Method for operating up-flow ion exchange column

Abstract

Provided is a method for operating an up-flow ion exchange tower in which deionized water is produced by introducing raw water into an ion exchange tower having a packed bed of an ion exchange resin between a water-permeable separator on the lower side and a water-permeable separator on the upper side in an up-flow manner by means of a water supply pump, the method for operating an up-flow ion exchange column comprises: a fixed bed formation step in which raw water is introduced into the ion exchange column at a high linear velocity at the beginning of water introduction, and a packed bed of an ion exchange resin in the ion exchange column is pushed upward to form a fixed bed in which the raw water is introduced into the ion exchange column at a high linear velocity; a water-permeable separator pushed to the upper side of the packed bed to form a fixed bed of an ion exchange resin; and a stable operation step in which, after the fixed bed formation step, the raw water is passed through at a linear velocity greater than the minimum linear velocity for maintaining the fixed bed, and the amount of the raw water passed through is controlled in accordance with the required amount of deionized water.

Description

Technical Field

[0001] This invention relates to an operation method of an upflow ion exchange tower, and more particularly to an operation method of an upflow ion exchange tower in which the upflow rate (LV) is varied according to the required amount of deionized water. Background Technology

[0002] As a method of operating an ion exchange tower to obtain deionized water by passing raw water into an ion exchange tower containing ion exchange resin in a container, there is an upward flow water method in which the raw water is passed upward.

[0003] When raw water is fed into an ion exchange tower in an upward flow manner, there is a concern that the ion exchange resin may not be able to completely adsorb ions and may leak if it flows. Therefore, in most cases, a fixed bed is formed in an upward flow ion exchange tower (Patent Document 1).

[0004] In a typical upflow ion exchange tower, a cylindrical container is positioned with its axis pointing vertically (especially in the vertical direction). Water-permeable baffles are installed in the upper and lower parts of the container, and ion exchange resin is contained between these baffles. The ion exchange resin expands and contracts due to water intake / regeneration, thus increasing / decreasing its volume. Therefore, to ensure uniform flow of the regenerated reagent into the resin layer, it is contained within the container with a predetermined height of free space.

[0005] If raw water is introduced into this ion exchange resin tower in an upward flow, the ion exchange resin is pushed upward by the upward flow, becoming a fixed bed pressed against the upper permeable baffle, and water is collected in this state. The treated water flows out from the outlet at the top of the container.

[0006] If the flow of raw water to the ion exchange tower is stopped, the force pushing the ion exchange resin upwards disappears, and the ion exchange resin forming the fixed bed settles down to the permeable baffle side of the lower side inside the container, returning to the containment state before the water flow.

[0007] Thus, as the ion exchange resin settles within the container, a slump is formed. This slump slowly moves upwards, eventually reaching the uppermost ion exchange resin, at which point the settling process ends. In this slump, the ion exchange resin particles mix as they fall. Therefore, if water intake is stopped midway through operation (when raw water flow is stopped) while the ion exchange resin on the lower side of the packing layer has broken through (broken) but the resin on the upper side has not, the broken resin on the lower side mixes with the unbroken resin on the upper side. This can sometimes lead to a deterioration in the treated water quality when water intake resumes.

[0008] Therefore, for ion exchange towers that operate with upward-flowing water, once water collection begins by flowing water upwards, the water flow continues until water collection is complete (the next regeneration).

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent document 1: Japanese Patent Application Publication No. 2017-170419.

[0012] Patent document 2: Japanese Patent Application Publication No. 2014-213263. Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] As described above, in the previous upflow ion exchange tower, water is passed through at a certain or higher speed (high linear velocity, LV) at the start of water intake to form a fixed bed of ion exchange resin. After the fixed bed is formed, raw water is passed through at a certain flow rate to produce deionized water such as pure water.

[0015] However, the water consumption of the pure water demand section varies depending on its operating conditions. Therefore, in previous pure water production facilities including ion exchange towers, the maximum amount of pure water required by the pure water demand section is produced, thereby generating surplus pure water. This surplus pure water is then reused as the water supply for the pure water production facility.

[0016] In a pure water production apparatus with a regenerable ion exchange tower, the ion exchange resin in the tower is regenerated after a predetermined amount of pure water is collected. When the remaining pure water is reused as supply water, as described above, the ion loading of the supply water decreases, thus increasing the volume of water that can be collected. However, since the amount of remaining pure water cannot be predicted, and it is unknown how much of the remaining pure water will be reused as supply water, a fixed volume of water is set in the design based on the ion loading of the raw water. Therefore, even when the actual ion loading is small, regeneration is performed when the water collection volume reaches the fixed volume. As a result, the regeneration frequency increases, and excess regeneration reagents are used.

[0017] The objective of this invention is to provide an operating method for an upflow ion exchange tower that can change the production rate of deionized water in response to variations in the required amount of deionized water at the point where deionized water is needed.

[0018] Methods for solving problems

[0019] The present invention discloses an operation method for an upward-flow ion exchange tower, wherein raw water is fed upward into the ion exchange tower, which has a packed bed of ion exchange resin between a lower permeable baffle and an upper permeable baffle, to produce deionized water. The operation method of the upward-flow ion exchange tower includes: a fixed bed formation step, in which raw water is fed into the ion exchange tower at a high linear velocity (LV) at the beginning of water flow, pushing the packed bed of ion exchange resin upward into the ion exchange tower to the upper permeable baffle to form a fixed bed of ion exchange resin; and a stable operation step, in which raw water is fed at a linear velocity (LV) greater than the minimum linear velocity (LV) required to maintain the fixed bed after the fixed bed formation step, and the flow rate of raw water is controlled according to the required amount of deionized water.

[0020] In one aspect of the invention, the operation method of the upflow ion exchange tower is an upflow ion exchange tower operation method in which deionized water from the ion exchange tower is introduced into a deionized water tank via a flow regulating valve and transported from the deionized water tank to the desired destination of the deionized water in the stable operation process. The opening of the flow regulating valve and / or the water supply pump are controlled in such a way that the water level in the deionized water tank is within a specified range and the fixed bed of the ion exchange tower is maintained.

[0021] In one aspect of the present invention, the control frequency of the water supply pump is less than 7 times / min.

[0022] [The effects of the invention]

[0023] According to the operating method of the upflow ion exchange tower of the present invention, the production rate of deionized water can be changed in response to the change in the required amount of pure water at the pure water demand location.

[0024] According to the operating method of the upward-flow ion exchange tower of the present invention, since the flow rate of water to the ion exchange tower is controlled according to the required amount of deionized water, the power consumption rate of the water supply pump can be reduced and the regeneration frequency or exchange frequency of the ion exchange resin can be reduced. Attached Figure Description

[0025] Figure 1 This is a structural diagram of a pure water production apparatus for an upward-flow ion exchange tower operating method according to the application implementation method.

[0026] Figure 2 This is a structural diagram of a pure water production apparatus for an upward-flow ion exchange tower operating method according to the application implementation method.

[0027] Figure 3 This is a structural diagram of an ion exchange device.

[0028] Figure 4 This is a structural diagram of an ion exchange device.

[0029] Figure 5 It is a graph representing the experimental results.

[0030] Figure 6 It is a graph representing the experimental results.

[0031] Figure 7 It is a graph representing the experimental results.

[0032] Figure 8 It is a graph representing the experimental results.

[0033] Figure 9 It is a graph representing the experimental results. Detailed Implementation

[0034] The embodiments will now be described with reference to the accompanying drawings.

[0035] Figure 1 This diagram illustrates an example of a pure water production apparatus using the operating method of the upward-flow ion exchange tower of the present invention. Raw water to be deionized is supplied to the ion exchange unit 3 via a first pump 1 and piping 2. The water is then introduced into the ion exchange tower of the ion exchange unit 3, where it comes into contact with the ion exchange resin and undergoes deionization treatment, thereby becoming pure water (deionized water). The raw water is introduced into the ion exchange tower of the ion exchange unit 3 in an upward flow manner.

[0036] When water is first introduced into the ion exchange tower, a fixed bed is formed by introducing water into the ion exchange tower at a high LV.

[0037] Pure water from the ion exchange unit 3 is introduced into the pure water tank 9 via pipe 4, second pump 5, pipe 6, flow regulating valve 7, and pipe 8, and then transported to the location where pure water is needed via pipe 10. A flow meter or pressure gauge 11 is installed on pipe 6, and a water level gauge 12 is installed on the pure water tank 9. All detection signals are input to the controller 13.

[0038] The controller 13 adjusts the opening of the flow regulating valve 7 by means of proportional-integral-derivative (PID) control, etc., so that the water level detected by the water level gauge 12 is within a specified range.

[0039] The flow rate of pure water from the pure water tank 9 to the pure water demand area varies depending on the pure water usage. Consequently, the water level in the pure water tank 9 changes. This is controlled by adjusting the opening of the flow regulating valve 7, thus controlling the raw water treatment rate to maintain the water level in the pure water tank 9 within a specified range. In other words, the flow rate to the ion exchange device 3 is controlled based on the amount of water delivered from the pure water tank 9 to the pure water demand area via the piping 10.

[0040] Furthermore, the controller 13 performs frequency conversion control on the water delivery rate (motor speed) of the first pump 1 or the second pump 5, ensuring that the flow rate or pressure detected by the flow meter or pressure gauge 11 is within a specified range after the opening of the flow regulating valve 7 is adjusted. Moreover, the specified range of flow rate or pressure is set to maintain the flow rate of the fixed bed within the ion exchange tower of the ion exchange device 3.

[0041] In this invention, the flow rate to the ion exchange tower is controlled according to the amount of pure water used at the point where pure water is needed, in a manner that maintains the fixed bed of the ion exchange tower.

[0042] This reduces the pump power consumption rate during ion exchange system operation and decreases the regeneration frequency or exchange frequency of ion exchange resin.

[0043] Figure 2 This is a diagram illustrating another example of a pure water production apparatus that utilizes the operating method of the upward-flow ion exchange tower of the present invention.

[0044] exist Figure 2 In the pure water production device, a flow meter or pressure gauge 11 is installed in the piping 8, and a pressure gauge 14 is installed in the piping 6. Various detection signals and the detection signal of the water level gauge 12 of the pure water tank 9 are input to the controller 13.

[0045] Figure 2 Other structures and Figure 1The same symbol indicates the same part. In the pure water production apparatus, when water is first introduced into the ion exchange unit 3, water is introduced into the ion exchange tower at a high LV to form a fixed bed.

[0046] In the Figure 2 In the pure water production unit, the opening of the flow regulating valve 7 is controlled by ensuring that the water level detected by the water level gauge 12 is within a specified range. Furthermore, the rotation speed of one or both of the first pump 1 and the second pump 5 is controlled by frequency conversion based on whether the pressure detected by the pressure gauge 14 after the opening of the flow regulating valve 7 is adjusted, or the flow rate or pressure detected by the flow meter or pressure gauge 11, is within a specified range (the range for maintaining the fixed bed of the ion exchange tower).

[0047] Through the above Figure 2 The pure water production apparatus also controls the flow rate to the ion exchange unit 3 based on the amount of water supplied from the pure water tank 9 through the piping 10 to the point where pure water is needed, in a manner that maintains the fixed bed of the ion exchange tower. This reduces the pump power consumption rate during operation of the pure water production apparatus and decreases the regeneration frequency or exchange frequency of the ion exchange resin.

[0048] In this invention, the frequency of flow adjustment operation of the first pump 1 or the second pump 5 is preferably less than 7 times / min, and the flow rate change amplitude of each operation is preferably less than half of the maximum flow rate.

[0049] The reason for setting the flow rate adjustment frequency to 7 times / min or less is as follows.

[0050] Generally speaking, if the metal used in the pump experiences friction 2×10 7 This will lead to wear and fatigue failure. If we assume the pump is used for 5 years, then it will become 2 × 10 7 The flow rate adjustment frequency is calculated as follows: times / 5 years / 365 days / 24 hours / 60 minutes = 7.62 times / min. Therefore, the optimal flow rate adjustment frequency is set to below 7 times / min.

[0051] Figure 1 or Figure 2 The pure water production device is suitable for assembly into the primary pure water system of an ultrapure water production unit, but it can also be used for other purposes.

[0052] In this invention, the structure of the ion exchange device 3 is not particularly limited. An example of a structure that can be used as the ion exchange device 3 is shown below. Figure 3 , Figure 4 middle.

[0053] exist Figure 3In the ion exchange device 3, a cylindrical cation exchange tower 21 and an anion exchange tower 23 are respectively arranged inside the shell 26. The cation exchange tower 21 and the anion exchange tower 23 are arranged with the axis of the cylinder in the vertical direction. Raw water from the piping 2 is introduced into the cation exchange tower 21 and undergoes cation exchange treatment by flowing water upward. After that, it is introduced into the anion exchange tower 23 through the piping 25 and undergoes anion exchange treatment by flowing water upward, becoming pure water, and then flows out through the piping 4.

[0054] A packed bed 22 containing strongly acidic cation exchange resin is provided in the cation exchange tower 21. Water-permeable baffles 21a and 21b, each with a water-passing section, are horizontally arranged on the lower and upper sides of the packed bed 22, respectively. The water-passing sections of the baffles 21a and 21b are configured to allow water to pass through but not the cation exchange resin particles. Under stable water flow conditions, the packed bed 22 is pushed upwards and pressed against the upper baffle 21b, thus becoming a fixed bed.

[0055] The distance between the upper surface of the packed bed 22 when it is not irrigated and the permeable baffle 21b is preferably more than 40% of the height of the packed bed 22 when it is not irrigated, and more preferably about 50% to 70%. The same applies to the anion exchange tower described later.

[0056] The regeneration of the cation exchange resin is carried out by passing hydrochloric acid through water in a downward flow.

[0057] The anion exchange tower 23 has a packed bed 24 of strongly basic anion exchange resin. Water-permeable baffles 23a and 23b, each with a water-passing section, are horizontally arranged on the lower and upper sides of the packed bed 24, respectively. Under stable water flow conditions, the packed bed 24 is pushed upwards and pressed against the upper water-permeable baffle 23b, thus becoming a fixed bed.

[0058] Regeneration of anion exchange resin is carried out by passing an aqueous sodium hydroxide solution through water in a downward flow.

[0059] exist Figure 4 In the ion exchange unit 3', raw water from pipe 2 is introduced into the cation exchange tower 30, where it undergoes cation exchange treatment by flowing upwards. Afterwards, it is transported through pipe 34 to the decarbonation tower 40 for decarbonation treatment. The decarbonated water is then introduced into the anion exchange tower 50 via pump 43 and pipe 44, where it undergoes anion exchange treatment by flowing upwards, becoming deionized water, and then flows out through pipe 4.

[0060] Furthermore, the cation exchange tower 30 is equipped with packed beds 31 and 32 containing strongly acidic cation exchange resin. Water-permeable baffles 30a, 30b, and 30c, each with a water-passing section, are horizontally arranged on the lower side of the lower packed bed 31 and the lower and upper sides of the upper packed bed 32, respectively. The water-passing sections of the water-permeable baffles 30a to 30c are configured to allow water to pass through but not cation exchange resin particles. Under stable water flow conditions, the packed beds 31 and 32 are pushed upwards and pressed against the upper water-permeable baffles 30b or 30c, thus becoming fixed beds.

[0061] The regeneration of the cation exchange resin is carried out by passing hydrochloric acid through water in a downward flow.

[0062] The decarbonation tower 40 has a packing layer 41. The pressure inside the decarbonation tower 40 is reduced by a vacuum pump (not shown). During flow along the packing layer 41, dissolved carbon dioxide in the water is degassed. Water falling into the groove 42 is pumped by a pump 43.

[0063] The anion exchange tower 50 has packed beds 51 and 52 containing strongly basic anion exchange resin. Permeable baffles 50a, 50b, and 50c, each with a water-passing section, are horizontally arranged on the lower side of the lower packed bed 51 and the lower and upper sides of the upper packed bed 52, respectively. Under stable water flow conditions, the packed beds 51 and 52 are pushed upwards and pressed against the upper permeable baffles 50b or 50c to become fixed beds.

[0064] Regeneration of anion exchange resin is carried out by passing an aqueous sodium hydroxide solution through water in a downward flow.

[0065] In this invention, during the fixed bed formation process when water is initially introduced into an ion exchange tower containing ion exchange resin with an average particle size of about 500 μm to 700 μm, it is more preferable to form the fixed bed by introducing water in an upward flow under LV conditions of 20 m / h or higher, for example, 20 m / h to 70 m / h, especially about 20 m / h to 50 m / h.

[0066] In subsequent stable operation, water is passed through in an upward flow at a relatively small LV (wherein, is at least the minimum LV required to maintain the fixed bed), and the flow rate is controlled according to the change in the required amount of deionized water. The minimum LV only needs to be sufficient to maintain the buoyancy of the ion exchange resin, for example, it can be appropriately set at around 6 m / h and 20 m / h.

[0067] [Example]

[0068] [Experimental Example 1]

[0069] like Figure 3 As shown, a water flow test was conducted using an ion exchange device 3, which has a cation exchange tower 21 and an anion exchange tower 23 within a single tower. The main conditions are as follows.

[0070] <Structure of Cation Exchange Tower 21>

[0071] Inner diameter: 700 mm.

[0072] The height between the partitions 21a and 21b of the cation exchange tower 21 is 700 mm.

[0073] The height of the fixed bed for cation exchange resin is 572 mm.

[0074] Average particle size of cation exchange resin: 650 μm.

[0075] <Structure of Anion Exchange Tower 23>

[0076] Inner diameter: 700 mm.

[0077] The height between partitions 23a and 23b of the anion exchange tower 23 is 1200 mm.

[0078] The height of the fixed bed for anion exchange resin is 1105 mm.

[0079] The average particle size of the anion exchange resin is 550 μm.

[0080] <The treated water>

[0081] A saline solution with a concentration of 8 mg / L (27°C).

[0082] <Fixed bed forming process>

[0083] A fixed bed is formed by circulating water at LV=20 m / h for 10 min.

[0084] <Stable Operation Process>

[0085] After the fixed bed is formed, a stable operation process is performed. In this stable operation process, the water flow rate is varied in a 20-minute cycle between LV=42.9 m / h and LV=90.9 m / h. It should be noted that within the range of LV=42.9 m / h to LV=90.9 m / h, the water flow rate is increased linearly every 10 minutes, and within the range of LV=90.9 m / h to LV=42.9 m / h, the water flow rate is decreased linearly every 10 minutes. The total water flow time is set to 6 hours.

[0086] <Results>

[0087] Even if the resistivity of the LV changes during stable operation, it remains constant (approximately 18 MΩ·cm).

[0088] [Experimental Example 2]

[0089] <Experimental Methods>

[0090] The cation exchange tower 21 used in Experimental Example 1 has the same structure as the cation exchange tower 21 used in Experimental Example 1.

[0091] An 8 mg / L saline solution (27°C) was passed through water in an upward flow. The upward flow velocity (LV) was gradually increased from 0 m / h to 91.0 m / h over 30 minutes, and the change in pressure difference over time was measured. The results are shown in Table 1 and... Figure 5 .

[0092] In addition, after the upward flow velocity (LV) reached 91.0 m / h, it gradually decreased to 0 m / h over a period of 30 minutes, and the change in pressure difference over time was measured. The results are shown in Table 2 and... Figure 6 .

[0093] It should be noted that Tables 1 and 2 also record the measured pressure difference (MPa) divided by the height of the packed bed (m) to obtain the value of MPa / m (pressure difference per 1 m of packed bed).

[0094] [Table 1]

[0095] [Table 2]

[0096] <Inspection>

[0097] As shown in Table 1, Table 2 and Figure 5 , Figure 6 As shown, it was confirmed that the pressure differential changes approximately proportionally to the change in LV. It should be noted that when the change in LV passes through the vicinity of 20 m / h (the LV at which the fixed bed is formed in Experimental Example 1), the pressure differential also changes approximately proportionally to the change in LV.

[0098] [Experiment Example 3]

[0099] <Experimental Methods>

[0100] The anion exchange tower 23 used in Experimental Example 1 has the same structure as the anion exchange tower 23.

[0101] An 8 mg / L saline solution (27.6℃) was passed through water in an upward flow. The upward flow velocity (LV) was gradually increased from 0 m / h to 91.0 m / h over 30 min, and the change in pressure difference over time was measured. The results are shown in Table 3. Figure 7 .

[0102] In addition, after the upward flow velocity (LV) reached 91.0 m / h, it gradually decreased to 0 m / h over a period of 30 minutes, and the change in pressure difference over time was measured. The results are shown in Table 4 and... Figure 8 .

[0103] It should be noted that Tables 3 and 4 also record the measured pressure difference (MPa) divided by the height of the packed bed (m) to obtain the value of MPa / m (pressure difference per 1 m of packed bed).

[0104] [Table 3]

[0105] [Table 4]

[0106] <Inspection>

[0107] As shown in Tables 3 and 4, and Figure 7 , Figure 8 As shown, it was confirmed that the pressure differential changes approximately proportionally to the change in LV. It should be noted that when the change in LV passes through the vicinity of 20 m / h (the LV at which the fixed bed is formed in Experimental Example 1), the pressure differential also changes approximately proportionally to the change in LV.

[0108] [Experimental Example 4-1, Experimental Example 4-2]

[0109] <Experimental Example 4-1>

[0110] Prepare two columns with an inner diameter of 40 mm and a height of 1000 mm. Pack 500 mL of H-type cation exchange resin into one column (packed bed height approximately 400 mm). Pack 1000 mL of OH-type anion exchange resin into the other column (packed bed height approximately 800 mm). Connect these columns using piping with the liquid flowing upwards from the cation-packed column to the anion-packed column. The H-type cation exchange resin is regenerated from Na-type cation exchange resin, with an average particle size of 650 μm. The OH-type anion exchange resin is regenerated from Cl-type anion exchange resin, with an average particle size of 550 μm.

[0111] Permeable baffles were installed on the lower side and upper part of the cation exchange resin packed bed, and on the lower side and upper part of the anion exchange resin packed bed. An 8 mg / L saline solution (27°C) was passed through at an LV of 50 m / h for 10 min to push each ion exchange resin bed upwards, forming a fixed bed within each column. Then, the saline solution was passed through at an LV of 20 m / h to maintain the fixed bed. The change in resistivity over time after the start of water flow under the LV of 20 m / h condition is shown in the figure. Figure 9 .

[0112] <Experimental Example 4-2>

[0113] In Experiment 4-1, the saline solution was circulated with water at LV = 20 m / h without forming a fixed bed. The change in resistivity over time after the start of water circulation is shown in the figure. Figure 9 .

[0114] <Inspection>

[0115] like Figure 9 As shown, it was confirmed that the resistivity of Example 4-1, in which a fixed bed was formed, was about 1 MΩ·cm higher than that of Example 4-2, in which a fixed bed was not formed.

[0116] Although the invention has been described in detail using specific methods, it will be apparent to those skilled in the art that various modifications can be made without departing from the intent and scope of the invention.

[0117] This application is based on Japanese Special Application 2023-127186, filed on August 3, 2023, and its entire contents are incorporated herein by reference.

[0118] Explanation of reference numerals in the attached figures

[0119] 3, 3': Ion exchange device.

[0120] 7: Flow regulating valve.

[0121] 9: Pure water tank.

[0122] 11: Flow meter or pressure gauge.

[0123] 12: Water level gauge.

[0124] 13: Controller.

[0125] 14: Pressure gauge.

[0126] 21: Cation exchange tower.

[0127] 21a, 21b: Permeable partitions.

[0128] 22: Cation exchange resin.

[0129] 23: Anion exchange tower.

[0130] 23a, 23b: Permeable partitions.

[0131] 24: Anion exchange resin.

[0132] 30: Cation exchange tower.

[0133] 30a, 30b, 30c: Permeable partitions.

[0134] 31, 32: Cation exchange resins.

[0135] 40: Decarbonation tower.

[0136] 50: Anion exchange tower.

[0137] 50a, 50b, 50c: Permeable partitions.

[0138] 51, 52: Anion exchange resins.

Claims

1. A method for operating an upward-flow ion exchange tower, wherein raw water is fed upward into the ion exchange tower, which contains a packed bed of ion exchange resin between a lower permeable baffle and an upper permeable baffle, to produce deionized water, wherein... The operation method of the upward flow ion exchange tower includes: The fixed bed formation process involves, at the beginning of water flow, allowing raw water to be fed into the ion exchange tower at a high linear velocity, pushing the packed bed of ion exchange resin in the ion exchange tower upwards to the permeable baffle on the upper side of the packed bed to form a fixed bed of ion exchange resin. as well as The stable operation process involves passing raw water through the fixed bed after the fixed bed formation process at a linear velocity greater than the minimum linear velocity required to maintain the fixed bed, and controlling the flow rate of the raw water according to the required amount of deionized water.

2. The method for operating an upward-flow ion exchange tower as described in claim 1, wherein, The operation method of the upflow ion exchange tower involves, during the stable operation process, introducing deionized water from the ion exchange tower into a deionized water tank via a flow regulating valve, and then transporting the deionized water from the deionized water tank to its desired destination. The opening of the flow regulating valve and / or the water supply pump are controlled in such a way that the water level in the ion exchange tank is kept within a specified range and the fixed bed of the ion exchange tower is maintained.

3. The operation method of the upward flow ion exchange tower as described in claim 2, wherein, The control frequency of the water supply pump is less than 7 times / min.

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