TW201300326A - Ion-exchange device - Google Patents

Abstract

The present invention provides an ion-exchange device which can substantially inhibit the reverse regeneration of anion exchange resin and cation exchange resin in a tower and which can produce de-ionized water with high quality even immediately after regeneration. During the regeneration of the ion-exchange device, a valve (12) is closed, and valves (7, 10) are opened for supplying the alkaline solution from an upper supply piping (3) and supplying the acidic solution from a third communicating piping (8). The alkaline solution flows according to the order of a water collection component (4), an inertia resin (22), an anion exchange resin (21), glass beads (23), a water collection component (6), a communicating piping (5) and the valve (7), so as to regenerate the anion exchange resin (21). The acidic solution flows according to the order of a water collection component (9), an inertia resin (32), an alkaline exchange resin (31), a water collection component (14), glass beads (33), and a lower supply piping (13), so as to regenerate the cation exchange resin (31).

Description

Ion exchange device

The present invention relates to a regenerative ion exchange apparatus comprising an anion exchange resin and a cation exchange resin.

Ion exchange devices have been widely used in pure water or ultrapure water manufacturing equipment in the electronics industry and the like. As one of the ion exchange devices, a mixed bed type ion exchange device is known.

The mixed bed ion exchange device comprises an ion exchange column having a mixed ion exchange resin layer in which a strongly acidic cation exchange resin and a strongly basic anion exchange resin are mixed, and the mixed bed ion exchange device is, for example, made of raw water. The descending circulating water simultaneously ion-exchanges cations and anions in the raw water in the ion exchange column to produce pure water of high purity. Further, when the regeneration of each ion exchange resin is carried out, the mixed ion exchange resin layer is backwashed and separated in the same column, and a strong basic anion exchange resin layer is formed in the upper layer by the difference in specific gravity of each ion exchange resin, and is formed in the lower layer. After the strongly acidic cation exchange resin layer, the respective regenerants are passed through the respective ion exchange resin layers to regenerate the two ion exchange resins. This regeneration operation may be carried out in the same column, and each ion exchange resin may be separately taken out to another column and separately regenerated in each column.

In the conventional mixed bed type ion exchange apparatus, there is a problem that the separation of the cation and the anion exchange resin is incomplete due to "reverse regeneration".

That is, the cation exchange resin is used in the form of H, and the regeneration is carried out by flowing an acid solution. On the other hand, the anion exchange resin is used in the form of OH, and the regeneration is carried out by flowing an alkali solution. As described above, before the regeneration of the ion exchange resin of the mixed bed desalting column, first, the upward flowing water is applied to the mixed bed, and the anion exchange resin and the cation exchange resin are separated by the specific gravity difference, and then, for example, HCl is introduced from the lower portion of the column to regenerate the cation exchange resin, and NaOH is introduced from the upper portion of the column to regenerate the anion exchange resin. Each of the regeneration waste liquid is discharged from a discharge pipe provided at an interface portion between the anion exchange resin bed and the cation exchange resin bed. Then, nitrogen gas was introduced from the bottom of the column to mix the anion exchange resin and the cation exchange resin into a mixed bed, and water was passed through.

In such a regenerative mixed bed ion exchange column, it is necessary to sufficiently separate the cation exchange resin and the anion exchange resin before the regeneration of each ion exchange resin by HCl or NaOH. This separation is not completely performed. For example, when a cation exchange resin is mixed in the anion exchange resin, the cation exchange resin is Na in the form of regeneration (reverse regeneration) using a base (mainly using sodium hydroxide), and the resin is used for deionization. When processed, sodium ions are released. Further, when an anion exchange resin is mixed in the cation exchange resin, the anion exchange resin is made into the SO ₄ form or the Cl form by regeneration (reverse regeneration) using an acid (mainly using sulfuric acid or hydrochloric acid), and sulfuric acid is released during deionization. Ion or chloride.

Japanese Patent Publication No. Hei 10-137751 (Patent Document 1) discloses an ion exchange device in which a column is partitioned into upper and lower chambers by a water-permeable separator. One room The cation exchange resin is filled and the anion exchange resin is filled in the other chamber. The separator allows the circulation of water, but prevents the flow of the ion exchange resin while preventing the mixing of the anion exchange resin and the cation exchange resin. The tower body of Patent Document 1 is a single tower type and has a small device area.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 10-137751

In the ion exchange apparatus of Japanese Laid-Open Patent Publication No. Hei 10-137751, since the separator partitioning the anion exchange resin layer and the cation exchange resin layer is water-permeable, the acid solution for regenerating the cation exchange resin passes through the separator during regeneration. The anion exchange resin is contacted, whereby reverse regeneration occurs. Further, the alkali solution for regenerating the anion exchange resin is brought into contact with the cation exchange resin through the separator, whereby reverse regeneration occurs. In paragraphs 0023, 0027, and 0018 of Patent Document 1, it is described that pure water is used as the balance water to pass water so that the regenerant does not flow into the other ion exchange resin layer during regeneration, but it is completely Preventing the incorporation of the regenerant is not sufficient, and reverse regeneration is still generated.

An object of the present invention is to provide an ion exchange apparatus capable of reliably preventing reverse regeneration of an anion exchange resin and a cation exchange resin inside a column, and capable of producing high-quality deionized water immediately after regeneration.

The ion exchange device of the present invention is filled with an ion exchange resin inside the column body, characterized in that the water-repellent separator is partitioned in the column body Forming an upper chamber and a lower chamber, and communicating the upper chamber and the lower chamber through a communication mechanism surrounding the outer surface of the tower, comprising: a cation exchange resin housed in one of an upper chamber and a lower chamber of the tower body; An anion exchange resin contained in the other of the upper chamber and the lower chamber of the tower; an upper supply pipe for supplying or discharging the liquid to the upper portion of the upper chamber; and a lower supply for the lower chamber Or discharging the lower portion of the liquid to the discharge pipe, the communication mechanism comprising: a first communication pipe for supplying and discharging the liquid to the lower portion of the upper chamber; a second communication pipe for supplying the liquid to the upper portion of the lower chamber; a third communication pipe of the first communication pipe and the second communication pipe; an opening and closing mechanism of the third communication pipe; and a supply and discharge mechanism of the regeneration liquid provided in the first communication pipe and the second communication pipe; In the upper portion of the upper chamber, the lower portion of the upper chamber, the upper portion of the lower chamber, and the lower portion of the lower chamber, a water collecting member that allows water to pass but blocks the passage of the ion exchange resin, and the upper supply pipe and the first communication pipe Second company The pipe and the end of the lower supply pipe are respectively connected to the water collecting member, and the upper portion of the upper chamber and the upper portion of the lower chamber are filled with granular inert resin, and the water collecting member at the upper portion of the upper chamber and the upper portion of the lower chamber The water collecting members are respectively embedded in the inert resin, and the lower portion of the upper chamber and the lower portion of the lower chamber are respectively filled with high specific gravity particles having a specific gravity higher than that of the ion exchange resin of the chamber, and the water collecting member at the lower portion of the upper chamber And the water collecting members at the lower portion of the lower chamber are respectively buried in the high specific gravity particles.

An ion exchange apparatus according to the second aspect of the invention is characterized in that in the ion exchange apparatus of the first aspect of the patent application, the high specific gravity particles are inert resin particles or glass beads.

In the ion exchange apparatus of the present invention, the upper chamber and the lower chamber are partitioned by a water-repellent separator, and a cation exchange resin is accommodated in one chamber and an anion exchange resin is accommodated in the other chamber. The treated water (raw water) is supplied to one chamber, and flows into another chamber via the communication mechanism, and is taken out from the other chamber.

In the ion exchange apparatus, an acid or a base is supplied to each chamber at the time of regeneration of the ion exchange resin. Therefore, the case where the cation exchange resin and the anion exchange resin are mixed does not occur at all, and the separator partitioning the two chambers is water-repellent, and the acid or alkali supplied to one chamber does not flow into the other chamber through the separator at all. In the case of reverse regeneration, it is prevented.

In the ion exchange device of the present invention, the partition is internally partitioned into upper and lower chambers, and the anion exchange column and the cation exchange column are respectively provided with less space, and the length of the pipe is also shorter, and further, The separation of the ion exchange resin space filled with the ion exchange resin by one separator can reduce the height of the ion exchange device. In addition, it can be produced at low cost.

In the ion exchange apparatus of the present invention, the first communication pipe and the second communication pipe can be easily and efficiently regenerated by flowing acid or alkali to the upper chamber and the lower chamber, respectively. At this time, by closing the third communication pipe, the mixing of the acid and the alkali is completely prevented. Moreover, the ion exchange resin of the upper chamber and the lower chamber can be simultaneously regenerated, and the regeneration time can be greatly shortened.

According to the ion exchange apparatus of the present invention, the water collecting member is disposed on both the upper portion and the lower portion of the upper chamber and the lower chamber, and water is supplied to the upper chamber and the lower chamber, so that local retention of water does not occur in the upper chamber and the lower chamber. The production of treated water (deionized water) and the regeneration of ion exchange resins can be carried out efficiently.

In the ion exchange apparatus of the present invention, an inert resin is filled in the upper portion of the upper chamber and the lower chamber to suppress the flow of the ion exchange resin. If the ion exchange resin flows, the liquid may not be uniformly contacted with the ion exchange resin during water collection or regeneration, and there is a possibility that the water quality is lowered. However, according to the fifth item of the patent application, the water quality can be prevented from being lowered, and the water can be obtained. Water treatment water. In addition, the water passage direction of the water to be treated and the regenerant at the time of water collection and regeneration is not particularly limited, but it is preferable to obtain a treatment water having high water quality so that the water is discharged upward during the water collection and the downstream of the regeneration. . It is considered that the ion exchange resin which is sufficiently regenerated is fixed to the upper portion of each ion exchange resin by the filling of the inert resin, so that the ion exchange resin is located on the outlet side of the water to be treated at the time of water collection.

In the ion exchange apparatus of the present invention, high-specific gravity particles are filled in the lower portions of the upper chamber and the lower chamber, and the water collecting members in the lower portion of the upper chamber and the lower chamber are buried in the high-specific gravity particles. When the members pass water to the respective chambers in the upward flow, the water flowing out of the water collecting member is widely and uniformly dispersed by the packed layer of the high specific gravity particles. Therefore, water is uniformly supplied to each chamber, and the ion exchange resin and water in each chamber are effectively brought into contact with each other, thereby improving ion exchange efficiency.

Hereinafter, an embodiment will be described with reference to Fig. 1 .

The tower body 1 is a casing formed by a cylindrical portion 1a whose vertical direction is the axial direction of the cylinder, a mirror plate portion 1b at the top, and a mirror plate portion 1c at the bottom. The mirror plate portion 1b is convexly curved upward, and the mirror plate portion 1c is convexly curved downward.

The partition 2 in which the water repellency is used in the tower body 1 is divided into two chambers of the upper chamber 20 and the lower chamber 30. In this embodiment, the separator 2 is made of metal or synthetic resin that does not allow water to pass therethrough, and is bent convexly like the mirror plate portion 1c. The peripheral edge portion of the separator 2 is bonded to the inner peripheral surface of the cylindrical portion 1a by watertightness or the like by welding or the like.

The first water collecting member 4 is disposed in an upper portion of the upper chamber 20, and the upper collecting pipe 3 is connected to the first collecting water member 4. A second water distribution member 6 is disposed at a lower portion of the upper chamber 20, and the first communication pipe 5 is connected to the water distribution member 6. A third water distribution member 9 is disposed in an upper portion of the lower chamber 30, and the second communication pipe 8 is connected to the water distribution member 9. The communication pipes 5 and 8 are connected by a third communication pipe 11 , and a valve 12 is provided in the communication pipe 11 .

Valves 7 and 10 serving as regenerating liquid supply and discharge devices are provided at the end portions of the communication pipes 5 and 8, respectively. A fourth water distribution member 14 is disposed at a lower portion of the lower chamber 30, and a lower supply pipe 13 is provided in the water distribution member 14.

The lower portions in the upper chamber 20 and the lower portions in the lower chamber 30 are filled with glass beads 22 and 33 as high specific gravity particles, respectively. The second water distribution member 6 is embedded in the layer of the glass beads 23, and the fourth water distribution member 14 is embedded in the layer of the glass beads 33. Further, instead of the glass beads, particles of an inert resin such as high-density polyethylene having a specific gravity higher than that of the ion-exchange resin, high-specific gravity polypropylene, or fluorine-based resin may be used. Preferably, the glass beads and the inert resin have the same particle size as the ion exchange resin. In addition, the high specific gravity particles should not flow at or above LV 150 m/h.

In the upper chamber 20, an anion exchange resin 21 is filled in an upper portion of the glass bead 23, and a granular shape is filled on the upper side of the anion exchange resin 21. Inert resin 22. The first water distribution member 4 is embedded in the inert resin 22.

In the lower chamber 30, a cation exchange resin 31 is filled in the upper portion of the glass beads 33, and a granular inert resin 32 is filled on the upper side of the cation exchange resin 31. The third water distribution member 9 is embedded in the inert resin 32.

As the inert resins 22 and 32, a polyacrylonitrile-based resin having a smaller specific gravity than the ion exchange resin is used. The particle diameter of the inert resins 22 and 32 is preferably the same as that of the ion exchange resin.

As the water collecting members 4, 6, 9, and 14, a water collecting plate used in a conventional ion exchange device or a filter having a large number of slits in a radially extending pipe can be used. For example, when the size of the ion exchange resin is about 0.4 mm, it is preferable to use a sieve having a slit width of about 0.2 mm as the sieve. The water collecting members 4, 6, 9, and 14 have shapes along the mirror plate portion 1b, the partition plate 2, and the mirror plate portion 1c, respectively, so that the dead space of the mirror plate portion 1b, the partition plate 2, and the mirror plate portion 1c is reduced. small.

The flow at the time of production (water collection) of deionized water using the ion exchange apparatus is shown in Fig. 1(a). In this case, the valve 12 is opened, the valves 7 and 10 are closed, and the raw water (treated water) is supplied from the lower supply pipe 13. The raw water flows through the water collecting member 14, the glass beads 33, the cation exchange resin 31, the inert resin 32, the water collecting member 9, the communicating pipes 8, 12, 5, the water collecting member 6, the glass beads 23, and the anion exchange resin 21 in this order. The inert resin 22, the water collecting member 4, and the upper supply and discharge pipe 3 are taken out as treated water (deionized water).

When the cation exchange resin 31 and the anion exchange resin 21 are regenerated, as shown in Fig. 1(b), the valve 12 is closed, the valves 7 and 10 are opened, an alkali solution such as NaOH is supplied from the upper supply and discharge pipe 3, and the third communication pipe is provided. 8 An acid solution such as HCl or H ₂ SO _{4 is} supplied. The alkali solution flows through the water collecting member 4, the inert resin 22, the anion exchange resin 21, the water collecting member 6, the glass beads 23, the communication pipe 5, and the valve 7 in this order, and flows out as regenerated wastewater (alkali). The anion exchange resin 21 is regenerated. The acid solution flows through the water distribution member 9, the inert resin 32, the cation exchange resin 31, the glass beads 33, the water collecting member 14, and the lower supply and discharge pipe 13 in order, and flows out as regenerated wastewater (acid), thereby The cation exchange resin 31 is regenerated.

After the completion of the regeneration, in place of the HCl solution and the NaOH solution of FIG. 1(b), pure water is passed through, and each path and resin are rinsed, and then the upper and lower chambers are separately flowed down with pure water as needed, and discharged. The net is drained, and then pure water is circulated between the upper chamber 20 and the lower chamber 30 for a specific time, and then returned to the water collecting step. At the time of this regeneration, the anion exchange resin 21 and the cation exchange resin 31 are not mixed at all. Further, there is no case where the alkali solution for regeneration flows into the lower chamber 30 or the acid solution is mixed into the upper chamber 20, and the reverse regeneration is completely prevented. Further, the anion exchange resin 21 and the cation exchange resin 31 can be simultaneously regenerated in parallel, and the regeneration time is remarkably shortened.

In the ion exchange apparatus, one column body 1 is partitioned into upper and lower chambers by one partition plate 2, and the height of the tower body is low, and the installation space is also small. Further, the pipes 5, 11, and 8 that connect the upper chamber 20 and the lower chamber 30 are also short.

In the ion exchange apparatus, the water collecting members 4, 6, 9, and 14 are provided along the mirror plate portion 1b, the partition plate 2, and the mirror plate portion 1c, and the water can be prevented. The Ministry is stranded.

In the ion exchange apparatus, the upper portions of the upper chamber 20 and the lower chamber 30 are filled with inert resins 22 and 32, and the flow of the anion exchange resin 21 and the cation exchange resin 31 can be prevented. Further, glass beads 23 and 33 are filled in the lower portions of the upper chamber 20 and the lower chamber 30, and the water collecting members 6 and 14 are embedded in the layers of the glass beads 23 and 33. Therefore, the liquid becomes uniformly contacted with the anion exchange resin 21 and the cation exchange resin 31 at the time of water collection and regeneration, and deionized water of high water quality can be obtained, and regeneration can be fully performed.

In the above embodiment, the anion exchange resin is accommodated in the upper chamber 20 and the cation exchange resin is accommodated in the lower chamber 30, but the reverse may be used. In the above embodiment, the upper chamber 20 and the lower chamber 30 communicate with each other via the pipes 5, 11, and 8. However, it is not limited thereto as long as it is around the outside of the tower body 1. Further, in this embodiment, three valves 7, 10, and 12 are used, but flow switching may be performed using two three-way valves.

Example

Hereinafter, examples and comparative examples will be described.

<Example 1>

The ion exchange apparatus shown in Fig. 1 was employed. The various specifications are as follows.

Tower diameter: 1000mm

Tower height: 3500mm

Upper chamber volume: 1000L

Lower chamber volume: 1000L

Anion exchange resin: Dow 550A

Cation exchange resin: Dow 650C

Filling amount of anion exchange resin: 500L

Filling amount of cation exchange resin: 500L

Filling amount of inert resin 22: 200L

Filling amount of inert resin 32: 200L

Filling amount of glass beads 23, 33 (average particle diameter 3 mm, specific gravity 2.5): 200 L each

<Comparative Example 1>

In Comparative Example 1, the glass beads 23 and 33 were not filled, and the amount of the ion exchange resin corresponding to this amount was increased, and the same as Example 1 except for the following.

Filling amount of cation exchange resin: 700L

Filling amount of anion exchange resin: 700L

<Water test>

For each ion exchange device, water for RO treatment water (conductivity: 5 μS/cm, metal Na: 1 ppm, chloride ion: 1 ppm, SiO ₂ : 1 ppm) was passed through a flow rate of water: 20 m ³ /h until the ion exchange device The specific resistance of treated water reaches 18MΩ. Cm. Then, the acid solution and the alkali solution described below were simultaneously regenerated, and the water collection/washing cycle was repeated five times.

[regeneration conditions]

HCl: 5% (water flow rate 1m ³ /h, 30 minutes)

NaOH: 5% (water flow rate 1 m ³ /h, heating 40 ° C, 30 minutes) The amount of water collected in each cycle is shown in Table 1.

As is clear from Table 1, according to Example 1, the amount of water collected was increased by about 20% compared with Comparative Example 1. This can be considered to be caused by the use of glass beads to homogenize the flow in the column.

1‧‧‧Tower

1b, 1c‧‧‧ mirror plate

2‧‧‧Baffle

3‧‧‧Upper supply and distribution piping

4, 6, 9, 14‧‧‧ water distribution components

5, 8, 11‧‧‧Connected piping

13‧‧‧Second supply and distribution piping

20‧‧‧上室

21‧‧‧ Anion exchange resin

22,32‧‧‧Inert resin

23, 33‧‧‧ glass beads

30‧‧‧下室

31‧‧‧Cation exchange resin

Fig. 1 is a schematic cross-sectional view showing an ion exchange apparatus of an embodiment.

1‧‧‧Tower

1b, 1c‧‧‧ mirror plate

2‧‧‧Baffle

3‧‧‧Upper supply and distribution piping

4, 6, 9, 14‧‧‧ water distribution components

5, 8, 11‧‧‧Connected piping

13‧‧‧Second supply and distribution piping

20‧‧‧上室

21‧‧‧ Anion exchange resin

22,32‧‧‧Inert resin

23, 33‧‧‧ glass beads

30‧‧‧下室

31‧‧‧Cation exchange resin

Claims (2)

An ion exchange device in an ion exchange device filled with an ion exchange resin inside a column body, wherein an upper chamber and a lower chamber are formed in the column by a water-blocking partition, and surrounded by the outer surface of the tower An ion exchange device that communicates the upper chamber and the lower chamber, and includes: a cation exchange resin housed in one of an upper chamber and a lower chamber of the tower body; and is housed in an upper chamber and a lower portion of the tower body An anion exchange resin in the other of the chambers; an upper supply pipe for supplying or discharging the liquid to the upper portion of the upper chamber; and a lower supply pipe for supplying or discharging the liquid to the lower portion of the lower chamber, the aforementioned The communication mechanism includes: a first communication pipe for supplying and discharging liquid to the lower portion of the upper chamber; a second communication pipe for supplying liquid to the upper portion of the lower chamber; and communicating the first communication pipe with the second communication a third communication pipe of the pipe; an opening and closing device of the third communication pipe; a supply and discharge mechanism of the regeneration liquid provided in the first communication pipe and the second communication pipe; and an upper portion and an upper chamber of the upper chamber, respectively Lower part, lower room The upper and lower water chamber arranged allowable but prevents the ion exchange resin by passing the water collecting and distributing member, The ends of the upper supply pipe, the first communication pipe, the second communication pipe, and the lower supply pipe are respectively connected to the water collecting member, and the upper portion of the upper chamber and the upper portion of the lower chamber are filled with granular inertness. The resin, and the water collecting member at the upper portion of the upper chamber and the water collecting member at the upper portion of the lower chamber are respectively embedded in the inert resin, and the lower portion of the upper chamber and the lower portion of the lower chamber are respectively filled with specific gravity than the ion exchange resin of the chamber. The high high specific gravity particles are respectively embedded in the high specific gravity particles in the water collecting member at the lower portion of the upper chamber and the water collecting member at the lower portion of the lower chamber. The ion exchange apparatus of claim 1, wherein the high specific gravity particles are inert resin particles or glass beads.