JP2020025923A - Ion exchange device and ultrapure water production device - Google Patents

Abstract

To prevent an ion exchange device from being damaged when an ion exchange resin is regenerated.SOLUTION: The ion exchange device has a container, first and second piping, a nozzle and a joint. In the container, an ion exchange resin is accommodated. At least one first piping is arranged and guides regenerated water of the ion exchange resin accommodated in the container to the ion exchange resin. The nozzle penetrates a side wall of the container. The second piping is arranged on the ion exchange resin accommodated in the container or in the ion exchange resin, and guides the regenerated water passed through the ion exchange resin to a nozzle side. The joint has a flexibility and is included between the second piping and the nozzle.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an ion exchange device for removing ionic components in water to be treated and an ultrapure water production device provided with the same.

  Conventionally, in water treatment, an ion exchange device in which an ion exchange resin is contained in a resin tower (container) formed in a cylindrical shape or the like has been used. When the water to be treated flows through the ion-exchange resin in the resin tower, the ionic components are adsorbed on the ion-exchange resin, thereby increasing the purity.

  When water treatment by this type of ion exchange device is continued for a long time, the adsorption performance of ion components on the ion exchange resin decreases. When the adsorption performance of the ion component decreases, the ion exchange resin is regenerated to recover the adsorption performance (exchange capability) of the ion component. In the regeneration of the ion exchange resin, an alkaline regenerant or an acidic regenerant is passed through the ion exchange resin in the resin tower. Thereby, the ionic component adsorbed on the ion exchange resin is replaced with a hydroxyl group or a hydrogen atom.

  By the way, it is known that the volume of the ion exchange resin increases in the process of regenerating the ion exchange resin in such an ion exchange device (for example, see Patent Documents 1 to 3).

JP-A-2005-80749 JP 2015-80750 A Japanese Utility Model Publication No. 3-66695

  When the volume of the ion exchange resin increases in the resin tower, there is a concern about the influence of stress applied to, for example, piping in the resin tower. Specifically, the deformation of the packing arranged at the connection part of the pipe or the breakage of the welded portion between the nozzle at the end of the pipe that penetrates the side wall of the resin tower and the side wall due to the deflection of the pipe, etc. , Etc.

  The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an ion exchange apparatus and an ultrapure water production apparatus that can avoid damage to an ion exchange apparatus body during regeneration of an ion exchange resin. I do.

  The ion exchange device of the present invention includes a container, first and second pipes, a nozzle, and a joint. An ion exchange resin is contained in the container. At least one first pipe is provided, and guides the regenerated water of the ion exchange resin contained in the container into the ion exchange resin. The nozzle penetrates the side wall of the container. The second pipe is disposed on or in the ion exchange resin accommodated in the container, and guides the regenerated water flowing through the ion exchange resin to the nozzle side. The joint has flexibility and is interposed between the second pipe and the nozzle.

  Further, the ion exchange device of the present invention is configured such that a plurality of third pipes for collecting the regenerated water flowing through the ion exchange resin, and the plurality of third pipes are collected and connected to the second pipe. And a fourth pipe.

  Further, the ion exchange device of the present invention, the welded portion that joins the side wall of the container and the outer wall of the nozzle, between the second pipe and the joint, and between the joint and the nozzle And a plurality of packings interposed respectively.

  In the ion exchange apparatus of the present invention, the second pipe is disposed on an ion exchange resin housed in a container for a single-bed or double-bed ion exchange apparatus, For a mixed bed type ion exchange device, it is placed in an ion exchange resin housed in a container.

  Further, the apparatus for producing ultrapure water of the present invention includes the ion exchange apparatus exemplified above.

  Advantageous Effects of Invention According to the present invention, it is possible to provide an ion exchange device and an ultrapure water production device that can prevent the ion exchange device main body from being damaged during regeneration of the ion exchange resin.

FIG. 1 is a block diagram schematically showing a configuration of an ultrapure water production apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a primary pure water production unit included in the ultrapure water production apparatus of FIG. 1. The figure which illustrated the structure of the ion exchange apparatus of the single bed type (or the double bed type) provided in the ultrapure water production apparatus of FIG. The figure which illustrated the structure of the ion exchange apparatus of the mixed bed type | formula with which the ultrapure water production apparatus of FIG. 1 is provided. FIG. 4 is a view for explaining all regeneration steps in the ion exchange device of FIG. 3. FIG. 5 is a perspective view schematically showing a configuration of a drain pipe unit in the ion exchange device of FIG. 3 or 4. FIG. 7 is a perspective view schematically showing a state where a resin expansion force acts on the drainage pipe unit of FIG. 6. FIG. 7 is a cross-sectional view illustrating a configuration around a drain pipe provided in the drain pipe unit in FIG. 6. FIG. 9 is a cross-sectional view showing a state where a resin expansion force is applied to the periphery of the drainage pipe in FIG. Sectional drawing which shows the structure of the periphery of the drainage pipe with which the ion exchange apparatus of a comparative example is provided. FIG. 11 is a sectional view showing a state where a resin expansion force is applied to the periphery of the drainage pipe in FIG. 10.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the ultrapure water production apparatus 10 according to the present embodiment includes a pretreatment unit 12, a primary pure water production unit 14, a tank 16, and a secondary pure water production unit 18. The pretreatment unit 12 introduces city water, well water, industrial water, and the like as raw water. The pretreatment unit 12 is appropriately configured according to the quality of the raw water and the like, and removes suspended substances of the raw water to generate pretreatment water. The pretreatment unit 12 includes, for example, a sand filtration device and a microfiltration device, and further includes a heat exchanger for adjusting the temperature of the water to be treated as necessary.

  The primary pure water producing unit 14 produces primary pure water by removing organic components, ionic components, dissolved gases, and the like in the pretreatment water, and supplies the primary pure water to the tank 16. The tank 16 stores the primary pure water and supplies a required amount thereof to the secondary pure water producing unit 18. On the other hand, the secondary pure water production unit 18 removes impurities from the primary pure water produced by the primary pure water production unit 14 to produce secondary pure water that becomes ultrapure water. To the use point POU (Point Of Use). The surplus ultrapure water that has passed through the use point POU is collected in the tank 16.

  On the downstream side of the tank 16, for example, the secondary pure water producing unit 18 is provided with a heat exchanger, an ultraviolet oxidizing device (TOC-UV), a hydrogen peroxide removing device, a degassing membrane device, a polisher (non-regenerative mixed-bed type). (An ion exchange resin device), an ultrafiltration membrane device, and the like. The heat exchanger regulates the temperature of the primary pure water supplied from the tank 16. The ultraviolet oxidizer irradiates the pure water whose temperature has been adjusted by the heat exchanger with ultraviolet rays to decompose and remove trace organic substances in the water. The hydrogen peroxide removing device is a device for decomposing and removing hydrogen peroxide in water. For example, a palladium-supported resin device that decomposes and removes hydrogen peroxide using a palladium (Pd) -supporting resin, a basic anion exchange resin And a reducing resin device filled with a reducing resin having a sulfite group and / or a hydrogen sulfite group.

  The degassing membrane device is a device that reduces the pressure on the secondary side of the gas-permeable membrane and allows only the dissolved gas in the water flowing through the primary side to pass through the secondary side and remove it. Non-regeneration type mixed bed that has a mixed bed type ion exchange resin in which a cation exchange resin and an anion exchange resin are mixed, and adsorbs and removes a small amount of cation and anion components in the water to be treated. It is a type ion exchange device. The ultrafiltration membrane apparatus removes fine particles having a particle diameter of, for example, 50 nm or more (more preferably, 10 nm or more) by treating the water to be treated with a polisher to obtain ultrapure water (secondary pure water). The water quality of ultrapure water is, for example, 50 pcs. / L or less, the total organic carbon (TOC) concentration is 1 μgC / L or less, and the resistivity is 18 MΩ · cm or more.

  On the other hand, as shown in FIG. 2, the primary pure water production unit 14 includes, for example, an activated carbon device (AC) 21, a two-bed three-tower type device (2B3T) 22, a reverse osmosis membrane device (RO) 23, An apparatus (TOC-UV) 24, a mixed-bed ion exchange apparatus (MB) 25, a deaerator (DG) 26, and the like are provided. The primary pure water has, for example, a total organic carbon (TOC) concentration of 5 μg C / L or less and a resistivity of 17 MΩ · cm or more.

  As shown in FIG. 2, the activated carbon device 21 is an activated carbon tower provided with activated carbon such as coconut shell activated carbon. The activated carbon device 21 removes organic substances contained in the water to be treated by adsorbing the activated carbon on the activated carbon. The two-bed three-tower (two-bed three-tower) type device 22 is an integrated device in which an ion exchange device 22a, a decarbonation device 22b, and an ion exchange device 22c are arranged in series. The ion exchange device 22a is, for example, a single-bed cation exchange resin tower in which a cation exchange resin is contained (filled) in a resin tower (container). The decarbonation device 22b removes a carbonate component from the water to be treated that has been treated by the ion exchange device 22a. On the other hand, the ion exchange device 22c is, for example, a single-bed type anion exchange resin tower in which an anion exchange resin is contained in a resin tower (vessel).

  The reverse osmosis membrane device 23 removes impurities and salts in the water to be treated treated by the two-bed three-tower type device 22 by using a reverse osmosis membrane (RO membrane). The ultraviolet oxidation device 24 irradiates the water to be treated that has passed through the reverse osmosis membrane device 23 with ultraviolet rays to decompose and remove trace organic substances in the water. The ion exchange device 25 is a mixed bed type ion exchange resin tower in which a cation exchange resin and an anion exchange resin are contained in a resin tower (vessel). The deaerator 26 is, for example, a membrane deaerator or a vacuum deaerator for removing gas components such as oxygen contained in the water to be treated that has passed through the ion exchange device 25.

  Next, the configurations of the single-bed ion exchange device 22a, the single-bed ion exchange device 22c, and the mixed-bed ion exchange device 25 included in the ultrapure water production device 10 of the present embodiment, and the configurations thereof The process at the time of normal ion exchange (at the time of passing water) and the process at the time of regeneration of the ion exchange resin in the ion exchange apparatus will be described. Here, FIG. 3A is a diagram exemplifying the configuration of the single-bed type (double-bed type) ion exchange devices 22a and 22c and the processing at the time of passing water, and FIG. FIG. 6 is a diagram illustrating an example of the processing. On the other hand, FIG. 4A is a diagram exemplifying a configuration of the mixed bed type ion exchange device 25 and a process at the time of passing water, and FIG. 4B is a diagram exemplifying a process at the time of regeneration. . Further, FIGS. 5A to 5C are diagrams for explaining a series of flows of all regeneration steps in, for example, a single-bed (double-bed) ion exchange device 22a, 22c. FIG. 5A shows a regeneration step, FIG. 5B shows an extrusion step, and FIG. 5C shows a cleaning step.

  As shown in FIGS. 3A and 3B, the ion exchange devices 22 a and 22 c include a resin container (resin tower main body) 31 which is a cylindrical container, and a first pipe above the resin tower 31. At least one inlet pipe 32 provided, a drain pipe unit 33 including a drain pipe 51 (see FIG. 6 described later) which is a second pipe provided at a middle stage (middle) of the resin tower 31, and below the resin tower 31. Is provided. An ion exchange resin 35 that is a cation exchange resin or an anion exchange resin is contained (filled) in the resin tower 31. The inlet pipe 32 guides and flows alkaline or acidic regenerated water for regenerating the ion exchange resin 35 contained in the resin tower 31 into the ion exchange resin 35.

  The drain pipe 51 and the drain pipe unit 33 including the same are provided on the ion exchange resin 35 housed in the resin tower 31 with respect to the single-bed (or double-bed) ion exchange devices 22a and 22c. , And guides the regenerated water flowing through the ion exchange resin 35 to the nozzle 61 (see FIG. 6 described later). Further, in order to prevent the displacement of the ion exchange resin 35 during regeneration, the resin tower 31 is placed above the ion exchange resin 35 and the drain pipe unit 33 so that the drain pipe unit 33 including the drain pipe 51 is embedded. Holds a pressing resin 36 constituting a resin layer having a height of, for example, 200 mm to 300 mm. The drainage pipe 51 (and the drainage pipe unit 33 including the same) is a buried pipe (buried pipe unit) buried between the ion exchange resin 35 and the holding resin 36.

  A free board 37 is formed above the holding resin 36 in the resin tower 31. The dual-purpose pipe 34 constitutes an outlet of the water to be treated at the time of ion exchange (at the time of passing water), and constitutes an inlet of the regenerated water at the time of regeneration of the ion exchange resin 35. That is, as shown in FIG. 3 (a), when water is passed through the ion exchange resin 35, the water to be treated introduced into the resin tower 31 from the inlet pipe 32 is replaced by the free board 37, the holding resin 36, and the ion exchange resin. The gas flows through the pipe 35 and is discharged from the combined pipe 34. On the other hand, as shown in FIG. 3B, when the ion exchange resin 35 is regenerated, the holding water is introduced from the inlet pipe 32 into the resin tower 31, and the regenerated water is introduced from the combined pipe 34 into the resin tower 31. The pressurized water and the reclaimed water are discharged from the drainage pipe unit 33 to the outside of the resin tower 31. As a result, upward flow regeneration with high regeneration efficiency is realized.

  As shown in FIGS. 4A and 4B, in the ion exchange device 25, the ion exchange devices 22a and 22c shown in FIGS. 3A and 3B are provided in the resin tower 31. A mixed bed resin 45 is contained (filled) in the resin tower 31 instead of the ion exchange resin 35 and the holding resin 36. As shown in FIG. 4B, the ion exchange device 25 includes a drain pipe 51 and a drain pipe unit 33 including the drain pipe 51 at the boundary between the anion resin 45 b and the cation resin 45 a obtained by backwash separation during regeneration. is set up. That is, for the mixed bed type ion exchange apparatus 25, the drain pipe 51 and the drain pipe unit 33 including the same are arranged in the ion exchange resin (mixed bed resin 45) housed in the resin tower 31. I have.

  Further, at the time of regeneration of the mixed bed resin 45 (anion resin 45b and cation resin 45a), the inlet pipe 32 also functions as a first pipe. At the time of regeneration of the mixed bed resin 45 (anion resin 45b and cation resin 45a), an alkaline regenerant (NaOH) is introduced into the resin tower 31 from the inlet pipe 32 as shown in FIG. On the other hand, an acidic regenerant (HCl) is introduced into the resin tower 31 from the combined pipe 34 (alternately or simultaneously), and these regenerants (regenerated water) are discharged from the drain pipe unit 33 to the outside of the resin tower 31. Is discharged.

  Here, as shown in FIG. 5A, in the ion exchange devices 22a and 22c (or the ion exchange device 25), as the main regeneration step, for example, the regenerated chemical is diluted with driving water for a period of 15 minutes to 40 minutes. The regenerant (regenerated water) is passed through the ion exchange resin 35 (or the anion resin 45b and the cation resin 45a). Subsequently, as shown in FIG. 5B, in the extrusion step, for example, by continuously supplying the driving water for a period of 30 to 80 minutes, the regenerating agent (regenerated water) in the middle of the inflow is ion-exchange resin 35 ( Alternatively, it is allowed to sufficiently flow through the anionic resin 45b and the cationic resin 45a). Further, as shown in FIG. 5C, as a washing step, washing water is introduced into the resin tower 31 from the inlet pipe 32 for a period of, for example, 60 minutes to 100 minutes, and the washing water is supplied to the ion exchange resin 35. It is allowed to flow and discharged from the dual-purpose pipe 34. Thereby, the regenerant (regenerated water) remaining in the resin tower 31 is washed out.

  In the ultrapure water production apparatus 10 of the present embodiment, a plurality of ion exchange apparatuses having the same function are provided in parallel with respect to the direction of the flow of the water to be treated, and are provided in parallel. Further, at least one ion exchange device is in a standby state in a stopped state. In other words, when there is an ion exchange apparatus that is performing the above-described series of regeneration steps, it is possible to continuously manufacture ultrapure water by operating the standby ion exchange apparatus instead. .

  Next, the structure of the drain pipe unit 33 will be described in detail with reference to FIGS. As shown in FIGS. 6 and 8, the drain pipe unit 33 includes the drain pipe 51, the nozzle 61, the plurality of branch pipes 53 as the third pipe, the main pipe 52 as the fourth pipe, and the flexibility. (Flexible pipe) 55 having a pair of support members 54 and a plurality of packings 64 and 67. The nozzle 61 penetrates the side wall of the resin tower (vessel) 31. The plurality of branch pipes 53 extend in the cylindrical resin tower 31 in the radial direction of the resin tower 31, and collect the regenerated water flowing through the ion-exchange resin from the respective tip end sides.

  The main pipe 52 collects a plurality of branch pipes 53 and is connected to the drain pipe 51. The main pipe 52 extends in the cylindrical resin tower 31 in the radial direction of the resin tower 31 and is arranged in a direction orthogonal to the plurality of branch pipes 53. The base ends of the plurality of branch pipes 53 are connected to the peripheral surface of the main pipe 52, respectively. One end 52a and the other end 52b of the main pipe 52 are supported by the resin tower 31 via a predetermined support member. Each of the pair of support members 54 has a columnar structure having a U-shaped cross section, and extends in the same direction as the main pipe 52. One end 54a and the other end 54b of the support member 54 are supported by the resin tower 31 via a predetermined support member while the support member 54 holds the plurality of branch pipes 53.

  The drain pipe 51 extends in the same direction as the main pipe 52, and is disposed immediately above the main pipe 52. The drain pipe 51 is formed in an L-shape, and a bent one end is joined to the peripheral surface of the main pipe 52. The joint 55 is a flexible joint interposed between the drain pipe 51 and the nozzle 61. The material of the joint 55 must withstand the hydrodynamic pressure in the resin tower 31 and have a resistance to the regenerant. As the material of the joint 55, for example, a material made of rubber, stainless steel such as SUS316, or a material obtained by applying a fluorine resin coating such as Teflon (registered trademark) to a base material can be used.

  One end of the joint 55 is connected to the other end of the drain pipe 51 via a flange 65, a packing 67, and a flange 66. The other end of the joint 55 is connected to one end of the nozzle 61 via a flange 63, a packing 64 and a flange 62. That is, the packing 67 is interposed between the drain pipe 51 and the joint 55. On the other hand, the packing 64 is interposed between the joint 55 and the nozzle 61. As shown in FIGS. 8 and 9, the side wall of the resin tower 31 and the outer wall of the nozzle 61 are joined to each other via welding portions 68 and 69.

  By the way, it is known that the above-mentioned ion exchange devices 22a, 22c, and 25 increase the volume of the ion exchange resin during the process of regenerating the ion exchange resin. Specifically, the volume of the cation exchange resin may increase by about 8% to 10% during regeneration, and the volume of the anion exchange resin may increase by about 18% to 30% during regeneration. In a relatively large ion exchange apparatus in which the diameter of the resin tower 31 is, for example, 3000 mm or more and the filling height of the ion exchange resin is 1500 mm or more, the expansion height of the ion exchange resin increases in proportion thereto. Alternatively, the moment applied to the drain pipe or the like during expansion increases. As shown in FIG. 7, when the resin expansion force Z2 of the ion exchange resin occurs in the resin tower 31, the drainage pipe 51, the packings 64 and 67, and the welding are performed through the plurality of branch pipes 53, the main pipe 52, and the support members 54. There is a concern that each part may be damaged due to the stress Z1 applied to the parts 68, 69 and the nozzle 61.

  Therefore, in the ion exchange devices 22a, 22c, and 25 of the present embodiment, a flexible joint 55 is interposed between the drain pipe 51 and the nozzle 61 as shown in FIGS. When the resin expansion force Z2 of the ion exchange resin is generated, the joint 55 is elastically deformed as shown in FIG. 9, and the joint 55 is eccentric (at least 5 mm to 10 mm or more) between the drain pipe 51 and the nozzle 61. Eccentricity), and mainly absorbs a stress (moment) Z1 that may be applied to the drain pipe 51. That is, the joint 55 has a structure that can be elastically deformed to a height equal to or higher than the height of the upper surface of the ion exchange resin whose volume has increased.

  On the other hand, as shown in FIGS. 10 and 11, in the ion exchange apparatus of the comparative example in which no flexible joint is interposed around the drain pipe 91, the stress applied to the drain pipe 91 due to the resin expansion force Z2 is a factor. (Moment) Due to the influence of Z1, deformation of the packing 64 interposed between the drain pipe 91 and the nozzle 61 and breakage of the welded portions 68 and 69 joining the nozzle 61 and the side wall of the resin tower 31 are prevented. May be invited. If the packing 64 is deformed or the welds 68 and 69 are broken, the regenerated water in the resin tower 31 leaks.

  In contrast, as described above, the ion exchange devices 22a, 22c, and 25 according to the present embodiment have the flexible joint 55 interposed between the water drain pipe 51 and the nozzle 61, and Even when the resin expansion force Z2 is generated at the time of regeneration of the exchange resin, the joint 55 can be elastically deformed to absorb the stress Z1 that may be applied to the drain pipe 51.

Therefore, according to the ultrapure water production apparatus 10 including the ion exchange devices 22a, 22c, and 25 of the present embodiment, the ion exchange devices 22a, 22c, and 25 are used when the ion exchange resin 35 (mixed bed resin 45) is regenerated. Damage can be avoided.
In addition, when the present invention is adopted in a conventional ion exchange apparatus, it can be dealt with without modifying the drainage pipe without any major work.
Further, conventionally, it was difficult to design a large resin tower having a tower height of 1500 mm or more and a tower diameter of 3000 mm or more in order to avoid breakage of the drain pipe, but by using the present invention, these large resin towers can be freely formed. It becomes possible to design.
As a result, the amount of ion exchange resin in the resin tower can be increased, so that the frequency of regeneration of the resin tower can be reduced, and the resin tower can be operated with a margin.

  As described above, the present invention has been described in detail with reference to the embodiment. However, the present invention is not limited to this embodiment as it is, and can be variously changed in an implementation stage without departing from the gist thereof. For example, some components may be deleted from all the components shown in the embodiments, and a plurality of components disclosed in the embodiments may be appropriately combined.

  10: Ultrapure water production apparatus, 14: Primary pure water production section, 22: Two-bed, three-tower type apparatus, 22a, 22c: Single-bed (or double-bed) ion exchange apparatus, 25: Mixed-bed ion Exchange device, 31: resin tower (resin tower main body), 32: inlet pipe, 33: drain pipe unit, 34: shared pipe, 35: ion exchange resin, 45: mixed bed resin, 45a: cationic resin, 45b: anionic resin Reference numeral 51: Drainage pipe, 52: Main pipe, 53: Branch pipe, 55: Flexible joint, 61: Nozzle, 64, 67: Packing, 68, 69: Welded part, Z1: Stress, Z2: Resin expansion Power.

Claims (5)

A container for accommodating the ion exchange resin,
At least one first pipe for guiding regenerated water of the ion exchange resin contained in the container into the ion exchange resin;
A nozzle penetrating the side wall of the container,
A second pipe that is disposed on or in the ion exchange resin contained in the container and guides the regenerated water flowing through the ion exchange resin to the nozzle side,
A flexible joint interposed between the second pipe and the nozzle,
An ion exchange device comprising: A plurality of third pipes for collecting reclaimed water flowing through the ion exchange resin;
A fourth pipe that collects the plurality of third pipes and is connected to the second pipe;
The ion exchange device according to claim 1, further comprising: A welded portion joining the side wall of the container and the outer wall of the nozzle,
A plurality of packings respectively interposed between the second pipe and the joint, and between the joint and the nozzle,
The ion exchange device according to claim 1, further comprising: The second pipe is disposed on the ion exchange resin accommodated in the container for a single-bed or double-bed ion exchange apparatus, while the second pipe is arranged for a mixed-bed ion exchange apparatus. Preferably, disposed in an ion exchange resin housed in the container,
The ion exchange device according to any one of claims 1 to 3.   An ultrapure water production apparatus comprising the ion exchange device according to any one of claims 1 to 4.

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