WO2015189908A1

WO2015189908A1 - Operating method for regeneration type ion exchange device

Info

Publication number: WO2015189908A1
Application number: PCT/JP2014/065309
Authority: WO
Inventors: 洋一宮▲崎▼; 長雄福井
Original assignee: 栗田工業株式会社
Priority date: 2014-06-10
Filing date: 2014-06-10
Publication date: 2015-12-17
Also published as: CN106458647A; KR20170016844A; KR102203041B1; CN106458647B

Abstract

Provided is a simple and economical operating method for a regeneration type ion exchange device that carries out an operating scheme of interrupting operation of ascending circulation of raw water and thereafter restarting the operation, said operating method not requiring the installation of a special means in the regeneration type ion exchange device, being simple to operate, and not taking time. The operating method for a regeneration type ion exchange device, which accommodates an ion exchange resin (4) within a container (1), has a raw water flow step for making raw water flow in an ascending current in the regeneration type ion exchange device and water flow stopping step for stopping the raw water flow in the regeneration type ion exchange device. The method comprises a force applying water flow step that makes a descending water flow for pressing the ion exchange resin (4) downward in the container after the raw water flow step is completed and before the water flow stopping step.

Description

Operation method of regenerative ion exchanger

The present invention relates to an operation method of a regenerative ion exchange apparatus in which an ion exchange resin is accommodated in a container, and more particularly to an operation method of a regenerative ion exchange apparatus that passes raw water in an upward flow during sampling. Specifically, the present invention relates to an improvement of a process when stopping water collection of the regenerative ion exchange apparatus.

As an operation method of the regenerative ion exchange device that obtains treated water by passing raw water through a regenerative ion exchange device containing an ion exchange resin in the container, an upward circulating water system that passes the raw water in an upward flow There is.

FIG. 2a is a schematic longitudinal sectional view showing the configuration of this regenerative ion exchange apparatus, in which a cylindrical container 1 is installed with the cylinder axis direction as the vertical direction (particularly the vertical direction). The dish-

shaped filters

2 and 3 are respectively provided in the upper and lower portions of the container 1, and the ion exchange resin 4 is accommodated between the

filters

2 and 3. Since the ion exchange resin 4 swells and increases its volume as a result of its use, normally, in anticipation of this increase in volume, a space having a predetermined height h (free board portion F) in the upper part of the container 1. Is stored in the container 1 in a state of leaving

When the raw water is passed in an upward flow from the raw water supply port 5 of this ion exchange resin, the ion exchange resin 4 is pushed up by this water pressure and becomes a fixed bed state pressed against the upper filter 2 as shown in FIG. Water sampling is performed in this state. The treated water flows out from the outlet 6 at the top of the container. When the flow of the raw water into the container 1 is stopped, the force for pushing up the ion exchange resin 4 disappears, so that the ion exchange resin 4 forming the fixed bed settles down to the lower filter 3 side in the container 1. It falls and returns to the accommodated state before water flow, that is, the state of FIG. 2a.

When the ion exchange resin 4 settles and falls in the container 1 in this way, a collapsed portion 4a of the ion exchange resin is formed as shown in FIG. 2c. The collapsing part 4a gradually moves upward, finally reaches the uppermost ion exchange resin 4 and the fall of the ion exchange resin 4 is finished, and returns to the state of FIG. 2a. At the collapsed portion 4a of the ion exchange resin, the ion exchange resin particles fall while being mixed. For this reason, the ion exchange resin located on the lower side of the packed bed of the ion exchange resin 4 breaks through, but the ion exchange resin located on the upper side does not break through yet. When the raw water flow is stopped in the state and the sampling is stopped, the lower-order resin that has passed through and the upper-side resin that has not passed through are mixed, and the quality of the treated water will be reduced when the next sampling operation is resumed. It sometimes worsened.

Therefore, a regenerative ion exchange device that operates in upward flow water sampling and downward flow regeneration (counter current regeneration method), once sampling is started with upward circulating water, continues to complete the water sampling (next regeneration). I had to keep passing water.

For this reason, even if it is better to temporarily stop the regenerative ion exchange device, such as when the amount of pure water or ultrapure water used is reduced, the circulating operation is continued and the chemical regeneration is performed. Because it was necessary, it took a lot of time and cost.

As described in the right upper column of page 2 of JP-A-51-77583, as a means for suppressing fluidization of the ion exchange resin when flowing in the upward flow, water flowing in the upward flow is used. At the same time, a method is known in which pressure water (balance water / downward flow) is introduced from above the resin bed to prevent the resin bed from rising. However, in this method, since the pressure water is introduced from above the resin bed simultaneously with the water flow in the upward flow, the adjustment of each flow rate and pressure becomes complicated. This method does not suppress the disturbance of the resin layer due to natural sedimentation when water flow is stopped.

In paragraphs 0034 and 0035 of Japanese Patent Application Laid-Open No. 2003-220387, the movement adjusting means is provided to reduce the rate at which the ion exchange resin drops toward the bottom of the resin cylinder at the end of water flow, thereby It is described that a problem like this is addressed. However, in the case where such movement adjusting means is provided, it is necessary to prepare and install the means separately, and in a large apparatus, the internal structure of the tower is particularly complicated, which causes a cost increase.

JP-A 51-77583 JP 2003-220387 A

As described above, the regenerative ion exchange device that collects water by flowing in the upward flow, once stopped in the middle of water collection, when the fixed bed falls, the ion exchange resin layer is disturbed and water collection starts again. The water quality before stopping is not always maintained. For this reason, the regenerative ion exchange apparatus that collects water by flowing in an upward flow must continue to operate even when it is desired to stop temporarily during sampling.

The present invention is a method for collecting raw water by flowing upward water, and in a regenerative ion exchange apparatus operating method for performing an operation method of interrupting the water sampling operation and then restarting the water sampling operation, It is an object of the present invention to provide an economical method of operating a regenerative ion exchange apparatus that does not require special means to be installed in the ion exchange apparatus, is simple in operation and does not take much time.

The method for operating a regenerative ion exchange apparatus containing an ion exchange resin in a container according to the present invention includes a raw water flow step for passing raw water through the regenerative ion exchange apparatus in an upward flow, and the regenerative ion A water flow stopping process in which the raw water flow to the exchange device is stopped, and an urging force for pushing and moving the ion exchange resin layer downward in the container after the raw water flow process and before the water flow stop process. An energizing water flow process for flowing water downward.

As the energizing water, it is preferable to use deionized water obtained from this regenerative ion exchange apparatus.

The height h of the free board portion of the regenerative ion exchange apparatus is preferably 10 to 200 mm.

The LV when the energizing water is passed is preferably 20 to 150 m / h. The energizing water is preferably passed for 10 to 60 seconds.

The present invention provides a regenerative ion exchange apparatus that performs water sampling in an upward flow operation, and when water sampling is stopped in the middle of water sampling or when water sampling is stopped such as when water sampling is completed, immediately after the water flow is stopped. In addition, energizing water for pressing the ion exchange resin layer downward is passed in a downward flow. By passing the energizing water in this way, the ion exchange resin layer inside the apparatus moves downward without being disturbed, and the ion exchange resin can maintain the fixed bed. For this reason, even after re-watering (re-startup), the water quality equivalent to that before the stop can be secured, and stable operation becomes possible. Even when the chemical regeneration of the ion exchange resin is performed, the regeneration can be performed with high efficiency, and the amount of the chemical can be reduced.

1a, 1b and 1c are explanatory views of the method of the present invention. 2a, 2b, and 2c are explanatory diagrams of a conventional example. FIG. 3 is a cross-sectional view of a single tower double bed type regenerative ion exchange apparatus. FIG. 4 is a cross-sectional view of a single-column, multi-bed type regenerative ion exchange apparatus. FIG. 5 is a cross-sectional view of a single tower double bed type regenerative ion exchange apparatus.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1a to 1c. In the regenerative ion exchange apparatus in which the ion exchange resin 4 is accommodated between the

filters

2 and 3 in the container 1, the present invention collects water by passing the raw water in an upward flow as shown in FIG. . When stopping the upward flowing water of the raw water, immediately after the upward flowing water is stopped, the energized water is passed downward in the container 1 as shown in FIG. As shown in FIG. 1C, the ion exchange resin 4 layer is brought into contact with the lower filter 3 while maintaining the fixed bed state. While the layer of the ion exchange resin 4 is moving downward, the collapsing portion 4a as shown in FIG. 2b is not formed in the layer of the ion exchange resin 4, and mixing of the ion exchange resin particles does not occur. Therefore, when the upward circulation water of the raw water to the regenerative ion exchanger is resumed, the quality of the treated water becomes good immediately after the restart.

In the present invention, the ion exchange resin may be regenerated after the downward movement of the layer of the ion exchange resin 4 as shown in FIG. 1c. If sufficient ion exchange capacity remains in the ion exchange resin, the regeneration is performed. It is only necessary to restart the raw water flow without performing.

As shown in FIG. 2a, when the height h of the free board portion F is excessively large, the ion exchange resin layer is likely to be disturbed. Since the sedimentation property of the ion exchange resin varies depending on the specific gravity, it is preferable to set the height h of the free board portion F in consideration of the specific gravity. The specific gravity of the anion exchange resin is usually 1.0 to 1.2, and the specific gravity of the cation exchange resin is usually 1.2 to 1.7. The height h of the free board portion is preferably 10 to 200 mm, more preferably 10 to 100 mm, and particularly preferably 10 to 50 mm. Since the cation exchange resin is heavier and easier to settle than the anion exchange resin, if the free board portion is too wide, it is easy to mix during settling. For this reason, it is more preferable to reduce the height of the free board portion when the cation exchange resin is filled as compared with the case where the anion exchange resin is filled.

It is more preferable to consider the height of the ion exchange resin layer when determining the height h of the free board portion. The height of the ion exchange resin layer is usually in the range of 500 to 2000 mm, and the ratio h / H between the height h of the free board part and the height H of the ion exchange resin layer is preferably 1/50 to 1/2. .5, more preferably 1/20 to 1/10.

When the energized water is flowed downward, the LV is preferably 20 m / h or more because the ion exchange resin layer cannot be moved integrally if it is too small. If this LV is excessive, the ion exchange resin in the vicinity of the upper surface of the ion exchange resin layer is disturbed, so this LV is preferably 150 m / h or less. Accordingly, the LV is preferably 20 to 150 m / h, particularly preferably 30 to 60 m / h.

It is preferable that the downward circulating water of the energizing water starts immediately after the upstream circulating water of the raw water is stopped. Specifically, the energizing water is immediately within 1 sec immediately after the upward circulating water of the raw water is stopped. It is preferable to start downward flowing water. The continuation time of the energized water is preferably about 10 to 60 seconds.

The regenerative ion exchange apparatus may be any one of a single tower multi-bed type, a multi tower multi bed type, a multi tower single bed type, a single bed type, and the like. In the case of a single-column, multi-bed type, for example, the structure shown in FIGS. 3 to 5 can be used.

FIGS. 3 to 5 are longitudinal sectional views of a one-column, two-bed type regenerative ion exchange apparatus, in which FIG. 3 shows water sampling, FIG. 4 shows regeneration, and FIG. 5 shows energized water flow. An anion (anion) exchange resin 21 is filled in the upper chamber 20 of the tower body 41 of the regenerative ion exchange apparatus 40, and a cation (cation) exchange resin 31 is filled in the lower chamber 30. Two beds are formed.

The outer body of the tower body 41 of the regenerative ion exchange apparatus 40 is composed of a cylindrical portion 41a whose vertical axis is the cylindrical axis direction, a top end plate portion 41b, and a bottom end plate portion 41c. The end plate portion 41b is convexly convex upward, and the end plate portion 41c is convexly convex downward.

The inside of the tower body 41 is divided into two chambers, an upper chamber 20 and a lower chamber 30, by a water shielding partition plate 42. In this embodiment, the partition plate 42 is made of metal or synthetic resin that does not allow water to pass through at all, and is curved downward and convex like the end plate portion 41c. The peripheral edge portion of the partition plate 42 is watertightly coupled to the inner peripheral surface of the cylindrical portion 41a by welding or the like.

A first water collection / distribution member 44 is disposed in the upper part of the upper chamber 20, and an upper water supply / discharge pipe 43 is connected to the first water collection / distribution member 44. A second water collection / distribution member 46 is installed in the lower part of the upper chamber 20, and a first communication pipe 45 is connected to the water collection / distribution member 46. A third water collection / distribution member 49 is installed in the upper part of the lower chamber 30, and a second communication pipe 48 is connected to the water collection / distribution member 49. The

communication pipes

45 and 48 are connected by a

third communication pipe

51, and 52 is installed in the communication pipe 51.

Valves

47 and 50 are provided at the end portions of the

communication pipes

45 and 48 as supply and discharge means for the regenerated liquid. A fourth water collection / distribution member 54 is installed in the lower part of the lower chamber 30, and a lower water supply / discharge pipe 53 is installed in the water collection / distribution member 54.

Most of the inside of the upper chamber 20 is filled with an anion exchange resin 21, and a granular inert resin 22 is filled above the anion exchange resin 21. The first water collecting and distributing member 44 is embedded in the inert resin 22.

Most of the inside of the lower chamber 30 is filled with a cation exchange resin 31, and a granular inert resin 32 is filled above the cation exchange resin 31. The third water collection and distribution member 49 is embedded in the inert resin 32. As the inert resin, a polyacrylonitrile resin having a specific gravity smaller than that of the ion exchange resin is used. The particle size of the inert resin is preferably about the same as that of the ion exchange resin.

As the water collection /

distribution members

44, 46, 49, 54, a water collection plate used in a conventional ion exchange device, a strainer provided with a large number of slits in a radially extending pipe, or the like can be used. . For example, when the size of the ion exchange resin is about 0.4 mm, it is preferable to use a strainer having a slit width of about 0.2 mm. The water collection and

distribution members

44, 46, 49, 54 have shapes along the end plate portion 41b, the partition plate 42, and the end plate portion 41c, and have a small dead space along the end plate portion 41b, the partition plate 42, and the end plate portion 41c. It has become.

Fig. 3 shows the flow of deionized water production (water sampling) using this ion exchange device. In this case, the valve 52 is opened, the

valves

47 and 50 are closed, and raw water (treated water) is supplied from the lower supply / discharge pipe 53. This raw water is a water collection / distribution member 54, a cation exchange resin 31, an inert resin 32, a water collection / distribution member 49, a

communication pipe

48, 52, 45, a water collection / distribution member 46, an anion exchange resin 21, an inert resin 22, and a water collection / distribution member 44. Then, it flows in the order of the upper supply / discharge pipe 43 and is taken out as treated water (deionized water).

As the raw water flows upward from the water collecting and distributing

members

54 and 46, the cation exchange resin 31 and the anion exchange resin 21 are levitated and pressed against the lower surfaces of the layers of the

inert resins

32 and 22, respectively. When stopping the water sampling, immediately after stopping the raw water flow, the valve 52 is closed and the

valves

47 and 50 are opened as shown in FIG. 5 so that the energized water flows downward from the water collecting and distributing

members

49 and 44. And the energized waste water is discharged from the water collecting and distributing

members

54 and 46, and the layers of the cation exchange resin 31 and the anion exchange resin 21 (in a fixed bed state) are moved downward integrally as a whole, The cation exchange resin 31 is bottomed on the end plate portion 41c, and the anion exchange resin 21 is bottomed on the partition plate. Thereby, free boards are formed between the cation exchange resin 31 and the inert resin 32 and between the anion exchange resin 21 and the inert resin 22, respectively.

While the cation exchange resin 31 and the anion exchange resin 21 are moving downward, the collapsed portion as shown in FIG. 2b is not formed in the layer of each cation exchange resin 31 and the layer of the anion exchange resin 21. The valve 52 is opened, the

valves

47 and 50 are closed, the energized water is passed through the water collecting member 44 in a downward flow, and the upper chamber and the lower chamber are connected so as to be discharged from the lower supply / discharge pipe 53. The energizing water may be allowed to flow excessively.

When the cation exchange resin 31 and the anion exchange resin 21 are regenerated, the valve 52 is closed and the

valves

47 and 50 are opened as shown in FIG. 4, and an alkaline solution such as NaOH is supplied from the upper supply / discharge pipe 43. An acid solution such as HCl or H ₂ SO ₄ is supplied from the communication pipe 48. The alkaline solution flows in the order of the water collection / distribution member 44, the inert resin 22, the anion exchange resin 21, the water collection / distribution member 46, the communication pipe 45, and the valve 47, and flows out as recycled wastewater (alkali), whereby the anion exchange resin 21 flows. Played. The acid solution flows in the order of the water collection / distribution member 49, the inert resin 32, the cation exchange resin 31, the water collection / distribution member 54, and the lower supply / discharge pipe 53, and flows out as recycled wastewater (acid). Played.

After the regeneration, instead of the HCl solution and NaOH solution in FIG. 4, pure water is passed through, rinsed through each path and resin, and the upper and lower chambers are individually lowered with pure water as necessary. The washing waste water is discharged while performing counter-current washing, and then pure water is circulated between the upper chamber 20 and the lower chamber 30 for a predetermined time, and then returns to the water sampling step. In this regeneration, the anion exchange resin 21 and the cation exchange resin 31 are not mixed at all. The alkaline solution for regeneration does not flow into the lower chamber 30 and the acid solution is not mixed into the upper chamber 20, so that reverse regeneration is completely prevented. The anion exchange resin 21 and the cation exchange resin 31 can be regenerated at the same time, and the regenerating time is remarkably short.

This ion-exchange apparatus is one in which one tower body 41 is partitioned into two upper and lower chambers by one partition plate 42, the height of the tower body is low, and the installation space is also small. The

pipes

45, 51, and 48 communicating the upper chamber 20 and the lower chamber 30 can be short.

In this ion exchange apparatus, the water collecting and distributing

members

54, 46, 49, 54 are provided along the end plate portion 41b, the partition plate 42, and the end plate portion 41c, and local stagnation of water is prevented.

In this ion exchange apparatus, 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 is prevented. Are evenly in contact with the anion exchange resin 21 and the cation exchange resin 31, so that high-quality deionized water can be obtained and sufficient regeneration can be performed.

3 to 5, 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 possible. 3 to 5, the upper chamber 20 and the lower chamber 30 communicate with each other via

pipes

45, 51, and 48, but the present invention is not limited to this as long as the outside of the tower body 41 is routed. 3 to 5 use three

valves

47, 50, and 52, the flow path may be switched using two three-way valves.

The energizing water used for the downward circulation water may be treated water of this regenerative ion exchange device or may be any of the treated water in the subsequent stage, but has treated water or a corresponding purity. It is preferable to use water.

The downward circulating water of the energized water may be either the simultaneous flow through the front tower and the rear tower separately (parallel water flow), or the method of passing in series from the rear tower to the front tower as it is. It is preferable that the front column and the rear column are individually passed in parallel.

[Example 1]
In the regenerative ion exchange apparatus shown in FIG. 3, an anion exchange resin is filled in an upper stage of a container having an inner diameter of 600 mm so that the height becomes 1000 mm, and a cation exchange resin is filled in a lower stage so that the height becomes 500 mm. Thus, a single tower double bed type regenerative ion exchange apparatus was constructed. The height h of the free board part was set to 200 mm.
Strongly basic anion exchange resin: Dow MONOSSPHERE 550A (OH) specific gravity 1.1
Strong acid cation exchange resin: Dow MONOSSPHERE 650C (H) specific gravity 1.4

Raw water having a specific resistance of 0.1 MΩ · cm (conductivity of 10 μS / cm) was circulated upward at 20 m ³ / h into this regenerative ion exchange apparatus (ion exchange resin tower). When 3 hours have passed since the start of water flow, the upward flow water is stopped, and the energized water is immediately flown downward for 15 sec at 10 m ³ / h (LV = 35 m / h), and then the flow is stopped for 1 hour. It was. This was defined as one cycle and repeated a plurality of cycles. Table 1 shows the change over time in the specific resistance of the treated water and the amount of water collected. The amount of collected water is the total amount of treated water until the specific resistance of treated water becomes 18 MΩ · cm or less.
As shown in Table 1, in Example 1, the specific resistance of the treated water was 18.2 MΩ · cm until 77 hours passed from the start of water flow, and became 18.0 MΩ · cm after 84 hours. The total amount of water collected for 84 hours was 1440L.

[Comparative Example 1]
The regenerative ion exchange apparatus was operated in the same manner as in Example 1 except that the energized water downward flowing water after the raw water flow stop was not performed. Table 1 shows the change over time in the specific resistance of the treated water and the amount of water collected.
As shown in Table 1, in Comparative Example 1, the specific resistance of treated water was 18.2 MΩ · cm until 28 hours passed from the start of water flow, but the specific resistance of treated water was 15.5 MΩ after 35 hours. -It fell to cm. Therefore, the total amount of water collected was 570L.

[Comparative Example 2]
The regenerative ion exchange apparatus was operated in the same manner as in Example 1 except that the water flow was not stopped and the water was continuously passed. Table 1 shows the change over time in the specific resistance of the treated water and the amount of water collected.
In Comparative Example 2, as in Example 1, the specific resistance of the treated water was 18.2 MΩ · cm until 77 hours passed from the start of water flow, and became 18.0 MΩ · cm after 84 hours. The total amount of water collected for 84 hours was 1440L.

[Comparative Example 3]
The regenerative ion exchange apparatus was operated in the same manner as in Example 1 except that the height h of the free board was 300 mm. Table 1 shows the change over time in the specific resistance of the treated water and the amount of water collected.
In Comparative Example 3, the specific resistance of the treated water was 18.2 MΩ · cm from the start of water flow to 42 hours, but decreased to 17.5 MΩ · cm after 49 hours. Therefore, the total amount of water collected was 680L.

As shown in Table 1, according to Example 1, the amount of water collected was large despite repeated interruption of the flow of raw water. The amount of water collected in Example 1 was the same as in Comparative Example 2 that was continuously operated, and it was confirmed that the exchange capacity of the ion exchange resin could be fully utilized.

Comparative Example 3 has less water sampling than Example 1. In Comparative Example 1, the amount of collected water is smaller than that.

As is clear from the above examples, according to the present invention, even when the raw water flow stop is repeatedly performed during the water sampling, it is possible to ensure the same amount of water sampling as when the continuous water flow.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2013-092659 filed on April 25, 2013, which is incorporated by reference in its entirety.

Claims

An operation method of a regenerative ion exchange apparatus containing an ion exchange resin in a container,
A raw water flow step for passing raw water through the regenerative ion exchanger in an upward flow;
In the operation method of the regenerative ion exchange apparatus, including a water flow stopping step of stopping raw water flow to the regenerative ion exchange apparatus,
After the completion of the raw water flow process, before the water flow stop process, the process has a biased water flow process for flowing downward flow of the bias water for moving the ion exchange resin layer downward in the container. A method of operating a regenerative ion exchange device characterized by the above.
2. The operation method of a regenerative ion exchange apparatus according to claim 1, wherein deionized water obtained from the regenerative ion exchange apparatus is used as the energizing water.
2. The method of operating a regenerative ion exchange apparatus according to claim 1, wherein the height of the free board portion of the regenerative ion exchange apparatus is 10 to 200 mm.
The method of operating a regenerative ion exchange apparatus according to claim 1, wherein the LV when the energized water is passed is 20 to 150 m / h.
5. The method of operating a regenerative ion exchange apparatus according to claim 1, wherein the energized water is passed for 10 to 60 seconds.