JP7217590B2 - Pure water production device and pure water production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pure water production apparatus and a pure water production method, and in particular, an ion exchange system for producing pure water or ultrapure water used for pharmaceutical production, semiconductor production, boiler water for power generation, food, etc. TECHNICAL FIELD The present invention relates to a pure water production device and a pure water production method that can be used for the pure water production device.

2. Description of the Related Art Ion-exchange pure water production apparatuses are known for producing pure water or ultrapure water used for the production of pharmaceuticals, the production of semiconductors, boiler water for power generation, food, and the like. An ion-exchange type pure water production apparatus is an apparatus for producing pure water by bringing raw water into contact with an ion-exchange resin or the like to remove anion and cation components contained in the raw water through an ion-exchange reaction. Ion exchange resins can be used repeatedly by periodically regenerating them with acid and alkali.

In recent years, due to the high integration of semiconductors, the purity of pure water required for pure water production equipment has increased, and there has been a demand for reducing the amount of chemicals used for regeneration and reducing running costs to the utmost limit. there is However, if the frequency of regeneration and the amount of regeneration chemicals are not adjusted appropriately, the regeneration of the ion-exchange resin will fail, increasing the risk of deteriorating the quality of pure water.

Conventionally, the most orthodox method for determining the frequency of regeneration is to regard the ion concentration of the raw water as constant, and to regenerate the ion-exchange resin when the flow rate of the raw water exceeds a certain amount.

However, when the ion concentration of raw water increases due to seasonal fluctuations, the frequency of regeneration becomes insufficient, and the quality of treated water deteriorates. If the amount of chemicals and the frequency of regeneration are set high in anticipation of seasonal fluctuations, the chemicals will be wasted, resulting in an increase in running costs. In addition, since the ion exchange resin deteriorates over time due to dirt such as organic matter contained in the raw water, the ion exchange capacity of the water purifier decreases even if there is no seasonal fluctuation, and the quality of the treated water deteriorates. If the amount of chemicals and regeneration frequency are set in consideration of the decrease in the ion exchange capacity of the water purifier, there is also the problem that the running cost will increase further.

As a further advanced conventional technology, for example, as described in Japanese Patent Application Laid-Open No. 3-181384 (Patent Document 1), the conductivity of raw water is measured to calculate the ion load, and the ion load of raw water is taken into consideration. There is a method of determining the regeneration frequency by obtaining the ion load in .

However, the method of calculating the ion load based on the conductivity has a limited accuracy because an error occurs depending on the ion species and pH. In particular, since silica is a weak electrolyte among ions, it is difficult to appear in the conductivity, and an error may occur when estimating the ion load from the conductivity of the raw water. Although it is possible to install other analyzers, initial costs and running costs increase. Furthermore, as in the conventional technology described above, ion exchange resin deteriorates over time due to dirt and the like. Therefore, the ion exchange capacity of the water purifier decreases even if there is no seasonal fluctuation, and the water quality of the treated water deteriorates. Considering these errors, even when the technique of Patent Document 1 is used, the reduction in regeneration frequency and regenerant amount is limited.

Furthermore, as another prior art, there is a method of measuring the pH of the regeneration waste liquid of the ion exchange resin and monitoring the amount of the regeneration agent passing through based on the measured value, thereby suppressing the amount of chemicals used for regeneration (Japanese Unexamined Patent Publication No. 9-117679 (Patent Document 2)) and a method of measuring silica in treated water with an analyzer.

However, in any method, there is a limit to the accuracy of monitoring, and the measuring device is expensive, the size of the device is large, and the running and maintenance costs are increased. In addition, little information can be obtained by visual inspection of an ion exchange tower containing an ion exchange resin, and it is difficult to grasp the internal conditions of the ion exchange tower even with a water quality meter or the like connected to the outside of the ion exchange tower.

Furthermore, in JP 2014-188456 A (Patent Document 3), water to be treated is passed through an anion exchange resin layer to perform anion exchange treatment, and the resistivity or electrical conductivity of the resulting treated water is measured. , describes a method of operating an ion-exchange resin apparatus in which the anion-exchange resin is regenerated or replaced based on measurement results.

However, Patent Document 3 discloses only a specific example of determining the specific resistance value of treated water using a resistivity meter connected to the outside of the ion exchange tower, and does not disclose any specific method for measuring electrical conductivity. not stated.

Furthermore, Japanese Patent Application Publication No. 2008-518232 (Patent Document 4) describes an example in which two conductivity probes 47 and 48 are extended into the resin layer 14 in the water softening tank 12 in an ion exchange type water softening device. It is The invention described in Patent Document 4 describes a method of measuring conductivity for a water softening device commonly recognized as a cation tower.

However, when a conductivity meter is inserted into the cation tower as described in Patent Document 4 and measured, the change in the conductivity of the liquid phase is greater than that of the solid phase in the cation tower. Therefore, as a result, we are observing changes in the conductivity of the liquid phase, and the conductivity of the solid phase cannot be evaluated appropriately. Therefore, there is still room for investigation into how to determine the state of the ion exchange tower more accurately while reducing the amount of regenerant.

JP-A-3-181384 JP-A-9-117679 JP 2014-188456 A Japanese Patent Publication No. 2008-518232

In view of the above problems, the present invention provides a pure water production apparatus and a pure water production method that enable the internal state of an ion exchange tower to be more accurately grasped.

Furthermore, the present invention provides a pure water production apparatus and a pure water production method that can process ion exchange resins with a more optimal regeneration frequency and amount of regenerant, reduce running costs, and suppress deterioration in the quality of pure water. .

In order to achieve the above object, the present inventors have made intensive studies and found that an ion exchange column filled with an ion exchange resin is provided with at least two conductivity meters capable of measuring the conductivity of the liquid phase and the solid phase. We have found that it is effective to arrange

One aspect of the present invention, which has been completed based on the above knowledge, is to provide a pure water production apparatus for producing pure water using an ion exchange tower filled with an ion exchange resin, wherein the ion exchange resin is brought into contact with the ion exchange tower. A first conductivity meter capable of measuring solid-phase conductivity and liquid-phase conductivity in the ion exchange tower, and in the ion exchange tower so as to be close to the first conductivity meter. A pure water production apparatus is provided, comprising: a second conductivity measuring instrument arranged in the ion exchange tower and capable of measuring the liquid phase conductivity in the ion exchange tower.

In one embodiment of the pure water production apparatus according to the present invention, the first conductivity meter is arranged so as to be in contact with both the liquid phase and the solid phase in the ion exchange tower, and the second conductivity meter is , is placed in the ion exchange column so as to be in contact only with the liquid phase.

In another embodiment of the pure water production apparatus according to the present invention, the conductivity measured by the second conductivity meter is subtracted from the conductivity measured by the first conductivity meter. , to calculate the conductivity of the ion exchange resin.

In still another embodiment of the pure water production apparatus according to the present invention, the first conductivity meter and the second conductivity meter are installed at the same height with respect to the water flow direction of the ion exchange tower. It is

In still another embodiment of the pure water production apparatus according to the present invention, the state of the ion exchange resin in the ion exchange tower is determined based on the measured values of the first conductivity meter and the second conductivity meter. An analysis means for simulating is provided.

In still another embodiment of the pure water production apparatus according to the present invention, the pure water production apparatus includes a two-bed, three-tower type pure water production apparatus comprising a cation tower, a decarboxylation tower and an anion tower, and the first A conductivity meter and a second conductivity meter are positioned inside the cation tower.

In still another embodiment of the pure water production apparatus according to the present invention, a third conductivity meter for measuring the solid phase conductivity in the anion tower is in contact with the anion exchange resin packed in the anion tower. are arranged as follows.

In another aspect of the present invention, there is provided a pure water production method for producing pure water using an ion exchange tower filled with an ion exchange resin, wherein the ion exchange tower is arranged to contact the ion exchange resin. measuring the solid-phase conductivity and the liquid-phase conductivity in the ion-exchange tower using the first conductivity meter and disposed in the ion-exchange tower so as to be proximate to the first conductivity meter measuring the liquid phase conductivity in the ion exchange column using the second conductivity meter and subtracting the measurement value of the second conductivity meter from the measurement value of the first conductivity meter By doing so, a pure water production method is provided that includes analyzing the solid-phase conductivity in the ion-exchange tower and controlling the operating conditions of the ion-exchange tower based on the calculation result of the solid-phase conductivity. be.

According to the present invention, it is possible to provide a pure water production apparatus capable of treating the ion exchange resin with a more optimum regeneration frequency and amount of regenerating agent, reducing running costs, and suppressing degradation of pure water quality.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the pure-water manufacturing apparatus which concerns on embodiment of this invention. FIG. 2(a) is a schematic diagram showing the conductivity of a liquid phase and a solid phase that can be detected by a pair of electrodes provided in the first conductivity meter, and FIG. 2(b) is a second conductivity measurement FIG. 4 is a schematic diagram showing the conductivity of a liquid phase that can be detected by a pair of electrodes provided in the meter. FIG. 3(a) is a cross-sectional view showing a specific example in which a pair of electrodes provided in the first conductivity meter are inserted into the ion exchange tower, and FIG. FIG. 3 is a plan view showing a configuration example of the first conductivity meter viewed from the side; FIG. 4 is a schematic diagram showing the relationship between the inter-electrode distance of a pair of electrodes and ion-exchange resin particles. It is explanatory drawing showing another example of the arrangement|positioning relationship of the ion exchange tower which concerns on embodiment of this invention, and an electrode. 5 is a graph showing an example of changes in liquid-phase conductivity and solid-phase conductivity in the cation tower of the water purifier according to the embodiment of the present invention; 1 is a graph showing an example of changes in liquid-phase conductivity and solid-phase conductivity when a conductivity measuring instrument is placed in a conventionally well-known softener. It is a block diagram showing the example of an analysis means. 4 is a flow chart showing an example of a method for analyzing the state of an ion-exchange resin based on conductivity measurements. FIG. 4 is a schematic diagram showing an example of an output result (screen) of analysis results; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an example of applying a water purifying apparatus according to an embodiment of the present invention to a 2-bed, 3-tower type water purifying apparatus; FIG. 2 is a schematic diagram showing an example in which a third conductivity meter is arranged in an anion tower of a two-bed, three-tower system pure water production apparatus according to an embodiment of the present invention. 13(a) and 13(b) are block diagrams showing a pure water production apparatus according to a modification of the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention. It is not specific.

A pure water production apparatus 1 according to an embodiment of the present invention, as shown in FIG. , a first conductivity meter 4a arranged to be in contact with the ion-exchange resin 3 in the ion-exchange tower 2 and capable of measuring the conductivity of the ion-exchange resin 3 and the liquid-phase conductivity in the ion-exchange tower 2; and a second conductivity meter 4b arranged in the ion exchange tower 2 so as to be close to the first conductivity meter 4a and capable of measuring the liquid-phase conductivity in the ion exchange tower 2. The electrical conductivity of the liquid phase and solid phase in the ion exchange tower 2 is continuously measured by the first electrical conductivity measuring instrument 4a and the second electrical conductivity measuring instrument 4b.

In addition, in the present embodiment, "continuous measurement" refers to the case where the conductivity is constantly measured, as well as every certain period (every several hours, every month, every year) during the operation period of the pure water production apparatus 1. ), including the case where the conductivity is measured periodically. The state of the ion exchange resin 3 (resin performance) can be grasped in real time. As a result, deterioration of the performance of the ion-exchange resin 3 can be determined more quickly, so that timing for regeneration and replacement of the ion-exchange resin 3 can be determined with high accuracy.

The ion exchange tower 2 accommodates an ion exchange resin 3 therein, and water to be treated is passed through the tower and brought into contact with the ion exchange resin 3, thereby removing charged dissolved impurities in the water to be treated. A specific configuration is not particularly limited as long as it is a possible device. As the ion exchange tower 2, a cation tower, an anion tower, or the like can be used. As the ion-exchange resin 3, a particulate cation-exchange resin, an anion-exchange resin, or a mixed-bed ion-exchange resin obtained by mixing these resins is used.

As shown in FIG. 1, the first conductivity meter 4a and the second conductivity meter 4b each include at least a pair of electrodes 41a, 41b and electrodes 41c, 41d. The first conductivity meter 4 a is arranged so as to be in contact with both the water to be treated, which is the liquid phase in the ion exchange tower 2 , and the ion exchange resin 3 , which is the solid phase in the ion exchange tower 2 . The second conductivity meter 4b is arranged so as to be in contact only with the liquid-phase water to be treated in the ion-exchange tower 2 and not with the solid-phase ion-exchange resin 3 .

Although the specific mode of the configuration in which the second conductivity meter 4b contacts only the liquid phase is not particularly limited, for example, as shown in FIG. By arranging the screen 5 for covering, it is possible to prevent contact between the ion exchange resin 3 and the electrodes 41c and 41d.

By arranging the first conductivity meter 4a so as to be in contact with the liquid phase and the solid phase in the ion exchange tower 2 in this way, as shown in the schematic diagram of FIG. A conductivity meter 4 a can measure the conductivity of the liquid phase and the solid phase in the ion exchange tower 2 . By arranging the second conductivity meter 4b so as to be in contact only with the liquid phase in the ion exchange tower 2, as shown in the schematic diagram of FIG. , the conductivity of the liquid phase in the ion exchange column 2 can be measured.

For example, when tap water containing 70 mg/L (as CaCO ₃ ) of cations is used as raw water and a cation tower is used as the ion exchange tower 2, the electrical conductivity of the liquid phase in the cation tower is generally 50 to 100 mS/m. and the electrical conductivity of the cation exchange resin, which is a solid phase, is 10 to 30 mS/m. The measured value of the conductivity measured by the first conductivity meter 4a is the total value of the conductivity of the ion exchange resin, which is the solid phase in the ion exchange tower 2, and the conductivity of the liquid phase, and is the second conductivity. Since the measured conductivity value measured by the conductivity meter 4b is the conductivity of the liquid phase, the conductivity value measured by the first conductivity meter 4a is converted to the conductivity value of the second conductivity meter 4a. By subtracting the measured value of , the conductivity of the ion exchange resin 3 packed in the ion exchange tower 2 can be calculated.

Calculation of the solid phase conductivity (also referred to as “resin conductivity”) in the ion exchange tower 2 may be performed by the operator of the pure water production apparatus 1 as necessary, or by the analysis means 10 in FIG. It may be calculated automatically. In addition to the calculation method described above, a calculation formula that takes into account the effects of the filling ratio and volume ratio of the liquid phase and solid phase in the ion exchange tower 2 is combined to obtain the conductivity of the ion exchange resin 3 in the ion exchange tower 2 You can calculate the rate.

In the example of FIG. 1, the first conductivity meter 4a and the second conductivity meter 4b are arranged so as to face each other on the outer surface of the ion exchange tower 2. It is preferable to have them placed closer to each other in the direction. By arranging the first conductivity meter 4a and the second conductivity meter 4b close to each other, the respective measurement regions can be brought close to each other. As a result, it is possible to more accurately grasp the state of the measurement areas where the first conductivity meter 4a and the second conductivity meter 4b are arranged.

The first conductivity meter 4a and the second conductivity meter 4b are installed at the same height with respect to the water flow direction of the ion exchange tower 2 (the direction from the top to the bottom of the ion exchange tower 2 in FIG. 1). preferably. In the ion exchange resin 3 inside the ion exchange tower 2, since the property of the water to be treated changes in the direction of water flow, the solid phase ion concentration changes, and the conductivity may change depending on the height of the ion exchange tower 2. be. By arranging the first conductivity meter 4a and the second conductivity meter 4b at the same height in the water flow direction of the ion exchange tower 2, the first conductivity meter 4a and the second conductivity It is possible to more accurately grasp the state of the measurement area in which the measurement meter 4b is arranged. In the present embodiment, the term “same height” does not mean only completely the same height, but is substantially the same, i.e., a height that does not affect the measurement in conductivity measurement. A mode in which there is a difference between is also included.

An analyzing means 10 for analyzing the internal state of the ion exchange tower 2 is connected to the first conductivity measuring device 4a and the second conductivity measuring device 4b. The analysis means 10 is means for simulating the state of the ion exchange resin 3 in the ion exchange tower 2 based on the measured values of the first conductivity meter 4a and the second conductivity meter 4b. Based on the analysis result by the analysis means 10, the control means 11 connected to the analysis means 10 controls at least one of the flow rate of the water to be treated supplied to the ion exchange tower 2, the amount of chemicals, and the regeneration frequency of the ion exchange resin. You can control whether

3(a) and 3(b) are a cross-sectional view of the first conductivity meter 4a and a plan view of the ion exchange tower 2 viewed from the outer side. As shown in FIG. 3, the electrodes 41a and 41b of the first conductivity meter 4a are inserted in a direction crossing the height direction (water flow direction) of the ion exchange tower 2. As shown in FIG.

The second conductivity meter 4b has substantially the same structure as the first conductivity meter 4a except that a screen is provided around the electrodes 41c and 41d to avoid contact with the ion exchange resin 3. A similar configuration can be adopted, and redundant description will be omitted in this embodiment.

The electrodes 41a and 41b are made of a corrosion-resistant material such as stainless steel. As shown in FIG. 3A, the electrodes 41a and 41b are surrounded by a support member (sleeve) 42. As shown in FIG. The sleeve 42 is made of an insulating material, supports the electrodes 41a and 41b at predetermined positions so that the tips of the electrodes 41a and 41b are in contact with the ion exchange resin 3, and prevents the electrodes 41a and 41b from coming into contact with each other. I'm in. A flange 43 is connected to one end of the electrodes 41a and 41b, and as shown in FIG. .

As shown as a schematic diagram in FIG. 4, the particle size of the ion exchange resin particles 31 constituting the ion exchange resin 3 is generally about 500 μm. , the conductivity of the ion exchange resin 3 can be stably measured. Therefore, the inter-electrode distance D (see FIG. 3A) of the electrodes 41a and 41b inserted in the ion exchange tower 2 is preferably 2 mm or more. The distance D between the electrodes is preferably 10 mm or less, more preferably 7 mm or less, and even more preferably 5 mm or less, because the conductivity may not be measured stably if the distance D is too large.

In order to accurately measure the conductivity of the ion exchange resin 3, the distance H from the inner surface of the ion exchange tower 2 to the tips of the electrodes 41a and 41b (see FIG. 3(a)) is preferably 30 mm or more. . The upper limit of the distance H is not particularly limited, but the flow of the resin constituting the ion exchange resin 3 may apply a mechanical load to the electrodes 41a and 41b, which may cause damage. preferably.

When the ion-exchange resin 3 is regenerated, the ion-exchange resin 3 often becomes particles and flows. Therefore, depending on the shape, the resin may stay in the vicinity of the electrodes 41a and 41b, and the electrical conductivity may not be measured with high accuracy. By making the shape of the electrodes 41a and 41b cylindrical (columnar) rather than plate-like, it is possible to prevent the electrodes 41a and 41b from interfering with the movement of the particles even when the ion exchange resin is being regenerated, resulting in more accurate measurement. can. Although not limited to the following, the diameter of the electrodes inserted into the ion exchange tower 2 is preferably 5 mm or more, and specifically can be about 10 mm.

The solid state conductivity of cation exchange resins is generally about 0-30 mS/m. Therefore, the electrodes 41a and 41b for measuring the solid phase conductivity of the ion exchange resin 3 are arranged inside the ion exchange tower so that the cell multiplier is 1 to 10 m ⁻¹ . preferably. The "cell multiplier" is expressed by the ratio of the electrode area to the inter-electrode distance, and the measurement conditions are calculated according to JIS K0130 "General Rules for Measuring Electrical Conductivity".

Alternatively, instead of inserting the electrodes 41a and 41b from the outer surface of the ion exchange tower 2 as shown in FIG. It can also be a support material for 41a and 41b. The inner tube 45 itself can also be used as the electrodes 41a and 41b. By using the inner tube 45, the central resin of the ion exchange resin 3 and the electrodes 41a and 41b can be brought into contact with each other, so that the conductivity can be measured more accurately.

It is preferable that the first conductivity measuring device 4a and the second conductivity measuring device 4b are arranged at two or more locations in the height direction of the ion exchange column. For example, a pair of electrodes 41a, 41b, 41c respectively provided in the first conductivity meter 4a and the second conductivity meter 4b in the upstream, midstream, and downstream regions of the ion exchange tower 2, respectively, 41d are arranged respectively to measure the conductivity of the ion exchange resin 3 on the upstream side, the midstream side, and the downstream side. In the ion exchange resin 3 inside the ion exchange tower 2, since the property of the water to be treated changes with respect to the water flow direction, a concentration gradient of ion concentration is generated, and the conductivity is different between the inlet side and the outlet side of the ion exchange tower 2. Although it may vary, by arranging a pair of electrodes 41 a, 41 b, 41 c, and 41 d at a plurality of locations and measuring the electrical conductivity in a local region of the ion exchange resin 3 from a plurality of locations, the ion exchange resin 3 Resin performance can be grasped in more detail.

The example of FIG. 1 shows an example in which the first conductivity meter 4a and the second conductivity meter 4b are arranged in the upper part of the tower, but the first conductivity meter 4a and the second conductivity The measuring meter 4b can be arranged downstream of the middle between the inlet and the outlet of the ion exchange tower 2 . Specifically, as shown in FIG. 1, one of the electrodes 41b and 41d positioned downstream in the direction of flow of the water to be treated of the first conductivity meter 4a and the second conductivity meter 4b is , respectively, when the inlet 21 (top of the tower) of the ion exchange tower 2 is 0% and the outlet 22 (bottom of the tower) is 100%, 30% or more, further 50% or more, further 60% or more, further It is preferable that the tips of the electrodes 41b and 41d are positioned at a position that is 70% or more of the downstream side (lower part of the tower). As a result, the ion-exchange resin in the ion-exchange tower 2 can be treated with a more optimum regeneration frequency and amount of regenerant, and the running cost can be reduced to suppress deterioration of pure water quality.

Measurement of the electrical conductivity of the ion exchange resin in the ion exchange tower 2 is preferably arranged near the exit of the ion exchange tower 2 regardless of whether it is an anion tower or a cation tower, from the viewpoint of pre-break detection.

For example, in a two-bed, three-tower (2B3T) type pure water production system, silica and boron are the substances most likely to leak from the anion tower. It is an index for estimating the adsorption state of In the case of the anion tower, when the inlet 21 (uppermost part of the tower) of the ion exchange tower 2 is 0% and the outlet 22 (lowermost part of the tower) is 100%, it is downstream in the direction of flow of the water to be treated. By arranging 70% or more downstream, it is possible to grasp the adsorption state of silica and boron in the anion exchange resin more accurately, so it is possible to take appropriate measures before silica leaks from the anion tower. As a result, deterioration of pure water quality can be suppressed more effectively.

On the other hand, the cation tower of the 2-bed, 3-tower (2B3T) type pure water production system is arranged on the inlet side of the water purifier, so that suspended solids (SS) containing Fe, Mn, etc. are produced more than the anion tower. There is a problem that the cation exchange resin is easily affected by contaminants, and the cation exchange resin is easily deteriorated due to the presence of oxides due to the mixing of chlorine or the like contained in the water to be treated. Furthermore, due to changes in the water quality and properties of the water to be treated, the water to be treated may contain various impurities such as humic substances, organic polymers, cationic detergents, neutral detergents, effluents from anion exchange resins, and flocculation aids. There is also a problem that the cation exchange resin is contaminated by these contaminants, which may be passed through the cation tower arranged on the inlet side of the water purifier. Furthermore, since the selectivity coefficient of the cation exchange resin (the selectivity coefficient of the ions Na ⁺ , Ca ²⁺ , etc. to be removed with respect to H ⁺ ) is lower than that of the anion exchange resin, the adsorptive power is weak, and the equilibrium reaction is dominant. There is a problem that the ion exchange band of the cation tower is broader than that of the anion tower, and cation leakage is likely to occur. According to the water purifier according to the embodiment of the present invention, by arranging the first conductivity meter 4a and the second conductivity meter 4b in the cation tower, it is possible to prevent the cation exchange resin from deteriorating due to the adhesion of these impurities. Performance deterioration can be grasped more accurately.

FIG. 6 is a graph showing an example of changes in the liquid-phase conductivity and solid-phase conductivity in the cation tower of the water purifier according to the embodiment of the present invention and the solid-phase ion concentration of sodium ions and hydrogen ions passing through the cation tower. is. In FIG. 6, solid phase ion concentration [−]=(Na ⁺ or H ⁺ ) ion solid phase concentration [mEq/L]/exchange capacity [mEq/L].

Since the liquid phase of the cation tower is an acidic solution, the electrical conductivity of the center of the liquid phase is detected rather than that of the solid phase. , the change in liquidus conductivity increases. That is, in the cation tower, one of the electrodes 41b and 41d located downstream in the water flow direction of the water to be treated is 0% at the inlet 21 (uppermost part of the tower) of the ion exchange tower 2 and 0% at the outlet 22 (uppermost part of the tower). When the lower part) is 100%, the tips of the electrodes 41b and 41d are located at a position that is 50% or more, further 60% or more, further 70% or more, on the downstream side (tower bottom). is preferred.

For reference, FIG. 7 shows changes in liquid-phase conductivity, solid-phase conductivity, and solid-phase ion concentrations of calcium ions and sodium ions in the softener when a conductivity measuring instrument is placed in a conventionally well-known softener. . In FIG. 7, solid-phase ion concentration [−]=(Na ⁺ or Ca ²⁺ ) ion solid-phase concentration [mEq/L]/exchange capacity [mEq/L].

A softener is conventionally known as a device that passes raw water through a sodium-type cation exchange resin and replaces calcium ions and magnesium ions in the raw water with sodium ions. Compared to the case of the cation tower in FIG. 6, the effect of highly accurate conductivity measurement and understanding of the internal state of the ion exchange resin is very small. On the other hand, in the water purifier according to the embodiment of the present invention, the change in liquid phase conductivity is very large compared to the softener. Using the total 4b, the state of the liquid phase and the solid phase in the cation exchange column can be predicted more appropriately, and deterioration of pure water quality due to cation leakage can be more appropriately prevented.

In addition, in order to increase the detection accuracy of conductivity by the electrodes 41a, 41b, 41c, and 41d, the inner surface of the ion exchange tower 2 may be provided with a lining layer (not shown) made of a non-conductive material such as resin. preferable. Alternatively, the ion exchange tower 2 itself may be made of a non-conductive material.

An AC voltage is preferably applied between the electrodes 41a and 41b and between the electrodes 41c and 41d. As compared with the case where a DC voltage is applied between the electrodes 41a and 41b and between the electrodes 41c and 41d, this prevents the surfaces of the electrodes 41a, 41b, 41c and 41d from being polarized, and stabilizes the ions for a long period of time. The conductivity of exchange resin 3 can be measured.

The analysis means 10 in FIG. 1 simulates the state of the ion-exchange resin 3 based on the measured value of conductivity. For example, the analysis means 10 uses the measured value of conductivity to calculate the ion exchange equilibrium (liquid phase-solid phase) in the ion exchange tower 2, the ion concentration diffusion calculation in the solid phase, and the ion concentration diffusion calculation in the liquid phase. Alternatively, estimation of the ion concentration in the solid phase in the ion exchange tower at an arbitrary water flow time using the load fluctuation of the water to be treated, the frequency of regeneration, and the amount of regenerant as parameters, or calculation of ion concentration diffusion based on the Nernst-Planck equation By performing the above, it is possible to simulate the resin performance of the ion-exchange resin constituting the ion-exchange resin 3 in the ion-exchange tower 2 (contamination state due to contaminants, resin regeneration failure state, aged deterioration, etc.).

Specifically, after calculating the initial state (solid phase ion concentration) of the ion exchange resin, the analysis means 10 uses the measured value of conductivity, the physical property constant, the diffusion coefficient, and other conditions, which are input in advance. Using the load fluctuation of the water to be treated, the frequency of regeneration of the ion exchange resin 3, and the amount of regeneration agent as parameters, sequential calculations are performed based on the Nernst-Planck equation and mass balance. Then, compare the calculated results at any time with the state of the ion exchange resin (solid-phase ion concentration) based on the conductivity measurement results, correct the calculations, recalculate, and confirm that the measured results and calculated results are close. It is possible to simulate the degree of deterioration of the resin from the state of the facility (understanding of the solid phase and liquid phase ion concentrations) and the value of the diffusion coefficient.

Therefore, for example, as shown in FIG. 8, the analysis means 10 includes a processing unit for analyzing the conductivity measurement values output from the first conductivity meter 4a and the second conductivity meter 4b. 100, a storage device 110, an input device 120 for input from the operator, and a display device 130 for displaying necessary information to the operator.

The processing unit 100 includes a conductivity detection unit 101 that detects the measured values of the conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b, and the conductivity detection unit 101 detects the conductivity. Results and analysis information stored in the storage device 110 (ion exchange equilibrium calculation information (liquid phase-solid phase), solid phase ion concentration diffusion calculation information, liquid phase ion concentration diffusion calculation, load fluctuation of water to be treated, regeneration Using the frequency and the amount of regenerant as parameters, estimated information on the ion concentration of the solid phase in the ion exchange tower at an arbitrary water flow time, ion concentration diffusion information based on the Nernst Planck equation, etc.) The simulation unit 102 that simulates the state of the ion exchange resin 3 filled in the chamber 2, the conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b, or the conductivity that is simulated from this conductivity. A comparison unit 103 that compares the simulation result obtained by the simulation with an existing simulation result, and if it is determined that the operation condition of the pure water production apparatus 1 needs to be changed from the comparison result by the comparison unit 103, the operating condition is changed. A condition changing unit 104 for outputting the correction information can be provided.

The control means 11 outputs a control signal for changing the operating conditions of the pure water production apparatus 1, specifically, to the ion exchange tower, based on the result of the comparison by the comparing section 103 or the operator's request to change the operating conditions. A control signal is output for controlling at least one of the amount of water to be treated to be supplied, the amount of chemicals, and the regeneration frequency of the ion exchange resin.

According to the pure water production apparatus 1 according to the embodiment of the present invention, the solid-phase and liquid-phase conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b are measured by the analyzing means 10. And using the measurement results of the conductivity of the liquid phase, the state of the solid phase and liquid phase in the ion exchange tower 2 can be simulated in real time, so the internal state in the ion exchange tower 2 and the inside of the ion exchange tower 2 The state (resin performance) of the ion exchange resin 3 filled in can be accurately grasped.

Furthermore, from the measurement results of the conductivity of the ion-exchange resin 3 continuously measured, changes in the conductivity over time are captured, and the comparison unit 103 constantly compares the simulation results with the simulation results, thereby adjusting the operating conditions as necessary. Since correction can be performed, the state of the entire facility can be accurately grasped. As a result, the state of equipment can be accurately visualized, improving reliability.

In particular, when the first conductivity meter 4a and the second conductivity meter 4b are introduced into the cation tower, the solid phase conductivity is affected by the acidic substances contained in the liquid phase (acid ion-exchanged in the cation tower). It may not be possible to know the exact rate. According to the pure water production apparatus according to the present embodiment, it is possible to grasp the state of the liquid phase and cation exchange resin (solid phase) in the cation tower at a low cost and with high accuracy. can be judged appropriately.

The first conductivity meter 4a and the second conductivity meter 4b can also be installed in the anion tower. Thereby, the solid phase conductivity of the anion exchange resin in the anion tower can be grasped more appropriately.

Furthermore, according to the present embodiment, the analyzing means 10 enables all operating conditions to be reflected in the simulation, so that the chemical amount, water flow rate, and regeneration frequency can be freely set according to the operating conditions. can.

In addition, according to the pure water production apparatus according to the present embodiment, the amount of water flow, the amount of chemicals, and the frequency of regeneration are parameters (variables). It is possible to set operating conditions that are more in line with on-site operation management conditions according to constraints such as schedule). In addition, by reflecting the optimum operating conditions in real time, it is possible to reduce the excessive supply of chemicals and unnecessary resin regeneration processes, so it is possible to reduce running costs.

A pure water production method according to an embodiment of the present invention will be described below with reference to the flow chart of FIG. The method described below is merely an example, and it goes without saying that there are various manufacturing methods other than the examples shown below using the pure water manufacturing apparatus according to the present embodiment.

First, necessary information (initial conditions, equipment conditions, operating conditions, etc.) is stored in the storage device 110 via the input device 120 . As initial conditions, a solid phase ion concentration (X _OS ), a liquid phase ion concentration (X _OL ), etc. for defining the initial state of the ion exchange tower 2 are input. Equipment conditions and operating conditions include resin amount V [m ³ ], flow rate Q [m ³ /h], raw water ion load CO [eq/m ³ ], regeneration conditions (frequency [h/cycle], chemical concentration [eq /m ³ ]), physical property constants (each diffusion coefficient D [m ² /sec], ionic valence, etc.) are input.

Next, in step S1, the conductivity (electrical conductivity) is measured using the first conductivity meter 4a and the second conductivity meter 4b arranged in the ion exchange tower 2. FIG. The conductivity detection unit 101 in FIG. 8 detects the measured values of the conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b.

In step S2, the simulation unit 102 uses the measured value of conductivity detected by the conductivity detection unit 101 to determine the state of the ion exchange resin 3, for example, the solid phase conductivity of the ion exchange resin 3, the ion exchange tower 2 The ion concentration gradients of the solid phase and the liquid phase are calculated, and the usage state of the ion exchange resin 3 is simulated. For example, based on the detected conductivity and the analysis information stored in the storage device 110, ion exchange equilibrium calculation (liquid phase-solid phase), solid phase ion concentration diffusion calculation, liquid phase ion concentration diffusion Calculations can be performed. Specifically, for example, the ion exchange tower 2 is divided into about 100 stages in the height direction, and the ion concentration of the liquid phase is calculated in order from the vicinity of the inlet. Furthermore, using the Nernst-Planck equation and the diffusion coefficient D as analytical information, for each element divided in the height direction, the ion exchange resin 3 as a solid phase and the ions in the surrounding liquid phase Concentration diffusion (diffusion concentration of ions) is simulated. The ion concentration of the ion-exchange resin can be simulated by, for example, dividing the ion-exchange resin into about 20 parts and performing differential calculation for each divided element. The simulation results are stored in the storage device 110. For example, information such as that shown in FIG. .

In step S3, the conductivity detection unit 101 again detects the measured values of the conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b. In step S4, the comparison unit 103 reads out the simulation results stored in the storage device 110, and the conductivity measured by the first conductivity meter 4a and the second conductivity meter 4b (or from this conductivity obtained simulation results) to determine whether or not the operating conditions of the ion exchange tower 2 need to be corrected. If it is determined that the operating conditions of the pure water production apparatus 1 need to be changed, the condition changing unit 104 outputs correction information for changing the operating conditions in step S5, and the process proceeds to step S6. If it is not necessary to change the operating conditions of the pure water production apparatus 1, the process proceeds directly to step S6.

In step S6, the condition changing unit 104 determines whether or not to end the analysis of the pure water production apparatus 1. If the analysis is to end, the process ends. If the analysis is not finished, steps S2 to S6 are repeated again.

In the conventional pure water production apparatus, even if a meter is installed outside the ion exchange tower 2, it is difficult to grasp the details of the inside of the ion exchange tower 2. Operating conditions were set.

According to the pure water production method according to the present embodiment, the solid-phase conductivity of the ion exchange resin 3 can be determined more accurately based on the measurement results of the first conductivity meter 4a and the second conductivity meter 4b. Since it can be measured, the internal state of the ion exchange tower 2 can be grasped in detail by simulating the ion concentration and the like of the ion exchange resin 3 for each region from the conductivity.

In addition, the internal conditions of the ion exchange tower 2 generally include parameters such as the flow of water that are difficult to model completely. A more accurate calculation result can be obtained by correcting the conductivity detection result by the conductivity measuring meter 4b of 2 by comparing it with the past simulation result or test result.

For example, FIG. 10 shows the output results of the analysis results. shows the ion concentration distribution of the cross section perpendicular to the height of the ion exchange resin. The operator can grasp the internal conditions of each tower constituting the pure water production apparatus in real time through a screen as shown in FIG. 10, for example.

(Modification)
It should be noted that the analysis means 10 may estimate the resin performance of the ion exchange resin 3 by focusing only on the temporal change in electrical conductivity without performing the above-described complicated simulation. For example, (1) when the conductivity of the ion-exchange resin 3 is measured at predetermined intervals while the water to be treated is passed through the ion-exchange tower 2, the resin regeneration step is performed when a decrease in conductivity is observed. Alternatively, a method of exchanging the resin, (2) measuring the conductivity immediately after the resin regeneration, comparing the conductivity value with the conductivity immediately after the previous resin regeneration, and determining that the conductivity decreases by a predetermined value or more. (3) Record the change in conductivity measurement results over time, and reduce the conductivity due to long-term use. There is a method of evaluating the deterioration of equipment depending on the condition.

That is, the electric conduction medium of water inside the ion exchange tower 2 is often ions, and the electric conductivity of water increases as the concentration of ions increases. Pure water, on the other hand, has a wide range of purities, from distilled water to ultrapure water. As the purity of pure water increases, only H ⁺ and OH ⁻ generated by water dissociation conduct electricity, approaching the theoretical conductivity of pure water of 0.056 μS/cm (0.0056 mS/m).

The organic polymer-based ion exchange resin has, for example, a styrene divinylbenzene copolymer as a skeleton, and the cation exchange resin has a structure having functional groups such as a sulfonic acid group and the anion exchange resin having a functional group such as a quaternary ammonium group. and quaternary ammonium groups are salts with acids, alkalis, metal ions, chloride ions, or the like with H ⁺ or OH ⁻ as counter ions.

The ion concentration in the ion exchange resin 3 varies depending on the concentration of the functional groups, but is relatively high concentration solid acid, solid alkali or salt such as 1 mol/L to 10 mol/L. In this way, the ion exchange resin 3 has a high ion concentration and is a highly mobile polymer. In pure water, the conductivity is several to several hundred times higher than in pure water.

In the ion-exchange resin 3, ions are the medium of electric conduction, so the conductivity of the ion-exchange resin greatly changes depending on the mobility and diffusivity of the counterions. In particular, the conductivity of the ion exchange resin varies greatly depending on the ion species, ^ion size, ^{and ion} adsorption state. In the case of ^- , the conductivity of the ion exchange resin is high.

The ion-exchange resin used in the water purifier is regenerated with acid or alkali, and the counter ions removed by ion exchange are returned to H ⁺ or OH ^- . are manufacturing. In other words, the counter ions of the ion exchange resin immediately after regeneration are filled with H ⁺ and OH ⁻ , and the conductivity of the ion exchange resin is high. Incorporation into the resin tends to lower the electrical conductivity.

As described above, silica and boron are weak electrolytes and have the property of polymerizing and growing into large molecules. Therefore, ion exchange resins adsorbing silica or boron have particularly low electrical conductivity. In a two-bed, three-tower (2B3T) type water purifier, the substances that are most likely to leak from the anion tower are silica and boron, so the solid phase conductivity of the anion exchange resin is an index for estimating the adsorption state of silica and boron. . For example, in the 2B3T system pure water system, electrodes are placed near the outlet of the anion tower where the treated water is particularly close to pure water and the ion concentration is low. It is possible to grasp the state and grasp the state of the anion exchange resin.

The anion exchange resin may also be contaminated with anionic polymer electrolytes, humic acid, organic substances, etc. contained in the raw water, and its performance may be lowered. Although these contaminants may be ionized to some extent, they tend to be difficult to regenerate once they are taken into the ion exchange resin by ion exchange because of their large molecular weight and low mobility. Furthermore, since the contaminants have a large mass, the solid phase conductivity of the contaminated ion exchange resin tends to be low. Therefore, by measuring the conductivity of the ion-exchange resin, it becomes possible to measure the degree of deterioration of the ion-exchange resin, and to determine the replacement time of the ion-exchange resin.

As described above, cation exchange resins are more durable than anion exchange resins. Performance is degraded due to deterioration due to cationic polymers and contamination by cationic polymers, and the solid-state conductivity decreases. Therefore, by measuring the electrical conductivity of the cation exchange resin, it becomes possible to accurately measure deterioration in the performance of the cation exchange resin, and it is possible to appropriately determine when to replace the ion exchange resin.

In addition to the above method, the resin and the liquid phase are periodically sampled at several points in the height direction of the resin tower, the state of the resin is directly measured, and the ion concentration of the liquid phase is directly measured. By reflecting the results in the above simulation results, the accuracy of the simulation can be further improved.

(Application example)
The ion exchange tower 2 described above can be suitably used in a 2B3T multi-bed tower pure water production apparatus or a mixed bed type pure water production apparatus. For example, as shown in FIG. 11, the pure water production apparatus according to the present embodiment includes a two-bed, three-tower type pure water production apparatus comprising a cation tower 30, a decarboxylation tower 40, and an anion tower 50. A conductivity meter 4a and a second conductivity meter 4b are arranged inside the cation tower 30, and arranged in the anion tower 50 so as to be in contact with the anion exchange resin packed in the anion tower 50. , comprising a third conductivity meter 4c for measuring the solid state conductivity of the anion exchange resin.

The third conductivity meter 4c can have the same configuration as the first conductivity meter. In the case of the anion tower 50, as shown in FIG. It is preferably located downstream of the middle (50%) of the bottom). More preferably, the tip of the electrode (conductivity detection portion) is located 60% or more, further preferably 70% or more downstream from the inlet (0%) toward the outlet (100%), and the ion exchange resin 3 and the arranged to be in contact with the anion exchange resin at a position that is 60% or more, further 70% or more downstream from the inlet 21 of the anion tower 50 toward the outlet 22, and the conductivity of the anion exchange resin is improved. It is preferable to arrange the third conductivity meter 4c so that the adsorption state of silica on the anion exchange resin can be grasped by continuously measuring the conductivity.

In the cation tower 30 for treating raw water containing many impurities, at least two of the first conductivity meter 4a and the second conductivity meter 4b are used to measure the conductivity of the solid phase and the liquid phase, respectively. The conductivity in the anion tower 50, in which the quality of the water to be treated is higher than that of the tower 30, can be measured with a small number of devices by measuring the solid phase conductivity using at least one third conductivity meter. , the accuracy of the evaluation of the state of the ion-exchange resin accommodated therein can be improved. Of course, the first to third conductivity meters 4a, 4b, 4c may be inserted into the decarboxylation tower 40 as required. In addition, it goes without saying that a conductivity meter 61 for measuring the conductivity of the raw water may be further arranged.

Alternatively, as shown in FIGS. 13(a) and 13(b), as the pure water production apparatus according to this embodiment, a polisher 70 is further arranged downstream of the anion tower, and the first and A second conductivity meter 4a, 4b may also be arranged. The polisher 70 may be of a mixed bed type as shown in FIG. 13(a) or of a form in which a cation polisher 71 and an anion polisher 72 are provided separately as shown in FIG. 13(b).

In this way, the present invention is represented by the matters specifying the invention in the scope of claims that are valid from the above disclosure, and can be modified and embodied in the implementation stage without departing from the gist of the invention.

Examples of the present invention are presented below along with comparative examples, which are provided for a better understanding of the invention and its advantages and are not intended to be limiting of the invention.

(Example 1)
In a two-bed, three-tower system pure water production apparatus of a countercurrent regeneration system, two conductivity meters were installed in the cation tower to measure the conductivity of the cation exchange resin. As the cation exchange resin, a cation exchange resin 650C×3000L manufactured by Dow Chemical was used. As the anion exchange resin, an anion exchange resin 550A×3000L (resin layer height after regeneration: 2300 mm) manufactured by Dow Chemical Co., Ltd. was used. The diameter of the cation tower was 1200 mm, and the diameter of the anion tower was 1300 mm. Treated well water (electrical conductivity 23 mS/m, silica concentration 60 mg/L as SiO ₂ ) was used as raw water, and the water quality of the treated water (pure water) was 0.2 mS/m or less and silica concentration 100 μg/L as SiO ₂ . It was carried out at a water flow rate of 50 m ³ /h.

As electrodes for cation exchange resin measurement, as shown in FIG. 2 placed a screen around the electrodes to avoid contact with the resin, and measured the resistance between the electrodes of the first and second conductivity meters 4a and 4b. The tip of the electrode (measurement tip) is placed at a position of 2000 mm in the water flow direction, the distance D between the electrodes is 6 mm, and the insertion depth of the electrode (from the inner surface of the ion exchange tower 2 to the tip of the electrodes 41a and 41b distance H) was set to 40 mm. In measuring the electrical conductivity, a converter WBM-100 manufactured by Toa DKK Co., Ltd. was used, and the electrical conductivity was measured every 3 hours of running water. Table 1 shows the results.

As shown in Table 1, the resin conductivity of the cation tower changed as shown in Table 1 when water was passed for 21 hours. Since a decrease in solid-phase conductivity was observed after 15 hours of operation, it was determined that the ion exchange band (a layer of ion exchange resin that has undergone ion exchange and has become a salt form) is moving in the direction of water flow. It was decided to perform regeneration at the timing when the conductivity decreased.

By performing regeneration using this method, it is possible to detect the optimal regeneration start timing even when the load of the raw water fluctuates, eliminating the need to perform regeneration in anticipation of fluctuations and reducing the frequency of regeneration. , it was possible to operate with about 30% less regenerative chemicals than the conventional water purifier.

(Example 2)
Using the same pure water production apparatus as in Example 1, in the process of repeating regeneration/flowing/regeneration of the ion-exchange resin, the electrical conductivity was measured immediately after the regeneration of the resin body was completed and water was passed. Table 2 shows the results.

RUN NO. Only No. 4 was found to have a low conductivity immediately after the completion of regeneration and immediately after water flow, indicating that regeneration was unsatisfactory. According to Example 2, the soundness of regeneration can be confirmed by controlling the conductivity immediately after water is passed after regeneration, and it is possible to prevent deterioration of water quality due to poor regeneration, and stable operation of the device. became possible.

(Example 3)
Using the same pure water production apparatus as in Example 1, the electrical conductivity was measured every six months. Table 3 shows the results.

It was confirmed that the electrical conductivity of the resin decreased year by year, and the electrical conductivity did not recover sufficiently even after regeneration, and it was confirmed that the performance of the resin deteriorated over time. After 36 months, it was confirmed that the conductivity had decreased, so the amount of the regeneration agent was increased and the regeneration operation was performed. However, after 60 months of continuous operation, the electrical conductivity decreased to about half of the initial level, and it was confirmed that the performance of the resin had significantly deteriorated, so the resin was replaced. As described above, according to the present embodiment, deterioration in performance of the resin over time can be grasped in real time, and appropriate resin regeneration operation and periodic replacement of the resin can be performed. As a result, the running cost could be reduced by 30% to 40%.

DESCRIPTION OF SYMBOLS 1... Pure water production apparatus 2... Ion-exchange tower 3... Ion-exchange resin 4a... 1st conductivity meter 4b... 2nd conductivity meter 4c... 3rd conductivity meter 5... Screen 10... Analysis means DESCRIPTION OF SYMBOLS 11... Control means 21... Inlet 22... Outlet 30... Cation tower 31... Ion exchange resin particles (particles)
DESCRIPTION OF SYMBOLS 40... Decarboxylation tower 41a-41d... Electrode 42... Sleeve 43... Flange 45... Internal tube 47... Conductivity probe 50... Anion tower 61... Conductivity meter 70... Polisher 71... Cation polisher 72... Anion polisher 100... Treatment unit 101 Conductivity detector 102 Simulation unit 103 Comparison unit 104 Condition change unit 110 Storage device 120 Input device 130 Display device

Claims (8)

In a pure water production apparatus that produces pure water using a cation tower filled with a cation exchange resin,
arranged at a position that is 50% or more downstream from the inlet to the outlet of the cation tower so as to be in contact with the cation exchange resin packed in the cation tower provided in the water purification apparatus, and in the cation tower a first conductivity meter comprising a pair of electrodes with a cell multiplier of 1 to 10 ^-1 m capable of measuring the solid-phase conductivity and liquid-phase conductivity of
It is inserted from a position different from the first conductivity meter on the outer circumference of the cation tower, and in the cation exchange resin in the vicinity of the measurement area of the first conductivity meter in the circumferential direction of the cation tower. or inserted into the cation exchange resin from a position different from the first conductivity meter so as to face the first conductivity meter from the outer surface of the cation tower to the inside. , a second conductivity meter comprising a pair of electrodes with a cell multiplier of 1 to 10 ^-1 m and a screen covering the electrodes, which can measure the liquid phase conductivity in the cation tower. and pure water production equipment. The first conductivity meter is arranged so as to be in contact with both the liquid phase and the solid phase in the cation tower, and the second conductivity meter is arranged so as to be in contact only with the liquid phase. 2. The pure water production apparatus according to claim 1, wherein the pure water production apparatus is arranged inside. The conductivity of the cation exchange resin is calculated by subtracting the measured conductivity value of the second conductivity meter from the conductivity value measured by the first conductivity meter. The pure water production apparatus according to claim 1 or 2. 4. Any one of claims 1 to 3, wherein the first conductivity meter and the second conductivity meter are installed at the same height with respect to the water flow direction of the cation tower. 1. The pure water production apparatus according to 1. Based on the measured values of the first conductivity meter and the second conductivity meter, the solid phase conductivity of the cation exchange resin and the ion concentration gradient of the solid phase and liquid phase in the cation tower are calculated. The pure water production apparatus according to any one of claims 1 to 4, further comprising analysis means for calculating and simulating the usage state of the cation exchange resin in the cation tower. 6. The pure water production device according to any one of claims 1 to 5, wherein the pure water production device comprises a two-bed, three-tower type pure water production device further comprising a decarbonation tower and an anion tower downstream of the cation tower. A pure water production apparatus as described. A third conductivity meter having a pair of electrodes for measuring the solid-state conductivity in the anion tower is connected from the inlet to the outlet of the anion tower so as to be in contact with the anion exchange resin packed in the anion tower. 7. The pure water production apparatus according to claim 6, which is arranged at a position that is 50% or more downstream toward the viewer and measures the solid phase conductivity of the anion exchange resin. A pure water production method for producing pure water using a cation tower filled with a cation exchange resin,
A step of treating using the cation tower filled with the cation exchange resin,
The inside of the cation tower is measured using a first conductivity meter arranged at a position that is 50% or more downstream from the entrance of the cation tower toward the exit so as to be in contact with the cation exchange resin in the cation tower. measuring the solid-phase conductivity and liquid-phase conductivity of
It is inserted from a position different from the first conductivity meter on the outer circumference of the cation tower, and in the cation exchange resin in the vicinity of the measurement area of the first conductivity meter in the circumferential direction of the cation tower. placed or inserted into the inside from the outer surface of the cation tower, and in the cation exchange resin from a position different from the first conductivity meter so as to face each other with the first conductivity meter measuring the liquid phase conductivity in the cation tower using a second conductivity meter located in
calculating the solid phase conductivity in the cation tower by subtracting the measured value of the second conductivity meter from the measured value of the first conductivity meter;
Based on the calculation result of the solid phase conductivity, the solid phase conductivity of the cation exchange resin and the ion concentration gradient of the solid phase and liquid phase in the cation tower are calculated, and the load fluctuation of the water to be treated, ion exchange simulating the state of use of the cation exchange resin in the cation tower at any given time by performing sequential calculations based on the material balance with the frequency of resin regeneration and the amount of regenerant used as parameters ;
The results of the simulation are compared with the existing simulation results, and based on the results of the comparison, at least one of the amount of water to be treated supplied to the ion exchange tower, the amount of chemicals, and the frequency of regeneration of the ion exchange resin is adjusted. Determining whether it is necessary to change the operating conditions of the cation tower containing
and changing the operating conditions of the cation tower when the operating conditions need to be changed.

Images