber base, and radiation-irradiation is performed on polyolefin-based fibers using radiation graft polymerization. Commercial products such as those into which an ion exchange group is introduced can be used. In the case of using ion-exchange fibers, the same amount of both ion-exchange fibers is exchanged at the exchange capacity, and the mixture is mixed with inert synthetic fibers and then formed into a nonwoven fabric.

[0011] The ion exchange resin is appropriately selected from ion exchange resins used in ordinary pure water production.
For example, as strongly acidic cation exchange resins, "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 "," PA316 "and the like.

The above-mentioned ion exchanger may be used in any of a regenerated form and a salt form, but it is preferable to use the regenerated form to speed up the rise of water quality. Moreover, unlike the ion-exchange membrane, the above-mentioned ion exchanger (non-woven fabric or resin-filled material) can freely pass not only ions but also water due to its porous structure.

[0013] A single anion exchanger is accommodated between the mixture of the above-mentioned ion exchangers and the anion exchange membrane accommodated in the desalination chamber, and the mixture of the above-mentioned ion exchangers and the cation exchange membrane are provided. In between contains a single cation exchanger. As such an ion exchanger, the same one as described above is used. In the same manner as described above, a non-woven fabric obtained by mixing inert synthetic fibers with ion-exchange fibers is used.

The thickness ratio of a single anion (cation) ion exchanger / a mixture of ion exchangers / a single cation (anion) ion exchanger in the desalting chamber is usually from 1: 0.1 to 10: 1, preferably from 1: 0.1 to 10: 1. Is 1: 1 to 10: 1.

In a preferred apparatus according to the invention, the enrichment compartment and / or the electrode compartment also contain a mixture of cation and anion exchangers. As the mixture of ion exchangers, the same mixture as in the case of the desalting chamber is used. In addition, a more preferable result is obtained when the mixture of the ion exchanger is housed in the concentration chamber than in the electrode chamber. Of course, it may be accommodated in both rooms.

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 flows through each of the above channels, impurity ions in the water to be treated in each of the desalting chambers are converted into a cation exchanger and a cation exchanger. The mixture (Z) of the anion exchanger is trapped and removed by the anion exchange group and the cation exchange group, thereby producing pure water and being trapped by the mixture (Z) of the cation exchanger and the anion exchanger. The impurity ions were electrodialyzed by an anion exchange membrane and a cation exchange membrane, which are also diaphragms of a desalting chamber, and moved to an adjacent concentration chamber,
It is concentrated and discharged from the outlet pipe (142).

In the apparatus of the present invention, a single anion exchanger (X) is accommodated between the above-mentioned mixture of ion exchangers (Z) and the anion exchange membrane, and the mixture of the above-mentioned ion exchangers (X) is contained. Since a single cation exchanger (Y) is accommodated between Z) and the cation exchange membrane, the boundary between each ion exchange membrane (X) and the mixture (Z) of (Y) and the ion exchanger is present. As a result, the device of the present invention is electrically stable, and therefore, can stabilize the treated water without deteriorating the quality of the treated water and reduce the power consumption. Can be done. In addition, such an effect is promoted by containing the mixture (Z) of the cation exchanger and the anion exchanger also in the concentration chamber and / or the electrode chamber. In addition. The anion (cation) ion exchange membrane / single anion (cation) ion exchanger / mixture of ion exchangers / single cation (anion) ion exchanger / cation (anion) ion exchange membrane are all in contact with each other. I have.

[0019]

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 6 and Comparative Examples 1 and 2 This is an electric regeneration type pure water producing 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 mixture of the ion exchanger contained in the desalting chamber, a strongly acidic cation exchange fiber ("Nichibi Co., Ltd.") in which a styrene-divinylbenzene sulfonate is uniformly dispersed in a matrix of polyvinyl alcohol. IEF-SC ") and a strongly basic anion exchange fiber obtained by adding a trimethylammonium group to the main chain of polyvinyl alcohol (" IEF-SA "manufactured by Nichibi Co., Ltd.). Then, a polyester fiber was mixed with the inert synthetic fiber at a ratio of 50% as a non-woven fabric.

In the desalting chamber, as the anion exchanger housed between the mixture of the ion exchanger and the anion exchange membrane, the strongly basic anion exchange fiber ("Nichibi Co., Ltd.") IEF-SA ") was prepared by mixing polyester fibers as inert synthetic fibers at a ratio of 50% and then forming a nonwoven fabric.

In the desalting chamber, as the cation exchanger contained between the mixture of the ion exchanger and the cation exchange membrane, the strongly acidic cation exchange fiber ("IEF" manufactured by Nichibi Co., Ltd.) may be used. -SC "), a polyester fiber was mixed at a ratio of 50% as an inert synthetic fiber and then formed into a nonwoven fabric.

The thickness ratio of anion exchanger (X) / ion exchanger mixture (Z) / cation exchanger (Y) in the desalting chamber was 1: 4: 1.

Then, as shown in Table 1 below, a mixture of a cation exchanger and an anion exchanger was accommodated in the concentration chamber and / or the electrode chamber of the apparatus constructed as described above.
As the mixture of the ion exchangers, a nonwoven fabric prepared in the same manner as in the case of the desalting chamber was used.

[0027]

[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.

[0029]

According to the present invention described above, it is electrically stable, so that the treated water can be stabilized without further lowering the water quality, and the power consumption can be further reduced. An improved electric regeneration type pure water production apparatus is provided, 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 of the present invention.

FIG. 2 shows the specific resistivity (KMΩ ··) 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 resistance (KMΩ ··) 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 (KMΩ · m) 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 K)

[Explanation of symbols]

 1: Electrodialysis tank 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 X : Anion exchanger Z: mixture of ion exchangers Y: cation exchanger

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Keiichiro Hirakawa 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 4D006 GA17 HA41 HA44 HA47 HA77 JA30Z JA41Z JA43Z JA44Z KA26 KB01 MA03 MA13 MA14 PA01 PB02 PC04 4D061 DA02 DB13 EA02 EA09 EB04 EB13 FA08 FA13

Claims (2)

[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. Wherein the desalination chamber contains a mixture of a cation exchanger and an anion exchanger, and is a regenerated pure water producing apparatus, wherein the mixture of the above-mentioned ion exchanger and an anion exchange membrane are A single anion exchanger is accommodated between the mixture, and a single cation exchanger is accommodated between the mixture of the ion exchanger and the cation exchange membrane. Water production equipment. 2. The apparatus according to claim 1, wherein the concentration chamber and / or the electrode chamber contain a mixture of a cation exchanger and an anion exchanger.